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Sample records for complex southern patagonian

  1. Complex brittle deformation pattern along the Southern Patagonian Andes (Argentina)

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    Barberón, Vanesa; Sue, Christian; Ronda, Gonzalo; Ghiglione, Matías

    2016-04-01

    The Southern Patagonian Andes is located in the southern extreme of the Pacific subduction zone, where the Antartic oceanic plate sinks underneath South America. The history of the area begins with compression during Paleozoic, Jurassic extension associated to the rift and opening of the South Atlantic Ocean, then a sag stage in the Lower Cretaceous followed by a foreland phase as a result of plate tectonics (Ghiglione et al., 2016). The kinematic study is concentrated in the Argentinean foothills, between 46°40' and 48° SL. We measured around 800 fault planes and their striaes with the sense of movement in order to characterize the stress field. The software used to make the stress inversion were Tensor (Delvaux, 2011) and Multiple Inverse Method MIM (Yamaji et al., 2011). The stress field map was built with the results of the MIM. We present new data from 48 sites located in the northern sector of the Southern Patagonian Andes. The measurements were made in several rocks from Paleozoic to Lower Cretaceous, even though most were taken in pyroclastic jurassic rocks from El Quemado Complex. Paleostress tensors obtained are mostly strike-slip, although a 25% is normal and there are a few compresional. The pattern of faults found is complex. In some sites the tensor can be locally linked to satellite images and observations from the field or be related to a major thrust front. There is no clear correlation between the age and/or lithology with the tensor since the youngest rocks measured are Lower Cretaceous. Probably there are several generations of family faults connected to different and recent tectonic phases then the paleostress tensors might correspond to the latest tectonic events.

  2. Patagonian and southern South Atlantic view of Holocene climate

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    Kaplan, M. R.; Schaefer, J. M.; Strelin, J. A.; Denton, G. H.; Anderson, R. F.; Vandergoes, M. J.; Finkel, R. C.; Schwartz, R.; Travis, S. G.; Garcia, J. L.; Martini, M. A.; Nielsen, S. H. H.

    2016-06-01

    We present a comprehensive 10Be chronology for Holocene moraines in the Lago Argentino basin, on the east side of the South Patagonian Icefield. We focus on three different areas, where prior studies show ample glacier moraine records exist because they were formed by outlet glaciers sensitive to climate change. The 10Be dated records are from the Lago Pearson, Herminita Península-Brazo Upsala, and Lago Frías areas, which span a distance of almost 100 km adjacent to the modern Icefield. New 10Be ages show that expanded glaciers and moraine building events occurred at least at 6120 ± 390 (n = 13), 4450 ± 220 (n = 7), 1450 or 1410 ± 110 (n = 18), 360 ± 30 (n = 5), and 240 ± 20 (n = 8) years ago. Furthermore, other less well-dated glacier expansions of the Upsala Glacier occurred between 1400 and ∼1000 and ∼2300 and ∼2000 years ago. The most extensive glaciers occurred over the interval from ∼6100 to ∼4500 years ago, and their margins over the last ∼600 years were well within and lower than those in the middle Holocene. The 10Be ages agree with 14C-limiting data for the glacier histories in this area. We then link southern South American, adjacent South Atlantic, and other Southern Hemisphere records to elucidate broader regional patterns of climate and their possible causes. In the early Holocene, a far southward position of the westerly winds fostered warmth, small Patagonian glaciers, and reduced sea ice coverage over the South Atlantic. Although we infer a pronounced southward displacement of the westerlies during the early Holocene, these conditions did not occur throughout the southern mid-high latitudes, an important exception being over the southwest Pacific sector. Subsequently, a northward locus and/or expansion of the winds over the Patagonia-South Atlantic sector promoted the largest glaciers between ∼6100 and ∼4500 years ago and greatest sea ice coverage. Over the last few millennia, the South Patagonian Icefield has experienced

  3. Impact of glaciations on the long-term erosion in Southern Patagonian Andes

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    Simon-Labric, Thibaud; Herman, Frederic; Baumgartner, Lukas; Shuster, David L.; Braun, Jean; Reiners, Pete W.; Valla, Pierre G.; Leuthold, Julien

    2014-05-01

    The Southern Patagonian Andes are an ideal setting to study the impact of Late-Cenozoic climate cooling and onset of glaciations impact on the erosional history of mountain belts. The lack of tectonic activity during the last ~12 Myr makes the denudation history mainly controlled by surface processes, not by tectonics. Moreover, the glaciations history of Patagonia shows the best-preserved records within the southern hemisphere (with the exception of Antarctica). Indeed, the dry climate on the leeward side of Patagonia and the presence of lava flows interbedded with glacial deposits has allowed an exceptional preservation of late Cenozoic moraines with precise dating using K-Ar analyses on lava flow. The chronology of moraines reveals a long history covering all the Quaternary, Pliocene, and up to the Upper Miocene. The early growth of large glaciers flowing on eastern foothills started at ~7-6 Myr, while the maximum ice-sheet extent dates from approximately 1.1 Myr. In order to quantify the erosion history of the Southern Patagonian Andes and compare it to the glaciations sediment record, we collected samples along an age-elevation profile for low-temperature thermochronology in the eastern side of the mountain belt (Torres del Paine massif). The (U-Th)/He age-elevation relationship shows a clear convex shape providing an apparent long-term exhumation rate of ~0.2 km/Myr followed by an exhumation rate increase at ~6 Myr. Preliminary results of 4He/3He thermochronometry for a subset of samples complete the erosion history for the Plio-Pleistocene epoch. We used inverse procedure predicting 4He distributions within an apatite grain using a radiation-damage and annealing model to quantify He-diffusion kinetics in apatite. The model also allows quantifying the impact of potential U-Th zonation throughout each apatite crystal. Inversion results reveal a denudation history composed by a pulse of denudation at ~6 Ma, as suggested by the age-elevation relationship

  4. Analysis of Production and Delivery Center Hydrogen Applied to the Southern Patagonian Circuit

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    Maximiliano Fernando Medina

    2016-08-01

    Full Text Available The Desire department of the province of Santa Cruz, Argentina, presents the greatest potential electrolytic Hydrogen Production Country, From Three primary sources of sustainable energy: wind, solar, biomass. There, the Hydrogen Plant of Pico Truncado has capacity central production of hydrogen 100m3 of H2 / day, enough to supply 353 vehicles with hybrid fuel called HGNC, made by cutting 12% V / V of hydrogen in CNG (in situ at each station. Puerto Deseado, Fitz Roy, Caleta Olivia, Las Heras, Comodoro Rivadavia, Sarmiento and the Ancients: From the production cost, the cost of delivering hydrogen to the Southern Patagonian circuit comprised analyzed. Considering various local parameters are determined as a way of delivering more profitable virtual pipeline, with total cost of hydrogen estimated 6.5 USD / kg H2 and HGNC shipped in the station at 0.50 USD / Nm3.

  5. Spatial Models of Abundance and Habitat Preferences of Commerson's and Peale's Dolphin in Southern Patagonian Waters.

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    Dellabianca, Natalia A; Pierce, Graham J; Raya Rey, Andrea; Scioscia, Gabriela; Miller, David L; Torres, Mónica A; Paso Viola, M Natalia; Goodall, R Natalie P; Schiavini, Adrián C M

    2016-01-01

    Commerson's dolphins (Cephalorhynchus c. commersonii) and Peale's dolphins (Lagenorhynchus australis) are two of the most common species of cetaceans in the coastal waters of southwest South Atlantic Ocean. Both species are listed as Data Deficient by the IUCN, mainly due to the lack of information about population sizes and trends. The goal of this study was to build spatially explicit models for the abundance of both species in relation to environmental variables using data collected during eight scientific cruises along the Patagonian shelf. Spatial models were constructed using generalized additive models. In total, 88 schools (212 individuals) of Commerson's dolphin and 134 schools (465 individuals) of Peale's dolphin were recorded in 8,535 km surveyed. Commerson's dolphin was found less than 60 km from shore; whereas Peale's dolphins occurred over a wider range of distances from the coast, the number of animals sighted usually being larger near or far from the coast. Fitted models indicate overall abundances of approximately 22,000 Commerson's dolphins and 20,000 Peale's dolphins in the total area studied. This work provides the first large-scale abundance estimate for Peale's dolphin in the Atlantic Ocean and an update of population size for Commerson's dolphin. Additionally, our results contribute to baseline data on suitable habitat conditions for both species in southern Patagonia, which is essential for the implementation of adequate conservation measures.

  6. Spatial Models of Abundance and Habitat Preferences of Commerson's and Peale's Dolphin in Southern Patagonian Waters.

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    Natalia A Dellabianca

    Full Text Available Commerson's dolphins (Cephalorhynchus c. commersonii and Peale's dolphins (Lagenorhynchus australis are two of the most common species of cetaceans in the coastal waters of southwest South Atlantic Ocean. Both species are listed as Data Deficient by the IUCN, mainly due to the lack of information about population sizes and trends. The goal of this study was to build spatially explicit models for the abundance of both species in relation to environmental variables using data collected during eight scientific cruises along the Patagonian shelf. Spatial models were constructed using generalized additive models. In total, 88 schools (212 individuals of Commerson's dolphin and 134 schools (465 individuals of Peale's dolphin were recorded in 8,535 km surveyed. Commerson's dolphin was found less than 60 km from shore; whereas Peale's dolphins occurred over a wider range of distances from the coast, the number of animals sighted usually being larger near or far from the coast. Fitted models indicate overall abundances of approximately 22,000 Commerson's dolphins and 20,000 Peale's dolphins in the total area studied. This work provides the first large-scale abundance estimate for Peale's dolphin in the Atlantic Ocean and an update of population size for Commerson's dolphin. Additionally, our results contribute to baseline data on suitable habitat conditions for both species in southern Patagonia, which is essential for the implementation of adequate conservation measures.

  7. Alkaline lavas from southern Mendoza, Argentina, extend the Patagonian DUPAL mantle field to the north

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    Soager, N.; Holm, P. M.; Llambias, E.

    2010-12-01

    The lavas sampled around Río Colorado ~37°S at the border of Mendoza and Neuquén provinces, Argentina, define an OIB-like end-member composition for the Pleistocene and Holocene activity in the Payún Matrú volcanic field. Although positioned in the far back-arc of the Andes, only a few lavas show signs of involvement of slab fluids or crustal contamination such as relatively high LILEs relative to Nb. The very low La/Nb (~0.66) and Zr/Nb (~5) and high U/Pb (0.3-0.4) of the end-member composition clearly distinguish the source from normal MORB mantle, while high Ba/Nb (~10) and K/Nb (370-400) compared to FOZO and HIMU type OIBs suggest an EM type of mantle. Overall, the trace element patterns of the Río Colorado lavas are similar to the central and north Patagonian intraplate basalts and to South Atlantic E-MORB affected by the Discovery plume and the LOMU component (le Roux et al., 2002, EPSL 203). The isotopic composition of the Río Colorado component has a 206Pb/204Pb = 18.4, 207Pb/204Pb = 15.58, 208Pb/204Pb = 38.3, 87Sr/86Sr = 0.70353 and 143Nd/144Nd = 0.51285. This composition overlaps the central and north Patagonian intraplate basalts in Pb-isotopic space but is slightly less enriched in Sr and Nd-isotopes. It is distinctly different from the FOZO like composition of the south Patagonian intraplate basalts and the nearby Juan Fernandéz plume but similar to the South Atlantic N-MORB and MORB from the southern Chile Ridge segment 4 (Sturm et al., 1999, JGR 104) described as DUPAL type. The DUPAL-MORB type isotopic composition and the plume-like trace element patterns of the Río Colorado lavas suggest the presence of a weak plume beneath the area. The eruption of the large Payún Matrú volcano and the gigantic Pleistocene flood basalts also calls for a thermal anomaly to produce these melts during a weakly compressive tectonic regime with no significant addition of slab fluids. This was supported by Burd et al. (2008, Abstr., 7th Int. Sym. And. Geo

  8. Structural control on arc volcanism: The Caviahue Copahue complex, Central to Patagonian Andes transition (38°S)

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    Melnick, Daniel; Folguera, Andrés; Ramos, Victor A.

    2006-11-01

    This paper describes the volcanostratigraphy, structure, and tectonic implications of an arc volcanic complex in an oblique subduction setting: the Caviahue caldera Copahue volcano (CAC) of the Andean margin. The CAC is located in a first-order morphotectonic transitional zone, between the low and narrow Patagonian and the high and broad Central Andes. The evolution of the CAC started at approximately 4-3 Ma with the opening of the 20 × 15 km Caviahue pull-apart caldera; Las Mellizas volcano formed inside the caldera and collapsed at approximately 2.6 Ma; and the Copahue volcano evolved in three stages: (1) 1.2-0.7 Ma formed the approximately 1 km thick andesitic edifice, (2) 0.7-0.01 Ma erupted andesitic-dacitic subglacial pillow lavas, and (3) 0.01-0 Ma erupted basaltic-andesites and pyroclastic flows from fissures, aligned cones, and summit craters. Magma ascent has occurred along planes perpendicular to the least principal horizontal stress, whereas hydrothermal activity and hot springs also occur along parallel planes. At a regional scale, Quaternary volcanism concentrates along the NE-trending, 90 km long Callaqui-Copahue-Mandolegüe lineament, the longest of the southern volcanic zone, which is here interpreted as an inherited crustal-scale transfer zone from a Miocene rift basin. At a local scale within the CAC, effusions are controlled by local structures that formed at the intersection of regional fault systems. The Central to Patagonian Andes transition occurs at the Callaqui-Copahue-Mandolegüe lineament, which decouples active deformation from the intra-arc strike-slip Liquiñe-Ofqui fault zone to the south and the backarc Copahue-Antiñir thrust system.

  9. Spatial Models of Abundance and Habitat Preferences of Commerson’s and Peale’s Dolphin in Southern Patagonian Waters

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    Dellabianca, Natalia A.; Pierce, Graham J.; Raya Rey, Andrea; Scioscia, Gabriela; Miller, David L.; Torres, Mónica A.; Paso Viola, M. Natalia; Schiavini, Adrián C. M.

    2016-01-01

    Commerson’s dolphins (Cephalorhynchus c. commersonii) and Peale’s dolphins (Lagenorhynchus australis) are two of the most common species of cetaceans in the coastal waters of southwest South Atlantic Ocean. Both species are listed as Data Deficient by the IUCN, mainly due to the lack of information about population sizes and trends. The goal of this study was to build spatially explicit models for the abundance of both species in relation to environmental variables using data collected during eight scientific cruises along the Patagonian shelf. Spatial models were constructed using generalized additive models. In total, 88 schools (212 individuals) of Commerson’s dolphin and 134 schools (465 individuals) of Peale’s dolphin were recorded in 8,535 km surveyed. Commerson’s dolphin was found less than 60 km from shore; whereas Peale’s dolphins occurred over a wider range of distances from the coast, the number of animals sighted usually being larger near or far from the coast. Fitted models indicate overall abundances of approximately 22,000 Commerson’s dolphins and 20,000 Peale’s dolphins in the total area studied. This work provides the first large-scale abundance estimate for Peale’s dolphin in the Atlantic Ocean and an update of population size for Commerson’s dolphin. Additionally, our results contribute to baseline data on suitable habitat conditions for both species in southern Patagonia, which is essential for the implementation of adequate conservation measures. PMID:27783627

  10. Transcriptome survey of Patagonian southern beech Nothofagus nervosa (= N. Alpina: assembly, annotation and molecular marker discovery

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    Torales Susana L

    2012-07-01

    Full Text Available Abstract Background Nothofagus nervosa is one of the most emblematic native tree species of Patagonian temperate forests. Here, the shotgun RNA-sequencing (RNA-Seq of the transcriptome of N. nervosa, including de novo assembly, functional annotation, and in silico discovery of potential molecular markers to support population and associations genetic studies, are described. Results Pyrosequencing of a young leaf cDNA library generated a total of 111,814 high quality reads, with an average length of 447 bp. De novo assembly using Newbler resulted into 3,005 tentative isotigs (including alternative transcripts. The non-assembled sequences (singletons were clustered with CD-HIT-454 to identify natural and artificial duplicates from pyrosequencing reads, leading to 21,881 unique singletons. 15,497 out of 24,886 non-redundant sequences or unigenes, were successfully annotated against a plant protein database. A substantial number of simple sequence repeat markers (SSRs were discovered in the assembled and annotated sequences. More than 40% of the SSR sequences were inside ORF sequences. To confirm the validity of these predicted markers, a subset of 73 SSRs selected through functional annotation evidences were successfully amplified from six seedlings DNA samples, being 14 polymorphic. Conclusions This paper is the first report that shows a highly precise representation of the mRNAs diversity present in young leaves of a native South American tree, N. nervosa, as well as its in silico deduced putative functionality. The reported Nothofagus transcriptome sequences represent a unique resource for genetic studies and provide a tool to discover genes of interest and genetic markers that will greatly aid questions involving evolution, ecology, and conservation using genetic and genomic approaches in the genus.

  11. Phylogeography of the Patagonian otter Lontra provocax: adaptive divergence to marine habitat or signature of southern glacial refugia?

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    Chehébar Claudio

    2011-02-01

    Full Text Available Abstract Background A number of studies have described the extension of ice cover in western Patagonia during the Last Glacial Maximum, providing evidence of a complete cover of terrestrial habitat from 41°S to 56°S and two main refugia, one in south-eastern Tierra del Fuego and the other north of the Chiloé Island. However, recent evidence of high genetic diversity in Patagonian river species suggests the existence of aquatic refugia in this region. Here, we further test this hypothesis based on phylogeographic inferences from a semi-aquatic species that is a top predator of river and marine fauna, the huillín or Southern river otter (Lontra provocax. Results We examined mtDNA sequences of the control region, ND5 and Cytochrome-b (2151 bp in total in 75 samples of L. provocax from 21 locations in river and marine habitats. Phylogenetic analysis illustrates two main divergent clades for L. provocax in continental freshwater habitat. A highly diverse clade was represented by haplotypes from the marine habitat of the Southern Fjords and Channels (SFC region (43°38' to 53°08'S, whereas only one of these haplotypes was paraphyletic and associated with northern river haplotypes. Conclusions Our data support the hypothesis of the persistence of L. provocax in western Patagonia, south of the ice sheet limit, during last glacial maximum (41°S latitude. This limit also corresponds to a strong environmental change, which might have spurred L. provocax differentiation between the two environments.

  12. Influence of oceanographic features on the spatial and seasonal patterns of mesozooplankton in the southern Patagonian shelf (Argentina, SW Atlantic)

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    Sabatini, M. E.; Reta, R.; Lutz, V. A.; Segura, V.; Daponte, C.

    2016-05-01

    Surveys conducted during spring, summer and late winter in 2005-2006 over the southern Patagonian shelf have allowed the seasonal distribution of mesozooplankton communities in relation to water masses and circulation to be investigated. In this system, most of the shelf is dominated by a distinct low salinity plume that is related to the runoff from the Magellan Strait (MSW), while the outer shelf is highly influenced by the cold and salty Subantarctic water (SAW) of the boundary Malvinas Current. Separating these two, the Subantarctic Shelf water mass (SASW) extends over the middle shelf. Correspondingly, the structure of the MSW and SAW mesozooplankton communities was found to be clearly different, while the former and the SASW assemblages were barely separable. This relatively fresh water mass is actually a variant of Subantarctic water that enters into the region from the south and the shelf-break, and hence its mesozooplankton community was not significantly different from that of the SAW water mass. Dissimilar species abundance, in turn associated with different life histories and population development, was more important than species composition in defining the assemblages. Total mesozooplankton abundance increased about 2.5-fold from the beginning of spring to late summer, and then decreased at least two orders of magnitude in winter. Across all seasons copepods represented > 70-80% of total mesozooplankton over most of the shelf. Copepod species best represented through all seasons, in terms of both relative abundance and occurrence, were Drepanopus forcipatus and Oithona helgolandica. Although seasonal differences in abundance were striking, the spatial distribution of mesozooplankton was largely similar across seasons, with relatively higher concentrations occurring mainly in Grande Bay and surroundings. The well defined spatial patterns of mesozooplankton that appear from our results in conjunction with the southward wide extension of the shelf and

  13. Trophic interference by Salmo trutta on Aplochiton zebra and Aplochiton taeniatus in southern Patagonian lakes.

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    Elgueta, A; González, J; Ruzzante, D E; Walde, S J; Habit, E

    2013-02-01

    The length and mass ratio, diet and isotopic composition of Aplochiton zebra and Aplochiton taeniatus inhabiting a Salmo trutta-invaded and a S. trutta-free lake in southern Patagonia were compared. Results indicate that S. trutta exercises important trophic interference over A. zebra and A. taeniatus, causing changes in their dietary composition by reducing the consumption of winged Diptera through changes in feeding behaviours that involve jumping out of the water. This effect is significantly higher in A. zebra than in A. taeniatus a species that has a highly specialized diet. The dietary changes of A. zebra and A. taeniatus in sympatry with S. trutta lead to an impoverishment of their isotopic nitrogen signals (δ(15)N), suggesting a reduction of their trophic position. In the case of A. zebra, this translates into a significant decrease in its body condition factor. Such interference could lead to a population decline of this species and would explain the current distribution range decline and allopatry with S. trutta in fluvial systems. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  14. Late cenozoic tectonic and geomorphic evolution of the Patagonian Andes between 42oS and 52oS, southern Chile assessed using fission-track thermochronology

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    Thomson, S.N; Herve, F; Stockhert, B.; Brix, M.R.; Adriasola, A

    2001-01-01

    Fission-track (FT) analysis has been applied in the Patagonian Andes of southern Chile to assess the late Cenozoic geomorphic and tectonic response of the overriding plate to subduction of the Chile rise active oceanic spreading centre (Thomson et al., 2001). The timing and nature of tectonic uplift and denudation along the southern parts of the major transpression intra-arc Liquine-Ofqui fault (LOF) system have also been investigated (Thomson, 2001, submitted). Results from 130 FT ages (72 zircon and 58 apatite ages) and 39 apatite track length measurements reveal initiation of rapid cooling and denudation at ca. 30 Ma at the western margin of southern continental South America. This was followed by a ca. 200km eastward migration of the locus of maximum denudation to the position of the present day topographic divide between ca. 30 Ma and ca. 12 to 10 Ma. East of the Andean divide less than 3 km of denudation has occurred since the Late Cretaceous. Enhanced denudation is interpreted to be the result of increased tectonic uplift driven by a large increase in convergence rates at ca. 28 to 26 Ma that triggered orographically enhanced precipitation on the west-side of the Patagonian Andes allowing increased erosion by fluvial incision and mass transport processes. The eastward migration of the locus of maximum denudation can be related to either coeval eastward migration of the retro-arc deformation front, the effects of subduction erosion in the overriding plate at the Peru-Chile trench or shallowing of the angle of subduction. Away from the influence of the LOF the process of spreading centre subduction and collision itself coincides with an overall slow-down in denudation rates in the overriding plate most likely caused by a major reduction in the main tectonic force driving tectonic uplift in the upper plate to subduction. In contrast to the Andes south of ca. 46 o S, increased cooling and denudation related to transpression induced rock uplift and erosion along

  15. First report on the contribution of small-sized species to the copepod community structure of the southern Patagonian shelf (Argentina, 47-55°S

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    Julieta Carolina Antacli

    2014-03-01

    Full Text Available The copepod community structure, with special emphasis on small-sized species, was studied over the southern Patagonian shelf in late summer 2004, applying the first plankton sampling in the region with a fine-mesh (66 μm net. The key role of the copepods Drepanopus forcipatus and Calanus australis was confirmed, but also the high abundance and frequency of occurrence of the microcopepods Oithona helgolandica and Microsetella norvegica and of the medium-sized copepod Ctenocalanus vanus were revealed. Copepod community structure was nearly homogenous over the entire study area. Drepanopus forcipatus, O. helgolandica and M. norvegica were identified as the typical species of the region, although secondarily C. australis and Oithona atlantica also contributed significantly to community similarity across the area. The study of interspecific relationships of dominant copepods indicated that D. forcipatus and C. australis were associated positively with O. helgolandica, while C. vanus, and M. norvegica constituted a separate assemblage with Clausocalanus brevipes and O. atlantica. The importance of fine-mesh-size nets for collecting the smaller size fractions of mesozooplankton and for accurately portraying the mesozooplankton assemblage structure in the area is stressed by this study.

  16. Use of AFLP and RAPD molecular genetic markers and cytogenetic analysis to explore relationships among taxa of the Patagonian Bromus setifolius complex

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    Ana M. García

    2009-01-01

    Full Text Available Bromus setifolius var. pictus (Hook Skottsb., B. setifolius var. setifolius Presl. and B. setifolius var. brevifolius Ness are three native Patagonian taxa in the section Pnigma Dumort of the genus Bromus L. AFLP and RAPD analysis, in conjunction with genetic distance measurements and statistical techniques, revealed variation within this group and indicated that B. setifolius var. brevifolius was closely related to B. setifolius var. pictus, with both taxa being more distantly related to B. setifolius var. setifolius. Cytogenetic analysis confirmed the chromosomal number of B. setifolius var. pictus (2n = 70 and B. setifolius var. setifolius (2n = 28 and showed for the first time that B. setifolius var. brevifolius had 2n = 70. The combination of molecular genetic and cytogenetic evidence supported a species status for two of the three taxa and suggested hypotheses for the evolutionary origin of these complex taxa. Species status was also indicated for B. setifolius var. setifolius. Based on these findings, we suggest that B. setifolius var. pictus be referred to as B. pictus Hook var. pictus, and B. setifolius var brevifolius as B. pictus Hook var brevifolius. The correlation between AFLP diversity and variation in ecological parameters suggested that this marker system could be used to assess breeding progress and to monitor the domestication of Patagonian Bromus species for agronomic use.

  17. Soil water availability and rooting depth as determinants of hydraulic architecture of Patagonian woody species

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    Sandra J. Bucci; Fabian G. Scholz; Guillermo Goldstein; Frederick C. Meinzer; Maria E. Arce

    2009-01-01

    We studied the water economy of nine woody species differing in rooting depth in a Patagonian shrub steppe from southern Argentina to understand how soil water availability and rooting depth determine their hydraulic architecture. Soil water content and potentials, leaf water potentials (Leaf) hydraulic conductivity, wood density (Pw), rooting depth, and specific leaf...

  18. The endemic Patagonian vespertilionid assemblage is a depauperate ecomorphological vicariant of species-rich neotropical assemblages

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    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.

  19. Spring northward juvenile migration of the Patagonian grenadier (Macruronus magellanicus from the Northwest Patagonian waters of Chile

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    Luis A Cubillos

    2015-11-01

    Full Text Available Important nursery grounds for Patagonian grenadier (Macruronus magellanicus are located mainly in the Northwest Patagonian Inner Sea (42ºS-44ºS, from which juvenile must to disperse or migrate offshore, then along the Chilean coast either northward or southward. The objective of this paper was to estimate northward spring juvenile migration of the Patagonian grenadier from nursery to feeding areas, which are located near Talcahuano (35º00’S-37º10’S. Length-frequency data (LFD were obtained from an acoustic survey carried out in November 1999, which covered from 35ºS to 47ºS. Generalized linear model was used to describe the presence of juvenile per latitude and depth, and to infer the origin and displacement of juveniles. Subsequently, LFD data were grouped according to latitudinal strata. Grouped LFD were decomposed into normal component groups, from which mean, standard deviation and proportion were estimated from the mixed LFD. The average length of the identified groups were sorted from south to north, and linked to compute significant increment in fish length and age per kilometers. The length increment per time was not due to growth, rather they was due to spatial displacement of juvenile from southern nursery grounds to northern feeding areas. Although homing to feeding areas and/or high residency (partial migration have been postulated, it seems that recruitment of juveniles to northern feeding areas are origintaed from NPIS nurseries. The West Wind Drift Current seems to be the main drive for dispersion of Patagonian grenadier to recruit northward in open waters along the continental shelf.

  20. Modelling spatial distribution of Patagonian toothfish through life-stages and sex and its implications for the fishery on the Kerguelen Plateau

    Science.gov (United States)

    Péron, Clara; Welsford, Dirk C.; Ziegler, Philippe; Lamb, Timothy D.; Gasco, Nicolas; Chazeau, Charlotte; Sinègre, Romain; Duhamel, Guy

    2016-02-01

    Size and sex specific habitat preferences are common in animal populations and can have important implications for sound spatial management of harvested species. Patagonian toothfish (Dissostichus eleginoides) is a commercially exploited fish species characterised by its longevity (>50 yo) and its extremely broad distribution in depths ranging from 10 m to 2500 m on most of the Plateaux, banks and seamounts of the Southern Ocean. As many bentho-pelagic fish species, Patagonian toothfish exhibits sexual dimorphism and ontogenetic habitat shift towards deeper waters as they grow. In this study, we modelled the spatial structure of Patagonian toothfish population (median total length and sex composition) in a data-rich area, the Kerguelen Plateau (Southern Indian Ocean), to better understand the ecological drivers of their distributional patterns and inform current and future fishery management strategies. We applied spatially-explicit statistical models to quantify and predict the effects of the complex topography of the Kerguelen Plateau in structuring the spatial distribution of Patagonian toothfish total length and sex ratio, while controlling for gear selectivity and season. Model predictions showed that juvenile toothfish live in shallow regions (shelf and banks) and move downward progressively up to 600 m while they grow. Between 600 m and 1200 m, the downward movement stops and fish settle at their preferred depths. While in this depth range, fish are ∼75 cm long and most vulnerable to fisheries. As they approach maturity large fish move downward to deep-sea habitats (from 1200 m to >2300 m) and head towards the spawning grounds on the western side of the plateau and around Skiff Bank. Importantly, the sex ratio was not evenly distributed across the Plateau; prediction maps revealed a higher proportion of females in the South whereas a strong male-bias sex ratio (70%) occurred in the North-West. Large-scale prediction maps derived from our models assisted in

  1. Synoptic events force biological productivity in Patagonian fjord ecosystems

    Science.gov (United States)

    Daneri, Giovanni

    2016-04-01

    The annual cycle of primary productivity of the Patagonian fjords has, to date, been described as a two phase system consisting of a short non productive winter phase (during June and July) and a productive phase extending from late winter (August) to autumn (May). Low levels of primary production, phytoplankton biomass and high concentrations of surface nutrients have been described as characterizing winter conditions while pulsed productivity events typifies the productivity pattern during the extended productive season. Pulsed productivity events characterize coastal waters where inorganic nutrients in surface layers are replenished following periods of intensive utilization by autotrophs. Freshwater input in Patagonian fjords in southern Chile (41-55°S) results in one of the largest estuarine regions worldwide. Here strong haline water column stratification prevents nutrient mixing to the surface layers thus potentially shutting off algal production. Our working hypothesis considered that in order to reconcile the observed pulsed productivity pattern, periodic breaking (associated to surface nutrient replenishment) and re-establishment of estuarine conditions (associated to water column stratification) would be required. Up to now however our understanding of the physical processes that control water column conditions in the Patagonian fjord area has been extremely limited. Here we present evidence linking the passage of synoptic low pressure fronts to pulsed productivity events in the Patagonian fjord area. These front controls and influence local processes of interaction between the fjord and the atmosphere generating a rapid water column response. In the specific case of the Puyuhuapi fjord we have been able to show that such synoptic fronts induce surface flow reversal and water column mixing. Phytoplankton blooming occurs after the passage of the synoptic front once calmer conditions prevail and estuarine conditions are re established. The occurrence of

  2. Kinematics of the southern Rhodope Core Complex (North Greece).

    NARCIS (Netherlands)

    Brun, J.P.; Sokoutis, D.

    2007-01-01

    The Southern Rhodope Core Complex is a wide metamorphic dome exhumed in the northern Aegean as a result of large-scale extension from mid-Eocene to mid-Miocene times. Its roughly triangular shape is bordered on the SW by the Jurassic and Cretaceous metamorphic units of the Serbo-Macedonian in the

  3. The Patagonian Orocline: Paleomagnetic evidence of a large counter-clockwise rotation during the closure of the Rocas Verdes basin.

    Science.gov (United States)

    Poblete, Fernando; Roperch, Pierrick; Herve, Francisco; Ramirez, Cristobal; Arriagada, Cesar

    2014-05-01

    The southernmost Andes of Patagonia and Tierra del Fuego present a prominent arc-shaped structure, the Patagonian Orocline. Despite the fact that this major structure was already described by Alfred Wegener in his famous textbook in 1929, few paleomagnetic studies have been attempted to describe the rotations associated with the formation of the Patagonian Orocline. In this study we present a paleomagnetic and anisotropy of magnetic susceptibility (AMS) study from more than 130 sites obtained from the Ultima Esperanza region (NS structures at ~51°S) to Península Hardy, south of the Beagle Channel at ~55°S. 45 sites were sampled in early-cretaceous gabbros (gabbro complex), mid-cretaceous tonalites and granodiorites (Canal Beagle group) and Paleocene intrusive rocks (Seno Año Nuevo group) from the South Patagonian batholith, 4 sites from the late Jurassic Hardy formation, a volcanic succession outcropping in Hardy Peninsula and Stewart Island, 9 sites were drilled in the lower cretaceous sedimentary infill of the Rocas Verdes Basin, 3 sites from the Tortuga ophiolite, a quasi-oceanic crust related to the opening of the Rocas Verdes basin. 80 sites were sampled in Cretaceous to Miocene sedimentary rocks from the Magallanes fold and thrust belt and Magallanes Basin. Characteristic Remanent Magnetizations (ChRMs) obtained from the Rocas Verdes Basin tectonic province correspond to secondary magnetizations postdating the early phase of folding. Pyrrhotite is the main magnetic carrier in some of these sites. ChRMs from the South Patagonian Batholith correspond to a primary magnetization. These rocks record about 90° counterclockwise rotations south of the Beagle channel. Few sites from sediments of the Magallanes fold and thrust belt have stable ChRM. The available paleomagnetic results show that no rotation has occurred in the Provincia of Ultima Esperanza (51.5°S), at least, for the last 60 Ma. In the southern part of Provincia de Magallanes and Tierra del Fuego

  4. Cambios latitudinales en la pesquería pelágica de merluza de cola (Macruronus magellanicus de la zona centro-sur (1986-2003 Latitudinal changes in the Patagonian grenadier (Macruronus magellanicus pelagic fishery off central-southern Chile (1986-2003

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    Luis A Cubillos

    2009-01-01

    Full Text Available Se analizaron los cambios espacio-temporales de las capturas de merluza de cola obtenidas por la flota industrial de cerco en la zona centro-sur de Chile (34°-41°30'S, para revisar la hipótesis de migración hacia el norte de la fracción juvenil de merluza de cola en primavera. Se utilizaron datos de bitácoras de pesca del periodo 1986-2003, y a partir de éstos se calcularon centros de gravedad de las capturas y su varianza. Se postula que si la flota sigue el comportamiento migratorio de la fracción juvenil, se esperaría que los centros de gravedad de las capturas migren latitudinalmente de sur a norte conforme la estación de pesca avanza. No obstante, sólo se encontró cuatro casos en que ocurrió una migración hacia el norte de los centroides. Más bien, los centros de gravedad se presentan estacionarios, al interior de cada temporada de pesca. Se postula que existe una fracción juvenil residente que sólo incrementa su accesibilidad y vulnerabilidad en aguas superficiales en primavera debido al régimen ambiental, que se caracteriza por la dominancia de eventos de surgencia y no a una migración de sur a norte.We analyzed spatio-temporal changes in Patagonian grenadier catches by the purse-seine fleet off central-southern Chile (34°-41°30'S in order to check the hypothesis that the juvenile fraction of the population migrates northward in spring. Log-book data from 1986 to 2003 were used to calculate the center of gravity of and variance of each catch. We proposed that, if the fleet follows the migratory behavior of the juvenile fraction, the centers of gravity of the catches will migrate from south to north as the fishing season progresses. Nevertheless, the centers of gravity migrated northward in only four cases. Unexpectedly, the centers of gravity remained stationary within each fishing season. Now we propose that, in spring, a resident juvenile fraction of Patagonian grenadier increases its accessibility and vulnerability

  5. Effects of Patagonian pine forestry on native breeding birds

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    Moises Pescador

    2014-12-01

    Full Text Available Aim of the study: The objective is to assess the influences of the tree stand age and other forestry management practices on species richness, composition, and distribution of the Patagonian pine plantation bird assemblages. Area of Study: The work was carried out in forested plots of Ponderosa pine located at the Lanín National Park (Patagonia, Argentina.Material and Methods: Birds were sampled using 25 m fixed radius point counts, at four plots varying in age, management, and forest structure. Main Results: A total of 2090 individuals belonging to 34 bird species were observed, their numbers vary significantly depending on the different modes of plantation management. The population density of the 14 most abundant bird species was compared among the four plantation plots and ten species don’t show statistically significant differences in their population density among the different forest plots. The California Quail, the White-Crested Elaenia and the Southern House Wren showed higher densities in pine plantations with lower tree densities and fewer cutting treatments. The Diuca Finch had high densities in the younger plantations not subjected to any treatment. Research highlights: Most of these bird species are opportunistic and a few are found more regularly in these non-native woods than in other native forested or afforested areas. Our data suggest that a mixed scenario based on a mosaic of plantation with patches of native deciduous forest may help maximize the bird diversity in the management of northwestern Patagonian plantation landscapes.Keywords: Bird population; diversity; exotic plantations; Patagonia; tree-age.

  6. How fast is the Patagonian shelf-break acidifying?

    Science.gov (United States)

    Orselli, Iole B. M.; Kerr, Rodrigo; Ito, Rosane G.; Tavano, Virginia M.; Mendes, Carlos Rafael B.; Garcia, Carlos A. E.

    2018-02-01

    Anthropogenic carbon (Cant) concentration is determined according to the TrOCA method, from carbonate system data and hydrographic parameters collected during two consecutive spring cruises (2007 and 2008) in the Argentinean Patagonian shelf-break zone between 36°S and 50°S. Cant has intruded the water column until intermediate depths, with no Cant below 1000 m, in the deeper waters (i.e., North Atlantic Deep Water and Antarctic Bottom Water) of the Northern sector of the study area (i.e., North of 38°S). The higher Cant concentration is observed in Subantarctic Shelf Water in the Southern region, whereas in the Northern sector both Tropical Water and South Atlantic Central Water are equally affected by Cant intrusion. The Antarctic Intermediate Water represents the depth-limit achieved by Cant penetration, reinforcing the role that this water mass plays as an important vehicle to transport Cant to the oceans interior. The estimated Cant average (± method precision) is 46.6 ± 5.3 μmol kg- 1, considering the full depth of the water column. The ocean acidification state (ΔpH) shows an average (± standard deviation) of - 0.11 ± 0.05, thus, indicating an annual pH reduction of - 0.0010 yr- 1 since the Industrial Revolution (c.a. 1750). The degree of aragonite saturation is lowered towards undersaturation levels of calcite. The Patagonian shelf and shelf-break zones-a strong CO2 sink region in the global ocean-are likely a key area for Cant intrusion in the southwestern South Atlantic Ocean.

  7. Miocene block uplift and basin formation in the Patagonian foreland: The Gastre Basin, Argentina

    Science.gov (United States)

    Bilmes, A.; D'Elia, L.; Franzese, J. R.; Veiga, G. D.; Hernández, M.

    2013-08-01

    The intraplate fault-block mountains and intermontane deposits of the Gastre Basin, which are recorded more than 550 km east of the Andean trench in central Patagonia, Argentina, are analyzed. The Gastre Basin is one of the largest Patagonian intermontane basins, limited by uplifted blocks strongly oblique to the Andean chain. It was originated by reverse faulting and inversion of pre-existing normal faults associated with a Mesozoic rift basin and defined by older crustal heterogeneities. The deformational event occurred during the middle Miocene, related to a short contractional episode (16.1-14.86 Ma), probably in response to an eastward migration of the Andean fold and thrust belt. During Pliocene to Quaternary times, neither younger fault-block uplifts nor reconfigurations of the basin occurred. Similarities between the study area and other parts of the Patagonian foreland - such as the presence of Miocene reverse or inversion tectonics, as well as the accommodation of the Miocene sedimentary successions - suggest that the Gastre Basin is part of a major late early to middle Miocene broken foreland system (i.e. the Patagonian broken foreland) that exhumed discrete fault-block mountains and generated contemporary basins along more than 950 km parallel to the Andean trench (i.e. between 40°00' and 48°00' south latitude). Based on recent studies on the southern Andean Margin, this continental-scale contractional episode may be the result of a flat-slab subduction segment. Nevertheless, such a hypothesis is very difficult to support when analyzing such a large flat subduction segment along the entire Patagonian trench. This suggests the need to consider alternative flat-slab trigger mechanisms or other factors in the generation of broken foreland systems.

  8. Links between Patagonian Ice Sheet fluctuations and Antarctic dust variability during the last glacial period (MIS 4-2)

    Science.gov (United States)

    Kaiser, Jérôme; Lamy, Frank

    2010-06-01

    Antarctic and Greenland ice-core records reveal large fluctuations of dust input on both orbital and millennial time-scales with potential global climate implications. At least during glacial periods, the Antarctic dust fluctuations appear to be largely controlled by environmental changes in southern South America. We compare dust flux records from two Antarctic ice-cores to variations in the composition of the terrigenous supply at ODP Site 1233 located off southern Chile and known to record fluctuations in the extent of the northern part of the Patagonian ice-sheet (NPIS) during the last glacial period (Marine Isotope Stage, MIS, 4 to 2). Within age uncertainties, millennial-scale glacial advances (retreats) of the NPIS correlate to Antarctic dust maxima (minima). In turn, NPIS fluctuations were closely related to offshore sea surface temperature (SST) changes. This pattern suggests a causal link involving changes in temperature, in rock flour availability, in latitudinal extensions of the westerly winds and in foehn winds in the southern Pampas and Patagonia. We further suggest that the long-term trend of dust accumulation is partly linked to the sea-level related changes in the size if the Patagonian source area due to the particular morphology of the Argentine shelf. We suggest that sea-level drops at the beginning of MIS 4 and MIS 2 were important for long-term dust increases, while changes in the Patagonian dust source regions primarily control the early dust decrease during the MIS 4/3 transition and Termination 1.

  9. Seafood substitutions obscure patterns of mercury contamination in Patagonian toothfish (Dissostichus eleginoides or "Chilean sea bass".

    Directory of Open Access Journals (Sweden)

    Peter B Marko

    Full Text Available Seafood mislabeling distorts the true abundance of fish in the sea, defrauds consumers, and can also cause unwanted exposure to harmful pollutants. By combining genetic data with analyses of total mercury content, we have investigated how species substitutions and fishery-stock substitutions obscure mercury contamination in Patagonian toothfish (Dissostichus eleginoides, also known as "Chilean sea bass". Patagonian toothfish show wide variation in mercury concentrations such that consumers may be exposed to either acceptable or unacceptable levels of mercury depending on the geographic origins of the fish and the allowable limits of different countries. Most notably, stocks of Patagonian toothfish in Chile accumulate significantly more mercury than stocks closer to the South Pole, including the South Georgia/Shag Rocks stock, a fishery certified by the Marine Stewardship Council (MSC as sustainably fished. Consistent with the documented geography of mercury contamination, our analysis showed that, on average, retail fish labeled as MSC-certified Patagonian toothfish had only half the mercury of uncertified fish. However, consideration of genetic data that were informative about seafood substitutions revealed a complex pattern of contamination hidden from consumers: species substitutions artificially inflated the expected difference in mercury levels between MSC-certified and uncertified fish whereas fishery stock substitutions artificially reduced the expected difference in mercury content between MSC-certified and uncertified fish that were actually D. eleginoides. Among MSC-certified fish that were actually D. eleginoides, several with exogenous mtDNA haplotypes (i.e., not known from the certified fishery had mercury concentrations on par with uncertified fish from Chile. Overall, our analysis of mercury was consistent with inferences from the genetic data about the geographic origins of the fish, demonstrated the potential negative impact of

  10. Testate amoebae communities sensitive to surface moisture conditions in Patagonian peatlands

    Science.gov (United States)

    Loisel, J.; Booth, R.; Charman, D.; van Bellen, S.; Yu, Z.

    2017-12-01

    Here we examine moss surface samples that were collected during three field campaigns (2005, 2010, 2014) across southern Patagonian peatlands to assess the potential use of testate amoebae and 13C isotope data as proxy indicators of soil moisture. These proxies have been widely tested across North America, but their use as paleoecological tools remains sparse in the southern hemisphere. Samples were collected along a hydrological gradient spanning a range of water table depth from 0cm in wet hollows to over 85cm in dry hummocks. Moss moisture content was measured in the field. Over 25 taxa were identified, with many of them not found in North America. Ordinations indicate statistically significant and dominant effects of soil moisture and water table depth on testate assemblages, though interestingly 13C is even more strongly correlated with testates amoebae than direct soil conditions. It is possible that moss 13C signature constitutes a compound indicator that represents seasonal soil moisture better than opportunistic sampling during field campaigns. There is no significant effect of year or site across the dataset. In addition to providing a training set that translates testate amoebae moisture tolerance range into water tabel depth for Patagonian peatlands, we also compare our results with those from the North American training set to show that, despite 'novel' Patagonian taxa, the robustness of international training sets is probably sufficient to quantify most changes in soil moisture from any site around the world. We also identify key indicator species that are shown to be of universal value in peat-based hydrological reconstructions.

  11. Whole-community facilitation regulates biodiversity on Patagonian rocky shores.

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    Brian R Silliman

    Full Text Available Understanding the factors that generate and maintain biodiversity is a central goal in ecology. While positive species interactions (i.e., facilitation have historically been underemphasized in ecological research, they are increasingly recognized as playing important roles in the evolution and maintenance of biodiversity. Dominant habitat-forming species (foundation species buffer environmental conditions and can therefore facilitate myriad associated species. Theory predicts that facilitation will be the dominant community-structuring force under harsh environmental conditions, where organisms depend on shelter for survival and predation is diminished. Wind-swept, arid Patagonian rocky shores are one of the most desiccating intertidal rocky shores ever studied, providing an opportunity to test this theory and elucidate the context-dependency of facilitation.Surveys across 2100 km of southern Argentinean coastline and experimental manipulations both supported theoretical predictions, with 43 out of 46 species in the animal assemblage obligated to living within the matrices of mussels for protection from potentially lethal desiccation stress and predators having no detectable impact on diversity.These results provide the first experimental support of long-standing theoretical predictions and reveal that in extreme climates, maintenance of whole-community diversity can be maintained by positive interactions that ameliorate physical stress. These findings have important conservation implications and emphasize that preserving foundation species should be a priority in remediating the biodiversity consequences of global climate change.

  12. Permian depositional age of metaturbidites of the Duque de York Complex, southern Chile: U-Pb SHRIMP data and palynology

    International Nuclear Information System (INIS)

    Sepulveda, Fernando A; Palma-Heldt, Sylvia; Herve, Francisco; Fanning, Mark

    2010-01-01

    The Duque de York Complex (DYC) is part of the low grade metamorphic accretionary complexes of the pre-Andean Patagonian 'basement'. It is a sedimentary succession exposed along the western margin of southernmost South America. New U-Pb zircon ages and palynological data restrict the maximum depositional age of the DYC to the limit between the early Permian (Kungurian) and the middle Permian (Roadian). The palynological association recorded in the DYC, characterized mainly by Gymnospermopsida pollen, indicates a humid environment of forest with an under-growth of ferns. Regional paleogeographic correlations point out that an interpretation of DYC as an autochthonous terrane cannot be discarded, contrasting with previous hypotheses which suggest an allochthonous character for this complex

  13. Combined U-Pb SHRIMP and Hf isotope study of the Late Paleozoic Yaminué Complex, Rio Negro Province, Argentina: Implications for the origin and evolution of the Patagonia composite terrane

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    Carlos J. Chernicoff

    2013-01-01

    Combining geological and isotope data, as well as geophysical models, we identify the Yaminué Complex within the La Esperanza-Yaminué crustal block flanked by two other, distinct crustal blocks: the Eastern block which forms part of the Patagonia terrane sensu stricto, located in the eastern Patagonian region, and the Western block forming part of the Southern Patagonia terrane. Their origins and timing of amalgamation to form the Patagonia composite terrane are also discussed.

  14. Taxonomic review of the species of Helina R.-D. (Diptera: Muscidae) from Andean-Patagonian forests.

    Science.gov (United States)

    Patitucci, Luciano Damián; Mulieri, Pablo Ricardo; Mariluis, Juan Carlos

    2016-08-12

    Helina Robineau-Desvoidy, 1830 is the second genus of Muscidae in terms of richness. This genus includes several species collected at high altitudes and high latitudes, and is poorly studied in the Neotropical region. Only 12 species of Helina have been recorded in the southern limit of South America in the Andean-Patagonian forests. In the present work, we studied all the species known from the Andean-Patagonian forests, with the exception of H. viola Malloch, 1934, present three new species, H. araucana sp. nov., H. dorada sp. nov., and H. ouina sp. nov., and provide the first description of the females of H. australis Carvalho & Pont, 1993 and H. rufoapicata Malloch, 1934. We also propose four new synonymies: H. nigrimana basilaris (Carvalho & Pont, 1993) and H. nigrimana grisea (Malloch, 1934) as new junior synonyms of H. nigrimana (Macquart, 1851); and H. fulvocalyptrata Malloch, 1934 and H. simplex Malloch, 1934 as new junior synonyms of H. chilensis Malloch, 1934. Finally, we provide a generic diagnosis and a new key for the Helina species of the Andean-Patagonian forests, as well as notes on the biology and distribution maps of each specimen, and discuss a preliminary contruction of groups of species.

  15. Understanding the Transport of Patagonian Dust and Its Influence on Marine Biological Activity in the South Atlantic Ocean

    Science.gov (United States)

    Johnson, Matthew; Meskhidze, Nicholas; Kiliyanpilakkil, Praju; Gasso, Santiago

    2010-01-01

    Modeling and remote sensing techniques were applied to examine the horizontal and vertical transport pathways of Patagonian dust and quantify the effect of soluble-iron- laden mineral dust deposition on marine primary productivity in the South Atlantic Ocean (SAO) surface waters. The global chemistry transport model GEOS-Chem, implemented with an iron dissolution scheme, was applied to evaluate the atmospheric transport and deposition of mineral dust and bioavailable iron during two dust outbreaks originating in the source regions of Patagonia. In addition to this "rapidly released" iron, offline calculations were also carried out to estimate the amount of bioavailable iron leached during the residence time of dust in the ocean mixed layer. Model simulations showed that the horizontal and vertical transport pathways of Patagonian dust plumes were largely influenced by the synoptic meteorological patterns of high and low pressure systems. Model-predicted horizontal and vertical transport pathways of Patagonian dust over the SAO were in reasonable agreement with remotely-sensed data. Comparison between remotely-sensed and offline calculated ocean surface chlorophyll-a concentrations indicated that, for the two dust outbreaks examined in this study, the deposition of bioavailable iron in the SAO through atmospheric pathways was insignificant. As the two dust transport episodes examined here represent typical outflows of mineral dust from South American sources, our study suggests that the atmospheric deposition of mineral dust is unlikely to induce large scale marine primary productivity and carbon sequestration in the South Atlantic sector of the Southern Ocean.

  16. Preandean geological configuration of the eastern North Patagonian Massif, Argentina

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    Daniel A. Gregori

    2013-11-01

    Full Text Available The Preandean geological configuration of the eastern North Patagonian Massif is established through the use of geological and geophysical analysis. The positive gravity anomalies located near the Atlantic coast are due to 535 and 540 Ma old rocks belonging to the Pampean Orogeny (Precambrian–middle Cambrian, which are widely recognized in central and northern Argentina. The Famatinian Cycle (Ordovician–Devonian is represented by a Silurian–Devonian marine basin equivalent to those of eastern-central Argentina and South Africa, and which was deformed at the end of the Devonian by an ∼E–W to WNW–ESE compressional event, part of the Famatinian Orogeny. Containing strong gravity gradients, the NW–SE belt is coincident with fault zones which were originated during the Gondwanide Orogeny. This event also produced NW–SE overthrusting of the Silurian–Devonian sequences and strike-slip faults that displaced blocks in the same direction. This deformation event belongs to the Gondwanide Orogeny that includes movements related to a counterclockwise rotation of blocks in northern Patagonia. The strong negative anomalies located in the western part of the area stem from the presence of rocks of the Jurassic Cañadón Asfalto basin interbedded in the Marifil Complex. These volcaniclastic sequences show mild deformation of accommodation zones in a pre-Jurassic paleorelief.

  17. Late cenozoic magmatism in the South Patagonian batholith: SHRIMP U-Pb zircon age evidence

    International Nuclear Information System (INIS)

    Fanning, C.M; Herve, F; Pankhurst, R.J; Thomson, S; Faundez, V

    2001-01-01

    The North Patagonian Batholith (NPB) has a zonal age pattern which includes a well defined belt of Miocene and Mio-Pliocene plutons in its central portion (Pankhurst et al., 1999) which are spatially, and probably genetically related to the Liquine-Ofqui Fault Zone. Previous geochronological studies in the Southern Patagonian Batholith (SPB), as summarized by Bruce et al. (1991), have yielded 9 late Cenozoic K-Ar or Ar-Ar ages out of a total of 116 age determinations. None of these young ages correspond to U-Pb determinations on zircons, and some of the young ages correspond to satellite plutons east of the SPB proper, such as the Torres del Paine intrusion. In this paper we present the first late Cenozoic SHRIMP U-Pb zircon ages in the area of the SPB. The morphology of the analysed zircon crystals is described and leads to some inferences on the methodology and on the geological interpretation of the obtained ages (au)

  18. Constraints on deformation of the Southern Andes since the Cretaceous from anisotropy of magnetic susceptibility

    Science.gov (United States)

    Maffione, Marco; Hernandez-Moreno, Catalina; Ghiglione, Matias C.; Speranza, Fabio; van Hinsbergen, Douwe J. J.; Lodolo, Emanuele

    2015-12-01

    The southernmost segment of the Andean Cordillera underwent a complex deformation history characterized by alternation of contractional, extensional, and strike-slip tectonics. Key elements of southern Andean deformation that remain poorly constrained, include the origin of the orogenic bend known as the Patagonian Orocline (here renamed as Patagonian Arc), and the exhumation mechanism of an upper amphibolite facies metamorphic complex currently exposed in Cordillera Darwin. Here, we present results of anisotropy of magnetic susceptibility (AMS) from 22 sites in Upper Cretaceous to upper Eocene sedimentary rocks within the internal structural domain of the Magallanes fold-and-thrust belt in Tierra del Fuego (Argentina). AMS parameters from most sites reveal a weak tectonic overprint of the original magnetic fabric, which was likely acquired upon layer-parallel shortening soon after sedimentation. Magnetic lineation from 17 sites is interpreted to have formed during compressive tectonic phases associated to a continuous N-S contraction. Our data, combined with the existing AMS database from adjacent areas, show that the Early Cretaceous-late Oligocene tectonic phases in the Southern Andes yielded continuous contraction, variable from E-W in the Patagonian Andes to N-S in the Fuegian Andes, which defined a radial strain field. A direct implication is that the exhumation of the Cordillera Darwin metamorphic complex occurred under compressive, rather than extensional or strike-slip tectonics, as alternatively proposed. If we agree with recent works considering the curved Magallanes fold-and-thrust belt as a primary arc (i.e., no relative vertical-axis rotation of the limbs occurs during its formation), then other mechanisms different from oroclinal bending should be invoked to explain the documented radial strain field. We tentatively propose a kinematic model in which reactivation of variably oriented Jurassic faults at the South American continental margin controlled

  19. Pluton emplacement and magmatic arc construction: A model from the Patagonian batholith

    Science.gov (United States)

    Bruce, Robert; Nelson, Eric; Weaver, Stephen

    1988-01-01

    A model of batholithic construction in Andean arcs and its applicability to possibly similar environments in the past is described. Age and compositional data from the Patagonian batholith of southern Chile show a long history of magmatism in any given area (total age range is 15 to 157 Ma), but different regions appear to have different magmatic starting ages. Furthermore, mafic rocks seem to be the oldest components of any given region. An assembly line model involving semicontinuous magmatism and uplift was outlined, which has implications for other terranes: uplift rates will be proportional to observed ranges in age, and total uplift will be proportional to the age of the oldest pluton in any given area. It is suggested that misleading results would be obtained if only small areas of similar terranes in the Archean were available for study.

  20. A model-based telecoupling analysis for the Patagonian shelf: a new suggested template on how to study global seabirds-fisheries interactions for sustainability

    Science.gov (United States)

    Huettmann, F.; Raya Rey, A.

    2016-12-01

    The Southwest Atlantic Ocean, and the extended Patagonian shelf in particular, presents us with a very complex ecosystem of global relevance for food security and global peace. It is a highly productive area and it maintains a great diversity and abundance of seabird species. Fisheries have been identified as a main stressor for the marine ecosystems and as one of the main causes of seabird population declines. Using the framework of telecoupling - a sophisticated description of natural and socioeconomic interactions over large distances - here we present a fresh holistic look at the dynamic fisheries and (endangered) seabird interactions for the Patagonian shelf. While data are sparse, we employ machine learning-based predictions for a more holistic overview. We found that these waters of the Patagonian Shelf are significantly affected by many nations and outside players. We found that the input, output and spill-over of the Patagonian shelf ecosystem are distributed virtually all over the globe. In addition, we also found `losers' (=nations and their citizens that are left out entirely from this global resource and its governance). Our findings are based on best-available public trade and fish harvest analysis for this region, linked with predictive modeling (machine learning and geographic information systems GIS) to generalize for nine seabird species. We conveniently extend this analysis with a perspective from the financial sector and policy that enables the Patagonian fisheries as international investment and development projects. As increasingly recognized elsewhere, we believe that telecoupling can serve as a new but rather sophisticated study template highlighting wider complexities, bottlenecks and sensitivities for a vastly improved conservation research on oceans and global sustainability questions.

  1. Late Jurassic rifting in the southern central Graben -A complex story simplified

    NARCIS (Netherlands)

    Verreussel, R.M.C.H.; Munsterman, D.K.; Ten Veen, J.H.; Weerd, A. van de; Dybkjaer, K.; Johannessen, P.N.

    2014-01-01

    In order to be able to predict the distribution of reservoir sands and of grainsize and porosity trends in a hydrocarbon province, it is essential to understand the basin evolution in detail. In this study, an attempt is made to reconstruct the complex basin evolution of the southern Central Graben

  2. Geographic/conceptual delimitation of the «Southern Mediterranean». A Regional Security Complex?

    Directory of Open Access Journals (Sweden)

    Alberto Priego Moreno

    2016-07-01

    Full Text Available This article seeks to analyse how the Mediterranean Area has evolved after the changes occurred with the so-called Arab Springs. The main idea is to focus on the Southern Mediterranean as a dynamic space that expands itself as a result of its internal transformations and subsequent external changes caused by the Arab Spring. We will use the IR theory of the Regional Security Complex as it is considered as the most adaptable to this changing reality.

  3. Traveling around Cape Horn: Otolith chemistry reveals a mixed stock of Patagonian hoki with separate Atlantic and Pacific spawning grounds

    Science.gov (United States)

    Schuchert, P.C.; Arkhipkin, A.I.; Koenig, A.E.

    2010-01-01

    Trace element fingerprints of edge and core regions in otoliths from 260 specimens of Patagonian hoki, Macruronus magellanicus L??nnberg, 1907, were analyzed by LA-ICPMS to reveal whether this species forms one or more population units (stocks) in the Southern Oceans. Fish were caught on their spawning grounds in Chile and feeding grounds in Chile and the Falkland Islands. Univariate and multivariate analyses of trace element concentrations in the otolith edges, which relate to the adult life of fish, could not distinguish between Atlantic (Falkland) and Pacific (Chile) hoki. Cluster analyses of element concentrations in the otolith edges produced three different clusters in all sample areas indicating high mixture of the stocks. Cluster analysis of trace element concentrations in the otolith cores, relating to juvenile and larval life stages, produced two separate clusters mainly distinguished by 137Ba concentrations. The results suggest that Patagonian hoki is a highly mixed fish stock with at least two spawning grounds around South America. ?? 2009 Elsevier B.V.

  4. Soft-bottom macrobenthic faunal associations in the southern Chilean glacial fjord complex

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    Carlos Ríos

    2005-12-01

    Full Text Available Macrobenthic associations were investigated at 29 sampling stations with a semi-quantitative Agassiz trawl, ranging from the South Patagonian Icefield to the Straits of Magellan in the South Chilean fjord system. A total of 1,895 individuals belonging to 131 species were collected. 19 species belong to colonial organisms, mainly Bryozoa (17 species and Octocorallia (2 species. The phylum Echinodermata was the most diverse in species number (47 species, with asteroids (25 species and ophiuroids (13 species being the best represented within this taxon. Polychaeta was the second dominant group in terms of species richness (46 species. Multidimensional scaling ordination (MDS separated two station groups, one related to fjords and channels off the South Patagonian Icefield and the second one to stations surrounding the Straits of Magellan. 45 species account for 90% of the dissimilarity between these two groups. These differences can mainly be explained by the influence of local environmental conditions determined by processes closely related to the presence/absence of glaciers. Abiotic parameters such as water depth, type of sediment and chemical features of the superficial sediment were not correlated with the numbers of individuals caught by the Agassiz trawl in each group of sampling stations.

  5. The dispersal of Homo sapiens across southern Asia: how early, how often, how complex?

    Science.gov (United States)

    Dennell, Robin; Petraglia, Michael D.

    2012-07-01

    The timing and the paths of colonization of southern Asia by Homo sapiens are poorly known, though many population geneticists, paleoanthropologists, and archaeologists have contended that this process began with dispersal from East Africa, and occurred between 60,000 and 40,000 years ago. However, the evidence for this scenario is very weak, particularly the lack of human skeletal evidence between the Levant and Borneo before 40 ka, and other explanations are possible. Here we argue that environmental and archaeological information is increasingly indicating the likelihood that H. sapiens exited Africa much earlier than commonly thought, and may have colonized much of southern Asia well before 60,000 years ago. Additionally, we cannot exclude the possibility that several dispersal events occurred, from both North and East Africa, nor the likelihood that early populations of H. sapiens in southern Asia interbred with indigenous populations of Neanderthals, Denisovans and Homo erectus. The population history of southern Asia during the Upper Pleistocene is likely far more complex than currently envisaged.

  6. Metamorphic complexes in accretionary orogens: Insights from the Beishan collage, southern Central Asian Orogenic Belt

    Science.gov (United States)

    Song, Dongfang; Xiao, Wenjiao; Windley, Brian F.; Han, Chunming; Yang, Lei

    2016-10-01

    The sources of ancient zircons and the tectonic attributions and origins of metamorphic complexes in Phanerozoic accretionary orogens have long been difficult issues. Situated between the Tianshan and Inner Mongolia orogens, the Beishan orogenic collage (BOC) plays a pivotal role in understanding the accretionary processes of the southern Central Asian Orogenic Belt (CAOB), particularly the extensive metamorphic and high-strained complexes on the southern margin. Despite their importance in understanding the basic architecture of the southern CAOB, little consensus has been reached on their ages and origins. Our new structural, LA-ICP-MS zircon U-Pb and Hf isotopic data from the Baidunzi, Shibandun, Qiaowan and Wutongjing metamorphic complexes resolve current controversial relations. The metamorphic complexes have varied lithologies and structures. Detrital zircons from five para-metamorphic rocks yield predominantly Phanerozoic ages with single major peaks at ca. 276 Ma, 286 Ma, 427 Ma, 428 Ma and 461 Ma. Two orthogneisses have weighted mean ages of 294 ± 2 Ma and 304 ± 2 Ma with no Precambrian inherited zircons. Most Phanerozoic zircons show positive εHf(t) values indicating significant crustal growth in the Ordovician, Silurian and Permian. The imbricated fold-thrust deformation style combined with diagnostic zircon U-Pb-Hf isotopic data demonstrate that the metamorphic rocks developed in a subduction-accretion setting on an arc or active continental margin. This setting and conclusion are supported by the nearby occurrence of Ordovician-Silurian adakites, Nb-rich basalts, Carboniferous-Permian ophiolitic mélanges, and trench-type turbidites. Current data do not support the presence of a widespread Precambrian basement in the evolution of the BOC; the accretionary processes may have continued to the early Permian in this part of the CAOB. These relationships have meaningful implications for the interpretation of the tectonic attributions and origins of other

  7. Tides and lake-level variations in the great Patagonian lakes: Observations, modelling and geophysical implications.

    Science.gov (United States)

    Marderwald, Eric; Richter, Andreas; Horwath, Martin; Hormaechea, Jose Luis; Groh, Andreas

    2016-04-01

    -level time series from Lagos Argentino and Viedma yields the amplitudes and phases of the lake tides for the four major tidal constituents M2, S2, O1 and K1. The maximum amplitude, corresponding to the semi-diurnal moon tide M2 in Lago Argentino, amounts to 3 mm. For the four lakes under investigation the theoretical amplitudes and phases of seven constituents (Q1, O1, P1, K1, N2, M2 and S2) are modelled accounting for the contributions of both the solid earth's body tides and the ocean tidal loading (Marderwald 2014). Both contributions involve a deformation of the earth surface and of the equipotential surfaces of the gravity field. For the load tide computation the global ocean tide model EOT11a (Savcenko and Bosch, 2012) and the Gutenberg-Bullen A earth model (Farrell, 1972) was applied and the conservation of water volume is taken into account. The comparison of the tidal signal extracted from the lake-level observations in Lagos Argentino and Viedma with the lake tide models indicates a phase shift which is most likely explained by an 1 hour phase lag of the employed global ocean tide model in the region of the highly fragmented Pacific coast. REFERENCES: Farrell, W. E., (1972). Deformation of the Earth by Surface Loads. Rev. Geophy. Space Phy., 10(3):761-797. Ivins, E., James, T., 2004. Bedrock response to Llanquihue Holocene and present-day glaciation in southernmost South America. Geophys. Res. Lett. 31 (L24613). Doi:10.1029/2004GL021500. Klemann, V., E. R. Ivins, Z. Martinec, and D. Wolf (2007), Models of active glacial isostasy roofing warm subduction: Case of the South Patagonian Ice Field, J. Geophys. Res., 112, B09405, doi: 10.1029/2006JB004818. Lange, H., Casassa, G., Ivins, E. R., Schröder, L., Fritsche, M., Richter, A., Groh, A., Dietrich, R., (2014). Observed crustal uplift near the Southern Patagonian Icefield constrains improved viscoelastic Earth models. Geophysical Research Letters, DOI: 10.1002/2013GL058419. Marderwald ER, 2014. Modelado de las mareas

  8. Egg masses of the Patagonian squid Doryteuthis (Amerigo gahi attached to giant kelp (Macrocystis pyrifera in the sub-Antarctic ecoregion

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    Sebastián Rosenfeld

    2014-11-01

    Full Text Available Egg masses of the Patagonian squid Doryteuthis (Amerigo gahi attached to giant kelp (Macrocystis pyrifera in the Magellanic channels of the sub-Antarctic ecoregion in southern South America is documented for the first time. Of seven egg masses observed between 2008 and 2011, one was taken to the laboratory to be analysed and photographed. Comprising long transparent capsules containing eggs, the masses were strongly attached to the stipes of M. pyrifera. This macroalgae is a potentially important economic resource due to its multiple industrial uses; this study shows that it also serves an important ecological role as a spawning substrate for D. gahi.

  9. Zoonotic parasites associated with felines from the Patagonian Holocene

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    Martín Horacio Fugassa

    2009-12-01

    Full Text Available Feline coprolites were examined for parasites with the aim of studying ancient infections that occurred in the Patagonian region during the Holocene period. Eggs compatible to Trichuris sp., Calodium sp., Eucoleus sp., Nematodirus sp., Oesophagostomum sp. (Nematoda, Monoecocestus sp. (Cestoda and Eimeria macusaniensis (Coccidia were recovered from faecal samples. The results obtained from the analysis provide evidence of consumption by felids of the viscera of both rodents and camelids. This knowledge allows for improved explanations as to the distribution of parasitism and its significance to the health of humans and animals inhabiting the area under study during the Middle Holocene.

  10. Melting of the Patagonian Ice Sheet and deglacial perturbations of the nitrogen cycle in the eastern South Pacific

    Science.gov (United States)

    De Pol-Holz, Ricardo; Ulloa, Osvaldo; Dezileau, Laurent; Kaiser, Jérôme; Lamy, Frank; Hebbeln, Dierk

    2006-02-01

    We report the last glacial-interglacial transition of marine denitrification off northern Chile based on sedimentary nitrogen isotopes. Our results show a relatively early, large and abrupt transition from low to high denitrification regimes consistent with recently-reported data from off Peru. The deglaciation is characterized by millennial-scale adjustments of the oxygen minimum zone that mimic the atmospheric temperature record from Antarctica. We also show that the sharp denitrification onset was not caused by an increase in local primary productivity, nor by ventilation changes occurring in the Southern Ocean, as previously proposed. We found that the magnitude and timing of the deglacial denitrification changes are in close agreement with the fresh-water pulses that resulted from the melting of the Patagonian Ice Sheet. We consequently attribute the deglacial onset of marine denitrification in the area to a collapse of the thermocline ventilation occurred at the mid-latitude subduction region of the eastern South Pacific.

  11. Petrology and chemistry of Jebel Tanumah complex, Khamis Mushayt, Southern Arabian shield, Saudi Arabia

    Science.gov (United States)

    Nassief, M. O.; Ali, H. M.; Zakir, F. A.

    The mafic intrusive complex at Jebel Tanumah is located 15 km north-west of Khamis Mushayt in the southern Arabian Shield and includes olivine-bearing gabbro as well as amphibole-diopside-hornblende gabbro cumulates. These rocks have been generally metamorphosed to upper greeenschist-lower amphibolite facies. Fourteen white rock silicate analyses indicate that the majority of the rocks are calc-alkaline to tholeiitic in composition. The two major structural units in the Khamis Mushayt region identified by Coleman consist of the basement complex of Asir Mountains and the younger metamorphic rocks. Syntectonic granitic rocks intruded the antiforms characterizing the younger rocks whereas the lower parts of the synforms are intruded by post-tectonic intrusions of layered gabbros such as the one studied at Jebel Tanumah.

  12. Complex utilization of the useful components of the andreye-yulyevskoe kyanite tecnogenic deposit (Southern Urals

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    Viktor Alekseyevich Koroteyev

    2013-03-01

    Full Text Available Utilization of sillimanite group’s minerals (kyanite, sillimanite, andalusite in high-aluminiferousrefractory industry with a purpose of following utilization in metallurgy to obtain silumine and aluminium by elctrothermic method is impossible without new resources. A one of them is the Andree-Yulyevskaya group of kyanite-bearing technogenic objects. Technogenic deposits formed as a result of alluvial gold deposits’ exploitation at the Southern Urals is an additional source of the complex mineral products. A concentration of minerals of the technogenic objects is higher than initial alluvial placers’ one in n10-n1000 times. During the valuation of industrial potential of the Andree-Yulyevskayakya tetechnogenic deposit, (Southern Urals a concentrate method of technogenicsands’ sampling has been used which permitsestimating a gold placers’ potential of thetechnogenic objects with poor gold and rutile as a useful additional mineral has been distinguished. As a result of researches a principal technological scheme of technogenic sands’ concentration permitting to obtain kyanite concentrates with content of Al2O3 of 55.5 (% to 60.2 (% — the main product and gold-bearing and rutile concentrates as additional products. Complex extraction of kyanite, gold, and rutile from technogenic objects has a commercial attraction of this type deposits’ exploitation.

