Sample records for composition mineral assemblages
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Modelling of acid-base titration curves of mineral assemblages
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Stamberg Karel
2016-01-01
Full Text Available The modelling of acid-base titration curves of mineral assemblages was studied with respect to basic parameters of their surface sites to be obtained. The known modelling approaches, component additivity (CA and generalized composite (GC, and three types of different assemblages (fucoidic sandstones, sedimentary rock-clay and bentonite-magnetite samples were used. In contrary to GC-approach, application of which was without difficulties, the problem of CA-one consisted in the credibility and accessibility of the parameters characterizing the individual mineralogical components.
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Borate mineral assemblages in the system Na2OCaOMgOB2O3H2O
Christ, C.L.; Truesdell, A.H.; Erd, Richard C.
1967-01-01
he significant known hydrated borate mineral assemblages (principally of the western United States) in the system Na2OCaOz.sbnd;MgOB2O3H2O are expressible in three ternary composition diagrams. Phase rule interpretation of the diagrams is consistent with observation, if the activity of H2O is generally considered to be determined by the geologic environment. The absence of conflicting tie-lines on a diagram indicates that the several mineral assemblages of the diagram were formed under relatively narrow ranges of temperature and pressure. The known structural as well as empirical formulas for the minerals are listed, and the more recent (since 1960) crystal structure findings are discussed briefly. Schematic Gibbs free energy-composition diagrams based on known solubility-temperature relations in the systems Na2B4O7-H2O and Na2B4O7-NaCl-H2O, are highly useful in the interpretation and prediction of the stability relations in these systems; in particular these diagrams indicate clearly that tincalconite, although geologically important, is everywhere a metastable phase. Crystal-chemical considerations indicate that the same thermodynamic and kinetic behavior observed in the Na2B4O7-H2O system will hold in the Ca2B6O11-H2O system. This conclusion is confirmed by the petrologic evidence. The chemical relations among the mineral assemblages of a ternary diagram are expressed by a schematic "activity-activity" diagram. These activity-activity diagrams permit the tracing-out of the paragenetic sequences as a function of changing cation and H2O activities. ?? 1967.
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International Nuclear Information System (INIS)
Montgomery, Michael T.; Coffin, Richard B.; Boyd, Thomas J.; Smith, Joseph P.; Walker, Shelby E.; Osburn, Christopher L.
2011-01-01
The nitrogenous energetic constituent, 2,4,6-Trinitrotoluene (TNT), is widely reported to be resistant to bacterial mineralization (conversion to CO 2 ); however, these studies primarily involve bacterial isolates from freshwater where bacterial production is typically limited by phosphorus. This study involved six surveys of coastal waters adjacent to three biome types: temperate broadleaf, northern coniferous, and tropical. Capacity to catabolize and mineralize TNT ring carbon to CO 2 was a common feature of natural sediment assemblages from these coastal environments (ranging to 270+/-38 μg C kg -1 d -1 ). More importantly, these mineralization rates comprised a significant proportion of total heterotrophic production. The finding that most natural assemblages surveyed from these ecosystems can mineralize TNT ring carbon to CO 2 is consistent with recent reports that assemblage components can incorporate TNT ring carbon into bacterial biomass. These data counter the widely held contention that TNT is recalcitrant to bacterial catabolism of the ring carbon in natural environments. - Highlights: → TNT mineralization is a common feature of natural bacterial assemblages in coastal sediments. → TNT mineralization rates comprised a significant proportion of total heterotrophic production. → These data counter the widely held contention that TNT is recalcitrant to bacterial catabolism of the ring carbon in natural environments. - The capacity to mineralize TNT ring carbon to CO 2 is a common feature of natural bacterial assemblages in coastal sediment.
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Energy Technology Data Exchange (ETDEWEB)
Montgomery, Michael T., E-mail: michael.montgomery@nrl.navy.mil [Naval Research Laboratory, Marine Biogeochemistry Section, Code 6114, 4555 Overlook Avenue, Washington, DC 20375 (United States); Coffin, Richard B., E-mail: richard.coffin@nrl.navy.mil [Naval Research Laboratory, Marine Biogeochemistry Section, Code 6114, 4555 Overlook Avenue, Washington, DC 20375 (United States); Boyd, Thomas J., E-mail: thomas.boyd@nrl.navy.mil [Naval Research Laboratory, Marine Biogeochemistry Section, Code 6114, 4555 Overlook Avenue, Washington, DC 20375 (United States); Smith, Joseph P., E-mail: joseph.smith@nrl.navy.mil [Naval Research Laboratory, Marine Biogeochemistry Section, Code 6114, 4555 Overlook Avenue, Washington, DC 20375 (United States); Walker, Shelby E., E-mail: Shelby.Walker@noaa.gov [Naval Research Laboratory, Marine Biogeochemistry Section, Code 6114, 4555 Overlook Avenue, Washington, DC 20375 (United States); Osburn, Christopher L., E-mail: chris_osburn@ncsu.edu [Marine, Earth and Atmospheric Sciences, North Carolina State University, Raleigh, NC 27695 (United States)
2011-12-15
The nitrogenous energetic constituent, 2,4,6-Trinitrotoluene (TNT), is widely reported to be resistant to bacterial mineralization (conversion to CO{sub 2}); however, these studies primarily involve bacterial isolates from freshwater where bacterial production is typically limited by phosphorus. This study involved six surveys of coastal waters adjacent to three biome types: temperate broadleaf, northern coniferous, and tropical. Capacity to catabolize and mineralize TNT ring carbon to CO{sub 2} was a common feature of natural sediment assemblages from these coastal environments (ranging to 270+/-38 {mu}g C kg{sup -1} d{sup -1}). More importantly, these mineralization rates comprised a significant proportion of total heterotrophic production. The finding that most natural assemblages surveyed from these ecosystems can mineralize TNT ring carbon to CO{sub 2} is consistent with recent reports that assemblage components can incorporate TNT ring carbon into bacterial biomass. These data counter the widely held contention that TNT is recalcitrant to bacterial catabolism of the ring carbon in natural environments. - Highlights: > TNT mineralization is a common feature of natural bacterial assemblages in coastal sediments. > TNT mineralization rates comprised a significant proportion of total heterotrophic production. > These data counter the widely held contention that TNT is recalcitrant to bacterial catabolism of the ring carbon in natural environments. - The capacity to mineralize TNT ring carbon to CO{sub 2} is a common feature of natural bacterial assemblages in coastal sediment.
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Directory of Open Access Journals (Sweden)
Vít Syrovátka
2012-10-01
Full Text Available Chironomid assemblages of helocrene springs were investigated in the Western Carpathians in order to identify potential effect of water mineral richness on the taxonomic structure of the assemblages. A complex gradient considering water chemistry and substratum was used as a measure of basicity (mineral richness. Taxonomic structure, total abundance and abundance of most frequent taxa were related to this gradient with regards to two contrasting habitats: trickle (A and water-loged soil with standing water (B. The variance in chironomid assemblage attributable to basicity was estimated and tested via PERMANOVA as well as the possible effect of the other environmental variables. The response of individual taxa was examined using GAM. The results indicate a strong relationship between basicity and substratum characteristics, with coarser mineral substrata at basic and high amount of organic matter at acidic conditions. Although water chemistry was correlated with and inseparable from these substratum properties, it could not be substituted with them, as they discriminated well only between acidic and basic springs, but did not follow the basicity gradient in either acidic or basic group of springs. Chironomid assemblage showed a strong and systematic response to the complex gradient of mineral richness, which explained the largest portion of variance in both the habitat A and B faunal data and was projected on the first axes of both NMDS ordinations. The assemblage response could be documented by the preference of several taxa for particular mineral richness conditions, while the number of taxa seemed to be highest in the middle of the basicity gradient. As only 17 samples were analysed so far, the results are considered preliminary and, hopefully, more confident results will be available in near future.doi: 10.5324/fn.v31i0.1403.Published online: 17 October 2012.
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Suwanich, Parkorn
Clay-mineral assemblages in Middle Clastic, Middle Salt, Lower Clastic, Potash Zone, and Lower Salt, totalling 13 samples from K-118 drill core, in the Maha Sarakham Formation, Khorat Basin, northeastern Thailand were studied. The clay-size particles were separated from the water-soluble salt by water leaching. Then the samples were leached again in the EDTA solution and separated into clay-size particles by using the timing sedimentation. The EDTA-clay residues were divided and analyzed by using the XRD and XRF method. The XRD peaks show that the major-clay minerals are chlorite, illite, and mixed-layer corrensite including traces of rectorite? and paragonite? The other clay-size particles are quartz and potassium feldspar. The XRF results indicate Mg-rich values and moderate MgAl atom ratio values in those clay minerals. The variable Fe, Na, and K contents in the clay-mineral assemblages can explain the environment of deposition compared to the positions of the samples from the core. Hypothetically, mineralogy and the chemistry of the residual assemblages strongly indicate that severe alteration and Mg-enrichment of normal clay detritus occurred in the evaporite environment through brine-sediment interaction. The various Mg-enrichment varies along the various members reflecting whether sedimentation is near or far from the hypersaline brine.
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Lyubimtseva, N. G.; Bortnikov, N. S.; Borisovsky, S. E.; Prokofiev, V. Yu.; Vikent'eva, O. V.
2018-03-01
The mineral assemblages, mode of occurrence, and chemical compositions of coexisting fahlore and sphalerite from the Darasun gold deposit have been described. Three generations of fahlore and three generations of sphalerite have been recognized. The FeS content in sphalerite coexisting with fahlore ranges from 0.8 to 9.4 mol %. The complete solid solution series Fe-tetrahedrite-Zn-tetrahedrite-Fe-tennantite-Zn-tennantite reflected in Sb/(Sb + As) and Fe/(Fe + Zn) ratios ranging from 0 to 0.97 and from 0.07 to 1.00, respectively, with a predominant negative relationship between these ratios has been identified for the first time at the deposit. Stepped, oscillatory, and combined stepped-oscillatory growth zonings within fahlore grains and heterogeneous aggregates of fahlore have been found. Fahlore is enriched in As with respect to Sb, and Zn-tetrahedrite is followed by Fe- and Zn-tennantite from early to late generation; Zn-tetrahedrite is followed by Fe-tennantite in zoned grains and overgrown rims; sphalerite crystallized at decreased temperature and sulfur fugacity. The evolution of the chemical composition of fahlores was caused by the evolving temperature, fluid salinity, and conditions of metal migration.
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Mineral assemblages and their distribution patterns in the sediments of the Gulf of Bohai Sea
Energy Technology Data Exchange (ETDEWEB)
Chen, L; Luan, Z; Zheng, T; Xu, W; Dong, T
1980-01-01
This paper presents the results of a study on the mineral assemblages and their distribution patterns in the sediments of the Gulf of Bohai Sea. The 212 bottom-surface sediment samples were collected from the Gulf of Bohai Sea and its tributaries.
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Leingärtner, Annette; Krauss, Jochen; Steffan-Dewenter, Ingolf
2014-06-01
Species richness patterns along altitudinal gradients are well-documented ecological phenomena, yet very little data are available on how environmental filtering processes influence the composition and traits of butterfly assemblages at high altitudes. We have studied the diversity patterns of butterfly species at 34 sites along an altitudinal gradient ranging from 600 to 2,000 m a.s.l. in the National Park Berchtesgaden (Germany) and analysed traits of butterfly assemblages associated with dispersal capacity, reproductive strategies and developmental time from lowlands to highlands, including phylogenetic analyses. We found a linear decline in butterfly species richness along the altitudinal gradient, but the phylogenetic relatedness of the butterfly assemblages did not increase with altitude. Compared to butterfly assemblages at lower altitudes, those at higher altitudes were composed of species with larger wings (on average 9%) which laid an average of 68% more eggs. In contrast, egg maturation time in butterfly assemblages decreased by about 22% along the altitudinal gradient. Further, butterfly assemblages at higher altitudes were increasingly dominated by less widespread species. Based on our abundance data, but not on data in the literature, population density increased with altitude, suggesting a reversed density-distribution relationship, with higher population densities of habitat specialists in harsh environments. In conclusion, our data provide evidence for significant shifts in the composition of butterfly assemblages and for the dominance of different traits along the altitudinal gradient. In our study, these changes were mainly driven by environmental factors, whereas phylogenetic filtering played a minor role along the studied altitudinal range.
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Determinants of Tree Assemblage Composition at the Mesoscale within a Subtropical Eucalypt Forest
Hero, Jean-Marc; Butler, Sarah A.; Lollback, Gregory W.; Castley, James G.
2014-01-01
A variety of environmental processes, including topography, edaphic and disturbance factors can influence vegetation composition. The relative influence of these patterns has been known to vary with scale, however, few studies have focused on environmental drivers of composition at the mesoscale. This study examined the relative importance of topography, catchment flow and soil in influencing tree assemblages in Karawatha Forest Park; a South-East Queensland subtropical eucalypt forest embedded in an urban matrix that is part of the Terrestrial Ecosystem Research Network South-East Queensland Peri-urban SuperSite. Thirty-three LTER plots were surveyed at the mesoscale (909 ha), where all woody stems ≥1.3 m high rooted within plots were sampled. Vegetation was divided into three cohorts: small (≥1–10 cm DBH), intermediate (≥10–30 cm DBH), and large (≥30 cm DBH). Plot slope, aspect, elevation, catchment area and location and soil chemistry and structure were also measured. Ordinations and smooth surface modelling were used to determine drivers of vegetation assemblage in each cohort. Vegetation composition was highly variable among plots at the mesoscale (plots systematically placed at 500 m intervals). Elevation was strongly related to woody vegetation composition across all cohorts (R2: 0.69–0.75). Other topographic variables that explained a substantial amount of variation in composition were catchment area (R2: 0.43–0.45) and slope (R2: 0.23–0.61). Soil chemistry (R2: 0.09–0.75) was also associated with woody vegetation composition. While species composition differed substantially between cohorts, the environmental variables explaining composition did not. These results demonstrate the overriding importance of elevation and other topographic features in discriminating tree assemblage patterns irrespective of tree size. The importance of soil characteristics to tree assemblages was also influenced by topography, where ridge top sites were
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Kuzmanovic, Maja; Dolédec, Sylvain; de Castro-Catala, Nuria; Ginebreda, Antoni; Sabater, Sergi; Muñoz, Isabel; Barceló, Damià
2017-07-01
We used the trait composition of macroinvertebrate communities to identify the effects of pesticides and multiple stressors associated with urban land use at different sites of four rivers in Spain. Several physical and chemical stressors (high metal pollution, nutrients, elevated temperature and flow alterations) affected the urban sites. The occurrence of multiple stressors influenced aquatic assemblages at 50% of the sites. We hypothesized that the trait composition of macroinvertebrate assemblages would reflect the strategies that the assemblages used to cope with the respective environmental stressors. We used RLQ and fourth corner analysis to address the relationship between stressors and the trait composition of benthic macroinvertebrates. We found a statistically significant relationship between the trait composition and the exposure of assemblages to environmental stressors. The first RLQ dimension, which explained most of the variability, clearly separated sites according to the stressors. Urban-related stressors selected taxa that were mainly plurivoltine and fed on deposits. In contrast, pesticide impacted sites selected taxa with high levels of egg protection (better egg survival), indicating a potentially higher risk for egg mortality. Moreover, the trait diversity of assemblages at urban sites was low compared to that observed in pesticide impacted sites, suggesting the homogenization of assemblages in urban areas. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.
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Analysis of Mineral Assemblages Containing Unstable Hydrous Phases
Vaniman, D. T.; Wilson, S. A.; Bish, D. L.; Chipera, S.
2011-12-01
for sampling cold-environment deposits at the lunar poles, at the poles of Mercury, on icy satellites, and on many other bodies that may host hydrous minerals. The problem of adequate in situ analysis of such mutable assemblages extends to Earth as well, for example in the need for improved understanding of polar and permafrost regions, deep sea clathrates, cave minerals, and mine dump efflorescence. Advanced methods of in situ analysis are needed, including but not limited to contact instruments and instrumentation that can be inserted by probe or operated within a borehole that could be advanced with minimal thermal disturbance. One of the lessons of robotic analysis is that field instruments, which by necessity are less capable than laboratory equivalents, provide greatly improved interpretations if data from several different instruments can be compared.
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Finley, B. K.; Schwartz, E.; Koch, B.; Dijkstra, P.; Hungate, B. A.
2017-12-01
The interactions between soil mineral assemblages and microbial communities are important drivers of soil organic carbon (SOC) cycling and storage, although the mechanisms driving these interactions remain unclear. There is increasing evidence supporting the importance of associations with poorly crystalline, short-range order (SRO) minerals in protection of SOC from microbial utilization. However, how the microbial processing of SRO-associated SOC may be influenced by fresh organic matter inputs (priming) remains poorly understood. The influence on SRO minerals on soil microbial community dynamics is uncertain as well. Therefore, we conducted a priming incubation by adding either a simulated root exudate mixture or conifer needle litter to three soils from a mixed-conifer ecosystem. The parent material of the soils were andesite, basalt, and granite and decreased in SRO mineral content, respectively. We also conducted a parallel quantitative stable isotope probing incubation by adding 18O-labelled water to the soils to isotopically label microbial DNA in situ. This allowed us to characterize and identify the active bacterial and archaeal community and taxon-specific growth under fresh organic matter input. While the granite soil (lowest SRO content), had the largest total mineralization, the least priming occurred. The andesite and basalt soils (greater SRO content) had lower total respiration, but greater priming. Across all treatments, the granite soil, while having the lowest species richness of the entire community (249 taxa, both active and inactive), had a larger active community (90%) in response to new SOC input. The andesite and basalt soils, while having greater total species richness of the entire community at 333 and 325 taxa, respectively, had fewer active taxa in response to new C compared to the granite soil (30% and 49% taxa, respectively). These findings suggest that the soil mineral assemblage is an important driver on SOC cycling under fresh
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Gilio, Mattia; Clos, Frediano; Van Roermund, Herman L. M.
2013-04-01
The Scandinavian Caledonides (SC) are a deeply eroded Alpine-type orogenic belt formed by closure of the Iapetus ocean and collision between Baltica and Laurentia (500-380 Ma). The SC consists of a stack of Nappe Complexes (from bottom to top called Lower, Middle, Upper and Uppermost Allochthons) thrusted to the east over the Baltic Shield (Brueckner and Van Roermund, 2004; Gee et al., 2008). Fossil lithospheric mantle fragments, called orogenic peridotites, have been found within the (upper part of) middle, upper and uppermost Allochthons, as well as in the reworked basement gneisses (a.o Western Gneiss Complex (WGC)) along the Norwegian west coast. They occur as isolated lenses that contain diverse mineral parageneses and/or bulk rock compositions. Crustal incorporation of orogenic peridotite is classically interpreted to be the result of plate collisional processes related to orogeny (Brueckner and Medaris, 2000). The WGC and parts of the upper part of the Middle Allochthon (a.o. Seve Nappe Complex (SNC) in N Jämtland/S Västerbotten, central Sweden), are well known for the occurrence of high (HP) and ultrahigh pressure (UHP) metamorphic terranes (of Caledonian age). The (U)HPM evidence clearly demonstrates the deep metamorphic origin of these rocks interpreted to be caused by continental subduction and/or collision. Other metamorphic rocks (of Caledonian age) exposed in allochthonous nappes are solely characterised by greenschist-, amphibolite- and/or MP granulite "facies" mineral assemblages that can be interpreted, in the absence of retrogression, to have formed in less deeply subducted (and/or metamorphic) environments. This duality in metamorphic "facies" allows for a discrimination (at least theoretically) between "deep" versus "shallow" rooted nappes (in central parts of the Scandinavian Caledonides). Conform this reasoning, this duality should also be present within the Caledonian mineral assemblages (= metamorphic overprint) of orogenic peridotites (in
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Surface water connectivity drives richness and composition of Arctic lake fish assemblages
Laske, Sarah M.; Haynes, Trevor B.; Rosenberger, Amanda E.; Koch, Joshua C.; Wipfli, Mark S.; Whitman, Matthew; Zimmerman, Christian E.
2016-01-01
Surface water connectivity can influence the richness and composition of fish assemblages, particularly in harsh environments where colonisation factors and access to seasonal refugia are required for species persistence.
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Jimenez, H.; Dumas, P.; Ponton, D.; Ferraris, J.
2012-03-01
Invertebrates represent an essential component of coral reef ecosystems; they are ecologically important and a major resource, but their assemblages remain largely unknown, particularly on Pacific islands. Understanding their distribution and building predictive models of community composition as a function of environmental variables therefore constitutes a key issue for resource management. The goal of this study was to define and classify the main environmental factors influencing tropical invertebrate distributions in New Caledonian reef flats and to test the resulting predictive model. Invertebrate assemblages were sampled by visual counting during 2 years and 2 seasons, then coupled to different environmental conditions (habitat composition, hydrodynamics and sediment characteristics) and harvesting status (MPA vs. non-MPA and islets vs. coastal flats). Environmental conditions were described by a principal component analysis (PCA), and contributing variables were selected. Permutational analysis of variance (PERMANOVA) was used to test the effects of different factors (status, flat, year and season) on the invertebrate assemblage composition. Multivariate regression trees (MRT) were then used to hierarchically classify the effects of environmental and harvesting variables. MRT model explained at least 60% of the variation in structure of invertebrate communities. Results highlighted the influence of status (MPA vs. non-MPA) and location (islet vs. coastal flat), followed by habitat composition, organic matter content, hydrodynamics and sampling year. Predicted assemblages defined by indicator families were very different for each environment-exploitation scenario and correctly matched a calibration data matrix. Predictions from MRT including both environmental variables and harvesting pressure can be useful for management of invertebrates in coral reef environments.
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Abundance, size composition and benthic assemblages of two Mediterranean echinoids off the
Directory of Open Access Journals (Sweden)
Elzahrae Elmasry
2015-12-01
Full Text Available This study is concerned with the variability in abundance, size composition and benthic assemblages of two echinoid species, the common sea urchin Paracentrotus lividus (Lamarck, 1816 and black urchin Arbacia lixula (Linnaeus, 1758 in the Southeastern Mediterranean (SEM along the coast of Alexandria, Egypt. Four seasonal trips were made during the years 2014–2015 covering 55 km of the shore with depths ranging between 3 and 9 m. The sea urchin species composition, density and size structure and distribution were compared. The associated macrobenthic invertebrates with prominent presence and biomass were observed as well as other benthic fauna and flora associations. The present results showed that P. lividus was the dominant echinoid spatially and temporally. A. lixula showed frequent occurrence in Sidi Bishr and Sidi Gaber stations in the spring season. The most dominant size class was the medium to large-sized classes for P. lividus and large-sized classes for A. lixula. The commercial size for the edible P. lividus represented 33% of the sampled population. Furthermore, the most dominant macrobenthic assemblages beside the echinoid population were primarily oysters, sea cucumbers, and mussels. Beside these, assemblage of seaweeds (red, green, brown and crustose algae, Porifera, Cnidaria, Crustacea, other Echinodermata, Bivalvia, Gastropoda, Tunicata, Bryozoa and Annelida were found. The present study shows that the investigated area represents stable habitats for the echinoid population with rich and diversified algal assemblages as well as other potential food resources.
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Moura, Mario R; Costa, Henrique C; Argôlo, Antônio J S; Jetz, Walter
2017-09-01
The ongoing biodiversity crisis increases the importance and urgency of studies addressing the role of environmental variation on the composition and evolutionary history of species assemblages, but especially the tropics and ectotherms remain understudied. In regions with rainy summers, coexistence of tropical ectothermic species may be determined by the partitioning of the climatic niche, as ectotherms can rely on water availability and thermoregulatory behaviour to buffer constraints along their climatic niche. Conversely, tropical ectotherms facing dry summers would have fewer opportunities to climatic niche partitioning and other processes rather than environmental filtering would mediate species coexistence. We used 218 snake assemblages to quantify the compositional (CBD) and phylogenetic (PBD) beta-diversity of snakes in the Atlantic Forest (AF) hotspot, South America. We identify two AF regions with distinct climatological regimes: dry summers in the northern-AF and rainy summers in the southern-AF. While accounting for the influence of multiscale spatial processes, we disentangle the relative contribution of thermal, water-related and topographic conditions in structuring the CBD and PBD of snake assemblages, and determine the extent in which snake assemblages under distinct climatological regimes are affected by environmental filtering. Thermal conditions best explain CBD and PBD of snakes for the whole AF, whereas water-related factors best explain the structure of snake assemblages within a same climatological regime. CBD and PBD patterns are similarly explained by spatial factors but snake assemblages facing dry summers are more affected by spatial processes operating at fine to intermediate spatial scale, whereas those assemblages in regions with rainy summers have a stronger signature of coarse-scale processes. As expected, environmental filtering plays a stronger role in southern-AF than northern-AF, and the synergism between thermal and water
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DEFF Research Database (Denmark)
Albouy, Camille; Guilhaumon, François; Bastos Araujo, Miguel
2012-01-01
future climatic niches of 288 coastal Mediterranean fish species based on a global warming scenario. We then aggregated geographically the species-level projections to analyse the projected changes in species richness and composition. Our results show that projected changes in assemblage composition....... nestedness), separately. We also present a mapping strategy to simultaneously visualize changes in species richness and assemblage composition. To illustrate our approach, we used the Mediterranean coastal fish fauna as a case study. Using Bioclimatic Envelope Models (BEMs) we first projected the potential......, the joint exploration of changes in species richness and composition coupled with the distinction between species replacement and nestedness bears important information for understanding the nature of climate change impacts on biodiversity. These methodological advances should help decision...
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González-Sansón, Gaspar; Aguilar, Consuelo; Hernández, Ivet; Cabrera, Yureidy; Suarez-Montes, Noelis; Bretos, Fernando; Guggenheim, David
2009-09-01
The main goal of the study was to obtain field data to build a baseline of fish assemblage composition that can be used comparatively for future analyses of the impact of human actions in the region. A basic network of 68 sampling stations was defined for the entire region (4,050 km2). Fish assemblage species and size composition was estimated using visual census methods at three different spatial scales: a) entire region, b) inside the main reef area and c) along a human impact coastal gradient. Multivariate numerical analyses revealed habitat type as the main factor inducing spatial variability of fish community composition, while the level of human impact appears to play the main role in fish assemblage composition changes along the coast. A trend of decreasing fish size toward the east supports the theory of more severe human impact due to overfishing and higher urban pollution in that direction. This is the first detailed study along the northwest coast of Cuba that focuses on fish community structure and the natural and human-induced variations at different spatial scales for the entire NW shelf. This research also provides input for a more comprehensive understanding of coastal marine fish communities' status in the Gulf of Mexico basin.
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Lybrand, R. A.; Rasmussen, C.
2011-12-01
strong indicator that the grain was transforming in situ to secondary weathering products. Other feldspar minerals in the sample appeared relatively un-weathered and were contained within perthite structural units where the plagioclase minerals were preserved as intergrowths of the orthoclase groundmasses. These results suggest differential plagioclase weathering pathways that may have resulted from variations in physical erosion rates or different geologic configurations of the feldspar minerals. Secondary mineral assemblages of the sample included kaolinite, dehydrated halloysite, illite, vermiculite, chlorite and gibbsite, indicating chemical alteration of both micas and feldspars. Current research is focused on additional electron microprobe analyses of surface and saprolite samples from other field areas along the gradient. The electron microprobe data aided in the constraint of chemical weathering processes as related to primary mineral composition.
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International Nuclear Information System (INIS)
Jahnke, Simone M.; Redaelli, Luiza R.; Soglio, Fabio K. Dal
2007-01-01
The structure and composition of the assemblage of pupal parasitoids of Phyllocnistis citrella Stainton, the citrus leaf miner, were studied in two citrus orchards (Citrus deliciosa Tenore cv. Montenegrina and Citrus sinensis (L.) Osbeck x Citrus reticulata Blanco hybrid Murcott), in Montenegro County (29 deg 68S and 51 deg 46W), southern Brazil. At fortnightly samplings, from July 2001 to June 2003, all the new shoots from 24 randomly selected trees were inspected. The species richness reached five native species in the Murcott orchard, and six in Montenegrina. In Murcott, the presence of Ageniaspis citricola (Hymenoptera: Encyrtidae), an exotic species, was detected in the first year of sampling, probably migrating from the nearby areas where it had been released for the miner control. In Montenegrina, its presence was only registered in the second year. A. citricola in both areas was dominant and changed the community structure of parasitoid complex of P. citrella in both orchards. (author)
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Anikina, E. Yu.; Bortnikov, N. S.; Klubnikin, G. K.; Gamyanin, G. N.; Prokof'ev, V. Yu.
2016-05-01
The succession of mineral assemblages, chemistry of gangue and ore minerals, fluid inclusions, and stable isotopes (C, O, S) in minerals have been studied in the Mangazeya silver-base-metal deposit hosted in terrigenous rocks of the Verkhoyansk Fold-Thrust Belt. The deposit is localized in the junction zone of the Kuranakh Anticlinorium and the Sartanga Synclinorium at the steep eastern limb of the Endybal Anticline. The deposit is situated at the intersection of the regional Nyuektame and North Tirekhtyakh faults. Igneous rocks are represented by the Endybal massif of granodiorite porphyry 97.8 ± 0.9 Ma in age and dikes varying in composition. One preore and three types of ore mineralization separated in space are distinguished: quartz-pyrite-arsenopyrite (I), quartz-carbonate-sulfide (II), and silver-base-metal (III). Quartz and carbonate (siderite) are predominant in ore veins. Ore minerals are represented by arsenopyrite, pyrite, sphalerite, galena, fahlore, and less frequent sulfosalts. Three types of fluid inclusions in quartz differ in phase compositions: two- or three-phase aqueous-carbon dioxide (FI I), carbon dioxide gas (FI II), and two-phase (FI III) containing liquid and a gas bubble. The homogenization temperature and salinity fall within the ranges of 367-217°C and 13.8-2.6 wt % NaCl equiv in FI I; 336-126°C and 15.4-0.8 wt % NaCl equiv in FI III. Carbon dioxide in FI II was homogenized in gas at +30.2 to +15.3°C and at +27.2 to 29.0°C in liquid. The δ34S values for minerals of type I range from-1.8 to +4.7‰ (V-CDT); of type II, from-7.4 to +6.6‰; and of type III, from-5.6 to +7.1‰. δ13C and δ18O vary from-7.0 to-6.7‰ (V-PDB) and from +16.6 to +17.1 (V-SMOW) in siderite-I; from-9.1 to-6.9‰ (V-PDB) and from +14.6 to +18.9 (V-SMOW) in siderite-II; from-5.4 to-3.1‰ (V-PDB) and from +14.6 to +19.5 (V-SMOW) in ankerite; and from-4.2 to-2.9‰ (V-PDB) and from +13.5 to +16.8 (V-SMOW) in calcite. The data on mineral assemblages, fluid
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Hutsinpiller, Amy
1988-01-01
The purpose of this study is to use airborne imaging spectrometer data to discriminate hydrothermal alteration mineral assemblages associated with silver and gold mineralization at Virginia City, NV. The data is corrected for vertical striping and sample gradients, and converted to flat-field logarithmic residuals. Log residual spectra from areas known to be altered are compared to field spectra for kaolinitic, illitic, sericitic, and propylitic alteration types. The areal distributions of these alteration types are estimated using a spectral matching technique. Both visual examination of spectra and the matching techniques are effective in distinguishing kaolinitic, illitic, and propylitic alteration types from each other. However, illitic and sericitic alteration cannot be separated using these techniques because the spectra of illite and sericite are very similar. A principal components analysis of 14 channels in the 2.14-2.38 micron wavelength region is also successful in discriminating and mapping illitic, kaolinitic, and propylitic alteration types.
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Temporal variation in fish assemblage composition on a tidal flat
Directory of Open Access Journals (Sweden)
Henry L. Spach
2004-03-01
Full Text Available Annual variation in the fish assemblage characteristics on a tidal flat was studied in coastal Paraná, in southern Brazil. Fish were collected between August 1998 and July 1999, during the diurnal high tide and diurnal and nocturnal low tide of the syzygial (full moon and quadrature (waning moon tides, to characterize temporal change in assemblage composition. A total of 64,265 fish in 133 species were collected. The average number of species and individuals, biomass, species richness, diversity (mass and equitability varied significantly over time . The dissimilarity of the assemblage was greatest in August, September and October in contrast with the period from November to January, with the lowest dissimilarity. The combined action of water temperature, salinity and wind intensity had a great influence over the structure of the fish assemblage.Os peixes de uma planície de maré da praia Balneário de Pontal do Sul, Paraná, foram coletados, na preamar diurna e na baixa-mar diurna e noturna das marés de sizígia e de quadratura, visando caracterizar as mudanças temporais entre agosto de 1998 e julho de 1999. As coletas totalizaram 64.265 peixes de 133 espécies. Foram observadas diferenças significativas na captura média em número de espécies e de peixes, peso total e nos índices de riqueza, diversidade (H' peso e eqüitatividade entre os meses de coleta. A dissimilaridade da ictiofauna foi maior entre os meses de agosto, setembro e outubro em comparação com o período de novembro a janeiro. A ação combinada da temperatura da água, salinidade e intensidade do vento, influenciaram mais sobre a estrutura da assembléia de peixes.
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Calc-silicate mineralization in active geothermal systems
Energy Technology Data Exchange (ETDEWEB)
Bird, D.K.; Schiffman, P.; Elders, W.A.; Williams, A.E.; McDowell, S.D.
1983-01-01
The detailed study of calc-silicate mineral zones and coexisting phase relations in the Cerro Prieto geothermal system were used as examples for thermodynamic evaluation of phase relations among minerals of variable composition and to calculate the chemical characteristics of hydrothermal solutions compatible with the observed calc-silicate assemblages. In general there is a close correlation between calculated and observed fluid compositions. Calculated fugacities of O{sub 2} at about 320{degrees}C in the Cerro Prieto geothermal system are about five orders of magnitude less than that at the nearby Salton Sea geothermal system. This observation is consistent with the occurrence of Fe{sup 3+} rich epidotes in the latter system and the presence of prehnite at Cerro Prieto.
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Mineral assemblage transformation of a metakaolin-based waste form after geopolymer encapsulation
Energy Technology Data Exchange (ETDEWEB)
Williams, Benjamin D., E-mail: Benjamin.Williams@pnnl.gov [Pacific Northwest National Laboratory, PO Box 999, MSIN P7-54, Richland, WA 99352 (United States); Neeway, James J., E-mail: James.Neeway@pnnl.gov [Pacific Northwest National Laboratory, PO Box 999, MSIN P7-54, Richland, WA 99352 (United States); Snyder, Michelle M.V., E-mail: Michelle.ValentaSnyder@pnnl.gov [Pacific Northwest National Laboratory, PO Box 999, MSIN P7-54, Richland, WA 99352 (United States); Bowden, Mark E., E-mail: Mark.Bowden@pnnl.gov [Pacific Northwest National Laboratory, PO Box 999, MSIN P7-54, Richland, WA 99352 (United States); Amonette, James E., E-mail: Jim.Amonette@pnnl.gov [Pacific Northwest National Laboratory, PO Box 999, MSIN P7-54, Richland, WA 99352 (United States); Arey, Bruce W., E-mail: Bruce.Arey@pnnl.gov [Pacific Northwest National Laboratory, PO Box 999, MSIN P7-54, Richland, WA 99352 (United States); Pierce, Eric M., E-mail: pierceem@ornl.gov [Oak Ridge National Laboratory, PO Box 2008, MS-6035, Room 372, Oak Ridge, TN 37831 (United States); Brown, Christopher F., E-mail: Christopher.Brown@pnnl.gov [Pacific Northwest National Laboratory, PO Box 999, MSIN P7-54, Richland, WA 99352 (United States); Qafoku, Nikolla P., E-mail: Nik.Qafoku@pnnl.gov [Pacific Northwest National Laboratory, PO Box 999, MSIN P7-54, Richland, WA 99352 (United States)
2016-05-15
Mitigation of hazardous and radioactive waste can be improved through conversion of existing waste to a more chemically stable and physically robust waste form. One option for waste conversion is the fluidized bed steam reforming (FBSR) process. The resulting FBSR granular material was encapsulated in a geopolymer matrix referred to here as Geo-7. This provides mechanical strength for ease in transport and disposal. However, it is necessary to understand the phase assemblage evolution as a result of geopolymer encapsulation. In this study, we examine the mineral assemblages formed during the synthesis of the multiphase ceramic waste form. The FBSR granular samples were created from waste simulant that was chemically adjusted to resemble Hanford tank waste. Another set of samples was created using Savannah River Site Tank 50 waste simulant in order to mimic a blend of waste collected from 68 Hanford tank. Waste form performance tests were conducted using the product consistency test (PCT), the Toxicity Characteristic Leaching Procedure (TCLP), and the single-pass flow-through (SPFT) test. X-ray diffraction analyses revealed the structure of a previously unreported NAS phase and indicate that monolith creation may lead to a reduction in crystallinity as compared to the primary FBSR granular product. - Highlights: • Simulated Hanford waste was treated by the Fluidized Bed Steam Reformer (FBSR) process. • The FBSR granular product was encapsulated in a geopolymer monolith. • Leach tests were performed to examine waste form performance. • XRD revealed the structure of a previously unreported sodium aluminosilicate phase. • Monolithing of granular waste forms may lead to a reduction in crystallinity.
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Composition and genesis of the Konevinsky gold deposit, Eastern Sayan, Russia
Damdinov, B. B.; Zhmodik, S. M.; Roshchektaev, P. A.; Damdinova, L. B.
2016-03-01
The Konevinsky gold deposit in southeast Eastern Sayan is distinguished from most known deposits in this region (Zun-Kholba, etc.) by the geological setting and composition of mineralization. To elucidate the cause of the peculiar mineralization, we have studied the composition, formation conditions, and origin of this deposit, which is related to the Ordovician granitoid pluton 445-441 Ma in age cut by intermediate and basic dikes spatially associated with metavolcanic rocks of the Devonian-Carboniferous Ilei Sequence. Four mineral assemblages are recognized: (1) quartz-pyrite-molybdenite, (2) quartz-gold-pyrite, (3) gold-polysulfide, and (4) telluride. Certain indications show that the ore was formed as a result of the superposition of two distinct mineral assemblages differing in age. The first stage dated at ~440 Ma is related to intrusions generating Cu-Mo-Au porphyry mineralization and gold-polysulfide veins. The second stage is controlled by dikes pertaining to the Devonian-Carboniferous volcanic-plutonic association. The second stage is characterized by gain of Hg and Te and formation of gold-mercury-telluride paragenesis.
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Denef, Vincent J; Carrick, Hunter J; Cavaletto, Joann; Chiang, Edna; Johengen, Thomas H; Vanderploeg, Henry A
2017-01-01
One approach to improve forecasts of how global change will affect ecosystem processes is to better understand how anthropogenic disturbances alter bacterial assemblages that drive biogeochemical cycles. Species invasions are important contributors to global change, but their impacts on bacterial community ecology are rarely investigated. Here, we studied direct impacts of invasive dreissenid mussels (IDMs), one of many invasive filter feeders, on freshwater lake bacterioplankton. We demonstrated that direct effects of IDMs reduced bacterial abundance and altered assemblage composition by preferentially removing larger and particle-associated bacteria. While this increased the relative abundances of many free-living bacterial taxa, some were susceptible to filter feeding, in line with efficient removal of phytoplankton cells of <2 μm. This selective removal of particle-associated and larger bacteria by IDMs altered inferred bacterial functional group representation, defined by carbon and energy source utilization. Specifically, we inferred an increased relative abundance of chemoorganoheterotrophs predicted to be capable of rhodopsin-dependent energy generation. In contrast to the few previous studies that have focused on the longer-term combined direct and indirect effects of IDMs on bacterioplankton, our study showed that IDMs act directly as a biological disturbance to which freshwater bacterial assemblages are sensitive. The negative impacts on particle-associated bacteria, which have been shown to be more active than free-living bacteria, and the inferred shifts in functional group representation raise the possibility that IDMs may directly alter bacterially mediated ecosystem functions. IMPORTANCE Freshwater bacteria play fundamental roles in global elemental cycling and are an intrinsic part of local food webs. Human activities are altering freshwater environments, and much has been learned regarding the sensitivity of bacterial assemblages to a variety of
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Source assemblage types for cratonic diamonds from X-ray synchrotron diffraction
Nestola, F.; Alvaro, M.; Casati, M. N.; Wilhelm, H.; Kleppe, A. K.; Jephcoat, A. P.; Domeneghetti, M. C.; Harris, J. W.
2016-11-01
Three single crystals of clinopyroxene trapped within three different gem-quality diamonds from the Udachnaya kimberlite (Siberia, Russia) were analysed in situ by single-crystal synchrotron X-ray diffraction in order to obtain information on their chemical composition and infer source assemblage type. A non-destructive approach was used with high-energy (≈ 60 keV; λ ≈ 0.206 Å) at I15, the extreme-conditions beamline at Diamond Light Source. A dedicated protocol was used to center the mineral inclusions located deep inside the diamonds in the X-ray beam. Our results reveal that two of the inclusions can be associated with peridotitic paragenesis whereas the third is eclogitic. This study also demonstrates that this non-destructive experimental approach is extremely efficient in evaluating the origin of minerals trapped in their diamond hosts.
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Effect of Mineral Composition on Thermoluminescence Analysis of Irradiated Garlics
International Nuclear Information System (INIS)
Sookkasem, Atitaya; Wanwisa, Sudprasert; Vitittheeranon, Arag
2009-07-01
Full text: Thermoluminescence (TL) is one of the most popular techniques used for identification of irradiated foods such as spices, herbs and dried fruits in accordance with the Codex Standards. TL analysis is based on the determination of TL of adhering or contaminating minerals in foods. This research aimed to study the effect of mineral composition on the TL intensity. The composited minerals were extracted from 3 types of non-irradiated and irradiated garlic powders by sodium polytungstate solution. X-ray diffraction (XRD) spectroscopy was employed to investigate the type and amount of minerals present in garlic powders. TL of separated minerals were analysed using a Harshaw 4500 TL reader. The results showed that the mineral composition of garlic powders was mainly quartz of varying amounts depending on types of garlics. The TL intensity linearly increased with the amount of quartz present in the samples. It can be concluded that the amount of minerals affect the TL intensity which might influence the identification of irradiated tretment of garlics by thermoluminescence
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The Private Lives of Minerals: Social Network Analysis Applied to Mineralogy and Petrology
Hazen, R. M.; Morrison, S. M.; Fox, P. A.; Golden, J. J.; Downs, R. T.; Eleish, A.; Prabhu, A.; Li, C.; Liu, C.
2016-12-01
Comprehensive databases of mineral species (rruff.info/ima) and their geographic localities and co-existing mineral assemblages (mindat.org) reveal patterns of mineral association and distribution that mimic social networks, as commonly applied to such varied topics as social media interactions, the spread of disease, terrorism networks, and research collaborations. Applying social network analysis (SNA) to common assemblages of rock-forming igneous and regional metamorphic mineral species, we find patterns of cohesion, segregation, density, and cliques that are similar to those of human social networks. These patterns highlight classic trends in lithologic evolution and are illustrated with sociograms, in which mineral species are the "nodes" and co-existing species form "links." Filters based on chemistry, age, structural group, and other parameters highlight visually both familiar and new aspects of mineralogy and petrology. We quantify sociograms with SNA metrics, including connectivity (based on the frequency of co-occurrence of mineral pairs), homophily (the extent to which co-existing mineral species share compositional and other characteristics), network closure (based on the degree of network interconnectivity), and segmentation (as revealed by isolated "cliques" of mineral species). Exploitation of large and growing mineral data resources with SNA offers promising avenues for discovering previously hidden trends in mineral diversity-distribution systematics, as well as providing new pedagogical approaches to teaching mineralogy and petrology.
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Composition of Mineral Produced by Dental Mesenchymal Stem Cells.
Volponi, A A; Gentleman, E; Fatscher, R; Pang, Y W Y; Gentleman, M M; Sharpe, P T
2015-11-01
Mesenchymal stem cells isolated from different dental tissues have been described to have osteogenic/odontogenic-like differentiation capacity, but little attention has been paid to the biochemical composition of the material that each produces. Here, we used Raman spectroscopy to analyze the mineralized materials produced in vitro by different dental cell populations, and we compared them with the biochemical composition of native dental tissues. We show that different dental stem cell populations produce materials that differ in their mineral and matrix composition and that these differ from those of native dental tissues. In vitro, BCMP (bone chip mass population), SCAP (stem cells from apical papilla), and SHED (stem cells from human-exfoliated deciduous teeth) cells produce a more highly mineralized matrix when compared with that produced by PDL (periodontal ligament), DPA (dental pulp adult), and GF (gingival fibroblast) cells. Principal component analyses of Raman spectra further demonstrated that the crystallinity and carbonate substitution environments in the material produced by each cell type varied, with DPA cells, for example, producing a more carbonate-substituted mineral and with SCAP, SHED, and GF cells creating a less crystalline material when compared with other dental stem cells and native tissues. These variations in mineral composition reveal intrinsic differences in the various cell populations, which may in turn affect their specific clinical applications. © International & American Associations for Dental Research 2015.
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Zajzon, Norbert; Szentpéteri, Krisztián; Szakáll, Sándor; Kristály, Ferenc
2015-10-01
The Băiţa metallogenic district in the Bihor Mountains is a historically important mining area in Romania. Uranium mining took place between 1952 and 1998 from various deposits, but very little is known about the geology and mineralogy of these deposits. In this paper, we describe geology and mineralogy of uranium mineralization of the Avram Iancu uranium mine from waste dump samples collected before complete remediation of the site. Texturally and mineralogically complex assemblages of nickeline, cobaltite-gersdorffite solid solution, native Bi, Bi-sulfosalts, molybdenite, and pyrite-chalcopyrite-sphalerite occur with uraninite, "pitchblende," and brannerite in most of the ore samples. The association of nickel, cobalt, and arsenic with uranium is reminiscent of five-element association of vein type U-Ni-Co-Bi-As deposits; however, the Avram Iancu ores appear to be more replacement-type stratiform/stratabound. Avram Iancu ore samples contain multistage complex, skarn, uranium sulfide, arsenide assemblages that can be interpreted to have been formed in the retrograde cooling stages of the skarn hydrothermal system. This mineralizing system may have built-up along Upper Cretaceous-Paleogene "Banatite" intrusions of diorite-to-granite composition. The intrusions crosscut the underlying uraniferous Permian formations in the stacked NW-verging Biharia Nappe System. The mineralization forms stacked, multilayer replacement horizons, along carbonate-rich lithologies within the metavolcanic (tuffaceous) Muncel Series. Mineral paragenesis and some mineral chemistry suggest moderate-to-high <450, i.e., 350-310 °C, formation temperatures for the uranium sulfide stage along stratigraphically controlled replacement zones and minor veins. Uranium minerals formed abundantly in this early stage and include botryoidal, sooty and euhedral uraninite, brannerite, and coffinite. Later and/or lower-temperature mineral assemblages include heterogeneous, complexly zoned arsenide
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International Nuclear Information System (INIS)
Fenton, B.R.; Waite, T.D.
1996-01-01
The uptake of U(VI) as UO 2+ 2 on a natural complex mineral assemblage has been studied using batch selective chemical extraction techniques and secondary ion mass spectroscopy (SIMS). Sediments used in the study consisted of a quartz/mica schist collected from the locale of the Koongarra Uranium ore body, Alligator Rivers Uranium Province, Northern Territory, Australia. The bulk sediment was gravity separated into four size fractions, with attention focused on the nominally <25 μm and 250-1000 μm fractions of the bulk sample, in order to assess the effects of particle size on uranium uptake. Investigation of the kinetics of elemental release in the presence of selective extractants show that uranium is bound largely within the iron and aluminium oxyhydroxides of the assemblage, with a highly mobile fraction of this associated with aluminol sites. SIMS analysis of the natural substrate confirms that significant quantities of aluminium are present in surface layers. The effect of particle size on the uptake of uranium indicates very little change with respect to particle size. This finding may be attributed to the presence of highly porous surface coatings. (orig.)
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International Nuclear Information System (INIS)
Absar, A.; Blattner, P.
1985-01-01
Fifteen drillholes at the Kawerau geothermal field penetrated a sequence of Quaternary volcanic rocks overlying Mesozoic greywackes and argillites in the depth range of 650 to 1220 m below sea level. Maximum temperature in the basement is 250 to 303 deg. C. Twelve greywacke cores were modally analysed in order to determine their intensity of alteration, which in turn was compared with their oxygen isotope composition. It is concluded that Kawerau geothermal field has experienced at least three hydrothermal regimes. The earliest was characterised by fluids with low m CO 2 and δ 18 O, as indicated by the wairakite-prehnite mineral assemblage in greywacke depleted by 5 ppm. This regime was followed by a period of hydraulic fracturing the formation of a mineral assemblage with abundant calcite indicative of fluids with high dissolved CO 2 . Precipitation of minerals during these two early successive hydrothermal regimes resulted in sealing of fractures in the southern part of the field. These two mineral assemblages are indicated to have formed prior to faulting. The latest mineral assemblage comprising quartz-calcite-adularia-calc silicates on the other hand, is related to a series of NE trending faults which enabled geothermal fluids to move northeastward after circulation was precluded in the southern part. This suggests that future exploration for production from the greywacke basement should be in the north where mineralogy and δ 18 O composition of calcite indicate that much better permeability occurs
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Burisch, Mathias; Walter, Benjamin F.; Gerdes, Axel; Lanz, Maximilian; Markl, Gregor
2018-02-01
The majority of hydrothermal vein systems of economic interest occur at relatively shallow crustal levels, although many of them formed at significantly greater depths. Their present position is a consequence of uplift and erosion. Although, many aspects of their formation are well constrained, the temporal chemical evolution of such systems during uplift and erosion is still poorly understood. These vein minerals comprise calcite, dolomite-ankerite, siderite-magnesite, anhydrite and gypsum forming the last gangue assemblages in Jurassic and Tertiary sulphide-fluorite-quartz-barite veins of the Schwarzwald mining district, SW Germany. Mineral textures of samples from nine localities reveal that in these sequences, mineral precipitation follows a recurring pattern: early calcite is followed by anhydrite or gypsum, siderite and/or dolomite. This succession may repeat up to three times. In-situ (LA-ICP-MS) U-Pb age dating of 15 carbonates from three subsequent generations of the late-stage vein assemblage yield robust ages between 20 and 0.6 Ma. Each mineral sequence forms in a distinctive period of about 2-5 Ma. These ages clearly relate these late-stage mineral phases to the youngest geological episode of the Schwarzwald, which is associated with the Cenozoic Rhine Graben rifting and basement uplift. Based on thermodynamic modelling, the formation of the observed mineral assemblages required an deeply sourced Mg-, Fe- and SO4-rich fluid (b), which was episodically mixed with a shallow crustal HCO3-rich fluid (a). As a consequence of fluid mixing, concentrations of Mg, Fe and SO4 temporarily increased and initiated the formation of the observed sulphate-carbonate mineral sequences. This discontinuous large-scale vertical fluid mixing was presumably directly related to episodes of active tectonics associated with the Cenozoic strike-slip regime of the Upper Rhine Graben. Analogously, episodic fluid mixing is a major key in the formation of older (Jurassic to early
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Proximate, Mineral and Phytochemical Composition of Dioscorea ...
African Journals Online (AJOL)
ADOWIE PERE
Keywords: Dioscorea dumetorum, proximate composition, mineral analysis, phytochemical screening ... were analyzed using atomic absorption ... determined using a Hack Dr/200 Spectrophotometer. ... Lead Acetate. +. +. + .... cosmetics.
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The Liana assemblage of a Congolian rainforest : diversity, structure and dynamics
Ewango Ekokinya, Corneille
2010-01-01
Key words: Liana assemblage, species composition, community, dynamics, canopy openness, Manniophyton fulvum, functional traits, population density, pervasive change.
This study analyzes the diversity, composition, and dynamics of the liana assemblage of the Ituri rain forest in -
Species composition and assemblages of ichthyoplankton during summer in the East China Sea
Lin, Han-Yang; Chiu, Mei-Yun; Shih, Yu-Ming; Chen, I.-Shiung; Lee, Ming-An; Shao, Kwang-Tsao
2016-09-01
The East China Sea (ECS) is one of the most important fish spawning and nursery grounds in the north Pacific. Even though summer is an important spawning season for many fishes in the region, large-scale molecular identification studies on ichthyoplankton during this season are few. In this study, we sampled 8,933 fish eggs and 12,161 fish larvae from 25 stations during the summer of 2009. Using DNA barcoding, a number of the fish eggs and larvae were identified and classified into 45 and 124 taxa, respectively. Principal component analysis (PCA) categorized the inshore stations of the Changjiang Diluted Water area as having the hydrographic features of low sea surface temperature (SST), salinity (SSS) and high chlorophyll a (SSC) contents, whereas the continental shelf and offshore stations under the influence of the Kuroshio Current displayed the opposite results. Ichthyoplankton was more abundant at the inshore stations than the offshore stations, but species diversity was lower at the former locations. Species compositions of both fish eggs and fish larvae at the 25 stations were categorized into three different assemblages based on a non-metric multidimensional scaling analysis. Combining the assemblage patterns of ichthyoplankton with the results of the PCA and satellite images of SST and SSC showed that the assemblage patterns of fish eggs were correlated with water mass, while those of the fish larvae were not.
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Energy Technology Data Exchange (ETDEWEB)
Tan, Guoxin, E-mail: tanguoxin@126.com [School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, 510006 (China); Zhou, Lei [School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, 510006 (China); Ning, Chengyun, E-mail: imcyning@scut.edu.cn [College of Materials Science and Technology, South China University of Technology, Guangzhou, 510641 (China); Tan, Ying [School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, 510006 (China); Ni, Guoxin [Department of Orthopedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515 (China); Liao, Jingwen; Yu, Peng; Chen, Xiaofeng [College of Materials Science and Technology, South China University of Technology, Guangzhou, 510641 (China)
2013-08-15
Immobilizing organic–inorganic hybrid composites onto the implant surface is a promising strategy to improve host acceptance of the implant. The objective of this present study was to obtain a unique macroporous titanium-surface with the organic–mineral composite coatings consisting of gelatin methacrylate hydrogel (GelMA) and hydroxyapatite (HA). A 3-(trimethoxysilyl) propyl methacrylate (TMSPMA) layer was first coated onto the titanium surface, and surface was then covalently functionalized with GelMA using a photochemical method. Mineralization of the GelMA coating on the titanium surface was subsequently carried out by a biomimetic method. After 3-day mineralization, a large number of mineral phases comprising spherical amorphous nanoparticles were found randomly deposited inside GelMA matrix. The resulting mineralized hydrogel composites exhibited a unique rough surface of macroporous structure. The structure of the prepared GelMA/HA composite coating was studied by field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectra (EDS), attenuated total refraction Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Water contact angle measurement revealed the hydrophilicity properties of composite coatings. GelMA/HA on titanium after the TMSPMA treatment is very stable when tested in vitro with a PBS solution at 37 °C, due to the role of TMSPMA as a molecular bridge. It was expected that the macroporous GelMA/HA composite coatings might potentially promote and accelerate titanium (Ti)-based implants osseointegration for bone repair and regeneration.
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Mass coral bleaching causes biotic homogenization of reef fish assemblages.
Richardson, Laura E; Graham, Nicholas A J; Pratchett, Morgan S; Eurich, Jacob G; Hoey, Andrew S
2018-04-06
Global climate change is altering community composition across many ecosystems due to nonrandom species turnover, typically characterized by the loss of specialist species and increasing similarity of biological communities across spatial scales. As anthropogenic disturbances continue to alter species composition globally, there is a growing need to identify how species responses influence the establishment of distinct assemblages, such that management actions may be appropriately assigned. Here, we use trait-based analyses to compare temporal changes in five complementary indices of reef fish assemblage structure among six taxonomically distinct coral reef habitats exposed to a system-wide thermal stress event. Our results revealed increased taxonomic and functional similarity of previously distinct reef fish assemblages following mass coral bleaching, with changes characterized by subtle, but significant, shifts toward predominance of small-bodied, algal-farming habitat generalists. Furthermore, while the taxonomic or functional richness of fish assemblages did not change across all habitats, an increase in functional originality indicated an overall loss of functional redundancy. We also found that prebleaching coral composition better predicted changes in fish assemblage structure than the magnitude of coral loss. These results emphasize how measures of alpha diversity can mask important changes in the structure and functioning of ecosystems as assemblages reorganize. Our findings also highlight the role of coral species composition in structuring communities and influencing the diversity of responses of reef fishes to disturbance. As new coral species configurations emerge, their desirability will hinge upon the composition of associated species and their capacity to maintain key ecological processes in spite of ongoing disturbances. © 2018 John Wiley & Sons Ltd.
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Directory of Open Access Journals (Sweden)
Veronica M. Ngole-Jeme
2015-07-01
Full Text Available This study compared the granulometric properties, mineralogical composition and concentrations of major and trace element oxides of commonly ingested soils (geophagic soil collected from different countries with a view of understanding how varied they may be in these properties and to understand the possible health implications of ingesting them. Soil samples were collected from three different countries (South Africa, Swaziland and Democratic Republic of Congo (DRC and their granulometric properties, concentrations of major and trace element oxides as well as mineralogical composition determined. Differences were observed in the granulometric properties of geophagic soil from the three different countries with most of them having <20% clay content. The soils also showed varied degrees of weathering with values of Chemical Index of Alteration (CIA and Chemical Index of Weathering (CIW being between 60% and 99.9% respectively. The mineral assemblages of the soils from South Africa and Swaziland were dominated by the primary minerals quartz and feldspar whereas soils from DRC had more of kaolinite, a secondary mineral than primary minerals. Soils from DRC were associated with silt, clay, Al2O3, and CIA unlike most samples from South Africa which were associated with SiO2, sand, K2O, CaO, and MgO. The soils from Swaziland were closely associated with silt, H2O and Fe2O3(t. These associations reflect the mineralogy of the samples. These soils are not likely to serve as nutrient supplements because of the low concentrations of the nutrient elements contained. The coarse texture of the samples may also result in dental destruction during mastication. Sieving of the soils before ingestion to remove coarse particles is recommended to reduce the potential health threat associated with the ingestion of coarse-textured soils.
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Ngole-Jeme, Veronica M.; Ekosse, Georges-Ivo E.
2015-01-01
This study compared the granulometric properties, mineralogical composition and concentrations of major and trace element oxides of commonly ingested soils (geophagic soil) collected from different countries with a view of understanding how varied they may be in these properties and to understand the possible health implications of ingesting them. Soil samples were collected from three different countries (South Africa, Swaziland and Democratic Republic of Congo (DRC)) and their granulometric properties, concentrations of major and trace element oxides as well as mineralogical composition determined. Differences were observed in the granulometric properties of geophagic soil from the three different countries with most of them having soils also showed varied degrees of weathering with values of Chemical Index of Alteration (CIA) and Chemical Index of Weathering (CIW) being between 60% and 99.9% respectively. The mineral assemblages of the soils from South Africa and Swaziland were dominated by the primary minerals quartz and feldspar whereas soils from DRC had more of kaolinite, a secondary mineral than primary minerals. Soils from DRC were associated with silt, clay, Al2O3, and CIA unlike most samples from South Africa which were associated with SiO2, sand, K2O, CaO, and MgO. The soils from Swaziland were closely associated with silt, H2O and Fe2O3(t). These associations reflect the mineralogy of the samples. These soils are not likely to serve as nutrient supplements because of the low concentrations of the nutrient elements contained. The coarse texture of the samples may also result in dental destruction during mastication. Sieving of the soils before ingestion to remove coarse particles is recommended to reduce the potential health threat associated with the ingestion of coarse-textured soils. PMID:26264010
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Snake assemblages of Marajó Island, Pará state, Brazil
Directory of Open Access Journals (Sweden)
Gerson Moreira Rodrigues
2016-01-01
Full Text Available ABSTRACT We describe the diversity, natural history and structure of snake assemblages from Marajó Island, state of Pará, Brazil, after analyzing 439 specimens deposited in herpetological collections. We tested the hypothesis that snake assemblages from forest and open areas of Marajó Island are distinct with regard to their structure, composition and functional groups. To compare the snake composition of the forest and open areas of Marajó with other comparable assemblages in Brazil, Principal Coordinate Analysis and Clustering tests were performed. A total of 61 species of snakes was recorded for Marajó, with ten species cited for the first time for the study area (Atractus natans Hoogmoed & Prudente, 2003, A. schach (Boie, 1827, Dendrophidion dendrophis (Schlegel, 1837, Helicops hagmanni Roux, 1910, Hydrops martii (Wagler in Spix, 1824, Lygophis meridionalis (Schenkel, 1901, Erythrolamprus typhlus (Linnaeus, 1758, Philodryas argentea (Daudin, 1803, Siphlophis cervinus (Laurenti, 1768, and Thamnodynastes sp.. The composition and structure of snake assemblages between forested and open were different, with five functional groups of snakes in forest areas, and three groups in open areas, based on habit and habitat. In all, 19 species were exclusive to forest areas, 10 were exclusive to open areas and 26 species were recorded in both areas. Our results revealed greater richness for forested areas, probably due to greater habitat heterogeneity. The species composition for forested area in Marajó was similar to that found in other Amazonian assemblages, while that for open areas was more similar to the Pantanal region than other open area assemblages. The general structure of the snake assemblage of Marajó was dominated by anurophagous, terrestrial and diurnal species. Terrestrial, arboreal and semi-arboreal snakes showed a seasonal offspring production pattern, while the pattern for aquatic and semi-aquatic species was aseasonal. The
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International Nuclear Information System (INIS)
Shirin-zade, I.N.; Ganbarov, D.M.
2008-01-01
With aim of acceleration of dissociation of carbonates in clay-dolomited compositions Na 2 SiF 6 was added. Addition mineralization raise stability of composition reaches 20-30 MPa. Na 2 SiF 6 mineralization makes more active decomposition of dolomite and accelerate appearance of new creations. It was experimentally proved that adding of mineralization of Na 2 SiF 6 promote to appearance in mixture of intermediate double salts which are bring down temperature of dissociation of carbonates. Accelerated action of mineralization Na 2 SiF 6 accepted by x-ray, DTA and x-ray spectroscopy
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Willis, Kyle V.; Srogi, LeeAnn; Lutz, Tim; Monson, Frederick C.; Pollock, Meagen
2017-12-01
Textures and compositions are critical information for interpreting rock formation. Existing methods to integrate both types of information favor high-resolution images of mineral compositions over small areas or low-resolution images of larger areas for phase identification. The method in this paper produces images of individual phases in which textural and compositional details are resolved over three orders of magnitude, from tens of micrometers to tens of millimeters. To construct these images, called Phase Composition Maps (PCMs), we make use of the resolution in backscattered electron (BSE) images and calibrate the gray scale values with mineral analyses by energy-dispersive X-ray spectrometry (EDS). The resulting images show the area of a standard thin section (roughly 40 mm × 20 mm) with spatial resolution as good as 3.5 μm/pixel, or more than 81 000 pixels/mm2, comparable to the resolution of X-ray element maps produced by wavelength-dispersive spectrometry (WDS). Procedures to create PCMs for mafic igneous rocks with multivariate linear regression models for minerals with solid solution (olivine, plagioclase feldspar, and pyroxenes) are presented and are applicable to other rock types. PCMs are processed using threshold functions based on the regression models to image specific composition ranges of minerals. PCMs are constructed using widely-available instrumentation: a scanning-electron microscope (SEM) with BSE and EDS X-ray detectors and standard image processing software such as ImageJ and Adobe Photoshop. Three brief applications illustrate the use of PCMs as petrologic tools: to reveal mineral composition patterns at multiple scales; to generate crystal size distributions for intracrystalline compositional zones and compare growth over time; and to image spatial distributions of minerals at different stages of magma crystallization by integrating textures and compositions with thermodynamic modeling.
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Hydrogen-isotopic composition of some hydrous manganese minerals
International Nuclear Information System (INIS)
Hariya, Y.; Tsutsumi, M.
1981-01-01
Initial data on the hydrogen-isotopic compositions in hydrous Mn minerals from various occurrences fall in a wide range from -298 to -84per thousand, relative to SMOW. deltaD-values of todorokite and cryptomelane from Tertiary deposits show -89 and -150per thousand. 10 A-manganite and delta-MnO 2 from deep-sea nodules have relatively restricted deltaD-values ranging from -96 to -84per thousand. The deltaD-values for manganese bog ores from recent hot springs show almost -105per thousand. It is recognized that the isotopic values obtained for the deep-sea nodules and recent bog ores are slightly different ranged. Manganite and groutite are unique in their hydrogen-isotopic compositions, having the most depleted deltaD-values ranging from -298 to -236per thousand. MnO(OH) minerals are more deuterium-depleted hydrous minerals than any other hydrothermal minerals from various ore deposits. Hydrogen-isotope fractionation factors between manganite and water were experimentally determined to be 0.7894, 0.7958 and 0.8078 at 150 0 , 200 0 and 250 0 C respectively. The present experimental results indicate that if manganites were formed at temperatures below 250 0 C, under isotopic equilibrium conditions most of the manganite mineralization in the Tertiary manganese deposits must have precipitated from meteoric hydrothermal solutions. (Auth.)
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Differences in biological traits composition of benthic assemblages between unimpacted habitats
DEFF Research Database (Denmark)
Bolam, S.G.; Garcia, C.; Eggleton, J.
2017-01-01
of unimpacted benthic assemblages vary between different sedimentary habitats. Assemblages in deep, muddy environments unaffected by anthropogenic disturbance show increased proportions of downward conveyors and surface deposit-feeders, while burrowing, diffusive mixing, scavenging and predation traits assume...... greater numerical proportions in shallower habitats. Deep, coarser sediments are numerically more dominated by sessile, upward conveyors and suspension feeders. In contrast, unimpacted assemblages of coarse sediments in shallower regions are proportionally dominated by the diffusive mixers, burrowers......, scavengers and predators. Finally, assemblages of gravelly sediments exhibit a relatively greater numerical dominance of non-bioturbators and asexual reproducers. These findings may be used to form the basis of ranking habitats along a functional sensitivity gradient...
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A composite sphere assemblage model for porous oolitic rocks: Application to thermal conductivity
Directory of Open Access Journals (Sweden)
F. Chen
2017-02-01
Full Text Available The present work is devoted to the determination of linear effective thermal conductivity of porous rocks characterized by an assemblage of grains (oolites coated by a matrix. Two distinct classes of pores, i.e. micropores or intra oolitic pores (oolite porosity and mesopores or inter oolitic pores (inter oolite porosity, are taken into account. The overall porosity is supposed to be connected and decomposed into oolite porosity and matrix porosity. Within the framework of Hashin composite sphere assemblage (CSA models, a two-step homogenization method is developed. At the first homogenization step, pores are assembled into two layers by using self-consistent scheme (SCS. At the second step, the two porous layers constituting the oolites and the matrix are assembled by using generalized self-consistent scheme (GSCS and referred to as three-phase model. Numerical results are presented for data representative of a porous oolitic limestone. It is shown that the influence of porosity on the overall thermal conductivity of such materials may be significant.
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Influence of composition of feed and lactation period on mineral composition of Mare's
Directory of Open Access Journals (Sweden)
Miroslav Fišera
2018-03-01
Full Text Available Normal 0 21 false false false CS X-NONE X-NONE Effects of lactation period and feed on essential minerals composition of mare's milk were studied. Average Ca, P, Na and Mg concentrations in feed DM were 0.66, 4.30, 0.13 and 2.21 g.kg-1 of DM (dry matter, respectively. In regard to milk all elements concentrations were not similar to each other due to the changes of the lactation day differences. Average Ca, P, Na and Mg concentrations (in DM caused by breed differences and lactation days were 1.95, 1.08, 0.53 and 0.22 g.kg-1, respectively. During the milk period, a high-quality feed were maintaining the major mineral composition of mare's milk in 1.5 - 2 times higher amount than milk of mare fed with pasture and a low-quality feed. The colostrum stage of mare was much shorter than other animals, the mare's milk on the 2nd day of lactation showed properties of initial milk in which its composition, particularly in minerals, were two times higher when compare to that on milk periods that was started from 5th day after parturition. It seemed that some factors, except well physiological conditions, such as mare's age, number of foaling, sex of foal etc. did not affect milk nutrient composition.
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Proximate, mineral composition, antioxidant activity, and total ...
African Journals Online (AJOL)
... of protein supplement, valuable minerals and dietary antioxidants. They can serve as scavengers of free radicals reported to be associated with occurrence of chronic and degenerative diseases such as cardiovascular diseases. Keywords: Peppers, phytochemicals, Nutritional composition, Free radicals, Diseases ...
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Predicting the mineral composition of dust aerosols - Part 1: Representing key processes
Perlwitz, J. P.; Pérez García-Pando, C.; Miller, R. L.
2015-02-01
Soil dust aerosols created by wind erosion are typically assigned globally uniform physical and chemical properties within Earth system models, despite known regional variations in the mineral content of the parent soil. Mineral composition of the aerosol particles is important to their interaction with climate, including shortwave absorption and radiative forcing, nucleation of cloud droplets and ice crystals, coating by heterogeneous uptake of sulfates and nitrates, and atmospheric processing of iron into bioavailable forms that increase the productivity of marine phytoplankton. Here, aerosol mineral composition is derived by extending a method that provides the composition of a wet-sieved soil. The extension accounts for measurements showing significant differences between the mineral fractions of the wet-sieved soil and the resulting aerosol concentration. For example, some phyllosilicate aerosols are more prevalent at silt sizes, even though they are nearly absent in a soil whose aggregates are dispersed by wet sieving during analysis. We reconstruct the undispersed size distribution of the original soil that is subject to wind erosion. An empirical constraint upon the relative emission of clay and silt is applied that further differentiates the soil and aerosol mineral composition. In addition, a method is proposed for mixing minerals with small impurities composed of iron oxides. These mixtures are important for transporting iron far from the dust source, because pure iron oxides are more dense and vulnerable to gravitational removal than most minerals comprising dust aerosols. A limited comparison to measurements from North Africa shows that the extension brings the model into better agreement, consistent with a more extensive comparison to global observations as well as measurements of elemental composition downwind of the Sahara, as described in companion articles.
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Phytochemical Screening, Proximate and Mineral Composition of ...
African Journals Online (AJOL)
Leaves of sweet potato (Ipomoea batatas) grown in Tepi area was studied for their class of phytochemicals, mineral and proximate composition using standard analytical methods. The phytochemical screening revealed the presence of alkaloids, flavonoid, terpenoids, saponins, quinones, phenol, tannins, amino acid and ...
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Variations in Urine Calcium Isotope: Composition Reflect Changes in Bone Mineral Balance in Humans
Skulan, Joseph; Anbar, Ariel; Bullen, Thomas; Puzas, J. Edward; Shackelford, Linda; Smith, Scott M.
2004-01-01
Changes in bone mineral balance cause rapid and systematic changes in the calcium isotope composition of human urine. Urine from subjects in a 17 week bed rest study was analyzed for calcium isotopic composition. Comparison of isotopic data with measurements of bone mineral density and metabolic markers of bone metabolism indicates the calcium isotope composition of urine reflects changes in bone mineral balance. Urine calcium isotope composition probably is affected by both bone metabolism and renal processes. Calcium isotope. analysis of urine and other tissues may provide information on bone mineral balance that is in important respects better than that available from other techniques, and illustrates the usefulness of applying geochemical techniques to biomedical problems.
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Andrade, L. S.; Frameschi, I. F.; Costa, R. C.; Castilho, A. L.; Fransozo, A.
2015-02-01
Three regions along the Brazilian coast characterized by the occurrence of contrasting natural phenomena, such as upwellings and continental input, were surveyed to determine the composition and structure of the assemblage of swimming crabs. Twelve monthly collections were undertaken (July 2010 to June 2011) in Macaé, Rio de Janeiro (MAC); Ubatuba, São Paulo (UBA); and São Francisco do Sul, Santa Catarina (SFS). The lowest values of the phi sediment grain size measure, bottom temperature and the highest values of organic matter and salinity were measured in MAC. In all, 10,686 individuals were collected, belonging to six species of Portunoidea: Arenaeus cribrarius, Callinectes danae, Callinectes ornatus, Callinectes sapidus, Achelous spinicarpus and Achelous spinimanus. A Multiple Response Permutation Procedure (MRPP) test indicated that the species composition differed significantly among the sampling sites, showing substantial heterogeneity in the composition and abundance of species among regions. The results suggest that C. danae was more abundant in waters with lower salinity and lower organic matter content. In contrast, A. spinimanus is positively correlated with these factors, showing a greater abundance under the opposite conditions. Callinectes ornatus appeared not to show strong selectivity for particular habitat characteristics. We conclude from these findings that areas affected by different phenomena produce changes in the composition and abundance of the assemblage of Portunoidea. Although the strength of eutrophication differs between UBA and MAC, the substantial continental inflow affecting SFS favors the development of species that complete their life cycle in the estuary.
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Bernardino, Angelo Fraga; Berenguer, Vanessa; Ribeiro-Ferreira, Venina P.
2016-05-01
Deep-sea continental slopes have valuable mineral and biological resources in close proximity to diverse, undersampled and fragile marine benthic ecosystems. The eastern Brazilian Continental Margin (19.01°S to 21.06°S, 37.88°W to 40.22°W) is an important economic region for both fishing and oil industries, but is poorly understood with respect to the structure of the soft-sediment benthic fauna, their regional distribution and their bathymetric patterns. To identify spatial and temporal patterns of benthic macrofaunal assemblages on the slope (400 to 3000 m), the Espirito Santo Basin Assessment Project (AMBES, coordinated by Cenpes-Petrobras) sampled 42 stations across the Brazilian Eastern Slope during both Summer 2012 and Winter 2013. We found a significant decrease in macrofaunal abundance at the 400 m isobath along the slope near the northern region of the Espirito Santo Basin, suggesting benthic responses to upwelling events towards the south in Campos Basin and southern Espirito Santo Basin. The taxonomic diversity and assemblage composition also changed significantly across depth zones with mid-slope peaks of diversity at 1000-1300 m. In general, macrofaunal assemblages were strongly related to slope depth, suggesting a strong influence of productivity gradients and water mass distribution on this oligotrophic margin. Sediment grain size was marginally important to macrofaunal composition on the upper slope. In general, macrofaunal assemblages on the slope of Espirito Santo Basin are similar to other areas of the SE Brazilian margin, but regional changes in response to productivity and depth need to be considered for management strategies in the face of increasing economic activities off-shore.
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Taxonomic and functional composition of arthropod assemblages across contrasting Amazonian forests.
Lamarre, Greg P A; Hérault, Bruno; Fine, Paul V A; Vedel, Vincent; Lupoli, Roland; Mesones, Italo; Baraloto, Christopher
2016-01-01
Arthropods represent most of global biodiversity, with the highest diversity found in tropical rain forests. Nevertheless, we have a very incomplete understanding of how tropical arthropod communities are assembled. We conducted a comprehensive mass sampling of arthropod communities within three major habitat types of lowland Amazonian rain forest, including terra firme clay, white-sand and seasonally flooded forests in Peru and French Guiana. We examined how taxonomic and functional composition (at the family level) differed across these habitat types in the two regions. The overall arthropod community composition exhibited strong turnover among habitats and between regions. In particular, seasonally flooded forest habitats of both regions comprised unique assemblages. Overall, 17·7% (26 of 147) of arthropod families showed significant preferences for a particular habitat type. We present a first reproducible arthropod functional classification among the 147 taxa based on similarity among 21 functional traits describing feeding source, major mouthparts and microhabitats inhabited by each taxon. We identified seven distinct functional groups whose relative abundance contrasted strongly across the three habitats, with sap and leaf feeders showing higher abundances in terra firme clay forest. Our novel arthropod functional classification provides an important complement to link these contrasting patterns of composition to differences in forest functioning across geographical and environmental gradients. This study underlines that both environment and biogeographical processes are responsible for driving arthropod taxonomic composition while environmental filtering is the main driver of the variance in functional composition. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.
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Recent saltmarsh foraminiferal assemblages from Iceland
Lübbers, Julia; Schönfeld, Joachim
2018-01-01
This study reports for the first time boreal to subarctic intertidal foraminiferal assemblages from saltmarshes at Borgarnes and Faskrudsfjördur on Iceland. The composition of living and dead foraminiferal assemblages was investigated along transects from the tidal flat to the highest reach of halophytic plants. The foraminiferal assemblages from Borgarnes showed 18 species in the total foraminiferal assemblage of which only 7 species were recorded in the living fauna. The assemblages were dominated by agglutinated taxa, whereas 3 calcareous species were recorded, of which only Haynesina orbicularis was found in the living fauna. The distribution limit of calcifying species corresponds to the lower boundary of the lower saltmarsh vegetation zone. Furthermore, calcareous tests showed many features of dissolution, which is an indication of a carbonate corrosive environment. The species forming the dead assemblages were mainly derived from the ambient intertidal areas and were displaced by tidal currents into the saltmarsh. The foraminiferal assemblages from Faskrudsfjördur showed two species, of which only one species was recorded in the living fauna. The assemblage was dominated by the agglutinated foraminifer Trochaminita irregularis. The foraminiferal species recorded on Iceland were the same as commonly found elsewhere in Europa. Since no species was found which is endemic to North America, Iceland is considered part of the European bio province. The foraminiferal could have been immigrated to Iceland from Europe through warm water currents, migratory birds or marine traffic since the last Ice Age.
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Progress in photon absorptiometric determination of bone mineral and body composition
International Nuclear Information System (INIS)
Mazess, R.B.; Witt, R.M.; Peppler, W.W.; Hanson, J.A.
1976-01-01
Single-photon absorptiometry, with low energy radionuclides, has become widely accepted for measurement of bone mineral content in vivo. Dual-photon absorptiometry is a newer approach which overcomes previous limitations and allows measurement of total body and spinal bone mineral with high accuracy and precision (2 percent error). Dual-photon absorptiometry also permits measurement of the lean-fat composition of soft-tissue and the monitoring of shifts in body composition and/or fluid balance
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Rapid biotic homogenization of marine fish assemblages
Magurran, Anne E.; Dornelas, Maria; Moyes, Faye; Gotelli, Nicholas J.; McGill, Brian
2015-01-01
The role human activities play in reshaping biodiversity is increasingly apparent in terrestrial ecosystems. However, the responses of entire marine assemblages are not well-understood, in part, because few monitoring programs incorporate both spatial and temporal replication. Here, we analyse an exceptionally comprehensive 29-year time series of North Atlantic groundfish assemblages monitored over 5° latitude to the west of Scotland. These fish assemblages show no systematic change in species richness through time, but steady change in species composition, leading to an increase in spatial homogenization: the species identity of colder northern localities increasingly resembles that of warmer southern localities. This biotic homogenization mirrors the spatial pattern of unevenly rising ocean temperatures over the same time period suggesting that climate change is primarily responsible for the spatial homogenization we observe. In this and other ecosystems, apparent constancy in species richness may mask major changes in species composition driven by anthropogenic change. PMID:26400102
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Nakashole, Albertina N.; Hodgson, David M.; Chapman, Robert J.; Morgan, Dan J.; Jacob, Roger J.
2018-02-01
Establishing relationships between the long-term landscape evolution of drainage basins and the fill of sedimentary basins benefits from analysis of bedrock river terrace deposits. These fragmented detrital archives help to constrain changes in river system character and provenance during sediment transfer from continents (source) to oceans (sink). Thick diamondiferous gravel terrace deposits along the lower Orange River, southern Namibia, provide a rare opportunity to investigate controls on the incision history of a continental-scale bedrock river. Clast assemblage and heavy mineral data from seven localities permit detailed characterisation of the lower Orange River gravel terrace deposits. Two distinct fining-upward gravel terrace deposits are recognised, primarily based on mapped stratigraphic relationships (cross-cutting relationships) and strath and terrace top elevations, and secondarily on the proportion of exotic clasts, referred to as Proto Orange River deposits and Meso Orange River deposits. The older early to middle Miocene Proto Orange River gravels are thick (up to 50 m) and characterised by a dominance of Karoo Supergroup shale and sandstone clasts, whereas the younger Plio-Pleistocene Meso Orange River gravels (6-23 m thick) are characterised by more banded iron formation clasts. Mapping of the downstepping terraces indicates that the Proto gravels were deposited by a higher sinuosity river, and are strongly discordant to the modern Orange River course, whereas the Meso deposits were deposited by a lower sinuosity river. The heavy minerals present in both units comprise magnetite, garnet, amphibole, epidote and ilmenite, with rare titanite and zircon grains. The concentration of amphibole-epidote in the heavy minerals fraction increases from the Proto to the Meso deposits. The decrease in incision depths, recorded by deposit thicknesses above strath terraces, and the differences in clast character (size and roundness) and type between the two
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comparative study on the minerals composition of the flesh of red
African Journals Online (AJOL)
Bashar
The analyses of mineral composition of red and yellow fruits varieties of Terminalia catappa using standard analytical ... the minerals content of these noble fruits and compare .... vitamins, helps to control the effects of stress and possibly result ...
