WorldWideScience

Sample records for metallicity natal environments

  1. Ultraluminous X-ray Sources forming in low metallicity natal environments

    CERN Document Server

    Zampieri, L; Mapelli, M; Patruno, A; Roberts, T P

    2010-01-01

    In the last few years multiwavelength observations have boosted our understanding of Ultraluminous X-ray Sources (ULXs). Yet, the most fundamental questions on ULXs still remain to be definitively answered: do they contain stellar or intermediate mass black holes? How do they form? We investigate the possibility that the black holes hosted in ULXs originate from massive (40-120 $M_\\odot$) stars in low metallicity natal environments. Such black holes have a typical mass in the range $\\sim 30-90 M_\\odot$ and may account for the properties of bright (above $\\sim 10^{40}$ erg s$^{-1}$) ULXs. More than $\\sim 10^5$ massive black holes might have been generated in this way in the metal poor Cartwheel galaxy during the last $10^7$ years and might power most of the ULXs observed in it. Support to our interpretation comes from NGC 1313 X-2, the first ULX with a tentative identification of the orbital period in the optical band, for which binary evolution calculations show that the system is most likely made by a massiv...

  2. Affinity for natal environments by dispersers impacts reproduction and explains geographical structure of a highly mobile bird.

    Science.gov (United States)

    Fletcher, Robert J; Robertson, Ellen P; Wilcox, Rebecca C; Reichert, Brian E; Austin, James D; Kitchens, Wiley M

    2015-09-07

    Understanding dispersal and habitat selection behaviours is central to many problems in ecology, evolution and conservation. One factor often hypothesized to influence habitat selection by dispersers is the natal environment experienced by juveniles. Nonetheless, evidence for the effect of natal environment on dispersing, wild vertebrates remains limited. Using 18 years of nesting and mark-resight data across an entire North American geographical range of an endangered bird, the snail kite (Rostrhamus sociabilis), we tested for natal effects on breeding-site selection by dispersers and its consequences for reproductive success and population structure. Dispersing snail kites were more likely to nest in wetlands of the same habitat type (lacustrine or palustrine) as their natal wetland, independent of dispersal distance, but this preference declined with age and if individuals were born during droughts. Importantly, dispersing kites that bred in natal-like habitats had lower nest success and productivity than kites that did not. These behaviours help explain recently described population connectivity and spatial structure across their geographical range and reveal that assortative breeding is occurring, where birds are more likely to breed with individuals born in the same wetland type as their natal habitat. Natal environments can thus have long-term and large-scale effects on populations in nature, even in highly mobile animals.

  3. Bioavailable metals in tourist beaches of Richards Bay, Kwazulu-Natal, South Africa.

    Science.gov (United States)

    Vetrimurugan, E; Jonathan, M P; Roy, Priyadarsi D; Shruti, V C; Ndwandwe, O M

    2016-04-15

    Acid Leachable Trace Metal (ALTMs) concentrations in tourist beaches of Richards Bay, Kwazulu-Natal, South Africa were assessed. 53 surface sediment samples were collected from five different beaches (Kwambonambi Long Beach; Nhlabane Beach; Five Mile Beach; Alkanstrand Beach and Port Durnford Beach). The results of ALTMs (Fe, Mn, Cr, Cu, Ni, Co, Pb, Cd, Zn, As, Hg) suggest that they are enriched naturally and with some local industrial sources for (avg. in μgg(-1)) Fe (3530-7219), Mn (46-107.11), Cd (0.43-1.00) and Zn (48-103.98). Statistical results indicate that metal concentrations were from natural origin attributed to leaching, weathering process and industrial sources. Comparative studies of metal concentrations with sediment quality guidelines and ecotoxicological values indicate that there is no adverse biological effect. Enrichment factor and geoaccumulation indices results indicate moderate enhancement of Fe (Igeo class 1 in FMB), Cd (EF>50; Igeo classes 2-4) and Zn (Igeo classes 1 & 2).

  4. Biomonitoring of trace metal contamination in the Potengi estuary, Natal (Brazil), using the oyster Crassostrea rhizophorae, a local food source.

    Science.gov (United States)

    Silva, C A; Rainbow, P S; Smith, B D; Santos, Z L

    2001-12-01

    The oyster Crassostrea rhizophorae was collected in September 1997 from 10 stations along the Potengi estuary, Natal, Brazil, a mangrove-lined estuary receiving anthropogenic inputs of trace metals. C. rhizophorae is a net accumulator of trace metals and can be used as a biomonitor, the accumulated soft tissue concentrations representing integrated records of bioavailable metal fractions over the life of the oyster. Significant differences in oyster accumulated concentrations (and hence bioavailabilities) of Fe, Zn, Cu, Cr, Pb, Cd, Ni and Ag (but not Mn) were found between stations, and attributed to anthropogenic inputs including discharges of sewage and industrial effluent. The oysters are also a local food source, and concentrations of zinc, copper and lead in some of the oysters are above typical public health recommended limits.

  5. Anthropogenic perturbation of coral reef environments near Natal, Brazil: Clues from symbiont-bearing benthic foraminifera

    Science.gov (United States)

    Eichler, P.; Vital, H.; Sen Gupta, B. K.

    2014-12-01

    Besides global stressors such as temperature rise and acidification, local anthropogenic disturbances, especially those connected with tourism, affect many Atlantic patch reefs off the Brazilian shore. Using reef-inhabiting foraminifera with algal symbionts as environmental indicators, we confirmed this problem in coastal reefs near Natal, Rio Grande do Norte. The foraminiferal community is particularly depauperate in the small reefs of Pirangi, about 25 km south of Natal (~6o S, water depth tourism. However, living Amphistegina is still rare, and the only living Amphisorus is found in seagrass habitats. In contrast, many symbiont-bearing taxa, including peneroplids (virtually absent in Pirangi and Maracajaú) exist in sizeable populations northwest of Maracajaú, in the small patch reefs of the drowned Açu river valley (~4o 50' S).

  6. Heavy metal distribution in Laportea peduncularis and growth soil from the eastern parts of KwaZulu-Natal, South Africa.

    Science.gov (United States)

    Mahlangeni, Nomfundo T; Moodley, Roshila; Jonnalagadda, Sreekantha B

    2016-02-01

    Laportea peduncularis is a medicinal plant consumed by the native communities in South Africa. Due to its oral consumption, its potential for harming the human health and the distribution of metals in the leaves of L. peduncularis as a function of soil characteristics were evaluated. Broadly, the concentrations of metals in the soil were in decreasing order of Fe > Ca > Mg > Mn > Zn > Cr > Cu > Ni > As > Co > Cd > Pb. Low-molecular-weight organic acid, calcium chloride, and ethylenediaminetetraacetic acid extraction methods were employed to assess for exchangeable forms of metals in the soil. Geoaccumulation indices and enrichment factors showed no contamination or enrichment for most of the heavy metals studied except for Cd, which showed moderate contamination and significant enrichment at Mona, KwaZulu-Natal. Principal component and cluster analyses revealed that As, Cd, Fe, and Ni in the soil came from the same source, whilst Cu, Pb, and Zn in the soil were from a common origin. Correlation analysis showed significantly positive correlation between heavy metals As, Cd, Fe, and Ni in the soil, as well as between Cu, Pb, and Zn, confirming the metals' common origin. Concentrations of metals in plants and soil were influenced by site, but the availability and uptake of the metals solely depended on the plant's inherent controls.

  7. Natal dispersal in a social landscape:Considering individual behavioral phenotypes and social environment in dispersal ecology

    Institute of Scientific and Technical Information of China (English)

    Tina W WEY; Orr SPIEGEL; Pierre-Olivier MONTIGLIO; Karen E MABRY

    2015-01-01

    Natal dispersal, the movement of an organism from its birthplace to the site of first reproduction, is fundamental to many ecological and evolutionary processes. Mechanistically, individual dispersal decisions can depend on both individual phe-notype and environmental cues. In particular, many established evolutionary theories of dispersal highlight the importance of the social environment. More recent research in behavioral ecology has focused on the importance of individual behavioral pheno-types. We reviewed the literature on individual behavioral phenotypes and dispersal and suggest that how individual behavioral phenotypes interact with the immediate social environment experienced by individuals in influencing dispersal is still poorly un-derstood, despite growing interest. We found that very few studies had examined the interaction of individual behavioral pheno-types and social factors, and behavioral phenotypes related to social tendencies were less commonly measured than were beha-vioral phenotypes related to exploration or response to risk. Further, and unsurprisingly, studies on social behavioral phenotypes and dispersal behaviors during the transience stage of dispersal were underrepresented compared to the departure or settlement stages. Future studies in this area should aim to: a) make explicit links between behavioral traits and their proposed effects on dispersal decisions throughout multiple stages of dispersal, b) integrate more continuous dispersal variables, and c) consider the effects of the spatial distribution and phenotypes of conspecifics (i.e., the social landscape) encountered by individual dispersers [Current Zoology 61 (3): 543–556, 2015].

  8. Platinum metals in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Zereini, Fathi [Frankfurt Univ. (Germany). Dept. of Environmental Analytical Chemistry; Wiseman, Clare L.S. (ed.) [Toronto Univ. (Canada). School of the Environment

    2015-03-01

    This book contains the five chapters with the following topics: 1. SOURCES OF PGE EMISSIONS ELEMENTS: Sources of Platinum Group Elements (PGE) in the Environment; Impact of Platinum Group Element Emissions from Mining and Production Activities. 2. ANALYTICAL METHODS FOR THE DETERMINATION OF PGE IN BIOLOGICAL AND ENVIRONMENTAL MATRICES: Appraisal of Biosorption for Recovery, Separation and Determination of Platinum, Palladium and Rhodium in Environmental Samples; On the Underestimated Factors Influencing the Accuracy of Determination of Pt and Pd by Electrothermal Atomic Absorption Spectrometry in Road Dust Samples; Application of Solid Sorbents for Enrichment and Separation of Platinum Metal Ions; Voltammetric Analysis of Platinum in Environmental Matrices; Speciation Analysis of Chloroplatinates; Analysis of Platinum Group Elements in Environmental Samples: A Review. 3. OCCURRENCE, CHEMICAL BEHAVIOR AND FATE OF PGE IN THE ENVIRONMENT: Brazilian PGE Research Data Survey on Urban and Roadside Soils; Platinum, Palladium and Rhodium in a Bavarian Roadside Soil; Increase of Platinum Group Element Concentrations in Soils and Airborne Dust During the Period of Vehicular Exhaust Catalysts Introduction; Platinum-Group Elements in Urban Fluvial Bed Sediments-Hawaii; Long-Term Monitoring of Palladium and Platinum Contents in Road Dust of the City of Munich, Germany; Characterization of PGEs and Other Elements in Road Dusts and Airborne Particles in Houston, Texas; Accumulation and Distribution of Pt and Pd in Roadside Dust, Soil and Vegetation in Bulgaria; Increase of the Environmental Pt Concentration in the Metropolitan Area of Mexico City Associated to the Use of Automobile Catalytic Converters; Solubility of Emitted Platinum Group Elements (Pt, Pd and Rh) in Airborne Particulate Matter (PM10) in the Presence of Organic Complexing Agents; The Influence of Anionic Species (Cl{sup -}, NO{sub 3}{sup -}, SO{sub 4}{sup 2-}) on the Transformation and Solubility of Platinum in

  9. Heavy metals in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Storm, G.L. [Fish and Wildlife Service, University Park, PA (United States); Fosmire, G.J. [Dept. of Nutrition, University Park, PA (United States); Bellis, E.D. [Pennsylvania State Univ., University Park, PA (United States)

    1994-05-01

    Concentration (Cd, Pb, Zn, and Cu) in soil and wildlife at the Palmerton zinc smelter site in eastern Pennsylvania were determined 6 yr after zinc smelting was terminated in 1980. Levels of the four metals were higher in litter (01 and 02 horizon) than in soil (A1 horizon), and the metals were at or near levels when the smelters were still in operation. Levels of metals in sod weft highest at sites close to the smelters and decreased as distances from the smelters increased. The relation of decreasing amounts of metals in body tissues with increasing distance from the smelters also held true for amphibians and mammals. An exception to this relation was higher level of Cu in red-lacked salamanders (Plethodon cinereus) captured {approx}17 km downwind than those captured {approx}12 km downwind. Levels of Zn, Pb, and Co in liver, kidney, and muscle tissue of white-footed mice (Peromyscus leucopus) were not different (P >0.05) among sites. Cadmium in kidneys in white-footed mice exceeded 10 mg&& which is reportedly considered an indication of environmental contamination. Levels of Cd in kidneys and liver of white-tailed deer (Odocoileus virginianus) at Palmerton were five times higher than those for white-tailed deer collected 180 km southwest of Palmerton in southcentral Pennsylvania. The abnormal amounts of metals in the tissues of terrestrial vertebrates, and the absence or low abundance of wildlife at Palmerton indicated that ecological processes within 5 km of the smelters were markedly influenced 6 yr after zinc smelting was discontinued. 41 refs., 5 figs., 4 tabs.

  10. Shark attack in Natal.

    Science.gov (United States)

    White, J A

    1975-02-01

    The injuries in 5 cases of shark attack in Natal during 1973-74 are reviewed. Experience in shark attacks in South Africa during this period is discussed (1965-73), and the value of protecting heavily utilized beaches in Natal with nets is assessed. The surgical applications of elasmobranch research at the Oceanographic Research Institute (Durban) and at the Headquarters of the Natal Anti-Shark Measures Board (Umhlanga Rocks) are described. Modern trends in the training of surf life-guards, the provision of basic equipment for primary resuscitation of casualties on the beaches, and the policy of general and local care of these patients in Natal are discussed.

  11. Fate of platinum metals in the environment.

    Science.gov (United States)

    Pawlak, Justyna; Łodyga-Chruścińska, Elżbieta; Chrustowicz, Jakub

    2014-07-01

    For many years now automotive exhaust catalysts have been used to reduce the significant amounts of harmful chemical substances generated by car engines, such as carbon monoxide, nitrogen oxides, and aromatic hydrocarbons. Although they considerably decrease environmental contamination with the above-mentioned compounds, it is known that catalysts contribute to the environmental load of platinum metals (essential components of catalysts), which are released with exhaust fumes. Contamination with platinum metals stems mainly from automotive exhaust converters, but other major sources also exist. Since platinum group elements (PGEs): platinum (Pt), palladium (Pd), rhodium (Rh), ruthenium (Ru) and iridium (Ir) seem to spread in the environment and accumulate in living organisms, they may pose a threat to animals and humans. This paper discusses the modes and forms of PGE emission as well as their impact on the environment and living organisms.

  12. EXTREMELY METAL-POOR GALAXIES: THE ENVIRONMENT

    Energy Technology Data Exchange (ETDEWEB)

    Filho, M. E. [Universidad de Las Palmas de Gran Canaria–Universidad de La Laguna, CIE Canarias: Tri-Continental Atlantic Campus, Canary Islands (Spain); Almeida, J. Sánchez; Muñoz-Tuñón, C. [Instituto Astrofísica de Canarias, E-38200 La Laguna, Tenerife (Spain); Nuza, S. E.; Kitaura, F.; Heß, S., E-mail: mfilho@astro.up.pt [Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany)

    2015-04-01

    We have analyzed bibliographical observational data and theoretical predictions, in order to probe the environment in which extremely metal-poor dwarf galaxies (XMPs) reside. We have assessed the H i component and its relation to the optical galaxy, the cosmic web type (voids, sheets, filaments and knots), the overdensity parameter and analyzed the nearest galaxy neighbors. The aim is to understand the role of interactions and cosmological accretion flows in the XMP observational properties, particularly the triggering and feeding of the star formation. We find that XMPs behave similarly to Blue Compact Dwarfs; they preferably populate low-density environments in the local universe: ∼60% occupy underdense regions, and ∼75% reside in voids and sheets. This is more extreme than the distribution of irregular galaxies, and in contrast to those regions preferred by elliptical galaxies (knots and filaments). We further find results consistent with previous observations; while the environment does determine the fraction of a certain galaxy type, it does not determine the overall observational properties. With the exception of five documented cases (four sources with companions and one recent merger), XMPs do not generally show signatures of major mergers and interactions; we find only one XMP with a companion galaxy within a distance of 100 kpc, and the H i gas in XMPs is typically well-behaved, demonstrating asymmetries mostly in the outskirts. We conclude that metal-poor accretion flows may be driving the XMP evolution. Such cosmological accretion could explain all the major XMP observational properties: isolation, lack of interaction/merger signatures, asymmetric optical morphology, large amounts of unsettled, metal-poor H i gas, metallicity inhomogeneities, and large specific star formation.

  13. Heavy Metals Toxicity and the Environment

    Science.gov (United States)

    Tchounwou, Paul B; Yedjou, Clement G; Patlolla, Anita K; Sutton, Dwayne J

    2013-01-01

    Heavy metals are naturally occurring elements that have a high atomic weight and a density at least 5 times greater than that of water. Their multiple industrial, domestic, agricultural, medical and technological applications have led to their wide distribution in the environment; raising concerns over their potential effects on human health and the environment. Their toxicity depends on several factors including the dose, route of exposure, and chemical species, as well as the age, gender, genetics, and nutritional status of exposed individuals. Because of their high degree of toxicity, arsenic, cadmium, chromium, lead, and mercury rank among the priority metals that are of public health significance. These metallic elements are considered systemic toxicants that are known to induce multiple organ damage, even at lower levels of exposure. They are also classified as human carcinogens (known or probable) according to the U.S. Environmental Protection Agency, and the International Agency for Research on Cancer. This review provides an analysis of their environmental occurrence, production and use, potential for human exposure, and molecular mechanisms of toxicity, genotoxicity, and carcinogenicity. PMID:22945569

  14. Quantum metal film in the dielectric environment

    Science.gov (United States)

    Babich, A. V.; Pogosov, V. V.

    2013-01-01

    A method has been proposed for self-consistent calculations of characteristics of a metal film in dielectrics. The most interesting (asymmetric) case of metal-dielectric sandwiches, where the dielectrics are different on both sides of the film, has been considered in terms of the modified Kohn-Sham method and the stabilized jellium model. The spectrum, electron work function, and surface energy of polycrystalline films placed in passive insulators have been calculated for the first time using Al and Na as an example. It has been found that the dielectric environment generally leads to a negative change in both the electron work function and the surface energy. In addition to the size changes, the shift of the work function is determined by the arithmetic mean of the dielectric constants of the surrounding media.

  15. Chemical tracers of high-metallicity environments

    CERN Document Server

    Bayet, E; Bell, T A; Viti, S

    2012-01-01

    We present for the first time a detailed study of the properties of molecular gas in metal-rich environments such as early-type galaxies (ETGs). We have explored Photon-Dominated Region (PDR) chemistry for a wide range of physical conditions likely to be appropriate for these sources. We derive fractional abundances of the 20 most chemically reactive species as a function of the metallicity, as a function of the optical depth and for various volume number gas densities, Far-Ultra Violet (FUV) radiation fields and cosmic ray ionisation rates. We also investigate the response of the chemistry to the changes in $\\alpha-$element enhancement as seen in ETGs. We find that the fractional abundances of CS, H$_{2}$S, H$_{2}$CS, H$_{2}$O, H$_{3}$O$^{+}$, HCO$^{+}$ and H$_{2}$CN seem invariant to an increase of metallicity whereas C$^{+}$, CO, C$_{2}$H, CN, HCN, HNC and OCS appear to be the species most sensitive to this change. The most sensitive species to the change in the fractional abundance of $\\alpha-$elements ar...

  16. Microbes and metals: interactions in the environment.

    Science.gov (United States)

    Haferburg, Götz; Kothe, Erika

    2007-12-01

    Research on the behaviour of microorganisms in geogenic or anthropogenic metallomorphic environments is an integral part of geomicrobiology. The investigation of microbial impact on the fate of minerals and geologically significant compounds of mining areas can lead to an understanding of biogeochemical cycles. Metabolic processes of microorganisms are the cause for the dissolution of minerals, and especially pyrite oxidation results in the generation of acid mine drainage which, in turn, leads to heavy metal contamination as a result of mining activities. On the other hand, microbial metabolism can also contribute to the formation of certain ore deposits over geological time. The adaptation to heavy metal rich environments is resulting in microorgansims which show activities for biosorption, bioprecipitation, extracellular sequestration, transport mechanisms, and/or chelation. Such resistance mechanisms are the basis for the use of microorganisms in bioremediation approaches. As only a small part of the worldwide occurring prokaryotes has been described yet, the understanding of the role bacteria play in a geogenic and pedogenic context is very likely to change deeply as soon as more habitat relevant microbial functions can be described. Examples for the identification of microbial processes from case studies may help to advance this field. The strongly interdisciplinary field of bio-geo-interactions spanning from the microorganism to the mineral holds much promise for future developments in both basic research as well as applied sciences. (c) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Properties of structural materials in liquid metal environment. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Borgstedt, H.U. [ed.

    1991-12-15

    The International Working Group on Fast Reactors (IWGFR) Specialists Meeting on Properties of Structural Materials in Liquid Metal Environment was held during June 18 to June 20, 1991, at the Nuclear Research Centre (Kernforschungszentrum) in Karlsruhe, Germany. The Specialists Meeting was divided into five technical sessions which addressed topics as follows: Creep-Rupture Behaviour of Structural Materials in Liquid Metal Environment; Behaviour of Materials in Liquid Metal Environments under Off-Normal Conditions;Fatigue and Creep-Fatigue of Structural Materials in Liquid Metal Environment; Crack Propagation in Liquid Sodium; and Conclusions and recommendations. Individual papers have been cataloged separately.

  18. Extreme Environment Ceramic-to-Metal Seal Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed Phase 1 program will demonstrate the feasibility of large ceramic to metal joints/seals that can tolerate extreme environments. The immediate...

  19. Toxic effect of heavy metals on aquatic environment | Baby ...

    African Journals Online (AJOL)

    Toxic effect of heavy metals on aquatic environment. ... International Journal of Biological and Chemical Sciences ... Remediation approaches such as excavation and land fill, thermal treatment, electroreclamation and soil capping have been ...

  20. REBATIMENTOS EM NATAL, BRASIL

    Directory of Open Access Journals (Sweden)

    Fábio Fonseca Figueiredo

    2013-01-01

    Full Text Available El artículo presenta la gestión de los residuos sólidos en Brasil y sus implicaciones en la ciudad de Natal/ RN, analizando sus aspectos ambientales, económicos y sociales. El fracaso del programa oficial de recogi - da selectiva constatado en las bajas tasas de recuperación de materiales; la poca relevancia de la inclusión socioeconómica de los trabajadores que participan en el programa asistencialista oficial; la inexistencia de estrategias oficiales para que se disminuya la cantidad de residuos que se generan cada día y el aumento exagerado del gasto público, especialmente con el tratamiento de los residuos en el relleno sanitario, demues - tran que la gestión de residuos en Natal, que tiene como parámetro los dictámenes de la Política Brasileña para los Residuos Sólidos, tiene como objetivo el control de los residuos en la ciudad y la consolidación del modelo de tratamiento finalista de residuos mediante el envío de éstos al relleno sanitario.

  1. Plasma-sprayed ceramic coatings for molten metal environments.

    Energy Technology Data Exchange (ETDEWEB)

    Hollis, K. J. (Kendall J.); Peters, M. I. (Maria I.); Bartram, B. D. (Brian D.)

    2002-01-01

    Coating porosity is an important parameter to optimize for plasma-sprayed ceramics which are intended for service in molten metal environments. Too much porosity and the coatings may be infiltrated by the molten metal causing corrosive attack of the substrate or destruction of the coating upon solidification of the metal. Too little porosity and the coating may fail due to its inability to absorb thermal strains. This study describes the testing and analysis of tungsten rods coated with aluminum oxide, yttria-stabilized zirconia, yttrium oxide, and erbium oxide deposited by atmospheric plasma spraying. The samples were immersed in molten aluminum and analyzed after immersion. One of the ceramic materials used, yttrium oxide, was heat treated at 1000 C and 2000 C and analyzed by X-ray diffractography and mercury intrusion porosimetry. Slight changes in crysl nl structure and significant changes in porosity were observed after heat treatments.

  2. Phytoremediation Opportunities with Alimurgic Species in Metal-Contaminated Environments

    Directory of Open Access Journals (Sweden)

    Marianna Bandiera

    2016-04-01

    Full Text Available Alimurgic species are edible wild plants growing spontaneously as invasive weeds in natural grassland and farmed fields. Growing interest in biodiversity conservation projects suggests deeper study of the multifunctional roles they can play in metal uptake for phytoremediation and their food safety when cultivated in polluted land. In this study, the responses of the tap-rooted perennial species Cichorium intybus L., Sonchus oleracerus L., Taraxacum officinale Web., Tragopogon porrifolius L. and Rumex acetosa L. were studied in artificially-highly Cd-Co-Cu-Pb-Zn-contaminated soil in a pot-scale trial, and those of T. officinale and R. acetosa in critical open environments (i.e., landfill, ditch sediments, and sides of highly-trafficked roads. Germination was not inhibited, and all species showed appreciable growth, despite considerable increases in tissue metal rates. Substantial growth impairments were observed in C. intybus, T. officinale and T. porrifolius; R. acetosa and S. oleracerus were only marginally affected. Zn was generally well translocated and reached a high leaf concentration, especially in T. officinale (~600 mg·kg−1·dry weight, DW, a result which can be exploited for phytoremediation purposes. The elevated Cd translocation also suggested applications to phytoextraction, particularly with C. intybus, in which leaf Cd reached ~16 mg·kg−1·DW. The generally high root retention of Pb and Cu may allow their phytostabilisation in the medium-term in no-tillage systems, together with significant reductions in metal leaching compared with bare soil. In open systems, critical soil Pb and Zn were associated with heavily trafficked roadsides, although this was only seldom reflected in shoot metal accumulation. It is concluded that a community of alimurgic species can serve to establish an efficient, long-lasting vegetation cover applied for phytoremediation and reduction of soil metal movements in degraded environments. However

  3. Removal of heavy metals from the environment by biosorption

    Energy Technology Data Exchange (ETDEWEB)

    Gavrilescu, M. [Technical University of Iasi, Faculty of Industrial Chemistry, Department of Environmental Engineering, Mangeron Blvd. 71, 6600-Iasi (Romania)

    2004-06-01

    The pollution of the environment with toxic metals is a result of many human activities, such as mining and metallurgy, and the effects of these metals on the ecosystems are of large economic and public-healthsignificance. This paper presents the features and advantages of the unconventional removal method of heavy metals - biosorption - as a part of bioremediation. Bioremediation consists of a group of applications, which involve the detoxification of hazardous substances instead of transferring them from one medium to another, by means of microbes and plants. This process is characterized as less disruptive and can be often carried out on site, eliminating the need to transport the toxic materials to treatment sites. The biosorption (sorption of metallic ions from solutions by live or dried biomass) offers an alternative to the remediation of industrial effluents as well as the recovery of metals contained in other media. Biosorbents are prepared from naturally abundant and/or waste biomass. Due to the high uptake capacity and very cost-effective source of the raw material, biosorption is a progression towards a perspective method. The mechanism by which microorganisms take up metals is relatively unclear, but it has been demonstrated that both living and non-living biomass may be utilized in biosorptive processes, as they often exhibit a marked tolerance towards metals and other adverse conditions. One of their major advantages is the treatment of large volumes of effluents with low concentrations of pollutants. Models developed were presented to determine both the number of adsorption sites required to bind each metal ion and the rate of adsorption, using a batch reactor mass balance and the Langmuir theory of adsorption to surfaces or continuous dynamic systems. Two main categories of bioreactors used in bioremediation - suspended growth and fixed film bioreactors - are discussed. Reactors with varying configurations to meet the different requirements for

  4. Combustion of Metals in Reduced-Gravity and Extraterrestrial Environment

    Science.gov (United States)

    Abbud-Madrid, A.; Omaly, P.; Branch, M. C.; Daily, J. W.

    1999-01-01

    -floating spherical metal samples and their corresponding long burning times available in reduced gravity. The first set of experiments has been conducted with magnesium (Mg) samples burning in the low-gravity environment generated by an aircraft flying parabolic trajectories. Owing to its high adiabatic flame temperature, oxidizer/fuel ratio, and heat per unit mass of fuel, as well as its low toxicity and low ignition temperature, Mg has been identified as a promising metal fuel with CO2 as oxidizer. The experimental effort is complemented by the development of a numerical model combining gas-phase chemical kinetics and transport mechanisms.

  5. Tribological researches of polimer-metal couples in environments

    Directory of Open Access Journals (Sweden)

    R. Kaczyński

    2010-01-01

    Full Text Available In the paper the results of experimental researches carried out for polymer strengthened carbon fibres-metal couple were presented. The binary scheme of surface layer’s wear in microarea was assumed.The attempt of kinetic’s analysis between matrix and filler with taking into consideration percentage share was carried out. The experiment were done using tribological model such as: probe-pin and antiprobe-disk. Qualitative and quantitative dependences of tribological couples in water and oil environment were determined.

  6. Trace Metal Source Terms in Carbon Sequestration Environments

    Energy Technology Data Exchange (ETDEWEB)

    Karamalidis, Athanasios K; Torres, Sharon G; Hakala, J Alexandra; Shao, Hongbo; Cantrell, Kirk J; Carroll, Susan

    2012-02-05

    Carbon dioxide sequestration in deep saline and depleted oil geologic formations is feasible and promising, however, possible CO₂ or CO₂-saturated brine leakage to overlying aquifers may pose environmental and health impacts. The purpose of this study was to experimentally define trace metal source terms from the reaction of supercritical CO₂, storage reservoir brines, reservoir and cap rocks. Storage reservoir source terms for trace metals are needed to evaluate the impact of brines leaking into overlying drinking water aquifers. The trace metal release was measured from sandstones, shales, carbonates, evaporites, basalts and cements from the Frio, In Salah, Illinois Basin – Decatur, Lower Tuscaloosa, Weyburn-Midale, Bass Islands and Grand Ronde carbon sequestration geologic formations. Trace metal dissolution is tracked by measuring solution concentrations over time under conditions (e.g. pressures, temperatures, and initial brine compositions) specific to the sequestration projects. Existing metrics for Maximum Contaminant Levels (MCLs) for drinking water as defined by the U.S. Environmental Protection Agency (U.S. EPA) were used to categorize the relative significance of metal concentration changes in storage environments due to the presence of CO₂. Results indicate that Cr and Pb released from sandstone reservoir and shale cap rock exceed the MCLs by an order of magnitude while Cd and Cu were at or below drinking water thresholds. In carbonate reservoirs As exceeds the MCLs by an order of magnitude, while Cd, Cu, and Pb were at or below drinking water standards. Results from this study can be used as a reasonable estimate of the reservoir and caprock source term to further evaluate the impact of leakage on groundwater quality.

  7. Trace metal source terms in carbon sequestration environments.

    Science.gov (United States)

    Karamalidis, Athanasios K; Torres, Sharon G; Hakala, J Alexandra; Shao, Hongbo; Cantrell, Kirk J; Carroll, Susan

    2013-01-02

    Carbon dioxide sequestration in deep saline and depleted oil geologic formations is feasible and promising; however, possible CO(2) or CO(2)-saturated brine leakage to overlying aquifers may pose environmental and health impacts. The purpose of this study was to experimentally define a range of concentrations that can be used as the trace element source term for reservoirs and leakage pathways in risk simulations. Storage source terms for trace metals are needed to evaluate the impact of brines leaking into overlying drinking water aquifers. The trace metal release was measured from cements and sandstones, shales, carbonates, evaporites, and basalts from the Frio, In Salah, Illinois Basin, Decatur, Lower Tuscaloosa, Weyburn-Midale, Bass Islands, and Grand Ronde carbon sequestration geologic formations. Trace metal dissolution was tracked by measuring solution concentrations over time under conditions (e.g., pressures, temperatures, and initial brine compositions) specific to the sequestration projects. Existing metrics for maximum contaminant levels (MCLs) for drinking water as defined by the U.S. Environmental Protection Agency (U.S. EPA) were used to categorize the relative significance of metal concentration changes in storage environments because of the presence of CO(2). Results indicate that Cr and Pb released from sandstone reservoir and shale cap rocks exceed the MCLs by an order of magnitude, while Cd and Cu were at or below drinking water thresholds. In carbonate reservoirs As exceeds the MCLs by an order of magnitude, while Cd, Cu, and Pb were at or below drinking water standards. Results from this study can be used as a reasonable estimate of the trace element source term for reservoirs and leakage pathways in risk simulations to further evaluate the impact of leakage on groundwater quality.

  8. War rape, natality and genocide.

    Science.gov (United States)

    Schott, Robin May

    2011-01-01

    Feminist philosophy can make an important contribution to the field of genocide studies, and issues relating to gender and war are gaining new attention. In this article I trace legal and philosophical analyses of sexual violence against women in war. I analyze the strengths and limitations of the concept of social death—introduced into this field by Claudia Card—for understanding the genocidal features of war rape, and draw on the work of Hannah Arendt to understand the central harm of genocide as an assault on natality. The threat to natality posed by the harms of rape, forced pregnancy and forced maternity lie in the potential expulsion from the public world of certain groups—including women who are victims, members of the 'enemy' group, and children born of forced birth.

  9. Trophic transfer of metal-based nanoparticles in aquatic environments

    DEFF Research Database (Denmark)

    Tangaa, Stine Rosendal; Selck, Henriette; Winther-Nielsen, Margrethe

    2016-01-01

    environment where they have been shown to be taken up by a variety of species. Therefore, there is a possibility that Me-ENPs will enter and pass through aquatic food webs, but research on this topic is limited. In this tutorial review, we discuss the factors contributing to trophic transfer of Me......-ENPs, and where this information is scarce, we utilize the existing literature on aqueous metal trophic transfer as a potential starting point for greater mechanistic insight and for setting directions for future studies. We identify four key factors affecting trophic transfer of Me-ENPs: (1) environmental...... transformations of Me-ENPs, (2) uptake and accumulation in prey organisms, (3) internal fate and localization in the prey, and (4) digestive physiology of the predator. Whilst much research has been conducted on the first two of these factors, key knowledge gaps exist in our understanding of how Me-ENP trophic...

  10. Biofouling of various metal oxides in marine environment

    Science.gov (United States)

    Kougo, T.; Kuroda, D.; Wada, N.; Ikegai, H.; Kanematsu, H.

    2012-03-01

    Biofouling has induced serious problems in various industrial fields such as marine structures, bio materials, microbially induced corrosion (MIC) etc. The effects of various metals on biofouling have been investigated so far and the mechanism has been clarified to some extent(1,2), and we proposed that Fe ion attracted lots of bacteria and formed biofilm very easily(3). In this study, we investigated the possibility for biofouling of Pseudomonas aeruginosa on various metal oxides such as Fe2O3, TiO2, WO3, AgO, Cr2O3 etc. And in addition of such a model experiment on laboratory scale, they were immersed into actual sea water as well as artificial sea water. As for the preparation of metal oxides, commercial oxide powders were used as starting material and those whose particle sizes were under 100 micrometers were formed into pellets by a press. Some of them were heated to 700 °C and sintered for 10 hours at the temperatures. After the calcinations, they were immersed into the culture of P. aeruginosa at 35 °C in about one week. After the immersion, they were taken out of the culture and the biofouling behaviors were observed by optical microscopy, low pressure scanning electron microscopy (low pressure SEM) etc. Biofouling is generally classified into several steps. Firstly, conditioning films composed of organic matters were formed on specimens. Then bacterial were attached to the specimen's surfaces, seeking for conditioning films as nutrition. Then bacteria formed biofilm on the specimens. In marine environment, more larger living matters such as shells etc would be attached to biofilms. However, in the culture media, only biofilms were formed.

  11. Trace metals in wine and vineyard environment in southern Ukraine.

    Science.gov (United States)

    Vystavna, Yuliya; Rushenko, Liliya; Diadin, Dmytro; Klymenko, Olga; Klymenko, Mykola

    2014-03-01

    The study was focused on measuring the concentration levels of trace metals in the environment, vines and wine within the wine-growing region of Ukraine and comparing the findings to the data from well known wine-growing areas. Analysis was carried out of Cr, Cu, Ni, Pb and Zn in irrigation water, grape juice and wine, Cu, Pb and Zn in soil (pseudo-total and acid-soluble fractions) and Vitis vinifera L. in leaves and grapes. The accumulation levels of Cu and Zn from soil to leaves were significantly higher than from soil to grapes. Pb had lower potential to accumulate in aerial parts than Cu and Zn. Higher contents of Cu and Zn were observed in Muscat white grape juice compared to Chardonnay. The concentration levels of Zn and Cu were higher in wine than in juice. Trace metals were regulated by the soil composition and biological specificity of cultivars. The data obtained from the study area did not exceed the international limits. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. How Environment Affects Galaxy Metallicity through Stripping and Formation History: Lessons from the Illustris Simulation

    CERN Document Server

    Genel, Shy

    2016-01-01

    Recent studies found higher galaxy metallicities in richer environments. It is not yet clear, however, whether metallicity-environment dependencies are merely an indirect consequence of environmentally-dependent formation histories, or of environment-related processes affecting metallicity directly. Here we present a first detailed study of metallicity-environment correlations in a cosmological hydrodynamical simulation, in particular the Illustris simulation. Illustris galaxies display similar relations to those observed. Utilizing knowledge of simulated formation histories, and leveraging the large simulation volume, we construct galaxy samples of satellites and centrals that are matched in formation histories. This allows us to find that ~1/3 of the metallicity-environment correlation is due to different formation histories in different environments. This is a combined effect of satellites (in particular in denser environments) having average lower z=0 star-formation rates (SFRs), and of their older stella...

  13. A New Strategy for Heavy Metal Polluted Environments: A Review of Microbial Biosorbents

    Directory of Open Access Journals (Sweden)

    Ayansina Segun Ayangbenro

    2017-01-01

    Full Text Available Persistent heavy metal pollution poses a major threat to all life forms in the environment due to its toxic effects. These metals are very reactive at low concentrations and can accumulate in the food web, causing severe public health concerns. Remediation using conventional physical and chemical methods is uneconomical and generates large volumes of chemical waste. Bioremediation of hazardous metals has received considerable and growing interest over the years. The use of microbial biosorbents is eco-friendly and cost effective; hence, it is an efficient alternative for the remediation of heavy metal contaminated environments. Microbes have various mechanisms of metal sequestration that hold greater metal biosorption capacities. The goal of microbial biosorption is to remove and/or recover metals and metalloids from solutions, using living or dead biomass and their components. This review discusses the sources of toxic heavy metals and describes the groups of microorganisms with biosorbent potential for heavy metal removal.

  14. A New Strategy for Heavy Metal Polluted Environments: A Review of Microbial Biosorbents

    Science.gov (United States)

    Ayangbenro, Ayansina Segun; Babalola, Olubukola Oluranti

    2017-01-01

    Persistent heavy metal pollution poses a major threat to all life forms in the environment due to its toxic effects. These metals are very reactive at low concentrations and can accumulate in the food web, causing severe public health concerns. Remediation using conventional physical and chemical methods is uneconomical and generates large volumes of chemical waste. Bioremediation of hazardous metals has received considerable and growing interest over the years. The use of microbial biosorbents is eco-friendly and cost effective; hence, it is an efficient alternative for the remediation of heavy metal contaminated environments. Microbes have various mechanisms of metal sequestration that hold greater metal biosorption capacities. The goal of microbial biosorption is to remove and/or recover metals and metalloids from solutions, using living or dead biomass and their components. This review discusses the sources of toxic heavy metals and describes the groups of microorganisms with biosorbent potential for heavy metal removal. PMID:28106848

  15. Capturing neon - the first experimental structure of neon trapped within a metal-organic environment.

    Science.gov (United States)

    Wood, Peter A; Sarjeant, Amy A; Yakovenko, Andrey A; Ward, Suzanna C; Groom, Colin R

    2016-08-21

    Despite being the fifth most abundant element in the atmosphere, neon has never been observed in an organic or metal-organic environment. This study shows the adsorption of this highly unreactive element within such an environment and reveals the first crystallographic observation of an interaction between neon and a transition metal.

  16. Natal Influences and Twin Differences: Draft.

    Science.gov (United States)

    Van den Daele, Leland D.

    1972-01-01

    A classification of natal influences is proposed with a model of their operation. Natal influences affect maternal capacity, maternal load, and maternal efficiency. Since maternal load is increased in twin pregnancy, results of twin studies must be generalized with caution. The method of co-twin control is exemplified by examination of a small…

  17. Survey of September 1987 Natal floods

    CSIR Research Space (South Africa)

    Badenhorst, P

    1989-01-01

    Full Text Available During the September 1987 floods in Natal various organisations collaborated by observing the effects of the floods. The efforts of the CSIR in Stellenbosch and Durban, and the Geology Departments of the Universities of Natal and Port Elizabeth were...

  18. Metal release from stainless steel in biological environments: A review.

    Science.gov (United States)

    Hedberg, Yolanda S; Odnevall Wallinder, Inger

    2015-03-29

    Due to its beneficial corrosion resistance, stainless steel is widely used in, e.g., biomedical applications, as surfaces in food contact, and for products intended to come into skin contact. Low levels of metals can be released from the stainless steel surface into solution, even for these highly corrosion resistant alloys. This needs to be considered in risk assessment and management. This review aims to compile the different metal release mechanisms that are relevant for stainless steel when used in different biological settings. These mechanisms include corrosion-induced metal release, dissolution of the surface oxide, friction-induced metal release, and their combinations. The influence of important physicochemical surface properties, different organic species and proteins in solution, and of biofilm formation on corrosion-induced metal release is discussed. Chemical and electrochemical dissolution mechanisms of the surface oxides of stainless steel are presented with a focus on protonation, complexation/ligand-induced dissolution, and reductive dissolution by applying a perspective on surface adsorption of complexing or reducing ligands and proteins. The influence of alloy composition, microstructure, route of manufacture, and surface finish on the metal release process is furthermore discussed as well as the chemical speciation of released metals. Typical metal release patterns are summarized.

  19. Super Lightweight, Metal Rubber Fabric for Extreme Space Environments Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NanoSonic has fabricated revolutionary nanostructured, yet macroscale, multifunctional Metal RubberTM films via layer-by-layer, molecular self-assembly, which...

  20. Tetracyclines metal complexation: Significance and fate of mutual existence in the environment.

    Science.gov (United States)

    Pulicharla, Rama; Hegde, Krishnamoorthy; Brar, Satinder Kaur; Surampalli, Rao Y

    2017-02-01

    Concern over tetracyclines (TCs) complexation with metals in the environment is growing as a new class of emerging contaminants. TCs exist as a different net charged species depending on their dissociation constants, pH and the surrounding environment. One of the key concerns about TCs is its strong tendency to interact with various metal ions and form metal complexes. Moreover, co-existence of TCs and metals in the environment and their interactions has shown increased antibiotic resistance. Despite extensive research on TCs complexation, investigations on their antibiotic efficiency and pharmacological profile in bacteria have been limited. In addition, the current knowledge on TCs metal complexation, their fate and risk assessment in the environment are inadequate to obtain a clear understanding of their consequences on living systems. This indicates that vital and comprehensive studies on TCs-metal complexation, especially towards growing antibiotic resistance trends are required. This review summarizes the role of TCs metal complexation on the development of antibiotic resistance. Furthermore, impact of metal complexation on degradation, toxicity and the fate of TCs in the environment are discussed and future recommendations have been made.

  1. Elemental distribution in seaweed, Gelidium abbottiorum along the KwaZulu-Natal Coastline, South Africa.

    Science.gov (United States)

    Misheer, Natasha; Kindness, Andrew; Jonnalagadda, Sreekanth B

    2006-01-01

    The total concentrations of 7 selected metals, namely manganese, iron, zinc, titanium, boron, arsenic and mercury, were monitored for one annual cycle covering four seasons in the seaweed, Gelidium abbottiorum, at four sampling sites at Zinkwasi, Ballito, Treasure beach and Park Rynie along the South-East coastline of KwaZulu-Natal, South Africa to assess the current status of the marine environment. Inductively Coupled Plasma Optical Emission Spectrophotometry, Mercury Cold Vapour AAS, and Hydride Generation AAS were used for the determination of metal concentrations. Mn concentrations were particularly high in the G. abbottiorum species, followed by Fe, As and B concentrations which were in the 3-8 ppm range. Ti and Zn were in the 100-400 ppb range, while Hg was low and below 100 ppb. A typical sample of G. abbottiorum at Treasure beach, a site close to Durban metropolis in winter had Mn (8.6 ppm), Fe (4.6 ppm), As (5.6 ppm), B (3.0 ppm), Ti (420 ppb), Zn (167 ppb) and Hg (7.5 ppb). All metals recorded a decrease in concentrations from winter to spring with the exception of Hg. The Hg levels increased considerably from winter to spring.

  2. The effect of colostrum on pigs pre-natally or post-natally exposed to Schistosoma japonicum

    DEFF Research Database (Denmark)

    Techau, M.E.; Johansen, M.V.; Lind, Peter

    2004-01-01

    Pre-natal infection of Schistosoma japonicum in pigs may prove to be a useful model in shedding light on human pre-natal schistosomiasis. This study describes the effects of immune colostrum on worm burdens, tissue egg counts, liver pathology and crude worm or egg antigen-specific IgG and Ig......A responses, in groups of pigs pre-natally, pre-natally + post-natally or post-natally exposed to S. japonicum. Results suggest that pre-natal exposure and immune colostrum did not affect the establishment of a post-natal challenge infection. However, immune colostrum seemed to increase the levels of septal...... fibrosis in pre-natally exposed pigs. These findings indicate that further investigations will prove valuable, elucidating the influence of the parasitological and immunological status of the sow, on pre-natally exposed pigs, and on the ability of these pigs to develop resistance against S. japonicum later...

  3. Modulation of Carbon Nanotube Metal Contacts in Gaseous Hydrogen Environment

    Directory of Open Access Journals (Sweden)

    A. R. Usgaocar

    2014-01-01

    Full Text Available Carbon nanotubes (CNTs, contacted by electrodeposited Pd0.59Ni0.41 alloys, are characterised using electrical measurements and Raman spectroscopy. The high workfunctions of Nickel and Palladium form an ohmic contact with the CNT valence band, but the contact properties change on Hydrogen exposure due to a reduction in the PdNi workfunction and the realignment of the PdNi Fermi level with the CNT band structure. A PdNi contacted semiconducting CNT exhibited significantly lower currents after Hydrogen exposure while a metallic CNT exhibited a small current increase. The semiconducting and metallic natures of the CNTs are confirmed by their Raman spectra. This study demonstrates a technique for modulating the PdNi-CNT contact and differentiating between semiconducting and metallic CNTs via contact modulation. It also provides experimental evidence of the theoretical allocation of features in the CNT Raman spectra.

  4. Bilingualism. Bilingual education. Natal/RN

    OpenAIRE

    Orlando Vian Jr; Janaina Weissheimer; Lígia Leite; Rodrigo Queiroz; Wilka Soares; José Mauro Uchôa; James Vasconcelos

    2013-01-01

    This paper aims at presenting a preliminary account of the bilingual education in Natal/RN based on the notions of bilingual (GROSJEAN, 1982; WEI, 2000) and bilingual education (HAMERS; BLANC, 2000; FISHMAN; LOVAS, 1970; DALE; TANNER, 2012). The data were collected through questionnaires and interviews in four private bilingual schools in Natal/RN. Results indicate that most of the schools include two languages concomitantly in their bilingual curriculum with differences as regards the hour l...

  5. Natural and active chemical remediation of toxic metals, organics, and radionuclides in the aquatic environment

    Energy Technology Data Exchange (ETDEWEB)

    McPherson, G.; Pintauro, P.; O`Connor, S. [and others

    1996-05-02

    This project focuses on the chemical aspects of remediation, with the underlying theme that chemical remediation does occur naturally. Included are studies on the fate of heavy metal and organic contaminants discharged into aquatic environments; accurate assay metal contaminants partitioned into soils, water and tissue; development of novel polymeric membranes and microporous solids for the entrapment of heavy metals; and the development of hybrid chemo-enzymatic oxidative schemes for aromatics decontamination. 49 refs.

  6. Metagenomic and Cultivation-Based Analysis of Novel Microorganisms and Functions in Metal-Contaminated Environments

    OpenAIRE

    Yelton, Alexis Pepper

    2012-01-01

    Some bacteria and archaea have evolved metabolic strategies that enable them to live in environments contaminated by toxic metals. In fact, many bacteria and archaea take advantage of the redox sensitivity of these very same metals to gain energy via anaerobic respiration. Here, metagenomic techniques were developed and applied along with conventional physiological and ecological methods to elucidate multiple modes of adaptation of bacteria and archaea in metal-contaminated acid mine drainage...

  7. Bioavailability and Bioaccumulation of Metal-Based Engineered Nanomaterials in Aquatic Environments

    DEFF Research Database (Denmark)

    Luoma, Samuel; Khan, Farhan R.; Croteau, Marie-Noelle

    2014-01-01

    Bioavailability of Me-ENMs to aquatic organisms links their release into the environment to ecological implications. Close examination shows some important differences in the conceptual models that define bioavailability for metals and Me-ENMs. Metals are delivered to aquatic animals from Me-ENMs...

  8. φXANES: In vivo imaging of metal-protein coordination environments

    Science.gov (United States)

    James, Simon A.; Hare, Dominic J.; Jenkins, Nicole L.; de Jonge, Martin D.; Bush, Ashley I.; McColl, Gawain

    2016-02-01

    We have developed an X-ray absorption near edge structure spectroscopy method using fluorescence detection for visualizing in vivo coordination environments of metals in biological specimens. This approach, which we term fluorescence imaging XANES (φXANES), allows us to spatially depict metal-protein associations in a native, hydrated state whilst avoiding intrinsic chemical damage from radiation. This method was validated using iron-challenged Caenorhabditis elegans to observe marked alterations in redox environment.

  9. An 'artificial mussel' for monitoring heavy metals in marine environments

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Rudolf S.S. [Centre for Coastal Pollution and Conservation, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)]. E-mail: bhrswu@cityu.edu.hk; Lau, T.C. [Centre for Coastal Pollution and Conservation, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Fung, Wendy K.M. [Centre for Coastal Pollution and Conservation, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Ko, P.H. [Centre for Coastal Pollution and Conservation, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Leung, Kenneth M.Y. [Swire Institute of Marine Science, Department of Ecology and Biodiversity, University of Hong Kong, Pokfulam, Hong Kong (China)

    2007-01-15

    A new chemical sampling device, artificial mussel (AM), has been developed for monitoring metals in marine environments. This device consists of a polymer ligand suspended in artificial seawater within a Perspex tubing, and enclosed with semi-permeable gel at both ends. Laboratory and field experiments were carried out to examine the uptake of five metals (Cd, Cr, Cu, Pb and Zn) by the AM. Uptake of metals by AM was proportional to the exposure metal concentrations, and the AM was able to accumulate the ASV labile fractions of metals. Uptake and release of the metals of AM are similar to those of the mussel Perna viridis, but less affected by salinity and temperature. Field studies demonstrated that the AM can not only provide a time-integrated estimate of metals concentrations, but also allows comparisons of metal levels in different environments and geographical areas beyond the natural distribution limits of biomonitors. - A new monitoring device to provide a time-integrated estimate for monitoring metals in marine environments.

  10. Genetic basis and importance of metal resistant genes in bacteria for bioremediation of contaminated environments with toxic metal pollutants.

    Science.gov (United States)

    Das, Surajit; Dash, Hirak R; Chakraborty, Jaya

    2016-04-01

    Metal pollution is one of the most persistent and complex environmental issues, causing threat to the ecosystem and human health. On exposure to several toxic metals such as arsenic, cadmium, chromium, copper, lead, and mercury, several bacteria has evolved with many metal-resistant genes as a means of their adaptation. These genes can be further exploited for bioremediation of the metal-contaminated environments. Many operon-clustered metal-resistant genes such as cadB, chrA, copAB, pbrA, merA, and NiCoT have been reported in bacterial systems for cadmium, chromium, copper, lead, mercury, and nickel resistance and detoxification, respectively. The field of environmental bioremediation has been ameliorated by exploiting diverse bacterial detoxification genes. Genetic engineering integrated with bioremediation assists in manipulation of bacterial genome which can enhance toxic metal detoxification that is not usually performed by normal bacteria. These techniques include genetic engineering with single genes or operons, pathway construction, and alternations of the sequences of existing genes. However, numerous facets of bacterial novel metal-resistant genes are yet to be explored for application in microbial bioremediation practices. This review describes the role of bacteria and their adaptive mechanisms for toxic metal detoxification and restoration of contaminated sites.

  11. Metal flame spray coating protects electrical cables in extreme environment

    Science.gov (United States)

    Brady, R. D.; Fox, H. A.

    1967-01-01

    Metal flame spray coating prevents EMF measurement error in sheathed instrumentation cables which are externally attached to cylinders which were cooled on the inside, but exposed to gamma radiation on the outside. The coating provides a thermoconductive path for radiation induced high temperatures within the cables.