  13. Natural Environmental Hazards Reflected in High-Altitude Patagonian Lake Sediments (lake Caviahue, Argentina)

    Science.gov (United States)

    Müller, Anne; Scharf, Burkhard; von Tümpling, Wolf; Pirrung, Michael

    2009-03-01

    Two 6-m long sediment cores drilled in the two basins of Lake Caviahue give new evidence of the impact of natural hazards such as ash fallouts linked to nearby volcanic eruptions in the ecologically sensitive environment of the high-altitude region of the Argentinan Patagonian Andes. The two cores show distinct signals of changes in autochthonous productivity and terrigenous input into the lake from ash fallout as well as from river load and shore erosion. Multiproxy records of the sediments indicate whether these changes can be related to volcanic activity. High values of magnetic susceptibility in the cores reflect periods of basaltic ash fallouts during eruptions of the nearby Copahue Volcano. The southern basin is located in the prevalent direction of ash fallouts and has been affected by these volcanic inputs more intensely than the northern basin of the lake. In contrast, sedimentation and authochthonous productivity in the northern basin are strongly affected by fluvial inputs such as suspended river load and acidic stream waters.

  14. Do soil organisms affect aboveground litter decomposition in the semiarid Patagonian steppe, Argentina?

    Science.gov (United States)

    Araujo, Patricia I; Yahdjian, Laura; Austin, Amy T

    2012-01-01

    Surface litter decomposition in arid and semiarid ecosystems is often faster than predicted by climatic parameters such as annual precipitation or evapotranspiration, or based on standard indices of litter quality such as lignin or nitrogen concentrations. Abiotic photodegradation has been demonstrated to be an important factor controlling aboveground litter decomposition in aridland ecosystems, but soil fauna, particularly macrofauna such as termites and ants, have also been identified as key players affecting litter mass loss in warm deserts. Our objective was to quantify the importance of soil organisms on surface litter decomposition in the Patagonian steppe in the absence of photodegradative effects, to establish the relative importance of soil organisms on rates of mass loss and nitrogen release. We estimated the relative contribution of soil fauna and microbes to litter decomposition of a dominant grass using litterboxes with variable mesh sizes that excluded groups of soil fauna based on size class (10, 2, and 0.01 mm), which were placed beneath shrub canopies. We also employed chemical repellents (naphthalene and fungicide). The exclusion of macro- and mesofauna had no effect on litter mass loss over 3 years (P = 0.36), as litter decomposition was similar in all soil fauna exclusions and naphthalene-treated litter. In contrast, reduction of fungal activity significantly inhibited litter decomposition (P soil fauna have been mentioned as a key control of litter decomposition in warm deserts, biogeographic legacies and temperature limitation may constrain the importance of these organisms in temperate aridlands, particularly in the southern hemisphere.

  15. Didymosphenia geminata invasion in South America: Ecosystem impacts and potential biogeochemical state change in Patagonian rivers

    Science.gov (United States)

    Reid, Brian; Torres, Rodrigo

    2014-01-01

    The diatom Didymosphenia geminata has emerged as a major global concern, as both an aggressive invader of rivers and streams in the southern hemisphere, and for its ability to form nuisance blooms in oligotrophic systems in its native range. South American D. geminata blooms were first documented in Chilean Patagonia in May 2010, and have spread to over five regions and three provinces, in Chile and Argentina respectively. The Patagonian invasion represents a distinct challenge compared to other regions; not only are affected systems poorly characterized, but also a general synthesis of the nature and magnitude of ecosystem impacts is still lacking. The latter is essential in evaluating impacts to ecosystem services, forms the basis for a management response that is proportional to the potentially valid threats, or aids in the determination of whether action is warranted or feasible. Based on a revision of the recent literature, some of the most significant impacts may be mediated through physical changes: substantially increased algal biomass, trapping of fine sediment, altered hydrodynamics, and consequent effects on biogeochemical states and processes such as redox condition, pH and nutrient cycling in the benthic zone. Surveys conducted during the early invasion in Chile show a strong correlation between benthic biomass and associated fine sediments, both of which were one-two orders of magnitude higher within D. geminata blooms. Experimental phosphorous amendments showed significant abiotic uptake, while interstitial water in D. geminata mats had nearly 10-20 fold higher soluble reactive phosphorous and a pronounced pH cycle compared to the water column. A dominant and aggressive stalk-forming diatom with this combination of characteristics is in sharp contrast to the colonial cyanobacteria and bare gravel substrate that characterize many Patagonian streams. The potential displacement of native benthic algal communities with contrasting functional groups

  16. Null models for study Rotifers and Crustaceans Zooplankton species richness in Chilean Patagonian lakes

    OpenAIRE

    Escalante, Patricio de los Ríos

    2016-01-01

    Abstract Aims The Patagonian lakes are characterized by their oligotrophy that is the cause of low species number in their zooplankton assemblage. The aim of the present study is to analyze the crustacean and rotifers species number pattern in Patagonian lakes among a latitudinal gradient (40-51 °S). Results The results revealed that there are direct significant correlations between total species with rotifer species, and chlorophyll concentration with crustacean species number, and an inve...

  17. A Reflection on Low Energy Renovation of Residential Complexes in Southern Europe

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    Helena Corvacho

    2016-09-01

    Full Text Available The transformation of European existing building stock towards very low energy buildings requires a new approach. In this context, it seems reasonable to think that buildings should no longer be renovated individually but as part of a global energy system. Focusing on larger urban units may present some scale advantages and may constitute an opportunity to change the urban environment in a smart energy way. Specificities of Southern European countries are addressed. Due either to the climate or the life style, there are large differences in energy consumption per dwelling among southern and northern European countries. How much heating energy will be saved by over-insulating building envelopes if people do not feel the need to heat their houses in the first place? In addition, real energy use in buildings frequently shows major differences with respect to the predicted consumption. The definition of realistic solutions demands the availability of realistic predictions. A case of a residential complex in Portugal is used to illustrate the main questions and to conclude that moving from a building to a group of buildings scale may be an interesting challenge for policy makers to look closer in the near future.

  18. Southern complex: geology, geochemistry, mineralogy, and mineral chemistry of selected uranium- and thorium-rich granites

    International Nuclear Information System (INIS)

    Hoffman, M.A.

    1987-01-01

    Four major rock groups are defined in the Southern Complex: the Bell Creek Granite (BCG), the Clotted Granitoids (CGR), the Albite Granite (AGR), and the Migmatite Complex. Metatexites of the Migmatite Complex are the oldest rocks and include paleosome of a metasedimentary and metavolcanic protolith represented by Banded Iron Formation, Banded Amphibolite, and Banded Gneisses, and interlayered or crosscutting leucogranites. The CGR span the range from metatexite to diatexite and represent in-situ partial melting of metapelitic layers in the protolith during intrusion of the BCG. The BCG cuts the migmatites, is locally cut by the CGR, and was derived by partial melting of a dominantly metasedimentary protolith at some depth below the presently exposed migmatites during a regional tectonothermal event. The Albite Granite is a 2km diameter, muscovite-fluorite-columbite-bearing intrusive stock that cuts all other major units. The thorium history of the BCG is a function of the history of monazite. The thorium history of the CGR is also dominated by monazite but the thorium content of this unit cannot be entirely accounted for by original restite monazite. The uranium history of the BCG and CGR was dominated by magmatic differentiation and post magmatic, metamorphic and supergene redistributions and is largely independent of the thorium history. The thorium and uranium history of the AGR was dominated by magmatic/deuteric processes unlike the BCG and CGR

  19. The eruptive chronology of the Ampato-Sabancaya volcanic complex (Southern Peru)

    Science.gov (United States)

    Samaniego, Pablo; Rivera, Marco; Mariño, Jersy; Guillou, Hervé; Liorzou, Céline; Zerathe, Swann; Delgado, Rosmery; Valderrama, Patricio; Scao, Vincent

    2016-09-01

    We have reconstructed the eruptive chronology of the Ampato-Sabancaya volcanic complex (Southern Peru) on the basis of extensive fieldwork, and a large dataset of geochronological (40K-40Ar, 14C and 3He) and geochemical (major and trace element) data. This volcanic complex is composed of two successive edifices that have experienced discontinuous volcanic activity from Middle Pleistocene to Holocene times. The Ampato compound volcano consists of a basal edifice constructed over at least two cone-building stages dated at 450-400 ka and 230-200 ka. After a period of quiescence, the Ampato Upper edifice was constructed firstly during an effusive stage (80-70 ka), and then by the formation of three successive peaks: the Northern, Southern (40-20 ka) and Central cones (20-10 ka). The Southern peak, which is the biggest, experienced large explosive phases, resulting in deposits such as the Corinta plinian fallout. During the Holocene, eruptive activity migrated to the NE and constructed the mostly effusive Sabancaya edifice. This cone comprised many andesitic and dacitic blocky lava flows and a young terminal cone, mostly composed of pyroclastic material. Most samples from the Ampato-Sabancaya define a broad high-K magmatic trend composed of andesites and dacites with a mineral assemblage of plagioclase, amphibole, biotite, ortho- and clino-pyroxene, and Fe-Ti oxides. A secondary trend also exists, corresponding to rare dacitic explosive eruptions (i.e. Corinta fallout and flow deposits). Both magmatic trends are derived by fractional crystallisation involving an amphibole-rich cumulate with variable amounts of upper crustal assimilation. A marked change in the overall eruptive rate has been identified between Ampato ( 0.1 km3/ka) and Sabancaya (0.6-1.7 km3/ka). This abrupt change demonstrates that eruptive rates have not been homogeneous throughout the volcano's history. Based on tephrochronologic studies, the Late Holocene Sabancaya activity is characterised by strong

  20. Pyroclastic Eruption Boosts Organic Carbon Fluxes Into Patagonian Fjords

    Science.gov (United States)

    Mohr, Christian H.; Korup, Oliver; Ulloa, Héctor; Iroumé, Andrés.

    2017-11-01

    Fjords and old-growth forests store large amounts of organic carbon. Yet the role of episodic disturbances, particularly volcanic eruptions, in mobilizing organic carbon in fjord landscapes covered by temperate rainforests remains poorly quantified. To this end, we estimated how much wood and soils were flushed to nearby fjords following the 2008 eruption of Chaitén volcano in south-central Chile, where pyroclastic sediments covered >12 km2 of pristine temperate rainforest. Field-based surveys of forest biomass, soil organic content, and dead wood transport reveal that the reworking of pyroclastic sediments delivered 66,500 + 14,600/-14,500 tC of large wood to two rivers entering the nearby Patagonian fjords in less than a decade. A similar volume of wood remains in dead tree stands and buried beneath pyroclastic deposits ( 79,900 + 21,100/-16,900 tC) or stored in active river channels (5,900-10,600 tC). We estimate that bank erosion mobilized 132,300+21,700/-30,600 tC of floodplain forest soil. Eroded and reworked forest soils have been accreting on coastal river deltas at >5 mm yr-1 since the eruption. While much of the large wood is transported out of the fjord by long-shore drift, the finer fraction from eroded forest soils is likely to be buried in the fjords. We conclude that the organic carbon fluxes boosted by rivers adjusting to high pyroclastic sediment loads may remain elevated for up to a decade and that Patagonian temperate rainforests disturbed by excessive loads of pyroclastic debris can be episodic short-lived carbon sources.

  1. The Nubian Complex of Dhofar, Oman: an African middle stone age industry in Southern Arabia.

    Directory of Open Access Journals (Sweden)

    Jeffrey I Rose

    Full Text Available Despite the numerous studies proposing early human population expansions from Africa into Arabia during the Late Pleistocene, no archaeological sites have yet been discovered in Arabia that resemble a specific African industry, which would indicate demographic exchange across the Red Sea. Here we report the discovery of a buried site and more than 100 new surface scatters in the Dhofar region of Oman belonging to a regionally-specific African lithic industry--the late Nubian Complex--known previously only from the northeast and Horn of Africa during Marine Isotope Stage 5, ∼128,000 to 74,000 years ago. Two optically stimulated luminescence age estimates from the open-air site of Aybut Al Auwal in Oman place the Arabian Nubian Complex at ∼106,000 years ago, providing archaeological evidence for the presence of a distinct northeast African Middle Stone Age technocomplex in southern Arabia sometime in the first half of Marine Isotope Stage 5.

  2. Sulfide mineralization in ultramafic rocks of the Faryab ophiolite complex, southern Kerman

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    Mohammad Ali Rajabzadeh

    2015-10-01

    Full Text Available Introduction Worldwide, Ni-Cu and PGE magmatic sulfide deposits are confined to the lower parts of stratiform mafic and ultramafic complexes. However, ophiolite mafic and ultramafic complexes have been rarely explored for sulfide deposits despite the fact that they have been extensively explored and exploited for chromite. Sulfide saturation during magmatic evolution is necessary for sulfide mineralization, in which sulfide melts scavenge chalcophile metals from the parent magma and concentrate them in specific lithological zones. The lack of exploration for sulfides in this environment suggests that sulfide saturation is rarely attained in ophiolite-related magmas. Some ophiolites, however, contain sulfide deposits, such as at Acoje in Philippines, and Cliffs in Shetland, U.K. (Evans, 2000; Naldrett, 2004. The Faryab ophiolite complex in southern Kerman Province, the most important mining area for chromite deposits in Iran, is located in the southwest part of the Makran Zone. Evidence of sulfide mineralization has been reported there by some authors (e.g. Rajabzadeh and Moosavinasab, 2013. This paper discusses the genesis of sulfides in the Faryab ophiolite using mineral chemistry of the major mineral phases in different rocks of the ophiolite column in order to determine the possible lithological location of sulfide deposits. Materials and methods Seventy three rock samples from cumulate units were collected from surficial occurrences and drill core. The samples were studied using conventional microscopic methods and the mineralogy confirmed by x-ray diffraction. Electron microprobe analysis was carried out on different mineral phases in order to determine the chemistry of the minerals used in the interpretation of magma evolution in the Faryab ophiolite. Lithologically, the Faryab ophiolite complex is divided into two major parts: the northern part includes magmatic rocks and the southern part is comprised of rocks residual after partial

  3. How much is too much? Assessment of prey consumption by Magellanic penguins in Patagonian colonies.

    Directory of Open Access Journals (Sweden)

    Juan E Sala

    Full Text Available Penguins are major consumers in the southern oceans although quantification of this has been problematic. One suggestion proposes the use of points of inflection in diving profiles ('wiggles' for this, a method that has been validated for the estimation of prey consumption by Magellanic penguins (Spheniscus magellanicus by Simeone and Wilson (2003. Following them, we used wiggles from 31 depth logger-equipped Magellanic penguins foraging from four Patagonian colonies; Punta Norte (PN, Bahía Bustamente (BB, Puerto Deseado (PD and Puerto San Julián (PSJ, all located in Argentina between 42-49° S, to estimate the prey captured and calculate the catch per unit time (CPUT for birds foraging during the early chick-rearing period. Numbers of prey caught and CPUT were significantly different between colonies. Birds from PD caught the highest number of prey per foraging trip, with CPUT values of 68±19 prey per hour underwater (almost two times greater than for the three remaining colonies. We modeled consumption from these data and calculate that the world Magellanic penguin population consumes about 2 million tons of prey per year. Possible errors in this calculation are discussed. Despite this, the analysis of wiggles seems a powerful and simple tool to begin to quantify prey consumption by Magellanic penguins, allowing comparison between different breeding sites. The total number of wiggles and/or CPUT do not reflect, by themselves, the availability of food for each colony, as the number of prey consumed by foraging trip is strongly associated with the energy content and wet mass of each colony-specific 'prey type'. Individuals consuming more profitable prey could be optimizing the time spent underwater, thereby optimizing the energy expenditure associated with the dives.

  4. Mohorovicic discontinuity depth analysis beneath North Patagonian Massif

    Science.gov (United States)

    Gómez Dacal, M. L.; Tocho, C.; Aragón, E.

    2013-05-01

    The North Patagonian Massif is a 100000 km2, sub-rectangular plateau that stands out 500 to 700 m higher in altitude than the surrounding topography. The creation of this plateau took place during the Oligocene through a sudden uplift without noticeable internal deformation. This quite different mechanical response between the massif and the surrounding back arc, the short time in which this process took place and a regional negative Bouguer anomaly in the massif area, raise the question about the isostatic compensation state of the previously mentioned massif. In the present work, a comparison between different results about the depth of the Mohorovicic discontinuity beneath the North Patagonian Massif and a later analysis is made. It has the objective to analyze the crustal thickness in the area to contribute in the determination of the isostatic balance and the better understanding of the Cenozoic evolution of the mentioned area. The comparison is made between four models; two of these were created with seismic information (Feng et al., 2006 and Bassin et al., 2000), another model with gravity information (Barzaghi et al., 2011) and the last one with a combination of both techniques (Tassara y Etchaurren, 2011). The latter was the result of the adaptation to the work area of a three-dimensional density model made with some additional information, mainly seismic, that constrain the surfaces. The work of restriction and adaptation of this model, the later analysis and comparison with the other three models and the combination of both seismic models to cover the lack of resolution in some areas, is presented here. According the different models, the crustal thickness of the study zone would be between 36 and 45 Km. and thicker than the surrounding areas. These results talk us about a crust thicker than normal and that could behave as a rigid and independent block. Moreover, it can be observed that there are noticeable differences between gravimetric and seismic

  5. Three tier transition of Neoarchean TTG-sanukitoid magmatism in the Beit Bridge Complex, Southern Africa

    Science.gov (United States)

    Rajesh, H. M.; Belyanin, G. A.; Van Reenen, D. D.

    2018-01-01

    Neoarchean TTG-sanukitoid associations of contrasting scales occur within the Beit Bridge Complex terrane of the Limpopo Complex in southern Africa. These include the smaller 2.65-2.63 Ga Avoca granitoid and the voluminous 2.73-2.64 Ga Alldays granitoid. This study characterizes the wide compositional spectrum preserved in these two granitoids. The elliptical Avoca pluton consists of a biotite-amphibole-orthopyroxene ± clinopyroxene-bearing core that is dominantly trondhjemite with less dominant tonalite and granodiorite variants, and a thin amphibole-biotite-bearing granite rim, with local occurrence of two-pyroxene-bearing metabasite boudins. While both the core and rim rocks exhibit a linear fabric, the granite in addition preserves a penetrative foliation. Field relations of granite enclaves in the core rocks together with available ages indicate that the core rocks intruded the granite. The foliated biotite ± amphibole-bearing Alldays granitoid contains inclusions of older supracrustals and rocks of the Messina layered intrusion, and is widely distributed. Compositionally, it include tonalites and granodiorites and to a lesser extent trondhjemites. Both the Avoca core and rim rocks are characterized by difference in mineral chemistry, with the mafic minerals Mg-rich in the TTG core, while they are Fe-rich in the granite and metabasite. In comparison, biotite is Mg-rich and amphibole is Fe-rich in the Alldays granitoid. Two groups of Alldays TTG can be delineated in terms of whole-rock geochemical characteristics, and are comparable to the low- to medium-pressure TTG groups delineated by Moyen (2011), while the Avoca TTG is similar to the high-pressure TTG group. The lowest silica samples from each group of granitoid have geochemical characteristics comparable to Archean sanukitoids, with those from the Avoca granitoid similar to low-Ti sanukitoids, and those from the Alldays granitoid similar to low-Ti and high-Ti sanukitoids. Separate petrogenetic models

  6. Uranium Isotopes as a Tracer of Groundwater Evolution in the Complexe Terminal Aquifer of Southern Tunisia

    Energy Technology Data Exchange (ETDEWEB)

    Hadj Ammar, F. [Laboratory of Radio-Analysis and Environment, National School of Engineering of Sfax, Sfax (Tunisia); Centre Europeen de Recherche et d' Enseignement de Geosciences de l' Environnement, Aix en Provence (France); Deschamps, P.; Hamelin, B. [Centre Europeen de Recherche et d' Enseignement de Geosciences de l' Environnement, Aix en Provence (France); Chkir, N.; Zouari, K. [Laboratory of Radio-Analysis and Environment, National School of Engineering of Sfax, Sfax (Tunisia)

    2013-07-15

    The Complexe Terminal (CT) aquifer system is the main water supply for remote areas of southern Tunisia. Its exploitation has resulted in significant draw-down of the water table. The CT aquifer is a multilayered aquifer lodged in Miocene sand deposits, Senonian limestones and Turonian carbonates. Little is known about the relationships and exchanges between the different layers. Here, uranium isotopic measurements carried out in groundwater samples from the CT aquifer are presented in order to constrain models for mixing of water masses, water-rock interaction and groundwater flow. Analyses were performed using a VG54 (TIMS) at the CEREGE. Results indicate a range in {sup 238}U concentration and {sup 234}U/{sup 238}U activity ratios of 1.5 to 8 ppb and 1.1 to 3.2 respectively. Together with major and trace analyses, uranium isotopic compositions provide important insights into the factors controlling the chemical evolution of groundwater and shows very distinct patterns between carbonate and sandstone layers. (author)

  7. A major light rare-earth element (LREE) resource in the Khanneshin carbonatite complex, southern Afghanistan

    Science.gov (United States)

    Tucker, Robert D.; Belkin, Harvey E.; Schulz, Klaus J.; Peters, Stephen G.; Horton, Forrest; Buttleman, Kim; Scott, Emily R.

    2012-01-01

    The rapid rise in world demand for the rare-earth elements (REEs) has expanded the search for new REE resources. We document two types of light rare-earth element (LREE)-enriched rocks in the Khanneshin carbonatite complex of southern Afghanistan: type 1 concordant seams of khanneshite-(Ce), synchysite-(Ce), and parisite-(Ce) within banded barite-strontianite alvikite, and type 2 igneous dikes of coarse-grained carbonatite, enriched in fluorine or phosphorus, containing idiomorphic crystals of khanneshite-(Ce) or carbocernaite. Type 1 mineralized barite-strontianite alvikite averages 22.25 wt % BaO, 4.27 wt % SrO, and 3.25 wt % ∑ LREE2O3 (sum of La, Ce, Pr, and Nd oxides). Type 2 igneous dikes average 14.51 wt % BaO, 5.96 wt % SrO, and 3.77 wt % ∑ LREE2O3. A magmatic origin is clearly indicated for the type 2 LREE-enriched dikes, and type 1 LREE mineralization probably formed in the presence of LREE-rich hydrothermal fluid. Both types of LREE mineralization may be penecontemporaneous, having formed in a carbonate-rich magma in the marginal zone of the central vent, highly charged with volatile constituents (i.e., CO2, F, P2O5), and strongly enriched in Ba, Sr, and the LREE. Based on several assumptions, and employing simple geometry for the zone of LREE enrichment, we estimate that at least 1.29 Mt (million metric tonnes) of LREE2O3 is present in this part of the Khanneshin carbonatite complex.

  8. The Riscos Bayos Ignimbrites of the Caviahue-Copahue volcanic caldera complex, southern Andes, Argentina

    Science.gov (United States)

    Colvin, A.; Merrill, M.; Demoor, M.; Goss, A.; Varekamp, J. C.

    2004-05-01

    The Caviahue-Copahue volcanic complex (38 S, 70 W) is located on the eastern margin of the active arc in the southern Andes, Argentina. Volcán Copahue, an active stratovolcano which hosts an active hydrothermal system, sits on the southwestern rim of the elliptical Caviahue megacaldera (17 x 15 km). The caldera wall sequences are up to 0.6 km thick and consist of lavas with 51 -69 percent SiO2 and 0.2 - 5 percent MgO as well as breccias, dikes, sills, domes and minor ignimbrites. Andesitic lava flows also occur within the caldera, and are overlain by a chaotic complex of silicic lava and intracaldera pyroclastic flow deposits. The eastern wall sequence is capped by several extracaldera ignimbrites (Riscos Bayos formation) of about 50 m maximum thickness which extend 30 km east-southeast of the caldera. Young back-arc alkali basalt scoria cones occur east of the Caviahue-Copahue volcanic complex. The eruption of the Riscos Bayos formation at about 1.1 Ma (12 km cubed) may be related to the Caviahue caldera formation, though the Riscos Bayos account for only about 7 percent of the caldera volume. The Riscos Bayos consists of three lithic-bearing flow units: a grey basal flow, a tan middle flow and a bright-white, highly indurated uppermost flow. The basal unit consists of white and grey pumice fragments, black scoria clasts, black obsidian clasts (which give it the grey color), and accidental volcanic lithics set in a matrix of ash and crystals. The middle unit is composed of large mauve pumice fragments and accidental lithics set in a fine tan ash groundmass. The uppermost unit is composed of small pink and white pumice fragments set in a matrix of fine white ash. These pumices carry quartz and biotite crystals, whereas the lower two units are orthopyroxene-bearing trachy-dacites. The Caviahue-Copahue magmas all bear arc signatures, but possibly some magma mixing between the andesitic arc magmas and basaltic back-arc magmas may have occurred. The evolved top layer

  9. Subsurface Permian reef complexes of southern Tunisia: Shelf carbonate setting and paleogeographic implications

    Science.gov (United States)

    Zaafouri, Adel; Haddad, Sofiene; Mannaî-Tayech, Beya

    2017-05-01

    2-D seismic reflection sections, borehole data as well as published and unpublished data have been investigated to reconstruct the paleogeography of southern Tunisia during Middle to Late Permian times. Paleogeographical reconstruction based on the integration of petroleum well data and 2-D seismic facies interpretation shows three main depositional areas with very contrasting sedimentary pile. These are 1) a subsiding basin; 2) an outer shelf carbonate, and 3) an inner shelf carbonate. Based on typical electric responses of reef buildups to seismic wave, we shall urge that during Middle Permian times, the outer carbonate shelf was subject of reef barrier development. Lithology evidences from core samples show that reef framework correspond mainly to fossiliferous limestone and dolomite. The WNW-ESE recognized reef barrier led between latitudes 33° 10‧ 00″N and 33° 20‧ 00″N. The Tebaga of Medenine outcrop constitutes the northern-edge of this barrier. Westward it may be extended to Bir Soltane area whereas its extension eastward is still to be determined. Biogenic buildups took place preferentially over faulted Carboniferous and lower Paleozoic paleohighs resulting likely from the Hercynian orogeny. The subsiding basin is located north of Tebaga of Medenine outcrop where Upper Permian sedimentary sequence is made entirely of 4000 m deep marine green silty shale facies. These are ascribed to unorganized and chaotic reflectors. Inner carbonate shelf facies succession corresponds to a typical interbedding of shallow marine carbonate deposits, shale, dolomite, and anhydrite inducing parallel-layered of strong amplitude and good continuity reflectors. Also within the inner carbonate shelf patch reef or reef pinnacles have been identified based on their seismic signature particularly their low vertical development as compared to reef complexes. Southward, towards Sidi Toui area, the Upper Permian depositional sequence thins out and bears witness of land

  10. The use and management of water in the Likangala Irrigation Scheme Complex in Southern Malawi

    Science.gov (United States)

    Mulwafu, Wapulumuka O.; Nkhoma, Bryson G.

    This paper examines the uses and management of water for agriculture in Lake Chilwa catchment area in Zomba district of Southern Malawi. It focuses on the Likangala Rice Irrigation Scheme Complex situated along the Likangala River. The scheme is one of the largest government-run schemes. Established in the late 1960s by the government to meet the growing demand for rice, the scheme contributes greatly to the agricultural industry of the country. Besides, the scheme was established to ensure maximum utilization of Malawi's largest wetland, which, due to its hydromorphic soils and the littoral floodplains, does not favour the production of traditional upland seasonal crops such as maize. The scheme's overdependence on water from the Likangala River has attracted a considerable degree of academic interest in the use and management of the river to ensure that there is equity and efficiency for both productive and domestic users. The paper focuses on four main issues: the historical development of the scheme, the distribution of water to farmers, social relations, and the overall contribution of the scheme towards the social and economic development of the area and the country in general. The paper contends that the growing population of the basin and the increase in the number of formal and informal smallholder farmers, contributes greatly to the growth of competition and conflicts over water, which tends to undermine the economic potential of the scheme. Furthermore, the paper provides clearest indication of the need for a realistic and informed water management policy and strategy to solve the growing problem of social inequity without necessarily compromising the production of rice in the scheme.

  11. Pine Plantations and Invasion Alter Fuel Structure and Potential Fire Behavior in a Patagonian Forest-Steppe Ecotone

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    Juan Paritsis

    2018-03-01

    Full Text Available Planted and invading non-native plant species can alter fire regimes through changes in fuel loads and in the structure and continuity of fuels, potentially modifying the flammability of native plant communities. Such changes are not easily predicted and deserve system-specific studies. In several regions of the southern hemisphere, exotic pines have been extensively planted in native treeless areas for forestry purposes and have subsequently invaded the native environments. However, studies evaluating alterations in flammability caused by pines in Patagonia are scarce. In the forest-steppe ecotone of northwestern Patagonia, we evaluated fine fuels structure and simulated fire behavior in the native shrubby steppe, pine plantations, pine invasions, and mechanically removed invasions to establish the relative ecological vulnerability of these forestry and invasion scenarios to fire. We found that pine plantations and their subsequent invasion in the Patagonian shrubby steppe produced sharp changes in fine fuel amount and its vertical and horizontal continuity. These changes in fuel properties have the potential to affect fire behavior, increasing fire intensity by almost 30 times. Pruning of basal branches in plantations may substantially reduce fire hazard by lowering the probability of fire crowning, and mechanical removal of invasion seems effective in restoring original fuel structure in the native community. The current expansion of pine plantations and subsequent invasions acting synergistically with climate warming and increased human ignitions warrant a highly vulnerable landscape in the near future for northwestern Patagonia if no management actions are undertaken.

  12. Phylogenetic relationships of leopard frogs (Rana pipiens complex) from an isolated coastal mountain range in southern Sonora, Mexico.

    Science.gov (United States)

    Pfeiler, E; Markow, T A

    2008-10-01

    Mitochondrial DNA sequence data from the control region and 12S rRNA in leopard frogs from the Sierra El Aguaje of southern Sonora, Mexico, together with GenBank sequences, were used to infer taxonomic identity and provide phylogenetic hypotheses for relationships with other members of the Rana pipiens complex. We show that frogs from the Sierra El Aguaje belong to the Rana berlandieri subgroup, or Scurrilirana clade, of the R. pipiens group, and are most closely related to Rana magnaocularis from Nayarit, Mexico. We also provide further evidence that Rana magnaocularis and R. yavapaiensis are close relatives.

  13. Silicic acid enrichment of subantarctic surface water from continental inputs along the Patagonian archipelago interior sea (41-56°S)

    Science.gov (United States)

    Torres, Rodrigo; Silva, Nelson; Reid, Brian; Frangopulos, Máximo

    2014-12-01

    We estimated Si∗, the surplus or deficit of orthosilicic acid (DSi) relative to nitrate available for diatom growth, in the Chilean Patagonian Archipelago Interior Sea (PAIS). Si∗ and salinity were negatively correlated in the PAIS because of the mixing of high nitrate, low DSi subantarctic surface water and high DSi, low nitrate continental freshwater runoff. Both the slope and the intercept of this relationship decreased from northern to southern Patagonia, which was likely a consequence of reduced DSi inputs from several overlapping hydrological, biological and geological drivers along this gradient. In general, lower freshwater DSi concentrations were expected below 46°S, and a lower total DSi load was expected from reduced runoff below 51°S. The north-south decreasing DSi concentration trend may be linked to dilutions from a higher proportion of runoff in latitudes with higher precipitation rates (45-53°S), the transition to more resistant granitic rocks and glacial melt-water from the Northern and Southern Patagonia Ice Fields (46-51°S) and a reduced density of volcanoes active during the Holocene (48-56°S). The intensification of a southward DSi deficit may be a forcing factor involved in the reported southward reductions in plankton biomass and a more frequent occurrence of non-diatom blooms in southern PAIS.

  14. Architecture, sedentism, and social complexity at Pre-Pottery Neolithic A WF16, Southern Jordan

    Science.gov (United States)

    Finlayson, Bill; Mithen, Steven J.; Najjar, Mohammad; Smith, Sam; Maričević, Darko; Pankhurst, Nick; Yeomans, Lisa

    2011-01-01

    Recent excavations at Pre-Pottery Neolithic A (PPNA) WF16 in southern Jordan have revealed remarkable evidence of architectural developments in the early Neolithic. This sheds light on both special purpose structures and “domestic” settlement, allowing fresh insights into the development of increasingly sedentary communities and the social systems they supported. The development of sedentary communities is a central part of the Neolithic process in Southwest Asia. Architecture and ideas of homes and households have been important to the debate, although there has also been considerable discussion on the role of communal buildings and the organization of early sedentarizing communities since the discovery of the tower at Jericho. Recently, the focus has been on either northern Levantine PPNA sites, such as Jerf el Ahmar, or the emergence of ritual buildings in the Pre-Pottery Neolithic B of the southern Levant. Much of the debate revolves around a division between what is interpreted as domestic space, contrasted with “special purpose” buildings. Our recent evidence allows a fresh examination of the nature of early Neolithic communities. PMID:21536900

  15. Architecture, sedentism, and social complexity at Pre-Pottery Neolithic A WF16, Southern Jordan.

    Science.gov (United States)

    Finlayson, Bill; Mithen, Steven J; Najjar, Mohammad; Smith, Sam; Maričević, Darko; Pankhurst, Nick; Yeomans, Lisa

    2011-05-17

    Recent excavations at Pre-Pottery Neolithic A (PPNA) WF16 in southern Jordan have revealed remarkable evidence of architectural developments in the early Neolithic. This sheds light on both special purpose structures and "domestic" settlement, allowing fresh insights into the development of increasingly sedentary communities and the social systems they supported. The development of sedentary communities is a central part of the Neolithic process in Southwest Asia. Architecture and ideas of homes and households have been important to the debate, although there has also been considerable discussion on the role of communal buildings and the organization of early sedentarizing communities since the discovery of the tower at Jericho. Recently, the focus has been on either northern Levantine PPNA sites, such as Jerf el Ahmar, or the emergence of ritual buildings in the Pre-Pottery Neolithic B of the southern Levant. Much of the debate revolves around a division between what is interpreted as domestic space, contrasted with "special purpose" buildings. Our recent evidence allows a fresh examination of the nature of early Neolithic communities.

  16. Understanding strain transfer and basin evolution complexities in the Salton pull-apart basin near the Southern San Andreas Fault

    Science.gov (United States)

    Kell, A. M.; Sahakian, V. J.; Kent, G. M.; Driscoll, N. W.; Harding, A. J.; Baskin, R. L.; Barth, M.; Hole, J. A.; Stock, J. M.; Fuis, G. S.

    2015-12-01

    Active source seismic data in the Salton Sea provide insight into the complexity of the pull-apart system development. Seismic reflection data combined with tomographic cross sections give constraints on the timing of basin development and strain partitioning between the two dominant dextral faults in the region; the Imperial fault to the southwest and the Southern San Andreas fault (SSAF) to the northeast. Deformation associated with this step-over appears young, having formed in the last 20-40 k.a. The complexity seen in the Salton Sea is similar to that seen in pull-apart basins worldwide. In the southern basin of the Salton Sea, a zone of transpression is noted near the southern termination of the San Andreas fault, though this stress regime quickly transitions to a region of transtension in the northern reaches of the sea. The evolution seen in the basin architecture is likely related to a transition of the SSAF dying to the north, and giving way to youthful segments of the Brawley seismic zone and Imperial fault. Stratigraphic signatures seen in seismic cross-sections also reveal a long-term component of slip to the southwest on a fault 1-2 km west of the northeastern Salton Sea shoreline. Numerous lines of evidence, including seismic reflection data, high-resolution bathymetry within the Salton Sea, and folding patterns in the Borrego Formation to the east of the sea support an assertion of a previously unmapped fault, the Salton Trough fault (STF), parallel to the SAF and just offshore within the Salton Sea. Seismic observations are seen consistently within two datasets of varying vertical resolutions, up to depths of 4-5 km, suggesting that this fault strand is much longer-lived than the evolution seen in the southern sub-basin. The existence of the STF unifies discrepancies between the onshore seismic studies and data collected within the sea. The STF likely serves as the current bounding fault to the active pull-apart system, as it aligns with the "rung

  17. Morphological characterization of Capsicum annuum L. accessions from southern Mexico and their response to the Bemisia tabaci-Begomovirus complex

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    Horacio Ballina-Gomez

    2013-12-01

    Full Text Available The high diversity of chili pepper (Capsicum annuum L. in Mexico offers an excellent alternative to search for wild and semi-domesticated genotypes as sources of resistance to the complex Bemisia tabaci (Genn. (Hemiptera: Aleyrodidae-Begomovirus, which has caused enormous losses in commercial production of various horticultural crops. The goal of the present work was to characterize ex situ 18 genotypes of C. annuum from southern Mexico through 47 morphological descriptors, and to evaluate its response to the B. tabaci-Begomovirus complex. Morphological characterization showed the variables calyx annular constriction (CAC, number of branch bifurcation (NBB, and calyx pigmentation (CP had the highest variation. Principal components analysis (PCA of 47 morphological characteristics showed that 12 components were selected as meaningful factors. These components explained 94% of the variation. Cluster analysis showed three major clusters and seven sub-clusters. On the other hand, evaluation of the response to B. tabaci-Begomovirus showed that the genotypes have differential susceptibility to this vector-pathogen complex. Genotypes 'Chawa', 'Blanco', 'Maax' and 'X'catic' were into the low susceptibility to B. tabaci and low severity of viral symptoms. Surprisingly, the genotype 'Simojovel' showed high susceptibility to whitefly, but was grouped into genotypes with low symptom severity. This study shows the potential of native germplasm of pepper to explore sources of resistance to the B. tabaci-Begomovirus complex.

  18. Thermally forced mesoscale atmospheric flow over complex terrain in Southern Italy

    International Nuclear Information System (INIS)

    Baldi, M.; Colacino, M.; Dalu, G. A.; Piervitali, E.; Ye, Z.

    1998-01-01

    In this paper the Authors discuss some results concerning the analysis of the local atmospheric flow over the southern part of Italy, the peninsula of Calabria, using a mesoscale numerical model. Our study is focused on two different but related topics: a detailed analysis of the meteorology and climate of the region based on a data collection, reported in Colacino et al., 'Elementi di Climatologia della Calabria', edited by A. Guerrini, in the series P. S., 'Clima, Ambiente e Territorio nel Mezzogiorno' (CNR, Rome) 1997, pp. 218, and an analysis of the results based on the simulated flow produced using a mesoscale numerical model. The Colorado State University mesoscale numerical model has been applied to study several different climatic situations of particular interest for the region, as discussed in this paper

  19. PGE mineralization and melt composition of chromitites in Proterozoic ophiolite complexes of Eastern Sayan, Southern Siberia

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    O. Kiseleva

    2017-07-01

    Full Text Available The Ospino-Kitoi and Kharanur ultrabasic massifs represent the northern and southern ophiolite branches respectively of the Upper Onot ophiolitic nappe and they are located in the southeastern part of the Eastern Sayan (SEPES ophiolites. Podiform chromitites with PGE mineralization occur as lensoid pods within dunites and rarely in harzburgites or serpentinized peridotites. The chromitites are classified into type I and type II based on their Cr#. Type I (Cr# = 59–85 occurs in both northern and southern branches, whereas type II (Cr# = 76–90 occurs only in the northern branch. PGE contents range from ∑PGE 88–1189 ppb, Pt/Ir 0.04–0.42 to ∑PGE 250–1700 ppb, Pt/Ir 0.03–0.25 for type I chromitites of the northern and southern branches respectively. The type II chromitites of the northern branch have ∑PGE contents higher than that of type I (468–8617 ppb, Pt/Ir 0.1–0.33. Parental melt compositions, in equilibrium with podiform chromitites, are in the range of boninitic melts and vary in Al2O3, TiO2 and FeO/MgO contents from those of type I and type II chromitites. Calculated melt compositions for type I chromitites are (Al2O3melt = 10.6–13.5 wt.%, (TiO2melt = 0.01–0.44 wt.%, (Fe/Mgmelt = 0.42–1.81; those for type II chromitites are: (Al2O3melt = 7.8–10.5 wt.%, (TiO2melt = 0.01–0.25 wt.%, (Fe/Mgmelt = 0.5–2.4. Chromitites are further divided into Os-Ir-Ru (I and Pt-Pd (II based on their PGE patterns. The type I chromitites show only the Os-Ir-Ru pattern whereas type II shows both Os-Ir-Ru and Pt-Pd patterns. PGE mineralization in type I chromitites is represented by the Os-Ir-Ru system, whereas in type II it is represented by the Os-Ir-Ru-Rh-Pt system. These results indicate that chromitites and PGE mineralization in the northern branch formed in a suprasubduction setting from a fluid-rich boninitic melt during active subduction. However, the chromitites and PGE mineralization of the southern

  20. Thermally forced mesoscale atmospheric flow over complex terrain in Southern Italy

    Energy Technology Data Exchange (ETDEWEB)

    Baldi, M.; Colacino, M.; Dalu, G. A.; Piervitali, E.; Ye, Z. [CNR, Rome (Italy). Ist. di Fisica dell`Atmosfera

    1998-07-01

    In this paper the Authors discuss some results concerning the analysis of the local atmospheric flow over the southern part of Italy, the peninsula of Calabria, using a mesoscale numerical model. Our study is focused on two different but related topics: a detailed analysis of the meteorology and climate of the region based on a data collection, reported in Colacino et al., `Elementi di Climatologia della Calabria`, edited by A. Guerrini, in the series P. S., `Clima, Ambiente e Territorio nel Mezzogiorno` (CNR, Rome) 1997, pp. 218, and an analysis of the results based on the simulated flow produced using a mesoscale numerical model. The Colorado State University mesoscale numerical model has been applied to study several different climatic situations of particular interest for the region, as discussed in this paper.

  1. Equatorial origin for Lower Jurassic radiolarian chert in the Franciscan Complex, San Rafael Mountains, southern California

    Science.gov (United States)

    Hagstrum, J.T.; Murchey, B.L.; Bogar, R.S.

    1996-01-01

    Lower Jurassic radiolarian chert sampled at two localities in the San Rafael Mountains of southern California (???20 km north of Santa Barbara) contains four components of remanent magnetization. Components A, B???, and B are inferred to represent uplift, Miocene volcanism, and subduction/accretion overprint magnetizations, respectively. The fourth component (C), isolated between 580?? and 680??C, shows a magnetic polarity stratigraphy and is interpreted as a primary magnetization acquired by the chert during, or soon after, deposition. Both sequences are late Pliensbachian to middle Toarcian in age, and an average paleolatitude calculated from all tilt-corrected C components is 1?? ?? 3?? north or south. This result is consistent with deposition of the cherts beneath the equatorial zone of high biologic productivity and is similar to initial paleolatitudes determined for chert blocks in northern California and Mexico. This result supports our model in which deep-water Franciscan-type cherts were deposited on the Farallon plate as it moved eastward beneath the equatorial productivity high, were accreted to the continental margin at low paleolatitudes, and were subsequently distributed northward by strike-slip faulting associated with movements of the Kula, Farallon, and Pacific plates. Upper Cretaceous turbidites of the Cachuma Formation were sampled at Agua Caliente Canyon to determine a constraining paleolatitude for accretion of the Jurassic chert sequences. These apparently unaltered rocks, however, were found to be completely overprinted by the A component of magnetization. Similar in situ directions and demagnetization behaviors observed in samples of other Upper Cretaceous turbidite sequences in southern and Baja California imply that these rocks might also give unreliable results.

  2. AMPLIFIED FRAGMENT LENGTH POLYMORPHISM ANALYSIS OF MYCOBACTERIUM AVIUM COMPLEX ISOLATES RECOVERED FROM SOUTHERN CALIFORNIA

    Science.gov (United States)

    Fine-scale genotyping methods are necessary in order to identify possible sources of human exposure to opportunistic pathogens belonging to the Mycobacterium avium complex (MAC). In this study, amplified fragment length polymorphism (AFLP) analysis was evaluated for fingerprintin...

  3. Complex interplay between intrinsic and extrinsic drivers of long-term survival trends in southern elephant seals

    Directory of Open Access Journals (Sweden)

    McMahon Clive R

    2007-03-01

    Full Text Available Abstract Background Determining the relative contribution of intrinsic and extrinsic factors to fluctuations in population size, trends and demographic composition is analytically complex. It is often only possible to examine the combined effects of these factors through measurements made over long periods, spanning an array of population densities or levels of food availability. Using age-structured mark-recapture models and datasets spanning five decades (1950–1999, and two periods of differing relative population density, we estimated age-specific probabilities of survival and examined the combined effects of population density and environmental conditions on juvenile survival of southern elephant seals at Macquarie Island. Results First-year survival decreased with density during the period of highest population size, and survival increased during years when the Southern Oscillation Index (SOI anomaly (deviation from a 50-year mean during the mother's previous foraging trip to sea was positive (i.e., El Niño. However, when environmental stochasticity and density were considered together, the effect of density on first-year survival effectively disappeared. Ignoring density effects also leads to models placing too much emphasis on the environmental conditions prevailing during the naïve pup's first year at sea. Conclusion Our analyses revealed that both the state of the environment and population density combine to modify juvenile survival, but that the degree to which these processes contributed to the variation observed was interactive and complex. This underlines the importance of evaluating the relative contribution of both the intrinsic and extrinsic factors that regulate animal populations because false conclusions regarding the importance of population regulation may be reached if they are examined in isolation.

  4. Cryptic elevational zonation in trapdoor spiders (Araneae, Antrodiaetidae, Aliatypus janus complex) from the California southern Sierra Nevada.

    Science.gov (United States)

    Starrett, James; Hayashi, Cheryl Y; Derkarabetian, Shahan; Hedin, Marshal

    2018-01-01

    The relative roles of ecological niche conservatism versus niche divergence in promoting montane speciation remains an important topic in biogeography. Here, our aim was to test whether lineage diversification in a species complex of trapdoor spiders corresponds with riverine barriers or with an ecological gradient associated with elevational tiering. Aliatypus janus was sampled from throughout its range, with emphasis on populations in the southern Sierra Nevada Mountains of California. We collected multi-locus genetic data to generate a species tree for A. janus and its close relatives. Coalescent based hypothesis tests were conducted to determine if genetic breaks within A. janus conform to riverine barriers. Ecological niche models (ENM) under current and Last Glacial Maximum (LGM) conditions were generated and hypothesis tests of niche conservatism and divergence were performed. Coalescent analyses reveal deeply divergent genetic lineages within A. janus, likely corresponding to cryptic species. Two primary lineages meet along an elevational gradient on the western slopes of the southern Sierra Nevada Mountains. ENMs under both current and LGM conditions indicate that these groups occupy largely non-overlapping niches. ENM hypothesis testing rejected niche identity between the two groups, and supported a sharp ecological gradient occurring where the groups meet. However, the niche similarity test indicated that the two groups may not inhabit different background niches. The Sierra Nevada Mountains provide a natural laboratory for simultaneously testing ecological niche divergence and conservatism and their role in speciation across a diverse range of taxa. Aliatypus janus represents a species complex with cryptic lineages that may have diverged due to parapatric speciation along an ecological gradient, or been maintained by the evolution of ecological niche differences following allopatric speciation. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Hydrothermal alteration in the Matok Igneous Complex, Southern Marginal Zone of the Limpopo Belt, South Africa

    International Nuclear Information System (INIS)

    Sieber, T.; Van Reenen, D.D.; Barton, J.M.

    1991-01-01

    Ductile shear zones associated with the 2700 to 2650 Ma Limpopo Orogeny locally contained gold mineralization. Some of these shear zones were reactivated under brittle conditions and contain zones of hydrothermal alteration that are of potential economic significance. Within the approximately 2670 Ma Matok Complex, two examples of this shear zone controlled alteration are exposed, the Dwars River and Sand River alteration zones. The granitic rocks of this Complex experienced early selective sericitization of plagioclase and the subsequent development of perthitic porphyroblasts. This early regional alteration was overprinted along brittle shear zones by pervasive propylitization and vein controlled quartz-albite alteration. The setting, composition, and the age of the Matok Complex make it a possible source for Archaean gold mineralization. The Dwars River and Sand River alteration zones are characterized by the absence of significant gold mineralization. The pattern of wall-rock alteration indicates that the hydrothermal processes were different from typical Archaean lode gold deposits. P-T conditions during the shear-zone controlled alteration were less than 400 degrees C and 1,9 - 2,8 kb. The shear zone hosted alteration could have taken place anytime between emplacement of the Matok Complex and about 1315 Ma ago. 35 refs., 10 figs., 4 tabs

  6. Grammar rules for the isiZulu complex verb | Maria Keet | Southern ...

    African Journals Online (AJOL)

    The isiZulu verb is known for its morphological complexity, which is a subject of on-going linguistics research, as well as for prospects of computational use, such as controlled natural language interfaces, machine translation and spellcheckers. To this end, we seek to answer the question as to what the precise grammar ...

  7. Volcanic tremor and local earthquakes at Copahue volcanic complex, Southern Andes, Argentina

    Science.gov (United States)

    Ibáñez, J. M.; Del Pezzo, E.; Bengoa, C.; Caselli, A.; Badi, G.; Almendros, J.

    2008-07-01

    In the present paper we describe the results of a seismic field survey carried out at Copahue Volcano, Southern Andes, Argentina, using a small-aperture, dense seismic antenna. Copahue Volcano is an active volcano that exhibited a few phreatic eruptions in the last 20 years. The aim of this experiment was to record and classify the background seismic activity of this volcanic area, and locate the sources of local earthquakes and volcanic tremor. Data consist of several volcano-tectonic (VT) earthquakes, and many samples of back-ground seismic noise. We use both ordinary spectral, and multi-spectral techniques to measure the spectral content, and an array technique [Zero Lag Cross Correlation technique] to measure the back-azimuth and apparent slowness of the signals propagating across the array. We locate VT earthquakes using a procedure based on the estimate of slowness vector components and S-P time. VT events are located mainly along the border of the Caviahue caldera lake, positioned at the South-East of Copahue volcano, in a depth interval of 1-3 km below the surface. The background noise shows the presence of many transients with high correlation among the array stations in the frequency band centered at 2.5 Hz. These transients are superimposed to an uncorrelated background seismic signal. Array solutions for these transients show a predominant slowness vector pointing to the exploited geothermal field of "Las Maquinitas" and "Copahue Village", located about 6 km north of the array site. We interpret this coherent signal as a tremor generated by the activity of the geothermal field.

  8. Structural control on basaltic dike and sill emplacement, Paiute Ridge mafic intrusion complex, southern Nevada

    International Nuclear Information System (INIS)

    Carter Krogh, K.E.; Valentine, G.A.

    1996-08-01

    Late Miocene basaltic sills and dikes in the Paiute Ridge area of southern nevada show evidence that their emplacement was structurally controlled. Basaltic dikes in this area formed by dilating pre-existing vertical to steeply E-dipping normal faults. Magma propagation along these faults must have required less energy than the creation of a self-propagated fracture at dike tips and the magma pressure must have been greater than the compressive stress perpendicular to the fault surface. N- to NE-trending en echelon dikes formed locally and are not obviously attached to the three main dikes in the area. The en echelon segments are probably pieces of deeper dikes, which are segmented perhaps as a result of a documented rotation of the regional stresses. Alternatively, changes in orientation of principal stresses in the vicinity of each en echelon dike could have resulted from local loads associated with paleotopographic highs or nearby structures. Sills locally branched off some dikes within 300 m of the paleosurface. These subhorizontal bodies occur consistently in the hanging wall block of the dike-injected faults, and intrude Tertiary tuffs near the Paleozoic-Tertiary contact. The authors suggest that the change in stresses near the earth's surface, the material strength of the tuff and paleozoic rocks, and the Paleozoic bedding dip direction probably controlled the location of sill formation and direction of sill propagation. The two largest sills deflected the overlying tuffs to form lopoliths, indicating that the magma pressure exceeded vertical stresses at that location and that the shallow level and large size of the sills allowed interaction with the free (earth's) surface. 32 refs., 4 figs., 1 tab

  9. Temporal complexity of southern Beaufort Sea polar bear diets during a period of increasing land use

    Science.gov (United States)

    McKinney, Melissa A.; Atwood, Todd C.; Iverson, Sara J.; Peacock, Elizabeth

    2017-01-01

    From 2000 to 2013, use of land as a seasonal habitat by polar bears (Ursus maritimus) of the southern Beaufort Sea (SB) subpopulation substantially increased. This onshore use has been linked to reduced spatial and temporal availability of sea ice, as well as to the availability of subsistence‐harvested bowhead whale (Balaena mysticetus) bone piles. Here, we evaluated the role of climate conditions on consumption of traditional ice‐associated prey relative to onshore bowhead whale bone piles. We determined seasonal and interannual trends in the diets of SB polar bears using fatty acid‐based analysis during this period of increasing land use. Diet estimates of 569 SB polar bears from 2004 to 2012 showed high seasonal fluctuations in the proportions of prey consumed. Higher proportions of bowhead whale, as well as ringed seal (Pusa hispida) and beluga whale (Delphinapterus leucas), were estimated to occur in the winter–spring diet, while higher proportions of bearded seal (Erignathus barbatus) were estimated for summer–fall diets. Trends in the annual mean proportions of individual prey items were not found in either period, except for significant declines in the proportion of beluga in spring‐sampled bears. Nonetheless, in years following a high winter Arctic oscillation index, proportions of ice‐associated ringed seal were lower in the winter–spring diets of adult females and juveniles. Proportions of bowhead increased in the winter–spring diets of adult males with the number of ice‐free days over the continental shelf. In one or both seasons, polar bears that were in better condition were estimated to have consumed less ringed seal and/or more bowhead whale than those in worse condition. Therefore, climate variation over this recent period appeared to influence the extent of onshore vs. on‐ice food use, which in turn, appeared to be linked to fluctuating condition of SB polar bears.

  10. Anatomy of nasal complex in the southern right whale, Eubalaena australis (Cetacea, Mysticeti).

    Science.gov (United States)

    Buono, Mónica R; Fernández, Marta S; Fordyce, R Ewan; Reidenberg, Joy S

    2015-01-01

    The nasal region of the skull has undergone dramatic changes during the course of cetacean evolution. In particular, mysticetes (baleen whales) conserve the nasal mammalian pattern associated with the secondary function of olfaction, and lack the sound-producing specializations present in odontocetes (toothed whales, dolphins and porpoises). To improve our understanding of the morphology of the nasal region of mysticetes, we investigate the nasal anatomy, osteology and myology of the southern right whale, Eubalaena australis, and make comparisons with other mysticetes. In E. australis external deflection surfaces around the blowholes appear to divert water off the head, and differ in appearance from those observed in balaenopterids, eschrichtiids and cetotherids. In E. australis the blowholes are placed above hypertrophied nasal soft tissues formed by fat and nasal muscles, a pattern also observed in balaenopterids (rorqual mysticetes) and a cetotherid (pygmy right whale, Caperea marginata). Blowhole movements are due to the action of five nasofacial muscles: dilator naris superficialis, dilator naris profundus, depressor alae nasi, constrictor naris, and retractor alae nasi. The dilator naris profundus found in E. australis has not been previously reported in balaenopterids. The other nasofacial muscles have a similar arrangement in balaenopterids, with minor differences. A novel structure, not reported previously in any mysticete, is the presence of a vascular tissue (rete mirabile) covering the lower nasal passage. This vascular tissue could play a role in warming inspired air, or may engorge to accommodate loss of respiratory space volume due to gas compression from increased pressure during diving. © 2014 Anatomical Society.

  11. Systematics of the hypervariable Moraea tripetala complex (Iridaceae: Iridoideae of the southern African winter rainfall zone

    Directory of Open Access Journals (Sweden)

    P. Goldblatt

    2012-12-01

    Full Text Available Field and laboratory research has shown that the Moraea tripetala complex of western South Africa, traditionally treated as a single species, sometimes with two additional varieties, has a pattern of morphological and cytological variation too complex to be accommodated in a single species. Variation in floral structure, especially the shape of the inner tepals, degree of union of the filaments, anther length and pollen colour form coherent patterns closely correlated with morphology of the corm tunics, mode of vegetative reproduction, and in some instances capsule and seed shape and size. The morphological patterns also correlate with geography, flowering time and sometimes habitat. It is especially significant that different variants of the complex may co-occur, each with overlapping or separate flowering times, a situation that conflicts with a single species taxonomy. We propose recognizing nine species and three additional subspecies for plants currently assigned to M. tripetala. M. grandis, from the western Karoo, has virtually free filaments and leaves often ± plane distally; closely allied M. amabilis, also with ± free filaments and often hairy leaves, is centred in the western Karoo and Olifants River Valley. Its range overlaps that of M. cuspidata, which has narrowly channelled, smooth leaves, linear inner tepals spreading distally and filaments united for up to 1.5 mm. M. decipiens from the Piketberg, M. hainebachiana, a local endemic of coastal limestone fynbos in the Saldanha District, M. ogamana from seasonally wet lowlands, and early flowering M. mutila constitute the remaining species of the complex in the southwestern Western Cape. M. helmei, a local endemic of middle elevations in the Kamiesberg, Namaqualand, has small flowers with short, tricuspidate inner tepals. All but M. amabilis and M. mutila are new species. We divide M. tripetala sensu stricto into three subspecies: widespread subsp. tripetala, subsp. violacea from

  12. Late extensional shear zones and associated recumbent folds in the Alpujarride subduction complex, Betic Cordillera, southern Spain

    Energy Technology Data Exchange (ETDEWEB)

    Orozco, M.; Alonso-Chaves, F.; Platt, J.

    2017-11-01

    The existence in the Alpujarride Complex (Betic Cordillera, southern Spain) of a relatively continuous extensional event (following crustal thickening) is based on detailed structural studies and is consistent with the P-T paths and geochronological data established for the Alpujarride rocks. According to our research, the Alpujarride Complex contains two large-scale shear zones accommodating early Miocene extension. The shear zones contain km-scale recumbent folds, some with sheath fold geometry, and megaboudinage structures, and are closely associated with detachment faults. Large-scale folds and boudins cause dome-like undulations in the detachments, which are inferred to overlap in time with the deformation in the shear zones. One shear zone in the eastern part of the orogen is top-N; the other, in the western part, is top-E. The change in the shear direction may represent a temporal evolution in the direction of shear, possibly related to a change in the subduction direction in space and time.

  13. Late extensional shear zones and associated recumbent folds in the Alpujarride subduction complex, Betic Cordillera, southern Spain

    International Nuclear Information System (INIS)

    Orozco, M.; Alonso-Chaves, F.; Platt, J.

    2017-01-01

    The existence in the Alpujarride Complex (Betic Cordillera, southern Spain) of a relatively continuous extensional event (following crustal thickening) is based on detailed structural studies and is consistent with the P-T paths and geochronological data established for the Alpujarride rocks. According to our research, the Alpujarride Complex contains two large-scale shear zones accommodating early Miocene extension. The shear zones contain km-scale recumbent folds, some with sheath fold geometry, and megaboudinage structures, and are closely associated with detachment faults. Large-scale folds and boudins cause dome-like undulations in the detachments, which are inferred to overlap in time with the deformation in the shear zones. One shear zone in the eastern part of the orogen is top-N; the other, in the western part, is top-E. The change in the shear direction may represent a temporal evolution in the direction of shear, possibly related to a change in the subduction direction in space and time.

  14. 3D Gravity Modeling of Complex Salt Features in the Southern Gulf of Mexico

    Directory of Open Access Journals (Sweden)

    Mauricio Nava-Flores

    2016-01-01

    Full Text Available We present a three-dimensional (3D gravity modeling and inversion approach and its application to complex geological settings characterized by several allochthonous salt bodies embedded in terrigenous sediments. Synthetic gravity data were computed for 3D forward modeling of salt bodies interpreted from Prestack Depth Migration (PSDM seismic images. Density contrasts for the salt bodies surrounded by sedimentary units are derived from density-compaction curves for the northern Gulf of Mexico’s oil exploration surveys. By integrating results from different shape- and depth-source estimation algorithms, we built an initial model for the gravity anomaly inversion. We then applied a numerically optimized 3D simulated annealing gravity inversion method. The inverted 3D density model successfully retrieves the synthetic salt body ensemble. Results highlight the significance of integrating high-resolution potential field data for salt and subsalt imaging in oil exploration.

  15. Screening level dose assessment of aquatic biota downstream of the Marcoule nuclear complex in southern France.

    Science.gov (United States)

    St-Pierre, S; Chambers, D B; Lowe, L M; Bontoux, J G

    1999-09-01

    Aquatic biota in the Rhone River downstream of the Marcoule nuclear complex in France are exposed to natural sources of radiation and to radioactivity released from the Marcoule complex. A simple conservative screening level model was used to estimate the range of concentrations in aquatic media (water, sediments, and aquatic organisms) of both artificial and natural radionuclides and the consequent absorbed (whole body) dose rates for aquatic organisms. Five categories of aquatic organisms were studied, namely, submerged aquatic plants (phanerogam), non-bottom-feeding fish, bottom-feeding fish, mollusca, and fish-eating birds. The analysis was based on the radionuclide concentrations reported in four consecutive annual radioecological monitoring reports published by French agencies with nuclear regulatory responsibilities. The results of this assessment were used to determine, qualitatively, the magnitude of any potential health impacts on each of the five categories of aquatic organisms studied. The range of dose rate estimates ranged over three orders of magnitude, with maximum dose rates estimated to be in the order of 1 to 10 microGy h(-1). These maximum dose rates are a factor 40 or more below the international guideline intended to ensure the protection of aquatic populations (about 400 microGy h(-1)), and a factor ten or more below the level which may trigger the need for a more detailed evaluation of potential ecological consequences to the exposed populations (about 100 microGy h(-1)). As a result, chronic levels of radioactivity, artificial and natural, measured in aquatic media downstream of Marcoule are unlikely to result in adverse health impacts on the categories and species of aquatic organisms studied. Thus, based on the screening level analysis discussed in this paper, a more detailed evaluation of the dose rates does not appear to be warranted.

  16. The complexity of rural contexts experienced by community disability workers in three southern African countries

    Directory of Open Access Journals (Sweden)

    Margaret Booyens

    2015-06-01

    Full Text Available An understanding of rural communities is fundamental to effective community-based rehabilitation work with persons with disabilities. By removing barriers to community participation, persons with disabilities are enabled to satisfy their fundamental human needs. However, insufficient attention has been paid to the challenges that rural community disability workers (CDWs face in trying to realise these objectives. This qualitative interpretive study, involving in-depth interviews with 16 community disability workers in Botswana, Malawi and South Africa, revealed the complex ways in which poverty, inappropriately used power and negative attitudes of service providers and communities combine to create formidable barriers to the inclusion of persons with disabilities in families and rural communities. The paper highlights the importance of understanding and working with the concept of ‘disability’ from a social justice and development perspective. It stresses that by targeting attitudes, actions and relationships, community disability workers can bring about social change in the lives of persons with disabilities and the communities in which they live.

  17. Decadal predictions of Southern Ocean sea ice : testing different initialization methods with an Earth-system Model of Intermediate Complexity

    Science.gov (United States)

    Zunz, Violette; Goosse, Hugues; Dubinkina, Svetlana

    2013-04-01

    The sea ice extent in the Southern Ocean has increased since 1979 but the causes of this expansion have not been firmly identified. In particular, the contribution of internal variability and external forcing to this positive trend has not been fully established. In this region, the lack of observations and the overestimation of internal variability of the sea ice by contemporary General Circulation Models (GCMs) make it difficult to understand the behaviour of the sea ice. Nevertheless, if its evolution is governed by the internal variability of the system and if this internal variability is in some way predictable, a suitable initialization method should lead to simulations results that better fit the reality. Current GCMs decadal predictions are generally initialized through a nudging towards some observed fields. This relatively simple method does not seem to be appropriated to the initialization of sea ice in the Southern Ocean. The present study aims at identifying an initialization method that could improve the quality of the predictions of Southern Ocean sea ice at decadal timescales. We use LOVECLIM, an Earth-system Model of Intermediate Complexity that allows us to perform, within a reasonable computational time, the large amount of simulations required to test systematically different initialization procedures. These involve three data assimilation methods: a nudging, a particle filter and an efficient particle filter. In a first step, simulations are performed in an idealized framework, i.e. data from a reference simulation of LOVECLIM are used instead of observations, herein after called pseudo-observations. In this configuration, the internal variability of the model obviously agrees with the one of the pseudo-observations. This allows us to get rid of the issues related to the overestimation of the internal variability by models compared to the observed one. This way, we can work out a suitable methodology to assess the efficiency of the

  18. Wing pattern variation in the Patagonian biting midge, Forcipomyia (Forcipomyia multipicta Ingram & Macfie (Diptera, Ceratopogonidae

    Directory of Open Access Journals (Sweden)

    Gustavo R. SPINELLI

    2012-01-01

    Full Text Available Examination of the type-series and non-type specimens of the Patagonian biting midge, Forcipomyia (Forcipomyia multipicta Ingram & Macfie (Diptera: Ceratopogonidae, revealed considerable variation in wing patterns of both sexes. One pattern includes several distinct light spot areas, whereas another pattern (e.g, in the holotype only features marginal light spots in cell r3, while other light spots are barely perceptible or absent. The cause(s of the differential lack of dark macrotrichia in certain areas of the wing membrane in specimens of some series could not be attributed either to their age, sex, or method of preservation.

  19. Ecology and management of the invasive lionfish Pterois volitans/miles complex (Perciformes: Scorpaenidae) in Southern Costa Rica.

    Science.gov (United States)

    Sandel, Vera; Martínez-Fernández, Damián; Wangpraseurt, Daniel; Sierra, Luis

    2015-03-01

    Invasive species alter ecosystem integrity and functioning and are considered one of the major threats to biodiversity on a global scale. The indopacific lionfish (Plerois volitans [Linnaeus, 1758] / miles [Bennet, 1882] complex) is the first non-native marine fish that has established itself in the Western Atlantic. It was first reported in Florida in the 1980s and then spread across the entire Caribbean in subsequent years. In Costa Rica, lionfish were first sighted by the end of 2008 and are now present in all South Caribbean reefs. Lionfish are a major problem for local fisherman by displacing native fish species. The aim of this study was to determine population density, size and diet of lionfish populations at four study sites along the Southern Caribbean coast of Costa Rica. Two of the sites were located inside the National Park Cahuita where regular lionfish removal occurs, whereas the other two study sides do not experiment this kind of management. Total length and wet weight of >450 lionfish individuals were determined between March and June 2011. Three relative metrics of prey quantity (percent number, percent frequency, and percent weight) were compared from approximately 300 lionfish caught with the polespear in shallow waters (invasive lionfish in Costa Rica.

  20. Unraveling the complex local-scale flows influencing ozone patterns in the southern Great Lakes of North America

    Directory of Open Access Journals (Sweden)

    I. Levy

    2010-11-01

    Full Text Available This study examines the complexity of various processes influencing summertime ozone levels in the southern Great Lakes region of North America. Results from the Border Air Quality and Meteorology (BAQS-Met field campaign in the summer of 2007 are examined with respect to land-lake differences and local meteorology using a large array of ground-based measurements, aircraft data, and simulation results from a high resolution (2.5 km regional air-quality model, AURAMS.

    Analyses of average ozone mixing ratio from the entire BAQS-Met intensive campaign period support previous findings that ozone levels are higher over the southern Great Lakes than over the adjacent land. However, there is great heterogeneity in the spatial distribution of surface ozone over the lakes, particularly over Lake Erie during the day, with higher levels located over the southwestern end of the lake. Model results suggest that some of these increased ozone levels are due to local emission sources in large nearby urban centers. While an ozone reservoir layer is predicted by the AURAMS model over Lake Erie at night, the land-lake differences in ozone mixing ratios are most pronounced during the night in a shallow inversion layer of about 200 m above the surface. After sunrise, these differences have a limited effect on the total mass of ozone over the lakes and land during the day, though they do cause elevated ozone levels in the lake-breeze air in some locations.

    The model also predicts a mean vertical circulation during the day with an updraft over Detroit-Windsor and downdraft over Lake St. Clair, which transports ozone up to 1500 m above ground and results in high ozone over the lake.

    Oscillations in ground-level ozone mixing ratios were observed on several nights and at several ground monitoring sites, with amplitudes of up to 40 ppbv and time periods of 15–40 min. Several possible mechanisms for these oscillations are discussed, but a

  1. Effectiveness of post-fire seeding in desert tortoise Critical Habitat following the 2005 Southern Nevada Fire Complex

    Science.gov (United States)

    DeFalco, Lesley; Drake, Karla K.; Scoles-Sciulla, S. J.; Bauer, Kyla L.

    2010-01-01

    In June 2005, lightning strikes ignited multiple wildfires in southern Nevada. The Southern Nevada Fire Complex burned more than 32,000 acres of designated desert tortoise Critical Habitat and an additional 403,000 acres of Mojave Desert habitat characterized as potentially suitable for the tortoise. Mortalities of desert tortoises were observed after the fires, but altered habitat is likely to prolong and magnify the impacts of wildfire on desert tortoise populations. To accelerate the re-establishment of plants commonly used by tortoises for food and shelter, the Bureau of Land Management (BLM) distributed seeds of native annual and perennial species in burned areas within desert tortoise Critical Habitat. The U.S. Geological Survey (USGS) established monitoring plots to evaluate broadcast seeding as a means to restore habitat and tortoise activity compared with natural recovery. Within the standard three-year Emergency and Stabilization Response (ESR) monitoring timeline, seeding augmented perennial seed banks by four to six-fold within a year of seed applications compared with unseeded areas. By the end of the three-year monitoring period, seedling densities of seeded perennial species were 33% higher in seeded areas than in unseeded areas, particularly for the disturbance-adapted desert globemallow (Sphaeralcea ambigua) and desert marigold (Baileya multiradiata). Seeded annuals, in contrast, did not increase significantly in seed banks or biomass production, likely due to low seeding rates of these species. Production of non-native annuals that helped carry the fires was not reduced by seeding efforts but instead was strongly correlated with site-specific rainfall, as were native annual species. The short-term vegetation changes measured in seeded areas were not yet associated with a return of tortoise activity to unburned levels. By focusing on a combination of native species that can withstand disturbance conditions, including species that are found in

  2. Numerical modelling of the M2 tide on the northern Patagonian Shelf

    Science.gov (United States)

    Glorioso, P. D.; Simpson, J. H.

    1994-02-01

    The previously reported occurrence of tidal fronts on the Patagonian Shelf ( CARRETOet al., 1986 , Journal of Plankton Research, 8, 15-28; GLORIOSO, 1987 , Continental Shelf Research, 7, 27-34), motivated the application of a numerical model to solve the shallow-water equations with external forcing by the principal-lunar semidiurnal tide (M2) prescribed along the open boundary. The mean width of the Patagonian Shelf is comparable with a quarter wavelength of the semidiurnal tide, giving the conditions for standing wave resonance at that frequency ( WEBB, 1975 , Deep-Sea Research, 23, 1-15). The region is well recognized by its large tidal elevations and by the speed of the tidal wave changing phase very rapidly. Some of the results obtained from the modelling exercise include the mapping of the M2 tidal constants, the Simpson-Hunter stratification parameter, the mean sea surface elevation, and the distribution of tidal energy dissipation by bottom friction. These results agree qualitatively with the ship data available and with satellite infrared imagery.