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Mineral composition of urinary calculi from miniature schnauzer dogs.
Klausner, J S; Osborne, C A; Clinton, C W; Stevens, J B; Griffith, D P
1981-05-15
The mineral composition of 150 calculi from the urinary tracts of Miniature Schnauzer dogs was determined by qualitative and quantitative methods. Struvite was the predominant mineral in 92% of the calculi. Other calculi contained predominantly apatite, calcium oxalate, ammonium urate, or silica. Most calculi were from the urinary bladder or urethra, or both. Four were from the renal pelves. Struvite calculi were more frequently encountered in females than males. The mean age of the dogs at the time of detection of calculi was 4.8 years. Qualitative analysis failed to detect some minerals that were identified by quantitative analysis.
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Land use structures fish assemblages in reservoirs of the Tennessee River
Miranda, Leandro E.; Bies, J. M.; Hann, D. A.
2015-01-01
Inputs of nutrients, sediments and detritus from catchments can promote selected components of reservoir fish assemblages, while hindering others. However, investigations linking these catchment subsidies to fish assemblages have generally focussed on one or a handful of species. Considering this paucity of community-level awareness, we sought to explore the association between land use and fish assemblage composition in reservoirs. To this end, we compared fish assemblages in reservoirs of two sub-basins of the Tennessee River representing differing intensities of agricultural development, and hypothesised that fish assemblage structure indicated by species percentage composition would differ among reservoirs in the two sub-basins. Using multivariate statistical analysis, we documented inter-basin differences in land use, reservoir productivity and fish assemblages, but no differences in reservoir morphometry or water regime. Basins were separated along a gradient of forested and non-forested catchment land cover, which was directly related to total nitrogen, total phosphorous and chlorophyll-a concentrations. Considering the extensive body of knowledge linking land use to aquatic systems, it is reasonable to postulate a hierarchical model in which productivity has direct links to terrestrial inputs, and fish assemblages have direct links to both land use and productivity. We observed a shift from an invertivore-based fish assemblage in forested catchments to a detritivore-based fish assemblage in agricultural catchments that may be a widespread pattern among reservoirs and other aquatic ecosystems.
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Directory of Open Access Journals (Sweden)
CFD. Rocha
Full Text Available Habitat fragmentation is well known to adversely affect species living in the remaining, relatively isolated, habitat patches, especially for those having small range size and low density. This negative effect has been critical in coastal resting habitats. We analysed the lizard composition and richness of restinga habitats in 16 restinga habitats encompassing three Brazilian states (Rio de Janeiro, Espírito Santo and Bahia and more than 1500km of the Brazilian coast in order to evaluate if the loss of lizard species following habitat reduction occur in a nested pattern or at random, using the “Nestedness Temperature Calculator” to analyse the distribution pattern of lizard species among the restingas studied. We also estimated the potential capacity that each restinga has to maintain lizard species. Eleven lizard species were recorded in the restingas, although not all species occurred in all areas. The restinga with the richest lizard fauna was Guriri (eight species whereas the restinga with the lowest richness was Praia do Sul (located at Ilha Grande, a large coastal island. Among the restingas analysed, Jurubatiba, Guriri, Maricá and Praia das Neves, were the most hospitable for lizards. The matrix community temperature of the lizard assemblages was 20.49° (= P <0.00001; 5000 randomisations; randomisation temperature = 51.45° ± 7.18° SD, indicating that lizard assemblages in the coastal restingas exhibited a considerable nested structure. The degree in which an area is hospitable for different assemblages could be used to suggest those with greater value of conservation. We concluded that lizard assemblages in coastal restingas occur at a considerable level of ordination in restinga habitats and that some restinga areas such as Jurubatiba, Guriri, Maricá and Praia das Neves are quite important to preserve lizard diversity of restinga environments.
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Predicting the Mineral Composition of Dust Aerosols. Part 1; Representing Key Processes
Perlwitz, J. P.; Garcia-Pando, C. Perez; Miller, R. L.
2015-01-01
Soil dust aerosols created by wind erosion are typically assigned globally uniform physical and chemical properties within Earth system models, despite known regional variations in the mineral content of the parent soil. Mineral composition of the aerosol particles is important to their interaction with climate, including shortwave absorption and radiative forcing, nucleation of cloud droplets and ice crystals, heterogeneous formation of sulfates and nitrates, and atmospheric processing of iron into bioavailable forms that increase the productivity of marine phytoplankton. Here, aerosol mineral composition is derived by extending a method that provides the composition of a wet-sieved soil. The extension accounts for measurements showing significant differences between the mineral fractions of the wetsieved soil and the emitted aerosol concentration. For example, some phyllosilicate aerosols are more prevalent at silt sizes, even though they are nearly absent at these diameters in a soil whose aggregates are dispersed by wet sieving. We calculate the emitted mass of each mineral with respect to size by accounting for the disintegration of soil aggregates during wet sieving. These aggregates are emitted during mobilization and fragmentation of the original undispersed soil that is subject to wind erosion. The emitted aggregates are carried far downwind from their parent soil. The soil mineral fractions used to calculate the aggregates also include larger particles that are suspended only in the vicinity of the source. We calculate the emitted size distribution of these particles using a normalized distribution derived from aerosol measurements. In addition, a method is proposed for mixing minerals with small impurities composed of iron oxides. These mixtures are important for transporting iron far from the dust source, because pure iron oxides are more dense and vulnerable to gravitational removal than most minerals comprising dust aerosols. A limited comparison to
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Klabi, Rim; Bell, Terrence H; Hamel, Chantal; Iwaasa, Alan; Schellenberg, Mike; Raies, Aly; St-Arnaud, Marc
2015-01-01
Adding inorganic P- and N-fixing legumes to semi-arid grasslands can increase forage yield, but soil nutrient concentrations and plant cover may also interact to modify soil fungal populations, impacting short- and long-term forage production. We tested the effect of plant assemblage (seven native grasses, seven native grasses + the domesticated N-fixing legume Medicago sativa, seven native grasses + the native N-fixing legume Dalea purpurea or the introduced grass Bromus biebersteinii + M. sativa) and soil P concentration (addition of 0 or 200 P2O5 kg ha(-1) at sowing) on the diversity and community structure of arbuscular mycorrhizal (AM) fungi and total fungi over two consecutive years, using 454-pyrosequencing of 18S rDNA and ITS amplicons. Treatment effects were stronger in the wet year (2008) than the dry year (2009). The presence of an N-fixing legume with native grasses generally increased AM fungal diversity, while the interaction between soil P concentration and plant assemblage modified total fungal community structure in 2008. Excluding interannual variations, which are likely driven by moisture and plant productivity, AM fungal communities in semi-arid grasslands appear to be primarily affected by plant assemblage composition, while the composition of other fungi is more closely linked to soil P. © FEMS 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
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COMPOSITION OF MINERAL PHASES OF THE GHIDIRIM DIATOMITE
Directory of Open Access Journals (Sweden)
Vasile Rusu
2007-06-01
Full Text Available Studies of the mineralogical composition of diatomite from the Ghidirim location of RM, as well as of the extracted clay phase are presented. The mineral phase of the diatomite contains a number of clay minerals, like montmorillonite (in a mixture with insignificant quantities of slightly chloritized montmorillonite, illite and kaolinite. Diatomite contains also non-clay components as fine-dispersed quartz and amorphous material, the more probable sources of which are opal, amorphous alumosilicates, aluminum and iron hydroxides. The applied procedure for separation of clay fractions by sizing settling in liquid media proves to be very useful, enabling possibilities for more accurate identification of the clay constituents of diatomic material. Procedure allows to separate very clean clay fraction especially rich in montmorillonite, which can be utilized itself as mineral adsorbent for practical purposes.
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Visible and near-infrared (0.4-2.5 μm) reflectance spectra of playa evaporite minerals
Crowley, James K.
1991-01-01
Visible and near-infrared (VNIR; 0.4–2.4 μm) reflectance spectra were recorded for 35 saline minerals that represent the wide range of mineral and brine chemical compositions found in playa evaporite settings. The spectra show that many of the saline minerals exhibit diagnostic near-infrared absorption bands, chiefly attributable to vibrations of hydrogen-bonded structural water molecules. VNIR reflectance spectra can be used to detect minor hydrate phases present in mixtures dominated by anhydrous halite or thenardite, and therefore will be useful in combination with X ray diffraction data for characterizing natural saline mineral assemblages. In addition, VNIR reflectance spectra are sensitive to differences in sample hydration state and should facilitate in situ studies of minerals that occur as fragile, transitory dehydration products in natural salt crusts. The use of spectral reflectance measurements in playa studies should aid in mapping evaporite mineral distributions and may provide insight into the geochemical and hydrological controls on playa mineral and brine development.
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A Mineralized Collagen-Polycaprolactone Composite Promotes Healing of a Porcine Mandibular Defect.
Weisgerber, Daniel W; Milner, Derek J; Lopez-Lake, Heather; Rubessa, Marcello; Lotti, Sammi; Polkoff, Kathryn; Hortensius, Rebecca A; Flanagan, Colleen L; Hollister, Scott J; Wheeler, Matthew B; Harley, Brendan A C
2018-02-01
A tissue engineering approach to address craniofacial defects requires a biomaterial that balances macro-scale mechanical stiffness and strength with the micron-scale features that promote cell expansion and tissue biosynthesis. Such criteria are often in opposition, leading to suboptimal mechanical competence or bioactivity. We report the use of a multiscale composite biomaterial that integrates a polycaprolactone (PCL) reinforcement structure with a mineralized collagen-glycosaminoglycan scaffold to circumvent conventional tradeoffs between mechanics and bioactivity. The composite promotes activation of the canonical bone morphogenetic protein 2 (BMP-2) pathway and subsequent mineralization of adipose-derived stem cells in the absence of supplemental BMP-2 or osteogenic media. We subsequently examined new bone infill in the acellular composite, scaffold alone, or PCL support in 10 mm dia. ramus mandibular defects in Yorkshire pigs. We report an analytical approach to quantify radial, angular, and depth bone infill from micro-computed tomography data. The collagen-PCL composite showed improved overall infill, and significantly increased radial and angular bone infill versus the PCL cage alone. Bone infill was further enhanced in the composite for defects that penetrated the medullary cavity, suggesting recruitment of marrow-derived cells. These results indicate a multiscale mineralized collagen-PCL composite offers strategic advantages for regenerative repair of craniofacial bone defects.
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Proximate, phytochemical and mineral compositions of seeds of ...
African Journals Online (AJOL)
ALLSWELL
2012-06-21
Jun 21, 2012 ... Evaluation of the proximate, phytochemical and mineral compositions of seeds of three tree species was carried out at the University of Agriculture, Umudike. Mature fruits of Allanblackia floribunda,. Garcinia kola and Poga oleosa were collected from the rainforest at Umudike and Oban National Park.
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Effect of Soaking Time on Proximate and Mineral Compositions and ...
African Journals Online (AJOL)
Effect of soaking time on some composition of yellow maize was investigated. Yellow maize seeds (Zea mays) were soaked in deionized water for 12, 24, 36 and 48 hours respectively followed by draining, drying and milling. The unsoaked seeds were milled and served as the control. Proximate and mineral compositions ...
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Partitioning of Cu between mafic minerals, Fe-Ti oxides and intermediate to felsic melts
Liu, Xingcheng; Xiong, Xiaolin; Audétat, Andreas; Li, Yuan
2015-02-01
This study used improved capsule technique i.e., Pt95Cu05 or Au95Cu05 alloy capsules as Cu sources to determine Cu partitioning between mafic minerals, Fe-Ti oxides and intermediate to felsic melts at 0.5-2.5 GPa, 950-1100 °C and various oxygen fugacities (fO2). In combination with the data from the mafic composition systems, the results demonstrate that Cu is generally highly incompatible in mafic minerals and moderately incompatible to compatible in Fe-Ti oxides. The general order of mineral/melt Cu partition coefficients (DCu) is garnet (0.01-0.06) ⩽ olivine (0.04-0.20) ≈ opx (0.04-0.24) ≈ amphibole (0.04-0.20) ⩽ cpx (0.04-0.45) ⩽ magnetite, titanomagnetite and Cr-spinel (0.18-1.83). The variations in DCu depend mainly on temperature, fO2 or mineral composition. In general, DCu for olivine (and perhaps opx) increases with decreasing temperature and increasing fO2. DCu increases for cpx with Na+ (pfu) in cpx, for magnetite and Cr-spinel with Fe3+ (pfu) in these phases and for titanomagnetite with Ti4+ (pfu) in this phase. The large number of DCu data (99 pairs) serves as a foundation for quantitatively understanding the behavior of Cu during magmatic processes. The generation of intermediate to felsic magmas via fractional crystallization or partial melting of mafic rocks (magmas) at deep levels of crust involves removal of or leaving assemblages of mafic minerals + Fe-Ti oxides ± sulfides. With our DCu data on mafic minerals and Fe-Ti oxides, DCubulk values around 0.2 were obtained for the sulfide-free assemblages. Cu will thus be concentrated efficiently in the derived melts during these two processes if sulfides are absent or negligible, explaining that high fO2 and sulfide-destabilization are favorable to formation of the porphyry Cu system.
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Rodriguez, J. M.; Gonzalez-Pola, C.; Lopez-Urrutia, A.; Nogueira, E.
2011-09-01
During summer, wind driven coastal upwelling dominates in the Central Cantabrian Sea (southern Bay of Biscay). Nevertheless, atmospheric forcing is highly variable and wind pulses may cause noticeable and fast hydrographic responses in the shelf region. In this paper, the composition and vertical distribution of the summer ichthyoplankton assemblage during the daytime at a fixed station, located on the Central Cantabrian Sea shelf, are documented. Also, the impact of a short-time scale hydrographic event on the abundance and structure of the larval fish assemblage is examined. Significant small-scale temporal hydrographic variability was observed. Currents showed changes in speed and direction and significant changes in thermocline depth were also observed. A total of 34 taxa of fish larvae were identified. Engraulis encrasicolus eggs and larvae of the shelf-dwelling species Trachurus trachurus, Capros aper and E. encrasicolus dominated the ichthyoplankton assemblage. The distribution of E. encrasicolus eggs and fish larvae was vertically structured. E. encrasicolus egg concentration increased exponentially towards the surface. Fish larvae showed a subsurface peak of concentration and their vertical distribution was not conditioned by thermocline depths. The short term hydrographic event did not affect the vertical distribution of fish larvae but it accounted for significant temporal changes in larval fish assemblage structure and abundance. Results suggest that temperature and light intensity are important factors in the vertical distribution of fish larvae. They also indicate that the temporal monitoring of the larval fish assemblage in this region requires multiple sampling sites.
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The impact of mineral composition on compressibility of saturated soils
Dolinar, Bojana
2012-01-01
This article analyses the impact of soils` mineral composition on their compressibility. Physical and chemical properties of minerals which influence the quantity of intergrain water in soils and, consequently, the compressibility of soils are established by considering the previous theoretical findings. Test results obtained on artificially prepared samples are used to determine the analytical relationship between the water content and stress state, depending on the mineralogical properties ...
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Proximate and mineral elements composition of five locally ...
African Journals Online (AJOL)
The proximate composition of the studied fruits were determined by the standard methods of Official Analytical Chemists, while the Mineral Elements (Ca and Mg) were analyzed using Atomic Absorption Spectrophotometry. The levels of Na+ and K+ were determined using Flame photometry and the level of P was ...
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Proximate, phytochemical and mineral compositions of seeds of ...
African Journals Online (AJOL)
Evaluation of the proximate, phytochemical and mineral compositions of seeds of three tree species was carried out at the University of Agriculture, Umudike. Mature fruits of Allanblackia floribunda, Garcinia kola and Poga oleosa were collected from the rainforest at Umudike and Oban National Park. The seeds were ...
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Directory of Open Access Journals (Sweden)
Gaston Eduardo Enrich Rojas
Full Text Available ABSTRACT: The Monte de Trigo alkaline suite is a SiO2-undersaturated syenite-gabbroid association from the Serra do Mar alkaline province. Eudialyte-group minerals (EGMs occur in one nepheline microsyenite dyke, associated with aegirine-augite, wöhlerite, låvenite, magnetite, zircon, titanite, britholite, and pyrochlore. Major compositional variations include Si (25.09- 25.57 apfu , Nb (0.31- 0.76 apfu , Fe (1.40-2.13 apfu , and Mn (1.36- 2.08 apfu . The EGMs also contain relatively high contents of Ca (6.13- 7.10 apfu , moderate enrichment of rare earth elements (0.38-0.67 apfu , and a relatively low Na content (11.02-12.28 apfu , which can be correlated with their transitional agpaitic assemblage. EGM compositions indicate a complex solid solution that includes eudialyte, kentbrooksite, feklichevite, zirsilite-(Ce, georgbarsanovite, and manganoeudialyte components. EGM trace element analyses show low Sr and Ba contents and a negative Eu/Eu* anomaly, which are interpreted as characteristic of the parental magma due to the previous fractionation of plagioclase and/or alkali feldspar. The EGMs from the dyke border have higher contents of Fe, Sr (2,161-2,699 ppm, Mg (1,179-3,582 ppm, and Zn (732- 852 ppm than those at the dyke center. These differences are related to the incorporation of xenoliths and xenocrysts of melatheralitic host rock into the nepheline-syenitic magma followed by crystal-melt diffusive exchange.
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Girard, Catherine; Dufour, Anne-Béatrice; Charruault, Anne-Lise; Renaud, Sabrina
2018-01-01
Benthic foraminifera have been used as proxies for various paleoenvironmental variables such as food availability, carbon flux from surface waters, microhabitats, and indirectly water depth. Estimating assemblage composition based on morphotypes, as opposed to genus- or species-level identification, potentially loses important ecological information but opens the way to the study of ancient time periods. However, the ability to accurately constrain benthic foraminiferal assemblages has been questioned when the most abundant foraminifera are fragile agglutinated forms, particularly prone to fragmentation. Here we test an alternate method for accurately estimating the composition of fragmented assemblages. The cumulated area per morphotype method is assessed, i.e., the sum of the area of all tests or fragments of a given morphotype in a sample. The percentage of each morphotype is calculated as a portion of the total cumulated area. Percentages of different morphotypes based on counting and cumulated area methods are compared one by one and analyzed using principal component analyses, a co-inertia analysis, and Shannon diversity indices. Morphotype percentages are further compared to an estimate of water depth based on microfacies description. Percentages of the morphotypes are not related to water depth. In all cases, counting and cumulated area methods deliver highly similar results, suggesting that the less time-consuming traditional counting method may provide robust estimates of assemblages. The size of each morphotype may deliver paleobiological information, for instance regarding biomass, but should be considered carefully due to the pervasive issue of fragmentation.
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Quantitative determination of mineral composition by powder X-ray diffraction
International Nuclear Information System (INIS)
Pawloski, G.A.
1986-01-01
A method is described of quantitatively determining the mineral composition in a test sample containing a number (m) of minerals from a group (n) of known minerals, wherein n=13, where mless than or equal ton, by x-ray diffraction, comprising: determining from standard samples of the known minerals a set of (n) standard coefficients K/sub j/=(X/sub j//X/sub l/)(I/sub l//I/sub j/) for each mineral (j=2...n) in the group of known minerals (j=2...n) relative to one mineral (l) in the group selected as a reference mineral, where X is the weight fraction of the mineral in a standard sample, and I is the x-ray integrated intensity peak of each mineral obtained from the standard sample; obtaining an x-ray diffraction pattern of the test sample; identifying each of the (m) minerals in the test sample for the x-ray diffraction pattern; calculating the relative weight fractions X/sub j//X/sub l/ for each mineral (j=2...m) compared to the reference mineral (l) from the ratio of the measured highest integrated intensity peak I/sub j/ of each mineral in the test sample to the measured highest integrated intensity peak I/sub l/ of the reference mineral in the test sample, and from the previously determined standard coefficients, X/sub j//X/sub l/=K/sub j/(I/sub j//I/sub l/
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International Nuclear Information System (INIS)
Clemmey, H.
1982-01-01
Some genetic models for Lower Proterozoic gold- and uranium-bearing pyritic conglomerates favour a modified placer origin in which low levels of atmospheric oxygen are used to account for the survival of uraninite and pyrite. There are many difficulties with such models. New evidence concerning the genesis of the deposits is derived from a clast of ferric iron clay thought to represent a precursor sediment of the Witwatersrand Basin. Reworking of such clays and transport of a magnetite and ferric clay assemblage with subsequent sulphidation, could account for the porous pyrites, the absence of magnetite and the lack of hydraulic equivalence of the mineral grains in the conglomerates. The presence of oxygen, as indicated by the ferric iron clasts, would account for the evidence of mobility of uranium and of gold and would enhance their extraction from source rocks; particularly the release of gold from a precursor auriferous iron formation source. It is suggested that some aspects of the genesis of uranium deposits of the Witwatersrand and Elliott Lake may be similar to those of the Phanerozoic 'Roll Front' ores involving interaction between oxidizing uraniferous groundwaters and previously sulphidized and reduzate facies sediments. (author)
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Zhang, Min; García Molinos, Jorge; Zhang, Xiaolin; Xu, Jun
2018-01-01
Human activities and the consequent extirpations of species have been changing the composition of species assemblages worldwide. These anthropogenic impacts alter not only the richness of assemblages but also the biological dissimilarity among them. One of the main gaps in the assessment of biodiversity change in freshwater ecosystems is our limited understanding regarding how taxonomic and functional facets of macrophyte assemblages respond to human impacts on regional scales. Here, we assess the temporal (before 1970s against after 2000s) changes in taxonomic and functional richness and compositional dissimilarities, partitioned into its turnover and nestedness components, of freshwater macrophyte assemblages across the floodplain lakes of the Yangtze River in China. We found that functional and taxonomic assemblage differentiation occurred simultaneously under increasing human impact, concomitant to a general decrease in functional and taxonomic richness. However, this effect weakened when the historical level of taxonomic dissimilarity among assemblages was high. Macrophyte species with large dispersal range and submersed life form were significantly more susceptible to extirpation. The impact of human activities on differentiation was complex but habitat loss and fishery intensity were consistently the main drivers of assemblage change in these lakes, whereas water quality (i.e., light pollution and nutrient enrichment) had weaker effects. Further, macrophyte taxonomic and functional differentiation was mainly driven by the nestedness component of dissimilarity, accounting for changes in assemblage composition related to changes in species richness independent of species replacement. This result, markedly different from previous studies on freshwater fish assemblages conducted in these lakes, represents a novel contribution toward achieving a more holistic understanding of how human impacts contribute to shape community assemblages in natural ecosystems.
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Fang, Linchuan; Huang, Qiaoyun; Wei, Xing; Liang, Wei; Rong, Xinming; Chen, Wenli; Cai, Peng
2010-08-01
Equilibrium adsorption experiments, isothermal titration calorimetry and potentiometric titration techniques were employed to investigate the adsorption of Cu(II) by extracellular polymeric substances (EPS) extracted from Pseudomonas putida X4, minerals (montmorillonite and goethite) and their composites. Compared with predicted values of Cu(II) adsorption on composites, the measured values of Cu(II) on EPS-montmorillonite composite increased, however, those on EPS-goethite composite decreased. Potentiometric titration results also showed that more surface sites were observed on EPS-montmorillonite composite and less reactive sites were found on EPS-goethite composite. The adsorption of Cu(II) on EPS molecules and their composites with minerals was an endothermic reaction, while that on minerals was exothermic. The positive values of enthalpy change (Delta H) and entropy change (DeltaS) for Cu(II) adsorption on EPS and mineral-EPS composites indicated that Cu(II) mainly interacts with carboxyl and phosphoryl groups as inner-sphere complexes on EPS molecules and their composites with minerals. (c) 2010 Elsevier Ltd. All rights reserved.
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Orogenic-type copper-gold-arsenic-(bismuth) mineralization at Flatschach (Eastern Alps), Austria
Raith, Johann G.; Leitner, Thomas; Paar, Werner H.
2015-10-01
high Hg content (up to 11 mass %). The Cu-Au deposits in the Flatschach area show similarities with meso- to epizonal orogenic lode gold deposits regarding the geological setting, the structural control of mineralization, the type of alteration, the early (stage 1) sulfide assemblage and composition of gold. Unique about the Flatschach district is the lower-temperature overprint of copper arsenides (domeykite and koutekite) and copper sulfides (djurleite, yarrowite/spionkopite) on earlier formed sulfide mineralization. Based on mineralogical considerations temperature of stage 2 mineralization was between about 70 °C and 160 °C. Gold was locally mobilized during this low-temperature hydrothermal overprint as well as during stage 3 supergene oxidation and cementation processes.
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Fibre fortification of wheat bread: impact on mineral composition and bioaccessibility.
Martins, Zita E; Pinto, Edgar; Almeida, Agostinho A; Pinho, Olívia; Ferreira, Isabel M P L V O
2017-05-24
In this work, wheat bread was fortified with fibre enriched extracts recovered from agroindustry by-products, namely, elderberry skin, pulp and seeds (EE); orange peel (OE); pomegranate peel and interior membranes (PE); and spent yeast (YE). The impact of this fortification on the total and bioaccessible mineral composition of wheat breads, estimated mineral daily intake, and the relationship between bioaccessibility and dietary fibre was evaluated. Fortification with OE, EE, and PE improved the content of essential minerals in bread when compared to control bread. The exception was bread fortified with YE, which presented a mineral content similar to control bread, but its mineral bioaccessibility was significantly higher than in all the other bread formulations. The opposite was observed for PE bread, which presented a significant reduction of bioaccessible minerals. We concluded that the origin of the fibre rich extract must be carefully selected, to avoid potential negative impact on mineral bioaccessibility.
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Proximate composition and mineral profile of eight different ...
African Journals Online (AJOL)
... eight different sun dried date varieties; (1) Daki, (2) Aseel, (3) Coconut, (4) Khuzravi, (5) Halavi, (6) Zahidi, (7) Deglet Noor and (8) Barkavi were examined to determine their proximate composition and mineral profile. All the date varieties were found to be rich in proteins, fiber, carbohydrates and net gross energy (352.329 ...
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Geochemistry and petrogenesis of the Kolah-Ghazi granitoid assemblage, south of Esfahan
Directory of Open Access Journals (Sweden)
Jamshid Ahmadian
2018-04-01
Full Text Available Introduction The Kolah-Ghazi granitoid assemblage is located in the south of Esfahan and in the Sanandaj-Sirjan magmatic-metamorphic zone. The Sanandaj-Sirjan zone is extended for 1500 km from Sirjan in the southeast to Sanandaj in the northwest of Iran and is situated in the west of Central Iranian terrane. The Sanandaj-Sirjan zone represents the metamorphic belt of the Zagros orogeny which is part of the Alpine- Himalayan orogenic belt. The Kolah-Ghazi granitoid assemblage consists of granodiorite, granites, quartz-rich granitoid and minor tonalite. The aim of this paper is to represent the mineralogy, geochemistry, petrogenesis and tectonic setting of this plutonic assemblage. Materials and methods More than 60 samples representing all of the rock units in the study area were chosen for microscopic studies. Then, 22 samples were selected for geochemical studies. The major elements were determined with XRF in the Naruto University, Japan. The trace and rare earth elements were analyzed by ICP-MS in the Acmelab, Canada. The geochemical results are presented in Table 1. Results and Discussion The Kolah-Ghazi granitoid assemblage intruded into the Jurassic sedimentary units and overlaid by lower Cretaceous sandstone and conglomerate which suggest Upper Jurassic as the possible age of the Kolah-Ghazi intrusion. Based on the modal studies, this granitoid assemblage is comprised of granite, granodiorite, quartz-rock granitoid and tonalite with different igneous textures including symplectic, myrmekitic, rapakivi, poikilitic and porphyroid. There are some xenoliths, microgranular enclaves and sur micaceous enclaves in the Kolah-Ghazi granitoid assemblage. Xenoliths are mostly derived from Jurassic shale and sandstones which have been trapped in the magma. The sur micaceousenclaves have tonalite composition. The sur micaceous enclaves are biotite-rich rock fragments which display metamorphic texture. The sur micaceous enclaves are classified as
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Tobi, A.C.
1974-01-01
Rocks can be named, described and compared in terms of their chemical analysis, or in terms of their actual mineral content measured in volume per cent (the "mode"). Both are of course related, although similar chemical compositions may lead to widely varying modes depending on subtle
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Mineral composition of non-conventional leafy vegetables.
Barminas, J T; Charles, M; Emmanuel, D
1998-01-01
Six non-conventional leafy vegetables consumed largely by the rural populace of Nigeria were analyzed for mineral composition. Mineral contents appeared to be dependent on the type of vegetables. Amaranthus spinosus and Adansonia digitata leaves contained the highest level of iron (38.4 mg/100 g and 30.6 mg/100 g dw, respectively). These values are low compared to those for common Nigerian vegetables but higher than those for other food sources. All the vegetables contained high levels of calcium compared to common vegetables, thus they could be a rich source of this mineral. Microelement content of the leaves varied appreciably. Zinc content was highest in Moringa oleifera, Adansonia digitata and Cassia tora leaves (25.5 mg/100 g, 22.4 mg/100 g and 20.9 mg/100 g dw, respectively) while the manganese content was comparatively higher in Colocasia esculenta. The concentrations of the mineral elements in the vegetables per serving portion are presented and these values indicate that the local vegetables could be valuable and important contributors in the diets of the rural and urban people of Nigeria. The mean daily intake of P, Mg, Ca, Fe, Cu and Zn were lower than their recommended dietary allowances (RDAs). However, the manganese daily intake was found not to differ significantly (p = 0.05) from the RDA value.
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Directory of Open Access Journals (Sweden)
C. J. Friedline
2012-06-01
Full Text Available Microbial communities are recognized as major drivers of the biogeochemical processes in the oceans. However, the genetic diversity and composition of those communities is poorly understood. The aim of this study is to investigate the composition of bacterial assemblages in three different water layer habitats: surface (2–20 m, deep chlorophyll maximum (DCM; 28–90 m, and deep (100–4600 m at nine stations along the eastern Atlantic Ocean from 42.8° N to 23.7° S. The sampling of three discrete, predefined habitat types from different depths, Longhurstian provinces, and geographical locations allowed us to investigate whether marine bacterial assemblages show spatial variation and to determine if the observed spatial variation is influenced by current environmental conditions, historical/geographical contingencies, or both. The PCR amplicons of the V6 region of the 16S rRNA from 16 microbial assemblages were pyrosequenced, generating a total of 352 029 sequences; after quality filtering and processing, 257 260 sequences were clustered into 2871 normalized operational taxonomic units (OTU using a definition of 97% sequence identity. Community ecology statistical analyses demonstrate that the eastern Atlantic Ocean bacterial assemblages are vertically stratified and associated with water layers characterized by unique environmental signals (e.g., temperature, salinity, and nutrients. Genetic compositions of bacterial assemblages from the same water layer are more similar to each other than to assemblages from different water layers. The observed clustering of samples by water layer allows us to conclude that contemporary environments are influencing the observed biogeographic patterns. Moreover, the implementation of a novel Bayesian inference approach that allows a more efficient and explicit use of all the OTU abundance data shows a distance effect suggesting the influence of historical contingencies on the composition of bacterial
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Friedline, C. J.; Franklin, R. B.; McCallister, S. L.; Rivera, M. C.
2012-06-01
Microbial communities are recognized as major drivers of the biogeochemical processes in the oceans. However, the genetic diversity and composition of those communities is poorly understood. The aim of this study is to investigate the composition of bacterial assemblages in three different water layer habitats: surface (2-20 m), deep chlorophyll maximum (DCM; 28-90 m), and deep (100-4600 m) at nine stations along the eastern Atlantic Ocean from 42.8° N to 23.7° S. The sampling of three discrete, predefined habitat types from different depths, Longhurstian provinces, and geographical locations allowed us to investigate whether marine bacterial assemblages show spatial variation and to determine if the observed spatial variation is influenced by current environmental conditions, historical/geographical contingencies, or both. The PCR amplicons of the V6 region of the 16S rRNA from 16 microbial assemblages were pyrosequenced, generating a total of 352 029 sequences; after quality filtering and processing, 257 260 sequences were clustered into 2871 normalized operational taxonomic units (OTU) using a definition of 97% sequence identity. Community ecology statistical analyses demonstrate that the eastern Atlantic Ocean bacterial assemblages are vertically stratified and associated with water layers characterized by unique environmental signals (e.g., temperature, salinity, and nutrients). Genetic compositions of bacterial assemblages from the same water layer are more similar to each other than to assemblages from different water layers. The observed clustering of samples by water layer allows us to conclude that contemporary environments are influencing the observed biogeographic patterns. Moreover, the implementation of a novel Bayesian inference approach that allows a more efficient and explicit use of all the OTU abundance data shows a distance effect suggesting the influence of historical contingencies on the composition of bacterial assemblages. Surface
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Rocha, C F D; Vrcibradic, D; Kiefer, M C; Menezes, V A; Fontes, A F; Hatano, F H; Galdino, C A B; Bergallo, H G; Van Sluys, M
2014-05-01
Habitat fragmentation is well known to adversely affect species living in the remaining, relatively isolated, habitat patches, especially for those having small range size and low density. This negative effect has been critical in coastal resting habitats. We analysed the lizard composition and richness of restinga habitats in 16 restinga habitats encompassing three Brazilian states (Rio de Janeiro, Espírito Santo and Bahia) and more than 1500km of the Brazilian coast in order to evaluate if the loss of lizard species following habitat reduction occur in a nested pattern or at random, using the "Nestedness Temperature Calculator" to analyse the distribution pattern of lizard species among the restingas studied. We also estimated the potential capacity that each restinga has to maintain lizard species. Eleven lizard species were recorded in the restingas, although not all species occurred in all areas. The restinga with the richest lizard fauna was Guriri (eight species) whereas the restinga with the lowest richness was Praia do Sul (located at Ilha Grande, a large coastal island). Among the restingas analysed, Jurubatiba, Guriri, Maricá and Praia das Neves, were the most hospitable for lizards. The matrix community temperature of the lizard assemblages was 20.49° (= P restingas exhibited a considerable nested structure. The degree in which an area is hospitable for different assemblages could be used to suggest those with greater value of conservation. We concluded that lizard assemblages in coastal restingas occur at a considerable level of ordination in restinga habitats and that some restinga areas such as Jurubatiba, Guriri, Maricá and Praia das Neves are quite important to preserve lizard diversity of restinga environments.
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Energy Technology Data Exchange (ETDEWEB)
Ma Yanxuan; Zheng Yudong; Huang Xiaoshan; Xi Tingfei; Han Dongfei [School of Materials Science and Engineering, Beijing University of Science and Technology, Beijing 100083 (China); Lin Xiaodan [College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640 (China); Song Wenhui, E-mail: zhengyudong@mater.ustb.edu.c, E-mail: wenhui.song@brunel.ac.u [Wolfson Center for Materials Processing, School of Engineering and Design, Brunel University, West London, UB8 3PH (United Kingdom)
2010-04-15
Due to the non-bioactivity and poor conjunction performance of present cartilage prostheses, the main work here is to develop the bioactive glass-polyvinyl alcohol hydrogel articular cartilage/bone (BG-PVA/bone) composite implants. The essential criterion for a biomaterial to bond with living bone is well-matched mechanical properties as well as biocompatibility and bioactivity. In vitro studies on the formation of a surface layer of carbonate hydroxyl apatite (HCA) and the corresponding variation of the properties of biomaterials are imperative for their clinical application. In this paper, the mineralization behavior and variation of the interface properties of BG-PVA/bone composites were studied in vitro by using simulated body fluid (SBF). The mineralization and HCA layer formed on the interface between the BG-PVA hydrogel and bone in SBF could provide the composites with bioactivity and firmer combination. The compression property, shear strength and interface morphology of BG-PVA/bone composite implants varying with the immersion time in SBF were characterized. Also, the influence laws of the immersion time, content of BG in the composites and aperture of bones to the mineralization behavior and interface properties were investigated. The good mineralization behavior and enhanced conjunction performance of BG-PVA/bone composites demonstrated that this kind of composite implant might be more appropriate cartilage replacements.
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Ma, Yanxuan; Zheng, Yudong; Huang, Xiaoshan; Xi, Tingfei; Lin, Xiaodan; Han, Dongfei; Song, Wenhui
2010-04-01
Due to the non-bioactivity and poor conjunction performance of present cartilage prostheses, the main work here is to develop the bioactive glass-polyvinyl alcohol hydrogel articular cartilage/bone (BG-PVA/bone) composite implants. The essential criterion for a biomaterial to bond with living bone is well-matched mechanical properties as well as biocompatibility and bioactivity. In vitro studies on the formation of a surface layer of carbonate hydroxyl apatite (HCA) and the corresponding variation of the properties of biomaterials are imperative for their clinical application. In this paper, the mineralization behavior and variation of the interface properties of BG-PVA/bone composites were studied in vitro by using simulated body fluid (SBF). The mineralization and HCA layer formed on the interface between the BG-PVA hydrogel and bone in SBF could provide the composites with bioactivity and firmer combination. The compression property, shear strength and interface morphology of BG-PVA/bone composite implants varying with the immersion time in SBF were characterized. Also, the influence laws of the immersion time, content of BG in the composites and aperture of bones to the mineralization behavior and interface properties were investigated. The good mineralization behavior and enhanced conjunction performance of BG-PVA/bone composites demonstrated that this kind of composite implant might be more appropriate cartilage replacements.
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International Nuclear Information System (INIS)
Liu Lu; Dai Mingjian
2014-01-01
Tengger depression of Erlian basin, which was a Cenozoic inland depression, developed in the late Variscan Orogeny and along the long axis trending of east to west. The upper member of Sanhan Formation is the main prospecting target horizon in Tengger area. Besides, the lower member of Sanhan Formation is also taken into account the prospecting target horizon in this area. Comprehensive analysis of the palynological assemblages collected from NO. TZK2-4 core samples in Tengger area indicates that the time of sediment occurred in Early Cretaceous and roughly equivalent to the Aptian-Albian age. Furthermore, it can determine those core sample should be the important prospecting target horizon-Sanhan Formation of Lower Cretaceous in studied area. And the climate characteristic was warm and humid subtropical climate, and had the transition to sub-humid to semi-hot condition. It can be inferred that ancient warm and humid or fluctuation station of warm and humid to semi-arid climate was favorable to the uranium mineralization. (authors)
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Performance Study of the Natural Rubber Composite with Clay Minerals
International Nuclear Information System (INIS)
Nyo Nyo Myint; Tin Tin Aye; Kyaw Myo Naing; Nyunt Wynn
2008-03-01
The preparation, characterization and some applications of natural rubber clay composite have been studied. This study investigated the possibility of natural rubber latex to replace some part of natural clays. In formulation of rubber clay composite from natural rubber latex and various clay minerals, three main steps were involved (i) preparation of latex cream (ii) prevulcanization of latex cream (iii) mixing vulcanized latex compound, with other ingredients. In each step, several parameters have been carefully investigated to optimize the performance of natural rubber clay composite production. The composite products were of better quality and can be considered to be more cost effective.
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Proximate, mineral and vitamin C composition of vegetable Gbolo ...
African Journals Online (AJOL)
Gbolo (Crassocephalum crepidioides and Crassocephalum rubens) is a traditional leafy vegetable highly consumed in southern and central Benin, as well as in some part of northern Benin. The nutritional potential of the two species of Gbolo were evaluated through their proximate composition, mineral and vitamin C ...
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Body composition and bone mineral density measurements by using a multi-energy method
International Nuclear Information System (INIS)
Herve, L.
2003-01-01
Dual-energy X-ray absorptiometry is a major technique to evaluate bone mineral density, thus allowing diagnosis of bone decalcification ( osteoporosis). Recently, this method has proved useful to quantify body composition (fat ratio). However, these measurements suffer from artefacts which can lead to diagnosis errors in a number of cases. This work has aimed to improve both the reproducibility and the accuracy of bone mineral density and body composition measurements. To this avail, the acquisition conditions were optimised in order to ameliorate the results reproducibility and we have proposed a new method to correct inaccuracies in the determination of bone mineral density. Experimental validations yield encouraging results on both synthetic phantoms and biological samples. (author)
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Directory of Open Access Journals (Sweden)
Benamara Abdelwaheb
2017-09-01
Full Text Available The extreme north-eastern Algeria, in particular the Guelma city conceals thermal springs, whose waters circulating at great depths allow the rain-waters to warm up (according to the average geothermal gradient of 1°C per 33 m and to acquire a mineralization which depends on the traversed rock. The goal of this research work was to determine mineralization origin of the thermo-mineral waters of Hammam Meskoutine (Algerian N-E. A hydro-chemical study involved analyses of a number of physical and chemical parameters of waters such as: temperature, hydrogen potential, electrolytical conductivity, Cl-, SO4 2-, HCO3 -, Ca2+, Mg2+, K+ and Na+. The data processing on the diagram revealed two dominating chemical facies: sulphate-magnesium and bicarbonate magnesium. With a high conductivity in excess of 2300 μS·cm-1, the temperature reaches 97°C. Calculation of the saturation index shows that the waters are supersaturated in carbonate minerals (calcite, dolomite and aragonite and less saturated with evaporite minerals (halite, anhydrite, sylvite and gypsum. The reconstitution in dissolved salts reveals a dominant salt rich in calcium bicarbonates, in calcium sulphates and secondarily in magnesium salts. Geological sections used in the study zone affirm that the chemical composition of the spring waters comes from the neritic limestone dissolution and the gypso-saline complex of Hammam Meskoutine.
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International Nuclear Information System (INIS)
Hiraga, Naoto; Ishii, Eiichi
2008-02-01
The following three kinds of analyses were conducted for the 1st phase of the Horonobe Underground Research Laboratory Project. Mineral composition analysis of core sample. Whole rock chemical composition analysis of core sample. Surface gas composition analysis. This document summarizes the results of these analyses. (author)
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Patterns in reef fish assemblages: Insights from the Chagos Archipelago.
Samoilys, Melita; Roche, Ronan; Koldewey, Heather; Turner, John
2018-01-01
Understanding the drivers of variability in the composition of fish assemblages across the Indo-Pacific region is crucial to support coral reef ecosystem resilience. Whilst numerous relationships and feedback mechanisms between the functional roles of coral reef fishes and reef benthic composition have been investigated, certain key groups, such as the herbivores, are widely suggested to maintain reefs in a coral-dominated state. Examining links between fishes and reef benthos is complicated by the interactions between natural processes, disturbance events and anthropogenic impacts, particularly fishing pressure. This study examined fish assemblages and associated benthic variables across five atolls within the Chagos Archipelago, where fishing pressure is largely absent, to better understand these relationships. We found high variability in fish assemblages among atolls and sites across the archipelago, especially for key groups such as a suite of grazer-detritivore surgeonfish, and the parrotfishes which varied in density over 40-fold between sites. Differences in fish assemblages were significantly associated with variable levels of both live and recently dead coral cover and rugosity. We suggest these results reflect differing coral recovery trajectories following coral bleaching events and a strong influence of 'bottom-up' control mechanisms on fish assemblages. Species level analyses revealed that Scarus niger, Acanthurus nigrofuscus and Chlorurus strongylocephalos were key species driving differences in fish assemblage structure. Clarifying the trophic roles of herbivorous and detritivorous reef fishes will require species-level studies, which also examine feeding behaviour, to fully understand their contribution in maintaining reef resilience to climate change and fishing impacts.
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Patterns in reef fish assemblages: Insights from the Chagos Archipelago
Roche, Ronan; Koldewey, Heather; Turner, John
2018-01-01
Understanding the drivers of variability in the composition of fish assemblages across the Indo-Pacific region is crucial to support coral reef ecosystem resilience. Whilst numerous relationships and feedback mechanisms between the functional roles of coral reef fishes and reef benthic composition have been investigated, certain key groups, such as the herbivores, are widely suggested to maintain reefs in a coral-dominated state. Examining links between fishes and reef benthos is complicated by the interactions between natural processes, disturbance events and anthropogenic impacts, particularly fishing pressure. This study examined fish assemblages and associated benthic variables across five atolls within the Chagos Archipelago, where fishing pressure is largely absent, to better understand these relationships. We found high variability in fish assemblages among atolls and sites across the archipelago, especially for key groups such as a suite of grazer-detritivore surgeonfish, and the parrotfishes which varied in density over 40-fold between sites. Differences in fish assemblages were significantly associated with variable levels of both live and recently dead coral cover and rugosity. We suggest these results reflect differing coral recovery trajectories following coral bleaching events and a strong influence of ‘bottom-up’ control mechanisms on fish assemblages. Species level analyses revealed that Scarus niger, Acanthurus nigrofuscus and Chlorurus strongylocephalos were key species driving differences in fish assemblage structure. Clarifying the trophic roles of herbivorous and detritivorous reef fishes will require species-level studies, which also examine feeding behaviour, to fully understand their contribution in maintaining reef resilience to climate change and fishing impacts. PMID:29351566
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Kubo, Joshua S.; Torgersen, Christian E.; Bolton, Susan M.; Weekes, Anne A.; Gara, Robert I.
2013-01-01
1. Aquatic habitats and biotic assemblages in subalpine headwaters are sensitive to climate and human impacts. Understanding biotic responses to such perturbations and the contribution of high-elevation headwaters to riverine biodiversity requires the assessment of assemblage composition among habitat types. We compared aquatic insect assemblages among headwater stream segment types in relict glaciated subalpine basins in Mt. Rainier National Park, Washington, USA. 2. Aquatic insects were collected during summer and autumn in three headwater basins. In each basin, three different stream segment types were sampled: colluvial groundwater sources, alluvial lake inlets, and cascade-bedrock lake outlets. Ward's hierarchical cluster analysis revealed high β diversity in aquatic insect assemblages, and non-metric multidimensional scaling indicated that spatial and temporal patterns in assemblage composition differed among headwater stream segment types. Aquatic insect assemblages showed more fidelity to stream segment types than to individual basins, and the principal environmental variables associated with assemblage structure were temperature and substrate. 3. Indicator species analyses identified specific aquatic insects associated with each stream segment type. Several rare and potentially endemic aquatic insect taxa were present, including the recently described species, Lednia borealis (Baumann and Kondratieff). 4. Our results indicate that aquatic insect assemblages in relict glaciated subalpine headwaters were strongly differentiated among stream segment types. These results illustrate the contribution of headwaters to riverine biodiversity and emphasise the importance of these habitats for monitoring biotic responses to climate change. Monitoring biotic assemblages in high-elevation headwaters is needed to prevent the potential loss of unique and sensitive biota.
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Directory of Open Access Journals (Sweden)
Gaspar González-Sansón
2009-09-01
Full Text Available The main goal of the study was to obtain field data to build a baseline of fish assemblage composition that can be used comparatively for future analyses of the impact of human actions in the region. A basic network of 68 sampling stations was defined for the entire region (4 050 km2. Fish assemblage species and size composition was estimated using visual census methods at three different spatial scales: a entire region, b inside the main reef area and c along a human impact coastal gradient. Multivariate numerical analyses revealed habitat type as the main factor inducing spatial variability of fish community composition, while the level of human impact appears to play the main role in fish assemblage composition changes along the coast. A trend of decreasing fish size toward the east supports the theory of more severe human impact due to overfishing and higher urban pollution in that direction. This is the first detailed study along the northwest coast of Cuba that focuses on fish community structure and the natural and human-induced variations at different spatial scales for the entire NW shelf. This research also provides input for a more comprehensive understanding of coastal marine fish communities’ status in the Gulf of Mexico basin. Rev. Biol. Trop. 57 (3: 721-740. Epub 2009 September 30.Se obtuvieron datos de campo para una línea base de la composición de la ictiofauna que pueda ser usada comparativamente para el análisis de impactos humanos futuros en la región. Se estableció una red básica de 68 estaciones de muestreo para la región completa (4 050 km2. La composición por especies y por tallas de la ictiofauna fue estimada utilizando métodos de censo visual en tres escalas espaciales diferentes: a La región completa, b dentro del área principal de arrecifes y c a lo largo de un gradiente costero de impacto humano. El tipo de hábitat es el factor principal que induce la variación espacial en la composición de la
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Chung, Chih-Ching; Gong, Gwo-Ching; Huang, Chin-Yi; Lin, Jer-Young; Lin, Yun-Chi
2015-10-01
The aim of this study was to elucidate how flooding of the Changjiang River affects the assemblage composition of phycoerythrin-rich (PE-rich) Synechococcus at the surface of the East China Sea (ECS). During non-flooding summers (e.g., 2009), PE-rich Synechococcus usually thrive at the outer edge of the Changjiang River diluted water coverage (CDW; salinity ≤31 PSU). In the summer of 2010, a severe flood occurred in the Changjiang River basin. The plentiful freshwater injection resulted in the expansion of the CDW over half of the ECS and caused PE-rich cells to show a uniform distribution pattern, with decreased abundance compared with the non-flooding summer. The phylogenetic diversity of 16S rRNA gene sequences indicated that the flooding event also shifted the picoplankton community composition from being dominated by Synechococcus, mainly attributed to the clade II lineage, to various orders of heterotrophic bacteria, including Actinobacteria, Flavobacteria, α-Proteobacteria, and γ-Proteobacteria. As an increasing number of studies have proposed that global warming might result in more frequent floods, combining this perspective with the information obtained from our previous [1] and this studies yield a more comprehensive understanding of the relationship between the composition of the marine Synechococcus assemblage and global environmental changes.
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Qualitative PIXE analysis of mineral elements in some dental composites
International Nuclear Information System (INIS)
Preoteasa, E.A.; Iordan, Andreea; Harangus, Livia; Ciortea, C.; Gugiu, M.; Moldovan, Maria
2002-01-01
Dental composites, made by particles of glass, ceramics and quartz embedded in an organic polymer, develop at a high rate. However, commercial composites are expensive and recently the 'Restacril' biomaterials company became prepared to offer a low-cost alternative. The durability of dental fillings depends not only on biomaterial's gross chemical composition, but also on impurities. These may influence the chemical, mechanical and surface properties of the inorganic particles and modify the composites' clinical behavior. Thus elemental analysis is necessary to improve the biomaterials' quality. Nuclear and atomic methods allow sensitive multielement detection, and we previously analyzed some commercial composites by particle-induced X-ray emission (PIXE). Here we applied PIXE in the qualitative analysis of six new Romanian biomaterials, aiming to compare their nominal and detected composition and paying attention to the impurities. The PIXE measurements were performed with 3 MeV protons at the 8.5 MV NIPNE-HH tandem accelerator, using a hyper pure Ge detector, normal to the beam and connected to a multichannel analyzer and to a computer. Solid samples of composites with a flat surface were fixed at 45 angle, absorber foil of Al 30 mm thick was used, and integration of beam current was done. In all composites PIXE detected mineral elements with Z > 19 down to trace levels. All major nominal elements with Z > 20 - Ca, Sr, Zr, Ba, and Yb - were detected by PIXE. In addition, many minor and trace elements absent from the nominal formulations were seen, including K, Ti, Mn, Fe, Ni, Cu, Zn, Ga, Ag, Cd, Hf, and As/Pb. Such impurities may come from rough materials and preparative technologies. The impurities in Romanian composites are comparable to those in some commercial biomaterials but higher than in other ones. Thus PIXE analysis of mineral elements in Romanian composites, even qualitative, appears useful for quality control and improvement. (authors)
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Directory of Open Access Journals (Sweden)
Lester L. Yuan
2007-06-01
Full Text Available This paper provides a brief introduction to the R package bio.infer, a set of scripts that facilitates the use of maximum likelihood (ML methods for predicting environmental conditions from assemblage composition. Environmental conditions can often be inferred from only biological data, and these inferences are useful when other sources of data are unavailable. ML prediction methods are statistically rigorous and applicable to a broader set of problems than more commonly used weighted averaging techniques. However, ML methods require a substantially greater investment of time to program algorithms and to perform computations. This package is designed to reduce the effort required to apply ML prediction methods.
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Directory of Open Access Journals (Sweden)
Yudakov Aleksandr A.
2015-01-01
Full Text Available The methods used to determine the gold content in the technogenic objects of gold mining were analyzed regarding their non-homogeneity and complexity of chemical and mineral compositions. A possible application of the neutron activation analysis with the use of the californium source of neutrons for determining the content of fine-grained and extra-fine-grained gold in the technogenic objects, including the bottom-ash waste of energy providers, is considered. It was demonstrated that the chemical composition of the sample affects the neuron flux distribution in the sample, which can essentially distort the results of the neutron activation analysis. In order to eliminate possible systematic errors investigations of the effect of the sample mineral composition on the results of the gold determination using the neutron activation analysis were carried out. Namely, a large mass of rock (3-5 kg was loaded into an activation zone using four matrix types such as silicate, carbon-containing, iron-containing, and titanium magnetite. It was shown that there wereno significant difference between the dispersal of the fluxes of thermal and resonance neutrons emitted from 252Cf during activation of the gold-containing technogenic samples with different mineral compositions.
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Mineral compositions of plutonic rocks from the Lewis Hills massif, Bay of Islands ophiolite
Smith, Susan E.; Elthon, Don
1988-01-01
Mineral compositions of residual and cumulate rocks from the Lewis Hills massif of the Bay of Islands ophiolite complex are reported and interpreted in the context of magnetic processes involved in the geochemical evolution of spatially associated diabase dikes. The mineral compositions reflect greater degrees of partial melting than most abyssal peridotites do and appear to represent the most depleted end of abyssal peridotite compositions. Subsolidus equilibration between Cr-Al spinal and olivine generally has occurred at temperatures of 700 to 900 C. The spinel variations agree with the overall fractionation of basaltic magmas producing spinels with progressively lower Cr numbers. The compositions of clinopyroxenes suggest that the fractionation of two different magma series produced the various cumulate rocks.
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Effect of breed on mineral composition of meat from light lambs
Directory of Open Access Journals (Sweden)
Zdravko Barać
2010-01-01
Full Text Available The proximate composition and mineral content of light lambs muscle (derived from Istrian and Dalmatian Pramenka breeds were studied. The M. Longissimus dorsi (MLD samples of 30 carcasses were analysed and the effects of breed and sex were studied. Although lambs of investigated breeds were similar for slaughter age (2.5 months, Dalmatian Pramenka had significantly higher carcass weights (CW; P<0.05. Breed had a significant influence on moisture and fat contents, whilst mineral composition (with the exception of selenium was scarcely affected by breed and sex. Fat and moisture contents were significantly correlated with cold CW. The magnesium, calcium, manganese and selenium contents were significantly correlated (r=0.50, -0.46, 0.44, 0.54; P<0.05 respectively with CW. This study contributes to characterization of lamb carcasses from Istrian Sheep and Dalmatian Pramenka breeds and provides new data on the composition of the MLD of light lambs.
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Preparation of pHEMA-CP composites with high interfacial adhesionvia template-driven mineralization
Energy Technology Data Exchange (ETDEWEB)
Song, Jie; Saiz, Eduardo; Bertozzi, Carolyn R.
2002-12-05
We report a template-driven nucleation and mineral growth process for the high-affinity integration of calcium phosphate (CP) with a poly(2-hydroxyethyl methacrylate) (pHEMA) hydrogel scaffold. A mineralization technique was developed that exposes carboxylate groups on the surface of crosslinked pHEMA, promoting high-affinity nucleation and growth of calcium phosphate on the surface along with extensive calcification of the hydrogel interior. External factors such as the heating rate, the agitation of the mineral stock solution and the duration of the process that affect the outcome of the mineralization were investigated. This template-driven mineralization technique provides an efficient approach toward bonelike composites with high mineral-hydrogel interfacial adhesion strength.
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Directory of Open Access Journals (Sweden)
Stela de Almeida Soares
2013-03-01
Full Text Available Temporal variation in the composition of ant assemblages (Hymenoptera, Formicidae on trees in the Pantanal floodplain, Mato Grosso do Sul, Brazil. In this paper we investigate how seasonal flooding influences the composition of assemblages of ants foraging on trees in the Pantanal of Mato Grosso do Sul. During the flood in the Pantanal, a large area is covered by floods that are the main forces that regulate the pattern of diversity in these areas. However, the effects of such natural disturbances in the ant communities are poorly known. In this sense, the objective of this study was to evaluate the effect of temporal variation in assemblages of ants foraging on trees in the Pantanal of Miranda. Samples were collected during a year in two adjacent areas, one who suffered flooding during the wet period and another that did not suffer flooding throughout the year. In 10 sites for each evaluated habitat, five pitfall traps were installed at random in trees 25 m apart from each other. In the habitat with flooding, the highest richness was observed during the flooding period, while there was no significant change in richness in the area that does not suffer flooding. The diversity of species between the two evaluated habitats varied significantly during the two seasons. Most ants sampled belong to species that forage and nest in soil. This suggests that during the flood in flooded habitats, ants that did not migrate to higher areas without flooding adopt the strategy to search for resources in the tree canopy.
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Benthic assemblages of mega epifauna on the Oregon continental margin
Hemery, Lenaïg G.; Henkel, Sarah K.; Cochrane, Guy R.
2018-01-01
Environmental assessment studies are usually required by a country's administration before issuing permits for any industrial activities. One of the goals of such environmental assessment studies is to highlight species assemblages and habitat composition that could make the targeted area unique. A section of the Oregon continental slope that had not been previously explored was targeted for the deployment of floating wind turbines. We carried out an underwater video survey, using a towed camera sled, to describe its benthic assemblages. Organisms were identified to the lowest taxonomic level possible and assemblages described related to the nature of the seafloor and the depth. We highlighted six invertebrate assemblages and three fish assemblages. For the invertebrates within flat soft sediments areas we defined three different assemblages based on primarily depth: a broad mid-depth (98–315 m) assemblage dominated by red octopus, sea pens and pink shrimps; a narrower mid-depth (250–270 m) assemblage dominated by box crabs and various other invertebrates; and a deeper (310–600 m) assemblage dominated by sea urchins, sea anemones, various snails and zoroasterid sea stars. The invertebrates on mixed sediments also were divided into three different assemblages: a shallow (~100 m deep) assemblage dominated by plumose sea anemones, broad mid-depth (170–370 m) assemblage dominated by sea cucumbers and various other invertebrates; and, again, a narrower mid-depth (230–270 m) assemblage, dominated by crinoids and encrusting invertebrates. For the fish, we identified a rockfish assemblage on coarse mixed sediments at 170–370 m and another fish assemblage on smaller mixed sediments within that depth range (250–370 m) dominated by thornyheads, poachers and flatfishes; and we identified a wide depth-range (98–600 m) fish assemblage on flat soft sediments dominated by flatfishes, eelpouts and thornyheads. Three of these assemblages (the two
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Benthic assemblages of mega epifauna on the Oregon continental margin
Hemery, Lenaïg G.; Henkel, Sarah K.; Cochrane, Guy R.
2018-05-01
Environmental assessment studies are usually required by a country's administration before issuing permits for any industrial activities. One of the goals of such environmental assessment studies is to highlight species assemblages and habitat composition that could make the targeted area unique. A section of the Oregon continental slope that had not been previously explored was targeted for the deployment of floating wind turbines. We carried out an underwater video survey, using a towed camera sled, to describe its benthic assemblages. Organisms were identified to the lowest taxonomic level possible and assemblages described related to the nature of the seafloor and the depth. We highlighted six invertebrate assemblages and three fish assemblages. For the invertebrates within flat soft sediments areas we defined three different assemblages based on primarily depth: a broad mid-depth (98-315 m) assemblage dominated by red octopus, sea pens and pink shrimps; a narrower mid-depth (250-270 m) assemblage dominated by box crabs and various other invertebrates; and a deeper (310-600 m) assemblage dominated by sea urchins, sea anemones, various snails and zoroasterid sea stars. The invertebrates on mixed sediments also were divided into three different assemblages: a shallow ( 100 m deep) assemblage dominated by plumose sea anemones, broad mid-depth (170-370 m) assemblage dominated by sea cucumbers and various other invertebrates; and, again, a narrower mid-depth (230-270 m) assemblage, dominated by crinoids and encrusting invertebrates. For the fish, we identified a rockfish assemblage on coarse mixed sediments at 170-370 m and another fish assemblage on smaller mixed sediments within that depth range (250-370 m) dominated by thornyheads, poachers and flatfishes; and we identified a wide depth-range (98-600 m) fish assemblage on flat soft sediments dominated by flatfishes, eelpouts and thornyheads. Three of these assemblages (the two broad fish assemblages and the deep
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Directory of Open Access Journals (Sweden)
Maznah Ismail
2012-09-01
Full Text Available This study presents the proximate and mineral composition of Peperomia pellucida L., an underexploited weed plant in Malaysia. Proximate analysis was performed using standard AOAC methods and mineral contents were determined using atomic absorption spectrometry. The results indicated Peperomia pellucida to be rich in crude protein, carbohydrate and total ash contents. The high amount of total ash (31.22% suggests a high-value mineral composition comprising potassium, calcium and iron as the main elements. The present study inferred that Peperomia pellucida would serve as a good source of protein and energy as well as micronutrients in the form of a leafy vegetable for human consumption.
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The study of ore minerals parageneses in Ponorogo area, East Java
Directory of Open Access Journals (Sweden)
Wiwik Dyah Hastuti Endang
2017-01-01
Full Text Available The present study was undertaken in the Southern Mountain Range of East Jawa, Ponorogo District. Tectonically, the region extends along the Magmatic Sunda-Banda Arc, which comprises predominantly volcanic rocks of Mandalika Formation, sedimentary rock units of Arjosari Formation, and intrusive sequences such as dacite, andesite and diorite. Structurally, the region is controlled by faults striking NE-SW, NW-SE and N-S. Mandalika Formation and Arjosari Formation have an interfingering relation and are Oligo-Miocene. Results of the field observation and analyses of petrography and mineragraphy on outcrops reveal that the region has commonly undergone alteration and mineralisation. The principle ore minerals occurring in the Ponorogo area are pyrite and sphalerite with abundant mineral assemblages of chalcopyrite, magnetite, hematite, galena, covelite, bornite, and limonite. Mineralisation occurs in argillic zone and subprophyllitic zone. Based on textures, structures and ore mineral assemblages, mineralisation in the study area can be devided at least into two stages. The earlier stage was present in relation to hypogene processes, and resulted in pyrite–sphalerite–chalcopyrite–magnetite– galena. The subsequent stage took place due to supergene enrichment processes, and yielded pyrite– sphalerite–covelite–bournite–limonite. Such mineral assemblages suggest that they are formed at temperatures of about 100–360° C.
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Mineral composite assessment of Kelkit River Basin in Turkey by ...
Indian Academy of Sciences (India)
Utilizing remote sensing (RS) and geographic information systems (GIS) tools, mineral composite characteristics ... MC index maps were summarized in nine classes by using 'natural breaks' classification method in. GIS. ... have the potential to help the decision makers ..... comes were supported by several literature. For.
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Mineral composition of five improved varieties of cassava | Adeniji ...
African Journals Online (AJOL)
Five new cassava mosaic disease resistant (CMD) varieties released to farmers in Nigeria were evaluated for mineral composition. Results show that TME 419 differed significantly (p<0.05) from other varieties in calcium (900ìg/ g) and manganese (32.3ìg/g) content. The hybrid check (TMS 30572) and TMS 98/0505 were ...
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Chemical composition and mineral elements of edible insects (at ...
African Journals Online (AJOL)
The Chemical Composition and Mineral Elements of two edible insects' larvae and termite soldiers were assayed. Their ash content were between 1.01% and 7.50%. The legless larva (LS) had 28.52% fat, while the solider ant had 7.14% and the Legged larva (LG) had 1.50%. The white ant (SA) had 15.61% protein while ...
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Changing bee and hoverfly pollinator assemblages along an urban-rural gradient.
Directory of Open Access Journals (Sweden)
Adam J Bates
Full Text Available The potential for reduced pollination ecosystem service due to global declines of bees and other pollinators is cause for considerable concern. Habitat degradation, destruction and fragmentation due to agricultural intensification have historically been the main causes of this pollinator decline. However, despite increasing and accelerating levels of global urbanization, very little research has investigated the effects of urbanization on pollinator assemblages. We assessed changes in the diversity, abundance and species composition of bee and hoverfly pollinator assemblages in urban, suburban, and rural sites across a UK city.Bees and hoverflies were trapped and netted at 24 sites of similar habitat character (churchyards and cemeteries that varied in position along a gradient of urbanization. Local habitat quality (altitude, shelter from wind, diversity and abundance of flowers, and the broader-scale degree of urbanization (e.g. percentage of built landscape and gardens within 100 m, 250 m, 500 m, 1 km, and 2.5 km of the site were assessed for each study site. The diversity and abundance of pollinators were both significantly negatively associated with higher levels of urbanization. Assemblage composition changed along the urbanization gradient with some species positively associated with urban and suburban land-use, but more species negatively so. Pollinator assemblages were positively affected by good site habitat quality, in particular the availability of flowering plants.Our results show that urban areas can support diverse pollinator assemblages, but that this capacity is strongly affected by local habitat quality. Nonetheless, in both urban and suburban areas of the city the assemblages had fewer individuals and lower diversity than similar rural habitats. The unique development histories of different urban areas, and the difficulty of assessing mobile pollinator assemblages in just part of their range, mean that complementary studies in
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Occurrence modes of As, Sb, Te, Bi, Ag in sulfide assemblages of gold deposits of the Urals
Vikent'eva, O.; Vikentev, I.
2016-04-01
Review of occurrence modes of trace toxic elements ("potential pollutants") in ores from large gold deposits (the Urals) of different genetic types is presented. Mineral forms of these elements as well as their presence in main minerals from gold-bearing sulfide assemblages according to SEM, EPMA, INAA, ICP-MS and LA-ICP-MS are demonstrated.
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Muñoz,Marcia; Aguirre,Luis; Vergara,Mario; Demant,Alain; Fuentes,Francisco; Fock,Andrés
2010-01-01
In the El Volcan and Rodeo de los Bueyes areas, Andean Principal Cordillera (east of Santiago; 33°50'S), an Upper Oligocene-Lower Miocene volcanic series belonging to the Abanico Formation (Late Eocene-Early Miocene) is exposed. The rock successions outcropping in both areas, ca. 3,300 m total thickness, have been affected by very low-grade, non-deformative metamorphism in the prehnite-pumpellyite facies. This is represented by the widespread development of secondary mineral assemblages compo...
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Gomes, L.C.; Bulla, C. K.; Agostinho, A. A.; Vasconcelos, L. P.; Miranda, Leandro E.
2012-01-01
The presence of aquatic macrophytes is a key factor in the selection of habitats by fish in floodplain lakes because these plants enhance the physical and biological complexities of aquatic habitats. The seasonal flood pulse may influence this interaction, but there is no information in the literature about the effects that flood events may have on macrophytes assemblages and its associated effects on fish assemblages. Thus, this article aimed to investigate whether species richness, evenness and similarities in fish assemblage composition differed between littoral areas vegetated with macrophytes and unvegetated areas, before and after a flood. We sampled three lakes in the floodplain of the upper Paraná River basin. Sampling was conducted before (December 2004 and January 2005) and after (early March, late March and May 2005) a flood event. Overall, species richness and evenness were higher in macrophytes-covered areas. Before the flood, the composition of fish assemblages was distinct when comparing vegetated and unvegetated areas. After the flood, the similarity in fish assemblage composition was higher, indicating a homogenization effect of floods for fish inhabiting littoral areas of floodplain lakes. After the flood, opportunistic species dominated the fish assemblages in aquatic macrophytes, apparently restructuring assemblages in the littoral, restarting a succession process. Thus, the observed homogenization effect of the flood could minimize biological interactions and could induce fish assemblages to begin a new process of structurization.
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Variations in the mineral composition and heavy metals content of ...
African Journals Online (AJOL)
Babayemi
The parts of Moringa oleifera were assessed for mineral composition and some heavy metal ... cadmium from aqueous system (Sharma et al., 2006). ... Crude extracts and essential oil from M. oleifera possess ... into some probable chemical interactions between the .... processing methods that may lead to detoxification and.
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Directory of Open Access Journals (Sweden)
AL Carmassi
Full Text Available The aim of this work was to determine the composition of the fish assemblage of Passa Cinco stream and verify changes in their structure on the altitudinal gradient. Six samples were performed at five different sites in Passa Cinco stream (from the headwater, at order two, to its mouth, at order six, using an electric fishery equipment and gill nets in May, July, September and November of 2005 and January and March of 2006. The indices of Shannon's diversity, Pielou's evenness and Margalef's richness were quantified separately considering the different fishery equipment (nets versus electric fishery equipment. An ANOVA was used to compare samples collected in relation to values of abundance, diversity, evenness and richness. The representativeness of the species was summarised by their average values of abundance and weight. We captured 5082 individuals distributed into 61 species. We observed a trend of increasing diversity, richness and evenness of species from site 1 to 3, with further decrease in sites 4 and 5. The values found for habitat diversity also followed this pattern. Significant differences were found for all three indices considering the electric fishery samples. For individuals caught with nets, only the richness index showed a significant difference. Characidium aff. zebra was an important species in the headwater and transition sites and Hypostomus strigaticeps in middle-lower course sites. Despite the small extension of the Passa Cinco stream, environments structurally well defined were evidenced by the species distribution and assemblage composition along the gradient.
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Ghazilou, Amir; Shokri, Mohammad Reza; Gladstone, William
2016-04-30
Seasonal dynamics of coral reef fish assemblages were assessed along a gradient of potential anthropogenic disturbance in the Northern Persian Gulf. Overall, the attributes of coral reef fish assemblages showed seasonality at two different levels: seasonal changes irrespective of the magnitude of disturbance level (e.g. species richness), and seasonal changes in response to disturbance level (e.g. total abundance and assemblage composition). The examined parameters mostly belonged to the second group, but the interpretation of the relationship between patterns of seasonal changes and the disturbance level was not straightforward. The abundance of carnivorous fishes did not vary among seasons. SIMPER identified the family Nemipteridae as the major contributor to the observed spatiotemporal variations in the composition of coral reef fish assemblages in the study area. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Influence of matrix type on tree community assemblages along tropical dry forest edges.
Benítez-Malvido, Julieta; Gallardo-Vásquez, Julio César; Alvarez-Añorve, Mariana Y; Avila-Cabadilla, Luis Daniel
2014-05-01
• Anthropogenic habitat edges have strong negative consequences for the functioning of tropical ecosystems. However, edge effects on tropical dry forest tree communities have been barely documented.• In Chamela, Mexico, we investigated the phylogenetic composition and structure of tree assemblages (≥5 cm dbh) along edges abutting different matrices: (1) disturbed vegetation with cattle, (2) pastures with cattle and, (3) pastures without cattle. Additionally, we sampled preserved forest interiors.• All edge types exhibited similar tree density, basal area and diversity to interior forests, but differed in species composition. A nonmetric multidimensional scaling ordination showed that the presence of cattle influenced species composition more strongly than the vegetation structure of the matrix; tree assemblages abutting matrices with cattle had lower scores in the ordination. The phylogenetic composition of tree assemblages followed the same pattern. The principal plant families and genera were associated according to disturbance regimes as follows: pastures and disturbed vegetation (1) with cattle and (2) without cattle, and (3) pastures without cattle and interior forests. All habitats showed random phylogenetic structures, suggesting that tree communities are assembled mainly by stochastic processes. Long-lived species persisting after edge creation could have important implications in the phylogenetic structure of tree assemblages.• Edge creation exerts a stronger influence on TDF vegetation pathways than previously documented, leading to new ecological communities. Phylogenetic analysis may, however, be needed to detect such changes. © 2014 Botanical Society of America, Inc.
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Costa, Pedro J.M.; Gelfenbaum, Guy R.; Dawson, Sue; La selle, Seanpaul; Milne, F; Cascalho, J.; Ponte Lira, C.; Andrade, C.; Freitas, M. C.; Jaffe, Bruce E.
2017-01-01
Recent work has applied microtextural and heavy mineral analyses to sandy storm and tsunami deposits from Portugal, Scotland, Indonesia and the USA. We looked at the interpretation of microtextural imagery (scanning electron microscopy) of quartz grains and heavy mineral compositions. We consider inundation events of different chronologies and sources (the AD 1755 Lisbon and 2004 Indian Ocean tsunamis, the Great Storm of 11 January 2005 in Scotland, and Hurricane Sandy in 2012) that affected contrasting coastal and hinterland settings with different regional oceanographic conditions. Storm and tsunami deposits were examined along with potential source sediments (alluvial, beach, dune and nearshore sediments) to determine provenance.Results suggest that tsunami deposits typically exhibit a significant spatial variation in grain sizes, microtextures and heavy minerals. Storm deposits show less variability, especially in vertical profiles. Tsunami and storm quartz grains had more percussion marks and fresh surfaces compared to potential source material. Moreover, in the studied cases, tsunami samples had fewer fresh surfaces than storm deposits.Heavy mineral assemblages are typically site-specific. The concentration of heavy minerals decreases upwards in tsunamigenic units, whereas storm sediments show cyclic concentrations of heavy minerals, reflected in the laminations observed macroscopically in the deposits.
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Vesicular delivery of crystalline calcium minerals to ECM in biomineralized nanoclay composites
International Nuclear Information System (INIS)
Katti, Kalpana S; Ambre, Avinash H; Payne, Scott; Katti, Dinesh R
2015-01-01
The mechanisms of mineralization and new bone formation were explored in newly formed extracellular matrix in a nanoclay based composite. Nanoclay films were prepared by intercalating the clays with amino acids and using the amino acids for mineralization of hydroxyapatite. The biomineralized hydroxyapatite (HAP) inside nanoclay galleries or in situ HAP/clay was further used to make films (substrates) using polycaprolactone (PCL) that were seeded with mesenchymal stem cells in a two-stage seeding process. SEM imaging experiments performed on PCL/in situ HAPclay composite films seeded with human MSCs indicated formation of matrix vesicles. The vesicles appear to emerge from the cells that are adhered to the nanoclay HAP films and also deposited in the extracellular space. Vesicles are also observed to be embedded in the cells or under the surface of cells. Crystalline structures with Ca and P were found inside vesicles. The Ca/P ratios obtained using energy dispersive spectroscopy indicate values ranging from below 0.7 to the stoichiometric HAP value of 1.67. The Ca/P ratios were obtained to be closer to the stoichiometric value for single seeding experiments as compared to the double seeding experiments indicating more new bone formation in double seeding experiments. New bone formation with bone mimetic mineralization is thus observed on the in situ HAP nanoclay PCL samples. Hence the PCL/in situ HAPclay composites besides being osteoinductive are also capable of providing a favorable micro-environment for cell dependent processes involved in bone mineral formation. (paper)
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Directory of Open Access Journals (Sweden)
Hugo Henrique Lanzi Saulino
2017-01-01
Full Text Available The invasive white ginger lily (Hedichium coronarium – J. Köenig, 1783 simplifies the trait composition of an insect assemblage in the littoral zone of a Savanna reservoir. Invasive plants are believed to shift the trait composition of aquatic insects dwelling in banks of lentic ecosystems. In this study, we analyzed the relationship between the presence of the invasive white ginger lily (H. coronarium and the functional trait indices of the aquatic insect assemblage in the littoral zone of a tropical reservoir. We sampled aquatic insects on the invaded and non-invaded banks of the reservoir and then analyzed the insect trait indices by estimating the Functional Dispersion (FDis, Functional Evenness (FEve and the Functional Divergence (FDiv, as well as the Community level Weight-Mean traits (CWM. Finally, we compared these indices between invaded and non-invaded banks as well as their relationship with the abiotic variables, such as dissolved oxygen, pH, depth and water temperature. The result confirmed that the invaded banks had lower values of functional indices as well as dissolved oxygen. However, this abiotic variable was found to have no effect on the functional indices. In addition, the white ginger lily bank presented higher contribution of collector-gathering to predator-piercer groups. We suggest that the invasion of white ginger lily promotes low heterogeneity habitat resulting in simplification on functional traits of aquatic insect assemblage. Keywords: Biodiversity, Biological invasions, Functional diversity, Lentic system
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Directory of Open Access Journals (Sweden)
Hugo Henrique Lanzi Saulino
Full Text Available ABSTRACT The invasive white ginger lily (Hedichium coronarium - J. Köenig, 1783 simplifies the trait composition of an insect assemblage in the littoral zone of a Savanna reservoir. Invasive plants are believed to shift the trait composition of aquatic insects dwelling in banks of lentic ecosystems. In this study, we analyzed the relationship between the presence of the invasive white ginger lily (H. coronarium and the functional trait indices of the aquatic insect assemblage in the littoral zone of a tropical reservoir. We sampled aquatic insects on the invaded and non-invaded banks of the reservoir and then analyzed the insect trait indices by estimating the Functional Dispersion (FDis, Functional Evenness (FEve and the Functional Divergence (FDiv, as well as the Community level Weight-Mean traits (CWM. Finally, we compared these indices between invaded and non-invaded banks as well as their relationship with the abiotic variables, such as dissolved oxygen, pH, depth and water temperature. The result confirmed that the invaded banks had lower values of functional indices as well as dissolved oxygen. However, this abiotic variable was found to have no effect on the functional indices. In addition, the white ginger lily bank presented higher contribution of collector-gathering to predator-piercer groups. We suggest that the invasion of white ginger lily promotes low heterogeneity habitat resulting in simplification on functional traits of aquatic insect assemblage.
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Uniform functional structure across spatial scales in an intertidal benthic assemblage.
Barnes, R S K; Hamylton, Sarah
2015-05-01
To investigate the causes of the remarkable similarity of emergent assemblage properties that has been demonstrated across disparate intertidal seagrass sites and assemblages, this study examined whether their emergent functional-group metrics are scale related by testing the null hypothesis that functional diversity and the suite of dominant functional groups in seagrass-associated macrofauna are robust structural features of such assemblages and do not vary spatially across nested scales within a 0.4 ha area. This was carried out via a lattice of 64 spatially referenced stations. Although densities of individual components were patchily dispersed across the locality, rank orders of importance of the 14 functional groups present, their overall functional diversity and evenness, and the proportions of the total individuals contained within each showed, in contrast, statistically significant spatial uniformity, even at areal scales functional groups in their geospatial context also revealed weaker than expected levels of spatial autocorrelation, and then only at the smaller scales and amongst the most dominant groups, and only a small number of negative correlations occurred between the proportional importances of the individual groups. In effect, such patterning was a surface veneer overlying remarkable stability of assemblage functional composition across all spatial scales. Although assemblage species composition is known to be homogeneous in some soft-sediment marine systems over equivalent scales, this combination of patchy individual components yet basically constant functional-group structure seems as yet unreported. Copyright © 2015 Elsevier Ltd. All rights reserved.
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International Nuclear Information System (INIS)
Batchelar, Deidre L.; Davidson, Melanie T.M.; Dabrowski, Waldemar; Cunningham, Ian A.
2006-01-01
Quantitative analysis of bone composition is necessary for the accurate diagnosis and monitoring of metabolic bone diseases. Accurate assessment of the bone mineralization state is the first requirement for a comprehensive analysis. In diagnostic imaging, x-ray coherent scatter depends upon the molecular structure of tissues. Coherent-scatter computed tomography (CSCT) exploits this feature to identify tissue types in composite biological specimens. We have used CSCT to map the distributions of tissues relevant to bone disease (fat, soft tissue, collagen, and mineral) within bone-tissue phantoms and an excised cadaveric bone sample. Using a purpose-built scanner, we have measured hydroxyapatite (bone mineral) concentrations based on coherent-scatter patterns from a series of samples with varying hydroxyapatite content. The measured scatter intensity is proportional to mineral density in true g/cm 3 . Repeated measurements of the hydroxyapatite concentration in each sample were within, at most, 2% of each other, revealing an excellent precision in determining hydroxyapatite concentration. All measurements were also found to be accurate to within 3% of the known values. Phantoms simulating normal, over-, and under-mineralized bone were created by mixing known masses of pure collagen and hydroxyapatite. An analysis of the composite scatter patterns gave the density of each material. For each composite, the densities were within 2% of the known values. Collagen and hydroxyapatite concentrations were also examined in a bone-mimicking phantom, incorporating other bone constituents (fat, soft tissue). Tomographic maps of the coherent-scatter properties of each specimen were reconstructed, from which material-specific images were generated. Each tissue was clearly distinguished and the collagen-mineral ratio determined from this phantom was also within 2% of the known value. Existing bone analysis techniques cannot determine the collagen-mineral ratio in intact specimens
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Energy Technology Data Exchange (ETDEWEB)
C. Doc Richardson; Nancy W. Hinman; Lindsay J. McHenry; J. Michelle Kotler; Jill R. Scott
2012-05-01
Secondary deposits associated with the basaltic caves of Craters of the Moon National Monument (COM) in southern Idaho were examined using X-ray powder diffraction, X-ray fluorescence spectrometry, Fourier transform infrared spectrometry, and Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). The secondary mineral assemblages are dominated by Na-sulfate minerals (thenardite, mirabilite) with a small fraction of the deposits containing minor concentrations of Na-carbonate minerals. The assemblages are found as white, efflorescent deposits in small cavities along the cave walls and ceilings and as localized mounds on the cave floors. Formation of the deposits is likely due to direct and indirect physiochemical leaching of meteoritic water through the overlying basalts. Whole rock data from the overlying basaltic flows are characterized by their extremely high iron concentrations, making them good analogs for martian basalts. Understanding the physiochemical pathways leading to secondary mineralization at COM is also important because lava tubes and basaltic caves are present on Mars. The ability of FTICR-MS to consistently and accurately identify mineral species within these heterogeneous mineral assemblages proves its validity as a valuable technique for the direct fingerprinting of mineral species by deductive reasoning or by comparison with reference spectra.