  12. Evaluation of the vehicle contributions of metals to indoor environments.

    Science.gov (United States)

    Kuo, Chung-Yih; Wang, Jing-Ya; Liu, Wan-Tzu; Lin, Pin-Yu; Tsai, Ching-Tsan; Cheng, Man-Ting

    2012-09-01

    A large number of diesel vehicles carrying gravel and sand shuttle back and forth every day on the major thoroughfares (Tai-16 and Tai-21) from Shinyi to Jiji in Nantou, Taiwan. A total of 10 stations along the major thoroughfares were selected as the exposure sites, whereas a small village located ∼9 km from a main traffic route was selected as the control site. Outdoor and indoor aerosol samples were collected using high-volume samplers and Harvard samplers, respectively. The metal concentrations of outdoor and indoor PM(10) at the exposure sites were, respectively, higher than those at the control site. The plots between metal contents in the aerosols and road dust showed that diesel vehicles contributed significant amounts of metals to the outdoor and indoor aerosols at the exposure sites. Household dust samples along the roadside within 30 m of the main road in the small towns were collected using the wipe method. Based on the results of principal component analysis (PCA), three major components for household dust were identified: resuspended from road dust, brake wear and diesel emissions. Enrichment factors were applied to assess the contribution of pollution sources to household dust. These factors were calculated with respect to unpolluted river dust samples (EF(river)) and road dust (EF(road)). The differences between EF(river) and EF(road) could be mainly attributed to the effects of resuspension by passing vehicles. Approximately 72%, 68%, 68%, 73% and 86% of the vehicle-related metals Pb, Zn, Cu, Ni and Mo content, respectively, in household dust were the result of the resuspension of road dust by passing vehicles. The data of daily intakes of five metals (i.e., Fe, Pb, Cu, Ni and Mo) from inhalation and ingestion pathways showed that the doses from the ingestion pathway were much higher than those from the inhalation pathway.

  13. Beyond Metal Detectors: Creating Safe School Environments. The Editor Reflects.

    Science.gov (United States)

    Erb, Tom

    2000-01-01

    Discusses a model for the interactions between the elements of a safe school environment. Elements are curriculum, climate, and instruction leading to a safe setting, resulting in positive student outcomes. (JPB)

  14. Electrophilic Metal Alkyl Chemistry in New Ligand Environments

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Richard F. [University of Chicago

    2013-06-30

    The goals of this project were to design new electrophilic metal alkyl complexes and to exploit these systems in fundamental studies of olefin polymerization and other important and new catalytic reactions. A key target reaction is insertion copolymerization of olefins and polar CH2=CHX vinyl monomers such as vinyl halides and vinyl ethers. During the period covered by this report we (i) investigated the properties of ortho-alkoxy-arylphosphine ligands in Ni-based olefin polymerization catalysts, (ii) studied the synthesis of double-end-capped polyethylene using group 4 metal catalysts that contain tris-pyrazolylborate ligands, (iii) explored the ethylene insertion reactivity of group 4 metal tris-pyrazolyl-borate complexes, (iv) showed that (α-diimine)PdMe{sup +} species undergo multiple insertion of silyl vinyl ethers, (v) synthesized and explored the reactivity of base-free Ni benzyl complexes that contain ortho-phosphino-arene sulfonate ligands, (vi) established the mechanism of the reaction of vinyl chloride with (α-diimine)PdMe{sup +} catalysts, (vii) explored the role of cationic polymerization and insertion chemistry in the reactions of vinyl ethers with (α-diimine)PdMe{sup +} species, (viii) discovered a new class of self-assembled tetranuclear Pd catalysts that produce high molecular weight linear polyethylene and copolymerize ethylene and vinyl fluoride, and (ix) developed model systems that enabled investigation of cis-trans isomerization of {phosphine-sulfonate}Pd(II) complexes.

  15. Assessment of Trace Metals in Soil, Vegetation and Rodents in Relation to Metal Mining Activities in an Arid Environment.

    Science.gov (United States)

    Méndez-Rodríguez, Lia C; Alvarez-Castañeda, Sergio Ticul

    2016-07-01

    Areas where abandoned metal-extraction mines are located contain large quantities of mineral wastes derived from environmentally unsafe mining practices. These wastes contain many pollutants, such as heavy metals, which could be released to the environment through weathering and leaching, hence becoming an important source of environmental metal pollution. This study evaluates differences in the levels of lead, iron, nickel, manganese, copper and cadmium in rodents sharing the same type of diet under different microhabitat use in arid areas with past mining activities. Samples of soil, roots, branches and seeds of Palo Adán (Fouquieria diguetii) and specimens of two rodent species (Chaetodipus arenarius and C. spinatus) were collected in areas with impact from past metal mining activities as well as from areas with no mining impact. Both rodent species mirrored nickel and iron levels in soil and seeds, as well as lead levels in soil; however, C. arenarius accumulated higher levels of manganese, copper and cadmium.

  16. Energy Characteristics of Metal Nanofilms in the Dielectric Environment

    Directory of Open Access Journals (Sweden)

    A.V. Korotun

    2015-06-01

    Full Text Available The influence of a dielectric on the oscillations of the Fermi energy of nanometer metal films has been theoretically investigated. It has been shown within the model of rectangular finite-depth asymmetric potential well that the presence of a dielectric from one side of the film leads to the reduction of the maxima and displacement of the peaks on the left side of the size dependence of the Fermi energy, in contrast to the idealized case of a hypothetical film in vacuum. The calculations have been carried out for Au, Al and Cu films on SiO2 and Al2O3. This work was supported by the Ministry of Education and Science (project №04313.

  17. Heavy metal capture by autochthonous yeasts from a volcanic influenced environment of Patagonia.

    Science.gov (United States)

    Russo, Gabriel; Libkind, Diego; Giraudo, María Rosa; Delgado, Osvaldo Daniel

    2016-11-01

    Heavy metals at elevated concentrations are a major threat to agricultural and human health. Typically, human activities tend to release these metals to the environment in aqueous solutions, generating high levels of pollution due to the mobility of the heavy metals. The aim of the present work was to assess heavy metal tolerance in yeasts isolated from Río Agrio - Lake Caviahue volcanic acidic aquatic environment and to evaluate the capacity of selected strains to capture metals in acidic culture media conditions. The ability of three yeast species, Cryptococcus agrionensis, Cryptococcus sp. 2, and Coniochaeta fodinicola, to tolerate and capture metals in live cultures has been evaluated. These three yeast species showed high tolerance to low pH and elevated concentrations of metals, thus implying their autochthonous status. Minimal inhibitory concentration (MIC) for growth obtained for these isolates showed elevated tolerance to the six heavy metals evaluated and were significantly higher than those registered for other microorganisms. C. agrionensis was able to capture 15.80 mg (g biomass)(-1) of Cu(2+) (MIC: 0.22 g L(-1) ), Cryptococcus sp. 2 was able to capture 36.25 and 65.28 mg (g biomass)(-1) of Ni(2+) and Zn(2+) , respectively (MIC: 0.56 and 1.68, respectively), and C. fodinicola was able to capture 67.11 mg (g biomass)(-1) of Zn(2+) (MIC: 3.75). This work reported the ability of yeasts to capture metals in acidic conditions for the first time. We hope that it represents the step-stone for future researches in the ability and metabolism of yeasts form acidic aquatic environment related to metal tolerance and capture. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. A review of the global emissions, transport and effects of heavy metals in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, J.R.; Ashton, W.B.; Rapoport, R.D.

    1993-06-01

    The purpose of this report is to describe the current state of knowledge regarding the sources and quantities of heavy metal emissions, their transport and fate, their potential health and environmental effects, and strategies to control them. The approach is to review the literature on this topic and to consult with experts in the field. Ongoing research activities and research needs are discussed. Estimates of global anthropogenic and natural emissions indicate that anthropogenic emissions are responsible for most of the heavy metals released into the atmosphere and that industrial activities have had a significant impact on the global cycling of trace metals. The largest anthropogenic sources of trace metals are coal combustion and the nonferrous metal industry. Atmospheric deposition is an important pathway by which trace metals enter the environment. Atmospheric deposition varies according to the solubility of the element and the length of time it resides in the atmosphere. Evidence suggests that deposition is influenced by other chemicals in the atmosphere, such as ozone and sulfur dioxide. Trace metals also enter the environment through leaching. Existing emissions-control technologies such as electrostatic precipitators, baghouses, and scrubbers are designed to remove other particulates from the flue gas of coal-fired power plants and are only partially effective at removing heavy metals. Emerging technologies such as flue gas desulfurization, lignite coke, and fluidized bed combustion could further reduce emissions. 108 refs.

  19. A review of the global emissions, transport and effects of heavy metals in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, J.R.; Ashton, W.B.; Rapoport, R.D.

    1993-06-01

    The purpose of this report is to describe the current state of knowledge regarding the sources and quantities of heavy metal emissions, their transport and fate, their potential health and environmental effects, and strategies to control them. The approach is to review the literature on this topic and to consult with experts in the field. Ongoing research activities and research needs are discussed. Estimates of global anthropogenic and natural emissions indicate that anthropogenic emissions are responsible for most of the heavy metals released into the atmosphere and that industrial activities have had a significant impact on the global cycling of trace metals. The largest anthropogenic sources of trace metals are coal combustion and the nonferrous metal industry. Atmospheric deposition is an important pathway by which trace metals enter the environment. Atmospheric deposition varies according to the solubility of the element and the length of time it resides in the atmosphere. Evidence suggests that deposition is influenced by other chemicals in the atmosphere, such as ozone and sulfur dioxide. Trace metals also enter the environment through leaching. Existing emissions-control technologies such as electrostatic precipitators, baghouses, and scrubbers are designed to remove other particulates from the flue gas of coal-fired power plants and are only partially effective at removing heavy metals. Emerging technologies such as flue gas desulfurization, lignite coke, and fluidized bed combustion could further reduce emissions. 108 refs.

  20. Bilingualism. Bilingual education. Natal/RN

    Directory of Open Access Journals (Sweden)

    Orlando Vian Jr

    2013-12-01

    Full Text Available This paper aims at presenting a preliminary account of the bilingual education in Natal/RN based on the notions of bilingual (GROSJEAN, 1982; WEI, 2000 and bilingual education (HAMERS; BLANC, 2000; FISHMAN; LOVAS, 1970; DALE; TANNER, 2012. The data were collected through questionnaires and interviews in four private bilingual schools in Natal/RN. Results indicate that most of the schools include two languages concomitantly in their bilingual curriculum with differences as regards the hour load to work with each of the languages

  1. Average Power Handling Capability of Microstrip Passive Circuits Considering Metal Housing and Environment Conditions

    OpenAIRE

    Sánchez-Soriano, Miguel Ángel; Queré, Yves; Le Saux, Vincent; Quendo, Cédric; Cadiou, Stephane

    2014-01-01

    In this paper, the average power handling capability (APHC) of microstrip passive circuits considering the metal housing and environment conditions is investigated in detail. A systematic method is proposed for the computation of the APHC of microstrip circuits in open and enclosed metal housing configurations, typically used in microwave components. The method also yields an estimate of the maximum temperature in a microstrip circuit for a given input power. Closed-form equations accounting ...

  2. Atomistic Modeling of Corrosion Events at the Interface between a Metal and Its Environment

    Directory of Open Access Journals (Sweden)

    Christopher D. Taylor

    2012-01-01

    Full Text Available Atomistic simulation is a powerful tool for probing the structure and properties of materials and the nature of chemical reactions. Corrosion is a complex process that involves chemical reactions occurring at the interface between a material and its environment and is, therefore, highly suited to study by atomistic modeling techniques. In this paper, the complex nature of corrosion processes and mechanisms is briefly reviewed. Various atomistic methods for exploring corrosion mechanisms are then described, and recent applications in the literature surveyed. Several instances of the application of atomistic modeling to corrosion science are then reviewed in detail, including studies of the metal-water interface, the reaction of water on electrified metallic interfaces, the dissolution of metal atoms from metallic surfaces, and the role of competitive adsorption in controlling the chemical nature and structure of a metallic surface. Some perspectives are then given concerning the future of atomistic modeling in the field of corrosion science.

  3. Conductor of high electrical current at high temperature in oxygen and liquid metal environment

    Energy Technology Data Exchange (ETDEWEB)

    Powell, IV, Adam Clayton; Pati, Soobhankar; Derezinski, Stephen Joseph; Lau, Garrett; Pal, Uday B.; Guan, Xiaofei; Gopalan, Srikanth

    2016-01-12

    In one aspect, the present invention is directed to apparatuses for and methods of conducting electrical current in an oxygen and liquid metal environment. In another aspect, the invention relates to methods for production of metals from their oxides comprising providing a cathode in electrical contact with a molten electrolyte, providing a liquid metal anode separated from the cathode and the molten electrolyte by a solid oxygen ion conducting membrane, providing a current collector at the anode, and establishing a potential between the cathode and the anode.

  4. Metal dispersion resulting from mining activities in coastal environments: A pathways approach

    Science.gov (United States)

    Koski, Randolph A.

    2012-01-01

    Acid rock drainage (ARD) and disposal of tailings that result from mining activities impact coastal areas in many countries. The dispersion of metals from mine sites that are both proximal and distal to the shoreline can be examined using a pathways approach in which physical and chemical processes guide metal transport in the continuum from sources (sulfide minerals) to bioreceptors (marine biota). Large amounts of metals can be physically transported to the coastal environment by intentional or accidental release of sulfide-bearing mine tailings. Oxidation of sulfide minerals results in elevated dissolved metal concentrations in surface waters on land (producing ARD) and in pore waters of submarine tailings. Changes in pH, adsorption by insoluble secondary minerals (e.g., Fe oxyhydroxides), and precipitation of soluble salts (e.g., sulfates) affect dissolved metal fluxes. Evidence for bioaccumulation includes anomalous metal concentrations in bivalves and reef corals, and overlapping Pb isotope ratios for sulfides, shellfish, and seaweed in contaminated environments. Although bioavailability and potential toxicity are, to a large extent, functions of metal speciation, specific uptake pathways, such as adsorption from solution and ingestion of particles, also play important roles. Recent emphasis on broader ecological impacts has led to complementary methodologies involving laboratory toxicity tests and field studies of species richness and diversity.

  5. Microplastics as vector for heavy metal contamination from the marine environment

    Science.gov (United States)

    Brennecke, Dennis; Duarte, Bernardo; Paiva, Filipa; Caçador, Isabel; Canning-Clode, João

    2016-09-01

    The permanent presence of microplastics in the marine environment is considered a global threat to several marine animals. Heavy metals and microplastics are typically included in two different classes of pollutants but the interaction between these two stressors is poorly understood. During 14 days of experimental manipulation, we examined the adsorption of two heavy metals, copper (Cu) and zinc (Zn), leached from an antifouling paint to virgin polystyrene (PS) beads and aged polyvinyl chloride (PVC) fragments in seawater. We demonstrated that heavy metals were released from the antifouling paint to the water and both microplastic types adsorbed the two heavy metals. This adsorption kinetics was described using partition coefficients and mathematical models. Partition coefficients between pellets and water ranged between 650 and 850 for Cu on PS and PVC, respectively. The adsorption of Cu was significantly greater in PVC fragments than in PS, probably due to higher surface area and polarity of PVC. Concentrations of Cu and Zn increased significantly on PVC and PS over the course of the experiment with the exception of Zn on PS. As a result, we show a significant interaction between these types of microplastics and heavy metals, which can have implications for marine life and the environment. These results strongly support recent findings where plastics can play a key role as vectors for heavy metal ions in the marine system. Finally, our findings highlight the importance of monitoring marine litter and heavy metals, mainly associated with antifouling paints, particularly in the framework of the Marine Strategy Framework Directive (MSFD).

  6. Metal dispersion resulting from mining activities in coastal environments: a pathways approach

    Science.gov (United States)

    Koski, Randolph A.

    2012-01-01

    Acid rock drainage (ARD) and disposal of tailings that result from mining activities impact coastal areas in many countries. The dispersion of metals from mine sites that are both proximal and distal to the shoreline can be examined using a pathways approach in which physical and chemical processes guide metal transport in the continuum from sources (sulfide minerals) to bioreceptors (marine biota). Large amounts of metals can be physically transported to the coastal environment by intentional or accidental release of sulfide-bearing mine tailings. Oxidation of sulfide minerals results in elevated dissolved metal concentrations in surface waters on land (producing ARD) and in pore waters of submarine tailings. Changes in pH, adsorption by insoluble secondary minerals (e.g., Fe oxyhydroxides), and precipitation of soluble salts (e.g., sulfates) affect dissolved metal fluxes. Evidence for bioaccumulation includes anomalous metal concentrations in bivalves and reef corals, and overlapping Pb isotope ratios for sulfides, shellfish, and seaweed in contaminated environments. Although bioavailability and potential toxicity are, to a large extent, functions of metal speciation, specific uptake pathways, such as adsorption from solution and ingestion of particles, also play important roles. Recent emphasis on broader ecological impacts has led to complementary methodologies involving laboratory toxicity tests and field studies of species richness and diversity.

  7. Imaging of intracellular metal partitioning in marine diatoms exposed to metal pollution: consequences to cellular toxicity and metal fate in the environment.

    Science.gov (United States)

    Godinho, Rita M; Cabrita, Maria Teresa; Alves, Luís C; Pinheiro, Teresa

    2014-09-01

    This study investigates the metal content and compartmentalization changes in whole cells of diatom Coscinodiscus eccentricus exposed to metal overload, examining consequences to cellular toxicity, tolerance mechanisms, and metal fate in the environment. Cells exposed to Ni, Cu and Zn were analysed using nuclear microprobe techniques. Particle induced X-ray emission (PIXE), Rutherford backscattering spectrometry (RBS), and scanning transmission ion microscopy (STIM) were used simultaneously to obtain high-resolution imaging of morphological and quantitative elemental distribution data. Elemental partitioning within cell compartments, such as cell wall, cytoplasm and major organelles, was assessed. Diatoms clearly responded to excess metal levels, by changing cytoplasm morphology, concentrating added metals, and altering Fe transport mechanisms. Different metal accumulation patterns indicated high susceptibility to Cu, retained in the cytoplasm, and detoxification capability for Ni and Zn, mobilized to the vacuole. Iron and Zn were accumulated in the siliceous wall. Different metal distributions within the cell imply distinct environmental fates, Cu and Ni remain available with potential for biomagnification through the food web, whereas Fe and Zn are deposited at the bottom through frustule sedimentation.

  8. Natal Host Plants Can Alter Herbivore Competition

    Science.gov (United States)

    Pan, Huipeng; Preisser, Evan L.; Su, Qi; Jiao, Xiaoguo; Xie, Wen; Wang, Shaoli; Wu, Qingjun

    2016-01-01

    Interspecific competition between herbivores is widely recognized as an important determinant of community structure. Although researchers have identified a number of factors capable of altering competitive interactions, few studies have addressed the influence of neighboring plant species. If adaptation to/ epigenetic effects of an herbivore’s natal host plant alter its performance on other host plants, then interspecific herbivore interactions may play out differently in heterogeneous and homogenous plant communities. We tested wether the natal host plant of a whitefly population affected interactions between the Middle-east Asia Minor 1 (MEAM1) and Mediterranean (MED) cryptic species of the whitefly Bemisia tabaci by rearing the offspring of a cabbage-derived MEAM1 population and a poinsettia-derived MED population together on three different host plants: cotton, poinsettia, and cabbage. We found that MED dominated on poinsettia and that MEAM1 dominated on cabbage, results consistent with previous research. MED also dominated when reared with MEAM1 on cotton, however, a result at odds with multiple otherwise-similar studies that reared both species on the same natal plant. Our work provides evidence that natal plants affect competitive interactions on another plant species, and highlights the potential importance of neighboring plant species on herbivore community composition in agricultral systems. PMID:28030636

  9. Natal Host Plants Can Alter Herbivore Competition.

    Science.gov (United States)

    Pan, Huipeng; Preisser, Evan L; Su, Qi; Jiao, Xiaoguo; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Zhang, Youjun

    2016-01-01

    Interspecific competition between herbivores is widely recognized as an important determinant of community structure. Although researchers have identified a number of factors capable of altering competitive interactions, few studies have addressed the influence of neighboring plant species. If adaptation to/ epigenetic effects of an herbivore's natal host plant alter its performance on other host plants, then interspecific herbivore interactions may play out differently in heterogeneous and homogenous plant communities. We tested wether the natal host plant of a whitefly population affected interactions between the Middle-east Asia Minor 1 (MEAM1) and Mediterranean (MED) cryptic species of the whitefly Bemisia tabaci by rearing the offspring of a cabbage-derived MEAM1 population and a poinsettia-derived MED population together on three different host plants: cotton, poinsettia, and cabbage. We found that MED dominated on poinsettia and that MEAM1 dominated on cabbage, results consistent with previous research. MED also dominated when reared with MEAM1 on cotton, however, a result at odds with multiple otherwise-similar studies that reared both species on the same natal plant. Our work provides evidence that natal plants affect competitive interactions on another plant species, and highlights the potential importance of neighboring plant species on herbivore community composition in agricultral systems.

  10. Climate change enhances the mobilisation of naturally occurring metals in high altitude environments.

    Science.gov (United States)

    Zaharescu, Dragos G; Hooda, Peter S; Burghelea, Carmen I; Polyakov, Viktor; Palanca-Soler, Antonio

    2016-08-01

    Manmade climate change has expressed a plethora of complex effects on Earth's biogeochemical compartments. Climate change may also affect the mobilisation of natural metal sources, with potential ecological consequences beyond mountains' geographical limits; however, this question has remained largely unexplored. We investigated this by analysing a number of key climatic factors in relationship with trace metal accumulation in the sediment core of a Pyrenean lake. The sediment metal contents showed increasing accumulation trend over time, and their levels varied in step with recent climate change. The findings further revealed that a rise in the elevation of freezing level, a general increase in the frequency of drier periods, changes in the frequency of winter freezing days and a reducing snow cover since the early 1980s, together are responsible for the observed variability and augmented accumulation of trace metals. Our results provide clear evidence of increased mobilisation of natural metal sources - an overlooked effect of climate change on the environment. With further alterations in climate equilibrium predicted over the ensuing decades, it is likely that mountain catchments in metamorphic areas may become significant sources of trace metals, with potentially harmful consequences for the wider environment.

  11. Draft Genome Sequences of 10 Microbacterium spp., with Emphasis on Heavy Metal-Contaminated Environments.

    Science.gov (United States)

    Corretto, Erika; Antonielli, Livio; Sessitsch, Angela; Kidd, Petra; Weyens, Nele; Brader, Günter

    2015-05-14

    Microbacterium spp. isolated from heavy metal (HM)-contaminated environments (soil and plants) can play a role in mobilization processes and in the phytoextraction of HM. Here, we report the whole-genome sequences and annotation of 10 Microbacterium spp. isolated from both HM-contaminated and -noncontaminated compartments. Copyright © 2015 Corretto et al.

  12. Natal foraging philopatry in eastern Pacific hawksbill turtles.

    Science.gov (United States)

    Gaos, Alexander R; Lewison, Rebecca L; Jensen, Michael P; Liles, Michael J; Henriquez, Ana; Chavarria, Sofia; Pacheco, Carlos Mario; Valle, Melissa; Melero, David; Gadea, Velkiss; Altamirano, Eduardo; Torres, Perla; Vallejo, Felipe; Miranda, Cristina; LeMarie, Carolina; Lucero, Jesus; Oceguera, Karen; Chácon, Didiher; Fonseca, Luis; Abrego, Marino; Seminoff, Jeffrey A; Flores, Eric E; Llamas, Israel; Donadi, Rodrigo; Peña, Bernardo; Muñoz, Juan Pablo; Ruales, Daniela Alarcòn; Chaves, Jaime A; Otterstrom, Sarah; Zavala, Alan; Hart, Catherine E; Brittain, Rachel; Alfaro-Shigueto, Joanna; Mangel, Jeffrey; Yañez, Ingrid L; Dutton, Peter H

    2017-08-01

    The complex processes involved with animal migration have long been a subject of biological interest, and broad-scale movement patterns of many marine turtle populations still remain unresolved. While it is widely accepted that once marine turtles reach sexual maturity they home to natal areas for nesting or reproduction, the role of philopatry to natal areas during other life stages has received less scrutiny, despite widespread evidence across the taxa. Here we report on genetic research that indicates that juvenile hawksbill turtles (Eretmochelys imbricata) in the eastern Pacific Ocean use foraging grounds in the region of their natal beaches, a pattern we term natal foraging philopatry. Our findings confirm that traditional views of natal homing solely for reproduction are incomplete and that many marine turtle species exhibit philopatry to natal areas to forage. Our results have important implications for life-history research and conservation of marine turtles and may extend to other wide-ranging marine vertebrates that demonstrate natal philopatry.

  13. The evaluation of different environments in ultra-high frequency induction sintered powder metal compacts

    Energy Technology Data Exchange (ETDEWEB)

    Cavdar, P. S.; Cavdar, U.

    2015-03-30

    The application of the iron based Powder Metal (PM) compacts in Ultra-High Frequency Induction Sintering (UHFIS) was reviewed for different environments. The three different environments: atmosphere, argon and vacuum were applied to the PM compacts. Iron based PM compacts were sintered at 1120 degree centigrade for a total of 550 seconds by using induction sintering machines with 2.8 kW power and 900 kHz frequency. Micro structural properties, densities, roughness and micro hardness values were obtained for all environments. The results were compared with each other. (Author)

  14. The High-Metallicity Explosion Environment of the Relativistic Supernova 2009bb

    CERN Document Server

    Levesque, E M; Foley, R J; Berger, E; Kewley, L J; Chakraborty, S; Ray, A; Torres, M A P; Challis, P; Kirshner, R P; Barthelmy, S D; Bietenholz, M F; Chandra, P; Chaplin, V; Chevalier, R A; Chugai, N; Connaughton, V; Copete, A; Fox, O; Fransson, C; Grindlay, J E; Hamuy, M A; Milne, P A; Pignata, G; Stritzinger, M D; Wieringa, M H

    2009-01-01

    We investigate the environment of the nearby (d ~ 40Mpc) broad-lined Type Ic supernova SN 2009bb. This event was observed to produce a relativistic outflow likely powered by a central accreting compact object. While such a phenomenon was previously observed only in long-duration gamma-ray bursts (LGRBs), no LGRB was detected in association with SN 2009bb. Using an optical spectrum of the SN 2009bb explosion site, we determine a variety of ISM properties for the host environment, including metallicity, young stellar population age, and star formation rate. We compare the SN explosion site properties to observations of LGRB and broad-lined SN Ic host environments on optical emission line ratio diagnostic diagrams. Based on these analyses, we find that the SN 2009bb explosion site has a very high metallicity of ~2x solar, in agreement with other broad-lined SN Ic host environments and at odds with the low-redshift LGRB host environments and recently proposed maximum metallicity limits for relativistic explosions...

  15. Behavior and Potential Impacts of Metal-Based Engineered Nanoparticles in Aquatic Environments

    Directory of Open Access Journals (Sweden)

    Cheng Peng

    2017-01-01

    Full Text Available The specific properties of metal-based nanoparticles (NPs have not only led to rapidly increasing applications in various industrial and commercial products, but also caused environmental concerns due to the inevitable release of NPs and their unpredictable biological/ecological impacts. This review discusses the environmental behavior of metal-based NPs with an in-depth analysis of the mechanisms and kinetics. The focus is on knowledge gaps in the interaction of NPs with aquatic organisms, which can influence the fate, transport and toxicity of NPs in the aquatic environment. Aggregation transforms NPs into micrometer-sized clusters in the aqueous environment, whereas dissolution also alters the size distribution and surface reactivity of metal-based NPs. A unique toxicity mechanism of metal-based NPs is related to the generation of reactive oxygen species (ROS and the subsequent ROS-induced oxidative stress. Furthermore, aggregation, dissolution and ROS generation could influence each other and also be influenced by many factors, including the sizes, shapes and surface charge of NPs, as well as the pH, ionic strength, natural organic matter and experimental conditions. Bioaccumulation of NPs in single organism species, such as aquatic plants, zooplankton, fish and benthos, is summarized and compared. Moreover, the trophic transfer and/or biomagnification of metal-based NPs in an aquatic ecosystem are discussed. In addition, genetic effects could result from direct or indirect interactions between DNA and NPs. Finally, several challenges facing us are put forward in the review.

  16. Type II supernovae as probes of environment metallicity: observations of host HII regions

    CERN Document Server

    Anderson, J P; Dessart, L; Hamuy, M; Galbany, L; Morrell, N I; Stritzinger, M D; Phillips, M M; Folatelli, G; Boffin, H M J; de Jaeger, T; Kuncarayakti, H; Prieto, J L

    2016-01-01

    Spectral modelling of SNII atmospheres indicates a clear dependence of metal line strengths on progenitor metallicity. This motivates further work to evaluate the accuracy with which these SNe can be used as metallicity indicators. To assess this accuracy we present a sample of SNII HII-region spectroscopy, from which environment abundances are derived. These environment abundances are compared to the observed strength of metal lines in SN spectra. Combining our sample with measurements from the literature, we present oxygen abundances of 119 host HII regions, by extracting emission line fluxes and using abundance diagnostics. Then, following Dessart et al., these abundances are compared to equivalent widths of Fe 5018 A at various time and colour epochs. Our distribution of inferred SNII host HII-region abundances has a range of ~0.6 dex. We confirm the dearth of SNeII exploding at metallicities lower than those found (on average) in the Large Magellanic Cloud. The equivalent width of Fe 5018 A at 50 days po...

  17. Heavy metals removal from aqueous environments by electrocoagulation process- a systematic review.

    Science.gov (United States)

    Bazrafshan, Edris; Mohammadi, Leili; Ansari-Moghaddam, Alireza; Mahvi, Amir Hossein

    2015-01-01

    Heavy metals pollution has become a more serious environmental problem in the last several decades as a result releasing toxic materials into the environment. Various techniques such as physical, chemical, biological, advanced oxidation and electrochemical processes were used for the treatment of domestic, industrial and agricultural effluents. The commonly used conventional biological treatments processes are not only time consuming but also need large operational area. Accordingly, it seems that these methods are not cost-effective for effluent containing toxic elements. Advanced oxidation techniques result in high treatment cost and are generally used to obtain high purity grade water. The chemical coagulation technique is slow and generates large amount of sludge. Electrocoagulation is an electrochemical technique with many applications. This process has recently attracted attention as a potential technique for treating industrial wastewater due to its versatility and environmental compatibility. This process has been applied for the treatment of many kinds of wastewater such as landfill leachate, restaurant, carwash, slaughterhouse, textile, laundry, tannery, petroleum refinery wastewater and for removal of bacteria, arsenic, fluoride, pesticides and heavy metals from aqueous environments. The objective of the present manuscript is to review the potential of electrocoagulation process for the treatment of domestic, industrial and agricultural effluents, especially removal of heavy metals from aqueous environments. About 100 published studies (1977-2016) are reviewed in this paper. It is evident from the literature survey articles that electrocoagulation are the most frequently studied for the treatment of heavy metal wastewater.

  18. Electromagnetic environment and Peltier effect in normal-metal/insulator/superconductor junction

    Science.gov (United States)

    Bardas, Athanassios

    1997-07-01

    The influence of external environment on the heat transport through a tunnel junction connecting a normal-metal and a superconductor is analyzed theoretically. It is demonstrated that at finite temperatures finite impedance of the junction electrodes, limits the maximum amount of heat that can be extracted from the normal-metal via the electric current and thus reduces the efficiency of the thermoelectric electron refrigeration. This behaviour is more pronounced for charging energies Ec of the junction, larger than the superconducting gap Δ and persists for a wide range of values of the impedance.

  19. Bioremediation of Heavy Metals from Soil and Aquatic Environment: An Overview of Principles and Criteria of Fundamental Processes

    OpenAIRE

    Ruchita Dixit; Wasiullah; Deepti Malaviya; Kuppusamy Pandiyan; Singh, Udai B; Asha Sahu; Renu Shukla; Singh, Bhanu P.; Jai P. Rai; Pawan Kumar Sharma; Harshad Lade; Diby Paul

    2015-01-01

    Heavy metals are natural constituents of the environment, but indiscriminate use for human purposes has altered their geochemical cycles and biochemical balance. This results in excess release of heavy metals such as cadmium, copper, lead, nickel, zinc etc. into natural resources like the soil and aquatic environments. Prolonged exposure and higher accumulation of such heavy metals can have deleterious health effects on human life and aquatic biota. The role of microorganisms and plants in bi...

  20. NATALITY AND BIOPOLITICS IN HANNAH ARENDT

    Directory of Open Access Journals (Sweden)

    MIGUEL VATTER

    2006-01-01

    Full Text Available This essay discusses the genesis of Arendt's concept of natality, and the reasons that led her to claim natality as a fundamental concept of political thought. The essay argues against the widespread thesis that Arendt took her idea of natality from Heidegger's existential analysis of human life. It argues, instead, that Arendt's account of natality should be situated within the discourse of bio-politics, and that it is based on a conception of life that is anti-Heideggerian. Arendt's political thought is a species of bio-politics that counters totalitarianism on its own terrain, namely, by identifying what in life poses a resistance to the totalitarian project of attaining total domination over lifeEste ensayo discute la génesis del concepto de la natalidad en Arendt, y las razones que la llevaron a proclamar la natalidad como un concepto fundamental del pensamiento político. El trabajo argumenta en contra de la tesis comúnmente aceptada según la cual Arendt habría sacado el concepto de natalidad de la analítica existencial de Heidegger. Por lo contrario, el escrito propone que el discurso arendtiano sobre la natalidad debe ser visto como parte de un discurso sobre la bio-política, y que está basado sobre un concepto de vida anti-Heideggeriano. El pensamiento político de Arendt es una especie de bio-política que contrasta al totalitarismo en su propio terreno, es decir, identificando los aspectos de la vida que oponen resistencia al proyecto totalitario de dominio absoluto sobre la vida

  1. 3. Martin Luther: Forerunner of Natalism?

    OpenAIRE

    McKeown, John

    2016-01-01

    Martin Luther is the most important figure in the 16th century change in attitudes toward marriage and childbearing in western Christianity. Although he had little to say about population size, he discussed human fertility more extensively than any other early Protestant leader. Luther paved the way for modern natalism through his rhetorical exaltation of the biological family. Before him the primary models of ideal Christian leadership had been celibate Jesus with his twelve disciples, or ce...

  2. Natal Host Plants Can Alter Herbivore Competition

    OpenAIRE

    Pan, Huipeng; Evan L. Preisser; Su, Qi; Jiao, Xiaoguo; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Zhang, Youjun

    2016-01-01

    Interspecific competition between herbivores is widely recognized as an important determinant of community structure. Although researchers have identified a number of factors capable of altering competitive interactions, few studies have addressed the influence of neighboring plant species. If adaptation to/ epigenetic effects of an herbivore’s natal host plant alter its performance on other host plants, then interspecific herbivore interactions may play out differently in heterogeneous and h...

  3. Combustion of Metals in Reduced-Gravity and Extra Terrestrial Environments

    Science.gov (United States)

    Branch, M.C.; Abbud-Madrid, A.; Daily, J. W.

    1999-01-01

    The combustion of metals is a field with important practical applications in rocket propellants, high-temperature flames, and material synthesis. Also, the safe operation of metal containers in high-pressure oxygen systems and with cryogenic fuels and oxidizers remains an important concern in industry. The increasing use of metallic components in spacecraft and space structures has also raised concerns about their flammability properties and fire suppression mechanisms. In addition, recent efforts to embark on unmanned and manned planetary exploration, such as on Mars, have also renewed the interest in metal/carbon-dioxide combustion as an effective in situ resource utilization technology. In spite of these practical applications, the understanding of the combustion properties of metals remains far behind that of the most commonly used fuels such as hydrocarbons. The lack of understanding is due to the many problems unique to metal- oxidizer reactions such as: low-temperature surface oxidation prior to ignition, heterogeneous reactions, very high combustion temperatures, product condensation, high emissivity of products, and multi-phase interactions. Very few analytical models (all neglecting the influence of gravity) have been developed to predict the burning characteristics and the flame structure details. Several experimental studies attempting to validate these models have used small metal particles to recreate gravity-free conditions. The high emissivity of the flames, rapid reaction, and intermittent explosions experienced by these particles have made the gathering of any useful information on burning rates and flame structure very difficult. The use of a reduced gravity environment is needed to clarify some of the complex interactions among the phenomena described above. First, the elimination of the intrusive buoyant flows that plague all combustion phenomena is of paramount importance in metal reactions due to the much higher temperatures reached during

  4. Definitions and principles for bioindication and biomonitoring of trace metals in the environment.

    Science.gov (United States)

    Markert, Bernd

    2007-01-01

    Clear-cut definitions are given for most terms used in monitoring studies. In these studies the observation or experimental investigation of living organisms give a qualitative or quantitative information on the state of the environment with special reference to trace metals. The focus and future goals of biogeochemical research must consider the direct effects on human health, by including modelling of active biogeochemical processes than they have done so far. Newly developed strategies as the multi-markered bioindication concept (MMBC) with its functional and integrated windows on prophylactic healthcare are essential tools for successfully observing the environment with respect to trace metals. An intensified training of students and a strong hand in hand work between industrial, educational and public institutions is necessary.

  5. The metal-driven biogeochemistry of gaseous compounds in the environment

    CERN Document Server

    Kroneck, Peter MH

    2014-01-01

    MILS-14 provides a most up-to-date view of the exciting biogeochemistry of gases in our environment as driven mostly by microorganisms. These employ a machinery of sophisticated metalloenzymes, where especially transition metals (such as Fe, Ni, Cu, Mo, W) play a fundamental role, that is, in the activation, transformation and syntheses of gases like dihydrogen, methane, carbon monoxide, acetylene and those of the biological nitrogen and sulfur cycles. The Metal-Driven Biogeochemistry of Gaseous Compounds in the Environment is a vibrant research area based mainly on structural and microbial biology, inorganic biological chemistry and environmental biochemistry. All this is covered in an authoritative manner in 11 stimulating chapters, written by 26 internationally recognized experts and supported by nearly 1200 references, informative tables and about 100 illustrations (two thirds in color). MILS-14 also provides excellent information for teaching. Peter M. H. Kroneck is a bioinorganic chemist who is explorin...

  6. Imprinted Genes and the Environment: Links to the Toxic Metals Arsenic, Cadmium and Lead

    Directory of Open Access Journals (Sweden)

    Lisa Smeester

    2014-06-01

    Full Text Available Imprinted genes defy rules of Mendelian genetics with their expression tied to the parent from whom each allele was inherited. They are known to play a role in various diseases/disorders including fetal growth disruption, lower birth weight, obesity, and cancer. There is increasing interest in understanding their influence on environmentally-induced disease. The environment can be thought of broadly as including chemicals present in air, water and soil, as well as food. According to the Agency for Toxic Substances and Disease Registry (ATSDR, some of the highest ranking environmental chemicals of concern include metals/metalloids such as arsenic, cadmium, lead and mercury. The complex relationships between toxic metal exposure, imprinted gene regulation/expression and health outcomes are understudied. Herein we examine trends in imprinted gene biology, including an assessment of the imprinted genes and their known functional roles in the cell, particularly as they relate to toxic metals exposure and disease. The data highlight that many of the imprinted genes have known associations to developmental diseases and are enriched for their role in the TP53 and AhR pathways. Assessment of the promoter regions of the imprinted genes resulted in the identification of an enrichment of binding sites for two transcription factor families, namely the zinc finger family II and PLAG transcription factors. Taken together these data contribute insight into the complex relationships between toxic metals in the environment and imprinted gene biology.

  7. Condensation of refractory metals in asymptotic giant branch and other stellar environments

    Energy Technology Data Exchange (ETDEWEB)

    Schwander, D.; Berg, T.; Schönhense, G.; Ott, U., E-mail: schwandd@uni-mainz.de [Institut für Physik, Johannes Gutenberg-Universität, Staudingerweg 7, D-55128 Mainz (Germany)

    2014-09-20

    The condensation of material from a gas of solar composition has been extensively studied, but less so condensation in the environment of evolved stars, which has been mainly restricted to major compounds and some specific element groups such as the Rare Earth elements. Also of interest, however, are refractory metals like Mo, Ru, Os, W, Ir, and Pt, which may condense to form refractory metal nuggets (RMNs) like the ones that have been found in association with presolar graphite. We have performed calculations describing the condensation of these elements in the outflows of s-process enriched AGB stars as well as from gas enriched in r-process products. While in carbon-rich environments (C > O), the formation of carbides is expected to consume W, Mo, and V (Lodders and Fegley), the condensation sequence for the other refractory metals under these conditions does not significantly differ from the case of a cooling gas of solar composition. The composition in detail, however, is significantly different due to the completely different source composition. Condensation from an r-process enriched source differs less from the solar case. Elemental abundance ratios of the refractory metals can serve as a guide for finding candidate presolar grains among the RMNs in primitive meteorites—most of which have a solar system origin—for confirmation by isotopic analysis. We apply our calculations to the case of the four RMNs found by Croat et al., which may very well be presolar.

  8. Applying physicochemical approaches to control phosphogypsum heavy metal releases in aquatic environment.

    Science.gov (United States)

    Ammar, Rawaa; El Samrani, Antoine G; Kazpard, Véronique; Bassil, Joseph; Lartiges, Bruno; Saad, Zeinab; Chou, Lei

    2013-12-01

    One of the most important sources of solid waste in the Mediterranean Basin ecosystem originated from the phosphate fertilizer industries, which discharge phosphogypsum (PG) directly into aquatic environments or are stacked on stockpiles. The present study investigates metal release from PG under the influence of variable pH, increasing PG mass content, and complexing organic matter ligands. Major ions from PG leachates, grain size and charge, main functional groups along with metal leachability (Pb, Cd, Cr, Cu, and Zn) were determined using ion chromatography, laser diffraction, zetameter, Fourier transform infrared spectroscopy, and atomic absorption spectroscopy, respectively. The complete dissolution of PG recorded is at 2 g/L. Saturation and supersaturation with respect to PG may occur at concentrations of 3 and 4 g/L, respectively, revealing a clustering phenomenon leading to heavy metal encapsulation within the aggregates. Organic ligands such as citrate may trigger the cationic exchange within the PG suspension leading to ion release. As these factors are considered as specific process involving the release of contaminants from PG during storage under natural conditions, this study could set the foundations for PG remediation in aquatic environment. Organic ligands under controlled pH conditions could be utilized in treating fertilizer industrial wastes by taking into consideration the particularity of the receiving area, thus decreasing metal hazardous impact on natural media.

  9. Nonequilibrium electron transport in a hybrid superconductor-normal metal entangler in a dissipative environment

    Science.gov (United States)

    Bubanja, Vladimir; Yamamoto, Mayumi; Iwabuchi, Shuichi

    2016-11-01

    We consider a three-terminal Cooper-pair splitting device with a superconducting electrode tunnel coupled to two normal metal electrodes. We employ the Nambu-Gor'kov and Schwinger-Keldysh formalisms to describe the nonequilibrium transport properties of the device for arbitrary transmissions of the barriers and for a general electromagnetic environment. We derive the analytic expressions for the current and the nonlocal differential conductance, and analyze the limits of clean and dirty superconductivity.

  10. Study of metal concentrations in the environment near diesel transport routes

    Science.gov (United States)

    Kuo, Chung-Yih; Wang, Jing-Ya; Chang, Shih-Hsien; Chen, Mei-Chun

    In recent years, a river-dredging project has been executed in Nantou, Taiwan. A large number of diesel vehicles carrying gravel and sand shuttle back and forth on the main traffic roads (Tai-16 and Tai-21). The purpose of this study is to figure out the levels of metals contributed by those vehicles to the surrounding environment. Eight stations along the roadside of diesel transport routes were selected as exposure sites, while a small village located about 9 km away from the diesel transport routes was selected as the control site. The mass concentrations of coarse and fine particulate matter indicated that contributions from traffic fleets resulted in a higher percentage of coarse particulate matter in the ambient air at exposure sites in comparison with that at control site. Significantly higher values of EC (elemental carbon) concentrations and ratios of EC/OC (organic carbon) at exposure sites indicate that diesel vehicles at exposure sites contributed a greater amount of pollutants than gasoline vehicles. Exposure site concentrations for all metals measured (Fe, Al, Mn, Pb, Zn, Cu, Ni, Mo and As) for fine and coarse particulate matter were all higher than those at the control site. Recorded levels of metal contents in road dust and riverside soil near Tai-16 and Tai-21 showed that while the traffic fleet did not increase the metal contents of crustal elements in the road dust, it did significantly increase the metal contents of traffic-related elements. Enrichment factors (EFs) were calculated with respect to road dust (EF road) and with respect to the samples of riverside soil (EF river). Among these metals, Mo was the most highly-enriched metal. The extremely high EF river value (4300) of Mo indicates that these stations were highly polluted by diesel emission. Whereas the significantly high EF road value (810) of Mo implies that a considerable of Mo was emitted from tailpipe of diesel vehicles.

  11. Relationships between metal concentrations in great tit nestlings and their environment and food

    Energy Technology Data Exchange (ETDEWEB)

    Dauwe, Tom; Janssens, Ellen; Bervoets, Lieven; Blust, Ronny; Eens, Marcel

    2004-10-01

    Metal concentrations (Ag, As, Cd, Cu, Hg, Ni, Pb, Zn) were determined in the feathers and excreta of nestling great tits (Parus major), in their main invertebrate prey (Lepidoptera larvae) and in vegetation samples, all collected from four sites along a pollution gradient. Metal contamination in vegetation samples increased significantly towards the pollution source. The Ag, As, Hg, Ni and Pb concentrations in food samples were significantly higher at the site closest to the pollution source compared to the other three sites. Great tit nestlings from the site closest to the pollution source had significantly higher concentrations of Ag, As, Hg and Pb in their excreta than did nestlings at the other three sites. For five metals (Ag, As, Cu, Ni and Pb), we found concentrations in caterpillars to be significantly positively correlated with vegetation samples. We also found clear significant positive correlations between excreta and caterpillars for Ag, As, Hg and Pb and between feathers and caterpillars for As and Pb. Our data suggest that excreta are a good monitor for the presence and concentrations of non-essential metals in the food and the environment of passerine birds.

  12. Periodical structures induced by femtosecond laser on metals in air and liquid environments

    Science.gov (United States)

    Albu, Catalina; Dinescu, Adrian; Filipescu, Mihaela; Ulmeanu, Magdalena; Zamfirescu, Marian

    2013-08-01

    Ripples or laser-induced periodic surface structures (LIPSS) are obtained on metallic films (Cr, Ti, and W) by femtosecond laser pulses working at both fundamental (775 nm) and frequency doubled (387 nm) wavelengths in air and liquid environments. The metallic samples were irradiated at normal incidence, in air and by immersing them in water (H2O), ethanol (C2H5OH) or chloroform (CHCl3). Different morphologies were observed after laser irradiation on the material surface, depending on material, environments and the laser irradiation parameters. We observed areas of ripples or nanostructures (NS) at both irradiation laser wavelengths in all environments used. The morphology of the formed structures was studied by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The analysis of images obtained revealed two kinds of ripples: low spatial frequency LIPSS (LSFL) with a periodicity from 350 to 600 nm, and high spatial frequency LIPSS (HSFL) with a periodicity from about 50 to 200 nm. We found that the periods of the structures formed in liquids are generally several times smaller than those formed in air. When samples are processed in air with 387 nm laser wavelength, the periods are similar to those obtained in liquids at 775 nm. The formation mechanisms of ripples structures are discussed.

  13. Periodical structures induced by femtosecond laser on metals in air and liquid environments

    Energy Technology Data Exchange (ETDEWEB)

    Albu, Catalina, E-mail: catalina.radu@inflpr.ro [National Institute for Laser, Plasma and Radiation Physics, Laser Department, Atomistilor Str. 409, P.O. Box MG-36, 077125 Magurele, Bucharest (Romania); Dinescu, Adrian [National Institute for Research and Development in Microtechnology, Erou Iancu Nicolae Str. 126A, 077190 Bucharest (Romania); Filipescu, Mihaela; Ulmeanu, Magdalena [National Institute for Laser, Plasma and Radiation Physics, Laser Department, Atomistilor Str. 409, P.O. Box MG-36, 077125 Magurele, Bucharest (Romania); Zamfirescu, Marian [National Institute for Laser, Plasma and Radiation Physics, Laser Department, Atomistilor Str. 409, P.O. Box MG-36, 077125 Magurele, Bucharest (Romania); National Institute for Research and Development in Microtechnology, Erou Iancu Nicolae Str. 126A, 077190 Bucharest (Romania)

    2013-08-01

    Ripples or laser-induced periodic surface structures (LIPSS) are obtained on metallic films (Cr, Ti, and W) by femtosecond laser pulses working at both fundamental (775 nm) and frequency doubled (387 nm) wavelengths in air and liquid environments. The metallic samples were irradiated at normal incidence, in air and by immersing them in water (H{sub 2}O), ethanol (C{sub 2}H{sub 5}OH) or chloroform (CHCl{sub 3}). Different morphologies were observed after laser irradiation on the material surface, depending on material, environments and the laser irradiation parameters. We observed areas of ripples or nanostructures (NS) at both irradiation laser wavelengths in all environments used. The morphology of the formed structures was studied by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The analysis of images obtained revealed two kinds of ripples: low spatial frequency LIPSS (LSFL) with a periodicity from 350 to 600 nm, and high spatial frequency LIPSS (HSFL) with a periodicity from about 50 to 200 nm. We found that the periods of the structures formed in liquids are generally several times smaller than those formed in air. When samples are processed in air with 387 nm laser wavelength, the periods are similar to those obtained in liquids at 775 nm. The formation mechanisms of ripples structures are discussed.

  14. Biostimulation of metal-resistant microbial consortium to remove zinc from contaminated environments.

    Science.gov (United States)

    Mejias Carpio, Isis E; Franco, Diego Castillo; Zanoli Sato, Maria Inês; Sakata, Solange; Pellizari, Vivian H; Seckler Ferreira Filho, Sidney; Frigi Rodrigues, Debora

    2016-04-15

    Understanding the diversity and metal removal ability of microorganisms associated to contaminated aquatic environments is essential to develop metal remediation technologies in engineered environments. This study investigates through 16S rRNA deep sequencing the composition of a biostimulated microbial consortium obtained from the polluted Tietê River in São Paulo, Brazil. The bacterial diversity of the biostimulated consortium obtained from the contaminated water and sediment was compared to the original sample. The results of the comparative sequencing analyses showed that the biostimulated consortium and the natural environment had γ-Proteobacteria, Firmicutes, and uncultured bacteria as the major classes of microorganisms. The consortium optimum zinc removal capacity, evaluated in batch experiments, was achieved at pH=5 with equilibrium contact time of 120min, and a higher Zn-biomass affinity (KF=1.81) than most pure cultures previously investigated. Analysis of the functional groups found in the consortium demonstrated that amine, carboxyl, hydroxyl, and phosphate groups present in the consortium cells were responsible for zinc uptake. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Advancing our understanding of plant adaptation to metal polluted environments - new insights from Biscutella laevigata

    Science.gov (United States)

    Babst-Kostecka, Alicja; Waldmann, Patrik; Frérot, Hélène; Vollenweider, Pierre

    2016-04-01

    divergent selection in response to metal contamination. These findings promote B. laevigata as constitutively zinc tolerant but non-hyperaccumulating organism to study plant adaptation to contaminated environments. Remarkably, tolerance differences between edaphic types emerged already at an environmentally relevant zinc concentration. This opens an unusual perspective on plant adaptation that should be tested in other non-hyperaccumulating species.

  16. Field effects of pollutants in dynamic environments; a case study on earthworm populations in river floodplains contaminated with heavy metals

    NARCIS (Netherlands)

    Klok, C.; Goedhart, P.W.; Vandecasteele, B.

    2007-01-01

    In industrialized countries river floodplains can be strongly polluted with heavy metals. Published studies on effects of heavy metal pollution on soil invertebrates in floodplains, however, are inconclusive. This is unexpected since studies in other less dynamic environments reported clear effects

  17. Field effects of pollutants in dynamic environments; a case study on earthworm populations in river floodplains contaminated with heavy metals

    NARCIS (Netherlands)

    Klok, C.; Goedhart, P.W.; Vandecasteele, B.

    2007-01-01

    In industrialized countries river floodplains can be strongly polluted with heavy metals. Published studies on effects of heavy metal pollution on soil invertebrates in floodplains, however, are inconclusive. This is unexpected since studies in other less dynamic environments reported clear effects

  18. Natal teeth in an infant with congenital hypothyroidism

    Directory of Open Access Journals (Sweden)

    C Venkatesh

    2011-01-01

    Full Text Available Teeth erupting at birth are referred to as natal teeth. It is a common and benign finding in the neonatal period. However, they may be associated with genetic syndromes like Ellis Van Creveld syndrome and Hallermann-Streiff syndrome. We report here a case of natal teeth in an infant with congenital hypothyroidism.