  3. Synergistic roles of climate warming and human occupation in Patagonian megafaunal extinctions during the Last Deglaciation

    Science.gov (United States)

    Metcalf, Jessica L.; Turney, Chris; Barnett, Ross; Martin, Fabiana; Bray, Sarah C.; Vilstrup, Julia T.; Orlando, Ludovic; Salas-Gismondi, Rodolfo; Loponte, Daniel; Medina, Matías; De Nigris, Mariana; Civalero, Teresa; Fernández, Pablo Marcelo; Gasco, Alejandra; Duran, Victor; Seymour, Kevin L.; Otaola, Clara; Gil, Adolfo; Paunero, Rafael; Prevosti, Francisco J.; Bradshaw, Corey J. A.; Wheeler, Jane C.; Borrero, Luis; Austin, Jeremy J.; Cooper, Alan

    2016-01-01

    The causes of Late Pleistocene megafaunal extinctions (60,000 to 11,650 years ago, hereafter 60 to 11.65 ka) remain contentious, with major phases coinciding with both human arrival and climate change around the world. The Americas provide a unique opportunity to disentangle these factors as human colonization took place over a narrow time frame (~15 to 14.6 ka) but during contrasting temperature trends across each continent. Unfortunately, limited data sets in South America have so far precluded detailed comparison. We analyze genetic and radiocarbon data from 89 and 71 Patagonian megafaunal bones, respectively, more than doubling the high-quality Pleistocene megafaunal radiocarbon data sets from the region. We identify a narrow megafaunal extinction phase 12,280 ± 110 years ago, some 1 to 3 thousand years after initial human presence in the area. Although humans arrived immediately prior to a cold phase, the Antarctic Cold Reversal stadial, megafaunal extinctions did not occur until the stadial finished and the subsequent warming phase commenced some 1 to 3 thousand years later. The increased resolution provided by the Patagonian material reveals that the sequence of climate and extinction events in North and South America were temporally inverted, but in both cases, megafaunal extinctions did not occur until human presence and climate warming coincided. Overall, metapopulation processes involving subpopulation connectivity on a continental scale appear to have been critical for megafaunal species survival of both climate change and human impacts. PMID:27386563

  4. Patagonian red wines: selection of Lactobacillus plantarum isolates as potential starter cultures for malolactic fermentation.

    Science.gov (United States)

    Bravo-Ferrada, Bárbara Mercedes; Hollmann, Axel; Delfederico, Lucrecia; Valdés La Hens, Danay; Caballero, Adriana; Semorile, Liliana

    2013-09-01

    The aim of this study was to evaluate fifty-three Lactobacillus plantarum isolates obtained from a Patagonian red wine, molecularly identified and typified using RAPD analysis, in order to select starter cultures for malolactic fermentation (MLF). The results obtained suggest a considerable genetic diversity, taking into account that all L. plantarum isolates were obtained from one cellar and one vintage. Based on the capacity to tolerate a concentration of 14 % ethanol in MRS broth for 2 days, eight isolates were selected for the subsequent analysis. The incidence of various wine stress factors (ethanol, acid pH, lysozyme and sulfur dioxide) on isolates growth was studied. Besides, glucosidase and tannase activities were evaluated, and the presence of genes involved in the synthesis of biogenic amines was examined by PCR. A previously characterized indigenous Oenococcus oeni strain was included with comparative purposes. Differences in technologically relevant characteristics were observed among the eight L. plantarum selected isolates, revealing an isolate-dependent behavior. Detectable glucosidase and tannase activities were found in all isolates. The presence of genes encoding histidine and tyrosine descarboxylases and putrescine carbamoyltransferase was not detected. The ability of L. plantarum isolates to grow and consume L-malic acid in simulated laboratory-scale vinifications revealed that two of them could be considered as possible MLF starter cultures for Patagonian red wines. These isolates will be subjected to further analysis, for a final winery technological characterization.

  5. Fire cue effects on seed germination of six species of northwestern Patagonian grasslands

    Science.gov (United States)

    Gonzalez, S. L.; Ghermandi, L.

    2012-09-01

    Postfire recruitment of seedlings has been attributed to a stimulation of germination by fire-related cues. The germination response to heat shock (80 °C - 5 min), smoke (60 min), the combination of both factors and no heat no smoke (control) was studied in six native species (two dominant grasses, two dominant shrubs and two annual fugitive herbs) of northwestern Patagonian grasslands. Seeds of the grasses Festuca pallescens and Stipa speciosa and the shrub Senecio bracteolatus (Asteraceae) germinated when they were exposed to heat shock, whereas seeds of the other shrub, Mulinum spinosum (Apiaceae), were killed by this fire cue. In grasses, probably the glume of caryopsis protected embryos from heat. Possibly, the seed size could explain the different responses of the two shrubs. Heat combined with smoke reduced seed germination for S. speciosa and S. bracteolatus. The heat could have scarified seeds and the longer exposure to smoke could have been toxic for embryos. The same treatment increased germination of the annual fugitive herb Boopis gracilis (Calyceraceae). We concluded that fire differentially affects the seedling recruitment of the studied species in the northwestern Patagonian grasslands.

  6. Glacial lakes of the Central and Patagonian Andes

    Science.gov (United States)

    Wilson, Ryan; Glasser, Neil F.; Reynolds, John M.; Harrison, Stephan; Anacona, Pablo Iribarren; Schaefer, Marius; Shannon, Sarah

    2018-03-01

    The prevalence and increased frequency of high-magnitude Glacial Lake Outburst Floods (GLOFs) in the Chilean and Argentinean Andes suggests this region will be prone to similar events in the future as glaciers continue to retreat and thin under a warming climate. Despite this situation, monitoring of glacial lake development in this region has been limited, with past investigations only covering relatively small regions of Patagonia. This study presents new glacial lake inventories for 1986, 2000 and 2016, covering the Central Andes, Northern Patagonia and Southern Patagonia. Our aim was to characterise the physical attributes, spatial distribution and temporal development of glacial lakes in these three sub-regions using Landsat satellite imagery and image datasets available in Google Earth and Bing Maps. Glacial lake water volume was also estimated using an empirical area-volume scaling approach. Results reveal that glacial lakes across the study area have increased in number (43%) and areal extent (7%) between 1986 and 2016. Such changes equate to a glacial lake water volume increase of 65 km3 during the 30-year observation period. However, glacial lake growth and emergence was shown to vary sub-regionally according to localised topography, meteorology, climate change, rate of glacier change and the availability of low gradient ice areas. These and other factors are likely to influence the occurrence of GLOFs in the future. This analysis represents the first large-scale census of glacial lakes in Chile and Argentina and will allow for a better understanding of lake development in this region, as well as, providing a basis for future GLOF risk assessments.

  7. Hydrological Response and Complex Impact Pathways of the 2015/2016 El Niño in Eastern and Southern Africa

    Science.gov (United States)

    Siderius, C.; Gannon, K. E.; Ndiyoi, M.; Opere, A.; Batisani, N.; Olago, D.; Pardoe, J.; Conway, D.

    2018-01-01

    The 2015/2016 El Niño has been classified as one of the three most severe on record. El Niño teleconnections are commonly associated with droughts in southern Africa and high precipitation in eastern Africa. Despite their relatively frequent occurrence, evidence for their hydrological effects and impacts beyond agriculture is limited. We examine the hydrological response and impact pathways of the 2015/2016 El Niño in eastern and southern Africa, focusing on Botswana, Kenya, and Zambia. We use in situ and remotely sensed time series of precipitation, river flow, and lake levels complemented by qualitative insights from interviews with key organizations in each country about awareness, impacts, and responses. Our results show that drought conditions prevailed in large parts of southern Africa, reducing runoff and contributing to unusually low lake levels in Botswana and Zambia. Key informants characterized this El Niño through record high temperatures and water supply disruption in Botswana and through hydroelectric load shedding in Zambia. Warnings of flood risk in Kenya were pronounced, but the El Niño teleconnection did not materialize as expected in 2015/2016. Extreme precipitation was limited and caused localized impacts. The hydrological impacts in southern Africa were severe and complex, strongly exacerbated by dry antecedent conditions, recent changes in exposure and sensitivity and management decisions. Improved understanding of hydrological responses and the complexity of differing impact pathways can support design of more adaptive, region-specific management strategies.

  8. Genesis and petrology of Late Neoproterozoic pegmatites and aplites associated with the Taba metamorphic complex in southern Sinai, Egypt

    Energy Technology Data Exchange (ETDEWEB)

    Abdelfadil, K.M.; Asimow, P.D.; Azer, M.K.; Gahlan, H.A.

    2016-07-01

    We present new field, petrographical, mineralogical and geochemical data from late Neoproterozoic pegmatites and aplites in southern Sinai, Egypt, at the northernmost limit of the Arabian-Nubian Shield. The pegmatites cross-cut host rocks in the Taba Metamorphic Complex (TMC) with sharp contacts and are divided into massive and zoned pegmatites. Massive pegmatites are the most common and form veins, dykes and masses of variable dimensions; strikes range mainly from E-W through NW-SE to N-S. Mineralogically, the massive pegmatites are divided into K-feldspar-rich and albite-rich groups. Zoned pegmatites occur as lenses of variable dimensions, featuring a quartz core, an intermediate zone rich in K-feldspars and an outer finer-grained zone rich in albite. All compositions are highly evolved and display geochemical characteristics of post-collisional A-type granites: high SiO2, Na2O+K2O, FeO*/MgO, Ga/Al, Zr, Nb, Ga and Y alongside low CaO, MgO, Ba and Sr. They are rich in Rare Earth Elements (REE) and have extreme negative Eu anomalies (Eu/Eu*= 0.03–0.09). A genetic linkage between the pegmatites, aplites and alkali granite is confirmed by their common mild alkaline affinity and many other geochemical characteristics. These pegmatites and aplites represent the last small fraction of liquid remaining after extensive crystallization of granitic magma, injected along the foliation and into fractures of the host metamorphic rocks. The extensional tectonic regime and shallow depth of emplacement are consistent with a post-collisional environment. (Author)

  9. Crustal seismicity associated to rpid surface uplift at Laguna del Maule Volcanic Complex, Southern Volcanic Zone of the Andes

    Science.gov (United States)

    Cardona, Carlos; Tassara, Andrés; Gil-Cruz, Fernando; Lara, Luis; Morales, Sergio; Kohler, Paulina; Franco, Luis

    2018-03-01

    Laguna del Maule Volcanic Complex (LMVC, Southern Andes of Chile) has been experiencing large rates (ca. 30 cm/yr) of surface uplift as detected since 2008 by satellite geodetic measurements. Previous works have modeled the source of this deformation as an inflating rectangular sub-horizontal sill underlying LMVC at 5 km depth, which is supposedly related to an active process of magmatic replenishment of a shallow silicic reservoir. However little is known about the tectonic context on which this activity is taking place, particularly its relation with crustal seismicity that could help understanding and monitoring the current deformation process. Here we present the first detailed characterization of the seismic activity taking place at LMVC and integrate it with structural data acquired in the field in order to illuminate the possible connection between the ongoing process of surface uplift and the activation of crustal faults. Our main finding is the recognition of repetitive volcano-tectonic (VT) seismic swarms that occur periodically between 2011 and 2014 near the SW corner of the sill modeled by InSAR studies. A cross-correlation analysis of the waveforms recorded for these VT events allows identifying three different seismic families. Families F1 and F3 share some common features in the stacked waveform and its locations, which markedly differ from those of family F2. Swarms belonging to this later family are more energetic and its energy was increasing since 2011 to a peak in January 2013, which coincide with maximum vertical velocities detected by local GPS stations. This points to a common process relating both phenomena. The location of VT seismic swarms roughly coincides with the intersection of a NE-SW lineament with a WNW-ESE lineament. The former shows clear field evidences of dextral strike-slip that are fully consistent with one nodal plane of focal mechanism for well-recorded F2 events. The conjugate nodal plane of these focal mechanisms could

  10. Linking the southern West Junggar terrane to the Yili Block: Insights from the oldest accretionary complexes in West Junggar, NW China

    Science.gov (United States)

    Ren, Rong; Han, Bao-Fu; Guan, Shu-Wei; Liu, Bo; Wang, Zeng-Zhen

    2018-06-01

    West Junggar is known to tectonically correlate with East Kazakhstan; however, the tectonic link of the southern West Junggar terrane to adjacent regions still remains uncertain. Here, we examined the oldest accretionary complexes, thus constraining its tectonic evolution and link during the Early-Middle Paleozoic. They have contrasting lithologic, geochemical, and geochronological features and thus, provenances and tectonic settings. The Laba Unit was derived from the Late Ordovician-Early Devonian continental arc system (peaking at 450-420 Ma) with Precambrian substrate, which formed as early as the Early Devonian and metamorphosed during the Permian; however, the Kekeshayi Unit was accumulated in an intra-oceanic arc setting, and includes the pre-Late Silurian and Late Silurian subunits with or without Precambrian sources. Integrated with the regional data, the southern West Junggar terrane revealed a tectonic link to the northern Yili Block during the Late Silurian to Early Devonian, as suggested by the comparable Precambrian zircon age spectra between the southern West Junggar terrane and the micro-continents in the southern Kazakhstan Orocline, the proximal accumulation of the Laba Unit in the continental arc atop the Yili Block, and the sudden appearance of Precambrian zircons in the Kekeshayi Unit during the Late Silurian. This link rejects the proposals of the southern West Junggar terrane as an extension of the northern Kazakhstan Orocline and the Middle Paleozoic amalgamation of West Junggar. A new linking model is thus proposed, in which the southern West Junggar terrane first evolved individually, and then collided with the Yili Block to constitute the Kazakhstan continent during the Late Silurian. The independent and contrasting intra-oceanic and continental arcs also support the Paleozoic archipelago-type evolution of the Central Asian Orogenic Belt.

  11. Glaciation effects on the phylogeographic structure of Oligoryzomys longicaudatus (Rodentia: Sigmodontinae in the southern Andes.

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    R Eduardo Palma

    Full Text Available The long-tailed pygmy rice rat Oligoryzomys longicaudatus (Sigmodontinae, the major reservoir of Hantavirus in Chile and Patagonian Argentina, is widely distributed in the Mediterranean, Temperate and Patagonian Forests of Chile, as well as in adjacent areas in southern Argentina. We used molecular data to evaluate the effects of the last glacial event on the phylogeographic structure of this species. We examined if historical Pleistocene events had affected genetic variation and spatial distribution of this species along its distributional range. We sampled 223 individuals representing 47 localities along the species range, and sequenced the hypervariable domain I of the mtDNA control region. Aligned sequences were analyzed using haplotype network, bayesian population structure and demographic analyses. Analysis of population structure and the haplotype network inferred three genetic clusters along the distribution of O. longicaudatus that mostly agreed with the three major ecogeographic regions in Chile: Mediterranean, Temperate Forests and Patagonian Forests. Bayesian Skyline Plots showed constant population sizes through time in all three clusters followed by an increase after and during the Last Glacial Maximum (LGM; between 26,000-13,000 years ago. Neutrality tests and the "g" parameter also suggest that populations of O. longicaudatus experienced demographic expansion across the species entire range. Past climate shifts have influenced population structure and lineage variation of O. longicaudatus. This species remained in refugia areas during Pleistocene times in southern Temperate Forests (and adjacent areas in Patagonia. From these refugia, O. longicaudatus experienced demographic expansions into Patagonian Forests and central Mediterranean Chile using glacial retreats.

  12. Major histocompatibility complex (MHC) class III genetics in two Amerindian tribes from southern Brazil: the Kaingang and the Guarani.

    Science.gov (United States)

    Weg-Remers, S; Brenden, M; Schwarz, E; Witzel, K; Schneider, P M; Guerra, L K; Rehfeldt, I R; Lima, M T; Hartmann, D; Petzl-Erler, M L; de Messias, I J; Mauff, G

    1997-10-01

    Population genetic studies of the major histocompatibility complex (MHC) class III region, comprising C2, BF and C4 phenotypes, and molecular genetic data are rarely available for populations other than Caucasoids. We have investigated three Amerindian populations from Southern Brazil: 131 Kaingang from Ivaí (KIV), 111 Kaingang (KRC) and 100 Guarani (GRC) from Rio das Cobras. Extended MHC haplotypes were derived after standard C2, BF, C4 phenotyping and restriction fragment length polymorphism (RFLP) analysis with TaqI, together with HLA data published previously by segregation analysis. C2 and BF frequencies corresponded to other Amerindian populations. C4B*Q0 frequency was high in the GRC (0.429) but low in the Kaingang. Unusual C4 alleles were found, viz. C4A*58, A*55 and C4B*22 (presumably non-Amerindian) and aberrant C4A*3 of Amerindian origin occurring with a frequency of 0.223 in the GRC. C4A*3 bands of homo- and heterozygous individuals carrying this variant were Rodgers 1 positive and Chido 1,3 positive, showed a C4A specific lysis type and a C4A like alpha-chain. Polymerase chain reaction studies and sequencing showed that this is based on a C4A*3 duplication with a regular C4A*3 and a partially converted C4A*0304 carrying the C4B specific epitopes Ch 6 and Ch 1,3. Associations of class III haplotypes with particular RFLP patterns were similar to those reported for Caucasoids. The previously described association between combined C4A and CYP21P deletions and the 6.4 kb TaqI fragment was not seen in these Amerindians. This fragment occurred within a regular two locus gene structure in the Kaingang, representing a "short" gene at C4 locus I. C4 and CYP21 duplications were frequently observed. The distribution of extended MHC haplotypes provides evidence for a close relationship between the KIV and KRC and a larger genetic distance between the two Kaingang groups and the GRC.

  13. Ecology and management of the invasive lionfish Pterois volitans/miles complex (Perciformes: Scorpaenidae in Southern Costa Rica

    Directory of Open Access Journals (Sweden)

    Vera Sandel

    2015-03-01

    Full Text Available Invasive species alter ecosystem integrity and functioning and are considered one of the major threats to biodiversity on a global scale. The indopacific lionfish (Pterois volitans [Linnaeus, 1758] / miles [Bennet, 1882] complex is the first non-native marine fish that has established itself in the Western Atlantic. It was first reported in Florida in the 1980s and then spread across the entire Caribbean in subsequent years. In Costa Rica, lionfish were first sighted by the end of 2008 and are now present in all South Caribbean reefs. Lionfish are a major problem for local fisherman by displacing native fish species. The aim of this study was to determine population density, size and diet of lionfish populations at four study sites along the Southern Caribbean coast of Costa Rica. Two of the sites were located inside the National Park Cahuita where regular lionfish removal occurs, whereas the other two study sides do not experiment this kind of management. Total length and wet weight of >450 lionfish individuals were determined between March and June 2011. Three relative metrics of prey quantity (percent number, percent frequency, and percent weight were compared from ~300 lionfish caught with the polespear in shallow waters (<7m depth. Population density was assessed weekly through visual transect surveys. Our results showed that lionfish preyed mostly upon teleosts and crustaceans. Teleosts dominated lionfish diet in percent frequency (71% and percent weight (85%, whereas crustaceans had the highest percent number (58%. The top five teleost families of dietary importance were Pomacentridae, Acanthuridae, Blennidae, Labridae and Serranidae. The average total length (±SD of lionfish was 18.7(±5.7cm and varied significantly between sites (p<0.001. Mean density of lionfish was 92fish/ha with no significant differences between sites. Smallest fish and lowest densities were found at the two sites inside the National Park Cahuita. Despite

  14. Glacial recession in the Tropical Andes from the Little Ice Age: the case of Ampato Volcanic Complex (Southern Peru

    Science.gov (United States)

    Alcalá, J.; Palacios, D.; Zamorano, J. J.

    2010-03-01

    Data published over the last decade reveal substantial glacial recession in the tropical Andes since the Little Ice Age (LIA), (Ramirez, et al., 2001; Rabatel, et al., 2005; Rabatel, et al., 2008; Vuille, et al., 2008; Hastenrath, 2009; Jomelli, et al., 2009), and a growing rate of recession since the 1980’s caused by global warming (Ramirez, et al., 2001; Vuille, et al., 2008). Today there is great interest in the evolution of these ice masses due to heightened awareness of climate change and of the strategic importance that glaciers have as a hydrologic resource for communities in arid climate zones in the tropical Andes (Mark, 2008; Vuille et al., 2008). Cordillera Blanca forms part of the Andes Mountains of northern Peru, and is a chosen site for many studies on glacier evolution. Vuille et al. 2008 determined that a considerable area of ice mass was lost at Huascarán-Chopicalqui glacier (18% from 1920-1970) and Astesonraju glacier (20% from 1962-2003). Studies at Coropuna volcano, which has the most extensive glacier field in the western range of southern Peru, also report a strong melting trend that began with only minimal recession from 1955-1986 (4%), but increased to 14% from 1986-2007 (Úbeda et al., 2009). Only a few of the Andes glaciers are consistently monitored, and the most comprehensive data are for Chacaltaya and Zongo glaciers (16º S) in Bolivia. Since the maximum LIA, Chacaltaya has lost 89% of its surface area, particularly in recent years. By 1983, the totaled loss was five times the shrinkage for the period 1940-1963 (Ramirez, et al., 2001). Zongo glacier maintained equilibrium from 1956-1975, but later experienced a period dominated by continuous recession (Soruco, et al., 2009). This study expands current knowledge of glacier evolution since the LIA in the Central Volcanic Zone (CVZ; 14º - 27º S) (Stern, 2004) of the Andes. The study site was chosen in an area that had never been used for preliminary research of this type, concretely

  15. A winter dinoflagellate bloom drives high rates of primary production in a Patagonian fjord ecosystem

    Science.gov (United States)

    Montero, P.; Pérez-Santos, I.; Daneri, G.; Gutiérrez, M. H.; Igor, G.; Seguel, R.; Purdie, D.; Crawford, D. W.

    2017-12-01

    A dense winter bloom of the dinoflagellate Heterocapsa triquetra was observed at a fixed station (44°35.3‧S; 72°43.6‧W) in the Puyuhuapi Fjord in Chilean Patagonia during July 2015. H. triquetra dominated the phytoplankton community in the surface waters between 2 and 15 m (13-58 × 109 cell m-2), with abundances some 3 to 15 times higher than the total abundance of the diatom assemblage, which was dominated by Skeletonema spp. The high abundance of dinoflagellates was reflected in high rates of gross primary production (GPP; 0.6-1.6 g C m-2 d-1) and chlorophyll-a concentration (Chl-a; 70-199.2 mg m-2) that are comparable to levels reported in spring diatom blooms in similar Patagonian fjords. We identify the main forcing factors behind a pulse of organic matter production during the non-productive winter season, and test the hypothesis that low irradiance levels are a key factor limiting phytoplankton blooms and subsequent productivity during winter. Principal Component Analysis (PCA) indicated that GPP rates were significantly correlated (r = -0.8, p bloom. The bloom occurred under low surface irradiance levels characteristic of austral winter and was accompanied by strong northern winds, associated with the passage of a low-pressure system, and a water column dominated by double diffusive layering. To our knowledge, this is the first report of a dense dinoflagellate bloom during deep austral winter in a Patagonian fjord, and our data challenge the paradigm of light limitation as a factor controlling phytoplankton blooms in this region in winter.

  16. Freezing resistance in Patagonian woody shrubs: the role of cell wall elasticity and stem vessel size.

    Science.gov (United States)

    Zhang, Yong-Jiang; Bucci, Sandra J; Arias, Nadia S; Scholz, Fabian G; Hao, Guang-You; Cao, Kun-Fang; Goldstein, Guillermo

    2016-08-01

    Freezing resistance through avoidance or tolerance of extracellular ice nucleation is important for plant survival in habitats with frequent subzero temperatures. However, the role of cell walls in leaf freezing resistance and the coordination between leaf and stem physiological processes under subzero temperatures are not well understood. We studied leaf and stem responses to freezing temperatures, leaf and stem supercooling, leaf bulk elastic modulus and stem xylem vessel size of six Patagonian shrub species from two sites (plateau and low elevation sites) with different elevation and minimum temperatures. Ice seeding was initiated in the stem and quickly spread to leaves, but two species from the plateau site had barriers against rapid spread of ice. Shrubs with xylem vessels smaller in diameter had greater stem supercooling capacity, i.e., ice nucleated at lower subzero temperatures. Only one species with the lowest ice nucleation temperature among all species studied exhibited freezing avoidance by substantial supercooling, while the rest were able to tolerate extracellular freezing from -11.3 to -20 °C. Leaves of species with more rigid cell walls (higher bulk elastic modulus) could survive freezing to lower subzero temperatures, suggesting that rigid cell walls potentially reduce the degree of physical injury to cell membranes during the extracellular freezing and/or thaw processes. In conclusion, our results reveal the temporal-spatial ice spreading pattern (from stem to leaves) in Patagonian shrubs, and indicate the role of xylem vessel size in determining supercooling capacity and the role of cell wall elasticity in determining leaf tolerance of extracellular ice formation. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Phenolic compounds as indicators of drought resistance in shrubs from Patagonian shrublands (Argentina).

    Science.gov (United States)

    Varela, M Celeste; Arslan, Idris; Reginato, Mariana A; Cenzano, Ana M; Luna, M Virginia

    2016-07-01

    Plants exposed to drought stress, as usually occurs in Patagonian shrublands, have developed different strategies to avoid or tolerate the lack of water during their development. Production of phenolic compounds (or polyphenols) is one of the strategies used by some native species of adverse environments to avoid the oxidative damage caused by drought. In the present study the relationship between phenolic compounds content, water availability and oxidative damage were evaluated in two native shrubs: Larrea divaricata (evergreen) and Lycium chilense (deciduous) of Patagonian shrublands by their means and/or by multivariate analysis. Samples of both species were collected during the 4 seasons for the term of 1 year. Soil water content, relative water content, total phenols, flavonoids, flavonols, tartaric acid esters, flavan-3-ols, proanthocyanidins, antioxidant capacity and lipid peroxidation were measured. According to statistical univariate analysis, L. divaricata showed high production of polyphenols along the year, with a phenolic compound synthesis enhanced during autumn (season of greatest drought), while L. chilense has lower production of these compounds without variation between seasons. The variation in total phenols along the seasons is proportional to the antioxidant capacity and inversely proportional to lipid peroxidation. Multivariate analysis showed that, regardless their mechanism to face drought (avoidance or tolerance), both shrubs are well adapted to semi-arid regions and the phenolic compounds production is a strategy used by these species living in extreme environments. The identification of polyphenol compounds showed that L. divaricata produces different types of flavonoids, particularly bond with sugars, while L. chilense produces high amount of non-flavonoids compounds. These results suggest that flavonoid production and accumulation could be a useful indicator of drought tolerance in native species. Copyright © 2016 Elsevier Masson

  18. Key role of organic complexation of iron in sustaining phytoplankton blooms in the Pine Island and Amundsen Polynyas (Southern Ocean)

    NARCIS (Netherlands)

    Thuroczy, Charles-Edouard; Alderkamp, Anne-Carlijn; Laan, Patrick; Gerringa, Loes J. A.; Mills, Matthew M.; Van Dijken, Gert L.; De Baar, Hein J. W.; Arrigo, Kevin R.

    2012-01-01

    Primary productivity in the Amundsen Sea (Southern Ocean) is among the highest in Antarctica. The summer phytoplankton bloom in 2009 lasted for > 70 days in both the Pine Island and Amundsen Polynyas. Such productive blooms require a large supply of nutrients, including the trace metal iron (Fe).

  19. Marine effect of introduced salmonids: Prey consumption by exotic steelhead and anadromous brown trout in the Patagonian Continental Shelf

    Science.gov (United States)

    Ciancio, J.; Beauchamp, D.A.; Pascual, M.

    2010-01-01

    On the basis of stable isotope analysis, we estimated the marine diet of the most abundant anadromous salmonid species in Patagonian Atlantic basins. The results were coupled with bioenergetic and population models to estimate the consumption of food by salmonids and was compared with that by seabirds, the most abundant top predators in the area. Amphipods were the main salmonid prey, followed by sprat, silversides, squid, and euphausiids. The total consumption, even assuming large anadromous salmonid populations, represented Limnology and Oceanography, Inc.

  20. Late Proterozoic island-arc complexes and tectonic belts in the southern part of the Arabian Shield, Kingdom of Saudi Arabia

    Science.gov (United States)

    Greenwood, William R.; Stoeser, D.B.; Fleck, R.J.; Stacey, J.S.

    1983-01-01

    Two main subdivisions of layered rocks are recognized in the southern Arabian Shield south of lat 22? N. These are an older ensimatic-arc complex, which formed 1100-800 m.y. ago, and a younger marginal-arc complex, which formed 800-690 m.y. ago. The older ensimatic-arc complex, located in the southwestern part of the Shield, includes graywacke and mafic to intermediate volcanic rocks of the essentially contemporaneous Baish, Bahah, and Jiddah groups. Although the younger arc complex is also dominantly ensimatic in character, it is also partly superimposed over the older ensimaticarc complex. The superimposed portions of the younger arc complex are represented by the Ablah, Samran, and possibly the Ararat groups. The ensimatic portion of the younger arc group is represented by the Halaban group, which was deposited to the east and northeast of the older ensimatic-arc complex. The Halaban group includes andesitic and dacitic volcanic rocks and associated clastic sedimentary rocks. The layered rocks of both arc complexes are intruded by dioritic (quartz diorite, tonalite, trondhjemite) plutonic rocks. The southern Shield is also subdivided into a number of structurally bounded, north-trending tectonic belts. Within the older ensimatic complex, three belts are recognized. From west to east, these are the Lith, Bidah, and Tayyah belts. Within these three belts, progressive facies changes indicate a gradation from deep-water facies in the south to shallow-water or-terrestrial facies in the north. The distribution of dioritic batholiths, as well as the distribution of layered-rock facies, suggests a northwest-trending axis for the older ensimatic-arc complex. The younger arc complex is present within six belts, the Makkah source papers. In Fleck and others (1980), the term 'quartz diorite' includes both tonalite and quartz diorite as defined in the International Union of Geological Sciences (IUGS) system of plutonic rock classification (Streckeisen, 1973). Initial 87Sr/86

  1. Occurrence of arbuscular mycorrhizal fungi in high altitude sites of the Patagonian Altoandina region in Nahuel Huapi National Park (Argentina

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    María Silvana Velázquez

    Full Text Available ABSTRACT Knowledge of the occurrence and diversity of arbuscular mycorrhizal fungi (AMF in National Parks is essential for the establishment of policies for conservation. The aim of this study was to characterize the AMF communities in the Patagonian Altoandina region in Nahuel Huapi National Park, Argentina. We surveyed AMF spores associated with the rhizospheres of 9 plant species in the Patagonian Steppe (PS, Challhuaco Hill (ChH, Catedral Hill (CH, and Tronador Hill (TH regions and detected a total of 27 Glomeromycota species. Acaulospora laevis was dominant at all sites. The AMF community was dominated by Acaulosporaceae, as regards the number of species and contribution of each one to the total number of spores. Three Glomeromycota families were detected at PS, the site with the lowest elevation; whereas five to six families were detected at ChH, CH, and TH. Cluster analysis indicated that the AMF communities were grouped according to habitat. We concluded that certain patterns of the AMFcommunity structure detected were equivalent to those of high-altitude environments from other studies, while others were unique to the Patagonian region; thus suggesting that historical influences like dispersion and speciation played a critical role in shaping AMF community composition in such high-altitude environments.

  2. Ignition probability of fine dead surface fuels of native Patagonian forests or Argentina

    Directory of Open Access Journals (Sweden)

    Lucas O. Bianchi

    2014-04-01

    Full Text Available Aim of study: The Canadian Forest Fire Weather Index (FWI is being implemented all over the world. This index is being adapted to the Argentinean ecosystems since the year 2000. With the objective of calibrating the Fine Fuel Moisture Code (FFMC of the FWI system to Patagonian forests, we studied the relationship between ignition probability and fine dead surface fuel moisture content (MC as an indicator of potential fire ignition.Area of study: The study area is located in northwestern Patagonia, Argentina, and comprised two main forest types (cypress and ñire grown under a Mediterranean climate, with a dry summer and precipitations during winter and autumn (~500-800 mm per year.Material and Methods: We conducted lab ignition tests fires to determine the threshold of fine dead fuel ignition at different MC levels. Moisture content of dead fine surface fuels in the field was measured every 10-15 days from November to March for three seasons. We calculated the FFMC during these seasons and correlated it with the measured MC by applying a logistic regression model. We combined the results of the ignition tests and of the regressions to suggest FFMC categories for estimating fire danger in Patagonian forests.Main results: The ignition threshold occurred at MC values of 21.5 and 25.0% for cypress and ñire sites, respectively. The MC measured varied from 7.3 to 129.6%, and the calculated FFMC varied between 13.4 and 92.6. Highly significant regressions resulted when FFMC was related to MC. The ignition threshold corresponded to a FFMC=85. We proposed to divide the FFMC scale in three fire danger categories: Low (FFMC≤85, High (8589.Research highlights: Our results provide a useful tool for predicting fire danger in these ecosystems, and are a contribution to the development of the Argentinean Fire Danger Rating and a reference for similar studies in other countries where the FWI is being implemented

  3. Tolerance to winemaking stress conditions of Patagonian strains of Saccharomyces eubayanus and Saccharomyces uvarum.

    Science.gov (United States)

    Origone, A C; Del Mónaco, S M; Ávila, J R; González Flores, M; Rodríguez, M E; Lopes, C A

    2017-08-01

    Evaluating the winemaking stress tolerance of a set of both Saccharomyces eubayanus and Saccharomyces uvarum strains from diverse Patagonian habitats. Yeast strains growth was analysed under increasing ethanol concentrations; all of them were able to grow until 8% v/v ethanol. The effect of different temperature and pH conditions as well as at SO 2 and hexose concentrations was evaluated by means of a central composite experimental design. Only two S. uvarum strains (NPCC 1289 and 1321) were able to grow in most stress conditions. Kinetic parameters analysed (μ max and λ) were statistically affected by temperature, pH and SO 2 , but not influenced by sugar concentration. The obtained growth model was used for predicting optimal growth conditions for both strains: 20°C, 0% w/v SO 2 and pH 4·5. Strains from human-associated environments (chichas) presented the highest diversity in the response to different stress factors. Two S. uvarum strains from chichas demonstrated to be the most tolerant to winemaking conditions. This work evidenced the potential use of two S. uvarum yeast strains as starter cultures in wines fermented at low temperatures. Saccharomyces eubayanus was significantly affected by winemaking stress conditions, limiting its use in this industry. © 2017 The Society for Applied Microbiology.

  4. Interannual variability in the skate assemblage on the South Patagonian shelf and slope.

    Science.gov (United States)

    Winter, A; Pompert, J; Arkhipkin, A; Brewin, P E

    2015-12-01

    Observer data from the commercial fishery on the Patagonian shelf and slope around the Falkland Islands (home to an assemblage of >16 skate species (Rajiformes), for which commercial catches have been recorded since 1987), as well as survey data from an area closed to skate target fishing after exploitation, were summarized by species to examine changes in the population status of individual skate species. Total skate catch per unit effort increased significantly in the target fishery since 1994, and four species have made up >85% of all skate catch. Bathyraja brachyurops and Zearaja chilensis increased significantly in catch proportions and abundance from 1994 to 2013. Bathyraja albomaculata and Bathyraja griseocauda decreased significantly before rebounding with trends of increasing abundance. Concurrently, B. brachyurops and Z. chilensis showed decreasing trends in size at 50% maturity in areas where skates continue to be targeted commercially. The increasing abundances and concomitant reductions in size at maturity of B. brachyurops and Z. chilensis suggest either plasticity in life-history traits or a density-dependent growth response to fishing pressure. Bathyraja griseocauda decreased in size at 50% maturity in the area that was closed to skate target fishing, where it was initially larger, but only decreased to the same average size as in the commercially targeted areas. Bathyraja albomaculata and Z. chilensis are IUCN-listed as vulnerable and B. griseocauda is listed as endangered, but their abundance trends since 1994 indicate that these populations are not declining in Falkland waters. © 2015 The Fisheries Society of the British Isles.

  5. The impact of predation by marine mammals on patagonian toothfish longline fisheries.

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    Marta Söffker

    Full Text Available Predatory interaction of marine mammals with longline fisheries is observed globally, leading to partial or complete loss of the catch and in some parts of the world to considerable financial loss. Depredation can also create additional unrecorded fishing mortality of a stock and has the potential to introduce bias to stock assessments. Here we aim to characterise depredation in the Patagonian toothfish (Dissostichus eleginoides fishery around South Georgia focusing on the spatio-temporal component of these interactions. Antarctic fur seals (Arctocephalus gazella, sperm whales (Physeter macrocephalus, and orcas (Orcinus orca frequently feed on fish hooked on longlines around South Georgia. A third of longlines encounter sperm whales, but loss of catch due to sperm whales is insignificant when compared to that due to orcas, which interact with only 5% of longlines but can take more than half of the catch in some cases. Orca depredation around South Georgia is spatially limited and focused in areas of putative migration routes, and the impact is compounded as a result of the fishery also concentrating in those areas at those times. Understanding the seasonal behaviour of orcas and the spatial and temporal distribution of "depredation hot spots" can reduce marine mammal interactions, will improve assessment and management of the stock and contribute to increased operational efficiency of the fishery. Such information is valuable in the effort to resolve the human-mammal conflict for resources.

  6. Revision of fleas of the genus Plocopsylla belonging to the 'angusticeps-lewisi' complex in the Andean biogeographic region, with the description of a new species.

    Science.gov (United States)

    Sanchez, J; Beaucournu, J-C; Lareschi, M

    2015-06-01

    In Argentina, the Andean biogeographic region accommodates the most diverse population of fleas in the country. The Craneopsyllinae (Siphonaptera: Stephanocircidae) represent one of the most commonly found subfamilies in this region and show some endemism and high diversity. Plocopsylla is the most diverse genus of Craneopsyllinae; it includes 10 species mainly distributed in the Patagonian subregion, which parasitize sigmodontine rodents (Rodentia: Cricetidae). We describe and illustrate the morphology of the aedeagus in species of Plocopsylla that belong to the 'angusticeps-lewisi' complex. This character is of diagnostic value in differentiating among species. A new species of this complex, Plocopsylla (Plocopsylla) linardii sp. n., is described and identified by the shape and chaetotaxy of the distal arm of sternite IX, as well as by the shape of the median dorsal lobe of the aedeagus. New host associations for this complex and range extensions for most of its species are reported. Plocopsylla (P.) silewi is recorded for the first time in Argentina. The southern limits of the distributions of Plocopsylla (P.) lewisi and Plocopsylla (P.) wilesi are extended to Santa Cruz Province. The angusticeps-lewisi complex is found for the first time in San Juan Province. The information may be useful in epidemiological studies of flea-borne diseases. © 2015 The Royal Entomological Society.

  7. Trace-element and Sr, Nd, Pb, and O isotopic composition of Pliocene and Quaternary alkali basalts of the Patagonian Plateau lavas of southernmost South America

    Science.gov (United States)

    Stern, C.R.; Frey, F.A.; Futa, K.; Zartman, R.E.; Peng, Z.; Kurtis, Kyser T.

    1990-01-01

    The Pliocene and Quaternary Patagonian alkali basalts of southernmost South America can be divided into two groups. The "cratonic" basalts erupted in areas of Cenozoic plateau volcanism and continental sedimentation and show considerable variation in 87Sr/86Sr (0.70316 to 0.70512), 143Nd/144Nd (e{open}Nd) and 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb ratios (18.26 to 19.38, 15.53 to 15.68, and 38.30 to 39.23, respectively). These isotopic values are within the range of oceanic island basalts, as are the Ba/La, Ba/Nb, La/Nb, K/Rb, and Cs/Rb ratios of the "cratonic" basalts. In contrast, the "transitional" basalts, erupted along the western edge of the outcrop belt of the Pliocene and Quaternary plateau lavas in areas that were the locus of earlier Cenozoic Andean orogenic arc colcanism, have a much more restricted range of isotopic composition which can be approximated by 87Sr/86Sr=0.7039??0.0004, e{open}Nd, 206Pb/204Pb=18.60??0.08, 207Pb/204Pb=15.60??0.01, and 208Pb/204Pb=38.50??0.10. These isotopic values are similar to those of Andean orogenic are basalts and, compared to the "cratonic" basalts, are displaced to higher 87Sr/86Sr at a given 143Nd/144Nd and to higher 207Pb/204Pb at a given 208Pb/204Pb. The "transitional" basalts also have Ba/La, Ba/Nb, La/Nb, and Cs/Rb ratios higher than the "cratonic" and oceanic island basalts, although not as high as Andean orogenic are basalts. In contrast to the radiogenic isotopes, ??18O values for both groups of the Patagonian alkali basalts are indistinguishable and are more restricted than the range reported for Andean orogenic are basalts. Whole rock ??18O values calculated from mineral separates for both groups range from 5.3 to 6.5, while measured whole rock ??18O values range from 5.1 to 7.8. The trace element and isotopic data suggest that decreasing degrees of partial melting in association with lessened significance of subducted slabderived components are fundamental factors in the west to east transition from arc

  8. 2003 assessment of PCDDs-PCDFs emissions from the Copesul/South Petrochemical complex located in southern Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Deschamps, M.; Allard, J.L. [SNC-Lavalin Environment Inc., Montreal, PQ (Canada); Rangel, C.M.P.; Ribeiro, C.; Dos Santos, S.T.F. [Companhia Petroquimica do Sul, Triunfo (Brazil)

    2004-09-15

    COPESUL is the Raw Material and Utilities Central of the South Petrochemical Complex, this, being the most modern industrial facility of its type in Brazil, and the second largest naphtha cracker in the country. Responsible for more than 40% of Brazilian olefins production, it is also among the largest crackers (on the same site) in the world. The majority of COPESUL products are transformed by downstream industries of the Complex into thermoplastics resins, synthetic rubber, styrene and solvents that are widely used in the manufacturing of packing material (food, hygiene, cleaning), electronic appliances, medical and surgical supplies, toys and in the car industries, to be consumed in Brazil and foreign countries. At the request of the state of Rio Grande do Sul Environmental Protection Agency (Fundacao Estadual de Protecao Ambiental or FEPAM), an Environmental Assessment of Priority Pollutants (EAPP) was performed by Copesul at the end of the year 2003. EAPPs have been voluntarily performed at the Petrochemical Complex since 1986 on a basis of once every three year. It is now performed as a requirement which is part of the petrochemical plant operational license. Among the different (organic and inorganic) parameters tested, PCDDs-PCDFs remained a main concern to the local State Agency with regards to the Complex activities and of it's potential impact on the human health and the environment, despite the fact that the Complex does not use nor produce any organochlorinated product.

  9. Conflicting evolutionary patterns due to mitochondrial introgression and multilocus phylogeography of the Patagonian freshwater crab Aegla neuquensis.

    Directory of Open Access Journals (Sweden)

    Brian R Barber

    Full Text Available BACKGROUND: Multiple loci and population genetic methods were employed to study the phylogeographic history of the Patagonian freshwater crab Aegla neuquensis (Aeglidae: Decopoda. This taxon occurs in two large river systems in the Patagonian Steppe, from the foothills of the Andes Mountains east to the Atlantic Ocean. METHODOLOGY/PRINCIPAL FINDINGS: A nuclear phylogeny and multilocus nested clade phylogeographic analysis detected a fragmentation event between the Negro and Chico-Chubut river systems. This event occurred approximately 137 thousand years ago. An isolation-with-migration analysis and maximum-likelihood estimates of gene flow showed asymmetrical exchange of genetic material between these two river systems exclusively in their headwaters. We used information theory to determine the best-fit demographic history between these two river systems under an isolation-with-migration model. The best-fit model suggests that the Negro and the ancestral populations have the same effective population sizes; whereas the Chico-Chubut population is smaller and shows that gene flow from the Chico-Chubut into the Negro is four times higher than in the reverse direction. Much of the Chico-Chubut system appears to have only been recently colonized while the Negro populations appear to have been in place for most of the evolutionary history of this taxon. CONCLUSIONS/SIGNIFICANCE: Due to mitochondrial introgression, three nuclear loci provided different phylogeographic resolution than the three mitochondrial genes for an ancient fragmentation event observed in the nuclear phylogeny. However, the mitochondrial locus provided greater resolution on more recent evolutionary events. Our study, therefore, demonstrates the need to include both nuclear and mitochondrial loci for a more complete understanding of evolutionary histories and associated phylogeographic events. Our results suggest that gene flow between these systems, before and after fragmentation

  10. Geomorphic response of an active metamorphic core-complex in a collisional orogen: Example from the Lunggar Shan, Southern Tibet

    International Nuclear Information System (INIS)

    Taylor, M H; Stockli, D F; Kapp, P A

    2008-01-01

    We present structural and neotectonic mapping from the Lunggar Shan rift in southern Tibet. The Lunggar Shan is a N-trending mountain range ∼70 km long N-S and up to 40 km wide E-W. The Lunggar Shan is bounded on its east side by a low-angle ( 0 ) east-dipping detachment fault that juxtaposes mylonitic gneiss and variably deformed granites in its footwall against alluvial fans and Neogene gravels in its hangingwall. Foliations in the mylonitic footwall dip 40 m of throw on individual scarps. An intriguing observation is that an intrabasinal topographic high is actively developing near areas of inferred maximum extension, with lacustrine sediments being uplifted and eroded. This observation indicates that the rift basin initially developed as a typical half-graben system that underwent a transition from deposition, to uplift and erosion perhaps as a result of isostatic rebound of the footwall at depth, warping the overlying hangingwall basin. If correct, the Lunggar Shan may represent a modern analogue to the supradetachment basin model

  11. Variation in Complexity of Infection and Transmission Stability between Neighbouring Populations of Plasmodium vivax in Southern Ethiopia.

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    Sisay Getachew

    Full Text Available P. vivax is an important public health burden in Ethiopia, accounting for almost half of all malaria cases. Owing to heterogeneous transmission across the country, a stronger evidence base on local transmission dynamics is needed to optimise allocation of resources and improve malaria interventions.In a pilot evaluation of local level P. vivax molecular surveillance in southern Ethiopia, the diversity and population structure of isolates collected between May and November 2013 were investigated. Blood samples were collected from microscopy positive P. vivax patients recruited to clinical and cross-sectional surveys from four sites: Arbaminch, Halaba, Badawacho and Hawassa. Parasite genotyping was undertaken at nine tandem repeat markers. Eight loci were successfully genotyped in 197 samples (between 36 and 59 per site. Heterogeneity was observed in parasite diversity and structure amongst the sites. Badawacho displayed evidence of unstable transmission, with clusters of identical clonal infections. Linkage disequilibrium in Badawacho was higher (IAS = 0.32, P = 0.010 than in the other populations (IAS range = 0.01-0.02 and declined markedly after adjusting for identical infections (IAS = 0.06, P = 0.010. Other than Badawacho (HE = 0.70, population diversity was equivalently high across the sites (HE = 0.83. Polyclonal infections were more frequent in Hawassa (67% than the other populations (range: 8-44%. Despite the variable diversity, differentiation between the sites was low (FST range: 5 x 10-3-0.03.Marked variation in parasite population structure likely reflects differing local transmission dynamics. Parasite genotyping in these heterogeneous settings has potential to provide important complementary information with which to optimise malaria control interventions.

  12. Discovery of uranium mineralizations in the rhyolite-granite complex in the Jabal Eghei area of southern Libya

    Directory of Open Access Journals (Sweden)

    Kovačević Jovan

    2013-01-01

    Full Text Available During investigation of the Jabal Eghei area in southern Libya and the production of geological maps at a scale of 1:250 000 (Tibesti sector, sheet Wadi Eghei NF 34-1 and NF 34-2, regional prospecting for mineral raw materials was performed. Radiometric survey of observed targets at the sites indicated two significant uranium mineralizations in rhyolites, and some smaller ones in granites that are in close contact with rhyolites. Rhyolites are located in the central part of the investigated region. They cut through granite rocks. The first mineralization is in the central part of the rhyolite region, which is mostly composed of silificated rhyolites. The second one was discovered near the granite-rhyolite contact zone, characterized by the presence of silicified breccia rocks. These findings were confirmed by laboratory measurements of more than seventy samples collected in the area, using high resolution gamma-ray spectrometry. The concentrations of uranium in these mineralizations were found to range from approx. 50 mg kg-1 to more than 600 mg kg-1. The latter value is about 240 times above the Earth’s average. Besides uranium, these measurements have also given concentrations of thorium and potassium. Additional geochemical analysis was performed on samples taken from locations where uranium anomalies were discovered using ICP-MS technique, in which concentrations of more than forty elements were determined. Uranium mineralizations are accompained by increased contents of silver (up to 17 times, arsenic (up to 8 times, molybdenum (up to 50 times, mercury (up to 9 times, and lead (up to 14 times, in regard to the Clark’s values. These results warrant a continued investigation of this region because of potential interest in the discovery of nuclear mineral raw materials.

  13. A novel complex A/C/G intergenotypic recombinant of hepatitis B virus isolated in southern China.

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    Heling Su

    Full Text Available Hepatitis B virus (HBV genotypes and subgenotypes may vary in geographical distribution and virological features. Previous investigations, including ours, showed that HBV genotypes B and C were respectively predominant in South and North China, while genotypes A and D were infrequently detected and genotype G was not found. In this study, a novel A/C/G intergenotype was identified in patients with chronic HBV infection in Guilin, a city in southern China. Initial phylogenetic analysis based on the S gene suggested the HBV recombinant to be genotype G. However, extended genotyping based on the entire HBV genome indicated it to be an A/C/G intergenotype with a closer relation to genotype C. Breakpoint analysis using the SIMPLOT program revealed that the recombinant had a recombination with a arrangement of genotypes A, G, A and C fragments. Compared with the HBV recombinants harboring one or two genotype G fragments found in Asian countries, this Guilin recombinant was highly similar to the Vietnam (98-99% and Long An recombinants (96-99%, but had a relatively low similarity to the Thailand one (89%. Unlike those with the typical genotype G of HBV, the patients with the Guilin recombinant were seropositive for HBeAg. Moreover, a relatively high HBV DNA viral load (>2 × 10(6 IU/ml was detected in the patients, and the analysis of viral replication capacity showed that the Guilin recombinant strains had a competent replication capacity similar to genotypes B and C strains. These findings can aid in not only the clarification of the phylogenetic origin of the HBV recombinants with the genotype G fragment found in Asian countries, but also the understanding of the virological properties of these complicated HBV recombinants.

  14. Chemical data and variation diagrams of igneous rocks from the Timber Mountain-Oasis Valley Caldera Complex, southern Nevada

    Science.gov (United States)

    Quinlivan, W.D.; Byers, F.M.

    1977-01-01

    Silica variation diagrams presented here are based on 162 chemical analyses of tuffs, lavas, and intrusives, representative of volcanic centers of the Timber Mountain-Oasis Valley caldera complex and cogenetic rocks of the Silent Canyon ca1dera. Most of the volcanic units sampled are shown on the U.S. Geological Survey geologic map of the Timber Mountain caldera area (I-891) and are described in U.S. Geological Survey Professional Paper 919. Early effusives of the complex, although slightly altered, are probably chemically, and petrographically, more like the calc-alkalic Fraction Tuff (Miocene) of the northern Nellis Air Force Base Bombing and Gunnery Range to the north, whereas effusives of later Miocene age, such as the Paintbrush and Timber Mountain Tuffs, are alkali-calcic.

  15. The Juchatengo complex: an upper-level ophiolite assemblage of late Paleozoic age in Oaxaca, southern Mexico

    Science.gov (United States)

    Grajales-Nishimura, José Manuel; Ramos-Arias, Mario Alfredo; Solari, Luigi; Murillo-Muñetón, Gustavo; Centeno-García, Elena; Schaaf, Peter; Torres-Vargas, Ricardo

    2018-04-01

    The Juchatengo complex (JC) suite is located between the Proterozoic Oaxacan complex to the north and the Xolapa complex to the south, and was amalgamated by late Paleozoic magmatism. It consists of mafic and sedimentary rocks that have oceanic affinities, with internal pseudostratigraphic, structural and metamorphic characteristics, which resemble a typical upper-level ophiolite assemblage. New U-Pb zircon and previous hornblende K-Ar analyses yield ages of ca. 291-313 Ma (U-Pb) for plagiogranites and ca. 282-277 Ma for tonalites intruding the entire sequence, including pelagic sediments at the top, with a maximum deposition age of ca. 278 Ma and noteworthy local provenance. These data constrain the age of the JC to the Late Pennsylvanian-Early Permian period. Hf isotopic analyses obtained from zircons in the JC plagiogranite and tonalite show that they come from a similar primitive mantle source (176Hf/177Hf: 0.282539-0.283091; ƐHf(t): + 3.2 to + 15.0). ƐHf(t) values from near 0 to - 2.8 in the tonalites indicate a contribution from the continental crust. Trace elements and REE patterns in whole rock and zircons point to a primitive mantle source for differentiated mafic, plagiogranite dykes and tonalitic plutons. Geochronological and geochemical data address the generation of new oceanic crust above the subduction zone, probably in a backarc setting. In this tectonic scenario, the JC ophiolite originated due to the convergence of the paleo-Pacific plate below the already integrated Oaxacan and Acatlán complexes in western Pangea. The dextral displacement places the deformation in a transtensional regime during the late Paleozoic age.

  16. Geodetic Mass Balance of the Northern Patagonian Icefield from 2000 to 2012 Using Two Independent Methods

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    Inés Dussaillant

    2018-02-01

    Full Text Available We compare two independent estimates of the rate of elevation change and geodetic mass balance of the Northern Patagonian Icefield (NPI between 2000 (3,856 km2 and 2012 (3,740 km2 from space-borne data. The first is obtained by differencing the Shuttle Radar Topography Mission (SRTM digital elevation model (DEM from February 2000 and a Satellite pour l'Observation de la Terre 5 (SPOT5 DEM from March 2012. The second is deduced by fitting pixel-based linear elevation trends over 118 DEMs calculated from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER stereo images acquired between 2000 and 2012. Both methods lead to similar and strongly negative icefield-wide mass balance rates of −1.02 ± 0.21 and −1.06 ± 0.14 m w.e. yr−1 respectively, which is in agreement with earlier studies. Contrasting glacier responses are observed, with individual glacier mass balance rates ranging from −0.15 to −2.30 m w.e. yr−1 (standard deviation = 0.49 m w.e. yr−1; N = 38. For individual glaciers, the two methods agree within error bars, except for small glaciers poorly sampled in the SPOT5 DEM due to clouds. Importantly, our study confirms the lack of penetration of the C-band SRTM radar signal into the NPI snow and firn except for a region above 2,900 m a.s.l. covering <1% of the total area. Ignoring penetration would bias the mass balance by only 0.005 m w.e. yr−1. A strong advantage of the ASTER method is that it relies only on freely available data and can thus be extended to other glacierized areas.

  17. Timing of tertiary extension in the Southern Canadian Cordillera: constraints from fission-track analysis in the Shuswap metamorphic complex

    International Nuclear Information System (INIS)

    Lorencak, M.; Seward, D.; Burg, J.-P.

    1999-01-01

    Full text: Nine zircon and eighteen apatite fission-track analyses have been made in order to determine the low temperature cooling history of the Shuswap metamorphic core complex, western Canada. The zircons vary in apparent age from 53.9 ± 5.6 to 37.5 ± 5.0 Ma and the apatites from 48.5 ± 3.2 to 27.7 ± 3.4 Ma. In the footwall of the detachment faults defining the core complex, the cooling histories show a similarity until temperatures of ∼250 C were reached at about 45 Ma. From then on, activity on two normal faults, the Columbia River Fault and the Victor Creek Fault, controlled the regional cooling pattern. The ages and the combination of ages fall into four groups and on the basis of the fission-track data, we suggest that the region can now be divided into four thermotectonic units which are the result of differing tectonic controls during regional extension. Additionally, a complete cooling history of the Shuswap core complex can now be reconstructed, using constraints from U-Pb, Rb-Sr and K-Ar age data from several authors as well as the fission track results presented here. Copyright (1999) Geological Society of Australia

  18. Synchronization and Causality Across Time-scales: Complex Dynamics and Extremes in El Niño/Southern Oscillation

    Science.gov (United States)

    Jajcay, N.; Kravtsov, S.; Tsonis, A.; Palus, M.

    2017-12-01

    A better understanding of dynamics in complex systems, such as the Earth's climate is one of the key challenges for contemporary science and society. A large amount of experimental data requires new mathematical and computational approaches. Natural complex systems vary on many temporal and spatial scales, often exhibiting recurring patterns and quasi-oscillatory phenomena. The statistical inference of causal interactions and synchronization between dynamical phenomena evolving on different temporal scales is of vital importance for better understanding of underlying mechanisms and a key for modeling and prediction of such systems. This study introduces and applies information theory diagnostics to phase and amplitude time series of different wavelet components of the observed data that characterizes El Niño. A suite of significant interactions between processes operating on different time scales was detected, and intermittent synchronization among different time scales has been associated with the extreme El Niño events. The mechanisms of these nonlinear interactions were further studied in conceptual low-order and state-of-the-art dynamical, as well as statistical climate models. Observed and simulated interactions exhibit substantial discrepancies, whose understanding may be the key to an improved prediction. Moreover, the statistical framework which we apply here is suitable for direct usage of inferring cross-scale interactions in nonlinear time series from complex systems such as the terrestrial magnetosphere, solar-terrestrial interactions, seismic activity or even human brain dynamics.

  19. The Quaternary calc-alkaline volcanism of the Patagonian Andes close to the Chile triple junction: geochemistry and petrogenesis of volcanic rocks from the Cay and Maca volcanoes (˜45°S, Chile)

    Science.gov (United States)

    D'Orazio, M.; Innocenti, F.; Manetti, P.; Tamponi, M.; Tonarini, S.; González-Ferrán, O.; Lahsen, A.; Omarini, R.

    2003-08-01

    Major- and trace-element, Sr-Nd isotopes, and mineral chemistry data were obtained for a collection of volcanic rock samples erupted by the Cay and Maca Quaternary volcanoes, Patagonian Andes (˜45°S, Chile). Cay and Maca are two large, adjacent stratovolcanoes that rise from the Chiloe block at the southern end of the southern volcanic zone (SVZ) of the Andes. Samples from the two volcanoes are typical medium-K, calc-alkaline rocks that form two roughly continuous, largely overlapping series from subalkaline basalt to dacite. The overall geochemistry of the samples studied is very similar to that observed for most volcanoes from the southern SVZ. The narrow range of Sr-Nd isotope compositions ( 87Sr/ 86Sr=0.70389-0.70431 and 143Nd/ 144Nd=0.51277-0.51284) and the major- and trace-element distributions indicate that the Cay and Maca magmas differentiated by crystal fractionation without significant contribution by crustal contamination. This is in accordance with the thin (Maca magmas is investigated by means of the relative concentration of fluid mobile (e.g. Ba) and fluid immobile (e.g. Nb, Ta, Zr, Y) elements and other relevant trace-element ratios (e.g. Sr/Y). The results indicate that small amounts (Maca volcanoes and that, despite the very young age (Maca magma sources to the northern edge of the slab window generated by the subduction of the Chile ridge under the South American plate, we did not find any geochemical evidence for a contribution of a subslab asthenospheric mantle. However, this mantle has been used to explain the peculiar geochemical features (e.g. the mild alkalinity and relatively low ratios between large ion lithophile and high field strength elements) of the Hudson volcano, which is located even closer to the slab window than the Cay and Maca volcanoes are.

  20. Two new species of the Liolaemus elongatus-kriegi complex (Iguania, Liolaemidae) from Andean highlands of southern Chile

    Science.gov (United States)

    Troncoso-Palacios, Jaime; Díaz, Hugo A.; Esquerré, Damien; Urra, Felix A.

    2015-01-01

    Abstract The elongatus-kriegi complex is one of the most diverse clades of the Liolaemus (sensu stricto) subgenus of lizards. There are currently 29 species recognized in this group distributed between Chile and Argentina. Based on molecular evidence, there seem to be five main clades nested within this complex: the elongatus, leopardinus, kriegi, petrophilus and punmahuida clades. Liolaemus buergeri and Liolaemus kriegi, both of the kriegi clade, were believed to inhabit the surroundings of the Laja Lagoon, in the Biobío Region of Chile. Moreover, this Chilean population of Liolaemus kriegi was recently recognized as an undescribed taxon called “Liolaemus sp. A” based on molecular phylogenetics. In this work, we studied these two populations of the Laja Lagoon and provided the morphological diagnosis to describe them as two new species: Liolaemus scorialis sp. n. and Liolaemus zabalai sp. n., previously considered Liolaemus buergeri and “Liolaemus kriegi/Liolaemus sp. A” respectively. Additionally, we identified another population of Liolaemus scorialis in the vicinity of La Mula Lagoon in the Araucanía Region of Chile. Liolaemus scorialis differs from almost all of the species of the elongatus-kriegi complex by its considerably smaller size. Nevertheless, without molecular data we cannot assign it to any particular subclade. Liolaemus zabalai belongs to the kriegi clade based on published molecular phylogenies. Finally, we provide some natural history data on both species and we document for the first time the presence of Liolaemus neuquensis in Chile from a museum specimen from La Mula Lagoon. PMID:25987873

  1. K-Ar ages of rocks from Lago Alumine, Rucachoroi and Quillen, North Patagonian Andes, Neuquen, Republica Argentina

    International Nuclear Information System (INIS)

    Latorre, Carlos O.; Vattuone, M.E; Linares, Enrique; Leal, Pablo R

    2001-01-01

    This study presents new K-Ar ages of granitic rocks from the Patagonian Batholit in the North Patagonian Andes (38 o 00'- 39 o 30' SL), from localities near Alumine lake and from Norquinco lake to Quillen valley, in the Neuquen Province, Argentine. The granitic rocks of Patagonia had been recognized as Upper Paleozoic to Middle Jurassic batholits and as Late Jurassic to Tertiary batholiths (Rapela and Pankhurst, 1992). Geochronologically, Rapela and Kay (1988) had distinguished Early Cretaceous (140 to 120 Ma) and Late Cretaceous (110 to 75 Ma ) magmatic episodes based in potassium-argon data. For the granitic rocks of the area of Paso Icalma, Moquehue and the Rahue granodiorites, Cingolani et al. (1991) presented Rb-Sr whole rock isochron ages of 70±10 Ma, 209±13 Ma and 237±37 Ma, respectively, and Varela et al. (1994), with the same method, cited an age of 285±5 Ma for the Rahue granodiorites and diorites (au)

  2. Infection with Toxoplasma gondii in a red kangaroo (Macropus rufus and a Patagonian mara (Dolichotis patagonum in captivity

    Directory of Open Access Journals (Sweden)

    Nataly Díaz-Ayala

    Full Text Available Abstract Toxoplasmosis is an infectious, zoonotic and parasitic disease, caused by Toxoplasma gondii. In this manucript, two cases of infection with T. gondii in captive animals from a zoological park in the central region of Chile are described. One case was a red kangaroo (Macropus rufus, which is highly susceptible to the infection, and the other was a Patagonian mara (Dolichotis patagonum, a rodent in which there is no previous report of the infection. Both animals had myocarditis, with the presence of intralesional tachizoites and cysts suggestive of infection with T. gondii. This infection was confirmed by immunohistochemistry in both animals. The origin of the infection is unknown, but it is likely that free ranging domestic felines were associated with the dissemination of the parasites. This highlights the importance of controlling the domestic animal populations in zoological parks. To the best of our knowledge, this is the first time that T. gondii infection is described in a Patagonian mara, adding a new host for this infectious agent.

  3. New insights into the morphology, reproduction and distribution of the large-tuberculate octopus Graneledone macrotyla from the Patagonian slope

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    Ángel Guerra

    2012-05-01

    Full Text Available The new information reported in this paper is based on 11 specimens of the large-tuberculate octopus Graneledone macrotyla. These specimens were caught in bottom trawl surveys ATLANTIS 2009 and 2010 carried out on the Patagonian slope off the Argentinean Economic Exclusive Zone between 24 February and 1 April 2009 and from 9 March to 5 April 2010 respectively. A new diagnosis and a complete description of the species are provided. This is the first time that stylets, beaks and spermatophores are described. This is also the first time in which mature females have been studied and the female genitalia described. Like other eledonid octopods, G. macrotyla does not have spermathecae in the oviducal glands. The presence of fertilized eggs inside the ovary suggests that fertilization takes place within the ovary. The simultaneous occurrence of oocyte cohorts at different oogenic stages suggests that the species is a multiple spawner. G. macrotyla inhabits shallower waters on the Patagonian slope (475-921 m than in the subantartic area (1647-2044 m. From a biogeographical point of view, our data show that G. macrotyla inhabits the plume of cold subantarctic waters, which is pushed far north into the southwestern Atlantic by the Falkland (Malvinas Current.

  4. Native and exotic fishes in a Patagonian reservoir with rainbow trout cage culture: spatial and trophic resource use

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    Nabaes Jodar Diego N.

    2017-01-01

    Full Text Available Although the interactions of exotic salmonids with native Patagonian fishes are well known, little is known about the ecology and impact of farmed fish escapees. Salmonid production in Argentina is largely concentrated in the Alicurá reservoir in north Patagonia, where fish community studies have been scarce. Here, we assess and compare the spatial distribution, body size–condition and diet of the different fish species in this reservoir. Strong vertical segregation was observed between exotic rainbow trout Oncorhynchus mykiss (both escapees and wild, dominating the littoral zone, and native Percichthys trucha which dominate the medium and deep strata. Low piscivory–benthivory and high zooplanktivory were observed for rainbow trout, both traits being uncommon at a regional scale. Escaped farmed rainbow trout (ERT diet included abundant indigestible items along with wild prey. Higher body condition of P. trucha close to farms, as well as the regionally unprecedented high incidence of Daphnia sp. in the guts of all the species suggest that farm nutrient discharges have had significant impacts. Finally, the high body condition of ERT, together with their wild food diet and the long dispersal distance observed, demonstrate post-escape success, drawing our attention to potential upstream dispersion affecting the biodiversity and fisheries of Patagonian rivers and lakes.

  5. Stability and change in the distribution of cytospecies of the Simulium damnosum complex (Diptera: Simuliidae) in southern Ghana from 1971 to 2011.

    Science.gov (United States)

    Post, Rory J; Cheke, Robert A; Boakye, Daniel A; Wilson, Michael D; Osei-Atweneboana, Mike Y; Tetteh-Kumah, Anthony; Lamberton, Poppy Hl; Crainey, J Lee; Yaméogo, Laurent; Basáñez, María-Gloria

    2013-07-13

    Simulium damnosum s.l., the most important vector of onchocerciasis in Africa, is a complex of sibling species that have been described on the basis of differences in their larval polytene chromosomes. These (cyto) species differ in their geographical distributions, ecologies and epidemiological roles. In Ghana, distributional changes have been recorded as a consequence of vector control and environmental change (e.g. deforestation), with potential disease consequences. We review the distribution of cytospecies in southern Ghana and report changes observed with reference to historical data collated from 1971 to 2005 and new identifications made between 2006 and 2011. Larvae were collected from riverine breeding sites, fixed in Carnoy's solution and chromosome preparations made. Cytotaxonomic identifications from 1,232 samples (including 49 new samples) were analysed. We report long-term stability in cytospecies distribution in the rivers Afram, Akrum, Pawnpawn and Pru. For the rivers Oda, Ofin and Tano we describe (for the first time) patterns of distribution. We could not detect cytospecies composition changes in the upper Pra, and the lower Pra seems to have been stable. The elimination of the Djodji form of S. sanctipauli in the Volta Region seems to have had no long-term effects on the distribution of the other cytospecies, despite an initial surge by S. yahense. There has been a recent increase in the occurrence of savannah cytospecies in the river Asukawkaw, and this might be related to continuing deforestation. Cytospecies' distributions have not been stable from 1971 to 2011. Although there are no obvious causes for the temporary appearance and subsequent disappearance of cytospecies in a particular location, a major influence has been vector control and migration patterns, probably explaining observed changes on the Black Volta and lower Volta rivers. Deforestation was previously implicated in an increase of savannah cytospecies in southern Ghana (1975

  6. Significant spread of extensively drug-resistant Acinetobacter baumannii genotypes of clonal complex 92 among intensive care unit patients in a university hospital in southern Iran.

    Science.gov (United States)

    Saffari, Fereshteh; Monsen, Tor; Karmostaji, Afsaneh; Azimabad, Fahimeh Bahadori; Widerström, Micael

    2017-11-01

    Infections associated with Acinetobacter baumannii represent an increasing threat in healthcare settings. Therefore, we investigated the epidemiological relationship between clinical isolates of A. baumannii obtained from patients in a university hospital in Bandar Abbas in southern Iran. Sixty-four consecutive non-duplicate clinical isolates collected during 2014-2015 were subjected to susceptibility testing, clonal relationship analysis using PFGE, multilocus variable-number tandem-repeat analysis (MLVA) and multilocus sequence typing (MLST), and examined for the presence of carbapenemases and integrons. Almost all A. baumannii isolates were extensively drug-resistant (XDR; 98 %) and carried an OXA carbapenemase gene (blaOXA-23-like; 98 %) and class 1 integrons (48 %). PFGE and MLST analysis identified three major genotypes, all belonging to clonal complex 92 (CC92): sequence type 848 (ST848) (n=23), ST451 (n=16) and ST195 (n=8). CC92 has previously been documented in the hospital setting in northern Iran, and ST195 has been reported in Arab States of the Persian Gulf. These data suggest national and global transmission of A. baumannii CC92. This report demonstrates the occurrence and potential spread of closely related XDR genotypes of A. baumannii CC92 within a university hospital in southern Iran. These genotypes were found in the majority of the investigated isolates, showed high prevalence of blaOXA-23 and integron class 1, and were associated with stay in the intensive care unit. Very few treatment options remain for healthcare-adapted XDR A. baumannii, and hence effective measures are desperately needed to reduce the spread of these strains and resultant infections in the healthcare setting.

  7. Stress near geometrically complex strike-slip faults - Application to the San Andreas fault at Cajon Pass, southern California

    Science.gov (United States)

    Saucier, Francois; Humphreys, Eugene; Weldon, Ray, II

    1992-01-01

    A model is presented to rationalize the state of stress near a geometrically complex major strike-slip fault. Slip on such a fault creates residual stresses that, with the occurrence of several slip events, can dominate the stress field near the fault. The model is applied to the San Andreas fault near Cajon Pass. The results are consistent with the geological features, seismicity, the existence of left-lateral stress on the Cleghorn fault, and the in situ stress orientation in the scientific well, found to be sinistral when resolved on a plane parallel to the San Andreas fault. It is suggested that the creation of residual stresses caused by slip on a wiggle San Andreas fault is the dominating process there.