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Ferreira, Fabio Cop; Souza, Ursulla Pereira; Petrere Junior2, Miguel
2015-01-01
Abstract The riparian vegetation in lakes and reservoirs is source of course wood structures such as trunks and branches and is used as sheltering, spawning and foraging habitats for fishes. The reduction of these submerged structures can thus, affect the composition and structure of fish assemblages in reservoirs. Aim To evaluate the influence of riparian vegetation on the biotic condition of fish assemblage by adapting the Reservoir Fish Assemblage Index (RFAI) to two reservoirs in the Upp...
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Airborne bacterial assemblage in a zero carbon building: A case study.
Leung, M H Y; Tong, X; Tong, J C K; Lee, P K H
2018-01-01
Currently, there is little information pertaining to the airborne bacterial communities of green buildings. In this case study, the air bacterial community of a zero carbon building (ZCB) in Hong Kong was characterized by targeting the bacterial 16S rRNA gene. Bacteria associated with the outdoor environment dominated the indoor airborne bacterial assemblage, with a modest contribution from bacteria associated with human skin. Differences in overall community diversity, membership, and composition associated with short (day-to-day) and long-term temporal properties were detected, which may have been driven by specific environmental genera and taxa. Furthermore, time-decay relationships in community membership (based on unweighted UniFrac distances) and composition (based on weighted UniFrac distances) differed depending on the season and sampling location. A Bayesian source-tracking approach further supported the importance of adjacent outdoor air bacterial assemblage in sourcing the ZCB indoor bioaerosol. Despite the unique building attributes, the ZCB microbial assemblage detected and its temporal characteristics were not dissimilar to that of conventional built environments investigated previously. Future controlled experiments and microbial assemblage investigations of other ZCBs will undoubtedly uncover additional knowledge related to how airborne bacteria in green buildings may be influenced by their distinctive architectural attributes. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
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Mineral and inorganic chemical composition of the Pernik coal, Bulgaria
Energy Technology Data Exchange (ETDEWEB)
Yossifova, Mariana G. [Geological Institute, Acad. G. Bonchev Str., Bl.24, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)
2007-11-22
The mineral and inorganic chemical composition of five types of samples from the Pernik subbituminous coals and their products generated from the Pernik preparation plant were studied. They include feed coal, low-grade coal, high-grade coal, coal slime, and host rock. The mineral matter of the coals contains 44 species that belong mainly to silicates, carbonates, sulphates, sulphides, and oxides/hydroxides, and to a lesser extent, chlorides, biogenic minerals, and organic minerals. The detrital minerals are quartz, kaolinite, micas, feldspars, magnetite, cristobalite, spessartine, and amphibole. The authigenic minerals include various sulphides, silicates, oxihydroxides, sulphates, and carbonates. Several stages and substages of formation were identified during the syngenetic and epigenetic mineral precipitations of these coals. The authigenic minerals show the greatest diversity of mineral species as the epigenetic mineralization (mostly sulphides, carbonates, and sulphates) dominates qualitatively and quantitatively. The epigenetic mineralization was a result of complex processes occurring mostly during the late development of the Pernik basin. These processes indicate intensive tectonic, hydrothermal and volcanic activities accompanied by a change from fresh to marine sedimentation environment. Thermally altered organic matter due to some of the above processes was also identified in the basin. Most of the trace elements in the Pernik coals (Mo, Be, S, Zr, Y, Cl, Ba, Sc, Ga, Ag, V, P, Br, Ni, Co, Pb, Ca, and Ti) show an affinity to OM and phases intimately associated with OM. Some of the trace elements (Sr, Ti, Mn, Ba, Pb, Cu, Zn, Co, Cr, Ni, As, Ag, Yb, Sn, Ga, Ge, etc.) are impurities in authigenic and accessory minerals, while other trace elements (La, Ba, Cu, Ce, Sb, Bi, Zn, Pb, Cd, Nd, etc.) occur as discrete phases. Elements such as Sc, Be, Y, Ba, V, Zr, S, Mo, Ti, and Ga exceed Clarke concentrations in all of the coal types studied. It was also found that
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[Composition of nutrients and minerals in some goat milk products].
Gajewska, R; Ganowiak, Z; Nabrzyski, M
1997-01-01
The paper contains results of determinations of protein, fat, carbohydrates, water and minerals (Ca, P, Fe, Mn, Cu, Zn, Na, K) in 12 goat milk products. The nutrient components were determined by general approved analytical methods. Minerals like Ca, Fe, Mn, Cu, Zn, Na and K were determined by the flame ASA method. Phosphorus was determined as phosphates by colorimetric method with ammonium molybdate. Mean percentage content of protein, fat, carbohydrates and water were: 9.7-25.7; 1.4-33.5; 2.2-70.2; and 3.0-77.4 respectively. The content of minerals according to the products of goat milk were as follow: 86-1113 mg% Ca; 96-846 mg% P; 0.2-2.4 mg% Fe; 6-148 mg% Mg; 0.002-0.284 mg% Mn; 0.071-0.754 mg% Cu; 1.1-3.9 mg% Zn; 63-1281 mg% K and 27-407 mg% Na. The levels of nutrients and mineral composition of the examined goat milk products were similar to that of the cows milk products.
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Doherty, Angela L.; Bodnar, Robert J.; De Vivo, Benedetto; Bohrson, Wendy A.; Belkin, Harvey E.; Messina, Antonia; Tracy, Robert J.
2012-01-01
The Aeolian Islands are an arcuate chain of submarine seamounts and volcanic islands, lying just north of Sicily in southern Italy. The second largest of the islands, Salina, exhibits a wide range of compositional variation in its erupted products, from basaltic lavas to rhyolitic pumice. The Monte dei Porri eruptions occurred between 60 ka and 30 ka, following a period of approximately 60,000 years of repose. The bulk rock composition of the Monte dei Porri products range from basaltic-andesite scoria to andesitic pumice in the Grey Porri Tuff (GPT), with the Monte dei Porri lavas having basaltic-andesite compositions. The typical mineral assemblage of the GPT is calcic plagioclase, clinopyroxene (augite), olivine (Fo72−84) and orthopyroxene (enstatite) ± amphibole and Ti-Fe oxides. The lava units show a similar mineral assemblage, but contain lower Fo olivines (Fo57−78). The lava units also contain numerous glomerocrysts, including an unusual variety that contains quartz, K-feldspar and mica. Melt inclusions (MI) are ubiquitous in all mineral phases from all units of the Monte dei Porri eruptions; however, only data from olivine-hosted MI in the GPT are reported here. Compositions of MI in the GPT are typically basaltic (average SiO2 of 49.8 wt %) in the pumices and basaltic-andesite (average SiO2 of 55.6 wt %) in the scoriae and show a bimodal distribution in most compositional discrimination plots. The compositions of most of the MI in the scoriae overlap with bulk rock compositions of the lavas. Petrological and geochemical evidence suggest that mixing of one or more magmas and/or crustal assimilation played a role in the evolution of the Monte dei Porri magmatic system, especially the GPT. Analyses of the more evolved mineral phases are required to better constrain the evolution of the magma.
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Dang, Jiaxiang; Zhou, Yongsheng; He, Changrong; Ma, Shengli
2018-06-01
There are two co-seismic bedrock surface ruptures from the Mw 7.9 Wenchuan earthquake in the northern and central parts of the Beichuan-Yingxiu fault, Sichuan Province, southwest China. In this study, we report on the macrostructure of the fault rocks and results from X-ray powder diffraction analysis of minerals from rocks in the fault zone. The most recent fault gouge (the gouge produced by the most recent co-seismic fault movement) in all the studied outcrops is dark or grayish-black, totally unconsolidated and ultrafine-grained. Older fault gouges in the same outcrops are grayish or yellowish and weakly consolidated. X-ray powder diffraction analysis results show that mineral assemblages in both the old fault gouge and the new fault gouge are more complicated than the mineral assemblages in the bedrock as the fault gouge is rich in clay minerals. The fault gouge inherited its major rock-forming minerals from the parent rocks, but the clay minerals in the fault gouge were generated in the fault zone and are therefore authigenic and synkinematic. In profiles across the fault, clay mineral abundances increase as one traverses from the bedrock to the breccia to the old gouge and from the old gouge to the new gouge. Quartz and illite are found in all collected gouge samples. The dominant clay minerals in the new fault gouge are illite and smectite along the northern part of the surface rupture and illite/smectite mixed-layer clay in the middle part of the rupture. Illite/smectite mixed-layer clay found in the middle part of the rupture indicates that fault slip was accompanied by K-rich fluid circulation. The existence of siderite, anhydrite, and barite in the northern part of the rupture suggests that fault slip at this locality was accompanied by acidic fluids containing ions of Fe, Ca, and Ba.
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Murugan, N.; Sundaramurthy, Anandhakumar; Chen, Shen-Ming; Sundramoorthy, Ashok K.
2017-12-01
Hydroxyapatite (Ca10(PO4)6(OH)2, HAP), a multi-mineral substituted calcium phosphate is the main mineral component of tooth enamel and bone, has become an important biomaterial for biomedical applications. However, as-synthesized HAP has poor mechanical properties and inferior wear resistance, so it is not suitable to use in bone tissue engineering applications. We report the successful incorporation of oxidized carbon nanofibers (O-CNF) and graphene oxide (GO) into the mineralized hydroxyapatite (M-HAP) which showed excellent mechanical and biological properties. GO improved the high mechanical strength and corrosion protection of the substrate in simulated body fluid (SBF) solution and promoted the viability of osteoblasts MG63 cells. As-prepared M-HAP/O-CNF/GO composite showed materials characteristics that similar to natural bone (M-HAP) with high mechanical strength. The resultant M-HAP/O-CNF/GO composite was characterized out by x-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), and Fourier-transform infrared spectroscopy (FT-IR), respectively. The mechanical strength of the material was determined by Vicker’s micro-hardness method and it was found that M-HAP/O-CNF/GO (468 ± 4 Hv) composite has superior mechanical properties than M-HAP (330 ± 3 Hv) and M-HAP/GO (425 ± 5 Hv) samples. In addition, antibacterial activity of the composite was studied against Staphylococcus aureus and Escherichia coli. Furthermore, the cell viability of the composite was observed in vitro against osteoblast cells. All these studies confirmed that the M-HAP/O-CNF/GO composite can be considered as potential candidate for dental and orthopedic applications.
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Changes in density and composition of algal assemblages in certain ...
African Journals Online (AJOL)
The water purification plants at Virginia and Bothaville, South Africa, experience problems with cyanobacteria and other algae. Their algal assemblages were studied during 2010 and 2011 to determine the dominant species that may pose problems in purification. Cyanobacteria, diatoms and green algae were the dominant ...
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The relationships of irisin with bone mineral density and body composition in PCOS patients.
Gao, Shanshan; Cheng, Yan; Zhao, Lingling; Chen, Yuxin; Liu, Yu
2016-05-01
Our study aims to assay the irisin level and investigate the relationships of irisin level with body mass index (BMI), body composition and bone metabolism in the polycystic ovary syndrome (PCOS) and control women. Fifty two PCOS and 39 control women were recruited. Serum sex hormone, fasting insulin and C-peptide were tested. Fasting serum irisin and adiponectin were measured with enzyme-linked immunosorbent assay. Body composition and bone mineral density were assayed by dual energy X-ray absorptiometry. Polycystic ovary syndrome women showed different body compositions compared with controls. Serum irisin level of PCOS did not show significant difference compared with controls although it was decreased. The level of adiponectin in PCOS patients was significantly reduced. BMI had no correlation with irisin level. It indicated a positive correlation between serum irisin levels and bone mineral density in the control group and a negative correlation in the PCOS group after BMI and age adjusted. Furthermore, total lean mass has a significant effect on irisin concentration in the PCOS group. There are no correlations between adiponection and body compositions and bone mineral density in both groups. The abnormal body composition in PCOS may contribute to the circulation irisin. The crosstalk of irisin in different organs was found and may be related to disease development in PCOS. Copyright © 2015 John Wiley & Sons, Ltd.
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Znaczenie analizy minerałów ciężkich w badaniach osadów czwartorzędowych Polski
Racinowski, Roman
2008-01-01
In most regions of Poland the composition of heavy minerals assemblage permits to distinguish the Quaternary deposits from the older ones. The pre-Quaternary deposits are characterized by high content of glauconite, carbonate-ferruginous-manganese concretions, muscovite and chlorites. In their transparent heavy minerals spectrum the following minerals predominate: zircon, tourmaline, rutile, staurolite, disthene. However, the Tertiary deposits in the Carpathians and their foreland contain a significant amount of garnet, and sometimes also amphiboles, pyroxenes and biotite. Pyroxenes and sillimanite are found in the Sudetes foreland. In many Tertiary deposits of the northwestern and western Poland there are rather high contents of amphiboles, biotite, pyroxenes, garnets, rutile. In all Quaternary deposits in Poland the qualitative composition of heavy minerals assemblage is similar but the contents of particular minerals are different depending on the examined grain fraction. In tills (Table 1) and glaciofluvial deposits (Table 2), with the decreasing grain diameter the contents of zircon, rutile, and partly epidote increase, and those of amphiboles and garnets decrease. In rubble of coastal zone in the Polish Baltic Sea, with the decreasing grain diameter the contents of zircon, rutile and epidote increase, and those of amphibole, biotite and pyroxenes decrease (Tables 3-7). In Poland, glacial, glaciofluvial and glaciolacustrine deposits are characterized by quantitatively similar composition of heavy minerals assemblage. Amphiboles, biotite, epidotes, garnets and pyroxenes are typical transparent minerals (Tables 8 and 9). Young Pleistocene and Holocene sands of river terraces and dune fields in the upland zone of Poland differ from glacial deposits in low contents of amphiboles, biotite and pyroxenes, and higher contents of garnets and epidotes (Tables 8 and 9). Fossil river and lacustrine deposits of Polish Lowlands have very similar assemblage of heavy minerals
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Directory of Open Access Journals (Sweden)
Irene Piccini
Full Text Available Cattle farming is a major source of greenhouse gases (GHGs. Recent research suggests that GHG fluxes from dung pats could be affected by biotic interactions involving dung beetles. Whether and how these effects vary among beetle species and with assemblage composition is yet to be established. To examine the link between GHGs and different dung beetle species assemblages, we used a closed chamber system to measure fluxes of carbon dioxide (CO2, methane (CH4 and nitrous oxide (N2O from cattle dung pats. Targeting a total of four dung beetle species (a pat-dwelling species, a roller of dung balls, a large and a small tunnelling species, we ran six experimental treatments (four monospecific and two mixed and two controls (one with dung but without beetles, and one with neither dung nor beetles. In this setting, the overall presence of beetles significantly affected the gas fluxes, but different species contributed unequally to GHG emissions. When compared to the control with dung, we detected an overall reduction in the total cumulative CO2 flux from all treatments with beetles and a reduction in N2O flux from the treatments with the three most abundant dung beetle species. These reductions can be seen as beneficial ecosystem services. Nonetheless, we also observed a disservice provided by the large tunneler, Copris lunaris, which significantly increased the CH4 flux-an effect potentially traceable to the species' nesting strategy involving the construction of large brood balls. When fluxes were summed into CO2-equivalents across individual GHG compounds, dung with beetles proved to emit less GHGs than did beetle-free dung, with the mix of the three most abundant species providing the highest reduction (-32%. As the mix of multiple species proved the most effective in reducing CO2-equivalents, the conservation of diverse assemblages of dung beetles emerges as a priority in agro-pastoral ecosystems.
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Berger, B.R.; King, T.V.V.; Morath, L.C.; Phillips, J.D.
2003-01-01
Synoptic views of hydrothermal alteration assemblages are of considerable utility in regional-scale minerals exploration. Recent advances in data acquisition and analysis technologies have greatly enhanced the usefulness of remotely sensed imaging spectroscopy for reliable alteration mineral assemblages mapping. Using NASA's Airborne Visible Infrared Imaging Spectrometer (AVIRIS) sensor, this study mapped large areas of advanced argillic and phyllic-argillic alteration assemblages in the southeastern Santa Rita and northern Patagonia mountains, Arizona. Two concealed porphyry copper deposits have been identified during past exploration, the Red Mountain and Sunnyside deposits, and related published hydrothermal alteration zoning studies allow the comparison of the results obtained from AVIRIS data to the more traditional field mapping approaches. The AVIRIS mapping compares favorably with field-based studies. An analysis of iron-bearing oxide minerals above a concealed supergene chalcocite deposit at Red Mountain also indicates that remotely sensed data can be of value in the interpretation of leached caps above porphyry copper deposits. In conjunction with other types of geophysical data, AVIRIS mineral maps can be used to discriminate different exploration targets within a region.
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Cruz, Bruna B.; Miranda, Leandro E.; Cetra, Mauricio
2013-01-01
We hypothesised and tested a hierarchical organisation model where riparian landcover would influence bank composition and light availability, which in turn would influence instream environments and control fish assemblages. The study was conducted during the dry season in 11 headwater tributaries of the Sorocaba River in the upper Paraná River Basin, south-eastern Brazil. We focused on seven environmental factors each represented by one or multiple environmental variables and seven fish functional traits each represented by two or more classes. Multivariate direct gradient analyses suggested that riparian zone landcover can be considered a higher level causal factor in a network of relations that control instream characteristics and fish assemblages. Our results provide a framework for a hierarchical conceptual model that identifies singular and collective influences of variables from different scales on each other and ultimately on different aspects related to stream fish functional composition. This conceptual model is focused on the relationships between riparian landcover and instream variables as causal factors on the organisation of stream fish assemblages. Our results can also be viewed as a model for headwater stream management in that landcover can be manipulated to influence factors such as bank composition, substrates and water quality, whereas fish assemblage composition can be used as indicators to monitor the success of such efforts.
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Geslin, Benoît; Le Féon, Violette; Folschweiller, Morgane; Flacher, Floriane; Carmignac, David; Motard, Eric; Perret, Samuel; Dajoz, Isabelle
2016-09-01
Given the predicted expansion of cities throughout the world, understanding the effect of urbanization on bee fauna is a major issue for the conservation of bees. The aim of this study was to understand how urbanization affects wild bee assemblages along a gradient of impervious surfaces and to determine the influence of landscape composition and floral resource availability on these assemblages. We chose 12 sites with a proportion of impervious surfaces (soil covered by parking, roads, and buildings) ranging from 0.06% to 64.31% within a 500 m radius. We collected using pan trapping and estimated the landscape composition of the sites within a 500 m radius and the species richness of plant assemblages within a 200 m radius. We collected 1104 bees from 74 species. The proportion of impervious surfaces at the landscape scale had a negative effect on wild bee abundance and species richness, whereas local flower composition had no effect. Ground-nesting bees were particularly sensitive to the urbanization gradient. This study provides new evidences of the impact of urbanization on bee assemblages and the proportion of impervious surfaces at the landscape scale emerged as a key factor that drives those assemblages.
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Influence of sulfur dioxide on the mineral composition of needles from spruces
Energy Technology Data Exchange (ETDEWEB)
Materna, J
1961-01-01
Until recently all the authors knew about changes in the mineral composition of plants exposed to air pollution was that the sulfur content increases considerably. The question arises whether other mineral substances, too, accumulate in the assimilating organs of smoke injured plants, particularly cations such as calcium, potassium and magnesium. Results of analyses of spruce needles from an air polluted forest in the Erzebirge in Czechoslovakia yielded no relationship between the accumulation of sulfates and the mentioned cations.
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Gradients in Catostomid assemblages along a reservoir cascade
Miranda, Leandro E.; Keretz, Kevin R.; Gilliland, Chelsea R.
2017-01-01
Serial impoundment of major rivers leads to alterations of natural flow dynamics and disrupts longitudinal connectivity. Catostomid fishes (suckers, family Catostomidae) are typically found in riverine or backwater habitats yet are able to persist in impounded river systems. To the detriment of conservation, there is limited information about distribution of catostomid fishes in impounded rivers. We examined the longitudinal distribution of catostomid fishes over 23 reservoirs of the Tennessee River reservoir cascade, encompassing approximately 1600 km. Our goal was to develop a basin-scale perspective to guide conservation efforts. Catostomid species composition and assemblage structure changed longitudinally along the reservoir cascade. Catostomid species biodiversity was greatest in reservoirs lower in the cascade. Assemblage composition shifted from dominance by spotted sucker Minytrema melanops and buffalos Ictiobus spp. in the lower reservoirs to carpsuckers Carpiodes spp. midway through the cascade and redhorses Moxostoma spp. in the upper reservoirs. Most species did not extend the length of the cascade, and some species were rare, found in low numbers and in few reservoirs. The observed gradients in catostomid assemblages suggest the need for basin-scale conservation measures focusing on three broad areas: (1) conservation and management of the up-lake riverine reaches of the lower reservoirs, (2) maintenance of the access to quality habitat in tributaries to the upper reservoirs and (3) reintroductions into currently unoccupied habitat within species' historic distributions
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Two-stage recovery of amphibian assemblages following selective logging of tropical forests.
Adum, Gilbert Baase; Eichhorn, Markus Peter; Oduro, William; Ofori-Boateng, Caleb; Rödel, Mark-Oliver
2013-04-01
There is a lack of quantitative information on the effectiveness of selective-logging practices in ameliorating effects of logging on faunal communities. We conducted a large-scale replicated field study in 3 selectively logged moist semideciduous forests in West Africa at varying times after timber extraction to assess post logging effects on amphibian assemblages. Specifically, we assessed whether the diversity, abundance, and assemblage composition of amphibians changed over time for forest-dependent species and those tolerant of forest disturbance. In 2009, we sampled amphibians in 3 forests (total of 48 study plots, each 2 ha) in southwestern Ghana. In each forest, we established plots in undisturbed forest, recently logged forest, and forest logged 10 and 20 years previously. Logging intensity was constant across sites with 3 trees/ha removed. Recently logged forests supported substantially more species than unlogged forests. This was due to an influx of disturbance-tolerant species after logging. Simultaneously Simpson's index decreased, with increased in dominance of a few species. As time since logging increased richness of disturbance-tolerant species decreased until 10 years after logging when their composition was indistinguishable from unlogged forests. Simpson's index increased with time since logging and was indistinguishable from unlogged forest 20 years after logging. Forest specialists decreased after logging and recovered slowly. However, after 20 years amphibian assemblages had returned to a state indistinguishable from that of undisturbed forest in both abundance and composition. These results demonstrate that even with low-intensity logging (≤3 trees/ha) a minimum 20-year rotation of logging is required for effective conservation of amphibian assemblages in moist semideciduous forests. Furthermore, remnant patches of intact forests retained in the landscape and the presence of permanent brooks may aid in the effective recovery of amphibian
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Minerals and nutritional composition of camel (camelus dromedarius) meat in Pakistan
International Nuclear Information System (INIS)
Muhmud, T.; Rehman, R.; Anwar, J.; Ali, S.
2011-01-01
The quality of camel meat has received little attention so far in Pakistan. It is nutritionally as good as that of the major sources of red or white meat. Camel is a desert animal but is not less than other red meat animals (beef, lamb and goat) in its composition. The proximate composition, fatty acid profile and mineral contents of the local camel (Camelus dromedarius) meat have been investigated. It contained 72.03 +- 0.014% water, 4.45 +- 0.011% ash, 5.79 +- 0.012% fat and 66.42 +- 0.534% protein. It has been found that camel meat has relatively more moisture, less fat, less ash and similar protein content than that of beef, lamb and goat [1]. It has similar mineral composition (Na, K, Ca, Fe, Zn, P, Mg, Cd, Cr, Co, Mo, Ni, and Pb) to beef except for sodium. Fatty acid profile for camel meat oil showed high content of palmitic acid and oleic acid. These two fatty acids are essential in human nutrition. In view of the above, it is possible that camel meat could make a greater contribution to the growing need for meat in developing countries like Pakistan. (author)
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King, Trude V.V.; Berger, Byron R.; Johnson, Michaela R.
2014-01-01
As part of the U.S. Geological Survey and Department of Defense Task Force for Business and Stability Operations natural resources revitalization activities in Afghanistan, four permissive areas for mineralization, Bamyan 1, Farah 1, Ghazni 1, and Ghazni 2, have been identified using imaging spectroscopy data. To support economic development, the areas of potential mineralization were selected on the occurrence of selected mineral assemblages mapped using the HyMap™ data (kaolinite, jarosite, hydrated silica, chlorite, epidote, iron-bearing carbonate, buddingtonite, dickite, and alunite) that may be indicative of past mineralization processes in areas with limited or no previous mineral resource studies. Approximately 30 sites were initially determined to be candidates for areas of potential mineralization. Additional criteria and material used to refine the selection and prioritization process included existing geologic maps, Landsat Thematic Mapper data, and published literature. The HyMapTM data were interpreted in the context of the regional geologic and tectonic setting and used the presence of alteration mineral assemblages to identify areas with the potential for undiscovered mineral resources. Further field-sampling, mapping, and supporting geochemical analyses are necessary to fully substantiate and verify the specific deposit types in the four areas of potential mineralization.
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Energy Technology Data Exchange (ETDEWEB)
Hirato, M.; Nagashima, S.; Okada, S. [Hachinohe Institute of Technology, Aomori (Japan)
1996-10-28
Coal ash is a substance that has been mixed into minerals in the earth`s crust during their coalification process. Estimation was made on what kinds of mineral composition have been mixed into coals. Noted first was the kinds of compounds contained in the ash, wherein the ratios of mass in the compounds and minerals were correlated, and selection was made on minerals which are thought correlated. The selection criterion was based on minerals containing silica, alumina, iron oxide, lime and magnesium as compounds. Then, a phase equilibrium line diagram was used to estimate compositions and melting points of minerals which are thought to have been produced from these compounds. By comparing the estimation with the measured melting points of the ashes, mineral compositions thought reasonable were all selected. Assumption was possible on minerals that are thought to have been transferred into coal ash. Compound indications of ashes from 29 kinds of the world`s typical coals were replaced with the subject minerals and expressed as mineral compositions. As a method of calculation, stoichiometric coefficients for each mineral were determined by taking material balance in atomic/molecular levels in masses of compound aggregates and mineral composition aggregates. 7 tabs.
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Diversity of non-biting midge larvae assemblages in the Jacuí River basin, Brazil.
Floss, Elzira Cecília Serafini; Kotzian, Carla Bender; Spies, Márcia Regina; Secretti, Elisangela
2012-01-01
The richness and composition of a mountain-river chironomid larvae assemblage in the Jacuí River basin, Brazil were studied, and compared with other riverine non-biting midge larvae assemblages previously studied in the country. Additionally, the influence of some regional-scale environmental characteristics on the spatial distribution of these assemblages was tested. The specimens were collected at 12 sites in the middle course of the Jacuí River basin (in the state of Rio Grande do Sul) between April 2000 and May 2002. Around 100 taxa were recorded. The dominant taxa belonged to the genera Rheotanytarsus, Cricotopus, Polypedilum, and Pseudochironomus. Twenty-two rare taxa were found, representing 22% of the total of taxa inventoried. Fourteen genera (Aedokritus, Axarus, Endotribelos, Kiefferulus, Manoa, Oukuriella, Phaenopsectra, Stenochironomus, Xenochironomus, Xestochironomus, Cardiocladius, Metriocnemus, Paracladius, and Rheocricotopus) represent new occurrences in Rio Grande do Sul. The similarity analysis of the chironomid larvae assemblages inventoried in 32 regions of Brazil indicated five groups with similarity higher than 50%. The groups, when the effects of spatial autocorrelation were removed, displayed a weak positive correlation between the assemblage composition and the aquatic system or hydraulic conditions and the hydrographic basin, and a weak negative correlation in relation to the biome. The altitude showed no correlation with the composition of the assemblage. The relatively high richness of the region surveyed in relation to other Brazilian regions corroborates some tendencies already noted in other parts of the world, such as: i) lotic systems may constitute an exception to the rule that diversity is greater in tropical regions, ii) regions of transitional relief may contain the greatest richness of Chironomidae, and iii) in rivers, the group might have its spatial distribution influenced to a greater extent by local environmental
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[MINERAL BONE DENSITY AND BODY COMPOSITION IN PARTICIPANTS IN EXPERIMENT MARS-500].
Novikov, V E; Oganov, V S; Kabitskaya, O E; Murashko, L M; Naidina, V P; Chernikhova, E A
2016-01-01
Investigations of the bone system and body composition in Mars-500 test-subjects (prior to and on completion of the experiment) involved dual-energy X-ray absorptiometry (DXA) using the HOLOGIC Delphy densitometer and the protocol performed to examine cosmonauts. Bone density of lumber vertebrae and femoral proximal epiphysis, and body composition were measured. Reliable changes in vertebral density found in 3 test-subjects displayed different trends from +2.6 to -2.4%. At the same time, the experiment decreased significantly mineral density of the femoral proximal epiphysis, including the neck, in all test-subjects. Four test-subjects had cranial mineralization increased by 5-9%, same as in some cosmonauts after space flight. All tests-subjects incurred adipose loss from 2 to 7 kg; one test-subject lost 20 kg, i.e. his adipose mass became three times less. Changes in lean mass (1-3 kg) typically were negative; as for changes in lean mass of extremities, they could be linked with adherence to one or another type of physical activity. Therefore, extended exposure to confinement may affect mineralization of some parts of the skeleton. Unlike real space missions and long-term bedrest studies conducted at the Institute of Biomedical Problems in the past, Mars-500 did not cause clinically significant mineral losses (osteoporosis, osteopenia), probably because of the absence of effects of microgravity.
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Moreno-Valcárcel, Raquel; Oliva-Paterna, Francisco J.; Arribas, Carmen; Fernández-Delgado, Carlos
2013-03-01
The Guadalquivir estuary is the largest estuarine area on the southern Atlantic coast of Europe; its anthropogenic tidally-restricted marshes are partly within the boundary of the Doñana National Park, southern Spain. Our two-year study describes the spatial and temporal patterns of the fish assemblages in the Doñana marshlands in terms of species richness, abundance and biomass. The main families were Mugilidae and Cyprinidae, which accounted for 40.9% of the total species richness. Unlike the fish assemblages found in other European estuaries, Doñana was dominated in both biomass and abundance by freshwater species, mainly invasive exotic species. The spatial analysis of the assemblage showed four significant fish groups corresponding to different habitats established a priori and related to the salinity gradient. Assemblages did not show a seasonal pattern and the temporal fish groups observed were mainly related to the hydrological cycle and the extreme drought that occurred during the study period.
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High phylogenetic diversity is preserved in species-poor high-elevation temperate moth assemblages
Zou, Yi; Sang, Weiguo; Hausmann, Axel; Axmacher, Jan Christoph
2016-01-01
Understanding the diversity and composition of species assemblages and identifying underlying biotic and abiotic determinants represent great ecological challenges. Addressing some of these issues, we investigated the α-diversity and phylogenetic composition of species-rich geometrid moth
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Directory of Open Access Journals (Sweden)
Fabio Cop Ferreira
2015-09-01
Full Text Available Abstract The riparian vegetation in lakes and reservoirs is source of course wood structures such as trunks and branches and is used as sheltering, spawning and foraging habitats for fishes. The reduction of these submerged structures can thus, affect the composition and structure of fish assemblages in reservoirs. Aim To evaluate the influence of riparian vegetation on the biotic condition of fish assemblage by adapting the Reservoir Fish Assemblage Index (RFAI to two reservoirs in the Upper Paranapanema river basin, São Paulo State, Brazil. Methods The RFAI was adapted from metrics related to the functional characteristics and composition of fish assemblages through a protocol of metric selection and validation, and to its response to the presence of riparian vegetation. Results The final RFAI was composed by nine metrics, been lower in sites without riparian vegetation as consequence of the predominance of larger individuals and the percent of piscivorous and detritivorous fishes. Conclusions These results suggest that increasing shore habitat complexity in reservoirs by maintaining riparian vegetation increases fish biotic integrity.
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Jiang, Si-Hong; Chen, Chun-Liang; Bagas, Leon; Liu, Yuan; Han, Ning; Kang, Huan; Wang, Ze-Hai
2017-08-01
The Xing-Mong Orogenic Belt (XMOB) is located in the eastern part of the Central Asian Orogenic Belt (CAOB) and has experienced multiple tectonic events. The Baiyinnuoer Pb-Zn deposit may be a rare case that documents two periods of mineralization in the tectonically complex XMOB. There are two types of Pb-Zn mineralization in the deposit: (1) skarn-type ore, hosted by the skarn in the contact zone between marble and granodiorite and within the marble and (2) vein-type ore, hosted by crystal tuff and feldspar porphyry. This study revealed that the host rocks, mineral assemblages, mineralization occurrences, S-Pb isotopes, and ages between the two types of ore are notably different. Zircon U-Pb dating indicates that the granodiorite was emplaced in the Early Triassic (244 ± 1 to 242 ± 1 Ma), the crystal tuff was deposited in the Early Cretaceous (140 ± 1 to 136 ± 1 Ma), and the feldspar porphyry was intruded in the Early Cretaceous (138 ± 2 to 136 ± 2 Ma). The first skarn mineralization occurred at ∼240 Ma and the second vein-type Pb-Zn mineralization took place between 136 and 129 Ma. Thus the Triassic orebodies were overprinted by Early Cretaceous mineralization. The sphalerite and galena from the skarn mineralization have higher δ34S values (-4.7 to +0.3‰) than the sphalerite, galena and aresenopyrite from the vein-type mineralization (-7.5 to -4.2‰), indicating different sulfur sources or ore-forming processes for the two types of mineralization. The Pb isotopic compositions of the two types of ore are very similar, suggesting similar lead sources. Geochemistry and Nd-Pb-Hf isotopic systematics of the igneous rocks in the region show that the Triassic granodiorite was generated from hybridization of mafic and felsic magmas due to strong crust-mantle interaction under the collisional setting that resulted following the closure of the Paleo-Asian Ocean and the collision of North China and Siberian cratons at the end of the Permian; while the
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Mineral composition of commonly consumed ethnic foods in Europe
Directory of Open Access Journals (Sweden)
Santosh Khokhar
2012-07-01
Full Text Available Background: Ethnic foods are an integral part of food consumption in Europe contributing towards the overall nutrient intake of the population. Food composition data on these foods are crucial for assessing nutrient intake, providing dietary advice and preventing diseases. Objective: To analyse selected minerals in authentic and modified ethnic foods commonly consumed in seven EU member states and Israel. Design: A list of ethnic foods commonly consumed in selected European countries was generated, primary samples collected and composite sample prepared for each food, which were analysed for dietary minerals at accredited laboratories. Methods for sampling, analysis, data scrutiny and documentation were based on harmonised procedures. Results: New data on 128 ethnic foods were generated for inclusion in the national databases of seven EU countries and Israel within the European Food Information Resource (EuroFIR, an EU Network of Excellence. The Na, K, Ca, P, Mg, Mn, Cl, Fe, Cu, Zn, Se and I contents of 39 foods is presented for the first time in this study. Conclusion: The data will serve as an important tool in future national and international food consumption surveys, to target provision of dietary advice, facilitate implementation of policies and inform policymakers, health workers, food industry and researchers.
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Rezvukhin, Dmitriy I.; Malkovets, Vladimir G.; Sharygin, Igor S.; Tretiakova, Irina G.; Griffin, William L.; O'Reilly, Suzanne Y.
2018-05-01
Cr-pyrope xenocrysts and associated inclusions of crichtonite-group minerals from the Internatsionalnaya kimberlite pipe were studied to provide new insights into processes in the lithospheric mantle beneath the Mirny kimberlite field, Siberian craton. Pyropes are predominantly of lherzolitic paragenesis (Cr2O3 2-6 wt%) and have trace-element spectra typical for garnets from fertile mantle (gradual increase in chondrite-normalized values from LREE to MREE-HREE). Crichtonite-group minerals commonly occur as monomineralic elongated inclusions, mostly in association with rutile, Mg-ilmenite and Cr-spinel within individual grains of pyrope. Sample INT-266 hosts intergrowth of crichtonite-group mineral and Cl-apatite, while sample INT-324 contains polymineralic apatite- and dolomite-bearing assemblages. Crichtonite-group minerals are Al-rich (1.1-4.5 wt% Al2O3), moderately Zr-enriched (1.3-4.3 wt% ZrO2), and are Ca-, Sr-, and occasionally Ba-dominant in terms of A-site occupancy; they also contain significant amounts of Na and LREE. T-estimates and chemical composition of Cr-pyropes imply that samples represent relatively low-T peridotite assemblages with ambient T ranging from 720 to 820°С. Projected onto the 35 mW/m2 cratonic paleogeotherm for the Mirny kimberlite field (Griffin et al., 1999b. Tectonophysics 310, 1-35), temperature estimates yield a P range of 34-42 kbar ( 110-130 km), which corresponds to a mantle domain in the uppermost part of the diamond stability field. The presence of crichtonite-group minerals in Cr-pyropes has petrological and geochemical implications as evidence for metasomatic enrichment of some incompatible elements in the lithospheric mantle beneath the Mirny kimberlite field. The genesis of Cr-pyropes with inclusions of crichtonite-group minerals is attributed to the percolation of Ca-Sr-Na-LREE-Zr-bearing carbonate-silicate metasomatic agents through Mg- and Cr-rich depleted peridotite protoliths. The findings of several potentially
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Monteiro, Lena V.S.; Xavier, R.P.; Carvalho, E.R.; Hitzman, M.W.; Johnson, C.A.; Souza, Filho C.R.; Torresi, I.
2008-01-01
The Sossego iron oxide–copper–gold deposit (245 Mt @ 1.1% Cu, 0.28 g/t Au) in the Carajás Mineral Province of Brazil consists of two major groups of orebodies (Pista–Sequeirinho–Baiano and Sossego–Curral) with distinct alteration assemblages that are separated from each other by a major high angle fault. The deposit is located along a regional WNW–ESE-striking shear zone that defines the contact between metavolcano–sedimentary units of the ∼2.76 Ga Itacaiúnas Supergroup and tonalitic to trondhjemitic gneisses and migmatites of the ∼2.8 Ga Xingu Complex. The deposit is hosted by granite, granophyric granite, gabbro, and felsic metavolcanic rocks. The Pista–Sequeirinho–Baiano orebodies have undergone regional sodic (albite–hematite) alteration and later sodic–calcic (actinolite-rich) alteration associated with the formation of massive magnetite–(apatite) bodies. Both these alteration assemblages display ductile to ductile–brittle fabrics. They are cut by spatially restricted zones of potassic (biotite and potassium feldspar) alteration that grades outward to chlorite-rich assemblages. The Sossego–Curral orebodies contain weakly developed early albitic alteration and very poorly developed subsequent calcic–sodic alteration. These orebodies contain well-developed potassic alteration assemblages that were formed during brittle deformation that resulted in the formation of breccia bodies. Breccia matrix commonly displays coarse mineral infill suggestive of growth into open space. Sulfides in both groups of deposits were precipitated first with potassic alteration and more importantly with a later assemblage of calcite–quartz–epidote–chlorite. In the Sequeirinho orebodies, sulfides range from undeformed to deformed; sulfides in the Sossego–Curral orebodies are undeformed. Very late, weakly mineralized hydrolytic alteration is present in the Sossego/Currral orebodies. The sulfide assemblage is dominated by chalcopyrite with
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Accuracy of dual photon absorptiometry for assessment of bone mineral and body composition
International Nuclear Information System (INIS)
Aoki, Manabu; Iwamura, Akira; Goto, Eisuke; Mori, Yutaka; Kawakami, Kenji; Soshi, Shigeru
1991-01-01
Accuracy of bone mineral measurement by the dual photon absorptiometry (DPA) was studied in comparison to ashed bone mineral (ash) on the lumbar spine of 23 cada vars. There was a high correlation (r=0.896) between the value of DPA and ash weight. Bone mineral content in the radius by the single photon absorptiometry (SPA) did not correlate to bone mineral density (BMD) by DPA in the patients with hemodialysis. SPA may be less useful to assess BMD of the whole body. Fat mass and lean mass measured by DPA were well correlated to the value obtained by the electrical impedance method. Precision in measurement of fat mass and lean mass was also confirmed by the electrical impedance method. These results suggest that DPA has a high precision for measurements of the bone mineral and the body composition. (author)
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International Nuclear Information System (INIS)
Fang Linchuan; Cai Peng; Li Pengxiang; Wu Huayong; Liang Wei; Rong Xingmin; Chen Wenli; Huang Qiaoyun
2010-01-01
In order to have a better understanding of the interactions of heavy metals with bacteria and minerals in soil and associated environments, isothermal titration calorimetry (ITC), potentiometric titration and equilibrium sorption experiments were conducted to investigate the adsorption behavior of Cu(II) by Bacillus thuringiensis, Pseudomonas putida and their composites with minerals. The interaction of montmorillonite with bacteria increased the reactive sites and resulted in greater adsorption for Cu(II) on their composites, while decreased adsorption sites and capacities for Cu(II) were observed on goethite-bacteria composites. A gram-positive bacterium B. thuringiensis played a more important role than a gram-negative bacterium P. putida in determining the properties of the bacteria-minerals interfaces. The enthalpy changes (ΔH ads ) from endothermic (6.14 kJ mol -1 ) to slightly exothermic (-0.78 kJ mol -1 ) suggested that Cu(II) is complexed with the anionic oxygen ligands on the surface of bacteria-mineral composites. Large entropies (32.96-58.89 J mol -1 K -1 ) of Cu(II) adsorption onto bacteria-mineral composites demonstrated the formation of inner-sphere complexes in the presence of bacteria. The thermodynamic data implied that Cu(II) mainly bound to the carboxyl and phosphoryl groups as inner-sphere complexes on bacteria and mineral-bacteria composites.
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Pearson, Daniel K.; Braun, Christopher L.; Moring, J. Bruce
2016-01-21
This report documents differences in the mapped spatial extents and physical characteristics of in-channel fish habitat evaluated at the mesohabitat scale during winter 2011–12 (moderate streamflow) and summer 2012 (low streamflow) at 15 sites on the Middle Rio Grande in New Mexico starting about 3 kilometers downstream from Cochiti Dam and ending about 40 kilometers upstream from Elephant Butte Reservoir. The results of mesohabitat mapping, physical characterization, and fish assemblage surveys are summarized from the data that were collected. The report also presents general comparisons of physical mesohabitat data, such as wetted area and substrate type, and biological mesohabitat data, which included fish assemblage composition, species richness, Rio Grande silvery minnow relative abundance, and Rio Grande silvery minnow catch per unit effort.
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Boot, Annemieke M.; van der Sluis, Inge M.; Krenning, Eric P.; Keizer-Schrama, Sabine M. P. F. de Muinck
2009-01-01
Background/Aims: The aim of the present study was to evaluate bone mineral density (BMD) and body composition of patients with childhood-onset growth hormone (GH) deficiency (GHD) treated with GH during the transition period. Methods: BMD and body composition, measured by dual-energy X-ray
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Energy Technology Data Exchange (ETDEWEB)
Daniels, E.J.; Marshak, S.; Altaner, S.P. [Chevron Oil Field Research Company, La Habra, CA (United States)
1996-10-15
Joints (cleat) in Pennsylvania anthracite contain two distinct clay-mineral assemblages, both of which formed by alteration of preexisting kaolinite at peak metamorphic conditions during the Alleghanian orogeny. The first assemblage, NH{sub 4} - illite or pyrophyllite {+-} quartz, formed by reaction of kaolinite with methane-rich fluids derived from within the coal. The second assemblage, sudoite {+-} tosudite {+-} rectorite {+-} berthierine, formed by the reaction of kaolinite with ferromagnesian-bearing hydrothermal fluids which must have come from outside the coal. In an earlier paper, the authors suggested that the first assemblage indicated clay diagenesis in low-permeability environments, and that the second assemblage indicated clay diagenesis in high-permeability environments. If this premise is correct, then the distribution of clay-mineral alteration assemblages serves to define syntectonic permeability variations in coal cleat. The first assemblage dominates in the coal matrix itself, in isolated cleat, in cleat that parallel the regional trend of Alleghanian folds, and in the mirror portions of cleat oriented perpendicular to the fold trends, suggesting that these regions are low-permeability environments. The second assemblage dominates in the hackle fringe of interconnected cleat that trend perpendicular to the strike of the Appalachian orogen, suggesting that these regions are high-permeability environments. These results emphasize that syntectonic cleat permeability is a function of cleat orientation, macroscopic cleat interconnetivity and orientation, as well as microscopic cleat-surface morphology.
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Routray, Sunita; Swain, Ranjita; Rao, Raghupatruni Bhima
2017-04-01
The present study is aimed at investigating the optimization of a mineral separator for processing of beach sand minerals of Bay of Bengal along Ganjam-Rushikulya coast. The central composite design matrix and response surface methodology were applied in designing the experiments to evaluate the interactive effects of the three most important operating variables, such as feed quantity, wash water rate and Shake amplitude of the deck. The predicted values were found to be in good agreement with the experimental values (R2 = 0.97 for grade and 0.98 for recovery). To understand the impact of each variable, three dimensional (3D) plots were also developed for the estimated responses.
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Directory of Open Access Journals (Sweden)
Batool Taghipour
2010-11-01
Full Text Available Northwest of Shir-Kuh batholith, a number of leucocratic granitic and granodioritic plutons have intruded sedimentary hosts including shale-sandstone (Triassic-Jurassic and sandstone-conglomerate (Lower Cretaceous. Contact metamorphism and hydrothermal alterations are widespread. Late alteration assemblage mainly occurs in arkosic sandstones of Sangestan Formation and includes propylitic, quartz-sericitic, advanced argillic and silicific zones. Quartz-sericite zone is the most widespread. Advanced argillic alteration is characterized by the following assemblage: jarosite, alunite, turquoise, from the Al-Phosphate-Sulfate group (APS. Considering this mineral assemblage and probable interactions taking place between the minerals, a geochemical environment with high fO2 and low pH is thought to be prevailing at the time of alteration and formation of alunite, jarosite and turquoise.
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Millet, Melanie; Poupard, Pascal; Le Quéré, Jean-Michel; Bauduin, Remi; Guyot, Sylvain
2017-08-09
Producers of apple-based beverages are confronted with colloidal instability. Haze is caused by interactions between molecules that lead to the formation of aggregates. Haze composition in three apple-based beverages, namely, French sparkling cider, apple juice, and pommeau, was studied. Phenolic compounds, proteins, polysaccharides, and minerals were analyzed using global and detailed analytical methods. The results explained apple juice hazes, where they were the main constituents (18 and 24%). Polysaccharides accounted for 0-30% of haze. Potassium and calcium were the main minerals.
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Martínez-Valdivieso, Damián; Font, Rafael; Gómez, Pedro; Blanco-Díaz, Teresa; Del Río-Celestino, Mercedes
2014-12-01
Efforts through conventional breeding to improve the mineral content in horticultural crops have not always been successful mainly due to the fact that standard analytical methods are both costly and time-consuming. We investigated the feasibility of applying near infrared reflectance spectroscopy (NIRS) to the estimation of essential mineral composition in the skin and flesh of summer squash fruits (Cucurbita pepo subsp. pepo) using a 200-sample set from diverse morphotypes. The coefficients of determination in the external validation (R(2) VAL) obtained for the skin and flesh of the fruit were: total mineral content, 0.84 and 0.70; P, 0.74 and 0.62; K, 0.83 and 0.67; Ca, 0.57 and 0.60; Mg, 0.78 and 0.45; Fe, 0.78 and 0.65; Cu, 0.67 and 0.66; Mn, 0.67 and 0.64; Zn, 0.80 and 0.79 and Na, 0.33 and 0.33; respectively. NIRS combined with different spectral transformations by modified partial least-squares (MPLS) regression has shown to be useful in determining the mineral composition of summer squash fruit, being a fast and low-cost analytical technique. Components such as chlorophyll, starch and lipids were used by MPLS for modelling the predicting equations. The promotion of micronutrient-rich summer squash varieties could have a significant long-term beneficial impact on the health of mineral deficient human populations. © 2014 Society of Chemical Industry.
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Indicator minerals as guides to base metal sulphide mineralisation ...
Indian Academy of Sciences (India)
figures 3C, D). At the Bhuyari prospect (figure 1), gahnite is present in the quartz + biotite + muscovite + plagio- clase + gahnite + garnet + chlorite assemblage along with disseminated sulphides and is closely associated with the mineralized zone.
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How complementary are epibenthic assemblages in artificial and nearby natural rocky reefs?
Carvalho, Susana
2013-12-01
The present study analyses the composition, structure and trophic function of epibenthic assemblages in two artificial reefs (ARs) 16 years after deployment and in nearby natural reefs (NRs), aiming at providing insights on the complementarity between both habitats. Current findings suggest that after 16 years the ARs (concrete blocks), located in southern Portugal, do not act as surrogates for NRs, as epibenthic assemblages differed between reef types in composition, structure and trophic function. NRs showed higher diversity and complementarity (i.e. beta-diversity) than ARs, evidencing higher redundancy. Higher heterogeneity within NRs was also evidenced by the multi-dimensional scaling analysis based on abundance, biomass and trophic composition. NRs presented higher abundance of molluscs and biomass of sponges, resulting in differences in the trophic function: suspension-feeding dominated the NRs, while within ARs there was an ascendency of carnivory. Although not acting as surrogates for NRs and provided that no adverse effects (e.g. establishment of non-native species) were detected, ARs may have a significant contribution for the increase of regional diversity, as evidenced by the highest complementarity levels observed between assemblages in both reefs. © 2013 Elsevier Ltd.
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How complementary are epibenthic assemblages in artificial and nearby natural rocky reefs?
Carvalho, Susana; Moura, Ana; Cú rdia, Joã o; Cancela da Fonseca, Luí s; Santos, Miguel N.
2013-01-01
The present study analyses the composition, structure and trophic function of epibenthic assemblages in two artificial reefs (ARs) 16 years after deployment and in nearby natural reefs (NRs), aiming at providing insights on the complementarity between both habitats. Current findings suggest that after 16 years the ARs (concrete blocks), located in southern Portugal, do not act as surrogates for NRs, as epibenthic assemblages differed between reef types in composition, structure and trophic function. NRs showed higher diversity and complementarity (i.e. beta-diversity) than ARs, evidencing higher redundancy. Higher heterogeneity within NRs was also evidenced by the multi-dimensional scaling analysis based on abundance, biomass and trophic composition. NRs presented higher abundance of molluscs and biomass of sponges, resulting in differences in the trophic function: suspension-feeding dominated the NRs, while within ARs there was an ascendency of carnivory. Although not acting as surrogates for NRs and provided that no adverse effects (e.g. establishment of non-native species) were detected, ARs may have a significant contribution for the increase of regional diversity, as evidenced by the highest complementarity levels observed between assemblages in both reefs. © 2013 Elsevier Ltd.
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Origin and prospectivity of heavy mineral enriched sand deposits along the Somaliland coastal areas
Ali, M. Y.; Hibberd, P.; Stoikovich, B.
2018-04-01
Sixty-one heavy mineral enriched samples along the Somaliland coast from Eil Sheikh to Ras Khatib, a distance of about 130 km, were analyzed using X-ray Fluorescence, X-ray Diffraction and SEM-EDS techniques. This study reveals that a considerable amount of heavy minerals is present along the Somaliland coast and confirms the presence of high concentration titanium and iron bearing minerals. However, the backshore deposits in the mouths of Waaheen and Biyo Gure ephemeral rivers as well as raised paleo-beaches in the east of port city of Berbera demonstrate the highest level of titaniferous heavy minerals with most samples showing concentration greater than 50 wt %. The titanium detected in geochemical analysis occurs in the form of ilmenite, rutile, titanite and titaniferous magnetite. Also, present in minor or trace amounts, are garnet, zircon and monazite. Heavy mineral accumulations in the east and west of Berbera have different mineralogical assemblages. The east of Berbera is dominated by quartz with moderate concentration of plagioclase, K-feldspar, magnetite, hematite and titanium bearing minerals, whereas in the west of Berbera, the dominant minerals are quartz, K-feldspar and plagioclase with variable proportions of ilmenite, rutile, mica, amphibole and pyroxene. These variations in mineral assemblages suggest different composition of the catchment areas that supply sediment to these deposits. The catchment area in the east of Berbera consists mainly of Proterozoic crystalline basement of the Qabri Bahar complex, Gabbro-Synenite belt and granitic intrusions that outcrop in Hudiso, Tulo Dibijo and surrounding areas. The primary sources of heavy minerals in the west of Berbera comprise of high-grade metamorphic rocks of the Mora and Qabri Bahar complexes as well as the Miocene volcanics that outcrop in Laferug and Hagabo areas. The heavy mineral sand deposits observed along the Somaliland coast have the potential to provide commercially important heavy
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The hydrogen isotopic composition of kaolin minerals in Japan
International Nuclear Information System (INIS)
Marumo, Katsumi; Nagasawa, Keinosuke; Kuroda, Yoshimasu.
1979-01-01
Hydrogen isotopic composition (D/H ratio) was determined for kaolin minerals from geothermal areas and sedimentary and hydrothermal kaolin deposits in Japan. On the Ohnuma, Matsukawa, and Ohtake geothermal areas, the hydrogen isotopic fractionation factor between kaolin minerals and water was calculated to fall between 0.97 and 0.99 for the temperature range of 50 to 200 0 C, a fact which shows that the temperature of formation has no important effect on the D/H ratio of kaolin minerals. D/H ratio of kaolinites and dickites from many kaolin deposits shows local variation, and seems to correlate with isotopic variation of the present-day meteoric surface water. Exceptions are seen in some kaolin deposits such as Shokozan, Hiroshima Prefecture, where kaolinite and dickite have considerably high values of D/H ratio, and seem to have reacted with water rich in deuterium. D/H ratio of halloysite is not correlated with that of the present-day meteoric surface water. As Lawrence and Taylor (1971) pointed out, the original D/H ratio of constitutional water of halloysite is not preserved because of the isotopic exchange between the interlayer water and the constitutional water. (author)
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Directory of Open Access Journals (Sweden)
Ana Paula Lopes Marques
2014-01-01
Full Text Available ABSTRACT. Marques A.P.L., Botteon R.C.C.M., Amorim E.B., Botteon P.T.L &Zonta E. [Mineral composition of pastures and mineral deficiencies in cattle of some properties in Middle Paraiba, RJ, Brazil.] Composição mineral das pastagens e deficiências minerais dos bovinos em algumas propriedades da região do Médio Paraíba, RJ, Brasil. Revista Brasileira de Medicina Veterinária, 36(1:71-78, 2014. Departamento de Medicina e Cirurgia Veterinária, Universidade Federal Rural do Rio de Janeiro, BR 465 Km 7, Seropédica, RJ 23851-900, Brasil. E-mail: marquesapl@ufrrj.br We studied levels and nutrient availability in the soil and grazing of cattle in Middle Paraíba, RJ, Brazil in the early dry season (May-June and rainy (November-December in seven cattle herds with a history of clinical deficiencies of Na, Cu, Co and P, identified through visits to farmers. The mineral contents in the samples were determined by atomic absorption spectrophotometry and values obtained were compared with clinical signs found. Low values of P and Na were confirmed and although the lack of Ca and Mg is uncommon, some samples showed low rates. We found high values of Fe with possible interference in the absorption of Cu, the main clinical deficiency identified in the region, and high values of Al, Zn and Mn. The results indicate that most mineral deficiencies diagnosed in those herds is due to antagonistic effects of minerals that are not deficient.
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Kamaruddin, Mohamad Anuar; Alrozi, Rasyidah; Aziz, Hamidi Abdul; Han, Tan Yong; Yusoff, Mohd Suffian
2017-09-01
This study investigates the treatability of composite adsorbent made from waste materials and minerals which is widely available in Malaysia. The composite adsorbent was prepared based on wet attrition method which focuses on the determination of optimum dosage of each of raw materials amount by conventional design of experiment work. Zeolite, activated carbon, rice husk and limestone were ground to obtained particle size of 150 µm. 45.94% zeolite, 15.31% limestone, 4.38% activated carbon, 4.38% rice husk carbon and 30% of ordinary Portland cement (OPC). The mixture was mixed together under pre-determined mixing time. About 60% (by weight) of water was added and the mixture paste was allowed to harden for 24 hours and then submersed in water for three days for curing. Batch experimental study was performed on synthetic dissolving a known amount of solid crystal phenol with distilled water into the volumetric flasks. From the batch experimental study, it was revealed that the optimum shaking speed for removal of phenol was 200 rpm. The removal efficiency was 65%. The optimum shaking time for removing phenol was 60 minutes; the percentage achieved was 55%. The removal efficiency increased with the increased of the amount of composite adsorbent. The removal efficiency for optimum adsorbent dosage achieved 86%. Furthermore, the influence of pH solution was studied. The optimum pH for removing phenol was pH 6, with the removal percentage of 95%. The results implies that carbon-mineral based composite adsorbent is promising replacement for commercial adsorbent that provides alternative source for industrial adsorption application in various types of effluent treatment system.
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Directory of Open Access Journals (Sweden)
UIEDA V. S.
2001-01-01
Full Text Available The species composition and spatial distribution of a fish assemblage were studied in three reaches of a river in the east coast of Brazil: a section of rapids (upper, another of water flowing on plain terrain (lowland and the other of a mangrove environment. Two methods were employed with the purpose of estimating their effectiveness in naturalistic studies of tropical fish assemblages. One method consisted of underwater observations and the other was characterized by catches using gears such as fish traps, sieves and fishing rods. Both methods showed that their effectiveness is dependent upon the characteristics of the environment and the biology of the species. In areas of high water transparency and flow speed, rocky substrate and no submerged marginal vegetation (upper reach, the employment of the traditional gears was quite inefficient, despite the excellent conditions for underwater observations. In areas of clear water and high flow speed with abundant submerged marginal vegetation (lowland and mangrove, the gears were rather efficient yielding excellent results when coupled with direct observation methods. Since the abiotic characteristics of a stream change longitudinally, it is appropriate to employ different methods in the study of the ichthyofauna composition and distribution in order to reduce the constraints imposed by sampling methods in running waters.
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Directory of Open Access Journals (Sweden)
V. S. UIEDA
Full Text Available The species composition and spatial distribution of a fish assemblage were studied in three reaches of a river in the east coast of Brazil: a section of rapids (upper, another of water flowing on plain terrain (lowland and the other of a mangrove environment. Two methods were employed with the purpose of estimating their effectiveness in naturalistic studies of tropical fish assemblages. One method consisted of underwater observations and the other was characterized by catches using gears such as fish traps, sieves and fishing rods. Both methods showed that their effectiveness is dependent upon the characteristics of the environment and the biology of the species. In areas of high water transparency and flow speed, rocky substrate and no submerged marginal vegetation (upper reach, the employment of the traditional gears was quite inefficient, despite the excellent conditions for underwater observations. In areas of clear water and high flow speed with abundant submerged marginal vegetation (lowland and mangrove, the gears were rather efficient yielding excellent results when coupled with direct observation methods. Since the abiotic characteristics of a stream change longitudinally, it is appropriate to employ different methods in the study of the ichthyofauna composition and distribution in order to reduce the constraints imposed by sampling methods in running waters.
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Lamy, F.; Hebbeln, D.; Wefer, G.
The regional patterns of texture and composition of modern continental slope and pelagic sediments off Chile between 25°S and 43°S reflect the latitudinal segmentation of geological, morphological, and climatic features of the continental hinterland. Grain-size characteristics are controlled by the grain-size of source rocks, the weathering regime, and mode of sediment input (eolian off northern Chile vs fluvial further south). Bulk-mineral assemblages reveal a low grade of maturity. Regional variations are governed by the source-rock composition of the different geological terranes and the relative source-rock contribution of the Coastal Range and Andes, as controlled by the continental hydrology. The relative abundance of clay minerals is also predominantly influenced by the source-rock composition and partly by continental smectite neoformation. Latitudinal variations of illite crystallinities along the Chilean continental slope (and west of the Peru-Chile trench) clearly reflect modifications of the weathering regime which correspond to the strong climatic zonation of Chile.
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Use of lead isotopic composition in sulfides for the mineral-formation geochronology
International Nuclear Information System (INIS)
Ordynets, G.E.
1977-01-01
A study of the isotopic composition of lead in pyrites and galenites of a hydrothermal uranium deposit makes it possible to determine the time of ore formation. A few types of lead ores are distinguished. Each type corresponds to a definite period of mineralization and is characterized by a specific isotopic composition. The Cimmerian age of carbonate-sulphide veins has been established, the deposit being formed over a period of 150-200 million years
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C. David, McIntire; Larson, Gary L.; Truitt, Robert E.
2007-01-01
Taxonomic composition and production dynamics of phytoplankton assemblages in Crater Lake, Oregon, were examined during time periods between 1984 and 2000. The objectives of the study were (1) to investigate spatial and temporal patterns in species composition, chlorophyll concentration, and primary productivity relative to seasonal patterns of water circulation; (2) to explore relationships between water column chemistry and the taxonomic composition of the phytoplankton; and (3) to determine effects of primary and secondary consumers on the phytoplankton assemblage. An analysis of 690 samples obtained on 50 sampling dates from 14 depths in the water column found a total of 163 phytoplankton taxa, 134 of which were identified to genus and 101 were identified to the species or variety level of classification. Dominant species by density or biovolume included Nitzschia gracilis, Stephanodiscus hantzschii, Ankistrodesmus spiralis, Mougeotia parvula, Dinobryon sertularia, Tribonema affine, Aphanocapsa delicatissima, Synechocystis sp., Gymnodinium inversum, and Peridinium inconspicuum. When the lake was thermally stratified in late summer, some of these species exhibited a stratified vertical distribution in the water column. A cluster analysis of these data also revealed a vertical stratification of the flora from the middle of the summer through the early fall. Multivariate test statistics indicated that there was a significant relationship between the species composition of the phytoplankton and a corresponding set of chemical variables measured for samples from the water column. In this case, concentrations of total phosphorus, ammonia, total Kjeldahl nitrogen, and alkalinity were associated with interannual changes in the flora; whereas pH and concentrations of dissolved oxygen, orthophosphate, nitrate, and silicon were more closely related to spatial variation and thermal stratification. The maximum chlorophyll concentration when the lake was thermally stratified
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International Nuclear Information System (INIS)
Jha, Surendra Kumar; Shrivastava, J.P.; Bhairam, C.L.
2012-01-01
Clays associated with the Precambrian unconformity-related (sensu lato) uranium mineralization that occur along fractures of Rohini carbonate, Bandai sandstone and clay-organic rich black carbonaceous Gorakalan shale of the Sonrai Formation from Bijawar Group is significant. Nature and structural complexity of these clays have been studied to understand depositional mechanism and palaeoenvironmental conditions responsible for the restricted enrichment of uranium in the Sonrai basin. Clays ( chlorite> illite > smectite mineral assemblages, whereas, Solda Formation contains kaolinite > illite > chlorite clays. It has been found that the former mineral assemblage resulted from the alteration process is associated with the uranium mineralization and follow progressive reaction series, indicating palaeoenvironmental (cycles of tropical humid to semi-arid/arid) changes prevailed during maturation of the Sonrai basin. The hydrothermal activity possibly associated with Kurrat volcanics is accountable for the clay mineral alterations
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Bone mineral density and body composition in adolescents with failure to thrive
Directory of Open Access Journals (Sweden)
Thiago Sacchetto de Andrade
2010-06-01
Full Text Available Objective: To evaluate bone mineral mass in adolescents with failure to thrive in relation to body composition. Methods: A case-control study involving 126 adolescents (15 to 19 years, in final puberty maturation being 76 eutrophic and 50 with failure to thrive (genetic or constitutional delay of growth, of matching ages, gender and pubertal maturation. The weight, height and calculated Z score for height/age and body mass index; bone mineral content, bone mineral density and adjusted bone mineral density were established for total body, lower back and femur; total fat-free mass and height-adjusted fat-free mass index, total fat mass and height-adjusted. The statistical analyses were performed using the Student’s t-test (weight, height and body composition; Mann-Whitney test (bone mass and multiple linear regression (bone mass determinants. Results: weight, height and height/age Z-score were significantly higher among eutrophic subjects. Both groups did not show statistically significant differences for fat mass, percentage of fat mass, total fat mass height adjusted and fat-free mass index height sadjusted. However, total free fat maass was smaller for the failure to thrive group. Conclusions: There was no statistically significant difference for bone mass measurements among adolescents with failure to thrive; however, the factors that determine bone mass formation should be better studied due to the positive correlation with free fat mass detected in these individuals.
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Directory of Open Access Journals (Sweden)
Euan S Harvey
Full Text Available Distributions of mobile animals have been shown to be heavily influenced by habitat and climate. We address the historical and contemporary context of fish habitats within a major zootone: the Recherche Archipelago, southern western Australia. Baited remote underwater video systems were set in nine habitat types within three regions to determine the species diversity and relative abundance of bony fishes, sharks and rays. Constrained ordinations and multivariate prediction and regression trees were used to examine the effects of gradients in longitude, depth, distance from islands and coast, and epibenthic habitat on fish assemblage composition. A total of 90 species from 43 families were recorded from a wide range of functional groups. Ordination accounted for 19% of the variation in the assemblage composition when constrained by spatial and epibenthic covariates, and identified redundancy in the use of distance from the nearest emergent island as a predictor. A spatial hierarchy of fourteen fish assemblages was identified using multivariate prediction and regression trees, with the primary split between assemblages on macroalgal reefs, and those on bare or sandy habitats supporting seagrass beds. The characterisation of indicator species for assemblages within the hierarchy revealed important faunal break in fish assemblages at 122.30 East at Cape Le Grand and subtle niche partitioning amongst species within the labrids and monacanthids. For example, some species of monacanthids were habitat specialists and predominantly found on seagrass (Acanthaluteres vittiger, Scobinichthys granulatus, reef (Meuschenia galii, Meuschenia hippocrepis or sand habitats (Nelusetta ayraudi. Predatory fish that consume molluscs, crustaceans and cephalopods were dominant with evidence of habitat generalisation in reef species to cope with local disturbances by wave action. Niche separation within major genera, and a sub-regional faunal break, indicate future
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Bioactive Polymeric Composites for Tooth Mineral Regeneration: Physicochemical and Cellular Aspects
Skrtic, Drago; Antonucci, Joseph M.
2011-01-01
Our studies of amorphous calcium phosphate (ACP)-based dental materials are focused on the design of bioactive, non-degradable, biocompatible, polymeric composites derived from acrylic monomer systems and ACP by photochemical or chemically activated polymerization. Their intended uses include remineralizing bases/liners, orthodontic adhesives and/or endodontic sealers. The bioactivity of these materials originates from the propensity of ACP, once exposed to oral fluids, to release Ca and PO4 ions (building blocks of tooth and bone mineral) in a sustained manner while spontaneously converting to thermodynamically stable apatite. As a result of ACP's bioactivity, local Ca- and PO4-enriched environments are created with supersaturation conditions favorable for the regeneration of tooth mineral lost to decay or wear. Besides its applicative purpose, our research also seeks to expand the fundamental knowledge base of structure-composition-property relationships existing in these complex systems and identify the mechanisms that govern filler/polymer and composite/tooth interfacial phenomena. In addition to an extensive physicochemical evaluation, we also assess the leachability of the unreacted monomers and in vitro cellular responses to these types of dental materials. The systematic physicochemical and cellular assessments presented in this study typically provide model materials suitable for further animal and/or clinical testing. In addition to their potential dental clinical value, these studies suggest the future development of calcium phosphate-based biomaterials based on composite materials derived from biodegradable polymers and ACP, and designed primarily for general bone tissue regeneration. PMID:22102967
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Energy Technology Data Exchange (ETDEWEB)
Fang Linchuan [State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070 (China); Key Laboratory of Subtropical Agriculture and Environment, Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070 (China); Cai Peng; Li Pengxiang; Wu Huayong; Liang Wei; Rong Xingmin [Key Laboratory of Subtropical Agriculture and Environment, Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070 (China); Chen Wenli [State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070 (China); Huang Qiaoyun, E-mail: qyhuang@mail.hzau.edu.cn [State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070 (China); Key Laboratory of Subtropical Agriculture and Environment, Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070 (China)
2010-09-15
In order to have a better understanding of the interactions of heavy metals with bacteria and minerals in soil and associated environments, isothermal titration calorimetry (ITC), potentiometric titration and equilibrium sorption experiments were conducted to investigate the adsorption behavior of Cu(II) by Bacillus thuringiensis, Pseudomonas putida and their composites with minerals. The interaction of montmorillonite with bacteria increased the reactive sites and resulted in greater adsorption for Cu(II) on their composites, while decreased adsorption sites and capacities for Cu(II) were observed on goethite-bacteria composites. A gram-positive bacterium B. thuringiensis played a more important role than a gram-negative bacterium P. putida in determining the properties of the bacteria-minerals interfaces. The enthalpy changes ({Delta}H{sub ads}) from endothermic (6.14 kJ mol{sup -1}) to slightly exothermic (-0.78 kJ mol{sup -1}) suggested that Cu(II) is complexed with the anionic oxygen ligands on the surface of bacteria-mineral composites. Large entropies (32.96-58.89 J mol{sup -1} K{sup -1}) of Cu(II) adsorption onto bacteria-mineral composites demonstrated the formation of inner-sphere complexes in the presence of bacteria. The thermodynamic data implied that Cu(II) mainly bound to the carboxyl and phosphoryl groups as inner-sphere complexes on bacteria and mineral-bacteria composites.
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Fang, Linchuan; Cai, Peng; Li, Pengxiang; Wu, Huayong; Liang, Wei; Rong, Xingmin; Chen, Wenli; Huang, Qiaoyun
2010-09-15
In order to have a better understanding of the interactions of heavy metals with bacteria and minerals in soil and associated environments, isothermal titration calorimetry (ITC), potentiometric titration and equilibrium sorption experiments were conducted to investigate the adsorption behavior of Cu(II) by Bacillus thuringiensis, Pseudomonas putida and their composites with minerals. The interaction of montmorillonite with bacteria increased the reactive sites and resulted in greater adsorption for Cu(II) on their composites, while decreased adsorption sites and capacities for Cu(II) were observed on goethite-bacteria composites. A gram-positive bacterium B. thuringiensis played a more important role than a gram-negative bacterium P. putida in determining the properties of the bacteria-minerals interfaces. The enthalpy changes (DeltaH(ads)) from endothermic (6.14 kJ mol(-1)) to slightly exothermic (-0.78 kJ mol(-1)) suggested that Cu(II) is complexed with the anionic oxygen ligands on the surface of bacteria-mineral composites. Large entropies (32.96-58.89 J mol(-1) K(-1)) of Cu(II) adsorption onto bacteria-mineral composites demonstrated the formation of inner-sphere complexes in the presence of bacteria. The thermodynamic data implied that Cu(II) mainly bound to the carboxyl and phosphoryl groups as inner-sphere complexes on bacteria and mineral-bacteria composites. Copyright 2010 Elsevier B.V. All rights reserved.
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A classic Late Frasnian chondrichthyan assemblage from southern Belgium
Ginter, Michał; Gouwy, Sofie; Goolaerts, Stijn
2017-09-01
Samples from the Upper Frasnian (Devonian) of Lompret Quarry and Nismes railway section in Dinant Synclinorium, southern Belgium, yielded several chondrichthyan teeth and scales. The teeth belong to three genera: Phoebodus, Cladodoides and Protacrodus. The comparison with selected Late Frasnian chondrichthyan assemblages from the seas between Laurussia and Gondwana revealed substantial local differences of taxonomic composition due to palaeoenvironmental conditions, such as depth, distance to submarine platforms, oxygenation of water, and possibly also temperature. The assemblage from Belgium, with its high frequency of phoebodonts, is the most similar to that from the Ryauzyak section, South Urals, Russia, and the Horse Spring section, Canning Basin, Australia.
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Role of riparian shade on the fish assemblage of a reservoir littoral
Raines, C. D.; Miranda, Leandro E.
2016-01-01
Research into the effects of shade on reservoir fish assemblages is lacking, with most investigations focused on streams. Unlike many streams, the canopy in a reservoir shades only a narrow fringe of water adjacent to the shoreline, and may not have the influential effect on the aquatic environment reported in streams. We compared fish assemblages between shaded and unshaded sites in a shallow reservoir. Overall species richness (gamma diversity) was higher in shaded sites, and fish assemblage composition differed between shaded and unshaded sites. Average light intensity was 66 % lower in shaded sites, and differences in average temperature and dissolved oxygen were small. Unlike streams where shade can have large effects on water physicochemistry, in reservoirs shade-related differences in fish assemblages seemed to be linked principally to differences in light intensity. Diversity in light intensity in shaded and unshaded sites in reservoirs can create various mosaics of light-based habitats that enable diversity of species assemblages. Managing to promote the habitat diversity provided by shade may require coping with the artificial nature of reservoir riparian zones and water level fluctuations.
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Jaime-Escalante, Nidia Gissell; Figueroa-Esquivel, Elsa Margarita; Villaseñor Gómez, José Fernando; Jacobo-Sapien, Edwin Alberto; Puebla-Olivares, Fernando
2016-12-01
Elevation gradient studies have strengthened the evaluation of changes in richness and composition of bird assemblages. They also provide information on environmental variables that determine bird distribution, and the variables that define their population structure. Our aim was to describe their variation through an elevational cline in Southern Nayarit, Mexico. To analyze the behavior of richness across the gradient, we gathered information through point counts in nine elevational intervals (300 m from each other) from sea level to 2 700 m of elevation. With a standardized sampling effort, we produced rarefaction curves and analyzed changes in species composition by hierarchical classification using the TWINSPAN technique. In order to identify variables associated with richness changes, we examined the effect of precipitation and habitat structure via regression trees. An analysis of nonmetric multidimensional scaling (NMDS) was implemented with the purpose to determine if the changes in composition correspond to changes in vegetation types. Species richness varied significantly across the gradient: high in the lower parts of the gradient, reached its peak in the middle, and decreased monotonically with elevation. Species responded to changes in the cline and were grouped in three elevational zones. Analyses suggest that changes in richness and species composition are influenced by vegetation, its structure and precipitation regime, as well as various aspects related to habitat features and disturbance. These aspects should be taken into account in order to design appropriate strategies for the conservation of the birds of Nayarit.
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Directory of Open Access Journals (Sweden)
Aurora M. Ricart
2016-11-01
Full Text Available Clipperton Atoll, one of the most isolated coral reefs worldwide, is of great scientific interest due to its geomorphology and high levels of endemism. This study explored the reef fish assemblage structure of Clipperton Atoll and its relationship with live coral cover. Nine stations were sampled at three sites and three depths (6, 12 and 20 m around the reef, measuring fish species richness and biomass and hermatypic coral cover (at genus level. We evaluated variation in species richness, biomass and diversity of fish assemblages among sites and depths, as well as the relationship between the entire fish assemblage composition and live coral cover. The results showed that species richness and biomass were similar among sites, but differed across depths, increasing with depth. In contrast, diversity differed among sites but not among depths. Multivariate analyses indicated that fish assemblage composition differed among sites and depths in relation to changes in cover of coral of the genera Pocillopora, Porites, Pavona and Leptoseris, which dominate at different depths. The results showed that fish species richness and diversity were low at Clipperton Atoll and that, in isolated coral reefs with a low habitat heterogeneity and low human disturbance, live coral cover has a significant influence on the spatial variation of the reef fish assemblages. This study highlights the importance of coral habitat structure in shaping coral reef fish assemblages.
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Patrick, Christopher J; Yuan, Lester L
2017-07-01
Flow alteration is widespread in streams, but current understanding of the effects of differences in flow characteristics on stream biological communities is incomplete. We tested hypotheses about the effect of variation in hydrology on stream communities by using generalized additive models to relate watershed information to the values of different flow metrics at gauged sites. Flow models accounted for 54-80% of the spatial variation in flow metric values among gauged sites. We then used these models to predict flow metrics in 842 ungauged stream sites in the mid-Atlantic United States that were sampled for fish, macroinvertebrates, and environmental covariates. Fish and macroinvertebrate assemblages were characterized in terms of a suite of metrics that quantified aspects of community composition, diversity, and functional traits that were expected to be associated with differences in flow characteristics. We related modeled flow metrics to biological metrics in a series of stressor-response models. Our analyses identified both drying and base flow instability as explaining 30-50% of the observed variability in fish and invertebrate community composition. Variations in community composition were related to variations in the prevalence of dispersal traits in invertebrates and trophic guilds in fish. The results demonstrate that we can use statistical models to predict hydrologic conditions at bioassessment sites, which, in turn, we can use to estimate relationships between flow conditions and biological characteristics. This analysis provides an approach to quantify the effects of spatial variation in flow metrics using readily available biomonitoring data. © 2017 by the Ecological Society of America.
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Mustonen, Kaisa-Riikka; Mykrä, Heikki; Marttila, Hannu; Sarremejane, Romain; Veijalainen, Noora; Sippel, Kalle; Muotka, Timo; Hawkins, Charles P
2018-06-01
Air temperature at the northernmost latitudes is predicted to increase steeply and precipitation to become more variable by the end of the 21st century, resulting in altered thermal and hydrological regimes. We applied five climate scenarios to predict the future (2070-2100) benthic macroinvertebrate assemblages at 239 near-pristine sites across Finland (ca. 1200 km latitudinal span). We used a multitaxon distribution model with air temperature and modeled daily flow as predictors. As expected, projected air temperature increased the most in northernmost Finland. Predicted taxonomic richness also increased the most in northern Finland, congruent with the predicted northwards shift of many species' distributions. Compositional changes were predicted to be high even without changes in richness, suggesting that species replacement may be the main mechanism causing climate-induced changes in macroinvertebrate assemblages. Northern streams were predicted to lose much of the seasonality of their flow regimes, causing potentially marked changes in stream benthic assemblages. Sites with the highest loss of seasonality were predicted to support future assemblages that deviate most in compositional similarity from the present-day assemblages. Macroinvertebrate assemblages were also predicted to change more in headwaters than in larger streams, as headwaters were particularly sensitive to changes in flow patterns. Our results emphasize the importance of focusing protection and mitigation on headwater streams with high-flow seasonality because of their vulnerability to climate change. © 2018 John Wiley & Sons Ltd.
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The scales of variability of stream fish assemblage at tributary confluences
Directory of Open Access Journals (Sweden)
István Czeglédi
2015-12-01
Full Text Available Tributary confluences play an important role in the dispersal of organisms, and consequently, in shaping regional scale diversity in stream networks. Despite their importance in dispersal processes, little is known about how ecological assemblages are organized in these habitats. We studied the scales of variability of stream fish assemblages over three seasons using a hierarchical sampling design, which incorporated three tributaries, three sites at the mouth of each tributary and using four sampling units at each site. We found strong scale dependent variability in species richness, composition and relative abundance. Most of the variation was accounted for by the interactive effect of season, between stream and between site effects, while habitat structure of the sampling units had a relatively minor role. Species richness showed a continuous decrease from the mainstem river in most cases, while species composition and relative abundance changed less consistently along the longitudinal profile. Consequently, we found that not only the junctions presented a strong filter on the species pool, but some species were filtered out if they passed this critical habitat bottleneck. Spatial position of the tributaries along the river also contributed to assemblage variability in the confluences. Overall, our results suggest high variability in fish assemblages across multiple scales at tributary confluences. Environmental management should take a more critical care on the filtering role of tributary confluences in species dispersal, for better understanding patterns and processes in the branches of dendritic stream networks.
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Zhao, D.