  19. Surface coating affects behavior of metallic nanoparticles in a biological environment

    Directory of Open Access Journals (Sweden)

    Darija Domazet Jurašin

    2016-02-01

    Full Text Available Silver (AgNPs and maghemite, i.e., superparamagnetic iron oxide nanoparticles (SPIONs are promising candidates for new medical applications, which implies the need for strict information regarding their physicochemical characteristics and behavior in a biological environment. The currently developed AgNPs and SPIONs encompass a myriad of sizes and surface coatings, which affect NPs properties and may improve their biocompatibility. This study is aimed to evaluate the effects of surface coating on colloidal stability and behavior of AgNPs and SPIONs in modelled biological environments using dynamic and electrophoretic light scattering techniques, as well as transmission electron microscopy to visualize the behavior of the NP. Three dispersion media were investigated: ultrapure water (UW, biological cell culture medium without addition of protein (BM, and BM supplemented with common serum protein (BMP. The obtained results showed that different coating agents on AgNPs and SPIONs produced different stabilities in the same biological media. The combination of negative charge and high adsorption strength of coating agents proved to be important for achieving good stability of metallic NPs in electrolyte-rich fluids. Most importantly, the presence of proteins provided colloidal stabilization to metallic NPs in biological fluids regardless of their chemical composition, surface structure and surface charge. In addition, an assessment of AgNP and SPION behavior in real biological fluids, rat whole blood (WhBl and blood plasma (BlPl, revealed that the composition of a biological medium is crucial for the colloidal stability and type of metallic NP transformation. Our results highlight the importance of physicochemical characterization and stability evaluation of metallic NPs in a variety of biological systems including as many NP properties as possible.

  20. Composition of heavy metals and airborne fibers in the indoor environment of a building during renovation.

    Science.gov (United States)

    Latif, Mohd Talib; Baharudin, Nor Hafizah; Velayutham, Puvaneswary; Awang, Normah; Hamdan, Harimah; Mohamad, Ruqyyah; Mokhtar, Mazlin B

    2011-10-01

    The renovation of a building will certainly affect the quality of air in the vicinity of where associated activities were undertaken, this includes the quality of air inside the building. Indoor air pollutants such as particulate matter, heavy metals, and fine fibers are likely to be emitted during renovation work. This study was conducted to determine the concentration of heavy metals, asbestos and suspended particulates in the Biology Building, at the Universiti Kebangsaan, Malaysia (UKM). Renovation activities were carried out widely in the laboratories which were located in this building. A low-volume sampler was used to collect suspended particulate matter of a diameter size less than 10 μm (PM₁₀) and an air sampling pump, fitted with a cellulose ester membrane filter, were used for asbestos sampling. Dust was collected using a small brush and scope. The concentration of heavy metals was determined through the use of inductively coupled plasma-mass spectroscopy and the fibers were counted through a phase contrast microscope. The concentrations of PM₁₀ recorded in the building during renovation action (ranging from 166 to 542 μg m⁻³) were higher than the value set by the Department of Safety and Health for respirable dust (150 μg m⁻³). Additionally, they were higher than the value of PM₁₀ recorded in indoor environments from other studies. The composition of heavy metals in PM₁₀ and indoor dust were found to be dominated by Zn and results also showed that the concentration of heavy metals in indoor dust and PM₁₀ in this study was higher than levels recorded in other similar studies. The asbestos concentration was 0.0038 ± 0.0011 fibers/cc. This was lower than the value set by the Malaysian Department of Occupational, Safety and Health (DOSH) regulations of 0.1 fibers/cc, but higher than the background value usually recorded in indoor environments. This study strongly suggests that renovation issues need to be considered seriously

  1. Content of heavy metals in the semen of bulls from various environments

    Energy Technology Data Exchange (ETDEWEB)

    Monkiewicz, J.; Jaczewski, S.; Dynarowicz, I.

    1975-01-01

    The content of metal ions (Cu, Pb, Zn) was examined in the semen of bulls kept under different environments. It was found that the content of Cu and Pb ions in the semen of bulls living near the copperworks and near to a highway was higher than that in the semen of bulls kept under normal conditions. The differences appeared to be highly significant statistically (P < 0.001). No significant statistical differences were found in the content of Zn. In addition, it was stated that the higher content of Pb influenced the survival of spermatozoons at highers temperature (46.5/sup 0/C). Further investigations will be performed under model conditions.

  2. Elastic–plastic adhesive impacts of tungsten dust with metal surfaces in plasma environments

    Energy Technology Data Exchange (ETDEWEB)

    Ratynskaia, S., E-mail: svetlana.ratynskaia@ee.kth.se [KTH Royal Institute of Technology, Association EUROfusion-VR, Stockholm (Sweden); Tolias, P. [KTH Royal Institute of Technology, Association EUROfusion-VR, Stockholm (Sweden); Shalpegin, A. [Université de Lorraine, Institut Jean Lamour, Vandoeuvre-lès-Nancy (France); Vignitchouk, L. [KTH Royal Institute of Technology, Association EUROfusion-VR, Stockholm (Sweden); De Angeli, M. [Istituto di Fisica del Plasma – Consiglio Nazionale delle Ricerche, Milan (Italy); Bykov, I. [KTH Royal Institute of Technology, Association EUROfusion-VR, Stockholm (Sweden); Bystrov, K.; Bardin, S. [FOM Institute DIFFER, Dutch Institute For Fundamental Energy Research, Edisonbaan 14, 3439MN Nieuwegein (Netherlands); Brochard, F. [Université de Lorraine, Institut Jean Lamour, Vandoeuvre-lès-Nancy (France); Ripamonti, D. [Istituto per l’Energetica e le Interfasi – Consiglio Nazionale delle Ricerche, Milan (Italy); Harder, N. den; De Temmerman, G. [FOM Institute DIFFER, Dutch Institute For Fundamental Energy Research, Edisonbaan 14, 3439MN Nieuwegein (Netherlands)

    2015-08-15

    Dust-surface collisions impose size selectivity on the ability of dust grains to migrate in scrape-off layer and divertor plasmas and to adhere to plasma-facing components. Here, we report first experimental evidence of dust impact phenomena in plasma environments concerning low-speed collisions of tungsten dust with tungsten surfaces: re-bouncing, adhesion, sliding and rolling. The results comply with the predictions of the model of elastic-perfectly plastic adhesive spheres employed in the dust dynamics code MIGRAINe for sub- to several meters per second impacts of micrometer-range metal dust.

  3. Metal concentrations in aquatic environments of Puebla River basin, Mexico: natural and industrial influences.

    Science.gov (United States)

    Morales-García, S S; Rodríguez-Espinosa, P F; Shruti, V C; Jonathan, M P; Martínez-Tavera, E

    2017-01-01

    The rapid urban expansion and presence of volcanoes in the premises of Puebla River basin in central Mexico exert significant influences over its aquatic environments. Twenty surface sediment samples from Puebla River basin consisting of R. Alseseca, R. Atoyac, and Valsequillo dam were collected during September 2009 and analyzed for major (Al, Fe, Mg, Ba, Ca, and K) and trace elements (As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sr, V, and Zn) in order to identify the metal concentrations and their enrichment. R. Atoyac sediments presented higher concentrations of Ba (1193.8 μg g(-1)) and Pb (27.1 μg g(-1)) in comparison with the local reference sample values. All the metal concentrations except Sr for R. Alseseca sediments were within the range of local reference sample values indicating no significant external influence, whereas Valsequillo dam sediments had elevated concentrations of all the metals suggesting both natural and external influences in the study region. The magnitude of metal contamination was assessed using several indices such as geoaccumulation index (I geo), enrichment factor (EF), degree of contamination (C d ), and pollution load index (PLI). The results suggest that As, Pb, and Zn were predominantly enriched in the Puebla River basin sediments. Comparing with sediment quality guidelines and ecotoxicological values, it is revealed that Cd, Cr, Cu, and Ni have possible harmful effects on the biological community. The present study provides an outlook of metal enrichment in Puebla River basin sediments, highlighting the necessity to conserve this river ecosystem for the near future.

  4. Autonomy, natality and freedom: a liberal re-examination of Habermas in the enhancement debate.

    Science.gov (United States)

    Pugh, Jonathan

    2015-03-01

    Jurgen Habermas has argued that carrying out pre-natal germline enhancements would be inimical to the future child's autonomy. In this article, I suggest that many of the objections that have been made against Habermas' arguments by liberals in the enhancement debate misconstrue his claims. To explain why, I begin by explaining how Habermas' view of personal autonomy confers particular importance to the agent's embodiment and social environment. In view of this, I explain that it is possible to draw two arguments against germline enhancements from Habermas' thought. I call these arguments 'the argument from negative freedom' and 'the argument from natality'. Although I argue that many of the common liberal objections to Habermas are not applicable when his arguments are properly understood, I go on to suggest ways in which supporters of enhancement might appropriately respond to Habermas' arguments.

  5. The influence of hydrogen on the fatigue life of metallic leaf spring components in a vacuum environment

    NARCIS (Netherlands)

    Kouters, M.H.M.; Slot, H.M.; Zwieten, W. van; Veer, J. van der

    2014-01-01

    Hydrogen is used as a process gas in vacuum environments for semiconductor manufacturing equipment. If hydrogen dissolves in metallic components during operation it can result in hydrogen embrittlement. In order to assess if hydrogen embrittlement occurs in such a vacuum environment a special fatigu

  6. Modeling and interpreting biological effects of mixtures in the environment: introduction to the metal mixture modeling evaluation project.

    Science.gov (United States)

    Van Genderen, Eric; Adams, William; Dwyer, Robert; Garman, Emily; Gorsuch, Joseph

    2015-04-01

    The fate and biological effects of chemical mixtures in the environment are receiving increased attention from the scientific and regulatory communities. Understanding the behavior and toxicity of metal mixtures poses unique challenges for incorporating metal-specific concepts and approaches, such as bioavailability and metal speciation, in multiple-metal exposures. To avoid the use of oversimplified approaches to assess the toxicity of metal mixtures, a collaborative 2-yr research project and multistakeholder group workshop were conducted to examine and evaluate available higher-tiered chemical speciation-based metal mixtures modeling approaches. The Metal Mixture Modeling Evaluation project and workshop achieved 3 important objectives related to modeling and interpretation of biological effects of metal mixtures: 1) bioavailability models calibrated for single-metal exposures can be integrated to assess mixture scenarios; 2) the available modeling approaches perform consistently well for various metal combinations, organisms, and endpoints; and 3) several technical advancements have been identified that should be incorporated into speciation models and environmental risk assessments for metals.

  7. Bioremediation of Heavy Metals from Soil and Aquatic Environment: An Overview of Principles and Criteria of Fundamental Processes

    Directory of Open Access Journals (Sweden)

    Ruchita Dixit

    2015-02-01

    Full Text Available Heavy metals are natural constituents of the environment, but indiscriminate use for human purposes has altered their geochemical cycles and biochemical balance. This results in excess release of heavy metals such as cadmium, copper, lead, nickel, zinc etc. into natural resources like the soil and aquatic environments. Prolonged exposure and higher accumulation of such heavy metals can have deleterious health effects on human life and aquatic biota. The role of microorganisms and plants in biotransformation of heavy metals into nontoxic forms is well-documented, and understanding the molecular mechanism of metal accumulation has numerous biotechnological implications for bioremediation of metal-contaminated sites. In view of this, the present review investigates the abilities of microorganisms and plants in terms of tolerance and degradation of heavy metals. Also, advances in bioremediation technologies and strategies to explore these immense and valuable biological resources for bioremediation are discussed. An assessment of the current status of technology deployment and suggestions for future bioremediation research has also been included. Finally, there is a discussion of the genetic and molecular basis of metal tolerance in microbes, with special reference to the genomics of heavy metal accumulator plants and the identification of functional genes involved in tolerance and detoxification.

  8. Tannin-Metal Interactions in Soils: An Incubation-Extraction Approach in Hill-Land Environments

    Science.gov (United States)

    Gonzalez, J. M.; Halvorson, J. J.

    2007-12-01

    Tannins, plant polyphenols known to react with proteins, metals and soil organic matter, are commonly found in the vegetation growing in Appalachian hill-lands. Establishing silvopastoral grazing systems in these environments is a means for improving productivity however the fate of tannins in soils and, in particular, the effect on solubility/mobility of metals in soils is poorly understood. Soils from forest and pasture systems were sampled from two depths, treated with tannic acid or related phenolic compounds, and analyzed for metals in solution. The amount of Mn and Ca detected in solution varied among the different phenolic treatments, highest for gallic acid, and was also influenced by depth and land use. As expected, the Ca content in solution was correlated with the electrical conductivity (EC) and the Mn content was correlated with the redox potential in solution. Interestingly, the EC was also correlated with both Mn content and redox potential. The higher Ca content found in solution may result from the low pH of the phenolic compounds. The higher Mn in solution may result from the redox reaction of Mn (IV) oxides with the phenolic compounds, producing soluble Mn2+ and quinones. These quinones are very reactive compounds that can self-polymerize and/or copolymerize with other biomolecules, such as amino-containing compounds and carbohydrates, to form humic-like substances. Successful management of silvopastures, requires an understanding of factors that affect the quality and quantity of plant secondary compounds like tannins entering soil not only to increase forage productivity but also to enhance formation/stabilization of soil organic matter to increase nutrient cycling and reduce the toxicity risk of some metals such as Mn.

  9. Metal release from contaminated estuarine sediment under pH changes in the marine environment.

    Science.gov (United States)

    Martín-Torre, M Camino; Payán, M Cruz; Verbinnen, Bram; Coz, Alberto; Ruiz, Gema; Vandecasteele, Carlo; Viguri, Javier R

    2015-04-01

    The contaminant release from estuarine sediment due to pH changes was investigated using a modified CEN/TS 14429 pH-dependence leaching test. The test is performed in the range of pH values of 0-14 using deionised water and seawater as leaching solutions. The experimental conditions mimic different circumstances of the marine environment due to the global acidification, carbon dioxide (CO2) leakages from carbon capture and sequestration technologies, and accidental chemical spills in seawater. Leaching test results using seawater as leaching solution show a better neutralisation capacity giving slightly lower metal leaching concentrations than when using deionised water. The contaminated sediment shows a low base-neutralisation capacity (BNCpH 12 = -0.44 eq/kg for deionised water and BNCpH 12 = -1.38 eq/kg for seawater) but a high acid-neutralisation capacity when using deionised water (ANCpH 4 = 3.58 eq/kg) and seawater (ANCpH 4 = 3.97 eq/kg). Experimental results are modelled with the Visual MINTEQ geochemical software to predict metal release from sediment using both leaching liquids. Surface adsorption to iron- and aluminium-(hydr)oxides was applied for all studied elements. The consideration of the metal-organic matter binding through the NICA-Donnan model and Stockholm Humic Model for lead and copper, respectively, improves the former metal release prediction. Modelled curves can be useful for the environmental impact assessment of seawater acidification due to its match with the experimental values.

  10. NATAL LUZ EM GRAMADO/RS

    Directory of Open Access Journals (Sweden)

    Ana Carolina Oliveira

    2010-06-01

    Full Text Available O presente estudo apresenta o case de sucesso Natal Luz, realizado nos meses de novembro, dezembro e janeiro, na cidade Gramado/RS. O evento foi concebido para resolver problemas de sazonalidade turística, pois a cidade tradicionalmente tinha como seu principal produto para atrair visitante o clima frio, às vezes até com presença de neve, dos meses de inverno. Desde sua concepção, três foram as marcas do evento: a participação da comunidade da concepção à produção, a inovação e a presença da tradição associada à tecnologia, e a hospitalidade.

  11. Interactions of noble metal nanoparticles with their environment; Wechselwirkungen von Edelmetallnanopartikeln mit ihrer Umgebung

    Energy Technology Data Exchange (ETDEWEB)

    Reismann, Maximilian

    2009-12-08

    Upon irradiating noble metal nanoparticles with light, unique optical phenomena can occur, such as resonantly enhanced light-scattering and light-absorption, or a tremendous enhancement of the exciting optical field close to the surface of the nanoparticles. These phenomena rely on the excitations of collective oscillations of the conduction electrons within a nanoparticle. The optical properties of a nanoparticle are determined by the resonance frequency of these so-called plasmon oscillations. This resonance frequency and the light-scattering spectrum of a nanoparticle depend (among other effects) on the dielectric environment of the particle. Due to this effect, noble metal nanoparticles can be applied for local optical sensing of chemical substances. The large light-absorption properties of a nanoparticle also enable the usage of light-irradiation to deposit heat in the nanoparticle in a selective and highly localized manner. Therefore, a local temperature increase can be induced in the nanoparticle and its immediate environment. This temperature increase could be used to trigger chemical or biological reactions, or it could be used for a selective hyperthermia of biological material. These and further possible applications rely on the detection or the systematic excitation of interactions between the noble metal nanoparticle and its environment. These interactions are the central subject of this thesis. Particular attention is paid to photothermal interactions. An interesting question is to what extend a nanoparticle-supported, photothermally-induced temperature rise can be applied to trigger a biomolecular reaction in a spatially confined volume. By carefully adjusting the photothermal treatment, one aims at affecting the molecules without damaging their chemical functionality. The photothermal interaction is addressed in two projects: First, networks built up by gold nanoparticles are investigated. In these networks, double-stranded DNA-molecules are used to

  12. Are Free Ion Activity Models Sufficient Alternatives to Biotic Ligand Models in Evaluating Metal Toxic Impacts in Terrestrial Environments?

    DEFF Research Database (Denmark)

    Owsianiak, Mikolaj; Rosenbaum, Ralph K.; Larsen, Henrik Fred

    Metal partitioning between solid and aqueous phases and speciation in soil pore water control the bioavailability of toxic forms of metals, while protons and base cations can mitigate metal ecotoxicity by competitive interactions with biotic ligands. e employment of BLMs to evaluate toxicity...... potential of metals in soils results in site-specic toxicity scores due to large variability of soil properties and dierences in ionic composition. Unfortunately, terrestrial BMLs are available only for few metals and few organisms, thus their applicability to hazard ranking or toxic impact assessment...... is low and alternatives must be found. In this study, we compared published terrestrial BLMs and their potential alternatives such as free ion activity models (FIAM), for applicability in addressing metal toxic impacts in terrestrial environments. A set of 1300 soils representative for the whole world...

  13. The evaluation of different environments in ultra-high frequency induction sintered powder metal compacts

    Directory of Open Access Journals (Sweden)

    Sari Çavdar, Pınar

    2015-03-01

    Full Text Available The application of the iron based Powder Metal (PM compacts in Ultra-High Frequency Induction Sintering (UHFIS was reviewed for different environments. The three different environments: atmosphere, argon and vacuum were applied to the PM compacts. Iron based PM compacts were sintered at 1120 °C for a total of 550 seconds by using induction sintering machines with 2.8 kW power and 900 kHz frequency. Micro structural properties, densities, roughness and micro hardness values were obtained for all environments. The results were compared with each other.Este trabajo comprende una revisión de la aplicación de la inducción de ultra-alta frecuencia (UHFIS en la sinterización de aleaciones pulvimetalúrgicas de base hierro para diferentes ambientes. Los tres ambientes estudiados son: atmósfera, argón y vacío aplicados a material ya consolidado. Aleaciones base hierro ya compactadas se sinterizan a temperaturas de 1120 °C durante 550 segundos por medio de máquinas de sinterizado por inducción de potencia de 2,8 kW y 900 kHz de frecuencia. Se compararán las propiedades microestructurales, y los valores obtenidos de densidad, rugosidad y microdureza para todos los ambientes estudiados.

  14. Assessment and management of heavy metal pollution in the marine environment of the Arabian Gulf: a review.

    Science.gov (United States)

    Naser, Humood A

    2013-07-15

    The Arabian Gulf is considered among the highest anthropogenically impacted regions in the world. Heavy metals contamination in coastal and marine environments is becoming an increasingly serious threat to both the naturally stressed marine ecosystems and humans that rely on marine resources for food, industry and recreation. Heavy metals are introduced to coastal and marine environments through a variety of sources and activities including sewage and industrial effluents, brine discharges, coastal modifications and oil pollution. The present paper reviews heavy metal contamination in a variety of marine organisms, and sediments, and suggests measures for environmental management of heavy metal pollution in the Arabian Gulf. Most of the reviewed literature confirmed that heavy metal concentrations in marine organisms were generally within allowable concentrations and pose no threat to public health. Likewise, studies suggested that levels of heavy metals in marine sediments are similar or lower compared to other regions. However, localized hotspots of chronic metal pollution in areas influenced by industrial facilities, desalination plants, and oil refineries have been reported. Holistic spatial and temporal monitoring and comprehensive national and regional strategies are critical to combat and manage heavy metal pollution in the Arabian Gulf.

  15. Competitive Coordination Strategy to Finely Tune Pore Environment of Zirconium-Based Metal-Organic Frameworks.

    Science.gov (United States)

    He, Ting; Ni, Bing; Xu, Xiaobin; Li, Haoyi; Lin, Haifeng; Yuan, Wenjuan; Luo, Jun; Hu, Wenping; Wang, Xun

    2017-07-12

    Metal-organic frameworks (MOFs) are a class of crystalline porous materials with reticular architectures. Precisely tuning pore environment of MOFs has drawn tremendous attention but remains a great challenge. In this work, we demonstrate a competitive coordination approach to synthesize a series of zirconium-metalloporphyrinic MOFs through introducing H2O and monocarboxylic acid as modulating reagents, in which well-ordered mesoporous channels could be observed clearly under conventional transmission electron microscopy. Owing to plenty of unsaturated Lewis acid catalytic sites exposed in the visualized mesoporous channels, these structures exhibit outstanding catalytic activity and excellent stability in the chemical fixation of carbon dioxide to cyclic carbonates. The zirconium-based MOFs with ordered channel structures are expected to pave the way to expand the potential applications of MOFs.

  16. Novel Nanocrystalline Intermetallic Coatings for Metal Alloys in Coal-fired Environments

    Energy Technology Data Exchange (ETDEWEB)

    Z. Zak Fang; H. Y. Sohn

    2009-08-31

    Intermetallic coatings (iron aluminide and nickel aluminide) were prepared by a novel reaction process. In the process, the aluminide coating is formed by an in-situ reaction between the aluminum powder fed through a plasma transferred arc (PTA) torch and the metal substrate (steel or Ni-base alloy). Subjected to the high temperature within an argon plasma zone, aluminum powder and the surface of the substrate melt and react to form the aluminide coatings. The prepared coatings were found to be aluminide phases that are porosity-free and metallurgically bonded to the substrate. The coatings also exhibit excellent high-temperature corrosion resistance under the conditions which simulate the steam-side and fire-side environments in coal-fired boilers. It is expected that the principle demonstrated in this process can be applied to the preparation of other intermetallic and alloy coatings.

  17. Microstructured hydroxyl environments and Raman spectroscopy in selected basic transition-metal halides

    Institute of Scientific and Technical Information of China (English)

    Liu Xiao-Dong; Meng Dong-Dong; Hagihala Masato; Zheng Xu-Guang

    2011-01-01

    Raman vibrational spectra of the selected basic(hydroxyl OH and deuteroxyl OD)transition-metal halides,geometrically frustrated material series α-,β-,γ-Cu2(OH)3Cl,α-Cu2(OH)3Br,β-Ni2(OH)3Cl,β-Co2(OH)3Cl,β-Co2(OH)3Br,γ-Cu2(OD)3Cl,and β-Co2(OD)3Cl are measured at room temperature and analysed to investigate the relationship between the microstructured OH environments and their respective Raman spectra.Among these selected samples,the last two are used to determine the OH stretching vibration region(3600 cm-1-3300 cm-1)and OH bending vibration region(1000 cm-1-600 cm-1)of OH systems in the spectra.Through the comparative analysis of the distances d(metal-O),d(O-halogen),and d(OH),the strong metal-O interaction and trimeric hydrogen bond(C3υ,Cs,or C1 symmetry)are found in every material,but both determine simultaneously an ultimate d(OH),and therefore an OH stretching vibration frequency.According to the approximately linear relationship between the OH stretching vibration frequency and d(OH),some unavailable d(OH)are guessed and some doubtful d(OH)are suggested to be corrected.In addition,it is demonstrated in brief that the OH bending vibration frequency is also of importance to check the more detailed crystal microstructure relating to the OH group.

  18. The assessment of optimal MERIS ocean colour products in the shelf waters of the KwaZulu-Natal Bight, South Africa

    CSIR Research Space (South Africa)

    Smith, ME

    2013-10-01

    Full Text Available The KwaZulu-Natal Bight is a highly variable bio-optical environment, where waters over the shelf can change from the oligotrophic case 1 conditions of the Agulhas Current to the case 2 inshore environment influenced by upwelling and riverine influx...

  19. Particle size distribution of aerosols and associated heavy metals in kitchen environments.

    Science.gov (United States)

    Gupta, Sandeep; Srivastava, Arun; Jain, V K

    2008-07-01

    Mass size distributions of total suspended particulate matter (TSPM) was measured from Sep 2002 to April 2003 in indoor kitchen environments of five locations in Jawaharlal Nehru University (JNU), New Delhi, with the help of a high volume cascade impactor. Particulate matters were separated in five different size ranges, i.e. >10.9 microm, 10.9-5.4 microm, 5.4-1.6 microm, 1.6-0.7 microm and particle size distribution at various sites appears to follow uni-modal trend corresponding to fine particles i.e. size range particles are estimated to be approximately 50% of TSPM and PM10.9, while PM10.9 comprises 80% of TSPM. Good correlations were observed between various size fractions. Regression results reveal that TSPM can adequately act as a surrogate for PM10.9 and fine particles, while PM10.9 can also act as surrogate for fine particles. The concentrations of heavy metals are found to be dominantly associated with fine particles. However, the concentration of some metals and their size distribution, to some extent is also site specific (fuel type used).

  20. Underground Corrosion of Activated Metals in an Arid Vadose Zone Environment

    Energy Technology Data Exchange (ETDEWEB)

    Adler Flitton, Mariana Kay; Mizia, Ronald Eugene; Bishop, Carolyn Wagoner

    2002-04-01

    The subsurface radioactive disposal site located at the Idaho National Engineering and Environmental Laboratory contains neutron-activated metals from nonfuel nuclear-reactor- core components. A long-term corrosion test is being conducted to obtain site-specific corrosion rates to support efforts to more accurately estimate the transfer of activated elements in an arid vadose zone environment. The tests use nonradioactive metal coupons representing the prominent neutron-activated material buried at the disposal location, namely, Type 304L stainless steel, Type 315L stainless steel, nickel-chromium alloy (UNS NO7718), beryllium, aluminum 6061-T6, and a zirconium alloy, (UNS R60804). In addition, carbon steel (the material presently used in the cask disposal liners and other disposal containers) and a duplex stainless steel (UNS S32550) (the proposed material for the high- integrity disposal containers) are also included in the test program. This paper briefly describes the test program and presents the early corrosion rate results after 1 year and 3 years of underground exposure.

  1. Underground Corrosion of Activated Metals in an Arid Vadose Zone Environment

    Energy Technology Data Exchange (ETDEWEB)

    Adler Flitton, M.K; Mizia, R.E.; Bishop, C.W.

    2001-10-24

    The subsurface radioactive disposal site located at the Idaho National Engineering and Environmental Laboratory contains neutron-activated metals from nonfuel nuclear-reactor- core components. A long-term corrosion test is being conducted to obtain site-specific corrosion rates to support efforts to more accurately estimate the transfer of activated elements in an arid vadose zone environment. The tests use nonradioactive metal coupons representing the prominent neutron-activated material buried at the disposal location, namely, Type 304L stainless steel, Type 315L stainless steel, nickel-chromium alloy (UNS NO7718), beryllium, aluminum 6061-T6, and a zirconium alloy, (UNS R60804). In addition, carbon steel (the material presently used in the cask disposal liners and other disposal containers) and a duplex stainless steel (UNS S32550) (the proposed material for the high- integrity disposal containers) are also included in the test program. This paper briefly describes the test program and presents the early corrosion rate results after 1 year and 3 years of underground exposure.

  2. Wetland vegetation of southern KwaZulu-Natal, South Africa

    Directory of Open Access Journals (Sweden)

    L. Perkins

    2000-12-01

    Full Text Available Vegetation data from southern KwaZulu-Natal were analysed. TWINSPAN classification separated the entire data set (547 releves into five subsets. One subset, representing the vegetation of the wetlands of southern Kw aZulu-Natal, was further classified by Braun-Blanquet procedures. Eight plant communities and fourteen subcommunities were identified and described. The results can be integrated with existing phytosociological classifications of the Grassland Biome.

  3. Analysis and Performance Improvement of WPT Systems in the Environment of Single Non-Ferromagnetic Metal Plates

    Directory of Open Access Journals (Sweden)

    Linlin Tan

    2016-07-01

    Full Text Available Wireless power transfer (WPT is greatly affected when the transmission channel is surrounded by non-ferromagnetic metallic objects and the alternating magnetic field interacts with the metal conductor, which is more of an issue in wirelessly charged electric vehicle (EV applications. This paper analyses the performances of a WPT system in an environment with a non-ferromagnetic metal plate. The impedance model of the WPT system in the metal environment is established. Moreover the variation law of a coil’s equivalent inductance and resistance is deduced when the coil is surrounded by the non-ferromagnetic metal plate. Meanwhile, simulations, theory and experiments all confirm that the model is correct. Finally, since the system performance of a wireless charging system is influenced by non-ferromagnetic metals, this paper puts forward a method to improve the performance, that is, to place ferrite cores between the receiving coil and a metal plate. Experiments are carried out to verify the method, and the desired results are achieved.

  4. Heavy metals in contaminated environment: Destiny of secondary metabolite biosynthesis, oxidative status and phytoextraction in medicinal plants.

    Science.gov (United States)

    Asgari Lajayer, Behnam; Ghorbanpour, Mansour; Nikabadi, Shahab

    2017-11-01

    Contamination of soils, water and air with toxic heavy metals by various human activities is a crucial environmental problem in both developing and developed countries. Heavy metals could be introduced into medicinal plant products through contaminated environment (soil, water and air resources) and/or poor production practices. Growing of medicinal plants in heavy metal polluted environments may eventually affect the biosynthesis of secondary metabolites, causing significant changes in the quantity and quality of these compounds. Certain medicinal and aromatic plants can absorb and accumulate metal contaminants in the harvestable foliage and, therefore, considered to be a feasible alternative for remediation of polluted sites without any contamination of essential oils. Plants use different strategies and complex arrays of enzymatic and non-enzymatic anti-oxidative defense systems to cope with overproduction of ROS causes from the heavy metals entered their cells through foliar and/or root systems. This review summarizes the reports of recent investigations involving heavy metal accumulation by medicinal plants and its effects on elicitation of secondary metabolites, toxicity and detoxification pathways, international standards regarding in plants and plant-based products, and human health risk assessment of heavy metals in soil-medicinal plants systems. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Interactions of noble metal nanoparticles with their environment; Wechselwirkungen von Edelmetallnanopartikeln mit ihrer Umgebung

    Energy Technology Data Exchange (ETDEWEB)

    Reismann, Maximilian

    2009-12-08

    Upon irradiating noble metal nanoparticles with light, unique optical phenomena can occur, such as resonantly enhanced light-scattering and light-absorption, or a tremendous enhancement of the exciting optical field close to the surface of the nanoparticles. These phenomena rely on the excitations of collective oscillations of the conduction electrons within a nanoparticle. The optical properties of a nanoparticle are determined by the resonance frequency of these so-called plasmon oscillations. This resonance frequency and the light-scattering spectrum of a nanoparticle depend (among other effects) on the dielectric environment of the particle. Due to this effect, noble metal nanoparticles can be applied for local optical sensing of chemical substances. The large light-absorption properties of a nanoparticle also enable the usage of light-irradiation to deposit heat in the nanoparticle in a selective and highly localized manner. Therefore, a local temperature increase can be induced in the nanoparticle and its immediate environment. This temperature increase could be used to trigger chemical or biological reactions, or it could be used for a selective hyperthermia of biological material. These and further possible applications rely on the detection or the systematic excitation of interactions between the noble metal nanoparticle and its environment. These interactions are the central subject of this thesis. Particular attention is paid to photothermal interactions. An interesting question is to what extend a nanoparticle-supported, photothermally-induced temperature rise can be applied to trigger a biomolecular reaction in a spatially confined volume. By carefully adjusting the photothermal treatment, one aims at affecting the molecules without damaging their chemical functionality. The photothermal interaction is addressed in two projects: First, networks built up by gold nanoparticles are investigated. In these networks, double-stranded DNA-molecules are used to

  6. Experiences of childbirth in Natal Indian women

    Directory of Open Access Journals (Sweden)

    H.B. Brookes

    1991-09-01

    Full Text Available Through fifteen in-depth case studies of primipara, Natal Indian women’s experiences of childbirth have been described Common problems were identified, including lack of a family support person throughout labour, lithotomy position for delivery, episiotomies and their sequelae, breast-feeding difficulties and lack of professional support in the early puerperium at home. Preparation for common medical interventions in labour, breast-feeding and parenting appeared inadequate. Pertinent sociocultural aspects have been identified. These include continuing family support and culturally prescribed behaviour pertaining most importantly to the early puerperium and affecting the maternal-neonatal dyad. In the early adaptation to motherhood informants continued their role as daughter or daughter-in-law and would only actively continue their role as wife later or at the end of the puerperium. These traditional patterns of behaviour persist despite marked changes in educational level, language spoken and employment status. In the light of this research and founded on scientific evidence, a number of recommendations are made and areas for further research are identified

  7. Solubility Behavior and Phase Stability of Transition Metal Oxides in Alkaline Hydrothermal Environments

    Energy Technology Data Exchange (ETDEWEB)

    S.E. Ziemniak

    2000-05-18

    The solubility behavior of transition metal oxides in high temperature water is interpreted by recognizing three types of chemical reaction equilibria: metal oxide hydration/dehydration, metal oxide dissolution and metal ion hydroxocomplex formation. The equilibria are quantified using thermodynamic concepts and the thermochemical properties of the metal oxides/ions representative of the most common constituents of construction metal alloys, i.e., element shaving atomic numbers between Z = 22 (Ti) and Z = 30 (Zn), are summarized on the basis of metal oxide solubility studies conducted in the laboratory. Particular attention is devoted to the uncharged metal ion hydrocomplex, M{sup Z}(OH){sub Z}(aq), since its thermochemical properties define minimum solubilities of the metal oxide at a given temperature. Experimentally-extracted values of standard partial molal entropy (S{sup 0}) for the transition metal ion neutral hydroxocomplex are shown to be influenced by ligand field stabilization energies and complex symmetry.

  8. Levels of heavy metals in the environment of a wastewater treatment plant. Metales pesados en aguas, sedimentos y suelos de las inmediaciones de una EDAR

    Energy Technology Data Exchange (ETDEWEB)

    Nuez Delgado, A.; Cardenas Botas, S.; Diaz-Fierros Viqueira, F. (Facultad de Farmacia. Universidad de Santiago de Compostela. Corua (Spain))

    1994-01-01

    The concentration levels of the heavy metals Zn, Cu, Ni, Pb, Cr, and Cd, were studied in different points of a wastewater treatment plant, in sediment and water samples of the riverbeds, and in soil samples of its environment. The concentrations of heavy metals in influent and effluent waters were not high: only Zn and Cu were detected and they were always below the legal threshold level, as they were in the waters of the riverbeds in the nearby. however, in several soil and sediment samples, phytotoxic levels of Pb and Zn were found.

  9. Formation of centimeter Fe-based bulk metallic glasses in low vacuum environment

    Energy Technology Data Exchange (ETDEWEB)

    Pan Jie; Chen Qi; Li Ning [State Key Lab of Materials Processing and Mould Technology, Department of Materials Science and Technology, Huazhong University of Science and Technology, 430074 Wuhan (China); Liu Lin [State Key Lab of Materials Processing and Mould Technology, Department of Materials Science and Technology, Huazhong University of Science and Technology, 430074 Wuhan (China)], E-mail: lliu2000@public.wh.hb.cn

    2008-09-08

    The formation of a Fe{sub 43.7}Co{sub 7.3}Cr{sub 14.7}Mo{sub 12.6}C{sub 15.5}B{sub 4.3}Y{sub 1.9} bulk metallic glass (BMG) was attempted in low vacuum environment and in air using commercial raw materials. The glass forming ability of the Fe-based alloys was studied by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and differential thermal analyzer (DTA). It was found that cylindric rods with diameters ranging from 10 mm to 5 mm could be successfully fabricated by copper-mold casting in the pressures from 1.5 Pa to 10{sup 5} Pa (10{sup 5} Pa = 1 atm). All BMGs exhibit a distinct glass transition and wide supercooled liquid region. The preparation condition seems not significantly affected by the thermodynamic parameters of BMG, such as supercooled liquid region, glass transition temperature and melting process. The oxygen content of the alloys prepared in different vacuum conditions was measured by a LECO oxygen analyzer, which revealed that the oxygen content was less than 100 ppm for all BMGs prepared, even in air. The good glass forming ability and excellent oxidation resistance for the present Fe-based alloy are discussed.

  10. Marine environment status assessment based on macrophytobenthic plants as bio-indicators of heavy metals pollution.

    Science.gov (United States)

    Zalewska, Tamara; Danowska, Beata

    2017-05-15

    The main aim of study was to develop the environmental quality standards (EQSMP) for selected heavy metals: Pb, Cd, Hg and Ni bioaccumulated in the tissues of marine macrophytobenthic plants: Chara baltica, Cladophora spp., Coccotylus truncatus, Furcellaria lumbricalis, Polysiphonia fucoides, Stuckenia pectinata and Zanichellia palustris, collected in designated areas of the southern Baltic Sea in period 2008-2015. The calculated concentration ratios (CR), which attained very high values: 10(4)Lkg(-1) for lead, 10(3)Lkg(-1) for nickel and mercury and even 10(5)Lkg(-1) for cadmium formed the basis for the determination of EQSMP values. The EQSMP values were: 26mgkg(-1)d.w. for Pb, 33mgkg(-1)d.w. for Cd, 32mgkg(-1)d.w. for Ni and 0.4mgkg(-1)d.w. for Hg. The application of macrophytobenthic plants as bioindicators in marine environment status assessment of certain areas of the Baltic Sea is also described in the paper. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Evaluation of candidate alloys for the construction of metal flex hoses in the STS launch environment

    Science.gov (United States)

    Ontiveros, Cordelia

    1988-01-01

    Various vacuum jacketed cryogenic supply lines at the Shuttle launch site use convoluted flexible expansion joints. The atmosphere at the launch site has a very high salt content, and during a launch, fuel combustion products include hydrochloric acid. This extremely corrosive environment has caused pitting corrosion failure in the flex hoses, which were made of 304L stainless steel. A search was done to find a more corrosion resistant replacement material. This study focused on 19 metal alloys. Tests which were performed include electrochemical corrosion testing, accelerated corrosion testing in a salt fog chamber, long term exposure at the beach corrosion testing site, and pitting corrosion tests in ferric chloride solution. Based on the results of these tests, the most corrosion resistant alloys were found to be (in order) Hastelloy C-22, Inconel 625, Hastelloy C-276, Hastelloy C-4, and Inco Alloy G-3. Of these top five alloys, the Hastelloy C-22 stands out as being the best of those tested for this application.

  12. Electrochemical impedance spectroscopy of metal alloys in the space transportation system launch environment

    Science.gov (United States)

    Calle, Luz

    1990-01-01

    AC impedance measurements were performed to investigate the corrosion resistance of 18 alloys under conditions similar to the Space Transportation System (STS) launch environment. The alloys were: (1) zirconium 702; (2) Hastelloy C-22, C-276, C-4, and B-2; (3) Inconel 600 and 825; (4) Ferralium 255; (5) Inco Alloy G-3; (6) 20Cb-3; (7) SS 904L, 304LN, 316L, 317L, and 304L; (8) ES 2205; and (9) Monel 400. AC impedance data were gathered for each alloy at various immersion times in 3.55 percent NaCl-0.1N HCl. Polarization resistance values were obtained for the Nyguist plots at each immersion time using the EQUIVALENT CIRCUIT software package available with the 388 electrochemical impedance software. Hastelloy C-22 showed the highest overall values for polarization resistance while Monel 400 and Inconel 600 had the lowest overall values. There was good general correlation between the corrosion performance of the alloys at the beach corrosion testing site, and the expected rate of corrosion as predicted based on the polarization resistance values obtained. The data indicate that electrochemical impedance spectroscopy can be used to predict the corrosion performance of metal alloys.

  13. Seasonal variations of troposheric ozone at Natal, Brazil

    Science.gov (United States)

    Logan, J. A.; Kirchhoff, V. W. J. H.

    1986-01-01

    An analysis of ozone measurements from Natal, Brazil (6 deg S, 35 W), with a focus on the seasonal behavior in the troposphere, is presented. The amplitude of seasonal cycle at Natal is much larger than at Panama (9 deg N), the only other tropical site for which similar data are available. Concentrations of ozone in the middle troposphere in the southern spring are unexpectedly high, 60-70 ppb, similar to values found at northern midlatitudes in summer, and larger by 20-30 ppb than values found at Panama and at southern midlatitudes. It is suggested that photochemical production of ozone associated with emissions of CO, hydrocarbons, and NO(x) from biomass burning may contribute significantly to the high values of ozone, but note that stratospheric intrusions could also play a role. The data available at present do not permit a definitive evaluation of the relative importance of these two sources of ozone. The data from Natal, in combination with recent aircraft and surface data, show that tropical ozone exhibits strong spatial and temporal inhomogeneities. The distribution of tropospheric ozone appears to be considerably more complex than the traditional view, which suggested a northern midlatitude maximum and north/-south hemispheric asymmetry. The seasonal cycle in the total column of ozone at Natal appears to mirror the behavior of the tropospheric contribution to the ozone column rather than the stratospheric contribution, and this may account for differences in the annual cycle of the total column at Natal versus other tropical locations.

  14. Coping, stress and suicide ideation in the South African Police Service in Kwazulu-Natal / Linda Strauss

    OpenAIRE

    Strauss, Linda

    2003-01-01

    Suicide in the South African Police Service is a reality. The inability to cope effectively with stressful events in a working environment could lead to chronic stress, burnout and even suicide. The purpose of this research was to establish the current level of suicide ideation in police officials in the KwaZulu-Natal Province. Secondly, the purpose was to determine the relationship between coping and stress, and thirdly, whether these factors could he used to predict suicide i...

  15. Environment

    DEFF Research Database (Denmark)

    Valentini, Chiara

    2017-01-01

    The term environment refers to the internal and external context in which organizations operate. For some scholars, environment is defined as an arrangement of political, economic, social and cultural factors existing in a given context that have an impact on organizational processes and structures....... For others, environment is a generic term describing a large variety of stakeholders and how these interact and act upon organizations. Organizations and their environment are mutually interdependent and organizational communications are highly affected by the environment. This entry examines the origin...... and development of organization-environment interdependence, the nature of the concept of environment and its relevance for communication scholarships and activities....

  16. Assistência pré-natal no Brasil

    Directory of Open Access Journals (Sweden)

    Elaine Fernandes Viellas

    2014-08-01

    Full Text Available O estudo tem por objetivo analisar a assistência pré-natal oferecida às gestantes usuárias de serviços de saúde públicos e/ou privados utilizando dados da pesquisa Nascer no Brasil, realizada em 2011 e 2012. As informações foram obtidas por meio de entrevista com a puérpera durante a internação hospitalar e dados do cartão de pré- natal. Os resultados mostram cobertura elevada da assistência pré-natal (98,7% tendo 75,8% das mulheres iniciado o pré-natal antes da 16a semana gestacional e 73,1% compareceram a seis ou mais consultas. O pré-natal foi realizado, sobretudo, em unidades básicas (89,6%, públicas (74,6%, pelo mesmo profissional (88,4%, em sua maioria médicos (75,6%, e 96% receberam o cartão de pré-natal. Um quarto das gestantes foi considerado de risco. Do total das entrevistadas, apenas 58,7% foram orientadas sobre a maternidade de referência, e 16,2% procuraram mais de um serviço para a admissão para o parto. Desafios persistem para a melhoria da qualidade dessa assistência, com a realização de procedimentos efetivos para a redução de desfechos desfavoráveis.

  17. Scaling of Natal Dispersal Distances in Terrestrial Birds and Mammals

    Directory of Open Access Journals (Sweden)

    Glenn D. Sutherland

    2000-07-01

    Full Text Available Natal dispersal is a process that is critical in the spatial dynamics of populations, including population spread, recolonization, and gene flow. It is a central focus of conservation issues for many vertebrate species. Using data for 77 bird and 68 mammal species, we tested whether median and maximum natal dispersal distances were correlated with body mass, diet type, social system, taxonomic family, and migratory status. Body mass and diet type were found to predict both median and maximum natal dispersal distances in mammals: large species dispersed farther than small ones, and carnivorous species dispersed farther than herbivores and omnivores. Similar relationships occurred for carnivorous bird species, but not for herbivorous or omnivorous ones. Natal dispersal distances in birds or mammals were not significantly related to broad categories of social systems. Only in birds were factors such as taxonomic relatedness and migratory status correlated with natal dispersal, and then only for maximum distances. Summary properties of dispersal processes appeared to be derived from interactions among behavioral and morphological characteristics of species and from their linkages to the dynamics of resource availability in landscapes. In all the species we examined, most dispersers moved relatively short distances, and long-distance dispersal was uncommon. On the basis of these findings, we fit an empirical model based on the negative exponential distribution for calculating minimum probabilities that animals disperse particular distances from their natal areas. This model, coupled with knowledge of a species' body mass and diet type, can be used to conservatively predict dispersal distances for different species and examine possible consequences of large-scale habitat alterations on connectedness between populations. Taken together, our results can provide managers with the means to identify species vulnerable to landscape-level habitat changes

  18. Environmental risk of heavy metal pollution and contamination sources using multivariate analysis in the soils of Varanasi environs, India.

    Science.gov (United States)

    Singh, Shubhra; Raju, N Janardhana; Nazneen, Sadaf

    2015-06-01

    This study assessed soil pollution in the Varanasi environs of Uttar Pradesh in India. Assessing the concentration of potentially harmful heavy metals in the soils is imperative in order to evaluate the potential risks to human. To identify the concentration and sources of heavy metals and assess the soil environmental quality, 23 samples were collected from different locations covering dumping, road and agricultural area. The average concentrations of the heavy metals were all below the permissible limits according to soil quality guidelines except Cu (copper) and Pb (lead) in dumping and road soils. Soil heavy metal contamination was assessed on the basis of geoaccumulation index (Igeo), pollution index (PI) and integrated pollution index (IPI). The IPI of the metals ranged from 0.59 to 9.94, with the highest IPI observed in the dumping and road soils. A very significant correlation was found between Pb and Cu. The result of principal component analysis suggested that PC1 was mainly affected by the use of agrochemicals, PC2 was affected by vehicular emission and PC3 was affected by dumping waste. Meanwhile, PC4 was mainly controlled by parent material along with anthropogenic activities. Appropriate measures should be taken to minimize the heavy metal levels in soils and thus protect human health.

  19. The genus Cliffortia (Rosaceae in KwaZulu-Natal

    Directory of Open Access Journals (Sweden)

    C. M. Whitehouse

    2004-12-01

    Full Text Available The only area of endemism for Cliffortia L. outside of the Cape Floristic Region (CFR is centred in the northern KwaZulu- Natal Drakensberg. Eleven species of Cliffortia have been recorded from KwaZulu-Natal and distribution maps are provided for each. Clarification of the circumscription of C. browniana Burtt Davy is discussed and a new species, C dracomon- tana. is described. C. paucistaminea Weim. is subdivided into two varieties: var. australis and var. paucistaniinea Comments on some of the other species that have frequently been misidentified are also provided along with a key to all the species in the area.

  20. Water quality in a rural river environment: distribution of metals among water and sediment compartments

    Science.gov (United States)

    Reis, A.; Parker, A.; Alencoao, A.

    2009-04-01

    Sediments have a significant influence on water quality, owing to their role both as a sink and a potential source of pollutants. In fluvial environments from mountainous catchments, the dynamics of sediment particles and particle-bound contaminants are still poorly understood. As stated by Symader et al. (2007), bottom sediments of small rivers in mountainous areas behave like a transport system of its own and show high temporal variation in their chemical composition. The transport of significant sedimentary loads, as suspended matter, in short periods of time, mainly in winter, poses some issues concerning monitoring and modelling approaches of the transport and fate of micro-pollutants at the catchment scale. On one hand, high stream-flow velocity peaks make it difficult or impossible to maintain suspended sediment samplers fixed in the river channel. On the other hand, the cycle of deposition and re-suspension of finer material, throughout the hydrological year, leads to temporal changes of sediment properties. Our contribution reports some results of an investigation on the water quality in a mountainous rural meso-scale catchment, located in the NE of Portugal. The study integrates the examination of metal contents in the sediments and the water body. The river-bottom sediments and water were simply collected in a planned sampling network, in two different periods of the hydrological year (high and low flow). The finer and most recently deposited sediment was preferentially sampled, and the Bierl R.; Kurtenbach, A.; Krein, A. (2007). Transport Indicators. In: Sediment Dynamics and Pollutant Mobility in Rivers (eds Westrich, B. & Forstner, U.), pp. 269-304, Springer.

  1. Molecular rare-earth-metal hydrides in non-cyclopentadienyl environments.

    Science.gov (United States)

    Fegler, Waldemar; Venugopal, Ajay; Kramer, Mathias; Okuda, Jun

    2015-02-02

    Molecular hydrides of the rare-earth metals play an important role as homogeneous catalysts and as counterparts of solid-state interstitial hydrides. Structurally well-characterized non-metallocene-type hydride complexes allow the study of elementary reactions that occur at rare-earth-metal centers and of catalytic reactions involving bonds between rare-earth metals and hydrides. In addition to neutral hydrides, cationic derivatives have now become available.

  2. HEAVY METALS IN ENVIRONMENT, LIVING SYSTEMS AND HERBAL PREPARATION: AN OVERVIEW

    Directory of Open Access Journals (Sweden)

    Sudhakar Gurpur Koldabadi

    2012-07-01

    Full Text Available Heavy metals occur as a natural constituent of earth’s crust. Due to the indiscriminate human activities there is drastic change in geochemical and biochemical balance which results in accumulation of metals in plant parts having secondary metabolites with particular pharmacological activity. All over the world the concentration of essential and non-essential heavy metals such as Cadmium, Copper, Lead, Nickel and Zinc beyond permissible limit is a matter of great concern for public wellbeing. Molecular understanding of plant metal accumulation is essential as it has many biotechnological implications.

  3. Anthropogenic natal environmental effects on life histories in a wild bird population.

    Science.gov (United States)

    Cartwright, Samantha J; Nicoll, Malcolm A C; Jones, Carl G; Tatayah, Vikash; Norris, Ken

    2014-03-03

    Recent work suggests that the environment experienced in early life can alter life histories in wild populations, but our understanding of the processes involved remains limited. Since anthropogenic environmental change is currently having a major impact on wild populations, this raises the possibility that life histories may be influenced by human activities that alter environmental conditions in early life. Whether this is the case and the processes involved remain unexplored in wild populations. Using 23 years of longitudinal data on the Mauritius kestrel (Falco punctatus), a tropical forest specialist, we found that females born in territories affected by anthropogenic habitat change shifted investment in reproduction to earlier in life at the expense of late life performance. They also had lower survival rates as young adults. This shift in life history strategy appears to be adaptive, because fitness was comparable to that of other females experiencing less anthropogenic modification in their natal environment. Our results suggest that human activities can leave a legacy on wild birds through natal environmental effects. Whether these legacies have a detrimental effect on populations will depend on life history responses and the extent to which these reduce individual fitness.

  4. Optical extinction spectrum of a single metal nanoparticle: Quantitative characterization of a particle and of its local environment

    Science.gov (United States)

    Muskens, O. L.; Billaud, P.; Broyer, M.; Del Fatti, N.; Vallée, F.

    2008-11-01

    Optical absorption spectroscopy of a single metal nanoparticle is used to characterize its properties and to obtain quantitative information on its local environment. Experiments were performed using the spatial modulation spectroscopy (SMS) technique on 16 nm mean diameter gold nanoparticles embedded in different medium (i.e., deposited on glass or embedded in a polymer layer). Extraction of the nanoparticle characteristics and determination of the dielectric constant of its environment are discussed, focusing on the impact of the particle shape assumption. The refractive index of the local environment deduced from these measurements shows large particle-to-particle variation, yielding information about fluctuations of the dielectric properties of the surrounding medium on a nanometric scale, inaccessible in ensemble measurements. The influence of the environment of a nanoparticle on its optically extracted geometry and its surface plasmon resonance broadening by surface effect are also studied at a single-particle level.

  5. An Automated Electronic Tongue for In-Situ Quick Monitoring of Trace Heavy Metals in Water Environment

    Science.gov (United States)

    Cai, Wei; Li, Yi; Gao, Xiaoming; Guo, Hongsun; Zhao, Huixin; Wang, Ping

    2009-05-01

    An automated electronic tongue instrumentation has been developed for in-situ concentration determination of trace heavy metals in water environment. The electronic tongue contains two main parts. The sensor part consists of a silicon-based Hg-coated Au microelectrodes array (MEA) for the detection of Zn(II), Cd(II), Pb(II) and Cu(II) and a multiple light-addressable potentiometric sensor (MLAPS) for the detection of Fe(III) and Cr(VI). The control part employs pumps, valves and tubes to enable the pick-up and pretreatment of aqueous sample. The electronic tongue realized detection of the six metals mentioned above at part-per-billion (ppb) level without manual operation. This instrumentation will have wide application in quick monitoring and prediction the heavy metal pollution in lakes and oceans.