  8. Parameterization of a complex landscape for a sediment routing model of the Le Sueur River, southern Minnesota

    Science.gov (United States)

    Belmont, P.; Viparelli, E.; Parker, G.; Lauer, W.; Jennings, C.; Gran, K.; Wilcock, P.; Melesse, A.

    2008-12-01

    Modeling sediment fluxes and pathways in complex landscapes is limited by our inability to accurately measure and integrate heterogeneous, spatially distributed sources into a single coherent, predictive geomorphic transport law. In this study, we partition the complex landscape of the Le Sueur River watershed into five distributed primary source types, bluffs (including strath terrace caps), ravines, streambanks, tributaries, and flat,agriculture-dominated uplands. The sediment contribution of each source is quantified independently and parameterized for use in a sand and mud routing model. Rigorous modeling of the evolution of this landscape and sediment flux from each source type requires consideration of substrate characteristics, heterogeneity, and spatial connectivity. The subsurface architecture of the Le Sueur drainage basin is defined by a layer cake sequence of fine-grained tills, interbedded with fluvioglacial sands. Nearly instantaneous baselevel fall of 65 m occurred at 11.5 ka, as a result of the catastrophic draining of glacial Lake Agassiz through the Minnesota River, to which the Le Sueur is a tributary. The major knickpoint that was generated from that event has propagated 40 km into the Le Sueur network, initiating an incised river valley with tall, retreating bluffs and actively incising ravines. Loading estimates constrained by river gaging records that bound the knick zone indicate that bluffs connected to the river are retreating at an average rate of less than 2 cm per year and ravines are incising at an average rate of less than 0.8 mm per year, consistent with the Holocene average incision rate on the main stem of the river of less than 0.6 mm per year. Ongoing work with cosmogenic nuclide sediment tracers, ground-based LiDAR, historic aerial photos, and field mapping will be combined to represent the diversity of erosional environments and processes in a single coherent routing model.

  9. New U-Pb ages in the Diablillos Intrusive Complex, Southern Puna, Argentina: A long magmatic event in the Paleozoic Arc, SW Gondwana

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, Agustin; Hauser, Natalia [Universidade de Brasilia (UnB), DF (Brazil). Instituto de Geociencias. Lab. de Geocronologia; Becchio, Raul; Nieves, Alexis; Suzano, Nestor [Universidad Nacional de Salta (UNSa)-CONICET, Salta (Argentina)

    2015-07-01

    The Puna geological region comprises Salta, Jujuy and Catamarca provinces, northwestern Argentina. This 4000 meter above sea level high-plateau region lies between the Central Argentinian Andes. The Puna basement in the central Andes consists of Proterozoic–Paleozoic metamorphic rocks and granitoids. Diverse authors, proposed different models to explain the origin of the basement, where two orogenic events are recognized: the Pampean (Upper Precambrian–Lower Cambrian) and Famatinian (Upper Cambrian–Lower Silurian) (e.g. Ramos et al., 1986; Ramos, 1988; Loewy et al., 2004; for opposite points of view see Becchio et al., 1999; Bock et al., 2000; Buttner et al., 2005). Hence, Lucassen et al. (2000) proposed for the Central Andean basement, an evolution in a mobile belt, where the Pampean and Famatinian cycles are not distinct events but, they are one single, non-differentiable event from 600 to 400 Ma. The mobile belt culminated in low-P/ high-T metamorphism at approximately 525-500 Ma. Then, these were followed by a long-lasting high-thermal gradient regime in the mid-crust until Silurian times. Becchio et al., (2011) defined the Diablillos Intrusive Complex (CID, by its Spanish name), emplaced in the Inca Viejo Range. This range splits the Salares Ratones-Centenario with the Salar Diablillos (Fig.1). This Complex is located in the Eastern Magmatic Belt, Southern Puna, Argentina. Here we present new zircons U-Pb ages by LA-MC-ICPMS in the Diablillos Intrusive Complex, contributing to understanding the magmatic event in the lower Paleozoic arc, SW Gondwana. (author)

  10. New U-Pb ages in the Diablillos Intrusive Complex, Southern Puna, Argentina: A long magmatic event in the Paleozoic Arc, SW Gondwana

    International Nuclear Information System (INIS)

    Ortiz, Agustin; Hauser, Natalia

    2015-01-01

    The Puna geological region comprises Salta, Jujuy and Catamarca provinces, northwestern Argentina. This 4000 meter above sea level high-plateau region lies between the Central Argentinian Andes. The Puna basement in the central Andes consists of Proterozoic–Paleozoic metamorphic rocks and granitoids. Diverse authors, proposed different models to explain the origin of the basement, where two orogenic events are recognized: the Pampean (Upper Precambrian–Lower Cambrian) and Famatinian (Upper Cambrian–Lower Silurian) (e.g. Ramos et al., 1986; Ramos, 1988; Loewy et al., 2004; for opposite points of view see Becchio et al., 1999; Bock et al., 2000; Buttner et al., 2005). Hence, Lucassen et al. (2000) proposed for the Central Andean basement, an evolution in a mobile belt, where the Pampean and Famatinian cycles are not distinct events but, they are one single, non-differentiable event from 600 to 400 Ma. The mobile belt culminated in low-P/ high-T metamorphism at approximately 525-500 Ma. Then, these were followed by a long-lasting high-thermal gradient regime in the mid-crust until Silurian times. Becchio et al., (2011) defined the Diablillos Intrusive Complex (CID, by its Spanish name), emplaced in the Inca Viejo Range. This range splits the Salares Ratones-Centenario with the Salar Diablillos (Fig.1). This Complex is located in the Eastern Magmatic Belt, Southern Puna, Argentina. Here we present new zircons U-Pb ages by LA-MC-ICPMS in the Diablillos Intrusive Complex, contributing to understanding the magmatic event in the lower Paleozoic arc, SW Gondwana. (author)

  11. Sarmatian Attributes in Archaeological Complexes of Catacombs Burials in Arys Culture of Southern Kazakhstan (1st Century B.C. - 3rd Century A.D.

    Directory of Open Access Journals (Sweden)

    Podushkin Aleksandr Nikolaevich

    2015-12-01

    Full Text Available The publication is devoted to archaeological research of monuments of the catacomb of Arys culture of Southern Kazakhstan (1st Century B.C. - 3rd Century A.D.. Now scientists have a complete understanding of the range and typology, periodization and chronology of monuments of this culture. There are three stages: Karaultobe (4th century B.C. - 1st century A.D.; Karatobe (1st Century B.C. - 4th century A.D.; Altintobe (4th-6th centuries A.D.. These stages are characterized by specific clusters of signs in the form of artifacts. The author also carried out the ethnic attribution of the Arys culture in association with the ancient state Kangiuj. As a result of this work, the ethnicity of the state Kangiuj was revealed: in particular, late Saka’s, Sarmatian, Huns and Kangiuj ethnic components which are relevant to archaeological complexes, were identified. In the Arys monuments of culture the author discovered complexes of findings which associated with the Sarmatian world of Eurasia by their ethno-cultural parameters. They include typical for the Sarmatians list of ritual action and the funerary equipment, including weapons, bronze mirrors, ritual and religious objects, signs-tamgas, jewelry (including Egyptian faience, articles in “animal”, gold-turquoise and polychrome style. The characteristics of the burial complexes of catacombs of the Arys culture discussed in the publication and corresponding to chronological calculations and ethno-cultural interpretations, allow to speak about presence in the territory of South Kazakhstan of the Asian Sarmatians or any local branch of the Union of the Sarmatian tribes in the 1st century B.C. - 3rd century A.D.

  12. Crystal and solution structures of an odorant-binding protein from the southern house mosquito complexed with an oviposition pheromone

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Yang; Xu, Xianzhong; Xu, Wei; Ishida, Yuko; Leal, Walter S.; Ames, James B.; Clardy, Jon (Harvard-Med); (UCD)

    2010-11-15

    Culex mosquitoes introduce the pathogens responsible for filariasis, West Nile virus, St. Louis encephalitis, and other diseases into humans. Currently, traps baited with oviposition semiochemicals play an important role in detection efforts and could provide an environmentally friendly approach to controlling their populations. The odorant binding proteins (OBPs) in the female's antenna play a crucial, if yet imperfectly understood, role in sensing oviposition cues. Here, we report the X-ray crystallography and NMR 3D structures of OBP1 for Culex quinquefasciatus (CquiOBP1) bound to an oviposition pheromone (5R,6S)-6-acetoxy-5-hexadecanolide (MOP). In both studies, CquiOBP1 had the same overall six-helix structure seen in other insect OBPs, but a detailed analysis revealed an important previously undescribed feature. There are two models for OBP-mediated signal transduction: (i) direct release of the pheromone from an internal binding pocket in a pH-dependent fashion and (ii) detection of a pheromone-induced conformational change in the OBP {center_dot} pheromone complex. Although CquiOBP1 binds MOP in a pH-dependent fashion, it lacks the C terminus required for the pH-dependent release model. This study shows that CquiOBP binds MOP in an unprecedented fashion using both a small central cavity for the lactone head group and a long hydrophobic channel for its tail.

  13. Resilience vs soft crisis: dynamic risk assessment in complex hybrid systems. Case history of Ginosa (Taranto, Southern Italy)

    Science.gov (United States)

    Parisi, Alessandro; Argentiero, Ilenia; Fidelibus, Maria Dolores; Pellicani, Roberta; Spilotro, Giuseppe

    2017-04-01

    Considering a natural system without human-induced modifications, its resilience can be altered by many natural drivers (e.g. geological characteristics, climate) and their spatial modifications over time. Therefore, natural hazardous phenomena could shift natural system over tipping points in an easier or more difficult way. So long as natural system does not involve human settlements or transport infrastructures, natural system risk assessment could not be a basic topic. Nowadays, human activities have modified many natural systems forming, as a result, hybrid systems (both human and natural), in which natural and human-induced drivers modify hybrid systems vulnerability in order to decrease or increase their resilience: scientists define this new age Anthropocene. In this context, dynamic risk assessment of hybrid systems is required in order to avoid disaster when hazardous phenomena occur, but it is a quite complex issue. In fact, soft crisis emerging signals are difficult to identify because of wrong risk perception and lack of communication. Furthermore, natural and human-induced modifications are rarely registered and supervised by governments, so it is fairly difficult defining how systems resilience changes over time. Inhabitants of Ginosa (Taranto, South of Italy) had modified many old rock dwellings over thousand years since the Middle Ages. Indeed, they had built up three-storey houses on three hypogeum levels of rock dwellings along the ravine. The Matrice street collapse in Ginosa is an example of how natural and human-induced spatial modifications over time had led a soft crisis to evolve in a disaster, fortunately without fatalities. This research aim is to revisit events before the Matrice street collapse on the 21st January 2014. The will is to define the relationship between the hybrid system resilience and soft crisis variation over time and how human and natural drivers were involved in the shift.

  14. Geology, petrography and geochemistry of the A-type granites from the Morro Redondo Complex (PR-SC, southern Brazil, Graciosa Province

    Directory of Open Access Journals (Sweden)

    FREDERICO C.J. VILALVA

    2014-03-01

    Full Text Available The Morro Redondo Complex is one of the most important occurrences of the Graciosa A-type Province, southern Brazil. It consists of the Papanduva and Quiriri granitic plutons and a contemporaneous bimodal volcanic association. The Papanduva Pluton includes massive and deformed peralkaline alkali-feldspar granites with Na-Ca and Na-amphiboles and clinopyroxenes. The deformed types are the most evolved rocks in the province and carry rare ‘agpaitic’ minerals, some being described for the first time in granites from Brazil. The larger Quiriri Pluton comprises massive, slightly peraluminous, biotite syeno- and monzogranites with rare Ca-amphibole. Biotite compositions are relatively homogeneous, whereas sodic amphiboles and clinopyroxenes show increasing Na and Fe3+ evolving paths. The Morro Redondo granites are ferroan, with high SiO2, alkalis and HFSE contents; the peralkaline types registering the highest fe#. LILE and HFSE abundances increase with the agpaitic index and the most evolved are HHP granites, with radiogenic heat production up to 5.7 µWm–3. Geothermobarometric estimates indicate emplacement under low pressures (∼100 MPa, at temperatures up to 850-800 °C, and relatively reduced (QFM and oxidized (+1 REPLACE_LT ΔQFM REPLACE_LT +3 environments for the Papanduva and Quiriri Plutons, respectively. In both cases, melts evolved to relatively high oxidation states upon crystallization progress.

  15. The petrology, geochronology and significance of Granite Harbour Intrusive Complex xenoliths and outcrop sampled in western McMurdo Sound, Southern Victoria Land, Antarctica

    International Nuclear Information System (INIS)

    Martin, A.P.; Cooper, A.F.; Price, R.C.; Turnbull, R.E.; Roberts, N.M.W.

    2015-01-01

    Granite Harbour Intrusive Complex xenoliths in McMurdo Volcanic Group rocks and in situ outcrops have been studied from Mount Morning, western McMurdo Sound, Antarctica. Calc-alkalic samples have whole rock signatures and normative compositions similar to the Dry Valleys 1b suite, and zircon grains in one specimen yield a 545.2 ± 4.4 Ma crystallisation age. This supports subduction-related magmatism initiating in Southern Victoria Land by 545 Ma. A second group of xenoliths is alkalic, with titanite grains in one xenolith from this group dated at 538 ± 8 Ma. Whole rock chemistry, normative compositions and geochronology of the alkalic group are comparable to the Koettlitz Glacier Alkaline Suite (KGAS). The position of a proposed lower crustal discontinuity that may form a significant basement suture in the McMurdo Sound region is newly constrained to the east of Mount Morning, perhaps along the trace of the Discovery Glacier. The boundary between East and West Antarctica may also pass along the trace of the Discovery Glacier if, as previously hypothesised, its location is controlled by the basement suture. A significant basement suture may also have provided the necessary egress for the (regionally) early and sustained magmatic activity observed at Mount Morning over the last 24 million years. (author).

  16. Eclogites and garnet clinopyroxenites in the Anrakhai complex, Central Asian Orogenic Belt, Southern Kazakhstan: P-T evolution, protoliths and some geodynamic implications

    Science.gov (United States)

    Pilitsyna, Anfisa V.; Tretyakov, Andrey A.; Degtyarev, Kirill E.; Cuthbert, Simon J.; Batanova, Valentina G.; Kovalchuk, Elena V.

    2018-03-01

    The Anrakhai Metamorphic Complex (AMC), located in the SE part of the Chu-Ili Mountains of Southern Kazakhstan in the western part of Central Asian Orogenic Belt, exhibits occurrences of HP metamorphic rocks in the form of eclogites and garnet clinopyroxenites with peak metamorphic conditions of 750-850° and 15-19 kbar estimated with both conventional geothermobarometric methods and phase diagram modeling. P-T estimates as well as intimate field relations evidently imply a common metamorphic history for eclogites and garnet clinopyroxenites of the AMC. These high-pressure, medium temperature eclogite facies P-T conditions are indicative of a collision or subduction tectonic setting. Major and trace element geochemistry suggests that they probably had a common magmatic origin as part of a suite of differentiated tholeiitic intrusions. Furthermore, distinctive mineral and chemical compositions of these eclogites and garnet clinopyroxenites correspond to the Fe-Ti type of ultramafic rocks suggesting that they may have been derivatives of intraplate tholeiitic melts, introduced into continental crust before HP metamorphism.

  17. Mafic-silicic magma interaction in the layered 1.87 Ga Soukkio Complex in Mäntsälä, southern Finland

    Directory of Open Access Journals (Sweden)

    Toni T. Eerola

    2002-01-01

    Full Text Available The Svecofennian layered Soukkio Complex (1.87 Ga in Mäntsälä, southern Finland, consists of layered tholeiitic gabbro and porphyritic calc-alkaline monzonite, quartz monzonite and granite, mingled together. The gabbro belongs to a group of ten mafic-ultramafic intrusions of Mäntsälä, part of the 150 km long and 20 km wide, linear, E-W trending Hyvinkää–Mäntsälä Gabbroic Belt(HMGB, representing syn-collisional magmatism. Structures and textures related to magma mingling and mixing occur in a 1–2 km wide zone around Lake Kilpijärvi, located at the center of the Soukkio Complex. The complex is compositionally stratified and consists of four zones:its base, found at the Western Zone, is a dynamically layered gabbro. The followingtonalite is probably a result of magma mixing. Felsic amoeboid layers and pipes, alternating with or cutting the fine-grained gabbro in the Central-Western Zone, resemble those of mafic-silicic layered intrusions in general. Mafic magmatic enclaves (MMEs and pillows form the South-Central Zone and disrupted synplutonic mafic dykes or sheets intruded the granite in the Eastern Zone. The MMEs and disrupted synplutonic mafic dykes or sheets show cuspate and chilled margins against the felsic host, quartz ocelli, corroded K-feldspar xenocrysts with or without plagioclase mantles, and acicular apatite, all typical features of magma mingling and mixing. Mixing is suggested by intermediate composition of MMEs between granitoid and gabbro, as well as by their partly linear trends in some Harker diagrams. REE composition of the MMEs is similar to that of the Soukkio Gabbro, as expected for granite hosted MMEs. The model proposed for evolution of the Soukkio Complex involves intrusion of mafic magma into the crust, causing its partial melting. This generated granitic magma above the mafic chamber. Injections of mafic magma invaded the felsic chamber and those magmas interacted mainly by intermingling. Mingling and

  18. Xanthophyllomyces dendrorhous (Phaffia rhodozyma on stromata of Cyttaria hariotii in northwestern Patagonian Nothofagus forests

    Directory of Open Access Journals (Sweden)

    Diego Libkind

    2011-09-01

    Full Text Available The occurrence and distribution of Xanthophyllomyces dendrorhous associated with Cyttaria hariotii parasitizing three Nothofagus species (N. dombeyi, N. antarctica and N. pumilio in northwestern Patagonia (Argentina, as well as the factors that may affect this distribution were herein studied. Between 2000 and 2007, samples were obtained from 18 different locations. Based on physiological tests and morphological characteristics of sexual structures, 72 isolates were identified as X. dendrorhous. Representative strains were studied by MSP-PCR fingerprinting and sequence analysis of the ITS region. MSP-PCR fingerprints were similar for the newly isolated strains, and were also identical to the profiles of the strains previously found in this region. Patagonian strains appear to be a genetically uniform and distinct population, supporting the hypothesis that the association with different host species has determined genetically distinct X. dendrorhous populations worldwide. X. dendrorhous was recovered from N. dombeyi and N. antarctica. Approximately half the sampling sites and samples were positive for X. dendrorhous, but the isolation recovery rate was low. X. dendrorhous was absent in the early stages of ascostromata maturation, becoming more abundant in later stages. The present work represents a step forward in the understanding of the natural distribution and ecology of this biotechnologically relevant yeast.Xanthophyllomyces dendrorhous (Phaffia rhodozyma asociado a estromas de Cyttaria hariotii en bosques de Nothofagus en el noroeste de la Patagonia. Se estudió la ocurrencia y la distribución de Xanthophyllomyces dendrorhous asociado a Cyttaria hariotii en tres especies de Nothofagus (N. dombeyi, N. antarctica y N. pumilio del noroeste de la Patagonia (Argentina, y los factores que podrían afectar esta distribución. El muestreo se realizó entre 2000 y 2007 en 18 sitios diferentes. Según las pruebas fisiológicas y las caracter

  19. Occurrences of ikaite and pseudomorphs after ikaite in Patagonian lakes - crystal morphologies and stable isotope composition

    Science.gov (United States)

    Oehlerich, Markus; Mayr, Christoph; Griesshaber, Erika; Ohlendorf, Christian; Zolitschka, Bernd; Sánchez-Pastor, Nuria; Kremer, Barbara; Lücke, Andreas; Oeckler, Oliver; Schmahl, Wolfgang

    2010-05-01

    Ikaite (CaCO3•6H2O), a hydrated calcium carbonate mineral occasionally found in marine sediments, has so far rarely been reported from non-marine sites. Modern ikaite and calcitic pseudomorphs after ikaite were recently discovered in Patagonian Argentina at the polymictic lakes of Laguna Potrok Aike (51°57´S, 70°23´W) and Laguna Cháltel (49°57´S, 71°07´W), respectively. Both lakes are of volcanic origin and have phosphorous-rich, alkaline waters, but differ in altitude (790 m asl and 110 m asl for Laguna Cháltel and Laguna Potrok Aike, respectively) and water temperature. The aim of this study is (1) to investigate conditions for the formation of ikaite and its transformation to more stable, water-free carbonate pseudomorphs after ikaite and (2) to assess the potential of ikaite and calcite pseudomorphs after ikaite as a paleoenvironmental tool in freshwater lakes. Crystallographic, morphological and isotopic characteristics of the pseudomorphs were investigated. Ikaite crystals were found (in September 2008) primarily on aquatic macrophytes and cyanobacteria colonies at Laguna Potrok Aike. Ikaite crystals transformed quickly to calcite pseudomorphs after ikaite after recovery from the cool lake water (4°C). The crystal structure of ikaite was investigated with single crystal X-ray diffraction on samples that were permanently kept cold (in the lake water). At Laguna Cháltel calcite pseudomorphs after ikaite were discovered in littoral sediment cores from 25 m water depth. The mm-sized, porous, polycrystalline calcium carbonate aggregates from the 104 cm long sediment core of Laguna Cháltel are morphologically pseudomorphs after ikaite. SEM and XRD analyses highlight that these pseudomorphs consist of several µm-small calcite crystals in a calcitic matrix. The shape of these micro-crystals changes from rounded to fibrous with increasing sediment depth. Some specimens show casts of cyanobacteria trichomes. The oxygen isotopic composition of calcite

  20. The Gondwana Orogeny in northern North Patagonian Massif: Evidences from the Caita Có granite, La Seña and Pangaré mylonites, Argentina

    Directory of Open Access Journals (Sweden)

    Daniel A. Gregori

    2016-07-01

    Full Text Available Structural analyses in the northern part of the North Patagonia Massif, in the foliated Caita Có granite and in La Seña and Pangaré mylonites, indicate that the pluton was intruded as a sheet-like body into an opening pull-apart structure during the Gondwana Orogeny. Geochronological studies in the massif indicate a first, lower to middle Permian stage of regional deformation, related to movements during indentation tectonics, with emplacement of foliated granites in the western and central areas of the North Patagonian Massif. Between the upper Permian and lower Triassic, evidence indicates emplacement of undeformed granitic bodies in the central part of the North Patagonian Massif. A second pulse of deformation between the middle and upper Triassic is related to the emplacement of the Caita Có granite, the development of mylonitic belts, and the opening of the Los Menucos Basin. During this pulse of deformation, compression direction was from the eastern quadrant.

  1. Rb/Sr and U/Pb isotopic ages in basement rocks of Mina Gonzalito and Arroyo Salado, Atlantic North-Patagonian Massif, Rio Negro, Argentina

    International Nuclear Information System (INIS)

    Varela, Ricardo; Sato, Ana M.; Cingolani, Carlos A.; Basei, Miguel A.S.; Siga, Oswaldo; Sato, Kei

    1998-01-01

    Isotopic ages from metamorphic and plutonic rocks of the Atlantic area of North Patagonian basement indicate that the main crustal tectonic events occurred during the late Proterozoic to early Paleozoic times. Rb/Sr and U/Pb data in the 550-470 Ma interval suggest an old tecto-thermal activity during the upper Brazilian Cycle (Rio Doce Orogeny). At regional scale, the comparable Neo proterozoic basement of Ventania and sedimentary for eland cover of Tandilia continues to the Northeast, in the Dom Feliciano Belt. A possible correlation of the North Patagonian basement with igneous-metamorphic relics of Central Argentina (Pampean Ranges of San Luis-Cordoba and at La Pampa province) is also indicated. (author)

  2. Further Studies on the Physical and Biogeochemical Causes for Large Interannual Changes in the Patagonian Shelf Spring-Summer Phytoplankton Bloom Biomass

    Science.gov (United States)

    Signorini, Sergio R.; Garcia, Virginia M.T.; Piola, Alberto R.; Evangelista, Heitor; McClain, Charles R.; Garcia, Carlos A.E.; Mata, Mauricio M.

    2009-01-01

    A very strong and persistent phytoplankton bloom was observed by ocean color satellites during September - December 2003 along the northern Patagonian shelf. The 2003 bloom had the highest extent and chlorophyll a (Chl-a) concentrations of the entire Sea-viewing Wide Field-of-view Sensor (SeaWiFS) period (1997 to present). SeaWiFS-derived Chl-a exceeded 20 mg/cu m in November at the bloom center. The bloom was most extensive in December when it spanned more than 300 km across the shelf and nearly 900 km north-south (35degS to 43degS). The northward reach and the deep penetration on the shelf of the 2003 bloom were quite anomalous when compared with other years, which showed the bloom more confined to the Patagonian shelf break (PSB). The PSB bloom is a conspicuous austral spring-summer feature detected by ocean color satellites and its timing can be explained using the Sverdrup critical depth theory. Based on high-resolution numerical simulations, in situ and remote sensing data, we provide some suggestions for the probable mechanisms responsible for that large interannual change of biomass as seen by ocean color satellites. Potential sources of macro and micro (e.g., Fe) nutrients that sustain the high phytoplankton productivity of the Patagonian shelf waters are identified, and the most likely physical processes that maintain the nutrient balance in the region are discussed.

  3. Holocene glacial fluctuations in southern South America

    Science.gov (United States)

    Reynhout, S.; Sagredo, E. A.; Kaplan, M. R.; Aravena, J. C.; Martini, M. A.; Strelin, J. A.; Schaefer, J. M.

    2016-12-01

    Understanding the timing and magnitude of former glacier fluctuations is critical to decipher long-term climatic trends and to unravel both natural cycles and human impact on the current glacial behavior. Despite more than seven decades of research efforts, a unifying model of Holocene glacial fluctuations in Southern South America remains elusive. Here, we present the state-of-the-art regarding the timing of Holocene glacial fluctuation in southern Patagonia-Tierra del Fuego, with a focus on a new generation of high-resolution radiocarbon and 10Be surface exposure dating chronologies. Recently acquired evidence suggest that after receding from advanced Late Glacial positions, Patagonian glaciers were for the most part close to, or even behind, present ice margins during the Early Holocene. On the other hand, emerging chronologies indicate that in some areas there were extensive expansions (century scale?) that punctuated the warm interval. Subsequently, we have evidence of multiple millennial timescale glacial advances starting in the middle Holocene. Several glacial maxima are defined by moraines and other landforms from 7000 years ago to the 19th century, with a gap sometime between 4,500 and 2,500 years ago. The last set of advances began around 800-600 years ago. Although glacial activity is documented in Patagonia at the same time as the European Little Ice Age, the extent of these glacial events are less prominent than those of the mid-Holocene. The causes that may explain these glacial fluctuations remain elusive. Finally, we discuss ongoing efforts to better define the timing and extent of Holocene glaciations in southern South America, and to establish the basis to test competing hypothesis of regional Holocene climate variability.

  4. Permian depositional age of metaturbidites of the Duque de York Complex, southern Chile: U-Pb SHRIMP data and palynology Edad pérmica de sedimentación de las metaturbiditas del Complejo Duque de York, sur de Chile: datos mediante U-Pb SHRIMP y palinología

    Directory of Open Access Journals (Sweden)

    Fernando A Sepúlveda

    2010-07-01

    Full Text Available The Duque de York Complex (DYC is part of the low grade metamorphic accretionary complexes of the pre-Andean Patagonian 'basement'. It is a sedimentary succession exposed along the western margin of southernmost South America. New U-Pb zircon ages and palynological data restrict the maximum depositional age of the DYC to the limit between the early Permian (Kungurian and the middle Permian (Roadian. The palynological association recorded in the DYC, characterized mainly by Gymnospermopsida pollen, indicates a humid environment of forest with an under-growth of ferns. Regional paleogeographic correlations point out that an interpretation of DYC as an autochthonous terrane cannot be discarded, contrasting with previous hypotheses which suggest an allochthonous character for this complex.El Complejo Duque de York (CDY forma parte de los complejos metamórficos acrecionarios del 'basamento' pre-Andino de la Patagonia, correspondiendo a una sucesión sedimentaria que añora a lo largo del margen occidental austral de Sudamérica. Nuevas edades U-Pb en circón, en combinación con información palinológica, permiten acotar la maxima edad de depósito posible del CDY al límite entre el Pérmico temprano (Kunguriano y el Pérmico medio (Roadiano. La asociación palinológica registrada en el CDY está caracterizada por Gymnospermopsida, e indica un ambiente húmedo de bosque con sotobosque de heléchos. Las correlaciones paleogeográñcas apuntan a que la condición de terreno autóctono del CDY no puede ser descartada, lo que se contrapone a hipótesis anteriores, las que sugieren un carácter alóctono para este complejo.

  5. New Patagonian Cretaceous theropod sheds light about the early radiation of Coelurosauria

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    Fernando E Novas

    2012-06-01

    Full Text Available Here we describe a new theropod, Bicentenaria argentina nov. gen. et nov. sp., from the early Late Cretaceous of Patagonia. It is represented by more than a hundred bones belonging to different sized individuals, which were buried together in disarticulation after little transportation. The available association of skeletal elements suggests a gregarious behaviour for Bicentenaria, an ethological trait also recorded among other theropod clades. Increasing documentation of monospecific assemblages of different groups of theropods suggests that a gregarious behaviour may have constituted the ancestral condition for Theropoda, at least. Bicentenaria characterizes for the surangular bone with a high dorsal margin and a prominent lateral shelf, a retroarticular process that is low, wide and spoon-shaped, and quadrate bone with its lateral condyle larger than the medial one. Phylogenetic analysis found the Chinese Tugulusaurus and the Patagonian Bicentenaria as successive sister taxa of all other coelurosaurs, thus revealing the importance of the new taxon in the understanding of the early diversification of Coelurosauria. In particular, Bicentenaria amplifies the array of basal coelurosaurs that inhabited Gondwana during the Cretaceous, also including compsognathids, Aniksosaurus and Santanaraptor. Although still restricted to a handful of forms, available information indicates that Gondwana was a cradle for the evolution of different lineages of basal coelurosaurs, different from those documented in Upper Cretaceous beds in the northern landmasses. Analysis of body size distribution in averostran theropods results in the identification of two main episodes of drastic size reduction in the evolutionary history of Coelurosauria: one occurred at the initial radiation of the group (as represented by Bicentenaria, Zuolong, Tugulusaurus, compsognathids, and Aniksosaurus, and a second episode occurred at the early diverification of Paraves or avialans

  6. Hydrological Response and Complex Impact Pathways of the 2015/2016 El Niño in Eastern and Southern Africa

    NARCIS (Netherlands)

    Siderius, C.; Gannon, K.E.; Ndiyoi, M.; Opere, A.; Batisani, N.; Olago, D.; Pardoe, J.; Conway, D.

    2018-01-01

    The 2015/2016 El Niño has been classified as one of the three most severe on record. El Niño teleconnections are commonly associated with droughts in southern Africa and high precipitation in eastern Africa. Despite their relatively frequent occurrence, evidence for their hydrological effects and

  7. The MIS 3 maximum of the Torres del Paine and Última Esperanza ice lobes in Patagonia and the pacing of southern mountain glaciation

    Science.gov (United States)

    García, Juan-Luis; Hein, Andrew S.; Binnie, Steven A.; Gómez, Gabriel A.; González, Mauricio A.; Dunai, Tibor J.

    2018-04-01

    The timing, structure and termination of the last southern mountain glaciation and its forcing remains unclear. Most studies have focused on the global Last Glacial Maximum (LGM; 26.5-19 ka) time period, which is just part of the extensive time-frame within the last glacial period, including Marine Isotope Stages 3 and 4. Understanding the glacial fluctuations throughout the glacial period is a prerequisite for uncovering the cause and climate mechanism driving southern glaciation and the interhemispheric linkages of climate change. Here, we present an extensive (n = 65) cosmogenic 10Be glacier chronology derived from moraine belts marking the pre-global LGM extent of the former Patagonian Ice Sheet in southernmost South America. Our results show the mountain ice sheet reached its maximum extent at 48.0 ± 1.8 ka during the local LGM, but attained just half this extent at 21.5 ± 1.8 ka during the global LGM. This finding, supported by nearby glacier chronologies, indicates that at orbital time scales, the southern mid-latitude glaciers fluctuated out-of-phase with northern hemisphere ice sheets. At millennial time-scales, our data suggest that Patagonian and New Zealand glaciers advanced in unison with cold Antarctic stadials and reductions in Southern Ocean sea surface temperatures. This implies a southern middle latitudes-wide millennial rhythm of climate change throughout the last glacial period linked to the north Atlantic by the bipolar seesaw. We suggest that winter insolation, acting alongside other drivers such as the strength and/or position of the southern westerlies, controlled the extents of major southern mountain glaciers such as those in southernmost South America.

  8. Residential energy use in one-family households with natural gas provision in a city of the Patagonian Andean region

    International Nuclear Information System (INIS)

    Gonzalez, A.D.; Carlsson-Kanyama, A.; Crivelli, E.S.; Gortari, S.

    2007-01-01

    Residential energy use was studied in one-family houses in the city of Bariloche, in the Patagonian Andean region of Argentina. A survey was conducted of households connected to the natural gas network to correlate use of gas, living area and number of inhabitants per house. The annual average consumption of gas was found to be 169 GJ, and consumption of electricity 8 GJ. This total energy use per household per year is almost double the average value reported for Stockholm, Sweden, although both locations have similar heating requirements. The difference was mainly due to heating energy consumption per unit living space, which in Bariloche was 1530 MJ/m 2 per year, while in Stockholm the average is around 570 MJ/m 2 per year. The high energy consumption in Bariloche is explained primarily by the construction characteristics of the buildings, and secondarily by the efficiency of the heating devices used. We were able to conclude that subsidies on natural gas tariffs given to the residential sector do not promote a rational use of the resource. Furthermore, almost 40% of the population (mostly households in poverty) are not connected to the subsidised gas resource, but pay prices for alternative fuels that are between 10- and 15 times higher. Policies to improve buildings and appliances would reduce emissions and make access to energy more equitable

  9. Genetic evidence and new morphometric data as essential tools to identify the Patagonian seahorse Hippocampus patagonicus (Pisces, Syngnathidae).

    Science.gov (United States)

    González, R; Dinghi, P; Corio, C; Medina, A; Maggioni, M; Storero, L; Gosztonyi, A

    2014-02-01

    A genetic study to support morphometric analyses was used to improve the description and validate the Patagonian seahorse Hippocampus patagonicus (Syngnathidae) on the basis of a large number of specimens collected in the type locality (San Antonio Bay, Patagonia, Argentina). DNA sequence data (from the cytochrome b region of the mitochondrial genome) were used to differentiate this species from its relatives cited for the west Atlantic Ocean. Both phylogenetic and genetic distance analyses supported the hypothesis that H. patagonicus is a species clearly differentiated from others, in agreement with morphometric studies. Hippocampus patagonicus can be distinguished from Hippocampus erectus by the combination of the following morphometric characteristics: (1) in both sexes and all sizes of H. patagonicus, the snout length is always less than the postorbital length, whereas the snout length of H. erectus is not shorter than the postorbital length in the largest specimens; (2) in both sexes of H. patagonicus, the trunk length:total length (LTr :LT ) is lower than in H. erectus (in female H. patagonicus: 0·27-0·39, H. erectus: 0·36-0·40 and in male H. patagonicus: 0·24-0·34, H. erectus: 0·33-0·43) and (3) in both sexes, tail length:total length (LTa :LT ) in H. patagonicus is larger than in H. erectus (0·61-0·78 v. 0·54-0·64). © 2014 The Fisheries Society of the British Isles.

  10. Migratory timing, rate, routes and wintering areas of White-crested Elaenia (Elaenia albiceps chilensis, a key seed disperser for Patagonian forest regeneration.

    Directory of Open Access Journals (Sweden)

    Susana Patricia Bravo

    Full Text Available Migratory animals often play key ecological roles within the communities they visit throughout their annual journeys. As a consequence of the links between biomes mediated by migrants, changes in one biome could affect remote areas in unpredictable ways. Migratory routes and timing of most Neotropical austral migrants, which breed at south temperate latitudes of South America and overwinter closer to or within tropical latitudes of South America, have yet to be described in detail. As a result, our understanding about how these birds provide links between South American biomes is almost non-existent. White-crested Elaenia (Elaenia albiceps chilensis is a long-distance austral migrant that breeds in the Patagonian Forest biome and overwinters in tropical South America. Because this small flycatcher plays a key role in the regeneration of this ecosystem, our objective was to describe the annual cycle of White-crested elaenias to evaluate the degree of migratory connectivity between breeding and wintering areas and therefore to determine if there are specific biomes of northern South America linked by elaenias to Patagonian forests. Fifteen individuals were successfully tracked throughout a complete migration cycle using miniature light-level geolocators. All individuals resided and moved through the same general regions. During fall (March-April-May, elaenias were located in the Caatinga and the Atlantic Forest biomes, from Rio de Janeiro to the region near Salvador da Bahia, Brazil. During winter (June-July-Aug., birds were located further inland, within the Cerrado biome. Birds used three different routes during fall migration. Our results indicate that some individuals use a direct route, flying between 500-600 km/day, crossing desert and grasslands, while others took a detour, flying 100-200 km/day through forested areas with refueling opportunities. All birds used the Yunga forest during spring migration, with ten out of 15 individuals

  11. Fault-controlled permeability and fluid flow in low-porosity crystalline rocks: an example from naturally fractured geothermal systems in the Southern Andes

    Science.gov (United States)

    Arancibia, G.; Roquer, T.; Sepúlveda, J.; Veloso, E. A.; Morata, D.; Rowland, J. V.

    2017-12-01

    Fault zones can control the location, emplacement, and evolution of economic mineral deposits and geothermal systems by acting as barriers and/or conduits to crustal fluid flow (e.g. magma, gas, oil, hydro-geothermal and groundwater). The nature of the fault control permeability is critical in the case of fluid flow into low porosity/permeability crystalline rocks, since structural permeability provides the main hydraulic conductivity to generate a natural fractured system. However, several processes accompanying the failure of rocks (i.e. episodic permeability given by cycling ruptures, mineral precipitation from fluids in veins, dissolution of minerals in the vicinity of a fracture) promote a complex time-dependent and enhancing/reducing fault-controlled permeability. We propose the Southern Volcanic Zone (Southern Andes, Chile) as a case study to evaluate the role of the structural permeability in low porosity crystalline rocks belonging to the Miocene North Patagonian Batholith. Recently published studies propose a relatively well-constrained first-order role of two active fault systems, the arc-parallel (NS to NNE trending) Liquiñe Ofqui Fault System and the arc-oblique (NW trending) Andean Transverse Fault Zones, in fluid flow at crustal scales. We now propose to examine the Liquiñe ( 39°S) and Maihue ( 40°S) areas as sites of interaction between these fault systems, in order to evaluate a naturally fractured geothermal system. Preliminary results indicate upwelling of thermal water directly from fractured granite or from fluvial deposits overlying granitoids. Measured temperatures of thermal springs suggest a low- to medium-enthalpy system, which could potentially be harnessed for use in geothermal energy applications (e.g. heating, wood dryer and green house), which are much needed in Southern Chile. Future work will aim to examine the nature of structural permeability from the regional to the microscopic scale connecting the paleo- and current- fluid

  12. Are there evidences of a complex mimicry system among Asclepias curassavica (Apocynaceae), Epidendrum fulgens (Orchidaceae), and Lantana camara (Verbenaceae) in Southern Brazil?

    OpenAIRE

    Fuhro, Daniela; Araújo, Aldo Mellender de; Irgang, Bruno Edgar

    2010-01-01

    The goal of this paper was to test the presence of mimicry in Asclepias curassavica L., Epidendrum fulgens Brong., and Lantana camara L. The study was carried out at the Parque Estadual de Itapeva, RS, southern Brazil, from 2004 to 2006. Flowering period of each of the three species was followed up; focal observations of butterflies visiting flowers, from fixed point and during random walks were carried out. We also estimated the frequency of pollinaria removal in the orchid, as well as its m...

  13. The Marbat metamorphic core-complex (Southern Arabian Peninsula) : reassessment of the evolution of a Neoproterozoic island-arc from petrological, geochemical and U-Pb zircon data

    OpenAIRE

    Barbey, P.; Denele, Y.; Paquette, J. L.; Berger, J.; Ganne, Jérôme; Roques, D.

    2018-01-01

    The Marbat basement (Sultanate of Oman) belongs to the Neoproterozoic accretion domain of the Arabian-Nubian shield. We present new geochronological, petrological and geochemical data as an extension of our previous study (Denele et al., 2017) re-interpreting this basement as a metamorphic core complex (MCC). We showed that this MCC consists of a metamorphic unit (Juffa complex) separated by an extensional detachment from a plutonic unit (Sadh complex and Tonalite plutons). Geochemical data s...

  14. Tectonic evolution of the North Patagonian Andes (41°-44° S) through recognition of syntectonic strata

    Science.gov (United States)

    Echaurren, A.; Folguera, A.; Gianni, G.; Orts, D.; Tassara, A.; Encinas, A.; Giménez, M.; Valencia, V.

    2016-05-01

    The North Patagonian fold-thrust belt (41°-44° S) is characterized by a low topography, reduced crustal thickness and a broad lateral development determined by a broken foreland system in the retroarc zone. This particular structural system has not been fully addressed in terms of the age and mechanisms that built this orogenic segment. Here, new field and seismic evidence of syntectonic strata constrain the timing of the main deformational stages, evaluating the prevailing crustal regime for the different mountain domains through time. Growth strata and progressive unconformities, controlled by extensional or compressive structures, were recognized in volcanic and sedimentary rocks from the cordilleran to the extra-Andean domain. These data were used to construct a balanced cross section, whose deep structure was investigated through a thermomechanical model that characterizes the upper plate rheology. Our results indicate two main compressive stages, interrupted by an extensional relaxation period. The first contractional stage in the mid-Cretaceous inverted Jurassic-Lower Cretaceous half graben systems, reactivating the western Cañadón Asfalto rift border ~ 500 km away from the trench, at a time of arc foreland expansion. For this stage, available thermochronological data reveal forearc cooling episodes, and global tectonic reconstructions indicate mid-ocean ridge collisions against the western edge of an upper plate with rapid trenchward displacement. Widespread synextensional volcanism is recognized throughout the Paleogene during plate reorganization; retroarc Paleocene--Eocene flare up activity is interpreted as product of a slab rollback, and fore-to-retroarc Oligocene slab/asthenospheric derived products as an expression of enhanced extension. The second stage of mountain growth occurred in Miocene time associated with Nazca Plate subduction, reaching nearly the same amplitude than the first compressive stage. Extensional weakening of the upper plate

  15. Genetic Structure in a Small Pelagic Fish Coincides with a Marine Protected Area: Seascape Genetics in Patagonian Fjords.

    Directory of Open Access Journals (Sweden)

    Cristian B Canales-Aguirre

    Full Text Available Marine environmental variables can play an important role in promoting population genetic differentiation in marine organisms. Although fjord ecosystems have attracted much attention due to the great oscillation of environmental variables that produce heterogeneous habitats, species inhabiting this kind of ecosystem have received less attention. In this study, we used Sprattus fuegensis, a small pelagic species that populates the inner waters of the continental shelf, channels and fjords of Chilean Patagonia and Argentina, as a model species to test whether environmental variables of fjords relate to population genetic structure. A total of 282 individuals were analyzed from Chilean Patagonia with eight microsatellite loci. Bayesian and non-Bayesian analyses were conducted to describe the genetic variability of S. fuegensis and whether it shows spatial genetic structure. Results showed two well-differentiated genetic clusters along the Chilean Patagonia distribution (i.e. inside the embayment area called TicToc, and the rest of the fjords, but no spatial isolation by distance (IBD pattern was found with a Mantel test analysis. Temperature and nitrate were correlated to the expected heterozygosities and explained the allelic frequency variation of data in the redundancy analyses. These results suggest that the singular genetic differences found in S. fuegensis from inside TicToc Bay (East of the Corcovado Gulf are the result of larvae retention bya combination of oceanographic mesoscale processes (i.e. the west wind drift current reaches the continental shelf exactly in this zone, and the local geographical configuration (i.e. embayment area, islands, archipelagos. We propose that these features generated an isolated area in the Patagonian fjords that promoted genetic differentiation by drift and a singular biodiversity, adding support to the existence of the largest marine protected area (MPA of continental Chile, which is the Tic-Toc MPA.

  16. Genetic Structure in a Small Pelagic Fish Coincides with a Marine Protected Area: Seascape Genetics in Patagonian Fjords.

    Science.gov (United States)

    Canales-Aguirre, Cristian B; Ferrada-Fuentes, Sandra; Galleguillos, Ricardo; Hernández, Cristián E

    2016-01-01

    Marine environmental variables can play an important role in promoting population genetic differentiation in marine organisms. Although fjord ecosystems have attracted much attention due to the great oscillation of environmental variables that produce heterogeneous habitats, species inhabiting this kind of ecosystem have received less attention. In this study, we used Sprattus fuegensis, a small pelagic species that populates the inner waters of the continental shelf, channels and fjords of Chilean Patagonia and Argentina, as a model species to test whether environmental variables of fjords relate to population genetic structure. A total of 282 individuals were analyzed from Chilean Patagonia with eight microsatellite loci. Bayesian and non-Bayesian analyses were conducted to describe the genetic variability of S. fuegensis and whether it shows spatial genetic structure. Results showed two well-differentiated genetic clusters along the Chilean Patagonia distribution (i.e. inside the embayment area called TicToc, and the rest of the fjords), but no spatial isolation by distance (IBD) pattern was found with a Mantel test analysis. Temperature and nitrate were correlated to the expected heterozygosities and explained the allelic frequency variation of data in the redundancy analyses. These results suggest that the singular genetic differences found in S. fuegensis from inside TicToc Bay (East of the Corcovado Gulf) are the result of larvae retention bya combination of oceanographic mesoscale processes (i.e. the west wind drift current reaches the continental shelf exactly in this zone), and the local geographical configuration (i.e. embayment area, islands, archipelagos). We propose that these features generated an isolated area in the Patagonian fjords that promoted genetic differentiation by drift and a singular biodiversity, adding support to the existence of the largest marine protected area (MPA) of continental Chile, which is the Tic-Toc MPA.

  17. Short-term variations in mesozooplankton, ichthyoplankton, and nutrients associated with semi-diurnal tides in a patagonian Gulf

    Science.gov (United States)

    Castro, L. R.; Cáceres, M. A.; Silva, N.; Muñoz, M. I.; León, R.; Landaeta, M. F.; Soto-Mendoza, S.

    2011-03-01

    The relationships between the distribution of different zooplankton and ichthyoplankton stages and physical and chemical variables were studied using samples and data (CTD profiles, ADCP and current meter measurements, nutrients, mesozooplankton, ichthyoplankton) obtained from different strata during two 24-h cycles at two oceanographic stations in a Chilean Patagonian gulf during the CIMAR 10-Fiordos cruise (November, 2004). A station located at the Chacao Channel was dominated by tidal mixing and small increments in surface stratification during high tides, leading to decreased nutrient availability. This agreed with short periods of increased phytoplankton abundance during slack waters at the end of flood currents. Increases in larval density for all zooplankton and ichthyoplankton taxa corresponded to the flooding phases of the tidal cycle. When the larval density data were fit to a sinusoidal model, the regression coefficients were high, suggesting that tides are important features that modulate short-term variations in plankton abundance. All larvae did not vary synchronously with the tidal phase; rather, time lags were observed among species. The abundances of older individuals of the copepodite Rhincalanus nasutus and all zoea stages of the squat lobster Munida gregaria increased during night flood tides, whereas younger stages increased during daytime flood tides. At a station located at the Queullin Pass, which was dominated by vertical stratification patterns, the variations in peak larval density were better fitted to the semi-diurnal sea level fluctuations. Other evidence indicated internal tides below the pycnocline, which could promote larval transport in deeper layers. In the overall picture that emerges from this study, planktonic organisms from different habitats and phylogenetic origins seem to respond to the local tidal regimes. In some cases, this response might be beneficial, transporting these individuals inshore to areas that are rich in

  18. Occurrence and levels of glyphosate and AMPA in shallow lakes from the Pampean and Patagonian regions of Argentina.

    Science.gov (United States)

    Castro Berman, M; Marino, D J G; Quiroga, María Victoria; Zagarese, Horacio

    2018-06-01

    Glyphosate (N-(phosphonomethyl)glycine) is a broad-spectrum systemic herbicide used to kill weeds that compete with commercial crops. In Argentina, the use of glyphosate-based herbicides increased dramatically (up to ∼200,000 tons on 2012) since the introduction of glyphosate-resistant crops, such as transgenic soy and resistant corn, and the adoption of non-till practices in the 1990's. Sallow lakes within the Pampa region may be potentially impacted by continuous herbicide usage. We surveyed 52 shallow lakes from the Pampa region (Buenos Aires Province, Argentina) to assess the occurrence and concentrations of glyphosate and its main degradation product (AMPA). For comparison, we also sampled 24 shallow lakes from an area with no agricultural use of glyphosate (Northern Patagonia). Glyphosate and AMPA were analyzed by UPLC-MS/MS ESI (±) in lake water, suspended particulate matter (SPM), and sediment samples. Within the Pampa region, glyphosate residues were detected in >40% of samples. Glyphosate residues were detected more frequently in sediment and surface water than in SPM samples. The mean (maximum) concentrations of glyphosate were 2.11 (4.52) μg l -1 for surface water; 0.10 (0.13) μg l -1 for SPM and 10.47 (20.34) μg kg -1 for sediment samples, respectively. Whereas, mean (maximum) concentrations of AMPA were 0.84 and (0.90) μg l -1 for surface water; 0.07 (0.07) μg l -1 for SPM; and 22.53 (32.89) μg kg -1 for sediment samples. The herbicide was not detected in samples from the Patagonian region. To our knowledge, this is the first study reporting the occurrence and concentrations of the herbicide in freshwater lakes of Argentina. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Assessment of geomorphological and hydrological changes produced by Pleistocene glaciations in a Patagonian basin

    Science.gov (United States)

    Scordo, Facundo; Seitz, Carina; Melo, Walter D.; Piccolo, M. Cintia; Perillo, Gerardo M. E.

    2018-04-01

    This work aims to assess how Pleistocene glaciations modeled the landscape in the upper Senguer River basin and its relationship to current watershed features (drainage surface and fluvial hydrological regime). During the Pleistocene six glacial lobes developed in the upper basin of the Senguer River localized east of the Andean range in southern Argentinean Patagonia between 43° 36' - 46° 27‧ S. To describe the topography and hydrology, map the geomorphology, and propose an evolution of the study area during the Pleistocene we employed multitemporal Landsat images, national geological sheets and a mosaic of the digital elevation model (Shuttle Radar Topography Mission) along with fieldwork. The main conclusion is that until the Middle Pleistocene, the drainage divide of the Senguer River basin was located to the west of its current limits and its rivers drained the meltwater of the glaciers during interglacial periods. However, processes of drainage inversion and drainage surface reduction occurred in the headwater of most rivers of the basin during the Late Pleistocene. Those processes were favored by a relative shorter glacial extension during LGM and the dam effect produced by the moraines of the Post GPG I and III glaciations. Thus, since the Late Pleistocene, the headwaters of several rivers in the basin have been reduced, and the moraines corresponding to the Middle Pleistocene glaciations currently divide the watersheds that drain towards the Senguer River from those that flow west towards the Pacific Ocean.

  20. Loligo gahi, the Patagonian longfin squid, has been the subject of a ...

    African Journals Online (AJOL)

    spamer

    the FIFD by the Renewable Resources Assessment. Group (RRAG) at Imperial College, London (FIFD. 1989). Assessments of Illex argentinus around the. Falkland Islands made using Delury depletion models have proved to be complex but tractable (Beddington et al. 1990, Rosenberg et al. 1990, Basson et al. 1996).

  1. Sea level anomaly on the Patagonian continental shelf: Trends, annual patterns and geostrophic flows

    Science.gov (United States)

    Saraceno, M.; Piola, A. R.; Strub, P. T.

    2016-01-01

    Abstract We study the annual patterns and linear trend of satellite sea level anomaly (SLA) over the southwest South Atlantic continental shelf (SWACS) between 54ºS and 36ºS. Results show that south of 42°S the thermal steric effect explains nearly 100% of the annual amplitude of the SLA, while north of 42°S it explains less than 60%. This difference is due to the halosteric contribution. The annual wind variability plays a minor role over the whole continental shelf. The temporal linear trend in SLA ranges between 1 and 5 mm/yr (95% confidence level). The largest linear trends are found north of 39°S, at 42°S and at 50°S. We propose that in the northern region the large positive linear trends are associated with local changes in the density field caused by advective effects in response to a southward displacement of the South Atlantic High. The causes of the relative large SLA trends in two southern coastal regions are discussed as a function meridional wind stress and river discharge. Finally, we combined the annual cycle of SLA with the mean dynamic topography to estimate the absolute geostrophic velocities. This approach provides the first comprehensive description of the seasonal component of SWACS circulation based on satellite observations. The general circulation of the SWACS is northeastward with stronger/weaker geostrophic currents in austral summer/winter. At all latitudes, geostrophic velocities are larger (up to 20 cm/s) close to the shelf‐break and decrease toward the coast. This spatio‐temporal pattern is more intense north of 45°S. PMID:27840784

  2. Tectono-metamorphic evolution of high-P/T and low-P/T metamorphic rocks in the Tia Complex, southern New England Fold Belt, eastern Australia: Insights from K-Ar chronology

    Science.gov (United States)

    Fukui, Shiro; Tsujimori, Tatsuki; Watanabe, Teruo; Itaya, Tetsumaru

    2012-10-01

    The Tia Complex in the southern New England Fold Belt is a poly-metamorphosed Late Paleozoic accretionary complex. It consists mainly of high-P/low-T type pumpellyite-actinolite facies (rare blueschist facies) schists, phyllite and serpentinite (T = 300 °C and P = 5 kbar), and low-P/high-T type amphibolite facies schist and gneiss (T = 600 °C and P Tia granodiorite). White mica and biotite K-Ar ages distinguish Carboniferous subduction zone metamorphism and Permian granitic intrusions, respectively. The systematic K-Ar age mapping along a N-S traverse of the Tia Complex exhibits a gradual change. The white mica ages become younger from the lowest-grade zone (339 Ma) to the highest-grade zone (259 Ma). In contrast, Si content of muscovite changes drastically only in the highest-grade zone. The regional changes of white mica K-Ar ages and chemical compositions of micas indicate argon depletion from precursor high-P/low-T type phengitic white mica during the thermal overprinting and recrystallization by granitoids intrusions. Our new K-Ar ages and available geological data postulate a model of the eastward rollback of a subduction zone in Early Permian. The eastward shift of a subduction zone system and subsequent magmatic activities of high-Mg andesite and adakite might explain formation of S-type granitoids (Hillgrove suite) and coeval low-P/high-T type metamorphism in the Tia Complex.

  3. Distributed ice thickness and glacier volume in southern South America

    Science.gov (United States)

    Carrivick, Jonathan L.; Davies, Bethan J.; James, William H. M.; Quincey, Duncan J.; Glasser, Neil F.

    2016-11-01

    South American glaciers, including those in Patagonia, presently contribute the largest amount of meltwater to sea level rise per unit glacier area in the world. Yet understanding of the mechanisms behind the associated glacier mass balance changes remains unquantified partly because models are hindered by a lack of knowledge of subglacial topography. This study applied a perfect-plasticity model along glacier centre-lines to derive a first-order estimate of ice thickness and then interpolated these thickness estimates across glacier areas. This produced the first complete coverage of distributed ice thickness, bed topography and volume for 617 glaciers between 41°S and 55°S and in 24 major glacier regions. Maximum modelled ice thicknesses reach 1631 m ± 179 m in the South Patagonian Icefield (SPI), 1315 m ± 145 m in the North Patagonian Icefield (NPI) and 936 m ± 103 m in Cordillera Darwin. The total modelled volume of ice is 1234.6 km3 ± 246.8 km3 for the NPI, 4326.6 km3 ± 865.2 km3 for the SPI and 151.9 km3 ± 30.38 km3 for Cordillera Darwin. The total volume was modelled to be 5955 km3 ± 1191 km3, which equates to 5458.3 Gt ± 1091.6 Gt ice and to 15.08 mm ± 3.01 mm sea level equivalent (SLE). However, a total area of 655 km2 contains ice below sea level and there are 282 individual overdeepenings with a mean depth of 38 m and a total volume if filled with water to the brim of 102 km3. Adjusting the potential SLE for the ice volume below sea level and for the maximum potential storage of meltwater in these overdeepenings produces a maximum potential sea level rise (SLR) of 14.71 mm ± 2.94 mm. We provide a calculation of the present ice volume per major river catchment and we discuss likely changes to southern South America glaciers in the future. The ice thickness and subglacial topography modelled by this study will facilitate future studies of ice dynamics and glacier isostatic adjustment, and will be important for projecting water resources and

  4. Surviving historical Patagonian landscapes and climate: molecular insights from Galaxias maculatus

    Directory of Open Access Journals (Sweden)

    Carrea Cecilia

    2010-03-01

    Full Text Available Abstract Background The dynamic geological and climatic histories of temperate South America have played important roles in shaping the contemporary distributions and genetic diversity of endemic freshwater species. We use mitochondria and nuclear sequence variation to investigate the consequences of mountain barriers and Quaternary glacial cycles for patterns of genetic diversity in the diadromous fish Galaxias maculatus in Patagonia (~300 individuals from 36 locations. Results Contemporary populations of G. maculatus, east and west of the Andes in Patagonia, represent a single monophyletic lineage comprising several well supported groups. Mantel tests using control region data revealed a strong positive relationship when geographic distance was modeled according to a scenario of marine dispersal. (r = 0.69, P = 0.055. By contrast, direct distance between regions was poorly correlated with genetic distance (r = -0.05, P = 0.463. Hierarchical AMOVAs using mtDNA revealed that pooling samples according to historical (pre-LGM oceanic drainage (Pacific vs. Atlantic explained approximately four times more variance than pooling them into present-day drainage (15.6% vs. 3.7%. Further post-hoc AMOVA tests revealed additional genetic structure between populations east and west of the Chilean Coastal Cordillera (coastal vs. interior. Overall female effective population size appears to have remained relatively constant until roughly 0.5 Ma when population size rapidly increased several orders of magnitude [100× (60×-190×] to reach contemporary levels. Maximum likelihood analysis of nuclear alleles revealed a poorly supported gene tree which was paraphyletic with respect to mitochondrial-defined haplogroups. Conclusions First diversifying in the central/north-west region of Patagonia, G. maculatus extended its range into Argentina via the southern coastal regions that join the Pacific and Atlantic oceans. More recent gene flow between northern

  5. Three-dimensional temperature fields of the North Patagonian Sea recorded by Magellanic penguins as biological sampling platforms

    Science.gov (United States)

    Sala, Juan E.; Pisoni, Juan P.; Quintana, Flavio

    2017-04-01

    Temperature is a primary determinant of biogeographic patterns and ecosystem processes. Standard techniques to study the ocean temperature in situ are, however, particularly limited by their time and spatial coverage, problems which might be partially mitigated by using marine top predators as biological platforms for oceanographic sampling. We used small archival tags deployed on 33 Magellanic penguins (Spheniscus magellanicus), and obtained 21,070 geo-localized profiles of water temperature, during late spring of 2008, 2011, 2012 and 2013; in a region of the North Patagonian Sea with limited oceanographic records in situ. We compared our in situ data of sea surface temperature (SST) with those available from satellite remote sensing; to describe the three-dimensional temperature fields around the area of influence of two important tidal frontal systems; and to study the inter-annual variation in the three-dimensional temperature fields. There was a strong positive relationship between satellite- and animal-derived SST data although there was an overestimation by remote-sensing by a maximum difference of +2 °C. Little inter-annual variability in the 3-dimensional temperature fields was found, with the exception of 2012 (and to a lesser extent in 2013) where the SST was significantly higher. In 2013, we found weak stratification in a region which was unexpected. In addition, during the same year, a warm small-scale vortex is indicated by the animal-derived temperature data. This allowed us to describe and better understand the dynamics of the water masses, which, so far, have been mainly studied by remote sensors and numerical models. Our results highlight again the potential of using marine top predators as biological platforms to collect oceanographic data, which will enhance and accelerate studies on the Southwest Atlantic Ocean. In a changing world, threatened by climate change, it is urgent to fill information gaps on the coupled ocean-atmosphere system

  6. Synoptic oceanography of San Jorge Gulf (Argentina): A template for Patagonian red shrimp (Pleoticus muelleri) spatial dynamics

    Science.gov (United States)

    Glembocki, Nora Gabriela; Williams, Gabriela Noemí; Góngora, María Eva; Gagliardini, Domingo Antonio; Orensanz, José María (Lobo)

    2015-01-01

    An extensive series of high-resolution satellite images from the advanced very high-resolution radiometer (AVHRR) and the sea-viewing wide field-of-view sensor (SeaWIFS) was used in a synoptic oceanographic characterization of San Jorge Gulf (SJG, Argentine Patagonia), an area of great significance for marine conservation and commercial fishing. Remotely sensed information was combined with on-board observer's data and published information to investigate the role of distinctive oceanographic features in relation to the life cycle of the Patagonian red shrimp (Pleoticus muelleri), main target of the industrial fleet in SJG. Three frontal systems-North, South and Outer SJG-are characterized. The North and South SJG fronts are associated with shrimp reproductive aggregations during late spring and summer. While both function as spawning/nursery grounds, they differ from each other in many respects. The thermohaline South SJG front has its maximum expression during the winter, reflecting the influence of the low-salinity Magellanic Plume, while the thermal North SJG front develops during spring and summer as the water column becomes stratified in the central basin of the gulf. Wind-related down-welling inshore of the front prevails in the North SJG, and upwelling in the South SJG frontal area. Chlorophyll a is concentrated near the thermocline on the stratified side of the North SJG, and for that reason, it is not detected by remote sensors during the spring bloom and the summer but becomes apparent offshore from the location of the front when the thermocline deepens during the fall (May). In the South SJG front, Chl-a concentration is apparent inshore from the front all year-round, related in part to upwelling-mediated resuspension. The northern end of the outer front coincides in time and space with a recurrent non-reproductive aggregation of red shrimp between November and January and is presumably related to foraging. It is argued that keeping the North and South

  7. Xylella fastidiosa CoDiRO strain associated with the olive quick decline syndrome in southern Italy belongs to a clonal complex of the subspecies pauca that evolved in Central America.

    Science.gov (United States)

    Marcelletti, Simone; Scortichini, Marco

    2016-12-01

    Xylella fastidiosa, a xylem-limited bacterium transmitted by xylem-fluid-feeding Hemiptera insects, causes economic losses of both woody and herbaceous plant species. A Xyl. fastidiosa subsp. pauca strain, namely CoDiRO, was recently found to be associated with the 'olive quick decline syndrome' in southern Italy (i.e. Apulia region). Recently, some Xyl. fastidiosa strains intercepted in France from Coffea spp. plant cuttings imported from Central and South America were characterized. The introduction of infected plant material from Central America in Apulia was also postulated even though an ad hoc study to confirm this hypothesis is lacking. In the present study, we assessed the complete and draft genome of 27 Xyl. fastidiosa strains. Through a genome-wide approach, we confirmed the occurrence of three subspecies within Xyl. fastidiosa, namely fastidiosa, multiplex and pauca, and demonstrated the occurrence of a genetic clonal complex of four Xyl. fastidiosa strains belonging to subspecies pauca which evolved in Central America. The CoDiRO strain displayed 13 SNPs when compared with a strain isolated in Costa Rica from Coffea sp. and 32 SNPs when compared with two strains obtained from Nerium oleander in Costa Rica. These results support the close relationships of the two strains. The four strains in the clonal complex contain prophage-like genes in their genomes. This study strongly supports the possibility of the introduction of Xyl. fastidiosa in southern Italy via coffee plants grown in Central America. The data also stress how the current global circulation of agricultural commodities potentially threatens the agrosystems worldwide.

  8. Northward subduction-related orogenesis of the southern Altaids: Constraints from structural and metamorphic analysis of the HP/UHP accretionary complex in Chinese southwestern Tianshan, NW China

    Directory of Open Access Journals (Sweden)

    Mark Scheltens

    2015-03-01

    Full Text Available The Chinese Tianshan belt of the southern Altaids has undergone a complicated geological evolution. Different theories have been proposed to explain its evolution and these are still hotly debated. The major subduction polarity and the way of accretion are the main problems. Southward, northward subduction and multiple subduction models have been proposed. This study focuses on the structural geology of two of the main faults in the region, the South Tianshan Fault and the Nikolaev Line. The dip direction in the Muzhaerte valley is southward and lineations all point towards the NW. Two shear sense motions have been observed within both of these fault zones, a sinistral one, and a dextral one, the latter with an age of 236–251 Ma. Structural analyses on the fault zones show that subduction has been northward rather than southward. The two shear sense directions indicate that the Yili block was first dragged along towards the east due to the clockwise rotation of the Tarim block. After the Tarim block stopped rotating, the Yili block still kept going eastward, inducing the dextral shear senses within the fault zones.

  9. On the differences between Last Glacial Maximum and Mid-Holocene climates in southern South America simulated by PMIP3 models

    Science.gov (United States)

    Berman, Ana Laura; Silvestri, Gabriel E.; Tonello, Marcela S.

    2018-04-01

    Differences between climate conditions during the Last Glacial Maximum (LGM) and the Mid-Holocene (MH) in southern South America inferred from the state-of-the-art PMIP3 paleoclimatic simulations are described for the first time in this paper. The aim is to expose characteristics of past climate changes occurred without human influence. In this context, numerical simulations are an indispensable tool for inferring changes in near-surface air temperature and precipitation in regions where proxy information is scarce or absent. The analyzed PMIP3 models describe MH temperatures significantly warmer than those of LGM with magnitudes of change depending on the season and the specific geographic region. In addition, models indicate that seasonal mean precipitation during MH increased with respect to LGM values in wide southern continental areas to the east of the Andes Cordillera whereas seasonal precipitation developed in areas to the west of Patagonian Andes reduced from LGM to MH.

  10. New taxa of Hesperantha (Iridaceae: Crocoideae from the southern African winter rainfall region and a review of the H. pilosa complex

    Directory of Open Access Journals (Sweden)

    P. Goldblatt

    2013-01-01

    Full Text Available The southern and tropical Africa genus Hesperantha Ker Gawl., now with 85 species, is distinguished in subfam. Crocoideae by the style dividing into relatively long, usually laxly spreading style branches at or shortly below the mouth of the perianth tube (rarely well within the tube or above the mouth of the tube and, with a few exceptions, by hard, woody corm tunics. We describe three new species here. H. dolomitica Goldblatt & J.C.Manning, a narrow endemic of limestone outcrops on slopes north of the Vars River in the Knersvlakte, Western Cape, has the bell-shaped corms characteristic of the small sect. Hesperantha but is distinctive in the section in its pure white perianth with relatively long tube and soft-textured, falcate to distally trailing leaves. H. laxifolia Goldblatt & J.C.Manning from the Pakhuis Mtns, Western Cape, stands out in sect. Hesperantha in its prostate, somewhat succulent foliage leaves, and spikes of 2–5 white flowers with unusually short filaments less than 1 mm long and particularly short anthers, ± 4 mm long. The short style branches, ± 4 mm long, remain suberect rather than laxly spreading. H. secunda Goldblatt & J.C.Manning from the Roggeveld Escarpment, Northern Cape, has until now been included in H. pilosa but differs in its secund spike of nodding flowers with short style branches, and leaves with broadly winged margins. We also recognize a new subsp. bracteolata (R.C.Foster Goldblatt & J.C.Manning of H. pilosa (L.f. Ker Gawl. for populations of plants with diurnal flowers with usually blue or purple (occasionally white tepals lacking dark pigmentation on the reverse. With additional material to hand, we reduce blue-flowered H. ciliolata Goldblatt to synonymy in subsp. bracteolata and report range extensions for H. pilosa subsp. pilosa, now recorded as far east as the Langeberg near Cloete’s Pass.

  11. Spatial structure of the meroplankton community along a Patagonian fjord - The role of changing freshwater inputs

    Science.gov (United States)

    Meerhoff, Erika; Tapia, Fabián J.; Castro, Leonardo R.

    2014-12-01

    Freshwater inputs are major drivers of circulation, hydrographic structure, and productivity patterns along estuarine systems. We assessed the degree to which meroplankton community structure in the Baker/Martinez fjord complex (Chilean Patagonia, 47.5°S) responds to spatial and temporal changes in hydrographic conditions driven by seasonal changes in Baker river outflow. Zooplankton and hydrographic measurements were conducted along the fjord in early spring (October) and late summer (February), when river outflow was minimal and maximal, respectively. Major meroplankton groups found on these surveys were larval barnacles, crabs, bivalves and gastropods. There was a clear change in community structure between October and February, explained by a switch in the numerically dominant group from barnacle to bivalve larvae. This change in community structure was related to changes in hydrographic structure along the fjord, which are mainly associated with seasonal changes in the Baker river outflow. A variance partition analysis showed no significant spatial trend that could account for the variation in meroplankton along the Martinez channel, whereas temporal variability and environmental variables accounted for 36.6% and 27.6% of the variance, respectively. When comparing meroplankton among the Baker and Martinez channels in October, changes in environmental variables explained 44.9% of total variance, whereas spatial variability accounted for 23.5%. Early and late-stage barnacle larvae (i.e. nauplii and cyprids) were more abundant in water with lower temperature, and higher dissolved oxygen and chlorophyll-a concentration, whereas bivalve larvae were more strongly associated to warmer waters. The seasonal shift in numerical dominance, from barnacle larvae in early spring to bivalve larvae in late summer, suggests that reproduction of these groups is triggered by substantially different sets of conditions, both in terms of hydrography and food availability. The

  12. Experiences in running a complex electronic data capture system using mobile phones in a large-scale population trial in southern Nepal

    OpenAIRE

    Style, S.; Beard, B. J.; Harris-Fry, H.; Sengupta, A.; Jha, S.; Shrestha, B. P.; Rai, A.; Paudel, V.; Thondoo, M.; Pulkki-Brannstrom, A-M; Skordis-Worrall, J.; Manandhar, D. S.; Costello, A.; Saville, N. M.

    2017-01-01

    The increasing availability and capabilities of mobile phones make them a feasible means of data collection. Electronic Data Capture (EDC) systems have been used widely for public health monitoring and surveillance activities, but documentation of their use in complicated research studies requiring multiple systems is limited. This paper shares our experiences of designing and implementing a complex multi-component EDC system for a community-based four-armed cluster-Randomised Controlled Tria...

  13. Experiences in running a complex electronic data capture system using mobile phones in a large-scale population trial in southern Nepal

    OpenAIRE

    Style, Sarah; Beard, B. James; Harris-Fry, Helen; Sengupta, Aman; Jha, Sonali; Shrestha, Bhim P.; Rai, Anjana; Paudel, Vikas; Thondoo, Meelan; Pulkki-Brannstrom, Anni-Maria; Skordis-Worrall, Jolene; Manandhar, Dharma S.; Costello, Anthony; Saville, Naomi M.