2009-05-01
To understand and contrast the origins of ultramafic assemblages from basaltic and kimberlitic rocks and their associated deposits, such as V-Ti magnetite and Ni-Cu-(PGE) sulfide deposits and diamond, applicable thermobarometers were evaluated and applied to the ultramafic assemblages from the Emeishan Large Igneous Province (ELIP), Southwest China and from the Nikos and Zulu Kimberlites of Nunavut, Canada. The ELIP is located in the Yangtze Block, Southwest China and composed of Permian Emeishan Flood basalt (EFB) and associated layered mafic-ultramafic intrusions. Some of these intrusions host V-Ti magnetite deposits; while others contain Ni-Cu-(PGE) sulfide deposits. It is not clear why some intrusions host magnetite deposits and others contain sulfide deposits. The P-T conditions for the ultramafic assemblages from the mafic-ultramafic intrusions in the ELIP were calculated in order to understand the origins and the associated mineral deposits. The ultramafic assemblages are peridotite, olivine pyroxenite, pyroxenite in the layered intrusions and the common minerals include spinel, olivine, clinopyroxene, orthopyroxene, and minor magnetite and ilmenite. Using a two pyroxene thermometer and a Ca-Mg exchange barometer between olivine and clinopyroxene, a spinel-olivine-clinopyroxene-orthopyroxene assemblage from the Xinjie intrusion yields a T-P of 905°C and 17 kbar; and a similar assemblage from the Jinbaoshan intrusion yields a T-P of 1124°C and 31 kbar. The Nikos kimberlite, near Elwin Bay on Somerset Island, is located at the northeast end of the northeast-southwest kimberlite zone; and the Zulu kimberlite is located on the neighboring Brodeur Peninsula of Baffin Island, Nunavut. The ultramafic assemblages from the Canadian Kimberlites include garnet lherzolite, garnet-spinel lherzolite, spinel lherzolite, dunite, garnet websterite, spinel websterite and garnet clinopyroxenite. The calculated P-T conditions are in the range of 760 to 1180°C and 25 to 60
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Koděra, Peter; Kozák, Jaroslav; Brčeková, Jana; Chovan, Martin; Lexa, Jaroslav; Jánošík, Michal; Biroň, Adrián; Uhlík, Peter; Bakos, František
2018-03-01
The Biely Vrch deposit in the Western Carpathians is assigned to the shallow, sulfide-poor porphyry gold deposit type and has an exceptionally low Cu/Au ratio. According to 3-D geochemical models, there is a limited spatial correlation between Au and Cu due to the primary introduction of gold by a salt melt and Cu by low-density vapor. Despite a rough spatial correlation of gold grades with quartz stockwork intensity, gold is hosted mostly by altered rock, exclusively in native form. Three main gold mineral assemblages were recognized here. In the deepest parts of the system, the K- and Ca-Na silicate gold assemblage is associated with minerals of high-temperature alteration (plagioclase, K-feldspar, actinolite), with gold grades and fineness depending on depth and potassium content of the host rock: K-silicate alteration hosts the lowest fineness gold ( 914), whereas Ca-Na silicate alteration has the highest ( 983). The intermediate argillic gold assemblage is the most widespread, with gold hosted mainly by chlorite, illite, smectite, and interstratified illite-chlorite-smectite minerals. The gold fineness is mostly variable (875-990) and inherited from the former gold mineral assemblages. The latest advanced argillic gold assemblage has its gold mostly in kaolinite. The extremely high fineness ( 994) results from gold remobilization by late-stage aqueous magmatic-hydrothermal fluids. Uncommon bonanza-grade appears where the earlier gold mineral assemblages were further enriched by this remobilized gold. Primary precipitation of gold occurred during ascent and cooling of salt melts at 450 to 309 °C, mostly during retrograde quartz solubility.
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Green, R. O.; Realmuto, V. J.; Thompson, D. R.; Mahowald, N. M.; Pérez García-Pando, C.; Miller, R. L.; Clark, R. N.; Swayze, G. A.; Okin, G. S.
2015-12-01
Mineral dust emitted from the Earth's surface is a principal contributor to direct radiative forcing over the arid regions, where shifts in climate have a significant impact on agriculture, precipitation, and desert encroachment around the globe. Dust particles contribute to both positive and negative forcing, depending on the composition of the particles. Particle composition is a function of the surface mineralogy of dust source regions, but poor knowledge of surface mineralogy on regional to global scales limits the skill of Earth System models to predict shifts in regional climate around the globe. Earth System models include the source, emission, transport and deposition phases of the dust cycle. In addition to direct radiative forcing contributions, mineral dust impacts include indirect radiative forcing, modification of the albedo and melting rates of snow and ice, kinetics of tropospheric photochemistry, formation and deposition of acidic aerosols, supply of nutrients to aquatic and terrestrial ecosystems, and impact on human health and safety. We demonstrate the ability to map mineral dust source composition in the Salton Sea dust source region with imaging spectroscopy measurements acquired as part of the NASA HyspIRI preparatory airborne campaign. These new spectroscopically derived compositional measurements provide a six orders of magnitude improvement over current atlases for this dust source region and provide a pathfinder example for a remote measurement approach to address this critical dust composition gap for global Earth System models.
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Diversity and composition of estuarine and lagoonal fish assemblages of Socotra Island, Yemen.
Lavergne, E; Zajonz, U; Krupp, F; Naseeb, F; Aideed, M S
2016-05-01
Estuarine and lagoonal surveys of Socotra Island and selected sites on the Hadhramout coast of Yemen were conducted with the objective of documenting and analysing fish diversity and assemblage structure. A total of 74 species in 35 families were recorded, among which 65 species in 32 families were from Socotra and 20 species in 17 families were from mainland Yemen. Twenty-one species represent new faunal records for Socotra. Including historic records re-examined in this study, the total fish species richness of estuaries and lagoons of Socotra Island reaches 76, which is relatively high compared to species inventories of well-researched coastal estuaries in southern Africa. Five species dominate the occurrence and abundance frequencies: Terapon jarbua, Hyporhamphus sindensis, Aphanius dispar, Ambassis gymnocephala and Chelon macrolepis. Rarefaction and extrapolation analyses suggest that the actual number of fish species inhabiting some of those estuaries might be higher than the one observed. Thus, additional sampling at specific sites should be conducted to record other less conspicuous species. Ordination and multivariate analyses identified four main distinct assemblage clusters. Two groups are geographically well structured and represent northern Socotra and mainland Yemen, respectively. The other two assemblage groups tend to be determined to a greater extent by the synchrony between physical (e.g. estuary opening periods) and biological (e.g. spawning and recruitment periods) variables than by geographical location. Finally, the single intertidal lagoon of Socotra represents by itself a specific fish assemblage. The high proportion of economically important fish species (38) recorded underscores the paramount importance of these coastal water bodies as nursery sites, and for sustaining vital provisioning ecosystem services. © 2016 The Fisheries Society of the British Isles.
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Large-scale spatial distribution patterns of gastropod assemblages in rocky shores.
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Patricia Miloslavich
Full Text Available Gastropod assemblages from nearshore rocky habitats were studied over large spatial scales to (1 describe broad-scale patterns in assemblage composition, including patterns by feeding modes, (2 identify latitudinal pattern of biodiversity, i.e., richness and abundance of gastropods and/or regional hotspots, and (3 identify potential environmental and anthropogenic drivers of these assemblages. Gastropods were sampled from 45 sites distributed within 12 Large Marine Ecosystem regions (LME following the NaGISA (Natural Geography in Shore Areas standard protocol (www.nagisa.coml.org. A total of 393 gastropod taxa from 87 families were collected. Eight of these families (9.2% appeared in four or more different LMEs. Among these, the Littorinidae was the most widely distributed (8 LMEs followed by the Trochidae and the Columbellidae (6 LMEs. In all regions, assemblages were dominated by few species, the most diverse and abundant of which were herbivores. No latitudinal gradients were evident in relation to species richness or densities among sampling sites. Highest diversity was found in the Mediterranean and in the Gulf of Alaska, while highest densities were found at different latitudes and represented by few species within one genus (e.g. Afrolittorina in the Agulhas Current, Littorina in the Scotian Shelf, and Lacuna in the Gulf of Alaska. No significant correlation was found between species composition and environmental variables (r≤0.355, p>0.05. Contributing variables to this low correlation included invasive species, inorganic pollution, SST anomalies, and chlorophyll-a anomalies. Despite data limitations in this study which restrict conclusions in a global context, this work represents the first effort to sample gastropod biodiversity on rocky shores using a standardized protocol across a wide scale. Our results will generate more work to build global databases allowing for large-scale diversity comparisons of rocky intertidal assemblages.
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Directory of Open Access Journals (Sweden)
B. B. Sysuev
2017-01-01
Full Text Available These days Natural mineral salts (biologically active ingredients, which are the components of thermal springs, sea water, brine lakes, minerals (bischofite are widely used in the composition of cosmetic products. The ability to influence the formulations stability and the sensory properties of cosmetics products is the specificity of this materials group, which creates certain difficulties in the development of a composition. The polymers’ use as gelling agents and thickeners is one of the means of formulations stability improving.The aim was scientific and technical literature review of the polymers assortment used in cosmetics with natural mineral salts, their application in the cosmetic compositions and the influence of mineral salts on the properties of polymers solutions.Materials and methods. Resources such as eLIBRARY, PubMed, Cyberleninca, as well as the websites of the manufacturers and suppliers of auxiliary materials, and finished cosmetic products were used to obtain the data.Results and discussion. Analysis of literature data and technical information suggests that cellulose derivatives, xanthan gum, and polyvinylpyrrolidone and carbomer are the most commonly used polymers in cosmetic compositions with natural mineral salts. These substances carry out functions of gelling agents, stabilizers, emulsifiers, binders, sensorial modifier agents. There is insufficient information about the interaction of polymers with the natural mineral salts and their influence on polymers properties in scientific and technical literature. The complexity and uniqueness of the composition of natural salts also represents certain difficulty in the evaluation of the interaction.Conclusion. Thus, regularities and peculiarities of natural mineral salts influence on the stability of solutions of polymers used in cosmetics as thickeners and gelling agents, is a promising direction of modern pharmaceutical practices study.
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Hitt, Nathaniel P.; Chambers, Douglas B.
2014-01-01
Mountaintop mining (MTM) affects chemical, physical, and hydrological properties of receiving streams, but the long-term consequences for fish-assemblage structure and function are poorly understood. We sampled stream fish assemblages using electrofishing techniques in MTM exposure sites and reference sites within the Guyandotte River basin, USA, during 2010–2011. We calculated indices of taxonomic diversity (species richness, abundance, Shannon diversity) and functional diversity (functional richness, functional evenness, functional divergence) to compare exposure and reference assemblages between seasons (spring and autumn) and across years (1999–2011). We based temporal comparisons on 2 sites that were sampled during 1999–2001 by Stauffer and Ferreri (2002). Exposure assemblages had lower taxonomic and functional diversity than reference assemblages or simulated assemblages that accounted for random variation. Differences in taxonomic composition between reference and exposure assemblages were associated with conductivity and aqueous Se concentrations. Exposure assemblages had fewer species, lower abundances, and less biomass than reference assemblages across years and seasons. Green Sunfish (Lepomis cyanellus) and Creek Chub (Semotilus atromaculatus) became numerically dominant in exposure assemblages over time because of their persistence and losses of other taxa. In contrast, species richness increased over time in reference assemblages, a result that may indicate recovery from drought. Mean individual biomass increased as fish density decreased and most obligate invertivores were apparently extirpated at MTM exposure sites. Effects of MTM were not related to physical-habitat conditions but were associated with water-quality variables, which may limit quality and availability of benthic macroinvertebrate prey. Simulations revealed effects of MTM that could not be attributed to random variation in fish assemblage structure.
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Leticia M. Mesa
2013-12-01
Full Text Available The nature of the riparian and surrounding landscape has been modified by anthropogenic activities, which may subsequently alter the composition and functional structure of macroinvertebrate assemblages. The effect of these changes on function of benthic fauna is difficult to assess due to the scarce knowledge on functional structures in tropical streams. In this study we evaluate whether sites impacted and unimpacted by anthropogenic alterations differed in assemblage composition and density, richness and diversity of each functional feeding group. The selection of the sites was related to their distinct riparian characteristics, following the QBRy riparian quality index. Collector-gatherer was the dominant functional feeding group, comprising 91% of total density, whereas the proportion of shredders was very low, representing less of 0.5% of total density. Asemblage composition of macroinvertebrates differed between impacted and unimpacted sites. Predators were dominant in taxa number, representing about 60% of total taxa richness. In addition, the diversity and richness of collector-gatherers differed significantly between degraded and unimpacted sites, reflecting the sensitivity of this group to environmental changes and the utility to be used in the assessment of anthropogenic modifications. The results of this study reinforce the idea that riparian corridor management is critical for the distribution of macroinvertebrate assemblages as well as functional organization of lotic streams.
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Fish assemblages in borrow-pit lakes of the Lower Mississippi River
Miranda, Leandro E.; Killgore, K. J.; Hoover, J.J.
2013-01-01
Borrow-pit lakes encompass about a third of the lentic water habitats (by area) in the active floodplain of the Lower Mississippi River, yet little is known about their fish assemblages. We investigated whether fish assemblages supported by borrow-pit lakes resembled those in oxbow lakes to help place the ecological relevance of borrow-pit lakes in context with that of natural floodplain lakes. In all, we collected 75 fish species, including 65 species in eight borrow-pit lakes, 52 species in four riverside oxbow lakes, and 44 species in eight landside oxbow lakes. Significant differences in several species richness metrics were evident between borrow-pit lakes and landside oxbow lakes but not between borrow-pit lakes and riverside oxbow lakes. All three lake types differed in fish assemblage composition. Borrow-pit lakes and riverside oxbow lakes tended to include a greater representation of fish species that require access to diverse environments, including lentic, lotic, and palustrine habitats; fish assemblages in landside oxbow lakes included a higher representation of lacustrine species. None of the fish species collected in borrow-pit lakes was federally listed as threatened or endangered, but several were listed as species of special concern by state governments in the region, suggesting that borrow-pit lakes provide habitat for sensitive riverine and wetland fish species. Differences in fish assemblages among borrow-pit lakes were linked to engineered morphologic features, suggesting that diversity in engineering can contribute to diversity in fish assemblages; however, more research is needed to match engineering designs with fish assemblage structures that best meet conservation needs.
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Relationships between structural complexity, coral traits, and reef fish assemblages
Darling, Emily S.; Graham, Nicholas A. J.; Januchowski-Hartley, Fraser A.; Nash, Kirsty L.; Pratchett, Morgan S.; Wilson, Shaun K.
2017-06-01
With the ongoing loss of coral cover and the associated flattening of reef architecture, understanding the links between coral habitat and reef fishes is of critical importance. Here, we investigate whether considering coral traits and functional diversity provides new insights into the relationship between structural complexity and reef fish communities, and whether coral traits and community composition can predict structural complexity. Across 157 sites in Seychelles, Maldives, the Chagos Archipelago, and Australia's Great Barrier Reef, we find that structural complexity and reef zone are the strongest and most consistent predictors of reef fish abundance, biomass, species richness, and trophic structure. However, coral traits, diversity, and life histories provided additional predictive power for models of reef fish assemblages, and were key drivers of structural complexity. Our findings highlight that reef complexity relies on living corals—with different traits and life histories—continuing to build carbonate skeletons, and that these nuanced relationships between coral assemblages and habitat complexity can affect the structure of reef fish assemblages. Seascape-level estimates of structural complexity are rapid and cost effective with important implications for the structure and function of fish assemblages, and should be incorporated into monitoring programs.
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Mars weathering analogs - Secondary mineralization in Antarctic basalts
Berkley, J. L.
1982-01-01
Alkalic basalt samples from Ross Island, Antarctica, are evaluated as terrestrial analogs to weathered surface materials on Mars. Secondary alteration in the rocks is limited to pneumatolytic oxidation of igneous minerals and glass, rare groundmass clay and zeolite mineralization, and hydrothermal minerals coating fractures and vesicle surfaces. Hydrothermal mineral assemblages consist mainly of K-feldspar, zeolites (phillipsite and chabazite), calcite, and anhydrite. Low alteration rates are attributed to cold and dry environmental factors common to both Antarctica and Mars. It is noted that mechanical weathering (aeolian abrasion) of Martian equivalents to present Antarctic basalts would yield minor hydrothermal minerals and local surface fines composed of primary igneous minerals and glass but would produce few hydrous products, such as palagonite, clay or micas. It is thought that leaching of hydrothermal vein minerals by migrating fluids and redeposition in duricrust deposits may represent an alternate process for incorporating secondary minerals of volcanic origin into Martian surface fines.
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Spatial and seasonal variations of fish assemblages in mangrove creek systems in Zanzibar (Tanzania)
Mwandya, Augustine W.; Gullström, Martin; Andersson, Mathias H.; Öhman, Marcus C.; Mgaya, Yunus D.; Bryceson, Ian
2010-11-01
Spatial and seasonal variations of fish assemblage composition were studied in three non-estuarine mangrove creeks of Zanzibar (Tanzania). Fish were collected monthly for one year at three sites (lower, intermediate and upper reaches) in each creek using a seine net (each haul covering 170 m 2). Density, species number and diversity of fish were all higher at sites with dense cover of macrophytes (seagrass and macroalgae) than over unvegetated sandy sites. In general, fish assemblages mainly comprised juveniles of a few abundant taxa, e.g. Mugil cephalus, Mugilidae spp. and Leiognathus equulus at sites with mud substratum and Gerres oyena, Lethrinus harak and Sillago sihama at sites dominated by macrophytes. Multivariate analyses revealed significant separations in fish assemblage composition within the two creeks where the bottom substratum differed among sites. Overall, season seemed to have little effect on density, species number, diversity index ( H') and assemblage structure of fish. Water condition variables were also relatively stable across the season, although a short-term fluctuation primarily induced by decreased salinity, occurred during the heavy rains in April and May. Fish assemblage structure was not significantly affected by any of the abiotic factors tested. However, significant regressions were found between the other fish variables and environmental variables, but since these associations were mostly species-specific and generally inconsistent, we suggest that the overall distribution patterns of fish were mainly an effect of particular substrate preferences of fish species rather than contemporary water conditions.
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Microbial composition of biofilms associated with lithifying rubble of Acropora palmata branches.
Beltrán, Yislem; Cerqueda-García, Daniel; Taş, Neslihan; Thomé, Patricia E; Iglesias-Prieto, Roberto; Falcón, Luisa I
2016-01-01
Coral reefs are among the most productive ecosystems on the planet, but are rapidly declining due to global-warming-mediated changes in the oceans. Particularly for the Caribbean region, Acropora sp. stony corals have lost ∼80% of their original coverage, resulting in vast extensions of dead coral rubble. We analyzed the microbial composition of biofilms that colonize and lithify dead Acropora palmata rubble in the Mexican Caribbean and identified the microbial assemblages that can persist under scenarios of global change, including high temperature and low pH. Lithifying biofilms have a mineral composition that includes aragonite and magnesium calcite (16 mole% MgCO(3)) and calcite, while the mineral phase corresponding to coral skeleton is basically aragonite. Microbial composition of the lithifying biofilms are different in comparison to surrounding biotopes, including a microbial mat, water column, sediments and live A. palmata microbiome. Significant shifts in biofilm composition were detected in samples incubated in mesocosms. The combined effect of low pH and increased temperature showed a strong effect after two-week incubations for biofilm composition. Findings suggest that lithifying biofilms could remain as a secondary structure on reef rubble possibly impacting the functional role of coral reefs. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
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Taxonomic and Phylogenetic Determinants of Functional Composition of Bolivian Bat Assemblages.
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Luis F Aguirre
Full Text Available Understanding diversity patterns and the potential mechanisms driving them is a fundamental goal in ecology. Examination of different dimensions of biodiversity can provide insights into the relative importance of different processes acting upon biotas to shape communities. Unfortunately, patterns of diversity are still poorly understood in hyper-diverse tropical countries. Here, we assess spatial variation of taxonomic, functional and phylogenetic diversity of bat assemblages in one of the least studied Neotropical countries, Bolivia, and determine whether changes in biodiversity are explained by the replacement of species or functional groups, or by differences in richness (i.e., gain or loss of species or functional groups. Further, we evaluate the contribution of phylogenetic and taxonomic changes in the resulting patterns of functional diversity of bats. Using well-sampled assemblages from published studies we examine noctilionoid bats at ten study sites across five ecoregions in Bolivia. Bat assemblages differed from each other in all dimensions of biodiversity considered; however, diversity patterns for each dimension were likely structured by different mechanisms. Within ecoregions, differences were largely explained by species richness, suggesting that the gain or loss of species or functional groups (as opposed to replacement was driving dissimilarity patterns. Overall, our results suggest that whereas evolutionary processes (i.e., historical connection and dispersal routes across Bolivia create a template of diversity patterns across the country, ecological mechanisms modify these templates, decoupling the observed patterns of functional, taxonomic and phylogenetic diversity in Bolivian bats. Our results suggests that elevation represents an important source of variability among diversity patterns for each dimension of diversity considered. Further, we found that neither phylogenetic nor taxonomic diversity can fully account for
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Taxonomic and Phylogenetic Determinants of Functional Composition of Bolivian Bat Assemblages.
Aguirre, Luis F; Montaño-Centellas, Flavia A; Gavilanez, M Mercedes; Stevens, Richard D
2016-01-01
Understanding diversity patterns and the potential mechanisms driving them is a fundamental goal in ecology. Examination of different dimensions of biodiversity can provide insights into the relative importance of different processes acting upon biotas to shape communities. Unfortunately, patterns of diversity are still poorly understood in hyper-diverse tropical countries. Here, we assess spatial variation of taxonomic, functional and phylogenetic diversity of bat assemblages in one of the least studied Neotropical countries, Bolivia, and determine whether changes in biodiversity are explained by the replacement of species or functional groups, or by differences in richness (i.e., gain or loss of species or functional groups). Further, we evaluate the contribution of phylogenetic and taxonomic changes in the resulting patterns of functional diversity of bats. Using well-sampled assemblages from published studies we examine noctilionoid bats at ten study sites across five ecoregions in Bolivia. Bat assemblages differed from each other in all dimensions of biodiversity considered; however, diversity patterns for each dimension were likely structured by different mechanisms. Within ecoregions, differences were largely explained by species richness, suggesting that the gain or loss of species or functional groups (as opposed to replacement) was driving dissimilarity patterns. Overall, our results suggest that whereas evolutionary processes (i.e., historical connection and dispersal routes across Bolivia) create a template of diversity patterns across the country, ecological mechanisms modify these templates, decoupling the observed patterns of functional, taxonomic and phylogenetic diversity in Bolivian bats. Our results suggests that elevation represents an important source of variability among diversity patterns for each dimension of diversity considered. Further, we found that neither phylogenetic nor taxonomic diversity can fully account for patterns of functional
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Vilisics, Ferenc; Bogyó, Dávid; Sattler, Thomas; Moretti, Marco
2012-01-01
Terrestrial isopods and millipedes, members of the invertebrate macro-decomposer guild, were collected through pitfall traps in three Swiss cities (Zurich, Lucerne, Lugano). A total of 7,198 individuals of 17 isopod species (7093 ind.), and 10 millipede species (105 ind.) were captured. Besides the Alpine endemic isopod (Trichoniscus alemannicus) and millipede (Cylindroiulus verhoeffi), urban assemblages were mainly composed of widespread, native European and even cosmopolitan species, which are frequent in anthropogenic areas. Overall species richness (isopods and millipedes combined) was similar in Zurich (17 species) and Lucerne (16), while only 13 species were sampled in Lugano. According to the Sørensen index of similarity, species composition of Zurich and Lucerne were more alike, while the one of Lugano was more distinct from the other two cities. This result can be explained by the spatial proximity of Zurich and Lucerne in the north of the Alps compared to Lugano, which is located more distantly and in the south of the Alps. Dominant isopods and millipedes in Zurich and Lucerne were found to be widespread synanthropic species in temperate Europe(Porcellio scaber, Trachelipus rathkii and Ophyiulus pilosus) while the dominant isopod in Lugano (Trachelipus razzautii) is a species with a north-eastern Mediterranean distribution. Our study reveals that the urban millipede and isopod fauna in Swiss cities mainly consists of widespread species, but species of narrower distribution (e.g. Trichoniscus alemannicus, Cylindroiulus verhoeffi) may also find suitable habitats in cities. Despite some signs of biotic homogenization, our study also found compositional differences of millipede and isopod assemblages between northern and southern cities that suggest geographical effects of the regional species pool.
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Wood, Jennifer A; Knights, Edmund J; Campbell, Grant M; Choct, Mingan
2014-05-01
Part I introduced the concept of easy- and difficult-to-mill chickpea genotypes, the broad chemical composition of their seed fractions and proposed mechanistic explanations for physical differences consistent with observed variation in milling ease. Part II continues this research by delving deeper into the amino acid, fatty acid and mineral components. No association between fatty acid composition and ease of milling was observed. However, particular amino acids and mineral elements were identified that further support roles of lectins, pectins and mineral-facilitated binding in the adhesion of chickpea seed coat and cotyledons. These differences suggest underlying mechanisms that could be exploited by breeding programmes to improve milling performance. This study shows that the content and composition of amino acids, fatty acids and minerals within different chickpea tissues vary with seed type (desi and kabuli) and within desi genotypes in ways that are consistent with physical explanations of how seed structure and properties relate to milling behaviour. © 2013 Society of Chemical Industry.
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Oyeyemi Adigun DADA
2010-12-01
Full Text Available The effect of defoliation on mineral and food value of two cassava varieties defoliated at varying phenological phases was studied to ascertain the appropriate phenological phase when harvested leaves would contain the optimum mineral and proximate composition, gross energy and the least cyanide content. Two cassava cultivars were subjected to defoliation at varying phenological stages including logarithmic, vegetative and physiological maturity phases. The mineral content was highest at the logarithmic phase than any other phases. The proximate composition of the cassava leaves showed that crude protein was highest at physiological maturity, while the least HCN was observed in cassava defoliated at logarithmic phase. Analysis of mineral and proximate content showed that leaf of the �TMS30572� cultivar had the highest mineral content, fat, fibre, ash, dry matter and gross energy at the logarithm phase while �Oko-Iyawo� had the highest crude protein and HCN at physiological maturity. This study indicates the high potential of cassava leaf as an unconventional source of protein for both humans and animals when defoliated at logarithmic growth phase.
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Magnetic minerals in soils across the forest-prairie ecotone in NW Minnesota
Maxbauer, D.; Feinberg, J. M.; Fox, D. L.; Nater, E. A.
2016-12-01
Soil pedogenesis results in a complex assemblage of iron oxide minerals that can be disentangled successfully using sensitive magnetic techniques to better delineate specific soil processes. Here, we evaluate the variability in soil processes within forest, prairie, and transitional soils along an 11 km transect of anthropogenically unaltered soils that span the forest-to-prairie ecotone in NW Minnesota. All soils in this study developed on relatively uniform topography, similar glacial till parent material, under a uniform climate, and presumably over similar time intervals. The forest-to-prairie transition zone in this region is controlled by naturally occurring fires, affording the opportunity to evaluate differences in soil processes related to vegetation (forest versus prairie) and burning (prairie and transitional soils). Results suggest that the pedeogenic fraction of magnetite/maghemite in soils is similar in all specimens and is independent of soil type, vegetation, and any effects of burning. Magnetically enhanced horizons have 45% of remanence held by a low-coercivity pedogenic component (likely magnetite/maghemite) regardless of vegetation cover and soil type. Enhancement ratios for magnetic susceptibility and low-field remanences, often used as indicators of pedogenic magnetic minerals, are more variable but remain statistically equivalent across the transect. These results support the hypothesis that pedogenic magnetic minerals in soils mostly reflect ambient climatic conditions regardless of the variability in soil processes related to vegetation and soil type. The non-pedogenic magnetic mineral assemblage shows clear distinctions between the forest, prairie, and transitional soils in hysteresis properties (remanence and coercivity ratios; Mr/Ms and Bc/Bcr, respectively), suggesting that variable processes in these settings influence the local magnetic mineral assemblage, and that it may be possible to use magnetic minerals in paleosols to constrain
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Natural calcium isotonic composition of urine as a marker of bone mineral balance
Skulan, J.; Bullen, T.; Anbar, A.D.; Puzas, J.E.; Shackelford, L.; LeBlanc, A.; Smith, S.M.
2007-01-01
Background: We investigated whether changes in the natural isotopic composition of calcium in human urine track changes in net bone mineral balance, as predicted by a model of calcium isotopic behavior in vertebrates. If so, isotopic analysis of natural urine or blood calcium could be used to monitor short-term changes in bone mineral balance that cannot be detected with other techniques. Methods: Calcium isotopic compositions are expressed as ??44Ca, or the difference in parts per thousand between the 44Ca/40Ca of a sample and the 44Ca/ 40Ca of a standard reference material. ??44Ca was measured in urine samples from 10 persons who participated in a study of the effectiveness of countermeasures to bone loss in spaceflight, in which 17 weeks of bed rest was used to induce bone loss. Study participants were assigned to 1 of 3 treatment groups: controls received no treatment, one treatment group received alendronate, and another group performed resistive exercise. Measurements were made on urine samples collected before, at 2 or 3 points during, and after bed rest. Results: Urine ??44Ca values during bed rest were lower in controls than in individuals treated with alendronate (P bone mineral density data. Conclusion: Results confirm the predicted relationship between bone mineral balance and calcium isotopes, suggesting that calcium isotopic analysis of urine might be refined into a clinical and research tool. ?? 2007 American Association for Clinical Chemistry.
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Harbi, Hesham M.; Ali, Kamal A.; McNaughton, Neal J.; Andresen, Arild
2018-04-01
The Sukhaybarat East and Red Hill deposits, in the northeastern part of the Arabian Shield, are mesothermal vein-type gold deposits hosted by late Cryogenian-Ediacaran intrusive rocks of the Idah suites (diorite, tonalite, granodiorite) and, at Sukhaybarat East, also by Ediacaran metasedimentary rocks. Gold mineralization comprises quartz-arsenopyrite veins (Sukhaybarat East), quartz-carbonate-pyrite veins (Red Hill), and subordinate gold-base metal sulfide veins. In the Red Hill deposit, alteration is complicated due to multiple overprinting hydrothermal events and is characteristically affected by pervasive, pink quartz-K-feldspar-hematite alteration which is overprinted by potassic alteration characterized by a quartz-biotite-carbonate-muscovite/sericite-rutile-apatite assemblage. This assemblage is associated with molybdenite veins which appear to form late in the paragenetic sequence and may represent either evolution of the ore fluid composition, or a later, unrelated mineralized fluids. Hydrothermal alteration at the Sukhaybarat East deposit is dominated by quartz-carbonate-sericite-arsenopyrite assemblages. Zircon from ore-hosting tonalite at Sukhaybarat East yields a U-Pb age of 629 ± 6 Ma, and biotite from the same rock gives an 40Ar/39Ar age of 622 ± 23 Ma. The 40Ar/39Ar age is within the uncertainty range for the U-Pb age of the host intrusion and is interpreted as a minimally disturbed cooling age for the tonalite. In the Red Hill area, granodiorite was emplaced at 615 ± 5 Ma, whereas muscovite/sericite separated from a mineralized sample of a quartz-carbonate-pyrite vein, that was overprinted by molybdenite-bearing veinlets, yields an 40Ar/39Ar age of 597 ± 8 Ma. We interpreted this age to represent the maximum age of the molybdenite mineralization and the probable minimum age of gold mineralization in the Red Hill deposit.
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Diel variation in the structure of fish assemblages in south western Amazon streams
Directory of Open Access Journals (Sweden)
Igor David da Costa
Full Text Available Abstract: Aim We investigate the influence of luminosity, habitat conservation and pluviometric periods in fish assemblages of in pasture and forest small streams in western amazon. Methods Sampling was conducted every two months from July 2013 to April 2014 in nine first- and second-order streams using seine nets and dip nets during the day and night. Fish composition, richness and total abundance were determined for each sampling period. The PERMANOVA was used to evaluate the effects of land use, season, and photoperiod, on fish assemblages. Fish assemblage structure for each stream in the presence and absence of photoperiod was ordered by NMDS analysis. Results In the light period, 3,484 specimens from 69 species were collected, while 4,574 specimens from 71 species where collected in the dark period. No significant differences in abundance and species richness were recorded between the presence and absence of luminosity periods, rainy and dry seasons and streams in forest and deforested areas. We found evidence of the dark phase composition and richness of exclusive species (22% of species collected were found at night, which were greater than in the light period (20% of species. Conclusion Despite our failure to identify any nycterohemeral segregation, the results complement existing knowledge of regional ichthyofauna and help provide a better understanding of the distributional, behavioral and functional ecological patterns of fish assemblages.
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Short-term responses of reptile assemblages to fire in native and weedy tropical savannah
Directory of Open Access Journals (Sweden)
Rickard Abom
2016-04-01
Full Text Available Fire is frequently used as a management tool to reduce the cover of weeds, to reduce the amount of fuel available for future fires, and to create succession mosaics that may enhance biodiversity. We determined the influence of fire on wildlife, by quantifying reptile assemblage composition in response to fire in a weedy environment characterised by very short-term fire return intervals (<2 years. We used reptiles because they are often understudied, and are only moderately vagile compared to other vertebrates, and they respond strongly to changes in vegetation structure. We repeatedly sampled 24 replicate sampling sites after they had been unburned for two years, just prior to burning (pre-burnt, just after burning (post-burnt, and up to 15 months after burning (revegetated and monitored vegetation structure and reptile richness, abundance and assemblage composition. Our sites were not spatially auto-correlated, and were covered by native kangaroo grass (Themeda triandra, black spear grass (Heteropogon contortus, or an invasive weed (grader grass, Themeda quadrivalvis. Reptile abundance and richness were highest when sites had been unburned for 2 years, and greatly reduced in all areas post burning. The lowest reptile abundances occurred in sites dominated by the weed. Reptile abundance and richness had recovered in all grass types 15 months after burning, but assemblage composition changed. Some species were present only in before our focus fire in native grass, and their populations did not recover even 15 months post-burning. Even in fire-prone, often-burnt habitats such as our study sites, in which faunal richness and abundance were not strongly influenced by fire, reptile assemblage composition was altered. To maintain faunal biodiversity in fire-prone systems, we suggest reducing the frequency of prescribed fires, and (if possible excluding fire from weedy invasions if it allows native grasses to return.
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Habitat specialization in tropical continental shelf demersal fish assemblages.
Directory of Open Access Journals (Sweden)
Ben M Fitzpatrick
Full Text Available The implications of shallow water impacts such as fishing and climate change on fish assemblages are generally considered in isolation from the distribution and abundance of these fish assemblages in adjacent deeper waters. We investigate the abundance and length of demersal fish assemblages across a section of tropical continental shelf at Ningaloo Reef, Western Australia, to identify fish and fish habitat relationships across steep gradients in depth and in different benthic habitat types. The assemblage composition of demersal fish were assessed from baited remote underwater stereo-video samples (n = 304 collected from 16 depth and habitat combinations. Samples were collected across a depth range poorly represented in the literature from the fringing reef lagoon (1-10 m depth, down the fore reef slope to the reef base (10-30 m depth then across the adjacent continental shelf (30-110 m depth. Multivariate analyses showed that there were distinctive fish assemblages and different sized fish were associated with each habitat/depth category. Species richness, MaxN and diversity declined with depth, while average length and trophic level increased. The assemblage structure, diversity, size and trophic structure of demersal fishes changes from shallow inshore habitats to deeper water habitats. More habitat specialists (unique species per habitat/depth category were associated with the reef slope and reef base than other habitats, but offshore sponge-dominated habitats and inshore coral-dominated reef also supported unique species. This suggests that marine protected areas in shallow coral-dominated reef habitats may not adequately protect those species whose depth distribution extends beyond shallow habitats, or other significant elements of demersal fish biodiversity. The ontogenetic habitat partitioning which is characteristic of many species, suggests that to maintain entire species life histories it is necessary to protect corridors of
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Bottom fish assemblages at the shelf and continental slope off East Greenland
DEFF Research Database (Denmark)
Jørgensen, Ole A; Hvingel, Carsten; Møller, P.R.
2015-01-01
During 2006 and 2008 two bottom trawl surveys were conducted at East Greenland to 72°N covering depths down to 1500 m. In the 149 trawl hauls in total 113 fish species were recorded of which 37 were considered pelagic and excluded from the analyses. As a first step the abundance data for the 76...... benthic species were used for analyses of the fish fauna diversity and fish assemblages. Nine assemblages were found by a standard type of cluster analysis. A Bayesian multinomial logit model was then applied to calculate vectors of probabilities defining the likelihood of each haul belonging to each...... distribution, species composition, temperature and depth. Three of the assemblages were located in the cold Iceland Sea while six were found in the somewhat warmer Irminger Sea...
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Li, Zengguang; Ye, Zhenjiang; Wan, Rong
2015-12-01
Surveys were conducted in five voyages in Haizhou Bay and its adjacent coastal area from March to December 2011 during full moon spring tides. The ichthyoplankton assemblages and the environmental factors that affect their spatial and seasonal patterns were determined. Totally 35 and 12 fish egg and larvae taxa were identified, respectively. Over the past several decades, the egg and larval species composition has significantly changed in Haizhou Bay and its adjacent waters, most likely corresponding with the alteration of fishery resources, which are strongly affected by anthropogenic activities and climate change. The Bray-Curtis dissimilarity index identified four assemblages: near-shore bay assemblage, middle bay assemblage and two closely related assemblages (near-shore/middle bay assemblage and middle/edge of bay assemblage). The primary species of each assemblage principally reflected the spawning strategies of adult fish. The near-shore bay assemblage generally occurred in near-shore bay, with depths measuring ichthyoplankton in each assemblage were determined by interactions between biological behavioral traits and oceanographic features, particularly the variation of local conditions within the constraint of a general reproductive strategy. The results of Spearman's rank correlation analysis indicated that both fish egg and larval abundance were positively correlated with depth, which is critical to the oceanographic features in Haizhou Bay.
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International Nuclear Information System (INIS)
Gaboreau, St.
2005-01-01
Aluminium phosphate sulfate minerals (APS) are particularly widespread and spatially associated with hydrothermal clay alteration in both the East Alligator River Uranium Field (Northern Territory, Australia) and the Athabasca basin (Saskatchewan, Canada), in the environment of proterozoic unconformity-related uranium deposits (URUD). The purpose of this study is both: 1) to characterize the nature and the origin of the APS minerals on both sides of the middle proterozoic unconformity between the overlying sandstones and the underlying metamorphic basement rocks that host the uranium ore bodies, 2) to improve our knowledge on the suitability of these minerals to indicate the paleo-conditions (redox, pH) at which the alteration processes relative to the uranium deposition operated. The APS minerals result from the interaction of oxidising and relatively acidic fluids with aluminous host rocks enriched in monazite. Several APS-bearing clay assemblages and APS crystal-chemistry have also been distinguished as a function of the distance from the uranium ore bodies or from the structural discontinuities which drained the hydrothermal solutions during the mineralisation event. One of the main results of this study is that the index mineral assemblages, used in the recent literature to describe the alteration zones around the uranium ore bodies, can be theoretically predicted by a set of thermodynamic calculations which simulate different steps of fluid-rock interaction processes related to a downward penetrating of hyper-saline, oxidizing and acidic diagenetic fluids through the lower sandstone units of the basins and then into the metamorphic basement rocks. The above considerations and the fact that APS with different crystal-chemical compositions crystallized in a range of fO 2 and pH at which uranium can either be transported in solution or precipitated as uraninite in the host-rocks make these minerals not only good markers of the degree of alteration of the
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International Nuclear Information System (INIS)
Singh, M.P.; Erickson, J.E.; Sollenberger, L.E.; Woodard, K.R.; Vendramini, J.M.B.; Fedenko, J.R.
2012-01-01
Biomass yield and tissue mineral composition can affect total energy yield potential, conversion efficiencies and environmental impacts, but relatively few data are available for sweet sorghum [Sorghum bicolor (L.) Moench] grown in the southeastern USA. Therefore, a study was conducted at two locations in North and Central Florida on marginal sand soils comparing the effects of planting date (PD) on dry biomass yield and mineral composition of leaf, stem, and grain heads for ‘M-81E’ and ‘Dale’ sweet sorghum cultivars. Overall tissue mineral concentrations were relatively low for sweet sorghum, attributable to low K and Ca concentrations. Ash and mineral concentrations were generally greater for Dale, especially for the early PD. Leaf and grain heads were greater in mineral concentrations compared to stems. Dry biomass yield averaged 19.4 Mg ha −1 and was greater for M-81E and the early PD. Stems accounted for 73% of the total biomass compared to leaves (13%) across all treatments. Total N, P, and K removals averaged 136, 27.6, and 81.4 kg ha −1 , respectively. Overall, leaves removed 30, 23, and 19% of total N, P, and K compared to 34, 34, and 61% by stem, respectively. Considering lower biomass but greater mineral concentrations in leaf and grain heads compared to stems, returning leaf residues and possibly grain heads to the soil have the potential to offset nutrient and energy inputs needed on these marginal soils and enhance the sustainability of sweet sorghum cropping systems.
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Czech Academy of Sciences Publication Activity Database
Martinec, Petr; Plasgura, P.; Machat, J.; Staněk, F.
2011-01-01
Roč. 10, č. 7 (2011), s. 462-462 ISSN 1569-9056. [EULIS 2011. London, 07.09.2011-10.09.2011] R&D Projects: GA ČR(CZ) GA203/09/1394 Institutional research plan: CEZ:AV0Z30860518 Keywords : urinary calculi * mineral association * chemical composition and trace elements Subject RIV: DD - Geochemistry Impact factor: 1.827, year: 2011 http://www.europeanurology.com/article/S1569-9056%2811%2961151-2/pdf/E03+Mineral+association,+composition+and+trace+elements+in+urinary+calculi+in+Ostrava+region+patients+from+1978+to+2010
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Examining shifts in Carabidae assemblages across a forest-agriculture ecotone.
Leslie, T W; Biddinger, D J; Rohr, J R; Hulting, A G; Mortensen, D A; Fleischer, S J
2014-02-01
Northeastern U.S. farms are often situated adjacent to forestland due to the heterogeneous nature of the landscape. We investigated how forested areas influence Carabidae diversity within nearby crop fields by establishing transects of pitfall traps. Trapping extended across a forest-agriculture ecotone consisting of maize, an intermediate mowed grass margin, and a forest edge. Carabidae diversity was compared among the three habitats, and community and population dynamics were assessed along the transect. We used a principal response curve to examine and visualize community change across a spatial gradient. The highest levels of richness and evenness were observed in the forest community, and carabid assemblages shifted significantly across the ecotone, especially at the forest-grass interface. Despite strong ecotone effects, population distributions showed that some species were found in all three habitats and seemed to thrive at the ecotone. Based on similarity indices, carabid assemblages collected in maize adjacent to forest differed from carabid assemblages in maize not adjacent to forest. We conclude that forest carabid assemblages exhibit high degrees of dissimilarity with those found in agricultural fields and forested areas should thus be retained in agricultural landscapes to increase biodiversity at the landscape scale. However, ecotone species found at forest edges can still noticeably influence carabid community composition within neighboring agricultural fields. Further studies should determine how these shifts in carabid assemblages influence agroecosystem services in relation to ecosystem services observed in fields embedded in an agricultural matrix.
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Performance of ground-penetrating radar on granitic regoliths with different mineral composition
Breiner, J.M.; Doolittle, James A.; Horton, Radley M.; Graham, R.C.
2011-01-01
Although ground-penetrating radar (GPR) is extensively used to characterize the regolith, few studies have addressed the effects of chemical and mineralogical compositions of soils and bedrock on its performance. This investigation evaluated the performance of GPR on two different granitic regoliths of somewhat different mineralogical composition in the San Jacinto Mountains of southern California. Radar records collected at a site where soils are Alfisols were more depth restricted than the radar record obtained at a site where soils are Entisols. Although the Alfisols contain an argillic horizon, and the Entisols have no such horizon of clay accumulation, the main impact on GPR effectiveness is related to mineralogy. The bedrock at the Alfisol site, which contains more mafic minerals (5% hornblende and 20% biotite), is more attenuating to GPR than the bedrock at the Entisol site, where mafic mineral content is less (<1% hornblende and 10% biotite). Thus, a relatively minor variation in bedrock mineralogy, specifically the increased biotite content, severely restricts the performance of GPR. Copyright ?? 2011 by Lippincott Williams & Wilkins.
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Treydte, A.C.; Baumgartner, S.; Heitkonig, I.M.A.; Grant, C.C.; Getz, W.M.
2013-01-01
Herbivores generally have strong structural and compositional effects on vegetation, which in turn determines the plant forage species available. We investigated how selected large mammalian herbivore assemblages use and alter herbaceous vegetation structure and composition in a southern African
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Landete-Castillejos, T; Currey, J D; Ceacero, F; García, A J; Gallego, L; Gomez, S
2012-01-01
It is well known that porosity has an inverse relationship with the mechanical properties of bones. We examined cortical and trabecular porosity of antlers, and mineral composition, thickness and mechanical properties in the cortical wall. Samples belonged to two deer populations: a captive population of an experimental farm having a high quality diet, and a free-ranging population feeding on plants of lower nutritive quality. As shown for minerals and mechanical properties in previous studies by our group, cortical and trabecular porosity increased from the base distally. Cortical porosity was always caused by the presence of incomplete primary osteons. Porosity increased along the length of the antler much more in deer with lower quality diet. Despite cortical porosity being inversely related to mechanical properties and positively with K, Zn and other minerals indicating physiological effort, it was these minerals and not porosity that statistically better explained variability in mechanical properties. Histochemistry showed that the reason for this is that Zn is located around incomplete osteons and also in complete osteons that were still mineralizing, whereas K is located in non-osteonal bone, which constitutes a greater proportion of bone where osteons are incompletely mineralized. This suggests that, K, Zn and other minerals indicate reduction in mechanical performance even with little porosity. If a similar process occurred in internal bones, K, Zn and other minerals in the bone may be an early indicator of decrease in mechanical properties and future osteoporosis. In conclusion, porosity is related to diet and physiological effort in deer. Copyright © 2011 Elsevier Inc. All rights reserved.
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Isotope analysis of closely adjacent minerals
International Nuclear Information System (INIS)
Smith, M.P.
1990-01-01
This patent describes a method of determining an indicator of at least one of hydrocarbon formation, migration, and accumulation during mineral development. It comprises: searching for a class of minerals in a mineral specimen comprising more than one class of minerals; identifying in the mineral specimen a target sample of the thus searched for class; directing thermally pyrolyzing laser beam radiation onto surface mineral substance of the target sample in the mineral specimen releasing surface mineral substance pyrolysate gases therefrom; and determining isotope composition essentially of the surface mineral substance from analyzing the pyrolysate gases released from the thus pyrolyzed target sample, the isotope composition including isotope(s) selected from the group consisting of carbon, hydrogen, and oxygen isotopes; determining an indicator of at least one of hydrocarbon formation, migration, and accumulation during mineral development of the target mineral from thus determined isotope composition of surface mineral substance pyrolysate
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Ciortescu, Catalina; Iancu, Ovidiu Gabriel; Bulgariu, Dumitru; Popa, Ciprian
2014-05-01
The present work focuses on the analyses of a selection of heavy mineral assemblages sampled from the Neagra Şarului River's alluvia, in order to determine their provenance and distribution, using their geochemical and physical characteristics. The study focused on a mountain river of about 30 km long, located in the north-western part of the Eastern Carpathians, an important tributary of the Bistria River. The bedrocks in the river drainage basin are constituted mainly by igneous rocks from Călimani Volcanic Complex in the west, and secondarily by a small area of low to medium grade metamorphic rocks, part of Crystalline-Mesozoic Zone, in the east. In order to trace the source of each individual mineral species, we prepared our samples via field separation and subsequent laboratory sieving using 8 different size fractions. An electromagnetic separator (Frantz Isodynamic) was used to separate and classify each heavy minerals species, depending on their magnetic susceptibility. Thus prepared, more than 500 grains per samples (from the 0.5-1 mm size fraction) were mounted on thin sections and analyzed using a Cambridge Microscan M9 with EDS system. These analyses served for mineral identification and relative abundance determination. The classification of the minerals and the nature of their inclusions are derived from the major element compositions computed from SEM-EDX analysis. We also used a stereo microscope in order to determine complementary properties of the grains, such as: color, degree of roundness and degree of alteration. In order of abundance, the main heavy minerals are magnetite, hematite, pyroxene, pyrite, manganese oxides, garnet, apatite, titanium oxides (ilmenite, titanite and rutile/anatase), chlorite, olivine, epidote, biotite and rhodochrosite. A particularity of the studied area is the presence of an altered magnetite caused first by the hydrothermal alteration and strong weathering of the source rocks and second by the river's acid water
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Tin in granitic melts: The role of melting temperature and protolith composition
Wolf, Mathias; Romer, Rolf L.; Franz, Leander; López-Moro, Francisco Javier
2018-06-01
Granite bound tin mineralization typically is seen as the result of extreme magmatic fractionation and late exsolution of magmatic fluids. Mineralization, however, also could be obtained at considerably less fractionation if initial melts already had enhanced Sn contents. We present chemical data and results from phase diagram modeling that illustrate the dominant roles of protolith composition, melting conditions, and melt extraction/evolution for the distribution of Sn between melt and restite and, thus, the Sn content of melts. We compare the element partitioning between leucosome and restite of low-temperature and high-temperature migmatites. During low-temperature melting, trace elements partition preferentially into the restite with the possible exception of Sr, Cd, Bi, and Pb, that may be enriched in the melt. In high-temperature melts, Ga, Y, Cd, Sn, REE, Pb, Bi, and U partition preferentially into the melt whereas Sc, V, Cr, Co, Ni, Mo, and Ba stay in the restite. This contrasting behavior is attributed to the stability of trace element sequestering minerals during melt generation. In particular muscovite, biotite, titanite, and rutile act as host phases for Sn and, therefore prevent Sn enrichment in the melt as long as they are stable phases in the restite. As protolith composition controls both the mineral assemblage and modal contents of the various minerals, protolith composition eventually also controls the fertility of a rock during anatexis, restite mineralogy, and partitioning behavior of trace metals. If a particular trace element is sequestered in a phase that is stable during partial melting, the resulting melt is depleted in this element whereas the restite becomes enriched. Melt generation at high temperature may release Sn when Sn-hosts become unstable. If melt has not been lost before the breakdown of Sn-hosts, Sn contents in the melt will increase but never will be high. In contrast, if melt has been lost before the decomposition of Sn
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Zhu, W.; Wu, C.; Wang, J.; Zhou, T.; Zhang, C.; Li, J.
2017-12-01
The Qaidam Basin is the largest intermountain basin within the Tibetan Plateau. The Cenozoic sedimentary flling characteristics of the basin was significantly influenced by the surrounding tectonic belt, such as the Altyn Tagh Range to the north-west and Qimen Tagh Range to the south. The tectonic evolution of the Qimen Tagh Range and the structural relationship between the Qaidam Basin and Qimen Tagh Range remain controversial. To address these issues, we analyzed thousands of heavy mineral data, 720 detrital zircon ages and seismic data of the Qaidam Basin. Based on the regional geological framework and our kinematic analyses, the Cenozoic tectonic evolution of the Qimen Tagh Range can be divided into two stages. From the Early Eocene to the Middle Miocene, the Devonian (400-360 Ma) and Permian to Triassic (300-200 Ma) zircons which were sourced from the Qimen Tagh Range and the heavy mineral assemblage of zircon-leucoxene-garnet-sphene on the north flank of the Qimen Tagh Range indicated that the Qimen Tagh Range has been exhumed before the Eocene and acted as the primary provenance of the Qaidam Basin. The Kunbei fault system (i.e. the Kunbei, Arlar and Hongliuquan faults) in the southwest of the Qaidam Basin, which can be seen as a natural study window of the Qimen Tagh Range, was characterized by left-lateral strike-slip faults and weak south-dipping thrust faults based on the seismic sections. This strike-slip motion was generated by the uplift of the Tibetan Plateau caused by the onset of the Indian-Eurasian collision. Since the Middle Miocene, the primary mineral assemblages along the northern flank of the Qimen Tagh Range changed from the zircon-leucoxene-garnet-sphene assemblage to the epidote-hornblende-garnet-leucoxene assemblage. Simultaneously, the Kunbei fault system underwent intense south-dipping thrusting, and a nearly 2.2-km uplift can be observed in the hanging wall of the Arlar fault. We attributed these variations to the rapid uplift event of
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Zhang, C.; Guo, Z.
2013-12-01
The Eocene-Oligocene Transition (EOT) between ~34.0 and 33.5 million years ago, where global climate cooled from 'greenhouse' to 'icehouse' at ~33.5 Ma ago, is one of the great events during Cenozoic climate deterioration. In contrast to the marine records of the EOT, significantly less research has focused on the continental climate change during this time, particularly in inner Asia. We present a comprehensive study of the upper Eocene to lower Oligocene succession with regular alternations of laterally continuous gypsum/gypsiferous layers and red mudstone beds in Tashan section of Xining Basin, which is located at the northeastern margin of the Tibetan Plateau. Clay minerals, which were extracted from this succession, were analyzed qualitatively and semi-quantitatively by using X-ray differaction (XRD). Base on detailed magnetostratigraphic time control, clay mineral compositions of this succession (33.1-35.5 Ma) are compared with open ocean marine records and Northern Hemisphere continental records to understand the process and characteristics of Asian climate change before, during and after EOT. Our results indicate that illite is the dominant clay mineral with less chlorite and variable smectite. Multi-parameter evidence suggests that the source areas of detrital inputs in Tashan have not changed and climate is the main control for the composition of the clay fraction. The characteristics of clay mineral concentrations suggest warm and humid fluctuations with cold and dry conditions and intense of seasonality during ~35.5-34.0 Ma in inner Asian. This changed to cold and dry condition at ~34 Ma and remained so from ~34-33.1 Ma. The comparisons between continental and marine records indicate that the climate changes experienced in the Xining basin region are more consistent with Northern Hemisphere rather than open oceans records. This indicates that paleoclimate changes for inner Asian before, during and after EOT was not controlled by Antarctic ice growth
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Cavin, Lionel; Boudad, Larbi; Tong, Haiyan; Läng, Emilie; Tabouelle, Jérôme; Vullo, Romain
2015-01-01
The mid-Cretaceous vertebrate assemblage from south-eastern Morocco is one of the most diversified continental vertebrate assemblages of this time worldwide. The bony fish component (coelacanths, lungfishes and ray-finned fishes) is represented by relatively complete specimens and, mostly, by fragmentary elements scattered along 250 kilometres of outcrops. Here we revisit the bony fish assemblage by studying both isolated remains collected during several fieldtrips and more complete material kept in public collections. The assemblage comprises several lungfish taxa, with the first mention of the occurrence of Arganodus tiguidiensis, and possibly two mawsoniid coelacanths. A large bichir cf. Bawitius, is recorded and corresponds to cranial elements initially referred to 'Stromerichthys' from coeval deposits in Egypt. The ginglymodians were diversified with a large 'Lepidotes' plus two obaichthyids and a gar. We confirm here that this gar belongs to a genus distinctive from Recent gars, contrary to what was suggested recently. Teleosteans comprise a poorly known ichthyodectiform, a notopterid, a probable osteoglossomorph and a large tselfatiiform, whose cranial anatomy is detailed. The body size and trophic level for each taxon are estimated on the basis of comparison with extant closely related taxa. We plotted the average body size versus average trophic level for the Kem Kem assemblage, together with extant marine and freshwater assemblages. The Kem Kem assemblage is characterized by taxa of proportionally large body size, and by a higher average trophic level than the trophic level of the extant compared freshwater ecosystems, but lower than for the extant marine ecosystems. These results should be regarded with caution because they rest on a reconstructed assemblage known mostly by fragmentary remains. They reinforce, however, the ecological oddities already noticed for this mid-Cretaceous vertebrate ecosystem in North Africa.
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Kerr, B J; Ziemer, C J; Weber, T E; Trabue, S L; Bearson, B L; Shurson, G C; Whitney, M H
2008-09-01
The objective of this study was to compare the use of thermal combustion (CNS) and inductively coupled plasma (ICP) to measure the total S content in plant-, animal-, and mineral-based feedstuffs, and to provide concentrations of other macro- and micro-minerals contained in these feedstuffs. Forty-five feedstuffs (464 total samples) were obtained from suppliers as well as swine feed and pet food manufacturers throughout the United States. Mineral data from IPC analysis were summarized on a DM basis using sample mean and SD, whereas the comparison of total S content between CNS and ICP was examined by bivariate plot and correspondence correlation. Analyses of a wide range of feedstuffs by CNS and ICP for total S were comparable for all but a few feedstuffs. For potassium iodide and tribasic copper chloride, ICP estimated total S to be lower than when analyzed by CNS (bias = 2.51 +/- 0.15 SE, P phosphate and limestone, ICP estimated total S to be greater than when analyzed by CNS (bias = -1.46 +/- 0.51 SE, P < 0.01). All other samples had similar estimates of total S, whether analyzed by CNS or ICP. As expected, S composition varied greatly among feedstuffs. For total S, plant-based feedstuffs generally had lower total S compared with animal-based feedstuffs, whereas minerals supplied in sulfate form had the greatest concentration of total S. In addition to total S, mineral composition data are provided for all feedstuffs as obtained by ICP analysis. Within specific feedstuffs, mineral composition was quite variable, potentially due to low concentrations in the feed-stuff causing high mathematical variation or due to the source of feedstock obtained. In general, analyzed values of P were similar to previous tabular values. These data provide feed formulators a database from which modifications in dietary minerals can be accomplished and from which mineral requirements can be met more precisely to reduce losses of minerals into the environment.
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A.M. Boot (Annemieke); S.M.P.F. de Muinck Keizer-Schrama (Sabine); H.A.P. Pols (Huib); E.P. Krenning (Eric); S.L.S. Drop (Stenvert)
1998-01-01
textabstractMajor changes in bone mineral density (BMD) and body composition occur during puberty. In the present longitudinal study, we evaluated BMD and calculated volumetric BMD [bone mineral apparent density (BMAD)], bone metabolism, and body composition of children
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Directory of Open Access Journals (Sweden)
Samir Rezki
2016-04-01
Full Text Available Seeds are involved in the vertical transmission of microorganisms from one plant generation to another and consequently act as reservoirs for the plant microbiota. However, little is known about the structure of seed-associated microbial assemblages and the regulators of assemblage structure. In this work, we have assessed the response of seed-associated microbial assemblages of Raphanus sativus to invading phytopathogenic agents, the bacterial strain Xanthomonas campestris pv. campestris (Xcc 8004 and the fungal strain Alternaria brassicicola Abra43. According to the indicators of bacterial (16S rRNA gene and gyrB sequences and fungal (ITS1 diversity employed in this study, seed transmission of the bacterial strain Xcc 8004 did not change the overall composition of resident microbial assemblages. In contrast seed transmission of Abra43 strongly modified the richness and structure of fungal assemblages without affecting bacterial assemblages. The sensitivity of seed-associated fungal assemblage to Abra43 is mostly related to changes in relative abundance of closely related fungal species that belong to the Alternaria genus. Variation in stability of the seed microbiota in response to Xcc and Abra43 invasions could be explained by differences in seed transmission pathways employed by these micro-organisms, which ultimately results in divergence in spatio-temporal colonization of the seed habitat.
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von Schiller, Daniel; Barberá, Gonzalo G.; Díaz, Angela M.; Arce, Maria Isabel; del Campo, Rubén; Tockner, Klement
2018-01-01
In the present study, we examined the effects of different drying conditions on the composition, structure and function of benthic invertebrate assemblages. We approached this objective by comparing invertebrate assemblages in perennial and intermittent sites along two intermittent Mediterranean streams with contrasting predictability, duration, and spatial patterns of drying: Fuirosos (high predictability, short duration, downstream drying pattern) and Rogativa (low predictability, long duration, patchy drying pattern). Specifically, we quantified the contribution of individual taxa to those differences, the degree of nestedness, and shifts in the composition, structure and function of benthic invertebrate assemblages along flow intermittence gradients. We observed greater effects of drying on the benthic invertebrate composition in Fuirosos than in Rogativa, resulting in a higher dissimilarity of assemblages between perennial and intermittent sites, as well as a lower degree of nestedness. Furthermore, a higher number of biotic metrics related to richness, abundance and biological traits were significantly different between perennial and intermittent sites in Fuirosos, despite a shorter dry period compared to Rogativa. At the same time, slightly different responses were detected during post-drying (autumn) than pre-drying (spring) conditions in this stream. In Rogativa, shifts in benthic invertebrate assemblages along increasing gradients of flow intermittence were found for three metrics (Ephemeroptera, Plecoptera and Trichoptera (EPT) and Odonata, Coleoptera and Heteroptera (OCH) abundances and aerial active dispersal. Furthermore, we demonstrated that combined gradients of dry period duration and distance to nearest perennial reach can generate complex, and different, responses of benthic invertebrate assemblages, depending on the flow intermittence metric. Our study advances the notion that special attention should be paid to the predictability, duration and
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Directory of Open Access Journals (Sweden)
Tassos Anastassiades
2017-10-01
Full Text Available Background: The toxicities of pharmaceuticals for chronic arthritis and osteoporosis should be of concern to consumers. This partially accounts for the popularity of consumption of the amino sugar glucosamine, in-spite of controversy about its efficacy. We chemically synthesized N-butyryl glucosamine (GlcNBu, which we discovered protected bone and cartilage in an inflammatory arthritis rat model when used as a feed supplement. GlcNBu can also be potentially synthesized biochemically, since we recently demonstrated that human acetyl-CoA: glucosamine-6-phosphate N-acetyltransferase 1 has a relaxed donor specificity and transfers acyl groups of up to four carbons in length, i.e. the butyryl moiety. Oral GlcNBu had no detectable toxicity and also protected against bone loss in ovariectomized (OVX rats as a model for osteoporosis. However, we demonstrated this only for bones excised at 6 months. Thus, the current study aims to determine when bone mineralization is maximized during daily GlcNBu supplementation, in both OVΧ and Sham-OVX rats, in addition to the relationship of bone mineralization to body composition. Methods: Female Sprague-Dawley rats were randomized into 4 groups, containing 8 rats each. The groups consisted of OVX or Sham-OVX rats whose diets were supplemented with either 200 mg/kg/day of GlcNBu or an equimolar amount of glucose. We performed sequential bone density and body composition measurements, by dual-energy X-ray absorptiometry in the live, anesthetised rats, over a 6-month experimental period, starting at the age of 8 weeks. Results were analyzed by descriptive statistics and 2-way ANOVA. Results: The major increases in the mineral content and density of the spine and the femur in GlcNBu-supplemented rats occurred early, from the baseline to week 8. Ovariectomy resulted in a number of significant differences in body composition, while feeding GlcNBu had no significant effects on body composition. The significant effects of
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Megabenthic assemblages at the Hudson Canyon head (NW Atlantic margin): Habitat-faunal relationships
Pierdomenico, Martina; Gori, Andrea; Guida, Vincent G.; Gili, Josep-Maria
2017-09-01
The distribution of megabenthic communities at the head of Hudson Canyon and adjacent continental shelf was studied by means of underwater video transects and still photo imagery collected using a towed camera system. The goal was to explore the relationships between faunal distribution and physical seafloor conditions and to test the hypothesis that increased seafloor heterogeneity in the Hudson Canyon supports a larger diversity of benthic communities, compared with the adjacent continental shelf. Hierarchical cluster analysis was performed to identify benthic assemblages as defined in imagery. The BIO-ENV procedure and the Canonical Correspondence Analysis were carried out to elucidate species groupings in relation to terrain variables extracted from bathymetric data. Species accumulation curves were generated to evaluate species turn over in and out of Hudson Canyon. The results indicate that seafloor morphology is the main physical factor related to benthic community composition and distribution. Assemblages dominated by sponges, zoanthids and cup corals colonized the canyon margins and flanks, and were associated with coarse-grained sediments, while sea pen assemblages were observed along muddy seafloor within the thalweg. An assemblage dominated by sea stars occurred on the shelf, associated with a sandy seafloor. Some assemblages were exclusively observed in the canyon area, suggesting that the increased variability of seafloor composition, together with the oceanographic processes specific to the canyon area, enhance beta diversity. The colonization by benthic suspension feeders within the canyon, in contrast to shelf assemblages, mainly composed of carnivores and detritus feeders could be favored the intense hydrodynamics at the canyon head that increase the availability of suspended organic matter. From the perspective of management and conservation of marine resources, the results obtained support the relevance of Hudson Canyon as a biodiversity hotspot
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Maksimovich, I. A.; Smirnov, S. Z.; Kotov, A. A.; Timina, T. Yu; Shevko, A. V.
2017-12-01
The Vetrovoy Isthmus and the Lvinaya Past’ Bay on the Iturup island (Kuril island arc) are the results of large Plinian eruptions of compositionally similar dacitic magmas. This study is devoted to a comparative analysis of the storage and crystallization conditions for magma reservoirs, which were a source of large-scale explosive eruptions. The plagioclase is most informative mineral in studying of the melt evolution. The studied plagioclases possess a complex zoning patterns, which are not typical for silicic rocks in island-arc systems. It was shown that increase of Ca in the plagioclase up to unusually high An95 is related to increase of H2O pressure in both volcanic magma chambers. The study revealed that minerals of the Vetrovoy Isthmus and Lvinaya Past’ crystallized from compositionally similar melts. Despite the compositional similarity of the melts, the phenocryst assemblage of the Lvinaya Past’ differs from the Vetrovoy Isthmus by the presence of the amphibole, which indicates that the pressure in the magmatic chamber exceeded 1-2 kbar at a 4-6 wt. % of H2O in the melt. The rocks of the Vetrovoy Isthmus do not contain amphibole phenocrysts, but melt and fluid inclusions assemblages in plagioclase demonstrate that the magma degassed in the course of evolution. This is an indication that the pressure did not exceed significantly 1-2 kbar.
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Dale, Jonathan J; Stankus, Austin M; Burns, Michael S; Meyer, Carl G
2011-02-10
Empirical data on the abundance and habitat preferences of coral reef top predators are needed to evaluate their ecological impacts and guide management decisions. We used longline surveys to quantify the shark assemblage at French Frigate Shoals (FFS) atoll from May to August 2009. Fishing effort consisted of 189 longline sets totaling 6,862 hook hours of soak time. A total of 221 sharks from 7 species were captured, among which Galapagos (Carcharhinus galapagensis, 36.2%), gray reef (Carcharhinus amblyrhynchos, 25.8%) and tiger (Galeocerdo cuvier, 20.4%) sharks were numerically dominant. A lack of blacktip reef sharks (Carcharhinus melanopterus) distinguished the FFS shark assemblage from those at many other atolls in the Indo-Pacific. Compared to prior underwater visual survey estimates, longline methods more accurately represented species abundance and composition for the majority of shark species. Sharks were significantly less abundant in the shallow lagoon than adjacent habitats. Recaptures of Galapagos sharks provided the first empirical estimate of population size for any Galapagos shark population. The overall recapture rate was 5.4%. Multiple closed population models were evaluated, with Chao M(h) ranking best in model performance and yielding a population estimate of 668 sharks with 95% confidence intervals ranging from 289-1720. Low shark abundance in the shallow lagoon habitats suggests removal of a small number of sharks from the immediate vicinity of lagoonal islets may reduce short-term predation on endangered monk seal (Monachus schauinslandi) pups, but considerable fishing effort would be required to catch even a small number of sharks. Additional data on long-term movements and habitat use of sharks at FFS are required to better assess the likely ecological impacts of shark culling.
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Courtland, Hayden-William; Nasser, Philip; Goldstone, Andrew B; Spevak, Lyudmila; Boskey, Adele L; Jepsen, Karl J
2008-11-01
Fracture susceptibility is heritable and dependent upon bone morphology and quality. However, studies of bone quality are typically overshadowed by emphasis on bone geometry and bone mineral density. Given that differences in mineral and matrix composition exist in a variety of species, we hypothesized that genetic variation in bone quality and tissue-level mechanical properties would also exist within species. Sixteen-week-old female A/J, C57BL/6J (B6), and C3H/HeJ (C3H) inbred mouse femora were analyzed using Fourier transform infrared imaging and tissue-level mechanical testing for variation in mineral composition, mineral maturity, collagen cross-link ratio, and tissue-level mechanical properties. A/J femora had an increased mineral-to-matrix ratio compared to B6. The C3H mineral-to-matrix ratio was intermediate of A/J and B6. C3H femora had reduced acid phosphate and carbonate levels and an increased collagen cross-link ratio compared to A/J and B6. Modulus values paralleled mineral-to-matrix values, with A/J femora being the most stiff, B6 being the least stiff, and C3H having intermediate stiffness. In addition, work-to-failure varied among the strains, with the highly mineralized and brittle A/J femora performing the least amount of work-to-failure. Inbred mice are therefore able to differentially modulate the composition of their bone mineral and the maturity of their bone matrix in conjunction with tissue-level mechanical properties. These results suggest that specific combinations of bone quality and morphological traits are genetically regulated such that mechanically functional bones can be constructed in different ways.
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Mineralization and geochemical studies in the Kalchouyeh occurrence, southwest of Naein
Hengameh Hosseini Dinani; Hashem Bagheri; Reza Shamsipour Dehkordi
2012-01-01
Kalchouyeh area in southwest of Naein is located in the Urumieh-Dokhtar volcano-plutonic belt. Mineralization occurred mainly as disseminations and veinlets hosted by trachy-andesite and pyroxene andesites. For mineralogy, alteration, fluid inclusion and geochemical studies, the two major mineralized zones: A (larger vein) from the north-northwest and B (smaller vein) from the east-southeast of the area were sampled. Alteration studies revealed that the main alteration assemblages are silicif...
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Development of a new test method for Mineral Based Composites
DEFF Research Database (Denmark)
Täljsten, Björn; Orosz, Katalin
2008-01-01
The well-known wedge splitting test, often used for characterizing brittle materials has been modified and adapted to testing MBC-reinforced concrete under splitting load. MBC (Mineral Based Composites) is a newly developed strengthening system for existing concrete structures where FRPs, mainly...... CFRP grids are externally bonded to the concrete surface by means of cementitious bonding agents. Crack development, crack patterns, crack opening displacement (COD) versus splitting load and fracture energy are investigated and evaluated. Development of a suitable test specimen and test setup has been...
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Comparing demersal fish assemblage between periods of contrasting climate and fishing pressure
Hofstede, ter R.; Rijnsdorp, A.D.
2011-01-01
Fish communities are dynamic and their structure is known to change over time. Traditionally, these changes were considered to be fisheries-induced, but recent analyses also suggest that global warming could affect the distribution, abundance, and assemblage composition of marine fish. However,
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Babin, Doreen; Ding, Guo-Chun; Pronk, Geertje Johanna; Heister, Katja; Kögel-Knabner, Ingrid; Smalla, Kornelia
2013-10-01
Microbial communities in soil reside in a highly heterogeneous habitat where diverse mineral surfaces, complex organic matter and microorganisms interact with each other. This study aimed to elucidate the long-term effect of the soil mineral composition and charcoal on the microbial community composition established in matured artificial soils and their response to phenanthrene. One year after adding sterile manure to different artificial soils and inoculating microorganisms from a Cambisol, the matured soils were spiked with phenanthrene or not and incubated for another 70 days. 16S rRNA gene and internal transcribed spacer fragments amplified from total community DNA were analyzed by denaturing gradient gel electrophoresis. Metal oxides and clay minerals and to a lesser extent charcoal influenced the microbial community composition. Changes in the bacterial community composition in response to phenanthrene differed depending on the mineral composition and presence of charcoal, while no shifts in the fungal community composition were observed. The abundance of ring-hydroxylating dioxygenase genes was increased in phenanthrene-spiked soils except for charcoal-containing soils. Here we show that the formation of biogeochemical interfaces in soil is an ongoing process and that different properties present in artificial soils influenced the bacterial response to the phenanthrene spike. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.
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PIXE studies of changes in host mineral compositions of plants due to Phytophthora Cinnamomi
International Nuclear Information System (INIS)
Papper, C.S.; Chaudhri, M.A.
1978-01-01
In order to study the effect of the disease due to Phytophthora Cinnamomi on the vegetation in Wilson's Promontory, the mineral compositions of tolerant and susceptible plants in both healthy and diseased areas have been compared, using proton-induced x-ray emission analysis
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Natural variations in calcium isotope composition as a monitor of bone mineral balance in humans.
Skulan, J.; Anbar, A.; Thomas, B.; Smith, S.
2004-12-01
The skeleton is the largest reservoir of calcium in the human body and is responsible for the short term control of blood levels of this element. Accurate measurement of changes in bone calcium balance is critical to understanding how calcium metabolism responds to physiological and environmental changes and, more specifically, to diagnosing and evaluating the effectiveness of treatments for osteoporosis and other serious calcium-related disorders. It is very difficult to measure bone calcium balance using current techniques, however, because these techniques rely either on separate estimates of bone resorption and formation that are not quantitatively comparable, or on complex and expensive studies of calcium kinetics using administered isotopic tracers. This difficulty is even more apparent and more severe for measurements of short-term changes in bone calcium balance that do not produce detectable changes in bone mineral density. Calcium isotopes may provide a novel means of addressing this problem. The foundation of this isotope application is the ca. 1.3 per mil fractionation of calcium during bone formation, favoring light calcium in the bone. This fractionation results in a steady-state isotopic offset between calcium in bone and calcium in soft tissues, blood and urine. Perturbations to this steady state due to changes in the net formation or resorption of bone should be reflected in changes in the isotopic composition of soft tissues and fluids. Here we present evidence that easily detectable shifts in the natural calcium isotope composition of human urine rapidly reflect changes in bone calcium balance. Urine from subjects in a 17-week bed rest study was analyzed for calcium isotopic composition. Bed rest promotes net resorption of bone, shifting calcium from bone to soft tissues, blood and urine. The calcium isotope composition of patients in this study shifted toward lighter values during bed rest, consistent with net resorption of isotopically
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Hakki, Sema S; SiddikMalkoc; Dundar, Niyazi; Kayis, Seyit Ali; Hakki, Erdogan E; Hamurcu, Mehmet; Baspinar, Nuri; Basoglu, Abdullah; Nielsen, Forrest H; Götz, Werner
2015-01-01
The objective of this study was to determine whether dietary boron (B) affects the strength, density and mineral composition of teeth and mineral density of alveolar bone in rabbits with apparent obesity induced by a high-energy diet. Sixty female, 8-month-old, New Zealand rabbits were randomly assigned for 7 months into five groups as follows: (1) control 1, fed alfalfa hay only (5.91 MJ/kg and 57.5 mg B/kg); (2) control 2, high energy diet (11.76 MJ and 3.88 mg B/kg); (3) B10, high energy diet + 10 mg B gavage/kg body weight/96 h; (4) B30, high energy diet + 30 mg B gavage/kg body weight/96 h; (5) B50, high energy diet + 50 mg B gavage/kg body weight/96 h. Maxillary incisor teeth of the rabbits were evaluated for compression strength, mineral composition, and micro-hardness. Enamel, dentin, cementum and pulp tissue were examined histologically. Mineral densities of the incisor teeth and surrounding alveolar bone were determined by using micro-CT. When compared to controls, the different boron treatments did not significantly affect compression strength, and micro-hardness of the teeth, although the B content of teeth increased in a dose-dependent manner. Compared to control 1, B50 teeth had decreased phosphorus (P) concentrations. Histological examination revealed that teeth structure (shape and thickness of the enamel, dentin, cementum and pulp) was similar in the B-treated and control rabbits. Micro CT evaluation revealed greater alveolar bone mineral density in B10 and B30 groups than in controls. Alveolar bone density of the B50 group was not different than the controls. Although the B treatments did not affect teeth structure, strength, mineral density and micro-hardness, increasing B intake altered the mineral composition of teeth, and, in moderate amounts, had beneficial effects on surrounding alveolar bone.
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PIXE studies of changes in mineral composition of plants infected with Phytophthora cinnamomi
Chaudhri, M. Anwar; Papper, C. S.; Weste, G.
1981-03-01
The mineral composition of susceptible and resistant plants from native forests infected with Phytophthora cinnamomi was compared between themselves and with the same species from disease-free areas. Root and shoot samples from different plants were carefully ashed, compressed into pellets and analysed with the thick target PIXE technique. A number of elements, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Rb, Sr, Zr, Sn and Pb, were detected. Many of the elements showed variations, sometimes large, between the composition of susceptible and resistant plants, and between the same species from infected and disease-free forests.
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Schopf, J. William; Kitajima, Kouki; Spicuzza, Michael J.; Kudryavtsev, Anatoliy B.; Valley, John W.
2018-01-01
Analyses by secondary ion mass spectroscopy (SIMS) of 11 specimens of five taxa of prokaryotic filamentous kerogenous cellular microfossils permineralized in a petrographic thin section of the ˜3,465 Ma Apex chert of northwestern Western Australia, prepared from the same rock sample from which this earliest known assemblage of cellular fossils was described more than two decades ago, show their δ13C compositions to vary systematically taxon to taxon from ‑31‰ to ‑39‰. These morphospecies-correlated carbon isotope compositions confirm the biogenicity of the Apex fossils and validate their morphology-based taxonomic assignments. Perhaps most significantly, the δ13C values of each of the five taxa are lower than those of bulk samples of Apex kerogen (‑27‰), those of SIMS-measured fossil-associated dispersed particulate kerogen (‑27.6‰), and those typical of modern prokaryotic phototrophs (‑25 ± 10‰). The SIMS data for the two highest δ13C Apex taxa are consistent with those of extant phototrophic bacteria; those for a somewhat lower δ13C taxon, with nonbacterial methane-producing Archaea; and those for the two lowest δ13C taxa, with methane-metabolizing γ-proteobacteria. Although the existence of both methanogens and methanotrophs has been inferred from bulk analyses of the carbon isotopic compositions of pre-2,500 Ma kerogens, these in situ SIMS analyses of individual microfossils present data interpretable as evidencing the cellular preservation of such microorganisms and are consistent with the near-basal position of the Archaea in rRNA phylogenies.
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Schopf, J William; Kitajima, Kouki; Spicuzza, Michael J; Kudryavtsev, Anatoliy B; Valley, John W
2018-01-02
Analyses by secondary ion mass spectroscopy (SIMS) of 11 specimens of five taxa of prokaryotic filamentous kerogenous cellular microfossils permineralized in a petrographic thin section of the ∼3,465 Ma Apex chert of northwestern Western Australia, prepared from the same rock sample from which this earliest known assemblage of cellular fossils was described more than two decades ago, show their δ 13 C compositions to vary systematically taxon to taxon from -31‰ to -39‰. These morphospecies-correlated carbon isotope compositions confirm the biogenicity of the Apex fossils and validate their morphology-based taxonomic assignments. Perhaps most significantly, the δ 13 C values of each of the five taxa are lower than those of bulk samples of Apex kerogen (-27‰), those of SIMS-measured fossil-associated dispersed particulate kerogen (-27.6‰), and those typical of modern prokaryotic phototrophs (-25 ± 10‰). The SIMS data for the two highest δ 13 C Apex taxa are consistent with those of extant phototrophic bacteria; those for a somewhat lower δ 13 C taxon, with nonbacterial methane-producing Archaea; and those for the two lowest δ 13 C taxa, with methane-metabolizing γ-proteobacteria. Although the existence of both methanogens and methanotrophs has been inferred from bulk analyses of the carbon isotopic compositions of pre-2,500 Ma kerogens, these in situ SIMS analyses of individual microfossils present data interpretable as evidencing the cellular preservation of such microorganisms and are consistent with the near-basal position of the Archaea in rRNA phylogenies.
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Ma, Yulin; Li, Xianping; Zhang, Hongbin; Ou, Yangna; Zhang, Zhimin; Li, Shuang; Wu, Feng; Sheng, Zhifeng; Liao, Eryuan
2016-08-01
Previous data suggest that myostatin has direct effects on the proliferation and differentiation of osteoprogenitor cells. The relationships between serum myostatin, body composition lipids and bone mineral density in postmenopausal women remain unclear. The aim of this study is to elucidate the relationships between serum myostatin, body composition, lipids and bone mineral density in central south Chinese postmenopausal women. A cross-sectional study was conducted in 175 healthy postmenopausal women, aged 51-75 years old. Bone mineral density (BMD) and body composition were measured by double energy X-ray absorptiometry (DXA). Serum myostatin, 25-dihydroxyvitamin D(25OH-D), parathyroid hormone (PTH), bone alkaline phosphatase (BAP) and carboxy-terminal telopeptide of type I collagen (CTX) were measured by enzyme-linked immunoabsorbent assay (ELISA). In contrast to the osteoporotic women, the women without osteoporosis had higher BMI, fat mass and lean mass (Pmyostatin after adjusted by age. BMD at each site was positively correlated with age at menopause, fat mass and lean mass, and also negatively correlated with age and serum BAP. Serum myostatin was positively correlated with tryglicerides, not correlated with either body composition or BMD at each site. Our data indicated that serum myostatin concentration did not correlate with muscle and bone mass. Further studies are needed to demonstrate the role of myostatin in regulating the bone metabolism.