  6. Negative phenotypic and genetic correlation between natal dispersal propensity and nest-defence behaviour in a wild bird.

    Science.gov (United States)

    Bize, Pierre; Daniel, Grégory; Viblanc, Vincent A; Martin, Julien G A; Doligez, Blandine

    2017-07-01

    Natural selection is expected to favour the integration of dispersal and phenotypic traits allowing individuals to reduce dispersal costs. Accordingly, associations have been found between dispersal and personality traits such as aggressiveness and exploration, which may facilitate settlement in a novel environment. However, the determinism of these associations has only rarely been explored. Here, we highlight the functional integration of individual personality in nest-defence behaviour and natal dispersal propensity in a long-lived colonial bird, the Alpine swift (Apus melba), providing insights into genetic constraints shaping the coevolution of these two traits. We report a negative association between natal dispersal and nest-defence (i.e. risk taking) behaviour at both the phenotypic and genetic level. This negative association may result from direct selection if risk-averseness benefits natal dispersers by reducing the costs of settlement in an unfamiliar environment, or from indirect selection if individuals with lower levels of nest defence also show lower levels of aggressiveness, reducing costs of settlement among unfamiliar neighbours in a colony. In both cases, these results highlight that risk taking is an important behavioural trait to consider in the study of dispersal evolution. © 2017 The Author(s).

  7. The Volatile Fraction of Comets as Quantified at Infrared Wavelengths - An Emerging Taxonomy and Implications for Natal Heritage

    Science.gov (United States)

    Mumma, M. J.; DiSanti, M. A.; Bonev, B. P.; Villanueva, G. L.; Magee-Sauer, K.; Gibb, E. L.; Paganini, L.; Radeva, Y. L.; Charnley, S. B.

    2012-01-01

    It is relatively easy to identify the reservoir from which a given comet was ejected. But dynamical models demonstrate that the main cometary reservoirs (Kuiper Belt, Oort Cloud) each contain icy bodies that formed in a range of environments in the protoplanetary disk, and the Oort Cloud may even contain bodies that formed in disks of sibling stars in the Sun s birth cluster. The cometary nucleus contains clues to the formative region(s) of its individual components. The composition of ices and rocky grains reflect a range of processes experienced by material while on the journey from the natal interstellar cloud core to the cometary nucleus. For that reason, emphasis is placed on classifying comets according to their native ices and dust (rather than orbital dynamics). Mumma & Charnley [1] reviewed the current status of taxonomies for comets and relation to their natal heritage.

  8. Natal dispersal and personalities in great tits (Parus major)

    NARCIS (Netherlands)

    Dingemanse, N.J.; Both, C.; Van Noordwijk, A.J.; Rutten, A.L.; Drent, P.J.

    2003-01-01

    Dispersal is a major determinant of the dynamics and genetic structure of populations, and its consequences depend not only on average dispersal rates and distances, but also on the characteristics of dispersing and philopatric individuals. We investigated whether natal dispersal correlated with a p

  9. Educational Leadership with an Ethics of Plurality and Natality

    Science.gov (United States)

    Berger, Iris

    2015-01-01

    This paper aims to impregnate the concept of educational leadership with new meanings and new possibilities. I draw on Hannah Arendt's ("The human condition." University of Chicago Press, Chicago, 1958/1998) political thought, particularly, her concepts of "plurality" and "natality" alongside the distinction she made…

  10. Natal dispersal and personalities in great tits (Parus major)

    NARCIS (Netherlands)

    Dingemanse, N.J.; Both, C.; Noordwijk, van A.J.; Rutten, A.L.; Drent, P.J.

    2003-01-01

    Dispersal is a major determinant of the dynamics and genetic structure of populations, and its consequences depend not only on average dispersal rates and distances, but also on the characteristics of dispersing and philopatric individuals. We investigated whether natal dispersal correlated with a

  11. FUNCTIONALLY UNIVENTRICULAR HEARTS: IMPACT OF PRE-NATAL DIAGNOSIS

    Directory of Open Access Journals (Sweden)

    Antonio Francesco Corno

    2015-02-01

    Full Text Available Within the last few decades the pre-natal echocardiographic diagnosis of congenital heart defects has made substantial progresses, particularly for the identification of complex malformation. Functionally univentricular hearts categorize a huge variety of heart malformations. Since no one of the patients with these congenital heart defects can ever undergo a bi-ventricular type of repair, early recognition and decision-making from the neonatal period are required in order to allow for appropriate multiple-step diagnostic and treatment procedures, either of interventional cardiology and/or surgery, on the pathway of univentricular heart. In the literature strong disagreements exist about the potential impact of the pre-natal diagnosis on the early and late outcomes of complex congenital heart defects. This review of the recent reports has been undertaken to better understand the impact of pre-natal diagnosis in functionally univentricular hearts taking into consideration the following topics:•pre-natal screening•outcomes and survival•general morbidity•neurologic and developmental consequences•pregnancy management and delivery planning•resources utilization and costs/benefits issues•ethical implications, parents counseling, interruption of pregnancy versus treatment

  12. Marine research in Natal: proceedings of a symposium and workshop

    CSIR Research Space (South Africa)

    Bowmaker, AP

    1987-01-01

    Full Text Available A two day mini-symposium and workshop held in Durban in February 1986 and attended by 70 marine scientists from Natal and KwaZulu is reported on. Summaries of 84 presentations are given, separated into relevant sections. Each section is summarized...

  13. Volleyball injuries in KwaZulu-Natal — epidemiology

    African Journals Online (AJOL)

    Abstract. Objective. This study explored the incidence, nature and ... Natal participated by informed voluntary consent Data were gathered using a ... Package for the Social Sciences (SPSS) for Windows and chi-square tests with a ... Volleyball is a popular recreational and professional sport code both locally .... the literature.

  14. A survey of natal and neonatal teeth in newborn infants

    Directory of Open Access Journals (Sweden)

    Chun-Hsiang Wang

    2017-03-01

    Conclusion: Most of the natal or neonatal teeth were in the mandibular primary incisor position and not all of them were supernumerary. No gender differences were found in tooth morphology, positive family history, and treatment methods. The tooth morphology was not significantly related to a positive family history, premature delivery, or the mother's physical condition before delivery.

  15. Iron Cycling in Low pH Environments - Potential Application for the Recovery of Precious Metals from Industrial Waste

    Science.gov (United States)

    Muehe, E. M.; Helle, T.; Kappler, A.

    2014-12-01

    The use of many different precious metals (gold, platinum…) and Rare Earth Elements (lanthanum, neodymium…) in the production of electronic products is drastically increasing. To meet this demand, not only mining activities but recently also the recovery of these elements from industrial waste is in the focus of research. It has been shown that the application of extracting solutions with pH values lower than 4 lead to an economically feasible recovery of industrially precious metals. This abiotic extraction efficiency can potentially be increased by using microorganisms capable of dissolving more stable minerals at low pH. In collaboration with industry, a waste incineration plant, and governmental authorities, we investigate the extraction and recovery of strategically important metals and Rare Earth Elements from industrial waste. We optimize the (bio)-geochemical conditions for the extraction of these elements. To this end, a variety of microorganisms are evaluated for efficient metal extraction. We focus on known laboratory cultures capable of oxidizing and reducing Fe minerals and S compounds. Additionally, unknown microbial communities able to increase the efficiency of precious metal extraction from the industrial waste are enriched from environments with comparable geochemical conditions found in the extraction solutions.

  16. Bioavailability and bioaccumulation of metal-based engineered nanomaterials in aquatic environments: concepts and processes: chapter 5

    Science.gov (United States)

    Luoma, Samuel N.; Khan, Farhan R.; Croteau, Marie-Noële

    2014-01-01

    Bioavailability of Me-ENMs to aquatic organisms links their release into the environment to ecological implications. Close examination shows some important differences in the conceptual models that define bioavailability for metals and Me-ENMs. Metals are delivered to aquatic animals from Me-ENMs via water, ingestion, and incidental surface exposure. Both metal released from the Me-ENM and uptake of the nanoparticle itself contribute to bioaccumulation. Some mechanisms of toxicity and some of the metrics describing exposure may differ from metals alone. Bioavailability is driven by complex interaction of particle attributes, environmental transformations, and biological traits. Characterization of Me-ENMs is an essential part of understanding bioavailability and requires novel methodologies. The relative importance of the array of processes that could affect Me-ENM bioavailability remains poorly known, but new approaches and models are developing rapidly. Enough is known, however, to conclude that traditional approaches to exposure assessment for metals would not be adequate to assess risks from Me-ENMs.

  17. METALert - an emergency response system for China for heavy metals in the environment

    Science.gov (United States)

    Joris, Ingeborg; Seuntjens, Piet; Dams, Jef; Desmet, Nele; Van Looy, Stijn; Raymaekers, Jens; Decorte, Lieve; Raben, Ingrid; Thijssen, Chris; Zhang, Hongzhen; Dong, Jingqi; Zhang, Qianwen

    2016-04-01

    The rapid industrialisation and economic growth of China has resulted in a mirrored increase of environmental issues and threats, which make the updating of the current environmental emergency response protocols very important. Heavy metal pollution accidents with high environmental risks are happening more frequently than ever in recent years. Despite efforts made by the authorites in respect to the formulation of sound policy, efficient technical methods and regulations for dealing with appropriate responses to emergency environmental incidents related to heavy metal pollution are still lacking. METALert is a generic Emergency Response System (ERS) for accidental pollution incidents caused by key heavy metal related industries in China and developed to support China in achieving its environmental targets. The METALert tool is based on environmental models for forecasting, simulation and visualisation of dispersion of heavy metal pollution in water, air and soil. The tool contains a generic database with scenarios for accidental release of metals in typical accidents related to the five key heavy metal industries in China. The tool can calculate the impact of an accident in water, air and soil and is evaluated and demonstrated for a river basin in the Chenzhou area, an important heavy metal mining area in China. The setup of the tool, the background models and the application in Chenzhou will be presented.

  18. A Selective Bioreduction of Toxic Heavy Metal Ions from Aquatic Environment by Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    A. M. Rahatgaonkar

    2008-01-01

    Full Text Available The need to remove or recover metal ions from industrial wastewater has been established in financial as well as environmental terms. This need has been proved financially in terms of cost saving through metal reuse or sale and environmentally as heavy metal toxicity can affect organisms throughout the food chain, including humans. Bioremediation of heavy metal pollution remains a major challenge in environmental biotechnology. Current removal strategies are mainly based on bioreduction of Co++, Ni++, Cu++ and Cd++ to their metallic forms by Saccharomyces cerevisiae in buffered aqueous solution. The rate of biotransformation was significantly influenced by pH of aqueous solution, concentration of biomass and hardness of water. All reaction conditions were optimized and maximum reduction of Co++, Cd++, Ni++ and Cu++ were observed as 80%, 63%, 50%, and 44% respectively. Unreacted Co++, Cd++, Ni++metal ions were extracted by 8-hydroxyquinoline and Cu++ by diethylthio carbamate in CHCl3 at different pH. Furthermore, the concentrations of unreacted metal ions were established spectrophotometrically.

  19. The effects of microstructure on crack initiation in liquid-metal environments

    CSIR Research Space (South Africa)

    Fernandes, PJL

    1997-09-01

    Full Text Available Liquid-metal-induced embrittlement under tensile test conditions is identified by the existence of a characteristic ductility trough. In this study, the effect of molten gallium on the behaviour of two brass alloys with different microstructures...

  20. Toxicity of certain heavy metals on fish in the aquatic environment

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — On the earth's crust there are 59 heavy metals of which 17 are considered toxic to biological communities. Here in Alaska, we have thus far considered the following...

  1. Metal-containing residues from industry and in the environment: geobiotechnological urban mining.

    Science.gov (United States)

    Glombitza, Franz; Reichel, Susan

    2014-01-01

    This chapter explains the manifold geobiotechnological possibilities to separate industrial valuable metals from various industrial residues and stored waste products of the past. In addition to an overview of the different microbially catalyzed chemical reactions applicable for a separation of metals and details of published studies, results of many individual investigations from various research projects are described. These concern the separation of rare earth elements from phosphorous production slags, the attempts of tin leaching from mining flotation residues, the separation of metals from spent catalysts, or the treatment of ashes as valuable metal-containing material. The residues of environmental technologies are integrated into this overview as well. The description of the different known microbial processes offers starting points for suitable and new technologies. In addition to the application of chemolithoautotrophic microorganisms the use of heterotrophic microorganisms is explained.

  2. Influence of Disposal Environment on Availability and Plant Uptake of Heavy Metals in Dredged Material.

    Science.gov (United States)

    1981-12-01

    heavy metals is increased by complex formation or colloid peptiza- tion due to humus contained in the organic matter of a soil. Soil organic matter...in the soil (Ellis and Knezek 1972; Stevenson and Ardakani 1972). The stabilities of the heavy metal-organic matter complexes appear to be greater...McGraw-Hill Book Company, Inc., New York, N. Y. pp 20-21, 106-107. Stevenson , F. J., and M. S. Ardakani. 1972. Organic matter reactions involving

  3. Are nanosized or dissolved metals more toxic in the environment? A meta-analysis.

    Science.gov (United States)

    Notter, Dominic A; Mitrano, Denise M; Nowack, Bernd

    2014-12-01

    Recently, much has been written about the extreme urgency of elaborating the regulations for engineered nanomaterials. Such regulations are needed both from lawmakers, to protect people from potentially adverse effects, and from industry representatives, to prove that nanoproducts are produced carefully and with caution to avoid possible lawsuits. However, developing regulations has proven to be a difficult task, and an ambiguous topic where errors can easily occur. In the present study, the authors present a meta-analysis of 3 different nanomaterials (nano-Ag, nano-ZnO, and nano-CuO) in which data from ecotoxicity studies and published half-maximal effective concentration (EC50) values are compared for both the nano form and the corresponding dissolved metal. A ratio equal to 1 means that the particle is as toxic as the dissolved metal ion, whereas a lower ratio signifies that the nano form is less toxic than the dissolved metal based on total metal concentrations. The results show that for 93.8% (Ag), 100% (Cu), and 81% (Zn) of the ratios considered, the nano form is less toxic than the dissolved metal in terms of total metal concentration. Very few of the studies surveyed found a ratio of EC50 values for (dissolved/nano) that was larger than 2 (Ag: 1.1%; Cu: 0%; Zn: 2.8%). Hence, a reduction in existing metal concentration thresholds by a factor of 2 in current freshwater and soil regulations for ecotoxicity may be sufficient to protect organisms and compartments from the nano form of these metals as well. © 2014 SETAC.

  4. Statistical significance of biomonitoring of marine algae for trace metal levels in a coral environment

    Digital Repository Service at National Institute of Oceanography (India)

    Gopinath, A.; Muraleedharan, N.S.; Chandramohanakumar, N.; Jayalakshmy, K.V.

    , which may limit algal growth (Lobban et al., 1985). It is found that tropical seaweeds tend to accumulate more Fe than Mn, Zn and Cu (Ganesan, et al., 1991). In temperate regions, uptake of Zn is less because of reduction of photosynthesis due to short..., UK Clijsters, H., and van Assche, F. 1985. Inhibition of photosynthesis by heavy metals. Photosynthetic Research 7: 31-40. Eisler, R. 1981. Trace Metal Concentration in Marine Organisms. Pergamon Press: New York. FAO, 1983. Compilation of legal...

  5. Assessment of Heavy Metals in Street Dust in Kathmandu Metropolitan City and their Possible Impacts on the Environment

    Directory of Open Access Journals (Sweden)

    Pawan Raj Shakya

    2011-12-01

    Full Text Available Street dust often contains elevated concentrations of heavy metals and can influence on environment and human health. Therefore, a study on the characteristics of heavy metals in street dusts at different localities was carried out in the metropolitan city of Kathmandu of Nepal. A total of 20 street dusts have been sampled from four sampling sites with various activities or characteristics such as mechanical workshops (MWK, motor parks (MPK, market areas (MKA and residential areas (RDA and analyzed for Zn, Pb, Ni, Cr and Cd using the atomic absorption spectrophotometric method. Results showed that street dust samples contained significant levels of the metals studied compared to the values from the control site. The variation in concentration of most of the heavy metals determined decreased in an order represented as MWK>MPK>MKA>RDA>Control. While the RDA and MKA give the same element abundance order as Zn > Pb > Ni > Cr > Cd, the MPK and MWK show different abundance order in some elemental contents. In all the street dusts, zinc is the most available and labile element followed by lead. From the place of low activity (RDA to the place of high activity (MWK, the metal concentrations in street dusts varied from 55.4-419.3 μg g-1 for Zn, 12.3-116.8 μg g-1 for Pb, 4.9-86.3 μg g-1 for Ni, 1.4-14.3 μg g-1 for Cr and 0.3-39.6 μg g-1 for Cd respectively. Results indicate that the metal pollutants in street dusts could significantly contribute to deteriorate the environmental status of the city of Kathmandu metropolis.

  6. Revealing the cold dust in low-metallicity environments. I. Photometry analysis of the Dwarf Galaxy Survey with Herschel

    Science.gov (United States)

    Rémy-Ruyer, A.; Madden, S. C.; Galliano, F.; Hony, S.; Sauvage, M.; Bendo, G. J.; Roussel, H.; Pohlen, M.; Smith, M. W. L.; Galametz, M.; Cormier, D.; Lebouteiller, V.; Wu, R.; Baes, M.; Barlow, M. J.; Boquien, M.; Boselli, A.; Ciesla, L.; De Looze, I.; Karczewski, O. Ł.; Panuzzo, P.; Spinoglio, L.; Vaccari, M.; Wilson, C. D.

    2013-09-01

    Context. We present new photometric data from our Herschel guaranteed time key programme, the Dwarf Galaxy Survey (DGS), dedicated to the observation of the gas and dust in low-metallicity environments. A total of 48 dwarf galaxies were observed with the PACS and SPIRE instruments onboard the Herschel Space Observatory at 70, 100, 160, 250, 350, and 500 μm. Aims: The goal of this paper is to provide reliable far-infrared (FIR) photometry for the DGS sample and to analyse the FIR/submillimetre (submm) behaviour of the DGS galaxies. We focus on a systematic comparison of the derived FIR properties (FIR luminosity, LFIR, dust mass, Mdust, dust temperature, T, emissivity index, β) with more metal-rich galaxies and investigate the detection of a potential submm excess. Methods: The data reduction method is adapted for each galaxy in order to derive the most reliable photometry from the final maps. The derived PACS flux densities are compared with the Spitzer MIPS 70 and 160 μm bands. We use colour-colour diagrams to analyse the FIR/submm behaviour of the DGS galaxies and modified blackbody fitting procedures to determine their dust properties. To study the variation in these dust properties with metallicity, we also include galaxies from the Herschel KINGFISH sample, which contains more metal-rich environments, totalling 109 galaxies. Results: The location of the DGS galaxies on Herschel colour-colour diagrams highlights the differences in dust grain properties and/or global environments of low-metallicity dwarf galaxies. The dust in DGS galaxies is generally warmer than in KINGFISH galaxies (TDGS ~ 32 K and TKINGFISH ~ 23 K). The emissivity index, β, is ~1.7 in the DGS, however metallicity does not make a strong effect on β. The proportion of dust mass relative to stellar mass is lower in low-metallicity galaxies: Mdust/Mstar ~ 0.02% for the DGS versus 0.1% for KINGFISH. However, per unit dust mass, dwarf galaxies emit about six times more in the FIR/submm than

  7. Interactions of the metal tolerant heterotrophic microorganisms and iron oxidizing autotrophic bacteria from sulphidic mine environment during bioleaching experiments.

    Science.gov (United States)

    Jeremic, Sanja; Beškoski, Vladimir P; Djokic, Lidija; Vasiljevic, Branka; Vrvić, Miroslav M; Avdalović, Jelena; Gojgić Cvijović, Gordana; Beškoski, Latinka Slavković; Nikodinovic-Runic, Jasmina

    2016-05-01

    Iron and sulfur oxidizing chemolithoautotrophic acidophilic bacteria, such as Acidithiobacillus species, hold the dominant role in mine environments characterized by low pH values and high concentrations of reduced sulfur and iron compounds, such as ores, rocks and acid drainage waters from mines. On the other hand, heterotrophic microorganisms, especially their biofilms, from these specific niches are receiving increased attention, but their potential eco-physiological roles have not been fully understood. Biofilms are considered a threat to human health, but biofilms also have beneficial properties as they are deployed in waste recycling and bioremediation systems. We have analyzed interactions of the metal tolerant heterotrophic microorganisms in biofilms with iron oxidizing autotrophic bacteria both from the sulphidic mine environment (copper mine Bor, Serbia). High tolerance to Cu(2+), Cd(2+) and Cr(6+) and the presence of genetic determinants for the respective metal tolerance and biofilm-forming ability was shown for indigenous heterotrophic bacteria that included strains of Staphylococcus and Rhodococcus. Two well characterized bacteria- Pseudomonas aeruginosa PAO1 (known biofilm former) and Cupriavidus metallidurans CH34 (known metal resistant representative) were also included in the study. The interaction and survivability of autotrophic iron oxidizing Acidithiobacillus bacteria and biofilms of heterotrophic bacteria during co-cultivation was revealed. Finally, the effect of heterotrophic biofilms on bioleaching process with indigenous iron oxidizing Acidithiobacillus species was shown not to be inhibitory under in vitro conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Metal isotope coded profiling of organic ligands by mass spectrometry in aquatic environments

    Science.gov (United States)

    Wichard, Thomas; Deicke, Michael; Frieder Mohr, Jan; Klein, Martin

    2017-04-01

    Metal isotope coded profiling (MICP) introduces a universal discovery platform for metal chelating natural products that act as metallophores, ion buffers or sequestering agents. The detection of cation and oxoanion complexing ligands is facilitated by the identification of unique isotopic signatures created by the application of isotopically pure metals. We present a targeted analysis of low-molecular-weight organic ligands based on fast UHPLC-ESI-MS measurements. Replacement of, for example, natural iron or molybdenum with isotopically pure 54Fe/58Fe (ratio 1:1) or 95Mo/98Mo (ratio 1:1) causes easily detectable unique isotopic signatures in the mass spectra of potential metal-complexing ligands. This can be achieved under laboratory conditions not only in growth media, but also by spiking directly aqueous samples or solid-phase extracts. Importantly, as the relative affinity of the metallophores for e.g., Mo or Fe is dependent on the pH, all experiments needs to be conducted under pH-controlled conditions. The improved ionization efficiency of some metal complexes helps to enhance the signal-to-noise ratio compared to the free ligand at the same chromatographic conditions. The methodology does not necessarily depend on HR-ESI-MS measurements (e.g., Q-Exactive Orbitrap) and can be applied to any mass spectrometer. With MICP, two birds can be killed with one stone: (i) the identification of metallophores (e.g., siderophores, molybdophores) for metal uptake by any organism and (ii) organic ligands which solely work as metal buffer in dissolved organic matter (DOM). We currently address following two main research lines: First, DOM has often been used as a proxy for bio-productivity in terms of a carbon source; however, the specific impact of DOM as a "metal buffer" for biological processes is still under-investigated. Upon the administration of individual isotopes or isotopic pairs, for example, 54Fe/58Fe, 63Cu/65Cu, 66Zn/68Zn, or 95Mo/98Mo and subsequent

  9. Remobilization of trace metals from contaminated marine sediment in a simulated dynamic environment.

    Science.gov (United States)

    Xu, Weihai; Li, Xiangdong; Wai, Onyx W H; Huang, Weilin; Yan, Wen

    2015-12-01

    In this study, release and redistribution of sediment bound trace metals due to resuspension were investigated by a lid-driven elongated annular flume (LEAF). The total suspended particulate matters (SPMs) increased significantly in quantity with the raised resuspension energies and varied distinctively in particle size and mineral composition. Except for Cu, Ni, Cd, Pb, and Zn showed an increase in dissolved phase as the resuspension energy increased. Relatively low Cu was observed in dissolved phase whereas it owned the highest original concentration in the sediment. This is primarily due to the very low solubility of Cu sulfide. In comparison to sediment, all metals were evidently enriched in SPMs which primarily contributed to the much more fine particles (silt/clay fraction) contained in the SPMs. Metals enrichment followed the Irving-Williams order of complex stability. However, metals content varied indistinctively in the SPMs among the three selected resuspension levels. The distribution coefficients (K d) exhibited opposite trend with the increasing resuspension level with the exception of Cu. It indicated that physical and chemical characters of sediment such as grain composition, Fe/Mn, and organic matter content may also act as major factors in the release of metals and control their phase distribution in the water column.

  10. Spatial distribution features and environment effect of heavy metal in intertidal surface sediments of Guanhe estuary,Northern Jiangsu Province

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In northern Jiangsu coastal zone area,Guanhe River is the biggest fiver and has the best navigation conditions among rivers which flow into the Yellow Sea.The grain sizes show gradual increase from the high intertidal zone to lower intertidal zone.The heavy metal values have slight changes along both sides of the fiver mouth,but show an evident change perpendicular to the tidal flat.In the latter case,they show a good correlation with grain size fluctuation,that is,the heavy metal values gradually decline when the grain size increases from the high intertidal zone to the lower intra-tidal zone.Analyses of the heavy metal elements show that on the Guanhe estuary surface sediment,the content of the elements Hg,As and Cu is above background values;Pb and Zn contents are rather close to the background values;and Cd content is less than the background values.The element Hg comes out to be harmful in a medium level to ecological environment,while the elements of Cr,As,Cu,Pb,Zn and Cd fall in a safe range of MPL.On the whole,Guanhe estuary tidal flat is not very harmful to the ecology in terms of the heavy metals.

  11. Computer aided process planning and die design in simulation environment in sheet metal forming

    Science.gov (United States)

    Tisza, Miklós; Lukács, Zsolt

    2013-12-01

    During the recent 10-15 years, Computer Aided Process Planning and Die Design evolved as one of the most important engineering tools in sheet metal forming, particularly in the automotive industry. This emerging role is strongly emphasized by the rapid development of Finite Element Modeling, as well. The purpose of this paper is to give a general overview about the recent achievements in this very important field of sheet metal forming and to introduce some special results in this development activity. Therefore, in this paper, an integrated process simulation and die design system developed at the University of Miskolc, Department of Mechanical Engineering will be analyzed. The proposed integrated solutions have great practical importance to improve the global competitiveness of sheet metal forming in the very important segment of industry. The concept described in this paper may have specific value both for process planning and die design engineers.

  12. Induction furnace testing of the durability of prototype crucibles in a molten metal environment

    Energy Technology Data Exchange (ETDEWEB)

    Jablonski, Paul D.

    2005-09-01

    Engineered ceramic crucibles are commonly used to contain molten metal. Besides high temperature stability, other desired crucible characteristics include thermal shock resistance, minimal reaction with the molten metal and resistance to attack from the base metal oxide formed during melting. When used in an induction furnace, they can be employed as a “semi-permanent” crucible incorporating a dry ram backup and a ceramic cap. This report covers several 250-lb single melt crucible tests in an air melt induction furnace. These tests consisted of melting a charge of 17-4PH stainless steel, holding the charge molten for two hours before pouring off the heat and then subsequently sectioning the crucible to review the extent of erosion, penetration and other physical characteristics. Selected temperature readings were made throughout each melt. Chemistry samples were also taken from each heat periodically throughout the hold. The manganese level was observed to affect the rate of chromium loss in a non-linear fashion.

  13. Study of the heavy metal phytoextraction capacity of two forage species growing in an hydroponic environment

    Energy Technology Data Exchange (ETDEWEB)

    Bonfranceschi, Barros A. [Centro de Investigacion y Desarrollo en Fermentaciones Industriales (CINDEFI, UNLP-CCT La Plata, CONICET), Facultad de Ciencias Exactas (UNLP), Calle 50 y 115, 1900 La Plata (Argentina); Flocco, C.G. [Consejo Nacional de Investigaciones Cientificas y Tecnologicas (CONICET), Buenos Aires (Argentina); Donati, E.R., E-mail: donati@quimica.unlp.edu.ar [Centro de Investigacion y Desarrollo en Fermentaciones Industriales (CINDEFI, UNLP-CCT La Plata, CONICET), Facultad de Ciencias Exactas (UNLP), Calle 50 y 115, 1900 La Plata (Argentina)

    2009-06-15

    Sorghum and alfalfa are two important forage crops. We studied their capacity for accumulating heavy metals in hydroponic experiments. Cadmium, nickel (as divalent cations) and chromium (trivalent and hexavalent) were added individually to the nutrient solution in a range of concentrations from 1 to 80 mg/l. Cr(III) was complexed with EDTA to increase its bioavailability. In alfalfa the increases in the concentration of Cr(III) and Cr(VI) favoured translocation of the metals to the upper parts of the plants, while with Ni(II) the level of translocated metal remained almost unchanged. In sorghum, both Cr(VI) and Ni(II) produced similar results to those in alfalfa, but increases in the concentrations of Cd(II) and Cr(III) in the solution lead to a higher accumulation of the metal at the root level. The concentrations referred to the dry biomass of alfalfa were 500 mg/kg (aerial parts) and 1500 mg/kg (roots) of Cr(III), simultaneously enhancing plant growth. Sorghum captured 500 and 1100 mg/kg (in aerial parts) and 300 and 2000 mg/kg (in roots) for Ni(II) and Cd(II) respectively, without significant damage to its biomass. The results show that alfalfa and sorghum can not only grow in the presence of high heavy metal concentration but also capture and translocate them to the aerial parts; because of these results special attention should be given to these crop plants for their possible use in phytoremediation of large contaminated areas but especially to avoid the possible introduction of the metals accumulated in aerial parts into the food chain when those plants grow in contaminated areas.

  14. Analysis of microfouling products formed on metallic surfaces exposed in a marine environment

    Digital Repository Service at National Institute of Oceanography (India)

    DeSouza, F.P.; Bhosle, N.B.

    -2454 online q 2003 Taylor & Francis Ltd DOI: 10.1080/0892701021000026147 *Corresponding author; e-mail: bhosle@csnio.ren.nic.in or bhosle@darya.nio.org Biofouling, 2003 Vo l 19 (2), pp 95–107 metallic or non-metallic surfaces. Rather, micro- organisms produce... of macroaggregates (Mopper et al., 1995). Carbohydrates are common structural and storage components of both marine and terrestrial organisms. They account for 20–40 wt% of micro- algae (Parsons et al., 1984), 40 wt% of bacteria (Moers et al., 1993), and 75 wt...

  15. Combined-load buckling behavior of metal-matrix composite sandwich panels under different thermal environments

    Science.gov (United States)

    Ko, William L.; Jackson, Raymond H.

    1991-01-01

    Combined compressive and shear buckling analysis was conducted on flat rectangular sandwich panels with the consideration of transverse shear effects of the core. The sandwich panel is fabricated with titanium honeycomb core and laminated metal matrix composite face sheets. The results show that the square panel has the highest combined load buckling strength, and that the buckling strength decreases sharply with the increases of both temperature and panel aspect ratio. The effect of layup (fiber orientation) on the buckling strength of the panels was studied in detail. The metal matrix composite sandwich panel was much more efficient than the sandwich panel with nonreinforced face sheets and had the same specific weight.

  16. Low-mass X-ray binaries in the outer halo of NGC 4472: a consequence of natal kicks?

    Science.gov (United States)

    Van Haaften, Lennart M.; Maccarone, Thomas J.; Sell, Paul; Mihos, Chris; Sand, David J.; Kundu, Arunav; Zepf, Stephen

    2017-01-01

    We present new Chandra observations of the outer halo of the giant elliptical galaxy NGC 4472 (M49) in the Virgo Cluster. The data extend to 130 kpc (28'), and have a total exposure time of 150 ks. After eliminating background active galactic nuclei and globular cluster (GC) sources, and correcting for completeness, we find that the number of field low-mass X-ray binaries (LMXBs) per unit stellar light increases significantly with galactocentric radius. The excess of field LMXBs at large galactocentric radii may be a consequence of natal kicks on neutron stars and black holes in binary systems in the inner part of the galaxy. These systems, some of which will become LMXBs, will generally move into wider galactic orbits. Since the metallicity in the halo of NGC 4472 strongly decreases towards larger galactocentric radii, the number of field LMXBs is anti-correlated with metallicity, in contrast to GCs. An alternative to natal kicks to explain the spatial distribution of field LMXBs is therefore a reversed metallicity effect.

  17. Contribution of soil, water and food consumption to metal exposure of children from geological enriched environments in the coastal zone of Lake Victoria, Kenya.

    NARCIS (Netherlands)

    E. Oyoo-Okoth; W. Admiraal; O. Osano; D Manguya-Lusega; V. Ngure; M.H.S. Kraak; V. Chepkirui-Boit; J. Makwali

    2013-01-01

    Geologically enriched environments may contain high concentrations of some metals. In areas where industrial exposures remain superficial, children may be exposed to these geological metals through soil, drinking water and consumption of food locally grown. The aim of this study was to assess the co

  18. Thermochemistry and Dynamics of Reactive Species: Nitrogen-rich Compounds, Metals and SiC Clusters in Free and Solvated Environment

    Science.gov (United States)

    2005-10-31

    of Reactive Species : Nitrogen-rich F49620-02-1-0371 Compounds, Metals and SiC clusters in Free and Solvated Environments Sb. GRANT NUMBER 5c. PROGRAM...F49620-02-1-0371 Thermochemistry and Dynamics of Reactive Species : Nitrogen-rich Compounds, Metals, and SiC clusters in Free and Solvated Environments...research program remain the same as before: obtaining fundamental thermochemical and dynamical data on reactive species Status of Effort This report

  19. Methodology to evaluate the crack growth rate by stress corrosion cracking in dissimilar metals weld in simulated environment of PWR nuclear reactor

    Energy Technology Data Exchange (ETDEWEB)

    Paula, Raphael G.; Figueiredo, Celia A.; Rabelo, Emerson G., E-mail: raphaelmecanica@gmail.com, E-mail: caf@cdtn.br, E-mail: egr@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2013-07-01

    Inconel alloys weld metal is widely used to join dissimilar metals in nuclear reactors applications. It was recently observed failures of weld components in plants, which have triggered an international effort to determine reliable data on the stress corrosion cracking behavior of this material in reactor environment. The objective of this work is to develop a methodology to determine the crack growth rate caused by stress corrosion in Inconel alloy 182, using the specimen (Compact Tensile) in simulated PWR environment. (author)

  20. Corrosion characteristics of seven metals in three aqueous environments for forensic applications

    Science.gov (United States)

    Tong, Tianqi

    Corrosion characteristics of seven varieties of metals---zinc, brass C260, stainless steel 302, stainless steel 316, stainless steel 420, stainless steel 430, and stainless steel 440---in three aqueous media---Atlantic Ocean, Charles River, and deionized waters---were assessed via mass loss methods over 32 weeks, with supplemental data in the form of photomicrographic records. Concurrently, tests were conducted to determine the degree of measurement error resulting from the analytical scale used during corrosion assessment. This was accomplished by using reference samples of each type of metal and a glass vial as the container that held the metal and water samples. These error tests indicated that while the mass error associated with the metal samples was low, the error in mass associated with the vial displayed error margins two orders of magnitude larger than the error margins for the smaller metal samples. Further, control tests and statistical analysis indicated that this variation was the result of some quality inherent to the vial. The metal samples involved in the corrosion assessment experiment generally displayed corrosion characteristics in agreement with trends reported in the literature. Zinc produced the greatest quantity of corrosion residues out of all the metals studied. Brass C260 also developed visible corrosion. For example, brass C260 developed dark green/brown adherent residue and whitish blue-tinted nonadherent residue in Atlantic Ocean water, faint greenish tarnishing and some dark green spots and dots over time in Charles River water, and only faint greenish tarnish in deionized water. In contrast with zinc and brass C260, the stainless steels did not exhibit signs of significant corrosion rates excepting stainless steel 420 (SS420), which displayed pitted features surrounded by multi-colored rings on all of its Atlantic Ocean immersion samples and 25% of its Charles River immersion samples. Atlantic Ocean water generally caused the greatest

  1. Sulfide oxidation and distribution of metals near abandoned copper mines in coastal environments, Prince William Sound, Alaska, USA

    Science.gov (United States)

    Koski, R.A.; Munk, L.; Foster, A.L.; Shanks, Wayne C.; Stillings, L.L.

    2008-01-01

    The oxidation of sulfide-rich rocks, mostly leftover debris from Cu mining in the early 20th century, is contributing to metal contamination of local coastal environments in Prince William Sound, Alaska. Analyses of sulfide, water, sediment, precipitate and biological samples from the Beatson, Ellamar, and Threeman mine sites show that acidic surface waters generated from sulfide weathering are pathways for redistribution of environmentally important elements into and beyond the intertidal zone at each site. Volcanogenic massive sulfide deposits composed of pyrrhotite and (or) pyrite + chalcopyrite + sphalerite with subordinate galena, arsenopyrite, and cobaltite represent potent sources of Cu, Zn, Pb, As, Co, Cd, and Hg. The resistance to oxidation among the major sulfides increases in the order pyrrhotite ??? sphalerite Hg (to 4100 ng/L) in the pore waters probably result from oxidation of sphalerite-rich rocks. The low-pH and high concentrations of dissolved Fe, Al, and SO4 are conducive to precipitation of interstitial jarosite in the intertidal gravels. Although pore waters from the intertidal zone at the Threeman mine site have circumneutral pH values, small amounts of dissolved Fe2+ in the pore waters are oxidized during mixing with seawater, resulting in precipitation of Fe-oxyhydroxide flocs along the beach-seawater interface. At the Beatson site, surface waters funneled through the underground mine workings and discharged across the waste dumps have near-neutral pH (6.7-7.3) and a relatively small base-metal load; however, these streams probably play a role in the physical transport of metalliferous particulates into intertidal and offshore areas during storm events. Somewhat more acidic fluids, to pH 5.3, occur in stagnant seeps and small streams emerging from the Beatson waste dumps. Amorphous Fe precipitates in stagnant waters at Beatson have high Cu (5.2 wt%) and Zn (2.3 wt%) concentrations that probably reflect adsorption onto the extremely high

  2. Noble Metal Nanostructures Influence of Structure and Environment on Their Optical Properties

    Directory of Open Access Journals (Sweden)

    Ondřej Kvítek

    2013-01-01

    Full Text Available Optical properties of nanostructured materials, isolated nanoparticles, and structures composed of both metals and semiconductors are broadly discussed. Fundamentals of the origin of surface plasmons as well as the surface plasmon resonance sensing are described and documented on a number of examples. Localized plasmon sensing and surface-enhanced Raman spectroscopy are subjected to special interest since those techniques are inherently associated with the direct application of plasmonic structures. The possibility of tailoring the optical properties of ultra-thin metal layers via controlling their shape and morphology by postdeposition annealing is documented. Special attention is paid to the contribution of bimetallic particles and layers as well as metal structures encapsulated in semiconductors and dielectrics to the optical response. The opportunity to tune the properties of materials over a large scale of values opens up entirely new application possibilities of optical active structures. The nature of surface plasmons predetermines noble metal nanostructures to be promising great materials for development of modern label-free sensing methods based on plasmon resonance—SPR and LSPR sensing.

  3. Airborne heavy metal pollution in the environment of a danish steel plant

    DEFF Research Database (Denmark)

    Vestergaard, N. K.; Stephansen, U.; Rasmussen, L.

    1986-01-01

    to electric-arc furnaces. The samples were analyzed for Cd, Cr, Cu, Fe, Mn, Pb and Zn.The results show that heavy metal pollution from the steelworks still is severe and that it follows a decreasing power curve when the distance to the steelworks is increased. However, a reduction in the deposition of heavy...

  4. A review of the global emissions, transport, and effects of heavy metals in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, J.R.; Ashton, W.B.; Rapoport, R.D.

    1993-05-01

    The purpose of this report is to describe the current state of knowledge regarding the sources and quantities of heavy metal emissions, their transport and fate, their potential health and environmental effects, and strategies to control them. The approach is to review the literature on this topic and to consult with experts in the field. Ongoing research activities and research needs are discussed.

  5. Biocompatible nanocarriers that respond to oxidative environments via interactions between chitosan and multiple metal ions

    Directory of Open Access Journals (Sweden)

    Zhang S

    2016-06-01

    Full Text Available Shichang Zhang, Liye Xia, Chenchen Ding, Lu Wen, Weihua Wan, Gang Chen Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, People’s Republic of China Abstract: Hydrogen peroxide (H2O2 functions as an early damage signal contributing to the oxidative stress response and can act as a trigger in smart oxidation-responsive drug delivery systems that are currently in development. Current H2O2-triggered oxidation-responsive polymeric systems are usually derived from chemical synthesis and rarely include natural polymers. Herein, we report two series of nanoparticle (NP complexes prepared with the biopolymer chitosan (CS and four different metal ions (Cu2+, Ca2+, Zn2+, and Fe3+, defined as CSNPs-metal complexes (Series 1 and CS-metal complexes NPs (Series 2, which responded to oxidation by dissolving upon H2O2 exposure. Experiments examining Nile red release and H2O2-triggered degradation confirmed that both series of complexes showed better sensitivity to oxidation than the CSNPs alone. Furthermore, preliminary cytotoxicity and histological observations indicated that the two series exhibited little or no cytotoxicity and generated a mild inflammatory response. Our work provides a novel and promising strategy for developing NPs for use as intelligent oxidation-responsive systems. Keywords: oxidation-responsive system, chitosan, nanoparticles, hydrogen peroxide, metal complexes

  6. A baseline study of trace metals in a coral reef sedimentary environment, Lakshadweep Archipelago

    Digital Repository Service at National Institute of Oceanography (India)

    Gopinath, A.; Nair, S.M.; Kumar, N.C.; Jayalakshmi, K.V.; Pamalal, D.

    remain polluted with respect to these elements. An evaluation based on pollution load index shows that none of the islands surveyed for this study posed a serious threat in trace metal pollution. Bray Curtis similarity index was computed to find out...

  7. Corrosion behavior of metals and alloys in marine-industrial environment.

    Science.gov (United States)

    Natesan, Mariappan; Selvaraj, Subbiah; Manickam, Tharmakkannu; Venkatachari, Gopalachari

    2008-12-01

    This work deals with atmospheric corrosion to assess the degrading effects of air pollutants on ferrous and non-ferrous metals and alloys, which are mostly used as engineering materials. An exposure study was conducted in the Tuticorin port area located on the east coast of South India, in the Gulf of Mannar with Sri Lanka to the southeast. Common engineering materials, namely mild steel, galvanized iron, Zn, Al, Cu and Cu-Zn alloys (Cu-27Zn, Cu-30Zn and Cu-37Zn), were used in the investigation. The site was chosen where the metals are exposed to marine and industrial atmospheres. Seasonal 1 to 12 month corrosion losses of these metals and alloys were determined by a weight loss method. The weight losses showed strong corrosion of mild steel, galvanized iron, Cu and Zn and minor effect on Al and Cu-Zn alloys. Linear regression analysis was conducted to study the mechanism of corrosion. The composition of corrosion products formed on the metal surfaces was identified by x-ray diffraction and Fourier transform infrared spectroscopy.

  8. Corrosion behavior of metals and alloys in marine-industrial environment

    Directory of Open Access Journals (Sweden)

    Mariappan Natesan, Subbiah Selvaraj, Tharmakkannu Manickam and Gopalachari Venkatachari

    2008-01-01

    Full Text Available This work deals with atmospheric corrosion to assess the degrading effects of air pollutants on ferrous and non-ferrous metals and alloys, which are mostly used as engineering materials. An exposure study was conducted in the Tuticorin port area located on the east coast of South India, in the Gulf of Mannar with Sri Lanka to the southeast. Common engineering materials, namely mild steel, galvanized iron, Zn, Al, Cu and Cu–Zn alloys (Cu–27Zn, Cu–30Zn and Cu–37Zn, were used in the investigation. The site was chosen where the metals are exposed to marine and industrial atmospheres. Seasonal 1 to 12 month corrosion losses of these metals and alloys were determined by a weight loss method. The weight losses showed strong corrosion of mild steel, galvanized iron, Cu and Zn and minor effect on Al and Cu–Zn alloys. Linear regression analysis was conducted to study the mechanism of corrosion. The composition of corrosion products formed on the metal surfaces was identified by x-ray diffraction and Fourier transform infrared spectroscopy.

  9. A review of the global emissions, transport, and effects of heavy metals in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, J.R.; Ashton, W.B.; Rapoport, R.D.

    1993-05-01

    The purpose of this report is to describe the current state of knowledge regarding the sources and quantities of heavy metal emissions, their transport and fate, their potential health and environmental effects, and strategies to control them. The approach is to review the literature on this topic and to consult with experts in the field. Ongoing research activities and research needs are discussed.

  10. Combustion of Metals in Carbon Dioxide and Reduced-Gravity Environments

    Science.gov (United States)

    Branch, M. C.; Abbud-Madrid, A.; Modak, A.; Dreyer, C. B.; Daily, J. W.

    2001-01-01

    Ongoing exploration and future mission2001110444 s to Mars have given impetus to research on the use of natural resources of the planet. Since carbon dioxide (CO2) constitutes approximately 95% of the Mars atmosphere and since it reacts directly and vigorously with several metals, this investigation focuses on metal-CO2 reactions as a possible combination for rocket-propellant production and energy generation. Magnesium (Mg) has been initially selected as the metal fuel owing to its low ignition temperature and high specific impulse and burning rate in CO2. Our studies in this field started with low gravity (g) combustion tests of Mg in O2, CO2, and CO. Reduced gravity provided a clear picture of the burning phenomena by eliminating the intrusive buoyant flows in high-temperature metal reactions and by removing the destructive effect of gravity on the shape of molten metal samples. Suspended cylindrical metal samples of 2, 3, and 4-mm in diameter and length were radiatively ignited in low-g to generate free-floating samples exhibiting a spherically symmetric flame with increasing metal-oxide accumulation in an outer shell. For the Mg-CO2 combination, burning times twice as long as in normal-g and five times longer than in Mg-O2 flames were observed, revealing a diffusion-controlled reaction. The burning time is proportional to the square of the sample diameter. In tests conducted with pure CO, combustion was not possible without constant heating of the sample due to the formation of a thick carbon-containing coating around the Mg sample generated by surface reactions. The following work presents two new studies that attempt to explain some of the low-g experimental observations. First, a simplified one-dimensional, quasi-steady numerical model is developed to obtain temperature, species concentrations, and burning rates of the spherically symmetric diffusion flame around the Mg sample burning in O2 and CO2. Second, a Planar Laser Induced Fluorescence (PLIF

  11. Natural versus anthropogenic dispersion of metals to the environment in the Wulik River area, western Brooks Range, northern Alaska

    Science.gov (United States)

    Kelley, K.D.; Hudson, T.

    2007-01-01

    Zinc-lead-silver mineral deposits in the Wulik River region, Alaska, contain an enormous accumulation of Zn. In addition to the giant deposits at Red Dog, at least nine other deposits are known. Natural weathering of these deposits has dispersed metals over a wide region over a long period of time (c. 10 000 years) through transport by stream and groundwater, stream sediments, formation of soils, and perhaps wind-blown atmospheric deposition from weathering of naturally enriched Pb-Zn surface deposits. Anthropogenic input also contributes metals to the environment. Mining of the Red Dog deposit, which began in 1989, produces fine-grained galena and sphalerite concentrates that are transported from the mine site by truck to a storage port facility. Wind-blown dispersion of concentrate dust along the road and around the port facility has been a source of local metal-rich surficial materials. Geochemical and mineralogical characteristics provide a means of distinguishing the natural versus anthropogenic metal sources. Soils over deposits have patterns of increasing metal contents with depth and proximity to the metal-bearing source, whereas ore concentrate dust is localized at the surface. The acidity produced by weathering of the sulphide deposits creates an environment in which elements such as Se and Mo are stable whereas Ca is not. Consequently, high Mo (up to 29 ppm) and Se (up to 17 ppm) and low Ca (<0.4%) concentrations characterize surficial materials near natural deposits. Acidic conditions also yield high Pb-Zn ratios (up to 70) because sphalerite is preferentially dissolved and Zn is mobilized during chemical weathering. In natural materials, secondary jarosite and anglesite are developed, and minor galena is etched and rounded due to a history of chemical and mechanical weathering. In contrast, dust-bearing samples have Pb/Zn ratios that are 0.4 or less, Ca contents are higher (0.2 to 3.6%), and Mo (<10 ppm) and Se (not detected) concentrations are low

  12. Drepanocitose Neo-Natal — Casa Clínco

    OpenAIRE

    Inácio, Rosa; Ribeiro, Maria José; Maurício, José; Miranda, Ana; Saldanha, Joana; Gomes, Pilar; Silva, L. Justo da

    2014-01-01

    Os autores descrevem um caso de drepanocitose com início no período neo-natal, chamando a atenção para a importância do diagnóstico precoce tendoem consideração os problemas consequentes desta doença nas fases mais adiantadas da vida da criança. Dada a presença em Portugal de uma importantecomunidade africana, os autores chamam a atenção para a importância da anamnese pré-natal que permite muitas vezes suspeitar e confirmar a existênciade uma hemoglobinopatia na família e no feto ou recém-nas...

  13. Construction of a self- luminescent cyanobacterial bioreporter that detects a broad range of bioavailable heavy metals in aquatic environments

    Directory of Open Access Journals (Sweden)

    Keila eMartin-Betancor

    2015-03-01

    Full Text Available A self-luminescent bioreporter strain of the unicellular cyanobacterium Synechococcus sp. PCC 7942 was constructed by fusing the promoter region of the smt locus (encoding the transcriptional repressor SmtB and the metallothionein SmtA to luxCDABE from Photorhabdus luminescens; the sensor smtB gene controlling the expression of smtA was cloned in the same vector. The bioreporter performance was tested with a range of heavy metals and was shown to respond linearly to divalent Zn, Cd, Cu, Co, Hg and monovalent Ag. Chemical modelling was used to link bioreporter response with metal speciation and bioavailability. Limits of Detection (LODs, Maximum Permissive Concentrations (MPCs and dynamic ranges for each metal were calculated in terms of free ion concentrations. The ranges of detection varied from 11 to 72 pM for Hg2+ (the ion to which the bioreporter was most sensitive to 1.54-5.35 µM for Cd2+ with an order of decreasing sensitivity as follows: Hg2+ >> Cu2+ >> Ag+ > Co2+ ≥ Zn2+ > Cd2+. However, the maximum induction factor reached 75-fold in the case of Zn2+ and 56-fold in the case of Cd2+, implying that Zn2+ is the preferred metal in vivo for the SmtB sensor, followed by Cd2+, Ag+ and Cu2+ (around 45-50-fold induction, Hg2+ (30-fold and finally Co2+ (20-fold. The bioreporter performance was tested in real environmental samples with different water matrix complexity artificially contaminated with increasing concentrations of Zn, Cd, Ag and Cu, confirming its validity as a sensor of free heavy metal cations bioavailability in aquatic environments.

  14. Distribution and Potential Mobility of Selected Heavy Metals in a Fluvial Environment Under the Influence of Tanneries

    Directory of Open Access Journals (Sweden)

    Rodrigues M. L. K.

    2013-04-01

    Full Text Available In this study we evaluated the occurrence of heavy metals in a fluvial environment under the influence of tanneries – the Cadeia and Feitoria rivers basin (RS, south Brazil, highlighting the distribution and potential mobility of the selected elements. Every three months, over one year-period, selected heavy metals and ancillary parameters were analyzed in water and sediment samples taken at ten sites along the rivers. Water analyses followed APHA recommendations, and sediment analyses were based on methods from USEPA (SW846 and European Community (BCR sequential extraction. The determinations were performed by ICP/OES, except for Hg (CV/ETA. Statistical factor analysis was applied to water and sediment data sets, in order to obtain a synthesis of the environmental diagnosis. The results revealed that water quality decreased along the rivers, and mainly on the dry period (January, showing the influence of tannery plants vicinity and flow variations. Except for Fe, Al, and eventually Mn, heavy metal contents in water were in agreement with Brazilian standards. Concerning sediments, Al, Cu, Fe, Ni, Mn, Ti, and Zn concentrations appeared to reflect the base levels, while Cr and Hg were enriched in the deposits from the lower part of the basin. The partition of heavy metals among the sediment geochemical phases showed higher mobility of Mn along the sampling sites, followed by Cr in the lower reach of the basin, most affected by tanneries. Since Cr was predominantly associated to the oxidizable fraction, its potential mobilization from contaminated sediments would be associated to redox conditions. The detection of Hg in the tissue of a bottom-fish species indicated that the environmental conditions are apparently favoring the remobilization of this metal from contaminated sediments.

  15. Natal location influences movement and survival of a spatially structured population of snail kites

    Science.gov (United States)

    Martin, J.; Kitchens, W.M.; Hines, J.E.