    2017-01-01

    ABSTRACT The increasing availability and capabilities of mobile phones make them a feasible means of data collection. Electronic Data Capture (EDC) systems have been used widely for public health monitoring and surveillance activities, but documentation of their use in complicated research studies requiring multiple systems is limited. This paper shares our experiences of designing and implementing a complex multi-component EDC system for a community-based four-armed cluster-Randomised Contro...

  14. Environmental Risks of Landscape Botanical Complexes and Minimization of Technogenic Influence Exerted by Objects of Oil&Gas Production in Steppe Zone of the Southern Urals

    Science.gov (United States)

    Ryabukhina, M. V.; Maiski, R. A.; Salikhova, R. H.

    2017-11-01

    The modern rates of oil and gas production, developed industry, high technologies in the field of the construction and operation of wells, pipelines and other facilities of the oil and gas industry, as well as growing environmental control do not fully solve the problem of the negative impacts on natural objects, in particular, landscape botanical complexes. Taking into account the increasing oil and gas production rates, the existing objects-Orenburg NGKM and constructed ones, for example, by 2015 in the Orenburg region was organized a “new thread” oil company, LLC, the activities of which include exploration, design and preparation of the Mogutovskoye deposits, a part of the Vorontsov and a part of Gremjacheskoye deposits, as well as their exploitation, should explore and develop some effective mechanisms to minimize and eliminate the environmental risks of industrial impact. In our view the multi-component continuous monitoring of environmental risks will help to formulate an effective strategy and develop an effective preventive mechanism of technological activities, identify landscape botanical complexes which are more exposed to environmental risks as well as the regional forecast component changes in terms of a landscape botanical complex in the zone of technogenic influence exerted by the objects of the oil and gas industry.

  15. Mineralogy and geochemistry of triassic carbonatites in the Matcha alkaline intrusive complex (Turkestan-Alai Ridge, Kyrgyz Southern Tien Shan), SW Central Asian orogenic belt

    Science.gov (United States)

    Vrublevskii, V. V.; Morova, A. A.; Bukharova, O. V.; Konovalenko, S. I.

    2018-03-01

    Postorogenic intrusions of essexites and alkaline and nepheline syenites in the Turkestan-Alai segment of the Kyrgyz Southern Tien Shan coexist with dikes and veins of carbonatites dated at ∼220 Ma by the Ar-Ar and Rb-Sr age methods. They are mainly composed of calcite and dolomite (60-85%), as well as sodic amphibole, phlogopite, clinopyroxene, microcline, albite, apatite, and magnetite, with accessory niobate, ilmenite, Nb-rutile, titanite, zircon, baddeleyite, monazite-(Ce), barite, and sulfides. The rocks share mineralogical and geochemical similarity with carbonatites that originated by liquid immiscibility at high temperatures above 500 °C. Alkaline silicate and salt-carbonate melts are derived from sources with mainly negative bulk εNd(t) ∼ from -11 to 0 and high initial 87Sr/86Sr ratios (∼0.7061-0.7095) which may be due to mixing of PREMA and EM-type mantle material. Pb isotopic ratios in accessory pyrrhotite (206Pb/204Pb = 18.38; 207Pb/204Pb = 15.64; 208Pb/204Pb = 38.41) exhibit an EM2 trend. The intrusions bear signatures of significant crustal contamination as a result of magma genesis by syntexis and hybridism. Concordant isotope composition changes of δ13C (-6.5 to -1.9‰), δ18O (9.2-23‰), δD (-58 to -41‰), and δ34S (12.6-12.8‰) in minerals and rocks indicate inputs of crustal material at the stage of melting and effect of hot fluids released during dehydration of metamorphosed oceanic basalts or sediments. The observed HFSE patterns of the oldest alkaline gabbro may be due to interaction of the primary mafic magma with IAB-type material. The isotope similarity of alkaline rocks with spatially proximal basalts of the Tarim large igneous province does not contradict the evolution of the Turkestan-Alai Triassic magmatism as the "last echo" of the Tarim mantle plume.

  16. Experiences in running a complex electronic data capture system using mobile phones in a large-scale population trial in southern Nepal.

    Science.gov (United States)

    Style, Sarah; Beard, B James; Harris-Fry, Helen; Sengupta, Aman; Jha, Sonali; Shrestha, Bhim P; Rai, Anjana; Paudel, Vikas; Thondoo, Meelan; Pulkki-Brannstrom, Anni-Maria; Skordis-Worrall, Jolene; Manandhar, Dharma S; Costello, Anthony; Saville, Naomi M

    2017-01-01

    The increasing availability and capabilities of mobile phones make them a feasible means of data collection. Electronic Data Capture (EDC) systems have been used widely for public health monitoring and surveillance activities, but documentation of their use in complicated research studies requiring multiple systems is limited. This paper shares our experiences of designing and implementing a complex multi-component EDC system for a community-based four-armed cluster-Randomised Controlled Trial in the rural plains of Nepal, to help other researchers planning to use EDC for complex studies in low-income settings. We designed and implemented three interrelated mobile phone data collection systems to enrol and follow-up pregnant women (trial participants), and to support the implementation of trial interventions (women's groups, food and cash transfers). 720 field staff used basic phones to send simple coded text messages, 539 women's group facilitators used Android smartphones with Open Data Kit Collect, and 112 Interviewers, Coordinators and Supervisors used smartphones with CommCare. Barcoded photo ID cards encoded with participant information were generated for each enrolled woman. Automated systems were developed to download, recode and merge data for nearly real-time access by researchers. The systems were successfully rolled out and used by 1371 staff. A total of 25,089 pregnant women were enrolled, and 17,839 follow-up forms completed. Women's group facilitators recorded 5717 women's groups and the distribution of 14,647 food and 13,482 cash transfers. Using EDC sped up data collection and processing, although time needed for programming and set-up delayed the study inception. EDC using three interlinked mobile data management systems (FrontlineSMS, ODK and CommCare) was a feasible and effective method of data capture in a complex large-scale trial in the plains of Nepal. Despite challenges including prolonged set-up times, the systems met multiple data

  17. Detrital zircon and igneous protolith ages of high-grade metamorphic rocks in the Highland and Wanni Complexes, Sri Lanka: Their geochronological correlation with southern India and East Antarctica

    Science.gov (United States)

    Kitano, Ippei; Osanai, Yasuhito; Nakano, Nobuhiko; Adachi, Tatsuro; Fitzsimons, Ian C. W.

    2018-05-01

    additional detritus derived from early to middle Neoproterozoic metamorphic rocks. The relic zircon core ages in the HC are comparable with those of the Trivandrum Block and Nagercoil Block of southern India. In contrast, those ages in the WC match the Achankovil Shear Zone and Southern Madurai Block of southern India. These comparisons are also supported by Th/U ratios of detrital zircon cores from paragneisses (Th/U ratios of >0.10 for the former and not only >0.10 but also ≤0.10 for the latter). Comparisons with the Lützow-Holm Complex of East Antarctica indicate that the geochronological characteristics of the HC and WC broadly match those of the Skallen Group, and the Ongul and Okuiwa Groups, respectively.

  18. Estado del conocimiento de humedales del norte patagónico (Argentina: aspectos relevantes e importancia para la conservación de la biodiversidad regional State of the knowledge of north Patagonian wetlands (Argentina: major aspects and importance for regional biodiversity conservation

    Directory of Open Access Journals (Sweden)

    MARÍA G PEROTTI

    2005-12-01

    Full Text Available Las áreas de humedal ocupan casi el 5 % del territorio de la Patagonia argentina. En la zona extrandina y el desierto patagónico estos ecosistemas son esenciales para sostener numerosas especies de fauna y flora silvestre. Además, los humedales del norte patagónico permiten el desarrollo de comunidades acuáticas complejas y constituyen el hábitat crítico de grupos de organismos como los peces y los anfibios incluidos en listados de conservación prioritaria. Estos ecosistemas tienen un funcionamiento complejo que depende estrechamente de las fluctuaciones de las variables meteorológicas y son por lo tanto muy sensibles a los efectos del cambio climático. En la actualidad el uso de la tierra, la introducción de especies y la interacción de estos aspectos con el cambio climático constituyen las variables de mayor impacto sobre estos ambientes patagónicos. En este trabajo se presenta información geográfica, geomorfológica y climática de un número de humedales del norte de la Patagonia argentina. Por otra parte, se sintetiza información sobre la flora y la distribución de peces y anfibios con el propósito de enfatizar la importancia de estos ambientes en el mantenimiento de la biodiversidad regional. Por último, se señalan los procesos que actualmente afectan a estos sistemas poniendo en evidencia la necesidad de obtención de conocimientos básicos para el diseño de planes de manejo y conservación de sus comunidades biológicasAlmost 5 % of the lansdscape of Patagonia is occupied by wetlands. In the extra-andean region and the patagonian desert, wetlands are essential for sustaining biodiversity and wildlife. Besides, North patagonian wetlands present complex aquatic communities and provide habitat for threatened species of fishes and amphibians. These ecosystems have complex dynamics mostly driven by climatic fluctuations which make them vulnerable to the effect of climate change. Nowadays, the main impact on patagonian

  19. Long term diet differences between morphs in trophically polymorphic Percichthys trucha (Pisces : Percichthyidae) populations from the southern Andes

    DEFF Research Database (Denmark)

    Logan, M.S.; Iverson, S.J.; Ruzzante, D.E.

    2000-01-01

    in resource use by two recently described sympatric morphs of Perichthys trucha, a common freshwater fish of the Andean and Patagonian regions of South America. Because dietary fatty acids are often stored in carnivorous animals with little modification after consumption, they can be used to infer information...... that certain fatty acids were correlated with diet as determined by gut content analysis. Consumption of anisopteran larvae was highly correlated with 14:0 in adipose and muscle tissue; and higher levels of longer chain unsaturated fatty acids (i.e. 20 and 22 carbons) were correlated with the presence of fish...... and also amphipods in the diets. Taken together, the results suggest that there are marked differences in the foraging ecology of the two morphs of P. trucha inhabiting southern Andean lakes. (C) 2000 The Linnean Society of London...

  20. sustainable management of rainforest in southern nigeria

    African Journals Online (AJOL)

    BARTH

    2012-07-23

    Jul 23, 2012 ... predict the stand structures of the most complex tropical rainforest ecosystem in Southern ... matrix R was 0.977, which is the intrinsic rate of natural increase with less than zero. ..... management of renewable resources with.

  1. Southern blotting.

    Science.gov (United States)

    Brown, T

    2001-05-01

    Southern blotting is the transfer of DNA fragments from an electrophoresis gel to a membrane support (the properties and advantages of the different types of membrane, transfer buffer, and transfer method are discussed in detail), resulting in immobilization of the DNA fragments, so the membrane carries a semipermanent reproduction of the banding pattern of the gel. After immobilization, the DNA can be subjected to hybridization analysis, enabling bands with sequence similarity to a labeled probe to be identified. This appendix describes Southern blotting via upward capillary transfer of DNA from an agarose gel onto a nylon or nitrocellulose membrane, using a high-salt transfer buffer to promote binding of DNA to the membrane. With the high-salt buffer, the DNA becomes bound to the membrane during transfer but not permanently immobilized. Immobilization is achieved by UV irradiation (for nylon) or baking (for nitrocellulose). A Support Protocol describes how to calibrate a UV transilluminator for optimal UV irradiation of a nylon membrane. An alternate protocol details transfer using nylon membranes and an alkaline buffer, and is primarily used with positively charged nylon membranes. The advantage of this combination is that no post-transfer immobilization step is required, as the positively charged membrane binds DNA irreversibly under alkaline transfer conditions. The method can also be used with neutral nylon membranes but less DNA will be retained. A second alternate protocol describes a transfer method based on a different transfer-stack setup. The traditional method of upward capillary transfer of DNA from gel to membrane described in the first basic and alternate protocols has certain disadvantages, notably the fact that the gel can become crushed by the weighted filter papers and paper towels that are laid on top of it. This slows down the blotting process and may reduce the amount of DNA that can be transferred. The downward capillary method described in

  2. Pup Vibrissae Stable Isotopes Reveal Geographic Differences in Adult Female Southern Sea Lion Habitat Use during Gestation.

    Directory of Open Access Journals (Sweden)

    Alastair M M Baylis

    Full Text Available Individuals within populations often differ substantially in habitat use, the ecological consequences of which can be far reaching. Stable isotope analysis provides a convenient and often cost effective means of indirectly assessing the habitat use of individuals that can yield valuable insights into the spatiotemporal distribution of foraging specialisations within a population. Here we use the stable isotope ratios of southern sea lion (Otaria flavescens pup vibrissae at the Falkland Islands, in the South Atlantic, as a proxy for adult female habitat use during gestation. A previous study found that adult females from one breeding colony (Big Shag Island foraged in two discrete habitats, inshore (coastal or offshore (outer Patagonian Shelf. However, as this species breeds at over 70 sites around the Falkland Islands, it is unclear if this pattern is representative of the Falkland Islands as a whole. In order to characterize habitat use, we therefore assayed carbon (δ13C and nitrogen (δ15N ratios from 65 southern sea lion pup vibrissae, sampled across 19 breeding colonies at the Falkland Islands. Model-based clustering of pup isotope ratios identified three distinct clusters, representing adult females that foraged inshore, offshore, and a cluster best described as intermediate. A significant difference was found in the use of inshore and offshore habitats between West and East Falkland and between the two colonies with the largest sample sizes, both of which are located in East Falkland. However, habitat use was unrelated to the proximity of breeding colonies to the Patagonian Shelf, a region associated with enhanced biological productivity. Our study thus points towards other factors, such as local oceanography and its influence on resource distribution, playing a prominent role in inshore and offshore habitat use.

  3. Detection of Fracture Patterns Within the Southern Portion of a Residential Complex (Tepozanes), Los Reyes-La Paz County (Edo. de Mexico)

    Science.gov (United States)

    Chavez, R. E.; Arango, C.; Tejero, A.; Cifuentes, G.; Hernandez, E.

    2008-12-01

    Most of the urban zone within the Valley of Mexico is built on top of the sediments of the ancient lakes of Chalco, Xochimilco, Mexico, Texcoco, Xaltocan and Zumpango. The sediments that cover this great valley are mainly composed by highly saturated clay-sandy materials; which offer a weak resistance to the constructions built on top. In addition, the increasing need of water supply for the population living in the valley (~22 million inhabitants) has weakened the main groundwater aquifers. This has lead to a differentiated subsidence and collapse of buildings, habitation units and roads. These effects put in a serious risk the inhabitants and the infrastructure of the city. As an example, we present a case of an area located in a densely populated zone, within a low-income residential complex denominated Tepozanes. This is located in the Los Reyes-La Paz County (Mexico State), towards the southeastern portion of the Valley of Mexico. The area is geologically limited by the Chimalhuacan Hill to the N, by the Santa Catarina volcanic range to the S. The previously mentioned effects are evident in the constructions of some buildings, where an exposed fracture is found in the NE-SW direction. This feature is affecting the structure of one of them in the residential complex, where the fracture runs underneath. A geophysical study was proposed to characterize the subsoil and to define the fracturing patterns in the zone. The electrical resistivity tomography (ETR) method employing the capacitive and galvanic modes was used to define the fracturing patters and the position at depth of the saturated layers, which might affect the Residential buildings. As a complement, GPR (Ground Penetrating Radar) profiles were carried out on the same profiles to correlate the information obtained from the ETR capacitive method which has a better resolution in the shallower zone. The computed results show that the buildings foundations were set on top of a high resistivity layer (~1000

  4. Applicability of major histocompatibility complex DRB1 alleles as markers to detect vertebrate hybridization: a case study from Iberian ibex × domestic goat in southern Spain

    Directory of Open Access Journals (Sweden)

    Alasaad Samer

    2012-09-01

    Full Text Available Abstract Background Hybridization between closely related wild and domestic species is of great concern because it can alter the evolutionary integrity of the affected populations. The high allelic variability of Major Histocompatibility Complex (MHC loci usually excludes them from being used in studies to detect hybridization events. However, if a the parental species don’t share alleles, and b one of the parental species possesses an exceptionally low number of alleles (to facilitate analysis, then even MHC loci have the potential to detect hybrids. Results By genotyping the exon2 of the MHC class II DRB1 locus, we were able to detect hybridization between domestic goats (Capra hircus and free-ranging Iberian ibex (Capra pyrenaica hispanica by molecular means. Conclusions This is the first documentation of a Capra pyrenaica × Capra hircus hybridization, which presented us the opportunity to test the applicability of MHC loci as new, simple, cost-effective, and time-saving approach to detect hybridization between wild species and their domesticated relatives, thus adding value to MHC genes role in animal conservation and management.

  5. Immature intra-oceanic arc-type volcanism on the Izanagi Plate revealed by the geochemistry of the Daimaruyama greenstones in the Hiroo Complex, southern Hidaka Belt, central Hokkaido, Japan

    Science.gov (United States)

    Yamasaki, Toru; Nanayama, Futoshi

    2018-03-01

    The Izanagi Plate is assumed to have underlain the western Panthalassa Ocean to the east of Eurasia, and to have been subducting under the Eurasian continent. Although the Izanagi Plate has been lost to subduction, the subduction complexes of the circum-Panthalassa continental margins provide evidence that subduction-related volcanism occurred within the Panthalassa Ocean, and not just along its margins. The Daimaruyama mass is a kilometer-sized allochthonous greenstone body in the Hiroo Complex in the southeastern part of the Nakanogawa Group in the southern Hidaka Belt, northern Japan. The Hiroo Complex is a subduction complex that formed within the Paleo-Kuril arc-trench system at 57-48 Ma. The Daimaruyama greenstones consist mainly of coarse volcaniclastic rocks with lesser amount of lava. Red bedded chert, red shale, and micritic limestone are also observed as blocks associated with the greenstones. The presence of Early Cretaceous (Aptian-Albian) radiolaria in red bedded cherts within the greenstones indicates that the Daimaruyama greenstones formed after this time. An integrated major and trace element geochemical dataset for whole-rocks and clinopyroxenes of the greenstones indicates a calc-alkaline magmatic trend with low TiO2 contents and increases in SiO2 and decreases in FeO* with increasing differentiation. Negative anomalies of Nb, Ta, and Ti in normal mid-ocean-ridge basalt type normalized patterns are interpreted as "arc-signatures". Using "rhyolite-MELTS", we conducted a numerical simulation of magmatic differentiation under conditions of 1.5 kbar and H2O = 3 wt% to reproduce the liquid line of descent of the Daimaruyama greenstones. Back-calculations of the equilibrium melt compositions from the trace element chemistry of the clinopyroxenes generally agree with the whole-rock rare earth element compositions of the Daimaruyama greenstones, therefore providing support for the conditions used for the rhyolite-MELTS calculations as well as the actual

  6. Predicting Effects of Climate Change on Habitat Suitability of Red Spruce (Picea rubens Sarg. in the Southern Appalachian Mountains of the USA: Understanding Complex Systems Mechanisms through Modeling

    Directory of Open Access Journals (Sweden)

    Kyung Ah Koo

    2015-04-01

    Full Text Available Alpine, subalpine and boreal tree species, of low genetic diversity and adapted to low optimal temperatures, are vulnerable to the warming effects of global climate change. The accurate prediction of these species’ distributions in response to climate change is critical for effective planning and management. The goal of this research is to predict climate change effects on the distribution of red spruce (Picea rubens Sarg. in the Great Smoky Mountains National Park (GSMNP, eastern USA. Climate change is, however, conflated with other environmental factors, making its assessment a complex systems problem in which indirect effects are significant in causality. Predictions were made by linking a tree growth simulation model, red spruce growth model (ARIM.SIM, to a GIS spatial model, red spruce habitat model (ARIM.HAB. ARIM.SIM quantifies direct and indirect interactions between red spruce and its growth factors, revealing the latter to be dominant. ARIM.HAB spatially distributes the ARIM.SIM simulations under the assumption that greater growth reflects higher probabilities of presence. ARIM.HAB predicts the future habitat suitability of red spruce based on growth predictions of ARIM.SIM under climate change and three air pollution scenarios: 10% increase, no change and 10% decrease. Results show that suitable habitats shrink most when air pollution increases. Higher temperatures cause losses of most low-elevation habitats. Increased precipitation and air pollution produce acid rain, which causes loss of both low- and high-elevation habitats. The general prediction is that climate change will cause contraction of red spruce habitats at both lower and higher elevations in GSMNP, and the effects will be exacerbated by increased air pollution. These predictions provide valuable information for understanding potential impacts of global climate change on the spatiotemporal distribution of red spruce habitats in GSMNP.

  7. Molecular species identification, host preference and detection of myxoma virus in the Anopheles maculipennis complex (Diptera: Culicidae) in southern England, UK.

    Science.gov (United States)

    Brugman, Victor A; Hernández-Triana, Luis M; Prosser, Sean W J; Weland, Chris; Westcott, David G; Fooks, Anthony R; Johnson, Nicholas

    2015-08-15

    Determining the host feeding patterns of mosquitoes by identifying the origin of their blood-meals is an important part of understanding the role of vector species in current and future disease transmission cycles. Collecting large numbers of blood-fed mosquitoes from the field is difficult, therefore it is important to maximise the information obtained from each specimen. This study aimed to use mosquito genome sequence to identify the species within Anopheles maculipennis sensu lato (An. maculipennis s.l.), identify the vertebrate hosts of field-caught blood-fed An. maculipennis s.l. , and to test for the presence of myxoma virus (Poxviridae, genus Leporipoxvirus) in specimens found to have fed on the European rabbit (Oryctolagus cuniculus). Blood-fed An. maculipennis s.l. were collected from resting sites at Elmley Nature Reserve, Kent, between June and September 2013. Hosts that An. maculipennis s.l. had fed on were determined by a PCR-sequencing approach based on the partial amplification of the mitochondrial cytochrome C oxidase subunit I gene. Mosquitoes were then identified to species by sequencing a region of the internal transcribed spacer-2. DNA extracts from all mosquitoes identified as having fed on rabbits were subsequently screened using PCR for the presence of myxoma virus. A total of 94 blood-fed Anopheles maculipennis s.l. were collected, of which 43 (46%) provided positive blood-meal identification results. Thirty-six of these specimens were identified as Anopheles atroparvus, which had fed on rabbit (n = 33, 92%) and cattle (n = 3, 8%). Seven mosquitoes were identified as Anopheles messeae, which had fed on cattle (n = 6, 86%) and dog (n = 1, 14%). Of the 33 An. atroparvus that contained rabbit blood, nine (27%) were positive for myxoma virus. Results demonstrate that a single DNA extract from a blood-fed mosquito can be successfully used for molecular identification of members of the An. maculipennis complex, blood

  8. The Dovyren Intrusive Complex (Southern Siberia, Russia): Insights into dynamics of an open magma chamber with implications for parental magma origin, composition, and Cu-Ni-PGE fertility

    Science.gov (United States)

    Ariskin, Alexey; Danyushevsky, Leonid; Nikolaev, Georgy; Kislov, Evgeny; Fiorentini, Marco; McNeill, Andrew; Kostitsyn, Yuri; Goemann, Karsten; Feig, Sandrin T.; Malyshev, Alexey

    2018-03-01

    The Dovyren Intrusive Complex (DIC, Northern Baikal region, 728 Ma) includes the layered dunite-troctolite-gabbronorite Yoko-Dovyren massif (YDM), associated mafic-ultramafic sills, and dykes of olivine-rich to olivine-free gabbronorite. Major rock types of the DIC are presented, including a diversity of olivine orthocumulates to olivine-plagioclase and gabbroic adcumulates, carbonate-contaminated ultramafics and Cu-Ni-PGE mineralisation. Detailed comparisons of complete cross-sections of the YDM in its centre and at the NE and SW margins demonstrate differences in the cumulate succession, mineral chemistry, and geochemical structure that likely reflect variations in parental magma compositions. Combining petrochemical reconstructions for most primitive rocks and calculations using the COMAGMAT-5 model, it is shown that the central and peripheral parts of the intrusion formed by olivine-laden parental magmas ranged in their temperatures by 100 °C, approximately from 1290 °C ( 11 wt% MgO, olivine Fo88) to 1190 °C ( 8 wt% MgO, olivine Fo86). Thermodynamic modelling suggests that the most primitive high-Mg magma was S-undersaturated, whereas its derivatives became S-saturated at T piles to generate poorly-mineralised plagiodunite. In the troctolite and gabbroic parts of the Dovyren chamber, sulphide immiscibility likely occurred at lower temperatures, producing Cu-rich sulphide precursors, which gave rise to the 'platinum group mineral' (PGM-containing) troctolite and low-mineralised PGE-rich anorthosite in the Main Reef. The geochemical structure of the YDM demonstrates C-shaped distributions of TiO2, K2O, P2O5, and incompatible trace elements, which are 3-5 fold depleted in the cumulate rocks from the inner horizons of the intrusion with respect to the relatively thin lower and upper contact zones. In addition, a marked misbalance between estimates of the average composition of the YDM and that of the proposed olivine-laden parental magmas is established. This

  9. Thermal effects of the Santa Eulália Plutonic Complex (southern Portugal on the meta-igneous and metasedimentary host rocks

    Directory of Open Access Journals (Sweden)

    Cruz, C.

    2014-12-01

    Full Text Available The Santa Eulália Plutonic Complex (SEPC is a late-Variscan granitic body located in the northern part of the Ossa Morena Zone, a inner zone of the Variscan Iberian Massif. The SEPC host rocks are composed of meta-igneous and metasedimentary units, from Upper Proterozoic to Paleozoic ages, with a NW-SE structure, cross-cut by the SEPC. The SEPC host rocks, with low grade metamorphism show well preserved primary sedimentary or igneous mineralogical, textural and structural features. The thermal effect induced by the SEPC is restricted to the roof pendants. At N and NE of the SEPC, textures and paragenesis resulting from thermal metamorphism, are not related to the SEPC intrusion but to a previous magmatism, controlled by the NW-SE regional anisotropies. The restriction of the thermal effects to the pluton roof may be caused by a combination of several interrelated factors: higher volume of granitic mass, thermal effect by advection of fluids and longer period of prevalence of high thermal conditions. The geochemical study of SEPC host rocks shows the heterogeneous character and diversity of metasedimentary, igneous and meta-igneous rocks. The whole rock geochemical data indicate that all the metasedimentary lithologies derived from an upper continental crustal source and the igneous and meta-igneous rocks show no evidence of metasomatic effects by the SEPC emplacement.El Complejo Plutónico de Santa Eulalia (CPSE es un cuerpo granítico tardi-Varisco situado en la parte norte de la Zona de Ossa Morena, en la zona interior del Macizo Ibérico Varisco. Las rocas encajantes del CPSE están compuestas por unidades meta-ígneas y metasedimentarias, de edades que van desde el Proterozoico Superior hasta el Paleozoico, con una estructura de dirección NW-SE, cortada por el CPSE. Las rocas encanjantes del CPSE, con metamorfismo de bajo grado conservan estructuras, mineralogía y textura primarias. El efecto térmicoinducido por el CPSE se limita a los

  10. Erosion and deposition by supercritical density flows during channel avulsion and backfilling: Field examples from coarse-grained deepwater channel-levée complexes (Sandino Forearc Basin, southern Central America)

    Science.gov (United States)

    Lang, Jörg; Brandes, Christian; Winsemann, Jutta

    2017-03-01

    Erosion and deposition by supercritical density flows can strongly impact the facies distribution and architecture of submarine fans. Field examples from coarse-grained channel-levée complexes from the Sandino Forearc Basin (southern Central America) show that cyclic-step and antidune deposits represent common sedimentary facies of these depositional systems and relate to the different stages of avulsion, bypass, levée construction and channel backfilling. During channel avulsion, large-scale scour-fill complexes (18 to 29 m deep, 18 to 25 m wide, 60 to > 120 m long) were incised by supercritical density flows. The multi-storey infill of the large-scale scour-fill complexes comprises amalgamated massive, normally coarse-tail graded or widely spaced subhorizontally stratified conglomerates and pebbly sandstones, interpreted as deposits of the hydraulic-jump zone of cyclic steps. The large-scale scour-fill complexes can be distinguished from small-scale channel fills based on the preservation of a steep upper margin and a coarse-grained infill comprising mainly amalgamated hydraulic-jump zone deposits. Channel fills include repeated successions deposited by cyclic steps with superimposed antidunes. The deposits of the hydraulic-jump zone of cyclic steps comprise regularly spaced scours (0.2 to 2.6 m deep, 0.8 to 23 m long) infilled by intraclast-rich conglomerates or pebbly sandstones, displaying normal coarse-tail grading or backsets. These deposits are laterally and vertically associated with subhorizontally stratified, low-angle cross-stratified or sinusoidally stratified sandstones and pebbly sandstones, which were deposited by antidunes on the stoss side of the cyclic steps during flow re-acceleration. The field examples indicate that so-called spaced stratified deposits may commonly represent antidune deposits with varying stratification styles controlled by the aggradation rate, grain-size distribution and amalgamation. The deposits of small-scale cyclic

  11. A fuzzy multi-objective linear programming approach for integrated sheep farming and wildlife in land management decisions: a case study in the Patagonian rangelands

    Science.gov (United States)

    Metternicht, Graciela; Blanco, Paula; del Valle, Hector; Laterra, Pedro; Hardtke, Leonardo; Bouza, Pablo

    2015-04-01

    Wildlife is part of the Patagonian rangelands sheep farming environment, with the potential of providing extra revenue to livestock owners. As sheep farming became less profitable, farmers and ranchers could focus on sustainable wildlife harvesting. It has been argued that sustainable wildlife harvesting is ecologically one of the most rational forms of land use because of its potential to provide multiple products of high value, while reducing pressure on ecosystems. The guanaco (Lama guanicoe) is the most conspicuous wild ungulate of Patagonia. Guanaco ?bre, meat, pelts and hides are economically valuable and have the potential to be used within the present Patagonian context of production systems. Guanaco populations in South America, including Patagonia, have experienced a sustained decline. Causes for this decline are related to habitat alteration, competition for forage with sheep, and lack of reasonable management plans to develop livelihoods for ranchers. In this study we propose an approach to explicitly determinate optimal stocking rates based on trade-offs between guanaco density and livestock grazing intensity on rangelands. The focus of our research is on finding optimal sheep stocking rates at paddock level, to ensure the highest production outputs while: a) meeting requirements of sustainable conservation of guanacos over their minimum viable population; b) maximizing soil carbon sequestration, and c) minimizing soil erosion. In this way, determination of optimal stocking rate in rangelands becomes a multi-objective optimization problem that can be addressed using a Fuzzy Multi-Objective Linear Programming (MOLP) approach. Basically, this approach converts multi-objective problems into single-objective optimizations, by introducing a set of objective weights. Objectives are represented using fuzzy set theory and fuzzy memberships, enabling each objective function to adopt a value between 0 and 1. Each objective function indicates the satisfaction of

  12. Preliminary study of the effects of gamma radiation on freshness parameters of the 'H and G' portion of Patagonian tooth fish (Dissostichus eleginoides)

    International Nuclear Information System (INIS)

    Principe, F.; Andreucetti, N.A.; Croci, C.A.

    2003-01-01

    The purpose of this work was to know the influence of gamma radiation ((1.0, 3.0 and 5.0 kGy ) over the average storage lifetime at -18 C degrees of the 'H and G' portion of Patagonian tooth fish in terms of freshness chemical parameters and certain organoleptic characteristics. In the post-irradiation short-term (90 day storage) the evolution was investigated regarding the following items: tissue pH, lipid oxidation regarding TBA index, and the basic volatile nitrogen. In reference to organoleptic quality, smell and taste were evaluated, under raw and cooked conditions. The aqueous extract pH of the 'H and G' was identical (p>0.7) for irradiated and non irradiated tissues during storage at -18 C degrees. The value of pH=7 remained almost constant during the 90 control days, both in the irradiated tissues as in the non-irradiated ones. The TBA index behaviour was similar (p>0.10) in the irradiated and non-irradiated samples throughout time. TBA values for control samples ranged from 4.5 and 5.6; and for irradiated, between 4.5 and 6.2 micro moles of tissue MA/Kg. The NBV values were not affected by the radiation doses applied (p>0.65). However, in every treatment (included the control one) a significant decrease was detected in NBV (p<0.05) from 17.3 to 14.0 mg of tissue N/100 g. Regarding smell and taste of the raw and cooked samples, all qualifications were between good and very good. Although no statistically relevant differences were detected, neither by the radiation dose applied nor by the storage time, the irradiated samples with 5.0 kGy showed a slight change in the typical taste. Based on the data obtained in this study, it can be stated that: a) Patagonian tooth fish in its H and G presentation kept at -18 C degrees shows an optimum commercial quality at least during 90 day storage. b) Ionizing radiation treatment at the doses employed had no adverse effects on the species quality under the experimental conditions used. c) This work is a useful basis for

  13. Bacterial community dynamics during polysaccharide degradation at contrasting sites in the Southern and Atlantic Oceans.

    Science.gov (United States)

    Wietz, Matthias; Wemheuer, Bernd; Simon, Heike; Giebel, Helge-Ansgar; Seibt, Maren A; Daniel, Rolf; Brinkhoff, Thorsten; Simon, Meinhard

    2015-10-01

    The bacterial degradation of polysaccharides is central to marine carbon cycling, but little is known about the bacterial taxa that degrade specific marine polysaccharides. Here, bacterial growth and community dynamics were studied during the degradation of the polysaccharides chitin, alginate and agarose in microcosm experiments at four contrasting locations in the Southern and Atlantic Oceans. At the Southern polar front, chitin-supplemented microcosms were characterized by higher fractions of actively growing cells and a community shift from Alphaproteobacteria to Gammaproteobacteria and Bacteroidetes. At the Antarctic ice shelf, chitin degradation was associated with growth of Bacteroidetes, with 24% higher cell numbers compared with the control. At the Patagonian continental shelf, alginate and agarose degradation covaried with growth of different Alteromonadaceae populations, each with specific temporal growth patterns. At the Mauritanian upwelling, only the alginate hydrolysis product guluronate was consumed, coincident with increasing abundances of Alteromonadaceae and possibly cross-feeding SAR11. 16S rRNA gene amplicon libraries indicated that growth of the Bacteroidetes-affiliated genus Reichenbachiella was stimulated by chitin at all cold and temperate water stations, suggesting comparable ecological roles over wide geographical scales. Overall, the predominance of location-specific patterns showed that bacterial communities from contrasting oceanic biomes have members with different potentials to hydrolyse polysaccharides. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  14. Southern elephant seals (Mirounga leonina Linn. depredate toothfish longlines in the midnight zone.

    Directory of Open Access Journals (Sweden)

    John van den Hoff

    Full Text Available Humans have devised fishing technologies that compete with marine predators for fish resources world-wide. One such fishery for the Patagonian toothfish (Dissostichus eleginoides has developed interactions with a range of predators, some of which are marine mammals capable of diving to extreme depths for extended periods. A deep-sea camera system deployed within a toothfish fishery operating in the Southern Ocean acquired the first-ever video footage of an extreme-diver, the southern elephant seal (Mirounga leonina, depredating catch from longlines set at depths in excess of 1000m. The interactions recorded were non-lethal, however independent fisheries observer reports confirm elephant seal-longline interactions can be lethal. The seals behaviour of depredating catch at depth during the line soak-period differs to other surface-breathing species and thus presents a unique challenge to mitigate their by-catch. Deployments of deep-sea cameras on exploratory fishing gear prior to licencing and permit approvals would gather valuable information regarding the nature of interactions between deep diving/dwelling marine species and longline fisheries operating at bathypelagic depths. Furthermore, the positive identification by sex and age class of species interacting with commercial fisheries would assist in formulating management plans and mitigation strategies founded on species-specific life-history strategies.

  15. Emergence of carbapenem non-susceptible multidrug resistant Acinetobacter baumannii strains of clonal complexes 103(B) and 92(B) harboring OXA-type carbapenemases and metallo-β-lactamases in Southern India.

    Science.gov (United States)

    Saranathan, Rajagopalan; Vasanth, Vaidyanathan; Vasanth, Thamodharan; Shabareesh, Pidathala Raghavendra Venkata; Shashikala, P; Devi, Chandrakesan Sheela; Kalaivani, Ramakrishnan; Asir, Johny; Sudhakar, Pagal; Prashanth, K

    2015-05-01

    The molecular epidemiology and carbapenem resistance mechanisms of clinical isolates of Acinetobacter baumannii obtained from a south Indian tertiary care hospital were investigated by repetitive extragenic palindromic sequence PCR (REP-PCR) and multi-locus sequence typing (MLST). Analysis of resistant determinants was achieved by PCR screening for the presence of genes encoding OXA-carbapenemases, metallo-β-lactamases (MBLs) and efflux pumps. REP-PCR generated around eight clusters of high heterogeneity; of these, two major clusters (I and V) appeared to be clonal in origin. Analysis of representative isolates from different clusters by MLST revealed that most of the isolates belonged to sequence type 103 of CC103(B) . Second most prevalent ST belonged to clonal complex (CC) 92(B) which is also referred to as international clone II. Most of the isolates were multi-drug resistant, being susceptible only to polymyxin-B and newer quinolones. Class D β-lactamases such as blaOXA-51-like (100%), blaOXA-23-like (56.8%) and blaOXA-24-like (14.8%) were found to be predominant, followed by a class B β-lactamase, namely blaIMP-1 (40.7%); none of the isolates had blaOXA-58 like, blaNDM-1 or blaSIM-1 . Genes of efflux-pump adeABC were predominant, most of isolates being biofilm producers that were PCR-positive for autoinducer synthase gene (>94%). Carbapenem non-susceptible isolates were highly diverse and present throughout the hospital irrespective of type of ward or intensive care unit. Although previous reports have documented diverse resistant mechanisms in A. baumannii, production of MBL and OXA-type of carbapenamases were found to be the predominant mechanism(s) of carbapenem resistance identified in strains isolated from Southern India. © 2015 The Societies and Wiley Publishing Asia Pty Ltd.

  16. Respuesta barotrópica de los golfos norpatagónicos argentinos forzados por mareas y vientos Barotropic response of north Patagonian gulfs in Argentina to tidal and wind forcing

    Directory of Open Access Journals (Sweden)

    Mariano H Tonini

    2011-11-01

    Full Text Available En este trabajo se presentan los resultados de un modelo hidrodinámico barotrópico de alta resolución no-lineal tridimensional para examinar la respuesta de los golfos norpatagónicos argentinos, San Matías (GSM, Nuevo (GN y San José (GSJ, ante forzante de marea y patrones idealizados de viento superficial. La estructura de la circulación inducida por el viento predominante (Oeste en los tres golfos consiste en dos giros independientes: uno anticiclónico en el Oeste con una corriente costera más intensa que fluye hacia el sur y un retorno más débil por el centro de los golfos y otro giro ciclónico en el Este, que establece la conexión con la Plataforma en el caso del GSM. El GN y GSJ tienen la comunicación con el exterior muy restringida. La inclusión de efectos disipativos producidos por la marea reduce la intensidad de los giros, pero la estructura espacial de la circulación permanece. Si se incrementa la magnitud del viento se intensifican principalmente los giros anticiclónicos y el transporte de intercambio en la boca del GSM y se profundiza la capa superficial de Ekman. En los experimentos forzados con vientos meridionales la circulación media se divide en dos giros cuyo sentido de circulación depende de la dirección del viento: un giro Norte ciclónico (anticiclónico y un giro Sur anticiclónico (ciclónico para vientos del Sur (Norte. Cuando los golfos son forzados simultáneamente por marea y vientos, las corrientes residuales de marea dominan la circulación media y contribuyen a un mayor aislamiento dinámico de los mismos con la plataforma exterior.This work presents the results of a high resolution three dimensional non-linear barotropic hydrodynamic model used to examine the response of three north Patagonian gulfs in Argentina (San Matías, SMG; Nuevo, NG; and San José, SJG forced by tides and idealized patterns of surface winds. The structure of the circulation induced by the dominant winds (Westerly in all

  17. Magnitude, geomorphologic response and climate links of lake level oscillations at Laguna Potrok Aike, Patagonian steppe (Argentina)

    DEFF Research Database (Denmark)

    Kliem, P.; Buylaert, Jan-Pieter; Hahn, A.

    2013-01-01

    in the rain-shadow of the Andes document high Last Glacial and low Holocene lake levels that could suggest increased precipitation during the Last Glacial period. As permafrost in semiarid Patagonia is documented and dated to the Last Glacial period we argue that the frozen ground might have increased...... surficial runoff from the catchment and thus influenced the water balance of the lake. This is important for investigating the glacial to Holocene latitudinal shift and/or strengthening of the Southern Hemispheric Westerlies by using lake level reconstructions as a means to assess the regional water balance...

  18. CO2 and CH4 fluxes of contrasting pristine bogs in southern Patagonia (Tierra del Fuego, Argentina)

    Science.gov (United States)

    Münchberger, Wiebke; Blodau, Christian; Kleinebecker, Till; Pancotto, Veronica

    2015-04-01

    South Patagonian peatlands cover a wide range of the southern terrestrial area and thus are an important component of the terrestrial global carbon cycle. These extremely southern ecosystems have been accumulating organic material since the last glaciation up to now and are - in contrast to northern hemisphere bogs - virtually unaffected by human activities. So far, little attention has been given to these pristine ecosystems and great carbon reservoirs which will potentially be affected by climate change. We aim to fill the knowledge gap in the quantity of carbon released from these bogs and in what controls their fluxes. We study the temporal and spatial variability of carbon fluxes in two contrasting bog ecosystems in southern Patagonia, Tierra del Fuego. Sphagnum-dominated bog ecosystems in Tierra del Fuego are similar to the ones on the northern hemisphere, while cushion plant-dominated bogs can almost exclusively be found in southern Patagonia. These unique cushion plant-dominated bogs are found close to the coast and their occurrence changes gradually to Sphagnum-dominated bogs with increasing distance from the coast. We conduct closed chamber measurements and record relevant environmental variables for CO2 and CH4 fluxes during two austral vegetation periods from December to April. Chamber measurements are performed on microforms representing the main vegetation units of the studied bogs. Gas concentrations are measured with a fast analyzer (Los Gatos Ultraportable Greenhouse Gas Analyzer) allowing to accurately record CH4 fluxes in the ppm range. We present preliminary results of the carbon flux variability from south Patagonian peat bogs and give insights into their environmental controls. Carbon fluxes of these two bog types appear to be highly different. In contrast to Sphagnum-dominated bogs, cushion plant-dominated bogs release almost no CH4 while their CO2 flux in both, photosynthesis and respiration, can be twice as high as for Sphagnum

  19. Environmental conditions, early life stages distributions and larval feeding of patagonian sprat Sprattusfuegensis and common sardine Strangomerabentincki in fjords and channels of the northern Chilean patagonia

    Science.gov (United States)

    Contreras, Tabit; Castro, Leonardo R.; Montecinos, Sandra; Gonzalez, Humberto E.; Soto, Samuel; Muñoz, Maria I.; Palma, Sergio

    2014-12-01

    We assessed ontogenetic changes in distribution and feeding of the Patagonian sprat Sprattus fuegensis and common sardine Strangomera bentincki, and their association with environmental characteristics (hydrography, larval food, gelatinous zooplankton predators), and actual feeding from inshore to offshore areas of the Chilean Patagonia. During the springs of 2007 and 2008, S. bentincki egg and larvae were present north of the Taitao Peninsula (47°S) and S. fuegensis was found to the south of the peninsula. Along the inshore-offshore axis, distributions also differed: while eggs and early larval stages of S. bentincki occurred inshore and seawards, larger larvae occurred mostly seawards. The opposite was observed in S. fuegensis. However, distributions of both species followed the same rule, determined by the size of their prey: eggs and early larval stages occurred in areas of higher abundance of small prey sizes, and larger larvae coincided with the highest abundances of larger prey sizes. No relationship was detected between potential gelatinous predators and the egg and larval distributions of both fish species. Mean ingested prey sizes in both species increased as larvae grew, while maintaining the capacity to feed on small sized items. This ontogenetic feeding pattern and the distributions linked to prey seem to be beneficial in order to take advantage of short term food pulses and to overcome the strong changes in environmental conditions east to west from fjords to open waters.

  20. Rare earth element and strontium isotopic study of seamount-type limestones in Mesozoic accretionary complex of Southern Chichibu Terrane, central Japan. Implication for incorporation process of seawater REE into limestones

    International Nuclear Information System (INIS)

    Tanaka, Kazuya; Miura, Noriko; Asahara, Yoshihiro; Kawabe, Iwao

    2003-01-01

    Ishimaki and Tahara limestones occur as exotic blocks juxtaposed in the Mesozoic (Jurassic) accretionary complex of Southern Chichibu Terrane in eastern Aichi Prefecture, central Japan. They are supposed to be of the seamount-type limestone, since they have no terrigenous materials and are intimately associated with greenstones. REE (rare earth elements) and Sr isotopic studies for the limestones have been made in order to know their geochemical characteristics, ages and origins. Their 87 Sr/ 86 Sr ratios, when referred to the seawater 87 Sr/ 86 Sr curve and relevant geological data, suggest that Ishimaki and Tahara limestones are the late Permian and the Carboniferous to the Early Permian, respectively. Two greenstone fragments found inside the Ishimaki limestone block and one greenstone sample associated with Tahara limestone block, resemble the Hawaiian alkali basalt in the their REE and Y patterns. This is supporting the idea that the limestone blocks may be parts of reef limestones on ancient volcanic seamounts. All the limestone samples, except three unusual Tahara ones, show seawater REE and Y signatures in their chondrite-normalized patterns. Their REE/Ca ratios, however, are 10 2 -10 4 times as high as those ratios of modern biogenic carbonates like corals and the seawater. Accordingly, seawater REE and Y were incorporated into the limestones, when originally biogenic carbonates transformed into inorganic calcite and its secondary growths occurred in diagenesis in contact with sufficient seawater. This view is favored by the reported REE partition experiment between calcite overgrowths and seawater solution. The seawater Ce anomaly as a function of water depth in the modern ocean is a key to infer the water depth of the REE and Y incorporation. The Ce anomalies given by log (Ce/Ce*) for about a half of Ishimaki samples and most of Tahara ones are between -0.5 and -0.2, which are compatible with the shallow water origin. Another half of Ishimaki samples

  1. Availability of vitamin D photoconversion weighted UV radiation in southern South America.

    Science.gov (United States)

    Diaz, Susana; Vernet, Maria; Paladini, Alejandro; Fuenzalida, Humberto; Deferrari, Guillermo; Booth, Charles R; Cabrera, Sergio; Casiccia, Claudio; Dieguez, Maria; Lovengreen, Charlotte; Pedroni, Jorge; Rosales, Alejandro; Vrsalovic, Jazmin

    2011-12-01

    Ultraviolet radiation (UVR) plays a key role in several biological functions, including human health. Skin exposure to UVR is the main factor in vitamin D photoconversion. There is also evidence relating low levels of vitamin D with certain internal cancers, mainly colon, breast and prostate, as well as other diseases. Several epidemiological studies have shown an inverse relationship between the above-mentioned diseases and latitude, in accordance with the ultraviolet radiation latitudinal gradient. The aim of this study is to determine whether UV irradiance levels in the southern South America are sufficient to produce suitable levels of vitamin D year around. For this purpose, vitamin D photoconversion weighted-irradiance was analyzed between S.S. de Jujuy (24.17°S, 65.02°W) and Ushuaia (54° 50'S, 68° 18'W). In addition to irradiance, skin type and area of body exposed to sunlight are critical factors in vitamin D epidemiology. Due to a broad ethnic variability, it was assumed that the skin type in this region varies between II and V (from the most to the less sensitive). All sites except South Patagonia indicate that skin II under any condition of body area exposure and skin V when exposing head, hands, arms and legs, would produce suitable levels of vitamin D year round (except for some days in winter at North Patagonian sites). At South Patagonian sites, minimum healthy levels of vitamin D year round can be reached only by the more sensitive skin II type, if exposing head, hands, arms and legs, which is not a realistic scenario during winter. At these southern latitudes, healthy vitamin D levels would not be obtained between mid May and beginning of August if exposing only the head. Skin V with head exposure is the most critical situation; with the exception of the tropics, sun exposure would not produce suitable levels of vitamin D around winter, during a time period that varies with latitude. Analyzing the best exposure time during the day in order to

  2. Noble gas composition of subcontinental lithospheric mantle: An extensively degassed reservoir beneath Southern Patagonia

    Science.gov (United States)

    Jalowitzki, Tiago; Sumino, Hirochika; Conceição, Rommulo V.; Orihashi, Yuji; Nagao, Keisuke; Bertotto, Gustavo W.; Balbinot, Eduardo; Schilling, Manuel E.; Gervasoni, Fernanda

    2016-09-01

    Patagonia, in the Southern Andes, is one of the few locations where interactions between the oceanic and continental lithosphere can be studied due to subduction of an active spreading ridge beneath the continent. In order to characterize the noble gas composition of Patagonian subcontinental lithospheric mantle (SCLM), we present the first noble gas data alongside new lithophile (Sr-Nd-Pb) isotopic data for mantle xenoliths from Pali-Aike Volcanic Field and Gobernador Gregores, Southern Patagonia. Based on noble gas isotopic compositions, Pali-Aike mantle xenoliths represent intrinsic SCLM with higher (U + Th + K)/(3He, 22Ne, 36Ar) ratios than the mid-ocean ridge basalt (MORB) source. This reservoir shows slightly radiogenic helium (3He/4He = 6.84-6.90 RA), coupled with a strongly nucleogenic neon signature (mantle source 21Ne/22Ne = 0.085-0.094). The 40Ar/36Ar ratios vary from a near-atmospheric ratio of 510 up to 17700, with mantle source 40Ar/36Ar between 31100-6800+9400 and 54000-9600+14200. In addition, the 3He/22Ne ratios for the local SCLM endmember, at 12.03 ± 0.15 to 13.66 ± 0.37, are higher than depleted MORBs, at 3He/22Ne = 8.31-9.75. Although asthenospheric mantle upwelling through the Patagonian slab window would result in a MORB-like metasomatism after collision of the South Chile Ridge with the Chile trench ca. 14 Ma, this mantle reservoir could have remained unhomogenized after rapid passage and northward migration of the Chile Triple Junction. The mantle endmember xenon isotopic ratios of Pali-Aike mantle xenoliths, which is first defined for any SCLM-derived samples, show values indistinguishable from the MORB source (129Xe/132Xe =1.0833-0.0053+0.0216 and 136Xe/132Xe =0.3761-0.0034+0.0246). The noble gas component observed in Gobernador Gregores mantle xenoliths is characterized by isotopic compositions in the MORB range in terms of helium (3He/4He = 7.17-7.37 RA), but with slightly nucleogenic neon (mantle source 21Ne/22Ne = 0.065-0.079). We

  3. Genetic variation in seedling water-use efficiency of Patagonian Cypress populations from contrasting precipitation regimes assessed through carbon isotope discrimination

    Energy Technology Data Exchange (ETDEWEB)

    Pastorino, M. J.; Aparicio, A. G.; Marchelli, P.; Gallo, L. A.

    2012-11-01

    Water-use efficiency (WUE) is a physiological parameter that plays a significant role in the evolutionary dynamics of many forest tree species. It can be estimated indirectly through carbon isotope discrimination (A). In general, plants of more arid origins have lower values of A. In order to study the degree of genetic control of this parameter and the genetic variation in A of Patagonian Cypress seedlings, three Argentinean natural populations chosen to represent two contrasting precipitation regimes were sampled in a common garden trial. The dry situation was represented by two neighboring marginal forest patches from the steppe, while the humid condition was represented by a population with 1,200 mm higher mean annual precipitation. Height (H) and A were measured in 246 five-year-old seedlings from 41 open-pollinated families. The factor family had a significant effect on both variables; however heritability for A was found not to be significant in two out of the three populations. This could be explained by low sample size in one of them and by a real evolutionary effect in the other. An inverse association between H and A was verified, which is interpreted as evidence of an adaptation process at the intra-population level. The studied populations were not shown to discriminate carbon isotopes differently; hence evidence of adaptation to current environmental conditions could not be obtained. On the other hand, the arid populations proved to be quite different in terms of genetic variation, which seems to be the consequence of genetic drift and isolation. (Author) 49 refs.

  4. Combined impact of ultraviolet radiation and increased nutrients supply: A test of the potential anthropogenic impacts on the benthic amphipod Amphitoe valida from Patagonian waters (Argentina

    Directory of Open Access Journals (Sweden)

    Macarena S. Valiñas

    2014-08-01

    Full Text Available Experiments were conducted during the Austral Summer of 2014 to determine the effects of increased nutrient input and ultraviolet radiation (UVR on the food consumption rate (FCR and food preference in the amphipod Amphitoe valida. We collected specimens from the Patagonian coast (Argentina, from beaches close (Barrancas Blancas; BB and further away (Cangrejales; C from the Chubut River, which constitutes the potential source of eutrophication. Organisms were exposed to different radiation regimes (full radiation vs. PAR only and fed with different macroalgae diets (i.e., from different geographical location and with different quality in terms on nutrient content. Males collected from C showed food compensation, consuming more food under low-nutrient diets, while no compensation was observed in males from BB. Regardless of their origin, UVR decreased the FCR when males where fed on ambient nutrient diets, but not when males fed on high-quality diets indicating that in the former case, individuals were in worse physiological conditions to cope with UVR; food quality, however, significantly counteracted the deleterious effects of UVR on FCR. Females collected from the two beaches showed similar FCR under high-nutrient diet and had no food compensation when fed in low-nutrient diets. Females were more vulnerable to UVR, since their FCR were lower when exposed to UV radiation independent of the diet. Our results show that under anthropogenic eutrophication and high solar UVR levels an increase in the nutrient input could favor only males of A. valida, by reducing the negative effects of UVR on their FCR. Nevertheless, these nutrient inputs might cause additional problems like anoxia, as a result of an unusual macroalgal growth, thus affecting amphipod’s survival.

  5. Knowing and doing: research leading to action in the conservation of forest genetic diversity of Patagonian temperate forests.

    Science.gov (United States)

    Gallo, Leonardo A; Marchelli, Paula; Chauchard, Luis; Peñalba, Marcelo Gonzalez

    2009-08-01

    Researchers dealing with conservation subjects usually do not put the results of their work into practice, even when the primary purpose of their research is the preservation of biodiversity. In the South American temperate forests we identified an area with the highest genetic diversity in Argentina of Nothofagus nervosa, one of the most relevant southern beech species. Based on the information of our scientific study and our recommendations, the authorities of Lanin National Park changed the protection status of this area to avoid logging. The new forestry management plans include consideration of "high genetic diversity" in decisions on where logging will be allowed. Results of our initial genetic study induced the analysis of biodiversity at the species and ecosystems levels, which yielded results similar to our genetic studies. A strong connection among researchers and managers from the onset of our study and the awareness of the former about the importance of the implementation of the research work were key to bridging the gap between conservation research and conservation practice.

  6. Mitochondrial and nuclear markers reveal a lack of genetic structure in the entocommensal nemertean Malacobdella arrokeana in the Patagonian gulfs

    Science.gov (United States)

    Alfaya, José E. F.; Bigatti, Gregorio; Machordom, Annie

    2013-06-01

    Malacobdella arrokeana is an entocommensal nemertean exclusively found in the bivalve geoduck Panopea abbreviata, and it is the only representative of the genus in the southern hemisphere. To characterize its genetic diversity, population structure and recent demographic history, we conducted the first genetic survey on this species, using sequence data for the cytochrome oxidase I gene (COI), 16S rRNA (16S) and the internal transcribed spacer (ITS2). Only four different ITS2 genotypes were found in the whole sample, and the two main haplotypes identified in the mitochondrial dataset were present among all localities with a diversity ranging from 0.583 to 0.939. Nucleotide diversity was low (π = 0.001-0.002). No significant genetic structure was detected between populations, and mismatch distribution patterns and neutrality tests results are consistent with a population in expansion or under selection. Analysis of molecular variance (AMOVA) revealed that the largest level of variance observed was due to intrapopulation variation (100, 100 and 94.39 % for 16S, COI and ITS2, respectively). F st values were also non-significant. The observed lack of population structure is likely due to high levels of genetic connectivity in combination with the lack or permeability of biogeographic barriers and episodes of habitat modification.

  7. Detailed chronology of a giant Pleistocene rock-avalanche sequence in the hyperarid southern Peru revealed by jointly applied 10Be and 3He cosmic ray exposure dating : The Study case of the Cerro Caquilluco landslide complex.

    Science.gov (United States)

    Swann, Zerathe; Laurence, Audin; Carlos, Benavente; Régis, Braucher; Pierre-Henri, Blard; Didier, Bourlès; Julien, Carcaillet; Fabrizio, Delgado; Pascal, Lacroix; Valderrama Patricio, Murillo; Aster Team

    2015-04-01

    Giant landslides are recognized to be remarkably abundant on the Western Andean front of southern Peru and northern Chile, especially in the Arica Bend region (e.g. Crosta et al., 2014a). This area is characterized by strong topographic gradients and subsequent incision of deep canyons, due to the evolution of the Andean range that provide suitable conditions for the development of such instabilities. The climate is hyper-arid (Atacama Desert), although rare but highly impulsive wet events have been evidenced since the Pleistocene. In parallel, this region is submitted to strong (Mw 8-9) and recurrent (~100 yrs) subduction earthquakes. Previous studies suggest that large landslides represent the main agent of erosion of the Western Cordillera, providing soft material for subsequent fluvial remobilization. However the lack of time constrains on the numerous fossil landslides identified away from major canyons still hamper to assess a real mass balance of sliding material versus the known fluvial erosion and tectonic uplift rates. Finally the role of landslides in the long-term erosion rates of the Andean range on its arid flank remains quantitatively unknown. Recently, two studies gave divergent opinions about the main factor supposed to control the slope failures in that region. Based on cosmogenic nuclides derived erosion rates, McPhillips et al. (2014) argue that the last Holocene climate variation did not have had any effect on the rate of landsliding, suggesting that here landslides are mainly triggered by earthquake. On the other hand, Margirier et al. (2014) have showed a temporal correlation between a failure episode of the giant Chuquibamba landslide and the Ouki wet climatic event identified on the Altiplano ~100 ka ago. In this study we focus on dating the Cerro Caquilluco rock avalanche complex described by Crosta et al. (2014). With a total volume of about 15 km3, a length of 43 km and an internal structure characterized by various depositional lobes

  8. Spatial distribution of the Ocypode quadrata (Crustacea: Ocypodidae along estuarine environments in the Paranaguá Bay Complex, southern Brazil Distribuição espacial de Ocypode quadrata (Crustacea: Ocypodidae ao longo de ambientes estuarinos no sul do Brasil

    Directory of Open Access Journals (Sweden)

    Leonardo C. da Rosa

    2008-09-01

    Full Text Available This study examines the spatial distribution of the ghost crabs, Ocypode quadrata Fabricius, 1787, in thirteen estuarine sandy beaches located along two main axes of the Paranaguá Bay Estuarine Complex, southern Brazil. Burrow densities of ghost crabs were measured at three beach levels established around the high tide mark during the summer and winter of 2005. All beaches showed a steep beach face slope (2.6 to 8.3º with sediment composition varying from well sorted fine sand to very poorly sorted coarse sand towards the upper estuary. Water salinity ranged from around 31 at those beaches near the bay inlet, to 14 at beaches in the inner estuary. The burrow densities of O. quadrata in the estuarine beaches were similar to those observed in the oceanic beaches. However, the absence of burrows at the four innermost beaches suggests that low salinity and sediment penetrability may prevent ghost crabs from occurring in this region of the estuary. Burrow densities showed strong seasonal variability. The low densities observed during the winter are probably related to a delay crab activities due to low temperatures in the early morning during this season. The absence of a clear zonation pattern was related to estuarine beach morphology.O presente estudo avalia a distribuição espacial de Ocypode quadrata Fabricius, 1787 em treze praias estuarinas distribuídas ao longo dos dois principais eixos do complexo estuarino da Baia de Paranaguá, sul do Brasil. Em cada praia, a densidade de tocas do caranguejo em três níveis distribuídos em torno da marca da preamar foi estimada durante os períodos de verão e de inverno. Todas as praias apresentaram uma declividade bem acentuada (2,6 a 8,3º de inclinação e a composição do sedimento variando, em direção ao interior do estuário, de areia fina bem selecionada a areia grossa muito pobremente selecionada. A salinidade da água variou entre 31 (próximo à desembocadura da baía e 14 nas praias

  9. Oxyvanite, V3O5, a new mineral species and the oxyvanite-berdesinskiite V2TiO5 series from metamorphic rocks of the Slyudyanka Complex, southern Baikal region

    Science.gov (United States)

    Reznitsky, L. Z.; Sklyarov, E. V.; Armbruster, T.; Ushchapovskaya, Z. F.; Galuskin, E. V.; Polekhovsky, Yu. S.; Barash, I. G.

    2010-12-01

    Oxyvanite has been identified as an accessory mineral in Cr-V-bearing quartz-diopside meta- morphic rocks of the Slyudyanka Complex in the southern Baikal region, Russia. The new mineral was named after constituents of its ideal formula (oxygen and vanadium). Quartz, Cr-V-bearing tremolite and micas, calcite, clinopyroxenes of the diopside-kosmochlor-natalyite series, Cr-bearing goldmanite, eskolaite-karelianite dravite-vanadiumdravite, V-bearing titanite, ilmenite, and rutile, berdesinskiite, schreyerite, plagioclase, scapolite, barite, zircon, and unnamed U-Ti-V-Cr phases are associated minerals. Oxyvanite occurs as anhedral grains up to 0.1-0.15 mm in size, without visible cleavage and parting. The new mineral is brittle, with conchoidal fracture. Observed by the naked eye, the mineral is black, with black streak and resinous luster. The microhardness (VHN) is 1064-1266 kg/mm2 (load 30 g), and the mean value is 1180 kg/mm2. The Mohs hardness is about 7.0-7.5. The calculated density is 4.66(2) g/cm3. The color of oxyvanite is pale cream in reflected light, without internal reflections. The measured reflectance in air is as follows (λ, nm- R, %): 440-17.8; 460-18; 480-18.2; 520-18.6; 520-18.6; 540-18.8; 560-18.9; 580-19; 600-19.1; 620-19.2; 640-19.3; 660-19.4; 680-19.5; 700-19.7. Oxyvanite is monoclinic, space group C2/ c; the unit-cell dimensions are a = 10.03(2), b = 5.050(1), c = 7.000(1) Å, β = 111.14(1)°, V = 330.76(5)Å3, Z = 4. The strongest reflections in the X-ray powder pattern [ d, Å, ( I in 5-number scale)( hkl)] are 3.28 (5) (20 bar 2 ); 2.88 (5) (11 bar 2 ); 2.65, (5) (310); 2.44 (5) (112); 1.717 (5) (42 bar 2 ); 1.633 (5) (31 bar 4 ); 1.446 (4) (33 bar 2 ); 1.379 (5) (422). The chemical composition (electron microprobe, average of six point analyses, wt %): 14.04 TiO2, 73.13 V2O3 (53.97 V2O3calc, 21.25 VO2calc), 10.76 Cr2O3, 0.04 Fe2O3, 0.01 Al2O3, 0.02 MgO, total is 100.03. The empirical formula is (V{1.70/3+} Cr0.30)2.0(V{0.59/4+} Ti0.41)1.0O

  10. Community management of coastal resources, southern Thailand

    OpenAIRE

    Chansnoh, P.

    1993-01-01

    The involvement of communities with the assistance and support of government and non government organizations on the management of the coastal resources in Southern Thailand are discussed. The 3 most important resources, mangrove, seagrass and coral, create a complex coastal ecology. Several man-made activities causing the deterioration of this resources are also presented.

  11. Fertilizing Southern Hardwoods

    Science.gov (United States)

    W. M. Broadfoot; A. F. Ike

    1967-01-01

    If present trends continue, fertilizing may soon be economically feasible in southern hardwood stands. Demands for the wood are rising, and the acreage alloted for growing it is steadily shrinking. To supply anticipated requests for information, the U. S. Forest Service has established tree nutrition studies at the Southern Hardwoods Laboratory in Stoneville,...

  12. Southern Gothic Literature

    DEFF Research Database (Denmark)

    Bjerre, Thomas Ærvold

    2017-01-01

    Provides an outline of Southern Gothic Literature, offers an argument about its history and shape, and discusses the scholarly literature surrounding Southern Gothic. Oxford Research Encyclopedia is an online peer-reviewed encyclopedia for researchers, teachers, and students interested in all...... facets of the study of literature...

  13. Southern Identity in "Southern Living" Magazine

    Science.gov (United States)

    Lauder, Tracy

    2012-01-01

    A fantasy-theme analysis of the editors' letters in "Southern Living" magazine shows an editorial vision of valuing the past and showcasing unique regional qualities. In addition, a content analysis of the visual representation of race in the magazine's formative years and recent past validates that inhabitants of the region were portrayed…

  14. Land-ocean gradient in haline stratification and its effects on plankton dynamics and trophic carbon fluxes in Chilean Patagonian fjords (47-50°S)

    Science.gov (United States)

    González, H. E.; Castro, L. R.; Daneri, G.; Iriarte, J. L.; Silva, N.; Tapia, F.; Teca, E.; Vargas, C. A.

    2013-12-01

    Patagonian fjord systems, and in particular the fjords and channels associated with the Baker/Pascua Rivers, are currently under conspicuous natural and anthropogenic perturbations. These systems display very high variability, where limnetic and oceanic features overlap generating strong vertical and horizontal physicochemical gradients. The CIMAR 14-Fiordos cruise was conducted in the Chilean fjords located between 47° and 50°S during the spring (October-November) of 2008. The main objectives were to study vertical and horizontal gradients in physical, chemical and biological characteristics of the water column, and to assess plankton dynamics and trophic carbon fluxes in the fjords and channels of central-south Patagonia. The water column was strongly stratified, with a pycnocline at ca. 20 m depth separating a surface layer of silicic acid-rich freshwater discharged by rivers, from the underlying nitrate- and orthophosphate-rich Subantarctic waters. The outflows from the Baker and Pascua Rivers, which range annually between 500 and 1500 m3 s-1, generate the strong land-ocean gradient in salinity (1-32 psu) and inorganic nutrient concentrations (2-8 and 2-24 μM in nitrate and silicic-acid, respectively) we observed along the Baker Fjord. The POC:chl-a ratio fluctuated from 1087 near the fjord’s head to 175 at its oceanic end in the Penas Gulf. This change was mainly due to an increase in diatom dominance and a concurrent decrease in allochthonous POC towards the ocean. Depth-integrated net primary production (NPP) and bacterial secondary production (BSP) fluctuated between 49 and 1215 and 36 and 150 mg C m-2 d-1, respectively, with higher rates in oceanic waters. At a time series station located close to the Baker River mouth, the average NPP was lower (average 360 mg C m-2 d-1) than at more oceanic stations (average 1063 mg C m-2 d-1), and numerically dominated (45%) by the picoplankton (food web is the main trophic pathway in these environments.

  15. Petrogenesis of volcanic rocks that host the world-class Agsbnd Pb Navidad District, North Patagonian Massif: Comparison with the Jurassic Chon Aike Volcanic Province of Patagonia, Argentina

    Science.gov (United States)

    Bouhier, Verónica E.; Franchini, Marta B.; Caffe, Pablo J.; Maydagán, Laura; Rapela, Carlos W.; Paolini, Marcelo

    2017-05-01

    We present the first study of the volcanic rocks of the Cañadón Asfalto Formation that host the Navidad world-class Ag + Pb epithermal district located in the North Patagonian Massif, Patagonia, Argentina. These volcanic and sedimentary rocks were deposited in a lacustrine environment during an extensional tectonic regime associated with the breakup of Gondwana and represent the mafic to intermediate counterparts of the mainly silicic Jurassic Chon Aike Volcanic Province. Lava flows surrounded by autobrecciated carapace were extruded in subaerial conditions, whereas hyaloclastite and peperite facies suggest contemporaneous subaqueous volcanism and sedimentation. LA-ICPMS Usbnd Pb ages of zircon crystals from the volcanic units yielded Middle Jurassic ages of 173.9 ± 1.9 Ma and 170.8 ± 3 Ma. In the Navidad district, volcanic rocks of the Cañadón Asfalto Formation show arc-like signatures including high-K basaltic-andesite to high-K dacite compositions, Rb, Ba and Th enrichment relative to the less mobile HFS elements (Nb, Ta), enrichment in light rare earth elements (LREE), Ysbnd Ti depletion, and high Zr contents. These characteristics could be explained by assimilation of crustal rocks in the Jurassic magmas, which is also supported by the presence of zircon xenocrysts with Permian and Middle-Upper Triassic ages (281.3 Ma, 246.5, 218.1, and 201.3 Ma) and quartz xenocrysts recognized in these volcanic units. Furthermore, Sr and Nd isotope compositions suggest a contribution of crustal components in these Middle Jurassic magmas. High-K basaltic andesite has initial 87Sr/86Sr ratios of 0.70416-0.70658 and ξNd(t) values of -5.3 and -4. High-K dacite and andesite have initial 87Sr/86Sr compositions of 0.70584-0.70601 and ξNd(t) values of -4,1 and -3,2. The range of Pb isotope values (206Pb/204Pb = 18.28-18.37, 207Pb/204Pb = 15.61-15.62, and 208Pb/204Pb = 38.26-38.43) of Navidad volcanic rocks and ore minerals suggest mixing Pb sources with contributions of

  16. Reductions of plant cover induced by sheep grazing change the above-belowground partition and chemistry of organic C stocks in arid rangelands of Patagonian Monte, Argentina.

    Science.gov (United States)

    Larreguy, C; Carrera, A L; Bertiller, M B

    2017-09-01

    The objective of this study was to estimate the size and chemical quality of the total organic C stock and its partition between above-belowground plant parts and soil at sites with different plant cover induced by sheep grazing in the arid Patagonian Monte. This study was conducted at six representative sites with increasing signs of canopy disturbance attributed to grazing pressure. We used faeces density as a proxy of grazing pressure at each site. We assessed the total plant cover, shrub and perennial grass cover, total standing aboveground biomass (AGB), litter mass and belowground biomass (BGB) at each site. We further estimated the content of organic C, lignin and soluble phenols in plant compartments and the content of organic C, organic C in humic substances (recalcitrant C) and water soluble C (labile C) in soil at each site. Total plant cover was significantly related to grazing pressure. Standing AGB and litter mass decreased with increasing canopy disturbance while BGB did not vary across sites. Total organic C stock and the organic C stock in standing AGB increased with increasing total plant, shrub, and perennial grass cover. The organic C stock in litter mass increased with increasing total plant and shrub cover, while the organic C stock in BGB did not vary across sites. Lignin content in plant compartments increased with increasing total and shrub cover, while soluble phenols content did not change across sites. The organic C stock and the water soluble C content in soil were positively associated with perennial grass cover. Changes in total plant cover induced by grazing pressure negatively affected the size of the total organic C stock, having minor impact on the size of belowground than aboveground components. The reduction of perennial grass cover was reflected in decreasing chemical quality of the organic C stock in soil. Accordingly, plant managerial strategies should not only be focused on the amount of organic C sequestered but also on the

  17. Southern westerly winds: a pacemaker of Holocene glacial fluctuations in Patagonia?

    Science.gov (United States)

    Sagredo, E. A.; Reynhout, S.; Kaplan, M. R.; Patricio, M. I.; Aravena, J. C.; Martini, M. A.; Schaefer, J. M.