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Fish assemblage structure and habitat associations in a large western river system
Smith, C.D.; Quist, Michael C.; Hardy, R. S.
2016-01-01
Longitudinal gradients of fish assemblage and habitat structure were investigated in the Kootenai River of northern Idaho. A total of 43 500-m river reaches was sampled repeatedly with several techniques (boat-mounted electrofishing, hoop nets and benthic trawls) in the summers of 2012 and 2013. Differences in habitat and fish assemblage structure were apparent along the longitudinal gradient of the Kootenai River. Habitat characteristics (e.g. depth, substrate composition and water velocity) were related to fish assemblage structure in three different geomorphic river sections. Upper river sections were characterized by native salmonids (e.g. mountain whitefish Prosopium williamsoni), whereas native cyprinids (peamouth Mylocheilus caurinus, northern pikeminnow Ptychocheilus oregonensis) and non-native fishes (pumpkinseed Lepomis gibbosus, yellow perch Perca flavescens) were common in the downstream section. Overall, a general pattern of species addition from upstream to downstream sections was discovered and is likely related to increased habitat complexity and additions of non-native species in downstream sections. Assemblage structure of the upper sections were similar, but were both dissimilar to the lower section of the Kootenai River. Species-specific hurdle regressions indicated the relationships among habitat characteristics and the predicted probability of occurrence and relative abundance varied by species. Understanding fish assemblage structure in relation to habitat could improve conservation efforts of rare fishes and improve management of coldwater river systems.
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Mineralization and hydrothermal alteration of the Tajroud vein system, south of Neyshabour
Directory of Open Access Journals (Sweden)
Mohsen Alikhani Banghani
2013-10-01
Full Text Available The Tajroud vein system is located 190 km southwest of Mashhad, and in the southern part of the Sabzevar zone. The vein host rocks consist of Eocene intermediate to silicic volcanic rocks. The mineralization occurs as open space filling, taking place as veins, veinlets and hydrothermal breccias. Based on field geology and textural evidence, three main stages of mineralization were identified. Stage I mainly contains quartz, pyrite, chalcopyrite and magnetite. Stage II, which has the same mineral assemblage as stage I, is the most important stage in terms of volume. Finally, stage III is characterized by repetitive quartz and calcite banding with negligible amounts of sulfide minerals. Hydrothermal alteration is developed around the veins and tends to be more intense in the vicinity of the veins. The plot of the Ishikawa alteration index (AI versus chlorite-carbonate-pyrite index (CCPI, known as alteration box plot, displays three main alteration trends. The hydrothermal alteration assemblage of quartz, adularia, chlorite, illite, calcite, and epidote that envelops the Tajroud vein system formed from the upwelling of near-neutral to weakly alkaline hydrothermal solutions. The mineralogic, alteration and geochemical characteristics of the studied area and comparison with epithermal ore deposits indicate that the Tajroud vein system represents an epithermal system of low-sulfidation type.
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Effects of Water Level Increase on Phytoplankton Assemblages in a Drinking Water Reservoir
Directory of Open Access Journals (Sweden)
Yangdong Pan
2018-03-01
Full Text Available Excessive water level fluctuation may affect physico-chemical characteristics, and consequently ecosystem function, in lakes and reservoirs. In this study, we assessed the changes of phytoplankton assemblages in response to water level increase in Danjiangkou Reservoir, one of the largest drinking water reservoirs in Asia. The water level increased from a low of 137 m to 161 m in 2014 as a part of the South–North Water Diversion Project. Phytoplankton assemblages were sampled four times per year before, during and after the water level increase, at 10 sites. Environmental variables such as total nitrogen as well as phytoplankton biomass decreased after the water level increase. Non-metric multi-dimensional scaling analysis indicated that before the water level increase, phytoplankton assemblages showed distinct seasonal variation with diatom dominance in both early and late seasons while such seasonal variation was much less evident after the water level increase. Month and year (before and after explained 13% and 6% of variance in phytoplankton assemblages (PERMANOVA, p < 0.001 respectively, and phytoplankton assemblages were significantly different before and after the water level increase. Both chlorophytes and cyanobacteria became more abundant in 2015. Phytoplankton compositional change may largely reflect the environmental changes, such as hydrodynamics mediated by the water level increase.
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Veganism, bone mineral density, and body composition: a study in Buddhist nuns.
Ho-Pham, L T; Nguyen, P L T; Le, T T T; Doan, T A T; Tran, N T; Le, T A; Nguyen, T V
2009-12-01
This cross-sectional study showed that, although vegans had lower dietary calcium and protein intakes than omnivores, veganism did not have adverse effect on bone mineral density and did not alter body composition. Whether a lifelong vegetarian diet has any negative effect on bone health is a contentious issue. We undertook this study to examine the association between lifelong vegetarian diet and bone mineral density and body composition in a group of postmenopausal women. One hundred and five Mahayana Buddhist nuns and 105 omnivorous women (average age = 62, range = 50-85) were randomly sampled from monasteries in Ho Chi Minh City and invited to participate in the study. By religious rule, the nuns do not eat meat or seafood (i.e., vegans). Bone mineral density (BMD) at the lumbar spine (LS), femoral neck (FN), and whole body (WB) was measured by DXA (Hologic QDR 4500). Lean mass, fat mass, and percent fat mass were also obtained from the DXA whole body scan. Dietary calcium and protein intakes were estimated from a validated food frequency questionnaire. There was no significant difference between vegans and omnivores in LSBMD (0.74 +/- 0.14 vs. 0.77 +/- 0.14 g/cm(2); mean +/- SD; P = 0.18), FNBMD (0.62 +/- 0.11 vs. 0.63 +/- 0.11 g/cm(2); P = 0.35), WBBMD (0.88 +/- 0.11 vs. 0.90 +/- 0.12 g/cm(2); P = 0.31), lean mass (32 +/- 5 vs. 33 +/- 4 kg; P = 0.47), and fat mass (19 +/- 5 vs. 19 +/- 5 kg; P = 0.77) either before or after adjusting for age. The prevalence of osteoporosis (T scores < or = -2.5) at the femoral neck in vegans and omnivores was 17.1% and 14.3% (P = 0.57), respectively. The median intake of dietary calcium was lower in vegans compared to omnivores (330 +/- 205 vs. 682 +/- 417 mg/day, P < 0.001); however, there was no significant correlation between dietary calcium and BMD. Further analysis suggested that whole body BMD, but not lumbar spine or femoral neck BMD, was positively correlated with the ratio of animal protein to vegetable protein. These
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Braun, Christopher L.; Pearson, Daniel K.; Porter, Michael D.; Moring, J. Bruce
2015-01-01
In winter 2011–12 and summer 2012, the U.S. Geological Survey (USGS), in cooperation with the U.S. Army Corps of Engineers, Albuquerque District and the U.S. Fish and Wildlife Service New Mexico Fish and Wildlife Conservation Office in Albuquerque, New Mexico, evaluated the physical characteristics and fish assemblage composition of available mesohabitats over a range of streamflows at 15 sites on the Middle Rio Grande in New Mexico. The fish assemblage of the Middle Rio Grande includes several minnow species adapted to hydrologically variable but seasonably predictable rivers, including theHybognathus amarus (Rio Grande silvery minnow), a federally listed endangered species. Gaining a better understanding of habitat usage by the Rio Grande silvery minnow was the impetus for studying physical characteristics and fish assemblages in the Middle Rio Grande during different streamflow conditions. Data were collected at all 15 sites during winter 2011–12 (moderate streamflow), and a subset was collected at the 13 most downstream sites in summer 2012 (low streamflow). Sites were grouped into four river reaches separated by diversion dams listed in downstream order (names of the diversion dams are followed by short names of the sites nearest each dam in parentheses, listed in downstream order): (1) Cochiti (Peña Blanca), (2) Angostura (Bernalillo, La Orilla, Barelas, Los Padillas), (3) Isleta (Los Lunas I, Los Lunas II, Abeytas, La Joya, Rio Salado), and (4) San Acacia (Lemitar, Arroyo del Tajo, San Pedro, Bosque del Apache I, and Bosque del Apache II). Stream habitat was mapped in the field by using a geographic information system in conjunction with a Global Positioning System. Fish assemblage composition was determined during both streamflow regimes, and fish were collected by seining in each mesohabitat where physical characteristic data (depth, velocity, dominant substrate type and size, and percent embeddedness) and water-quality properties (temperature
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Unique biochemical and mineral composition of whale ear bones.
Kim, Sora L; Thewissen, J G M; Churchill, Morgan M; Suydam, Robert S; Ketten, Darlene R; Clementz, Mark T
2014-01-01
Abstract Cetaceans are obligate aquatic mammals derived from terrestrial artiodactyls. The defining characteristic of cetaceans is a thick and dense lip (pachyosteosclerotic involucrum) of an ear bone (the tympanic). This unique feature is absent in modern terrestrial artiodactyls and is suggested to be important in underwater hearing. Here, we investigate the mineralogical and biochemical properties of the involucrum, as these may hold clues to the aquatic adaptations of cetaceans. We compared bioapatites (enamel, dentine, cementum, and skeletal bone) of cetaceans with those of terrestrial artiodactyls and pachyosteosclerotic ribs of manatees (Sirenia). We investigated organic, carbonate, and mineral composition as well as crystal size and crystallinity index. In all studied variables, bioapatites of the cetacean involucrum were intermediate in composition and structure between those of tooth enamel on the one hand and those of dentine, cementum, and skeletal bone on the other. We also studied the amino acid composition of the cetacean involucrum relative to that of other skeletal bone. The central involucrum had low glycine and hydroxyproline concentrations but high concentrations of nonessential amino acids, unlike most bone samples but similar to the tympanic of hippos and the (pachyosteosclerotic) ribs of manatees. These amino acid results are evidence of rapid bone development. We hypothesize that the mineralogical and amino acid composition of cetacean bullae differs from that of other bone because of (1) functional modifications for underwater sound reception and (2) structural adaptations related to rapid ossification.
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Energy Technology Data Exchange (ETDEWEB)
García Moreno, O.; Corretgé, L.G.; Holtz, F.; García-Arias, M.; Rodriguez, C.
2017-07-01
Experimental investigations and thermodynamic calculations of the phase relations of a cordierite-rich monzogranite from the Cabeza de Araya batholith (Cáceres, Spain) have been performed to understand the formation of cordierite. The experiments failed to crystallize cordierite in the pressure range 200-600MPa, in the temperature range 700-975ºC and for different water activities (melt water contents between 2 and 6 wt.%). In contrast, clinopyroxene and orthopyroxene (absent in the natural mineral rock assemblage), together with biotite, were observed as ferromagnesian assemblage in a wide range of experimental conditions. Thermodynamic calculations, using the software PERPLE{sub X}, describe the formation of cordierite only at 200 and 400MPa and very low water contents, and the amount of cordierite formed in the models is always below 3.5 vol.%. The results indicate that cordierite is not in equilibrium with the bulk rock compositions. The most probable explanation was that cordierite nucleated and crystallized from a melt that is not in equilibrium with part of the mineral assemblage present in the magma. This “non-reactive” mineral assemblage was mainly composed of plagioclase. The silicate melts from which cordierite crystallized was more Al-rich and K-rich than the silicate melt composition in equilibrium with the bulk composition. One possible process for the high Al content of the silicate melt is related to assimilation and partial melting of Al-rich metasediments. An exo-perictetic reaction is assumed to account for both textural and geochemical observations. On the other hand, hybridization processes typical for calc-alkaline series can also explain the high proportions of “non-reactive” minerals observed in relatively high temperature magmas. This study clearly demonstrates that silicate melts in a crystal mush can depart significantly from the composition of melt that should be in equilibrium with the bulk solid assemblage.
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Nutrient dynamics and plant assemblages of Macrotermes falciger mounds in a savanna ecosystem
Muvengwi, Justice; Ndagurwa, Hilton G. T.; Nyenda, Tatenda; Mbiba, Monicah
2016-10-01
Termites through mound construction and foraging activities contribute significantly to carbon and nutrient fluxes in nutrient-poor savannas. Despite this recognition, studies on the influence of termite mounds on carbon and nitrogen dynamics in sub-tropical savannas are limited. In this regard, we examined soil nutrient concentrations, organic carbon and nitrogen mineralization in incubation experiments in mounds of Macrotermes falciger and surrounding soils of sub-tropical savanna, northeast Zimbabwe. We also addressed whether termite mounds altered the plant community and if effects were similar across functional groups i.e. grasses, forbs or woody plants. Mound soils had significantly higher silt and clay content, pH and concentrations of calcium (Ca), magnesium (Mg), potassium (K), organic carbon (C), ammonium (NH4+) and nitrate (NO3-) than surrounding soils, with marginal differences in phosphorus (P) and sodium (Na) between mounds and matrix soils. Nutrient enrichment increased by a factor ranging from 1.5 for C, 4.9 for Mg up to 10.3 for Ca. Although C mineralization, nitrification and nitrification fraction were similar between mounds and matrix soils, nitrogen mineralization was elevated on mounds relative to surrounding matrix soils. As a result, termite mounds supported unique plant communities rich and abundant in woody species but less diverse in grasses and forbs than the surrounding savanna matrix in response to mound-induced shifts in soil parameters specifically increased clay content, drainage and water availability, nutrient status and base cation (mainly Ca, Mg and Na) concentration. In conclusion, by altering soil properties such as texture, moisture content and nutrient status, termite mounds can alter the structure and composition of sub-tropical savanna plant communities, and these results are consistent with findings in other savanna systems suggesting that increase in soil clay content, nutrient status and associated changes in the plant
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Perlwitz, J. P.; Garcia-Pando, C. Perez; Miller, R. L.
2015-01-01
A global compilation of nearly sixty measurement studies is used to evaluate two methods of simulating the mineral composition of dust aerosols in an Earth system model. Both methods are based upon a Mean Mineralogical Table (MMT) that relates the soil mineral fractions to a global atlas of arid soil type. The Soil Mineral Fraction (SMF) method assumes that the aerosol mineral fractions match the fractions of the soil. The MMT is based upon soil measurements after wet sieving, a process that destroys aggregates of soil particles that would have been emitted from the original, undisturbed soil. The second method approximately reconstructs the emitted aggregates. This model is referred to as the Aerosol Mineral Fraction (AMF) method because the mineral fractions of the aerosols differ from those of the wet-sieved parent soil, partly due to reaggregation. The AMF method remedies some of the deficiencies of the SMF method in comparison to observations. Only the AMF method exhibits phyllosilicate mass at silt sizes, where they are abundant according to observations. In addition, the AMF quartz fraction of silt particles is in better agreement with measured values, in contrast to the overestimated SMF fraction. Measurements at distinct clay and silt particle sizes are shown to be more useful for evaluation of the models, in contrast to the sum over all particles sizes that is susceptible to compensating errors, as illustrated by the SMF experiment. Model errors suggest that allocation of the emitted silt fraction of each mineral into the corresponding transported size categories is an important remaining source of uncertainty. Evaluation of both models and the MMT is hindered by the limited number of size-resolved measurements of mineral content that sparsely sample aerosols from the major dust sources. The importance of climate processes dependent upon aerosol mineral composition shows the need for global and routine mineral measurements.
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Cruz-Motta, Juan José; Miloslavich, Patricia; Palomo, Gabriela; Iken, Katrin; Konar, Brenda; Pohle, Gerhard; Trott, Tom; Benedetti-Cecchi, Lisandro; Herrera, César; Hernández, Alejandra; Sardi, Adriana; Bueno, Andrea; Castillo, Julio; Klein, Eduardo; Guerra-Castro, Edlin; Gobin, Judith; Gómez, Diana Isabel; Riosmena-Rodríguez, Rafael; Mead, Angela; Bigatti, Gregorio; Knowlton, Ann; Shirayama, Yoshihisa
2010-01-01
Assemblages associated with intertidal rocky shores were examined for large scale distribution patterns with specific emphasis on identifying latitudinal trends of species richness and taxonomic distinctiveness. Seventy-two sites distributed around the globe were evaluated following the standardized sampling protocol of the Census of Marine Life NaGISA project (www.nagisa.coml.org). There were no clear patterns of standardized estimators of species richness along latitudinal gradients or among Large Marine Ecosystems (LMEs); however, a strong latitudinal gradient in taxonomic composition (i.e., proportion of different taxonomic groups in a given sample) was observed. Environmental variables related to natural influences were strongly related to the distribution patterns of the assemblages on the LME scale, particularly photoperiod, sea surface temperature (SST) and rainfall. In contrast, no environmental variables directly associated with human influences (with the exception of the inorganic pollution index) were related to assemblage patterns among LMEs. Correlations of the natural assemblages with either latitudinal gradients or environmental variables were equally strong suggesting that neither neutral models nor models based solely on environmental variables sufficiently explain spatial variation of these assemblages at a global scale. Despite the data shortcomings in this study (e.g., unbalanced sample distribution), we show the importance of generating biological global databases for the use in large-scale diversity comparisons of rocky intertidal assemblages to stimulate continued sampling and analyses. PMID:21179546
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Directory of Open Access Journals (Sweden)
Juan José Cruz-Motta
2010-12-01
Full Text Available Assemblages associated with intertidal rocky shores were examined for large scale distribution patterns with specific emphasis on identifying latitudinal trends of species richness and taxonomic distinctiveness. Seventy-two sites distributed around the globe were evaluated following the standardized sampling protocol of the Census of Marine Life NaGISA project (www.nagisa.coml.org. There were no clear patterns of standardized estimators of species richness along latitudinal gradients or among Large Marine Ecosystems (LMEs; however, a strong latitudinal gradient in taxonomic composition (i.e., proportion of different taxonomic groups in a given sample was observed. Environmental variables related to natural influences were strongly related to the distribution patterns of the assemblages on the LME scale, particularly photoperiod, sea surface temperature (SST and rainfall. In contrast, no environmental variables directly associated with human influences (with the exception of the inorganic pollution index were related to assemblage patterns among LMEs. Correlations of the natural assemblages with either latitudinal gradients or environmental variables were equally strong suggesting that neither neutral models nor models based solely on environmental variables sufficiently explain spatial variation of these assemblages at a global scale. Despite the data shortcomings in this study (e.g., unbalanced sample distribution, we show the importance of generating biological global databases for the use in large-scale diversity comparisons of rocky intertidal assemblages to stimulate continued sampling and analyses.
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International Nuclear Information System (INIS)
Chaudri, M.A.; Lee, M.M.; Rouse, J.L.; Weste, G.
1978-01-01
As part of a study of disease caused by Phytophthora cinnamomi in native vegetation, the mineral composition of diseased plants was compared with those free from disease, but grown under the same conditions. Young plants of Eucalyptus obliqua, three years old and with well-formed lignotubers, were selected (a) diseased plant from soil containing a high concentration of P. cinnamomi, and (b) unaffected plant from an adjacent area where the soil was free from this pathogen. The plants were ashed and their mineral composition was compared by activation analysis using proton beams from the Melbourne University Cyclotron. Results showed a 70% reduction in iron and 41% in titanium from diseased plants compared with disease-free plants. The reduction in iron is associated with severe chlorosis which occurs as a primary symptom in most plants attacked by this pathogen
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Uthicke, S.; Thompson, A.; Schaffelke, B.
2010-03-01
Although the debate about coral reef decline focuses on global disturbances (e.g., increasing temperatures and acidification), local stressors (nutrient runoff and overfishing) continue to affect reef health and resilience. The effectiveness of foraminiferal and hard-coral assemblages as indicators of changes in water quality was assessed on 27 inshore reefs along the Great Barrier Reef. Environmental variables (i.e., several water quality and sediment parameters) and the composition of both benthic foraminiferal and hard-coral assemblages differed significantly between four regions (Whitsunday, Burdekin, Fitzroy, and the Wet Tropics). Grain size and organic carbon and nitrogen content of sediments, and a composite water column parameter (based on turbidity and concentrations of particulate matter) explained a significant amount of variation in the data (tested by redundancy analyses) in both assemblages. Heterotrophic species of foraminifera were dominant in sediments with high organic content and in localities with low light availability, whereas symbiont-bearing mixotrophic species were dominant elsewhere. A similar suite of parameters explained 89% of the variation in the FORAM index (a Caribbean coral reef health indicator) and 61% in foraminiferal species richness. Coral richness was not related to environmental setting. Coral assemblages varied in response to environmental variables, but were strongly shaped by acute disturbances (e.g., cyclones, Acanthaster planci outbreaks, and bleaching), thus different coral assemblages may be found at sites with the same environmental conditions. Disturbances also affect foraminiferal assemblages, but they appeared to recover more rapidly than corals. Foraminiferal assemblages are effective bioindicators of turbidity/light regimes and organic enrichment of sediments on coral reefs.
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Schaafsma, A; Pakan, [No Value; Hofstede, GJH; Muskiet, FAJ; Van Der Veer, E; De Vries, PJF
2000-01-01
Chicken eggshell powder (ESP) might be an attractive source of Ca for human nutrition. To study its nutritional value, we analyzed minerals, amino acids, and hormones in commercially available Slovakian ESP. The mineral composition was compared with three Dutch ESP samples that differed in feed and
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Effect of Wood Aging on Wine Mineral Composition and 87Sr/86Sr Isotopic Ratio.
Kaya, Ayse D; Bruno de Sousa, Raúl; Curvelo-Garcia, António S; Ricardo-da-Silva, Jorge M; Catarino, Sofia
2017-06-14
The evolution of mineral composition and wine strontium isotopic ratio 87 Sr/ 86 Sr (Sr IR) during wood aging were investigated. A red wine was aged in stainless steel tanks with French oak staves (Quercus sessiliflora Salisb.), with three industrial scale replicates. Sampling was carried out after 30, 60, and 90 days of aging, and the wines were evaluated in terms of general analysis, phenolic composition, total polysaccharides, multielement composition, and Sr IR. Li, Be, Mg, Al, Sc, Ti, V, Mn, Co, Ni, Cu, Zn, Ga, Ge, As, Rb, Sr, Y, Zr, Mo, Sb, Cs, Ba, Pr, Nd, Sm, Eu, Dy, Ho, Er, Yb, Lu, Tl, and Pb elements and 87 Sr/ 86 Sr were determined by quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS) and Na, K, Ca, and Fe by flame atomic absorption spectrometry (FAAS). Two-way ANOVA was applied to assess wood aging and time effect on Sr IR and mineral composition. Wood aging resulted in significantly higher concentrations of Mg, V, Co, Ni, and Sr. At the end of the aging period, wine exhibited statistically identical Sr IR compared to control. Study suggests that wood aging does not affect 87 Sr/ 86 Sr, not precluding the use of this parameter for wine traceability purposes.
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Characteristics in mineral compositions of lunar latest mare volcanism revealed from spectral data
Kato, S.; Morota, T.; Yamaguchi, Y.; Watanabe, S.; Otake, H.; Ohtake, M.; Nimura, T.
2016-12-01
Lunar mare basalts provide insights into the composition and thermal history of the lunar mantle. According to crater counting analysis with remote sensing data, the ages of mare basalts suggest a first peak of magma activity at 3.2-3.8 Ga and a second peak at 2 Ga. In order to understand the mechanism for causing the second peak and its magma source, we reassess the correlation between the titanium contents and the eruption ages of mare basalt units using the compositional and chronological data updated by SELENE (Kaguya). In the Procellarum KREEP Terrane, where the latest mare basalt units are concentrated, an increase in the mean titanium content is observed in the Eratosthenian Period, as reported by previous studies. We found that, however, a rapid increase in mean titanium content occurred near 2.3 Ga. This result suggests that the magma source of the mare basalts changed at this particular age. Moreover, the high-titanium basaltic eruptions are correlated with the second peak in mare volcanism at 2 Ga. The latest mare volcanism may have been induced by a super-hot plume originating from the core-mantle boundary. In this study, to reveal the difference between the volcanic activities before and after 2.3 Ga, we developed the method to estimate the mineral components and elemental compositions of lunar mare basalts by using the Kaguya Spectral Profiler data. We will introduce the detail of the method and discuss about the difference between the mineral compositions of mare basalts before and after 2.3 Ga based on our preliminary results.
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Bone mineral density and body composition in Noonan's syndrome: effects of growth hormone treatment
Noordam, C.; Span, J.; van Rijn, R. R.; Gomes-Jardin, E.; van Kuijk, C.; Otten, B. J.
2002-01-01
We assessed bone mineral density (BMD) and body composition in children with Noonan's syndrome (NS) before and during growth hormone (GH) treatment. Sixteen children (12 boys, 4 girls) with NS aged 5.8-14.2 (mean 10.0) years were studied for 2 years. Anthropometry, BMD measurements by radiographic
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Silvey, Colin J; Hayward, Matthew W; Gibb, Heloise
2015-06-01
Species loss can result in changes in assemblage structure and ecosystem function through ecological cascades. Australian vertebrate assemblages changed significantly following European colonisation, which resulted in the establishment of invasive vertebrates and the loss of native marsupials, many of which consume invertebrates. Conservation focusses on the removal of invasive carnivores and the reintroduction of regionally extinct species to fenced sites, resulting in what could be considered a reconstruction of pre-European vertebrate assemblages. In semi-arid Australian spinifex mallee ecosystems, we asked: (1) what is the effect of reconstructed pre-European vertebrate assemblages on native arachnid assemblages? and (2) what direct or indirect mechanisms (predation, disturbance and/or competition) could plausibly be responsible for these effects? We compared sites with reconstructed vertebrate assemblages with paired control sites. Arachnids were sampled using pitfall trapping and direct searching. Hypotheses regarding mechanisms were tested using scat analysis (predation) and by comparing burrow depth (disturbance) and scorpion mass (competition) between control and reconstructed sites. The dominant dune scorpion, Urodacus yaschenkoi, was less abundant and a wolf spider (Lycosa gibsoni species group) more abundant in reconstructed sites. Differences in spider assemblage composition were marginally non-significant. Scat analysis confirmed native vertebrate predation on scorpions and we found no evidence that competition or disturbance affected scorpions. We, thus, suggest that changes in spider assemblages may have resulted from ecological cascades via decreases in dune scorpions. The loss of omnivorous mammals and other changes associated with the invasion of carnivores may, therefore, have had broad-reaching consequences for native arachnid assemblages in Australian ecosystems.
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Rock encrusting assemblages: Structure and distribution along the Baltic Sea
Grabowska, Monika; Grzelak, Katarzyna; Kukliński, Piotr
2015-09-01
Aquatic community structure and dynamics are generally controlled by a variety of biological and physical factors. Among these factors in marine ecosystems, salinity is known to have a significant effect on species occurrence and composition. In this study, we investigated the large-scale distribution and abundance of encrusting fauna along a salinity gradient on the shallow Baltic Sea rocky coast. Rock samples collected from 14 locations distributed between the Gulf of Bothnia (salinity 0.6) and Skagerrak (salinity 28) supported a total number of 24 encrusting species. The faunas were composed mostly of marine species with opportunistic life histories; however, some brackish water specialists were also present. The number of species and abundance counts is strongly positively correlated with increases in salinity. No encrusting faunas were recorded below salinity level 4. Multivariate analysis (nMDS) revealed three major groups based on species composition that differed in terms of abundance and number of species. Each group was associated with specific salinity conditions. The first assemblage type occurred within salinity 4-7, the second within salinity between 22 and 27, and the third type was a mixture between the two observed at a salinity of approximately 17. This study indicates that to determine the assemblage structure of the Baltic Sea encrusting fauna, analyses at the family level were found to be a reliable surrogate for species composition.
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Mineral composition and ash content of six major energy crops
Energy Technology Data Exchange (ETDEWEB)
Monti, Andrea; Venturi, Gianpietro [Department of Agroenvironmental Science and Technologies (DiSTA), University of Bologna, Viale G. Fanin, 44, 40127 Bologna (Italy); Di Virgilio, Nicola [Institute of Biometeorology, National Research Council, Via P. Gobetti, 101 I, 40129 Bologna (Italy)
2008-03-15
The chemical composition of biofuels has not received adequate attention given that it is an important aspect in the introduction of energy crops. In this study, the ash content and mineral composition (C, N, Al, Ca, Cl, Fe, K, Mg, Na, P, S, Si) of stems, leaves and reproductive organs of some promising energy crops were determined and compared with the respective recommended thresholds reported in literature. Overall, cynara exhibited the highest ash and mineral contents, which indicate high slagging, fouling and corrosion tendencies. However, cynara also showed the lowest Si content, both in leaves (4.3 g kg{sup -1}) and in stems (0.9 g kg{sup -1}). Sweet sorghum and giant reed exhibited the highest N content (up to 16 g kg{sup -1}), which greatly exceeded the recommended limits in leaves. Importantly, Cl always exceeded the recommended limits (up to 18 mg kg{sup -1} in cynara), both in stems and in leaves, thus resulting in a major stumbling block for all crops. Several significant correlations among elements were found at a single plant part; conversely these correlations were generally very weak considering different plant components, with the exception of K (r=0.91**), P (r=0.94**) and ashes (r=0.64**). Generally, leaves resulted in a significant deterioration of biofuel quality when compared with stems and flower heads. Therefore, agricultural strategies aimed at reducing the leaf component (e.g. by delaying the harvest) may considerably improve the suitability of biofuels for current combustion plants. (author)
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International Nuclear Information System (INIS)
Deuerling, Justin M.; Rudy, David J.; Niebur, Glen L.; Roeder, Ryan K.
2010-01-01
Purpose: Microcomputed tomography (micro-CT) is increasingly used as a nondestructive alternative to ashing for measuring bone mineral content. Phantoms are utilized to calibrate the measured x-ray attenuation to discrete levels of mineral density, typically including levels up to 1000 mg HA/cm 3 , which encompasses levels of bone mineral density (BMD) observed in trabecular bone. However, levels of BMD observed in cortical bone and levels of tissue mineral density (TMD) in both cortical and trabecular bone typically exceed 1000 mg HA/cm 3 , requiring extrapolation of the calibration regression, which may result in error. Therefore, the objectives of this study were to investigate (1) the relationship between x-ray attenuation and an expanded range of hydroxyapatite (HA) density in a less attenuating polymer matrix and (2) the effects of the calibration on the accuracy of subsequent measurements of mineralization in human cortical bone specimens. Methods: A novel HA-polymer composite phantom was prepared comprising a less attenuating polymer phase (polyethylene) and an expanded range of HA density (0-1860 mg HA/cm 3 ) inclusive of characteristic levels of BMD in cortical bone or TMD in cortical and trabecular bone. The BMD and TMD of cortical bone specimens measured using the new HA-polymer calibration phantom were compared to measurements using a conventional HA-polymer phantom comprising 0-800 mg HA/cm 3 and the corresponding ash density measurements on the same specimens. Results: The HA-polymer composite phantom exhibited a nonlinear relationship between x-ray attenuation and HA density, rather than the linear relationship typically employed a priori, and obviated the need for extrapolation, when calibrating the measured x-ray attenuation to high levels of mineral density. The BMD and TMD of cortical bone specimens measured using the conventional phantom was significantly lower than the measured ash density by 19% (p<0.001, ANCOVA) and 33% (p<0.05, Tukey's HSD
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Directory of Open Access Journals (Sweden)
Saïkou Oumar Kidé
Full Text Available Environmental changes and human activities can have strong impacts on biodiversity and ecosystem functioning. This study investigates how, from a quantitative point of view, simultaneously both environmental and anthropogenic factors affect species composition and abundance of exploited groundfish assemblages (i.e. target and non-target species at large spatio-temporal scales. We aim to investigate (1 the spatial and annual stability of groundfish assemblages, (2 relationships between these assemblages and structuring factors in order to better explain the dynamic of the assemblages' structure. The Mauritanian Exclusive Economic Zone (MEEZ is of particular interest as it embeds a productive ecosystem due to upwelling, producing abundant and diverse resources which constitute an attractive socio-economic development. We applied the multi-variate and multi-table STATICO method on a data set consisting of 854 hauls collected during 14-years (1997-2010 from scientific trawl surveys (species abundance, logbooks of industrial fishery (fishing effort, sea surface temperature and chlorophyll a concentration as environmental variables. Our results showed that abiotic factors drove four main persistent fish assemblages. Overall, chlorophyll a concentration and sea surface temperature mainly influenced the structure of assemblages of coastal soft bottoms and those of the offshore near rocky bottoms where upwellings held. While highest levels of fishing effort were located in the northern permanent upwelling zone, effects of this variable on species composition and abundances of assemblages were relatively low, even if not negligible in some years and areas. The temporal trajectories between environmental and fishing conditions and assemblages did not match for all the entire time series analyzed in the MEEZ, but interestingly for some specific years and areas. The quantitative approach used in this work may provide to stakeholders, scientists and fishers a
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PIXE studies of changes in mineral composition of plants infected with Phytophthora cinnamomi
International Nuclear Information System (INIS)
Chaudhri, M.A.; Melbourne Univ., Austin; Weste, G.; Papper, C.S.
1981-01-01
The mineral composition of susceptible and resistant plants from native forests infected with Phytophthora cinnamomi was compared between themselves and with the same species from disease-free areas. Root and shoot samples from different plants were carefully ashed, compressed into pellets and analysed with the thick target PIXE technique. A number of elements, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Rb, Sr, Zr, Sn, and Pb, were detected. Many of the elements showed variations, sometimes large, between the composition of suspectible and resistant plants, and between the same species from infected and disease-free forests. (orig.)
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The diversity of beetle assemblages in different habitat types in Sabah, Malaysia.
Chung, A Y; Eggleton, P; Speight, M R; Hammond, P M; Chey, V K
2000-12-01
The diversity of beetle assemblages in different habitat types (primary forest, logged forest, acacia plantation and oil palm plantation) in Sabah, Malaysia was investigated using three different methods based on habitat levels (Winkler sampling, flight-interception-trapping and mist-blowing). The overall diversity was extremely high, with 1711 species recorded from only 8028 individuals and 81 families (115 family and subfamily groups). Different degrees of environmental changes had varying effects on the beetle species richness and abundance, with oil palm plantation assemblage being most severely affected, followed by acacia plantation and then logged forest. A few species became numerically dominant in the oil palm plantation. In terms of beetle species composition, the acacia fauna showed much similarity with the logged forest fauna, and the oil palm fauna was very different from the rest. The effects of environmental variables (number of plant species, sapling and tree densities, amount of leaf litter, ground cover, canopy cover, soil pH and compaction) on the beetle assemblage were also investigated. Leaf litter correlated with species richness, abundance and composition of subterranean beetles. Plant species richness, tree and sapling densities correlated with species richness, abundance and composition of understorey beetles while ground cover correlated only with the species richness and abundance of these beetles. Canopy cover correlated only with arboreal beetles. In trophic structure, predators represented more than 40% of the species and individuals. Environmental changes affected the trophic structure with proportionally more herbivores (abundance) but fewer predators (species richness and abundance) in the oil palm plantation. Biodiversity, conservation and practical aspects of pest management were also highlighted in this study.
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Composite bulk Heat Insulation Made of loose Mineral and Organic Aggregate
Directory of Open Access Journals (Sweden)
Namsone Eva
2015-12-01
Full Text Available The task of building energy-efficiency is getting more important. Every house owner wishes to save up exploitation costs of heating, cooling, hot water production, ventilation, etc. and find cost-effective investments. One of the ways to reduce greenhouse gas emissions (GHGE is to minimize the heat transfer through the building by insulating it. Loose heat insulation is a good alternative to traditional board insulation, it is simple in use and cost-effective. Main drawback of this insulation is tendency to compact during exploitation. In the frame of this research composite loose heat insulation is elaborated, consisting on porous mineral foamed glass aggregate and local organic fiber materials (hemp and flaxen shives. Composite bulk insulation is an alternative solution which combines heat insulating properties and mechanical stability.
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Evaluation of the mineral composition of breadstuff and frequency its consumption.
Winiarska-Mieczan, Anna; Kwiecień, Małgorzata
2011-01-01
The aim of the study was to assess some selected minerals (Ca, Mg, Na, K, P, Fe, Zn, Cu, Mn) in different types of breadstuff. Moreover, the frequency of breadstuff consumption was determined in a selected group of students at one of Lublin universities. The material for the study was breadstuff available on the consumer market, produced from wheat and rye flour, of varied degree of grinding. In the samples the content of dry matter, crude ash and minerals (Ca, Mg, Na, K, P, Mn, Cu, Fe and Zn) was determined. A questionnaire investigation was performed in a group of 100 university students in Lublin. The questionnaire included questions which were helpful in determining the frequency of the consumed breadstuff. The content of mineral elements in breadstuff depended on its recipe's composition and their higher share was noted in rye and mixed-flour bread. Whole wheat bread was richer in minerals in comparison with white bread. Assuming that a statistical Pole consumes daily 166 g of bread, it may be calculated that the men consumes daily with bread 512 mg of P (73% of RDA) and 0.7 mg of Cu (ca. 78% of RDA), ca. 20 mg of Ca (1.6-2.0% of AI), 93 mg of Mg (ca. 22-30% of RDA), 602 mg of Na (40-50% of AI), 183 mg of K (3.9% of AI), 4.5 mg of Fe (25-45% of RDA) and 3 mg of Zn (29-40% of RDA). Bread is an important source of minerals, especially phosphorus and copper. Among students an excessive consumption of white bread should be noted contrasting with a low intake of whole wheat or whole meal bread.
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Netburn, Amanda N.; Koslow, J. Anthony
2018-04-01
With strong horizontal gradients in physical properties, oceanic frontal regions can lead to disproportionately high biological productivity. We examined cross-frontal changes in mesopelagic fish assemblages at three separate frontal systems in the southern California Current Ecosystem (CCE) as part of the CCE Long Term Ecological Research program: the A-Front sampled in October 2008, the C-Front in June/July 2011, and the E-Front in July/August 2012. We analyzed the differential effects of front-associated regions on density and species composition of adult migratory and non-migratory fishes and larvae, and the larval to adult ratio (as a possible index of a population growth potential) for migratory and non-migratory species. The fronts did not have a strong effect on densities of any subset of the mesopelagic fish assemblage. The species composition of the vertical migratory fishes (and their larvae) was typically altered across fronts, with different assemblages present on either side of each front. The migratory assemblages at the fronts themselves were indistinguishable from those at the more productive side of the frontal system. In contrast, the assemblage composition of the non-migratory fishes was indistinguishable between regions across all three of the fronts. The differences between the Northern and Southern assemblages at the A-Front were primarily based on biogeographic provinces, while the assemblages at the E-Front were largely distinguishable by their oceanic or coastal-upwelling zone associations. These results generally confirm those of previous studies on frontal systems in the California Current Ecosystem and elsewhere. The ratio of larvae to adults, a potential index of population growth potential, was altered across two of the fronts for migratory species, elevated on the colder side of the A-Front and the warmer side of the E-Front. This finding suggests that fronts may be regions of enhanced reproduction. The larvae to adult ratio was
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Mineral composition of enamel from two South African population groups
Energy Technology Data Exchange (ETDEWEB)
Retief, D H [University of the Witwatersrand, Johannesburg (South Africa). Dental Research Unit; Turkstra, J [University of Fort Hare, Alice (South Africa). Department of Chemistry; Cleaton-Jones, P E; Biddlecombe, F [Atomic Energy Board, Pelindaba, Pretoria (South Africa). Chemistry Div.
1979-10-01
The mineral composition of pooled bulk enamel from Black and White South Africans respectively, resident in the Johannesburg area, was determined by neutron activation analysis and high resolution gamma spectromety. The differences between the concentrations of Ca, Cl, Mg, Na, Br and Co in the enamel of the two population groups were apparently not significant. There was a trend for the concentrations of Al, Ag, Au, Fe, Sb, and Zn to be higher in the enamel from the White subjects and for the concentrations of Mn, Se and Sr to be higher in the enamel from the Black subjects.
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Rare Earth Element Fluorocarbonate Minerals from the Olympic Dam Cu-U-Au-Ag Deposit, South Australia
Directory of Open Access Journals (Sweden)
Danielle S. Schmandt
2017-10-01
Full Text Available Olympic Dam is a world-class breccia-hosted iron-oxide copper-gold-uranium ore deposit located in the Gawler Craton, South Australia. It contains elevated concentrations of rare earth elements (REE which occur as the REE minerals bastnäsite, synchysite, florencite, monazite, and xenotime. This is the first study to focus on the mineralogy and composition of the most abundant REE mineral at Olympic Dam, bastnäsite, and subordinate synchysite. The sample suite extends across the deposit and represents different sulfide mineralization styles (chalcopyrite-bornite and bornite-chalcocite and breccias of various types, ranging from those dominated by clasts of granite, dykes, and hematite. The REE-fluorocarbonates (bastnäsite and synchysite typically occur as fine-grained (<50 μm disseminations in Cu-Fe-sulfides and gangue minerals, and also within breccia matrix. They are also locally concentrated within macroscopic REE-mineral-rich pockets at various locations across the deposit. Such coarse-grained samples formed the primary target of this study. Three general textural groups of bastnäsite are recognized: matrix (further divided into disseminated, fine-grained, and stubby types, irregular (sulfide-associated, and clast replacement. Textures are largely driven by the specific location and prevailing mineral assemblage, with morphology and grain size often controlled by the associated minerals (hematite, sulfides. Major element concentration data reveal limited compositional variation among the REE-fluorocarbonates; all are Ce-dominant. Subtle compositional differences among REE-fluorocarbonates define a spectrum from relatively La-enriched to (Ce + Nd-enriched phases. Granite-derived hydrothermal fluids were the likely source of F in the REE-fluorocarbonates, as well as some of the CO2, which may also have been contributed by associated mafic-ultramafic magmatism. However, transport of REE by Cl-ligands is the most likely scenario. Stubby bastn
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Metamorphism, metasomatism and mineralization at Lagoa Real, Bahia, Brazil
International Nuclear Information System (INIS)
Lobato, L.M.
1985-09-01
Uranium deposits cumulatively in the 100,000 tonne U 3 O 8 range occur within ductile shear zones transecting Archean basement gneisses of the Sao Francisco Craton, at the Lagoa Real region of south-central Bahia, Brasil. The gneisses, dated at 2.6-3.0Ga, are at amphibolite and granulite facies and overlie to the west, the Proterozoic Espinhaco metasedimentary sequence along a thrust fault. Petrography and mineral chemistry show that in the zones of alteration/mineralization, the original K-feldspar + quartz + albite/oligoclase + hastingsite assemblage, is replaced by albite + aegirine - angite + andradite + hematite assemblages, with or without uraninite. This information along with oxygen isotope, whole rock geochemistry and fluid inclusion studies indicate that the alteration process involves removal of Si, K, Rb, Ba and addition of Na under oxidizing conditions. V, Pb and Sr were introduced along with U via interaction with saline SO 2 - rich, isotopically light fluids under varying water/rock ratios and at temperatures of 500 - 550 0 C. 87 Sr/ 86 Sr systematics suggest that it is unlikely that Sr, and by extension uranium, were introduced by fluids originating from the basement gneisses. Geological constraints and the general alteration pattern are consistent with the release of the mineralizing fluids in response to the overloading of the basement rocks onto the Sedimentary Espinhaco via a thrust mechanism. (Author) [pt
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International Nuclear Information System (INIS)
Liu Zhangyue; Dong Wenming; Cai Genqing; Liu Hongxu; Deng Huabo
2011-01-01
By studying the palaeoclimate and metallogenesis related geochemical indexes, this paper proposes that the hosting rocks should form in geochemical oxidation setting under arid palaeoclimate. The study on element assemblage associated with uranium mineralization indicates that the target hosting rocks suffered from different degrees of reworking of reducing fluid at first and then being superimposed by supergene oxidative fluid at tectonic uplifting stage. The uranium mineralization is located in reworked and superimposed places of two types of fluid. (authors)
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Energy Technology Data Exchange (ETDEWEB)
Ribeiro, Roberto Carlos da C.; Seidl, Peter Rudolf [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica; Correia, Julio Cesar Guedes [Centro de Tecnologia Mineral - CETEM, Rio de Janeiro, RJ (Brazil)
2004-07-01
The performance of asphalt pavements depends mainly on the properties of their constituents: mineral aggregates and asphalt cement. The mineral aggregate represents about 95% in weight of asphalt mixtures having a significant influence on the properties and performance of these mixtures. Asphalt cement (CAP) corresponds to the smaller fraction but it is mainly responsible for adsorption on the mineral aggregates. The objective of this study was to evaluate the interaction between different CAPs with residues from granite saw wills in place of mineral aggregates that run up costs with extraction and processing in asphalt production. This way asphalt production costs as well as the environmental problems that are caused by mineral residue are reduced. Five different asphalt cements, referred to as A, B, C, D and E, and a granite residue were used in this work. The results indicated that the residue strongly absorbs all the CAPs that were studied; particularly CAP A, which is considered the most adequate for the production of asphalt from this residue. Preliminary tests this indicate that asphalt production can use mineral residues instead of mineral aggregates in its composition. (author)
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Chavagnac, Valérie; Ceuleneer, Georges; Monnin, Christophe; Lansac, Benjamin; Hoareau, Guilhem; Boulart, Cédric
2013-07-01
We report on the mineralogical assemblages found in the hyperalkaline springs hosted on Liguria and Oman ophiolites based on exhaustive X-ray diffraction and scanning electron microprobe analyses. In Liguria, hyperalkaline springs produce a thin brownish calcite precipitate that covers the bedrock due to the concomitant atmospheric CO2 uptake and neutralization of the hyperalkaline waters. No brucite and portlandite minerals are observed. The discharge of alkaline waters in Oman ophiolite forms white-orange precipitates. Calcium carbonate minerals (calcite and/or aragonite) are the most abundant and ubiquitous precipitates and are produced by the same mechanism as in Liguria. This process is observed as a thin surface crust made of rhombohedral calcite. Morphological features of aragonite vary from needle-, bouquet-, dumbbell-, spheroidal-like habitus according to the origin of carbon, temperature, and ionic composition of the hyperalkaline springs, and the biochemical and organic compounds. Brucite is observed both at hyperalkaline springs located at the thrust plane and at the paleo-Moho. The varying mixing proportions between the surface runoff waters and the hyperalkaline ones control brucite precipitation. The layered double hydroxide minerals occur solely in the vicinity of hyperalkaline springs emerging within the bedded gabbros. Finally, the dominant mineralogical associations we found in Oman (Ca-bearing carbonates and brucite) in a serpentinizing environment driven by the meteoric waters are surprisingly the same as those observed at the Lost City hydrothermal site in a totally marine environment.
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Reproducibility of DXA measurements of bone mineral density and body composition in children
Energy Technology Data Exchange (ETDEWEB)
Leonard, Cheryl M.; Roza, Melissa A.; Webber, Colin E. [Hamilton Health Sciences, Department of Nuclear Medicine, Hamilton, ON (Canada); Barr, Ronald D. [McMaster Children' s Hospital, Hamilton, ON (Canada)
2009-02-15
The technique of X-ray-based dual photon absorptiometry (DXA) is frequently used in children for the detection of changes in bone mass or body composition. Such changes can only be considered real if the uncertainties arising from the measurement technique are exceeded. Our objectives were twofold: (1) to determine the reproducibility of bone mineral density (BMD) measurements in children at the spine and the hip and from the whole body, as well as of whole-body measurements of mineral mass, lean body mass and fat mass in children; and (2) to estimate, from the measured precision, the time interval that needs to elapse before a statistically significant change in a DXA variable can be detected. The reproducibility of techniques for the measurement of BMD and body composition using DXA was measured in 15 young children (9 girls and 6 boys) and 17 older children (9 girls and 8 boys). Reproducibility was derived from the standard deviation of three repeated measurements of spine BMD, total hip BMD, whole-body BMD (WBBMD), whole-body bone mineral content (WBBMC), lean mass and fat mass. Technique precision was better than 0.01 g cm{sup -2} for spine BMD and for WBBMD. Hip BMD measurements were slightly less precise, particularly in younger children (0.013 g cm{sup -2}). For body composition variables, technique precision was 13 g for WBBMC, 201 g for lean body mass and 172 g for fat mass in younger children. Technique precision for older children was 18 g, 251 g and 189 g for the corresponding variables. Predictions showed that the absence of a normal increase in WBBMC in a small-for-age girl could be established after 12 months. For spine BMD, a significant increase should be observable after 6 months for boys over the age of 11 years. For younger boys, more than 12 months has to elapse before anticipated changes can be detected with confidence. The time intervals required to elapse before decisions can be made concerning the significance of observed differences
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Reproducibility of DXA measurements of bone mineral density and body composition in children
International Nuclear Information System (INIS)
Leonard, Cheryl M.; Roza, Melissa A.; Webber, Colin E.; Barr, Ronald D.
2009-01-01
The technique of X-ray-based dual photon absorptiometry (DXA) is frequently used in children for the detection of changes in bone mass or body composition. Such changes can only be considered real if the uncertainties arising from the measurement technique are exceeded. Our objectives were twofold: (1) to determine the reproducibility of bone mineral density (BMD) measurements in children at the spine and the hip and from the whole body, as well as of whole-body measurements of mineral mass, lean body mass and fat mass in children; and (2) to estimate, from the measured precision, the time interval that needs to elapse before a statistically significant change in a DXA variable can be detected. The reproducibility of techniques for the measurement of BMD and body composition using DXA was measured in 15 young children (9 girls and 6 boys) and 17 older children (9 girls and 8 boys). Reproducibility was derived from the standard deviation of three repeated measurements of spine BMD, total hip BMD, whole-body BMD (WBBMD), whole-body bone mineral content (WBBMC), lean mass and fat mass. Technique precision was better than 0.01 g cm -2 for spine BMD and for WBBMD. Hip BMD measurements were slightly less precise, particularly in younger children (0.013 g cm -2 ). For body composition variables, technique precision was 13 g for WBBMC, 201 g for lean body mass and 172 g for fat mass in younger children. Technique precision for older children was 18 g, 251 g and 189 g for the corresponding variables. Predictions showed that the absence of a normal increase in WBBMC in a small-for-age girl could be established after 12 months. For spine BMD, a significant increase should be observable after 6 months for boys over the age of 11 years. For younger boys, more than 12 months has to elapse before anticipated changes can be detected with confidence. The time intervals required to elapse before decisions can be made concerning the significance of observed differences between
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Directory of Open Access Journals (Sweden)
Wes Toller
Full Text Available Saba Bank is a 2,200 km(2 submerged carbonate platform in the northeastern Caribbean Sea off Saba Island, Netherlands Antilles. The presence of reef-like geomorphic features and significant shelf edge coral development on Saba Bank have led to the conclusion that it is an actively growing, though wholly submerged, coral reef atoll. However, little information exists on the composition of benthic communities or associated reef fish assemblages of Saba Bank. We selected a 40 km(2 area of the bank for an exploratory study. Habitat and reef fish assemblages were investigated in five shallow-water benthic habitat types that form a gradient from Saba Bank shelf edge to lagoon. Significant coral cover was restricted to fore reef habitat (average cover 11.5% and outer reef flat habitat (2.4% and declined to near zero in habitats of the central lagoon zone. Macroalgae dominated benthic cover in all habitats (average cover: 32.5--48.1% but dominant algal genera differed among habitats. A total of 97 fish species were recorded. The composition of Saba Bank fish assemblages differed among habitat types. Highest fish density and diversity occurred in the outer reef flat, fore reef and inner reef flat habitats. Biomass estimates for commercially valued species in the reef zone (fore reef and reef flat habitats ranged between 52 and 83 g/m(2. The composition of Saba Bank fish assemblages reflects the absence of important nursery habitats, as well as the effects of past fishing. The relatively high abundance of large predatory fish (i.e. groupers and sharks, which is generally considered an indicator of good ecosystem health for tropical reef systems, shows that an intact trophic network is still present on Saba Bank.
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Recent disturbances augment community shifts in coral assemblages in Moorea, French Polynesia
Pratchett, Morgan S.; Trapon, Melanie L.; Berumen, Michael L.; Chong-Seng, Karen M.
2010-01-01
Coral reefs are often subject to disturbances that can cause enduring changes in community structure and abundance of coral reef organisms. In Moorea, French Polynesia, frequent disturbances between 1979 and 2003 caused marked shifts in taxonomic composition of coral assemblages. This study explores recent changes in live cover and taxonomic structure of coral communities on the north coast of Moorea, French Polynesia, to assess whether coral assemblages are recovering (returning to a previous Acropora-dominated state) or continuing to move towards an alternative community structure. Coral cover declined by 29.7% between July 2003 and March 2009, mostly due to loss of Acropora and Montipora spp. Coral mortality varied among habitats, with highest levels of coral loss on the outer reef slope (7-20 m depth). In contrast, there was limited change in coral cover within the lagoon, and coral cover actually increased on the reef crest. Observed changes in coral cover and composition correspond closely with the known feeding preferences and observed spatial patterns of Acanthaster planci L., though observed coral loss also coincided with at least one episode of coral bleaching, as well as persistent populations of the corallivorous starfish Culcita novaeguineae Muller & Troschel. While climate change poses an important and significant threat to the future structure and dynamics coral reef communities, outbreaks of A. planci remain a significant cause of coral loss in Moorea. More importantly, these recent disturbances have followed long-term shifts in the structure of coral assemblages, and the relative abundance of both Pocillopora and Porites continue to increase due to disproportionate losses of Acropora and Montipora. Moreover, Pocillopora and Porites dominate assemblages of juvenile corals, suggesting that there is limited potential for a return to an Acropora-dominated state, last recorded in 1979. © 2010 Springer-Verlag.
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Directory of Open Access Journals (Sweden)
Vanessa Ernandes de Amo
2017-12-01
Full Text Available Abstract Aim: Identify the effects of sediment composition and water conditions on diversity, richness, evenness, density and composition of freshwater Oligochaeta in shallow floodplain lakes. Methods We sampled 13 shallow floodplain lakes quarterly during the year 2010 in the Upper Paraná River floodplain. In each lake, four sediment samples were taken from the shore and central regions, three of them were used for biological analysis, and one for granulometric analysis. Concomitantly, temperature, dissolved oxygen, pH, conductivity, alkalinity, turbidity and chlorophyll-a were also measured. Initially, the biological samples were analyzed by a stereoscopic microscope. Oligochaeta individuals were identified under optical microscope at the lowest possible taxonomic level. For data analysis, we quantified density, richness, evenness and diversity index of freshwater Oligochaeta. In order to show differences between the months and the analyzed lakes, in relation to the percentages of coarse and fine organic material, the nonparametric Kruskal Wallis test was used. We also calculated the sediment granulometric diversity using the Shannon-Wienner index, using a simple regression analysis. We correlated assemblage attributes of Oligochaeta with sediment diversity and the assemblage species with the limnological variables using the Spearman correlation. Results A total of 2,090 individuals were found distributed among 27 species. From the total individuals number, 57% were Pristina americana, followed by Dero (Dero righii with 13%. Assemblage attributes were not significantly correlated with sediment diversity, and 7 of the 27 species recorded showed significant correlations with at least some of the abiotic variables. Conclusions We verified that the abiotic variables of the water present greater influence on the attributes of the assemblage of freshwater Oligochaeta, when compared with sediment influences. Although we found low local diversity of
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Recent disturbances augment community shifts in coral assemblages in Moorea, French Polynesia
Pratchett, Morgan S.
2010-09-19
Coral reefs are often subject to disturbances that can cause enduring changes in community structure and abundance of coral reef organisms. In Moorea, French Polynesia, frequent disturbances between 1979 and 2003 caused marked shifts in taxonomic composition of coral assemblages. This study explores recent changes in live cover and taxonomic structure of coral communities on the north coast of Moorea, French Polynesia, to assess whether coral assemblages are recovering (returning to a previous Acropora-dominated state) or continuing to move towards an alternative community structure. Coral cover declined by 29.7% between July 2003 and March 2009, mostly due to loss of Acropora and Montipora spp. Coral mortality varied among habitats, with highest levels of coral loss on the outer reef slope (7-20 m depth). In contrast, there was limited change in coral cover within the lagoon, and coral cover actually increased on the reef crest. Observed changes in coral cover and composition correspond closely with the known feeding preferences and observed spatial patterns of Acanthaster planci L., though observed coral loss also coincided with at least one episode of coral bleaching, as well as persistent populations of the corallivorous starfish Culcita novaeguineae Muller & Troschel. While climate change poses an important and significant threat to the future structure and dynamics coral reef communities, outbreaks of A. planci remain a significant cause of coral loss in Moorea. More importantly, these recent disturbances have followed long-term shifts in the structure of coral assemblages, and the relative abundance of both Pocillopora and Porites continue to increase due to disproportionate losses of Acropora and Montipora. Moreover, Pocillopora and Porites dominate assemblages of juvenile corals, suggesting that there is limited potential for a return to an Acropora-dominated state, last recorded in 1979. © 2010 Springer-Verlag.
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Granitoid-associated gold mineralization in Egypt: a case study from the Atalla mine
Zoheir, Basem; Deshesh, Fatma; Broman, Curt; Pitcairn, Iain; El-Metwally, Ahmed; Mashaal, Shabaan
2018-06-01
Gold-bearing sulfide-quartz veins cutting mainly through the Atalla monzogranite intrusion in the Eastern Desert of Egypt are controlled by subparallel NE-trending brittle shear zones. These veins are associated with pervasive sericite-altered, silicified, and ferruginated rocks. The hosting shear zones are presumed as high-order structures of the Najd-style faults in the Central Eastern Desert ( 615-585 Ma). Ore minerals include an early pyrite-arsenopyrite (±pyrrhotite) mineralization, partly replaced by a late pyrite-galena-sphalerite-chalcopyrite (±gold/electrum ± tetrahedrite ± hessite) assemblage. Gold occurs as small inclusions in pyrite and arsenopyrite, or more commonly as intergrowths with galena and sphalerite/tetrahedrite in microfractures. Arsenopyrite geothermometry suggests formation of the early Fe-As-sulfide mineralization at 380-340 °C, while conditions of deposition of the late base metal-gold assemblage are assumed to be below 300 °C. Rare hessite, electrum, and Bi-galena are associated with sphalerite and gold in the late assemblage. The early and late sulfide minerals show consistently a narrow range of δ34S ‰ (3.4-6.5) that overlaps with sulfur isotopic values in ophiolitic rocks. The Au-quartz veins are characterized by abundant CO2 and H2O ± CO2 ± NaCl inclusions, where three-dimensional clusters of inclusions show variable aqueous/carbonic proportions and broad range of total (bimodal) homogenization temperatures. Heterogeneous entrapment of immiscible fluids is interpreted to be caused by unmixing of an originally homogenous, low salinity ( 2 eq. mass % NaCl) aqueous-carbonic fluid, during transition from lithostatic to hydrostatic conditions. Gold deposition occurred generally under mesothermal conditions, i.e., 1.3 kbar and 280 °C, and continued during system cooling to chemistry of the ore fluids.
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Ahmadia, Gabby N.; Tornabene, Luke; Smith, David J.; Pezold, Frank L.
2018-03-01
Factors shaping coral-reef fish species assemblages can operate over a wide range of spatial scales (local versus regional) and across both proximate and evolutionary time. Niche theory and neutral theory provide frameworks for testing assumptions and generating insights about the importance of local versus regional processes. Niche theory postulates that species assemblages are an outcome of evolutionary processes at regional scales followed by local-scale interactions, whereas neutral theory presumes that species assemblages are formed by largely random processes drawing from regional species pools. Indo-Pacific cryptobenthic coral-reef fishes are highly evolved, ecologically diverse, temporally responsive, and situated on a natural longitudinal diversity gradient, making them an ideal group for testing predictions from niche and neutral theories and effects of regional and local processes on species assemblages. Using a combination of ecological metrics (fish density, diversity, assemblage composition) and evolutionary analyses (testing for phylogenetic niche conservatism), we demonstrate that the structure of cryptobenthic fish assemblages can be explained by a mixture of regional factors, such as the size of regional species pools and broad-scale barriers to gene flow/drivers of speciation, coupled with local-scale factors, such as the relative abundance of specific microhabitat types. Furthermore, species of cryptobenthic fishes have distinct microhabitat associations that drive significant differences in assemblage community structure between microhabitat types, and these distinct microhabitat associations are phylogenetically conserved over evolutionary timescales. The implied differential fitness of cryptobenthic fishes across varied microhabitats and the conserved nature of their ecology are consistent with predictions from niche theory. Neutral theory predictions may still hold true for early life-history stages, where stochastic factors may be more
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Kotková, Jana; Kullerud, Kåre; Šrein, Vladimír; Drábek, Milan; Škoda, Radek
2018-04-01
The Kongsberg silver district has been investigated by microscopy and electron microprobe analysis, focusing primarily on the Ag-Hg-Sb mineralization within the context of the updated mineral paragenesis. The earliest mineralization stage is represented by sulfides, including acanthite, and sulfosalts. Native silver formed initially through breakdown of early Ag-bearing phases and later through influx of additional Ag-bearing fluids and silver remobilization. The first two generations of native silver were separated in time by the formation of Ni-Co-Fe sulfarsenides and the monoarsenide niccolite along rims of silver crystals. The presence of As-free sulfosalts and the absence of di- and tri-arsenides suggest a lower arsenic/sulfur activity ratio for the Kongsberg deposits compared to other five-element deposits. Native silver shows binary Ag-Hg and Ag-Sb solid solutions, in contrast to the ternary Ag-Hg-Sb compositions typical for other deposits of similar type. Antimonial silver together with allargentum, dyscrasite, and pyrargyrite was documented exclusively from the northern area of the district. Elsewhere, the only Sb-bearing minerals are polybasite and tetrahedrite/freibergite. Hg-rich silver (up to 21 wt% Hg) has been documented only in the central-western area. Myrmekite of freibergite and chalcopyrite reflects exsolution from an original Ag-poor tetrahedrite upon cooling, while myrmekite of pyrite and silver, forming through breakdown of low-temperature phases (argentopyrite or lenaite) upon heating, characterizes the Kongsberg silver district. Based on the stabilities of minerals and mineral assemblages, the formation of the silver mineralization can be constrained to temperatures between 180 and 250 °C.
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Arthropod assemblages on native and nonnative plant species of a coastal reserve in California.
Fork, Susanne K
2010-06-01
Biological invasions by nonnative plant species are a widespread phenomenon. Many studies have shown strong ecological impacts of plant invasions on native plant communities and ecosystem processes. Far fewer studies have examined effects on associated animal communities. From the perspective of a reserve's land management, I addressed the question of whether arthropod assemblages on two nonnative plant species of concern were impoverished compared with those assemblages associated with two predominant native plant species of that reserve. If the nonnative plant species, Conium maculatum L., and Phalaris aquatica L., supported highly depauperate arthropod assemblages compared with the native plant species, Baccharis pilularis De Candolle and Leymus triticoides (Buckley) Pilger, this finding would provide additional support for prioritizing removal of nonnatives and restoration of natives. I assessed invertebrate assemblages at the taxonomic levels of arthropod orders, Coleoptera families, and Formicidae species, using univariate analyses to examine community attributes (richness and abundance) and multivariate techniques to assess arthropod assemblage community composition differences among plant species. Arthropod richness estimates by taxonomic level between native and nonnative vegetation showed varying results. Overall, arthropod richness of the selected nonnative plants, examined at higher taxonomic resolution, was not necessarily less diverse than two of common native plants found on the reserve, although differences were found among plant species. Impacts of certain nonnative plant species on arthropod assemblages may be more difficult to elucidate than those impacts shown on native plants and ecosystem processes.
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Mineral Composition of Organically Grown Wheat Genotypes: Contribution to Daily Minerals Intake
Hussain, Abrar; Larsson, Hans; Kuktaite, Ramune; Johansson, Eva
2010-01-01
In this study, 321 winter and spring wheat genotypes were analysed for twelve nutritionally important minerals (B, Cu, Fe, Se, Mg, Zn, Ca, Mn, Mo, P, S and K). Some of the genotypes used were from multiple locations and years, resulting in a total number of 493 samples. Investigated genotypes were divided into six genotype groups i.e., selections, old landraces, primitive wheat, spelt, old cultivars and cultivars. For some of the investigated minerals higher concentrations were observed in selections, primitive wheat, and old cultivars as compared to more modern wheat material, e.g., cultivars and spelt wheat. Location was found to have a significant effect on mineral concentration for all genotype groups, although for primitive wheat, genotype had a higher impact than location. Spring wheat was observed to have significantly higher values for B, Cu, Fe, Zn, Ca, S and K as compared to winter wheat. Higher levels of several minerals were observed in the present study, as compared to previous studies carried out in inorganic systems, indicating that organic conditions with suitable genotypes may enhance mineral concentration in wheat grain. This study also showed that a very high mineral concentration, close to daily requirements, can be produced by growing specific primitive wheat genotypes in an organic farming system. Thus, by selecting genotypes for further breeding, nutritional value of the wheat flour for human consumption can be improved. PMID:20948934
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Directory of Open Access Journals (Sweden)
Kérley Braga Pereira Bento Casaril
2011-10-01
Full Text Available The antimicrobial activity and mineral composition of shiitake mushrooms were evaluated in four isolates of Lentinula edodes. Mushrooms were cultivated on artificial logs, based on eucalyptus sawdust enriched with 20% rice, wheat, or soybean bran, or combination of 10% of two of these supplements. The substrates were humidified with a 0.1% mate tea extract or water. Logs of Eucalyptus grandis were also used to cultivate the shiitake mushrooms. The antimicrobial activity of an aqueous extract, corresponding to 40 mg of mushroom dry matter, was in some cases, depending on the isolate, able to inhibit both Bacillus subtilis and Escherichia coli K-12, independent of substrate composition or the growth stage of the mushrooms. Nitrogen, phosphorus, potassium, magnesium and calcium concentrations varied according to the substrate on which the mushrooms were cultivated, being, generally, higher with cultivation on artificial rather than natural eucalyptus logs. It could be concluded that, in addition to the fungal isolate, substrate composition and, processing methods must be considered during the production of antimicrobial substance(s as well as in the mushroom nutritional composition.
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Van Diedenhoven, Bastiaan; Stangl, Alexander; Perlwitz, Jan; Fridlind, Ann M.; Chowdhary, Jacek; Cairns, Brian
2015-01-01
The physical and chemical properties of soil dust aerosol particles fundamentally affect their interaction with climate, including shortwave absorption and radiative forcing, nucleation of cloud droplets and ice crystals, heterogeneous formation of sulfates and nitrates on the surface of dust particles, and atmospheric processing of iron into bioavailable forms that increase the productivity of marine phytoplankton. Lidar measurements, such as extinction-to-backscatter, color and depolarization ratios, are frequently used to distinguish between aerosol types with different physical and chemical properties. The chemical composition of aerosol particles determines their complex refractive index, hence affecting their backscattering properties. Here we present a study on how dust aerosol backscattering and depolarization properties at wavelengths of 355, 532 and 1064 nm are related to size and complex refractive index, which varies with the mineral composition of the dust. Dust aerosols are represented by collections of spheroids with a range of prolate and oblate aspect ratios and their optical properties are obtained using T-matrix calculations. We find simple, systematic relationships between lidar observables and the dust size and complex refractive index that may aid the use of space-based or airborne lidars for direct retrieval of dust properties or for the evaluation of chemical transport models using forward simulated lidar variables. In addition, we present first results on the spatial variation of forward-simulated lidar variables based on a dust model that accounts for the atmospheric cycle of eight different mineral types plus internal mixtures of seven mineral types with iron oxides, which was recently implemented in the NASA GISS Earth System ModelE2.
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Directory of Open Access Journals (Sweden)
Majzlan Juraj
2016-02-01
Full Text Available Numerous small deposits and occurrences of Mn-Fe-fluorite-barite mineralization have developed at the contact of the Thuringian Basin, Thüringer Wald and Thüringer Schiefergebirge in central Germany. The studied mineralizations comprise the assemblages siderite+ankerite-calcite-fluorite-barite and hematite-Mn oxides-calcite-barite, with the precipitation sequence in that order within each assemblage. A structural geological analysis places the origin of the barite veins between the Middle Jurassic and Early Cretaceous. Primary fluid inclusions contain water vapour and an aqueous phase with NaCl and CaCl2 as the main solutes, with salinities mostly between 24–27 mass. % CaCl2 eq. Th measurements range between 85 °C and 160 °C in barite, between 139 °C and 163 °C in siderite, and between 80 °C and 130 °C in fluorite and calcite. Stable isotopes (S, O point to the evaporitic source of sulphur in the observed mineralizations. The S,C,O isotopic compositions suggest that barite and calcite could not have precipitated from the same fluid. The isotopic composition of the fluid that precipitated barite is close to the sea water in the entire Permo–Mesozoic time span whereas calcite is isotopically distinctly heavier, as if the fluids were affected by evaporation. The fluid evolution in the siliciclastic/volcanic Rotliegend sediments (as determined by a number of earlier petrological and geochemical studies can be correlated with the deposition sequence of the ore minerals. In particular, the bleaching of the sediments by reduced Rotliegend fluids (basinal brines could be the event that mobilized Fe and Mn. These elements were deposited as siderite+ankerite within the Zechstein carbonate rocks and as hematite+Mn oxides within the oxidizing environment of the Permian volcanic and volcanoclastic rocks. A Middle-Jurassic illitization event delivered Ca, Na, Ba, and Pb from the feldspars into the basinal brines. Of these elements, Ba was
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Directory of Open Access Journals (Sweden)
Rafael Fagnani
2014-05-01
Full Text Available This study aimed to associate the occurrence of acid-base disorders with the alcoholic stability of milk from animals in the field, and to evaluate differences between the mineral composition of milk that was both stable and unstable in alcohol. The sample comprised 96 dairy cows, where the milk and blood of each corresponding animal was collected. The mineral composition of stable and unstable milk in alcohol was different and may be related to acid-base disturbances. The average amount of phosphate was lower in the milk that was unstable in alcohol, while potassium was greater. Frequency of the alcoholically unstable milk cases was higher in the cows with acid-base disturbances. Respiratory alkalosis was the disorder that was most observed.
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Directory of Open Access Journals (Sweden)
Lifu Sun
Full Text Available Fungal diversity within plant roots is affected by several factors such as dispersal limitation, habitat filtering, and plant host preference. Given the differences in life style between symbiotic and non-symbiotic fungi, the main factors affecting these two groups of fungi may be different. We assessed the diversity of root associated fungi of Rhododendron decorum using internal transcribed spacer (ITS sequencing and terminal restriction fragment length polymorphism (T-RFLP analysis, and our aim was to evaluate the role of different factors in structuring ericoid mycorrhizal (ERM and non-ericoid mycorrhizal (NEM fungal communities. Thirty-five fungal operational taxonomic units (OTUs were found in roots of R. decorum, of which 25 were putative ERM fungal species. Of the two main groups of known ERM, helotialean fungi were more abundant and common than sebacinalean species. Geographic and host patterning of the fungal assemblages were different for ERM and NEM. The distribution of putative ERM fungal terminal restriction fragments (TRFs showed that there were more common species within ERM than in the NEM fungal assemblages. Results of Mantel tests indicated that the composition of NEM fungal assemblages correlated with geographic parameters while ERM fungal assemblages lacked a significant geographic pattern and instead were correlated with host genotype. Redundancy analysis (RDA showed that the NEM fungal assemblages were significantly correlated with latitude, longitude, elevation, mean annual precipitation (MAP, and axis 2 of a host-genetic principle component analysis (PCA, while ERM fungal assemblages correlated only with latitude and axis 1 of the host-genetic PCA. We conclude that ERM and NEM assemblages are affected by different factors, with the host genetic composition more important for ERM and geographic factors more important for NEM assemblages. Our results contribute to understanding the roles of dispersal limitation, abiotic
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Institute of Scientific and Technical Information of China (English)
Analía L.GIM(E)NEZ; Norberto P. GIANNINI
2017-01-01
Vespertilionidae is the most diverse chiropteran family,and its diversity is concentrated in warm regions of the World;however,due to physiological and behavioral adaptations,these bats also dominate bat faunas in temperate regions.Here we performed a comparative study of vespertilionid assemblages from two broad regions of the New World,the cold and harsh Patagonia,versus the remaining temperate-to-subtropical,extra-Patagonian eco-regions of the South American Southern Cone.We took an ecomorphological approach and analyzed the craniodental morphological structure of these assemblages within a phylogenetic framework.We measured 17 craniodental linear variables from 447 specimens of 22 currently recognized vespertilionid species of the study regions.We performed a multivariate analysis to define the morphofunctional space,and calculated the pattern and degree of species packing for each assemblage.We assessed the importance of phylogeny and biogeography,and their impact on depauperate (Patagonian) versus rich (extra-Patagonian) vespertilionid assemblages as determinants of morphospace structuring.We implemented a sensitivity analysis associated to small samples of rare species.The morphological patterns were determined chiefly by the evolutionary history of the family.The Patagonian assemblage can be described as a structurally similar but comparatively depauperate ecomorphological version of those assemblages from neighboring extra-Patagonian eco-regions.The Patagonian assemblage seems to have formed by successively adding populations from Northern regions that eventually speciated in the region,leaving corresponding sisters (vicariants) in extraPatagonian eco-regions that continued to be characteristically richer.Despite being structurally akin,degree of species packing in Patagonia was comparatively very low,which may reflect the effect of limited dispersal success into a harsh region for bat survival.
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Specificity of pyrometamorphic minerals of the ellestadite group
Zateeva, S. N.; Sokol, E. V.; Sharygin, V. V.
2007-12-01
Numerous rare and new mineral species are synthesized during the process of pyrometamorphism (Gross, 1977; Chesnokov et al., 1987; Chesnokov and Shcherbakova, 1991; Chesnokov, 1999), including silicooxides, chloride-, fluoride, and sulfate-silicates, carbonate-sulfides, chloride-oxides, etc. Having made sense of numerous findings of compounds of this type, Chesnokov (1999) set forth the concept of the crystallochemical transition at extreme temperatures attaining 1200-1450°C in pyrogenic systems. First of all, intertype transitions (oxygen-bearing-oxygen-free) and interclass transitions (chloride-silicate, carbonate-sulfide, chlorideoxide) are realized. The specificity of pyrometamorphic mineral assemblages consists in the abundance of silicates with additional anions (F-, Cl-, (CO3)2-) (Sokol et al., 2005). Minerals of the ellestadite group Ca10(SiO4)3 - x (SO4)3 - x (PO4)2 x (OH,F,Cl)2 are a spectacular example of these features. In the general case, they are silicate-sulfate-phosphate-hydroxide-chlorides-fluorides. The detailed description of these minerals based on the study of the original collection of pyrometamorphic minerals is presented in this paper.
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Buosi, Alessandro; Sfriso, Adriano
2017-12-15
Macrophyte assemblages are one of the most sensitive biological communities to assess anthropogenic impacts and climate changes. Community composition responds very quickly to environmental changes driving towards a predictable composition. The increase or decrease of the trophic status (i.e. nutrient concentrations, suspended particulate matter, Chlorophyll-a) and temperature are the most important factors responsible for the replacement of taxa of high ecological value (sensitive taxa) with opportunistic species. A qualitative and quantitative study of macrophytes in 4 areas along the coasts of the Northern Adriatic Sea, from Venice (Italy) to Savudrija (Croatia) and the analysis of river outflows in this region during one year (May 2012-April 2013) provided information about their spatial variability. The coasts of the Veneto Region and Friuli-Venezia Giulia, which are affected by significant freshwater inputs, showed a strong biodiversity reduction or a dominance of thionitrophilic taxa. No seagrasses colonized these areas. On the other hand, the coasts of Croatia had negligible fresh water inputs and macrophyte communities were dominated by sensitive taxa such as the seagrass Cymodocea nodosa and some species belonging to genus Cystoseira. Copyright © 2017 Elsevier B.V. All rights reserved.
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Directory of Open Access Journals (Sweden)
Helen R. Watling
2015-07-01
Full Text Available In heap bioleaching, acidophilic extremophiles contribute to enhanced metal extraction from mineral sulphides through the oxidation of Fe(II and/or reduced inorganic sulphur compounds (RISC, such as elemental sulphur or mineral sulphides, or the degradation of organic compounds derived from the ore, biota or reagents used during mineral processing. The impacts of variable solution acidity and composition, as well as temperature on the three microbiological functions have been examined for up to four bacterial species found in mineral sulphide heaps. The results indicate that bacteria adapt to sufficiently high metal concentrations (Cu, Ni, Co, Zn, As to allow them to function in mineral sulphide heaps and, by engaging alternative metabolic pathways, to extend the solution pH range over which growth is sustained. Fluctuating temperatures during start up in sulphide heaps pose the greatest threat to efficient bacterial colonisation. The large masses of ores in bioleaching heaps mean that high temperatures arising from sulphide oxidation are hard to control initially, when the sulphide content of the ore is greatest. During that period, mesophilic and moderately thermophilic bacteria are markedly reduced in both numbers and activity.
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Environmental Factors Support the Formation of Specific Bacterial Assemblages on Microplastics
Oberbeckmann, Sonja; Kreikemeyer, Bernd; Labrenz, Matthias
2018-01-01
While the global distribution of microplastics (MP) in the marine environment is currently being critically evaluated, the potential role of MP as a vector for distinct microbial assemblages or even pathogenic bacteria is hardly understood. To gain a deeper understanding, we investigated how different in situ conditions contribute to the composition and specificity of MP-associated bacterial communities in relation to communities on natural particles. Polystyrene (PS), polyethylene (PE), and wooden pellets were incubated for 2 weeks along an environmental gradient, ranging from marine (coastal Baltic Sea) to freshwater (waste water treatment plant, WWTP) conditions. The associated assemblages as well as the water communities were investigated applying high-throughput 16S rRNA gene sequencing. Our setup allowed for the first time to determine MP-dependent and -independent assemblage factors as subject to different environmental conditions in one system. Most importantly, plastic-specific assemblages were found to develop solely under certain conditions, such as lower nutrient concentration and higher salinity, while the bacterial genus Erythrobacter, known for the ability to utilize polycyclic aromatic hydrocarbons (PAH), was found specifically on MP across a broader section of the gradient. We discovered no enrichment of potential pathogens on PE or PS; however, the abundant colonization of MP in a WWTP by certain bacteria commonly associated with antibiotic resistance suggests MP as a possible hotspot for horizontal gene transfer. Taken together, our study clarifies that the surrounding environment prevailingly shapes the biofilm communities, but that MP-specific assemblage factors exist. These findings point to the ecological significance of specific MP-promoted bacterial populations in aquatic environments and particularly in plastic accumulation zones. PMID:29403454
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Environmental Factors Support the Formation of Specific Bacterial Assemblages on Microplastics
Directory of Open Access Journals (Sweden)
Sonja Oberbeckmann
2018-01-01
Full Text Available While the global distribution of microplastics (MP in the marine environment is currently being critically evaluated, the potential role of MP as a vector for distinct microbial assemblages or even pathogenic bacteria is hardly understood. To gain a deeper understanding, we investigated how different in situ conditions contribute to the composition and specificity of MP-associated bacterial communities in relation to communities on natural particles. Polystyrene (PS, polyethylene (PE, and wooden pellets were incubated for 2 weeks along an environmental gradient, ranging from marine (coastal Baltic Sea to freshwater (waste water treatment plant, WWTP conditions. The associated assemblages as well as the water communities were investigated applying high-throughput 16S rRNA gene sequencing. Our setup allowed for the first time to determine MP-dependent and -independent assemblage factors as subject to different environmental conditions in one system. Most importantly, plastic-specific assemblages were found to develop solely under certain conditions, such as lower nutrient concentration and higher salinity, while the bacterial genus Erythrobacter, known for the ability to utilize polycyclic aromatic hydrocarbons (PAH, was found specifically on MP across a broader section of the gradient. We discovered no enrichment of potential pathogens on PE or PS; however, the abundant colonization of MP in a WWTP by certain bacteria commonly associated with antibiotic resistance suggests MP as a possible hotspot for horizontal gene transfer. Taken together, our study clarifies that the surrounding environment prevailingly shapes the biofilm communities, but that MP-specific assemblage factors exist. These findings point to the ecological significance of specific MP-promoted bacterial populations in aquatic environments and particularly in plastic accumulation zones.
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Pérez García-Pando, Carlos; Miller, Ron L.; Perlwitz, Jan P.; Rodríguez, Sergio; Prospero, Joseph M.