    2007-01-01

    Despite the accepted importance of the need to better understand how natal location affects movement decisions and survival of animals, robust estimates of movement and survival in relation to the natal location are lacking. Our study focuses on movement and survival related to the natal location of snail kites in Florida and shows that kites, in addition to exhibiting a high level of site tenacity to breeding regions, also exhibit particular attraction to their natal region. More specifically, we found that estimates of movement from post-dispersal regions were greater toward natal regions than toward non-natal regions (differences were significant for three of four regions). We also found that estimates of natal philopatry were greater than estimates of philopatry to non-natal regions (differences were statistically significant for two of four regions). A previous study indicated an effect of natal region on juvenile survival; in this study, we show an effect of natal region on adult survival. Estimates of adult survival varied among kites that were hatched in different regions. Adults experienced mortality rates characteristic of the region occupied at the time when survival was measured, but because there is a greater probability that kites will return to their natal region than to any other regions, their survival was ultimately influenced by their natal region. In most years, kites hatched in southern regions had greater survival probabilities than did kites hatched in northern regions. However, during a multiregional drought, one of the northern regions served as a refuge from drought, and during this perturbation, survival was greater for birds hatched in the north. Our study shows that natal location may be important in influencing the ecological dynamics of kites but also highlights the importance of considering temporal variation in habitat conditions of spatially structured systems when attempting to evaluate the conservation value of habitats.

  16. Centenary of the Natal Herbarium, Durban, 1882-1982

    Directory of Open Access Journals (Sweden)

    B. D. Shrire

    1983-12-01

    Full Text Available The history of the Natal Herbarium is described from its inception in 1882 to 1982, the year of its centenary. Its history is inextricably linked with that of the Durban Botanic Gardens which started as an Agricultural Garden in 1848, and the Durban Botanic Station. The roles played by various curators and officers-in-charge, especially John Medley Wood, who held office for 32 years and did much to put the Herbarium on the botanical map, are emphasized.

  17. Simulation study of irradiated Si sensors equipped with metal- overhang for applications in LHC environment

    CERN Document Server

    Chatterji, Sudeep; Bhardwaj, Ashutosh; Srivastava-Ajay, K; Kumar, Ashish; Jha, Manoj Kumar; Shivpuri, R K; Khanna, S L

    2004-01-01

    The performance of metal-overhang (MO) equipped silicon micro-strip sensors, after irradiation for the preshower detector to be used in the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC), CERN, has been studied through simulations. Detailed calculations using Hamburg model have allowed the parameterization of these effects and helped to simulate the operation scenario of MO equipped sensors over ten years of LHC operation. The utility of overhanging metal extension as junction termination technique after space charge sign inversion (SCSI) has been explored in detail for the first time in this work. Several interesting results like a shift in the optimal oxide thickness in MO equipped structures after irradiation have been reported. The comparison of dielectric and semi-insulator passivated MO equipped structures after irradiation has been studied. Also, the impact of various crucial geometrical parameters like device depth (W//N), width of back N **+ layer used for ohmic contact (W/...

  18. Impact of harsh radiation on metal-overhang equipped sensors in the LHC environment

    CERN Document Server

    Chatterji, S; Bhardwaj, A; Namrata, S; Srivastava-Ajay, K; Kumar, A; Jha, Manoj Kumar; Shivpuri, R K

    2004-01-01

    The utility of silicon microstrip detectors in future high luminosity colliders, like LHC requires some serious issues concerning radiation hardness to be carefully considered. The performance of metal- overhang (MO) equipped Si micro-strip sensors has been studied after irradiation for the preshower detector to be used in CMS experiment at LHC, CERN. The parameterization of these effects has been performed using Hamburg model to simulate the operation scenario of MO equipped sensors over 10 years of LHC operation. The utility of overhanging metal extension as junction termination technique after type-inversion has been explored for the first time in this work Several interesting results like a shift in the optimal oxide thickness in MO equipped structures after irradiation have been reported. It has been found that the breakdown performance of the device actually improves after irradiation due to the beneficial effect of type-inversion. Dielectric and semi-insulator passivated MO equipped structures have bee...

  19. Compressive and shear buckling analysis of metal matrix composite sandwich panels under different thermal environments

    Science.gov (United States)

    Ko, William L.; Jackson, Raymond H.

    1993-01-01

    Combined inplane compressive and shear buckling analysis was conducted on flat rectangular sandwich panels using the Raleigh-Ritz minimum energy method with a consideration of transverse shear effect of the sandwich core. The sandwich panels were fabricated with titanium honeycomb core and laminated metal matrix composite face sheets. The results show that slightly slender (along unidirectional compressive loading axis) rectangular sandwich panels have the most desirable stiffness-to-weight ratios for aerospace structural applications; the degradation of buckling strength of sandwich panels with rising temperature is faster in shear than in compression; and the fiber orientation of the face sheets for optimum combined-load buckling strength of sandwich panels is a strong function of both loading condition and panel aspect ratio. Under the same specific weight and panel aspect ratio, a sandwich panel with metal matrix composite face sheets has much higher buckling strength than one having monolithic face sheets.

  20. Nature and extent of metal-contaminated soils in urban environments (keynote talk).

    Science.gov (United States)

    Mielke, Howard W

    2016-08-01

    Research on the nature and extent of metal-contaminated soil began with an urban garden study in Baltimore, MD (USA). Largest quantities of soil metals were clustered in the inner city with lesser amounts scattered throughout metropolitan Baltimore. The probability values of metal clustering varied from P value 10(-15)-10(-23) depending on element. The inner-city clustering of lead (Pb) could not be explained by Pb-based paint alone. A major Pb source was tetraethyl lead (TEL), developed as an anti-knock agent for use in vehicle fuel, thereby making highway traffic flow a toxic substance delivery system in cities. Further study in Minneapolis and St. Paul confirmed the clustering of inner-city soil metals, especially Pb. Based on the evidence, the Minnesota State Legislature petitioned Congress to curtail Pb additives resulting in the rapid phasedown of TEL on January 1, 1986, 10 years ahead of the EPA scheduled ban. Further research in New Orleans, Louisiana (NOLA), verified the link between soil Pb, blood Pb, morbidity, and societal health. Although Pb is a known cause of clinical impairment, there is no known effective medical intervention for reducing children's blood Pb exposure. Ingestion and inhalation are routes of exposure requiring prevention, and soil is a reservoir of Pb. Children's blood Pb exposure observed in pre-Hurricane Katrina (August 29, 2005) NOLA underwent substantial decreases 10 years post-Katrina due to many factors including input of low Pb sediment residues by the storm surge and the introduction of low Pb landscaping materials from outside of the city. Investigation on the topic is ongoing.

  1. Mechanistic Models for Ignition and Combustion of Metallic Powders in Different Environments

    Science.gov (United States)

    2010-09-17

    contradicting the expected higher oxidation rate that would be caused a non-continuous Al2O3 layer. A new model of heterogeneous oxidation of Al...accelerated Al oxidation during melting, contradicting the expected higher oxidation rate that would be caused by a non-continuous Al2O3 layer. A model of...particle, respectively, and the constant c accounts for the differences in molar weight and in density between the metal core and the oxide shell

  2. Heavy metal composition of particulate matter in rural and urban residential built environments in Pakistan

    OpenAIRE

    Nasar, ZA; Colbeck, I.; Ali, Z; Ahmed, S

    2015-01-01

    Heavy metals in outdoor and indoor airborne particulate matter (PM) and dust in different residential built environmentsat two rural and one urban site in Pakistan were analysed. An eight stage non-viable impactor (Thermo Fisher Scientific Inc., USA) loaded with EMP 2000 glass microfiber filter papers (Whatman, England) was used to collect airborne PM.The indoordust samples (settled dust) were collected from different indoor surfaces (floor, cupboards) in living rooms and kitchens...

  3. Comparative study on the uptake and bioimpact of metal nanoparticles released into environment

    Science.gov (United States)

    Andries, Maria; Pricop, Daniela; Grigoras, Marian; Lupu, Nicoleta; Sacarescu, Liviu; Creanga, Dorina; Iacomi, Felicia

    2015-12-01

    Metallic particles of very small size are ubiquitously released in the air, water and soil from various natural and artificial sources - the last ones with enhanced extent since nanotechnology development accelerated exponentially. In this study we focused on the impact of metal nanoparticles in vegetal species of agroindustrial interest namely the maize (Zea mais L.). Laboratory simulation of environmental pollution was carried out by using engineered nanoparticles of two types: iron oxides with magnetic properties and gold nanoparticles supplied in the form of dilutes stable suspensions in the culture medium of maize seedlings. Magnetic nanoparticle (MNPs) preparation was performed by applying chemical route from iron ferric and ferrous precursor salts in alkali reaction medium at relatively high temperature (over 80 °C). Gold nanoparticles (GNPs) synthesis was accomplished from auric hydrochloride acid in alkali reaction medium in similar temperature conditions. In both types of metallic nanoparticles citrate ions were used as coating shell with role of suspension stabilization. Plantlet response was assessed at the level of assimilatory pigment contents in green tissue of seedlings in early ontogenetic stages.

  4. Environmentally assisted cracking behavior of dissimilar metal weldments in simulated BWR coolant environments

    Science.gov (United States)

    Huang, J. Y.; Chiang, M. F.; Jeng, S. L.; Huang, J. S.; Kuo, R. C.

    2013-01-01

    The environmentally assisted cracking behavior of dissimilar metal (DM) welds, including Alloy 52-A 508 and Alloy 82-A508, under simulated BWR coolant conditions was studied. Effects of postweld heat treatment and sulfur content of the base metal on the corrosion fatigue and SCC growth rates of DM welds were evaluated. The crack growth rates for the DM weld heat-treated at 621 °C for 24 h were observed to be faster than those for the as-welded. But the DM weld heat-treated at 621 °C for 8 h + 400 °C for 200 h showed better SCC resistance than the as-welded. The longer the heat treatment at 621 °C, the higher the chromium carbides density along the grain boundary was observed. Sulfur could diffuse out of the base metal and segregate along the grain boundaries of the dilution zone, leading to weakening the grain boundary strength and the SCC resistance of the Alloy 52-A508 weld.

  5. Corrosion-fatigue study of a Zr-based bulk-metallic glass in a physiologically relevant environment

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Lu [Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, XueYuan Road No. 37, HaiDian District, Beijing 100191 (China); Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN 37996-2200 (United States); Wang, Gongyao; Qiao, Dongchun; Liaw, Peter K. [Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN 37996-2200 (United States); Pang, Shujie; Wang, Jianfeng [Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, XueYuan Road No. 37, HaiDian District, Beijing 100191 (China); Zhang, Tao, E-mail: zhangtao@buaa.edu.c [Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, XueYuan Road No. 37, HaiDian District, Beijing 100191 (China)

    2010-08-15

    Four-point-bend corrosion-fatigue experiments were conducted in a physiologically relevant environment to study the environmental effects on the fatigue behavior of (Zr{sub 0.55}Al{sub 0.10}Ni{sub 0.05}Cu{sub 0.30}){sub 99}Y{sub 1} (at.%) bulk-metallic glasses (BMGs), and the results were compared with those obtained in air at room temperature. At high stress ranges, the corrosive environment did not significantly affect the fatigue lifetime; while at low stress ranges, the corrosive environment exhibited a detrimental effect on the fatigue resistance. The fatigue strength was decreased by 40% in the physiologically relevant environment. Fracture morphologies after fatigue tests were studied by the scanning electron microscopy. The mechanism for the environmental effects on the fatigue life of the (Zr{sub 0.55}Al{sub 0.10}Ni{sub 0.05}Cu{sub 0.30}){sub 99}Y{sub 1} BMG was determined to be anodic dissolution.

  6. Correlation between radioactivity levels and heavy metal content in the soils of the North Kosovska Mitrovica environment.

    Science.gov (United States)

    Gulan, Ljiljana; Milenkovic, Biljana; Stajic, Jelena M; Vuckovic, Biljana; Krstic, Dragana; Zeremski, Tijana; Ninkov, Jordana

    2013-09-01

    This paper reports the results of radioactivity concentrations and heavy metal content in soil samples collected from non-agricultural areas in the municipality and vicinity of North Kosovska Mitrovica, formerly the most important mining area in Europe. The estimated average activity concentrations of (226)Ra, (232)Th, (40)K and (137)Cs are 40.6 ± 19, 48 ± 25.4, 743.2 ± 200.5 and 81 ± 119 Bq kg(-1), respectively. The estimated average absorbed dose rate in the air and the annual effective dose are 78.7 nGy h(-1) and 96.6 μSv, respectively. The radium equivalent activity and external hazard index were also calculated. High contents of Pb, Zn, Cu, Cd, As and Ni were found in the analyzed soil samples, thus indicating pollution of the environment. Most metals have a wide range of values spanning 2 to 3 orders of magnitude, which is particularly evident for Pb and Zn. Correlations between the activity concentrations of the radionuclides, the heavy metal content in soil and the basic soil properties were determined by means of the Pearson linear coefficient. Strong positive correlations between the naturally occurring radionuclides, and also among Pb, Zn, Cu and Cd were found.

  7. Diagnostic prénatal: quelles sont les techniques actuelles et futures ? (flyer)

    CERN Multimedia

    2002-01-01

    La majorité des bébés qui viennent au monde ne présentent pas d'anomalies particulières. Cependant, il faut savoir qu'environ 1 foetus 170 présente une anomalie chromosomique (défaut de la structure ou du nombre de chromosomes) qui va peser plus ou moins lourdement sur sa vie future et 1 foetus sur 100 présente une maladie génique due à un changement dans un gène. Le diagnostic prénatal a connu et connaît une formidable expansion grâce aux progrès technologiques en génétique et imagerie foetale.

  8. Development of integrated protocols to track the deposition and impacts of metal contaminants in tidal riverine environments

    Science.gov (United States)

    Roe, Helen M.; Patterson, R. Timothy; Nasser, Nawaf; Edwards, Robin J.; Graham, Conor

    2016-04-01

    Tidally-influenced rivers are particularly vulnerable to the effects of metal contamination, yet are amongst the most complex fluvial environments in terms of their sediment deposition and transport patterns. We present the results of an interdisciplinary study that aims to elucidate the fluxes and deposition of metal contaminants in a tidally-influenced river system in Northern Ireland, with a view to developing protocols that will have wide applicability for the monitoring and assessment of metal contaminants in similar environments in other regions. We employ a novel methodology that combines ICPMS analysis of sediments, ITRAX-based core analysis and the examination a important group of shelled protozoans (foraminifera), which occur widely in tidal riverine environments, and which are highly sensitive to metal contamination. The responses shown by the group vary between species and with different levels of contaminant exposure. Some species, for example, show increased relative abundances in proximity to discharge sources, whilst others develop chamber deformities. Application of our integrated multiproxy approach to the analysis of surface sediment samples and cores provides a framework for assessing both the spatial and temporal patterns of metal deposition and the impact of contaminants on the biota. Modern sediment samples (n=90) were collected at varying distances from a point contamination source (a former industrial site) in different morpho-sedimentary settings. The impact of 25 measured variables on the modern foraminiferal faunas was considered, including 20 metals, pH, conductivity, elevation and particle size. Channel sediments in close proximity to the contamination source and with the highest levels of Fe, Cu, Zn, Mg and As, yielded the sparsest foraminiferal faunas (Shannon Diversity Index values 0-1.5), whilst the highest prevalence of foraminiferids showing chamber deformities were observed in channel edge and levée bank sites. Kernal density

  9. Metals in the environment around smelters at Rouyn-Noranda, Quebec, and Belledune, New Brunswick : results and conclusions of the GSC MITE point source project

    Energy Technology Data Exchange (ETDEWEB)

    Bonham-Carter, G.F. (ed.) [Natural Resources Canada, Ottawa, ON (Canada). Geological Survey of Canada

    2005-07-01

    The Geological Survey of Canada (GSC) examines surface geological processes and forces that influence climate. The potential impacts of climate change on ground temperature were examined based on compiled data within the Metals in the Environment (MITE) geoscience database. Metals are a natural component of the environment. While they originate from natural geological sources, their release into the environment can be accelerated by human activities such as mining, mineral processing, burning of fossil fuels, and urban living. Human activities have changed the natural balance and cycling of metals in many locations, resulting in pollution and changes to ecosystems. In order to effectively manage the risks associated with metals in the environment, it is important to understand the sources, transport pathways, and specific forms of metals. The GSC MITE program has provided a geological basis for environmental studies, defining the range of natural background metal concentrations, the mineral form and reactivity of metals, and the processes controlling their movement in the surface environment. The project was launched in response to the need to develop national and international policies regarding metals and their release into the environment, and to create appropriate regulations. This compact disk (CD) contains over 20 layers of geoscience data including the geochemistry of lake sediments, soils, peat, and snow. Data on bedrock geology, surficial geology, and topographic data for the Rouyn-Noranda and Belledune study areas is also included. This CD provides a complete, digital, internally consistent and georeferenced collection of spatial data that will aid scientists in environmental studies, land use planning, mineral exploration and other investigations requiring earth science information. tabs., figs.

  10. Multi-metal contamination with uranium trend impact on aquatic environment and consequences for fish immune system and adaptive responses

    Energy Technology Data Exchange (ETDEWEB)

    Le Guernic, A.; Gagnaire, B. [IRSN/PRP-ENV/SERIS/LECO (France); Sanchez, W. [Institut national de l' environnement industriel et des risques - INERIS (France); Betoulle, S. [Champagne Ardenne University (France)

    2014-07-01

    Human activities have conducted to an increase of concentrations of various metals in aquatic ecosystems, including uranium. Its extraction and use have been rapidly magnified because of its role in the nuclear fuel cycle. These activities have led to high concentrations of uranium in the aquatic environment and thus a potential risk to exposed organisms, including fish. Consequences can be observed through metabolic and physiological responses, called biomarkers. Some biomarkers are interesting in order to evaluate the effects of metal contamination, among other immunotoxicity markers, antioxidant defenses and genotoxicity. The aims of this study are: i) to investigate the effects of a multi-metal contamination on a fish, the three-spined stickleback, Gasterosteus aculeatus, and ii) to observe the adaptive capacity of fish due to a combination of stress (chemical stress and biological stress). To meet the first objective, six water bodies (ponds and lakes) located in two departments (Cantal and Haute-Vienne, France) were chosen according to their proximity to old uranium mines and to their levels of metal contamination related to chemical processes appeared during extraction. 240 three-spined sticklebacks were caged for 28 days in the six selected sites. A battery of biomarkers was measured in fish sampled after 14 and 28 of caging. The results for the Haute-Vienne department showed that caged fish in the pond with the highest uranium concentration (20 μg.L{sup -1}) presented the most DNA damage after 14 days of caging. Leukocyte phagocytosis (marker of immunotoxicity) of caged fish in this pond was lower at 14 days and greater at 28 days compared to other ponds without uranium. The multi-metal contamination negatively affected other parameters such as the condition index, oxidative activity, viability of lysosomal membrane and leukocytes distribution. In order to study the response of fish to a combined stress (chemical + biological) (objective ii), a second

  11. Nesting fidelity and molecular evidence for natal homing in the freshwater turtle, Graptemys kohnii

    OpenAIRE

    Freedberg, Steven; Ewert, Michael A; Ridenhour, Benjamin J.; Neiman, Maurine; Nelson, Craig E

    2005-01-01

    Numerous studies of sea turtle nesting ecology have revealed that females exhibit natal homing, whereby they imprint on the nesting area from which they hatch and subsequently return there to nest as adults. Because freshwater turtles comprise the majority of reptiles known to display environmental sex determination (ESD), the study of natal homing in this group may shed light on recent evolutionary models of sex allocation that are predicated on natal homing in reptiles with ESD. We examined...

  12. Sensitivity of metal nanoparticle surface plasmon resonance to the dielectric environment.

    Science.gov (United States)

    Miller, Molly M; Lazarides, Anne A

    2005-11-24

    Electrodynamic simulations of gold nanoparticle spectra were used to investigate the sensitivity of localized surface plasmon band position to the refractive index, n, of the medium for nanoparticles of various shapes and nanoshells of various structures. Among single-component nanoparticles less than 130 nm in size, sensitivities of dipole resonance positions to bulk refractive index are found to depend only upon the wavelength of the resonance and the dielectric properties of the metal and the medium. Among particle plasmons that peak in the frequency range where the real part of the metal dielectric function varies linearly with wavelength and the imaginary part is small and slowly varying, the sensitivity of the peak wavelength, lambda, to refractive index, n, is found to be a linearly increasing function of lambda, regardless of the structural features of the particle that determine lambda. Quasistatic theory is used to derive an analytical expression for the refractive index sensitivity of small particle plasmon peaks. Through this analysis, the dependence of sensitivity on band position is found to be determined by the wavelength dependence of the real part, epsilon', of the particle dielectric function, and the sensitivity results are found to extend to all particles with resonance conditions of the form, epsilon' = -2chin(2), where chi is a function of geometric parameters and other constants. The sensitivity results observed using accurate computational methods for dipolar plasmon bands of gold nanodisks, nanorods, and hollow nanoshells extend, therefore, to particles of other shapes (such as hexagonal and chopped tetrahedral), composed of other metals, and to higher-order modes. The bulk refractive index sensitivity yielded by the theory serves as an upper bound to sensitivities of nanoparticles on dielectric substrates and sensitivities of nanoparticles to local refractive index changes, such as those associated with biomolecule sensing.

  13. Deflection of a liquid metal jet/drop in a tokamak environment

    Energy Technology Data Exchange (ETDEWEB)

    Pelekasis, Nikos, E-mail: pel@uth.gr [Department of Mechanical Engineering, University of Thessaly, Volos 38334 (Greece); Benos, Lefteris [Department of Mechanical Engineering, University of Thessaly, Volos 38334 (Greece); Gomes, Rui [Associação EURATOM/IST, Centro de Fusão Nuclear, Av. Rovisco Pais, 1049-001 Lisboa (Portugal)

    2014-12-15

    Highlights: • We model steady flow of a liquid metal jet inside an electromagnetic field in the presence of inertia and capillary forces. • Similar analysis is performed for the motion of a liquid metal spherical drop. • The deflection of the trajectory is predicted as a function of the intensity of the externally imposed magnetic and electric fields. • The analysis is used as a proof of principle study in reference to experimental observations of jet/drop deflection due to j{sup →}×B{sup →} effects in the ISTTOK tokamak. • We discuss the possibility of using liquid metal flows as an alternative approach toward enhancing power exhaust in tokamak facilities. - Abstract: The interaction of a liquid gallium jet with plasma has been investigated in the ISTTOK tokamak. The jet was observed to remain intact during its interaction with plasma, within a certain length beyond which drop formation was observed. Significant deflection of the jet was detected as soon as plasma production was started. Furthermore, a strong dependency of the deflection magnitude on plasma position was observed that could be correlated with plasma potential gradients. As a means to capture and, possibly, quantify this effect, a preliminary magnetohydrodynamic analysis was performed in order to predict the trajectory of a jet that is traveling inside an electromagnetic field. The effect of Lorentz forces, gravity and pressure drop are accounted for in a unidirectional model that assumes a small jet radius in comparison with the trajectory length. The effect of external electric potential gradients on jet deflection was ascertained in conjunction with the importance of electric stresses in modulating the jet speed and radius. Analysis of the results reported in the ISTTOK experiments identifies the process of jet break-up as a capillary instability. The trajectory of the ensuing droplets is modeled and intensification of the deflection process is predicted in the presence of Lorentz

  14. Role of Fe-Oxidizing Bacteria in Metal Bio-Corrosion in the Marine Environment

    Science.gov (United States)

    2015-06-30

    biocorrosion. PATENT INFORMATION : No patents applied for. AWARD INFORMATION : PI has been awarded two grants from the National Science Foundation...environment off the Mid-Atlantic Ridge. Frontiers of Microbiology. In Prep Peer-reviewed publications ( Google Scholar citations as of 6.29.15 in

  15. Use of small mammals for bioindication of influence of heavy metals emissions on the environment

    Directory of Open Access Journals (Sweden)

    O. A. Zemlianyj

    2009-04-01

    Full Text Available Microelements level in common small mammals from biogeocoenoses situated at different distances from the technogenic emission source was studied. The microelements concentrations were determined in the studied biotopes. Small mammals can be used as bioindicators of the natural environment contamination of industrial wastes.

  16. Effects of loading variables on fatigue-crack growth in liquid-metal environments

    CSIR Research Space (South Africa)

    Fernandes, PJL

    1995-10-01

    Full Text Available is examined using standard LEFM testing procedures. The effects of environment, load ratio, cyclic frequency and load waveform on the rate of crack growth are investigated. At Delta K > Delta K-th, crack growth rates are approximately an order of magnitude...

  17. Mechanisms of nanoparticle formation by ultra-short laser ablation of metals in liquid environment.

    Science.gov (United States)

    Povarnitsyn, Mikhail E; Itina, Tatiana E; Levashov, Pavel R; Khishchenko, Konstantin V

    2013-03-07

    Laser ablation in liquids is now commonly used to produce colloidal nanoparticles (NPs) that have found numerous applications in different areas. In experiments, NPs of different materials can be rather easily obtained by using laser systems with various pulse durations, shapes, wavelengths, and fluences. In this paper, we focus our attention on metal (gold) NPs produced by ultra-short laser pulses. To better understand the mechanisms of the NPs formation, we perform modeling of femtosecond laser interactions with a gold target in the presence of liquid (water). Simulation of the ablation process over several nanoseconds shows that most of the primary NPs originate from the ablated metastable liquid layer, whereas only a minority is formed by condensation inside the cavitation bubble. These particles will further grow/evaporate, and coagulate during a much longer collision stage in the liquid colloid.

  18. Geochemical behavior of heavy metals in differents environments in Rodrigo de Freitas lagoon - RJ/Brazil

    Directory of Open Access Journals (Sweden)

    Estefan M Fonseca

    2011-06-01

    Full Text Available The accelerated urbanisation without a planning, brought several environmental problems to Rio de Janeiro coastal zone, especially in areas such as Rodrigo de Freitas lagoon, which receives a great amount of untreated sewage every day. To assess the nature, potentially sources and extent of heavy metal pollution in the lagoon, sediments from the surrounding streets, from the entrance of the main canal that drains to the lagoon and from the bottom of the lagoon were collected and analysed by a modified selective extraction procedure in order to study the geochemical partitioning and bioavailability of Zn, Cu, Cr, Ni and Pb in these three compartments. The present study verified an increase in the Cu, Pb and Zn concentrations in the north of the Rodrigo de Freitas lagoon. Despite the different levels of oxidation between the sediments accumulated in the streets and in the bottom of the lagoon, the geochemical partitioning of the heavy metals did not show any pattern of variation for the metals, except for the element Cu. No concentrations were found in the soluble phase of samples collected in the surfacial sediments of the lagoon, suggesting no bioavailability of heavy metalsA urbanização acelerada, sem planejamento, resultou em uma série de problemas à zona costeira do Rio de Janeiro, especialmente em áreas como a Lagoa Rodrigo de Freitas, a qual recebe uma grande descarga de esgoto não tratado todos os dias. No intuito de avaliar a natureza, as fontes potenciais e a extensão da poluição por metais pesados na lagoa, sedimentos das ruas do entorno, das entradas do principal canal de drenagem e de superfície de fundo foram coletados. As análises se deram através de um método modificado de extração sequencial, com o objetivo de estudar o fracionamento geoquímico e a biodisponibilidade de Zn, Cu, Cr, Ni e Pb, nestes três compartimentos. O presente estudo verificou um aumento nas concentrações de Cu, Pb, e Zn no setor norte da

  19. Identification of traffic-related metals and the effects of different environments on their enrichment in roadside soils along the Qinghai-Tibet highway.

    Science.gov (United States)

    Zhang, Hua; Wang, Zhaofeng; Zhang, Yili; Ding, Mingjun; Li, Lanhui

    2015-07-15

    The road transportation could affect roadside soils environment detrimentally, including heavy metal enrichment. In order to identify and evaluate the enrichment of heavy metals resulted from road transportation on the Tibetan Plateau, the 11 heavy metals (V, Cr, Co, Ni, Cu, Zn, As, Cd, Rb, Pb and Tl) in the topsoil (0-10 cm depth) from four sites along the Qinghai-Tibet highway were discussed in this study. Our results indicate that heavy metals such as Cr, Cu, Zn, As, Cd and Pb are related to road transportation. The content of most of these heavy metals in roadside soils decreased exponentially with the distance from the road, as did some of the Nemero Synthesis Indexes (PN values). The contamination factor for the traffic-related metals ranged from 0.56 (no pollution) to 5.67 (considerable pollution) and the Nemero Synthesis Indexes of these heavy metals ranged from 0.80 (no pollution) to 4.49 (severe pollution). Cd was of priority concern as it had the highest contamination factor. The highest PN value for these traffic-related heavy metals was found in soils at site TTH (alpine steppe). Although transportation contributed to the high contents of these traffic-related metals in roadside environments, regional differences such as wind and the terrain also had significant relationship with their enrichment in these roadside soils. The roadside distance at which there is a potential risk to livestock and wildlife from the contamination of soils by heavy metals should be determined scientifically along the Qinghai-Tibet highway, based on the different natural environments found in the region.

  20. Risk factors associated with nonvaccination rabies status of dogs in KwaZulu-Natal, South Africa

    Directory of Open Access Journals (Sweden)

    Hergert M

    2016-06-01

    Full Text Available Melinda Hergert,1 Kevin le Roux,2 Louis H Nel3,4 1Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria, 2KwaZulu-Natal Department of Environment, Agriculture and Rural Development, Government Veterinary Services, Pietermaritzburg, 3Department of Microbiology and Plant Pathology, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, South Africa; 4Global Alliance for Rabies Control, Manhattan, KS, USA Abstract: Canine rabies has been enzootic in the dog population of the KwaZulu-Natal ­province of South Africa since the mid-1970s and has been associated with high rates of human exposures and frequent transmissions to other domestic animal species. Several decades of control efforts, consisting primarily of mass vaccination programs, failed to sufficiently curb rabies in this province. For meaningful progression toward better control and elimination, the factors contributing to the persistence of this disease need to be elucidated and addressed. This paper reports evaluated observations from survey records captured through a cross-sectional observational study regarding owned canine populations in this South African province. We used logistic regression modeling to predict variables associated with risk of nonvaccination of rabies in owned dogs. The study indicated that husbandry practices, rabies knowledge, geographical area/location, and the ages of dogs were important factors associated with the risk of nonvaccination. High population turnover, together with large free roaming dog populations, compromised the levels of vaccination achieved and contributed to the persistence of dog rabies in the province. Dog owners in this study also reported that they were more likely to present their dogs for vaccination when the vaccines were free of charge (52% and less than a kilometer from their homes (91%. It has been suggested that effective dog rabies control

  1. Geological hazards associated with intense rain and flooding in Natal

    Science.gov (United States)

    Thomas, M. A.; van Schalkwyk, A.

    1993-02-01

    The combination of rugged topography and climate predisposes the province of Natal to severe floods. Information available since 1856 shows that bridge and slope failures have been recorded in twenty out of twenty-five flood episodes. Bridge failures are caused mostly by geological factors. The mechanism of failure can be classified broadly into foundation failures and changes of river course. Scour and debris build-up have led to failures of foundations located in rock and alluvial sediments. In preparing and replacing bridges the aims have been to increase the area of waterway, increase foundation depths to reach more competent strata and lay protection along banks and abutments to counteract scour. Historically, slope failures have not been well documented but following the 1987/88 storms 223 slope failures were recorded. The classification of the failures allowed the mechanisms of failure to be ascertained, and general design considerations to be reviewed. In areas adjacent to the Drakensberg Mountains slope failures are part of a natural erosion cycle which may be accelerated in periods of heavy rain. Throughout Natal, hummocky ground adjacent to dolerite intrusions reveals the on-going history of failure caused by water ingress and the generation of high pore water pressures on the slip planes. Classic flows occurred throughout the Greater Durban area where residual sandy soils of the Natal Group sandstone became supersaturated. Slumping was common on steep terrain underlain by granite-gneiss in the Kwa-Zulu area. Shales of the Pietermaritzburg Formation are notoriously unstable, yet few failures occurred during the summer storms of 1987/88. Inadequate drainage was responsible for many failures, this was particularly so along the railways.

  2. Analisis Kandungan Merkuri (Hg) Pada Air Sumur Gali Masyarakat Di Sekitar Penambangan Emas Tradisional Desa Saba Padang Kecamatan Huta Bargot Kabupaten Mandailing Natal Tahun 2015

    OpenAIRE

    Musthofa, Saddam

    2016-01-01

    The contamination of wells is influenced by any factors, such as condition of geographic, hydrogeology, soil topography, season, ground water flow rate and construction of physics of wells. With the founding of prospect area for gold in Mandailing Natal especially at sub-district of Huta Bargot, the higher of gold mining by the local people without permission.Generally, the mining activities cause the damage of environment,, it cause the contamination or pollution in the mining location. T...

  3. Mineral formation on metallic copper in a `future repository site environment`

    Energy Technology Data Exchange (ETDEWEB)

    Amcoff, Oe.; Holenyi, K.

    1996-04-01

    Since reducing conditions are expected much effort has been concentrated on Cu-sulfides and CuFe-sulfides. However, oxidizing conditions are also discussed. A list of copper minerals are included. It is concluded that mineral formation and mineral transitions on the copper canister surface will be governed by kinetics and metastabilities rather than by stability relations. The sulfides formed are less likely to form a passivating layer, and the rate of sulfide growth will probably be governed by the rate of transport of reacting species to the canister surface. A series of tests are recommended, in an environment resembling the initial repository site conditions. 82 refs, 8 figs.

  4. Hydrogen generation by metal corrosion in simulated Waste Isolation Pilot Plant environments. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Telander, M.R.; Westerman, R.E. [Battelle Pacific Northwest Lab., Richland, WA (United States)

    1997-03-01

    The corrosion and gas-generation characteristics of four material types: low-carbon steel (the current waste packaging material for the Waste Isolation Pilot Plant), Cu-base and Ti-base (alternative packaging) materials, and Al-base (simulated waste) materials were determined in both the liquid and vapor phase of Brine A, a brine representative of an intergranular Salado Formation brine. Test environments consisted primarily of anoxic brine with overpressures of N{sub 2}, CO{sub 2}, H{sub 2}S, and H{sub 2}. Limited tests of low-carbon steel were also performed in simulated-backfill environments and in brine environments with pH values ranging from 3 to 11. Low-carbon steel reacted at a slow, measurable rate with anoxic brine, liberating H{sub 2} on an equimolar basis with Fe reacted. Presence of CO{sub 2} caused the initial reaction to proceed more rapidly, but CO{sub 2}-induced passivation stopped the reaction if the CO{sub 2} were present in sufficient quantities. Addition of H{sub 2}S to a CO{sub 2}-passivated system caused reversal of the passivation. Low-carbon steel immersed in brine with H{sub 2}S showed no reaction, apparently because of passivation of the steel by formation of FeS. Addition of CO{sub 2} to an H{sub 2}S-passivated system did not reverse the passivation. Cu- and Ti-base materials showed essentially no corrosion when exposed to brine and overpressures of N{sub 2}, CO{sub 2}, and H{sub 2}S except for the rapid and complete reaction between Cu-base materials and H{sub 2}S. The Al-base materials reacted at approximately the same rate as low-carbon steel when immersed in anoxic Brine A; considerably more rapidly in the presence of CO{sub 2} or H{sub 2}S; and much more rapidly when iron was present in the system as a brine contaminant. High-purity Al was much more susceptible to corrosion than the 6061 alloy. No significant reaction took place on any material in any environment in the vapor-phase exposures.

  5. New perspectives on Natal Pulses from satellite observations

    CSIR Research Space (South Africa)

    Rouault, MJ

    2011-07-01

    Full Text Available temperature (SST) [Lutjeharms and Roberts, 1988] or altimetry [de Ruijter et al., 1999; van Leeuwen and de Ruijter, 2000], as well as from numerical modeling experiments [Biastoch et al., 2008; Tsugawa and Hasumi, 2010]. Previous studies on Natal Pulses... leakage of warm and salty Agulhas Current water into the Atlantic ocean. In par- ticular, they have been linked to the formation of Agulhas Rings [van Leeuwen and de Ruijter, 2000] and on some occa- sion to early retroflections [Lutjeharms and van...

  6. Anthropogenic heavy metals in the environment of Eurasian Arctic Nature Reserves

    Science.gov (United States)

    Vinogradova, Anna; Ivanova, Yulia; Karpov, Alexey

    2014-05-01

    The Russian Arctic Nature Reserves are situated far from the main industrial regions. In spite of this, there are anthropogenic constituents (for example, heavy metals - HM) in the environmental objects (air, water, etc.) and in food chains (plants, birds, and so on). We studied the long-range atmospheric transport of some heavy metals (such as nickel, copper, lead, arsenic, and so on) to four Nature Reserves situated near the shore of the Arctic Ocean - in the Deltas of the Pechora River (Nenets reserve), the Ob River (Gydansky reserve), the Lena River (Ust-Lensky reserve), and at Wrangel Island. The air mass trajectories to each reserve were calculated with the help of the site (www.arl.noaa.gov/ready) for each day of January, April, July, and October for the period of 2001-2010. Analyzing the spatial distributions of these trajectories we studied seasonal variations in air transport of pollution to different Russian Arctic points. Modeling the HM transport in the atmosphere was as in [1]. The main assumption is that HM are transported with submicron aerosol particles. The annual source emissions for the last decade are generalized from the data published by Roshydromet of Russia (http://www.nii-atmosphere.ru/files/PUBL/Eg_2008.doc). The main important source-regions were found for each point. Mean anthropogenic HM concentrations in air and precipitations, as well as HM fluxes onto the surface were estimated at different arctic regions. The spatial distributions of so called "potential function of pollution" were calculated and presented on the maps. These results allow to analyze the role of a real pollution source or of a planned source for each reserve. So, the influence of northern oil and gas industry may be of great importance because of its proximity to the reserves under investigation. The work was partly supported by RFBR, grant No. 14-05-00059. Authors thank the NOAA service for possibility to use their data and products. ________________ 1. Vinogradova

  7. Biocorrosion rate and mechanism of metallic magnesium in model arterial environments

    Science.gov (United States)

    Bowen, Patrick K.

    A new paradigm in biomedical engineering calls for biologically active implants that are absorbed by the body over time. One popular application for this concept is in the engineering of endovascular stents that are delivered concurrently with balloon angioplasty. These devices enable the injured vessels to remain patent during healing, but are not needed for more than a few months after the procedure. Early studies of iron- and magnesium-based stents have concluded that magnesium is a potentially suitable base material for such a device; alloys can achieve acceptable mechanical properties and do not seem to harm the artery during degradation. Research done up to the onset of research contained in this dissertation, for the most part, failed to define realistic physiological corrosion mechanisms, and failed to correlate degradation rates between in vitro and in vivo environments. Six previously published works form the basis of this dissertation. The topics of these papers include (1) a method by which tensile testing may be applied to evaluate biomaterial degradation; (2) a suite of approaches that can be used to screen candidate absorbable magnesium biomaterials; (3) in vivo-in vitro environmental correlations based on mechanical behavior; (4) a similar correlation on the basis of penetration rate; (5) a mid-to-late stage physiological corrosion mechanism for magnesium in an arterial environment; and (6) the identification of corrosion products in degradable magnesium using transmission electron microscopy.

  8. Metal-bearing fine particle sources in a coastal industrialized environment

    Science.gov (United States)

    Mbengue, Saliou; Alleman, Laurent Y.; Flament, Pascal

    2017-01-01

    Fine (primary or secondary submicron particles and mechanical procedures in open air, or local traffic, which lead to the emission of coarser particles (> 1 μm). The trace elements As, Cd, Ni, Pb, Sb, V and Zn, characteristics of the local industrial activities display 60% to 85% of their mass in the submicron and ultrafine fractions and appear highly enriched, by reference to the crustal source. High atmospheric pressure periods, corresponding to northeasterly winds, induce the highest contributions of metalworking emissions and the highest PM2.5 concentrations (32.5 ± 11.9 μg·m- 3). A Principal Component Analysis of the dataset produces 7 factors associated to metallurgy-, steelworks-, oil processing-, coal combustion-, neighboring traffic-, dust resuspension- and sea salt-sources, that explain the obtained concentrations. A Multiple Linear Regression Analysis confirms that Fe-Mn alloy refining, iron- and steel-making are the main sources (> 40%) controlling metal concentrations in PM2.5. Less predictably, resuspended dust and fresh/aged sea salts are also significant contributors (≈ 20%). Considering the related health hazards, authorities should pay more attention to the exposure of people living in this area and the possible impact of fine particles in terms of public health.

  9. Genetic differentiation of Arthrobacter population from heavy metal-contaminated environment

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hanbo; REN Weimin; SHAO Qiyong; DUAN Changqun

    2007-01-01

    Six samples containing extremely high concentration of Pb,Zn,and Cd were obtained from the layers of 5-10 cm and 25-30 cm three tailing piles,with ages of about 10,20 and more than 80 years,respectively.Then,48 bacterial strains were obtained from these samples,and subsequently their phylogenetic positions were determined by analysis on the partial sequence of 16S rRNA gene (fragment length ranging from 474 to 708 bp).These isolates were members of the Arthrobacter genus,phylogenetically close to A.keyseri and A.ureafaciens,with sequence ranging from 99.1%to 100%.Furthermore,genetic variation between subpopulations from different samples was revealed by analysis on their randomly amplified polymorphic DNA profile.Nei genetic distance showed that the greatest differentiation occurred between subpopulation A and C.Notably,either genetic distance between subpopulations from the layers of 5-10 cm and 25-30 cm of each tailing pile or between same layers of different tailing pile increased with the history of tailings.Moreover,correlation analysis showed that soluble Pb has a significantly negative relationship with Nei'gene diversity of subpopulation.It was assumed that soluble Pb may be responsible for the reduced genetic diversity of the Arthrobacter population.Our data provided evidence that genetic differentiation of microbial populations was consistent with the changes of environmental factors,particularly heavy metals.

  10. Diatom diversity and response in metal-polluted river environment: preliminary reports from Gromolo Torrent (Liguria, Italy)

    Science.gov (United States)

    Capello, Marco; Tolotti, Raffaella; Bernabè, Dimitri; Carbone, Cristina; Consani, Sirio; Vagge, Greta; Cutroneo, Laura

    2016-04-01

    Mineral content and physico-chemical properties of the freshwaters are the main factors affecting both algal assemblages and distributions, while presence of dissolved silicon, low water conductivity, and rocky-mountain habitats host benthic diatom assemblages of high species richness. It is shown that diatoms are sensible to the freshwater acidification (used as pH indicators in acid waters), environmental and climate changes, river organic load, and heavy metal water pollution. For this characteristic, diatoms are among the major biological markers for a variety of environmental and stratigraphic applications. In particular, qualitative and quantitative analyses (assemblage analyses) together with biotic indices as well as morphological and ultrastructure parameterisation provide tools for detailed environmental control and paleo-environmental reconstructions. Severe environmental problems are typically caused by "abandoned mine" and are consequences of the cessation of the mining activity with a lack in infrastructure maintenance. The mine waters which flow into the Gromolo Torrent are almost acidic (pH varying from 2.4 to 5) and enriched in heavy metals and SO42-. This pollution is caused by Acid Mine Drainage (AMD) processes that interest the Libiola mining area, known as a typical example of active AMD processes. The aim of this work is: 1) to characterise the local benthic diatom assemblages along the acidic mine effluents that discharge from Libiola mine, the entire Gromolo torrent course, and in the marine area off the torrent mouth; 2) to identify the main diatom biomarker taxa; 3) to highlight striking situations of equilibrium-disequilibrium in the algal communities, and 4) to point out types and frequency of some teratologies affecting specific diatom taxa as a response to environmental stressors (such as metal-metalloid enrichment). A total of 17 diatom samples was collected and examined, including some marine samples. Diatoms were collected in the

  11. Chemical species of metallic elements in the aquatic environment of an ex-mining catchment.

    Science.gov (United States)

    Ashraf, Muhammad Aqeel; Ahmad, Mushtaq; Akib, Shatirah; Balkhair, Khaled S; Abu Bakar, Nor Kartini

    2014-08-01

    This study was conducted to investigate the chemical speciation of dissolved and particulate elements (lead, zinc, copper, chromium, arsenic, and tin) in the mining wastewater of a former tin-mining catchment. The speciation patterns of dissolved elements were estimated by an adsorptive stripping voltammeter (ASV), while particulate elements were analyzed by using a newly developed sequential-extraction leaching procedure. The procedure has been operationally defined among five host fractions, namely exchangeable, carbonate, reducible, organic bound, and residual fractions. A total of six elements (lead, zinc, copper, chromium, arsenic, and tin) were analyzed in thirty samples at ten locations (P1-P10), with three samples taken from each of the ten locations, to get the average value from the former tin-mining catchment. The results showed that the heavy metal pollutions in locations P4 and P8 were more severe than in other sampling sites, especially tin and lead pollution. In the water samples from locations P4 and P8, both the total contents and the most dangerous non-residual fractions of tin and lead were extremely high. More than 90% of the total concentrations of arsenic and chromium existed in the residual fraction. Concentrations of copper and zinc mainly occurred in the residual fraction (more than 60%), while lead and tin presented mostly in the non-residual fractions in surface water. For all of the six dissolved elements, the less-labile species formed the predominant fraction in their speciation patterns. The speciation patterns of particulate elements showed that most of the concentrations of zinc, copper, chromium, and arsenic were found in the reducible fraction; whereas lead and tin were mainly associated with the organic fraction.

  12. Equity and Excellence: The Emergence, Consolidation and Internalization of Education Development at the University of Natal

    Science.gov (United States)

    Odendaal, Marie; Deacon, Roger

    2009-01-01

    Education development in South Africa emerged during the transition from apartheid to democracy, in a context especially marked by political and financial pressures. This case study of the University of Natal (now the University of KwaZulu-Natal) demonstrates how a strategy combining equity with excellence aimed to facilitate increased access to…

  13. Machado de Assis's "Dom Casmurro" and "Soneto De Natal": The Calculated Mediocrity of a Mute Prophet

    Science.gov (United States)

    Lewis, Christopher T.

    2016-01-01

    Joaquim Maria Machado de Assis's poem "Soneto de Natal" and the chapter "Um soneto" from his novel "Dom Casmurro" exhibit striking points of intersection that describe the same process: the creation of a sonnet. In the novel, Bentinho abandons his attempt with only a first and last line. "Soneto de Natal"…

  14. cooperation and conflict – the british army, the natal government and ...

    African Journals Online (AJOL)

    hennie

    He suggested that they should be allowed to go back to their farms and that the Natal Government ... stated that some of the Natal Afrikaners were misled into taking up arms, and having realised their .... These strategically timed and pragmatic ...

  15. Machado de Assis's "Dom Casmurro" and "Soneto De Natal": The Calculated Mediocrity of a Mute Prophet

    Science.gov (United States)

    Lewis, Christopher T.

    2016-01-01

    Joaquim Maria Machado de Assis's poem "Soneto de Natal" and the chapter "Um soneto" from his novel "Dom Casmurro" exhibit striking points of intersection that describe the same process: the creation of a sonnet. In the novel, Bentinho abandons his attempt with only a first and last line. "Soneto de Natal"…

  16. An environment-friendly and multi-functional absorbent from chitosan for organic pollutants and heavy metal ion.

    Science.gov (United States)

    Li, Ang; Lin, Runjun; Lin, Chong; He, Bianyang; Zheng, Tingting; Lu, Lingbin; Cao, Yang

    2016-09-05

    Developing environment-friendly green absorbents for disposal of wastewater remains to be studied. In this paper, the cross-linked chitosan aerogel (CsA) as an environment-friendly absorbent was obtained by a simple method involving cross-linked process and freeze drying technique. Compared with conventional absorbents, the porous chitosan aerogel was provided with unique properties such as low density (0.0283g/cm(3)), high porosity (97.98%) and outstanding adsorption performance. The chitosan aerogel also displayed good reusability and excellent elasticity with a maximal thickness recovery up to 96.8% of the original thickness. The as-prepared absorbent exhibited preferable adsorption capacities for crude oil, diesel and copper ion (41.07g/g, 31.07g/g and 21.38mg/g, respectively). The aerogel can collect a wide range of organic solvents and oils with absorption capacities up to 40 times their own weight, depending on the density and viscosity of the liquids. The adsorption capacity for heavy metal ion was also considerable and the maximum adsorption capacity (qm) of the aerogel for copper ion was 35.08mg/g according to Langmuir isotherm model. Consequently, the chitosan aerogel with versatile adsorption properties has a good potential for wastewater treatment in environmental application.

  17. Occurrence and role of algae and fungi in acid mine drainage environment with special reference to metals and sulfate immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Das, B.K.; Roy, A.; Koschorreck, M.; Mandal, S.M.; Wendt-Potthoff, K.; Bhattacharya, J. [Indian Institute for Technology, Kharagpur (India). Dept. of Mining Engineering

    2009-03-15

    Passive remediation of Acid Mine Drainage (AMD) is a popular technology under development in current research. Roles of algae and fungi, the natural residents of AMD and its attenuator are not emphasized adequately in the mine water research. Living symbiotically various species of algae and fungi effectively enrich the carbon sources that help to maintain the sulfate reducing bacterial (SRB) population in predominantly anaerobic environment. Algae produce anoxic zone for SRB action and help in biogenic alkalinity generation. While studies on algal population and actions are relatively available those on fungal population are limited. Fungi show capacity to absorb significant amount of metals in their cell wall, or by extracellular polysaccharide slime. This review tries to throw light on the roles of these two types of microorganisms and to document their activities in holistic form in the mine water environment. This work, inter alia, points out the potential and gap areas of likely future research before potential applications based on fungi and algae initiated AMD remediation can be made on sound understanding.

  18. Modern beachrock formation in Durban, KwaZulu-Natal

    Directory of Open Access Journals (Sweden)

    Hayley Cawthra

    2012-07-01

    Full Text Available We explored the recent cementation of modern beachrock on the seaward margin of the Durban Bluff, central KwaZulu-Natal. The low latitude and subtropical climatic setting is a unique context compared to the more commonly documented contemporary beachrock formation in the tropics. Geological field mapping was carried out and here we present results based on sedimentary facies of a clastic shoreline and carbonate diagenesis of interstitial cements using transmitted light microscopy. The beachrock was cemented by micrite and aragonite, and iron oxide infilled voids. The presence of human artefacts within the deposit showed evidence for cementation within the last century. The elevation (at Mean Low Water and correlation to rates of sea level change for the east coast of South Africa showed that the beachrock is less than 72 years in age. In contrast to older local Pleistocene deposits, beachrocks have cemented along this stretch of coast during successive sea level highstands with similar climatic regimes – the last Interglacial, the Holocene High and the present. Here we report the most southerly documentation of modern beachrock in KwaZulu-Natal, which, to our knowledge, represents the youngest deposit reported in southern Africa.

  19. Post-natal growth in the rat pineal gland: a stereological study.

    Science.gov (United States)

    Erbagci, H; Kizilkan, N; Ozbag, D; Erkilic, S; Kervancioglu, P; Canan, S; Gumusburun, E

    2012-10-01

    The purpose was to observe the changes in a rat pineal gland using stereological techniques during lactation and post-weaning periods. Thirty Wistar albino rats were studied during different post-natal periods using light microscopy. Pineal gland volume was estimated using the Cavalieri Method. Additionally, the total number of pinealocytes was estimated using the optical fractionator technique. Pineal gland volume displayed statistically significant changes between lactation and after weaning periods. A significant increase in pineal gland volume was observed from post-natal day 10 to post-natal day 90. The numerical density of pinealocytes became stabilized during lactation and decreased rapidly after weaning. However, the total number of pinealocytes continuously increased during post-natal life of all rats in the study. However, this increment was not statistically significant when comparing the lactation and after weaning periods. The increase in post-natal pineal gland volume may depend on increment of immunoreactive fibres, capsule thickness or new synaptic bodies.

  20. Erosion Characteristics of Aluminum-based Metal Matrix Composites in Slurry Environments

    Institute of Scientific and Technical Information of China (English)

    Tu Jiangping

    2000-01-01

    The erosion resistance of the Al18B4O33 whisker reinforced AC4C Al composites in water and saline slurry were investigated using a jet-in-slit rig. Erosion tests were performed at slurry velocities between 6.4 m/s to 15.2 m/s and at normal impact angle. The detachment of flake and dislodgement of whisker were identified as the major mechanisms of material removal in slurry environments. The composites showed better erosion resistance due to the protection of the matrix by the whisker at low slurry velocities. Because of reduced fracture strain, the erosion rates of the composites were generally greater than that of the unreinforced alloy at high slurry velocities. Owing to interfacial reaction which resulted in decrease in hardness and fracture strain,the T6 treatment for the composites had a deleterious influence on the erosion resistance. By considering the material removal processes in the water slurry, a simple rationalization of the inverse dependence of slurry erosion rate on Hεf was obtained. In the saline slurry, there exists a strong synergistic effect between erosion and corrosion. The volume loss of the composites was enhanced through cracking of flakes and detaching of whisker induced by stress and corrosion.

  1. Study of metal corrosion using ac impedance techniques in the STS launch environment

    Science.gov (United States)

    Calle, Luz M.