    2017-12-01

    A well-resolved glacial chronology is crucial to compare sequences of glacial/climate events within and between regions, and thus, to unravel mechanisms underlying past climate changes. Important efforts have been made towards understanding the Holocene climate evolution of the Southern Andes; however, the timing, patterns and causes of glacial fluctuations during this period still remain elusive. Recent advances in terrestrial cosmogenic nuclide surface exposure dating, together with the establishment of a Patagonian 10Be production rate, have opened new possibilities for establishing high-resolution glacial chronologies at centennial/decadal scale. Here we present a 10Be surface exposure chronology of fluctuations of a small, climate-sensitive mountain glacier at Mt. Fitz Roy area (49.3°S), spanning from the last glacial termination to the present. Thirty new 10Be ages show glacial advances and moraine building events at 17.1±0.9 ka, 13.5±0.5 ka, 10.2±0.7 ka or 9.9±0.5 ka, 6.9±0.2 ka, 6.1±0.3 ka, 4.5±0.2 ka and 0.5±0.1 ka. Similar to the pattern observed in New Zealand, this sequence features progressively less extensive glacial advances during the late-glacial and early Holocene, followed by advances of roughly similar extent during the mid- to late-Holocene. We suggest that while the magnitude of Holocene glacial fluctuations in Patagonia is modulated by SH summer insolation ("modulator"), the specific timing of these glacial events is influenced by centennial-scale shifts of the Southern Westerly Winds ("pacemaker").

  18. European Southern Observatory

    CERN Multimedia

    CERN PhotoLab

    1970-01-01

    Professor A. Blaauw, Director general of the European Southern Observatory, with George Hampton on his right, signs the Agreement covering collaboration with CERN in the construction of the large telescope to be installed at the ESO Observatory in Chile.

  19. University of Southern California

    Data.gov (United States)

    Federal Laboratory Consortium — The focus of the University of Southern California (USC) Children''s Environmental Health Center is to develop a better understanding of how host susceptibility and...

  20. Southern African Business Review

    African Journals Online (AJOL)

    The Southern African Business Review is a refereed and accredited scientific journal of the College of Economic and Management Sciences of the .... The effects of extended water supply disruptions on the operations of SMEs · EMAIL FREE ...

  1. Southern African Business Review

    African Journals Online (AJOL)

    Southern African Business Review. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 20, No 1 (2016) >. Log in or Register to get access to full text downloads.

  2. Fuels management in the southern Appalachian Mountains, hot continental division

    Science.gov (United States)

    Matthew J. Reilly; Thomas A. Waldrop; Joseph J. O’Brien

    2012-01-01

    The Southern Appalachian Mountains, Hot Continental Mountains Division, M220 (McNab and others 2007) are a topographically and biologically complex area with over 10 million ha of forested land, where complex environmental gradients have resulted in a great diversity of forest types. Abundant moisture and a long, warm growing season support high levels of productivity...

  3. Differential use of the Argentine shelf by wintering adults and juveniles southern giant petrels, Macronectes giganteus, from Patagonia

    Science.gov (United States)

    Blanco, Gabriela S.; Quintana, Flavio

    2014-08-01

    To study habitat use and at-sea movements of southern giant petrels (SGP) during non-breeding period, we deployed 15 satellite transmitters (six adults, nine juveniles) at Isla Arce and Isla Gran Robredo colonies in Patagonia, Argentina. Birds were instrumented during 81.4 ± 37 days. Adult birds used 74% of the Argentine shelf concentrating mainly at the shelf break, middle shelf waters, and the surroundings of the colony. After fledging, juveniles spread to the Argentine, Uruguayan and Brazilian shelves within the South Atlantic. Adults alternated at-sea excursions (12 ± 5 days) with periods at the colony of 3 ± 0.3 days. Contrarily, juveniles moved first to the shelf break and then traveled northwards reaching the south of Brazil. There was some spatial overlap between age classes, but only during the first 30 days after juveniles had fledged; thereafter there was not overlap between the areas used by both age classes. The Argentine shelf is widely used by different species offering a suitable environment for foraging; this may be why adults SGP from Patagonian colonies spend all year-round within the Argentine shelf. The identification of used areas of non-breeding SGP fills a gap in the species knowledge contributing not only to the preservation the species, but also to the management of marine areas globally recognized as important for many other Procellariiformes.

  4. Bell Inequalities for Complex Networks

    Science.gov (United States)

    2015-10-26

    AFRL-AFOSR-VA-TR-2015-0355 YIP Bell Inequalities for Complex Networks Greg Ver Steeg UNIVERSITY OF SOUTHERN CALIFORNIA LOS ANGELES Final Report 10/26...performance report PI: Greg Ver Steeg Young Investigator Award Grant Title: Bell Inequalities for Complex Networks Grant #: FA9550-12-1-0417 Reporting...October 20, 2015 Final Report for “Bell Inequalities for Complex Networks” Greg Ver Steeg Abstract This effort studied new methods to understand the effect

  5. Southern pulpwood production, 1962

    Science.gov (United States)

    Joe F. Christopher; Martha E. Nelson

    1963-01-01

    Pulpwood production in the south rose to an all-time high of 25,586,300 cords in 1962-58 percent of the Nation's total. At the year's end, 80 southern pulpmills were operating; their combined daily pulping capacity was more than 52,000 tons. Nine mills outside the region were using wood grown in the South.

  6. Multilingualism in Southern Africa.

    Science.gov (United States)

    Peirce, Bonny Norton; Ridge, Stanley G. M.

    1997-01-01

    Reviews recent research in multilingualism in Southern Africa, focusing on the role of languages in education, sociolinguistics, and language policy. Much of the research is on South Africa. Topics discussed include language of instruction in schools, teacher education, higher education, adult literacy, language contact, gender and linguistic…

  7. NREL + Southern California Gas

    Energy Technology Data Exchange (ETDEWEB)

    Berdahl, Sonja E [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-10-09

    NREL and Southern California Gas Company are evaluating a new 'power-to-gas' approach - one that produces methane through a biological pathway and uses the expansive natural gas infrastructure to store it. This approach has the potential to change how the power industry approaches renewable generation and energy storage.

  8. Los conjuntos palaciegos reales de las Tierras Bajas Mayas del sur: una evaluación de los datos arqueológicos e iconográficos Royal palace complexes in Southern Maya Lowlands: evaluating archaeological and iconographical data

    Directory of Open Access Journals (Sweden)

    Kai Delvendahl

    2010-01-01

    Full Text Available Este artículo va a trazar algunas conclusiones de una evaluación de los aspectos físicos, espaciales, funcionales y sociales de los conjuntos palaciegos reales tomando en cuenta evidencia arqueológica e iconográfica. Para el componente iconográfico se analizaron representaciones de escenas palaciegas pintadas sobre 87 vasijas cilíndricas de cerámica, mientras que para el componente arqueológico se evaluó información de conjuntos palaciegos bien documentados como el Grupo Palaciego M7 de Aguateca, el Palacio de Palenque, Los 27 Escalones de Kohunlich, el Grupo 10L-2 de Copán, la Acrópolis Central de Tikal y el Grupo Gran Acrópolis de Calakmul. Uno de los objetivos generales de este trabajo es proporcionar un ejemplo de cómo se puede capitalizar la información que las escenas palaciegas proveen (al comparar el corpus iconográfico con el dato arqueológico. Esto permitiría plantear ideas más ajustadas sobre los aspectos físicos, espaciales, funcionales y sociales de los conjuntos palaciegos del Clásico Tardío en el área maya.This paper will present some conclusions of an evaluation of the physical, spatial, functional, and social aspects of Classic Maya royal palaces taking into account archaeological and iconographic evidence. For the iconographic evaluation, the analysis examined representations of palace-like ambience on 87 cylindrical ceramic vases, while the archaeological information includes data from the better documented palace groups of the Southern Maya Lowlands, including the Palace Group M7 of Aguateca, the Palace of Palenque, Los 27 Escalones of Kohunlich, Group 10L-2 of Copan, the Central Acropolis of Tikal and the Grand Acropolis Group of Calakmul. In comparing the iconographic corpus with the archaeological evidence, one of the general objectives of this presentation is to provide an example of how the information inherent in the palace scenes can be capitalized to propose more adjusted ideas about the

  9. Southern Universities Nuclear Institute

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    The Southern Universities Nuclear Institute was created in 1961 to provide postgraduate research and teaching facilities for the universities of Cape Town and Stellenbosch. The main research tool is the 6,0 MV Van de Graaff accelerator installed in 1964. Developments and improvements over the years have maintained the Institute's research effectiveness. The work of local research groups has led to a large number of M Sc and doctorate degrees and numerous publications in international journals. Research at the Institute includes front-line studies of basic nuclear and atomic physics, the development and application of nuclear analytical techniques and the application of radioisotope tracers to problems in science, industry and medicine. The Institute receives financial support from the two southern universities, the Department of National Education, the CSIR and the Atomic Energy Board

  10. Southern Alberta system reinforcement

    Energy Technology Data Exchange (ETDEWEB)

    Rehman, A. [Alberta Electric System Operator, Calgary, AB (Canada)

    2008-07-01

    System planning for the Alberta Electric System Operator's (AESO) southern system was discussed in view of the growing interest in developing wind energy resources in the province. While Alberta currently has a total of 11,500 MW of installed wind power, southern Alberta has a very small capability for interconnecting additional wind resources. There are 3 main agencies involved in system planning for the southern region: (1) the Alberta Utilities Commission (AUC), (2) the AESO, and (3) the transmission facility owners. Transmission needs are studied by the AESO, who then applies to the AUC for approval. Transmission facility owners also apply to the AUC for approval to construct facilities. The AESO's roles are to operate the wholesale electricity market; plan the transmission system; arrange access for loads and generation; and oversee transmission system operation. The AESO is an independent agency with a public interest mandate. The AESO's queue management process has been designed to facilitate non-discriminatory system access. Development options currently being considered by the AESO include a 240 kV AC transmission line; a 500 kV AC transmission line; a 765 kV AC transmission line; a high voltage direct current (HVDC) system; and a voltage source converter (VSC) HVDC system. Radial and looped configurations are also being considered. The AESO is currently conducting a participant involvement program that involves open houses with the Canadian Wind Energy Association (CanWEA) and other provincial stakeholders. tabs., figs.

  11. By-catch composition of the Patagonian scallop fishery: the fishes Composición de la captura incidental en la pesquería de vieira patagónica: los peces

    Directory of Open Access Journals (Sweden)

    Laura Schejter

    2012-11-01

    Full Text Available An inventory of 24 fish species incidentally caught by the Patagonian scallop fleet in the SW Atlantic Ocean is provided for the first time. The most frequent species were Psammobatis spp. (81.4%, Bathyraja brachyurops (75.1%, B. macloviana (73.5%, Patagonotothen ramsayi (66.1%, Merluccius hubbsi (53.7% and B. albomaculata (50.3%. Many of the recorded chondrichthyes are considered vulnerable or endangered species. The number of taxa (fishes + invertebrates that conforms the by-catch of the fishery was increased and updated to nearly 200 species.Este estudio presenta por primera vez un inventario con 24 especies de peces registradas en la captura incidental de la pesca de la vieira patagónica en el Océano Atlántico sudoccidental por la flota pesquera comercial. Las especies más frecuentes fueron Psammobatis spp. (81,4%, Bathyraja brachyurops (75,1%, B. macloviana (73,5%, Patagonotothen ramsayi (66,1%, Merluccius hubbsi (53,7% y B. albomaculata (50,3%. Muchos de los condrictios registrados se encuentran actualmente considerados como especies vulnerables o en peligro. El número de taxa (peces + invertebrados que conforman la captura incidental de esta pesquería se incrementó y actualizó con estos resultados a aproximadamente 200 especies.

  12. The Southern Ocean Observing System

    OpenAIRE

    Rintoul, Stephen R.; Meredith, Michael P.; Schofield, Oscar; Newman, Louise

    2012-01-01

    The Southern Ocean includes the only latitude band where the ocean circles the earth unobstructed by continental boundaries. This accident of geography has profound consequences for global ocean circulation, biogeochemical cycles, and climate. The Southern Ocean connects the ocean basins and links the shallow and deep limbs of the overturning circulation (Rintoul et al., 2001). The ocean's capacity to moderate the pace of climate change is therefore influenced strongly by the Southern Ocean's...

  13. Fourier analysis of temporal NDVI in the Southern African and American continents

    NARCIS (Netherlands)

    Azzali, S.; Menenti, M.

    1996-01-01

    Results of applying Fourier analysis of temporal NDVI in southern Africa and southern America are summarized. The decomposition of complex time series of images in simpler periodic components by Fourier analysis allowed the factors that affect the vegetation cover to be analysed much easier. The

  14. Southern Pine Beetle Information System (SPBIS)

    Science.gov (United States)

    Valli Peacher

    2011-01-01

    The southern pine beetle (SPB) is the most destructive forest insect in the South. The SPB attacks all species of southern pine, but loblolly and shortleaf are most susceptible. The Southern Pine Beetle Information System (SPBIS) is the computerized database used by the national forests in the Southern Region for tracking individual southern pine beetle infestations....

  15. Towards Marine Spatial Planning in Southern Taiwan

    Directory of Open Access Journals (Sweden)

    Meng-Tsung Lee

    2014-11-01

    Full Text Available Due to population growth, rapid economic development and inadequate marine control, the use of ocean and coastal regions in Taiwan has become more frequent and intense in recent years. However, the lack of comprehensive marine and coastal planning in this island nation has led to many conflicts over space and resources and limited its ability to prepare for and respond to environmental hazards, thus threatening national security as well as the safety and property of its citizens. This study proposes a marine zoning scheme for southern Taiwan. The results show that many important habitats in the southern sea areas have not been properly protected due to the extremely small size of the marine protected area. Furthermore, the majority of the conflicts derive from the exclusive fishing right vs. other uses such as marine conservation. Therefore, it is crucial to establish the marine spatial planning (MSP for the Southern Taiwan to deal with the conflicts of use seas and uncertainties associated with complex, heterogeneous, and dynamic marine system.

  16. A history of southern forest science, management, and sustainability issues

    Science.gov (United States)

    H. Michael Rauscher

    2004-01-01

    The 13 Southern States from Virginia to Texas have a combined area of approximately 500 million acres. Our understanding of the complex cultural and ecological history of this large region is still evolving. It may be fair to say that until recently, our view of the native peoples of the South and the landscape in which they lived derived chiefly from reports provided...

  17. Fusiform Rust of Southern Pines

    Science.gov (United States)

    W. R. Phelps; F. L. Czabator

    1978-01-01

    Fusiform rust, caused by the fungus Cronartium fusiforme Hedg. & Hunt ex Cumm., is distributed in the Southern United States from Maryland to Florida and west to Texas and southern Arkansas. Infections by the fungus, which develops at or near the point of infection, result in tapered, spindle-shaped swells, called galls, on branches and stems of pines. (see photo...

  18. Shakespeare in Southern Africa: Submissions

    African Journals Online (AJOL)

    Shakespeare in Southern Africa publishes articles, commentary and reviews on all aspects of Shakespearean studies and performance, with a particular emphasis on responses to Shakespeare in southern Africa. Submissions are reviewed by at least two referees. The practice of 'blind' reviewing is adhered to. The Journal ...

  19. Tornado Strikes Southern Maryland

    Science.gov (United States)

    2002-01-01

    Evening light catches the tops of towering thunderheads over the Mid-Atlantic states on April 28, 2002. The powerful storms spawned several tornados, one of which was classified as an F4 tornado. The powerful tornado touched down in the southern Maryland town of La Plata, destroying most of the historic downtown. The twister-one of the strongest ever to hit the state-beat a 24-mile swath running west to east through the state and claimed at least three lives. The image above was taken by the Geostationary Operational Environmental Satellite (GOES) at 7:15 PM Eastern Daylight Savings Time. A large version of the animation shows more detail. (5.9 MB Quicktime) Image courtesy National Oceanic and Atmospheric Administration (NOAA) and the GOES Project Science Office. Animation by Robert Simmon, NASA GSFC.

  20. Complexity explained

    CERN Document Server

    Erdi, Peter

    2008-01-01

    This book explains why complex systems research is important in understanding the structure, function and dynamics of complex natural and social phenomena. Readers will learn the basic concepts and methods of complex system research.

  1. Complex chemistry

    International Nuclear Information System (INIS)

    Kim, Bong Gon; Kim, Jae Sang; Kim, Jin Eun; Lee, Boo Yeon

    2006-06-01

    This book introduces complex chemistry with ten chapters, which include development of complex chemistry on history coordination theory and Warner's coordination theory and new development of complex chemistry, nomenclature on complex with conception and define, chemical formula on coordination compound, symbol of stereochemistry, stereo structure and isomerism, electron structure and bond theory on complex, structure of complex like NMR and XAFS, balance and reaction on solution, an organo-metallic chemistry, biology inorganic chemistry, material chemistry of complex, design of complex and calculation chemistry.

  2. The Mysterious Southern Torque

    Science.gov (United States)

    McDowell, M. S.

    2004-05-01

    Something weird happened to twist the southern hemisphere out of alignment with the northern, as evidenced by the positions of the mountain ranges of North and South America, the Atlantic MAR, and the closure of West Africa to North America - all smooth were the torque reversed. What happened, and when, and why? We identify a number of global "cracks" of almost exactly the same length and direction, with some, even more peculiarly, turning the same angle, and proceeding an equal distance in the new direction. The Emperor-Hawaiian chain, the Louisville chain and the west coast of North America, as examples, are essentially parallel. Their northerly legs follow the angle of the axis of orbital ellipse. But then they all make equal 45 degree easterly bends, to 17.5 NW, and continue on, still parallel, for very similar distances. It is the same at the north coast of South America, and the mid-section of the MAR from 46W to 12W. It is the distance from the Cameroons to Kenya, from the south end of the Red Sea to the SE Indian Ridge at the Nema Fracture zone, from west to east of the Nazca plate.What is all this? Coincidence? Seeing things? Researchers have attributed plate motion or hot spot motion or both or absolutely none, to all of the above. Geophysicists have dated the surfaces from Archean to Pleistocene by all possible scientific means, certainly no possible correlation can be made. Yet we postulate the physical reality can be demonstrated. It is so global a phenomenon that it is well beyond what a hot spot or a plate could do. Even a really tremendous impact would have trouble making such precise geometric arrangements. So what is it - perhaps the angle of rotation, or the inertia of northern hemisphere mass above the geoid? And if so, then, what changed it? It would seem that some huge imbalance occurred. Suppose the whole bottom blew out of the southern hemisphere, and the center of mass drastically altered. Suppose some unknown universal force changed our

  3. Potential zooplankton preys (Copepoda and Appendicularia for Engraulis anchoita in relation to early larval and spawning distributions in the Patagonian frontal system (SW Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    Mariela L. Spinelli

    2011-11-01

    Full Text Available We investigated the spatial distribution of the abundance, biomass and size of zooplankton (nauplii, calanoids, cyclopoids and appendicularians in relation to the distribution of first-feeding larvae and eggs of Engraulis anchoita across the frontal system of Peninsula Valdés. Twelve samples of zooplankton and ichthyoplankton were taken with small Bongo (67 μm and Pairovet (200 μm nets during the spring of 2004 along two transects. The total abundance of zooplankton and the chlorophyll a concentration were higher in homogeneous waters, while total biomasses were higher in stratified waters. Temperature was negatively correlated with biological variables and was the main factor affecting the zooplankton distribution. In both transects, abundance peaks of first-feeding larvae were detected at coastal stations along with the smallest fraction of zooplankton ( < 500 μm, while the largest fraction was dominant at the external stations, coinciding with the highest egg abundance. The physical structure of this front generates different levels of food availability for first-feeding larvae. Calanoids (southern transect and cyclopoids (northern transect are predominant followed by nauplii and appendicularians. The biomass of zooplankton preys contributes to the carbon transfer to the upper trophic levels and is probably important for the survival and growth of anchovy larvae in this frontal system.

  4. Growth and reproduction investment of the young of the year of the squat lobster Munida gregaria (Crustacea: Anomura in the Patagonian coast

    Directory of Open Access Journals (Sweden)

    Martin Varisco

    2015-09-01

    Full Text Available The growth and reproduction investment of the young of the year (0+ of the squat lobster Munida gregaria in San Jorge Gulf, Argentina, were analysed. Moult cycle and size frequency distribution were studied in monthly field samples. Experiments to determine moult increments and intermoult duration were conducted. Sexual maturity, fecundity and reproductive output were analysed in field samples. In addition, maturity experiments in laboratory cultures were conducted. After settlement (November, juveniles showed fast growth until winter (July and growth restarted in September-October. At the beginning of the mating period (early June, males 0+ exhibited mature gonads, whereas females 0+ only showed previtellogenic oocytes. Experimental data showed that females with developed gonads had smaller-size increments in the previous moult. Fecundity and reproductive output were significantly lower in females 0+ than in older females. The early life history of M. gregaria in San Jorge Gulf differs from that of southern populations as those of Beagle Channel and Strait of Magellan due to faster growth and early reproductive investment. Our results suggest that females 0+ of M. gregaria have two investment strategies: early maturity with low fecundity and delayed maturity with higher future fecundity.

  5. Increased drought impacts on temperate rainforests from southern South America: results of a process-based, dynamic forest model.

    Directory of Open Access Journals (Sweden)

    Alvaro G Gutiérrez

    Full Text Available Increased droughts due to regional shifts in temperature and rainfall regimes are likely to affect forests in temperate regions in the coming decades. To assess their consequences for forest dynamics, we need predictive tools that couple hydrologic processes, soil moisture dynamics and plant productivity. Here, we developed and tested a dynamic forest model that predicts the hydrologic balance of North Patagonian rainforests on Chiloé Island, in temperate South America (42°S. The model incorporates the dynamic linkages between changing rainfall regimes, soil moisture and individual tree growth. Declining rainfall, as predicted for the study area, should mean up to 50% less summer rain by year 2100. We analysed forest responses to increased drought using the model proposed focusing on changes in evapotranspiration, soil moisture and forest structure (above-ground biomass and basal area. We compared the responses of a young stand (YS, ca. 60 years-old and an old-growth forest (OG, >500 years-old in the same area. Based on detailed field measurements of water fluxes, the model provides a reliable account of the hydrologic balance of these evergreen, broad-leaved rainforests. We found higher evapotranspiration in OG than YS under current climate. Increasing drought predicted for this century can reduce evapotranspiration by 15% in the OG compared to current values. Drier climate will alter forest structure, leading to decreases in above ground biomass by 27% of the current value in OG. The model presented here can be used to assess the potential impacts of climate change on forest hydrology and other threats of global change on future forests such as fragmentation, introduction of exotic tree species, and changes in fire regimes. Our study expands the applicability of forest dynamics models in remote and hitherto overlooked regions of the world, such as southern temperate rainforests.

  6. Increased drought impacts on temperate rainforests from southern South America: results of a process-based, dynamic forest model.

    Science.gov (United States)

    Gutiérrez, Alvaro G; Armesto, Juan J; Díaz, M Francisca; Huth, Andreas

    2014-01-01

    Increased droughts due to regional shifts in temperature and rainfall regimes are likely to affect forests in temperate regions in the coming decades. To assess their consequences for forest dynamics, we need predictive tools that couple hydrologic processes, soil moisture dynamics and plant productivity. Here, we developed and tested a dynamic forest model that predicts the hydrologic balance of North Patagonian rainforests on Chiloé Island, in temperate South America (42°S). The model incorporates the dynamic linkages between changing rainfall regimes, soil moisture and individual tree growth. Declining rainfall, as predicted for the study area, should mean up to 50% less summer rain by year 2100. We analysed forest responses to increased drought using the model proposed focusing on changes in evapotranspiration, soil moisture and forest structure (above-ground biomass and basal area). We compared the responses of a young stand (YS, ca. 60 years-old) and an old-growth forest (OG, >500 years-old) in the same area. Based on detailed field measurements of water fluxes, the model provides a reliable account of the hydrologic balance of these evergreen, broad-leaved rainforests. We found higher evapotranspiration in OG than YS under current climate. Increasing drought predicted for this century can reduce evapotranspiration by 15% in the OG compared to current values. Drier climate will alter forest structure, leading to decreases in above ground biomass by 27% of the current value in OG. The model presented here can be used to assess the potential impacts of climate change on forest hydrology and other threats of global change on future forests such as fragmentation, introduction of exotic tree species, and changes in fire regimes. Our study expands the applicability of forest dynamics models in remote and hitherto overlooked regions of the world, such as southern temperate rainforests.

  7. THE SOUTHERN AEGEAN SYSTEM

    Directory of Open Access Journals (Sweden)

    Ina Berg

    2015-08-01

    Full Text Available Although world-systems theory was originally formulated with our modern economic system in mind (Wallerstein 1974, it was not long before archaeologists began to apply it to ancient societies. Archaeologists and world-system theorists alike both argued that Wallerstein had disregarded evidence of interconnected, hierarchical systems in prehistoric times (Schneider 1977; Chase-Dunn & Hall 1991, 1997; Kardulias 1999a. Pailes and Whitecotton (1979 were among the first to modify world-systems theory for use in pre-capitalist settings. Since then many archaeologists have looked at data and regions with a world-systems perspective in mind (e.g. Champion 1989; Bilde et al. 1993; Rowlands & Larsen 1987; Kardulias 1999a. Some have attempted to map Wallerstein's theory directly onto prehistory (Kohl 1979; Whitecotton & Pailes 1986; Ekholm & Friedman 1982. Others have found the world systems model heuristically useful but lacking the analytical power needed for their prehistoric cases (Blanton et al. 1981; Upham 1982; Plog 1983; Alcock 1993. Building on the assumption that ancient societies were not qualitatively, but only quantitatively, different from modern capitalist ones (Schneider 1977; Sherratt & Sherratt 1991, this study applies world systems theory to the Southern Aegean during the Middle and Late Bronze Age (ca. 2000-1550 BC.

  8. Automated design of genomic Southern blot probes

    Directory of Open Access Journals (Sweden)

    Komiyama Noboru H

    2010-01-01

    Full Text Available Abstract Background Sothern blotting is a DNA analysis technique that has found widespread application in molecular biology. It has been used for gene discovery and mapping and has diagnostic and forensic applications, including mutation detection in patient samples and DNA fingerprinting in criminal investigations. Southern blotting has been employed as the definitive method for detecting transgene integration, and successful homologous recombination in gene targeting experiments. The technique employs a labeled DNA probe to detect a specific DNA sequence in a complex DNA sample that has been separated by restriction-digest and gel electrophoresis. Critically for the technique to succeed the probe must be unique to the target locus so as not to cross-hybridize to other endogenous DNA within the sample. Investigators routinely employ a manual approach to probe design. A genome browser is used to extract DNA sequence from the locus of interest, which is searched against the target genome using a BLAST-like tool. Ideally a single perfect match is obtained to the target, with little cross-reactivity caused by homologous DNA sequence present in the genome and/or repetitive and low-complexity elements in the candidate probe. This is a labor intensive process often requiring several attempts to find a suitable probe for laboratory testing. Results We have written an informatic pipeline to automatically design genomic Sothern blot probes that specifically attempts to optimize the resultant probe, employing a brute-force strategy of generating many candidate probes of acceptable length in the user-specified design window, searching all against the target genome, then scoring and ranking the candidates by uniqueness and repetitive DNA element content. Using these in silico measures we can automatically design probes that we predict to perform as well, or better, than our previous manual designs, while considerably reducing design time. We went on to

  9. Invertebrate diversity in southern California

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This shapefile displays mean invertebrate diversity within 5 minute grid cells. The Shannon Index of diversity was calculated from Southern California Coastal Water...

  10. Southern African Business Review: Submissions

    African Journals Online (AJOL)

    The Southern African Business Review is a refereed and accredited journal of the College of Economic and Management Sciences of the University of South Africa. ... the right to make minor editorial adjustments without consulting the author.

  11. Utilization of the southern pines

    Energy Technology Data Exchange (ETDEWEB)

    Koch, P

    1972-01-01

    After several years out of print, this book is again available. The two-volume reference characterizes the southern pine tree as raw material and describes the process by which it is converted to use. All 10 species are considered. The book is addressed primarily to the incoming generation of researchers and industrial managers in the southern pine industry. Foremen, superintendents, quality control personnel, wood procurement men, forest managers, extension workers, professors, and students of wood technology should find the handbook of value.

  12. Energy Trade in Southern Africa

    International Nuclear Information System (INIS)

    Holland, W F.

    1996-01-01

    This document deals with possible energy growth in Southern African countries. This region possesses substantial energy resources (including fossil fuels), but because of political instability, government intervention, financial paralysis and lack of adequate transportation infrastructure, this region faces problems in satisfying energy needs. Two key international actions, namely the South African Development Community (SADC) Energy Protocol and the Southern African Power Pool (SAPP) are expected to enhance energy trade and promote economic development. (TEC)

  13. Range expansion of Oligoryzomys longicaudatus (Rodentia, Sigmodontinae in Patagonian Chile, and first record of Hantavirus in the region Ampliación del rango de distribución de Oligoryzomys longicaudatus (Rodentia, Sigmodontinae en la Patagonia de Chile y primer registro de Hantavirus en la región

    Directory of Open Access Journals (Sweden)

    SEBASTIÁN BELMAR-LUCERO

    2009-06-01

    Full Text Available At present, 20 species of Oligoryzomys (Rodentia, Sigmodontinae are recognized in the Neotropical region, most of them distinguished by their karyotypes, which fluctuates between 46-70 chromosomes. Two species are currently recognized in Chile, Oligoryzomys longicaudatus (Bennet, 1832; "colilargo" or the long-tailed pygmy rice rat; 2n = 56, which ranges from 27° to approximately 51° S, and O. magellanicus (Bennet, 1836; Magellanic pygmy rice rat; 2n = 54, south of 51° S in the Patagonian region of Chile and Argentina. As part of an ongoing research on the southern Patagonia of Chile, we report the results of small mammal samplings in six localities. We karyotyped 28 specimens and we also sequenced the hypervariable mtDNA region I in 22 individuals, aligning these sequences with an under development phylogeny of O. longicaudatus. We also evaluated the serology and viral charge in all captured specimens to detect the presence of antibodies to Andes virus (ANDV through Strip Immunoblot Assay (SIA, and of viral genome by RT-PCR. The results consistently showed that the karyotype of southern Patagonia specimens was 2n = 56, equal to that of O. longicaudatus, and that individuals from this area do not differentiate phylogenetically from those of the northern range of distribution. In addition, the serology showed the presence of antibodies IgG anti-ANDV and of viral genome in heart, kidney, spleen, and lungs of a single specimen of Oligoryzomys from the locality of Fuerte Bulnes in the Magallanes region. We conclude that all specimens trapped south of 51° S correspond to Oligoryzomys longicaudatus, thus expanding the distribution of this specie! from 51° to at least 55° S. The results also extended the disiribution of the Andes strain of Hantavirus to southernmost Patagonia.Actualmente se reconocen 20 especies de Oligoryzomys (Rodentia, Sigmodontinae en la región Neotropical, la mayoría de ellas distinguidas por sus cariotipos, los que fluct

  14. (II) complexes

    African Journals Online (AJOL)

    activities of Schiff base tin (II) complexes. Neelofar1 ... Conclusion: All synthesized Schiff bases and their Tin (II) complexes showed high antimicrobial and ...... Singh HL. Synthesis and characterization of tin (II) complexes of fluorinated Schiff bases derived from amino acids. Spectrochim Acta Part A: Molec Biomolec.

  15. Climate change induced by Southern Hemisphere desertification

    Science.gov (United States)

    Wang, Ye; Yan, Xiaodong

    2017-12-01

    Some 10-20% of global dry-lands are already degraded, and the ongoing desertification threatens the world's poorest populations. Studies on desertification effects are essential for humans to adapt to the environmental challenges posed by desertification. Given the importance of the much larger southern ocean to the global climate and the Southern Hemisphere (SH) climate changes in phase with those in the north, the biogeophysical effects of the SH desertification on climate are assessed using an Earth system model of intermediate complexity, MPM-2. This analysis focuses on differences in climate among the averages of simulations with desert expansion in different latitude bands by year 2000. The localized desertification causes significant global changes in temperature and precipitation as well as surface albedo. On the global scale, cooling dominates the SH desertification effects. However, the biogeophysical effects are most significant in regions with desertification, and the cooling is also prominent in northern mid-latitudes. Desert expansion in 15°-30°S reveals statistically most significant cooling and increased precipitation over the forcing regions during spring. The global and regional scale responses from desertification imply the climate teleconnection and address the importance of the effects from the SH which are contingent on the location of the forcing. Our study indicates that biogeophysical mechanisms of land cover changes in the SH need to be accounted for in the assessment of land management options especially for latitude band over 15°-30°S.

  16. Treasures of the Southern Sky

    CERN Document Server

    Gendler, Robert; Malin, David

    2011-01-01

    In these pages, the reader can follow the engaging saga of astronomical exploration in the southern hemisphere, in a modern merger of aesthetics, science, and a story of human endeavor. This book is truly a celebration of southern skies.  Jerry Bonnell, Editor - Astronomy Picture of the Day The southern sky became accessible to scientific scrutiny only a few centuries ago, after the first European explorers ventured south of the equator. Modern observing and imaging techniques have since revealed what seems like a new Universe, previously hidden below the horizon, a fresh astronomical bounty of beauty and knowledge uniquely different from the northern sky. The authors have crafted a book that brings this hidden Universe to all, regardless of location or latitude. Treasures of the Southern Sky celebrates the remarkable beauty and richness of the southern sky in words and with world-class imagery. In part, a photographic anthology of deep sky wonders south of the celestial equator, this book also celebrates th...

  17. Communication complexity and information complexity

    Science.gov (United States)

    Pankratov, Denis

    Information complexity enables the use of information-theoretic tools in communication complexity theory. Prior to the results presented in this thesis, information complexity was mainly used for proving lower bounds and direct-sum theorems in the setting of communication complexity. We present three results that demonstrate new connections between information complexity and communication complexity. In the first contribution we thoroughly study the information complexity of the smallest nontrivial two-party function: the AND function. While computing the communication complexity of AND is trivial, computing its exact information complexity presents a major technical challenge. In overcoming this challenge, we reveal that information complexity gives rise to rich geometrical structures. Our analysis of information complexity relies on new analytic techniques and new characterizations of communication protocols. We also uncover a connection of information complexity to the theory of elliptic partial differential equations. Once we compute the exact information complexity of AND, we can compute exact communication complexity of several related functions on n-bit inputs with some additional technical work. Previous combinatorial and algebraic techniques could only prove bounds of the form theta( n). Interestingly, this level of precision is typical in the area of information theory, so our result demonstrates that this meta-property of precise bounds carries over to information complexity and in certain cases even to communication complexity. Our result does not only strengthen the lower bound on communication complexity of disjointness by making it more exact, but it also shows that information complexity provides the exact upper bound on communication complexity. In fact, this result is more general and applies to a whole class of communication problems. In the second contribution, we use self-reduction methods to prove strong lower bounds on the information

  18. REC profile 2: Southern Electric

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    A review is presented of South Electric plc, one of the United Kingdom's Regional Electricity Companies (RECs), at present distributing electric power in central southern England. Known in financial markets as an efficient performer, the staff reductions and changes of employment conditions undertaken to achieve this end are described. The need to maintain success in its core business, while simultaneously seeking diversification, drive the company's keen competitive edge. The relationship between the RECs and the electricity regulator is also explored, as Southern Electric considers a friendly merger with another REC to improve its market competitiveness in price terms. (UK)

  19. Southern states' routing agency report

    International Nuclear Information System (INIS)

    1989-02-01

    The Southern states' routing agency report is a compendium of 16-southern states' routing programs relative to the transportation of high-level radioactive materials. The report identifies the state-designated routing agencies as defined under 49 Code of Federal Regulations (CFR) Part 171 and provides a reference to the source ad scope of the agencies' rulemaking authority. Additionally, the state agency and contact designated by the state's governor to receive advance notification and shipment routing information under 10 CFR Parts 71 and 73 are also listed

  20. Southern States' Routing Agency Report

    International Nuclear Information System (INIS)

    1990-03-01

    The Southern States' Routing Agency Report is a compendium of 16-southern states' routing program for the transportation of high-level radioactive materials. The report identifies the state-designated routing agencies as defined under 49 Code of Federal Regulations (CFR) Part 171 and provides a reference to the source and scope of the agencies' rulemaking authority. Additionally, the state agency and contact designated by the state's governor to receive advance notification and shipment routing information under 10 CFR Parts 71 and 73 are also listed

  1. Sexty Southerners: Sexting Content and Behaviors among Selected Southern Undergraduates

    Science.gov (United States)

    Hudson, Heather K.; Marshall, S. Alexandra

    2016-01-01

    Sexting is defined as sending/posting/sharing sexually explicit messages or nude/semi-nude images via electronic communication. Purpose: The purpose of this study was to assess and determine relationships of sexting behavioral intentions, sexting behaviors, and sexting content among selected Southern undergraduate students. Methods: Survey…

  2. Complexity Plots

    KAUST Repository

    Thiyagalingam, Jeyarajan

    2013-06-01

    In this paper, we present a novel visualization technique for assisting the observation and analysis of algorithmic complexity. In comparison with conventional line graphs, this new technique is not sensitive to the units of measurement, allowing multivariate data series of different physical qualities (e.g., time, space and energy) to be juxtaposed together conveniently and consistently. It supports multivariate visualization as well as uncertainty visualization. It enables users to focus on algorithm categorization by complexity classes, while reducing visual impact caused by constants and algorithmic components that are insignificant to complexity analysis. It provides an effective means for observing the algorithmic complexity of programs with a mixture of algorithms and black-box software through visualization. Through two case studies, we demonstrate the effectiveness of complexity plots in complexity analysis in research, education and application. © 2013 The Author(s) Computer Graphics Forum © 2013 The Eurographics Association and Blackwell Publishing Ltd.

  3. Efectos del pastoreo sobre el suelo y la vegetación en la Estepa Patagónica Grazing effects on soil and vegetation in the Patagonian Steppe

    Directory of Open Access Journals (Sweden)

    Juan José Gaitán

    2009-12-01

    Full Text Available La ganadería ovina durante más de 100 años produjo grandes cambios en los ecosistemas y es una de las principales causas de la desertificación en la estepa patagónica. Este trabajo tiene por objetivo evaluar los efectos del pastoreo sobre el suelo y la vegetación mediante la aplicación de una versión modificada de la metodología «Landscape Function Analysis» desarrollada en Australia. El estudio se realizó en siete sitios con distintos niveles de degradación por pastoreo en Pilcaniyeu (noroeste de Río Negro: tres clausurados al pastoreo (CLA, tres bajo pastoreo moderado (PM y uno bajo pastoreo intenso (PI. Se evaluaron indicadores de la composición florística y estructura espacial de la vegetación, del estado de la superficie del suelo en los interparches, los cuales fueron integrados en tres Índices de Función (Estabilidad -EST-, Infiltración -INFy Reciclaje de nutrientes -NUT- y el stock de carbono orgánico (CO. Al incrementarse la intensidad de pastoreo se observó una disminución en la cobertura basal de la vegetación (47,4; 23,2 y 17,4% en CLA, PM y PI, respectivamente, parches vegetados más distanciados entre sí (61,9; 117,9 y 181,7 cm, menor cobertura de gramíneas palatables (26,3; 3,4 y 2,1% y mayor de no palatables (4,4; 15,8 y 17,6%. También se observó una tendencia a disminuir en los Índices de Función del suelo (EST: 43,0; 42,3 y 36,2; INF: 48,3; 41,7 y 36,2; NUT: 33,1; 23,5 y 18,1 y del CO (33,8; 26,5 y 7,9 t/ha al incrementarse la intensidad de pastoreo. Se requieren más estudios para adaptar esta metodología a las condiciones de Patagonia y testear con datos experimentales de que manera los índices reflejan adecuadamente los procesos y funciones de estos ecosistemas.More than 100 years of sheep breeding has caused profound changes to ecosystems and is one of the main causes of desertification in the Patagonian steppe. The aim of this study was to evaluate sheep grazing effects on soils and

  4. An evaluation of methods for modelling distribution of Patagonian insects Una evaluación de los métodos para modelizar la distribución de insectos patagónicos

    Directory of Open Access Journals (Sweden)

    MARCELO F TOGNELLI

    2009-01-01

    Full Text Available Various studies have shown that model performance may vary depending on the species being modelled, the study área, or the number of sampled localities, and suggest that it is necessary to assess which model is better for a particular situation. Thus, in this study we evalúate the performance of different techniques for modelling the distribution of Patagonian insects. We applied eight of the most widely used modelling methods (artificial neural networks, BIOCLIM, classification and regression trees, DOMAIN, generalized additive models, GARP, generalized linear models, and Maxent to the distribution of ten Patagonian insect species. We compared model performance with five accuracy measures. To overeóme the problem of not having reliable absence data with which to evalúate model performance, we used randomly selected pseudo-absences located outside of the polygon área defined by taxonomic experts. Our analyses show significant differences among modelling methods depending on the chosen accuracy measure. Maxent performed the best according to four out of the five accuracy measures, although its accuracy did not differ significantly from that obtained with artificial neural networks. When assessed on per species basis, Maxent was also one of the strongest performing methods, particularly for species sampled from a relatively low number of localities. Overall, our study identified four groups of modelling techniques based on model performance. The top-performing group is composed of Maxent and artificial neural networks, followed closely by the DOMAIN technique. The third group includes GARP, GAM, GLM, and CART, and the fourth best performer is the BIOCLIM technique. Although these results may allow obtaining better distributional predictions for reserve selection, it is necessary to be cautious in their use due to the provisional nature of these simulations.Varios estudios han mostrado que el desempeño de los modelos de distribución puede

  5. Outreach in southern France

    International Nuclear Information System (INIS)

    Jackson, D.

    1992-01-01

    France's Europort South community lives cheek by jowl with the chemical industry, with major complexes at For, Berre, and Lavera. Xavier Segond, technical adviser at the regional chemical industry association, Le Syndicat General des Industries Chimiques Provence-Alpes-Cote d'Azur Corse (SGIC), says a good relationship has grown over a period of 20 years. Segond describes Arco Chimie as an effective driving force for the Responsible Care effort in the region - partly because its US parent introduced the program on a worldwide basis in 1989, ahead of national industry association Union des Industries Chimiques (UIC; Paris). Arco's F2-billion ($373 million)/year Fos-sur-Mer site makes it a significant player. But in 1986 the company was a complete newcomer. We came to Fos as a US company, we had no Paris headquarters or French president, explains Dominique Lequeux, director/human resources. The community viewed the company with a mixture of curiosity and enthusiasm as a potential employer - about 330 people now work at the site. The day before the officials propylene oxide plant opening, we invited in local people, says Lequeux. That formed a good basis for its Responsible Care community outreach program. Now, schools, professional groups, and political groups make 20-25 plant visits each year

  6. Southern African Journal of Environmental Education

    African Journals Online (AJOL)

    The Southern African Journal of Environmental Education (SAJEE) is an accredited and ... It is published at least once a year, by the Environmental Education Association of Southern Africa (EEASA). ... AJOL African Journals Online. HOW TO ...

  7. Southern Coal Corporation Clean Water Settlement

    Science.gov (United States)

    Southern Coal Corporation is a coal mining and processing company headquartered in Roanoke, VA. Southern Coal Corporation and the following 26 affiliated entities are located in Alabama, Kentucky, Tennessee, Virginia and West Virginia

  8. Review of Southern African Studies: Journal Sponsorship

    African Journals Online (AJOL)

    Review of Southern African Studies: Journal Sponsorship. Journal Home > About the Journal > Review of Southern African Studies: Journal Sponsorship. Log in or Register to get access to full text downloads.

  9. Review of Southern African Studies

    African Journals Online (AJOL)

    Review of Southern African Studies is a multidisciplinary journal of Arts, Social and Behavioural Sciences. Vol 13, No 1 (2009). DOWNLOAD FULL TEXT Open Access DOWNLOAD FULL TEXT Subscription or Fee Access. Table of Contents. Articles. Health-Care Waste Practices in Selected Health-Care Facilities in Maseru ...

  10. Unprecedented emergency in Southern Africa.

    Science.gov (United States)

    1999-03-01

    Despite knowledge of better prevention strategies, AIDS continues to be an unprecedented emergency in southern Africa. Statistics show that in 1998, 1.4 million people between the ages of 15 and 49 in the 9 countries of southern Africa were infected, with nearly three-quarters of a million of these new infections occurring in South Africa. In addition, some 2 million people died of AIDS in sub-Saharan Africa in 1998 and millions of new infections are occurring every year. Factors such as the loneliness suffered by migrant laborers, the wars and armed conflicts in Rwanda, and the stigma of shame, silence, and denial associated with AIDS all generate fertile conditions for the spread of HIV in southern Africa. Overcoming silence and denial, and bringing AIDS out into the open, has been considered by some countries in southern Africa. In Botswana and South Africa, appeals for greater awareness and openness by the top leadership have been coupled with a decision to set up government funding and AIDS. The challenge now will be to translate these into effective prevention and care programs.

  11. Pteropods in Southern Ocean ecosystems

    Science.gov (United States)

    Hunt, B. P. V.; Pakhomov, E. A.; Hosie, G. W.; Siegel, V.; Ward, P.; Bernard, K.

    2008-09-01

    To date, little research has been carried out on pelagic gastropod molluscs (pteropods) in Southern Ocean ecosystems. However, recent predictions are that, due to acidification resulting from a business as usual approach to CO 2 emissions (IS92a), Southern Ocean surface waters may begin to become uninhabitable for aragonite shelled thecosome pteropods by 2050. To gain insight into the potential impact that this would have on Southern Ocean ecosystems, we have here synthesized available data on pteropod distributions and densities, assessed current knowledge of pteropod ecology, and highlighted knowledge gaps and directions for future research on this zooplankton group. Six species of pteropod are typical of the Southern Ocean south of the Sub-Tropical Convergence, including the four Thecosomes Limacina helicina antarctica, Limacina retroversa australis, Clio pyramidata, and Clio piatkowskii, and two Gymnosomes Clione limacina antarctica and Spongiobranchaea australis. Limacina retroversa australis dominated pteropod densities north of the Polar Front (PF), averaging 60 ind m -3 (max = 800 ind m -3) and 11% of total zooplankton at the Prince Edward Islands. South of the PF L. helicina antarctica predominated, averaging 165 ind m -3 (max = 2681 ind m -3) and up to >35% of total zooplankton at South Georgia, and up to 1397 ind m -3 and 63% of total zooplankton in the Ross Sea. Combined pteropods contributed 40% of community grazing impact. Further research is required to quantify diet selectivity, the effect of phytoplankton composition on growth and reproductive success, and the role of carnivory in thecosomes. Life histories are a significant knowledge gap for Southern Ocean pteropods, a single study having been completed for L. retroversa australis, making population studies a priority for this group. Pteropods appear to be important in biogeochemical cycling, thecosome shells contributing >50% to carbonate flux in the deep ocean south of the PF. Pteropods may also

  12. Complexity Theory

    Science.gov (United States)

    Lee, William H K.

    2016-01-01

    A complex system consists of many interacting parts, generates new collective behavior through self organization, and adaptively evolves through time. Many theories have been developed to study complex systems, including chaos, fractals, cellular automata, self organization, stochastic processes, turbulence, and genetic algorithms.

  13. Thunderstorms caused by southern cyclones in Estonia

    OpenAIRE

    Kaupo Mändla; Sven-Erik Enno; Mait Sepp

    2014-01-01

    The relationships between the frequency and duration of thunderstorms, lightning and southern cyclones over Estonia are presented for the period 1950–2010. A total of 545 southern cyclones and 2106 thunderstorm days were detected, whereas 11.3% of the observed thunder days were associated with southern cyclones. At the same time, 29.2% of all southern cyclones were accompanied by thunderstorms. In the thunder season, however, this percentage was much higher, reaching up to 80% in summer month...

  14. The Southern Ocean biogeochemical divide.

    Science.gov (United States)

    Marinov, I; Gnanadesikan, A; Toggweiler, J R; Sarmiento, J L

    2006-06-22

    Modelling studies have demonstrated that the nutrient and carbon cycles in the Southern Ocean play a central role in setting the air-sea balance of CO(2) and global biological production. Box model studies first pointed out that an increase in nutrient utilization in the high latitudes results in a strong decrease in the atmospheric carbon dioxide partial pressure (pCO2). This early research led to two important ideas: high latitude regions are more important in determining atmospheric pCO2 than low latitudes, despite their much smaller area, and nutrient utilization and atmospheric pCO2 are tightly linked. Subsequent general circulation model simulations show that the Southern Ocean is the most important high latitude region in controlling pre-industrial atmospheric CO(2) because it serves as a lid to a larger volume of the deep ocean. Other studies point out the crucial role of the Southern Ocean in the uptake and storage of anthropogenic carbon dioxide and in controlling global biological production. Here we probe the system to determine whether certain regions of the Southern Ocean are more critical than others for air-sea CO(2) balance and the biological export production, by increasing surface nutrient drawdown in an ocean general circulation model. We demonstrate that atmospheric CO(2) and global biological export production are controlled by different regions of the Southern Ocean. The air-sea balance of carbon dioxide is controlled mainly by the biological pump and circulation in the Antarctic deep-water formation region, whereas global export production is controlled mainly by the biological pump and circulation in the Subantarctic intermediate and mode water formation region. The existence of this biogeochemical divide separating the Antarctic from the Subantarctic suggests that it may be possible for climate change or human intervention to modify one of these without greatly altering the other.

  15. Abiotic factors affect the recruitment and biomass of perennial grass and evergreen shrub seedlings in denuded areas of Patagonian Monte rangelands.

    Science.gov (United States)

    Bosco, Tomás; Bertiller, Mónica Beatriz; Carrera, Analía Lorena

    2018-07-15

    recruitment of the small-seeded perennial grasses and A. lampa. Ambient UV had negative effects on seedling biomass of perennial grasses. These complex relationships among abiotic factors and seed and plant traits should be taken into account when planning management actions after disturbances. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Managing Complexity

    DEFF Research Database (Denmark)

    Maylath, Bruce; Vandepitte, Sonia; Minacori, Patricia

    2013-01-01

    and into French. The complexity of the undertaking proved to be a central element in the students' learning, as the collaboration closely resembles the complexity of international documentation workplaces of language service providers. © Association of Teachers of Technical Writing.......This article discusses the largest and most complex international learning-by-doing project to date- a project involving translation from Danish and Dutch into English and editing into American English alongside a project involving writing, usability testing, and translation from English into Dutch...

  17. Complex variables

    CERN Document Server

    Fisher, Stephen D

    1999-01-01

    The most important topics in the theory and application of complex variables receive a thorough, coherent treatment in this introductory text. Intended for undergraduates or graduate students in science, mathematics, and engineering, this volume features hundreds of solved examples, exercises, and applications designed to foster a complete understanding of complex variables as well as an appreciation of their mathematical beauty and elegance. Prerequisites are minimal; a three-semester course in calculus will suffice to prepare students for discussions of these topics: the complex plane, basic

  18. Softball Complex

    Science.gov (United States)

    Ellis, Jim

    1977-01-01

    The Parks and Recreation Department of Montgomery, Alabama, has developed a five-field softball complex as part of a growing community park with facilities for camping, golf, aquatics, tennis, and picnicking. (MJB)

  19. Lecithin Complex

    African Journals Online (AJOL)

    1Department of Food Science and Engineering, Xinyang College of Agriculture and ... Results: The UV and IR spectra of the complex showed an additive effect of polydatin-lecithin, in which .... Monochromatic Cu Ka radiation (wavelength =.

  20. Photographs of the southern heavens

    CERN Document Server

    West, R M

    1975-01-01

    The 1 m Schmidt telescope of the European Southern Observatory (ESO) has been used for a number of sky surveys. In particular a main task has been an examination of the southern night sky between declinations of -20 degrees and -90 degrees . This exercise is known as the ESO(B) Survey (or Quick Blue Survey); some of the more interesting results are shown and are briefly discussed. The photographic plates used were Kodak II a-o. There are photographs of the two Magellanic Clouds and of the galaxy NGC 1313 and the globular cluster NGC 6752. A spectrogram of our Galaxy for wavelengths in the band 3900 A to 4900 A, taken with the telescope's large objective prism is also shown. (0 refs).

  1. Identification of southern radio sources

    International Nuclear Information System (INIS)

    Savage, A.; Bolton, J.G.; Wright, A.E.

    1976-01-01

    Identifications are suggested for 36 radio sources from the southern zones of the Parkes 2700 MHz survey, 28 with galaxies, six with confirmed and two with suggested quasi-stellar objects. The identifications were made from the ESO quick blue survey plates, the SRC IIIa-J deep survey plates and the Palomar sky survey prints. Accurate optical positions have also been measured for nine of the objects and for five previously suggested identifications. (author)

  2. Southern Great Plains Safety Orientation

    Energy Technology Data Exchange (ETDEWEB)

    Schatz, John

    2014-05-01

    Welcome to the Atmospheric Radiation Measurement (ARM) Climate Research Facility (ARM) Southern Great Plains (SGP) site. This U.S. Department of Energy (DOE) site is managed by Argonne National Laboratory (ANL). It is very important that all visitors comply with all DOE and ANL safety requirements, as well as those of the Occupational Safety and Health Administration (OSHA), the National Fire Protection Association, and the U.S. Environmental Protection Agency, and with other requirements as applicable.

  3. Southern Appalachian Regional Seismic Network

    Energy Technology Data Exchange (ETDEWEB)

    Chiu, S.C.C.; Johnston, A.C.; Chiu, J.M. [Memphis State Univ., TN (United States). Center for Earthquake Research and Information

    1994-08-01

    The seismic activity in the southern Appalachian area was monitored by the Southern Appalachian Regional Seismic Network (SARSN) since late 1979 by the Center for Earthquake Research and Information (CERI) at Memphis State University. This network provides good spatial coverage for earthquake locations especially in east Tennessee. The level of activity concentrates more heavily in the Valley and Ridge province of eastern Tennessee, as opposed to the Blue Ridge or Inner Piedmont. The large majority of these events lie between New York - Alabama lineament and the Clingman/Ocoee lineament, magnetic anomalies produced by deep-seated basement structures. Therefore SARSN, even with its wide station spacing, has been able to define the essential first-order seismological characteristics of the Southern Appalachian seismic zone. The focal depths of the southeastern U.S. earthquakes concentrate between 8 and 16 km, occurring principally beneath the Appalachian overthrust. In cross-sectional views, the average seismicity is shallower to the east beneath the Blue Ridge and Piedmont provinces and deeper to the west beneath the Valley and Ridge and the North American craton. Results of recent focal mechanism studies by using the CERI digital earthquake catalog between October, 1986 and December, 1991, indicate that the basement of the Valley and Ridge province is under a horizontal, NE-SW compressive stress. Right-lateral strike-slip faulting on nearly north-south fault planes is preferred because it agrees with the trend of the regional magnetic anomaly pattern.

  4. Southern Appalachian Regional Seismic Network

    International Nuclear Information System (INIS)

    Chiu, S.C.C.; Johnston, A.C.; Chiu, J.M.

    1994-08-01

    The seismic activity in the southern Appalachian area was monitored by the Southern Appalachian Regional Seismic Network (SARSN) since late 1979 by the Center for Earthquake Research and Information (CERI) at Memphis State University. This network provides good spatial coverage for earthquake locations especially in east Tennessee. The level of activity concentrates more heavily in the Valley and Ridge province of eastern Tennessee, as opposed to the Blue Ridge or Inner Piedmont. The large majority of these events lie between New York - Alabama lineament and the Clingman/Ocoee lineament, magnetic anomalies produced by deep-seated basement structures. Therefore SARSN, even with its wide station spacing, has been able to define the essential first-order seismological characteristics of the Southern Appalachian seismic zone. The focal depths of the southeastern U.S. earthquakes concentrate between 8 and 16 km, occurring principally beneath the Appalachian overthrust. In cross-sectional views, the average seismicity is shallower to the east beneath the Blue Ridge and Piedmont provinces and deeper to the west beneath the Valley and Ridge and the North American craton. Results of recent focal mechanism studies by using the CERI digital earthquake catalog between October, 1986 and December, 1991, indicate that the basement of the Valley and Ridge province is under a horizontal, NE-SW compressive stress. Right-lateral strike-slip faulting on nearly north-south fault planes is preferred because it agrees with the trend of the regional magnetic anomaly pattern

  5. Agro-fuels: southern impacts

    International Nuclear Information System (INIS)

    Duterme, B.

    2011-01-01

    At a time of controversies about global warming, agro-fuels production is often presented as a future solution for automotive fuels and as a new way of development for southern countries. However, in Asia, South America and Africa, it very often takes the form of huge mono-culture areas of sugar cane, palm oil and soy bean in the hands of multinational companies of the agriculture and food industry. The consequences of these land, social and environmental impacts in Southern countries is an increase of disequilibria and a threat for the diet of local populations by changing the appropriation of lands. Deforestation, private monopolization of lands, concentration of profits, soils and water pollution, biodiversity impoverishment, exploitation of vulnerable manpower, populations migration, violation of human rights are today the consequences of mass production of agro-fuels in Southern countries. To what conditions a fair re-appropriation and a sustainable development of agro-fuels production and consumption is foreseeable? The solutions require a re-shaping of economical and agricultural politics. The book gathers testimonies and analyses from specialists who have evaluated locally the consequences of these energy choices. (J.S.)

  6. Atmospheric Chemistry Over Southern Africa

    Science.gov (United States)

    Gatebe, Charles K.; Levy, Robert C.; Thompson, Anne M.

    2011-01-01

    During the southern African dry season, regional haze from mixed industrial pollution, biomass burning aerosol and gases from domestic and grassland fires, and biogenic sources from plants and soils is worsened by a semi-permanent atmosphere gyre over the subcontinent. These factors were a driver of several major international field campaigns in the 1990s and early 2000s, and attracted many scientists to the region. Some researchers were interested in understanding fundamental processes governing chemistry of the atmosphere and interaction with climate change. Others found favorable conditions for evaluating satellite-derived measurements of atmospheric properties and a changing land surface. With that background in mind a workshop on atmospheric chemistry was held in South Africa. Sponsored by the International Commission for Atmospheric Chemistry and Global Pollution (ICACGP; http://www.icacgp.org/), the workshop received generous support from the South African power utility, Eskom, and the Climatology Research Group of the University of the Witwatersrand, Johannesburg, South Africa. The purpose of the workshop was to review some earlier findings as well as more recent findings on southern African climate vulnerability, chemical changes due to urbanization, land-use modification, and how these factors interact. Originally proposed by John Burrows, president of ICACGP, the workshop was the first ICACGP regional workshop to study the interaction of air pollution with global chemical and climate change. Organized locally by the University of the Witwatersrand, the workshop attracted more than 60 delegates from South Africa, Mozambique, Botswana, Zimbabwe, France, Germany, Canada, and the United States. More than 30 presentations were given, exploring both retrospective and prospective aspects of the science. In several talks, attention was focused on southern African chemistry, atmospheric pollution monitoring, and climate processes as they were studied in the field

  7. Complex analysis

    CERN Document Server

    Freitag, Eberhard

    2005-01-01

    The guiding principle of this presentation of ``Classical Complex Analysis'' is to proceed as quickly as possible to the central results while using a small number of notions and concepts from other fields. Thus the prerequisites for understanding this book are minimal; only elementary facts of calculus and algebra are required. The first four chapters cover the essential core of complex analysis: - differentiation in C (including elementary facts about conformal mappings) - integration in C (including complex line integrals, Cauchy's Integral Theorem, and the Integral Formulas) - sequences and series of analytic functions, (isolated) singularities, Laurent series, calculus of residues - construction of analytic functions: the gamma function, Weierstrass' Factorization Theorem, Mittag-Leffler Partial Fraction Decomposition, and -as a particular highlight- the Riemann Mapping Theorem, which characterizes the simply connected domains in C. Further topics included are: - the theory of elliptic functions based on...

  8. Simulating Coral Reef Connectivity in the Southern Red Sea

    KAUST Repository

    Wang, Yixin

    2018-05-01

    Connectivity is an important component of coral reef studies for its role in the enhancement of ecosystem resilience. Previous genetic structure and physical circulation studies in the Red Sea reveal a homogeneity within the coral reef complexes in the central and northern parts of the basin. Yet, genetic isolation and relatively low connectivity has been observed in the southern Red Sea. Raitsos et al. (2017) recently hypothesized that coral reefs in the southern Red Sea are more connected with regions outside the basin, rather than with the central and northern Red Sea. Using a physical circulation approach based on a 3-D backward particle tracking simulation, we further investigate this hypothesis. A long-term (> 10 years), very high resolution (1km) MITgcm simulation is used to provide detailed information on velocity in the complex coastal regions of the Red Sea and the adjacent narrow Bab-El-Mandeb Strait. The particle tracking simulation results support the initial hypothesis that the coastal regions in the southern Red Sea exhibit a consistently higher connectivity with the regions outside the Bab-El-Mandeb Strait, than with the central and northern Red Sea. Substantially high levels of connectivity, facilitated by the circulation and eddies, is observed with the coastal regions in the Gulf of Aden. A strong seasonality in connectivity, related to the monsoon-driven circulation, is also evident with the regions outside of the Red Sea. The winter surface intrusion plays a leading role in transporting the particles from the Gulf of Aden and the Indian Ocean into the Red Sea, while the summer subsurface intrusion also supports the transport of particles into the Red Sea in the intermediate layer. In addition, the connectivity with the central and northern Red Sea is more affected by the intensity of the eddies. Evidence also suggests that potential connectivity exists between the coastal southern Red Sea and the coasts of Oman, Socotra, Somalia, Kenya

  9. Thunderstorms caused by southern cyclones in Estonia

    Directory of Open Access Journals (Sweden)

    Kaupo Mändla

    2014-05-01

    Full Text Available The relationships between the frequency and duration of thunderstorms, lightning and southern cyclones over Estonia are presented for the period 1950–2010. A total of 545 southern cyclones and 2106 thunderstorm days were detected, whereas 11.3% of the observed thunder days were associated with southern cyclones. At the same time, 29.2% of all southern cyclones were accompanied by thunderstorms. In the thunder season, however, this percentage was much higher, reaching up to 80% in summer months. The number of thunder days was largest when the centres of southern cyclones passed a measuring station at a distance less than 500 km. The number of cloud-to-ground lightning strikes related to southern cyclones was larger than that of any other thunder events. The results of our study demonstrate that the intensity of thunderstorms related to southern cyclones is higher than that of other thunderstorms. Correlation analysis revealed statistically significant relationships between the frequency of thunder days related to southern cyclones and the frequency of southern cyclones, also between the frequency of thunder days related to southern cyclones and days of other thunder events.

  10. Subgroup complexes

    CERN Document Server

    Smith, Stephen D

    2011-01-01

    This book is intended as an overview of a research area that combines geometries for groups (such as Tits buildings and generalizations), topological aspects of simplicial complexes from p-subgroups of a group (in the spirit of Brown, Quillen, and Webb), and combinatorics of partially ordered sets. The material is intended to serve as an advanced graduate-level text and partly as a general reference on the research area. The treatment offers optional tracks for the reader interested in buildings, geometries for sporadic simple groups, and G-equivariant equivalences and homology for subgroup complexes.

  11. Complex manifolds

    CERN Document Server

    Morrow, James

    2006-01-01

    This book, a revision and organization of lectures given by Kodaira at Stanford University in 1965-66, is an excellent, well-written introduction to the study of abstract complex (analytic) manifolds-a subject that began in the late 1940's and early 1950's. It is largely self-contained, except for some standard results about elliptic partial differential equations, for which complete references are given. -D. C. Spencer, MathSciNet The book under review is the faithful reprint of the original edition of one of the most influential textbooks in modern complex analysis and geometry. The classic

  12. Biological activity of some Patagonian plants.

    Science.gov (United States)

    Cuadra, Pedro; Furrianca, María; Oyarzún, Alejandra; Yáñez, Erwin; Gallardo, Amalia; Fajardo, Víctor

    2005-12-01

    Citotoxicity (inhibition of cell division in fertilized eggs of Loxechinus albus) and general toxicity (using embryos of Artemia salina) of plants belonging to the genera Senecio, Deschampsia, Alstroemeria, Anarthrophyllum, Chloraea and Geranium were investigated.

  13. Southern marl prairies conceptual ecological model

    Science.gov (United States)

    Davis, S.M.; Loftus, W.F.; Gaiser, E.E.; Huffman, A.E.

    2005-01-01

    About 190,000 ha of higher-elevation marl prairies flank either side of Shark River Slough in the southern Everglades. Water levels typically drop below the ground surface each year in this landscape. Consequently, peat soil accretion is inhibited, and substrates consist either of calcitic marl produced by algal periphyton mats or exposed limestone bedrock. The southern marl prairies support complex mosaics of wet prairie, sawgrass sawgrass (Cladium jamaicense), tree islands, and tropical hammock communities and a high diversity of plant species. However, relatively short hydroperiods and annual dry downs provide stressful conditions for aquatic fauna, affecting survival in the dry season when surface water is absent. Here, we present a conceptual ecological model developed for this landscape through scientific concensus, use of empirical data, and modeling. The two major societal drivers affecting the southern marl prairies are water management practices and agricultural and urban development. These drivers lead to five groups of ecosystem stressors: loss of spatial extent and connectivity, shortened hydroperiod and increased drought severity, extended hydroperiod and drying pattern reversals, introduction and spread of non-native trees, and introduction and spread of non-native fishes. Major ecological attributes include periphyton mats, plant species diversity and community mosaic, Cape Sable seaside sparrow (Ammodramus maritimus mirabilis), marsh fishes and associated aquatic fauna prey base, American alligator (Alligator mississippiensis), and wading bird early dry season foraging. Water management and development are hypothesized to have a negative effect on the ecological attributes of the southern marl prairies in the following ways. Periphyton mats have decreased in cover in areas where hydroperiod has been significantly reduced and changed in community composition due to inverse responses to increased nutrient availability. Plant species diversity and

  14. Complex Networks

    CERN Document Server

    Evsukoff, Alexandre; González, Marta

    2013-01-01

    In the last decade we have seen the emergence of a new inter-disciplinary field focusing on the understanding of networks which are dynamic, large, open, and have a structure sometimes called random-biased. The field of Complex Networks is helping us better understand many complex phenomena such as the spread of  deseases, protein interactions, social relationships, to name but a few. Studies in Complex Networks are gaining attention due to some major scientific breakthroughs proposed by network scientists helping us understand and model interactions contained in large datasets. In fact, if we could point to one event leading to the widespread use of complex network analysis is the availability of online databases. Theories of Random Graphs from Erdös and Rényi from the late 1950s led us to believe that most networks had random characteristics. The work on large online datasets told us otherwise. Starting with the work of Barabási and Albert as well as Watts and Strogatz in the late 1990s, we now know th...

  15. Subduction in the Southern Caribbean

    Science.gov (United States)

    Levander, A.; Schmitz, M.; Bezada, M.; Masy, J.; Niu, F.; Pindell, J.

    2012-04-01

    The southern Caribbean is bounded at either end by subduction zones: In the east at the Lesser Antilles subduction zone the Atlantic part of the South American plate subducts beneath the Caribbean. In the north and west under the Southern Caribbean Deformed Belt accretionary prism, the Caribbean subducts under South America. In a manner of speaking, the two plates subduct beneath each other. Finite-frequency teleseismic P-wave tomography confirms this, imaging the Atlantic and the Caribbean subducting steeply in opposite directions to transition zone depths under northern South America (Bezada et al, 2010). The two subduction zones are connected by the El Pilar-San Sebastian strike-slip fault system, a San Andreas scale system. A variety of seismic probes identify where the two plates tear as they begin to subduct (Niu et al, 2007; Clark et al., 2008; Miller et al. 2009; Masy et al, 2009). The El Pilar system forms at the southeastern corner of the Antilles subduction zone by the Atlantic tearing from South America. The deforming plate edges control mountain building and basin formation at the eastern end of the strike-slip system. In northwestern South America the Caribbean plate tears, its southernmost element subducting at shallow angles under northernmost Colombia and then rapidly descending to transition zone depths under Lake Maracaibo (Bezada et al., 2010). We believe that the flat slab produces the Merida Andes, the Perija, and the Santa Marta ranges. The southern edge of the nonsubducting Caribbean plate underthrusts northern Venezuela to about the width of the coastal mountains (Miller et al., 2009). We infer that the underthrust Caribbean plate supports the coastal mountains, and controls continuing deformation.

  16. Source and fractionation controls on subduction-related plutons and dike swarms in southern Patagonia (Torres del Paine area) and the low Nb/Ta of upper crustal igneous rocks

    Science.gov (United States)

    Müntener, Othmar; Ewing, Tanya; Baumgartner, Lukas P.; Manzini, Mélina; Roux, Thibaud; Pellaud, Pierre; Allemann, Luc

    2018-05-01

    The subduction system in southern Patagonia provides direct evidence for the variability of the position of an active continental arc with respect to the subducting plate through time, but the consequences on the arc magmatic record are less well studied. Here we present a geochemical and geochronological study on small plutons and dykes from the upper crust of the southern Patagonian Andes at 51°S, which formed as a result of the subduction of the Nazca and Antarctic plates beneath the South American continent. In situ U-Pb geochronology on zircons and bulk rock geochemical data of plutonic and dyke rocks are used to constrain the magmatic evolution of the retro-arc over the last 30 Ma. We demonstrate that these combined U-Pb and geochemical data for magmatic rocks track the temporal and spatial migration of the active arc, and associated retro-arc magmatism. Our dataset indicates that the rear-arc area is characterized by small volumes of alkaline basaltic magmas at 29-30 Ma that are characterized by low La/Nb and Th/Nb ratios with negligible arc signatures. Subsequent progressive eastward migration of the active arc culminated with the emplacement of calc-alkaline plutons and dikes 17-16 Ma with elevated La/Nb and Th/Nb ratios and typical subduction signatures constraining the easternmost position of the southern Patagonian batholith at that time. Geochemical data on the post-16 Ma igneous rocks including the Torres del Paine laccolith indicate an evolution to transitional K-rich calc-alkaline magmatism at 12.5 ± 0.2 Ma. We show that trace element ratios such as Nb/Ta and Dy/Yb systematically decrease with increasing SiO2, for both the 17-16 Ma calc-alkaline and the 12-13 Ma K-rich transitional magmatism. In contrast, Th/Nb and La/Nb monitor the changes in the source composition of these magmas. We suggest that the transition from the common calc-alkaline to K-rich transitional magmatism involves a change in the source component, while the trace element ratios

  17. Identification of southern radio sources

    International Nuclear Information System (INIS)

    Savage, A.; Bolton, J.G.; Wright, A.E.

    1977-01-01

    Identifications are suggested for 53 radio sources from the southern zones of the Parkes 2700-MHz survey, 32 with galaxies, 11 with suggested QSOs and 10 with confirmed QSOs. The identifications were made from the ESO quick blue survey plates, the SRC IIIa-J deep survey plates and the Palomar Sky Survey prints. Accurate optical positions have been measured for four of the new identifications and for two previously suggested identifications. A further nine previously suggested QSO identifications have also been confirmed by two-colour photography or spectroscopy. (author)

  18. Rural migration in southern Nevada

    International Nuclear Information System (INIS)

    Mosser, D.; Soden, D.L.