2016-10-01
Regional variations of dust mineral composition are fundamental to climate impacts but generally neglected in climate models. A challenge for models is that atlases of soil composition are derived from measurements following wet sieving, which destroys the aggregates potentially emitted from the soil. Aggregates are crucial to simulating the observed size distribution of emitted soil particles. We use an extension of brittle fragmentation theory in a global dust model to account for these aggregates. Our method reproduces the size-resolved dust concentration along with the approximately size-invariant fractional abundance of elements like Fe and Al in the decade-long aerosol record from the Izaña Observatory, off the coast of West Africa. By distinguishing between Fe in structural and free forms, we can attribute improved model behavior to aggregation of Fe and Al-rich clay particles. We also demonstrate the importance of size-resolved measurements along with elemental composition analysis to constrain models.
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Roux, S; Baudoin, C; Boute, D; Brazier, M; De La Guéronniere, V; De Vernejoul, M C
2004-01-01
To compare the effects of 2 drinking waters containing similar calcium (Ca) concentration in order to analyze the role of ions other than Ca on bone metabolism. These mineral drinking-waters differed by their mineral composition primarily concerning the concentration of bicarbonate (HCO3-), high in the HB, and sulfate, high in HS water. Of 60 included women, 39 completed the study. Patients were randomly assigned to an intake of 1 liter per day of mineral water HB or HS for 28 d, followed by cross-over to the alternative drinking-water for a further 28 d. At baseline and after each period of one month, Ca metabolism parameters, acid-base status, and bone remodeling markers were measured. Changes in Ca metabolism were significant in the HB group where the ionized Ca increased and the PTH decreased. Serum pH showed a similar increase whatever the used drinking water compared to baseline. In the HB group, significant increase in urine pH, and significant decrease in AT-HCO3- and NH4+ were observed. Bone resorption markers, urinary CTx/Cr, Pyr/Cr, and D-Pyr/Cr, significantly decreased in the HB group compared to baseline, and were not significantly modified in the HS group. These results showed a beneficial effect of the bicarbonaterich HB water on bone metabolism. This may account for a better bioavailability of the Ca, a greater alkalinization, and a larger decrease in PTH level secondary to a higher ionized Ca level. The higher content of silica in HB water may have also participated to the positive action on bone balance that was observed. In this short term study, these data underlined the potential role of the mineral drinking water composition on bone metabolism.
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Directory of Open Access Journals (Sweden)
Khadijeh Mikaeili
2018-04-01
Full Text Available The Shah-Ali-Beiglou epithermal base metal-silver deposit is located in the Tarom-Hashjin metallogenic province (THMP in northwestern Iran. This deposit is hosted by quartz monzonite dikes of Oligocene age and surrounded by andesite to trachyandesite volcanic and volcaniclastic rocks of Eocene age. The subvolcanic rocks in the study area vary in composition from quartz-monzonite to monzonite and have metaluminous, calc-alkaline to shoshonitic affinity. These rocks have I-type geochemical characteristic and are related to post-collisional tectonic setting. The mineralization occurs as NE-SW and E-W-trending brecciated veins controlled by strike-slip and normal faults, which are associated to the Late Oligocene compressional regime. The mineral paragenesis of the vein mineralization is subdivided into pre-ore stage, ore stage, post-ore stage, and supergene stage. Pre-ore stage is dominated by quartz, sericite, and subhedral to anhedral pyrite as disseminated form. Ore-stage is represented by quartz, sphalerite (from 0.1 mol % to 4 mol % FeS, galena, chalcopyrite, tetrahedrite-tennantite, minor seligmannite and enargite, as vein-veinlet, cement and clast breccias. Post-ore stage is defined by deposition of quartz and carbonate along with minor barite, and supergene stage is characterized by bornite, chalcocite, covellite, hematite, goethite, and jarosite. The ore mineralization is associated with the silicic alteration. The styles of alteration are silicic, carbonate, sericitic, chloritic, and propylitic. Fluid inclusions in sphalerite have a wide range of salinities between 0.35 wt % and 21.4 wt % NaCl equivalent and homogenization temperatures range from 123 to 320 °C. The isotopic values of sulfides vary from 2.8‰ to 6.7‰ suggesting a magmatic source for the sulfur. In the present study, based on geological setting, alteration style of the host and wall rocks, main textures, mineral assemblages, composition of ore minerals, and structural
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Lobo, Alexandre Rodrigues; Filho, Jorge Mancini; Alvares, Eliana Parisi; Cocato, Maria Lucia; Colli, Célia
2009-02-01
This study reports the effects of feeding with a combination of inulin-type fructans (ITF) and fish oil (FO) on mineral absorption and bioavailability as part of a semipurified diet offered to rats. Male Wistar rats (n = 24) were fed a 15% lipid diet (soybean oil [SO] or a 1:0.3 fish:soybean oil mixture [FSO]) and diets containing the same sources of lipids supplemented with 10% ITF (Raftilose Synergy 1) ad libitum for 15 d. Feces and urine were collected for mineral analyses during the last 5 d of the test period. Fatty acid composition was determined in liver and cecal mucosa homogenates. Liver and bone mineral analyses were performed by atomic absorption spectrophotometry. Bone biomechanical analyses were evaluated by a 3-point bending test. Compared with the controls, ITF-fed rats had enlarged ceca and a significant decrease in cecal content pH (P mineral absorption was improved in these rats, and this effect was enhanced by dietary combination with FO for all minerals except for magnesium. Addition of ITF to the diet resulted in higher bone mineral content (calcium and zinc) and bone strength, but increased bone mineral content was only statistically significant in FO-fed animals. A decrease in liver iron stores (P = 0.015) was observed in rats fed FO, considering that ITF consumption returned to levels comparable to the SO control group. These findings confirm the positive influence of ITF on mineral bioavailability, which was potentiated by addition of FO to the diet.
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Mineralogical composition of the meteorite El Pozo (Mexico): a Raman, infrared and XRD study.
Ostrooumov, Mikhail; Hernández-Bernal, Maria del Sol
2011-12-01
The Raman (RMP), infrared (IR) and XRD analysis have been applied to the examination of mineralogical composition of El Pozo meteorite (an ordinary chondrite L5 type; village Valle of Allende, founded in State of Chihuahua, Mexico: 26°56'N and 105°24'W, 1998). RMP measurements in the range of 100-3500 cm(-1) revealed principal characteristic bands of the major minerals: olivine, two polymorph modifications of pyroxene (OPx and CPx) and plagioclase. Some bands of the minor minerals (hematite and goethite) were also identified. All these minerals were clearly distinguished using IR and XRD techniques. XRD technique has shown the presence of some metallic phases such as kamacite and taenite as well as troilite and chromite. These minerals do not have characteristic Raman spectra because Fe-Ni metals have no active modes for Raman spectroscopy and troilite is a weak Raman scatterer. Raman mapping microspectroscopy was a key part in the investigation of El Pozo meteorite's spatial distribution of the main minerals because these samples are structurally and chemically complex and heterogeneous. The mineral mapping by Raman spectroscopy has provided information for a certain spatial region on which a spatial distribution coexists of the three typical mineral assemblages: olivine; olivine+orthopyroxene; and orthopyroxene. Copyright © 2011 Elsevier B.V. All rights reserved.
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Directory of Open Access Journals (Sweden)
Sidinei Magela Thomaz
2013-08-01
Full Text Available Aquatic macrophytes are an important component in the structure of lakes in Neotropical floodplains, for example, because they support a high diversity of invertebrates and vertebrates. In this paper, we tested whether or not the variability of macrophyte assemblages is lower in spatially close quadrats than among quadrats of different lakes. The study was carried in four lakes in a large Amazonian floodplain (Purus river, where floating meadows were investigated. A total of 49 taxa of macrophytes were found. Five species dominated and three species were rare. Taxa richness, composition and beta diversity differed more between than within lakes. Because high beta diversity was found among the lakes, they should be considered individually important for maintaining the gamma diversity of macrophytes within the Purus River floodplain, and this should be considered in plans of lake management.
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Influence of landscape structure on reef fish assemblages
Grober-Dunsmore, R.; Frazer, T.K.; Beets, J.P.; Lindberg, W.J.; Zwick, P.; Funicelli, N.A.
2008-01-01
Management of tropical marine environments calls for interdisciplinary studies and innovative methodologies that consider processes occurring over broad spatial scales. We investigated relationships between landscape structure and reef fish assemblage structure in the US Virgin Islands. Measures of landscape structure were transformed into a reduced set of composite indices using principal component analyses (PCA) to synthesize data on the spatial patterning of the landscape structure of the study reefs. However, composite indices (e.g., habitat diversity) were not particularly informative for predicting reef fish assemblage structure. Rather, relationships were interpreted more easily when functional groups of fishes were related to individual habitat features. In particular, multiple reef fish parameters were strongly associated with reef context. Fishes responded to benthic habitat structure at multiple spatial scales, with various groups of fishes each correlated to a unique suite of variables. Accordingly, future experiments should be designed to test functional relationships based on the ecology of the organisms of interest. Our study demonstrates that landscape-scale habitat features influence reef fish communities, illustrating promise in applying a landscape ecology approach to better understand factors that structure coral reef ecosystems. Furthermore, our findings may prove useful in design of spatially-based conservation approaches such as marine protected areas (MPAs), because landscape-scale metrics may serve as proxies for areas with high species diversity and abundance within the coral reef landscape. ?? 2007 Springer Science+Business Media B.V.
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Directory of Open Access Journals (Sweden)
Annah Mabidi
Full Text Available This study aims to investigate macroinvertebrate assemblage structure and composition across the three major waterbody types (temporary rivers, depression wetlands and semi-permanent dams of the Eastern Cape Karoo, and to identify important environmental and spatial correlates of macroinvertebrate assemblage composition in the region. A total of 33 waterbodies (9 dams, 13 depression wetlands and 11 rivers were sampled. Altogether, 91 taxa were recorded in November 2014 and 82 in April 2015. Twenty-seven taxa were common to all three waterbody types (across both sampling occasions, with 17 of these observed in November and 19 in April. The ANOSIM tests revealed significant differences in assemblage composition between the depression wetlands and rivers for both sampling occasions, but dams did not differ from the other waterbody types. SIMPER analyses indicated that the notonectid Anisops varia and the corixid Micronecta scutellaris were abundant across all three waterbody types during both sampling occasions. The mayfly Cloeon africanum and the damselfly Pseudagrion sp. were abundant in river habitats during both sampling occasions, while the gastropod mollusc Bulinus tropicus and the copepod Lovenula falcifera best characterised depression wetlands on both occasions. Non-metric multidimensional scaling ordination highlighted a clear separation of assemblages between November and April, while distance-based Redundancy Analysis revealed that conductivity, altitude, turbidity and pH were the most important variables explaining the variation in macroinvertebrate assemblage patterns. These results provide baseline information which is important for future biological monitoring of impacts associated with hydraulic fracturing activities and climatic changes in the region.
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Lecumberri-Sanchez, Pilar; Newton, M. Claiborne; Westman, Erik C.; Kamilli, Robert J.; Canby, Vertrees M.; Bodnar, Robert J.
2013-01-01
Red Mountain, Arizona, is a Laramide porphyry Cu system (PCD) that has experienced only a modest level of erosion compared to most other similar deposits in the southwestern United States. As a result, the upper portion of the magmatic–hydrothermal system, which represents the transition from shallower high-sulfidation epithermal mineralization to deeper porphyry Cu mineralization, is well preserved. Within the Red Mountain system, alteration, mineralization and fluid inclusion assemblages show a systematic distribution in both time and space. Early-potassic alteration (characterized by the minerals biotite and magnetite) is paragenetically earlier than late-potassic alteration (K-feldspar–anhydrite) and both are followed by later phyllic (sericite–pyrite) alteration. Advanced argillic alteration (pyrophyllite–alunite–other clay minerals) is thought to be coeval with or postdate phyllic alteration. Minerals characteristic of advanced argillic alteration are present in the near surface. Phyllic alteration extends to greater depths compared to advanced argillic alteration. Early-potassic and late-potassic alteration are only observed in the deepest part of the system. Considerable overlap of phyllic alteration with both early-potassic and late-potassic alteration zones is observed. The hypogene mineralization contains 0.4–1.2% Cu and is spatially and temporally related to the late-potassic alteration event. Molybdenum concentration is typically In the deepest part of the system, an early generation of low-to-moderate density and salinity liquid + vapor inclusions with opaque daughter minerals is followed in time by halite-bearing inclusions that also contain opaque daughter minerals indicating that an early intermediate-density magmatic fluid evolved to a high-density, high-salinity mineralizing fluid. The increase in density and salinity of fluids with time observed in the deeper parts of the system may be the result of immiscibility (“boiling”) of
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Seagrass Parameter Affect the Fish Assemblages in Karimunjawa Archipelago
Sri Susilo, Endang; Nugroho Sugianto, Denny; Munasik; Nirwani; Adhi Suryono, Chrisna
2018-02-01
Seagrass beds promote high species diversity, abundance and biomass, and become important habitats for some economically important fishes. Plants of seagrasses result in structurally highly complex habitats and offering feeding grounds, shelter from predation as well as nursery areas for diverse fish assemblages. However, research on fish communities in Southeast Asian seagrass bed is rarely conducted. In the present study fish assemblages in seagrass beds with different parameters (cover, diversity and similarity indices, domination) was investigated in the Karimunjawa Islands, Indonesia. The purpose of this study were to assess whether fish assemblages differ concerning on the abundance and the species number. This study was conducted on the seagrass bed on Karimunjawa Islands in Java Sea, particularly in the water of Menjangan Besar and Menjangan Kecil Island. Line-quadrant transect was used to assess seagrass data, while the occurrence and individual number of fish harboured in the selected seagrass bed was counted by using underwater visual census in the stationary point count transects. Seagrass cover in Menjangan Kecil Island (41%) with various canopy included both upper and lower canopy was considerable higher than those in Menjangan Besar Island (5%). Fish diversity, species composition and abundance are considerably different between the two study sites. This study revealed that seagrass density or cover and canopy structure affected the fish abundance and species number harboured.
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Directory of Open Access Journals (Sweden)
Guohuan Su
2015-07-01
Full Text Available Human activities and the consequent extinctions of native species and invasions of non-native species have been changing the composition of species assemblages worldwide. These anthropogenic impacts alter not only the richness of assemblages but also the biological dissimilarity among them. However, much of the research effort to date has focused on changes in taxonomic dissimilarity (i.e. accounting for species composition whether assessments of functional dissimilarity (i.e. accounting for the diversity of biological traits are much more scarce, despite revealing important complimentary information by accounting for changes in the diversity of biological traits. Here, we assess the temporal (1950s against 2000s changes in both taxonomic and functional dissimilarities of freshwater fish assemblages across lakes from the Yunnan Plateau in China. The Jaccard index to quantify the changes in both taxonomic and functional dissimilarity. We then partitioned dissimilarity to extract its turnover component and measured the changes in the contribution of turnover to dissimilarity. We found that functional and taxonomic homogenization occurred simultaneously. However, patterns between these two processes differed for some lakes. Taxonomic and functional homogenizations were stronger when the historical level of taxonomic dissimilarity among assemblages was high. The impact of extinctions of native species and invasions of non-native species on homogenization was otherwise complex to disentangle with no significant effect of any of the studied environmental factors. In agreement with other studies, our study proved that change in taxonomic dissimilarity cannot be used to predict changes in functional dissimilarity and, as an indicator of ecosystem functioning, functional dissimilarity should be used together with taxonomic dissimilarity to attain a more holistic understanding of human impacts on natural ecosystems.
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Impact of soils and cropping systems on composition of mineral elements of dry cacao beans
In view of its high economic value, cacao (Theobroma cacao L.) researchers are seeking technological innovations that increase production and improve the quality of cacao beans. The objective of this study was to characterize the mineral (P, K, Ca, Mg, Si, Fe, Mn, Zn, Cu, Cd, Ba) composition of caca...
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Ignacio Vilchis, L.; Ballance, Lisa T.; Watson, William
2009-01-01
Considerable evidence exists, showing an accelerated warming trend on earth during the past 40-50 years, attributed mainly to anthropogenic factors. Much of this excess heat is stored in the world's oceans, likely resulting in increased environmental variability felt by marine ecosystems. The long-term effects of this phenomenon on oceanic tropical ecosystems are largely unknown, and our understanding of its effects could be facilitated by long-term studies of how species compositions change with time. Ichthyoplankton, in particular, can integrate physical, environmental and ecological factors making them excellent model taxa to address this question. While on eight (1987-1990, 1992 and 1998-2000) NOAA Fisheries cruises to the eastern Pacific warm pool, we characterized the thermal and phytoplankton pigment structure of the water column, as well as the neustonic ichthyoplankton community using CTD casts and Manta (surface) net tows. Over the 13-year period, 852 CTD and Manta tow stations were completed. We divided the study area into three regions based on regional oceanography, thermocline depth and productivity, as well as a longitudinal gradient in species composition among stations. We then analyzed temporal trends of ichthyoplankton species composition within each region by pooling stations by region and year and making pairwise comparisons of community similarity between all combinations of the eight cruises within each region. We also identified environment-specific species assemblages and station groupings using hierarchical clustering and non-metric multi-dimensional scaling (MDS). Our analyses revealed a longitudinal gradient in community structure and temporal stability of ichthyoplankton species composition. Over the 13 years ichthyoplankton assemblages in the two westernmost regions varied less than in the eastern region. MDS and cluster analyses identified five ichthyoplankton assemblages that corresponded to oceanographic habitats and a gradient in
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International Nuclear Information System (INIS)
Clauer, N.
1979-01-01
The 87 Sr/ 86 Sr ratios of recent montmorillonites and kaolinites newly formed in weathering profiles of western and central Africa and of Nosy Be and La Reunion islands near Madagascar are directly related to the composition and age of the parent rocks or minerals. They may, therefore, be used as a genetic tracer. The 87 Sr/ 86 Sr ratios are about 0.704 when these clays crystallise from recent basalts and they are higher than 0.715 when the parent rocks are of sialic composition and old in age. Kaolinites newly formed in situ from feldspars contain small amounts of Sr with abnormally high 87 Sr/ 86 Sr ratios: in this study they are higher than 1.094. When these minerals crystallize from biotites, their 87 Sr/ 86 Sr ratios are much lower and can be close to the value of the primary Sr trapped in the biotites during their crystallization. On the other hand, the 87 Sr/ 86 Sr of continental montmorillonites are less scattered: they range, in this study, between 0.704 and 0.722. These low values, as well as the high adsorption capacities of these minerals in the sedimentary environment, allow the assumption that they frequently have 87 Sr/ 86 Sr ratios close to that of marine Sr during sedimentation. Therefore, montmorillonites are able to form homogeneous authigenic minerals by synsedimentary alterations. (Auth.)
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Directory of Open Access Journals (Sweden)
Noorfarahzilah, M.
2017-06-01
Full Text Available Tarap seed (Artocarpus odoratissimus is one of the popular snacks among Borneo Island people especially in Sabah, Malaysia. Their flesh and seed are such a potential food source but they are not fully exploited. Therefore, this study was conducted to determine its nutritional composition, mineral content and functional properties of Tarap seed flour (TSF. The proximate analysis (protein, carbohydrate, fat, crude fiber, ash, moisture, minerals content and functional properties (powder particle size, bulk density, oil and water absorption capacity, emulsion capacity, foaming ability, least gelling concentration, swelling ability and pasting properties were determined. The proximate analysis results obtained showed that TSF had 49.65% carbohydrate, 15.60% crude fat, 12.3% crude fibers, 8.8% crude protein, 1.17 % ash and 12.5% moisture. Most abundant mineral found in Tarap flour was potassium, followed by magnesium, calcium, and natrium. The results showed that TSF has an average particle size of 166.02μm with low bulk density (0.57g/cm3 as compared to wheat flour. Water and oil absorption capacities of TSF were 2.61 and 1.69g/g, respectively, while the efficiency of emulsification was 14.8%. Least gelation concentration was found to be 12% while foaming ability was 7%. Swelling ability results showed a steady increment from 60°C to 70°C but sharp increased observed from 70°C to 80°C. From the results presented, it can be concluded that TSF has a great potential for use in the formulation of composite flours to be used as ingredients in the food industry.
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Bačík, Peter; Dikej, Jakub; Fridrichová, Jana; Miglierini, Marcel; Števko, Martin
2017-09-01
Tourmaline-supergroup minerals are common gangue minerals in Sb-hydrothermal veins on Betliar - Straková, Čučma - Gabriela and Rožňava - Peter-Pavol vein deposits in the Rožňava area, Slovakia. Tourmaline-supergroup minerals form relatively large prismatic to radial aggregates of parallel black to greyish-black crystals. Tourmaline-supergroup minerals from Betliar - Straková and Rožňava - Peter-Pavol are almost homogeneous with intermediate schorl-dravite composition. Čučma - Gabriela tourmaline have distinct zoning with massive core of the schorlitic-to-feruvitic shifting to schorlitic-to-dravitic composition, and dravitic to magnesio-foititic rim. The tourmaline composition is influenced by two main substitutions, namely Ca(Mg,Fe)Na-1Al-1 and X □AlNa-1(Mg,Fe)-1. Betliar - Straková and Rožňava - Peter-Pavol tourmaline-supergroup minerals exhibit only small extents of the X □AlNa-1(Mg,Fe)-1 substitution. This substitution shifts the composition to magnesio-foitite in Čučma - Gabriela tourmaline. The decrease of Al in the core of Čučma - Gabriela tourmaline crystals is caused by extensive Ca(Mg,Fe)Na-1Al-1 substitution. The unit-cell dimensions of all investigated tourmaline-supergroup minerals indicate an octahedral disorder with the Z (Fe3++Mg) proportion calculated from empirical equations varying between 0.85 and 0.87 apfu (atoms per formula unit). Based on Mössbauer spectra, the Z Fe3+ content varied between 0.25 apfu in Betliar - Straková tourmaline and 0.45 apfu in Čučma - Gabriela sample. Based on Fe/(Fe + Mg) ratio, Betliar - Straková tourmaline is slightly enriched in Fe compared to Rožňava - Peter-Pavol, suggesting the impact of the host-rock composition; first are grown in Fe-richer acidic metarhyolitic rocks, latter in metapelites. In Čučma - Gabriela, the variations in Fe/(Fe + Mg) are very likely reflecting the change in fluid composition. Magnesio-foitite is the product of second-stage crystallization forming rims and
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DEFF Research Database (Denmark)
Samson, Kristine
the paper raises the questions where to locate aesthetics when planners and architects wishes to design for aesthetical experiences and sensations rather than formal objects. The paper will proceed through a brief outline of the recent notion of assemblage and affect in urban studies, planning theory...... happens to aesthetics and how does it change the existing social and geographical understanding of urban space? The paper sets out to reintroduce aesthetical aspects of affects and assemblages in relation to urban space and urban planning. It presupposes urban space as a continuous state of becoming where...
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Fast XRF analysis of mineral elements in dental composites
International Nuclear Information System (INIS)
Preoteasa, E. A.; Constantinescu, B.; Preoteasa, E.
2001-01-01
Dental composites, made of particles of glass, ceramics or quartz embedded in an organic polymer matrix, extensively replaced silver amalgam in tooth fillings and enabled new applications for restorative dentistry. Long-term alteration of dental fillings together with market pressure motivates the development of composites at a high rate, largely by progress of materials forming their mineral phase. Therefore, dental composites constantly bring at the interface with enamel and dentine new elements foreign to the organism, whose biological action has not been studied. Atomic and nuclear methods for surface multielemental analysis have been used in dental research but not for composites. X-ray fluorescence (XRF) is suited for the fast microanalytical screening of the elements and of their changes at the biomaterial's surface. The potential of radioisotope-excited XRF for the analysis of dental composites has been examined. Flat disk-shaped samples of composites have been prepared and polymerized chemically or by irradiation with intense 420-500 nm light. The measurements were performed with a spectrometric chain containing a 30 mCi source of 241 Am, a Si(Li) detector, and a multichannel analyzer. The spectra were built up for 2000-6000 sec. The characteristic X lines were integrated and normalized to source lines. The following Z ≥ 20 elements were detected in the studied composites: Ba only in Charisma (Kulzer) and Pekafill (Bayer); Zr, Ba, Yb in Tetric Ceram, and Ca, Ba, Yb together with traces of possibly Ti and Fe in Ariston (both from Vivadent); Zr, Hf in Valux Plus (3M Dental); and Sr, Ba together with some trace element, seemingly Cu, in F2000 Compomer (3M Dental) and with other trace elements like Ca, Fe in Surefil (Dentsply). Among older materials, Concise (3M Dental) contained only light (Z 3 that releases F for protection of enamel and dentine. Yb, Zr, Ba, Hf improve the radiological opacity of the materials. Some elements may accompany others as
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Transformation kinetics of corn and clover residues in mineral substrates of different composition
Pinskii, D. L.; Maltseva, A. N.; Zolotareva, B. N.; Dmitrieva, E. D.
2017-06-01
Mineralization kinetics of corn and clover residues in quartz sand, loam, sand + 15% bentonite, and sand + 30% kaolinite have been studied. A scheme has been proposed for the transformation of plant residues in mineral substrates. Kinetic parameters of mineralization have been calculated with the use of a first-order two-term exponential polynomial. It has been shown that the share of labile organic carbon pool in the clover biomass is higher (57-63%) than in the corn biomass (47-49%), which is related to the biochemical composition of plant residues. The mineralization constants of clover residues generally significantly exceed those of corn because of the stronger stabilization of the decomposition products of corn residues. The turnover time of the labile clover pool (4-9 days) in all substrates and that of the labile corn pool (8-10 days) in sands and substrates containing kaolinites and bentonite are typical for organic acids, amino acids, and simple sugars. In the loamy substrate, the turnover time of labile corn pool is about 46 days due to the stronger stabilization of components of the labile pool containing large amounts of organic acids. The turnover time of the stable clover pool (0.95 years) is significantly lower than that of the stable corn pool (1.60 years) and largely corresponds to the turnover time of plant biomass.
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Azadeh Malekzadeh Shafaroudi; Mohammad Reza Hidarian Shahri; Mohammad Hassan Karimpour
2009-01-01
Maherabad prospect area, which is studied in detail, is the first porphyry Cu-Au mineralization in the east of Iran. Based on relation of mineralization with subvolcanic intrusive bodies mostly monzonitic with porphyry texture, extent and types of alteration including potassic, sericitic- potassic, quartz- sericite- carbonate- pyrite, quartz- carbonate- pyrite, silicification- propylitic, propylitic, stockwork mineralization, assemblages hypogene mineralization including pyrite, chalcopyrite,...
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Mohamed, Rania M A; Fageer, Aisha S M; Eltayeb, Mohamed M; Mohamed Ahmed, Isam A
2014-01-01
The aim of the present work was to investigate the chemical composition, mineral extractability, and antioxidant capacity of six date palm varieties grown in Sudan. The results showed that Sudanese date varieties contained significantly different (P varieties contained significantly varied (P varieties were as follows: ferric-reducing antioxidant power (FRAP) was within the range of 2.82–27.5 mmol/100 g, chelation of Fe2+ ion ranged from 54.31% to 94.98%, and scavenging of H2O2 ranged from 38.48% to 49.13%. There were many correlations (positive, negative, and weak) between antioxidant and mineral extractability of Sudanese date fruits. PMID:25473506
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BODY COMPOSITION AND BONE MINERAL DENSITY IN WOMEN WITH RHEUMATOID ARTHRITIS
Directory of Open Access Journals (Sweden)
S. E. Myasoedova
2016-01-01
Full Text Available Objective: to establish specific features of body composition, skeletal muscle changes and bone mineral density (BMD in middle-aged and elderly female patients with rheumatoid arthritis (RA as compared to female subjects without RA.Materials and methods. The study included 86 female patients with RA aged 59.06 ± 7.52 years and 81 female subjects without RA aged 57.4 ± 5.3 years. Body composition and BMD in spine and femur was assessed using Lunar Prodidgy device (General Electric. Sarcopenia was defined as lean mass index (LMI of < 5.64 kg/m2 .Results. We have detected statistically significant decrease in fat, muscle and femoral BMD in female patients with RA as compared to their non-RA counterparts. Sarcopenia in the form of osteopenic sarcopenia and osteosarcopenia obesity was detected in 13.95 % RA patients vs 4.94 % non-RA subjects based on LMI findings. Both groups had high prevalence of osteopenia obesity.Conclusions. Assessment of the body composition by radiographic densitometry in female RA patients with osteopenia or osteoporosis may be used to detect sarcopenia and its phenotypes in order to inform prognosis and adjust the management plan.
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Wei, Na; Finneran, Kevin T
2011-04-01
Anaerobic mineralization of tert-butyl alcohol (TBA) and methyl tert-butyl ether (MTBE) were studied in sediment incubations prepared with fuel-contaminated aquifer material. Microbial community compositions in all incubations were characterized by amplified ribosomal DNA restriction analysis (ARDRA). The aquifer material mineralized 42.3±9.9% of [U-(14)C]-TBA to 14CO2 without electron acceptor amendment. Fe(III), sulfate, and Fe(III) plus anthraquinone-2,6-disulfonate addition also promoted U-[14C]-TBA mineralization at levels similar to those of the unamended controls. Nitrate actually inhibited TBA mineralization relative to unamended controls. In contrast to TBA, [U-(14)C]-MTBE was not significantly mineralized in 400 days regardless of electron acceptor amendment. Microbial community analysis indicated that the abundance of one dominant clone group correlated closely with anaerobic TBA mineralization. The clone was phylogenetically distinct from known aerobic TBA-degrading microorganisms, Fe(III)- or sulfate-reducing bacteria. It was most closely associated with organisms belonging to the alphaproteobacteria. Microbial communities were different in MTBE and TBA amended incubations. Shannon indices and Simpson indices (statistical community comparison tools) both demonstrated that microbial community diversity decreased in incubations actively mineralizing TBA, with distinct "dominant" clones developing. These data contribute to our understanding of anaerobic microbial transformation of fuel oxygenates in contaminated aquifer material and the organisms that may catalyze the reactions.
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Jordán-Garza, A. G.; González-Gándara, C.; Salas-Pérez, J. J.; Morales-Barragan, A. M.
2017-04-01
Corals on the reef corridor of the southwestern Gulf of Mexico have evolved on a terrigenous shallow continental shelf under the influence of several natural river systems. As a result, water turbidity on these reefs can be high, with visibility as low as turbidity and chlorophyll-a, the coral species composition and environmental variables were analyzed for the three main reef systems of the reef corridor of the southwestern Gulf of Mexico. Completeness of the data set was assessed using species accumulation curves and non-parametric estimators of species richness. Differences in coral assemblages' composition between the reef systems were investigated using univariate (ANOVA) and multivariate (nMDS, ANOSIM, SIMPER) analyses and the relationship between the assemblages and environmental data was assessed using a forward selection process in canonical correspondence analysis (CCA) to eliminate non-significant environmental variables. The northern and central Veracruz reef systems share a similar number of coral species (p=0.78 mult. comp.) and both showed higher species richness than the southern system (pturbidity and productivity were significant on the final CCA configuration, which showed a gradient of increasing turbidity from north to south. Reef geomorphology and the effect of turbidity help explain differences in coral assemblages' composition. More studies are necessary to establish if turbidity could function as a refuge for future environmental stress. Each Veracruz reef system is at the same time unique and shares a pool of coral species. To protect these ecosystems it is necessary to effectively manage water quality and consider coral diversity on the reef corridor of the southwestern Gulf of Mexico.
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Bone mineral and body composition alterations in paediatric cystic fibrosis patients
Energy Technology Data Exchange (ETDEWEB)
Reix, Philippe; Bellon, Gabriel [Hopital Femme Mere Enfant, Service de Pediatrie, Pneumologie, Allergologie, Mucoviscidose, Bron (France); Braillon, Pierre [Hospices Civils de Lyon, Service d' Imagerie Foetale et Pediatrique, Bron (France)
2010-03-15
With the increased life span of cystic fibrosis (CF) patients, CF-related bone diseases could have an increased prevalence and morbidity in this group. In children, previous retrospective and prospective studies have yielded conflicting results on bone mineralization. To monitor body composition and bone mineral status of children with CF. We reviewed the dual-energy X-ray absorptiometry (DXA) data of 161 children with CF (age 10 {+-} 4.8 years). Total body bone mineral content (BMCt), total lean tissue mass (LTMt) and total fat mass (FMt) were measured and compared to expected data calculated from ideal weight for height (Wi; e.g. BMCti, LTMti, FMti). The bt (BMCt/BMCti), lt (LTMt/LTMti) and ft (FMt/FMti) ratios were used as quantitative variables. Low bt ratio was found at all ages (mean bt ratio 0.94{+-}0.10; P<0.001), even in children <6 years of age. However, the children's BMCt was satisfactorily adapted to their weight. lt and ft ratios were not constant across age groups. Children <10 years had 8% reduction of their lt ratio, maintaining normal levels thereafter. The opposite trend was found for ft ratio. Poor clinical, nutritional status and vitamin A levels were correlated with bt and lt ratios. Our results indicate that children with CF could have early alterations in their bone status and that lt and ft ratios did not have constant values across ages. Interpreting DXA data using this approach is suitable in children with CF. (orig.)
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Bone mineral and body composition alterations in paediatric cystic fibrosis patients
International Nuclear Information System (INIS)
Reix, Philippe; Bellon, Gabriel; Braillon, Pierre
2010-01-01
With the increased life span of cystic fibrosis (CF) patients, CF-related bone diseases could have an increased prevalence and morbidity in this group. In children, previous retrospective and prospective studies have yielded conflicting results on bone mineralization. To monitor body composition and bone mineral status of children with CF. We reviewed the dual-energy X-ray absorptiometry (DXA) data of 161 children with CF (age 10 ± 4.8 years). Total body bone mineral content (BMCt), total lean tissue mass (LTMt) and total fat mass (FMt) were measured and compared to expected data calculated from ideal weight for height (Wi; e.g. BMCti, LTMti, FMti). The bt (BMCt/BMCti), lt (LTMt/LTMti) and ft (FMt/FMti) ratios were used as quantitative variables. Low bt ratio was found at all ages (mean bt ratio 0.94±0.10; P<0.001), even in children <6 years of age. However, the children's BMCt was satisfactorily adapted to their weight. lt and ft ratios were not constant across age groups. Children <10 years had 8% reduction of their lt ratio, maintaining normal levels thereafter. The opposite trend was found for ft ratio. Poor clinical, nutritional status and vitamin A levels were correlated with bt and lt ratios. Our results indicate that children with CF could have early alterations in their bone status and that lt and ft ratios did not have constant values across ages. Interpreting DXA data using this approach is suitable in children with CF. (orig.)
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Directory of Open Access Journals (Sweden)
David Robert Cole
2014-08-01
Full Text Available This paper contends that the power of Deleuze & Guattari’s (1988 notion of assemblage as theorised in 1000 Plateaus can be normalised and reductive with reference to its application to any social-cultural context where an open system of dynamic and fluid elements are located. Rather than determining the assemblage in this way, this paper argues for an alternative conception of ‘strange assemblage’ that must be deliberately and consciously created through rigorous and focused intellectual, creative and philosophical work around what makes assemblages singular. The paper will proceed with examples of ‘strange assemblage’ taken from a film by Peter Greenaway (A Zed and 2 Noughts; the film ‘Performance’; educational research with Sudanese families in Australia; the book, Bomb Culture by Jeff Nuttall (1970; and the band Hawkwind. Fittingly, these elements are themselves chosen to demonstrate the concept of ‘strange assemblage’, and how it can be presented. How exactly the elements of a ‘strange assemblage’ come together and work in the world is unknown until they are specifically elaborated and created ‘in the moment’. Such spontaneous methodology reminds us of the 1960s ‘Happenings’, the Situationist International and Dada/Surrealism. The difference that will be opened up by this paper is that all elements of this ‘strange assemblage’ cohere in terms of a rendering of ‘the unacceptable.'
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International Nuclear Information System (INIS)
Zhou, Dandan; Chen, Bingfa; Wu, Min; Liang, Ni; Zhang, Di; Li, Hao; Pan, Bo
2014-01-01
Intensive human activities in agricultural areas resulted in significant alteration of soil properties, which consequently change their interactions with various contaminants. This process needs to be incorporated in contaminant behavior prediction and their risk assessment. However, the relevant study is missing. This work was designed to examine the change of soil properties and ofloxacin (OFL) sorption after tillage. Soil samples were collected in Yuanyang, Mengzi, and Dianchi areas with different agricultural activities. Although the mineral compositions of soils from Yuanyang and Dianchi differed greatly, these compositions are similar after tillage, especially for paddy soils. Soil pH decreased generally after OFL sorption, suggesting that ion exchange of OFL with protons in soil organic matter (SOM) was important for OFL sorption. However, a positive relationship between SOM and OFL sorption was not observed. On the contrary, increased SOM decreased OFL sorption when soils from the same geological location were compared. Generally speaking, tillage activities or dense vegetations greatly decreased OFL sorption. The higher OFL sorption in B horizon than A horizon suggested limited leaching of OFL through soil columns. The summed sorption calculated based on the sorption of individual soil components and their percentages in soils was higher than the intact soil. This phenomenon may be understood from the interactions between soil components, such as the coating of SOM on mineral particles. This study emphasizes that soil should be treat as a dynamic environmental matrix when assessing antibiotic behaviors and risks, especially in the area with intense human activities. - Highlights: • Mineral compositions tend to be similar after tillage. • Increased SOM decreases OFL sorption for soils from the same geological location. • Tillage activities or dense vegetations greatly decrease OFL sorption. • The summed sorption of individual soil components is
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Fajemila, Olugbenga; Langer, Martin R.
2015-04-01
Reefal and shallow lagoonal environments around the island Moorea (Society Islands, French Polynesia) offer a spectacular variety of microhabitats providing a multitude niches and ideal settings for rich assemblages of tropical benthic foraminifera. The Society Islands are located near the hotspot of tropical marine diversity and represent a transitional location between the high diversity assemblages of the coral triangle and the low diversity biotas of the eastern Pacific. This area constitutes an important biogeographic link and stepping stone between the eastern and western biotas of the tropical Pacific Ocean. We have analyzed the structure, diversity and composition of benthic foraminiferal assemblages from around Moorea to document the composition, species richness and environmental role of larger and smaller benthic foraminifera from within the lagoonal system, the mangrove habitats and fore-reef sites. Foraminifera are prominent producers of calcium carbonate and contribute significantly to structures in reefal settings of the tropical Pacific. We evaluate the potential of larger symbiont-bearing foraminifera as environmental engineers and apply the FORAM-Index as proxy to assess the conditions around Moorea Island. We also evaluate the role of the Society Islands as stepping stone between biogeographic regions of the Pacific Ocean.
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Biological diversity can be divided into: alpha (α, local), beta (β, difference in assemblage composition among locals), and gamma (γ, total diversity). We assessed the partitioning of taxonomic diversity of Ephemeroptera, Plecoptera and Trichoptera (EPT) and of functional feedin...
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Decapod crustacean assemblages off the West coast of central Italy (western Mediterranean
Directory of Open Access Journals (Sweden)
Emanuela Fanelli
2007-03-01
Full Text Available Community structure and faunal composition of decapod crustaceans off the west coast of central Italy (western Mediterranean were investigated. Samples were collected during five trawl surveys carried out from June 1996 to June 2000 from 16 to 750 m depth. Multivariate analysis revealed the occurrence of five faunistic assemblages: 1 a strictly coastal community over sandy bottoms at depths
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Gao, Feng; Men, XingYuan; Ge, Feng
2014-09-01
Biodiversity research has shown that primary productivity increases with plant species number, especially in many experimental grassland systems. Here, we assessed the correlation between productivity and diversity of phytophages and natural enemy assemblages associated with planting date and intercropping in four cotton agroecosystems. Twenty-one pairs of data were used to determine Pearson correlations between species richness, total number of individuals, diversity indices and productivity for each assemblage every five days from 5 June to 15 September 2012. At the same trophic level, the productivity exhibited a significant positive correlation with species richness of the phytophage or predator assemblage. A significant correlation was found between productivity and total number of individuals in most cotton fields. However, no significant correlations were observed between productivity and diversity indices (including indices of energy flow diversity and numerical diversity) in most cotton fields for either the phytophage or the predator assemblages. Species richness of phytophage assemblage and total individual numbers were significantly correlated with primary productivity. Also, species richness of natural enemy assemblage and total number of individuals correlated with phytophage assemblage productivity. A negative but not significant correlation occurred between the indices of numerical diversity and energy flow diversity and lower trophic-level productivity in the cotton-phytophage and phytophage-predator assemblages for most intercropped cotton agroecosystems. Our results clearly showed that there were no correlations between diversity indices and productivity within the same or lower trophic levels within the phytophage and predator assemblages in cotton agroecosystems, and inter-cropped cotton fields had a stronger ability to support the natural enemy assemblage and potentially to reduce phytophages.
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International Nuclear Information System (INIS)
Ali, B.H.; Abdel Warith, A.
2003-01-01
Numerous pegmatite pockets of un zoned and zoned types are the most important rock types from the radioactive point of view. They occur at the marginal parts and higher topographic level of G.Dara younger granites. Zoned pegmatites are composed of extremely coarse-grained milky quartz core, intermediate zone and wall zone. The alteration zone is found at the contact between quartz core and intermediate zone. It is recorded the highest radioactive values due to their mineral composition, as a result of alteration processes associated with radioactive minerals. Only two alteration zones (P1 and P2) has been studied in this paper. The late magmatic alteration process (hematization, kaolinization, chloritization and fluortization) of the pegmatite resulted in the formation of chlorite, fluorite, clay minerals and carbonates (calcite) in the alteration zones as mineral assemblage. opaque minerals are found as pyrite, iron oxyhydroxide and garnet. Fluid inclusion studies by microthermometry were carried out on authigenic minerals (such as quartz and fluorite) in alteration zones (primary fluid inclusions). This study revealed that, at least two stages of the post-magmatic hydrothermal alteration are involved. The first stages of high temperature, low saline fluids are involved. The first stage is of high temperature, low saline fluids which characterized with hematization and/or chloritization resulted from fluid-rock interaction with late magmatic fluids that very probably mixed with external low salinity fluids along brittle structure. The second stage is of low temperature the main role in re high saline fluids characterized the fluoritized alteration due to consequent reaction with wall rocks and mixing with meteoric water. Mixing of low salinity meteoric water with hot a sending saline hydrothermal solution leads to ph change and continuous interaction with wall rock
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PIXE analysis of trace and other mineral elements in Romanian dental composites
International Nuclear Information System (INIS)
Preoteasa, E. A.; Iordan, Andreea; Harangus, Livia; Ciortea, C.; Moldovan, Maria
2002-01-01
Dental composites made of silicates and oxides particles embedded in an organic polymer, show a dynamic evolution but are rather expensive. Recently, the Romanian biomaterial 'Restacril' offered a low-cost alternative. Because the durability of the composite dental fillings depends both on the main chemical composition and on the impurities that may influence the inorganic particles' properties and thus modifying the bio material clinical behaviour, the elemental analysis of the material is necessary for improving its quality. Particle-induced X-ray emission (PIXE), a sensitive method for multielemental trace detection widely used in biomedical applications, allowed us to evidence 21 mineral elements with Z > 14 in some commercial dental composites. Here we evaluate the performances of PIXE for the control of dental composites by carrying out qualitative analysis of three Romanian biomaterials. PIXE measurements on thick composite samples with a flat surface were done with 3 MeV protons at the NIPNE-HH (Horia Hulubei National Institute for Physics and Nuclear Engineering) tandem accelerator, using a hyper-pure Ge detector, 30 mm thick Al absorber foil and integration of beam current. Up to 21 elements with Z > 19 were detected: K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Ga, Sr, Zr, Nb, Ru, Ag, Ba, Yb, Nd, Hf, Au, As and Pb. The orders of magnitude of relative concentrations were evaluated using X-ray yields obtained for another light element thick composite target. The Romanian composites have specific and diverse compositions, containing a great number of minor and trace elements, many of whom are impurities. Use of higher purity raw materials is suggested to reduce the latter and improve the materials' quality. Refinement of X-ray yields by better matching matrixes calculations and use of concentration standards are proposed for quantitative PIXE analysis of the dental composites. (authors)
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Directory of Open Access Journals (Sweden)
Hanja B Brandl
Full Text Available Bacteria play a central role in animal health. Yet, little is known about the acquisition of bacteria and the extent to which bacteria are acquired from different environmental sources. For example, bird nests host diverse bacteria associated with the eggs, nestlings and nesting material, but previous research has typically focussed on only a limited number of nest components at a time. It therefore remains unknown to what extent bacteria are transmitted between these components. Using both molecular and culture techniques, we characterised nest-associated bacterial assemblages throughout the entire nesting cycle of reed warblers by sampling bacteria on eggs before and during incubation, within nestling faeces, and on the nesting material of post-breeding nests. We found that bacterial assemblages clustered by nest component. Yet some overlap existed between nest components, suggesting that bacterial transmission across components is likely to occur. Eggs and nestlings from the same nest harboured more similar bacteria than expected by chance, suggesting an influence of environment or genetics on bacterial assemblages. Bacterial loads were not lower on incubated eggs. Instead, incubation was associated with a change in the structure of assemblages, including a decrease in potentially-harmful Gram-negative bacteria. In addition we show for the first time, that incubation is associated with the complete extinction of harmful haemolytic bacteria. Overall, our study appears to be the first to demonstrate differences in bacterial assemblages between bird nest components. In addition, we highlight the complexity of nest bacterial assemblages and provide new insights into the benefits of incubation.
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Functional redundancy patterns reveal non-random assembly rules in a species-rich marine assemblage.
Directory of Open Access Journals (Sweden)
Nicolas Guillemot
Full Text Available The relationship between species and the functional diversity of assemblages is fundamental in ecology because it contains key information on functional redundancy, and functionally redundant ecosystems are thought to be more resilient, resistant and stable. However, this relationship is poorly understood and undocumented for species-rich coastal marine ecosystems. Here, we used underwater visual censuses to examine the patterns of functional redundancy for one of the most diverse vertebrate assemblages, the coral reef fishes of New Caledonia, South Pacific. First, we found that the relationship between functional and species diversity displayed a non-asymptotic power-shaped curve, implying that rare functions and species mainly occur in highly diverse assemblages. Second, we showed that the distribution of species amongst possible functions was significantly different from a random distribution up to a threshold of ∼90 species/transect. Redundancy patterns for each function further revealed that some functions displayed fast rates of increase in redundancy at low species diversity, whereas others were only becoming redundant past a certain threshold. This suggested non-random assembly rules and the existence of some primordial functions that would need to be fulfilled in priority so that coral reef fish assemblages can gain a basic ecological structure. Last, we found little effect of habitat on the shape of the functional-species diversity relationship and on the redundancy of functions, although habitat is known to largely determine assemblage characteristics such as species composition, biomass, and abundance. Our study shows that low functional redundancy is characteristic of this highly diverse fish assemblage, and, therefore, that even species-rich ecosystems such as coral reefs may be vulnerable to the removal of a few keystone species.
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Orihuela, Rodrigo L L; Peres, Carlos A; Mendes, Gabriel; Jarenkow, João A; Tabarelli, Marcelo
2015-01-01
We examine the effects of forest fragmentation on the structure and composition of tree assemblages within three seasonal and aseasonal forest types of southern Brazil, including evergreen, Araucaria, and deciduous forests. We sampled three southernmost Atlantic Forest landscapes, including the largest continuous forest protected areas within each forest type. Tree assemblages in each forest type were sampled within 10 plots of 0.1 ha in both continuous forests and 10 adjacent forest fragments. All trees within each plot were assigned to trait categories describing their regeneration strategy, vertical stratification, seed-dispersal mode, seed size, and wood density. We detected differences among both forest types and landscape contexts in terms of overall tree species richness, and the density and species richness of different functional groups in terms of regeneration strategy, seed dispersal mode and woody density. Overall, evergreen forest fragments exhibited the largest deviations from continuous forest plots in assemblage structure. Evergreen, Araucaria and deciduous forests diverge in the functional composition of tree floras, particularly in relation to regeneration strategy and stress tolerance. By supporting a more diversified light-demanding and stress-tolerant flora with reduced richness and abundance of shade-tolerant, old-growth species, both deciduous and Araucaria forest tree assemblages are more intrinsically resilient to contemporary human-disturbances, including fragmentation-induced edge effects, in terms of species erosion and functional shifts. We suggest that these intrinsic differences in the direction and magnitude of responses to changes in landscape structure between forest types should guide a wide range of conservation strategies in restoring fragmented tropical forest landscapes worldwide.
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Directory of Open Access Journals (Sweden)
Rodrigo L L Orihuela
Full Text Available We examine the effects of forest fragmentation on the structure and composition of tree assemblages within three seasonal and aseasonal forest types of southern Brazil, including evergreen, Araucaria, and deciduous forests. We sampled three southernmost Atlantic Forest landscapes, including the largest continuous forest protected areas within each forest type. Tree assemblages in each forest type were sampled within 10 plots of 0.1 ha in both continuous forests and 10 adjacent forest fragments. All trees within each plot were assigned to trait categories describing their regeneration strategy, vertical stratification, seed-dispersal mode, seed size, and wood density. We detected differences among both forest types and landscape contexts in terms of overall tree species richness, and the density and species richness of different functional groups in terms of regeneration strategy, seed dispersal mode and woody density. Overall, evergreen forest fragments exhibited the largest deviations from continuous forest plots in assemblage structure. Evergreen, Araucaria and deciduous forests diverge in the functional composition of tree floras, particularly in relation to regeneration strategy and stress tolerance. By supporting a more diversified light-demanding and stress-tolerant flora with reduced richness and abundance of shade-tolerant, old-growth species, both deciduous and Araucaria forest tree assemblages are more intrinsically resilient to contemporary human-disturbances, including fragmentation-induced edge effects, in terms of species erosion and functional shifts. We suggest that these intrinsic differences in the direction and magnitude of responses to changes in landscape structure between forest types should guide a wide range of conservation strategies in restoring fragmented tropical forest landscapes worldwide.
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Directory of Open Access Journals (Sweden)
Mohammad Hassan Karimpour
2017-11-01
Full Text Available Introduction The Irankuh mining district area located at the southern part of the Malayer-Isfahan metallogenic belt, south of Isfahan, consists of several Zn-Pb deposits and occurrences such as Tappehsorkh, Rowmarmar 5, Kolahdarvazeh, Blind ore, and Gushfil deposits as well as Rowmarmar 1-4 and Gushfil 1 prospects. Based on geology, alteration, form and texture of mineralization, and paragenesis assemblages, Pb-Zn mineralization is Mississippi-type deposit (Rastad, 1981; Ghazban et al., 1994; Ghasemi, 1995; Reichert, 2007; Timoori-Asl (2010; Ayati et al., 2013; Hosseini-Dinani et al., 2015. Geology of the area consists of Jurassic siltstone and shale and different types of Cretaceous dolostone and limestone. The aim of this research is new geological studies such as revision of old geologic map, study of different types of textures and mineral assemblages within carbonate and clastic host rocks, and chemistry of galena, sphalerite, and dolomite. Finally, we combined these results with isotopic and fluid inclusion data and discussed on ore-fluid conditions. Materials and Methods In order to achieve the aims of this work, at first field surveying and sampling were done. Then, 200 thin and 70 polished thin sections were prepared. Some of the samples were selected for microprobe analysis and galena and sphalerite minerals were analyzed by using JEOL- JAX-8230 analyzer at Colorado University, USA. The chemistry of dolomite and fluid inclusion data are used after Boveiri Konari and Rastad (2016 and stable isotope is used after Ghazban et al. (1994. Discussion The Irankuh mineralization is hosted by carbonate rocks (dolostone and limestone and minor clastic rocks as epigenetic. Mineralization has occurred as breccia, veinlet, open space filling, spoted, dessiminated, and replacement (carbonate hosted rock. The mineral assemblages are Fe-rich sphalerite, galena, minor pyrite, Fe- and Mn-rich dolomite, bituminous, ankrite, calcite ± quartz ± barite
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Weber, Kristina; Zuschin, Martin
2013-01-15
Life-death (LD) studies of shelly macrofauna are important to evaluate how well a fossil assemblage can reflect the original living community, but can also serve as a proxy for recent ecological shifts in marine habitats and in practice this has to be distinguished using taphonomic preservation pattern and estimates of time-averaging. It remains to be rigorously evaluated, however, how to distinguish between sources of LD disagreement. In addition, death assemblages (DAs) also preserve important information on regional diversity which is not available from single censuses of the life assemblages (LAs). The northern Adriatic Sea is an ecosystem under anthropogenic pressure, and we studied the distribution and abundance of living and dead bivalve and gastropod species in the physically stressful environments (tidal flat and shallow sublittoral soft bottoms) associated with the delta of the Isonzo River (Gulf of Trieste). Specifically we evaluated the fidelity of richness, evenness, abundance, habitat discrimination and beta diversity. A total of 10,740 molluscs from fifteen tidal flat and fourteen sublittoral sites were analyzed for species composition and distribution of living and dead molluscs. Of 78 recorded species, only eleven were numerically abundant. There were many more dead than living individuals and rarefied species richness in the DA was higher at all spatial scales, but the differences are lower in habitats and in the region than at individual stations. Evenness was always higher in death assemblages, and probably due to temporally more variable LAs the differences are stronger in the sublittoral habitats. Distinct assemblages characterized intertidal and sublittoral habitats, and the distribution and abundance of empty shells generally corresponded to that of the living species. Death assemblages have lower beta diversity than life assemblages, but empty shells capture compositional differences between habitats to a higher degree than living shells
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Directory of Open Access Journals (Sweden)
Cristiana L. Ciobanu
2016-10-01
Full Text Available This paper comprises a review of the rapidly expanding application of nanoscale mineral characterization methodology to the study of ore deposits. Utilising bismuth sulphosalt minerals from a reaction front in a skarn assemblage as an example, we illustrate how a complex problem in ore petrology, can be approached at scales down to that of single atoms. We demonstrate the interpretive opportunities that can be realised by doing this for other minerals within their petrogenetic contexts. From an area defined as Au-rich within a sulphosalt-sulphide assemblage, and using samples prepared on a Focused Ion Beam–Scanning Electron Microscopy (SEM platform, we identify mineral species and trace the evolution of their intergrowths down to the atomic scale. Our approach progresses from a petrographic and trace element study of a larger polished block, to high-resolution Transmission Electron Microscopy (TEM and High Angle Annular Dark Field (HAADF Scanning-TEM (STEM studies. Lattice-scale heterogeneity imaged in HAADF STEM mode is expressed by changes in composition of unit cell slabs followed by nanoparticle formation and their growth into “veins”. We report a progressive transition from sulphosalt species which host lattice-bound Au (neyite, lillianite homologues; Pb-Bi-sulphosalts, to those that cannot accept Au (aikinite. This transition acts as a crystal structural barrier for Au. Fine particles of native gold track this progression over the scale of several hundred microns, leading to Au enrichment at the reaction front defined by an increase in the Cu gradient (several wt %, and abrupt changes in sulphosalt speciation from Pb-Bi-sulphosalts to aikinite. Atom-scale resolution imaging in HAADF STEM mode allows for the direct visualisation of the three component slabs in the neyite crystal structure, one of the largest and complex sulphosalts of boxwork-type. We show for the first time the presence of aikinite nanoparticles a few nanometres in
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Prado, Patricia
2018-05-01
Wastewater pulses from rice agriculture are persistently discharged into the northern shore of the Alfacs Bay (Ebro Delta, NW Mediterranean) from April to November. The bay also receives water from coastal lagoons which are subjected to freshwater inputs from the Ebro River mixed to an unknown extent with agricultural wastewater during the same period. This paper compares epiphyte assemblages growing on leaves of Cymodocea nodosa in sites exposed to agricultural drainage channels, lagoon connection channels, and control sites in the Ebro Delta Natural Park (southern shore of the bay). Leaf epiphytic assemblages of Zostera noltii patches in the northern shore of the bay were also compared with those of adjacent beds of C. nodosa. Drainage channel sites had consistently distinctive assemblages (higher species richness, biomass load, and taxa composition) than control sites. Assemblages from lagoon channel sites were more variable, with three sites showing particularly high covers of epiphytic algae and two sites more similar to controls. Epiphyte patterns clearly matched in situ measures of nutrient availability, and were consistent with decreased shoot densities in discharge sites. In contrast, differences in epiphyte assemblages between seagrass species were minor, and mostly a result of higher epiphytic loads on C. nodosa than on Z. noltii, which features thinner leaves. Further research is needed to investigate the consequences of these plant and epiphyte alterations in important ecosystem processes such as decomposition and export rates, as well as overall effects of nutrients and salinity in secondary producers such as associated macroinvertebrate assemblages supporting locally important marine fisheries.
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Directory of Open Access Journals (Sweden)
Heitor Bruno de Araújo Souza
2012-03-01
Full Text Available Termites are abundant organisms in tropical ecosystems and strongly influence the litter decomposition and soil formation. Despite their importance, few studies about their assemblage structures have been made in Brazilian Atlantic Forest fragments, especially in the area located north of the São Francisco River. This study aims to analyze the assemblage composition of five Atlantic Forest fragments located in the northern biome limit along the Brazilian coast. A standardized sampling protocol of termites was applied in each fragment. Thirty-three termite species belonging to twenty genera and three families were found in the forest fragments. The wood-feeder group was dominant both concerning to species richness and number of encounters in all areas. In sites northern to 7°S, there is an evident simplification of the termite assemblage composition regarding species richness and number of encounters by feeding group. This fact is apparently due to a higher sandy level in soils and to semideciduous character of the vegetation in the northern fragments. Thus, even on the north of São Francisco River, termite biodiversity is heterogeneously spread with highest density of species in the portion between 07°S and São Francisco River mouth (10°29'S.
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Directory of Open Access Journals (Sweden)
Josias Henrique de Amorim Xavier
Full Text Available Reefs, mangroves and seagrass biotopes often occur in close association, forming a complex and highly productive ecosystem that provide significant ecologic and economic goods and services. Different anthropogenic disturbances are increasingly affecting these tropical coastal habitats leading to growing conservation concern. In this field-based study, we used a visual census technique (belt transects 50 m x 2 m to investigate the interactions between fishes and microhabitats at the Mamanguape Mangrove-Reef system, NE Brazil. Overall, 144 belt transects were performed from October 2007 to September 2008 to assess the structure of the fish assemblage. Fish trophic groups and life stage (juveniles and adults were recorded according to literature, the percent cover of the substrate was estimated using the point contact method. Our results revealed that fish composition gradually changed from the Estuarine to the Reef zone, and that fish assemblage was strongly related to the microhabitat availability, as suggested by the predominance of carnivores at the Estuarine zone and presence of herbivores at the Reef zone. Fish abundance and diversity were higher in the Reef zone and estuary margins, highlighting the importance of structural complexity. A pattern of nursery area utilization, with larger specimens at the Transition and Reef Zone and smaller individuals at the Estuarine zone, was recorded for Abudefduf saxatilis, Anisotremus surinamensis, Lutjanus alexandrei, and Lutjanus jocu. Our findings clearly suggests ecosystem connectivity between mangrove, seagrass and reef biotopes, and highlighted the importance of Mamanguape Mangrove-Reef System as a priority area for conservation and research, whose habitat mosaics should be further studied and protected.
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Henkel, S. K.; Politano, K. K.
2017-07-01
Increasing interest in offshore development has motivated intensified efforts to map the seafloor for marine spatial planning. However, surficial geologic maps do not accurately represent habitats for various species groups of concern. This study used a bottom-up approach to integrate macrofaunal densities and benthic conditions on the Pacific Northwest shelf to identify macrofaunal assemblages and associated habitat features. Benthic cores and water-column profiles were collected from 137 stations from 50 to 110 m depth. Analyses grouping stations based on both similar species abundances and benthic conditions resulted in six broad habitats. Within the sampled depth and latitudinal range, sediment characteristics were the primary structuring variable. A major break in assemblages was detected between sediment that had less than 1% silt/clay and those containing more than 1% silt/clay. Assemblages differed primarily in the bivalve species present and secondarily in polychaete species. Within the greater than and less than 1% silt/clay habitats, further discretization of assemblages was based mostly on differing abundances of characteristic bivalves and polychaetes associated with differing median grain sizes, which did not correspond to traditional definitions of fine or medium sand. These data show that a bottom-up methodology is necessary to discern habitats for macrofauna and that site-specific physical sampling is necessary to predict macrofaunal assemblage composition. However, if detailed sediment characteristics are known, macrofaunal assemblages may be predicted without time-intensive biological sampling and processing. These results also indicate that seemingly small sedimentary changes due to offshore installations may have measureable effects on the relative abundances and even the species composition of macrofauna.
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Microplastic-associated bacterial assemblages in the intertidal zone of the Yangtze Estuary.
Jiang, Peilin; Zhao, Shiye; Zhu, Lixin; Li, Daoji
2018-05-15
Plastic trash is common in oceans. Terrestrial and marine ecosystem interactions occur in the intertidal zone where accumulation of plastic frequently occurs. However, knowledge of the plastic-associated microbial community (the plastisphere) in the intertidal zone is scanty. We used high-throughput sequencing to profile the bacterial communities attached to microplastic samples from intertidal locations around the Yangtze estuary in China. The structure and composition of plastisphere communities varied significantly among the locations. We found the taxonomic composition on microplastic samples was related to their sedimentary and aquatic origins. Correlation network analysis was used to identify keystone bacterial genera (e.g. Rhodobacterales, Sphingomonadales and Rhizobiales), which represented important microbial associations within the plastisphere community. Other species (i.e. potential pathogens) were considered as hitchhikers in the plastic attached microbial communities. Metabolic pathway analysis suggested adaptations of these bacterial assemblages to the plastic surface-colonization lifestyle. These adaptations included reduced "cell motility" and greater "xenobiotics biodegradation and metabolism." The findings illustrate the diverse microbial assemblages that occur on microplastic and increase our understanding of plastisphere ecology. Copyright © 2017 Elsevier B.V. All rights reserved.
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Patch dynamics of a foraging assemblage of bees.
Wright, David Hamilton
1985-03-01
The composition and dynamics of foraging assemblages of bees were examined from the standpoint of species-level arrival and departure processes in patches of flowers. Experiments with bees visiting 4 different species of flowers in subalpine meadows in Colorado gave the following results: 1) In enriched patches the rates of departure of bees were reduced, resulting in increases in both the number of bees per species and the average number of species present. 2) The reduction in bee departure rates from enriched patches was due to mechanical factors-increased flower handling time, and to behavioral factors-an increase in the number of flowers visited per inflorescence and in the number of inflorescences visited per patch. Bees foraging in enriched patches could collect nectar 30-45% faster than those foraging in control patches. 3) The quantitative changes in foraging assemblages due to enrichment, in terms of means and variances of species population sizes, fraction of time a species was present in a patch, and in mean and variance of the number of species present, were in reasonable agreement with predictions drawn from queuing theory and studies in island biogeography. 4) Experiments performed with 2 species of flowers with different corolla tube lengths demonstrated that manipulation of resources of differing availability had unequal effects on particular subsets of the larger foraging community. The arrival-departure process of bees on flowers and the immigration-extinction process of species on islands are contrasted, and the value of the stochastic, species-level approach to community composition is briefly discussed.
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Directory of Open Access Journals (Sweden)
Isaac Rodriguez
2014-01-01
Full Text Available The application of freeze-dried gelatin sponges as alternative bone grafting substitutes has many advantages, including the ability to swell, high porosity, tailorable degradation, and versatility to incorporate multiple components such as growth factors and nanofillers. The purpose of this study was to mineralize (M and further characterize 1-Ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC cross-linked gelatin sponges enhanced with preparations rich in growth factors, hydroxyapatite, and chitin whiskers (PHCE. Sponges were characterized for their swelling and in vitro mineralization potential, surface characteristics, protein release, mechanical properties, and MG-63 cell attachment and infiltration. All sponges swelled up to 50% of their original volume upon hydration. Scanning electron microscopy showed sparse mineral deposition for gelatin-M scaffolds while PHCE-M scaffolds exhibited more uniform mineral nucleation. Over 21 days, PHCE-M scaffolds cumulatively released significantly more (30% of its initial protein content than all other scaffolds. PHCE-M scaffolds reported lower modulus values (1.3–1.6 MPa when compared to gelatin control scaffolds (1.6–3.2 MPa. Increased cell attachment and infiltration was noticed on PHCE and PHCE-M scaffolds. The results of the study demonstrate the enhanced performance of PHCE and PHCE-M scaffolds to serve as bone healing scaffolds. Their potential to release incorporated factors, comparable composition/mechanical properties to tissues developed in the early stages of bone healing, and enhanced initial cellular response make them suitable for further studies evaluating more complex cellular interactions.
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Dijk, van J.; Didden, W.A.M.; Kuenen, F.; Bodegom, van P.M.; Verhoef, H.A.; Aerts, R.
2009-01-01
Reducing decomposition and mineralization of organic matter by increasing groundwater levels is a common approach to reduce plant nutrient availability in many peat meadow restoration projects. The soil community is the main driver of these processes, but how community composition is affected by
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Microplastic-associated Bacterial Assemblages in the Intertidal Zone
Jiang, P.; Zhao, S.; Zhu, L.; Li, D.
2017-12-01
Plastic debris is posing a planetary-scale threat. As a zone where terrestrial and marine ecosystems interactions occur, the accumulation of plastic marine debris (PMD) in intertidal environments has been well documented. But the information of plastic-associated microbial community (the "Plastisphere") in the intertidal zone is scanty. Utilizing the high-throughput sequencing, we profiled the bacterial communities attached to microplastic samples from the intertidal locations around Yangtze estuary. The structure and composition of Plastisphere communities in current study varied significantly with geographical stations. The taxonomic composition on microplastic samples implied their sedimental and aquatic origins. Some members of hydrocarbon degrading microorganisms and potential pathogens were detected on microplastic. Overall, our findings fuel the evidence for the occurrence of diverse microbial assemblages on PMD and improving our understanding of Plastisphere ecology, which could support the management action and policy change related to PMD.
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Multi-scale analysis of hermatypic coral assemblages at Mexican Central Pacific
Directory of Open Access Journals (Sweden)
Joicye Hernández-Zulueta
2017-03-01
Full Text Available The Mexican Central Pacific is located in a zone of oceanographic transition between two biogeographic provinces with particular conditions that affect the associated fauna. The objective of this study was to evaluate the variation of hermatypic coral assemblages in this region and to determine their relationship with the heterogeneity of the benthonic habitat and spatial variables. A total of 156 transects were carried out at 41 sites in the years 2010 and 2011. The sampling effort returned 96.7% of the coral richness expected for the area, with a total of 15 species recorded. The results showed that richness, diversity and cover of corals varied only at the site and state scales. However, the composition and coverage of all coral species, as well as the benthonic habitat structure, differed significantly across the study scales (i.e. sites, zones and states. Canonical redundancy analysis showed that variation in the richness, diversity and assemblages of corals was explained by the cover of live corals, articulated calcareous algae, sandy substrate, sponges and fleshy macroalgae. This study suggests that local scale (i.e. site variation in the coral assemblages of the Mexican Central Pacific is the result of the heterogeneity of the benthonic habitat, while geomorphological and oceanographic characteristics play a greater role at regional scale.
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Coastal Upwelling Drives Intertidal Assemblage Structure and Trophic Ecology.
Reddin, Carl J; Docmac, Felipe; O'Connor, Nessa E; Bothwell, John H; Harrod, Chris
2015-01-01
Similar environmental driving forces can produce similarity among geographically distant ecosystems. Coastal oceanic upwelling, for example, has been associated with elevated biomass and abundance patterns of certain functional groups, e.g., corticated macroalgae. In the upwelling system of Northern Chile, we examined measures of intertidal macrobenthic composition, structure and trophic ecology across eighteen shores varying in their proximity to two coastal upwelling centres, in a hierarchical sampling design (spatial scales of >1 and >10 km). The influence of coastal upwelling on intertidal communities was confirmed by the stable isotope values (δ13C and δ15N) of consumers, including a dominant suspension feeder, grazers, and their putative resources of POM, epilithic biofilm, and macroalgae. We highlight the utility of muscle δ15N from the suspension feeding mussel, Perumytilus purpuratus, as a proxy for upwelling, supported by satellite data and previous studies. Where possible, we used corrections for broader-scale trends, spatial autocorrelation, ontogenetic dietary shifts and spatial baseline isotopic variation prior to analysis. Our results showed macroalgal assemblage composition, and benthic consumer assemblage structure, varied significantly with the intertidal influence of coastal upwelling, especially contrasting bays and coastal headlands. Coastal topography also separated differences in consumer resource use. This suggested that coastal upwelling, itself driven by coastline topography, influences intertidal communities by advecting nearshore phytoplankton populations offshore and cooling coastal water temperatures. We recommend the isotopic values of benthic organisms, specifically long-lived suspension feeders, as in situ alternatives to offshore measurements of upwelling influence.
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The mineral matter characteristics of some Chinese coal
Energy Technology Data Exchange (ETDEWEB)
Liu, X. [China University of Mining and Technology (China). Dept. of Coal Preparation and Utilization
1994-12-01
The mineral matter has been separated from 18 coal samples with a low temperature ashes and analyzed by means of X-ray diffraction method. Based on the results of chemical analysis of the coal ash, with reference to the standard composition of minerals, the content of various mineral phases in the coal ash has been determined. Furthermore, this paper summarizes the mineral matter characteristics of the coal samples and discusses the relationship between the composition of mineral matter in coal and its depositional environment.
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Neumann, Jessica L.; Griffiths, Geoffrey H.; Foster, Christopher W.; Holloway, Graham J.
2016-01-01
Context\\ud Landscape heterogeneity (the composition and configuration of different landcover types) plays a key role in shaping woodland bird assemblages in wooded-agricultural mosaics. Understanding how species respond to landscape factors could contribute to preventing further decline of woodland bird populations.\\ud Objective\\ud To investigate how woodland birds with different species traits respond to landscape heterogeneity, and to identify whether specific landcover types are important ...
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Biologically controlled minerals as potential indicators of life
Schwartz, D. E.; Mancinelli, R. L.; Kaneshiro, E.
1991-01-01
Minerals can be produced and deposited either by abiotic or biologic means. Regardless of their origin, mineral crystals reflect the environment conditions (e.g., temperature, pressure, chemical composition, and redox potential) present during crystal formation. Biologically-produced mineral crystals are grown or reworked under the control of their host organism and reflect an environment different from the abiotic environment. In addition, minerals of either biologic or abiotic origin have great longevities. For these reasons, biologically produced minerals have been proposed as biomarkers. Biomarkers are key morphological, chemical, and isotopic signatures of living systems that can be used to determine if life processes have occurred. Studies of biologically controlled minerals produced by the protist, Paramecium tetraurelia, were initiated since techniques have already been developed to culture them and isolate their crystalline material, and methods are already in place to analyze this material. Two direct crystalline phases were identified. One phase, whose chemical composition is high in Mg, was identified as struvite. The second phase, whose chemical composition is high in Ca, has not been previously found occurring naturally and may be considered a newly discovered material. Analyses are underway to determine the characteristics of these minerals in order to compare them with characteristics of these minerals in order to compare them with characteristics of minerals formed abiotically, but with the same chemical composition.
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Radioisotopes in plant mineral nutrition
International Nuclear Information System (INIS)
Singh, Bhupinder
2016-01-01
Extensive investigations on mineral composition of different plant species growing on various soils, helped in realizing that neither the presence nor the concentration of a mineral element in a plant can be regarded as a criterion for essentially. Plants have a limited capability for selective uptake of those mineral elements which are essential for their growth. They also take up mineral element which are not necessary for growth and may even be toxic. The mineral composition of plants growing in soils cannot, therefore, be used to establish essentially of a mineral element. Once this fact was appreciated, both water and sand culture experiments were carried out in which particular mineral elements were omitted. Von Sach and Knop are credited with reintroduction of the solution culture method using which they demonstrated the absolute requirement of ten macronutrients. As evident, these techniques made possible a more precise characterization of essentially of mineral elements and led to a better understanding of their role in plant metabolism. By the beginning of 20"t"h century importance of micronutrients like B, Mn, Cu, Mo and CI was also established
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Röpke, Cristhiana P; Amadio, Sidinéia; Zuanon, Jansen; Ferreira, Efrem J G; Deus, Cláudia Pereira de; Pires, Tiago H S; Winemiller, Kirk O
2017-01-10
Combined effects of climate change and deforestation have altered precipitation patterns in the Amazon. This has led to changes in the frequency of extreme events of flood and drought in recent decades and in the magnitude of the annual flood pulse, a phenomenon that influences virtually all aspects of river-floodplain ecosystem dynamics. Analysis of long-term data revealed abrupt and synchronous changes in hydrology and fish assemblage structure of a floodplain lake near the confluence of Amazon and Negro rivers. After an intense drought in 2005, the assemblage assumed a different and fairly persistent taxonomic composition and functional structure. Declines in abundance after 2005 were more pronounced for species of all sizes having equilibrium life history strategy, large species with periodic life history strategy, and for all trophic levels except primary consumers. Our results suggest that the extreme drought triggered changes in the fish assemblage and subsequent anomalous hydrological conditions have hampered assemblage recovery. These findings stress the need to account for climatic-driven hydrological changes in conservation efforts addressing aquatic biodiversity and fishery resources in the central Amazon.
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Directory of Open Access Journals (Sweden)
Marcia Muñoz
2010-01-01
Full Text Available In the El Volcan and Rodeo de los Bueyes areas, Andean Principal Cordillera (east of Santiago; 33°50'S, an Upper Oligocene-Lower Miocene volcanic series belonging to the Abanico Formation (Late Eocene-Early Miocene is exposed. The rock successions outcropping in both areas, ca. 3,300 m total thickness, have been affected by very low-grade, non-deformative metamorphism in the prehnite-pumpellyite facies. This is represented by the widespread development of secondary mineral assemblages composed of epidote, mixed-layer chlorite-smectite, albite, quartz, white mica, and titanite. These mineral assemblages also contain pumpellyite, prehmte or prehnite+actinolite in a few samples. Chemical characteristics, such as low compositional variability of mixed-layer chlorite-smectite and actino-lite independent from the metadomain where these phases are hosted, along with a high proportion of chlorite layers in the former, suggest that these phases closely represent the whole rock effective bulk composition. On the contrary, pumpellyite compositions show a higher variability and a strong metadomain control evidencing its lower equilibration kinetics and leaving only those that grow in the rock matrix as the more closely representative of a whole rock effective bulk compositional control. Mineral assemblages from both areas show evidence of having been formed during the same metamorphic event where reactions have ocurred equivalently between them. However, local differences in chemical variables controlling this process are recognizable. A higher CO2 concentration in the fluids during the metamorphism in the El Volcán area than in the Rodeo de los Bueyes area is suggested by the scarce development of prehnite and the ubiquitous presence of calcite in the metamorphic assemblages of the former. Pressure and temperature of this metamorphic event have been roughly estimated to be lower than 2-3 kbar and 320°C, respectively.En las areas de El Volcán y Rodeo de
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International Nuclear Information System (INIS)
Luukkonen, A.; Pitkaenen, P.; Partamies, S.
2004-03-01
This study attempts to make scenarios what geochemical effects the future underground excavations in the Olkiluoto bedrock have on naturally occurring fracture mineral buffers. The excavations of underground research facilities, and final repository galleries will cause steep hydraulic gradients in the bedrock fractures. These gradients likely draw surficial waters within the fracture network and activate weathering processes deeper in rock fractures than in the natural undisturbed conditions. The studies are concentrated on the meteoric and seawater infiltration in the rock fractures, and on the selected minerals considered significant buffers against pH/redox variations in groundwater. Two approaches to calculate the scenarios are utilised. The equilibrium geochemical calculations consider variety of problems including several surficial water compositions, mixing cases between surficial water types, and couple buffer mineral assemblages. These equilibrium calculations indicate that meteoric water by far presents the most potential hazard for the Olkiluoto fracture minerals. In the calculated cases, seawater and the contamination of meteoric water with seawater during the water infiltration usually improved the performance of mineral buffers compared to the pure meteoric water cases. Of the Olkiluoto fracture minerals, calcite and pyrite turn out to be the most important buffer minerals against dissolved O 2 and low pH in groundwater. The kinetic geochemical approach concentrated on two meteoric water cases infiltrating into a narrow fracture channel. Calculations consider the possibilities that the infiltrating meteoric water is dissolved carbon containing soil water or almost 'distilled' rain water. Pyrite and calcite are taken into account as the buffering minerals. Several simulations are done by varying the recharge water compositions and the flow rates of water. It turns out that as long as volumetric flow rates within the 500-metre-channel considered are in
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Directory of Open Access Journals (Sweden)
Francílio da Silva Rodrigues
2011-08-01
Full Text Available This study records and analyzes the diversity and structure of a snake assemblage in a transition area between Cerrado and Caatinga, in the municipality of Castelo do Piauí, state of Piauí, comparing the distribution and similarity of the species composition with other open localities already studied in Brazil. We used three complementary sampling methods: time constrained search (TCS, pitfall traps with drift fences (PFT, and incidental encounters (IE. During the TCS and PFT, 912 hours/observer and 6,468 days/trap were used, respectively. We estimated 23 species of snakes for the locality, although only 19 species were recorded. Philodryas nattereri Steindachner, 1870 (n = 10, Liophis poecilogyrus (Schlegel, 1837 (n = 9, Liophis viridis Günther, 1862 (n = 8 and Thamnodynastes sp. (n = 8 were the most abundant species. Terrestrial, cryptozoic, and diurnal snakes predominated in the assemblage (Boidae = 2 species, Dipsadidae = 12, Colubridae = 2, Elapidae = 1, Viperidae = 2. The results indicate that the fauna of the locality is similar with that of other open formations, especially the Caatinga, corroborating previous floristic studies. Comparisons between snake assemblages analyzed by different authors suggest structural differences between the assemblages of the Cerrado and the Caatinga, contradicting the hypothesis of mixed composition of fauna in these biomes.
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Directory of Open Access Journals (Sweden)
Mafalda Júnior Paulo
2006-01-01
Full Text Available Two ichthyoplankton surveys were conducted during July 1994 and July 1995 in the Gulf of Cádiz with the aim of describing composition, abundance, distribution patterns and interannual variations of larval fish assemblages. Interannual differences were found in this study. In 1994, higher salinities were observed at external sites, though in 1995, higher values were observed at intermediate sites. The upper water column was warmer in 1994 and had less fish larvae density. During 1994, Sardinella aurita and Engraulis encrasicolus were abundant but spatial location was opposite. In 1995, abundance of both species was very different, but with similar spatial pattern. Cluster analysis revealed well-defined groups of stations and assemblages of larvae, primarily related to bathymetry. The "inshore assemblage" occupied the shallow coast area; its characteristics species being closely related to the estuarine system, mainly comprising Engraulis encrasicolus and Gobiidae. The "shelf assemblage" occupied the continental shelf and its characteristics species consisted of larvae whose adults inhabited the shelf province and spawn in the same zone, like Sardinella aurita and Trachurus spp. Interannual variations in composition and extension of the subgroups could be attributed to the main circulation patterns, continental water discharge and spawning strategies of fishes.
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Clay mineral distribution and provenance in the Heuksan mud belt, Yellow Sea
Cho, Hyen Goo; Kim, Soon-Oh; Kwak, Kyeong Yoon; Choi, Hunsoo; Khim, Boo-Keun
2015-12-01
The Heuksan mud belt (HMB), located in the southeastern Yellow Sea, runs parallel to the southwest coast of Korea. In this study, the distribution and relative contribution of four major clay minerals are investigated using 101 surface sediment samples collected in the course of KIOST (2001, 2010, 2011) and KIGAM (2012) cruises, as well as 33 river sediment samples (four from the Huanghe River, three from the Changjiang River, and 26 from Korean rivers) in order to clarify the provenance of fine-grained sediments in the HMB. Based on this currently largest and most robust dataset available for interpretation, the clay mineral assemblages of the fine-grained sediments in the HMB are found to be on average composed of 64.7% illite, 17.9% chlorite, 11.4% kaolinite, and 5.9% smectite. Overall, the clay mineral assemblages are similar in both the northern and the southern parts of the HMB, although smectite seems to be relatively enriched in the southern part, whereas kaolinite is slightly more dominant in the northern part. This clearly indicates that the clays are mostly derived from Korean rivers and, in the southern part of the HMB, partly also from the Huanghe River in China. The new data thus confirm and strengthen the tentative interpretation of some earlier work based on a more limited dataset.