    1989-01-01

    AC impedance measurements were performed to investigate the corrosion resistance of 19 alloys under conditions similar to the STS launch environment. The alloys were: Zirconium 702, Hastelloy C-22, Inconel 625, Hastelloy C-276, Hastelloy C-4, Inconel 600, 7Mo + N, Ferralium 255, Inco Alloy G-3, 20Cb-3, SS 904L, Inconel 825, SS 304LN, SS 316L, SS 317L, ES 2205, SS 304L, Hastelloy B-2, and Monel 400. AC impedance data were gathered for each alloy after one hour immersion time in each of the following three electrolyte solutions: 3.55 percent NaCl, 3.55 percent NaCl-0.1N HCl, and 3.55 percent NaCl-1.0N HCl. The data were analyzed qualitatively using the Nyquist plot and quantitatively using the Bode plot. Polarization resistance, Rp, values were obtained using the Bode plot. Zirconium 702 was the most corrosion resistant alloy in the three electrolytes. The ordering of the other alloys according the their resistance to corrosion varied as the concentration of hydrochloric acid in the electrolyte increased. The corrosion resistance of Zirconium 702 and Ferralium 255 increased as the concentration of hydrochloric acid in the electrolyte increased. The corrosion resistance of the other 17 alloys decreased as the concentration of the hyrdochloric acid in the electrolyte increased.

  2. Heavy-Metal and Benzalkonium Chloride Resistance of Listeria monocytogenes Isolates from the Environment of Turkey-Processing Plants▿ †

    Science.gov (United States)

    Mullapudi, S.; Siletzky, R. M.; Kathariou, S.

    2008-01-01

    The resistance of Listeria monocytogenes to cadmium and arsenic has been used extensively for strain subtyping. However, limited information is available on the prevalence of such resistance among isolates from the environment of food-processing plants. In addition, it is not known whether the resistance of such isolates to heavy metals may correlate with resistance to quaternary ammonium compounds extensively used as disinfectants in the food-processing industry. In this study, we characterized 192 L. monocytogenes isolates (123 putative strains) from the environment of turkey-processing plants in the United States for resistance to cadmium and arsenic and to the quaternary ammonium disinfectant benzalkonium chloride (BC). Resistance to cadmium was significantly more prevalent among strains of serotypes 1/2a (or 3a) and 1/2b (or 3b) (83% and 74%, respectively) than among strains of the serotype 4b complex (19%). Resistance to BC was encountered among 60% and 51% of the serotype 1/2a (or 3a) and 1/2b (or 3b) strains, respectively, and among 7% of the strains of the serotype 4b complex. All BC-resistant strains were also resistant to cadmium, although the reverse was not always the case. In contrast, no correlation was found between BC resistance and resistance to arsenic, which overall was low (6%). Our findings suggest that the processing environment of turkey-processing plants may constitute a reservoir for L. monocytogenes harboring resistance to cadmium and to BC and raise the possibility of common genetic elements or mechanisms mediating resistance to quaternary ammonium disinfectants and to cadmium in L. monocytogenes. PMID:18192428

  3. The host galaxy and environment of a neutron star merger

    CERN Document Server

    Postigo, A de Ugarte; Rowlinson, A; Garcia-Benito, R; Levan, A J; Gorosabel, J; Goldoni, P; Schulze, S; Zafar, T; Wiersema, K; Sanchez-Ramirez, R; Melandri, A; D'Avanzo, P; Oates, S; D'Elia, V; De Pasquale, M; Kruehler, T; van der Horst, A J; Xu, D; Watson, D; Piranomonte, S; Vergani, S; Milvang-Jensen, B; Kaper, L; Malesani, D; Fynbo, J P U; Cano, Z; Covino, S; Flores, H; Greiss, S; Hammer, F; Hartoog, O E; Hellmich, S; Heuser, C; Hjorth, J; Jakobsson, P; Mottola, S; Sparre, M; Sollerman, J; Tagliaferri, G; Tanvir, N R; Vestergaard, M; Wijers, R A M J

    2013-01-01

    The mergers of neutron stars have been predicted to cause an r-process supernova - a luminous near-infrared transient powered by the radioactive decay of freshly formed heavy metals. An r-process supernova, or kilonova, has recently been discovered coincident with the short-duration gamma-ray burst GRB 130603B, simultaneously confirming the widely-held theory of the origin of most short-durations GRBs in neutron star mergers. We report here the absorption spectrum of the afterglow of this GRB. From it we determine the redshift of the burst and the properties of the host galaxy and the environment in which the merger occurred. The merger is not associated with the most star-forming region of the galaxy; however, it did occur in a dense region, implying a rapid merger or a low natal kick velocity for the neutron star binary.

  4. Modular construction of oxide structures--compositional control of transition metal coordination environments.

    Science.gov (United States)

    Tenailleau, Christophe; Allix, Mathieu; Claridge, John B; Hervieu, Maryvonne; Thomas, Michael F; Hirst, James P; Rosseinsky, Matthew J

    2008-06-18

    The effects of reaction temperature and pO2 were investigated on a series of (Ba,Ca,Nd)FeO3-delta perovskite systems in order to isolate phases containing ordered arrangements of the distinct vacancy and cation ordering patterns identified in less compositionally complex iron oxide systems. Initial synthesis in air at high temperature yields cubic perovskite phases (I) with average iron oxidation states higher than 3; selected area electron diffraction together with diffuse features observed in the synchrotron X-ray diffraction (SXRD) patterns of these materials show evidence of small domains of short-range cation and vacancy order. Annealing these materials in nitrogen or in a sealed tube in the presence of an NiO/Ni buffer yielded the Fe(3+) phase Ca2Ba2Nd2Fe6O16 (II), closely related to Sr2LaFe3O8 but with partial cation order as well as anion order present the larger Ba cations are largely present in the 12-coordinate site between the octahedral iron layers, and Ca is largely present in 10-coordinate sites between octahedral and tetrahedral sites. Further reduction of Ca2Ba2Nd2Fe6O16 using a Zr getter yields the mixed-valence phase Ca2Ba2Nd2Fe6O15.6 (III). The structure of III was solved by maximum entropy analysis of XRD data coupled with analysis of high-temperature neutron diffraction data and refined against combined SXRD and high-Q ambient-temperature neutron data. This material crystallizes in a 20-fold perovskite super cell (Imma, a approximately square root(2 x a(p), b approximately 10 x a(p), c approximately square root(x 2a(p)) and can be visualized as an intergrowth between brownmillerite (Ca2Fe2O5) and the YBa2Fe3O8 structure. There are three distinct iron coordination environments, octahedral (O), square-pyramidal (Sp), and trigonal planar (Tp, formed by distorting the tetrahedral site in brownmillerite), which form a Sp-O-Tp-O-Sp repeat. Bond valence calculations indicate that Tp is an Fe(2+) site, while the O and Sp sites are Fe(3+). The A

  5. Draft Genome Sequence of Bacillus cereus LCR12, a Plant Growth-Promoting Rhizobacterium Isolated from a Heavy Metal-Contaminated Environment.

    Science.gov (United States)

    Egidi, Eleonora; Wood, Jennifer L; Mathews, Elizabeth; Fox, Edward; Liu, Wuxing; Franks, Ashley E

    2016-09-29

    Bacillus cereus LCR12 is a plant growth-promoting rhizobacterium, isolated from a heavy metal-contaminated environment. The 6.01-Mb annotated genome sequence provides the genetic basis for revealing its potential application to remediate contaminated soils in association with plants. Copyright © 2016 Egidi et al.

  6. The potential human health effect(s) of the metal uranium in the environment. Report on the known human health effects associated with the exposure to the metal uranium

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-31

    Concern over the levels of the metal uranium in the environment as a result of industrial activities has been expressed by several Federal and State agencies. This concern is associated with potential human health effects of this metal on kidney function and bone formation. Although limits for the Metal uranium in the environment remain to be set, the Environmental Protection Agency (EPA) is currently in the process of establishing guidance limits for this metal in water and soil. These limits will be established for both the metal and the associated radioactivity. The suggested limits currently being considered for water and soil are, 20 pCi/liter and 10 pCi/gram wet weight, respectively. For naturally occurring uranium EPA assumes that 1 ug of uranium metal equals 0.67 pCi at equilibrium (i.e. at equilibrium the mass ratio of {sup 234}uranium to {sup 238}uranium is small but their activities are equal). Thus the limits for water and soil on weight basis for the uranium metal would be 30 ug/liter and 15 ug/gram wet weight, respectively. These limits are being established based on the potential increase in cancer death in populations that exceed this limit. Since there does not appear to be a significant correlation between cancer deaths and.uranium metal exposure (see discussion below), these limits will probably be established based on the known association between radionuclides exposure and cancer deaths. The exposure limits for other health effects such as kidney damage and retardation in bone formation apparently are not being considered by EPA.

  7. An Ordination of the Vegetation of Ntshongweni, Natal*

    Directory of Open Access Journals (Sweden)

    J. W. Morris

    1969-12-01

    Full Text Available The physiography, soils, climate and dense woody vegetation are briefly described for Ntshongweni, a cone-shaped hill in Natal, South Africa (29° 51' S and 30° 43' E. A primary ordination of the woody plants, based on Bray & Curtis’s (1957 method, was carried out using 60 quadrats. Four stand noda were delimited and another four noda within a secondary ordination of a cluster of quadrats which could not be interpreted within the primary ordination. Edaphic and atmospheric moisture conditions and slope aspect were proposed as the main site factors correlated with species performance. Tables of density, local frequency and constancy for species occurring in each nodum were drawn up.

  8. A new methodology for automating acoustic emission detection of metallic fatigue fractures in highly demanding aerospace environments: An overview

    Science.gov (United States)

    Holford, Karen M.; Eaton, Mark J.; Hensman, James J.; Pullin, Rhys; Evans, Sam L.; Dervilis, Nikolaos; Worden, Keith

    2017-04-01

    The acoustic emission (AE) phenomenon has many attributes that make it desirable as a structural health monitoring or non-destructive testing technique, including the capability to continuously and globally monitor large structures using a sparse sensor array and with no dependency on defect size. However, AE monitoring is yet to fulfil its true potential, due mainly to limitations in location accuracy and signal characterisation that often arise in complex structures with high levels of background noise. Furthermore, the technique has been criticised for a lack of quantitative results and the large amount of operator interpretation required during data analysis. This paper begins by introducing the challenges faced in developing an AE based structural health monitoring system and then gives a review of previous progress made in addresing these challenges. Subsequently an overview of a novel methodology for automatic detection of fatigue fractures in complex geometries and noisy environments is presented, which combines a number of signal processing techniques to address the current limitations of AE monitoring. The technique was developed for monitoring metallic landing gear components during pre-flight certification testing and results are presented from a full-scale steel landing gear component undergoing fatigue loading. Fracture onset was successfully identify automatically at 49,000 fatigue cycles prior to final failure (validated by the use of dye penetrant inspection) and the fracture position was located to within 10 mm of the actual location.

  9. Natal and breeding philopatry of female Steller sea lions in southeastern Alaska

    Science.gov (United States)

    2017-01-01

    Information on drivers of dispersal is critical for wildlife conservation but is rare for long-lived marine mammal species with large geographic ranges. We fit multi-state mark-recapture models to resighting data of 369 known-aged Steller sea lion (Eumetopias jubatus) females marked as pups on their natal rookeries in southeastern Alaska from 1994–2005 and monitored from 2001–15. We estimated probabilities of females being first observed parous at their natal site (natal philopatry), and of not moving breeding sites among years (breeding philopatry) at large (> 400 km, all five rookeries in southeastern Alaska) and small (reproductive strategies of sea lions. PMID:28591130

  10. Invertebrates control metal/metalloid sequestration and the quality of DOC/DON released during litter decay in slightly acidic environments.

    Science.gov (United States)

    Schaller, Jörg; Machill, Susanne

    2012-11-01

    Plant litter and organic sediments are a main sink for metals and metalloids in aquatic ecosystems. The effect of invertebrate shredder (a key species in litter decay) on metal/metalloid fixation by organic matter is described only under alkaline water conditions whereas for slightly acidic waters nothing can be found. Furthermore, less is known about the effect of invertebrate shredders on the quality of dissolved organic carbon (DOC) and nitrogen (DON) released during litter decay. We conducted an experiment to investigate the impact of invertebrate shredder (Gammarus pulex) on metal/metalloid fixation/remobilization and on the quality of DOC/DON released under slightly acidic water conditions. During decomposition of leaf litter, invertebrate shredder facilitated significantly the emergence of smaller particle sizes of organic matter. The capacity of metal fixation was significantly higher in smaller particles (POM 2,000-63 μm) compared to original leaf litter and litter residues. Thus, G. pulex enhanced metal fixation by organic partition of sediments by increasing the amount of smaller particle of organic matter in aquatic ecosystems. In contrast, the capacity of metal/metalloid fixation in the smallest fraction of POM (treatment without invertebrates. Remobilization of metals and metalloids was very low for all measured elements. A significant effect of invertebrates on quantitative formation of DOC/DON was confirmed. The quality of released DOC/DON, which may affect metal/metalloid remobilization, was also significantly affected by invertebrate shredders (e.g., more carboxylates). Hence, invertebrate shredder enhanced significantly the fixation of metals/metalloids into POM in slightly acidic environments.

  11. A research for environmental problems in the vicinity of mining area. Investigation into the impact of metallic mining on the environment and solutions

    Energy Technology Data Exchange (ETDEWEB)

    Min, Jeong Sik; Cheong, Young Wook; Lee, Hyun Joo; Song, Duk Young [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of)

    1995-12-01

    This study is focused on the impacts of metalliferous mines on the environment in the vicinity of the abandoned and active mines and establishment of abatements of mining environmental problems. Total number of metalliferous mines surveyed were 40 in which samples of waters, mine wastes and soil were taken. Water parameters such as the pH, Eh, TDS, conductivity, turbidity, dissolved oxygen and temperature were measured in the field. Elements such as As, Cd, Pb, Zn, Cu, Al, Mn, sulfate and cyanide were analyzed. Significant concentrations of heavy metals, mainly Cd, Zn, Cu, Fe, Mn and Al, were found in mine waters from adit and in leachates extracted from mine wastes. The mine waters flowing out from the Dalsung and Ilgwang mines were the typical acid mine drainage(AMD) contaminated by the heavy metals. Passive biological systems(Anoxic wetland) to treat AMD for metals were designed and monitored for effluents from the reactors with 4 types of composts, cow manure and limestones, Results showed that the mushroom compost with cow manure and limestone was the best substrates in metal removing efficiencies. Results from leaching of mine wastes showed that As, Cd and Cu were extracted from some of mine wastes. AMD from the mine waste dump of the Daduk mine was found. These mean that mine wastes can contaminate the soil, surface water and ground waters in vicinity of mines. Therefore cover systems or liner system for containments of mine wastes were suggested to preserve the environment. Cu and As concentrations in soils surveyed were below the heavy metal concentrations in soils of Korean standard preventing plant of the crops. However, most of the acid mine waters are drained untreated, and mine wastes with heavy metals are distributed near soil environment. Therefore efforts to reduce possibilities of soil contamination in the vicinity of mining areas is required. (author). 33 refs.

  12. COOPERATION AND CONFLICT – THE BRITISH ARMY, THE NATAL GOVERNMENT AND THE PROSECUTION OF NATAL REBELS DURING THE ANGLO-BOER WAR

    Directory of Open Access Journals (Sweden)

    Johan Wassermann

    2011-08-01

    Full Text Available The Natal Afrikaner rebels hardly feature in the historiography of the Anglo-BoerWar of 1899–1902. The Times History of the War in South Africa dismisses theirrebellion in one sentence, while the Natal Mercury of 25 April 1900 correctly pointsout that the number of rebels and the scale of the rebellion are rather insignificant whencompared with that of the Cape Colony. In the latter, where in contrast to Natal,Afrikaners formed the bulk of the white population, the dynamics of the rebellion wasvery different. The large number of Afrikaners resident in the Cape Colony acted as amagnet for the Republican forces and as a result, large numbers of Afrikaners took uparms against Britain. From their side, the British authorities acted with a vengeancetowards the Cape rebels, executing and imprisoning large numbers.

  13. A study of the water quality of the Mhlathuze River, KwaZulu-Natal ...

    African Journals Online (AJOL)

    A study of the water quality of the Mhlathuze River, KwaZulu-Natal (RSA): microbial ... The results showed that most of the physical and chemical values obtained were ... study, Felixton continues to be the site with major faecal contamination.

  14. Nesting fidelity and molecular evidence for natal homing in the freshwater turtle, Graptemys kohnii.

    Science.gov (United States)

    Freedberg, Steven; Ewert, Michael A; Ridenhour, Benjamin J; Neiman, Maurine; Nelson, Craig E

    2005-07-07

    Numerous studies of sea turtle nesting ecology have revealed that females exhibit natal homing, whereby they imprint on the nesting area from which they hatch and subsequently return there to nest as adults. Because freshwater turtles comprise the majority of reptiles known to display environmental sex determination (ESD), the study of natal homing in this group may shed light on recent evolutionary models of sex allocation that are predicated on natal homing in reptiles with ESD. We examined natal homing in Graptemys kohnii, a freshwater turtle with ESD, using mitochondrial sequencing, microsatellite genotyping and mark and recapture of 290 nesting females. Females showed high fidelity to nesting areas, even after being transplanted several kilometres away. A Mantel test revealed significant genetic isolation by distance with respect to nesting locations (r=0.147; psex ratios.

  15. The Ven. Charles Theophilus Hahn, a hitherto unknown Edwardian botanical illustrator in Natal, 1908—1916

    Directory of Open Access Journals (Sweden)

    J. P. Rourke

    1992-12-01

    Full Text Available A brief biographical sketch is given of the Rev. C.T. Hahn, an English-born, Oxford-educated Anglican missionary in Zululand who painted some 235 watercolours of Natal flora between 1908 and 1913. Hahn (who later changed his name to Headley was one of the most productive of the early botanical illustrators in Natal but as a collection of his paintings has only recently been discovered, his work has until hitherto remained unknown.

  16. Neutrino-Triggered Asymmetric Magnetorotational Pulsar Natal Kick Cherry-Stone Shooting" Mechanism)

    Science.gov (United States)

    Kuznetsov, A. V.; Mikheev, N. V.

    2013-11-01

    The sterile neutrino mechanisms for natal neutron stars kicks are re-analyzed. It is shown that the magnetic field strengths needed for a kick were underestimated essentially. Another mechanism with standard neutrinos is discussed where the outgoing neutrino flux in a supernova explosion with a strong toroidal magnetic field generation causes the field redistribution in "upper" and "lower" hemispheres of the supernova envelope. The resulting magnetic field pressure asymmetry causes the pulsar natal kick.

  17. Institutionalizing elites: political elite formation and change in the KwaZulu-Natal provincial legislature

    OpenAIRE

    Francis, Suzanne

    2011-01-01

    This book expands and redefines the approach to the study of political elites through an interrogation of political elite formation in the context of the provincial legislature of KwaZulu-Natal, South Africa, over the period 1994-2004. The period covers two successive provincial government elections and two terms of office. KwaZulu-Natal is the only province where the Inkatha Freedom Party remains a significant political contender. The author presents a detailed study of the realization, accu...

  18. Factors contributing to non-compliance to routine ante-natal haematinics among pregnant women attending ante-natal clinic in University of Maiduguri Teaching Hospital, Borno, Nigeria

    Directory of Open Access Journals (Sweden)

    Idris Umar Hambali

    2016-11-01

    Conclusions: In conclusion, this study provided information on the general response to factors contributing to non-compliance to routine ante natal haematinics among pregnant women attending ante natal clinic in UMTH which was about 62%. It is therefore recommended that the government should put in place relevant agencies to pro-actively inform pregnant women cut across all age groups, level of education, occupational classes, culture inclinations and financial status on the medical importance of haematinics intake during the gestation period. [Int J Reprod Contracept Obstet Gynecol 2016; 5(11.000: 3824-3831

  19. Geomagnetic imprinting: A unifying hypothesis of long-distance natal homing in salmon and sea turtles.

    Science.gov (United States)

    Lohmann, Kenneth J; Putman, Nathan F; Lohmann, Catherine M F

    2008-12-09

    Several marine animals, including salmon and sea turtles, disperse across vast expanses of ocean before returning as adults to their natal areas to reproduce. How animals accomplish such feats of natal homing has remained an enduring mystery. Salmon are known to use chemical cues to identify their home rivers at the end of spawning migrations. Such cues, however, do not extend far enough into the ocean to guide migratory movements that begin in open-sea locations hundreds or thousands of kilometers away. Similarly, how sea turtles reach their nesting areas from distant sites is unknown. However, both salmon and sea turtles detect the magnetic field of the Earth and use it as a directional cue. In addition, sea turtles derive positional information from two magnetic elements (inclination angle and intensity) that vary predictably across the globe and endow different geographic areas with unique magnetic signatures. Here we propose that salmon and sea turtles imprint on the magnetic field of their natal areas and later use this information to direct natal homing. This novel hypothesis provides the first plausible explanation for how marine animals can navigate to natal areas from distant oceanic locations. The hypothesis appears to be compatible with present and recent rates of field change (secular variation); one implication, however, is that unusually rapid changes in the Earth's field, as occasionally occur during geomagnetic polarity reversals, may affect ecological processes by disrupting natal homing, resulting in widespread colonization events and changes in population structure.

  20. Crustal formation and evolution processes in the Natal Valley and Mozambique Ridge, off South Africa

    Science.gov (United States)

    Hanyu, Tomoko; Nogi, Yoshifumi; Fujii, Masakazu

    2017-09-01

    The evolution of seafloor spreading of Africa, South America, and Antarctica is key to understanding the initial break-up of Gondwana. Vector geomagnetic surveys were conducted in the Natal Valley and Mozambique Ridge, off South Africa. We summarize the nature of the crust using the results of dense vector geomagnetic anomaly data, as well as satellite gravity data. Based on both inversion and forward analytical results, we identified areas of stretched continental crust, with basaltic magma intrusion in parts, as the northern Natal Valley, north part of the Mozambique Ridge, and north part of the southern Natal Valley. Oceanic crust was identified in the south part of the southern Natal Valley and south part of the Mozambique Ridge. Magnetic isochrons M0-M10 were identified in the south part of the southern Natal Valley. Clear magnetic lineations were observed in the south part of the Mozambique Ridge, where some areas were distorted by hotspot volcanism. The location of the continental ocean boundary in the Natal Valley, along with a four-stage model of tectonic evolution of the study area since about 183 Ma, are newly proposed.

  1. Is there continental crust underneath the northern Natal Valley and the Mozambique Coastal Plains?

    Science.gov (United States)

    Leinweber, Volker Thor; Jokat, W.

    2011-07-01

    To draw conclusions about the crustal nature and history of the Natal Valley and the Mozambique Ridge, systematic potential field data were obtained during the AISTEK III cruise with R/V Pelagia in 2009. This paper presents and interprets the results of that expedition. The new magnetic data reveal a pattern of linear magnetic spreading anomalies, NW-SE trending in the southwestern part of the Mozambique Ridge and E-W trending on its central part. The Ariel Graben, which separates the Mozambique Ridge from the Northern Natal Valley, is represented by a pronounced negative anomaly in the magnetic- as well as the free-air gravity field. The Northern Natal Valley bears a complicated pattern of anomalies with mainly SW-NE trends. In the Northern Natal Valley, no indications for a continent-ocean-boundary between continental crust in the north and oceanic crust in the south exist, either in the free-air gravity or in the magnetic field. The magnetic wavelengths of the Mozambique Coastal Plains are similar to those of the Northern Natal Valley and the Mozambique Ridge. Particularly in the gravity data, the Mozambique coastal plains, the Northern Natal Valley and the Mozambique Ridge appear as one continuous geological province. We interpret the region from the Mateke-Sabi monocline in the north to the southwestern tip of the Mozambique Ridge as mainly being floored by thickened oceanic crust.

  2. Perspective: What is known, and not known, about the connections between alkane oxidation and metal uptake in alkanotrophs in the marine environment

    Science.gov (United States)

    Kenney, Grace E.; Rosenzweig, Amy C.

    2014-01-01

    Article Summary Should iron and copper be added to the environment to stimulate the natural bioremediation of marine oil spills? The key enzymes that catalyze the oxidation of alkanes require either iron or copper, and the concentration of these ions in seawater is vanishingly low. Nevertheless, the dependence of alkane oxidation activity on external metal concentrations remains unclear. This perspective will summarize what is known about the co-regulation of alkane oxidation and metal acquisition and pose a series of critical questions to which, for the most part, we do not yet have answers. The paucity of answers points to the need for additional studies to illuminate the cellular biology connecting microbial growth on alkanes to the acquisition of metal ions. PMID:24710692

  3. Potential Environment and Public Health Risk Due to Contamination of Heavy Metals from Industrial Waste Water in Lam Thao, Phu Tho, Vietnam

    Directory of Open Access Journals (Sweden)

    Nguyen C. Vinh

    2012-01-01

    Full Text Available Problem statement: In Vietnam, rice cultivation plays an important role in national economic development and food security. However, rice production is facing many problems associated with rapid industrialization and urbanization in the country. Resultant emissions of solid and liquid wastes are often untreated and discharged directly to agricultural land. These practices have potential impacts on the environment and human health. Approach: The research was carried out within the frame of the collaborative research project “Towards the mitigation of environment and public health risks due to heavy metal contamination in irrigated rice-based systems of Vietnam” in 2006-2010. The study was implemented in the Lam Thao district, Phu Tho province with the aim to assess the effects of wastewater and other contamination sources on the environment and public health. Results: Surface water and soil in the field showed signs of significant contamination by wastewater from the industrial zones. Bio-indicators (DO, COD, BOD5 in the surface water were also strongly affected by waste. Paddy fields around the industrial zones had an elevated risk of heavy metal contamination (Cu, Zn, As, Cd and Pb, with concentrations exceeding Vietnamese Maximum Acceptable Concentrations (MACs for Cu, Zn, Cd and Pb. Soil contamination with heavy metals was resulting in elevated concentrations in rice grain. Where consumption of locally-produced food was high, exposure of individuals to heavy metals could present a public health risk. The partial Hazard Quotient (HQ; a ratio derived from comparing estimated exposure to heavy metals, i.e., Cd, (with toxicologically-derived„ safe’ daily doses for rice and vegetables (water spinach and the integrated Hazard Quotient of rice and vegetables (HQi was consistently greater in areas with soil contamination than in the reference area using Red River water for irrigation. The HQi for Cd was particularly high for children below the

  4. Effects of environmental factors on corrosion behaviors of metal-fiber porous components in a simulated direct methanol fuel cell environment

    Institute of Scientific and Technical Information of China (English)

    Wei Yuan; Bo Zhou; Yong Tang; Zhao-chun Zhang; Jun Deng

    2014-01-01

    To enable the use of metallic components in direct methanol fuel cells (DMFCs), issues related to corrosion resistance must be considered because of an acid environment induced by the solid electrolyte. In this study, we report the electrochemical behaviors of metal-fiber-based porous sintered components in a simulated corrosive environment of DMFCs. Three materials were evaluated:pure copper, AISI304, and AISI316L. The environmental factors and related mechanisms affecting the corrosion behaviors were analyzed. The results demonstrated that AISI316L exhibits the best performance. A higher SO42-concentration increases the risk of material corrosion, whereas an increase in methanol concentration inhibits corrosion. The morphological features of the corroded samples were also characterized in this study.

  5. Adsorption of Toxic Metals and Control of Mosquitos-borne Disease by Lysinibacillus sphaericus: Dual Benefits for Health and Environment.

    Science.gov (United States)

    Javier, Edo Vargas; Jenny, Dussán

    2016-03-01

    Assessment of the bacterium L. sphaericus as a dual-action candidate for biological control of mosquito-borne diseases and bioremediation of toxic metals. Larvae of the mosquito, C. quinquefasciatus, were first evaluated for metal tolerance and then exposed to 5 ppm cadmium, chromium, arsenic, and lead in assays together with seven strains of L. sphaericus. A probit regression analysis was used to estimate the LC(50) of Cd, Cr, As, and Pb to C. quinquefasciatus. An analysis of covariance and multifactorial ANOVA examined the metal biosorption and larvicidal properties of the seven strains of L. sphaericus. We found that L. sphaericus adsorbed the toxic metal ions and was toxic against mosquito larvae. The L. sphaericus strain III(3)7 resulted in a larvae mortality of over 80% for all the tested metals. This strain also exhibited the capacity to adsorb 76% of arsenic, 32% of lead, 25% of chromium, and 7% of cadmium. This study found combined metal adsorption and larval toxicity associated with three strains of L. sphaericus [III(3)7, OT4b.31, and CBAM5]. This suggests that a combination of these strains shows strong dual potential for biological control of mosquitos in heavy metal-contaminated areas and remediate the heavy metal contamination as well. Copyright © 2016 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  6. Evaluation of Heavy Metals Contamination from Environment to Food Matrix by TXRF: The Case of Rice and Rice Husk

    Directory of Open Access Journals (Sweden)

    Fabjola Bilo

    2015-01-01

    Full Text Available This paper is devoted to the chemical analysis of contaminated soils of India and the rice grown in the same area. Total reflection X-ray fluorescence spectroscopy is a well-established technique for elemental chemical analysis of environmental samples, and it can be a useful tool to assess food safety. Metals uptake in rice crop grown in soils from different areas was studied. In this work soil, rice husk and rice samples were analyzed after complete solubilization of samples by microwave acid digestion. Heavy metals concentration detected in rice samples decreases in the following order: Mn > Zn > Cu > Ni > Pb > Cr. The metal content in rice husk was higher than in rice. This study suggests, for the first time, a possible role of heavy metals filter played by rice husk. The knowledge of metals sequestration capability of rice husk may promote some new management practices for rice cultivation to preserve it from pollution.

  7. A comparative assessment of heavy metal accumulation in soft parts and byssus of mussels from subarctic, temperate, subtropical and tropical marine environments

    Energy Technology Data Exchange (ETDEWEB)

    Szefer, P. [Department of Food Sciences, Medical University of Gdansk, Al. Gen. J. Hallera 107, PL 80-416 Gdansk (Poland)]. E-mail: pszef@amg.gda.pl; Fowler, S.W. [IAEA Marine Environment Laboratory, 4 Quai Antoine 1er, MC-98000 (Monaco); Ikuta, K. [Laboratory of Aquatic Environment and Ecology, Department of Fisheries, Faculty of Agriculture, Miyazaki University, 889-21 Miyazaki (Japan); Osuna, F. Paez [Institute of Marine Sciences and Limnology, Mazatlan Station, National Autonomous University of Mexico, Mazatlan 82000, Sinaloa (Mexico); Ali, A.A. [Faculty of Science, Arts and Education, University of Aden, PO Box 6014, Khormaksar, Aden (Yemen); Kim, B.-S. [School of Earth and Environmental Science, Seoul National University, 56-1 Shillimdong, 151-742 (Korea, Republic of); Fernandes, H.M. [Instituto de Radioprotecao e Dosimetria, Cz. Postal 37 750 - CEP: 22642-970, Rio de Janeiro (Brazil); Belzunce, M.-J. [Instituto Tecnnologico Pesquero y Alimentario, Dpto de Oceanografia y Medio Ambiente Marino, Herrera Kaia, Portualdea z/g, 20110 Pasaia (Gipuzkoa) (Spain); Guterstam, B. [Stensund Ecological Center, 61991 Trosa, Sweden and Global Water Partnership Secretariat, Hantverkargatan 5, SE-112 21 Stockholm (Sweden); Kunzendorf, H. [Gamma Dating Center (GDC), Institute of Geography, University of Copenhagen, Oster Voldgage 10 DK-1350 Copenhagen K (Denmark); Wolowicz, M. [Laboratory of Estuarine Ecology, Institute of Oceanography, University of Gdansk, Al. Pilsudskiego 46, 81-378, Gdynia (Poland); Hummel, H. [Centre for Estuarine and Marine Ecology, Netherlands Institute of Ecology, Korringaweg 7, 4401 NT Yerseke (Netherlands); Deslous-Paoli, M. [IFREMER, Unite Ecologie Conchylicole, 1, rue Jean Vilar, 34200 Sete (France)

    2006-01-15

    Existing data on metal concentrations in mussels from subarctic, temperate, subtropical and tropical waters were analyzed using multivariate statistics in order to assess regional variations in metal contamination. Potential errors were reduced by only analyzing data from surveys that employed the same protocols, analytical methodologies and analysts. Factor analysis demonstrated that mussels inhabiting extremely contaminated areas (e.g. from Japanese and Swedish metallurgy sources) could be separated from mussels from other contaminated areas, and that metals such as Cd, Pb, Cu and Zn could be used to identify heavily contaminated samples while Co, Fe, Cr and Ni concentrations were good markers for exposure to inputs from different industrial sources. Furthermore byssus, like soft tissue, selectively and sensitively reflects variations of certain metal concentrations in ambient waters and thus serves as a reliable biomonitor for these contaminants in a variety of coastal and estuarine areas. - Byssus of mytilids, like soft tissues can be used as efficient biomonitor for heavy metals in the marine environment.

  8. Occurrence of heavy metals in fish: a study for impact assessment in industry prone aquatic environment around Kolkata in India.

    Science.gov (United States)

    Aktar, Md Wasim; Sengupta, Dwaipayan; Chowdhury, Ashim

    2011-10-01

    A study was conducted during November 2005-October 2006 for determining the heavy metal contamination in surface water and sediments and giving prime thrust to determine the heavy metal concentrations fish samples collected from various points of the river Ganga at different time interval. Fish samples (viz., Channa marulius and Aorichthys seengala) were analyzed for heavy metals using standard laboratory procedures by AAS method. In impact points the annual average values for Cu, Cr, Cd, Pb and Zn were 0.15, 0.04, 0.03, 0.02 and 0.29 ppm, respectively. The concentrations of heavy metals in the riverine water collected from middle point had the order Zn > Cu > Cr > Cd > Pb. The data indicated that copper was maximally accumulated in the riverine sediments whereas least annual average concentration was obtained for lead. The trend of accumulation suggested deposition was maximum for zinc and minimum for cadmium in the muscles of both fish species. Only zinc has shown some significant seasonal variation in relation to metal deposition in fish muscles (minimum in monsoon and maximum in summer). The heavy metal contamination to fish may be due to indiscriminate discharge of polluted and untreated sewage sludge to the river. The heavy metal contents in fish at some places are alarming.

  9. Elena Natale ja Mikko Fritze: kultuuripealinna tiimi motivatsioon on töö ise / Elena Natale, Mikko Fritze ; intervjueerinud Tiina Saar

    Index Scriptorium Estoniae

    Natale, Elena

    2009-01-01

    SA Tallinn 2011 tegevjuht Mikko Fritze ja administratiivjuht Elena Natale vastavad küsimustele, mis puudutavad Eesti töökultuuri, , toimiva koostöö saavutamist meeskonnas, kasutatavaid motivatsiooni- ja juhtimissüsteeme, personalivalikut, majanduskriisi mõju SA Tallinn 2011 tegevusele

  10. Elena Natale ja Mikko Fritze: kultuuripealinna tiimi motivatsioon on töö ise / Elena Natale, Mikko Fritze ; intervjueerinud Tiina Saar

    Index Scriptorium Estoniae

    Natale, Elena

    2009-01-01

    SA Tallinn 2011 tegevjuht Mikko Fritze ja administratiivjuht Elena Natale vastavad küsimustele, mis puudutavad Eesti töökultuuri, , toimiva koostöö saavutamist meeskonnas, kasutatavaid motivatsiooni- ja juhtimissüsteeme, personalivalikut, majanduskriisi mõju SA Tallinn 2011 tegevusele

  11. Metabolites associated with adaptation of microorganisms to an acidophilic, metal-rich environment identified by stable-isotope-enabled metabolomics

    National Research Council Canada - National Science Library

    Mosier, Annika C; Justice, Nicholas B; Bowen, Benjamin P; Baran, Richard; Thomas, Brian C; Northen, Trent R; Banfield, Jillian F

    2013-01-01

    ... associated with the environmental matrix. We identified key metabolites associated with acidophilic and metal-tolerant microorganisms using stable isotope labeling coupled with untargeted, high-resolution mass spectrometry. We observed...

  12. Heavy metal contamination in the environs of the Zn-pB Mine in North-West of Tunisia

    Energy Technology Data Exchange (ETDEWEB)

    Ben Guirat, S.; Ben Aissa, N.; Mhiri, A.

    2009-07-01

    The impact of industrial heavy metals (HM) pollution on soil quality and plant growth has become a public concern. To evaluate heavy metals concentration a Zn-Pb mine site was selected, as source of pollution, localized in BouGrine (BG) region at 120 km North-west of Tunis characterized by calcareous soils. Soils of the imine site are occupied by forest pine. (Author)

  13. Variable primary coordination environments of Cd(II) binding to three helix bundles provide a pathway for rapid metal exchange.

    Science.gov (United States)

    Tebo, Alison G; Hemmingsen, Lars; Pecoraro, Vincent L

    2015-12-01

    Members of the ArsR/SmtB family of transcriptional repressors, such as CadC, regulate the intracellular levels of heavy metals like Cd(II), Hg(II), and Pb(II). These metal sensing proteins bind their target metals with high specificity and affinity, however, a lack of structural information about these proteins makes defining the coordination sphere of the target metal difficult. Lingering questions as to the identity of Cd(II) coordination in CadC are addressed via protein design techniques. Two designed peptides with tetrathiolate metal binding sites were prepared and characterized, revealing fast exchange between CdS3O and CdS4 coordination spheres. Correlation of (111m)Cd PAC spectroscopy and (113)Cd NMR spectroscopy suggests that Cd(II) coordinated to CadC is in fast exchange between CdS3O and CdS4 forms, which may provide a mechanism for rapid sensing of heavy metal contaminants by this regulatory protein.

  14. Virtual Visit to the ATLAS Control Room by the Federal Institute of Rio Grande do Norte (IFRN), Natal

    CERN Multimedia

    ATLAS Experiment

    2012-01-01

    In the next October 18th, the Science Club of the Federal Institute of Rio Grande do Norte (IFRN) will host the video-conference "The Particle's Universe : Discovering the LHC and the ATLAS Detector" in partnership with CERN and with the participation of the teachers Amadeu Albino Júnior (IFRN), Anderson Guimarães Guedes (PIBID/UFRN - Natal), and Denis Damazio (ATLAS Detector - LHC/CERN). The Event will take place in the Auditorium of the IFRN Campus Natal-Central at 1:00 pm, Natal local time. http://atlas-live-virtual-visit.web.cern.ch/atlas-live-virtual-visit/2012/Natal-2012.html

  15. E.G. Jansen se rol in belang van die Afrikaners in Natal / P.J.J. Prinsloo

    OpenAIRE

    Prinsloo PJJ

    1987-01-01

    The purpose of this study is to analyse the extensive services delivered to the people in Natal by E.G. Jansen. This analysis also presents an image regarding the most important cultural achievements obtained by the Afrikaners in Natal, during the first half of the century. The necessity of this study lies in the fact that it analyses the fundamentals of the cultural awakening of the Afrikaners in Natal, during the first half of the century. The dominant British character of Natal is another ...

  16. Microbially influenced corrosion: studies on enterobacteria isolated from seawater environment and influence of toxic metals on bacterial biofilm and bio-corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Bermond-Tilly, D.; Pineau, S.; Dupont-Morral, I. [Corrodys, 50 - Equeurdreville (France); Janvier, M.; Grimont, P.A.D. [Institut Pasteur, Unite BBPE, 75 - Paris (France)

    2004-07-01

    Full text of publication follows: The most widely involved bacteria in Microbially Induced Corrosion (MIC usually called bio-corrosion) are sulfate/thiosulfate-reducing bacteria. The sulfate-reducing bacteria (SRB) are major contributors to the anaerobic bio-corrosion of steel. However, corrosion process of pipelines (or off shores platforms) was found to be associated with many other bacteria. These bacteria are able to produce sulfides from the reduction of thiosulfate in anaerobic conditions. By this way, a thiosulfate-reducing non sulfate-reducing bacteria, Dethiosulfovibrio peptidovorans, showed a significant corrosive activity similar to or higher than that recorded for SRB involved in bio-corrosion, (Magot et al., 1997). Furthermore, a bacteria, Citrobacter amalonaticus, which belongs to the family of the Enterobacteriaceae, is involved in severe pitting corrosion process (Angeles Chavez et al., 2002). Recently, some bacteria (Citrobacter freundii, Proteus mirabilis and Klebsiella planticola characterized as belonging to the family of Enterobacteriaceae) were isolated from biofilm developed on carbon steel coupons immersed in natural seawater. The latter bacteria were also associated in severe pitting corrosion process on carbon steel coupons (Bermond-Tilly et al., 2003). Biofilm forms a protective layer, reducing the exposure of the metal surface to the external environment. However, bacteria included in the biofilm could also cause localized corrosion by consuming cathodic hydrogen from the steel or by producing corrosive metabolic end products and by the Extracellular Polymeric Substances (EPS) production. Thus, EPS can also play an important role in the corrosion of the metals (e.g. can complex metal ions). However, sulfate/thiosulfate-reducing bacteria and some Enterobacteria are highly efficient to bioremediation by precipitation of toxic metals from wastewater as metal sulfides. Recently it was shown that toxic metal may be involved in the formation

  17. Enzyme-based glucose delivery: a possible tool for biosorbent preparation for heavy metal removal from polluted environments.

    Science.gov (United States)

    Palela, Mihaela; Bahrim, Gabriela Elena; Glazyrina, Julia; Brand, Eva; Neubauer, Peter

    2013-11-01

    This study was performed to examine the influence of the controlled glucose supply technology, EnBase(®) Flo, on growth and heavy metals uptake capacity of two Bacillus strains isolated from food industry wastewater. Bacillus sp. growth on EnBase Flo (mineral salt complex medium containing starch-derived polymer as substrate) was examined in 24 deep well plates, controlling the glucose amount release by adding two amyloglucosidase concentrations (3 and 6 UL(-1)). Adsorption of the heavy metals Zn(2+), Cd(2+) and Pb(2+) was assessed in a single component system using synthetic metal solutions and as a function of the initial concentration of adsorbate, equilibrium time and removal efficiency. The Langmuir and Freundlich adsorption models were used for the mathematical description of the biosorption equilibrium and isotherm constants. A pseudo second-order model was applied to describe the uptake rate for two isolates. The EnBase(®) Flo technology improved the cells growth over ten times after 24 h of fed-batch cultivation. The EnBase(®) Flo technology improved the Cd(2+) and Pb(2+) uptake capacity of the bacterial strains by approximately 55 and 44 %, respectively. The biosorption of each metal was fairly rapid (within 30 min), which could be an advantage for large scale treatment of contaminated sites. This initial study may be a basis for future developments to apply EnBase Flo for the biomass production used further as biosorbent for heavy metal removal from aqueous solutions.

  18. Regulatory Differences in Natal Down Development between Altricial Zebra Finch and Precocial Chicken.

    Science.gov (United States)

    Chen, Chih-Kuan; Ng, Chen Siang; Wu, Siao-Man; Chen, Jiun-Jie; Cheng, Po-Liang; Wu, Ping; Lu, Mei-Yeh Jade; Chen, Di-Rong; Chuong, Cheng-Ming; Cheng, Hsu-Chen; Ting, Chau-Ti; Li, Wen-Hsiung

    2016-08-01

    Birds can be classified into altricial and precocial. The hatchlings of altricial birds are almost naked, whereas those of precocial birds are covered with natal down. This regulatory divergence is thought to reflect environmental adaptation, but the molecular basis of the divergence is unclear. To address this issue, we chose the altricial zebra finch and the precocial chicken as the model animals. We noted that zebra finch hatchlings show natal down growth suppressed anterior dorsal (AD) skin but partially down-covered posterior dorsal (PD) skin. Comparing the transcriptomes of AD and PD skins, we found that the feather growth promoter SHH (sonic hedgehog) was expressed higher in PD skin than in AD skin. Moreover, the data suggested that the FGF (fibroblast growth factor)/Mitogen-activated protein kinase (MAPK) signaling pathway is involved in natal down growth suppression and that FGF16 is a candidate upstream signaling suppressor. Ectopic expression of FGF16 on chicken leg skin showed downregulation of SHH, upregulation of the feather growth suppressor FGF10, and suppression of feather bud elongation, similar to the phenotype found in zebra finch embryonic AD skin. Therefore, we propose that FGF16-related signals suppress natal down elongation and cause the naked AD skin in zebra finch. Our study provides insights into the regulatory divergence in natal down formation between precocial and altricial birds.

  19. Sewage impact on metal accumulation in sediments and fish (Clarias gariepinus from the University of Cape Coast community and its environs

    Directory of Open Access Journals (Sweden)

    Sarfo D.K

    2013-07-01

    Full Text Available The objectives of this study was to measure the concentration levels of the heavy metals As, Co, Cr, Cu, Fe and Hg upon samples of mudfish(Clarias gariepinus and sediments in wastewater discharge from the University of Cape Coast community and environs. This measurement was done using Instrumental Neutron Activation Analysis. The average concentration of elements (in mg/kg in the fish samples, in decreasing order of magnitude were: Fe (130.63 > Cu (3.77 > Cr(0.16 > Co(0.04 and Fe(209.67 > Cu(2.74 > Cr(0.57 > Co(0.09 from piont A and point B respectively. Arsenic and Hg concentrations were below detection limits of INAA in samples from both point A and point B. The chronic daily intake (CDI obtained for each of the metals in the fish sample shows that the population is not prone to adverse health effects (i.e CDI>>1 due to the concentrations of the metals. From the sediments, Fe recorded the highest concentration of 9808 mg/kg whilst Hg was below the detection limits of INAA. The metals As, Cu, Cr and Co recorded concentrations in mg/kg of 2.04, 4.82, 0.21 and 3.73 respectively in the sediments.

  20. Information literacy: uma análise nas bibliotecas escolares da rede privada em Natal/RN Information literacy: an analysis of the school library of the private schools network in Natal/RN p. 110-133

    Directory of Open Access Journals (Sweden)

    Gabriela Farias

    2007-01-01

    Full Text Available Apresenta a information literacy, como competência em informação, relata, de forma geral, seu surgimento, desenvolvimento e importância de sua prática na biblioteca escolar. Aborda-se os principais focos da competência em informação: tecnologia da informação, processos cognitivos, e aprendizado ao longo da vida. Relata-se a análise dos dados dos questionários aplicados nas bibliotecas escolares da rede de escolas privadas da cidade de Natal RN com fins de identificar e analisar a competência em informação neste ambiente. Apresenta-se a necessidade de integração entre escola-biblioteca, e a inserção do bibliotecário na comunidade educacional para criação de programas educacionais voltados para a competência em informação. Palavras-chave Competência em informação; Habilidades informativas; Biblioteca escolar; Educação e aprendizagem Abstract It presents information literacy as information competence, as well as reporting, in a general way its appearance, development and the importance of its practice in the school library. Focuses on the main information competences: information technology, cognitive processes and life long learning. It reports on the analysis of data obtained from the questionnaire applied in school libraries of the private schools network in the city of Natal RN, as a means to identify and analyze information competence in this environment. The need for school-library integration is presented, as is the need for the insertion of the librarian in the educational community for the creation of educational programs directed towards information competence. Key words Information competence; Informative skills; School library; Education and learning

  1. DEVELOPMENT AND MASTERING OF TECHNOLOGIES OF USE OF METALLIZED PELLETS WITH A HIGH CONTENT OF PHOSPHORUS IN THE ENVIRONMENT OF «BSW – MANAGEMENT COMPANY OF «BMC»

    Directory of Open Access Journals (Sweden)

    O. M. Grudnitsky

    2013-01-01

    Full Text Available It is shown that it is economically reasonable to use metallized pellets with a high content of phosphorus in the environment of “BMP”, produced in the Bolivarian Republic of Venezuela.

  2. Historical DNA documents long-distance natal homing in marine fish.

    Science.gov (United States)

    Bonanomi, Sara; Overgaard Therkildsen, Nina; Retzel, Anja; Berg Hedeholm, Rasmus; Pedersen, Martin Waever; Meldrup, Dorte; Pampoulie, Christophe; Hemmer-Hansen, Jakob; Grønkjaer, Peter; Nielsen, Einar Eg

    2016-06-01

    The occurrence of natal homing in marine fish remains a fundamental question in fish ecology as its unequivocal demonstration requires tracking of individuals from fertilization to reproduction. Here, we provide evidence of long-distance natal homing (>1000 km) over more than 60 years in Atlantic cod (Gadus morhua), through genetic analysis of archived samples from marked and recaptured individuals. Using a high differentiation single-nucleotide polymorphism assay, we demonstrate that the vast majority of cod tagged in West Greenland and recaptured on Icelandic spawning grounds belonged to the Iceland offshore population, strongly supporting a hypothesis of homing. The high degree of natal fidelity observed provides the evolutionary settings for development of locally adapted populations in marine fish and emphasize the need to consider portfolio effects in marine fisheries management strategies.

  3. Transnational Islam and Public Sphere Dynamics in KwaZulu-Natal

    DEFF Research Database (Denmark)

    Kaarsholm, Preben

    2011-01-01

    coming into KwaZulu-Natal. The essay discusses two different examples of Islamic practice in an African informal settlement on the outskirts of Durban, and demonstrates their different understandings of the relationship between Islam and African cultural ‘custom’. It places these differences of local......Islam in KwaZulu-Natal has typically been seen as an Indian preserve and as closely linked with contestations around South African Indian identities. Against this background, dedication to Islam among Africans has appeared as exceptional, represented by groupings with particular histories...... theology and politics in the context of propagations of Islam as manifested in the writings of Ahmed Deedat and recent examples of pamphlet literature by African Muslims. It argues that understandings of Islam in KwaZulu-Natal as an African religion relate the area to the Indian Ocean world not only though...

  4. Facile synthesis of multiple enzyme-containing metal-organic frameworks in a biomolecule-friendly environment.

    Science.gov (United States)

    Wu, Xiaoling; Ge, Jun; Yang, Cheng; Hou, Miao; Liu, Zheng

    2015-09-07

    The one-step and facile synthesis of multi-enzyme-containing metal-organic framework (MOF) nanocrystals in aqueous solution at 25 °C was reported in this study. The GOx&HRP/ZIF-8 nanocomposite displayed high catalytic efficiency, high selectivity and enhanced stability due to the protecting effect of the framework.

  5. Decrease in air pollution load in urban environment of Bratislava (Slovakia) inferred from accumulation of metal elements in lichens.

    Science.gov (United States)

    Guttová, Anna; Lackovičová, Anna; Pišút, Ivan; Pišút, Peter

    2011-11-01

    The study illustrates the response of epiphytic lichens to changing atmospheric conditions in Central Europe, where the emission of air pollutants has significantly decreased from 1990, in the area in and around Bratislava City. Variation in concentrations of seven metal elements (Cu, Cd, Cr, Mn, Ni, Pb and Zn) in the thalli of Evernia prunastri, Hypogymnia physodes and Parmelia sulcata is assessed. Samples of these species were exposed in lichen bags in 39 sites throughout the territory of the city (more than 300 km(2)) during the period December 2006-February 2007. The samples were analyzed by AAS for metal element contents prior to and after exposure. The decrease in air pollution (for all studied elements by more than 90%) corresponded to a decrease in the accumulation of elements in lichen thalli, e.g. the contents of Pb decreased by 69% and of Cd by 34% on average. The results show also variations in accumulation between with different lichen species. The background values of metal element contents in thalli of H. physodes growing in situ were measured in semi-natural sites in Slovakia. It is suggested that these can be used as a reference in large-scale monitoring studies in Central Europe. Analysis of compatible data from the current study, and the study performed at the end of 1990s shows a significant decrease of metal elements in the air pollution load.

  6. Secondary sulfate minerals associated with acid drainage in the eastern US: Recycling of metals and acidity in surficial environments

    Science.gov (United States)

    Hammarstrom, J.M.; Seal, R.R.; Meier, A.L.; Kornfeld, J.M.

    2005-01-01

    Weathering of metal-sulfide minerals produces suites of variably soluble efflorescent sulfate salts at a number of localities in the eastern United States. The salts, which are present on mine wastes, tailings piles, and outcrops, include minerals that incorporate heavy metals in solid solution, primarily the highly soluble members of the melanterite, rozenite, epsomite, halotrichite, and copiapite groups. The minerals were identified by a combination of powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron-microprobe. Base-metal salts are rare at these localities, and Cu, Zn, and Co are commonly sequestered as solid solutions within Fe- and Fe-Al sulfate minerals. Salt dissolution affects the surface-water chemistry at abandoned mines that exploited the massive sulfide deposits in the Vermont copper belt, the Mineral district of central Virginia, the Copper Basin (Ducktown) mining district of Tennessee, and where sulfide-bearing metamorphic rocks undisturbed by mining are exposed in Great Smoky Mountains National Park in North Carolina and Tennessee. Dissolution experiments on composite salt samples from three minesites and two outcrops of metamorphic rock showed that, in all cases, the pH of the leachates rapidly declined from 6.9 to 30 mg L-1), Fe (>47 mg L-1), sulfate (>1000 mg L-1), and base metals (>1000 mg L-1 for minesites, and 2 mg L-1 for other sites). Geochemical modeling of surface waters, mine-waste leachates, and salt leachates using PHREEQC software predicted saturation in the observed ochre minerals, but significant concentration by evaporation would be needed to reach saturation in most of the sulfate salts. Periodic surface-water monitoring at Vermont minesites indicated peak annual metal loads during spring runoff. At the Virginia site, where no winter-long snowpack develops, metal loads were highest during summer months when salts were dissolved periodically by rainstorms following sustained evaporation during dry

  7. Techniques for assessing the performance of in situ bioreduction and immobilization of metals and radionuclides in contaminated subsurface environments

    Energy Technology Data Exchange (ETDEWEB)

    Jardine, P.M.; Watson, D.B.; Blake, D.A.; Beard, L.P.; Brooks, S.C.; Carley, J.M.; Criddle, C.S.; Doll, W.E.; Fields, M.W.; Fendorf, S.E.; Geesey, G.G.; Ginder-Vogel, M.; Hubbard, S.S.; Istok, J.D.; Kelly, S.; Kemner, K.M.; Peacock, A.D.; Spalding, B.P.; White, D.C.; Wolf, A.; Wu, W.; Zhou, J.