    1993-01-01

    This study reviews the history of migration in two rural counties in Southern Nevada. It is part of a larger study about the impact of a proposed high-level nuclear waste repository on, in and out-migration patterns in the state. The historical record suggests a boom and bust economic cycle has predominated in the region for the past century creating conditions that should be taken into account, by decision makers, when ascertaining the long-term impacts of the proposed repository

  19. TTVs study in southern stars

    Science.gov (United States)

    Petrucci, Romina; Jofré, Emiliano; Schwartz, Martín; Buccino, Andrea; Mauas, Pablo

    2012-07-01

    In this contribution we present 4 complete planetary transits observed with the 40-cm telescope ``Horacio Ghielmetti'' located in San Juan(Argentina). These objects correspond to a continuous photometric monitoring program of Southern planet host-stars that we are carrying out since mid-2011. The goal of this project is to detect additional planetary mass objects around stars with known transiting-planets through Transit Timing Variations (TTVs). For all 4 transits the depth and duration are in good agreement with the values published in the discovery papers.

  20. Identification of southern radio sources

    International Nuclear Information System (INIS)

    Savage, A.

    1976-01-01

    Identifications are suggested for 32 radio sources from the southern zones of the Parkes 2700 MHz survey, 18 with galaxies, one with a confirmed and 12 with possible quasistellar objects, and one with a supernova remnant in the Large Magellanic Cloud. The identifications were made from the ESO IIa-O quick blue survey plates, the SRC IIIa-J deep survey plates and the Palomar sky survey prints. Accurate optical positions have also been measured for 10 of the objects and for five previously suggested QSOs. (author)

  1. Southern high-velocity stars

    International Nuclear Information System (INIS)

    Augensen, H.J.; Buscombe, W.

    1978-01-01

    Using the model of the Galaxy presented by Eggen, Lynden-Bell and Sandage (1962), plane galactic orbits have been calculated for 800 southern high-velocity stars which possess parallax, proper motion, and radial velocity data. The stars with trigonometric parallaxes were selected from Buscombe and Morris (1958), supplemented by more recent spectroscopic data. Photometric parallaxes from infrared color indices were used for bright red giants studied by Eggen (1970), and for red dwarfs for which Rodgers and Eggen (1974) determined radial velocities. A color-color diagram based on published values of (U-B) and (B-V) for most of these stars is shown. (Auth.)

  2. Preparing Soil for Turfgrass Establishment - Southern Utah

    OpenAIRE

    Caron, Michael; Schaible, Candace; Heflebower, Rick; Cardon, Grant; Beddes, Taun; Kopp, Kelly

    2017-01-01

    This fact sheet provides information for successfully establishing a lawn including planning, soil preparation, appropriate seed or sod choice, and an understanding of turfgrass requirements in southern Utah.

  3. Managing Complexity

    Energy Technology Data Exchange (ETDEWEB)

    Chassin, David P.; Posse, Christian; Malard, Joel M.

    2004-08-01

    Physical analogs have shown considerable promise for understanding the behavior of complex adaptive systems, including macroeconomics, biological systems, social networks, and electric power markets. Many of today’s most challenging technical and policy questions can be reduced to a distributed economic control problem. Indeed, economically-based control of large-scale systems is founded on the conjecture that the price-based regulation (e.g., auctions, markets) results in an optimal allocation of resources and emergent optimal system control. This paper explores the state of the art in the use physical analogs for understanding the behavior of some econophysical systems and to deriving stable and robust control strategies for them. In particular we review and discussion applications of some analytic methods based on the thermodynamic metaphor according to which the interplay between system entropy and conservation laws gives rise to intuitive and governing global properties of complex systems that cannot be otherwise understood.

  4. Description, microhabitat selection and infection patterns of sealworm larvae (Pseudoterranova decipiens species complex, nematoda: ascaridoidea) in fishes from Patagonia, Argentina

    Science.gov (United States)

    2013-01-01

    Background Third-stage larvae of the Pseudoterranova decipiens species complex (also known as sealworms) have been reported in at least 40 marine fish species belonging to 21 families and 10 orders along the South American coast. Sealworms are a cause for concern because they can infect humans who consume raw or undercooked fish. However, despite their economic and zoonotic importance, morphological and molecular characterization of species of Pseudoterranova in South America is still scarce. Methods A total of 542 individual fish from 20 species from the Patagonian coast of Argentina were examined for sealworms. The body cavity, the muscles, internal organs, and the mesenteries were examined to detect nematodes. Sealworm larvae were removed from their capsules and fixed in 70% ethanol. For molecular identification, partial fragments of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1) were amplified for 10 isolates from 4 fish species. Morphological and morphometric data of sealworms were also obtained. Results A total of 635 larvae were collected from 12 fish species. The most infected fish was Prionotus nudigula, followed by Percophis brasiliensis, Acanthistius patachonicus, Paralichthys isosceles, and Pseudopercis semifasciata. Sequences obtained for the cox1 of sealworms from A. patachonicus, P. isosceles, P. brasiliensis and P. nudigula formed a reciprocally monophyletic lineage with published sequences of adult specimens of Pseudoterranova cattani from the South American sea lion Otaria flavescens, and distinct from the remaining 5 species of Pseudoterranova. A morphological description, including drawings and scanning electron microscopy photomicrographs of these larvae is provided. Sealworms collected from Argentinean fishes did not differ in their diagnostic traits from the previously described larvae of P. cattani. However a discriminant analysis suggests that specimens from P. nudigula were significantly larger than those from other fishes

  5. Description, microhabitat selection and infection patterns of sealworm larvae (Pseudoterranova decipiens species complex, nematoda: ascaridoidea) in fishes from Patagonia, Argentina.

    Science.gov (United States)

    Hernández-Orts, Jesús S; Aznar, Francisco J; Blasco-Costa, Isabel; García, Néstor A; Víllora-Montero, María; Crespo, Enrique A; Raga, Juan A; Montero, Francisco E

    2013-08-29

    Third-stage larvae of the Pseudoterranova decipiens species complex (also known as sealworms) have been reported in at least 40 marine fish species belonging to 21 families and 10 orders along the South American coast. Sealworms are a cause for concern because they can infect humans who consume raw or undercooked fish. However, despite their economic and zoonotic importance, morphological and molecular characterization of species of Pseudoterranova in South America is still scarce. A total of 542 individual fish from 20 species from the Patagonian coast of Argentina were examined for sealworms. The body cavity, the muscles, internal organs, and the mesenteries were examined to detect nematodes. Sealworm larvae were removed from their capsules and fixed in 70% ethanol. For molecular identification, partial fragments of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1) were amplified for 10 isolates from 4 fish species. Morphological and morphometric data of sealworms were also obtained. A total of 635 larvae were collected from 12 fish species. The most infected fish was Prionotus nudigula, followed by Percophis brasiliensis, Acanthistius patachonicus, Paralichthys isosceles, and Pseudopercis semifasciata. Sequences obtained for the cox1 of sealworms from A. patachonicus, P. isosceles, P. brasiliensis and P. nudigula formed a reciprocally monophyletic lineage with published sequences of adult specimens of Pseudoterranova cattani from the South American sea lion Otaria flavescens, and distinct from the remaining 5 species of Pseudoterranova. A morphological description, including drawings and scanning electron microscopy photomicrographs of these larvae is provided. Sealworms collected from Argentinean fishes did not differ in their diagnostic traits from the previously described larvae of P. cattani. However a discriminant analysis suggests that specimens from P. nudigula were significantly larger than those from other fishes. Most of the sealworms were

  6. Duean sip, théâtre de l’ethnorégionalisme sud. Les nomades de la mer et le cycle rituel du dixième mois dans la province de Phang Nga (sud de la Thaïlande) Duean sip, Theater of the Southern Ethnoregionalism. The Sea Nomads and the Tenth Lunar Month Ritual Complex in the Phang Nga Province (Southern Thailand)

    OpenAIRE

    Olivier Ferrari

    2012-01-01

    La cérémonie bouddhique du dixième mois lunaire, connue comme la fête des morts et des revenants, revêt dans la région de Phang Nga, au sud de la Thaïlande une importance et un rôle qui vont bien au-delà de sa signification religieuse. Il s’agit en effet d’un complexe rituel qui, en s’emboîtant avec les cérémonies du festival végétarien des Sino-Thaïs et avec d’autres cérémonies propres aux nomades de la mer (Moken, Moklen et Urak Lawoi), met en scène les fondements des relations interethniqu...

  7. Constraints on deformation of the Southern Andes since the Cretaceous from anisotropy of magnetic susceptibility

    NARCIS (Netherlands)

    Maffione, Marco; Hernandez-Moreno, Catalina; Ghiglione, Matias C.; Speranza, Fabio; van Hinsbergen, Douwe J.J.; Lodolo, Emanuele

    2015-01-01

    The southernmost segment of the Andean Cordillera underwent a complex deformation history characterized by alternation of contractional, extensional, and strike-slip tectonics. Key elements of southern Andean deformation that remain poorly constrained, include the origin of the orogenic bend known

  8. Ecology of fire in shortgrass prairie of the southern Great Plains

    Science.gov (United States)

    Paulette L. Ford; Guy R. McPherson

    1996-01-01

    The ecology of fire in shortgrass prairie of the southern Great Plains includes a complex interaction between the shortgrass prairie ecosystem and its inhabitants, all inextricably linked to land-use patterns. The history of the relationship between man and fire has been filled with ambivalence and mistrust, along with an appreciation of the power of fire as a...

  9. Climate-induced changes in vulnerability to biological threats in the southern United States

    Science.gov (United States)

    Rabiu Olatinwo; Qinfeng Guo; Songlin Fei; William Otrosina; Kier Klepzig; Douglas Streett

    2014-01-01

    Forest land managers face the challenges of preparing their forests for the impacts of climate change. However, climate change adds a new dimension to the task of developing and testing science-based management options to deal with the effects of stressors on forest ecosystems in the southern United States. The large spatial scale and complex interactions make...

  10. How seed orchard culture affects seed quality: experience with the southern pines

    Science.gov (United States)

    James P. Barnett

    1996-01-01

    Tree improvement programs have influenced significantly the quality of southern pine seeds produced when compared to collections from native stands. Seed orchard management practices such as fertilization can increase seed size and reduce seed dormancy. These result in the need for less complex pregermination treatments. Repeated cone collections from the same clones...

  11. Interacting effects of wildfire severity and liming on nutrient cycling in a southern Appalachian wilderness area

    Science.gov (United States)

    Katherine Elliott; Jennifer D. Knoepp; James M. Vose; William A. Jackson

    2013-01-01

    Aims Wilderness and other natural areas are threatened by large-scale disturbances (e.g., wildfire), air pollution, climate change, exotic diseases or pests, and a combination of these stress factors (i.e., stress complexes). Linville Gorge Wilderness (LGW) is one example of a high elevation wilderness in the southern Appalachian region that has been subject to stress...

  12. A pan-tropical cascade of fire driven by El Niño/Southern Oscillation

    NARCIS (Netherlands)

    Chen, Yang; Morton, Douglas C.; Andela, Niels; Van Der Werf, Guido R.; Giglio, Louis; Randerson, James T.

    2017-01-01

    The El Niño/Southern Oscillation (ENSO) has a pronounced influence on year-to-year variations in climate 1 . The response of fires to this forcing 2 is complex and has not been evaluated systematically across different continents. Here we use satellite data to create a climatology of burned-area and

  13. Composition and biogeography of forest patches on the inland mountains of the southern Cape

    CSIR Research Space (South Africa)

    Geldenhuys, CJ

    1997-05-01

    Full Text Available Patterns in species richness of 23 small, isolated forests on the inland mountains of the southern Cape were studied. Species richness of woody plants and vines of the Kouga-Baviaanskloof Forests was higher than in the western mountain complexes...

  14. Invasive Potential of Cattle Fever Ticks in the Southern United States

    Science.gov (United States)

    For >100 years cattle production in the southern United States has been threatened by cattle fever. It is caused by an invasive parasite-vector complex that includes the protozoan hemoparasites Babesia bovis and B. bigemina, which are transmitted among domestic cattle via Rhipicephalus tick vectors ...

  15. Forecast skill of synoptic conditions associated with Santa Ana winds in Southern California

    Science.gov (United States)

    Charles Jones; Francis Fujioka; Leila M.V. Carvalho

    2010-01-01

    Santa Ana winds (SAW) are synoptically driven mesoscale winds observed in Southern California usually during late fall and winter. Because of the complex topography of the region, SAW episodes can sometimes be extremely intense and pose significant environmental hazards, especially during wildfire incidents. A simple set of criteria was used to identify synoptic-scale...

  16. Complex variables

    CERN Document Server

    Flanigan, Francis J

    2010-01-01

    A caution to mathematics professors: Complex Variables does not follow conventional outlines of course material. One reviewer noting its originality wrote: ""A standard text is often preferred [to a superior text like this] because the professor knows the order of topics and the problems, and doesn't really have to pay attention to the text. He can go to class without preparation."" Not so here-Dr. Flanigan treats this most important field of contemporary mathematics in a most unusual way. While all the material for an advanced undergraduate or first-year graduate course is covered, discussion

  17. Future climate change over Southern Africa

    CSIR Research Space (South Africa)

    Davis, Claire L

    2017-10-01

    Full Text Available This chapter presents key messages drawn from recent subsets of future climate projections for the southern Africa region. Material in this chapter is drawn from Chapter 3 of Climate Risk and Vulnerability: A Handbook for Southern Africa (Davis 2011...

  18. The Southern Forest Futures Project: technical report

    Science.gov (United States)

    David N. Wear; John G. Greis

    2013-01-01

    Please visit the Southern Forest Futures Project website for more information.The Southern Forest Futures Project provides a science-based “futuring” analysis of the forests of the 13 States of the Southeastern United States. With findings...

  19. Complex dynamics

    CERN Document Server

    Carleson, Lennart

    1993-01-01

    Complex dynamics is today very much a focus of interest. Though several fine expository articles were available, by P. Blanchard and by M. Yu. Lyubich in particular, until recently there was no single source where students could find the material with proofs. For anyone in our position, gathering and organizing the material required a great deal of work going through preprints and papers and in some cases even finding a proof. We hope that the results of our efforts will be of help to others who plan to learn about complex dynamics and perhaps even lecture. Meanwhile books in the field a. re beginning to appear. The Stony Brook course notes of J. Milnor were particularly welcome and useful. Still we hope that our special emphasis on the analytic side will satisfy a need. This book is a revised and expanded version of notes based on lectures of the first author at UCLA over several \\Vinter Quarters, particularly 1986 and 1990. We owe Chris Bishop a great deal of gratitude for supervising the production of cour...

  20. THE ORIGINS OF THE SOUTHERN AFRICAN MAMMAL FAUNA ...

    African Journals Online (AJOL)

    Southern Africa can be geographically subdivided into different biotic zones, differing from .... The greater part of the southern African mammal fauna consists of savanna .... spread into southern Africa by way of the Savanna biotic zone.

  1. Power generation in Southern Africa

    International Nuclear Information System (INIS)

    Beer, J.A. de

    2002-01-01

    This paper outlines the main characteristics of power generation in Southern Africa, in terms of primary energy resources, existing and projected power supply and demand, types and location of power plants, regional integration, and environmental management aspects. Various options for future development of power generation are presented as part of an overall integrated resource planning (IRP) process for the power industry. These include coal and natural gas based options, hydro power and other renewable energy, and nuclear power plants. A specific option, the pebble bed modular reactor (PBMR), under development by Eskom Enterprises and other international and local partners, is described in terms of overall design parameters, inherent safety features, economics and environmental aspects. Included is a high level discussion on the selection of materials for the design of this PBMR plant, an advanced design version of a high temperature gas reactor (HTGR). (orig.)

  2. Southern Energy Efficiency Center (SEEC)

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Robin; Sonne, Jeffrey; Withers, Charles; Cummings, James; Verdict, Malcolm; Roberts, Sydney

    2009-09-30

    The Southern Energy Efficiency Center (SEEC) builds collaborative partnerships with: state and local governments and their program support offices, the building delivery industry (designers, contractors, realtors and commissioning agents), product manufacturers and their supply chains, utilities and their program implementers, consumers and other stakeholders in order to forge a strong regional network of building energy efficiency allies. Through a project Steering Committee composed of the state energy offices and building industry stakeholders, the SEEC works to establish consensus-based goals, priorities and strategies at the regional, state and local levels that will materially advance the deployment of high-performance “beyond code” buildings. In its first Phase, SEEC will provide limited technical and policy support assistance, training, certification and education to a wide spectrum of the building construction, codes and standards, and the consumer marketplace.

  3. Discussing epigenetics in Southern California

    Science.gov (United States)

    2012-01-01

    With the goal of discussing how epigenetic control and chromatin remodeling contribute to the various processes that lead to cellular plasticity and disease, this symposium marks the collaboration between the Institut National de la Santé et de la Recherche Médicale (INSERM) in France and the University of California, Irvine (UCI). Organized by Paolo Sassone-Corsi (UCI) and held at the Beckman Center of the National Academy of Sciences at the UCI campus December 15–16, 2011, this was the first of a series of international conferences on epigenetics dedicated to the scientific community in Southern California. The meeting also served as the official kick off for the newly formed Center for Epigenetics and Metabolism at the School of Medicine, UCI (http://cem.igb.uci.edu). PMID:22414797

  4. A Southern African positron beam

    International Nuclear Information System (INIS)

    Britton, D.T.; Haerting, M.; Teemane, M.R.B.; Mills, S.; Nortier, F.M.; Van der Walt, T.N.

    1997-01-01

    The first stage of a state of the art positron beam, being constructed at the University of Cape Town, is currently being brought into operation. This is the first positron beam on the African continent, as well as being the first positron beam dedicated to solid and surface studies in the southern hemisphere. The project also contains a high proportion of local development, including the encapsulated 22 Na positron source developed by our collaboration. Novel features in the design include a purely magnetic in-line deflector, working in the solenoidal guiding field, to eliminate unmoderated positrons and block the direct line of sight to the source. A combined magnetic projector and single pole probe forming lens is being implemented in the second phase of construction to achieve a spot size of 10 μm without remoderation

  5. The southern cone petroleum market

    International Nuclear Information System (INIS)

    Pisani, W.

    1992-01-01

    The Argentine oil sector has been moving strongly toward complete deregulation since 1989. Price controls on byproducts has been lifted, old petroleum contracts became into concessions, and the state oil company, YPF, is under process of privatization. In this context, the international companies scouting for opportunities can find an important menu of potential investments But here remain some problems connected with this deregulation, too. The lack of a reference crude and product market price is one of them. This paper focuses how to overcome this trouble with the establishment of an institutional market for crude and products, not only for Argentina but also for the entire Southern Cone Region (Argentina, Bolivia, Brazil, Chile, Paraguay and Uruguay), inquiring into the benefits of its creation

  6. Cosmic Complexity

    Science.gov (United States)

    Mather, John C.

    2012-01-01

    What explains the extraordinary complexity of the observed universe, on all scales from quarks to the accelerating universe? My favorite explanation (which I certainty did not invent) ls that the fundamental laws of physics produce natural instability, energy flows, and chaos. Some call the result the Life Force, some note that the Earth is a living system itself (Gaia, a "tough bitch" according to Margulis), and some conclude that the observed complexity requires a supernatural explanation (of which we have many). But my dad was a statistician (of dairy cows) and he told me about cells and genes and evolution and chance when I was very small. So a scientist must look for me explanation of how nature's laws and statistics brought us into conscious existence. And how is that seemll"!gly Improbable events are actually happening a!1 the time? Well, the physicists have countless examples of natural instability, in which energy is released to power change from simplicity to complexity. One of the most common to see is that cooling water vapor below the freezing point produces snowflakes, no two alike, and all complex and beautiful. We see it often so we are not amazed. But physlc!sts have observed so many kinds of these changes from one structure to another (we call them phase transitions) that the Nobel Prize in 1992 could be awarded for understanding the mathematics of their common features. Now for a few examples of how the laws of nature produce the instabilities that lead to our own existence. First, the Big Bang (what an insufficient name!) apparently came from an instability, in which the "false vacuum" eventually decayed into the ordinary vacuum we have today, plus the most fundamental particles we know, the quarks and leptons. So the universe as a whole started with an instability. Then, a great expansion and cooling happened, and the loose quarks, finding themselves unstable too, bound themselves together into today's less elementary particles like protons and

  7. Southern African Phanerozoic Carbonatites: Perspectives on Their Sources and Petrogeneses

    Science.gov (United States)

    Janney, P. E.; Ogungbuyi, P. I.; Marageni, M.; Harris, C.; Reid, D. L.

    2017-12-01

    Found worldwide, carbonatites are particularly numerous in southern Africa and reflect one expression of abundant intraplate alkaline magmatism of Proterozoic to Paleogene age in the region. Phanerozoic southern African carbonatites tend to be concentrated near the margins of the continent (especially the western margin), and near the East African Rift, and often occur in discrete magmatic lineations also containing kimberlites, melilitites, nephelinites and differentiated silica-undersaturated rocks such as phonolites and syenites. We present a synthesis of geochemical and radiogenic and stable isotope results for southern African carbonatites, including new trace element and isotope data from four Phanerozoic carbonatite complexes in South Africa and Namibia: Marinkas Quellen (MQ; southernmost Namibia, ≈525 Ma), Saltpeterkop (SPK; near Sutherland, South Africa, 74 Ma), Zandkopsdrift (ZKD; near Garies, South Africa, 55 Ma, a major REE deposit in development), and Dicker Willem (DW; near Aus, southern Namibia, 49 Ma). All are located in the Early-mid Proterozoic Namaqua-Natal mobile belt. These carbonatite complexes are each associated with linear, NE-SW oriented magmatic provinces, i.e., the Kuboos-Bremen Line of felsic alkaline intrusions and ultramafic lamprophyres (MQ); the Western Cape olivine melilitite province (SPK); the Namaqualand-Bushmanland-Warmbad province of olivine melilitites and kimberlites (ZKD) and the Schwarzeberg-Klinghardt-Gibeon swarm of nephelinites, phonolites and kimberlites (DW), the latter three provinces are of Paleogene to Late Cretaceous age and are clearly age progressive. Each of the four carbonatite complexes contain silica-undersaturated igneous rocks such as potassic trachyte (MQ, SPK & DW), alkaline lamprophyre (ZKD), ijolite (MQ & DW) and olivine melilitite (ZKD and SPK). Most also contain hybrid silicate-carbonate igneous rocks with <35 wt.% SiO2 and ≥20 wt.% CO2 such as nepheline sövite (DW), aillikite (ZKD) and other

  8. On the benefits of an integrated nuclear complex for Nevada

    International Nuclear Information System (INIS)

    Blink, J.A.; Halsey, W.G.

    1994-01-01

    An integrated nuclear complex is proposed for location at the Nevada Test Site. In addition to solving the nuclear waste disposal problem, this complex would tremendously enhance the southern Nevada economy, and it would provide low cost electricity to each resident and business in the affected counties. Nuclear industry and the national economy would benefit because the complex would demonstrate the new generation of safer nuclear power plants and revitalize the industry. Many spin-offs of the complex would be possible, including research into nuclear fusion and a world class medical facility for southern Nevada. For such a complex to become a reality, the cycle of distrust between the federal government and the State of Nevada must be broken. The paper concludes with a discussion of implementation through a public process led by state officials and culminating in a voter referendum

  9. Lutzomyia reducta Feliciangeli et al., 1988, a host of Leishmania amazonensis, sympatric with two other members of the Flaviscutellata complex in southern Amazonas and Rondônia, Brazil (Diptera: Psychodidae Lutzomyia reducta Feliciangeli et al., 1988 um hospedeiro de Leishmania amazonensis, simpátrico com duas outras espécies do complexo flaviscutellata no sul do Amazonas e Rondônica, Brasil (Diptera: Psychodidae

    Directory of Open Access Journals (Sweden)

    R. A. Freitas

    1989-09-01

    Full Text Available A member of the Lutzomyia flaviscutellata complex from Rondônia and southern Amazonas States, Brazil, is so close to the Venezuelan Lutzomyia olmeca recuta Feliciangeli et al., 1988, that it is regarded as belonging to the same species. Since this phlebotomine co-extis with L. olmeca nociva in Brazil, the subspecific status of the former is untenable and is rased to specific rank, as Lutzomyia reducta. The Brazilian material is described and illustrated, and compared with specimens of L. o. nociva and L. flaviscutellata from the same area. Keys to the known taxa of the flaviscutellata complex are presented. Leishmania amazonensis was isolated from one heavily infected specimen of L. reducta, making this the third species of the flaviscutellata complex to be implicated as a vector of this parasite in Brazil. The relative abundance of the three sympatric flaviscutellata complex species varies locally and appears to be related to soil drainage. L. reducta constituted about 25% if all phlebotomines captured in Disney traps at poorly drained and well drained site, but appears not to coloniza areas subject to periodic flooding. L. olmeca nociva was restricted to poorly drained areas not subject to flooding, whereas L. flaviscutellata was ubiquitous L. reducta has never been detected north of the Amazon river in Brazil, but absence of recosrds from western and northwestern Amazonas State may reflect lack of collecting in these areas.Um flebotomíneo do complexo Lutzomyia flaviscutellata, de Rondônia e sul do Amazonas, Brasil é tão parecido com Lutzomyia olmeca reducta, que é considerado como sendo da mesma espécie. Este flebotomíneo ocorre junto com L. olmeca nociva, portanto o nome é emendado para o nível de espécie, como Lutzomyia reducta. O material do Brasil é descrito e ilustrado, e comparado com exemplares de L. o. nociva e L. flaviscutellata da mesma área. Chaves para as espécies e subespécies do complexo flaviscutellata são inclu

  10. The Patagonian scallop fishing grounds in shelf break frontal areas: the non assessed benthic fraction Bancos de pesca de vieira patagónica en áreas del frente de talud: fracción bentónica no evaluada

    Directory of Open Access Journals (Sweden)

    María de los Ángeles Sánchez

    2011-01-01

    Full Text Available In this study, a Picard dredge was used to sample the benthic community in shelf break frontal areas off Argentina in order to detect species that could be sensitive to fishing activities but are not usually caught during the annual monitoring of Patagonian scallop and associated fauna. The present results show at least 62 taxa not reported previously as components of the benthos in the scallop grounds that are potentially subjected to trawling disturbance.En este trabajo se utilizó una rastra Picard para muestrear la comunidad bentónica en áreas del frente de talud, Argentina, para detectar especies que serían sensibles a la actividad pesquera pero no son capturadas usualmente durante los monitoreos anuales de vieira patagónica y fauna asociada. Los resultados muestran que al menos 62 taxa, no reportados previamente como componentes del bentos en los bancos de vieira, están potencialmente sujetos a perturbaciones por el arrastre.

  11. Southern company energy storage study :

    Energy Technology Data Exchange (ETDEWEB)

    Ellison, James; Bhatnagar, Dhruv; Black, Clifton; Jenkins, Kip

    2013-03-01

    This study evaluates the business case for additional bulk electric energy storage in the Southern Company service territory for the year 2020. The model was used to examine how system operations are likely to change as additional storage is added. The storage resources were allowed to provide energy time shift, regulation reserve, and spinning reserve services. Several storage facilities, including pumped hydroelectric systems, flywheels, and bulk-scale batteries, were considered. These scenarios were tested against a range of sensitivities: three different natural gas price assumptions, a 15% decrease in coal-fired generation capacity, and a high renewable penetration (10% of total generation from wind energy). Only in the elevated natural gas price sensitivities did some of the additional bulk-scale storage projects appear justifiable on the basis of projected production cost savings. Enabling existing peak shaving hydroelectric plants to provide regulation and spinning reserve, however, is likely to provide savings that justify the project cost even at anticipated natural gas price levels. Transmission and distribution applications of storage were not examined in this study. Allowing new storage facilities to serve both bulk grid and transmission/distribution-level needs may provide for increased benefit streams, and thus make a stronger business case for additional storage.

  12. Geology, petrology and geochemistry of the dome complex of Huequi volcano, southern Chile Geología, petrología y geoquímica de los domos volcánicos del volcán Huequi, Chile meridional

    Directory of Open Access Journals (Sweden)

    Sebastian F.L Watt

    2011-07-01

    Full Text Available Huequi, a little-known volcano in the southern part of the Andean southern volcanic zone (SSVZ, shows a regionally unusual eruption style, mineralogy and geochemistry. The volcano comprises multiple highly-eroded lava domes. Past eruptions were accompanied by relatively minor explosive activity, most recently from 1890-1920. The rocks erupted by Huequi range from basaltic andesite to dacite, and are highly distinctive when compared to other volcanoes of the SSVZ, being K-poor and Al-rich, and containing euhedral hornblende phenocrysts. Overall compositions suggest a notably water-rich magma source, evolving through high levels of fractionation and subsequent degassing to produce highly porphyritic dome-forming andesites. The ultimate causes of water-rich magmas at this point in the arc remain unclear.El volcán Huequi es poco conocido, que se ubica en la provincia sur de la zona Volcánica Sur de los Andes (ZVSS. Sus tipos de erupción y características mineralógicas y geoquímicas son poco comunes a nivel regional. El volcán presenta múltiples domos poco erosionados. Las erupciones estuvieron acompañadas por una actividad explosiva secundaria, siendo las más recientes las ocurridas entre los años 1890 y 1920. Los magmas del Huequi son de composición andesítico-basáltica a dacítica. Si se las compara con rocas eruptadas por otros centros volcánicos de la ZVSS de los Andes, las del Huequi se caracterizan por ser pobres en K, ricas en Al y por presentar fenocristales euhedrales de anfíbola. Las composiciones totales sugieren una fuente magmática rica en H2O, que se desarrolla a través de niveles de cristalización fraccionada y desgasificación subsecuente, que producen domos volcánicos andesíticos altamente porfíricos. Sin embargo, la causa última que genera magmas ricos en H2O, en esta parte de los Andes, sigue aún sin explicación.

  13. Submarine earthquake rupture, active faulting and volcanism along the major Liquiñe-Ofqui Fault Zone and implications for seismic hazard assessment in the Patagonian Andes Ruptura sísmica submarina, tectónica y volcanismo activo a lo largo de la Falla Liquiñe-Ofqui e implicancias para el peligro sísmico en los Andes patagónicos

    Directory of Open Access Journals (Sweden)

    Gabriel Vargas

    2013-01-01

    Full Text Available The Liquiñe-Ofqui fault zone (LOFZ in the Patagonian Andes is an active major transpressional intra-arc fault system along which Quaternary faulting and volcanism develop. Subaerial and submarine geomorphologic and structural characterization of latest Pleistocene-Holocene faults and monogenetic volcanoes allows us to assess geological cartography of active faults and the kinematic model for recent tectonics during postglacial times, since 12,000 cal. years BP. This allows increasing the basic geological knowledge necessary for determining the seismic hazard associated with cortical structures in the Aysén region in southern Chile. Fault cartography and field observations suggest dominant dextral-reverse strike slip along north-south and locally NNW-striking faults, dextral-normal strike slip along NE to NNE- striking faults, and sinistral strike slip along east-west faults. This kinematics is consistent with regional SW-NE shortening in the context of a major transpressional fault zone. Holocene and even historic monogenetic and sub-aquatic volcanism occurred in this tectonic setting in a close spatial relationship and probably favored by the activity and local architecture of faults. Submarine fault scarps and deformed sediments observed at the bottom of the Aysén Fjord were associated with the destructive April 2007 Mw6.2 earthquake located along the LOFZ. Our observations show that this earthquake occurred along dextral 15-20 km long N-S structure named Punta Cola Fault (PCF. This fault system is located some kilometres to the east of the main N-S Río Cuervo Fault (RCF. Most of the epicentres of the seismic swarm during 2007 were located along or in between both structures. The study area is a transference zone between N-S regional branches of the LOFZ. The cartography of fault segments proposed here together with geophysical and geologic data suggest that large earthquakes Mw6.2-6.5 can be typically expected along most of the active

  14. South African southern ocean research programme

    CSIR Research Space (South Africa)

    SASCAR

    1987-01-01

    Full Text Available This document describes the South African National Antarctic Research Programme's (SANARP) physical, chemical and biological Southern Ocean research programme. The programme has three main components: ecological studies of the Prince Edward Islands...

  15. Arctic and Southern Ocean Sea Ice Concentrations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Monthly sea ice concentration for Arctic (1901 to 1995) and Southern oceans (1973 to 1990) were digitized on a standard 1-degree grid (cylindrical projection) to...

  16. Southern Forests: a Journal of Forest Science

    African Journals Online (AJOL)

    Southern Hemisphere Forestry Journal. ... The journal particularly encourages contributions from South America, Africa and tropical/subtropical ... Alternative eucalypts for commercial pulpwood production at moderately dry sites in the warm ...

  17. Southern African Development Research Network | IDRC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... to craft policies for fruitful integration into the global economy and inclusive growth. ... The grant will support a broad-based research network, the Southern Africa ... researchers based in regional institutions; transforming selected institutions ...

  18. Southern African Business Review: Editorial Policies

    African Journals Online (AJOL)

    The Southern African Business Review is a refereed and accredited scientific ... Accounting, Public Management, Tourism Management and related fields. ... This journal provides immediate open access to its content on the principle that ...

  19. Introduction to prescribed fires in Southern ecosystems

    Science.gov (United States)

    Thomas A. Waldrop; Scott L. Goodrick

    2012-01-01

    This publication is a guide for resource managers on planning and executing prescribed burns in Southern forests and grasslands. It includes explanations of reasons for prescribed burning, environmental effects, weather, and techniques as well as general information on prescribed burning.

  20. Climate Prediction Center Southern Oscillation Index

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This is one of the CPC?s Monthly Atmospheric and Sea Surface Temperature (SST)Indices. It contains Southern Oscillation Index which is standardized sea level...

  1. Eastern and Southern Africa Seismological Working Group

    International Nuclear Information System (INIS)

    Ogubazghi, G.

    2002-01-01

    Member countries of the Eastern and Southern Africa Seismologica Working Group are listed. The presentation also gives the objectives, activities, date of birth and sponsors of the said ESARSWG. Areas of possible cooperation with CTBTO are indicated

  2. Exploring sustainable transportation for Texas Southern University.

    Science.gov (United States)

    2014-05-01

    Texas Southern University is a commuter campus with students, faculty, and staff traveling from the : Greater Houston area to the university. Over the past few years, the TSU campus has made marked : improvements to move towards a greener more ...

  3. Southern African Journal of Environmental Education

    African Journals Online (AJOL)

    ... knowledge and community based management of wildlife resources: a study of the Mumbwa and Lupande Game Management areas of Zambia. ... Southern African Journal of Environmental Education ... AJOL African Journals Online.

  4. Mental Health Services in Southern Sudan

    African Journals Online (AJOL)

    Siegal_D

    Editorial: Mental Health Services in Southern Sudan – a. Vision for the Future. Major mental illness exists all over the world with a remarkably .... minus one or both parents. ... There he taught and inspired child health professionals from all over.

  5. Southern Hemisphere Ice Limits, 1973-1978

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Weekly Southern Ocean ice limits, have been digitized from U.S. Navy Fleet Weather Facility ice charts, at the Max-Planck Institut fur Meteorologie, Hamburg....

  6. Southern Great Plains Atmospheric Radiation Measurement Site

    Data.gov (United States)

    Federal Laboratory Consortium — The Southern Great Plains Atmospheric Radiation Measurement Site (SGP-ARM) is the oldest and largest of DOE's Arm sites. It was established in 1992. It consists of...

  7. Leveraging Emerging Technologies in Southern Thailand

    National Research Council Canada - National Science Library

    Valentine, Albert R

    2005-01-01

    .... This thesis examines the history of southern Thailand, including the political factors behind the Malay-Muslim rebellions of the past, the roots of this rebellion back to the era of Patani Raya...

  8. Irreplaceable Acting | Wright | Shakespeare in Southern Africa

    African Journals Online (AJOL)

    Shakespeare in Southern Africa. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 25 (2013) >. Log in or Register to get access to full text downloads.

  9. Two Hamlets | Burnett | Shakespeare in Southern Africa

    African Journals Online (AJOL)

    Shakespeare in Southern Africa. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 23 (2011) >. Log in or Register to get access to full text downloads.

  10. The Southern Forest Futures Project: summary report

    Science.gov (United States)

    David N. Wear; John G. Greis

    2012-01-01

    The Southern Forest Futures Project provides a science-based “futuring” analysis of the forests of the 13 States of the Southeastern United States. With findings organized in a set of scenarios and using a combination of computer models and science synthesis, the authors of the Southern Forest Futures Project examine a variety of possible futures that could shape...

  11. Marketing of organic products in southern Poland

    OpenAIRE

    Kuboń Maciej; Olech Elżbieta

    2018-01-01

    The article presents an outline of the issue concerning formulation of a marketing strategy and the possibility of using the knowledge on consumers' preferences for organic development of farms and their products on the example of southern Poland. The paper analyses the distribution process of organic food in the aspect of developing innovative marketing strategies. The studies were performed in 50 organic farms and on the example of 100 respondents from the region of southern Poland. In the ...

  12. Southern Ocean carbon-wind stress feedback

    Science.gov (United States)

    Bronselaer, Ben; Zanna, Laure; Munday, David R.; Lowe, Jason

    2018-02-01

    The Southern Ocean is the largest sink of anthropogenic carbon in the present-day climate. Here, Southern Ocean pCO2 and its dependence on wind forcing are investigated using an equilibrium mixed layer carbon budget. This budget is used to derive an expression for Southern Ocean pCO2 sensitivity to wind stress. Southern Ocean pCO2 is found to vary as the square root of area-mean wind stress, arising from the dominance of vertical mixing over other processes such as lateral Ekman transport. The expression for pCO2 is validated using idealised coarse-resolution ocean numerical experiments. Additionally, we show that increased (decreased) stratification through surface warming reduces (increases) the sensitivity of the Southern Ocean pCO2 to wind stress. The scaling is then used to estimate the wind-stress induced changes of atmospheric pCO_2 in CMIP5 models using only a handful of parameters. The scaling is further used to model the anthropogenic carbon sink, showing a long-term reversal of the Southern Ocean sink for large wind stress strength.

  13. Characteristics of Southern California coastal aquifer systems

    Science.gov (United States)

    Edwards, B.D.; Hanson, R.T.; Reichard, E.G.; Johnson, T.A.

    2009-01-01

    Most groundwater produced within coastal Southern California occurs within three main types of siliciclastic basins: (1) deep (>600 m), elongate basins of the Transverse Ranges Physiographic Province, where basin axes and related fluvial systems strike parallel to tectonic structure, (2) deep (>6000 m), broad basins of the Los Angeles and Orange County coastal plains in the northern part of the Peninsular Ranges Physiographic Province, where fluvial systems cut across tectonic structure at high angles, and (3) shallow (75-350 m), relatively narrow fluvial valleys of the generally mountainous southern part of the Peninsular Ranges Physiographic Province in San Diego County. Groundwater pumped for agricultural, industrial, municipal, and private use from coastal aquifers within these basins increased with population growth since the mid-1850s. Despite a significant influx of imported water into the region in recent times, groundwater, although reduced as a component of total consumption, still constitutes a significant component of water supply. Historically, overdraft from the aquifers has caused land surface subsidence, flow between water basins with related migration of groundwater contaminants, as well as seawater intrusion into many shallow coastal aquifers. Although these effects have impacted water quality, most basins, particularly those with deeper aquifer systems, meet or exceed state and national primary and secondary drinking water standards. Municipalities, academicians, and local water and governmental agencies have studied the stratigraphy of these basins intensely since the early 1900s with the goals of understanding and better managing the important groundwater resource. Lack of a coordinated effort, due in part to jurisdictional issues, combined with the application of lithostratigraphic correlation techniques (based primarily on well cuttings coupled with limited borehole geophysics) have produced an often confusing, and occasionally conflicting

  14. Effects of Regulation on Induced Seismicity in Southern Kansas

    Science.gov (United States)

    Rubinstein, J. L.; Ellsworth, W. L.; Dougherty, S. L.

    2016-12-01

    The appearance of seismicity concurrent with the expansion of oil and gas activities in southern Kansas since September 2012 suggests that industrial operations are inducing earthquakes there. Much of the seismicity can be related to high-rate injection wells within 5 km of the earthquakes. There is significant complexity to the situation, though. Some of the seismicity, including the 2014 M4.8 Milan earthquake, the largest earthquake to occur in the area, lies at least 10km from high-rate injection wells. Additionally, the presence of high-rate wells does not guarantee that there will be nearby seismicity. Many of the highest-rate injection wells are located to the southwest of our study area, where there is minimal seismicity. We have also seen changes in earthquake rates shortly following the March 2015 enactment of new limits on the rate of wastewater disposal in five areas in southern Kansas. Overall, the earthquake rate has decreased significantly since these rules went into place. In more detail, however, earthquake rates within the five areas decreased, but the rate outside the five zones increased. It is likely that fluid-pressure diffusion is responsible for the migration of seismicity outside the areas of reduced injection because there is little injection in the areas unaffected by the new injection rules. This increase is also a reminder that seismicity can persist long after the reduction or cessation of injection. In addition to the effect of the new injection rules, it is possible that the reduction in injection may be partially caused by economic factors that have resulted in a decrease in the production of oil and gas. We have yet to disentangle the effects of the new injection rules and the low prices of oil and gas on the induced seismicity in southern Kansas.

  15. Silvicultural Considerations in Managing Southern Pine Stands in the Context of Southern Pine Beetle

    Science.gov (United States)

    James M. Guldin

    2011-01-01

    Roughly 30 percent of the 200 million acres of forest land in the South supports stands dominated by southern pines. These are among the most productive forests in the nation. Adapted to disturbance, southern pines are relatively easy to manage with even-aged methods such as clearcutting and planting, or the seed tree and shelterwood methods with natural regeneration....

  16. Microcystin Prevalence throughout Lentic Waterbodies in Coastal Southern California

    Directory of Open Access Journals (Sweden)

    Meredith D. A. Howard

    2017-07-01

    Full Text Available Toxin producing cyanobacterial blooms have increased globally in recent decades in both frequency and intensity. Despite the recognition of this growing risk, the extent and magnitude of cyanobacterial blooms and cyanotoxin prevalence is poorly characterized in the heavily populated region of southern California. Recent assessments of lentic waterbodies (depressional wetlands, lakes, reservoirs and coastal lagoons determined the prevalence of microcystins and, in some cases, additional cyanotoxins. Microcystins were present in all waterbody types surveyed although toxin concentrations were generally low across most habitats, as only a small number of sites exceeded California’s recreational health thresholds for acute toxicity. Results from passive samplers (Solid Phase Adsorption Toxin Tracking (SPATT indicated microcystins were prevalent throughout lentic waterbodies and that traditional discrete samples underestimated the presence of microcystins. Multiple cyanotoxins were detected simultaneously in some systems, indicating multiple stressors, the risk of which is uncertain since health thresholds are based on exposures to single toxins. Anatoxin-a was detected for the first time from lakes in southern California. The persistence of detectable microcystins across years and seasons indicates a low-level, chronic risk through both direct and indirect exposure. The influence of toxic cyanobacterial blooms is a more complex stressor than presently recognized and should be included in water quality monitoring programs.

  17. Climate and Southern Africa's Water-Energy-Food Nexus

    Science.gov (United States)

    Conway, D.; Osborn, T.; Dorling, S.; Ringler, C.; Lankford, B.; Dalin, C.; Thurlow, J.; Zhu, T.; Deryng, D.; Landman, W.; Archer van Garderen, E.; Krueger, T.; Lebek, K.

    2014-12-01

    Numerous challenges coalesce to make Southern Africa emblematic of the connections between climate and the water-energy-food nexus. Rainfall and river flows in the region show high levels of variability across a range of spatial and temporal scales. Physical and socioeconomic exposure to climate variability and change is high, for example, the contribution of electricity produced from hydroelectric sources is over 30% in Madagascar and Zimbabwe and almost 100% in the DRC, Lesotho, Malawi, and Zambia. The region's economy is closely linked with that of the rest of the African continent and climate-sensitive food products are an important item of trade. Southern Africa's population is concentrated in regions exposed to high levels of hydro-meteorological variability, and will increase rapidly over the next four decades. The capacity to manage the effects of climate variability tends, however, to be low. Moreover, with climate change annual precipitation levels, soil moisture and runoff are likely to decrease and rising temperatures will increase evaporative demand. Despite high levels of hydro-meteorological variability, the sectoral and cross-sectoral water-energy-food linkages with climate in Southern Africa have not been considered in detail. Lack of data and questionable reliability are compounded by complex dynamic relationships. We review the role of climate in Southern Africa's nexus, complemented by empirical analysis of national level data on climate, water resources, crop and energy production, and economic activity. Our aim is to examine the role of climate variability as a driver of production fluctuations in the nexus, and to improve understanding of the magnitude and temporal dimensions of their interactions. We first consider national level exposure of food, water and energy production to climate in aggregate economic terms and then examine the linkages between interannual and multi-year climate variability and economic activity, focusing on food and

  18. Last Glacial vegetation and climate change in the southern Levant

    Science.gov (United States)

    Miebach, Andrea; Chen, Chunzhu; Litt, Thomas

    2015-04-01

    limiting factor for tree growth was precipitation. Consequently, the precipitation gradient was not as strong as today, and semiarid conditions prevailed in the southern Levant during the Last Glacial. Our study will contribute to the overall aim to reconstruct the way of modern humans to Europe and to understand the complex connection between climate and vegetation change in the Eastern Mediterranean.

  19. Refining Southern California Geotherms Using Seismologic, Geologic, and Petrologic Constraints

    Science.gov (United States)

    Thatcher, W. R.; Chapman, D. S.; Allam, A. A.; Williams, C. F.

    2017-12-01

    Lithospheric deformation in tectonically active regions depends on the 3D distribution of rheology, which is in turn critically controlled by temperature. Under the auspices of the Southern California Earthquake Center (SCEC) we are developing a 3D Community Thermal Model (CTM) to constrain rheology and so better understand deformation processes within this complex but densely monitored and relatively well-understood region. The San Andreas transform system has sliced southern California into distinct blocks, each with characteristic lithologies, seismic velocities and thermal structures. Guided by the geometry of these blocks we use more than 250 surface heat-flow measurements to define 13 geographically distinct heat flow regions (HFRs). Model geotherms within each HFR are constrained by averages and variances of surface heat flow q0 and the 1D depth distribution of thermal conductivity (k) and radiogenic heat production (A), which are strongly dependent on rock type. Crustal lithologies are not always well known and we turn to seismic imaging for help. We interrogate the SCEC Community Velocity Model (CVM) to determine averages and variances of Vp, Vs and Vp/Vs versus depth within each HFR. We bound (A, k) versus depth by relying on empirical relations between seismic wave speed and rock type and laboratory and modeling methods relating (A, k) to rock type. Many 1D conductive geotherms for each HFR are allowed by the variances in surface heat flow and subsurface (A, k). An additional constraint on the lithosphere temperature field is provided by comparing lithosphere-asthenosphere boundary (LAB) depths identified seismologically with those defined thermally as the depth of onset of partial melting. Receiver function studies in Southern California indicate LAB depths that range from 40 km to 90 km. Shallow LAB depths are correlated with high surface heat flow and deep LAB with low heat flow. The much-restricted families of geotherms that intersect peridotite

  20. Glacier Mass Changes of Lake-Terminating Grey and Tyndall Glaciers at the Southern Patagonia Icefield Derived From Geodetic Observations and Energy and Mass Balance Modeling

    Directory of Open Access Journals (Sweden)

    Stephanie S. Weidemann

    2018-06-01

    Full Text Available In this study we demonstrate how energy and mass fluxes vary in space and time for Grey and Tyndall glaciers at the Southern Patagonia Icefield (SPI. Despite the overall glacier retreat of most Patagonian glaciers, a recent increase in mass loss has been observed, but individual glaciers respond differently in terms of spatial and temporal changes. In this context, the detailed investigation of the effect of mass balance processes on recent glacier response to climate forcing still needs refinement. We therefore quantify surface energy-fluxes and climatic mass balance of the two neighboring glaciers, Grey and Tyndall. The COupled Snow and Ice energy and MAss balance model COSIMA is applied to assess recent surface energy and climatic mass balance variability with a high temporal and spatial resolution for a 16-year period between April 2000 and March 2016. The model is driven by downscaled 6-hourly atmospheric data derived from ERA-Interim reanalysis and MODIS/Terra Snow Cover and validated against ablation measurements made in single years. High resolution precipitation fields are determined by using an analytical orographic precipitation model. Frontal ablation is estimated as residual of climatic mass balance and geodetic mass balance derived from TanDEM-X/SRTM between 2000 and 2014. We simulate a positive glacier-wide mean annual climatic mass balance of +1.02 ± 0.52 m w.e. a−1 for Grey Glacier and of +0.68 ± 0.54 m w.e. a−1 for Tyndall Glacier between 2000 and 2014. Climatic mass balance results show a high year to year variability. Comparing climatic mass balance results with previous studies underlines the high uncertainty in climatic mass balance modeling with respect to accumulation on the SPI. Due to the lack of observations accumulation estimates differ from previous studies based on the methodological approaches. Mean annual ice loss by frontal ablation is estimated to be 2.07 ± 0.70 m w.e. a−1 for Grey Glacier and 3.26 ± 0

  1. Arsenic in Water Resources of the Southern Pampa Plains, Argentina

    Directory of Open Access Journals (Sweden)

    Juan D. Paoloni

    2009-01-01

    Full Text Available Confronted with the need for accessible sources of good quality water and in view of the fact that the threat to public health posed by arsenic occurs mainly through the ingestion of contaminated drinking water, the presence and distribution of arsenic was evaluated in the southern Pampa Plains of Bahía Blanca district in Argentina. The findings show variable concentrations of arsenic in a complex distribution pattern. Complementary information is provided on the behavior of the groundwater resource and its salinity in terms of dissolved ions. Groundwater is the most severely affected, 97% of the samples exceeding the guideline value for arsenic in drinking water as recommended by the WHO (Guidelines for Drinking Water Quality, 2004. and showing maximum concentrations of up to 0.30 mg/L. Informing those responsible for preventive medicine and alerting the community at large will facilitate measures to mitigate exposure and ensure the safety of drinking water.

  2. Arsenic in Water Resources of the Southern Pampa Plains, Argentina

    Science.gov (United States)

    Paoloni, Juan D.; Sequeira, Mario E.; Espósito, Martín E.; Fiorentino, Carmen E.; Blanco, María del C.

    2009-01-01

    Confronted with the need for accessible sources of good quality water and in view of the fact that the threat to public health posed by arsenic occurs mainly through the ingestion of contaminated drinking water, the presence and distribution of arsenic was evaluated in the southern Pampa Plains of Bahía Blanca district in Argentina. The findings show variable concentrations of arsenic in a complex distribution pattern. Complementary information is provided on the behavior of the groundwater resource and its salinity in terms of dissolved ions. Groundwater is the most severely affected, 97% of the samples exceeding the guideline value for arsenic in drinking water as recommended by the WHO (Guidelines for Drinking Water Quality, 2004). and showing maximum concentrations of up to 0.30 mg/L. Informing those responsible for preventive medicine and alerting the community at large will facilitate measures to mitigate exposure and ensure the safety of drinking water. PMID:19936127

  3. Arsenic in Water Resources of the Southern Pampa Plains, Argentina

    International Nuclear Information System (INIS)

    Paoloni, J.D.; Sequeira, M.E.; Esposito, M.E.; Fiorentino, C.E.; Blanco, M.D.C.

    2010-01-01

    Confronted with the need for accessible sources of good quality water and in view of the fact that the threat to public health posed by arsenic occurs mainly through the ingestion of contaminated drinking water, the presence and distribution of arsenic was evaluated in the southern Pampa Plains of Bahia Blanca district in Argentina. The findings show variable concentrations of arsenic in a complex distribution pattern. Complementary information is provided on the behavior of the groundwater resource and its salinity in terms of dissolved ions. Groundwater is the most severely affected, 97% of the samples exceeding the guideline value for arsenic in drinking water as recommended by the Who (Guidelines for Drinking Water Quality, 2004). and showing maximum concentrations of up to 0.30 mg/L. Informing those responsible for preventive medicine and alerting the community at large will facilitate measures to mitigate exposure and ensure the safety of drinking water.

  4. Indirect taxes on food in Southern Brazil

    Directory of Open Access Journals (Sweden)

    Denize Mirian da Silva

    2013-12-01

    Full Text Available The objective of this paper is to estimate the indirect tax burden on food for ten income classes, based on income and household total expenditure in southern Brazil. Thus it can be seen as indirect taxes on foods affect the monetary income and consumption pattern of households. To reach the objectives proposed, will be used the Pintos-Payeras (2008 model. The database iscomposed by microdata from the Household Budgeting Survey (POF 2008-2009 and the tax regulations of the country and the southern states of Brazil. The results show that indirect taxes on food in Southern Brazil is regressive when based on income and expenditure of household , ie , the poorest people pay proportionately more taxes and have their consumption pattern highest taxed ICMS (Brazilian value added tax is the tax that contributes most to the regressivity.

  5. The genetic prehistory of southern Africa.

    Science.gov (United States)

    Pickrell, Joseph K; Patterson, Nick; Barbieri, Chiara; Berthold, Falko; Gerlach, Linda; Güldemann, Tom; Kure, Blesswell; Mpoloka, Sununguko Wata; Nakagawa, Hirosi; Naumann, Christfried; Lipson, Mark; Loh, Po-Ru; Lachance, Joseph; Mountain, Joanna; Bustamante, Carlos D; Berger, Bonnie; Tishkoff, Sarah A; Henn, Brenna M; Stoneking, Mark; Reich, David; Pakendorf, Brigitte

    2012-01-01

    Southern and eastern African populations that speak non-Bantu languages with click consonants are known to harbour some of the most ancient genetic lineages in humans, but their relationships are poorly understood. Here, we report data from 23 populations analysed at over half a million single-nucleotide polymorphisms, using a genome-wide array designed for studying human history. The southern African Khoisan fall into two genetic groups, loosely corresponding to the northwestern and southeastern Kalahari, which we show separated within the last 30,000 years. We find that all individuals derive at least a few percent of their genomes from admixture with non-Khoisan populations that began ∼1,200 years ago. In addition, the East African Hadza and Sandawe derive a fraction of their ancestry from admixture with a population related to the Khoisan, supporting the hypothesis of an ancient link between southern and eastern Africa.

  6. The Southern Alberta Information Resources (SAIR Project

    Directory of Open Access Journals (Sweden)

    Kathy Crewdson

    2008-06-01

    Full Text Available Abstract Southern Alberta Information Resources (SAIR is a collaborative bibliography of published resources significant to southern Alberta. Objectives and progress with evolving methodology, technology, issues and challenges are explored within the context of the library field. We investigate a collaborative digital library that allows librarians and non-librarians alike to share information on specific topics through MARC records. An outcome of a collaborative digital library is how to create and sustain interest within the library community. Southern Alberta region was selected based on the authors’ familiarity with the region. Some issues and questions remain to be resolved. Digital formats present a number of challenges in terms of selection and presentation. Legal issues relating to technology such as linking and location information have emerged. Basic technical issues remain, such as, how best to update links.

  7. Assessment of ozone impacts on vegetation in southern Africa and directions for future research

    CSIR Research Space (South Africa)

    Van Tienhoven, AM

    2005-03-01

    Full Text Available in the high ozone levels measured at the beginning of the southern African summer.17,23,24 The concentrations of ozone precursors, the complex production and removal pro- cesses, and the short lifespan of ozone, mean that ozone concentration in the atmosphere... jointoformextensiveareasofchlorosisas the leaf ages. Damage to foliage can be extensive enough to cause complete loss ofleafycropssuchaslettuceandchicory.39 Visible symptoms of ozone effects must be interpreted with caution, particularly in field studies where interactions...

  8. Fire Ants (Solenopsis spp.) and Their Natural Enemies in Southern South America

    OpenAIRE

    Briano, Juan; Calcaterra, Luis; Varone, Laura

    2012-01-01

    We review the fire ant research conducted by the ARS-South American Biological Control Laboratory (SABCL) since 1987 to find a complex of natural enemies in southern South America and evaluate their specificity and suitability for field release as self-sustaining biological control agents. We also include those studies conducted by the ARS-Center for Medical, Agriculture, and Veterinary Entomology in the United States with the SABCL collaboration. Ecological and biological information is repo...

  9. A conspicuous globule in the Southern Coalsack

    International Nuclear Information System (INIS)

    Bok, B.J.; Sim, M.E.; Hawarden, T.G.

    1977-01-01

    It is stated that the Southern Coalsack is the finest dark nebula in the Southern Milky Way. Two photographs are here shown taken in October 1976 with the SRC 1.2 m Schmidt telescope at the Siding Spring Observatory, Australia. These show the whole of the Coalsack in all its beauty, and its features are discussed. It is shown how much can be learned by simple star counting techniques. A large number of potential globules are indicated, some of which are described. (U.K.)

  10. New Moho map of southern Norway

    DEFF Research Database (Denmark)

    Stratford, Wanda Rose; Thybo, Hans; Faleide, J.-I.

    2009-01-01

    A recent seismic refraction study across southern Norway has revealed that the up to 2469 m high Southern Scandes Mountains are not isostatically compensated by a thick crust. Rather, the Moho depths are close to average for continental crust with elevations of ~1 km. Evidence from new seismic data......, low densities in the upper-mantle or mantle dynamics, is likely. The relationship between topography and Moho depth breaks down for the Oslo Graben and the Fennoscandian Shield to the east and north. High density lower crustal rocks below Oslo Graben and increasing crust and lithospheric thicknesses...

  11. Natural road construction materials of Southern Africa

    CSIR Research Space (South Africa)

    Weinert, HH

    1980-01-01

    Full Text Available respectively. p. 210. column 4: Insert Notre in rect311glc directly below heading Matrix. p. 240, paragraph 5, line 4: J 770 should read I 700. I ~I -~ r THE NATURAL ROAD CONSTRUCTION MATERIALS OF SOUTHERN AFRICA ACADEMICA I PRETORIA ICAPE TOWN ISBN... and the author acknowledges gratefully the valuable assistance and the trouble taken by the following persons: Southern African road authorities: Mr W. J. Biesenbach, Mr H. K. Geel, Mr C. L. Laubscher, Mr G. P. Marais, Mr R. L. Mitchell, Mr I. P. A. Smit, Mr C...

  12. The Southern Kalahari: a potential new dust source in the Southern Hemisphere?

    International Nuclear Information System (INIS)

    Bhattachan, Abinash; D’Odorico, Paolo; Baddock, Matthew C; Zobeck, Ted M; Okin, Gregory S; Cassar, Nicolas

    2012-01-01

    Most sources of atmospheric dust on Earth are located in the Northern Hemisphere. The lower dust emissions in the Southern Hemisphere in part limit the supply of micronutrients (primarily soluble iron) to the Southern Ocean, thereby constraining its productivity. Climate and land use change can alter the current distribution of dust source regions on Earth. Can new dust sources be activated in the Southern Hemisphere? Here we show that vegetation loss and dune remobilization in the Southern Kalahari can promote dust emissions comparable to those observed from major contemporary dust sources in the Southern African region. Dust generation experiments support the hypothesis that, in the Southern Kalahari, aeolian deposits that are currently mostly stabilized by savanna vegetation are capable of emitting substantial amounts of dust from interdune areas. We show that dust from these areas is relatively rich in soluble iron, an important micronutrient for ocean productivity. Trajectory analyses show that dust from the Kalahari commonly reaches the Southern Ocean and could therefore enhance its productivity. (letter)

  13. Characterization of southern yellow pine bark layers by Attenuated Total Reflectance (ATR) and Fourier Transform Infrared (FT-IR) Spectroscopy

    Science.gov (United States)

    Thomas L. Eberhardt

    2009-01-01

    The outer bark (rhytidome) of the southern yellow pines is a complex structure comprised of alternating layers of obliterated phloem and periderm tissues, with the latter comprised of three layers, those being phellem, phellogen, and phelloderm. An attenuated total reflectance (ATR) sampling accessory, coupled with a Fourier transform infrared (FTIR) spectrometer,...

  14. Consistency of cruise data of the CARINA database in the Atlantic sector of the Southern Ocean

    Directory of Open Access Journals (Sweden)

    M. Hoppema

    2009-12-01

    Full Text Available Initially a North Atlantic project, the CARINA carbon synthesis was extended to include the Southern Ocean. Carbon and relevant hydrographic and geochemical ancillary data from cruises all across the Arctic Mediterranean Seas, Atlantic and Southern Ocean were released to the public and merged into a new database as part of the CARINA synthesis effort. Of a total of 188 cruises, 37 cruises are part of the Southern Ocean, including 11 from the Atlantic sector. The variables from all Southern Ocean cruises, including dissolved inorganic carbon (TCO2, total alkalinity, oxygen, nitrate, phosphate and silicate, were examined for cruise-to-cruise consistency in one collective effort. Seawater pH and chlorofluorocarbons (CFCs are also part of the database, but the pH quality control (QC is described in another Earth System Science Data publication, while the complexity of the Southern Ocean physics and biogeochemistry prevented a proper QC analysis of the CFCs. The area-specific procedures of quality control, including crossover analysis between stations and inversion analysis of all crossover data (i.e. secondary QC, are briefly described here for the Atlantic sector of the Southern Ocean. Data from an existing, quality controlled database (GLODAP were used as a reference for our computations – however, the reference data were included into the analysis without applying the recommended GLODAP adjustments so the corrections could be independently verified. The outcome of this effort is an internally consistent, high-quality carbon data set for all cruises, including the reference cruises. The suggested corrections by the inversion analysis were allowed to vary within a fixed envelope, thus accounting for natural variability. The percentage of cruises adjusted ranged from 31% (for nitrate to 54% (for phosphate depending on the variable.

  15. Southern Fireworks above ESO Telescopes

    Science.gov (United States)

    1999-05-01

    New Insights from Observations of Mysterious Gamma-Ray Burst International teams of astronomers are now busy working on new and exciting data obtained during the last week with telescopes at the European Southern Observatory (ESO). Their object of study is the remnant of a mysterious cosmic explosion far out in space, first detected as a gigantic outburst of gamma rays on May 10. Gamma-Ray Bursters (GRBs) are brief flashes of very energetic radiation - they represent by far the most powerful type of explosion known in the Universe and their afterglow in optical light can be 10 million times brighter than the brightest supernovae [1]. The May 10 event ranks among the brightest one hundred of the over 2500 GRB's detected in the last decade. The new observations include detailed images and spectra from the VLT 8.2-m ANTU (UT1) telescope at Paranal, obtained at short notice during a special Target of Opportunity programme. This happened just over one month after that powerful telescope entered into regular service and demonstrates its great potential for exciting science. In particular, in an observational first, the VLT measured linear polarization of the light from the optical counterpart, indicating for the first time that synchrotron radiation is involved . It also determined a staggering distance of more than 7,000 million light-years to this GRB . The astronomers are optimistic that the extensive observations will help them to better understand the true nature of such a dramatic event and thus to bring them nearer to the solution of one of the greatest riddles of modern astrophysics. A prime example of international collaboration The present story is about important new results at the front-line of current research. At the same time, it is also a fine illustration of a successful collaboration among several international teams of astronomers and the very effective way modern science functions. It began on May 10, at 08:49 hrs Universal Time (UT), when the Burst

  16. Current Writing: Text and Reception in Southern Africa: Advanced ...

    African Journals Online (AJOL)

    Current Writing: Text and Reception in Southern Africa: Advanced Search. Journal Home > Current Writing: Text and Reception in Southern Africa: Advanced Search. Log in or Register to get access to full text downloads.

  17. Southern Africa Journal of Education, Science and Technology ...

    African Journals Online (AJOL)

    Southern Africa Journal of Education, Science and Technology: Journal Sponsorship. Journal Home > About the Journal > Southern Africa Journal of Education, Science and Technology: Journal Sponsorship. Log in or Register to get access to full text downloads.

  18. Southern Africa Journal of Education, Science and Technology: Site ...

    African Journals Online (AJOL)

    Southern Africa Journal of Education, Science and Technology: Site Map. Journal Home > About the Journal > Southern Africa Journal of Education, Science and Technology: Site Map. Log in or Register to get access to full text downloads.

  19. Prevalence of Risk Factors for Coronary Artery Disease in Southern ...

    African Journals Online (AJOL)

    CAD) in Southern Punjab, Pakistan. Methods: A cross-sectional survey was conducted for the prevalence of risk factors for CAD among 200 patients admitted at the different hospitals of Southern Punjab, Pakistan from December 2012 to April ...

  20. Climate and southern Africa's water-energy-food nexus

    CSIR Research Space (South Africa)

    Conway, D

    2015-09-01

    Full Text Available be strengthened for this purpose: the Southern African Development Community, the Southern African Power Pool and trade of agricultural products amounting to significant transfers of embedded water....

  1. 78 FR 34151 - Notice of Public Hearing: Norfolk Southern Corporation

    Science.gov (United States)

    2013-06-06

    ... DEPARTMENT OF TRANSPORTATION Federal Railroad Administration [Docket Number FRA-2012-0087] Notice of Public Hearing: Norfolk Southern Corporation The Norfolk Southern Corporation (NS) petitioned the Federal Railroad Administration (FRA) seeking the approval of the proposed discontinuance of automatic...

  2. Comparing internal and external drivers in the southern Benguela ...

    African Journals Online (AJOL)

    Comparing internal and external drivers in the southern Benguela and the southern and ... during the model fitting: internal forcing by means of the trophic flow controls ... and two kinds of external forcing, namely fishing and the environment.

  3. The lithospheric mantle below southern West Greenland

    DEFF Research Database (Denmark)

    Sand, Karina Krarup; Waight, Tod Earle; Pearson, D. Graham

    2009-01-01

    Geothermobarometry of primarily garnet lherzolitic xenoliths from several localities in southern West Greenland is applied to address the diamond potential, pressure and temperature distribution and the stratigraphy of the subcontinental lithospheric mantle ~600 Ma ago. The samples are from kimbe...... into the reworked Archean North of the Naqssugtoqidian deformation front....

  4. Sequence crystallization during isotherm evaporation of southern ...

    African Journals Online (AJOL)

    Southern Algerian's natural brine sampled from chott Baghdad may be a source of mineral salts with a high economic value. These salts are recoverable by simple solar evaporation. Indeed, during isothermal solar evaporation, it is possible to recover mineral salts and to determine the precipitation sequences of different ...

  5. Optical observations of southern planetary nebula candidates

    NARCIS (Netherlands)

    VandeSteene, GC; Sahu, KC; Pottasch, [No Value

    1996-01-01

    We present H alpha+[NII] images and low resolution spectra of 16 IRAS-selected, southern planetary nebula candidates previously detected in the radio continuum. The H alpha+[NII] images are presented as finding charts. Contour plots are shown for the resolved planetary nebulae. From these images

  6. First Hemolivia from southern Africa: reassigning chelonian ...

    African Journals Online (AJOL)

    To date, only a single species of Hemolivia, Hemolivia mauritanica (Sergent & Sergent, 1904), has been described from African terrestrial tortoises. Although various haemogregarines have been described from southern African terrapins and tortoises, including species from the genus Haemogregarina and one from the ...

  7. Southern Europeans in France: Invisible Migrants?

    NARCIS (Netherlands)

    Eremenko, T.; El Qadim, N.; Steichen, E.; Lafleur, J.-M.; Stanek, M.

    2016-01-01

    France fared relatively well at the start of the current economic crisis, but has experienced low economic growth and high unemployment rates in the recent years. As a result it has been a less popular destination with Southern Europeans and EU migrants in general in search of economic

  8. On some birds from southern Mexico

    NARCIS (Netherlands)

    Mees, G.F.

    1970-01-01

    In the years 1962/64 our museum purchased from Mr. Otto Epping, now of Pittsburgh, U.S.A., a collection of 700 bird-specimens from southern Mexico (mainly from Vera Cruz and Oaxaca, a few specimens from Puebla). As our museum was poorly provided with material from Mexico, this was a very welcome

  9. Structural Change in Southern Softwood Stumpage Markets

    Science.gov (United States)

    Douglas R. Carter

    1998-01-01

    The potential for structural change in southern stumpage market models has impacts on not only our basic understanding of those markets, but also on harvest, inventory and price projections, and related policy. In this paper, we test for structural change in both sawtimber and pulpwood softwood stumpage markets in the U.S. South over the period 1950-1994. Test...

  10. Invasive species in southern Nevada [Chapter 4

    Science.gov (United States)

    Mathew L. Brooks; Steven M. Ostoja; Jeanne C. Chambers

    2013-01-01

    Southern Nevada contains a wide range of topographies, elevations, and climatic zones emblematic of its position at the ecotone between the Mojave Desert, Great Basin, and Colorado Plateau ecoregions. These varied environmental conditions support a high degree of biological diversity (Chapter 1), but they also provide opportunities for a wide range of invasive species...

  11. Southern Forest Resource Assessment - Summary Report

    Science.gov (United States)

    David N. Wear; John G. Greis

    2002-01-01

    The Southern Forest Resource Assessment was initiated in 1999 as a result of concerns raised by natural resource managers, the science community, and the public regarding the status and likely future of forests in the South. These included changes to the region’s forests brought about by rapid urbanization, increasing timber demand, increasing numbers of...

  12. Economic Impacts of the Southern Pine Beetle

    Science.gov (United States)

    John M. Pye; Thomas P. Holmes; Jeffrey P. Prestemon; David N. Wear

    2011-01-01

    This paper provides an overview of the timber economic impacts of the southern pine beetle (SPB). Although we anticipate that SPB outbreaks cause substantial economic losses to households that consume the nonmarket economic services provided by healthy forests, we have narrowly focused our attention here on changes in values to timber growers and wood-products...

  13. Gold deposits of the southern Piedmont

    Science.gov (United States)

    Pardee, J.T.; Park, C.F.

    1948-01-01

    This report deals chiefly with the gold mines in the Southern Appalachian gold belt whose workings were accessible at the time of examination, but it also · summarizes available information concerning many mines that were not accessible. Most of the mines lie within a belt, 10 to 100 miles wide, that extends

  14. Assessing estuarine biota in southern California

    Science.gov (United States)

    Kevin D. Lafferty

    2005-01-01

    In southern California, most estuarine wetlands are gone, and what little habitat remains is degraded. For this reason, it is often of interest to assess the condition of estuaries over time, such as when determining the success of a restoration project. To identify impacts or opportunities for restoration, we also may want to know how a particular estuary, or area...

  15. Marketing University Education: The Southern African Experience.

    Science.gov (United States)

    Maringe, Felix; Foskett, Nick

    2002-01-01

    Examined the perceptions of university marketers in southern Africa. Found a varying awareness of the significance of marketing, with more mature institutions exhibiting more developed marketing orientations. Strategies ranged from marketing as public relations to marketing as sales, with universities in South Africa the only ones demonstrating a…

  16. Soyabeans and sustainable agriculture in southern Africa

    NARCIS (Netherlands)

    Giller, K.E.; Murwira, M.S.; Dhliwayo, D.K.C.; Mafongoya, P.L.; Mpepereki, S.