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Novaes, J L C; Moreira, S I L; Freire, C E C; Sousa, M M O; Costa, R S
2014-05-01
The aim of this study was to analyse the composition, structure and spatial and temporal patterns of diversity and abundance of the ichthyofauna of the Santa Cruz Reservoir in semi-arid Brazil. Data were collected quarterly at eight sampling locations on the reservoir between February 2010 and November 2011 using gillnets from 12- to 70-mm mesh that were left in the water for 12h00min during the night. We evaluated the composition, structure and assemblage descriptors (Shannon-Wiener diversity index and equitability, respectively) and catch per unit effort by the number (CPUEn) and biomass (CPUEb) of the ichthyofauna. The 6,047 individuals (399,211.6 g) captured represented three orders, ten families and 20 species, of which four belonged to introduced species. The family Characidae was the most abundant with a total of 2,772 (45.8%) individuals captured. The species-abundance curve fit the log-normal model. In the spatial analysis of diversity, there were significant differences between sampling sites in the lacustrine and fluvial regions, and the highest values were found in the lacustrine region. In the temporal analysis of diversity, significant differences were also observed between the rainy and dry seasons, and the higher values were found during the dry season. Equitability followed the same spatiotemporal pattern as diversity. The Spearman correlation was significantly negative between diversity and rainfall. A cluster analysis spatially separated the ichthyofauna into two groups: one group formed by sampling sites in the fluvial region and another group formed by the remainder of the points in the lacustrine region. Both the CPUEn and CPUEb values were higher at point 8 (fluvial region) and during the rainy season. A two-way ANOVA showed that the CPUEn and CPUEb values were spatially and temporally significant. We conclude that the spatial and temporal trends of diversity in the Santa Cruz reservoir differ from those of other Brazilian reservoirs but that
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International Nuclear Information System (INIS)
Mariotti, A.; Guillemot, J.
1980-01-01
This study was intended to follow the variations of isotope composition of mineral nitrogen formed during incubation of calcareous soils (rendzine), humidity and temperature conditions approximating natural ones. We compared the isotope composition with that of mineral nitrogen formed in a lysimeter cut out from a natural soil with the same pedological features. During the incubation experiments, two steps were recognized. A step with production of nitrates and nitrites depleted in 15 N and a second step where the isotope composition leans towards an equilibrium value. During the first step, the 15 N depletion for the sum NO 3 + NO 2 correlates with a 15 N enrichment for ammonium. On the whole, the total mineral nitrogen isotope composition is approximately constant. This first step corresponds also to a great speed of nitrification, to the presence of nitrite and to a large evolution (production or use) of ammonium. On the contrary, nitrites have disappeared and ammonium is in dynamic equilibrium (constant concentration) when the delta 15 N of nitrates is stabilized. In another set of experiments, with the same conditions, small quantity of a nitrogen substrate (vegetal proteins or amino acids) easily mineralizable, was added to the soil: the 15 N depletion of NO 3 + NO 2 formed during the first step is much greater than with the mere soil. It is concluded that the initial step corresponds to the fast mineralization of a very labile organic component which could be, for the mere soil, the microbial biomass destroyed during air-drying of sample before incubations: this could correspond to the 'flush effect'. On the contrary, the step when nitrates becomes constant could correspond to the mineralization (slower and more regular) of an another organic pool, perhaps part of humified organic matter [fr
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Directory of Open Access Journals (Sweden)
Ana Carolina B. Sodré
2011-10-01
Full Text Available Melissa officinalis L., Lamiaceae, is an herb with great growth prospects in the cosmetic industry due to its essential oil. In order to improve its production, it is necessary to study related agricultural practices. This study evaluated the effect of organic and mineral fertilization on the chemical composition of lemon balm (Melissa officinalis L. essential oil. The assay was conducted at the "Fazenda Experimental do Glória" of the Federal University of Uberlândia, and essential oil extraction and GC/MS analyses were completed by the Centre for Research and Development on Plant Genetic Resources of the Campinas Agronomic Institute. The assay was conducted in a randomized complete block design with three replications. The tested treatments were six types of fertilization (0, 1, 2, 4, 8 kg.m-2 of cattle manure and mineral fertilizing with 60 g.m-2 of NPK 4-14-8 + 4 g.m-2 of boric acid with four replications. The essential oil was extracted by hydrodistillation in a modified Clevenger apparatus. The chemical composition was analyzed by GC/MS. The essential oil presented the same compounds for all treatments; however, the relative proportion of some chemical constituents was altered according to the treatment. Neral, geranial, and citronellal were the major constituents.
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Directory of Open Access Journals (Sweden)
Ana Carolina B. Sodré
2012-02-01
Full Text Available Melissa officinalis L., Lamiaceae, is an herb with great growth prospects in the cosmetic industry due to its essential oil. In order to improve its production, it is necessary to study related agricultural practices. This study evaluated the effect of organic and mineral fertilization on the chemical composition of lemon balm (Melissa officinalis L. essential oil. The assay was conducted at the "Fazenda Experimental do Glória" of the Federal University of Uberlândia, and essential oil extraction and GC/MS analyses were completed by the Centre for Research and Development on Plant Genetic Resources of the Campinas Agronomic Institute. The assay was conducted in a randomized complete block design with three replications. The tested treatments were six types of fertilization (0, 1, 2, 4, 8 kg.m-2 of cattle manure and mineral fertilizing with 60 g.m-2 of NPK 4-14-8 + 4 g.m-2 of boric acid with four replications. The essential oil was extracted by hydrodistillation in a modified Clevenger apparatus. The chemical composition was analyzed by GC/MS. The essential oil presented the same compounds for all treatments; however, the relative proportion of some chemical constituents was altered according to the treatment. Neral, geranial, and citronellal were the major constituents.
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Protocol for Monitoring Fish Assemblages in Pacific Northwest National Parks
Brenkman, Samuel J.; Connolly, Patrick J.
2008-01-01
Rivers and streams that drain from Olympic, Mount Rainier, and North Cascades National Parks are among the most protected corridors in the lower 48 States, and represent some of the largest tracts of contiguous, undisturbed habitat throughout the range of several key fish species of the Pacific Northwest. These watersheds are of high regional importance as freshwater habitat sanctuaries for native fish, where habitat conditions are characterized as having little to no disturbance from development, channelization, impervious surfaces, roads, diversions, or hydroelectric projects. Fishery resources are of high ecological and cultural importance in Pacific Northwest National Parks, and significantly contribute to economically important recreational, commercial, and tribal fisheries. This protocol describes procedures to monitor trends in fish assemblages, fish abundance, and water temperature in eight rivers and five wadeable streams in Olympic National Park during summer months, and is based on 4 years of field testing. Fish assemblages link freshwater, marine, and terrestrial ecosystems. They also serve as focal resources of national parks and are excellent indicators of ecological conditions of rivers and streams. Despite the vital importance of native anadromous and resident fish populations, there is no existing monitoring program for fish assemblages in the North Coast and Cascades Network. Specific monitoring objectives of this protocol are to determine seasonal and annual trends in: (1) fish species composition, (2) timing of migration of adult fish, (3) relative abundance, (4) age and size structure, (5) extent of non-native and hatchery fish, and (6) water temperature. To detect seasonal and annual trends in fish assemblages in reference sites, we rely on repeated and consistent annual sampling at each monitoring site. The general rationale for the repeated sampling of reference sites is to ensure that we account for the high interannual variability in fish
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Boot, Annemieke M; Krenning, Eric P; de Muinck Keizer-Schrama, Sabine M P F
2011-01-01
The associations between peak bone mineral density (BMD) and body composition with 25 hydroxyvitamin D (25OHD) levels in healthy young adults were evaluated. The number of participants was 464; 347 women and 117 men. The mean age was 24.3 years (range 17-31 years). BMD of the lumbar spine, total body and femoral neck (FN) and body composition were measured by dual energy X-ray absorptiometry. Volumetric BMD, bone mineral apparent density (BMAD), of the lumbar spine and FN was calculated. In females, 25OHD level was positively associated with FN BMD and BMAD (both ppercentage body fat (pbody BMD and lean body mass (p=0.03 and p=0.01). 25OHD level is a determinant of peak BMD in both sexes. Vitamin D status was associated with body fat in females and with lean body mass in males.
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Influence of environmental factors on fish assemblages in streams of the Elbe and Oder basins
Directory of Open Access Journals (Sweden)
Luboš Kůra
2015-11-01
Full Text Available The effects of environmental parameters on changes in the structure of fish assemblages were studied in the Elbe and the Odra basin. Research was done at 819 sites surveyed in the field during the period 1993-2007. The impact of 46 factors derived from the maps through a GIS was tested as well as the impact of 10 factors recognized in the field. To evaluate the influence of these factors the indirect (DCA and direct (CCA multivariate cluster analysis were used. Analyses were performed with data on presence-absence and relative abundance of each species. DCA well reflects changes in assemblages in the longitudinal profile of streams. CCA refers to a significant influence of regional and temporal variability and influence of individual factors. The fish assemblages are best characterized by distance from the source location, stream slope, altitude of locality, representation of arable land in the basin, number of ponds in the sub-basin above the locality, type of waters (salmonid or cyprinid, and water temperature (the only of the parameters of the field. The analyzed factors better reflect the variability in fish assemblages of the Odra than of Elbe river basin. The analysis showed good practical efficiency of processing information from a large sample of data from ichthyological surveys. The tools of GIS and the use of statistical methods make possible to characterize basic ecological requirements of most species and specify conditions determining specific composition of fish assemblages.
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Probabilistic Failure Analysis of Bone Using a Finite Element Model of Mineral-Collagen Composites
Dong, X. Neil; Guda, Teja; Millwater, Harry R.; Wang, Xiaodu
2008-01-01
Microdamage accumulation is a major pathway for energy dissipation during the post-yield deformation of bone. In this study, a two-dimensional probabilistic finite element model of a mineral-collagen composite was developed to investigate the influence of the tissue and ultrastructural properties of bone on the evolution of microdamage from an initial defect in tension. The probabilistic failure analyses indicated that the microdamage progression would be along the plane of the initial defect...
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Laser-induced breakdown spectroscopy analysis of minerals: Carbonates and silicates
International Nuclear Information System (INIS)
McMillan, Nancy J.; Harmon, Russell S.; De Lucia, Frank C.; Miziolek, Andrzej M.
2007-01-01
Laser-induced breakdown spectroscopy (LIBS) provides an alternative chemical analytical technique that obviates the issues of sample preparation and sample destruction common to most laboratory-based analytical methods. This contribution explores the capability of LIBS analysis to identify carbonate and silicate minerals rapidly and accurately. Fifty-two mineral samples (18 carbonates, 9 pyroxenes and pyroxenoids, 6 amphiboles, 8 phyllosilicates, and 11 feldspars) were analyzed by LIBS. Two composite broadband spectra (averages of 10 shots each) were calculated for each sample to produce two databases each containing the composite LIBS spectra for the same 52 mineral samples. By using correlation coefficients resulting from the regression of the intensities of pairs of LIBS spectra, all 52 minerals were correctly identified in the database. If the LIBS spectra of each sample were compared to a database containing the other 51 minerals, 65% were identified as a mineral of similar composition from the same mineral family. The remaining minerals were misidentified for two reasons: 1) the mineral had high concentrations of an element not present in the database; and 2) the mineral was identified as a mineral with similar elemental composition from a different family. For instance, the Ca-Mg carbonate dolomite was misidentified as the Ca-Mg silicate diopside. This pilot study suggests that LIBS has promise in mineral identification and in situ analysis of minerals that record geological processes
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Energy Technology Data Exchange (ETDEWEB)
Gomes, J.M.; Martinez, G.M.; Wong, M.M.
1979-01-01
The Bureau of Mines, as part of an effort to maximize minerals and metals recovery from domestic resources, has investigated the feasibility of recovering heavy minerals as byproducts from sand and gravel, placer gold, and industrial mineral operations in northern California. Sand samples from about 50 locations were treated by gravity separation to yield heavy-mineral cocentrates (black sands). Mineral compositions of the concentrates were determined by chemical analysis and mineralogical examination. Individual zircon, ilmenite, magnetite, platinum-group metals, thoria, and silica products were prepared from heavy-mineral concentrates by selective separation using low- and high-intensity magnetic, high-tension, and flotation equipment.
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gold mineralization in Masjeddaghi area, east of Jolfa, NW Iran
Directory of Open Access Journals (Sweden)
Ali Imamalipour
2010-11-01
Full Text Available Two types of mineralization including porphyry copper and epithermal gold mineralization have occurred in relation with an intermediate volcano-plutonic complex in Masjeddaghi area. Different alterations including silica, advanced argillic, intermediate argillic and propylitic have been distinguished in relation with epithermal mineralization, which have a zonal pattern. Elemental mass gains and losses during alterations were calculated using Zr as an immobile monitor. Silica zone has enriched in SiO2 and relatively in Al2O3 and K2O, and has depleted in Na2O, MgO and CaO. Ba, Sr, Pb, Rb and Cu elements have also enriched. The advanced argillic zone shows enrichment in SO3, Al2O3, SiO2, K2O, MgO and L.O.I; and depletion in Fe2O3, CaO, Na2O, MnO and MgO. Barium, Cu, Sr and Zn have depleted in this zone. Propylitic zone has enriched in MgO, CaO, L.O.I and SiO2, and has depleted in Na2O and K2O. Geochemical and mineralogical evidences indicate that the hydrothermal leaching of mafic minerals in parent rocks and formation of quartz, kaolinite, sericite and alunite assemblage in advanced argillic zone; and chlorite, epidote and calcite assemblage in propylitic zone is responsible for the above mentioned chemical variations. It is likely that the gains and losses of elements have been controlled by agents such as water/rock ratios, temperature changes and chemistry of hydrothermal solutions. The CIA and MIA indicators in the altered rocks indicate the intensity of alteration in silica and advanced argillic zones in comparison with propylitic zone.
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International Nuclear Information System (INIS)
Belgin, E.E.; Aycik, G.A.
2017-01-01
Filler particle size is an important particle that effects radiation attenuation performance of a composite shielding material but the effects of it have not been exploited so far. In this study, two mineral (hematite-ilmenite) with different particle sizes were used as fillers in a polymer-matrix composite and effects of particle size on shielding performance was investigated within a widerange of radiation energy (0-2000 keV). The thermal and structural properties of the composites were also examined. The results showed that as the filler particle size decreased the shielding performance increased. The highest shielding performance reached was 23% with particle sizes being between <7 and <74 µm. (author)
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Torres-Roldan, Rafael L.; Garcia-Casco, Antonio; Garcia-Sanchez, Pedro A.
2000-08-01
CSpace is a program for the graphical and algebraic analysis of composition relations within chemical systems. The program is particularly suited to the needs of petrologists, but could also prove useful for mineralogists, geochemists and other environmental scientists. A few examples of what can be accomplished with CSpace are the mapping of compositions into some desired set of system/phase components, the estimation of reaction/mixing coefficients and assessment of phase-rule compatibility relations within or between complex mineral assemblages. The program also allows dynamic inspection of compositional relations by means of barycentric plots. CSpace provides an integrated workplace for data management, manipulation and plotting. Data management is done through a built-in spreadsheet-like editor, which also acts as a data repository for the graphical and algebraic procedures. Algebraic capabilities are provided by a mapping engine and a matrix analysis tool, both of which are based on singular-value decomposition. The mapping engine uses a general approach to linear mapping, capable of handling determined, underdetermined and overdetermined problems. The matrix analysis tool is implemented as a task "wizard" that guides the user through a number of steps to perform matrix approximation (finding nearest rank-deficient models of an input composition matrix), and inspection of null-reaction space relationships (i.e. of implicit linear relations among the elements of the composition matrix). Graphical capabilities are provided by a graph engine that directly links with the contents of the data editor. The graph engine can generate sophisticated 2-D ternary (triangular) and 3D quaternary (tetrahedral) barycentric plots and includes features such as interactive re-sizing and rotation, on-the-fly coordinate scaling and support for automated drawing of tie lines.
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Brasher, Anne M.D.; Konrad, Chris P.; May, Jason T.; Edmiston, C. Scott; Close, Rebecca N.
2010-01-01
Hydrographic characteristics of streamflow, such as high-flow pulses, base flow (background discharge between floods), extreme low flows, and floods, significantly influence aquatic organisms. Streamflow can be described in terms of magnitude, timing, duration, frequency, and variation (hydrologic regime). These characteristics have broad effects on ecosystem productivity, habitat structure, and ultimately on resident fish, invertebrate, and algae communities. Increasing human use of limited water resources has modified hydrologic regimes worldwide. Identifying the most ecologically significant hydrographic characteristics would facilitate the development of water-management strategies.Benthic invertebrates include insects, mollusks (snails and clams), worms, and crustaceans (shrimp) that live on the streambed. Invertebrates play an important role in the food web, consuming other invertebrates and algae and being consumed by fish and birds. Hydrologic alteration associated with land and water use can change the natural hydrologic regime and may affect benthic invertebrate assemblage composition and structure through changes in density of invertebrates or taxa richness (number of different species).This study examined associations between the hydrologic regime and characteristics of benthic invertebrate assemblages across the western United States and developed tools to identify streamflow characteristics that are likely to affect benthic invertebrate assemblages.
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Mukhopadhyay, Anirban; Mondal, Parimal; Barik, Jyotiskona; Chowdhury, S M; Ghosh, Tuhin; Hazra, Sugata
2015-06-01
The composition and assemblage of mangroves in the Bangladesh Sundarbans are changing systematically in response to several environmental factors. In order to understand the impact of the changing environmental conditions on the mangrove forest, species composition maps for the years 1985, 1995 and 2005 were studied. In the present study, 1985 and 1995 species zonation maps were considered as base data and the cellular automata-Markov chain model was run to predict the species zonation for the year 2005. The model output was validated against the actual dataset for 2005 and calibrated. Finally, using the model, mangrove species zonation maps for the years 2025, 2055 and 2105 have been prepared. The model was run with the assumption that the continuation of the current tempo and mode of drivers of environmental factors (temperature, rainfall, salinity change) of the last two decades will remain the same in the next few decades. Present findings show that the area distribution of the following species assemblages like Goran (Ceriops), Sundari (Heritiera), Passur (Xylocarpus), and Baen (Avicennia) would decrease in the descending order, whereas the area distribution of Gewa (Excoecaria), Keora (Sonneratia) and Kankra (Bruguiera) dominated assemblages would increase. The spatial distribution of projected mangrove species assemblages shows that more salt tolerant species will dominate in the future; which may be used as a proxy to predict the increase of salinity and its spatial variation in Sundarbans. Considering the present rate of loss of forest land, 17% of the total mangrove cover is predicted to be lost by the year 2105 with a significant loss of fresh water loving mangroves and related ecosystem services. This paper describes a unique approach to assess future changes in species composition and future forest zonation in mangroves under the 'business as usual' scenario of climate change.
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International Nuclear Information System (INIS)
Yokota, Satoshi; Mae, Tadahiko; Ojima, Kunihiko; Ishii, Keizo.
1994-01-01
PIXE analysis was applied to study alteration of mineral composition (Al, P, K, and Cl) of alfalfa root-tip exposed to low pH or aluminum stress. These minerals were detectable using one or two pieces of root-tips. Short-term (within 4 h) decreases in K/P and Cl/P ratios were observed under low pH and aluminum stress conditions. However, degree of the decrease was not same. Differences in toxic effects of low pH and Al on the root-tip of alfalfa are discussed. (author)
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Bavestrello, Giorgio; Bo, Marzia; Betti, Federico; Canessa, Martina; Gaggero, Laura; Rindi, Fabio; Cattaneo-Vietti, Riccardo
2018-01-01
On marine rocky shores, several physical, chemical and biological processes operate to maintain the benthic assemblages' heterogeneity, but among the abiotic factors, the composition and texture of the rocky substrata have been only sporadically considered. However, biomineralogical studies have demonstrated an unsuspected ability of the benthic organisms to interact at different levels with rocky substrata. Therefore, the mineralogy of the substratum can affect the structure of benthic communities. To evaluate this hypothesis, the macrobenthic assemblages developed on two different ophiolitic rocks (serpentinites and metagabbros) in contact at a restricted stretch of the western Ligurian Riviera (western Mediterranean Sea), with identical environmental and climatic conditions, were analysed. Samplings were carried out at four bathymetric levels (+1m, 0m, -1m, and -3m respect to the mean sea level) and the analysis of the data evidenced differences in terms of species distribution and percent coverage. Algal communities growing on metagabbros were poorer in species richness and showed a much simpler structure when compared to the assemblages occurring on the serpentinites. The most widely distributed animal organism, the barnacle Chthamalus stellatus, was dominant on serpentinites, and virtually absent on metagabbros. Our results suggest a complex pattern of interactions between lithology and benthic organisms operating through processes of inhibition/facilitation related to the mineral properties of the substratum.
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Granite-related hypothermal uranium mineralization in South China
International Nuclear Information System (INIS)
Liu, X.; Wu, J.; Pan, J.; Zhu, M.
2014-01-01
As one of the important geological types, granite-related uranium deposits account for about 29% of the total discovered natural uranium resources in China. Most of the granite-related uranium deposits located in Taoshan - Zhuguang uranium metallogenic belt, South China. In addition to the typical pitchblende vein-type uranium mineralization of epithermal metallogenic system, a new type of granite-related uranium mineralization with characteristics of hypothermal matallogenic system was discovered in South China by current studies. However, hypothermal is contact thermal to epithermal mineralization, and not the conventional intrusive high temperature mineralization. Hypothermal uranium mineralization is presented by disseminated uraninite or pitchblende stockwork in fissures in granites normally with extensive alkaline alteration. The high temperature mineral assemblage of uraninite associate with scheelite and tourmaline was identified in hypothermal uranium mineralization. Fluid inclusion studies on this type mineralization indicated the middle to high temperature (>250℃) mineralization with the mixing evidence of ore forming solution derived from deep level, and the boiling and mixing of ore forming solution are regarded as the dominant mineralization mechanism for the precipitating of uranium. In contrast to the mineralization ages of 67 Ma to 87 Ma for typical pitchblende vein mineralization of epithermal metallogenic system, the mineralization age is older than 100 Ma for hypothermal uranium mineralization in granite. In the Shituling deposit, Xiazhuang uranium ore field, uraninite and pitchblende micro veins with extensive potassic alteration, chloritization and sericitization are hosted in fissures of Indo-Chinese epoch granites with the uranium mineralization age of 130 Ma to 138 Ma with a mineralization temperature of 290℃ to 330℃ indicated. Other examples sharing the similar characters of hypothermal uranium mineralization have been recognized in
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Veter, Marina; Foley, Stephen F.; Mertz-Kraus, Regina; Groschopf, Nora
2017-11-01
Carbonate-rich ultramafic lamprophyres (aillikites) and associated rocks characteristically occur during the early stages of thinning and rifting of cratonic mantle lithosphere, prior to the eruption of melilitites, nephelinites and alkali basalts. It is accepted that they require volatile-rich melting conditions, and the presence of phlogopite and carbonate in the source, but the exact source rock assemblages are debated. Melts similar to carbonate-rich ultramafic lamprophyres (aillikites) have been produced by melting of peridotites in the presence of CO2 and H2O, whereas isotopes and trace elements appear to favor distinct phlogopite-bearing rocks. Olivine macrocrysts in aillikites are usually rounded and abraded, so that it is debated whether they are phenocrysts or mantle xenocrysts. We have analyzed minor and trace element composition in olivines from the type aillikites from Aillik Bay in Labrador, Canada. We characterize five groups of olivines: [1] mantle xenocrysts, [2] the main phenocryst population, and [3] reversely zoned crystals interpreted as phenocrysts from earlier, more fractionated, magma batches, [4] rims on the phenocrysts, which delineate aillikite melt fractionation trends, and [5] rims around the reversely zoned olivines. The main phenocryst population is characterized by mantle-like Ni (averaging 3400 μg g- 1) and Ni/Mg at Mg# of 88-90, overlapping with phenocrysts in ocean island basalts and Mediterranean lamproites. However, they also have low 100 Mn/Fe of 0.9-1.3 and no correlation between Ni and other trace elements (Sc, Co, Li) that would indicate recycled oceanic or continental crust in their sources. The low Mn/Fe without high Ni/Mg, and the high V/Sc (2-5) are inherited from phlogopite in the source that originated by solidification of lamproitic melts at the base of the cratonic lithosphere in a previous stage of igneous activity. The olivine phenocryst compositions are interpreted to result from phlogopite and not high modal
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Effects of CO2 hydrate on deep-sea foraminiferal assemblages
International Nuclear Information System (INIS)
Ricketts, E. R.; Kennett, J. P.; Hill, T. M.; Barry, J. P.
2005-01-01
This study, conducted with the Monterey Bay Aquarium Research Institute (MBARI), is the first to investigate potential effects of carbon dioxide (CO2) hydrates on benthic microfossils, specifically oraminifera. The experiment was conducted in September 2003 aboard the R/V Western Flier using the ROV Tiburon. Experimental (CO2 exposed) and control cores were collected at 3600m and stained to distinguish live (stained) from dead (unstained) individuals. Foraminifera are ideal for these investigations because of differing test composition (calcareous and agglutinated) and thickness, and diverse epifaunal and infaunal depth preferences. The effects of the CO2 on assemblages have been tracked both vertically (10cm depth) and horizontally, and between live and dead individuals. Increased mortality and dissolution of calcareous forms resulted from exposure to CO2 hydrate. Preliminary results suggest several major effects on surface sediment assemblages: 1) total number of foraminifera in a sample decreases; 2) foraminiferal diversity decreases in both stained and unstained specimens. The number of planktonic and hyaline calcareous tests declines greatly, with milliolids being more resistant to dissolution when stained; and 3) percentage of stained (live) forms is higher. Down-core trends (up to 10cm) indicate: 1) percent agglutinated forms decline and calcareous forms increasingly dominate; 2) agglutinated diversity decreases with depth; and 3) assemblages become increasingly similar with depth to those in control cores not subjected to CO2 hydrate. These results imply almost complete initial mortality and dissolution upon CO2 hydrate emplacement in the corrals. (Author)
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Goodfellow, Bradley W.
2012-12-01
A review of published literature was undertaken to determine if there was a fingerprint of chemical weathering in regoliths subjected to periglacial conditions during their formation. If present, this fingerprint would be applied to the question of when blockfields in periglacial landscapes were initiated. These blocky diamicts are usually considered to represent remnants of regoliths that were chemically weathered under a warm, Neogene climate and therefore indicate surfaces that have undergone only a few metres to a few 10s of metres of erosion during the Quaternary. Based on a comparison of clay and silt abundances and secondary mineral assemblages from blockfields, other regoliths in periglacial settings, and regoliths from non-periglacial settings, a fingerprint of chemical weathering in periglacial landscapes was identified. A mobile regolith origin under, at least seasonal, periglacial conditions is indicated where clay(%) ≤ 0.5*silt(%) + 8 across a sample batch. This contrasts with a mobile regolith origin under non-periglacial conditions, which is indicated where clay(%) ≥ 0.5*silt(%) - 6 across a sample batch with clay(%) ≥ 0.5*silt(%) + 8 in at least one sample. A range of secondary minerals, which frequently includes interstratified minerals and indicates high local variability in leaching conditions, is also commonly present in regoliths exposed to periglacial conditions during their formation. Clay/silt ratios display a threshold response to temperature, related to the freezing point of water, but there is little response to precipitation or regolith residence time. Lithology controls clay and silt abundances, which increase from felsic, through intermediate, to mafic compositions, but does not control clay/silt ratios. Use of a sedigraph or Coulter Counter to determine regolith granulometry systematically indicates lower clay abundances and intra-site variability than use of a pipette or hydrometer. In contrast to clay/silt ratios, secondary
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McGarvey, Daniel J.; Falke, Jeffrey A.; Li, Hiram W.; Li, Judith; Hauer, F. Richard; Lamberti, G.A.
2017-01-01
Methods to sample fishes in stream ecosystems and to analyze the raw data, focusing primarily on assemblage-level (all fish species combined) analyses, are presented in this chapter. We begin with guidance on sample site selection, permitting for fish collection, and information-gathering steps to be completed prior to conducting fieldwork. Basic sampling methods (visual surveying, electrofishing, and seining) are presented with specific instructions for estimating population sizes via visual, capture-recapture, and depletion surveys, in addition to new guidance on environmental DNA (eDNA) methods. Steps to process fish specimens in the field including the use of anesthesia and preservation of whole specimens or tissue samples (for genetic or stable isotope analysis) are also presented. Data analysis methods include characterization of size-structure within populations, estimation of species richness and diversity, and application of fish functional traits. We conclude with three advanced topics in assemblage-level analysis: multidimensional scaling (MDS), ecological networks, and loop analysis.
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Digital Repository Service at National Institute of Oceanography (India)
Singh, R.; Miljutin, D.M.; Miljutina, M.; Martinez, P.A.; Ingole, B.S.
was to investigate nematode assemblages inhabiting nodule fields in the CIOB in terms of species composition, diversity, density, biomass, size spectra and sex ratio. Samples were collected by box corer from a depth of 5000–5100 m during the 39th cruise of RV...
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Directory of Open Access Journals (Sweden)
Jörn Buse
Full Text Available Large valleys with opposing slopes may act as a model system with which the effects of strong climatic gradients on biodiversity can be evaluated. The advantage of such comparisons is that the impact of a change of climate can be studied on the same species pool without the need to consider regional differences. The aim of this study was to compare the assemblage of saproxylic beetles on such opposing slopes at Lower Nahal Oren, Mt. Carmel, Israel (also known as "Evolution Canyon" with a 200-800% higher solar radiation on the south-facing (SFS compared to the north-facing slope (NFS. We tested specific hypotheses of species richness patterns, assemblage structure, and body size resulting from interslope differences in microclimate. Fifteen flight-interception traps per slope were distributed over three elevation levels ranging from 50 to 100 m a.s.l. Richness of saproxylic beetles was on average 34% higher on the SFS compared with the NFS, with no detected influence of elevation levels. Both assemblage structure and average body size were determined by slope aspect, with more small-bodied beetles found on the SFS. Both the increase in species richness and the higher prevalence of small species on the SFS reflect ecological rules present on larger spatial grain (species-energy hypothesis and community body size shift hypothesis, and both can be explained by the metabolic theory of ecology. This is encouraging for the complementary use of micro- and macroclimatic gradients to study impacts of climate warming on biodiversity.
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Probabilistic failure analysis of bone using a finite element model of mineral-collagen composites.
Dong, X Neil; Guda, Teja; Millwater, Harry R; Wang, Xiaodu
2009-02-09
Microdamage accumulation is a major pathway for energy dissipation during the post-yield deformation of bone. In this study, a two-dimensional probabilistic finite element model of a mineral-collagen composite was developed to investigate the influence of the tissue and ultrastructural properties of bone on the evolution of microdamage from an initial defect in tension. The probabilistic failure analyses indicated that the microdamage progression would be along the plane of the initial defect when the debonding at mineral-collagen interfaces was either absent or limited in the vicinity of the defect. In this case, the formation of a linear microcrack would be facilitated. However, the microdamage progression would be scattered away from the initial defect plane if interfacial debonding takes place at a large scale. This would suggest the possible formation of diffuse damage. In addition to interfacial debonding, the sensitivity analyses indicated that the microdamage progression was also dependent on the other material and ultrastructural properties of bone. The intensity of stress concentration accompanied with microdamage progression was more sensitive to the elastic modulus of the mineral phase and the nonlinearity of the collagen phase, whereas the scattering of failure location was largely dependent on the mineral to collagen ratio and the nonlinearity of the collagen phase. The findings of this study may help understanding the post-yield behavior of bone at the ultrastructural level and shed light on the underlying mechanism of bone fractures.
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Demersal and larval fish assemblages in the Chukchi Sea
Norcross, Brenda L.; Holladay, Brenda A.; Busby, Morgan S.; Mier, Kathryn L.
2010-01-01
A multidisciplinary research cruise was conducted in the Chukchi Sea in summer 2004 during which we investigated assemblages of small demersal fishes and ichthyoplankton and the water masses associated with these assemblages. This study establishes a baseline of 30 demersal fish and 25 ichthyoplankton taxa in US and Russian waters of the Chukchi Sea. Presence/absence of small demersal fish clustered into four assemblages: Coastal Fishes, Western Chukchi Fishes, South Central Chukchi Fishes, and North Central Chukchi Fishes. Habitats occupied by small demersal fishes were characterized by sediment type, bottom salinity, and bottom temperature. Abundance of ichthyoplankton grouped into three assemblages with geographical extent similar to that of the bottom assemblages, except that there was a single assemblage for Central Chukchi Fishes. Water-column temperature and salinity characterized ichthyoplankton habitats. Three water masses, Alaska Coastal Water, Bering Sea Water, and Winter Water, were identified from both bottom and depth-averaged water-column temperature and salinity. A fourth water mass, Resident Chukchi Water, was identified only in the bottom water. The water mass and habitat characteristics with which demersal and larval fish assemblages were associated create a baseline to measure anticipated effects of climate change that are expected to be most severe at high latitudes. Monitoring fish assemblages could be a tool for assessing the effects of climate change. Climate-induced changes in distributions of species would result in a restructuring of fish assemblages in the Chukchi Sea.
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Ronowicz, Marta; Kukliński, Piotr; Włodarska-Kowalczuk, Maria
2018-05-01
Kelp forests are complex underwater habitats that support diverse assemblages of animals ranging from sessile filter feeding invertebrates to fishes and marine mammals. In this study, the diversity of invertebrate fauna associated with kelp holdfasts was surveyed in a high Arctic glacial fjord (76 N, Hornsund, Svalbard). The effects of algal host identity (three kelp species: Laminaria digitata, Saccharina latissima and Alaria esculenta), depth (5 and 10 m) and glacier-derived disturbance (three sites with varying levels of mineral sedimentation) on faunal species richness and composition were studied based on 239 collected algal holdfasts. The species pool was mostly made up by three taxa: colonial Bryozoa and Hydrozoa, and Polychaeta. While the all-taxa species richness did not differ between depths, algal hosts and sites, the patterns varied when the two colonial sessile filter-feeding taxa were analysed alone (Hydrozoa and Bryozoa). The Hydrozoa sample species richness and average taxonomic distinctness were the highest at undisturbed sites, whereas Bryozoa species richness was higher in sediment-impacted localities, indicating relative insensitivity of this phylum to the increased level of mineral suspension in the water column. The average taxonomic distinctness of Bryozoa did not vary between sites. The species composition of kelp-associated fauna varied between sites and depths for the whole community and the most dominant taxa (Bryozoa, Hydrozoa). The high load of inorganic suspension and sedimentation did not cause pauperization of kelp holdfast-associated fauna but instead triggered the changes in species composition and shifts between dominant taxonomic groups.
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Guinda, Xabier; Juanes, José Antonio; Puente, Araceli; Echavarri-Erasun, Beatriz
2012-01-01
The extensive field work carried out over the last century has allowed the worldwide description of general distribution patterns and specific composition of rocky intertidal communities. However, the information concerning subtidal communities on hard substrates is more recent and scarce due to the difficulties associated with working in such environments. In this work, a non-destructive method is applied to the study and mapping of subtidal rocky bottom macroalgae assemblages on the coast of Cantabria (N Spain) which is quick, easy and economical. Gelidium corneum and Cystoseira baccata were the dominant species, however, the composition and coverage of macroalgae assemblages varied significantly at different locations and depth ranges. The high presence of Laminaria ochroleuca and Saccorhiza polyschides, characteristic of colder waters, shows the transitional character of this coastal area. The results obtained throughout this study have been very useful to the application of the European Water Framework Directive (WFD 2000/60/EC) and could be of great interest for the future conservation and management of these ecosystems (e.g. Habitats Directive 92/43/EEC).
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Jahanbin, Arezoo; Farzanegan, Fahimeh; Atai, Mohammad; Jamehdar, Saeed Amel; Golfakhrabadi, Parvaneh; Shafaee, Hooman
2017-02-01
The aim of this 'split-mouth design' trial was to evaluate the effect of the nano amorphous calcium phosphate (NACP) containing composite on enamel mineral contents and streptococcus mutans population in fixed orthodontic patients. Randomized, prospective, single-center controlled trial. Twenty-four patients between the ages of 13-18 years participated in this study. The control and test sides were randomly selected by a coin toss (1:1 ratio). On the control side orthodontic brackets were bonded on the buccal surfaces of upper premolars and laterals using an orthodontic composite (Transbond XT), and on the study side NACP-containing composite was used. Outcome measures were the mineral content around the brackets and S.mutans count. The later were calculated in the plaque around the brackets by real-time PCR at 3 months, and 6 months after the initiation of treatment. All stages of the study were blind using coding system. Paired t-test and repeated measurements were used for data analysis. In the third and sixth month, the bacterial population was significantly lower in the study side than the control side (P = 0.01 and 0.000).The mineral content of the study side was significantly higher than the controls, 6 months after brocket bonding (P = 0.004). There were no significant differences between the premolars and lateral teeth for all measurements. This research was performed in a single-center by one experienced clinician. NACP-containing composites have the potential to inhibit mineral content loss and S.mutans colonization around orthodontic brackets during fixed orthodontic treatments. This trial was not registered. The protocol was not published before trial commencement. © The Author 2016. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.
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Li, Chuanchang; Fu, Liangjie; Ouyang, Jing; Yang, Huaming
2013-01-01
A novel mineral-based composite phase change materials (PCMs) was prepared via vacuum impregnation method assisted with microwave-acid treatment of the graphite (G) and bentonite (B) mixture. Graphite and microwave-acid treated bentonite mixture (GBm) had more loading capacity and higher crystallinity of stearic acid (SA) in the SA/GBm composite. The SA/GBm composite showed an enhanced thermal storage capacity, latent heats for melting and freezing (84.64 and 84.14 J/g) was higher than those of SA/B sample (48.43 and 47.13 J/g, respectively). Addition of graphite was beneficial to the enhancement in thermal conductivity of the SA/GBm composite, which could reach 0.77 W/m K, 31% higher than SA/B and 196% than pure SA. Furthermore, atomic-level interfaces between SA and support surfaces were depicted, and the mechanism of enhanced thermal storage properties was in detail investigated.
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International Nuclear Information System (INIS)
Kopp, O.C.
1986-12-01
The purpose of this study was to review available data concerning the properties reported for shales and clay-rich rocks and clay minerals to determine whether such information could be instrumental in selecting the more favorable assemblages of clays for high-level waste repository purposes. Literature searches were conducted for reports dealing with the properties of these argillaceous materials. The properties that were obtained from appropriate references were recorded in an Appleworks Database. The data are divided into five major goups: chemical properties, general physical properties, hydrologic properties, mechanical properties, and thermal properties. The Database includes such information as the type of material, formation name, geological age, location, depth, test conditions, results, and reference(s). In general, noticeable correlations were not apparent when mineralogical information was compared with various properties using plots of the data for each individual property. The best correlations were obtained for chemical and certain mechanical and hydrologic properties. Thermal properties appear to be least influenced by clay mineral composition. An important reason for the inability to correlate mineralogical compositions with most properties was the lack of uniformity of test methods, test conditions, and even the units used for reporting the final data. There was very limited information concerning the mineralogical compositions of most of the shales tested. The potential exists for identifying the more suitable formations (or specific horizons within formations) using mineralogical data; however, in order to make such selections, it will be necessary to collect future data using standardized test methods and conditions. The mineralogical compositions of the samples tested need to be determined quantitatively rather than qualitatively
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Directory of Open Access Journals (Sweden)
Guoxi Shi
Full Text Available Both deterministic and stochastic processes are expected to drive the assemblages of arbuscular mycorrhizal (AM fungi, but little is known about the relative importance of these processes during the spreading of toxic plants. Here, the species composition and phylogenetic structure of AM fungal communities colonizing the roots of a toxic plant, Ligularia virgaurea, and its neighborhood plants, were analyzed in patches with different individual densities of L. virgaurea (represents the spreading degree. Community compositions of AM fungi in both root systems were changed significantly by the L. virgaurea spreading, and also these communities fitted the neutral model very well. AM fungal communities in patches with absence and presence of L. virgaurea were phylogenetically random and clustered, respectively, suggesting that the principal ecological process determining AM fungal assemblage shifted from stochastic process to environmental filtering when this toxic plant was present. Our results indicate that deterministic and stochastic processes together determine the assemblage of AM fungi, but the dominant process would be changed by the spreading of toxic plants, and suggest that the spreading of toxic plants in alpine meadow ecosystems might be involving the mycorrhizal symbionts.
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Directory of Open Access Journals (Sweden)
Maria Chavideh
2018-03-01
Full Text Available The Oligo-Miocene Qazan granitoid body caused contact metamorphic of surrounding rocks and skarn formation in the wall limestone. The main intrusive rocks are essentially granite to diorite in composition. Two different types of skarn, exo and endoskarn have been developed. On the base of microprobe data, the northern skarn are characterized by zoning and the amounts of andradite and grossular changes oscillatory. While garnets from the southwestern skarn is predominantly andradite in composition. Using Fe/Ti vs. Al/ (Al+Fe+Mn diagram that were calculated based on the mole percent of the used elements, it is estimated that about less than 50 percent hydrothermal waters were involved for the northern skarn whereas it was over this amount for the southwestern skarn. This leds to difference in garnet composition. The composition of clinopyroxene in both skarns is the same (diopside. As a result, hydrothermal fluids have not had much influence on pyroxene genesis. With regards to the occurrence of mineral assemblage and the presence of wollastonite in the skarns under study, these rocks have evolved in temperature above 500 ° C and O2 fugacity in the range of 10-17 to 10-15.
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Ramírez-Villada, Jhon F; León-Ariza, Henry H; Argüello-Gutiérrez, Yenny P; Porras-Ramírez, Keyla A
2016-01-01
Osteoporosis is characterised by loss of bone mass and deterioration of bone tissue microarchitecture that leads to fragility related to the risk of fractures. The aim of the study is to analyse the effects of a training program based on explosive movements and impact, assessed in a swimming pool, on body composition, explosive strength and bone mineral density in women over 60 years old. A total of 35 healthy physically active women (60±4.19 years) were divided into a training pool group using multi jumps (JG) and a control group (CG). JG trained for 24 weeks, 3 times a week, an hour and a half per session. Body composition testing, explosive strength, and bone mineral density were assessed before and after the program. There were differences in the explosive force (JG vs CG=P<.05 to .001) and the estimated power (JG vs CG=P<.05 to .002) between JG vs CG, with significant increases in JG. There were no significant differences in the percentage of fat and lean mass, bone mineral density lumbar and femoral between groups, although slightly significant increases in bone mineral density lumbar and femoral could be seen in JG after program implementation (JG pre-test vs JG post- test=P<.05). The training program with impact and explosive movements assessed in a pool induces gains in muscle strength and power with slight adaptations in body mass index in women over 60 years. Copyright © 2015 SEGG. Published by Elsevier Espana. All rights reserved.
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Mineral composition of organically grown tomato
Ghambashidze, Giorgi
2014-05-01
In recent years, consumer concerns on environmental and health issues related to food products have increased and, as a result, the demand for organically grown production has grown. Results indicate that consumers concerned about healthy diet and environmental degradation are the most likely to buy organic food, and are willing to pay a high premium. Therefore, it is important to ensure the quality of the produce, especially for highly consumed products. The tomato (Lycopersicon esculentum) is one of the most widely consumed fresh vegetables in the world. It is also widely used by the food industries as a raw material for the production of derived products such as purees or ketchup. Consequently, many investigations have addressed the impact of plant nutrition on the quality of tomato fruit. The concentrations of minerals (P, Na, K, Ca and Mg) and trace elements (Cu, Zn and Mn) were determined in tomatoes grown organically in East Georgia, Marneuli District. The contents of minerals and Mn seem to be in the range as shown in literature. Cu and Zn were found in considerably high amounts in comparison to maximum permissible values established in Georgia. Some correlations were observed between the minerals and trace elements studied. K and Mg were strongly correlated with Cu and Zn. Statistically significant difference have shown also P, K and Mg based between period of sampling.
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Bait effects in sampling coral reef fish assemblages with stereo-BRUVs.
Dorman, Stacey R; Harvey, Euan S; Newman, Stephen J
2012-01-01
Baited underwater video techniques are increasingly being utilised for assessing and monitoring demersal fishes because they are: 1) non extractive, 2) can be used to sample across multiple habitats and depths, 3) are cost effective, 4) sample a broader range of species than many other techniques, 5) and with greater statistical power. However, an examination of the literature demonstrates that a range of different bait types are being used. The use of different types of bait can create an additional source of variability in sampling programs. Coral reef fish assemblages at the Houtman Abrolhos Islands, Western Australia, were sampled using baited remote underwater stereo-video systems. One-hour stereo-video recordings were collected for four different bait treatments (pilchards, cat food, falafel mix and no bait (control)) from sites inside and outside a targeted fishery closure (TFC). In total, 5209 individuals from 132 fish species belonging to 41 families were recorded. There were significant differences in the fish assemblage structure and composition between baited and non-baited treatments (Pcat food and pilchards contained similar ingredients and were found to record similar components of the fish assemblage. There were no significant differences in the fish assemblages in areas open or closed to fishing, regardless of the bait used. Investigation of five targeted species indicated that the response to different types of bait was species-specific. For example, the relative abundance of Pagrus auratus was found to increase in areas protected from fishing, but only in samples baited with pilchards and cat food. The results indicate that the use of bait in conjunction with stereo-BRUVs is advantageous. On balance, the use of pilchards as a standardised bait for stereo-BRUVs deployments is justified for use along the mid-west coast of Western Australia.
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Bait effects in sampling coral reef fish assemblages with stereo-BRUVs.
Directory of Open Access Journals (Sweden)
Stacey R Dorman
Full Text Available Baited underwater video techniques are increasingly being utilised for assessing and monitoring demersal fishes because they are: 1 non extractive, 2 can be used to sample across multiple habitats and depths, 3 are cost effective, 4 sample a broader range of species than many other techniques, 5 and with greater statistical power. However, an examination of the literature demonstrates that a range of different bait types are being used. The use of different types of bait can create an additional source of variability in sampling programs. Coral reef fish assemblages at the Houtman Abrolhos Islands, Western Australia, were sampled using baited remote underwater stereo-video systems. One-hour stereo-video recordings were collected for four different bait treatments (pilchards, cat food, falafel mix and no bait (control from sites inside and outside a targeted fishery closure (TFC. In total, 5209 individuals from 132 fish species belonging to 41 families were recorded. There were significant differences in the fish assemblage structure and composition between baited and non-baited treatments (P<0.001, while no difference was observed with species richness. Samples baited with cat food and pilchards contained similar ingredients and were found to record similar components of the fish assemblage. There were no significant differences in the fish assemblages in areas open or closed to fishing, regardless of the bait used. Investigation of five targeted species indicated that the response to different types of bait was species-specific. For example, the relative abundance of Pagrus auratus was found to increase in areas protected from fishing, but only in samples baited with pilchards and cat food. The results indicate that the use of bait in conjunction with stereo-BRUVs is advantageous. On balance, the use of pilchards as a standardised bait for stereo-BRUVs deployments is justified for use along the mid-west coast of Western Australia.
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Proximate composition, minerals and vitamins content of selected vegetables grown in Peshawar
International Nuclear Information System (INIS)
Bangash, J.A.; Arif, M.; Khan, M.A.; Khan, F.; Amin-ur-Rrahma; Hussain, I.
2011-01-01
Ten vegetables namely Pot purslane, Spinach, Turnip, Garlic, Mustard (Sarson), Radish, Bitter gourd, Lady finger, Bath sponge and Brinjal were analyzed for their proximate composition, vitamin and mineral contents to evaluate their importance in human nutrition. The results showed that almost all vegetables contain appreciable amount of essential nutrients. The maximum content of moisture, carbohydrate, crude protein, crude fat, crude fiber, and ash recorded in these vegetables was (92.50 %, 26.88 %, 5.0%, 0.40%, 1.4% and 1.9%), respectively, with a minimum content (66.80 %, 3.91 %, 0.7%, 0.08%, 0.4% and 0.38%), respectively. Maximum concentration of macro minerals K, Ca, Mg, and Na, observed was (400, 210, 109, and 55) mg/100 g, respectively, with a minimum concentration (26, 15, 17, and 10) mg/100 g, respectively. Maximum concentration of micro minerals Fe, Cu, Zn, Mn and Cr observed was (29, 0.33, 3.05, 1.70, and 0.36) mg/100 g with a minimum concentration (2, 0.05, 0.43, 0.21, and 0.06) mg/100 g, respectively. Maximum concentration of water soluble vitamins i.e. thiamine, riboflavin, niacin and ascorbic acid recorded was (0.280, 0.190, 0.69, and 65) mg/100 g with a minimum concentration (0.011, 0.015, 0.23, and 4.00) mg/100 g, respectively. From this study it can be concluded that consumption of vegetables in different combinations could provide a reasonable daily recommended amount of essential nutrients for the maintenance of healthy life and normal body functioning. (author)
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High-latitude steppe vegetation and the mineral nutrition of Pleistocene herbivores
Davydov, S. P.; Davydova, A.; Makarevich, R.; Loranty, M. M.; Boeskorov, G.
2014-12-01
High-latitude steppes were widespread and zonal in the Late Pleistocene and formed a landscape basis for the Mammoth Biome. Now the patches of these steppes survived on steep slopes under southern aspects. These steppes serve as unique information sources about the Late Pleistocene "Mammoth" steppe. Numerous data obtained by palynological, carpological, and DNA analysis of plant remains from feces and stomach contents of Pleistocene herbivore mummies, as well as from buried soils and enclosing deposits show that they are similar to modern steppe plant assemblage in taxa composition. Plant's nutrient concentrations are of fundamental importance across Pleistocene grass-rich ecosystems because of their role in the support of large herbivores. The average weight of an adult mammoth skeleton (about 0.5 tons) and of a woolly rhinoceros (about 0.2 tons) clearly suggests this. Detailed studies on fossil bone remains showed mineral deficiency in large Pleistocene herbivores. A three-year study of ash and mineral contents of two types of relict steppe vegetation at the Kolyma Lowland, Arctic Siberia has been carried out. Nowadays refugia of similar vegetation are located not far (1 - 15km) from the Yedoma permafrost outcrops were abundant fossil remains are found. Dominant species of the steppe vegetation were sampled. Preliminary studies indicate that the ash-content varied 1.5-2 times in speceies of steppe herbs. The Ca, P, Mg, K element contents was higher for most steppe species than in the local herbaceous vegetation, especially in Ca and P. One of the most important elements of the mineral nutrition, the phosphorus, was always found in higher concentrations in the steppe vegetation than in plants of recently dominant landscapes of the study area. It should be noted that the mineral nutrient content of the modern steppe vegetation of Siberian Arctic is comparable to that of the recent zonal steppe of Transbaikal Region. This study supports the hypothesis that
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Marion, Giles M.
2001-06-01
Carbonate minerals have played an important role in the geochemical evolution of Earth, and may have also played an important role in the geochemical evolution of Mars and Europa. Several models have been published in recent years that describe chloride and sulfate mineral solubilities in concentrated brines using the Pitzer equations. Few of these models are parameterized for subzero temperatures, and those that are do not include carbonate chemistry. The objectives of this work are to estimate Pitzer-equation bicarbonate-carbonate parameters and carbonate mineral solubility products and to incorporate them into the FREZCHEM model to predict carbonate mineral solubilities in the Na-K-Mg-Ca-H-Cl-SO 4-OH-HCO 3-CO 3-CO 2-H 2O system at low temperatures (≤25°C) with a special focus on subzero temperatures. Most of the Pitzer-equation parameters and equilibrium constants are taken from the literature and extrapolated into the subzero temperature range. Solubility products for 14 sodium, potassium, magnesium, and calcium bicarbonate and carbonate minerals are included in the model. Most of the experimental data are at temperatures ≥ -8°C; only for the NaHCO 3-NaCl-H 2O and Na 2CO 3-NaCl-H 2O systems are there bicarbonate and carbonate data to temperatures as low as -21.6°C. In general, the fit of the model to the experimental data is good. For example, calculated eutectic temperatures and compositions for NaHCO 3, Na 2CO 3, and their mixtures with NaCl and Na 2SO 4 salts are in good agreement with experimental data to temperatures as low as -21.6°C. Application of the model to eight saline, alkaline carbonate waters give predicted pHs ranging from 9.2 to 10.2, in comparison with measured pHs that range from 8.7 to 10.2. The model suggests that the CaCO 3 mineral that precipitates during seawater freezing is probably calcite and not ikaite. The model demonstrates that a proposed salt assemblage for the icy surface of Europa consisting of highly hydrated MgSO 4
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Andrew M. Liebhold; Takehiko Yamanaka; Alain Roques; Sylvie Augustin; Steven L. Chown; Eckehard G. Brockerhoff; Petr Pysek
2016-01-01
Insects are among the world's most ecologically and economically important invasive species. Here we assemble inventories of native and nonnative species from 20 world regions and contrast relative numbers among these species assemblages. Multivariate ordination indicates that the distribution of species among insect orders is completely different between native...
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Directory of Open Access Journals (Sweden)
Fatemeh Sarjoughian
2017-02-01
Full Text Available Introduction Mineral composition is sensitive to variations in the composition of the magma and can be used to characterize the physical conditions of crystallization such as temperature, pressure, oxygen fugacity and water content. The studies have demonstrated that geobarometery by amphibole provides a tool for determining the depth of crystallization and knowledge of the depth of crystallization of hornblende through to solidification of calc-alkaline plutons (Anderson and Smith, 1995. The composition of pyroxene can be used as crystallization pressure and temperature indicators of pyroxene too. Anlytical methods The mineral compositions of the Nasrand intrusion were determined by electron microprobe, with special emphasis on the amphibole, feldspar, and pyroxene at the Naruto University, Japan, the EPMA (Jeol- JXA-8800R was used at operating conditions of 15 kV, 20 nA acceleration voltage and 20s counting time. Results The Nasrand intrusion (33°13'–33°15' N, 52°33'–52°34'E with an outcrop area of about 40 km2 is situated in the Urumieh–Dokhtar magmatic belt, SE of Ardestan. It is composed of granite and granodiorite and various dikes of diorite and gabbro which are intruded in it. It is intruded into Eocene volcanic rocks, including andesite, rhyolite, and dacite. The petrographical studies indicate that the granitic and granodioritic rocks contain major minerals such as quartz, K-feldspar, plagioclase, and amphibole, which are in an approximate equilibrium state. The gabbroic-dioritic dikes usually show microgranular porphyric texture. They mainly consist of plagioclase, amphibole, and pyroxene. The plagioclase shows variable composition from albite to oligoclase in the granitoid rocks and from oligoclase to bytownite in dioritic and gabbroic dikes (Deer et al., 1991. The amphiboles are calcic and their composition varies from hornblende to actinolite, whereas the composition of the basic dikes is inclined to hastingsite (Leake et
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Castellanos-Galindo, G. A.; Krumme, U.
2014-08-01
Intertidal fish assemblages are thought to respond to tidal and diel rhythms although the assumption that these patterns are stable over long time scales (>1 year) is largely untested. Testing the validity of this assumption is necessary to assess whether short-term temporal patterns, once established, can be extrapolated over time and give a better understanding of the temporal dynamics of fish assemblages in coastal habitats. Here, we compare the fish assemblage structure from two intertidal mangrove creeks in North Brazil (Bragança Peninsula, Caeté estuary) sampled with the same sampling methodology (block nets), effort (two lunar cycles) and design (accounting for the combination of tidal and diel cycle) in the rainy seasons of 1999 and 2012 to evaluate the persistence, stability and recurrence of short-term patterns in the fish community organization. The interaction of tidal and diel cycles (inundations at spring tide-night, spring tide-day, neap tide-night, neap tide-day), found to be stable after 13 years, resulted in recurrent and stable intertidal mangrove fish assemblage compositions. The intertidal mangrove creek fish assemblage consisted of a persistent number of dominant species (seven). However, there were notable changes in fish catch mass, abundance and species dominance between 1999 and 2012. The most severe drought in North Brazil in 30 years, linked to lower precipitation and river runoff in the rainy season of 2012, may have resulted in (1) lower abundance of small juveniles of several dominant species in this assemblage (especially Ariidae - Cathorops agassizii and Sciades herzbergii) and (2) increased dominance of large-sized specimens of the tetraodontid Colomesus psittacus. Our findings highlight: (1) the overriding importance and stability of the interactive pulse of the tidal and diel cycles in determining short-term temporal patterns in intertidal mangrove fish assemblages in neotropical macrotidal estuaries despite the occurrence of
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Dmitrenko, O. B.
2012-02-01
The nannofosssil assemblages have been analyzed in five cores taken from the Titanic area of the northwestern Atlantic (˜41°-42° N, ˜47°-50° W, water depths >3500 m) during cruises 41 and 43 of the R/V Akademik Mstislav Keldysh in 1998 and 2000. They correlate the host sediments with the upper Pleistocene-Holocene Emiliania huxleyi zone. The changes in the structure of the nannofossil assemblages and the lithological characteristics such as the content of biogenic CaCO3, the abundance of ice-rafted debris, and the grain-size composition were used for the high-resolution stratigraphy of sections with defining marine isotopic stages 1-3 of the last 24 kyr. A characteristic feature of the nannofossil assemblages from this area is their enrichment with the cold-resistant species Coccolthus pelagicus during the warm climatic stages and the lack of allochthonous coccolitophorid remains.
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Reservoir floodplains support distinct fish assemblages
Miranda, Leandro E.; Wigen, S. L.; Dagel, Jonah D.
2014-01-01
Reservoirs constructed on floodplain rivers are unique because the upper reaches of the impoundment may include extensive floodplain environments. Moreover, reservoirs that experience large periodic water level fluctuations as part of their operational objectives seasonally inundate and dewater floodplains in their upper reaches, partly mimicking natural inundations of river floodplains. In four flood control reservoirs in Mississippi, USA, we explored the dynamics of connectivity between reservoirs and adjacent floodplains and the characteristics of fish assemblages that develop in reservoir floodplains relative to those that develop in reservoir bays. Although fish species richness in floodplains and bays were similar, species composition differed. Floodplains emphasized fish species largely associated with backwater shallow environments, often resistant to harsh environmental conditions. Conversely, dominant species in bays represented mainly generalists that benefit from the continuous connectivity between the bay and the main reservoir. Floodplains in the study reservoirs provided desirable vegetated habitats at lower water level elevations, earlier in the year, and more frequently than in bays. Inundating dense vegetation in bays requires raising reservoir water levels above the levels required to reach floodplains. Therefore, aside from promoting distinct fish assemblages within reservoirs and helping promote diversity in regulated rivers, reservoir floodplains are valued because they can provide suitable vegetated habitats for fish species at elevations below the normal pool, precluding the need to annually flood upland vegetation that would inevitably be impaired by regular flooding. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.
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Actual methods of nuclear physics in the analysis of the elemental composition of rocks and minerals
International Nuclear Information System (INIS)
Leonard, M.; Tsipenyuk, Yu. M.
1981-01-01
In this paper two methods are described for the Nuclear Physical analysis of the elementary composition of ores, mineral rocks and principles, elementary particles and radiation sources. Some examples are given showing their applications, high sensibility, selectivity, quichness and economy in comparison with other analytical methods. They are classified by their sensibilities among other analytical techniques in the determination of a large quantity of elements. (author)
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Beaufort group uranium mineralization - a model that may aid exploration
International Nuclear Information System (INIS)
Stuart-Williams, V.
1982-01-01
The ore bodies examined while working on the Pristerognathus Diictodon Assemblage Zone West of Beaufort West are of the URAVAN type (URA - uranium, VAN - vanadium). It was found that uranium mineralization in any one ore body was not strictly random and tends to be associated with a fairly consistent sandstone and siltstone geometry. Mineralization is only found where coalescence between the two sandstones has occurred and it disappears where the sandstones remain coalesced. At a point of coalescence the fluids from the upper and lower sandstone are mixed, the oxidizing fluid penetrating progressively deeper in the sandstone couplet until the entire couplet is oxidizing. This generates a weakly dipping REDOX front. The REDOX front is not considered strong enough to have precipitated uranyl carbonate complexes in transport
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Alam, Md Amirul; Juraimi, Abdul Shukor; Rafii, M Y; Hamid, Azizah Abdul; Aslani, Farzad; Hakim, M A
2016-04-18
This study was undertaken to determine the effects of varied salinity regimes on the morphological traits (plant height, number of leaves, number of flowers, fresh and dry weight) and major mineral composition of 13 selected purslane accessions. Most of the morphological traits measured were reduced at varied salinity levels (0.0, 8, 16, 24 and 32 dS m(-1)), but plant height was found to increase in Ac1 at 16 dS m(-1) salinity, and Ac13 was the most affected accession. The highest reductions in the number of leaves and number of flowers were recorded in Ac13 at 32 dS m(-1) salinity compared to the control. The highest fresh and dry weight reductions were noted in Ac8 and Ac6, respectively, at 32 dS m(-1) salinity, whereas the highest increase in both fresh and dry weight was recorded in Ac9 at 24 dS m(-1) salinity compared to the control. In contrast, at lower salinity levels, all of the measured mineral levels were found to increase and later decrease with increasing salinity, but the performance of different accessions was different depending on the salinity level. A dendrogram was also constructed by UPGMA based on the morphological traits and mineral compositions, in which the 13 accessions were grouped into 5 clusters, indicating greater diversity among them. A three-dimensional principal component analysis also confirmed the output of grouping from cluster analysis.
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Boot, Annemieke M.; Krenning, Eric P.; Keizer-Schrama, Sabine M. P. F. de Muinck
Objective: The associations between peak bone mineral density (BMD) and body composition with 25 hydroxyvitamin D (25OHD) levels in healthy young adults were evaluated. Methods: The number of participants was 464; 347 women and 117 men. The mean age was 24.3 years (range 17-31 years). BMD of the
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Microanalysis of vitrous char and associated polymers: reference and ancient assemblages
Allue, E.; Bonnamy, S.; Courty, M. M.; Gispert I Guirado, F.
2012-12-01
Formation of vitrous char that occur in ancient charcoal assemblages have remained unsolved. Laboratory experiments refuted vitrification to resulting from high temperature charring of green or resinous wood. This puzzling problem has been refreshed by showing the association to the charcoal and vitrous char of plastics that were originally supposed to only be produced by petroleum industry. Extraction of similar polymers within geological glassy products from cosmic airbursts has suggested impact processes to possibly forming the carbonaceous polymorphs. The pulverisation at the ground in the Angles village (French Eastern Pyrenees) following the 2011 August 2nd high altitude meteor explosion of exotic debris with vitrous char and polymers, just alike the puzzling ones of the geological and archaeological records, has provided potential reference materials. We present here their microanalysis by Environmental SEM with EDS, Raman micro-spectrometry and FTIR, XRD, TEM, ICP-MS and isotope analyses. The characterization helps elucidating how the carbonaceous polymorphs formed by transient heating and transient high pressure of atmospheric aerosols. Under TEM the vesicular, dense, vitrous char show high structural organization with a dense pattern of nano-sized graphitized domains, metals and mineral inclusions. The coupled Raman-ESEM has allowed identifying a complex pattern at micro scales of ordered "D" peak at 1320-1350 cm-1 and the graphitic, ordered peak at 1576-1590 cm-1, in association to amorphous and poorly graphitic ordered carbon. The later occurs within plant cells that have been extracted from the dense vitrous char by performing controlled combustion under nitrogen up to 1000°C. In contrast, the brittle, vesicular vitrous char and the polymers encountered at the rear of the pulverised airburst debris reveal to be formed of agglutinated micro spherules of amorphous carbon with rare crystallized carbon nano-domains and scattered mineral inclusions. They
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Ndidi, Uche Samuel; Ndidi, Charity Unekwuojo; Olagunju, Abbas; Muhammad, Aliyu; Billy, Francis Graham; Okpe, Oche
2014-01-01
This research was aimed at evaluating the proximate composition, level of anti-nutrients, and the mineral composition of raw and processed Sphenostylis stenocarpa seeds and at examining the effect of processing on the parameters. From the proximate composition analysis, the ash content showed no significant difference (P > 0.05) between the processed and unprocessed (raw) samples. However, there was significant difference (P < 0.05) in the levels of moisture, crude lipid, nitrogen-free extract, gross energy, true protein, and crude fiber between the processed and unprocessed S. stenocarpa. Analyses of the antinutrient composition show that the processed S. stenocarpa registered significant reduction in levels of hydrogen cyanide, trypsin inhibitor, phytate, oxalate, and tannins compared to the unprocessed. Evaluation of the mineral composition showed that the level of sodium, calcium, and potassium was high in both the processed and unprocessed sample (150–400 mg/100 g). However, the level of iron, copper, zinc, and magnesium was low in both processed and unprocessed samples (2–45 mg/100 g). The correlation analysis showed that tannins and oxalate affected the levels of ash and nitrogen-free extract of processed and unprocessed seeds. These results suggest that the consumption of S. stenocarpa will go a long way in reducing the level of malnutrition in northern Nigeria. PMID:24967265
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Paradzayi Tagwireyi
Full Text Available Although the principles of landscape ecology are increasingly extended to include riverine landscapes, explicit applications are few. We investigated associations between patch heterogeneity and riparian ant assemblages at 12 riverine landscapes of the Scioto River, Ohio, USA, that represent urban/developed, agricultural, and mixed (primarily forested, but also wetland, grassland/fallow, and exurban land-use settings. Using remotely-sensed and ground-collected data, we delineated riverine landscape patch types (crop, grass/herbaceous, gravel, lawn, mudflat, open water, shrub, swamp, and woody vegetation, computed patch metrics (area, density, edge, richness, and shape, and conducted coordinated sampling of surface-active Formicidae assemblages. Ant density and species richness was lower in agricultural riverine landscapes than at mixed or developed reaches (measured using S [total number of species], but not using Menhinick's Index [DM], whereas ant diversity (using the Berger-Park Index [DBP] was highest in agricultural reaches. We found no differences in ant density, richness, or diversity among internal riverine landscape patches. However, certain characteristics of patches influenced ant communities. Patch shape and density were significant predictors of richness (S: R2 = 0.72; DM: R2=0.57. Patch area, edge, and shape emerged as important predictors of DBP (R2 = 0.62 whereas patch area, edge, and density were strongly related to ant density (R2 = 0.65. Non-metric multidimensional scaling and analysis of similarities distinguished ant assemblage composition in grass and swamp patches from crop, gravel, lawn, and shrub as well as ant assemblages in woody vegetation patches from crop, lawn, and gravel (stress = 0.18, R2 = 0.64. These findings lend insight into the utility of landscape ecology to river science by providing evidence that spatial habitat patterns within riverine landscapes can influence assemblage characteristics of riparian
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Status of bone mineral content and body composition in boys engaged in intensive physical activity
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Madić Dejan
2010-01-01
Full Text Available Background/Aim. It is well known that physical activity has an anabolic effect on bone tissue. But there is a lack of information about the effect of intensive physical activity in childhood, particularly at the prepubertal stage. To examine the influence of training on body composition and bone mineral density we have studied a group of prepubertal soccer players as well as a group of inactive prepubertal boys at the starting phase of their peak bone mass acquisition. Methods. A total of 62 healthy prepubertal boys took part in this study. They were divided into two groups. The first one consisted of 32 soccer players (aged 10.7 ± 0.5 years, who had been playing football for at least 1 year (10-15 h per week. The second group a control group 30 boys (aged 11.2 ± 0.7 years doing 1.5 h per week physical activity at school. Body composition was assessed by a Body Fat Analyzer 'BES 200 Z'. Bone mineral density measurements of the left and the right calcaneus were done by using ultrasound densitometer 'Sahara' (Hologic, Inc., MA, USA. Results. There were significant differences between soccer players and the control group in fat mass (p = 0.01. Besides, a significant difference was determined between the group of athletes and the control group in bone mineral density of both calcaneal bones (p = 0.01. Conclusion. The results of this study confirm the significant effects of physical activity on reducing body mass and increasing bone density. Considering that football training can be very easily implemented in the broader population of children and young people, which does not apply to many other sports, it should be used more in the prevention of obesity and osteoporosis.
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Vadim Valer'evich Klimontov
2015-03-01
Full Text Available Aim. To determine the relationship between bone mineral density (BMD and total body composition in postmenopausal women with type 2 diabetes. Materials and Methods. The study included 78 women, from 50 to 70 years of age (median 63 years. Twenty women had normal body mass index (BMI, 29 ones were overweight and 29 had obesity. The body composition and BMD was studied by dual-energy X-ray absorptiometry. Results. Women with normal BMD had higher BMI, total and truncal fat mass, as well lean mass as compared to women with osteoporosis and osteopenia (all p
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Digital Repository Service at National Institute of Oceanography (India)
Nath, B.N.
flux. Circulation of seawater through the oceanic crust and upper mantle gives rise to a complex series of physical and chemical reactions that lead to the 1) formation of seafloor mineral deposits; 2) alteration of oceanic crust; 3) control... temperature in the high-temperature reaction zone near the heat source. Important parameters in determining the high- temperature fluid composition are • pressure, • temperature, • water/rock ratio, • rock composition, • recharge fluid...
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Tripati, Aradhna K.; Hill, Pamela S.; Eagle, Robert A.; Mosenfelder, Jed L.; Tang, Jianwu; Schauble, Edwin A.; Eiler, John M.; Zeebe, Richard E.; Uchikawa, Joji; Coplen, Tyler B.; Ries, Justin B.; Henry, Drew
2015-10-01
;Clumped-isotope; thermometry is an emerging tool to probe the temperature history of surface and subsurface environments based on measurements of the proportion of 13C and 18O isotopes bound to each other within carbonate minerals in 13C18O16O22- groups (heavy isotope ;clumps;). Although most clumped isotope geothermometry implicitly presumes carbonate crystals have attained lattice equilibrium (i.e., thermodynamic equilibrium for a mineral, which is independent of solution chemistry), several factors other than temperature, including dissolved inorganic carbon (DIC) speciation may influence mineral isotopic signatures. Therefore we used a combination of approaches to understand the potential influence of different variables on the clumped isotope (and oxygen isotope) composition of minerals. We conducted witherite precipitation experiments at a single temperature and at varied pH to empirically determine 13C-18O bond ordering (Δ47) and δ18O of CO32- and HCO3- molecules at a 25 °C equilibrium. Ab initio cluster models based on density functional theory were used to predict equilibrium 13C-18O bond abundances and δ18O of different DIC species and minerals as a function of temperature. Experiments and theory indicate Δ47 and δ18O compositions of CO32- and HCO3- ions are significantly different from each other. Experiments constrain the Δ47-δ18O slope for a pH effect (0.011 ± 0.001; 12 ⩾ pH ⩾ 7). Rapidly-growing temperate corals exhibit disequilibrium mineral isotopic signatures with a Δ47-δ18O slope of 0.011 ± 0.003, consistent with a pH effect. Our theoretical calculations for carbonate minerals indicate equilibrium lattice calcite values for Δ47 and δ18O are intermediate between HCO3- and CO32-. We analyzed synthetic calcites grown at temperatures ranging from 0.5 to 50 °C with and without the enzyme carbonic anhydrase present. This enzyme catalyzes oxygen isotopic exchange between DIC species and is present in many natural systems. The two
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Simier, M.; Blanc, L.; Aliaume, C.; Diouf, P. S.; Albaret, J. J.
2004-01-01
As a consequence of the Sahelian drought, the Sine Saloum, a large estuarine system located in Senegal (West Africa), has become an "inverse estuary" since the late sixties, i.e. salinity increases upstream and reaches 100 in some places. To study the fish assemblages of such a modified system, a survey was conducted in 1992, collecting fish every two months with a purse seine at eight sites spread over the three main branches of the estuary. A total of 73 species belonging to 35 families were identified. Eight species comprised 97% of the total numbers of fish. The predominant species was a small clupeid, Sardinella maderensis, representing more than half of the total biomass and nearly 70% of the total number of fish. The spatio-temporal structure of the fish assemblages was studied using the STATIS-CoA method, which combines the multitable approach with the correspondence analysis method. Whatever the season, a strong spatial organization of fish assemblages was observed, mainly related to depth and salinity. Three types of assemblages were identified. In shallow water areas, fish assemblages were dominated by Mugilidae, Gerreidae and Cichlidae and were stable with time. In open water areas, large fluctuations in the species composition were observed, due to the occasional presence of large schools of pelagic species: in the southern area, where salinity and water transparency were the lowest, the main species were Ilisha africana, Brachydeuterus auritus and Chloroscombrus chrysurus, associated with a few Sciaenidae and Tetraodontidae, while the poorest areas were characterized by only two dominant species, S. maderensis and Scomberomorus tritor.
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Identification of provenance rocks based on EPMA analyses of heavy minerals
Shimizu, M.; Sano, N.; Ueki, T.; Yonaga, Y.; Yasue, K. I.; Masakazu, N.
2017-12-01
Information on mountain building is significant in the field of geological disposal of high-level radioactive waste, because this affects long-term stability in groundwater flow system. Provenance analysis is one of effective approaches for understanding building process of mountains. Chemical compositions of heavy minerals, as well as their chronological data, can be an index for identification of provenance rocks. The accurate identification requires the measurement of as many grains as possible. In order to achieve an efficient provenance analysis, we developed a method for quick identification of heavy minerals using an Electron Probe Micro Analyzer (EPMA). In this method, heavy mineral grains extracted from a sample were aligned on a glass slide and mounted in a resin. Concentration of 28 elements was measured for 300-500 grains per sample using EPMA. To measure as many grains as possible, we prioritized swiftness of measurement over precision, configuring measurement time of about 3.5 minutes for each grain. Identification of heavy minerals was based on their chemical composition. We developed a Microsoft® Excel® spread sheet input criteria of mineral identification using a typical range of chemical compositions for each mineral. The grains of 110 wt.% total were rejected. The criteria of mineral identification were revised through the comparison between mineral identification by optical microscopy and chemical compositions of grains classified as "unknown minerals". Provenance rocks can be identified based on abundance ratio of identified minerals. If no significant difference of the abundance ratio was found among source rocks, chemical composition of specific minerals was used as another index. This method was applied to the sediments of some regions in Japan where provenance rocks had lithological variations but similar formation ages. Consequently, the provenance rocks were identified based on chemical compositions of heavy minerals resistant to
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John, D.A.; Sisson, T.W.; Breit, G.N.; Rye, R.O.; Vallance, J.W.
2008-01-01
Hydrothermal alteration at Mount Rainier waxed and waned over the 500,000-year episodic growth of the edifice. Hydrothermal minerals and their stable-isotope compositions in samples collected from outcrop and as clasts from Holocene debris-flow deposits identify three distinct hypogene argillic/advanced argillic hydrothermal environments: magmatic-hydrothermal, steam-heated, and magmatic steam (fumarolic), with minor superimposed supergene alteration. The 3.8??km3 Osceola Mudflow (5600??y BP) and coeval phreatomagmatic F tephra contain the highest temperature and most deeply formed hydrothermal minerals. Relatively deeply formed magmatic-hydrothermal alteration minerals and associations in clasts include quartz (residual silica), quartz-alunite, quartz-topaz, quartz-pyrophyllite, quartz-dickite/kaolinite, and quartz-illite (all with pyrite). Clasts of smectite-pyrite and steam-heated opal-alunite-kaolinite are also common in the Osceola Mudflow. In contrast, the Paradise lahar, formed by collapse of the summit or near-summit of the edifice at about the same time, contains only smectite-pyrite and near-surface steam-heated and fumarolic alteration minerals. Younger debris-flow deposits on the west side of the volcano (Round Pass and distal Electron Mudflows) contain only low-temperature smectite-pyrite assemblages, whereas the proximal Electron Mudflow and a formed at higher temperatures. The pre-Osceola Mudflow alteration geometry is inferred to have consisted of a narrow feeder zone of intense magmatic-hydrothermal alteration limited to near the conduit of the volcano, which graded outward to more widely distributed, but weak, smectite-pyrite alteration within 1??km of the edifice axis, developed chiefly in porous breccias. The edifice was capped by a steam-heated alteration zone, most of which resulted from condensation of fumarolic vapor and oxidation of H2S in the unsaturated zone above the water table. Weakly developed smectite-pyrite alteration extended into
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Carmen G. Montaña
Full Text Available Morichales are lowland streams in South American savannas with riparian forest dominated by the moriche palm (Mauritia flexuosa. We sampled littoral habitats from ten flooded vegetated patches (dominated by Mauritiella aculeate and six sand banks in two months of the dry season (Feb-Mar 2005 in a stream in the savannas of Apure State, Venezuela. We collected samples that compromised 12,407 individual fishes of 107 species. Small-bodied fishes (< 100 mm, representing diverse trophic and life history strategies, were abundant. The most abundant species were in the families Characidae and Cichlidae. Fish assemblages from flooded vegetated patches differed significantly from those on adjacent sand banks. High structural complexity along vegetated shoreline habitats of morichal streams likely contributes to species richness and affects assemblage composition.
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Ren, G. L.; Yi, H.; Yang, M.; Liang, N.; Li, J. Q.; Yang, J. L.
2016-11-01
Hyperspectral information of altered minerals plays an important role in the identifications of mineralized zones. In this study, the altered minerals of two gold deposits from Fangshankou-Laojinchang regions of Beishan metallogenic belt were measured by ASD field Spectrometer. Many gold deposits would have a close relationship with Variscan magma intrusion, which have been found in study region. The alteration minerals have been divided six types by the spectral results, i.e. sericite, limonite, dolomite, chlorite, epidote and calcite. The distribution characteristics and formations of altered minerals were discussed here. By the ASD, the spectral curve of different geological units in the Jintanzi and Fangshankou gold deposits were analysed and summarized. The results show that the sericite and limonite are mainly related with the gold mineralization and widely occurred in the gold deposits. Therefore, we proposed that the sericite and limonite are the iconic alteration mineral assemblages for gold mineralization and the models of altered minerals for gold deposits could be established in this region.
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Boron enhances strength and alters mineral composition of bone in rabbits fed a high energy diet.
Hakki, Sema S; Dundar, Niyazi; Kayis, Seyit Ali; Hakki, Erdogan E; Hamurcu, Mehmet; Kerimoglu, Ulku; Baspinar, Nuri; Basoglu, Abdullah; Nielsen, Forrest H
2013-04-01
An experiment was performed to determine whether boron had a beneficial effect on bone strength and composition in rabbits with apparent adiposity induced by a high energy diet. Sixty female New Zealand rabbits, aged 8 months, were randomly divided into five groups with the following treatments for seven months: control 1, fed alfalfa hay only (5.91 MJ/kg); control 2, high energy diet (11.76 MJ and 3.88 mg boron/kg); B10, high energy diet+10 mg/kg body weight boron gavage/96 h; B30, high energy diet+30 mg/kg body weight boron gavage/96 h; B50, high energy diet+50mg/kg body weight boron gavage/96 h. Bone boron concentrations were lowest in rabbits fed the high energy diet without boron supplementation, which suggested an inferior boron status. Femur maximum breaking force was highest in the B50 rabbits. Tibia compression strength was highest in B30 and B50 rabbits. All boron treatments significantly increased calcium and magnesium concentrations, and the B30 and B50 treatments increased the phosphorus concentration in tibia of rabbits fed the high energy diet. The B30 treatment significantly increased calcium, phosphorus and magnesium concentrations in femur of rabbits fed the high energy diet. Principal component analysis of the tibia minerals showed that the three boron treatments formed a separate cluster from controls. Discriminant analysis suggested that the concentrations of the minerals in femur could predict boron treatment. The findings indicate boron has beneficial effects on bone strength and mineral composition in rabbits fed a high energy diet. Copyright © 2012 Elsevier GmbH. All rights reserved.
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A.M. Boot (Annemieke); M.A. Engels (Melanie); G.J.M. Boerma (Geert); E.P. Krenning (Eric); S.M.P.F. de Muinck Keizer-Schrama (Sabine)
1997-01-01
textabstractAdults with childhood onset GH deficiency (GHD) have reduced bone mass, increased fat mass, and disorders of lipid metabolism. The aim of the present study was to evaluate bone mineral density (BMD), bone metabolism, body composition, and lipid metabolism in
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Late Neogene leaf assemblage from Bełchatów Lignite Mine (central Poland
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Worobiec Grzegorz
2014-12-01
Full Text Available Leaf macroremains collected in the Bełchatów Lignite Mine (central Poland were investigated. The fossil assemblage consists of leaves of Acer, Betula, Carpinus, Dicotylophyllum, Fagus, ?Magnolia, “Parrotia”, Pinus, Quercus, and Zelkova. Mesophytic (zonal elements dominate, with admixture of riparian (azonal leaf taxa. The floristic composition points to late Neogene (late Miocene to late Pliocene age and suggests favourable temperate climate with mild winters.
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Lochmüller E. M.