    2004-11-14

    Department of Energy (DOE) facilities within the weapons complex face a daunting challenge of remediating huge below inventories of legacy radioactive and toxic metal waste. More often than not, the scope of the problem is massive, particularly in the high recharge, humid regions east of the Mississippi river, where the off-site migration of contaminants continues to plague soil water, groundwater, and surface water sources. As of 2002, contaminated sites are closing rapidly and many remediation strategies have chosen to leave contaminants in-place. In situ barriers, surface caps, and bioremediation are often the remedial strategies of chose. By choosing to leave contaminants in-place, we must accept the fact that the contaminants will continue to interact with subsurface and surface media. Contaminant interactions with the geosphere are complex and investigating long term changes and interactive processes is imperative to verifying risks. We must be able to understand the consequences of our action or inaction. The focus of this manuscript is to describe recent technical developments for assessing the performance of in situ bioremediation and immobilization of subsurface metals and radionuclides. Research within DOE's NABIR and EMSP programs has been investigating the possibility of using subsurface microorganisms to convert redox sensitive toxic metals and radionuclides (e.g. Cr, U, Tc, Co) into a less soluble, less mobile forms. Much of the research is motivated by the likelihood that subsurface metal-reducing bacteria can be stimulated to effectively alter the redox state of metals and radionuclides so that they are immobilized in situ for long time periods. The approach is difficult, however, since subsurface media and waste constituents are complex with competing electron acceptors and hydrogeological conditions making biostimulation a challenge. Performance assessment of in situ biostimulation strategies is also difficult and typically requires detailed

  8. Experiences of homosexual patients’ access to primary health care services in Umlazi, KwaZulu-Natal

    Directory of Open Access Journals (Sweden)

    Nokulunga H. Cele

    2015-07-01

    Full Text Available Background: Homosexual patients are affected by social factors in their environment, and as a result may not have easy access to existing health care services. Prejudice against homosexuality and homosexual patients remains a barrier to them seeking appropriate healthcare. The concern is that lesbians and gays might delay or avoid seeking health care when they need it because of past discrimination or perceived homophobia within the health care thereby putting their health at risk.Aim of the study: The aim of the study was to explore and describe the experiences of homosexual patients utilising primary health care (PHC services in Umlazi in the province ofKwaZulu-Natal (KZN.Method: A qualitative, exploratory, descriptive study was conducted which was contextual innature. Semi-structured interviews were conducted with 12 participants. The findings of this study were analysed using content analysis.Results: Two major themes emerged from the data analysis, namely, prejudice against homosexual patients by health care providers and other patients at the primary health care facilities, and, homophobic behaviour from primary health care personnel.Conclusion: Participants experienced prejudice and homophobic behaviour in the course of utilising PHC clinics in Umlazi, which created a barrier to their utilisation of health services located there. Nursing education institutions, in collaboration with the National Department of Health, should introduce homosexuality and anti-homophobia education programmes during the pre-service and in-service education period. Such programmes will help to familiarise health care providers with the health care needs of homosexual patients and may decrease homophobic attitudes.

  9. Specific features of insulator-metal transitions under high pressure in crystals with spin crossovers of 3 d ions in tetrahedral environment

    Science.gov (United States)

    Lobach, K. A.; Ovchinnikov, S. G.; Ovchinnikova, T. M.

    2015-01-01

    For Mott insulators with tetrahedral environment, the effective Hubbard parameter U eff is obtained as a function of pressure. This function is not universal. For crystals with d 5 configuration, the spin crossover suppresses electron correlations, while for d 4 configurations, the parameter U eff increases after a spin crossover. For d 2 and d 7 configurations, U eff increases with pressure in the high-spin (HS) state and is saturated after the spin crossover. Characteristic features of the insulator-metal transition are considered as pressure increases; it is shown that there may exist cascades of several transitions for various configurations.

  10. Gastro-intestinal parasites of the Samango monkey, Cercopithecus mitis, in Natal, South Africa.

    Science.gov (United States)

    Appleton, C C; Krecek, R C; Verster, A; Bruorton, M R; Lawes, M J

    1994-01-01

    Eight gastro-intestinal tracts of Cercopithecus mitis labiatus from Karkloof, Natal, and 121 fecal samples from C. m. erythrarchus from Cape Vidal, Natal, were examined for helminth parasites and/or their eggs. Fecal samples from six of the C. m. labiatus were examined for protozoan cysts. Five protozoon and six helminth species were identified from C. m labiatus. Most adult worms occurred in the caecum and colon, gut regions which also contained the highest volatile fatty acid levels. The eggs of nine helminth species were recovered from C. m. erythrarchus fecal samples; protozoans were not looked for in these samples.

  11. Brucella melitensis biotype 1 outbreak in goats in northern KwaZulu-Natal.

    Science.gov (United States)

    Reichel, R; Nel, J R; Emslie, R; Bishop, G C

    1996-06-01

    Brucella melitensis biotype 1 was confirmed in indigenous, outbred goats in three northern districts of the KwaZulu-Natal province following the diagnosis of human Malta fever in the same area. Six foci of infection were found during an extensive serological survey involving 6266 goats carried out in most of the districts of the KwaZulu-Natal province. The prevalence in the positive herds varied between 17% and 100%. The diagnosis was confirmed by culturing milk samples from serologically positive animals. Infected goats were found in only three districts (Ubombo, Ingwavuma and Pongola) and all infected herds fell within a 50-km radius.

  12. Exposure assessment of metal-based nanoparticles in aquatic environments: interactive influence of water chemistry and nanopaticle characteristics

    CSIR Research Space (South Africa)

    Thwala, Melusi

    2014-09-01

    Full Text Available in aquatic environments: interactive influence of water chemistry and nanopaticle characteristics Thwala M; Radebe N; Tancu Y and Musee N Abstract Transformation and bioavailability information of engineered nanoparticles (ENPs) in environmental...

  13. Ergonomics and environmental sustainability: a case study of raft fisherman activity at Ponta Negra Beach, Natal-RN.

    Science.gov (United States)

    Celestino, Joyce Elanne Mateus; Bispo, Cristina de Souza; Saldanha, Maria Christine Werba; Mattos, Karen Maria da Costa

    2012-01-01

    This paper aims to present the significance of methods used by the Ergonomic Analysis of Work for the construction of the scenario of craft fishing with rafts, held by 42 fishermen on the beach of Ponta Negra, Natal - RN; and relate the knowledge in ergonomics to environmental aspects / impacts, aiming the sustainability in this activity. This research is characterized as a case study, of the descriptive and exploratory type and of applied nature. To collect data, we used observational methods, in order to expand information about the activity, and interaction, as conversational action and photographic/videos records to clarify points not covered by observation. It was observed problematic as the reduction of fishing productivity, alterations of the sea, difficulty in docking the rafts, and inadequate waste disposal, noting that this activity needs care regarding the use of the environment. The obtained results contributed to the organization of environmental education workshops, seeking to enhance good individual / collective environmental practices focused on the sustainability of the environment in which they live. Add the need for proposals aimed for managing the activity, involving fishermen, institutions and society, to ensure the improvement of the environment, hence the quality of life of the population.

  14. Decoding Metal Associations in an Arid Urban Environment with Active and Legacy Mining: the Case of Copiapó, Chile

    Science.gov (United States)

    Pasten, P.; Moya, P.; Coquery, M.; Bonilla, C. A.; Vega, A.; Carkovic, A.; Calcagni, M.

    2015-12-01

    The urban and periurban area of Copiapó in the arid Atacama desert has more than 30 abandoned mine tailings, one active copper smelter, and 150,000 inhabitants. Fast development of the mining industry during the 19th century and unplanned growth has led to public concern about the presence of metals in soils and street dust. Recent floods and mud currents in the Copiapó watershed have introduced new solid material in about 40% of the urban area. We conducted a geochemical screening before and after the disaster in March 2015. We found concentrations as high as 1000 mg/kg of copper and 180 mg/kg of arsenic in urban soils. Since effective control measures require connecting sites of metal enrichment with the possible sources, we have performed a statistical analysis of metal association and complemented it with other analyses like x-ray diffraction. Cluster analyses of elemental compositions suggest that mud and tailing have different origins from the rest of the matrices, while soils and street dust have a similar one. Some clusters have a mix of matrices that suggest anthropogenic enrichment of some areas of Copiapó. Our initial results indicate that a correlation between observed enrichment and the copper smelter can be hypothesized for Cu, Pb, and Zn. Further spatial, statistical, and chemical analyses are needed to further confirm such findings, complemented with a thorough analysis of the baseline values that could be considered representative of the area. Future work include Principal Component Analysis (PCA) and Positive matrix factorization (PMF) to test the link contaminant sources and metal occurrence, while scanning electron microscopy can be used to identify the presence of smelter-related particles. The information generated by this research will be a necessary input for defining urban planning strategies and land use guidelines, defining health risk assessment studies, and for future evaluation of intervention priorities. Acknowledgements: Proyecto

  15. Heavy Metal Contamination in Urban Soils I Zinc Accumulation Phenomenon in Urban Environments as Clues of Study

    OpenAIRE

    Komai, Yutaka

    1981-01-01

    As an introduction of the continuing study on the heavy metal contamination in urban soils, zinc accumulation phenomenon observed in urban areas in south Osaka was reported. The survey of zinc concentration in soybean leaves taken in urban and suburban arable lands indicated its accumulation in a wide area. And a correlation between easy soluble zinc level in soils and leaf zinc content were shown. Zinc concentrations in suspended particles in air, falling dust and some water samples were che...

  16. P-N junction and metal contact reliability of SiC diode in high temperature (873 K) environment

    Science.gov (United States)

    Chand, R.; Esashi, M.; Tanaka, S.

    2014-04-01

    This paper reports the high temperature test results of SiC p-n junction diode up to 873 K. No significant change in diode series resistance (Rs) and a diode ideality factor of 1.02 were confirmed in air. We used the 4H-SiC diode which had a contact pad area of 300 μm × 300 μm and a junction area of 220 μm × 220 μm. Ohmic contact on both p and n (i.e. front and back) sides were made by Ni, because nickel silicide (NiSi) provides good ohmic contact for high temperature applications. The electrical contact pads of the SiC diode were made by sputter-depositing Ni or Pt on the NiSi ohmic contact. High temperature aging tests at 673 K, 773 K and 873 K were carried out in air, and the forward current-voltage (I-V) characteristics of the SiC diodes were measured at different time intervals to observe change in the junction and series resistance. Stable p-n junction characteristic and constant series resistance were confirmed for the Pt-metalized diodes at 673 K, 773 K and 873 K. However, the Ni-metallized diodes showed marginal increase in series resistance due to the oxidation of Ni metal contacts.

  17. Odonata larvae as a bioindicator of metal contamination in aquatic environments: application to ecologically important wetlands in Iran.

    Science.gov (United States)

    Nasirian, Hassan; Irvine, K N

    2017-09-01

    The objectives of this study were twofold: (i) assess the bioaccumulation characteristics of a suite of metals associated with several different species of Odonata and (ii) examine Odonata species richness as a reflection of ecosystem health in two ecologically important wetlands of southwestern Iran, the Shadegan and Hawr Al Azim wetlands. Levels of arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), mercury (Hg), manganese (Mn), lead (Pb), and zinc (Zn) were determined using inductively coupled plasma optical emission spectrometry (ICP-OES) in nine different Odonata larva species. Based on these data, biota-sediment accumulation factors (BSAFs) were calculated and generally, it was found that Cr, Cu, Mn, and Zn were being taken up by the Odonata (BSAFs >1). Because of its prevalence in the wetland and its observed ability to take up metals, it is suggested that Ischnura ramburii is an appropriate indicator of ecosystem health for these wetlands with respect to metal contamination. Odonata species richness across all sites was 49, while for the individual sites, the greatest species richness was 26 and the lowest species richness was 13. The species richness value across all sites is quite healthy, given the arid climate of the region.

  18. Basic research on interactions of heavy metals with pharmaceutical substances with relevance to the environment and residual toxicology

    Energy Technology Data Exchange (ETDEWEB)

    Gaede, W.; Kuehnert, M.

    1986-01-01

    Studies were conducted into interactions between long-time exposure of rats to subtoxic doses of lead and copper and humic acids orally applied to them in parallel. Tests were based on established activities of erythrocytic delta-aminolaevulinic acid dehydratase and on the length of hexobarbital-induced sleep. Also investigated were the effects of heavy metal on the blood level of a sulphonamide (sulphaclomide). Lead and copper interactions under the impact of pharmaceutical substances (humic acids and sulphaclomide) produced affirmative evidence to the well-known depression of activity of delta-aminolaevulinic acid dehydratase. There was also a high probability that cytochrome-P-450 had been induced by lead and copper and, perhaps, by humic acids, as well. Enteral absorption of sulphaclomide was clearly affected by protein-denaturing and permeability-reducing action of heavy metals on the gastro-intestinal mucosa. That locally delimited action of lead and copper was widely offset under the impact of humic acids, and sulphaclomide levels in the blood were renormalised. The above findings are likely to suggest that in the context of environmental toxicology long-time exposure of warm-blooded animals to heavy metals may impair the therapeutic effectiveness of pharmaceuticals (sulphaclomide in this case).

  19. X-ray fluorescence spectrometry used to assess the dispersion of metals within mining environments; Aplicacion de la tecnica de espectrometria de fluorescencia de rayos-X en el estudio de la dispersion de metales en areas mineras

    Energy Technology Data Exchange (ETDEWEB)

    Margui, E.; Gonzalez-Fernandez, O.; Hidalgo, M.; Pardini, G.; Queralt, I.

    2011-07-01

    One critical factor for success in characterizing metals polluting mining environments so as to be able to eliminate them and subsequently recover these areas depends upon a speedy and correct response in the analysis of samples. Rapid, simultaneous, multi-element analysis can be undertaken using X-ray fluorescence spectrometry, a versatile, non-destructive analytical technique commonly employed to identify both major and minor elements in samples related to environmental studies. An additional advantage of this technique is the possibility of conducting the analysis directly on solid samples, which is extremely convenient when dealing with environmental samples that are difficult to dissolve, such as soils, sediments and mining wastes. Moreover, in recent years the development of spectrometers equipped with digital-signal processors combined with enlarged X-ray production, using better designs for excitation-detection, has contributed to an improvement in instrumental sensitivity, thus allowing us to detect important polluting elements such as Cd and Pb at trace levels. In this paper the authors describe, on the basis of their own experience, some interesting applications of XRF spectrometry for the analysis of several types of environmental samples related to the study of the dispersion of metals within mining environments: (A) analysis of mining wastes, soils and sediments; (B) analysis of samples of vegetation used as bio indicators or related to phyto remediation studies; and (C) analysis of water samples related to mining operations. (Author) 26 refs.

  20. Role of the pre- and post-natal environment in developmental programming of health and productivity.

    Science.gov (United States)

    Reynolds, Lawrence P; Caton, Joel S

    2012-05-06

    The concept that developmental insults (for example, poor pre- or postnatal nutrition) can have long-term consequences on health and well-being of the offspring has been termed developmental programming. In livestock, developmental programming affects production traits, including growth, body composition, and reproduction. Although low birth weight was used as a proxy for compromised fetal development in the initial epidemiological studies, based on controlled studies using livestock and other animal models in the last two decades we now know that developmental programming can occur independently of any effects on birth weight. Studies in humans, rodents, and livestock also have confirmed the critical role of the placenta in developmental programming. In addition, the central role of epigenetic regulation in developmental programming has been confirmed. Lastly, relatively simple therapeutic/management strategies designed to 'rescue' placental development and function are being developed to minimize the effects of developmental programming on health and productivity of humans, livestock, and other mammals.

  1. Relationships between the diversity of animal communities and the lighting environment and content of heavy metals in soils in Guizhou Zhijin Cave

    Directory of Open Access Journals (Sweden)

    Chengxiang Xu

    2013-01-01

    Full Text Available We investigated the community diversity of cave animals in different light zones of the Guizhou Zhijin Cave in August, 2011. We used principal components analysis (PCA to examine the relationships between animal community diversity and environment factors. We assessed the potential ecological risk degree of heavy metals in the cave based on the Hakanson potential ecological risk index. We identified 1,080 specimens, which belong to three phyla, five classes, 26 families and 41 species or groups of species, which could be divided into five communities. The highest community diversity, richness index, evenness index, and dominance index were light zone of exit (2.7996, light zone of entrance (4.5399, light zone of exit(0.9196 and weak-light zone of exit (0.1868, respectively. Index of similarity between light zone of entrance and light zone of exit (0.6248 was highest. The richness and dominance indices of the communities were low, but community diversity and richness tended to decrease based on the order of the light intensity (i.e., light zone>weak-light zone>dark zone. Dominant species included Hemiphaedusa pluviatilis and H.moellendorffiana. Organic matter of soil, content of CO2 in the air, cave humidity, cave temperature, and heavy metal contamination of soil were the dominant factors to affect animal community diversity in the cave. Although Cu, Zn, Ni, Cr, As in soils were at ecologically low levels, Hg pollution was relatively high inthe whole cave and at especially severe level of ecological risk (Eri=256.000 in the light zone of cave entrance. As far as the average potential ecological risk level (RI=192.714 of six heavy metals were concerned, the cave was contaminated at a certain degree with heavy metals.

  2. THE SPITZER SPECTROSCOPIC SURVEY OF THE SMALL MAGELLANIC CLOUD (S{sup 4}MC): PROBING THE PHYSICAL STATE OF POLYCYCLIC AROMATIC HYDROCARBONS IN A LOW-METALLICITY ENVIRONMENT

    Energy Technology Data Exchange (ETDEWEB)

    Sandstrom, Karin M. [Max Planck Institut fuer Astronomie, D-69117 Heidelberg (Germany); Bolatto, Alberto D. [Department of Astronomy and Laboratory for Millimeter-wave Astronomy, University of Maryland, College Park, MD 20742 (United States); Bot, Caroline [Universite de Strasbourg, Observatoire Astronomique de Strasbourg, F-67000 Strasbourg (France); Draine, B. T. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Ingalls, James G. [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Israel, Frank P.; Tielens, A. G. G. M. [Sterrewacht Leiden, Leiden University, 2300 RA Leiden (Netherlands); Jackson, James M. [Institute for Astrophysical Research, Boston University, Boston, MA 02215 (United States); Leroy, Adam K. [National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States); Li, Aigen [Department of Physics and Astronomy, University of Missouri, Columbia, MO 65213 (United States); Rubio, Monica [Departamento de Astronomia, Universidad de Chile, Casilla 36-D, Santiago (Chile); Simon, Joshua D. [Observatories of the Carnegie Institution of Washington, Pasadena, CA 91101 (United States); Smith, J. D. T. [Ritter Astrophysical Research Center, University of Toledo, Toledo, OH 43603 (United States); Stanimirovic, Snezana [Department of Astronomy, University of Wisconsin, Madison, Madison, WI 53703 (United States); Van Loon, Jacco Th., E-mail: sandstrom@mpia.de [Astrophysics Group, Lennard-Jones Laboratories, Keele University, Staffordshire ST5 5BG (United Kingdom)

    2012-01-01

    We present results of mid-infrared spectroscopic mapping observations of six star-forming regions in the Small Magellanic Cloud (SMC) from the Spitzer Spectroscopic Survey of the SMC (S{sup 4}MC). We detect the mid-IR emission from polycyclic aromatic hydrocarbons (PAHs) in all of the mapped regions, greatly increasing the range of environments where PAHs have been spectroscopically detected in the SMC. We investigate the variations of the mid-IR bands in each region and compare our results to studies of the PAH bands in the SINGS sample and in a sample of low-metallicity starburst galaxies. PAH emission in the SMC is characterized by low ratios of the 6-9 {mu}m features relative to the 11.3 {mu}m feature and weak 8.6 and 17.0 {mu}m features. Interpreting these band ratios in the light of laboratory and theoretical studies, we find that PAHs in the SMC tend to be smaller and less ionized than those in higher metallicity galaxies. Based on studies of PAH destruction, we argue that a size distribution shifted toward smaller PAHs cannot be the result of processing in the interstellar medium, but instead reflects differences in the formation of PAHs at low metallicity. Finally, we discuss the implications of our observations for our understanding of the PAH life-cycle in low-metallicity galaxies-namely that the observed deficit of PAHs may be a consequence of PAHs forming with smaller average sizes and therefore being more susceptible to destruction under typical interstellar medium conditions.

  3. Metal-rich Scales in the Reykjanes Geothermal System, SW Iceland: Sulfide Minerals in a Seawater-dominated Hydrothermal Environment

    Science.gov (United States)

    Hardardottir, Vigdis

    Downhole sampling of unboiled liquid at 1350 and 1500 m depth in the seawater-dominated Reykjanes high-temperature geothermal system in Iceland shows that metal concentrations measured at surface are minimum values due to mineral precipitation in the wells; by analogy of similar tectonic setting, host rocks and fluid composition, the metal concentrations measured in many black smoker vents at the seafloor are also minima. Fluids in the Reykjanes geothermal system react with mid-ocean ridge basalt at temperatures as high as 346°C and contain Fe 9-140 ppm, Cu 14-17 ppm, Zn 5-27 ppm, Pb 120-290 ppb, 1-6 ppb Au, and 28-107 ppb Ag. Fluids discharged at surface from the same wells have orders of magnitude lower metal concentrations due to precipitation caused by boiling and vapor loss during depressurization. Upstream of the orifice plate at high pressure (40 bar, 252°C) the precipitates consist mainly of sphalerite and chalcopyrite with a trace of galena and bornite. At the orifice plate of old wells, the pressure decreased sharply to 11 bar (188°C), resulting in abundant deposition of amorphous silica together with minor sphalerite and traces of chalcopyrite. In new wells the pressure at the orifice plate decreases to 22 bar (220°C); this pressure decrease and concomitant boiling causes deposition of fine-grained bornite-digenite solid solution together with sphalerite and galena on the fluid flow control valve. In high-pressure wells (average wellhead pressure 45-35 bar) most metals (mainly as sphalerite) are deposited downstream of the orifice plate, with up to 950 ppm Au and 2.5 wt.% Ag. Bulk concentrations in the scales vary between 15-60 wt.% upstream and downstream of the orifice plate and diminish from there. Iron increases up well from 8 to ˜20 wt.% and decreases downstream of the orifice plate from 6 to 2 wt.% at the separation station; Cu downhole is ˜3 wt.% but increases to 25 wt.% on the fluid flow control valve and then decreases; Pb downhole 100s

  4. Distribution and Risk Assessment of Heavy Metals in Surface Water from Pristine Environments and Major Mining Areas in Ghana

    Directory of Open Access Journals (Sweden)

    George Yaw Hadzi

    2015-01-01

    Conclusions. The concentrations of heavy metals in the Nyam, Subri, Bonsa and Birim Rivers from the mining sites and the Atiwa Range, Oda, Ankasa and Bosomkese Rivers from the pristine sites were found to be either below or within the USEPA and WHO's recommended limits for surface water. The health risk assessment values for the hazard quotient for ingestion of water (HQing, dermal contact (HQderm and chronic daily intake (CDI indicated no adverse effects as a result of ingestion or dermal contact from the rivers. However, arsenic (As in both the pristine and mining sites and chromium (Cr in the pristine sites pose a carcinogenic threat to the local residents.

  5. The Barefoot Teacher on the Telematic Highway--Serving Rural Communities in Kwa Zulu Natal.

    Science.gov (United States)

    Fregona, Charl; Harris, Maureen; Kruger, Johann

    The Department of Community Nursing and the Open Learning Centre of Technikon Natal (South Africa) and the community-owned Community Development Programme are collaborating to provide online learning to rural and urban community nurses. The project involves the development of a multimedia pharmacology course, a virtual Internet class, and the…

  6. Sex biased natal dispersal is not a fixed trait in a stable population of Seychelles warblers

    NARCIS (Netherlands)

    Eikenaar, Cas; Brouwer, Lyanne; Komdeur, Jan; Richardson, David S.

    2010-01-01

    We observed a change in the sex-specific rate of delayed natal dispersal in a stable population of Seychelles warblers over a period of 20 years. At first, females were more likely to delay dispersal in their first year of life than were males, whereas later there was no sex bias in the rate of dela

  7. Sex biased natal dispersal is not a fixed trait in a stable population of Seychelles warblers

    NARCIS (Netherlands)

    Eikenaar, Cas; Brouwer, Lyanne; Komdeur, Jan; Richardson, David S.

    2010-01-01

    We observed a change in the sex-specific rate of delayed natal dispersal in a stable population of Seychelles warblers over a period of 20 years. At first, females were more likely to delay dispersal in their first year of life than were males, whereas later there was no sex bias in the rate of

  8. Mercury concentrations at a historically mercury-contaminated site in KwaZulu-Natal, South Africa

    CSIR Research Space (South Africa)

    Williams, CR

    2011-02-01

    Full Text Available A mercury (Hg) processing plant previously operating in KwaZulu-Natal Province (South Africa) discharged Hg waste into a nearby river system causing widespread contamination since the 1980s. Although the processing plant ceased operation in the 1990...

  9. Virtual Visit to the ATLAS Control Room by University of Kwazulu-Natal

    CERN Multimedia

    2013-01-01

    The University of KwaZulu-Natal (UKZN) was formed on 1st January 2004 as a result of the merger between the University of Durban-Westville and the University of Natal. During the "Be a Scientist for a Week" program high school learners in their final two years of school will have the opportunity to spend a week at either the Westville, or Pietermaritzburg campus of the University of Kwazulu-Natal. The Westville campus will host approximately 30 students who were the top achievers in mathematics and science from the 20 feeder schools to the university. Within the physics department students will follow the masterclasses progam where they will be given an introduction to particle physics, the LHC and the ATLAS Experiment, before having the chance to analyse real LHC data. Their session will end with the virtual visit to the ACR. - See more at: http://atlas-live-virtual-visit.web.cern.ch/atlas-live-virtual-visit/2013/Kwazulu-Natal-2013.html

  10. Early meiotic-specific protein expression in post-natal rat ovaries.

    Science.gov (United States)

    Zhang, P; Lv, L X; Xing, W J

    2010-12-01

    Recent studies in mice challenged the basic doctrine that most mammalian females lose neo-oogenesis in post-natal ovaries. In order to provide more information in other species, we examined post-natal rat ovaries by histological sections and detected the germline cell marker protein RVLG (rat vasa-like gene), BrdU (5-bromodeoxyuridine) incorporation in RVLG-expressing cells, for identification of germline cells undergoing mitosis and meiosis in the ovarian surface epithelium (OSE). We also detected the expression of early meiotic-specific proteins disruption of meiotic control 1 (DMC1), stimulated by retinoic acid gene 8 (STRA8) and synaptonemal complex protein 3 (SCP3) by immunohistochemical analysis and Western blotting, and the transcript of SCP1, SCP3 and Sporulation-specific protein 11 (SPO11) by RT-PCR in the post-natal ovarian cortex. However we failed in detecting large ovoid cells in the OSE, which may represent the putative germline stem cells (GSCs) that are supposed to sustain neo-oogenesis, and the transcription of the meiotic-specific genes SCP1, SCP3 and SPO11 by RT-PCR as well as the translation of DMC1, STRA8 and SCP3 by Western blotting. Our data support the postulation that there is no neo-oogenesis occurring in the OSE of rat post-natal ovary through meiosis of GSCs.

  11. Riga-Fede Disease Associated with Natal Teeth: Two Different Approaches in the Same Case

    Directory of Open Access Journals (Sweden)

    Luiz Evaristo Ricci Volpato

    2015-01-01

    Full Text Available Natal teeth are those present in the oral cavity at the child’s birth. These teeth can cause ulcers on the ventral surface of the tongue, lip, and the mother’s breast characterizing the Riga-Fede Disease. The treatment depends on the tooth’s mobility and the risk of aspiration or swallowing; whether it is supernumerary or regular primary teeth; whether it is causing interference in breastfeeding; breast and oral soft tissue injuries; and the general state of child’s health. A 1-month-old female infant was diagnosed with two natal teeth and an ulcerated lesion on the ventral surface of the tongue, leading to the clinical diagnosis of Riga-Fede Disease. The treatment performed consisted of the maintenance of the natal tooth that showed no increased mobility, adding a small increment of glass ionomer cement to its incisal edge, and orientation for hygiene with saline solution. Due to the increased mobility of the other natal tooth, surgical removal was performed. There was regular monitoring of the patient and complete wound healing was observed after 15 days. The proposed treatment was successful and the patient is still in follow-up without recurrence of the lesion after one year.

  12. Temporarily new: on low fertility and the prospect of pro-natal policies

    NARCIS (Netherlands)

    van de Kaa, D.J.

    2006-01-01

    Concern about the low levels of fertility in Europe appears to be spreading. In political circles voices advocating the design and implementation of pro-natal policies are growing louder. The traditional fear of population decline is refuelled in numerous conference papers and at meetings specifical

  13. Multi-scale analysis of soil erosion dynamics in Kwazulu-natal, South Africa

    NARCIS (Netherlands)

    Sonneveld, M.P.W.; Everson, T.M.; Veldkamp, A.

    2005-01-01

    For a case study area in the Okhombe catchment in the province of KwaZulu-Natal, South Africa, a multi-scale analysis of soil erosion dynamics was performed. At sub-catchment level, the dynamics of erosional features were investigated by means of aerial photographs. At site level, the changes in soi

  14. Mopeia Virus-related Arenavirus in Natal Multimammate Mice, Morogoro, Tanzania

    DEFF Research Database (Denmark)

    Günther, Stephan; Hoofd, Guy; Charrel, Remi

    2009-01-01

    A serosurvey involving 2,520 small mammals from Tanzania identified a hot spot of arenavirus circulation in Morogoro. Molecular screening detected a new arenavirus in Natal multimammate mice (Mastomys natalensis), Morogoro virus, related to Mopeia virus. Only a small percentage of mice carry Moro...

  15. Corona textures in Proterozoic olivine melanorites of the equeefa suite, Natal metamorphic province, South-Africa

    CSIR Research Space (South Africa)

    Grantham, GH

    1993-01-01

    Full Text Available Olivine-plagioclase and phlogopite-plagioclase coronas have been identified from olivine melanorites of the mid- to late Proterozoic Equeefa Suite in southern Natal, South Africa. Olivine, in contact with plagioclase, is mantled by a shell of clear...

  16. Juvenile Survival in Common Loons Gavia Immer: Effects of Natal Lake Size and pH

    Science.gov (United States)

    Survival is a vexing parameter to measure in many young birds because of dispersal and delayed impacts of natal rearing conditions on fitness. Drawing upon marking and resighting records from an 18-year study of territorial behavior, we used Cormack-Jolly-Seber analysis with Prog...

  17. Opportunities to Develop Mathematical Proficiency in Grade 6 Mathematics Classrooms in KwaZulu-Natal

    Science.gov (United States)

    Ally, Noor; Christiansen, Iben Maj

    2013-01-01

    In this article, we propose a rubric for assessing the teacher's provision of opportunities to develop mathematical proficiency in classrooms. The rubric is applied to data from 30 video recordings of mathematics lessons taught in Grade 6 in one district of KwaZulul-Natal. The results suggest that opportunities to develop procedural fluency…

  18. Hunger for Knowledge: Food Insecurity among Students at the University of KwaZulu-Natal

    Science.gov (United States)

    Munro, Nicholas; Quayle, Michael; Simpson, Heather; Barnsley, Shelley

    2013-01-01

    The experience of food insecurity in the South African university student population is not well documented or researched. Data to assess vulnerability to food insecurity in a sample of 1.083 students from the University of KwaZulu-Natal (Pietermaritzburg Campus) was collected between 2007 and 2010 via a questionnaire developed specifically for…

  19. Invasive alien plants in the terrestrial ecosystems of Natal, South Africa

    CSIR Research Space (South Africa)

    Macdonald, IAW

    1985-01-01

    Full Text Available This report consists of two types of chapters. Most of the chapters are short syntheses of particular aspects of the alien plant problem in Natal, written by groups of participants during the workshop meeting. They are brief accounts of the state...

  20. Exploring Teachers' Practices in Teaching Mathematics and Statistics in Kwazulu-Natal Schools

    Science.gov (United States)

    Umugiraneza, Odette; Bansilal, Sarah; North, Delia

    2017-01-01

    Teaching approaches and assessment practices are key factors that contribute to the improvement of learner outcomes. The study on which this article is based, explored the methods used by KwaZulu-Natal (KZN) teachers in teaching and assessing mathematics and statistics. An instrument containing closed and open-ended questions was distributed to…

  1. The rabbit as an animal model for post-natal vitreous matrix differentiation and degeneration

    NARCIS (Netherlands)

    Los, L. I.

    2008-01-01

    Purpose This study evaluates whether rabbits are a suitable animal model to study post-natal vitreous differentiation and degeneration. Methods Human and rabbit eyes of various ages were studied by complementary anatomical techniques, light microscopy, and transmission electron microscopy. Results T

  2. Post-natal exposure to corticosterone affects standard metabolic rate in the zebra finch (Taeniopygia guttata)

    NARCIS (Netherlands)

    Spencer, K. A.; Verhulst, S.

    2008-01-01

    Post-natal stress has been shown to have important short and long term effects on many adult traits in birds. During stress, metabolic alterations often result in the mobilization of energy away from energy-sensitive functions such as growth, which could have significant implications for developing

  3. Metabolites Associated with Adaptation of Microorganisms to an Acidophilic, Metal-Rich Environment Identified by Stable-Isotope-Enabled Metabolomics

    Science.gov (United States)

    Mosier, Annika C.; Justice, Nicholas B.; Bowen, Benjamin P.; Baran, Richard; Thomas, Brian C.; Northen, Trent R.; Banfield, Jillian F.

    2013-01-01

    ABSTRACT Microorganisms grow under a remarkable range of extreme conditions. Environmental transcriptomic and proteomic studies have highlighted metabolic pathways active in extremophilic communities. However, metabolites directly linked to their physiology are less well defined because metabolomics methods lag behind other omics technologies due to a wide range of experimental complexities often associated with the environmental matrix. We identified key metabolites associated with acidophilic and metal-tolerant microorganisms using stable isotope labeling coupled with untargeted, high-resolution mass spectrometry. We observed >3,500 metabolic features in biofilms growing in pH ~0.9 acid mine drainage solutions containing millimolar concentrations of iron, sulfate, zinc, copper, and arsenic. Stable isotope labeling improved chemical formula prediction by >50% for larger metabolites (>250 atomic mass units), many of which were unrepresented in metabolic databases and may represent novel compounds. Taurine and hydroxyectoine were identified and likely provide protection from osmotic stress in the biofilms. Community genomic, transcriptomic, and proteomic data implicate fungi in taurine metabolism. Leptospirillum group II bacteria decrease production of ectoine and hydroxyectoine as biofilms mature, suggesting that biofilm structure provides some resistance to high metal and proton concentrations. The combination of taurine, ectoine, and hydroxyectoine may also constitute a sulfur, nitrogen, and carbon currency in the communities. PMID:23481603

  4. Fraction distribution and bioavailability of sediment heavy metals in the environment surrounding MSW landfill: a case study.

    Science.gov (United States)

    Sayadi, M H; Rezaei, M R; Rezaei, A

    2015-01-01

    The aim of this study was to characterize the sediment samples from vicinity of a landfill in Qayen City, Iran. The samples were obtained from four different sampling stations. Sequential extraction was performed via a four-step procedure defined to evaluate the distribution of the element fraction in various samples. In the stations 3 and 4, Cd was found in large quantities during the first extraction F1, accounting for 40.4 and 38.7%, respectively. Pb was primarily presented in F2 of station 1 (approximately 44.80%), station 2 (approximately 41.8%), and station 4 (approximately 37.7%). Moreover, principal component analysis showed that heavy metal fraction in the sediment samples can be explained by two principal components (PCs). PC1 represented Cd, Cr, Ni, and Zn, while PC2 represented Pb and Cu. Pearson correlation coefficient indicated significant correlations in Cu-Pb, Zn-Cu, and Cr-Zn pairings. The present study concluded that the spatial distributions of sediment heavy metals were influenced by MSW landfill.

  5. Reduced survival and body size in the terrestrial isopod Porcellio scaber from a metal-polluted environment.

    Science.gov (United States)

    Jones, D T; Hopkin, S P

    1998-01-01

    Terrestrial isopods (woodlice) may show trade-offs in life history parameters when exposed to toxins. We have shown previously [Jones and Hopkin (1996) Functional Ecology 10, 741-750] that woodlice which survive to reproduce in sites heavily polluted with metals from an industrial smelting works do not alter their reproductive allocation. This study investigates whether there are differences in the survival and body size of Porcellio scaber from these same populations. Specimens were collected from eight sites at different distances from the Avonmouth smelter, UK. The sites represented a gradient of concentrations of Zn, Cd, Pb and Cu in the woodlice, from background levels to a grossly contaminated sites close to the smelter. In laboratory trials, the number of days survived by starved males showed a significant decline with increased concentrations of Zn in those animals. The maximum size of both sexes declined significantly from the least to the most polluted sites. The most polluted sites had significantly fewer large animals. The cost of detoxifying assimilated metals appears to be reduced energy reserves and smaller body size.

  6. Submillimeter Line Emission from LMC 30Dor: The Impact of a Starburst on a Low Metallicity Environment

    CERN Document Server

    Pineda, Jorge L; Roellig, Markus; Stutzki, Juergen; Kramer, Carsten; Klein, Ulrich; Rubio, Monica

    2012-01-01

    (Abridged) The 30 Dor region in the Large Magellanic Cloud (LMC) is the most vigorous star-forming region in the Local Group. Star formation in this region is taking place in low-metallicity molecular gas which is exposed to an extreme far--ultraviolet (FUV) radiation field powered by the massive compact star cluster R136. We used the NANTEN2 telescope to obtain high-angular resolution observations of the 12CO 4-3, 7-6, and 13CO 4-3 rotational lines and [CI] 3P1-3P0 and 3P2-3P1 fine-structure sub-millimeter transitions in 30Dor-10, the brightest CO and FIR-emitting cloud at the center of the 30Dor region. We derive the properties of the low-metallicity molecular gas using an excitation/radiative transfer code and find a self-consistent solution of the chemistry and thermal balance of the gas in the framework of a clumpy cloud PDR model. We compare the derived properties with those in the N159W region, which is exposed to a more moderate far-ultraviolet radiation field compared with 30Dor-10, but has similar m...

  7. Evidence for geomagnetic imprinting and magnetic navigation in the natal homing of sea turtles.

    Science.gov (United States)

    Brothers, J Roger; Lohmann, Kenneth J

    2015-02-02

    Natal homing is a pattern of behavior in which animals migrate away from their geographic area of origin and then return to reproduce in the same location where they began life [1-3]. Although diverse long-distance migrants accomplish natal homing [1-8], little is known about how they do so. The enigma is epitomized by loggerhead sea turtles (Caretta caretta), which leave their home beaches as hatchlings and migrate across entire ocean basins before returning to nest in the same coastal area where they originated [9, 10]. One hypothesis is that turtles imprint on the unique geomagnetic signature of their natal area and use this information to return [1]. Because Earth's field changes over time, geomagnetic imprinting should cause turtles to change their nesting locations as magnetic signatures drift slightly along coastlines. To investigate, we analyzed a 19-year database of loggerhead nesting sites in the largest sea turtle rookery in North America. Here we report a strong association between the spatial distribution of turtle nests and subtle changes in Earth's magnetic field. Nesting density increased significantly in coastal areas where magnetic signatures of adjacent beach locations converged over time, whereas nesting density decreased in places where magnetic signatures diverged. These findings confirm central predictions of the geomagnetic imprinting hypothesis and provide strong evidence that such imprinting plays an important role in natal homing in sea turtles. The results give credence to initial reports of geomagnetic imprinting in salmon [11, 12] and suggest that similar mechanisms might underlie long-distance natal homing in diverse animals.

  8. Splashing phenomena of room temperature liquid metal droplet striking on the pool of the same liquid under ambient air environment

    CERN Document Server

    Li, Haiyan; Wang, Lei; Gao, Yunxia; Liu, Jing

    2013-01-01

    In this article, the fluid dynamics of room temperature liquid metal (RTLM) droplet impacting onto a pool of the same liquid in ambient air was investigated. A series of experiments were conducted in order to disclose the influence of the oxidation effect on the impact dynamics. The droplet shape and impact phenomenology were recorded with the aid of a high-speed digital camera. The impact energy stored in the splash structures was estimated via a theoretical model and several morphological parameters obtained from instantaneous images of the splash. It was observed that the droplet shape and the splashing morphology of RTLM were drastically different from those of water, so was the impact dynamics between room temperature LM pool and high temperature LM pool. The energy analysis disclosed that the height of the jet is highly sensitive to the viscosity of the fluid, which is subjected to the oxidation effect and temperature effect simultaneously, and thus perfectly explained the phenomena. These basic finding...

  9. Simultaneous determination of silver and other heavy metals in aquatic environment receiving wastewater from industrial area, applying an enrichment method

    Directory of Open Access Journals (Sweden)

    Naeemullah

    2016-01-01

    Full Text Available In the present study, silver (Ag, cadmium (Cd, nickel (Ni, cobalt (Co and lead (Pb were simultaneously determined in water samples of fresh water canal receiving untreated effluents from an industrial area, of Sindh Pakistan. The analytes in the water sample were determined by CPE using ammonium pyrrolidinedithiocarbamate (APDC as a complexing agent and then entrapped in non-ionic surfactant, octylphenoxypolyethoxyethanol (Triton X-114. The surfactant rich phase was diluted with acidic ethanol prior to analysis by flame atomic absorption spectrometry. The variables affecting the complexation and extraction steps such as pH of sample solution, concentration of oxine and Triton X-114, equilibration temperature and time period for shaking were investigated in detail. The validation of the procedure was carried out by analysis of a certified reference sample of water (CRM1634e. Reliability of the proposed method was also checked by the standard addition method in a real sample at three concentration levels of all metals. Under the optimum conditions, the preconcentration of 10 mL sample solutions, allowed preconcentration factor of 20-fold. The lower limit of detection obtained for Ag, Cd, Ni, Co and Pb was 0.42, 0.48, 0.92, 0.62, and 1.42 μg L−1, respectively. The proposed procedure was successfully applied to waste and fresh water samples for simultaneous determination of different metals. The concentration of Ag, Cd, Ni, Co and Pb has shown a decreased trend from 46.5–6.96, 23.0–8.92, 30.2–12.8, 14.2–4.45 and 15.3–5.32 μg L−1, respectively from initial entrance of waste water along the downstream of canal.

  10. INFECTIONS OF URIC SYSTEM OF NEWBORNS: PECULIARITIES OF URINE DYNAMICS IN LOWER URINARY TRACTS DURING PRE-NATAL DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    L.K. Vasilevich

    2008-09-01

    Full Text Available For the purpose of revealing pre-natal urine dynamics preconditions ofdevelopment ofan infection ofurinary system atnewborns, feature urine dynamics functions of 101 fetus have been studied. Studying urine dynamics indicators of upper and lower urinary tracts of a fetus was carried out with the help of pre-natal ultrasonic cystometry process of filling and clearing the urinary bladder. It is established, that preconditions to development of urinary system infection in newborns are changes of urinary bladder capacity, frequency and speed of urination pre-natal developments.

  11. Influence of accumulation of heaps of steel slag on the environment: determination of heavy metals content in the soils

    Directory of Open Access Journals (Sweden)

    Javier Garcia-Guinea

    2010-06-01

    Full Text Available The presence of high level of heavy metals involves a human healthy risk that could induce chronic diseases. This work reports on the metal contamination due to heaps of steel-slag accumulated during more than 40 years in allotments and industrial areas in the southern part of Madrid (Spain. Several slag and soil samples were collected in an area of 10 km² and characterized by different conventional (XRD and XRF and no so common methods (ESEM, thermoluminescence and EDS-WDS. The analysis reveal the presence of: (i important amounts of Fe (43%, Mg (26%, Cr (1.1%, Mn (4.6%, S (6.5% in the form of Fe-rich slag phases (wustite, magnetite..., Si and Ca-rich phases (larnite, ghelenite..., Cr (chromite, Mn (bustamite and graphite, (ii traces of some other contaminants such as Cr (7700 ppm, Zn (3500 ppm, Ba (3000 ppm, Pb (700 ppm or Cu (500 ppm on pathway soil samples that come from the steel slag, and (iii Co (13 ppm, Pb (78 ppm and V (54 ppm in farmland soil samples. Although the existing heavy metals content is not appropriate for the current use, the extremely high metal contamination of the surrounding areas is more worrying. The properties of the soil farmlands (pH circa 7, 13% of clay, mainly illite, and 1-4% of organic matter content show suitable conditions for the retention of cationic metals, but further studies on the movilization of these elements have to be performed to determine the possibility of severe human health risks. This sort of study can provide useful information for the politicians regarding the appropriate use of the territory to prevent possible health hazard for the population.A presença de altos niveis de metais pesados envolve riscos à saúde humana e pode induzir doenças crônicas. Este trabalho relata a contaminação metálica causada por pilhas de escória siderúrgica acumulada durante mais de 40 anos em áreas industriais na parte sul de Madrid (Espanha. Amostras de escória e solo foram coletadas em uma área de

  12. Corrosion behavior of Fe-Si metallic coatings added with NiCrAlY in an environment of fuel oil ashes at 700 C

    Energy Technology Data Exchange (ETDEWEB)

    Salinas-Bravo, V.M.; Porcayo-Calderon, J.; Romero-Castanon, T. [Instituto de Investigaciones Electricas, Gerencia de Procesos Termicos., Av. Reforma 113, C.P. 62490 Col. Palmira. Temixco. Morelos (Mexico); Dominguez-Patino, G.; Gonzalez-Rodriguez, J.G. [U.A.E.M. Centro de Investigaciones en Ingenieria y Ciencias Aplicadas., Av. Universidad 1001, C.P. 62210, Col. Chamilpa. Cuernavaca, Morelos (Mexico)

    2005-07-01

    Electrochemical potentiodynamic polarization curves and immersion tests for 300 h at 700 C in a furnace have been used to evaluate the corrosion resistance of Fe-Si metallic coatings added with up to 50 wt.% of NiCrAIY. The corrosive environment was fuel oil ashes from a steam generator. The composition of fuel oil ashes includes high content of vanadium, sodium and sulfur. The results obtained show that only the addition of 20 wt.% NiCrAlY to the Fe-Si coating improves its corrosion resistance. The behavior of all tested coatings is explained by the results obtained from the analysis of every coating using electron microscopy and energy dispersive X-ray analysis. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  13. Specific features of insulator-metal transitions under high pressure in crystals with spin crossovers of 3d ions in tetrahedral environment

    Energy Technology Data Exchange (ETDEWEB)

    Lobach, K. A., E-mail: ks-ad@yandex.ru; Ovchinnikov, S. G., E-mail: sgo@iph.krasn.ru [Siberian Federal University (Russian Federation); Ovchinnikova, T. M. [Russian Academy of Sciences, Sukachev Institute of Forest, Siberian Branch (Russian Federation)

    2015-01-15

    For Mott insulators with tetrahedral environment, the effective Hubbard parameter U{sub eff} is obtained as a function of pressure. This function is not universal. For crystals with d{sup 5} configuration, the spin crossover suppresses electron correlations, while for d{sup 4} configurations, the parameter U{sub eff} increases after a spin crossover. For d{sup 2} and d{sup 7} configurations, U{sub eff} increases with pressure in the high-spin (HS) state and is saturated after the spin crossover. Characteristic features of the insulator-metal transition are considered as pressure increases; it is shown that there may exist cascades of several transitions for various configurations.

  14. Assimilation of metal ions bound to porphyrins or porphyrin-peptides by vibrio vulnificus, a human pathogen inhabiting estuarine and marine environments.

    Science.gov (United States)

    Miyoshi, Shin-ichi; Sasaki, Tomoko; Kaku, Nahoko; Inoue, Takaharu; Uozumi, Natsuki; Maehara, Yoko; Nakao, Hiroshi

    2010-03-01

    Vibrio vulnificus, a ubiquitous microorganism in aquatic environments, causes serious septicemia to the immunocompromised host. In addition to protoheme, this species can utilize Fe-TCPP [ferric tetrakis (4-carboxyphenyl) porphine] as an iron source. In the present study, heme c bound covalently to the protein in cytochrome c, as well as the Fe-TCPP complex formed with a nanopeptide with a high affinity, was found to be useful iron sources for V. vulnificus. This bacterium was also revealed to use Zn-TCPP as a single zinc source. However, other metalloporphyrins such as Mn-TCPP and Pt-TCPP delayed the bacterial growth in the broth containing Fe-TCPP, suggesting interference in the iron assimilation. These results indicate that V. vulnificus may acquire metal ions from both free and peptide-bound metalloporphyrins.

  15. Heavy metals in the farming environment and in some selected aquaculture species in the Van Phong Bay and Nha Trang Bay of the Khanh Hoa Province in Vietnam.

    Science.gov (United States)

    Nghia, Ngo Dang; Lunestad, Bjørn Tore; Trung, Trang Si; Son, Nguyen Thanh; Maage, Amund

    2009-01-01

    Aquaculture is currently one of the most rapidly growing production sectors in Vietnam. This publication describes the concentrations of heavy metals in the farming environment and some aquaculture species in the Khanh Hoa Province in Vietnam. The concentration of total As in the sediments ranged from 0.07 to 0.64 mg/kg, whereas the concentration of Hg varied from <0.0005 to 0.56 mg/kg. The corresponding concentration span for Cd and Pb, were 0.001-0.069 and 0.016-0.078 mg/kg, respectively. The concentrations of As in the aquaculture organisms spanned from 0.14 to 1.03 mg/kg. For Hg the concentrations varied from 0.1 to 0.45 mg/kg, for Cd from 0.02 to 0.10 mg/kg and for Pb from 0.07 to 0.37 mg/kg.

  16. Progress on Detection Methods of Heavy Metals in Water Environment%水环境中重金属检测方法研究进展

    Institute of Scientific and Technical Information of China (English)

    孙博思; 赵丽娇; 任婷; 钟儒刚

    2012-01-01

    Heavy metals pollution is one of the most important problems of water pollution, which is threatening the living of hydrobiological species and health of human. Detection methods for heavy metals in water environment in recent years including atomic absorption spectrometry, inductively coupled plasma spectrometry, atomic fluorescence spectrometry, stripping voltammetry, enzyme inhibition method, immunoassay and biochemistry sensor method were reviewed, and their sensitivity, accuracy and scope of application were analyzed, and merits and disadvantages of different methods were compared as well.%重金属污染是水污染的主要问题之一,严重威胁水生生物的生存和人类健康.文章对近年来水环境中重金属的检测方法进行了综述,主要介绍了原子吸收光谱法、电感藕合等离子体法、原子荧光光谱法、溶出伏安法、生物酶抑制法、免疫分析法和生物化学传感器法等.列举了不同方法的灵敏度、准确性和适用范围等,并对各自优点进行了比较.

  17. A new fast and standardless method for direct determination of metals associated with particulate matter in air: avoiding errors in the determination of Pb in an urban environment.

    Science.gov (United States)

    Torsi, G; Reschiglian, P; Locatelli, C; Melucci, D

    1997-01-01

    We describe a new method and the relevant instrumentation necessary for its implementation in the analysis of metals associated with particulate matter in air. The procedure can be divided into two steps: in the first step the sample is accumulated in a device through electrostatic precipitation whose center is a graphite tube; in the second step the graphite tube itself is used as an atomization device for the determination of the metals present in the sample through the electrothermal atomic absorption technique. The method is simple, fast, accurate, and inexpensive. Moreover, if the experimental conditions are well chosen, there is no need for calibration, which is very convenient in the case of samples such as particulate matter in the air. The elements that can be determined with the present apparatus are Hg, Cd, Tl, Ag, Mg, and Mn. These are highly or medium volatile because the materials used cannot reach very high temperatures for long periods. The experiments are confined to air, but other gases, in which a corona discharge is possible, would give the same results. With the method proposed, it was possible to show that the official method for Pb determination in the urban environment of Bologna presents a negative systematic error of about 25%.