    2011-01-01

    Maize is the dominant staple crop across most of southern Africa - it is so dominant in some areas that more than 80 per cent of the smallholder land area is planted with maize. Soyabean was identified as the crop with a potential to address the need for diversifying the cropping systems, which

  17. Field guide to trees of Southern Africa

    OpenAIRE

    Rishan Singh

    2012-01-01

    The mainland region of Africa is Southern Africa because it is considered to be robust with an estimate of around 1700 tree species that are native and a couple 100 more that are alien, but have become accustomed to the natural environment; invading, penetrating and replacing vegetation.

  18. Zoogeography of the southern African echinoderm fauna

    African Journals Online (AJOL)

    1988-04-17

    Apr 17, 1988 ... Pertinent features of the oceanography of southern Africa are reviewed and an analysis of the echinoderm fauna in relation to the genera] ..... five extant echinoderm classes (all species). Crinoids. Asteroids Ophiuroids .... Australia and New Zealand, which are included with. R eprod u ced by Sabin et G.

  19. Southern forests: Yesterday, today, and tomorrow

    Science.gov (United States)

    R. Neil Sampson

    2004-01-01

    In the 20th century, southern forests changed dramatically. Those changes pale, however, when compared to what happened to the people of the region. In addition to growing over fourfold in numbers, the South's population has urbanized, globalized, and intellectualized in 100 years. Rural and isolated in the 19th century, they are today urban and cosmopolitan. One...

  20. Rabies vaccine and neuraxial anaesthesia | Rewari | Southern ...

    African Journals Online (AJOL)

    Southern African Journal of Anaesthesia and Analgesia. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 16, No 5 (2010) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file. The PDF ...

  1. Towards a Southern African English Defining Vocabulary

    African Journals Online (AJOL)

    user

    of parameters, such as avoiding synonyms and antonyms, to determine which words are necessary to write definitions in a concise and simple way. It has been found that existing defining vocabularies lack certain words that would make definitions more accessible to southern African learners, and therefore there is a need ...

  2. Risk Assessment for the Southern Pine Beetle

    Science.gov (United States)

    Andrew Birt

    2011-01-01

    The southern pine beetle (SPB) causes significant damage (tree mortality) to pine forests. Although this tree mortality has characteristic temporal and spatial patterns, the precise location and timing of damage is to some extent unpredictable. Consequently, although forest managers are able to identify stands that are predisposed to SPB damage, they are unable to...

  3. A MEAT PRODUCTION STRATEGYFOR SOUTHERN AFRICA

    African Journals Online (AJOL)

    the task of formulating a rneat prclduction strategy fclr. Southern Africa .... Ch ickcn. '55. '5? '59. '61. 6l. '65. '61. '69. '71. '7-f is. "47. Fig. I Edible protein deived from various animal products ...... of the effort and finance expended on the original.

  4. Globalisation, transport and HIV | Andrews | Southern African ...

    African Journals Online (AJOL)

    No Abstract Southern African Journal of HIV Medicine Vol. 5 (4) 2004: 41-44. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL ...

  5. Globalisation, transport and HIV | Andrews | Southern African ...

    African Journals Online (AJOL)

    Southern African Journal of HIV Medicine. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 5, No 4 (2004) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file. The PDF file you selected ...

  6. Southern Nevada ecosystem stressors [Chapter 2

    Science.gov (United States)

    Burton K. Pendleton; Jeanne C. Chambers; Mathew L. Brooks; Steven M. Ostoja

    2013-01-01

    Southern Nevada ecosystems and their associated resources are subject to a number of global and regional/local stressors that are affecting the sustainability of the region. Global stressors include elevated carbon dioxide (CO2) concentrations and associated changes in temperature and precipitation patterns and amounts, solar radiation, and nutrient cycles (Smith and...

  7. Anatomical characteristics of southern pine stemwood

    Science.gov (United States)

    Elaine T. Howard; Floyd G. Manwiller

    1968-01-01

    To obtain a definitive description of the wood and anatomy of all 10 species of southern pine, juvenile, intermediate, and mature wood was sampled at three heights in one tree of each species and examined under a light microscope. Photographs and three-dimensional drawings were made to illustrate the morphology. No significant anatomical differences were found...

  8. Home garden system dynamics in Southern Ethiopia

    NARCIS (Netherlands)

    Mellisse, Beyene Teklu; Ven, van de Gerrie W.J.; Giller, Ken E.; Descheemaeker, Katrien

    2017-01-01

    Home gardens in southern Ethiopia are regarded as efficient farming systems, allowing interactions and synergies between crop, tree and livestock components. However, these age-old traditional home gardens are evolving rapidly in response to changes in both the socio-economic and biophysical

  9. Radio broadcasting for sustainable development in southern ...

    African Journals Online (AJOL)

    Patrick O. Waeber and Yvonne Orengo

    2008-12-01

    Dec 1, 2008 ... ABSTRACT. The Millennium Development Goals have been written into the Madagascar Road Map (2007 - 2012) in order to improve the Malagasy social, economic and environmental situation. The Andrew Lees Trust Radio Broadcasting Project in southern. Madagascar has been set up to alleviate ...

  10. Resource reviews | Naude | Southern African Journal of ...

    African Journals Online (AJOL)

    Petro Naude. Walk through the wilderness by Don Richards and Clive. Walker. Published by Endangered Wildlife Trust and Wilderness Trust of Southern Africa, Johannesburg. Second (revised) edition 1986. 146 pp., photographs, maps, charts and line drawings. Price R9,95. 2. Pat Irwin. Trout in South Africa edited by P.H. ...

  11. PLANT DERMATITIS IN THE SOUTHERN TRANSVAAL*

    African Journals Online (AJOL)

    le bush stinging-nettle may be encountered in bush ps in Southern Transvaal veld. vo patients with seasonal rashes of the face suggestive lant dermatitis were seen in this series, but no definite es were found. MANAGEMENT. ~rential Diagnosis mditions seen in the survey period which could be used with plant dermatitis ...

  12. Faulkner's Southern belle - myth or reality?

    Directory of Open Access Journals (Sweden)

    Nataša Intihar Klančar

    2011-12-01

    Full Text Available The article deals with heroines of William Faulkner's novels Light in August, Absalom, Absalom!, The Sound and the Fury, The Unvanquished, The Town and his short story "A Rose for Emily". The Southern belle features as a recurring character in Faulkner's fiction, her fragility, modesty, weakness yet strength, beauty, sincerity, generous nature, status and her fall from innocence comprise her central characteristics. Confronted with various expectations of Southern society and with the hardships of war, the belle is faced with many obstacles and challenges. Faulkner's heroines face a wide array of problems that prevent them from being and/or remaining a Southern belle. Let us name a few: Lena's inappropriate social status, Joanna's wrong roots, Mrs. Hightower's inability to fulfill her duties as the minister's wife, Ellen's miserable marriage, Judith's sad love life, Rosa's feelings of inferiority and humiliation, Mrs. Compson's failure as a mother, Caddy's weak rebellion against male convention, Drusilla's male characteristics, Linda's unrequited love and Emily's dark secret, to name a few. Through these characters and their destinies Faulkner shows a decaying South whose position has changed considerably over the years. Can the Southern belle save it? Can she save herself?

  13. Review of Southern African Studies: Submissions

    African Journals Online (AJOL)

    Author Guidelines. 1. Every manuscript should be accompanied with a statement that it has not been submitted for publication elsewhere. 2. The Review of Southern African Studies prefers articles which cut across disciplinary boundaries. Articles with narrow foci and incomprehensible to people outside those disciplines ...

  14. Review of Southern African Studies: Editorial Policies

    African Journals Online (AJOL)

    Editorial Board. Prof. R.C. Leduka Institute of Southern African Studies, NUL. Dr. F. Baffoe Baffoe and Associates, Maseru. Prof. Q. Chakela National University of Lesotho. Prof. L.B.B.J. Machobane Machobane and Associates, Maseru. Prof. E.M. Sebatane National University of Lesotho. Dr. E. Obioha National University of ...

  15. Las cuencas cenozoicas y su control en el volcanismo de los Complejos Nevados de Chillan y Copahue-Callaqui (Andes del Sur, 36-39°S Cenozoic basins and their control on volcanism of Nevados de Chillan and Copahue-Callaqui complexes (36-39°S, Southern Andes

    Directory of Open Access Journals (Sweden)

    Juan Pablo Radic

    2010-01-01

    previous extensional faults and sedimentary fill. The accommodation zones prevailed as first order structures and acted as weakened zones that enabled the volcanism and magmatism at the Nevados de Chillan and Copahue-Callaqui volcanic complexes. Each one of these volcanic complexes is characterized by an oriented series of emission centers, volcanic morphology and deposits that are subparallel to the underlying accommodation zone.

  16. Complex analysis and geometry

    CERN Document Server

    Silva, Alessandro

    1993-01-01

    The papers in this wide-ranging collection report on the results of investigations from a number of linked disciplines, including complex algebraic geometry, complex analytic geometry of manifolds and spaces, and complex differential geometry.

  17. Complex Systems: An Introduction

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 9. Complex Systems: An Introduction - Anthropic Principle, Terrestrial Complexity, Complex Materials. V K Wadhawan. General Article Volume 14 Issue 9 September 2009 pp 894-906 ...

  18. Early German Plans for a Southern Observatory

    Science.gov (United States)

    Wolfschmidt, Gudrun

    As early as the 18th and 19th centuries, French and English observers were active in South Africa. Around the beginning of the 20th century the Heidelberg astronomer Max Wolf (1863-1932) proposed a southern observatory. In 1907 Hermann Carl Vogel (1841-1907), director of the Astrophysical Observatory Potsdam, suggested a southern station in Spain. His ideas for building an observatory in Windhuk for photographing the sky and measuring the solar constant were taken over by the Göttingen astronomers. In 1910 Karl Schwarzschild (1873-1916), after having visited the observatories in America, pointed out the usefulness of an observatory in South West Africa, where it would have better weather than in Germany and also give access to the southern sky. Seeing tests were begun in 1910 by Potsdam astronomers, but WW I stopped the plans. In 1928 Erwin Finlay-Freundlich (1885-1964), inspired by the Hamburg astronomer Walter Baade (1893-1960), worked out a detailed plan for a southern observatory with a reflecting telescope, spectrographs and an astrograph with an objective prism. Paul Guthnick (1879-1947), director of the Berlin observatory, in cooperation with APO Potsdam and Hamburg, made a site survey to Africa in 1929 and found the conditions in Windhuk to be ideal. Observations were started in the 1930s by Berlin and Breslau astronomers, but were stopped by WW II. In the 1950s, astronomers from Hamburg and The Netherlands renewed the discussion in the framework of European cooperation, and this led to the founding of ESO in 1963, as is well described by Blaauw (1991). Blaauw, Adriaan: ESO's Early History. The European Southern Observatory from Concept to Reality. Garching bei München: ESO 1991.

  19. Unravelling the magmatic system beneath a monogenetic volcanic complex (Jagged Rocks Complex, Hopi Buttes, AZ, USA)

    Science.gov (United States)

    Re, G.; Palin, J. M.; White, J. D. L.; Parolari, M.

    2017-12-01

    The Jagged Rocks complex is the eroded remnant of the plumbing systems of closely spaced monogenetic alkaline volcanic centres in the southern Hopi Buttes Volcanic Field (AZ, USA). It contains different clinopyroxene populations with distinctive textures and geochemical patterns. In the Northwestern part of the complex, which exposes the best developed system of conduits, most of the clinopyroxenes consist of large- to medium-sized resorbed cores overgrown by euhedral rims (type 1), small moderately resorbed greenish cores with the same overgrown rims (type 2), and phlogopite as an accessory phase. By contrast, in the Southern part of the complex the majority of clinopyroxenes are euhedral with oscillatory zonation (type 3) and are accompanied by minor euhedral olivine. The differences between these mineral assemblages indicate a composite history of crystallization and magmatic evolution for the two parts of the complex, governed by different mechanisms and ascent patterns from a single source at 50 km depth (16 kbar). The Northwest system preserves a high-pressure assemblage that cooled rapidly from near-liquidus conditions, suggesting direct ascent from the source to the surface at high-to-moderate transport rates (average 1.25 m/s). By contrast, the Southern system represents magma that advanced upward at much lower overall ascent rates, stalling at times to form small-volume mid-crustal storage zones (e.g., sills or a network of sheeted intrusions); this allowed the re-equilibration of the magma at lower pressure ( 30 km; 8 kbar), and led to nucleation and growth of euhedral clinopyroxene and olivine phenocrysts.

  20. Southern Forest Resource Assessment and Linkages to the National RPA

    Science.gov (United States)

    Fredrick Cubbage; Jacek Siry; Steverson Moffat; David N. Wear; Robert Abt

    1998-01-01

    We developed a Southern Forest Resource Assessment Consortium (SOFAC) in 1994, which is designed to enhance our capabilities to analyze and model the southern forest and timber resources. Southern growth and yield analyses prepared for the RPA via SOFAC indicate that substantial increases in timber productivity can occur given current technology. A survey about NIPF...

  1. Southern Voice State of the Sustainable Development Goals (SDGs ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    The Southern Voice on post-MDG International Development Goals (Southern ... conceived by the Southern Voice network that will generate and disseminate ... this project will help expand ownership of the SDGs in case study countries and ... think tanks as effective interlocutors between national capitals, regional hubs, ...

  2. Straight studs are produced from southern pine cordwood

    Science.gov (United States)

    Peter Koch

    1967-01-01

    A Process for converting southern pine veneer cores into 8-foot 2 by 4's of SPIB Stud grade and better has been developed at the Alexandria, Louisiana, Utilization Laboratory of the Southern Forest Experiment Station. The research leading to this development suggests that a similiar process would be practical for converting 8-foot southern pine cordwood into studs...

  3. Southern hardwood forestry group going strong after 50 years

    Science.gov (United States)

    Brian Roy Lockhart; Steve Meadows; Jeff Portwood

    2005-01-01

    On November 15,200 1, the Southern Hardwood Forestry Group (referred to as the Group) met at the U.S. Forest Service Southern Research Station's Southern Hardwoods Laboratory in Stoneville, hlississippi to celebrate the Group's 50th anniversary. About 130 members and guests attended to celebrate the 50th anniversary of the Group and to honor its charter...

  4. 77 FR 15994 - Southern Region Recreation Resource Advisory Committee

    Science.gov (United States)

    2012-03-19

    ... DEPARTMENT OF AGRICULTURE Forest Service Southern Region Recreation Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting via teleconference. SUMMARY: The Southern Region... and requests to Southern Region Recreation RAC, Caroline Mitchell, P.O. Box 1270, Hot Springs, AR...

  5. Comparisons of invasive plants in southern Africa originating from southern temperate, northern temperate and tropical regions

    Directory of Open Access Journals (Sweden)

    L. Henderson

    2006-08-01

    Full Text Available A subset of invasive alien plant species in southern Africa was analysed in terms of their history of introduction, rate of spread, countries/region of origin, taxonomy, growth forms, cultivated uses, weed status and current distribution in southern Africa, and comparisons made of those originating from south of the tropic of Capricorn, north of the tropic of Cancer and from the tropics. The subset of 233 species, belonging to 58 families, includes all important declared species and some potentially important species. Almost as many species originate from temperate regions (112 as from the tropics (121. Most southern temperate species came from Australia (28/36, most tropical species from tropical America (92/121 and most northern temperate species from Europe (including the Mediterranean and Asia (58/76. Transformers account for 33% of  all species. More transformers are of tropical origin (36 than of northern temperate (24 and southern temperate origin (18. However. 50% of southern temperate species are transformers, compared to 32% of northern temperate and 29% of tropical species. Southern temperate transformer species are mainly woody trees and shrubs that were established on a grand scale as silvicultural crops, barriers (hedges, windbreaks and screens and cover/binders. Most aquatics, herbs, climbers and succulent shrubs an. trom the tropics. Ornamentals are the single largest category of plants from all three regions, the tropics having contributed twice as many species as temperate regions.

  6. Support for the Confederate Battle Flag in the Southern United States: Racism or Southern Pride?

    Directory of Open Access Journals (Sweden)

    Joshua D. Wright

    2017-05-01

    Full Text Available Supporters of the Confederate battle flag often argue that their support is driven by pride in the South, not negative racial attitudes. Opponents of the Confederate battle flag often argue that the flag represents racism, and that support for the flag is an expression of racism and an attempt to maintain oppression of Blacks in the Southern United States. We evaluate these two competing views in explaining attitudes toward the Confederate battle flag in the Southern United States through a survey of 526 Southerners. In the aggregate, our latent variable model suggests that White support for the flag is driven by Southern pride, political conservatism, and blatant negative racial attitudes toward Blacks. Using cluster-analysis we were able to distinguish four distinct sub-groups of White Southerners: Cosmopolitans, New Southerners, Traditionalists, and Supremacists. The greatest support for the Confederate battle flag is seen among Traditionalists and Supremacists; however, Traditionalists do not display blatant negative racial attitudes toward Blacks, while Supremacists do. Traditionalists make up the majority of Confederate battle flag supporters in our sample, weakening the claim that supporters of the flag are generally being driven by negative racial attitudes toward Blacks.

  7. The Gulf of Aden Intermediate Water Intrusion Regulates the Southern Red Sea Summer Phytoplankton Blooms.

    Science.gov (United States)

    Dreano, Denis; Raitsos, Dionysios E; Gittings, John; Krokos, George; Hoteit, Ibrahim

    2016-01-01

    Knowledge on large-scale biological processes in the southern Red Sea is relatively limited, primarily due to the scarce in situ, and satellite-derived chlorophyll-a (Chl-a) datasets. During summer, adverse atmospheric conditions in the southern Red Sea (haze and clouds) have long severely limited the retrieval of satellite ocean colour observations. Recently, a new merged ocean colour product developed by the European Space Agency (ESA)-the Ocean Color Climate Change Initiative (OC-CCI)-has substantially improved the southern Red Sea coverage of Chl-a, allowing the discovery of unexpected intense summer blooms. Here we provide the first detailed description of their spatiotemporal distribution and report the mechanisms regulating them. During summer, the monsoon-driven wind reversal modifies the circulation dynamics at the Bab-el-Mandeb strait, leading to a subsurface influx of colder, fresher, nutrient-rich water from the Indian Ocean. Using satellite observations, model simulation outputs, and in situ datasets, we track the pathway of this intrusion into the extensive shallow areas and coral reef complexes along the basin's shores. We also provide statistical evidence that the subsurface intrusion plays a key role in the development of the southern Red Sea phytoplankton blooms.

  8. The Gulf of Aden Intermediate Water Intrusion Regulates the Southern Red Sea Summer Phytoplankton Blooms

    KAUST Repository

    Dreano, Denis; Raitsos, Dionysios E.; Gittings, John; Krokos, George; Hoteit, Ibrahim

    2017-01-01

    Knowledge on large-scale biological processes in the southern Red Sea is relatively limited, primarily due to the scarce in situ, and satellite-derived chlorophyll-a (Chl-a) datasets. During summer, adverse atmospheric conditions in the southern Red Sea (haze and clouds) have long severely limited the retrieval of satellite ocean colour observations. Recently, a new merged ocean colour product developed by the European Space Agency (ESA)-the Ocean Color Climate Change Initiative (OC-CCI)-has substantially improved the southern Red Sea coverage of Chl-a, allowing the discovery of unexpected intense summer blooms. Here we provide the first detailed description of their spatiotemporal distribution and report the mechanisms regulating them. During summer, the monsoon-driven wind reversal modifies the circulation dynamics at the Bab-el-Mandeb strait, leading to a subsurface influx of colder, fresher, nutrient-rich water from the Indian Ocean. Using satellite observations, model simulation outputs, and in situ datasets, we track the pathway of this intrusion into the extensive shallow areas and coral reef complexes along the basin's shores. We also provide statistical evidence that the subsurface intrusion plays a key role in the development of the southern Red Sea phytoplankton blooms.

  9. Genetic diversity of Dahongjun, the commercially important "Big Red Mushroom" from southern China.

    Directory of Open Access Journals (Sweden)

    Mochan Li

    Full Text Available BACKGROUND: In southern China, a wild ectomycorrhizal mushroom commonly called "Dahongjun" or "Big Red Mushroom" by the local residents, has been harvested, consumed, and/or exported as an exotic food for many years. Although ecologically and economically important, very little is known about this mushroom, including its diversity and population structure. METHODOLOGY AND PRINCIPAL FINDINGS: In this study, we analyzed 122 samples from five local populations representing the known distribution ranges of this mushroom in southern China. We investigated the genetic diversity and geographic structure of this mushroom using sequences from four DNA fragments. Our analyses identified that this mushroom contained at least three divergent lineages: one corresponds to a recently described species Russula griseocarnosa from southern China and the remaining two likely represent two novel species. While these lineages were prominently structured geographically based on ITS sequences, evidence for ancient and/or recent gene flow was also identified within individual lineages. In addition, a local population from Ailaoshan in central Yunnan Province where 85 of our 122 specimens came from showed clear evidence of recombination. CONCLUSION AND SIGNIFICANCE: The ectomycorrhizal mushroom "Dahongjun" from southern China is a species complex with at least three divergent lineages. These lineages are largely geographically structured and there is evidence for recombination in nature. Our results indicate mature Dahongjun mushrooms with abundant basidiospores are important for the reproduction of this mushroom in nature and that individual populations of this species should be managed separately.

  10. The Gulf of Aden Intermediate Water Intrusion Regulates the Southern Red Sea Summer Phytoplankton Blooms

    KAUST Repository

    Dreano, Denis

    2017-01-09

    Knowledge on large-scale biological processes in the southern Red Sea is relatively limited, primarily due to the scarce in situ, and satellite-derived chlorophyll-a (Chl-a) datasets. During summer, adverse atmospheric conditions in the southern Red Sea (haze and clouds) have long severely limited the retrieval of satellite ocean colour observations. Recently, a new merged ocean colour product developed by the European Space Agency (ESA)-the Ocean Color Climate Change Initiative (OC-CCI)-has substantially improved the southern Red Sea coverage of Chl-a, allowing the discovery of unexpected intense summer blooms. Here we provide the first detailed description of their spatiotemporal distribution and report the mechanisms regulating them. During summer, the monsoon-driven wind reversal modifies the circulation dynamics at the Bab-el-Mandeb strait, leading to a subsurface influx of colder, fresher, nutrient-rich water from the Indian Ocean. Using satellite observations, model simulation outputs, and in situ datasets, we track the pathway of this intrusion into the extensive shallow areas and coral reef complexes along the basin\\'s shores. We also provide statistical evidence that the subsurface intrusion plays a key role in the development of the southern Red Sea phytoplankton blooms.

  11. Shallow Carbon Export from an Iron fertilised Plankton Bloom in the Southern Ocean

    Science.gov (United States)

    Sanders, R.; Pollard, R.; Morris, P.; Statham, P.; Moore, C. M. M.; Lucas, M.

    2009-04-01

    Some regions of the global ocean, notably the Southern Ocean, have high levels of macronutrients yet low levels of chlorophyll (the high nutrient, low chlorophyll or HNLC condition). Numerous artificial iron fertilization experiments conducted in the Southern Ocean have resulted in enhanced phytoplankton biomass and macronutrient drawdown. However the subsequent long-term biogeochemical consequences of such iron fertilization are unclear due in part to the limited size and duration of such experiments. An alternative way to assess the affect of iron over the Southern Ocean biological carbon pump is to observe the evolution of plankton production in regions of the Southern Ocean where shallow topography and Ocean currents interact to promote to release terrestrial iron into HNLC waters. During 2004-5 RRS Discovery conduced a complex programme of observations in such a region around the Crozet Islands in the SW Indian Ocean. The results of this programme, focussing on a quantitative estimate of carbon export per unit iron addition, will be presented.

  12. 76 FR 35508 - Alabama Southern Railroad, L.L.C.-Temporary Trackage Rights Exemption-Norfolk Southern Railway...

    Science.gov (United States)

    2011-06-17

    ... Railroad, L.L.C.--Temporary Trackage Rights Exemption--Norfolk Southern Railway Company Norfolk Southern... grant nonexclusive overhead temporary trackage rights to Alabama Southern Railroad, L.L.C. (ABS) over a... http://www.stb.dot.gov . Decided: June 13, 2011. By the Board. Rachel D. Campbell, Director, Office of...

  13. The Southern Nevada Agency Partnership Science and Research Synthesis: Science to support land management in Southern Nevada

    Science.gov (United States)

    Jeanne C. Chambers; Matthew L. Brooks; Burton K. Pendleton; Carol B. Raish

    2013-01-01

    This synthesis provides information related to the Southern Nevada Agency Partnership (SNAP) Science and Research Strategy Goal 1 - to restore, sustain and enhance southern Nevada’s ecosystems - and Goal 2 - to provide for responsible use of southern Nevada’s lands in a manner that preserves heritage resources and promotes an understanding of human interaction with the...

  14. The Southern Nevada Agency Partnership Science and Research Synthesis: Science to support land management in Southern Nevada - Executive Summary

    Science.gov (United States)

    Jeanne C. Chambers; Matthew L. Brooks; Burton K. Pendleton; Carol B. Raish

    2013-01-01

    This synthesis provides information related to the Southern Nevada Agency Partnership (SNAP) Science and Research Strategy Goal 1 - to restore, sustain and enhance southern Nevada’s ecosystems - and Goal 2 - to provide for responsible use of southern Nevada’s lands in a manner that preserves heritage resources and promotes an understanding of human interaction with the...

  15. A tropospheric ozone maximum over the equatorial Southern Indian Ocean

    Directory of Open Access Journals (Sweden)

    L. Zhang

    2012-05-01

    Full Text Available We examine the distribution of tropical tropospheric ozone (O3 from the Microwave Limb Sounder (MLS and the Tropospheric Emission Spectrometer (TES by using a global three-dimensional model of tropospheric chemistry (GEOS-Chem. MLS and TES observations of tropospheric O3 during 2005 to 2009 reveal a distinct, persistent O3 maximum, both in mixing ratio and tropospheric column, in May over the Equatorial Southern Indian Ocean (ESIO. The maximum is most pronounced in 2006 and 2008 and less evident in the other three years. This feature is also consistent with the total column O3 observations from the Ozone Mapping Instrument (OMI and the Atmospheric Infrared Sounder (AIRS. Model results reproduce the observed May O3 maximum and the associated interannual variability. The origin of the maximum reflects a complex interplay of chemical and dynamic factors. The O3 maximum is dominated by the O3 production driven by lightning nitrogen oxides (NOx emissions, which accounts for 62% of the tropospheric column O3 in May 2006. We find the contribution from biomass burning, soil, anthropogenic and biogenic sources to the O3 maximum are rather small. The O3 productions in the lightning outflow from Central Africa and South America both peak in May and are directly responsible for the O3 maximum over the western ESIO. The lightning outflow from Equatorial Asia dominates over the eastern ESIO. The interannual variability of the O3 maximum is driven largely by the anomalous anti-cyclones over the southern Indian Ocean in May 2006 and 2008. The lightning outflow from Central Africa and South America is effectively entrained by the anti-cyclones followed by northward transport to the ESIO.

  16. Evidence of Incipient Forest Transition in Southern Mexico

    Science.gov (United States)

    Vaca, Raúl Abel; Golicher, Duncan John; Cayuela, Luis; Hewson, Jenny; Steininger, Marc

    2012-01-01

    Case studies of land use change have suggested that deforestation across Southern Mexico is accelerating. However, forest transition theory predicts that trajectories of change can be modified by economic factors, leading to spatial and temporal heterogeneity in rates of change that may take the form of the Environmental Kuznets Curve (EKC). This study aimed to assess the evidence regarding potential forest transition in Southern Mexico by classifying regional forest cover change using Landsat imagery from 1990 through to 2006. Patterns of forest cover change were found to be complex and non-linear. When rates of forest loss were averaged over 342 municipalities using mixed-effects modelling the results showed a significant (p<0.001) overall reduction of the mean rate of forest loss from 0.85% per year in the 1990–2000 period to 0.67% in the 2000–2006 period. The overall regional annual rate of deforestation has fallen from 0.33% to 0.28% from the 1990s to 2000s. A high proportion of the spatial variability in forest cover change cannot be explained statistically. However analysis using spline based general additive models detected underlying relationships between forest cover and income or population density of a form consistent with the EKC. The incipient forest transition has not, as yet, resulted in widespread reforestation. Forest recovery remains below 0.20% per year. Reforestation is mostly the result of passive processes associated with reductions in the intensity of land use. Deforestation continues to occur at high rates in some focal areas. A transition could be accelerated if there were a broader recognition among policy makers that the regional rate of forest loss has now begun to fall. The changing trajectory provides an opportunity to actively restore forest cover through stimulating afforestation and stimulating more sustainable land use practices. The results have clear implications for policy aimed at carbon sequestration through reducing

  17. Evidence of incipient forest transition in Southern Mexico.

    Science.gov (United States)

    Vaca, Raúl Abel; Golicher, Duncan John; Cayuela, Luis; Hewson, Jenny; Steininger, Marc

    2012-01-01

    Case studies of land use change have suggested that deforestation across Southern Mexico is accelerating. However, forest transition theory predicts that trajectories of change can be modified by economic factors, leading to spatial and temporal heterogeneity in rates of change that may take the form of the Environmental Kuznets Curve (EKC). This study aimed to assess the evidence regarding potential forest transition in Southern Mexico by classifying regional forest cover change using Landsat imagery from 1990 through to 2006. Patterns of forest cover change were found to be complex and non-linear. When rates of forest loss were averaged over 342 municipalities using mixed-effects modelling the results showed a significant (p<0.001) overall reduction of the mean rate of forest loss from 0.85% per year in the 1990-2000 period to 0.67% in the 2000-2006 period. The overall regional annual rate of deforestation has fallen from 0.33% to 0.28% from the 1990s to 2000s. A high proportion of the spatial variability in forest cover change cannot be explained statistically. However analysis using spline based general additive models detected underlying relationships between forest cover and income or population density of a form consistent with the EKC. The incipient forest transition has not, as yet, resulted in widespread reforestation. Forest recovery remains below 0.20% per year. Reforestation is mostly the result of passive processes associated with reductions in the intensity of land use. Deforestation continues to occur at high rates in some focal areas. A transition could be accelerated if there were a broader recognition among policy makers that the regional rate of forest loss has now begun to fall. The changing trajectory provides an opportunity to actively restore forest cover through stimulating afforestation and stimulating more sustainable land use practices. The results have clear implications for policy aimed at carbon sequestration through reducing

  18. Evidence of incipient forest transition in Southern Mexico.

    Directory of Open Access Journals (Sweden)

    Raúl Abel Vaca

    Full Text Available Case studies of land use change have suggested that deforestation across Southern Mexico is accelerating. However, forest transition theory predicts that trajectories of change can be modified by economic factors, leading to spatial and temporal heterogeneity in rates of change that may take the form of the Environmental Kuznets Curve (EKC. This study aimed to assess the evidence regarding potential forest transition in Southern Mexico by classifying regional forest cover change using Landsat imagery from 1990 through to 2006. Patterns of forest cover change were found to be complex and non-linear. When rates of forest loss were averaged over 342 municipalities using mixed-effects modelling the results showed a significant (p<0.001 overall reduction of the mean rate of forest loss from 0.85% per year in the 1990-2000 period to 0.67% in the 2000-2006 period. The overall regional annual rate of deforestation has fallen from 0.33% to 0.28% from the 1990s to 2000s. A high proportion of the spatial variability in forest cover change cannot be explained statistically. However analysis using spline based general additive models detected underlying relationships between forest cover and income or population density of a form consistent with the EKC. The incipient forest transition has not, as yet, resulted in widespread reforestation. Forest recovery remains below 0.20% per year. Reforestation is mostly the result of passive processes associated with reductions in the intensity of land use. Deforestation continues to occur at high rates in some focal areas. A transition could be accelerated if there were a broader recognition among policy makers that the regional rate of forest loss has now begun to fall. The changing trajectory provides an opportunity to actively restore forest cover through stimulating afforestation and stimulating more sustainable land use practices. The results have clear implications for policy aimed at carbon sequestration through

  19. Multifractality as a Measure of Complexity in Solar Flare Activity

    Science.gov (United States)

    Sen, Asok K.

    2007-03-01

    In this paper we use the notion of multifractality to describe the complexity in H α flare activity during the solar cycles 21, 22, and 23. Both northern and southern hemisphere flare indices are analyzed. Multifractal behavior of the flare activity is characterized by calculating the singularity spectrum of the daily flare index time series in terms of the Hölder exponent. The broadness of the singularity spectrum gives a measure of the degree of multifractality or complexity in the flare index data. The broader the spectrum, the richer and more complex is the structure with a higher degree of multifractality. Using this broadness measure, complexity in the flare index data is compared between the northern and southern hemispheres in each of the three cycles, and among the three cycles in each of the two hemispheres. Other parameters of the singularity spectrum can also provide information about the fractal properties of the flare index data. For instance, an asymmetry to the left or right in the singularity spectrum indicates a dominance of high or low fractal exponents, respectively, reflecting a relative abundance of large or small fluctuations in the total energy emitted by the flares. Our results reveal that in the even (22nd) cycle the singularity spectra are very similar for the northern and southern hemispheres, whereas in the odd cycles (21st and 23rd) they differ significantly. In particular, we find that in cycle 21, the northern hemisphere flare index data have higher complexity than its southern counterpart, with an opposite pattern prevailing in cycle 23. Furthermore, small-scale fluctuations in the flare index time series are predominant in the northern hemisphere in the 21st cycle and are predominant in the southern hemisphere in the 23rd cycle. Based on these findings one might suggest that, from cycle to cycle, there exists a smooth switching between the northern and southern hemispheres in the multifractality of the flaring process. This new

  20. A review of the geology and major economic mineral provinces of Southern Africa

    International Nuclear Information System (INIS)

    Van Biljon, W.J.

    1982-01-01

    The sequences that are considered to contain the oldest rocks (3500 Ma), the greenstone belts, are surrounded and intruded by granitic rocks. Within these granitic terranes, ages of up to 3800 Ma have been obtained. These formations together constitute the basement complex in Southern Africa. Deposits of gold, antimony, copper, lead, zinc, and tin are found in these rocks. Around 2000 Ma ago in the Bushveld Complex with its enormous deposits of chromium, platinum, and vanadium was intruded into the sedimentary sequences in the central Transvaal. Overlying the Namaqualand gneisses, volcano-sedimentary sequences were deposited in South West Africa/Namibia. These sequences were deformed and metamorphosed some 500 to 700 Ma ago along the Damara Belt. Deposits of copper, lead, zinc, vanadium, and tin, as well as a large uranium deposit, exist within this belt. Around 500 Ma ago, sedimentary rocks were deposited in a sea along the southern edge of the present continent. These rocks were deformed into the Cape Fold Belt. Further north, the above-mentioned rocks were followed by the sedimentary and volcanic rocks of the Karoo Sequence, which contain not only all the major coal deposits of Southern Africa, but also deposits of uranium and fireclay

  1. Reemergence of Dengue in Southern Texas, 2013

    Science.gov (United States)

    Thomas, Dana L.; Santiago, Gilberto A.; Abeyta, Roman; Hinojosa, Steven; Torres-Velasquez, Brenda; Adam, Jessica K.; Evert, Nicole; Caraballo, Elba; Hunsperger, Elizabeth; Muñoz-Jordán, Jorge L.; Smith, Brian; Banicki, Alison; Tomashek, Kay M.; Gaul, Linda

    2016-01-01

    During a dengue epidemic in northern Mexico, enhanced surveillance identified 53 laboratory-positive cases in southern Texas; 26 (49%) patients acquired the infection locally, and 29 (55%) were hospitalized. Of 83 patient specimens that were initially IgM negative according to ELISA performed at a commercial laboratory, 14 (17%) were dengue virus positive by real-time reverse transcription PCR performed at the Centers for Disease Control and Prevention. Dengue virus types 1 and 3 were identified, and molecular phylogenetic analysis demonstrated close identity with viruses that had recently circulated in Mexico and Central America. Of 51 household members of 22 dengue case-patients who participated in household investigations, 6 (12%) had been recently infected with a dengue virus and reported no recent travel, suggesting intrahousehold transmission. One household member reported having a recent illness consistent with dengue. This outbreak reinforces emergence of dengue in southern Texas, particularly when incidence is high in northern Mexico. PMID:27191223

  2. Emerging arboviral human diseases in Southern Europe.

    Science.gov (United States)

    Papa, Anna

    2017-08-01

    Southern Europe is characterized by unique landscape and climate which attract tourists, but also arthropod vectors, some of them carrying pathogens. Among several arboviral diseases that emerged in the region during the last decade, West Nile fever accounted for high number of human cases and fatalities, while Crimean-Congo hemorrhagic fever expanded its geographic distribution, and is considered as a real threat for Europe. Viruses evolve rapidly and acquire mutations making themselves stronger and naive populations more vulnerable. In an effort to tackle efficiently the emerging arboviral diseases, preparedness and strategic surveillance are needed for the early detection of the pathogen and containment and mitigation of probable outbreaks. In this review, the main human arboviral diseases that emerged in Southern Europe are described. © 2017 Wiley Periodicals, Inc.

  3. Marketing of organic products in southern Poland

    Directory of Open Access Journals (Sweden)

    Kuboń Maciej

    2018-01-01

    Full Text Available The article presents an outline of the issue concerning formulation of a marketing strategy and the possibility of using the knowledge on consumers' preferences for organic development of farms and their products on the example of southern Poland. The paper analyses the distribution process of organic food in the aspect of developing innovative marketing strategies. The studies were performed in 50 organic farms and on the example of 100 respondents from the region of southern Poland. In the opinion of the surveyed representatives of the organic food producers, a competitive advantage of their offer depends the most on the health values, brand, reputation, and taste. Moreover, information on products and the form and place of their sale are significant. The analysis shows that the knowledge is the most eagerly obtained from the Internet. Thus, producers should publish their profiles and pages on social media and business portals.

  4. Treaty aids 'detensioning of southern Africa'

    International Nuclear Information System (INIS)

    Stumpf, W.

    1991-01-01

    South Africa's accession to the Treaty on the Non-Proliferation of Nuclear Weapons is a significant step forward in trading non-weapons related nuclear technology with other world powers. In an interview with Dr Waldo Stumpf, chief executive officer of the Atomic Energy Corporation of South Africa, the impact of this decision on the Corporation and the whole of southern Africa is discussed

  5. Photometry of Southern Hemisphere red dwarf stars

    Science.gov (United States)

    Weistrop, D.

    1980-01-01

    Results are presented for a photometric investigation of a spectroscopically selected sample of red dwarf stars in the Southern Hemisphere. Absolute magnitudes and distances for the stars are estimated from broadband red colors. Three stars which may be subluminous are identified, as are several stars which may be within 25 pc. The tangential velocity and velocity dispersion of the sample are similar to values found in other studies of nearby late-type stars.

  6. Entrepreneurship and Income Inequality in Southern Ethiopia

    OpenAIRE

    Kimhi, Ayal

    2009-01-01

    This paper uses inequality decomposition techniques in order to analyse the consequences of entrepreneurial activities to household income inequality in southern Ethiopia. A uniform increase in entrepreneurial income reduces per capita household income inequality. This implies that encouraging rural entrepreneurship may be favourable for both income growth and income distribution. Such policies could be particularly successful if directed at the low-income, low-wealth, and relatively uneducat...

  7. Southern Woods-Burners: A Descriptive Analysis

    Science.gov (United States)

    M.L. Doolittle; M.L. Lightsey

    1979-01-01

    About 40 percent of the South's nearly 60,000 wildfires yearly are set by woods-burners. A survey of 14 problem areas in four southern States found three distinct sets of woods-burners. Most active woods-burners are young, white males whose activities are supported by their peers. An older but less active group have probably retired from active participation but...

  8. Aspidonepsis (Asclepiadaceae, a new southern African genus

    Directory of Open Access Journals (Sweden)

    A. Nicholas

    1992-10-01

    Full Text Available Aspidonepsis, an endemic southern African genus, is described and compared to the closely allied genus Aspidoglossum. This newly described genus is composed of two subgenera, Aspidonepsis and Unguilobium. consisting of three and two species respectively.  Asclepias diploglossa, A. flava, A. cognata and A. reneensis are transferred to Aspidonepsis. and A. shebae is newly described. All species are discussed, illustrated and a key is given to aid in their identification.

  9. Southern Ocean Phytoplankton in a Changing Climate

    OpenAIRE

    Deppeler, Stacy L.; Davidson, Andrew T.

    2017-01-01

    Phytoplankton are the base of the Antarctic food web, sustain the wealth and diversity of life for which Antarctica is renowned, and play a critical role in biogeochemical cycles that mediate global climate. Over the vast expanse of the Southern Ocean (SO), the climate is variously predicted to experience increased warming, strengthening wind, acidification, shallowing mixed layer depths, increased light (and UV), changes in upwelling and nutrient replenishment, declining sea ice, reduced sal...

  10. Southern hemisphere searches for short period pulsars

    International Nuclear Information System (INIS)

    Manchester, R.N.

    1984-01-01

    Two searches of the southern sky for short period pulsars are briefly described. The first, made using the 64-m telescope at Parkes, is sensitive to pulsars with periods greater than about 10 ms and the second, made using the Molonglo radio telescope, has sensitivity down to periods of about 1.5 ms. Four pulsars were found in the Parkes survey and none in the Molonglo survey, although analysis of the latter is as yet incomplete. 10 references, 1 figure, 2 tables

  11. Southern Africa’s Transnational Threats

    Science.gov (United States)

    2013-04-01

    private sectors lends evidence to sophisticated criminal activities.”5 As regional organizations contemplated on how to prevent and/or deter these crimes...distribution of Cannabis (also known as marijuana) is prevalent throughout Southern Africa. In most incidences, Cannabis profits dwarfs local income...had its source in Tanzania and Tanzanians have identified markets for their fake US dollars in South Africa. Cannabis South Africa, Lesotho

  12. Contemporary Russia Policy for the Southern Caucasus

    Directory of Open Access Journals (Sweden)

    Karen P. Marabyan

    2014-01-01

    Full Text Available The bilateral relations between Russia on the one hand, and the countries of the Southern Caucasus region on the other hand are examined in the article. The main directions of Russian policy in the Southern Caucasus region are examined there. The article focusses attention to the value of the Southern Caucasus region for Russia and also to the key role of Russia in the Southern Caucasus region. The overview of Russian-Azerbaijani, Russian-Armenian and Russian- Georgian relations is given in the article. Russian relations with unrecognized Nagorno-Karabakh Republic and with partially recognized Abkhazia and South Ossetia are examined in the context of above-mentioned bilateral relations. The Caucasian direction of Russian foreign policy is of great importance in questions of ensuring Russian national security. The Caucasian crisis of2008 showed potential conflictness of the region and safety hazard of Russia. Now other processes proceed already in the region. Armenian intention to join the Customs union, the change of Georgian leadership and signing of the agreement on association with EU by Georgia start new mechanisms of interaction between the region countries on the one hand and Russia on the other hand. The relation format between region republics can be changed. The main purpose of the article is to show Russian role in questions of the South Caucasus regional security. The region has the conflict territories, from which the Nagorno-Karabakh Republic, the Abkhazian Republic and the South Ossetia Republic are distinguished especially. And Russia won't be able to keep aloof in case of escalation of the conflicts around above-mentioned subjects. The vital questions for the region are peace and stability. And Russia plays a key role in these questions.

  13. Southern Pine Based on Biorefinery Center

    Energy Technology Data Exchange (ETDEWEB)

    Ragauskas, Arthur J. [Georgia Inst. of Technology, Atlanta, GA (United States); Singh, Preet [Georgia Inst. of Technology, Atlanta, GA (United States)

    2013-12-20

    This program seeks to develop an integrated southern pine wood to biofuels/biomaterials processing facility on the Recipient’s campus, that will test advanced integrated wood processing technologies at the laboratory scale, including: The generation of the bioethanol from pines residues and hemicelluloses extracted from pine woodchips; The conversion of extracted woodchips to linerboard and bleach grade pulps; and the efficient conversion of pine residues, bark and kraft cooking liquor into a useful pyrolysis oil.

  14. Electron Microscopy Society of Southern Africa : proceedings

    International Nuclear Information System (INIS)

    Snyman, H.C.; Coetzee, J.; Coubrough, R.I.

    1987-01-01

    The proceedings of the 26th annual conference of the Electron Microscopy Society of Southern Africa are presented. Papers were presented on the following topics: techniques and instrumentation used in electron microscopy, and applications of electron microscopy in the life sciences, including applications in medicine, zoology, botany and microbiology. The use of electron microscopy in the physical sciences was also discussed. Separate abstracts were prepared for seven of the papers presented. The remaining papers were considered outside the subject scope of INIS

  15. Intensity of plant collecting in southern Africa

    Directory of Open Access Journals (Sweden)

    G. E. Gibbs Russell

    1984-12-01

    Full Text Available The intensity of plant collecting in southern Africa is mapped using records from the Pretoria National Herbarium Computerized Information System (PRECIS, For the entire area, over 85% of the quarter degree grid squares have fewer than 100 specimens recorded. Collecting intensities are compared for different countries, biomes and climatic zones. Future field work from the National Herbarium will be concentrated in areas most seriously under-collected.

  16. Parameterized and resolved Southern Ocean eddy compensation

    Science.gov (United States)

    Poulsen, Mads B.; Jochum, Markus; Nuterman, Roman

    2018-04-01

    The ability to parameterize Southern Ocean eddy effects in a forced coarse resolution ocean general circulation model is assessed. The transient model response to a suite of different Southern Ocean wind stress forcing perturbations is presented and compared to identical experiments performed with the same model in 0.1° eddy-resolving resolution. With forcing of present-day wind stress magnitude and a thickness diffusivity formulated in terms of the local stratification, it is shown that the Southern Ocean residual meridional overturning circulation in the two models is different in structure and magnitude. It is found that the difference in the upper overturning cell is primarily explained by an overly strong subsurface flow in the parameterized eddy-induced circulation while the difference in the lower cell is mainly ascribed to the mean-flow overturning. With a zonally constant decrease of the zonal wind stress by 50% we show that the absolute decrease in the overturning circulation is insensitive to model resolution, and that the meridional isopycnal slope is relaxed in both models. The agreement between the models is not reproduced by a 50% wind stress increase, where the high resolution overturning decreases by 20%, but increases by 100% in the coarse resolution model. It is demonstrated that this difference is explained by changes in surface buoyancy forcing due to a reduced Antarctic sea ice cover, which strongly modulate the overturning response and ocean stratification. We conclude that the parameterized eddies are able to mimic the transient response to altered wind stress in the high resolution model, but partly misrepresent the unperturbed Southern Ocean meridional overturning circulation and associated heat transports.

  17. [The new migratory deal in Southern Europe].

    Science.gov (United States)

    Simon, G

    1986-09-01

    The author examines migration patterns in Southern Europe during the 1970s and early 1980s, noting particularly the reduction in migration northward from this region. It is noted that "departure potential remains sizable in certain areas of Portugal, Spain, Southern Italy, and most particularly, of Turkey and Yugoslavia. Transoceanic migrations have by no means ceased, as new flows of skilled labor have, since 1974, gone towards Arab states endowed with petrol (oil) revenues. And yet, the paramount fact is most surely the emergence and the proliferation in Greece, Spain, and (especially) in Italy, of basically clandestine (illegal) immigration. This movement is due to the convergence of several factors: economic and demographic disparities between northern and southern shores of the Mediterranean Sea, the sealing-off of borders in Northwestern Europe and the 'carry-over' effect upon nations of 'transit', the extent of the flow of refugees, and--most particularly--the appeal provided by the development, in these new employer countries, of an underground economy accompanied by the extension into industry of the practice of 'undeclared' work. And notwithstanding the series of rules lastly drawn up in Spain and in Greece, such forms of clandestine (unauthorized) migration appear highly likely--to say the least--to persist." (SUMMARY IN ENG AND SPA) excerpt

  18. Water. Unresolved emergency of the Southern hemisphere

    International Nuclear Information System (INIS)

    Lotti, C.

    2001-01-01

    Among the serious dramas in the Southern hemisphere, the most serious relates to health, and the most serious health problem is dysentery among the rural population, caused by the lack of unpolluted water. Bad management frustrates much of the aid sent to this part of the world, including projects to help the water crisis. In view of the success, it would appear that a concrete solution could be found within a decade, at a cost that can easily be sustained by the rich world, so long as funds are managed honestly. Much more ambitious and, at least for the moment, beyond all concrete possibility, is the project to provide a barrel of water per head to each person in the southern hemisphere. Providing unpolluted water and facilitating farming development through minor irrigation and family cattle-raising schemes is an idea that appears entirely Utopian. The conclusion provides a critical analysis of the major hydraulic works essential for true development, but effective only if the human environment is ready to receive them, whereas minor works are useful in any case - at village level - to resolve the thirst of the southern hemisphere [it

  19. Early German plans for southern observatories

    Science.gov (United States)

    Wolfschmidt, G.

    2002-07-01

    As early as the 18th and 19th centuries, French and English observers were active in South Africa. Around the beginning of the 20th century, Heidelberg and Potsdam astronomers proposed a southern observatory. Then Göttingen astronomers suggested building an observatory in Windhoek for photographing the sky and measuring the solar constant. In 1910 Karl Schwarzschild (1873-1916), after a visit to observatories in the United States, pointed out the usefulness of an observatory in South West Africa, in a climate superior to that in Germany, giving German astronomers access to the southern sky. Seeing tests were begun in 1910 by Potsdam astronomers, but WW I stopped the plans. In 1928 Erwin Finlay-Freundlich (1885-1964), inspired by the Hamburg astronomer Walter Baade (1893-1960), worked out a detailed plan for a southern observatory with a reflecting telescope, spectrographs and an astrograph with an objective prism. Paul Guthnick (1879-1947), director of the Berlin observatory, in cooperation with APO Potsdam and Hamburg, made a site survey to Africa in 1929 and found the conditions in Windhoek to be ideal. Observations were started in the 1930s by Berlin and Breslau astronomers, but were stopped by WW II. In the 1950s, astronomers from Hamburg and The Netherlands renewed the discussion in the framework of European cooperation, and this led to the founding of ESO in 1963.

  20. Industrial Physics---Southern California Style

    Science.gov (United States)

    Leslie, Stuart

    2013-03-01

    Only in Southern California did space-age style really come into its own as a unique expression of Cold War scientific culture. The corporate campuses of General Atomic in San Diego and North American Aviation in Los Angeles perfectly expressed the exhilarating spirit of Southern California's aerospace era, scaling up the residential version of California modernism to industrial proportion. Architects William Pereira and A.C. Martin Jr., in collaboration with their scientific counterparts, fashioned military-industrial `dream factories' for industrial physics that embodied the secret side of the space-age zeitgeist, one the public could only glimpse of in photographs, advertisements, and carefully staged open houses. These laboratories served up archetypes of the California dream for a select audience of scientists, engineers, and military officers, live-action commercials for a lifestyle intended to lure the best and brightest to Southern California. Paradoxically, they hid in plain sight, in the midst of aerospace suburbs, an open secret, at once visible and opaque, the public face of an otherwise invisible empire. Now, at the end of the aerospace era, these places have become an endangered species, difficult to repurpose, on valuable if sometimes highly polluted land. Yet they offer an important reminder of a more confident time when many physicists set their sights on the stars.

  1. Dynamics of the Water Circulations in the Southern South China Sea and Its Seasonal Transports.

    Science.gov (United States)

    Daryabor, Farshid; Ooi, See Hai; Samah, Azizan Abu; Akbari, Abolghasem

    2016-01-01

    A three-dimensional Regional Ocean Modeling System is used to study the seasonal water circulations and transports of the Southern South China Sea. The simulated seasonal water circulations and estimated transports show consistency with observations, e.g., satellite altimeter data set and re-analysis data of the Simple Ocean Data Assimilation. It is found that the seasonal water circulations are mainly driven by the monsoonal wind stress and influenced by the water outflow/inflow and associated currents of the entire South China Sea. The intrusion of the strong current along the East Coast of Peninsular Malaysia and the eddies at different depths in all seasons are due to the conservation of the potential vorticity as the depth increases. Results show that the water circulation patterns in the northern part of the East Coast of Peninsular Malaysia are generally dominated by the geostrophic currents while those in the southern areas are due solely to the wind stress because of negligible Coriolis force there. This study clearly shows that individual surface freshwater flux (evaporation minus precipitation) controls the sea salinity balance in the Southern South China Sea thermohaline circulations. Analysis of climatological data from a high resolution Regional Ocean Modeling System reveals that the complex bathymetry is important not only for water exchange through the Southern South China Sea but also in regulating various transports across the main passages in the Southern South China Sea, namely the Sunda Shelf and the Strait of Malacca. Apart from the above, in comparision with the dynamics of the Sunda Shelf, the Strait of Malacca reflects an equally significant role in the annual transports into the Andaman Sea.

  2. Complex systems fractionality, time-delay and synchronization

    CERN Document Server

    Sun, Jian-Qiao

    2012-01-01

    "Complex Systems: Fractionality, Time-delay and Synchronization" covers the most recent developments and advances in the theory and application of complex systems in these areas. Each chapter was written by scientists highly active in the field of complex systems. The book discusses a new treatise on fractional dynamics and control, as well as the new methods for differential delay systems and control. Lastly, a theoretical framework for the complexity and synchronization of complex system is presented. The book is intended for researchers in the field of nonlinear dynamics in mathematics, physics and engineering. It can also serve as a reference book for graduate students in physics, applied mathematics and engineering. Dr. Albert C.J. Luo is a Professor at Southern Illinois University Edwardsville, USA. Dr. Jian-Qiao Sun is a Professor at the University of California, Merced, USA.

  3. The 1998-1999 Pollino (Southern Apennines, Italy seismic crisis: tomography of a sequence

    Directory of Open Access Journals (Sweden)

    A. B. Rosa

    2005-06-01

    Full Text Available In 1998-1999 a seismic sequence occurred in the Southern Apennines, after the moderate size (mb=5.0 9th September 1998 Pollino earthquake. It lasted about 14 months and was clearly localized to the sole north-west area of the main shock epicenter. Its peculiarity consisted in sudden changes of activity from a series of normal faults with Apenninic (NW-SE trend and transfer, presumably strike slip, faults with Antiapenninic (NE-SW and E-W trend. The complexity of the behavior and the different orientations of the activated systems suggest that the area acts as a hinge between the NW-SE trending Southern Apennines and the locally N-S trending Calabrian Arc.

  4. Complex differential geometry

    CERN Document Server

    Zheng, Fangyang

    2002-01-01

    The theory of complex manifolds overlaps with several branches of mathematics, including differential geometry, algebraic geometry, several complex variables, global analysis, topology, algebraic number theory, and mathematical physics. Complex manifolds provide a rich class of geometric objects, for example the (common) zero locus of any generic set of complex polynomials is always a complex manifold. Yet complex manifolds behave differently than generic smooth manifolds; they are more coherent and fragile. The rich yet restrictive character of complex manifolds makes them a special and interesting object of study. This book is a self-contained graduate textbook that discusses the differential geometric aspects of complex manifolds. The first part contains standard materials from general topology, differentiable manifolds, and basic Riemannian geometry. The second part discusses complex manifolds and analytic varieties, sheaves and holomorphic vector bundles, and gives a brief account of the surface classifi...

  5. Origin of calcite in the glacigenic Virttaankangas complex

    OpenAIRE

    Nina M. Kortelainen; Petri J. Korkeakoski; Juha A. Karhu

    2007-01-01

    Groundwaters of the glacigenic Virttaankangas complex in southern Finland are characterized by high pH values ranging up to 9.5. These values are significantly higher than those observed in silicate-rich shallow groundwater formations in crystalline bedrock areas. TheVirttaankangas sediments were discovered to contain small amounts of fine grained, dispersed calcite, which has a high tendency to increase the pH of local groundwaters. The primary goal of this study was to determine the mode of...

  6. Complex and symplectic geometry

    CERN Document Server

    Medori, Costantino; Tomassini, Adriano

    2017-01-01

    This book arises from the INdAM Meeting "Complex and Symplectic Geometry", which was held in Cortona in June 2016. Several leading specialists, including young researchers, in the field of complex and symplectic geometry, present the state of the art of their research on topics such as the cohomology of complex manifolds; analytic techniques in Kähler and non-Kähler geometry; almost-complex and symplectic structures; special structures on complex manifolds; and deformations of complex objects. The work is intended for researchers in these areas.

  7. Late Sarmatian Elite Military Burial From the Southern Urals

    Directory of Open Access Journals (Sweden)

    Krivosheev Mikhail Vasilyevich

    2015-12-01

    Full Text Available The article is devoted to the burial of a warrior of Late Sarmatian time from the Southern Urals. The complex from mound no. 4 of the burial mound Taksai I is distinguished by large size of barrow and grave. The reconstructed height of the mound was less than 2 meters. The depth of the burial pit was more than 3 meters. For Late Sarmatian culture such dimensions of sepulchral structures are unique. Under the mound the ritual platform from mainland soil was discovered. The found inventory of a warrior-rider included: horse bridle, a set of bladed weapons consisting of a long sword, dagger and knife, as well as a small bronze cauldron. Analysis of inventory allows us to date this burial to the second half of the 3rd century A.D. This burial belongs to an elite funerary complexes of Late Sarmatian culture and is a burial of professional warriors. This social stratum was formed in Late Sarmatian society at the end of the 2nd - first half of the 3rd century A.D. Most of these graves are dating back to the first half of the 3rd century A.D and were found in the Low Don and in the Volga region. The situation in these regions changed in that period due to the invasion of the tribes of the North-Caucasian origin. Their occurrence is associated with the destruction of the Tanais in the Lower Don region and the spread of graves in the T-shaped catacombs in the steppe monuments. The tradition of burying warriors-horsemen of high social status almost disappears in the Volga-Don steppes after the middle of 3rd century A.D. In the Southern Urals where these processes had an indirect influence, the existence of traditional hierarchies of Late Sarmatian society could continue until the end of the 3rd century A.D. Among the parts of a horse bridle the researchers discovered bronze B-shape buckle. These buckles are widely distributed in the 4th-5th centuries A.D. in the basin of the Kama river and the Danube river. The found buckle is the earliest currently known

  8. How fault evolution changes strain partitioning and fault slip rates in Southern California: Results from geodynamic modeling

    Science.gov (United States)

    Ye, Jiyang; Liu, Mian

    2017-08-01

    In Southern California, the Pacific-North America relative plate motion is accommodated by the complex southern San Andreas Fault system that includes many young faults (faults and their impact on strain partitioning and fault slip rates are important for understanding the evolution of this plate boundary zone and assessing earthquake hazard in Southern California. Using a three-dimensional viscoelastoplastic finite element model, we have investigated how this plate boundary fault system has evolved to accommodate the relative plate motion in Southern California. Our results show that when the plate boundary faults are not optimally configured to accommodate the relative plate motion, strain is localized in places where new faults would initiate to improve the mechanical efficiency of the fault system. In particular, the Eastern California Shear Zone, the San Jacinto Fault, the Elsinore Fault, and the offshore dextral faults all developed in places of highly localized strain. These younger faults compensate for the reduced fault slip on the San Andreas Fault proper because of the Big Bend, a major restraining bend. The evolution of the fault system changes the apportionment of fault slip rates over time, which may explain some of the slip rate discrepancy between geological and geodetic measurements in Southern California. For the present fault configuration, our model predicts localized strain in western Transverse Ranges and along the dextral faults across the Mojave Desert, where numerous damaging earthquakes occurred in recent years.

  9. Oligocyclopentadienyl transition metal complexes

    Energy Technology Data Exchange (ETDEWEB)

    de Azevedo, Cristina G.; Vollhardt, K. Peter C.

    2002-01-18

    Synthesis, characterization, and reactivity studies of oligocyclopentadienyl transition metal complexes, namely those of fulvalene, tercyclopentadienyl, quatercyclopentadienyl, and pentacyclopentadienyl(cyclopentadienyl) are the subject of this account. Thermal-, photo-, and redox chemistries of homo- and heteropolynuclear complexes are described.

  10. Photocytotoxic lanthanide complexes

    Indian Academy of Sciences (India)

    Among many applications of lanthanides, gadolinium complexes are used as magnetic resonance imaging (MRI) contrast agents in clinical radiology and luminescent lanthanides for bioanalysis, imaging and sensing. The chemistry of photoactive lanthanide complexes showing biological applications is of recent origin.

  11. ComplexRec 2017

    DEFF Research Database (Denmark)

    a single step in the user's more complex background need. These background needs can often place a variety of constraints on which recommendations are interesting to the user and when they are appropriate. However, relatively little research has been done on these complex recommendation scenarios....... The ComplexRec 2017 workshop addressed this by providing an interactive venue for discussing approaches to recommendation in complex scenarios that have no simple one-size-fits-all-solution....

  12. Landscape Change in the Southern Piedmont: Challenges, Solutions, and Uncertainty Across Scales

    Directory of Open Access Journals (Sweden)

    Michael J. Conroy

    2003-12-01

    Full Text Available The southern Piedmont of the southeastern United States epitomizes the complex and seemingly intractable problems and hard decisions that result from uncontrolled urban and suburban sprawl. Here we consider three recurrent themes in complicated problems involving complex systems: (1 scale dependencies and cross-scale, often nonlinear relationships; (2 resilience, in particular the potential for complex systems to move to alternate stable states with decreased ecological and/or economic value; and (3 uncertainty in the ability to understand and predict outcomes, perhaps particularly those that occur as a result of human impacts. We consider these issues in the context of landscape-level decision making, using as an example water resources and lotic systems in the Piedmont region of the southeastern United States.

  13. Landscape change in the Southern Piedmont: Challenges, solutions and uncertainty across scales

    Science.gov (United States)

    Conroy, M.J.; Allen, Craig R.; Peterson, J.T.; Pritchard, L.; Moore, C.T.

    2003-01-01

    The southern Piedmont of the southeastern United States epitomizes the complex and seemingly intractable problems and hard decisions that result from uncontrolled urban and suburban sprawl. Here we consider three recurrent themes in complicated problems involving complex systems: (1) scale dependencies and cross-scale, often nonlinear relationships; (2) resilience, in particular the potential for complex systems to move to alternate stable states with decreased ecological and/or economic value; and (3) uncertainty in the ability to understand and predict outcomes, perhaps particularly those that occur as a result of human impacts. We consider these issues in the context of landscape-level decision making, using as an example water resources and lotic systems in the Piedmont region of the southeastern United States. Copyright ?? 2003 by the author(s). Published here under licence by The Resilience Alliance.

  14. Ecology of southern ocean pack ice.

    Science.gov (United States)

    Brierley, Andrew S; Thomas, David N

    2002-01-01

    Around Antarctica the annual five-fold growth and decay of sea ice is the most prominent physical process and has a profound impact on marine life there. In winter the pack ice canopy extends to cover almost 20 million square kilometres--some 8% of the southern hemisphere and an area larger than the Antarctic continent itself (13.2 million square kilometres)--and is one of the largest, most dynamic ecosystems on earth. Biological activity is associated with all physical components of the sea-ice system: the sea-ice surface; the internal sea-ice matrix and brine channel system; the underside of sea ice and the waters in the vicinity of sea ice that are modified by the presence of sea ice. Microbial and microalgal communities proliferate on and within sea ice and are grazed by a wide range of proto- and macrozooplankton that inhabit the sea ice in large concentrations. Grazing organisms also exploit biogenic material released from the sea ice at ice break-up or melt. Although rates of primary production in the underlying water column are often low because of shading by sea-ice cover, sea ice itself forms a substratum that provides standing stocks of bacteria, algae and grazers significantly higher than those in ice-free areas. Decay of sea ice in summer releases particulate and dissolved organic matter to the water column, playing a major role in biogeochemical cycling as well as seeding water column phytoplankton blooms. Numerous zooplankton species graze sea-ice algae, benefiting additionally because the overlying sea-ice ceiling provides a refuge from surface predators. Sea ice is an important nursery habitat for Antarctic krill, the pivotal species in the Southern Ocean marine ecosystem. Some deep-water fish migrate to shallow depths beneath sea ice to exploit the elevated concentrations of some zooplankton there. The increased secondary production associated with pack ice and the sea-ice edge is exploited by many higher predators, with seals, seabirds and whales

  15. Southern Hemisphere Upper Thermospheric Wind Climatology

    Science.gov (United States)

    Dhadly, M. S.; Emmert, J. T.; Drob, D. P.

    2017-12-01

    This study is focused on the poorly understood large-scale upper thermospheric wind dynamics in the southern polar cap, auroral, and mid latitudes. The gaps in our understanding of the dynamic high-latitude thermosphere are largely due to the sparseness of thermospheric wind measurements. Using data from current observational facilities, it is unfeasible to construct a synoptic picture of the Southern Hemisphere upper thermospheric winds. However, enough data with wide spatial and temporal coverage have accumulated to construct a meaningful statistical analysis of winds as function of season, magnetic latitude, and magnetic local time. We use long-term data from nine ground-based stations located at different southern high latitudes and three space-based instruments. These diverse data sets possess different geometries and different spatial and solar coverage. The major challenge of the effort is to combine these disparate sources of data into a coherent picture while overcoming the sampling limitations and biases among the datasets. Our preliminary analyses show mutual biases present among some of them. We first address the biases among various data sets and then combine them in a coherent way to construct maps of neutral winds for various seasons. We then validate the fitted climatology against the observational data and compare with corresponding fits of 25 years of simulated winds from the National Center for Atmospheric Research Thermosphere-Ionosphere-Electrodynamics General Circulation Model. This study provides critical insight into magnetosphere-ionosphere-thermosphere coupling and sets a necessary benchmark for validating new observations and tuning first-principles models.

  16. Building the Southern California Earthquake Center

    Science.gov (United States)

    Jordan, T. H.; Henyey, T.; McRaney, J. K.

    2004-12-01

    Kei Aki was the founding director of the Southern California Earthquake Center (SCEC), a multi-institutional collaboration formed in 1991 as a Science and Technology Center (STC) under the National Science Foundation (NSF) and the U. S. Geological Survey (USGS). Aki and his colleagues articulated a system-level vision for the Center: investigations by disciplinary working groups would be woven together into a "Master Model" for Southern California. In this presentation, we will outline how the Master-Model concept has evolved and how SCEC's structure has adapted to meet scientific challenges of system-level earthquake science. In its first decade, SCEC conducted two regional imaging experiments (LARSE I & II); published the "Phase-N" reports on (1) the Landers earthquake, (2) a new earthquake rupture forecast for Southern California, and (3) new models for seismic attenuation and site effects; it developed two prototype "Community Models" (the Crustal Motion Map and Community Velocity Model) and, perhaps most important, sustained a long-term, multi-institutional, interdisciplinary collaboration. The latter fostered pioneering numerical simulations of earthquake ruptures, fault interactions, and wave propagation. These accomplishments provided the impetus for a successful proposal in 2000 to reestablish SCEC as a "stand alone" center under NSF/USGS auspices. SCEC remains consistent with the founders' vision: it continues to advance seismic hazard analysis through a system-level synthesis that is based on community models and an ever expanding array of information technology. SCEC now represents a fully articulated "collaboratory" for earthquake science, and many of its features are extensible to other active-fault systems and other system-level collaborations. We will discuss the implications of the SCEC experience for EarthScope, the USGS's program in seismic hazard analysis, NSF's nascent Cyberinfrastructure Initiative, and other large collaboratory programs.

  17. Southern Ocean Convection and tropical telleconnections

    Science.gov (United States)

    Marinov, I.; Cabre, A.; Gnanadesikan, A.

    2014-12-01

    We show that Southern Ocean (SO) temperatures in the latest generation of Earth System Models exhibit two major modes of variation, one driven by deep convection, the other by tropical variability. We perform a CMIP5 model intercomparison to understand why different climate models represent SO variability so differently in long, control simulations. We show that multiyear variability in Southern Ocean sea surface temperatures (SSTs) can in turn influence oceanic and atmospheric conditions in the tropics on short (atmospheric) time-scales. We argue that the strength and pattern of SO-tropical teleconnections depends on the intensity of SO deep convection. Periodic convection in the SO is a feature of most CMIP5 models under preindustrial forcing (deLavergne et al., 2014). Models show a wide distribution in the spatial extent, periodicity and intensity of their SO convection, with some models convecting most of the time, and some showing very little convection. In a highly convective coupled model, we find that multidecadal variability in SO and global SSTs, as well as SO heat storage are driven by Weddell Sea convective variability, with convective decades relatively warm due to the heat released from the deep southern ocean and non-convective decades cold due to the subsurface storage of heat. Furthermore, pulses of SO convection drive SST and sea ice variations, influencing absorbed shortwave and emitted longwave radiation, wind, cloud and precipitation patterns, with climatic implications for the low latitudes via fast atmospheric teleconnections. We suggest that these high-low latitude teleconnection mechanisms are relevant for understanding hiatus decades. Additionally, Southern Ocean deep convection varied significantly during past, natural climate changes such as during the last deglaciation. Weddell Sea open convection was recently weakened, likely as a consequence of anthropogenic forcing and the resulting surface freshening. Our study opens up the

  18. The Herpetology of the Southern Kalahari domain

    Directory of Open Access Journals (Sweden)

    W. D Haacke

    1984-12-01

    Full Text Available The herpetofauna of the southern Kalahari has mixed affinities, as this area lies on a rainfall gradient in a critical area where a transition between the arid south-west and the moister north-east takes place. As the variation in substrate type is relatively limited, the effect of the rainfall gradient appears to influence and determine the range limits of many taxa in both directions, resulting in an area in which of 55 recorded reptiles, 11 western taxa overlap or form a parapatric zone with 25 eastern taxa, while the remaining taxa are endemic or wideranging.

  19. The Southern Ocean and South Pacific Region

    OpenAIRE

    Kelleher, K.; Warnau, Michel; Failler, Pierre; Pecl, Gretta; Turley, Carol; Boeuf, Gilles; Laffoley, Dan; Parker, Laura; Gurney, Leigh

    2012-01-01

    The Region comprises three sub-regions (FAO Statistical Areas) with very different characteristics. The South Pacific includes the vast and virtually unpopulated Southern Ocean surrounding the Antarctic. It has the world’s largest fisheries off Peru and Chile and some of the world’s best managed fisheries in Australia and New Zealand. The Region has over 27% of the world’s ocean area and over 98% of the Region’s total area of 91 million km2 is ‘open ocean’. The Region contains less than 5% of...

  20. Epidemiology of cerebral palsy in Southern Denmark

    DEFF Research Database (Denmark)

    Frøslev-Friis, Christina; Dunkhase-Heinl, Ulrike; Andersen, Johnny Dohn Holmgren

    2015-01-01

    INTRODUCTION: The aim of this study was to describe the prevalence, subtypes, severity and neuroimaging findings of cerebral palsy (CP) in a cohort of children born in Southern Denmark. Risk factors were analysed and aetiology considered. METHODS: A population-based cohort study covering 17...... prevention of CP is possible if the numbers of preterm births and multiple pregnancies can be reduced. FUNDING: The Danish Cerebral Palsy Follow-up Programme is supported by the foundation "Ludvig og Sara Elsass Fond". TRIAL REGISTRATION: 2008-58-0034....