2001-01-01
Full Text Available The purpose of this study was to analyze the in situ precision (reproducibility of bone mineral and body composition measurements in mice of different body weights and rats, using a high-resolution DXA (dual energy X-ray absorptiometry scanner. We examined 48 NMRI mice weighing approximately 10 to 60 g, and 10 rats weighing approximately 140 g. Four repeated measurements were obtained on different days. In mice, the standard deviations of repeated measurements ranged from 2.5 to 242 mg for bone mineral content (BMC, from 0.16 to 3.74 g for fat, and from 0.40 to 4.21 g for lean mass. The coefficient of variation in percent (CV% for BMC/BMD (bone mineral density was highest in the 10 g mice (12.8% / 4.9% and lowest in the 40 g mice (3.5% /1.7%. In rats, it was 2.5 /1.2% in the lower extremity, 7.1/3.0 % in the spine, 5.7/2.0 % in the femur, and 3.6%/2.1% in the tibia. The CV% for fat and lean mass in mice was higher than for BMC. The study demonstrates good precision of bone mineral and moderate precision of body composition measure-ments in small animals, using a high-resolution DXA system. The technique can be used for testing the efficacy of drugs in small animal models, for muta-genesis screens, and for the phenotypic characterization of transgenic mice.
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Olguin, Cesar A; Landete-Castillejos, Tomas; Ceacero, Francisco; García, Andrés J; Gallego, Laureano
2013-01-01
Few studies in wild animals have assessed changes in mineral profile in long bones and their implications for mechanical properties. We examined the effect of two diets differing in mineral content on the composition and mechanical properties of femora from two groups each with 13 free-ranging red deer hinds. Contents of Ca, P, Mg, K, Na, S, Cu, Fe, Mn, Se, Zn, B and Sr, Young's modulus of elasticity (E), bending strength and work of fracture were assessed in the proximal part of the diaphysis (PD) and the mid-diaphysis (MD). Whole body measures were also recorded on the hinds. Compared to animals on control diets, those on supplemented diets increased live weight by 6.5 kg and their kidney fat index (KFI), but not carcass weight, body or organ size, femur size or cortical thickness. Supplemental feeding increased Mn content of bone by 23%, Cu by 9% and Zn by 6%. These differences showed a mean fourfold greater content of these minerals in supplemental diet, whereas femora did not reflect a 5.4 times greater content of major minerals (Na and P) in the diet. Lower content of B and Sr in supplemented diet also reduced femur B by 14% and Sr by 5%. There was a subtle effect of diet only on E and none on other mechanical properties. Thus, greater availability of microminerals but not major minerals in the diet is reflected in bone composition even before marked body effects, bone macro-structure or its mechanical properties are affected.
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Cesar A Olguin
Full Text Available Few studies in wild animals have assessed changes in mineral profile in long bones and their implications for mechanical properties. We examined the effect of two diets differing in mineral content on the composition and mechanical properties of femora from two groups each with 13 free-ranging red deer hinds. Contents of Ca, P, Mg, K, Na, S, Cu, Fe, Mn, Se, Zn, B and Sr, Young's modulus of elasticity (E, bending strength and work of fracture were assessed in the proximal part of the diaphysis (PD and the mid-diaphysis (MD. Whole body measures were also recorded on the hinds. Compared to animals on control diets, those on supplemented diets increased live weight by 6.5 kg and their kidney fat index (KFI, but not carcass weight, body or organ size, femur size or cortical thickness. Supplemental feeding increased Mn content of bone by 23%, Cu by 9% and Zn by 6%. These differences showed a mean fourfold greater content of these minerals in supplemental diet, whereas femora did not reflect a 5.4 times greater content of major minerals (Na and P in the diet. Lower content of B and Sr in supplemented diet also reduced femur B by 14% and Sr by 5%. There was a subtle effect of diet only on E and none on other mechanical properties. Thus, greater availability of microminerals but not major minerals in the diet is reflected in bone composition even before marked body effects, bone macro-structure or its mechanical properties are affected.
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Emmanuelle Buecher
2000-12-01
Full Text Available The assemblages of medusae and ctenophores were examined from samples collected each winter from St Helena Bay, over the 10-year period 1988-1997. A total of 50 hydromedusae, 1 scyphozoan and 2 ctenophore species were identified from 243 samples. Although the data set is characterised by great interannual variability, two main assemblages could be identified each year. These were characterised by either holoplanktonic medusae (e.g. Liriope tetraphylla, Aglaura hemistoma or meroplanktonic medusae (e.g. Mitrocomella millardae, Chrysaora hysoscella and ctenophores (e.g. Pleurobrachia pileus. The holoplanktonic medusae were typical of samples at the southern edge of the Bay, and were positively associated with both depth and temperature. Their abundances tended to increase during warm years (1992, 1993 and 1997 as warm surface water flooded the Bay. The meroplanktonic medusae and ctenophores were typical of samples collected within the Bay, and the density of species tended to be negatively correlated with temperature and depth. In spite of the eurythermal nature of the meroplanktonic species, they were more common during cold years (1990 and 1995. This paper represents the first Bay-wide, interannual study of any zooplankton group, and contributes important base line information on the structure of regional pelagic assemblages.
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Tripati, Aradhna K.; Hill, Pamela S.; Eagle, Robert A.; Mosenfelder, Jed L.; Tang, Jianwu; Schauble, Edwin A.; Eiler, John M.; Zeebe, Richard E.; Uchikawa, Joji; Coplen, Tyler B.; Ries, Justin B.; Henry, Drew
2015-01-01
“Clumped-isotope” thermometry is an emerging tool to probe the temperature history of surface and subsurface environments based on measurements of the proportion of 13C and 18O isotopes bound to each other within carbonate minerals in 13C18O16O22- groups (heavy isotope “clumps”). Although most clumped isotope geothermometry implicitly presumes carbonate crystals have attained lattice equilibrium (i.e., thermodynamic equilibrium for a mineral, which is independent of solution chemistry), several factors other than temperature, including dissolved inorganic carbon (DIC) speciation may influence mineral isotopic signatures. Therefore we used a combination of approaches to understand the potential influence of different variables on the clumped isotope (and oxygen isotope) composition of minerals.We conducted witherite precipitation experiments at a single temperature and at varied pH to empirically determine 13C-18O bond ordering (Δ47) and δ18O of CO32- and HCO3- molecules at a 25 °C equilibrium. Ab initio cluster models based on density functional theory were used to predict equilibrium 13C-18O bond abundances and δ18O of different DIC species and minerals as a function of temperature. Experiments and theory indicate Δ47 and δ18O compositions of CO32- and HCO3- ions are significantly different from each other. Experiments constrain the Δ47-δ18O slope for a pH effect (0.011 ± 0.001; 12 ⩾ pH ⩾ 7). Rapidly-growing temperate corals exhibit disequilibrium mineral isotopic signatures with a Δ47-δ18O slope of 0.011 ± 0.003, consistent with a pH effect.Our theoretical calculations for carbonate minerals indicate equilibrium lattice calcite values for Δ47 and δ18O are intermediate between HCO3− and CO32−. We analyzed synthetic calcites grown at temperatures ranging from 0.5 to 50 °C with and without the enzyme carbonic anhydrase present. This enzyme catalyzes oxygen isotopic exchange between DIC species and is present in many
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D. Andrew R. Drake
2014-04-01
Full Text Available The spread and impact of alien species among freshwater ecosystems has increased with global trade and human movement; therefore, quantifying the role of anthropogenic and ecological factors that increase the risk of invasion is an important conservation goal. Two factors considered as null models when assessing the potential for invasion are colonization pressure (i.e., the number of species introduced and propagule pressure [i.e., the number (propagule size, and frequency (propagule number, of individuals of each species introduced]. We translate the terminology of species abundance distributions to the invasion terminology of propagule size and colonization size (PS and CS, respectively. We conduct hypothesis testing to determine the underlying statistical species abundance distribution for zooplankton assemblages transported between freshwater ecosystems; and, on the basis of a lognormal distribution, construct four hypothetical assemblages spanning assemblage structure, rank-abundance gradient (e.g., even vs uneven, total abundance (of all species combined, and relative contribution of PS vs CS. For a given CS, many combinations of PS and total abundance can occur when transported assemblages conform to a lognormal species abundance distribution; therefore, for a given transportation event, many combinations of CS and PS are possible with potentially different ecological outcomes. An assemblage exhibiting high PS but low CS (species poor, but highly abundant may overcome demographic barriers to establishment, but with lower certainty of amenable environmental conditions in the recipient region; whereas, the opposite extreme, high CS and low PS (species rich, but low abundance per species may provide multiple opportunities for one of n arriving species to circumvent environmental barriers, albeit with lower potential to overcome demographic constraints. Species abundance distributions and the corresponding influence of CS and PS are some of
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Marta Leiva
2017-12-01
Full Text Available Abstract Aim: Our aim in this study was evaluate the effects of flow regulation for irrigation on the macroinvertebrate assemblages in a semiarid river. Methods We sampled two reaches in Dulce River; one placed upstream a weir that diverts flow into a network of irrigation channels and the other downstream that weir, in the assessment of the fluvial discontinuity. We assess the differences among reaches and sites, environmental variables, invertebrate density, richness and Shannon-Wiener index applying non-parametric analyses of variance Kruskal Wallis. The similarity percentage analysis (SIMPER was used to identify which species contributed to the dissimilarities on macroinvertebrate assemblage structure. Canonical Correspondence Analysis (CCA was performed with the total set of samples to explore macroinvertebrate distribution in reaches and associations of the assemblages with habitat variables. Results The density, richness and Shannon index values did not show differences between the reaches located upstream and downstream. Beta diversity (Whittaker was 0.72 among upstream sites, 0.56 among downstream sites and higher species turnover (0.73 was obtained between both reaches. The Canonical Correspondence Analysis explained 46.71% of the variance differentiating upstream sites explained by higher values of organic matter of bottom sediments and discharge, high density of Nais communis, Bothrioneurum americanum, Pelomus, Stephensoniana trivandrana, Pristina menoni, P. jenkinae, P.longidentata, P. americana, Dero obtusa, Endotribelos, Heleobia and Turbellaria. The downstream sites were associated to coarser substratum and higher density of Lopescladius, Polypedilum, Cricotopus, Thienamaniella, Cryptochironomus, Baetidae, Nematoda and Corbicula fluminea. Conclusions The low-flow disturbance had effects on the composition of the benthic invertebrate assemblages, but attributes (such as density and richness showed a lower variability probably
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Corinaldesi, Cinzia; Dell'Anno, Antonio; Danovaro, Roberto
2012-06-01
Mud volcanoes are geological structures in the oceans that have key roles in the functioning of the global ecosystem. Information on the dynamics of benthic viruses and their interactions with prokaryotes in mud volcano ecosystems is still completely lacking. We investigated the impact of viral infection on the mortality and assemblage structure of benthic prokaryotes of five mud volcanoes in the Mediterranean Sea. Mud volcano sediments promote high rates of viral production (1.65-7.89 × 10(9) viruses g(-1) d(-1)), viral-induced prokaryotic mortality (VIPM) (33% cells killed per day) and heterotrophic prokaryotic production (3.0-8.3 μgC g(-1) d(-1)) when compared with sediments outside the mud volcano area. The viral shunt (that is, the microbial biomass converted into dissolved organic matter as a result of viral infection, and thus diverted away from higher trophic levels) provides 49 mgC m(-2) d(-1), thus fuelling the metabolism of uninfected prokaryotes and contributing to the total C budget. Bacteria are the dominant components of prokaryotic assemblages in surface sediments of mud volcanoes, whereas archaea dominate the subsurface sediment layers. Multivariate multiple regression analyses show that prokaryotic assemblage composition is not only dependant on the geochemical features and processes of mud volcano ecosystems but also on synergistic interactions between bottom-up (that is, trophic resources) and top-down (that is, VIPM) controlling factors. Overall, these findings highlight the significant role of the viral shunt in sustaining the metabolism of prokaryotes and shaping their assemblage structure in mud volcano sediments, and they provide new clues for our understanding of the functioning of cold-seep ecosystems.
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Autumn ichthyoplankton assemblage in the Yangtze Estuary shaped by environmental factors.
Zhang, Hui; Xian, Weiwei; Liu, Shude
2016-01-01
This study investigated the response of the ichthyoplankton community to environmental changes in the Yangtze Estuary using canonical correspondence analysis. Ichthyoplankton community and environmental data were recorded during the autumns of 1998, 2000, 2002, 2003, 2004, 2007 and 2009. Among the ichthyoplankton, the dominant larval and juvenile families were the Engraulidae, Gobiidae and Salangidae, and the most common eggs were from Trichiurus lepturus. The ichthyoplankton was identified via canonical correspondence analysis to three assemblages: an estuary assemblage dominated by Chaeturichthys stigmatias, a coastal assemblage dominated by Engraulis japonicus and Stolephorus commersonii, and an offshore assemblage dominated by Trichiurus lepturus. Regarding environmental factors in the Yangtze Estuary, suspended matter and surface seawater salinity were the main factors influencing the distributions of the different assemblages, while sediment from the Yangtze River during the rainy season and chlorophyll a were the principle drivers of the annual variances in the distribution of ichthyoplankton assemblages. Our aims in this study were to provide detailed characterizations of the ichthyoplankton assemblage in the autumns of seven years, examine the long-term dynamics of autumn ichthyoplankton assemblages, and evaluate the influence of environmental factors on the spatial distribution and inter-annual variations of ichthyoplankton assemblages associated with the Yangtze Estuary.
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Autumn ichthyoplankton assemblage in the Yangtze Estuary shaped by environmental factors
Directory of Open Access Journals (Sweden)
Hui Zhang
2016-04-01
Full Text Available This study investigated the response of the ichthyoplankton community to environmental changes in the Yangtze Estuary using canonical correspondence analysis. Ichthyoplankton community and environmental data were recorded during the autumns of 1998, 2000, 2002, 2003, 2004, 2007 and 2009. Among the ichthyoplankton, the dominant larval and juvenile families were the Engraulidae, Gobiidae and Salangidae, and the most common eggs were from Trichiurus lepturus. The ichthyoplankton was identified via canonical correspondence analysis to three assemblages: an estuary assemblage dominated by Chaeturichthys stigmatias, a coastal assemblage dominated by Engraulis japonicus and Stolephorus commersonii, and an offshore assemblage dominated by Trichiurus lepturus. Regarding environmental factors in the Yangtze Estuary, suspended matter and surface seawater salinity were the main factors influencing the distributions of the different assemblages, while sediment from the Yangtze River during the rainy season and chlorophyll a were the principle drivers of the annual variances in the distribution of ichthyoplankton assemblages. Our aims in this study were to provide detailed characterizations of the ichthyoplankton assemblage in the autumns of seven years, examine the long-term dynamics of autumn ichthyoplankton assemblages, and evaluate the influence of environmental factors on the spatial distribution and inter-annual variations of ichthyoplankton assemblages associated with the Yangtze Estuary.
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Tezuka, N.; Tsuboi, M.; Asahara, Y.
2017-12-01
The Cretaceous Katsuragi tonalite in southwestern Japan has been regarded as adakite formed by the partial melting of lower crust a) b). The tonalite is 10 x 15 km in areal extent, is composed of hornblende-biotite tonalite with a mineral assemblage of plagioclase, biotite, quartz and hornblende, and contains mafic microgranular enclaves (MME). The MME has dioritic composition with a mineral assemblage of plagioclase, biotite, hornblende and quartz. The boundary between the tonalite and the MME is sharp. To reveal the relationship between the MME and adakitic feature of the host tonalite, we have focused on the chemical and Sr-Nd isotopic compositions of the MME in the Katsuragi tonalite. Three models have been proposed for the origin of MME: restite, magma-mixing, and cumulate c). In the restite model, MME is regarded as a residual material of partial melting, and therefore chemical compositions of MME and host should show a linear trend on the Harker's diagram. However, the Katsuragi tonalite and its MME do not show one linear trend. Based on mixing of two magmas, initial 87Sr/86Sr (SrI) value of MME is basically different from that of its host. However, the SrI value of the MME is 0.70725-0.70749 and is identical to the value of 0.70728 in the Katsuragi tonalite d), indicating one magma source for the MME and its host. According to the cumulate model, MME forms from cumulate piles by subsequent feeding of congenetic magma immediately after the early crystallized minerals are solidified. The concordance of the age and SrI between the Katsuragi tonalite and its MME strongly indicate the cumulate origin c). Furthermore, the mineral assemblage of the MME resembles with the common mineral assemblage of andesitic cumulate such as plagioclase, hornblende and quartz c), and this is consistent with the cumulate model. Based on the cumulate origin of the MME, the adakitic feature of chemical composition in the host rock is potentially formed by the separation of cumulate
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Variation in Symbiodinium ITS2 sequence assemblages among coral colonies.
Stat, Michael; Bird, Christopher E; Pochon, Xavier; Chasqui, Luis; Chauka, Leonard J; Concepcion, Gregory T; Logan, Dan; Takabayashi, Misaki; Toonen, Robert J; Gates, Ruth D
2011-01-05
Endosymbiotic dinoflagellates in the genus Symbiodinium are fundamentally important to the biology of scleractinian corals, as well as to a variety of other marine organisms. The genus Symbiodinium is genetically and functionally diverse and the taxonomic nature of the union between Symbiodinium and corals is implicated as a key trait determining the environmental tolerance of the symbiosis. Surprisingly, the question of how Symbiodinium diversity partitions within a species across spatial scales of meters to kilometers has received little attention, but is important to understanding the intrinsic biological scope of a given coral population and adaptations to the local environment. Here we address this gap by describing the Symbiodinium ITS2 sequence assemblages recovered from colonies of the reef building coral Montipora capitata sampled across Kāne'ohe Bay, Hawai'i. A total of 52 corals were sampled in a nested design of Coral Colony(Site(Region)) reflecting spatial scales of meters to kilometers. A diversity of Symbiodinium ITS2 sequences was recovered with the majority of variance partitioning at the level of the Coral Colony. To confirm this result, the Symbiodinium ITS2 sequence diversity in six M. capitata colonies were analyzed in much greater depth with 35 to 55 clones per colony. The ITS2 sequences and quantitative composition recovered from these colonies varied significantly, indicating that each coral hosted a different assemblage of Symbiodinium. The diversity of Symbiodinium ITS2 sequence assemblages retrieved from individual colonies of M. capitata here highlights the problems inherent in interpreting multi-copy and intra-genomically variable molecular markers, and serves as a context for discussing the utility and biological relevance of assigning species names based on Symbiodinium ITS2 genotyping.
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DEFF Research Database (Denmark)
Horváth, R.; Elek, Zoltán; Lövei, Gabor L
2014-01-01
Spider (Araneae) assemblages were studied over two years by pitfall trapping along an urbanisation gradient of forested habitats (rural forest - suburban forest fragment - urban forest fragment) in a Danish town, using the Globenet protocol. During the two years, we collected 4340 individuals of 90...... species, with money spiders (Linyphiidae) and wolf spiders (Lycosidae) being most numerous. One species, Ero aphana, was new to the Danish fauna. In 2004, 45-47 species were captured in the habitats in various stages of urbanisation, while in 2005 (with a smaller collection effort), 28 (urban) - 37 (rural...
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Global assemblages and structural models of International Relations
DEFF Research Database (Denmark)
Corry, Olaf
2014-01-01
-category of assemblages – those constructed as malleable and governable which I call ‘governance-objects’ – is central to structure in international relations. The chapter begins with standard definitions of what structures are – patterns of interaction between elements – and briefly covers the range of models currently...... used to simplify different structures. Next the chapter points to the blindness of most structural theories of IR to the role of assemblages in general and governance-objects in particular. Thirdly, the idea that a polity is constituted precisely by the assemblage of a governance...
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Directory of Open Access Journals (Sweden)
J.M. Njinkoue
2016-10-01
Full Text Available Background: Knowledge of chemical composition of fish from Cameroon is poor. The genera Pseudotolithus are nutritionally and economically important in Cameroon. Thus the knowledge on their chemical composition could help in functional food elaboration. Purpose: In this study, Proximate composition, fatty acid profiles and mineral composition were determined in two fish species, Pseudotolithus typus and Pseudotolithus elongatus from Cameroonian coasts. Basic procedure: AOAC standard method was used. Fatty acids were identified by GC/MS as N-acylpyrolidides. Mineral compositions were determined by atomic absorption spectrophotometry for Ca, Na, K, Mg, Fe, Zn, Cu, Mn, and by UV spectrophotometry for phosphorus (P. Main finding: Results indicated that chemical composition was not similar in the two fish species. Results also showed that water is the main constituent in the edible parts and in the bones with 76.17% to 78.24% and 51.21% to 55.28% respectively. Pseudotolithus typus and Pseudotolithus elongatus were good sources of proteins with 16.17% and 13.4% respectively. All the fish analyzed for fat were lean with fat contents less than 0.5%. These species of fish were poor in ω6PUFA and were rich in ω3PUFA with about one third of total fatty acids. The main ω3 fatty acids were eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA. The most abundant main elements were the potassium in the edible parts (1.39% and calcium in the bones (18.26%. The most abundant trace elements were Zn and Fe in the edible parts and in the bones. Principal conclusion: The Na/K ratio values and ω3 fatty acids contents suggest that consumption of these two fish species could be recommended to prevent cardiovascular diseases. Keywords: Proximal composition, Mineral content, Fatty acid profiles, Pseudotolithus typus, Pseudotolithus elongates
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Koehler, Geoff; Wassenaar, Leonard I
2012-04-17
Hydrogen isotopic compositions of hydrous minerals and organic materials were measured by combustion to water, followed by optical isotopic analysis of the water vapor by off-axis integrated cavity output spectroscopy. Hydrogen and oxygen isotopic compositions were calculated by numerical integration of the individual isotopologue concentrations measured by the optical spectrometer. Rapid oxygen isotope exchange occurs within the combustion reactor between water vapor and molecular oxygen so that only hydrogen isotope compositions may be determined. Over a wide range in sample sizes, precisions were ±3-4 per mil. This is comparable but worse than continuous flow-isotope ratio mass spectroscopy (CF-IRMS) methods owing to memory effects inherent in water vapor transfer. Nevertheless, the simplicity and reduced cost of this analysis compared to classical IRMS or CF-IRMS methods make this an attractive option to determine the hydrogen isotopic composition of organic materials where the utmost precision or small sample sizes are not needed.
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Consequences of organ choice in describing bacterial pathogen assemblages in a rodent population.
Villette, P; Afonso, E; Couval, G; Levret, A; Galan, M; Tatard, C; Cosson, J F; Giraudoux, P
2017-10-01
High-throughput sequencing technologies now allow for rapid cost-effective surveys of multiple pathogens in many host species including rodents, but it is currently unclear if the organ chosen for screening influences the number and identity of bacteria detected. We used 16S rRNA amplicon sequencing to identify bacterial pathogens in the heart, liver, lungs, kidneys and spleen of 13 water voles (Arvicola terrestris) collected in Franche-Comté, France. We asked if bacterial pathogen assemblages within organs are similar and if all five organs are necessary to detect all of the bacteria present in an individual animal. We identified 24 bacteria representing 17 genera; average bacterial richness for each organ ranged from 1·5 ± 0·4 (mean ± standard error) to 2·5 ± 0·4 bacteria/organ and did not differ significantly between organs. The average bacterial richness when organ assemblages were pooled within animals was 4·7 ± 0·6 bacteria/animal; Operational Taxonomic Unit accumulation analysis indicates that all five organs are required to obtain this. Organ type influences bacterial assemblage composition in a systematic way (PERMANOVA, 999 permutations, pseudo-F 4,51 = 1·37, P = 0·001). Our results demonstrate that the number of organs sampled influences the ability to detect bacterial pathogens, which can inform sampling decisions in public health and wildlife ecology.
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Directory of Open Access Journals (Sweden)
Xin Sun
2017-06-01
Full Text Available The ozone-depleting and greenhouse gas, nitrous oxide (N2O, is mainly consumed by the microbially mediated anaerobic process, denitrification. N2O consumption is the last step in canonical denitrification, and is also the least O2 tolerant step. Community composition of total and active N2O consuming bacteria was analyzed based on total (DNA and transcriptionally active (RNA nitrous oxide reductase (nosZ genes using a functional gene microarray. The total and active nosZ communities were dominated by a limited number of nosZ archetypes, affiliated with bacteria from marine, soil and marsh environments. In addition to nosZ genes related to those of known marine denitrifiers, atypical nosZ genes, related to those of soil bacteria that do not possess a complete denitrification pathway, were also detected, especially in surface waters. The community composition of the total nosZ assemblage was significantly different from the active assemblage. The community composition of the total nosZ assemblage was significantly different between coastal and off-shore stations. The low oxygen assemblages from both stations were similar to each other, while the higher oxygen assemblages were more variable. Community composition of the active nosZ assemblage was also significantly different between stations, and varied with N2O concentration but not O2. Notably, nosZ assemblages were not only present but also active in oxygenated seawater: the abundance of total and active nosZ bacteria from oxygenated surface water (indicated by nosZ gene copy number was similar to or even larger than in anoxic waters, implying the potential for N2O consumption even in the oxygenated surface water.
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Sun, Xin; Jayakumar, Amal; Ward, Bess B.
2017-01-01
The ozone-depleting and greenhouse gas, nitrous oxide (N2O), is mainly consumed by the microbially mediated anaerobic process, denitrification. N2O consumption is the last step in canonical denitrification, and is also the least O2 tolerant step. Community composition of total and active N2O consuming bacteria was analyzed based on total (DNA) and transcriptionally active (RNA) nitrous oxide reductase (nosZ) genes using a functional gene microarray. The total and active nosZ communities were dominated by a limited number of nosZ archetypes, affiliated with bacteria from marine, soil and marsh environments. In addition to nosZ genes related to those of known marine denitrifiers, atypical nosZ genes, related to those of soil bacteria that do not possess a complete denitrification pathway, were also detected, especially in surface waters. The community composition of the total nosZ assemblage was significantly different from the active assemblage. The community composition of the total nosZ assemblage was significantly different between coastal and off-shore stations. The low oxygen assemblages from both stations were similar to each other, while the higher oxygen assemblages were more variable. Community composition of the active nosZ assemblage was also significantly different between stations, and varied with N2O concentration but not O2. Notably, nosZ assemblages were not only present but also active in oxygenated seawater: the abundance of total and active nosZ bacteria from oxygenated surface water (indicated by nosZ gene copy number) was similar to or even larger than in anoxic waters, implying the potential for N2O consumption even in the oxygenated surface water. PMID:28702012
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Meiofaunal assemblages associated with native and non-indigenous macroalgae
Veiga, Puri; Sousa-Pinto, Isabel; Rubal, Marcos
2016-07-01
Meiofauna is a useful tool to detect effects of different disturbances; however, its relevance in the frame of biological invasions has been almost fully neglected. Meiofaunal assemblages associated with the invasive macroalga Sargassum muticum were studied and compared with those associated with two native macroalgae (Bifurcaria bifurcata and Chondrus crispus). We used a linear mixed model to determine the influence of habitat size (i.e. macroalgal biomass) in shaping meiofaunal assemblages. Results showed that habitat size (i.e. macroalgal biomass) shaped meiofaunal assemblages influencing its abundance, richness and structure. However, the identity of macroalga (i.e. species) appears also to play a significant role, particularly the differences of complexity among the studied species may shape their meiofaunal assemblages. Finally, the invasive macroalga appears to influence positively species richness. Our results highlight the need of including different faunal components to achieve a comprehensive knowledge on effects of invasive macroalgae and that meiofaunal assemblages may be a valuable tool to examine them.
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Brown, Marion B; Schlacher, Thomas A; Schoeman, David S; Weston, Michael A; Huijbers, Chantal M; Olds, Andrew D; Connolly, Rod M
2015-10-01
Species composition is expected to alter ecological function in assemblages if species traits differ strongly. Such effects are often large and persistent for nonnative carnivores invading islands. Alternatively, high similarity in traits within assemblages creates a degree of functional redundancy in ecosystems. Here we tested whether species turnover results in functional ecological equivalence or complementarity, and whether invasive carnivores on islands significantly alter such ecological function. The model system consisted of vertebrate scavengers (dominated by raptors) foraging on animal carcasses on ocean beaches on two Australian islands, one with and one without invasive red foxes (Vulpes vulpes). Partitioning of scavenging events among species, carcass removal rates, and detection speeds were quantified using camera traps baited with fish carcasses at the dune-beach interface. Complete segregation of temporal foraging niches between mammals (nocturnal) and birds (diurnal) reflects complementarity in carrion utilization. Conversely, functional redundancy exists within the bird guild where several species of raptors dominate carrion removal in a broadly similar way. As predicted, effects of red foxes were large. They substantially changed the nature and rate of the scavenging process in the system: (1) foxes consumed over half (55%) of all carrion available at night, compared with negligible mammalian foraging at night on the fox-free island, and (2) significant shifts in the composition of the scavenger assemblages consuming beach-cast carrion are the consequence of fox invasion at one island. Arguably, in the absence of other mammalian apex predators, the addition of red foxes creates a new dimension of functional complementarity in beach food webs. However, this functional complementarity added by foxes is neither benign nor neutral, as marine carrion subsidies to coastal red fox populations are likely to facilitate their persistence as exotic
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International Nuclear Information System (INIS)
Chaudhri, M.A.; Lee, M.M.; Rouse, J.L.; Weste, G.
1978-01-01
As part of a study of disease caused by Phytophthora cinnamomi in native vegetation, the mineral composition of diseased plants has been compared with those free from disease, but grown under the same conditions. Using proton activation it has been shown that a reduction of 70% in iron and 41% in titanium occurs for diseased Eucalytus obliqua compared with disease-free plants. The reduction in iron is associated with severe chlorosis which occurs as a primary symptom in most plants attacked by this pathogen. (author)
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Environmental gradients structure gorgonian assemblages on coral reefs in SE Sulawesi, Indonesia
Rowley, Sonia J.
2018-06-01
Indonesian coral reefs are the epicenter of marine biodiversity, yet are under rapid anthropogenically induced decline. Therefore, ecological monitoring of high diversity taxa is paramount to facilitate effective management and conservation. This study presents an initial report from a comprehensive survey of shallow-water (0-15 m) gorgonian assemblage composition and structure across sites with varying habitat quality within the Wakatobi Marine National Park (WMNP), SE Sulawesi, Indonesia. Current estimates of over 90 morphospecies from 38 genera and 12 families within the calcaxonian, holaxonian and scleraxonian groups are reported. This extensive survey confirms high local gorgonian abundance, diversity and species richness in the absence of anthropogenic influence and increasing with depth. Notably, morphological variants of the zooxanthellate species Isis hippuris Linnaeus, 1758, and Briareum Blainville, 1830, drive site and habitat assemblage differences across environmental gradients. Azooxanthellate taxa, particularly within the Plexauridae, drive species richness and diversity with depth. Of the 14 predictor variables measured, benthic characteristics, water flow and natural light explained just 30% of gorgonian assemblage structure. Furthermore, zooxanthellate and azooxanthellate taxa partitioned distinct gorgonian communities into two trophic groups—autotrophs and heterotrophs, respectively—with contrasting diversity and abundance patterns within and between study sites. This study strongly supports the WMNP as an area of high regional gorgonian abundance and diversity. Varying ecological patterns across environmental clines can provide the foundation for future research and conservation management strategies in some of the most biodiverse marine ecosystems in the world.
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Directory of Open Access Journals (Sweden)
Mônica Kanashiro Oyafuso
2010-02-01
Full Text Available O estudo teve como objetivo avaliar os casos de urolitíase canina em que a composição mineral dos urólitos foi analisada quantitativamente. Foi avaliada quantitativamente a composição mineral de 156 urólitos obtidos de cães (nefrólitos, ureterólitos, urocistólitos e uretrólitos. Desse total, 79,5% (n=124 eram simples, 18% (n=28 eram compostos e apenas 2,5% (n=4 eram mistos. A estruvita foi o tipo mineral mais frequente nos urólitos simples (47,6%; n=59, em todos os mistos (100%; n=4 e nas camadas núcleo e pedra de urólitos compostos (32,1 e 75%, respectivamente. O oxalato de cálcio foi o segundo mineral mais frequente dos urólitos simples (37,9%, n=47. Ao contrário do que é preconizado para os urólitos simples, as recomendações para o tratamento de urólitos compostos são mais complexas, tais como protocolos de tratamento de dissolução diferentes (se composto por minerais distintos e passíveis de dissolução como urato e estruvita. Além disso, a dissolução pode não ser viável, caso ocorra presença de material insolúvel envolvendo o urólito ou se este representar mais de 20% da camada. Vinte e dois urólitos compostos (78,7% apresentaram uma camada externa não passível de dissolução (oxalato de cálcio ou fosfato de cálcio; dois (7,1% apresentaram camadas externas passíveis de dissolução (estruvita ou urato, porém camadas mais internas não solúveis, o que permitiria apenas a dissolução parcial do urólito. Assim, o conhecimento da composição de todas as camadas que compõem o urólito é essencial para o entendimento da formação do cálculo e consequentemente para a indicação do tratamento adequado, assim como para prevenção de recidivas.The aim of this study was to evaluate dogs with urolithiasis in which mineral composition of calculi was quantitatively analyzed. Quantitative mineral composition was performed in 156 canine uroliths. Simple uroliths represented 79.5% (n=124 of the cases, 18
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Mangrove macrobenthos: Assemblages, services, and linkages
Lee, S. Y.
2008-02-01
Macrobenthic assemblages are relatively poorly known compared to other components of the mangrove ecosystem. Tropical mangroves support macrobenthic biodiversity resources yet to be properly documented and interpreted. Some methodological challenges, such as the generally high spatial heterogeneity and complexity of the habitat, evidently reduce sampling efficiency and accuracy, while also leaving some microhabitats under-sampled. Macrobenthic assemblage structure seems to be influenced by local environmental conditions, such as hydroperiod, organic matter availability and sediment characteristics. Brachyurans, gastropods and oligochaetes dominate in the sediment, with the former two groups also common on hard surfaces provided by tree trunks, while insects and arachnids inhabit the canopy. Traditionally, studies of mangrove macrobenthos have focused on assemblage structure or the biology of individual species, but more complex inter-specific interactions and the inter-relationship between habitat and the biota are recently being addressed. Brachyuran crabs are the best-studied macrobenthos group, but many issues about their role in mangrove ecosystem dynamics are still controversial. Despite many species of mangrove macrobenthos being referred to as 'trophic dead ends', most serve as important links between recalcitrant mangrove organic matter and estuarine secondary production, through feeding excursion by mobile nekton during the high tide, and macrobenthos-mediated processing and exportation of organic matter. A significant difference in the standing crop biomass of forests between the Indo-west-Pacific (IWP)' and Atlantic-east-Pacific (AEP) mangroves may be related to the difference in species richness of mangrove as well as macrobenthos diversity in the two bioregions. Such differences in assemblage structure may also result in different ecosystem functioning, but the nature of the links is, however, yet to be explored. There is also a strong need for
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Olguin, Cesar A.; Landete-Castillejos, Tomas; Ceacero, Francisco; Garc?a, Andr?s J.; Gallego, Laureano
2013-01-01
Few studies in wild animals have assessed changes in mineral profile in long bones and their implications for mechanical properties. We examined the effect of two diets differing in mineral content on the composition and mechanical properties of femora from two groups each with 13 free-ranging red deer hinds. Contents of Ca, P, Mg, K, Na, S, Cu, Fe, Mn, Se, Zn, B and Sr, Young's modulus of elasticity (E), bending strength and work of fracture were assessed in the proximal part of the diaphysi...
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Characterization of clay minerals
International Nuclear Information System (INIS)
Diaz N, C.; Olguin, M.T.; Solache R, M.; Alarcon H, T.; Aguilar E, A.
2002-01-01
The natural clays are the more abundant minerals on the crust. They are used for making diverse industrial products. Due to the adsorption and ion exchange properties of these, a great interest for developing research directed toward the use of natural clays for the waste water treatment has been aroused. As part of such researches it is very important to carry out previously the characterization of the interest materials. In this work the results of the mineral and elemental chemical composition are presented as well as the morphological characteristics of clay minerals from different regions of the Mexican Republic. (Author)
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[Characteristics of ichthyoplankton assemblages in Yangtze Estuary and adjacent waters in spring].
Liu, Shu-De; Xian, Wei-Wei; Liu, Dong
2008-10-01
Based on the investigation data of ichthyoplankton assemblages and environmental factors in Yangtze Estuary and adjacent waters in May 1999 and 2001, the characteristics of ichthyoplankton assemblages in these areas in spring were studied by using TWINSPAN (two-way indicator species analysis) and CCA (canonical correspondence analysis). A total of 11 540 ichthyoplankton individuals were taxonomically identified, belonging to 11 orders, 18 families and 32 species, of which, Coilia mystus, Engraulis japonicus, Chaeturichthys hexanema, Allanetta bleekeri, and Trachidermis fasciatus were the dominant species. The ichthyoplankton communities were classified into three assemblages by using TWINSPAN, i.e., estuarine assemblage dominated by C. mystus, coastal assemblage dominated by A. bleekeri and T. fasciatus; and shelf assemblage featured by E. japonicus and C. hexanema. The CCA ordination of the interrelations among the three assemblages and their correlations to the environmental variables revealed that salinity, depth, dissolved oxygen, and total suspended particulate matter were the major factors affecting the ichthyoplankton assemblages in the study areas.
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Faunistic assemblages of a sublittoral coarse sand habitat of the northwestern Mediterranean
Directory of Open Access Journals (Sweden)
Eva Pubill
2011-02-01
Full Text Available The sublittoral megabenthic assemblages of a northwestern Mediterranean coarse sandy beach exploited for the bivalve Callista chione were studied. The spatial and bathymetric variability of its distinctive faunal assemblages was characterised by quantitative sampling performed with a clam dredge. The taxa studied were Mollusca Bivalvia and Gastropoda, Crustacea Decapoda, Echinodermata and Pisces, which accounted for over 99% of the total biomass. Three well-differentiated species assemblages were identified: (1 assemblage MSS (Medium Sand Shallow in medium sand (D50=0.37 mm and shallow waters (mean depth =6.5 m, (2 assemblage CSS (Coarse Sand Shallow in coarse sand (D50=0.62 mm in shallow waters (mean depth =6.7 m, and (3 assemblage CSD (Coarse Sand Deep in coarse sand (D50=0.64 mm in deeper waters (mean depth =16.2 m. Assemblage MSS was characterised by the codominance of the bivalves Mactra stultorum and Acanthocardia tuberculata. C. chione was dominant in both density and biomass in assemblages CSS and CSD. The occurrence of the crab Thia scutellata also characterised assemblage CSS, whereas the occurrence of the sea urchin Echinocardium mediterraneum characterised assemblage CSD. A depth breaking point of around 10 m determined the discontinuity between assemblages CSS and CSD, which was related to the closure depth of the beaches in the study area. Species richness was highest in the coarse sand communities; however, Shannon-Wiener diversity and Pielou equitability indexes were higher in the shallow fine sand community.
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Moral assemblages of volunteer tourism development in Cusco, Peru
Burrai, Elisa.; Mostafanezhad, Mary.; Hannam, Kevin.
2016-01-01
In this paper, we develop a conceptual approach from which to examine the moral landscape of volunteer tourism development in Cusco, Peru. Drawing from recent work on assemblage theory in geography and tourism studies, we explore how assemblage thinking can facilitate new understandings of volunteer tourism development. Using assemblage as an analytical framework allows us to understand volunteer tourism as a series of relational, processual, unequal and mobile practices. These practices, we ...
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Zhao, Yifei; Zou, Xinqing; Gao, Jianhua; Wang, Chenglong; Li, Yali; Yao, Yulong; Zhao, Wancang; Xu, Min
2018-02-01
We examined the source-to-sink sediment transport processes from the Changjiang River to the estuarine coastal shelf area by analyzing the clay mineral assemblages in suspended sediment samples from the Changjiang River catchment and surface samples from the estuarine coastal shelf area following the impoundment of the Three Gorges Dam (TGD) in 2003. The results indicate that the clay mineral compositions throughout the study area are dominated by illite, with less abundant kaolinite and chlorite and scarce smectite. The clay minerals display distinct differences in the tributaries and exhibit obvious changes in the trunk stream compared with the periods before 2003, and the source of sediment has largely shifted to the mid- to lower reaches of the river after 2003. Spatially, the clay mineral assemblages in the estuarine area define two compositionally distinct provinces. Province I covers the mud area of the Changjiang River estuary and the Zhe-Min coastal region, where sediment is primarily supplied by the Changjiang River. Province II includes part of the Changjiang River estuary and the southeastern portion of the study area, where the sediment is composed of terrestrial material from the Changjiang River and re-suspended material from the Huanghe River carried by the Jiangsu coastal current. Moreover, the other smaller rivers in China (including the Oujiang and Minjiang rivers of mainland China and the rivers of West Taiwan) also contribut sediments to the estuarine and inner shelf areas. In general, the clay mineral assemblages in the Changjiang River estuarine area are have mainly been controlled by sediment supplied from upstream of the Changjiang River tributaries. However, since the completion of the TGD in 2003, the mid- to downstream tributaries have become the main source of sediments from the Changjiang catchment into the East China Sea. These analyses further demonstrate that the coastal currents and the decrease in the sediment load of the river
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BurnMan: A lower mantle mineral physics toolkit
Cottaar, Sanne; Heister, Timo; Rose, Ian; Unterborn, Cayman
2014-01-01
We present BurnMan, an open-source mineral physics toolbox to determine elastic properties for specified compositions in the lower mantle by solving an Equation of State (EoS). The toolbox, written in Python, can be used to evaluate seismic velocities of new mineral physics data or geodynamic models, and as the forward model in inversions for mantle composition. The user can define the composition from a list of minerals provided for the lower mantle or easily include their own. BurnMan provides choices in methodology, both for the EoS and for the multiphase averaging scheme. The results can be visually or quantitatively compared to observed seismic models. Example user scripts show how to go through these steps. This paper includes several examples realized with BurnMan: First, we benchmark the computations to check for correctness. Second, we exemplify two pitfalls in EoS modeling: using a different EoS than the one used to derive the mineral physical parameters or using an incorrect averaging scheme. Both pitfalls have led to incorrect conclusions on lower mantle composition and temperature in the literature. We further illustrate that fitting elastic velocities separately or jointly leads to different Mg/Si ratios for the lower mantle. However, we find that, within mineral physical uncertainties, a pyrolitic composition can match PREM very well. Finally, we find that uncertainties on specific input parameters result in a considerable amount of variation in both magnitude and gradient of the seismic velocities. © 2014. American Geophysical Union. All Rights Reserved.
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BurnMan: A lower mantle mineral physics toolkit
Cottaar, Sanne
2014-04-01
We present BurnMan, an open-source mineral physics toolbox to determine elastic properties for specified compositions in the lower mantle by solving an Equation of State (EoS). The toolbox, written in Python, can be used to evaluate seismic velocities of new mineral physics data or geodynamic models, and as the forward model in inversions for mantle composition. The user can define the composition from a list of minerals provided for the lower mantle or easily include their own. BurnMan provides choices in methodology, both for the EoS and for the multiphase averaging scheme. The results can be visually or quantitatively compared to observed seismic models. Example user scripts show how to go through these steps. This paper includes several examples realized with BurnMan: First, we benchmark the computations to check for correctness. Second, we exemplify two pitfalls in EoS modeling: using a different EoS than the one used to derive the mineral physical parameters or using an incorrect averaging scheme. Both pitfalls have led to incorrect conclusions on lower mantle composition and temperature in the literature. We further illustrate that fitting elastic velocities separately or jointly leads to different Mg/Si ratios for the lower mantle. However, we find that, within mineral physical uncertainties, a pyrolitic composition can match PREM very well. Finally, we find that uncertainties on specific input parameters result in a considerable amount of variation in both magnitude and gradient of the seismic velocities. © 2014. American Geophysical Union. All Rights Reserved.
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Khromova, E. A.; Doroshkevich, A. G.; Sharygin, V. V.; Izbrodin, L. A.
2017-12-01
Pyrochlore-group minerals are the main concentrators of niobium in carbonatites of the Belaya Zima alkaline pluton. Fluorcalciopyrochlore, kenopyrochlore and hydropyrochlore were identified in chemical composition. Their main characteristics are given: compositional variation, morphology, and zoning. During evolution from early calcite to late ankerite carbonatites, the UO2, TiO2, REE, and Y contents gradually increased. All carbonatite types are suggested to contain initial fluorcalciopyrochlore. However, in calcite-dolomite and ankerite carbonatites, it is partially or completely hydrated due to hydrothermal processes at the late stage of the pluton. This hydration resulted in the appearance of kenopyrochlore and hydropyrochlore due to removal of Ca, Na and F, and input of Ba, H2O, K, Si, Fe, and probably U and REE. At the last stage of the pluton, this hydrated pyrochlore was replaced by Fe-bearing columbite.
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de Paiva, Carina Kaory Sasahara; de Faria, Ana Paula Justino; Calvão, Lenize Batista; Juen, Leandro
2017-08-01
The production of oil palm is expected to increase in the Amazon region. However, expansion of oil palm plantation leads to significant changes in the physical structure of aquatic ecosystems, mainly through the reduction of riparian vegetation that is essential for aquatic biodiversity. Here, we evaluated the effects of oil palm on the physical habitat structure of Amazonian stream environments and assemblages of Plecoptera and Trichoptera (PT), both found in these streams. We compared streams sampled in oil palm plantations (n = 13) with natural forest areas ("reference" streams, n = 8), located in the eastern Amazon, Brazil. Our results showed that oil palm streams were more likely to be in close proximity to roads, had higher pH values, and higher amounts of fine substrate deposited in the channel than reference streams. Further, these environmental changes had important effects on the aquatic invertebrate assemblages, reducing the abundance and richness of PT. Nevertheless, the genera composition of the assemblages did not differ between reference and oil palm (PERMANOVA, pseudo-F (1,19) = 1.891; p = 0.111). We conclude that oil palm production has clear negative impacts on aquatic environments and PT assemblages in Amazonian streams. We recommend that oil palm producers invest more in planning of road networks to avoid the construction of roads near to the riparian vegetation. This planning can minimize impacts of oil palm production on aquatic systems in the Amazon.
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Energy Technology Data Exchange (ETDEWEB)
Razvigorova, M.; Budinova, T.; Tsyntsarski, B.; Petrova, B. [Bulgarian Academy of Sciences, Institute of Organic Chemistry, 1113 Sofia, Acad. Bonchev Str., bl. 9 (Bulgaria); Ekinci, E. [ISIK University, Kumbaba Mevkii, 34980 Istanbul (Turkey); Atakul, H. [Istanbul Technical University, Department of Chemical Engineering, Maslak, 34469 Istanbul (Turkey)
2008-11-03
In order to obtain more information and to understand the nature of relation between organic and mineral matter in oil shales, the compositions of soluble bitumen fractions obtained by extraction from Bulgarian oil shales before and after demineralization with 10% HCl, concentrated HF, and a HF/HCl mixture were investigated. The four extracts were quantitatively examined by IR and {sup 1}H NMR spectroscopy. The investigation of isolated acidic material of the bitumen fractions showed that the fatty acids are present in bitumen fractions as free acids, esters and salts. The amount of free acids in bitumen is very small. The dominant part of bitumen acids is associated with mineral components of the oil shales as well as part of them is included in the mineral matrix, and can be separated only after deep demineralization. The kerogen of the oil shales, obtained after separation of the bitumen fractions and mineral components, was subjected to saponification in order to determine the amount of acids, bound as esters to the kerogen matrix. The major components found were n-carboxylic, {alpha},{omega}-di-carboxylic, and aromatic acids. The connection of kerogen with mineral components is accomplished by the participation of carboxylic and complicated ester bonds. Experimental data for the composition of bitumen acids give evidence that algae and terrestrial materials are initial sources in the formation of soluble organic matter of Bulgarian oil shale. (author)
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Predicting consumer preferences for mineral composition of bottled and tap water.
Platikanov, Stefan; Hernández, Alejandra; González, Susana; Luis Cortina, Jose; Tauler, Roma; Devesa, Ricard
2017-01-01
The overall liking for taste of water was correlated with the mineral composition of selected bottled and tap waters. Sixty-nine untrained volunteers assessed and rated twenty-five different commercial bottled and tap waters from. Water samples were physicochemical characterised by analysing conductivity, pH, total dissolved solids (TDS) and major anions and cations: HCO 3 - , SO 4 2- , Cl - , NO 3 - , Ca 2+ , Mg 2+ , Na + , and K + . Residual chlorine levels were also analysed in the tap water samples. Globally, volunteers preferred waters rich in calcium bicarbonate and sulfate, rather than in sodium chloride. This study also demonstrated that it was possible to accurately predict the overall liking by a Partial Least Squares regression using either all measured physicochemical parameters or a reduced number of them. These results were in agreement with previously published results using trained panellists. Copyright © 2016 Elsevier B.V. All rights reserved.
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Directory of Open Access Journals (Sweden)
Ignasiak Z
2016-03-01
Full Text Available Zofia Ignasiak,1 Malgorzata Radwan-Oczko,2 Krystyna Rozek-Piechura,3 Marta Cholewa,4 Anna Skrzek,5 Tomasz Ignasiak,6 Teresa Slawinska1 1Department of Biostructure, University School of Physical Education, Wroclaw, Poland; 2Department of Periodontology, Wroclaw Medical University, Wroclaw, Poland; 3Department of Physiotherapy and Occupation Therapy in Internal Diseases, University School of Physical Education, Wroclaw, Poland; 4DENTARAMA Dentistry Center, Walbrzych, Poland; 5Department of Physiotherapy and Ocupation Therapy in Motor-System Dysfunction, University School of Physical Education, Wroclaw, Poland; 6Karkonosze State Higher School in Jelenia Gora, Jelenia Gora, Poland Objective: The relationship between bone mineral density (BMD and tooth loss in conjunction with periodontal disease is not clear. The suggested effects include alteration in bone remodeling rates as well as the multifaceted etiology of edentulism. There is also a question if other body-related variables besides BMD, such as body composition, may be associated with tooth number and general periodontal health. The aim of this study was to evaluate if tooth number and marginal periodontal status are associated with body composition and BMD in a sample of elderly women. Materials and methods: The study involved 91 postmenopausal women. Data included basic anthropometric characteristics, body composition via bioelectrical impedance analysis, and BMD analysis at the distal end of the radial bone of the nondominant arm via peripheral dual-energy X-ray absorptiometry. A dental examination was performed to assess tooth number, periodontal pocket depth (PD, and gingival bleeding. Results: In nonosteoporotic women, a significant positive correlation was found between BMD and lean body mass, total body water, and muscle mass. The indicators of bone metabolism correlated negatively with PD. Such relationships did not appear in osteoporotic women. In both groups, basic anthropometric
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Chaves-Ulloa, Ramsa; Umaña-Villalobos, Gerardo; Springer, Monika
2014-04-01
Despite the fact that little is known about the consequences of hydropower production in tropical areas, many large dams (> 15 m high) are currently under construction or consideration in the tropics. We researched the effects of large hydroelectric dams on aquatic macroinvertebrate assemblages in two Costa Rican rivers. We measured physicochemical characteristics and sampled aquatic macroinvertebrates from March 2003 to March 2004 in two dammed rivers, Peñas Blancas and San Lorenzo, as well as in the undammed Chachagua River. Sites above and below the dam had differences in their physicochemical variables, with wide variation and extreme values in variables measured below the dam in the San Lorenzo River. Sites below the dams had reduced water discharges, velocities, and depths when compared with sites above the dams, as well as higher temperatures and conductivity. Sites above dams were dominated by collector-gatherer-scrapers and habitat groups dominated by swimmer-clingers, while sites below dams had a more even representation of groups. In contrast, a comparison between two sites at different elevation in the undammed river maintained a similar assemblage composition. Tributaries might facilitate macroinvertebrate recovery above the turbine house, but the assemblage below the turbine house resembled the one below the dam. A massive sediment release event from the dam decreased the abundance per sample and macroinvertebrate taxa below the dam in the Peñas Blancas River. Our study illustrates the effects of hydropower production on neotropical rivers, highlighting the importance of using multiple measures of macroinvertebrate assemblage structure for assessing this type of environmental impact.
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Boot, A. M.; Nauta, J.; de Jong, M. C.; Groothoff, J. W.; Lilien, M. R.; van Wijk, J. A.; Kist-van Holthe, J. E.; Hokken-Koelega, A. C.; Pols, H. A.; de Muinck Keizer-Schrama, S. M.
1998-01-01
OBJECTIVE: Osteopenia has been reported in adult patients with chronic renal failure (CRF). Only a few studies have been performed in children. The objective of this study was to evaluate bone mineral density (BMD), bone turnover, body composition in children with CRF and to study the effect of GH
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Mineralization and geochemical studies in the Kalchouyeh occurrence, southwest of Naein
Directory of Open Access Journals (Sweden)
Hengameh Hosseini Dinani
2012-10-01
Full Text Available Kalchouyeh area in southwest of Naein is located in the Urumieh-Dokhtar volcano-plutonic belt. Mineralization occurred mainly as disseminations and veinlets hosted by trachy-andesite and pyroxene andesites. For mineralogy, alteration, fluid inclusion and geochemical studies, the two major mineralized zones: A (larger vein from the north-northwest and B (smaller vein from the east-southeast of the area were sampled. Alteration studies revealed that the main alteration assemblages are silicification and propylitic. The ore minerals are chalcopyrite, galena, pyrite, bornite, chalcocite, covellite, goethite, malachite, azurite, cerussite and cuprite with quartz, calcite and barite as the main gangues. Fluid inclusion studies demonstrated that salinity and homogenization temperatures were 0.38-4.23 and 0.166-9.188 wt% NaCl and 175-252°C and 250-324°C at the A and B veins, respectively. Rare Earth Element (REE plots show negative slopes that is one of the features for calc-alkaline magmas. La/Y is higher than 1 showing that mineralizing fluids were neutral to basic. According to the data, direction of ore-bearing fluids movement was determined to be from east-southeast toward north-northwest (from B to A veins(, approximate site of mineralization center is located adjacent to smaller vein and the mineralization is epithermal in type.
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Esselman, P.C.; Freeman, Mary C.; Pringle, C.M.
2006-01-01
Linkages between geology and fish assemblages have been inferred in many regions throughout the world, but no studies have yet investigated whether fish assemblages differ across geologies in Mesoamerica. The goals of our study were to: 1) compare physicochemical conditions and fish-assemblage structure across 2 geologic types in headwaters of the Monkey River Basin, Belize, and 2) describe basin-scale patterns in fish community composition and structure for the benefit of conservation efforts. We censused headwater-pool fishes by direct observation, and assessed habitat size, structure, and water chemistry to compare habitat and fish richness, diversity, evenness, and density between streams in the variably metamorphosed sedimentary geologic type typical of 80% of Belize's Maya Mountains (the Santa Rosa Group), and an anomalous extrusive geologic formation in the same area (the Bladen Volcanic Member). We also collected species-presence data from 20 sites throughout the basin for analyses of compositional patterns from the headwaters to the top of the estuary. Thirty-nine fish species in 21 families were observed. Poeciliids were numerically dominant, making up 39% of individuals captured, followed by characins (25%), and cichlids (20%). Cichlidae was the most species-rich family (7 spp.), followed by Poeciliidae (6 spp.). Habitat size and water chemistry differed strongly between geologic types, but habitat diversity did not. Major fish-assemblage differences also were not obvious between geologies, despite a marked difference in the presence of the aquatic macrophyte, Marathrum oxycarpum (Podostemaceae), which covered 37% of the stream bottom in high-nutrient streams draining the Santa Rosa Group, and did not occur in the low-P streams draining the Bladen Volcanic Member. Correlation analyses suggested that distance from the sea and amount of cover within pools are important to fish-assemblage structure, but that differing abiotic factors may influence
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Non-destructive identification of micrometer-scale minerals and their position within a bulk sample
DEFF Research Database (Denmark)
Sørensen, Henning O.; Hakim, Sepide S.; Pedersen, Stefan
2012-01-01
. Crushing or disintegrating a sample annihilates any possibility for gathering information from the texture of the porous media or the mineral assemblage close to the grains in question. A new method using three-dimensional X-ray diffraction (3DXRD) microscopy can be successfully applied to natural...... materials. We combined X-ray microtomography (XMT) and 3DXRD to investigate a sample of very fine-grained chalk containing fracture minerals. The XMT technique provides three-dimensional images of the particles and pore structure at very high resolution (350 nm voxel dimension) on samples less than 500 μm......Using the conventional techniques of mineralogy, it has been a challenge to determine mineral identity, crystal orientation and spatial position of micrometer-sized crystals that are embedded in a rock, sediment or soil. Traditionally, the individual grains must be extracted and analyzed separately...
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Directory of Open Access Journals (Sweden)
Liudmila I. Gorjaeva
2017-01-01
Full Text Available Introduction. The results of development of a certified reference material (CRM of mineral composition of natural water are presented. A solution prepared from the material of the CRM specimen imitates mineral composition of natural surface water. The certified values are mass fractions of nitrate ions, chloride ions, fluoride ions, and total iron and turbidity according to formazine scale. Materials and methods. The certified values of mass concentrations of the components were determined using calculated experimental evaluation procedure;the certified turbidity value was determinedusing the certified turbidimetric method. Results. The relative expanded uncertainty (k = 2 of the certified turbidity values does not exceed 5 %, the same value for mass concentrationsis not more than 3.5 %. Relative standard uncertainty from heterogeneity does not exceed 1.0 %. The shelf life of the developed CRM is set to 3 years. Discussion and conclusion. Developed CRM was registered in the State Register of CRM's as GSO 10815-2016. The CRM is designed to control the accuracy of results of the certified characteristics measurements, including proficiency testing of laboratories using interlaboratory comparative tests. The CRM can be used for validation of measurement procedures.
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Directory of Open Access Journals (Sweden)
Polchaninova Nina
2016-12-01
Full Text Available Fire is an important structuring force for grassland ecosystems. Despite increased incidents of fire in European steppes, their impact on arthropod communities is still poorly studied. We assessed short-term changes in cursorial beetle and spider assemblages after a summer fire in the meadow steppe in Central European Russia. The responses of spider and beetle assemblages to the fire event were different. In the first post-fire year, the same beetle species dominated burnt and unburnt plots, the alpha-diversity of beetle assemblages was similar, and there were no pronounced changes in the proportions of trophic groups. Beetle species richness and activity density increased in the second post-fire year, while that of the spiders decreased. The spider alpha-diversity was lowest in the first post-fire year, and the main dominants were pioneer species. In the second year, the differences in spider species composition and activity density diminished. The main conclusion of our study is that the large-scale intensive summer fire caused no profound changes in cursorial beetle and spider assemblages of this steppe plot. Mitigation of the fire effect is explained by the small plot area, its location at the edge of the fire site and the presence of adjacent undisturbed habitats with herbaceous vegetation.
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Mangrove clearing impacts on macrofaunal assemblages and benthic food webs in a tropical estuary.
Bernardino, Angelo Fraga; Gomes, Luiz Eduardo de Oliveira; Hadlich, Heliatrice Louise; Andrades, Ryan; Correa, Lucas Barreto
2018-01-01
Despite over 21,000ha of mangrove forests being removed per year in Brazil, ecological changes following mangrove deforestation have been overlooked. Here we evaluated changes in benthic macrofaunal assemblages and food-webs at a mangrove removal and natural sites in a tropical estuary in Eastern Brazil. The impacted site had coarser sediment particle sizes suggesting significant changes in sedimentation processes after forest clearing. Spatial differences in macrofaunal abundance, biomass and diversity were not directly associated with the removal of mangrove forests, supporting recolonization of impacted areas by estuarine fauna. However, benthic assemblage composition, infaunal δ 13 C signatures and food-web diversity markedly differed at the impacted site being strongly related to sedimentary changes. The loss of infaunal trophic diversity that followed mangrove removal suggests that large-scale forest clearing may impact estuarine food webs, with potential consequences to nearby coastal ecosystems given the high clearing rate of mangrove forests in Brazil. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Bennett, Ashley B; Gratton, Claudio
2013-01-01
Declines in species diversity resulting from anthropogenic alterations of the environment heighten the need to develop management strategies that conserve species and ecosystem services. This study examined how native plant species and their diversity influence the abundance and richness of beneficial arthropods, a functionally important group that provides ecosystem services such as pollination and natural pest suppression. Beneficial arthropods were sampled in replicated study plots containing native perennials planted in one-, two-, and seven-species mixtures. We found plant diversity had a positive impact on arthropod richness but not on arthropod abundance. An analysis of arthropod community composition revealed that each flower species attracted a different assemblage of beneficial arthropods. In addition, the full seven-species mixture also attracted a distinct arthropod community compared to single-species monocultures. Using a multivariate approach, we determined whether arthropod assemblages in two- and seven-species plots were additive and could be predicted based on assemblages from their component single-species plots. On average, assemblages in diverse plots were nonadditive when compared to assemblages predicted using single-species plots. Arthropod assemblages in two-species plots most closely resembled those of only one of the flower species in the mixture. However, the arthropod assemblages in seven-species plots, although statistically deviating from the expectation of an additive model, more closely resembled predicted communities compared to the assemblages found in two-species plots, suggesting that variability in arthropod community composition decreased as planting diversity increased. Our study demonstrates that careful selection of plants in managed landscapes can augment beneficial arthropod richness and support a more predictable arthropod community, suggesting that planning and design efforts could shape arthropod assemblages in natural
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Energy Technology Data Exchange (ETDEWEB)
Wang, TsingHai; Chiang, Chu-Ling; Wang, Chu-Fang [National Tsing Hua Univ., Hsinchu, Taiwan (China). Biomedical Engineering and Environmental Sciences
2015-07-01
Selenium-79 (Se-79) is a radioactive isotope of selenium, which is considered as one of the highly mobile nuclides since Se-79 would be presented in an anion species when dissolving into the intruded groundwater. Being an anionic species, the transport of Se-79 would be regulated by the metal oxides relevant minerals such as goethite and hematite (Jan et al., 2008). This is true that the transport of selenium in the shallow surface environment could be relatively easy to estimate by considering the amount of these metal oxides presenting in the soils and sediments. However, when dealing with deep geological repository, the transport of Se-79 becomes less predictable because of the much less content of metal oxide residing in the host rock such as granite. In order to conduct a reliable performance assessment of repository, it is very important to establish the correlation between selenium adsorption and the properties of potential host rock, in this study, the mineral and chemical compositions of Taiwan local granite. From this point of view, selenium adsorption experiments were conducted with 54 different Taiwan local granite samples collected from the depth ranging from 100 ∝ 400 meters below the surface. These granite samples represent a variety of deep geological environments, including the intact rock, groundwater intruded zones, and some weathered samples. Based upon our preliminary results, several solid conclusions could be made. First, the correlation coefficients between the Kd values and the mineral and chemical compositions are rather low (R-square values are often < 0.2). This points out the complexity of these geological samples and strongly suggests more efforts should be put into to acquire more relevant information. Second, the correlation between the selenium Kd values and the content of iron oxide (R-square 0.110) is much higher than that between the CEC of these granite samples (R-square 0.001). This clearly indicates that the minerals that
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van der Stap, Tim; Coolen, Joop W P; Lindeboom, Han J
2016-01-01
Offshore platforms are known to act as artificial reefs, though there is on-going debate on whether this effect is beneficial or harmful for the life in the surrounding marine environment. Knowing what species exist on and around the offshore platforms and what environmental variables influence this species assemblage is crucial for a better understanding of the impact of offshore platforms on marine life. Information on this is limited for offshore platforms in the southern North Sea. This study aims to fill this gap in our knowledge and to determine how the composition and the abundance of species assemblages changes with depth and along a distance-from-shore gradient. The species assemblages on five offshore gas platforms in the southern North Sea have been inventoried using Remotely Operated Vehicles inspection footage. A total of 30 taxa were identified. A Generalised Additive Model of the species richness showed a significant non-linear relation with water depth (p = 0.001): from a low richness in shallow waters it increases with depth until 15-20 m, after which richness decreases again. Using PERMANOVA, water depth (p≤0.001), community age (p≤0.001) and the interaction between distance from shore and community age (p≤0.001) showed a significant effect on the species assemblages. Future research should focus on the effect additional environmental variables have on the species assemblages.
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Directory of Open Access Journals (Sweden)
Tim van der Stap
Full Text Available Offshore platforms are known to act as artificial reefs, though there is on-going debate on whether this effect is beneficial or harmful for the life in the surrounding marine environment. Knowing what species exist on and around the offshore platforms and what environmental variables influence this species assemblage is crucial for a better understanding of the impact of offshore platforms on marine life. Information on this is limited for offshore platforms in the southern North Sea. This study aims to fill this gap in our knowledge and to determine how the composition and the abundance of species assemblages changes with depth and along a distance-from-shore gradient. The species assemblages on five offshore gas platforms in the southern North Sea have been inventoried using Remotely Operated Vehicles inspection footage. A total of 30 taxa were identified. A Generalised Additive Model of the species richness showed a significant non-linear relation with water depth (p = 0.001: from a low richness in shallow waters it increases with depth until 15-20 m, after which richness decreases again. Using PERMANOVA, water depth (p≤0.001, community age (p≤0.001 and the interaction between distance from shore and community age (p≤0.001 showed a significant effect on the species assemblages. Future research should focus on the effect additional environmental variables have on the species assemblages.
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van der Stap, Tim; Coolen, Joop W. P.; Lindeboom, Han J.
2016-01-01
Offshore platforms are known to act as artificial reefs, though there is on-going debate on whether this effect is beneficial or harmful for the life in the surrounding marine environment. Knowing what species exist on and around the offshore platforms and what environmental variables influence this species assemblage is crucial for a better understanding of the impact of offshore platforms on marine life. Information on this is limited for offshore platforms in the southern North Sea. This study aims to fill this gap in our knowledge and to determine how the composition and the abundance of species assemblages changes with depth and along a distance-from-shore gradient. The species assemblages on five offshore gas platforms in the southern North Sea have been inventoried using Remotely Operated Vehicles inspection footage. A total of 30 taxa were identified. A Generalised Additive Model of the species richness showed a significant non-linear relation with water depth (p = 0.001): from a low richness in shallow waters it increases with depth until 15–20 m, after which richness decreases again. Using PERMANOVA, water depth (p≤0.001), community age (p≤0.001) and the interaction between distance from shore and community age (p≤0.001) showed a significant effect on the species assemblages. Future research should focus on the effect additional environmental variables have on the species assemblages. PMID:26745870
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Determinants of fish assemblage structure in Northwestern Great Plains streams
Mullen, J.A.; Bramblett, R.G.; Guy, C.S.; Zale, A.V.; Roberts, D.W.
2011-01-01
Prairie streams are known for their harsh and stochastic physical conditions, and the fish assemblages therein have been shown to be temporally variable. We assessed the spatial and temporal variation in fish assemblage structure in five intermittent, adventitious northwestern Great Plains streams representing a gradient of watershed areas. Fish assemblages and abiotic conditions varied more spatially than temporally. The most important variables explaining fish assemblage structure were longitudinal position and the proportion of fine substrates. The proportion of fine substrates increased proceeding upstream, approaching 100% in all five streams, and species richness declined upstream with increasing fine substrates. High levels of fine substrate in the upper reaches appeared to limit the distribution of obligate lithophilic fish species to reaches further downstream. Species richness and substrates were similar among all five streams at the lowermost and uppermost sites. However, in the middle reaches, species richness increased, the amount of fine substrate decreased, and connectivity increased as watershed area increased. Season and some dimensions of habitat (including thalweg depth, absolute distance to the main-stem river, and watershed size) were not essential in explaining the variation in fish assemblages. Fish species richness varied more temporally than overall fish assemblage structure did because common species were consistently abundant across seasons, whereas rare species were sometimes absent or perhaps not detected by sampling. The similarity in our results among five streams varying in watershed size and those from other studies supports the generalization that spatial variation exceeds temporal variation in the fish assemblages of prairie and warmwater streams. Furthermore, given longitudinal position, substrate, and stream size, general predictions regarding fish assemblage structure and function in prairie streams are possible. ?? American
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Systèmes multimatériaux – Assemblage par collage Multimaterial systems – Adhesive bonding
Directory of Open Access Journals (Sweden)
Zuanna C. Dalla
2013-11-01
Full Text Available L'assemblage par collage multimatériaux (métal/composite, métal/verre, métal/plastiques, verre/plastiques… offre de nombreux avantages par rapport aux techniques d'assemblages traditionnelles (pas d'affaiblissement des matériaux par la température, tenues en fatigue et à la corrosion améliorées, esthétisme, étanchéité…. Cependant la qualité et la durabilité à long terme des assemblages collés dépendent d'une bonne conception de ces assemblages : Le choix de préparations de surfaces efficaces, robustes, facilement industrialisables et respectueuses de l'environnement, Le choix d'adhésifs aptes à répondre au cahier des charges fonctionnel de l'assemblage (performances mécaniques, thermiques, chimiques… dont la mise en œuvre est compatible avec les contraintes d'industrialisation (cadences, temps de manipulation des pièces, environnement du poste collage…, Le dessin et le dimensionnement de la liaison de façon à transmettre les efforts mécaniques spécifiés dans la plage de températures de fonctionnement des pièces collées (en tenant compte des dilatations différentielles des matériaux assemblés. Cette démarche sera développée en donnant l'état de l'art actuel et les avancées les plus récentes sur les trois thèmes cités ci-dessus. Adhesive-bonding offers many advantages over traditional joining techniques (no weakening of materials by temperature, required fatigue and improved corrosion resistance, aesthetics, sealing… for multimaterial assembly (metal/composite, metal/glass, metal/plastic, glass/plastic…. However the quality and long term durability of bonded assemblies depend on a correct design of the joint: Choice of eco-efficient surfaces preparations, robust, and easily processed, Choice of adhesive in good adequation with the functional specifications of the assembly (mechanical performance, thermal, chemical… whose implementation is compatible with industrialization constraints
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Energy Technology Data Exchange (ETDEWEB)
Gaboreau, St
2005-07-01
Aluminium phosphate sulfate minerals (APS) are particularly widespread and spatially associated with hydrothermal clay alteration in both the East Alligator River Uranium Field (Northern Territory, Australia) and the Athabasca basin (Saskatchewan, Canada), in the environment of proterozoic unconformity-related uranium deposits (URUD). The purpose of this study is both: 1) to characterize the nature and the origin of the APS minerals on both sides of the middle proterozoic unconformity between the overlying sandstones and the underlying metamorphic basement rocks that host the uranium ore bodies, 2) to improve our knowledge on the suitability of these minerals to indicate the paleo-conditions (redox, pH) at which the alteration processes relative to the uranium deposition operated. The APS minerals result from the interaction of oxidising and relatively acidic fluids with aluminous host rocks enriched in monazite. Several APS-bearing clay assemblages and APS crystal-chemistry have also been distinguished as a function of the distance from the uranium ore bodies or from the structural discontinuities which drained the hydrothermal solutions during the mineralisation event. One of the main results of this study is that the index mineral assemblages, used in the recent literature to describe the alteration zones around the uranium ore bodies, can be theoretically predicted by a set of thermodynamic calculations which simulate different steps of fluid-rock interaction processes related to a downward penetrating of hyper-saline, oxidizing and acidic diagenetic fluids through the lower sandstone units of the basins and then into the metamorphic basement rocks. The above considerations and the fact that APS with different crystal-chemical compositions crystallized in a range of fO{sub 2} and pH at which uranium can either be transported in solution or precipitated as uraninite in the host-rocks make these minerals not only good markers of the degree of alteration of the
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Modeling soluble salt assemblages on Mars: past aqueous history and present-day habitability
Toner, J. D.; Catling, D. C.; Light, B.
2014-12-01
Soluble salt assemblages formed through aqueous processes are widespread on Mars. These minerals are important for understanding the past aqueous history of Mars and indicate critical habitability parameters such as pH, temperature, water activity, and salinity. Equilibrium models have been used to determine solution chemistry and salt precipitation sequences from aqueous chemical data; however, current models are limited by a lack of experimental data for low-temperature perchlorates, and some model predictions are clearly anomalous. To address the need for accurate equilibrium models, we have developed a comprehensive model for low-temperature perchlorate-rich brines using (1) previously neglected literature data, (2) experimental solubilities determined in low-temperature perchlorate solutions, and (3) solubility and heat capacity results determined using Differential Scanning Calorimetry (DSC). Our resulting model is a significant improvement over existing models, such as FREZCHEM, particularly for perchlorate mixtures. We have applied our model to evaporation and freezing of a nominal Wet Chemistry Laboratory (WCL) solution measured at the Phoenix site. For a freezing WCL solution, our model indicates that ice, KClO4, hydromagnesite (3MgCO3·Mg(OH)2·3H2O), calcite (CaCO3), meridianiite (MgSO4·11H2O), MgCl2·12H2O, NaClO4·2H2O, and Mg(ClO4)2·6H2O form at the eutectic (209 K); whereas, KClO4, hydromagnesite, kieserite (MgSO4·H2O), anhydrite (CaSO4), halite (NaCl), NaClO4·H2O, and Mg(ClO4)2·6H2O form upon complete evaporation at 298 K. In general, evaporation yields more dehydrated mineral assemblages than salts produced by freezing. Hydrated phases that form during evaporation contain 0.3 wt. % water, which compares with 1.2 wt. % during freezing. Given independent evidence for the presence of calcite and minimum water contents in Martian soils of ~1.5 wt. %, salts at the Phoenix site, and possibly elsewhere, appear more likely to have formed during
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Nestedness and successional trajectories of macroinvertebrate assemblages in man-made wetlands.
Ruhí, Albert; Boix, Dani; Gascón, Stéphanie; Sala, Jordi; Quintana, Xavier D
2013-02-01
Current successional models, primarily those based on floral succession, propose several distinct trajectories based on the integration of two key hypotheses from succession theory: convergence versus divergence in species composition among successional sites, and progression towards versus deviation from a desired reference state. We applied this framework to faunal succession, including differential colonization between active and passive dispersers, and the nested patterns generated as a consequence of this peculiarity. Nine man-made wetlands located in three different areas, from 0-3 years from wetland creation, were assessed. In addition, 91 wetlands distributed throughout the region were used as references for natural macroinvertebrate communities. We predicted the following: (1) highly nested structures in pioneering assemblages will decrease to lower mid-term values due to a shift from active pioneering taxa to passive disperser ones; (2) passive idiosyncratic taxa will elicit divergent successional trajectories among areas; (3) the divergent trajectories will provoke lower local and higher regional diversity values in the mid-term assemblages than in pioneer assemblages. Our results were largely congruent with hypotheses (1) and (2), diverging from the anticipated patterns only in the case of the temporary wetlands area. However, overall diversity trends based on hypothesis (3) did not follow the expected pattern. The divergent successional trajectories did not compensate for regional biodiversity losses that occurred as a consequence of pioneering colonizer decline over time. Consequently, we suggest reconsidering wetland construction for mitigation purposes within mid-term time frames (≤ 3 years). Wetlands may not offset, within this temporal scenario, regional biodiversity loss because the ecosystem may not support idiosyncratic taxa from natural wetlands.
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Razik, S.; Dekkers, M.J.; Von Dobeneck, T.
2014-01-01
Sediment dynamics in limnic, fluvial and marine environments can be assessed by granulometric and rock-magnetic methodologies. While classical grain-size analysis by sieving or settling mainly bears information on composition and transport, the magnetic mineral assemblages reflect to a larger extent
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Impacts of shrimp farming cultivation cycles on macrobenthic assemblages and chemistry of sediments
International Nuclear Information System (INIS)
Ribeiro, Luisa F.; Eça, Gilmara F.; Barros, Francisco; Hatje, Vanessa
2016-01-01
Abstract: The aim of this study was to evaluate the influence of a shrimp farm cultivation cycle in the composition of sediments and on the structure of macrobenthic assemblages. Concentrations of nutrients, Zn and Cu were significantly higher in impact than control areas. In general, the level of contaminants was highest during the harvesting period and in sites closest to the discharge of effluents. Abundances and number of taxa of benthic invertebrates were at least one order of magnitude smaller in impacted areas than in controls. The structure of the benthic assemblages was significantly different at these two treatments. The combined use of biological and chemical data showed to be efficient to provide precise answers regarding the extent of impacts caused by shrimp cultivation. The results provide the basis for a better understanding of impacts of this activity and can subsidize the development of better management practices for coastal areas. - Highlights: • Aquaculture impacts significantly the ecosystems that surround a shrimp farm. • Negative impacts were observed through contamination and benthic macrofauna. • Concentrations of metals and nutrients were higher in impact than control sites. • Negative impacts changed the structure of benthic assemblages. • Regulation is urgently needed to avoid the jeopardizing of ecosystem services. - The combined use of biological and chemical data showed to be efficient to provide precise answers regarding the extent of temporal and spatial impacts caused by shrimp cultivation.
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Directory of Open Access Journals (Sweden)
Youzhi Feng
2017-12-01
Full Text Available Although increasing evidences have emerged for responses of soil microorganisms to fertilizations, the knowledge regarding community assemblages that cause variations in composition is still lacking, as well as the possible feedback to soil fertility. Phylogenetic conservatism of species indicates their similar environmental preferences and/or function traits and phylogenetic signals further can infer community assemblages and influenced ecological processes. Here, we calculated the mean pairwise phylogenetic distance and nearest relative index, characterizing phylogenetic signal and the undergone ecological process to evaluate the community assembly of soil bacterial phylotypes in 20-year fertilized soils. The bacterial community assembly is structured by environmental filtering, regardless of fertilization regime. Soil phosphorous (P availability imposes selection on community assemblage and influences their community turnover among fertilizations. When P nutrient lacks, the effect of environmental filtering becomes stronger, hence bacterial functional traits become more coherent; this process results into increased intraspecific interactions characterized by co-occurrence network analysis. In contrast, when P nutrient becomes abundant, the environmental selection is mitigated; function traits are evened. This process reduces intraspecific interactions and increases carbon sequestration efficiency, which is finally of great favor to the increases in soil fertility. This study has made the first attempt, at the bacterial level, to understand how fertilization affects agroecosystems. When more phylogenetic information on how nutrient cycling-related microbes respond to fertilization becomes available, the systematic knowledge will eventually provide guidance to optimal fertilization strategies.
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Consumer–brand assemblages in advertising
DEFF Research Database (Denmark)
Bjerrisgaard, Sofie Møller; Kjeldgaard, Dannie; Bengtson, Anders
2013-01-01
This paper discusses how the use of tattoos in advertising renders diverse brand–consumer assemblages visible. In considering advertising practitioners as professionals of entanglement, the paper emphasizes the embeddedness of practitioners’ use of tattoo symbolism in institutionalized marketing...... systems and in the cultural history of tattooing. In accordance with recent emphasis on the importance of material devices for understanding contemporary sociality, this paper presents a semiotic analysis of a convenience sample of advertisements depicting tattoos. Tattoos are productive for the study...... potency. This analysis demonstrates how the emergence of brand tattoos in advertising challenges the dominant consumer centrism in consumer research and suggests a networked, emerging understanding of the subject in which agency is distributed in socio-technical assemblages....
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Mizerna, Kamila; Król, Anna; Mróz, Adrian
2017-10-01
This paper undertakes an assessment of the impact of a mineral-organic composite on the environment as well as the potential for its application for land rehabilitation purposes. The analysis involves the release of the leachable contaminations from the material subjected to testing. This material was formed by a composite manufactured on the basis of communal bottom ash and stabilized sewage sludge. The sludge resulting from wastewater treatment was subjected to stabilization and dehydration in waste pounds at the phase of pre-watering until 20% of dry mass is obtained. Subsequently, they were mixed with bottom ash, which was obtained from selective waste collection, in a 1:1 mass ratio. The analysis involved the leaching of inorganic contaminants in the form of heavy metals, sulphates (VI), chlorides, and fluorides as well as organic compounds in the form of organic carbon solution under the effect of leachant with a various level of pH. The analysed components were characterized by various leaching behaviour depending on the leachant pH. On the basis of the results, it was able to assess the potential hazard posed by the examined material on the environment as a consequence of its application for landfill area rehabilitation.
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Directory of Open Access Journals (Sweden)
Mizerna Kamila
2017-01-01
Full Text Available This paper undertakes an assessment of the impact of a mineral-organic composite on the environment as well as the potential for its application for land rehabilitation purposes. The analysis involves the release of the leachable contaminations from the material subjected to testing. This material was formed by a composite manufactured on the basis of communal bottom ash and stabilized sewage sludge. The sludge resulting from wastewater treatment was subjected to stabilization and dehydration in waste pounds at the phase of pre-watering until 20% of dry mass is obtained. Subsequently, they were mixed with bottom ash, which was obtained from selective waste collection, in a 1:1 mass ratio. The analysis involved the leaching of inorganic contaminants in the form of heavy metals, sulphates (VI, chlorides, and fluorides as well as organic compounds in the form of organic carbon solution under the effect of leachant with a various level of pH. The analysed components were characterized by various leaching behaviour depending on the leachant pH. On the basis of the results, it was able to assess the potential hazard posed by the examined material on the environment as a consequence of its application for landfill area rehabilitation.