  18. The Spitzer Spectroscopic Survey of the Small Magellanic Cloud (S4MC): Probing the Physical State of Polycyclic Aromatic Hydrocarbons in a Low-Metallicity Environment

    CERN Document Server

    Sandstrom, Karin M; Bot, Caroline; Draine, B T; Ingalls, James G; Israel, Frank P; Jackson, James M; Leroy, Adam K; Li, Aigen; Rubio, Mónica; Simon, Joshua D; Smith, J D T; Stanimirović, Snežana; Tielens, A G G M; van Loon, Jacco Th

    2011-01-01

    We present results of mid-infrared spectroscopic mapping observations of six star-forming regions in the Small Magellanic Cloud from the Spitzer Spectroscopic Survey of the SMC (S4MC). We detect the mid-IR emission from polycyclic aromatic hydrocarbons (PAHs) in all of the mapped regions, greatly increasing the range of environments where PAHs have been spectroscopically detected in the SMC. We investigate the variations of the mid-IR bands in each region and compare our results to studies of the PAH bands in the SINGS sample and in a sample of low-metallicity starburst galaxies. PAH emission in the SMC is characterized by low ratios of the 6-9 micron features relative to the 11.3 micron feature and weak 8.6 and 17.0 micron features. Interpreting these band ratios in the light of laboratory and theoretical studies, we find that PAHs in the SMC tend to be smaller and less ionized than those in higher metallicity galaxies. Based on studies of PAH destruction, we argue that a size distribution shifted towards sm...

  19. A new method to determine the structure of the metal environment in metalloproteins: investigation of the prion protein octapeptide repeat Cu(2+) complex.

    Science.gov (United States)

    Mentler, Matthias; Weiss, Andreas; Grantner, Klaus; del Pino, Pablo; Deluca, Dominga; Fiori, Stella; Renner, Christian; Klaucke, Wolfram Meyer; Moroder, Luis; Bertsch, Uwe; Kretzschmar, Hans A; Tavan, Paul; Parak, Fritz G

    2005-03-01

    Since high-intensity synchrotron radiation is available, "extended X-ray absorption fine structure" spectroscopy (EXAFS) is used for detailed structural analysis of metal ion environments in proteins. However, the information acquired is often insufficient to obtain an unambiguous picture. ENDOR spectroscopy allows the determination of hydrogen positions around a metal ion. However, again the structural information is limited. In the present study, a method is proposed which combines computations with spectroscopic data from EXAFS, EPR, electron nuclear double resonance (ENDOR) and electron spin echo envelope modulation (ESEEM). From EXAFS a first picture of the nearest coordination shell is derived which has to be compatible with EPR data. Computations are used to select sterically possible structures, from which in turn structures with correct H and N positions are selected by ENDOR and ESEEM measurements. Finally, EXAFS spectra are re-calculated and compared with the experimental data. This procedure was successfully applied for structure determination of the Cu(2+) complex of the octapeptide repeat of the human prion protein. The structure of this octarepeat complex is rather similar to a pentapeptide complex which was determined by X-ray structure analysis. However, the tryptophan residue has a different orientation: the axial water is on the other side of the Cu.

  20. Diversity and role of plasmids in adaptation of bacteria inhabiting the Lubin copper mine in Poland, an environment rich in heavy metals

    Science.gov (United States)

    Dziewit, Lukasz; Pyzik, Adam; Szuplewska, Magdalena; Matlakowska, Renata; Mielnicki, Sebastian; Wibberg, Daniel; Schlüter, Andreas; Pühler, Alfred; Bartosik, Dariusz

    2015-01-01

    The Lubin underground mine, is one of three mining divisions in the Lubin-Glogow Copper District in Lower Silesia province (Poland). It is the source of polymetallic ore that is rich in copper, silver and several heavy metals. Black shale is also significantly enriched in fossil organic matter in the form of long-chain hydrocarbons, polycyclic aromatic hydrocarbons, organic acids, esters, thiophenes and metalloporphyrins. Biological analyses have revealed that this environment is inhabited by extremophilic bacteria and fungi. Kupfershiefer black shale and samples of water, bottom and mineral sediments from the underground (below 600 m) Lubin mine were taken and 20 bacterial strains were isolated and characterized. All exhibited multi-resistant and hypertolerant phenotypes to heavy metals. We analyzed the plasmidome of these strains in order to evaluate the diversity and role of mobile DNA in adaptation to the harsh conditions of the mine environment. Experimental and bioinformatic analyses of 11 extrachromosomal replicons were performed. Three plasmids, including a broad-host-range replicon containing a Tn3 family transposon, carried genes conferring resistance to arsenic, cadmium, cobalt, mercury and zinc. Functional analysis revealed that the resistance modules exhibit host specificity, i.e., they may increase or decrease tolerance to toxic ions depending on the host strain. The other identified replicons showed diverse features. Among them we identified a catabolic plasmid encoding enzymes involved in the utilization of histidine and vanillate, a putative plasmid-like prophage carrying genes responsible for NAD biosynthesis, and two repABC-type plasmids containing virulence-associated genes. These findings provide an unique molecular insight into the pool of extrachromosomal replicons and highlight their role in the biology and adaptation of extremophilic bacteria inhabiting terrestrial deep subsurface. PMID:26074880

  1. Diversity and role of plasmids in adaptation of bacteria inhabiting the Lubin copper mine in Poland, an environment rich in heavy metals

    Directory of Open Access Journals (Sweden)

    Lukasz eDziewit

    2015-03-01

    Full Text Available The Lubin underground mine, is one of three mining divisions in the Lubin-Glogow Copper District in Lower Silesia province (Poland. It is the source of polymetallic ore that is rich in copper, silver and several heavy metals. Black shale is also significantly enriched in fossil organic matter in the form of long-chain hydrocarbons, polycyclic aromatic hydrocarbons, organic acids, esters, thiophenes and metalloporphyrins. Biological analyses have revealed that this environment is inhabited by extremophilic bacteria and fungi. Kupfershiefer black shale and samples of water, bottom and mineral sediments from the underground (below 600 m Lubin mine were taken and twenty bacterial strains were isolated and characterized. All exhibited multi-resistant and hypertolerant phenotypes to heavy metals. We analyzed the plasmidome of these strains in order to evaluate the diversity and role of mobile DNA in adaptation to the harsh conditions of the mine environment. Experimental and bioinformatic analyses of 11 extrachromosomal replicons were performed. Three plasmids, including a broad-host-range replicon containing a Tn3 family transposon, carried genes conferring resistance to arsenic, cadmium, cobalt, mercury and zinc. Functional analysis revealed that the resistance modules exhibit host specificity, i.e. they may increase or decrease tolerance to toxic ions depending on the host strain. The other identified replicons showed diverse features. Among them we identified a catabolic plasmid encoding enzymes involved in the utilization of histidine and vanillate, a putative plasmid-like prophage carrying genes responsible for NAD biosynthesis, and two repABC-type plasmids containing virulence-associated genes. These findings provide an unique molecular insight into the pool of extrachromosomal replicons and highlight their role in the biology and adaptation of extremophilic bacteria inhabiting terrestrial deep subsurface.

  2. Diversity and role of plasmids in adaptation of bacteria inhabiting the Lubin copper mine in Poland, an environment rich in heavy metals.

    Science.gov (United States)

    Dziewit, Lukasz; Pyzik, Adam; Szuplewska, Magdalena; Matlakowska, Renata; Mielnicki, Sebastian; Wibberg, Daniel; Schlüter, Andreas; Pühler, Alfred; Bartosik, Dariusz

    2015-01-01

    The Lubin underground mine, is one of three mining divisions in the Lubin-Glogow Copper District in Lower Silesia province (Poland). It is the source of polymetallic ore that is rich in copper, silver and several heavy metals. Black shale is also significantly enriched in fossil organic matter in the form of long-chain hydrocarbons, polycyclic aromatic hydrocarbons, organic acids, esters, thiophenes and metalloporphyrins. Biological analyses have revealed that this environment is inhabited by extremophilic bacteria and fungi. Kupfershiefer black shale and samples of water, bottom and mineral sediments from the underground (below 600 m) Lubin mine were taken and 20 bacterial strains were isolated and characterized. All exhibited multi-resistant and hypertolerant phenotypes to heavy metals. We analyzed the plasmidome of these strains in order to evaluate the diversity and role of mobile DNA in adaptation to the harsh conditions of the mine environment. Experimental and bioinformatic analyses of 11 extrachromosomal replicons were performed. Three plasmids, including a broad-host-range replicon containing a Tn3 family transposon, carried genes conferring resistance to arsenic, cadmium, cobalt, mercury and zinc. Functional analysis revealed that the resistance modules exhibit host specificity, i.e., they may increase or decrease tolerance to toxic ions depending on the host strain. The other identified replicons showed diverse features. Among them we identified a catabolic plasmid encoding enzymes involved in the utilization of histidine and vanillate, a putative plasmid-like prophage carrying genes responsible for NAD biosynthesis, and two repABC-type plasmids containing virulence-associated genes. These findings provide an unique molecular insight into the pool of extrachromosomal replicons and highlight their role in the biology and adaptation of extremophilic bacteria inhabiting terrestrial deep subsurface.

  3. Development of a realistic photonic modeling for the evaluation of infrared reflections in the metallic environment of ITER.

    Science.gov (United States)

    Aumeunier, M-H; Travere, J-M

    2010-10-01

    In nuclear fusion experiments, the plasma facing components are exposed to high heat fluxes and infrared (IR) imaging diagnostics are routinely used for surveying their surface temperature for preventing damages. However the future use of metallic components in the ITER tokamak adds complications in temperature estimation. Indeed, low and variable emissivity of the observed surface and the multiple reflections of the light coming from hot regions will have to be understood and then taken into account. In this paper, a realistic photonic modeling based on Monte Carlo ray-tracing codes is used to predict the global response of the complete IR survey system. This also includes the complex vessel geometry and the thermal and optical surface properties using the bidirectional reflectivity distribution function that models the photon-material interactions. The first results of this simulation applied to a reference torus are presented and are used as a benchmark to investigate the validity of the global model. Finally the most critical key model parameters in the reflected signals are identified and their contribution is discussed.

  4. Comparative evaluation of several small mammal species as monitors of heavy metals, radionuclides, and selected organic compounds in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Talmage, S.S. (Tennessee Univ., Knoxville, TN (USA) Oak Ridge National Lab., TN (USA)); Walton, B.T. (Oak Ridge National Lab., TN (USA))

    1990-08-01

    The primary purpose of this study was to evaluate which small mammal species are the best monitors of specific environmental contaminants. The evaluation is based on the published literature and on an analysis of small mammals trapped at several sites on the Oak Ridge National Laboratory (ORNL) Reservation in Oak Ridge, Tennessee. Studies on the uptake of heavy metals, radionuclides, and organic chemicals are reviewed in Chapter II to evaluate several small mammal species for their capacity to serve as sentinels for the presence, accumulation, and effects of various contaminants. Where several species were present at a site, a comparative evaluation was made and species are ranked for their capacity to serve as monitors of specific contaminants. Food chain accumulation and food habits of the species are used to establish a relationship with suitability as a biomonitor. Tissue-specific concentration factors were noted in order to establish target tissues. Life histories, habitat, and food habits are reviewed in order to make generalizations concerning the ability of similar taxa to serve as biomonitor. Finally, the usefulness of several small mammal species as monitors of three contaminants -- benzo(a)pyrene, mercury, and strontium-90 -- present on or near the ORNL facilities was investigated. 133 refs., 5 figs., 20 tabs.

  5. Impact of silver nanoparticles on benthic prokaryotes in heavy metal-contaminated estuarine sediments in a tropical environment.

    Science.gov (United States)

    Antizar-Ladislao, B; Bhattacharya, B D; Ray Chaudhuri, S; Sarkar, S K

    2015-10-15

    Little knowledge is available about the potential impact of commercial silver nanoparticles (Ag-NPs) on estuarine microbial communities. The Hugli river estuary, India, is susceptible to heavy metals pollution through boat traffic, and there is the potential for Ag-NP exposure via effluent discharged from ongoing municipal and industrial activities located in close proximity. This study investigated the effects of commercial Ag-NPs on native microbial communities in estuarine sediments collected from five stations, using terminal restriction fragment length polymorphism (T-RFLP) technique. An increase in the number of bacteria in consortium in sediments was observed following exposure to Ag-NPs. In general microbial communities may be resistant in estuarine systems to the antimicrobial effects of commercial Ag-NPs, but key microorganisms, such as Pelobacter propionicus, disappeared following exposure to Ag-NPs. In conclusion, the T-RFLP analysis indicated that Ag-NPs have the potential to shape estuarine sediment bacterial community structure. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Epidemiologic study of anisometropia in students of Natal, Brazil Estudo epidemiológico da anisometropia em estudantes da cidade de Natal, Brasil

    Directory of Open Access Journals (Sweden)

    Carlos Alexandre de Amorim Garcia

    2005-02-01

    Full Text Available PURPOSE: To perform an epidemiologic study in students in Natal/Brazil, with relation to refractional anisometropia, evaluating criteria such as: gender, age, and association with strabismus and amblyopia. METHODS: A study of 1,024 students randomly selected from several districts of Natal/Brazil was undertaken by the Department of Ophthalmology of the Federal University of Rio Grande do Norte (UFRN, observing the following criteria of > 2 spherical or cylindrical diopter refractional anisometropia relating it to sex, age, association with strabismus, amblyopia and anisometropia classification. RESULTS: We found a prevalence of 2% (N=21 anisometropia in the students. The female gender predominated with 81% (N=17. In students with anisometropia, we observed an association with strabismus in 9.5% of cases (N=2, both with exotropia. The association of anisometropia with amblyopia occurred in 47.6% of the cases (N=10, with 8 cases of unilateral amblyopia and 2 cases of bilateral amblyopia. CONCLUSIONS: There was a predominance of anisometropia in females, and an increased prevalence of strabismus and amblyopia in students with anisometropia.OBJETIVO: Realizar um estudo epidemiológico em estudantes de Natal/Brasil, com relação à anisometropia refracional, avaliando os seguintes critérios: sexo, idade e associação com estrabismo e ambliopia. MÉTODOS: Foram estudados 1.024 estudantes, randomicamente selecionados, pertencentes aos diversos distritos da cidade de Natal/Brasil, pelo Departamento de Oftalmologia, da Universidade Federal do Rio Grande do Norte (UFRN, observando os seguintes aspectos, quanto à anisometropia > 2 dioptrias esférica ou cilíndrica, sexo, idade, associação com estrabismo e ambliopia, e os tipos de anisometropia. RESULTADOS: Encontrou-se prevalência de anisometropia de 2% (N=21 nos estudantes. O sexo feminino predominou com 81% (N=17. Nos estudantes com anisometropia, observou-se associação com estrabismo em 9

  7. NLO in correlation of phase transition and the alkaline metal environment effect on it in KDP family

    Energy Technology Data Exchange (ETDEWEB)

    Ennaceur, Nasreddine, E-mail: nasr.ennaceur@yahoo.fr [Laboratoire Physico-chimie de l' État Solide, Faculté des Sciences, Université de Sfax, BP 1171, 3000 (Tunisia); Laboratoire de Photonique Quantique et Moléculaire Institut d’Alembert—École Normale Supérieure, 61 avenue du Président Wilson, 94230 Cachan (France); Ledoux-Rak, Isabelle; Singh, Anu [Laboratoire de Photonique Quantique et Moléculaire Institut d’Alembert—École Normale Supérieure, 61 avenue du Président Wilson, 94230 Cachan (France); Mhiri, Tahar; Jarraya, Khaled [Laboratoire Physico-chimie de l' État Solide, Faculté des Sciences, Université de Sfax, BP 1171, 3000 (Tunisia)

    2013-11-01

    The NaH{sub 2}(P{sub 0.48}As{sub 0.52})O{sub 4}·H{sub 2}O (NDAP) compounds allow favorable conditions to the study of evolution of the NLO response during the non-centrosymmetry phases transitions. In fact, NDAP shows the existence of three reversible non-centrosymmetry phase transitions between 272 and 313 K. These experiments are good tools for probing phase transitions and their nature. In this process, several experiments are useful to reveal not only an agreement between the thermal and the quadratic nonlinear (NLO) studies, but also an attempt amongst other things to correlate the probable effect of the alkaline environment of the KDP family on the effectiveness of the NLO intensity.

  8. General corrosion of metallic materials in boric acid environments; La corrosion generalisee des materiaux metalliques en milieu acide borique

    Energy Technology Data Exchange (ETDEWEB)

    Gras, J.M.

    1994-05-01

    Certain low-alloy steel components in PWR primary circuit were corroded by leaking water containing boric acid. A number of studies have been performed by manufacturers in the USA and by EDF in France to determine the rate of general corrosion for low-alloy steels in media containing varying concentrations of boric acid. The first part of this paper summarizes the studies performed and indicates how far work has advanced to date in establishing the resistance of stainless steels to general corrosion in concentrated boric acid solutions. The second part of the paper discusses the mechanism of corrosion and proposes a model. Carbon steels and low-alloy steels - carbon steels and low-alloy steels in deaerated diluted boric acid solutions (pH > 4) corrode very slowly (<20{mu}m/year). The corrosion rate is approximately 1 {mu}m/year in the nominal primary water in static conditions; - in non-deaerated solutions, the corrosion rate is determined by the solubility of iron. Important factors are the pH, the temperature and the operating conditions, which determine the iron solubility in the medium: the rate of renewal of the medium or the S/V ratio of the metal surface exposed to the volume of solution. The steel composition is not a determinant factor. Stainless steels. General corrosion of stainless steels in concentrated boric acid solutions depends primarily on their chromium content. Steels containing less than 15% chromium offer excellent resistance to corrosion regardless of their structure or nickel content. The corrosion rate is less than 10 {mu}m/year at 250 deg C and approximately 40 {mu}m/year at 300 deg C. Steels containing 13% chromium corrode in hot concentrated media. The apparent activation energy of general corrosion is approximately 25 kJ.mol{sup -1}. (author). 31 refs., 12 figs., 13 tabs.

  9. Gender Preference, Attitude and Awareness of Young Eligible Couples towards Pre Natal Sex Determination in Lucknow District

    Directory of Open Access Journals (Sweden)

    Ashish Srivastava, Jai V Singh, Om P Singh, Vijay K Singh, Neelam Singh

    2014-01-01

    Conclusion: The study clearly shows that son preference and pre natal sex determination still finds favour with a substantial proportion of young couples and emphasises the need for proper counselling and behaviour change communication among them.

  10. Sulfide stress corrosion study of a super martensitic stainless steel in H2S sour environments: Metallic sulfides formation and hydrogen embrittlement

    Science.gov (United States)

    Monnot, Martin; Nogueira, Ricardo P.; Roche, Virginie; Berthomé, Grégory; Chauveau, Eric; Estevez, Rafael; Mantel, Marc

    2017-02-01

    Thanks to their high corrosion resistance, super martensitic stainless steels are commonly used in the oil and gas industry, particularly in sour environments. Some grades are however susceptible to undergo hydrogen and mechanically-assisted corrosion processes in the presence of H2S, depending on the pH. The martensitic stainless steel EN 1.4418 grade exhibits a clear protective passive behavior with no sulfide stress corrosion cracking when exposed to sour environments of pH ≥ 4, but undergoes a steep decrease in its corrosion resistance at lower pH conditions. The present paper investigated this abrupt loss of corrosion resistance with electrochemical measurements as well as different physicochemical characterization techniques. Results indicated that below pH 4.0 the metal surface is covered by a thick (ca 40 μm) porous and defect-full sulfide-rich corrosion products layer shown to be straightforwardly related to the onset of hydrogen and sulfide mechanically-assisted corrosion phenomena.

  11. Nutrients, heavy metals and microbial communities co-driven distribution of antibiotic resistance genes in adjacent environment of mariculture.

    Science.gov (United States)

    Zhao, Zelong; Wang, Jing; Han, Ying; Chen, Jingwen; Liu, Guangfei; Lu, Hong; Yan, Bin; Chen, Shiaoshing

    2017-01-01

    With the rapid development of aquaculture, the large amounts of pollutants were discharged into the aquatic environment, where the detected antibiotic resistance genes (ARGs) have drawn increasing attention due to their potential threats to ecological environment and human health. Thus, the impact of mariculture on ARGs was assessed and the underlying mechanism of their propagation was explained. Sediments from eight sampling sites were collected along a mariculture drainage ditch, and the sediment in Yellow River Delta National Park was used as a non-mariculture control. Microbial ARGs qPCR array and illumina sequencing of 16S rRNA gene were applied to examine the changing patterns of ARGs and bacterial communities. Results showed that 18 ARGs (3 fluoroquinolone, 1 aminoglycoside, 3 macrolide-lincosamide-streptogramin B, 2 tetracycline, and 9 beta-lactam resistance genes) were influenced by mariculture, and ARGs abundance and diversity were significantly increased in mariculture sediments (p < 0.05). A remarkable shift in bacterial community structure and composition was also observed. The abundance of most of ARGs were significantly decreased in the estuary samples, implying that seawater had a significant dilution effect on the ARGs emission from the mariculture sites. Partial redundancy analysis showed that nutrients, heavy metals, and bacteria communities might directly and indirectly contribute to ARGs propagation, suggesting that the profile and dissemination of ARGs were driven by the combined effects of multiple factors in mariculture-impacted sites. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Avaliação da assistência pré-natal: relevância dos exames laboratoriais

    Directory of Open Access Journals (Sweden)

    Dayanna Joyce Marques Queiroz

    2015-12-01

    Full Text Available Objetivo: Avaliar a assistência pré-natal de mulheres assistidas ao parto e verificar a relevância dos exames laboratoriais na qualidade do pré-natal. Métodos: Estudo de corte transversal desenvolvido em um hospital universitário de referência na cidade de Santa Cruz- RN, no período de junho a julho de 2014, com 50 parturientes assistidas ao parto. As mulheres tinham entre 18-40 anos e possuíam baixo risco obstétrico. Os dados foram coletados a partir do cartão do pré-natal e aplicação de questionário estruturado. A caracterização da adequação do pré-natal foi elaborada com base nas diretrizes do Programa de Humanização do Pré-natal e Puerpério (PHPN e no Manual Técnico de Pré-natal e Puerpério (MTPP.Realizou-se análise descritiva dos dados e o teste Qui-quadrado para a verificação de diferenças entre as proporções. Resultados: Observou-se que 86% (n=43 iniciaram o pré-natal precocemente e obtiveram uma média de 7,3 consultas. Os procedimentos clínicos obstétricos tiveram cinco ou mais registros em 58% (n=29 da amostra. Quando avaliado o registro de exames laboratoriais, observou-se um baixo percentual de adequação na 2ª rotina de exame preconizada (32%, n=16. De acordo com os parâmetros (PHPN e MTPP, o pré-natal esteve adequado apenas em 24% (n=12 dos casos. Quando avaliada a classificação da assistência do pré-natal sem o uso dos exames laboratoriais, a adequação subiu para 48% (n=24, com diferença estatisticamente significantes (p<0,001. Conclusão: O acesso ao pré-natal foi satisfatório, entretanto, a qualidade do pré-natal foi deficiente e a maior fragilidade parece estar relacionada aos registros dos exames laboratoriais.

  13. Metastable alloy nanoparticles, metal-oxide nanocrescents and nanoshells generated by laser ablation in liquid solution: influence of the chemical environment on structure and composition.

    Science.gov (United States)

    Scaramuzza, Stefano; Agnoli, Stefano; Amendola, Vincenzo

    2015-11-14

    Alloy nanoparticles are characterized by the combination of multiple interesting properties, which are attractive for technological and scientific purposes. A frontier topic of this field is nanoalloys with compositions not thermodynamically allowed at ordinary temperature and pressure (i.e. metastable), because they require out-of-equilibrium synthetic approaches. Recently, laser ablation synthesis in solution (LASiS) was successfully applied for the realization of metastable nanoalloys because of the fast kinetics of nanoparticle formation. However, the role played by the chemical environment on the final composition and structure of laser generated nanoalloys still has to be fully elucidated. Here, we investigated the influence of different synthetic conditions on the LASiS of metastable nanoalloys composed of Au and Fe, such as the use of water instead of ethanol, the bubbling of inert gases and the addition of a few vol% of H2O2 and H2O. The two elements showed different reactivity when LASiS was performed in water instead of ethanol, while minor effects were observed from bubbling pure gases such as N2, Ar and CO2 in the liquid solution. Moreover, the plasmonic response and the structure of the nanoalloys were sensibly modified by adding H2O2 to water. We also found that nanoparticle production is dramatically influenced just by adding 0.2% of H2O in ethanol. These results suggest that the formation of a cavitation bubble with long lifetime and large size during LASiS is useful for the preservation of the metastable alloy composition, whereas an oxidative environment hampers the formation of metastable alloy nanoparticles. Overall, by acting on the type of solvent and solutes, we were able to switch from a traditional synthetic approach for the composition of Au-Fe nanoalloys to one using a reactive environment, which gives unconventional structures such as metal@iron-oxide nanoshells and nanocrescents of oxide supported on metal nanospheres. These results

  14. O cuidado pré-natal em hospital universitário: uma avaliação de processo

    Directory of Open Access Journals (Sweden)

    Nagahama Elizabeth Eriko Ishida

    2006-01-01

    Full Text Available O objetivo do estudo foi avaliar o processo de atenção pré-natal referente à utilização do cuidado pré-natal do Programa Assistência Pré-natal às Gestantes de Baixo Risco do Hospital Universitário de Maringá, Paraná, Brasil. Compreendeu a seleção de critérios de qualidade que avaliaram a precocidade no ingresso e a adequação do número de consultas de pré-natal, mensuradas conforme o Programa de Humanização do Pré-natal e Nascimento do Ministério da Saúde e Índice de Adequação da Utilização do Cuidado Pré-natal. O estudo demonstrou que 44,5% gestantes iniciaram tardiamente o pré-natal, o que pode sugerir uma oferta limitada de vagas e a busca por melhor qualidade na atenção, demonstrada pela transferência espontânea de gestantes de outros serviços para o programa. As consultas de pré-natal foram garantidas, sendo o número médio - 9,8 consultas por gestante - superior aos parâmetros nacionais recomendados. Os indicadores utilizados e desenvolvidos para a avaliação de processo identificaram que o serviço ainda apresenta obstáculos ao acesso organizacional, necessitando, assim, da definição de estratégias que garantam essa diretriz fundamental do SUS.

  15. Mineral formation on metallic copper in a `Future repository site environment`: Textural considerations based on natural analogs

    Energy Technology Data Exchange (ETDEWEB)

    Amcoff, Oe. [Uppsala Univ. (Sweden). Inst. of Earth Sciences

    1998-01-01

    Copper mineral formation in the Swedish `repository site environment` is discussed. Special attention is given to ore mineral textures (=the spatial relation among minerals), with examples given from nature. It is concluded: By analogy with observations from natural occurrences, an initial coating of Cu-oxide on the canister surface (because of entrapped air during construction) will probably not hinder a later sulphidation process. Early formation of Cu-sulphides on the canister surface may be accompanied by formation of CuFe-sulphides. The latter phase(s) may form through replacement of the Cu-sulphides or, alternatively, by means of reaction between dissolved copper and fine-grained iron sulphide (pyrite) in the surrounding bentonite. Should for some reason the bentonite barrier fail and the conditions become strongly oxidizing, we can expect crustifications and rhythmic growths of Cu(II)-phases, like malachite (Cu{sub 2}(OH){sub 2}CO{sub 3}). A presence of Fe{sup 2} in the clay minerals making up the bentonite might prove to have an adverse effect on the canister stability, since, in this case, the bentonite might be expected to act as a sink for dissolved copper. The mode of mineral growth along the copper - bentonite interface remains an open question.

  16. Enfermagem obstétrica no acompanhamento pré - natal

    Directory of Open Access Journals (Sweden)

    Lucia Helena Garcia Penna

    1999-09-01

    Full Text Available Consiste em um relato de experiência acerca de um projeto de pesquisa iniciado em agosto de 1997, envolvendo docentes do Departamento Materno-infantil da Faculdade de Enfermagem da UERJ e profissionais do Centro Municipal de Saúde do Rio de Janeiro da S.M.S./RJ. Tem por objetivo, descrever o processo de inserção da Consulta de Enfermagem de Pré-natal no conteúdo da graduação, bem como sua estruturação e implantação no referido Centro Municipal de Saúde. Esse trabalho propõe rever também, o modelo biomédico das consultas, a fim de proporcionar reflexões e rupturas de paradigmas, e com isso auxiliar no aprendizado e na ampliação do acompanhamento de pré-natal no Rio de Janeiro.

  17. Flood frequency analysis at ungauged sites in the KwaZulu-Natal Province, South Africa

    DEFF Research Database (Denmark)

    Kjeldsen, Thomas Rodding; Smithers, J.C.; Schulze, R.E.

    2001-01-01

    Use of the index-flood method at ungauged sites requires methods for estimation of the index-flood parameter at these sites. This study attempts to relate the mean annual flood to site characteristics of catchments in KwaZulu-Natal, South Africa. The ordinary, weighted and generalised least squar...... of the study area. The study also revealed problems with the estimation of the mean annual flood in the coastal areas of the study region.......Use of the index-flood method at ungauged sites requires methods for estimation of the index-flood parameter at these sites. This study attempts to relate the mean annual flood to site characteristics of catchments in KwaZulu-Natal, South Africa. The ordinary, weighted and generalised least square...

  18. Indian hedgehog roles in post-natal TMJ development and organization.

    Science.gov (United States)

    Ochiai, T; Shibukawa, Y; Nagayama, M; Mundy, C; Yasuda, T; Okabe, T; Shimono, K; Kanyama, M; Hasegawa, H; Maeda, Y; Lanske, B; Pacifici, M; Koyama, E

    2010-04-01

    Indian hedgehog (Ihh) is essential for embryonic mandibular condylar growth and disc primordium formation. To determine whether it regulates those processes during post-natal life, we ablated Ihh in cartilage of neonatal mice and assessed the consequences on temporomandibular joint (TMJ) growth and organization over age. Ihh deficiency caused condylar disorganization and growth retardation and reduced polymorphic cell layer proliferation. Expression of Sox9, Runx2, and Osterix was low, as was that of collagen II, collagen I, and aggrecan, thus altering the fibrocartilaginous nature of the condyle. Though a disc formed, it exhibited morphological defects, partial fusion with the glenoid bone surface, reduced synovial cavity space, and, unexpectedly, higher lubricin expression. Analysis of the data shows, for the first time, that continuous Ihh action is required for completion of post-natal TMJ growth and organization. Lubricin overexpression in mutants may represent a compensatory response to sustain TMJ movement and function.

  19. AUTOBIOGRAFISMO E DIALOGO FILOSOFICO: IL CASO STORIOGRAFICO DE LA FESTA DI NATALE DI FRIEDRICH SCHLEIERMACHER

    Directory of Open Access Journals (Sweden)

    Francesca D'Alberto

    2014-01-01

    Full Text Available Die Weihnachtsfeier. Ein Gespräch di Friedrich Schleiermacher è uno degli esempi più interessanti di come, nel romanticismo, forma letteraria, contesto vitale e autobiografico, tesi filosofiche costituissero un complesso unitario e spesso di difficile interpretazione. Nel caso del dialogo schleiermacheriano sul Natale è possibile distinguere due livelli di lettura storiografica: uno, rivolto soprattutto al contesto, consente di identificare i riferimenti biografici e l'ambiente reale a cui allude l'autore; un secondo, strettamente legato al primo, ma non necessariamente riducibile ad esso, ha invece un valore, per così dire, "autointerpretativo". Alla luce di questo secondo livello di lettura, questa breve opera di Schleiermacher mostra di essere ben più di uno scritto occasionale per il Natale del 1806. Esso nasconde e rivela al contempo, nelle trame di un gioco di rimandi e allusioni biografiche, la volontà...

  20. QUALITY ASSESSEMENT OF ANTE-NATAL CARE USING THE METHOD OF LOT QUALITY ASSURANCE SAMPLING

    Directory of Open Access Journals (Sweden)

    Sh. Salarilak

    1999-08-01

    Full Text Available To determine the coverage rate, timeliness and quality of ante-natal care in rural areas under the coverage of Health Houses in West Azerbaijan province, 30 Health Houses (HH were randomly selected out of 731 HH in the province. In each HH, using the method of Lot Quality Assurance Sampling (LQAS 28 women having recently born babies was selected. Data were collected using check-list for facilities, and questionnaires and forms to be completed from the files by interview. The study showed that the method of LQAS is quite effective for evaluation of this service at HH level. The weighted total coverage of ante-natal care was 46.2%. Quality of care was acceptable for 53.9% of mothers. The weighted average of time lines of care was 49.8%. Availability of facilities in delivery of this service was 100%, showing there was no short coming in this respect.

  1. Flood frequency analysis at ungauged sites in the KwaZulu-Natal Province, South Africa

    DEFF Research Database (Denmark)

    Kjeldsen, Thomas Rodding; Smithers, J.C.; Schulze, R.E.

    2001-01-01

    Use of the index-flood method at ungauged sites requires methods for estimation of the index-flood parameter at these sites. This study attempts to relate the mean annual flood to site characteristics of catchments in KwaZulu-Natal, South Africa. The ordinary, weighted and generalised least square...... methods for estimating model parameters are compared and found to perform equally well, with preference given to the generalised least square model. A separation of KwaZulu-Natal (KZN) into two regions was found to improve predictive ability of the models in the western and north-western parts...... of the study area. The study also revealed problems with the estimation of the mean annual flood in the coastal areas of the study region....

  2. Effect of chemical structure of S-nitrosothiols on nitric oxide release mediated by the copper sites of a metal organic framework based environment.

    Science.gov (United States)

    Taylor-Edinbyrd, Kiara; Li, Tanping; Kumar, Revati

    2017-05-17

    The effect of chemical structure of different biologically compatible S-nitrosothiols on the solvation environment at catalytic copper sites in a metal organic framework (MOF) suspended in a solution of ethanol is probed using computational methods. The use of a copper based MOF as a storage vehicle and catalyst (copper sites of the MOF) in the controlled and sustained release of chemically stored nitric oxide (NO) from S-nitrosocysteine has been shown to occur both experimentally and computationally [J. Am. Chem. Soc., 2012, 134, 3330-3333; Phys. Chem. Chem. Phys., 2015, 17, 23403]. Previous studies on a copper based MOF, namely HKUST-1, concluded that modifications in the R-group of s-nitrosothiols and/or organic linkers of MOFs led to a method capable of modulating NO release. In order to test the hypothesis that larger R-groups slow down NO release, four different RSNOs (R = cysteine, N-acetylcysteine, N-acetyl-d,l-penicillamine or glutathione) of varying size were investigated, which in turn required the use of a larger copper based MOF. Due to its desirable copper centers and more extensive framework, MOF-143, an analog of HKUST-1 was chosen to further explore both the effect of different RSNOs as well as MOF environments on NO release. Condensed phase classical molecular dynamics simulations are utilized to study the effect of the complex MOF environment as well as the chemical structure and size of the RSNO on the species on the catalytic reaction. The results indicate that in addition to the size of the RSNO species and the organic linkers within the MOF, the reaction rates can be modulated by the molecular structure of the RSNO and furthermore combining different RSNO species can also be used to tune the rate of NO release.

  3. Utilização de medicamentos durante a gravidez na cidade de Natal, Rio Grande do Norte, Brasil Drug use during pregnancy in Natal, Brazil

    Directory of Open Access Journals (Sweden)

    Gerlane Coelho Bernardo Guerra

    2008-01-01

    Full Text Available OBJETIVO: estudar o uso de medicamentos por gestantes atendidas durante o pré-natal em unidades básicas do Sistema Único de Saúde (SUS na cidade de Natal, rio Grande do Norte, Brasil. MÉTODOS: foram entrevistadas 610 grávidas, entre o primeiro e o terceiro trimestre de gestação, que compareceram para consulta pré-natal em unidades de saúde localizadas nos quatro distritos sanitários de Natal, entre maio e julho de 2006. Os dados foram coletados com entrevistas estruturadas, baseando-se em perguntas uso-orientadas e medicamento-orientadas. Os fármacos foram classificados de acordo com o Anatomical Therapeutic Chemical Classification System (ATC e segundo critérios de risco para a gestação da Food and Drug Administration (FDA. Utilizou-se teste do chi2 para análise dos dados. RESULTADOS: eram utilizados 1.505 medicamentos, obtendo-se uma média de 2,4 drogas por mulher. O uso de pelo menos um fármaco na gravidez foi relatado por 86,6% das gestantes. As classes mais utilizadas foram os antianêmicos (35,6% dos medicamentos, analgésicos (24,9%, drogas para distúrbios gastrintestinais (9,1% e vitaminas (7%. De acordo com a classificação do FDA, dos medicamentos empregados 42,7% pertencem a categoria A de risco; 27,1% à categoria B, 29,3% à categoria C; 0,3 à categoria D e nenhum à categoria X. Foram usados, no primeiro trimestre da gestação, 43,6% dos fármacos. Observou-se maior uso de medicamentos quanto maior a escolaridade e a renda familiar da mulher. A automedicação ocorreu em 12,2% dos medicamentos; esse índice foi maior no primeiro trimestre de gravidez e em gestantes de baixa escolaridade e multigestas. CONCLUSÕES: as gestantes de Natal estão sendo expostas a uma variedade de medicamentos, cuja segurança na gravidez ainda é incerta, o que exige prescrição criteriosa para evitar possíveis danos ao feto.PURPOSE: to study the use of medicines by pregnant women during prenatal care in clinics of the national

  4. Caracterização da cobertura do pré-natal no Estado do Maranhão, Brasil

    Directory of Open Access Journals (Sweden)

    Geny Rose Cardoso Costa

    2010-12-01

    Full Text Available O objetivo do estudo foi caracterizar a cobertura do pré-natal no Estado do Maranhão. Um estudo de base populacional em 30 municípios do Maranhão, com 2.075 mulheres em idade fértil, com gravidez prévia, de julho de 2008 a janeiro de 2009. Os resultados mostraram que as unidades de saúde da família foram responsáveis por 45,9% dos atendimentos de gestantes sendo que 46,8% relataram a realização de seis consultas ou mais de pré-natal durante a última gravidez e 64,6% iniciaram o pré-natal ainda no 1º trimestre. A cobertura do pré-natal foi de 85,6%, no entanto, ao se considerar a cobertura de pré-natal adequado, este foi de 43,4%, de acordo com o preconizado pelo Ministério da Saúde (Brasil. Apesar de uma cobertura de pré-natal acima de 80%, menos da metade é considerada adequada, demonstrando um descompasso na atenção primária com qualidade.

  5. Natality and ethnocentrism: Some relationships suggested by an analysis of catholic-protestant differentials.

    Science.gov (United States)

    Day, L H

    1968-03-01

    Abstract At the time of writing, the Roman Catholic Church is engaged in a major re-evaluation of its position on contraception. Judging from newspaper interest, there exists a widespread assumption that Catholic teaching, together with the political and social influence of the Catholic clergy, is an important deterrent to the practice of contraception and, for that reason, to the reduction of human natality.

  6. EMERGÊNCIA DOS "CONDOMÍNIOS-CLUBE" NA ZONA SUL DE NATAL/RN, BRASIL

    Directory of Open Access Journals (Sweden)

    Felipe Fernandes de Araújo

    2012-01-01

    Full Text Available Este documento tiene como objetivo discutir el surgimiento de una nueva tipología residencial que se ha extendido en el sur de Natal / RN, los condominios llamado Club. Su principal característica es la apelación a los artículos de ocio más diversos, que son utilizados por los empresarios urbanos como una forma de crear un nuevo estilo de vida y un nuevo producto que se vende. La base teórica de este trabajo se basa en el enfoque heterodoxo de la coordinación espacial realizada por Pedro Abramo. Esta perspectiva considera el espacio urbano como un conjunto de inventario de viviendas que son ofrecidas por los empresarios urbanos. En general, el orden urbano y el ambiente residencial es incierto, porque sufren cambios derivados de la aparición de las innovaciones de espacio causadas por empresarios urbanos en busca de beneficios extraordinarios. En el caso de la zona sur de Natal, la construcción de carreteras principales que conectan esta zona de la ciudad al vecino municipio de Parnamirim, que ha sido el blanco de la abundancia del mercado inmobiliario de Natal. El ciclo de vida de los inventarios residenciales de la Zona Sur de Natal ha cambiado con el tiempo, desde el principio de la vivienda en grandes alojamientos para la producción de proyectos verticais. En la actualidad, un fenómeno nuevo que se plantea es la propagación de una nueva clasificación, los condominios club. Al ser un caso reciente en que los proyectos se encuentran todavía en fase de lanzamiento o de la construcción, el estudio se llevará a cabo mediante el análisis de marketing utilizadas por los empresarios urbanos para atraer a los consumidores a través de panfletos y folletos.

  7. The influence of turbidity on juvenile marine fish in the estuaries of Natal, South africa

    Science.gov (United States)

    Cyrus, D. P.; Blaber, S. J. M.

    1987-11-01

    Results from field studies in Natal estuaries show that the distribution of juvenile marine fish is influenced by turbidity. Laboratory studies on turbidity preference, with other variables excluded, showed good correlation with the field data for eight of ten species tested. The importance of turbidity and other factors to juvenile fish is discussed in relation to the role which estuaries play as nursery areas for juveniles of numerous marine species.

  8. Recovery distances of nestling Bald Eagles banded in Florida and implications for natal dispersal and philopatry

    Science.gov (United States)

    Wood, Petra Bohall

    2009-01-01

    I used band recovery data to examine distances between banding and recovery locations for 154 nestling Florida Bald Eagles and discuss the implications for understanding natal dispersal and philopatry in this species. Band recoveries occurred in 23 U.S. states and five Canadian provinces between 1931–2005. Recovery distance from the natal nest averaged longer for the youngest age classes (ANOVA: F  =  3.59; df  =  5, 153; P  =  0.005), for individuals banded in earlier decades (F  =  1.94; df  =  5, 153; P  =  0.093), and for the months of May through October (F  =  3.10; df  =  12, 153;P < 0.001). Of 35 individuals classed as mature (≥3.9 yr old when recovered; range 3.9–36.5 yr), 31 were located within Florida, which suggested a strong degree of philopatry to the natal state. Among 21 mature eagles of known sex with known banding and recovery locations in Florida, females, particularly younger birds, had longer recovery distances (N  =  9, mean  =  93 km, SE  =  22.4) than did males (N  =  12, mean  =  31 km, SE  =  5.3; t  =  2.67, df  =  19, P  =  0.026). The records examined here suggest a high degree of philopatry and relatively short natal dispersal distances, particularly in male Bald Eagles.

  9. Beginners on Stage: Arendt, Natality and the Appearance of Children in Contemporary Performance

    OpenAIRE

    Senior, A.

    2016-01-01

    This paper examines the complex questions that arise around the appearance of children in contemporary performance. Drawing on performances by Nottingham-based theatre company Zoo Indigo and Tim Etchells and the Flemish theatre company Victoria, I consider the extent to which Hannah Arendt’s theorisation of natality as ‘the new beginning inherent in birth’ that gives rise to the political potential to ‘begin something anew’ can help us to understand the ethico-political dimensions of children...

  10. Challenges in the prenatal and post-natal diagnosis of mediastinal cystic hygroma: a case report

    Directory of Open Access Journals (Sweden)

    Nazir Sarfraz

    2008-08-01

    Full Text Available Abstract Introduction Cystic hygroma is a benign congenital neoplasm that mostly presents as a soft-tissue mass in the posterior triangle of the neck. Pure mediastinal lesions are uncommon; the vast majority are asymptomatic and are an incidental finding in adulthood. The diagnosis is often made intra- or postoperatively. Prenatal identification is exceptional and post-natal diagnosis also proves challenging. Case presentation We report one such case that was mistaken for other entities in both the prenatal and immediate post-natal period. Initial and follow-up antenatal ultrasound scans demonstrated a multicystic lesion in the left chest, and the mother was counselled about the possibility of her baby having a congenital diaphragmatic hernia. Initial post-natal chest radiographs were reported as normal. An echocardiogram and thoracic computed tomography scan confirmed a complex multiloculated cystic mediastinal mass. The working diagnoses were of a mediastinal teratoma or congenital cystic adenomatous malformation. At operation, the lesion was compressed by the left lung and was found to be close to the left phrenic nerve, which was carefully identified and preserved. After excision, histopathological examination of the mass confirmed the diagnosis of cystic hygroma. Postoperative dyspnoea was observed secondary to paradoxical movement of the left hemidiaphragm and probable left phrenic neuropraxia. This settled conservatively with excellent recovery. Conclusion Despite the fact that isolated intrathoracic cystic hygroma is a rare entity, it needs to be considered in the differential diagnosis of foetal and neonatal mediastinal masses, particularly for juxtadiaphragmatic lesions. The phrenic nerve is not identifiable on prenatal ultrasound imaging, and it is therefore understandable that a mass close to the diaphragm may be mistaken for a congenital diaphragmatic hernia because of the location, morphology and potential phrenic nerve compression

  11. Natal Dispersal in the North Island Robin (Petroica longipes: the Importance of Connectivity in Fragmented Habitats

    Directory of Open Access Journals (Sweden)

    Askia K. Wittern

    2007-12-01

    Full Text Available Natal dispersal is an important component in bird population dynamics and can influence the persistence of local and metapopulations. We examined natal dispersal in the North Island robin (Petroica longipes, a sedentary bird species distributed in a fragmented forest habitat on Tiritiri Matangi Island, New Zealand. Earlier studies have shown that the only dispersal phase in this species takes place when juveniles leave their natal patch, and that juveniles who fail to find suitable habitat do not survive their first winter. These findings suggest that natal dispersal behavior in this species is important for population viability. We found that juveniles were highly affected by the fragmentation of the forest habitat, with patch occupancy being positively correlated with degree of connectivity of the landscape. Most juvenile movements (52.1% were observed between patches that were separated by less than 20 m. Juvenile North Island robins were found in all forest habitat types, including young and open stands. This suggests that the juveniles are not dependent on old forest stands during their dispersal phase. Based on these findings, we suggest that management of this regionally-threatened species should focus not only on maintaining populations in occupied patches and increasing the habitat quality of these patches, but also on protecting existing forest patches acting as corridors and creating new forest habitat among patches. This would greatly increase the viability of the species' metapopulations by increasing dispersal success between both unoccupied patches and subpopulations. Additionally, increased connectivity between forest patches could also be expected to increase the probability of successful dispersal of other threatened native species, many of which are also sensitive to the high degree of fragmentation of their habitats.

  12. Metabolism correlates with variation in post-natal growth rate among songbirds at three latitudes

    Science.gov (United States)

    Ton, Riccardo; Martin, Thomas E.

    2016-01-01

    1. Variation in post-natal growth rates is substantial among organisms and especially strong among latitudes because tropical and south temperate species typically have slower growth than north temperate relatives. Metabolic rate is thought to be a critical mechanism underlying growth rates after accounting for allometric effects of body mass. However, comparative tests on a large spatial scale are lacking, and the importance of metabolism for growth rates remains unclear both within and particularly across latitudes.

  13. Incidência de lúpus eritematoso sistêmico em Natal, RN - Brasil Incidence of systemic lupus erythematosus in Natal, RN, Brazil

    Directory of Open Access Journals (Sweden)

    Maria José Pereira Vilar

    2003-12-01

    Full Text Available OBJETIVO: estudar a incidência de lúpus eritematoso sistêmico (LES na cidade de Natal, RN, Brasil. MÉTODOS: foram incluídos somente pacientes residentes em Natal, RN, com idade > 15 anos, com pelo menos, quatro critérios do ACR, entre 1/1/ 2000 e 31/12/2000, excluindo lúpus droga-induzido. Foram utilizadas quatro fontes para identificação de pacientes: 1 hospital universitário; 2 postos de saúde de hospitais da rede pública; 3 especialistas (reumatologistas, dermatologistas, nefrologistas e hematologistas em clínicas e hospitais privados e 4 resultados positivos de FAN (> 1:80 de três principais laboratórios da cidade. Médicos foram informados, por cartas, dos procedimentos para notificação. Dados do Censo 2000 foram utilizados para o cálculo das taxas de incidência. Standardized Mortality Ratio (SMR foi aplicado para comparação das taxas de incidência. O valor de p OBJECTIVE: To study the incidence of Systemic Lupus Erythematosus (SLE in the city of Natal, Brazil. METHODS: Only patients living in the city of Natal, older than 15 years old, who fulfilled at least 4 of ACR criteria between January 1st, 2000 and December 31st, 2000, were included. Four sources were used to identify new cases of SLE: 1 the University Hospital; 2 "health units" and hospitals of the public health network; 3 specialists at private hospitals and outpatient clinics; 4 three laboratories performing antinuclear antibody (ANA determination. Physicians were contacted by mail, receiving explanations about the study and directions on how to collaborate. Brazilian population census data (2000 was used to calculate incidence rate. The Standardized Mortality Ratio (SMR was used to compare the incidence rates. The 95% confidence intervals (95% CI were calculated and a P value < 0.05 was considered statistically significant. RESULTS: Forty three patients were diagnosed as SLE new cases in 2000. The calculated incidence was 8.7/100 000/year (95% CI 6

  14. CONDOMÍNIOS HORIZONTAIS FECHADOS E TRANSFORMAÇOES SOCIOESPACIAIS NA CIDADE DE NATAL/RN

    Directory of Open Access Journals (Sweden)

    Matheus Augusto Avelino Tavares

    2009-01-01

    Full Text Available En 1995 tenemos la producción del primer condominio horizontal en la área urbana de Natal, emprendimiento que, de alguna manera, revoluciona el mercado de propiedades inmobiliarias local, una vez que a contar de entonces una serie de otros condominios fueran lanzados en el mercado de propiedades inmobiliarias. Así, el objetivo de este trabajo consiste en entender cuáles son las transformaciones socioespaciaiales que estes emprendimientos producen. Los resultados conseguidos nos permiten afirmar que estes emprendimientos traen una serie de implicaciones socioespaciaiales para la ciudad de Natal, por ejemplo: redefinición en el uso de la tierra en las áreas donde surgen, una vez que si expanden en áreas periféricas de Natal; transformaciones en la estructura urbana y el estándar de la segregación socioespacial de la ciudad, debido a eso los condominios horizontales colocan los diversos grupos sociales conviviendo lado a lado, sin embargo no guardando relaciones entre sí; aparecimiento de espacios que tenden a la homogeneización; la fragmentación de la ciudad y la privatización del espacio urbano.

  15. Virtual Visit to the ATLAS Control Room by University of KwaZulu-Natal, South Africa

    CERN Multimedia

    ATLAS Experiment

    2012-01-01

    The University of KwaZulu-Natal (UKZN) was formed on 1st January 2004 as a result of the merger between the University of Durban-Westville and the University of Natal. The new University brought together the rich histories of both former universities which encompass disadvantage and advantage respectively. During the "Be a Scientist for a Week" program high school learners in their final two years of school will have the opportunity to spend a week at either the Westville, or Pietermaritzburg campus of the University of Kwazulu-Natal. The Westville campus will host approximately 30 students who were the top achievers in mathematics and science from the 20 feeder schools to the university. In order to foster their appreciation for science and assist the students to explore the wide variety of scientific endeavors available to them they will spend blocks of 3 hours hosted by research groups in physics, chemistry, environmental science, mathematics, geology, biological sciences, and computer science. Within the ...

  16. Pericytes in the myovascular niche promote post-natal myofiber growth and satellite cell quiescence.

    Science.gov (United States)

    Kostallari, Enis; Baba-Amer, Yasmine; Alonso-Martin, Sonia; Ngoh, Pamela; Relaix, Frederic; Lafuste, Peggy; Gherardi, Romain K

    2015-04-01

    The satellite cells, which serve as adult muscle stem cells, are both located beneath myofiber basement membranes and closely associated with capillary endothelial cells. We observed that 90% of capillaries were associated with pericytes in adult mouse and human muscle. During post-natal growth, newly formed vessels with their neuroglial 2 proteoglycan (NG2)-positive pericytes became progressively associated with the post-natal muscle stem cells, as myofibers increased in size and satellite cells entered into quiescence. In vitro, human muscle-derived pericytes promoted myogenic cell differentiation through insulin-like growth factor 1 (IGF1) and myogenic cell quiescence through angiopoietin 1 (ANGPT1). Diphtheria toxin-induced ablation of muscle pericytes in growing mice led both to myofiber hypotrophy and to impaired establishment of stem cells quiescence. Similar effects were observed following conditional in vivo deletion of pericyte Igf1 and Angpt1 genes, respectively. Our data therefore demonstrate that, by promoting post-natal myogenesis and stem cell quiescence, pericytes play a key role in the microvascular niche of satellite cells. © 2015. Published by The Company of Biologists Ltd.

  17. Aquatic snails from mining sites have evolved to detect and avoid heavy metals.

    Science.gov (United States)

    Lefcort, H; Abbott, D P; Cleary, D A; Howell, E; Keller, N C; Smith, M M

    2004-05-01

    Toxicants in polluted environments are often patchily distributed. Hence, rather than being passive absorbers of pollution, some organisms have evolved the ability to detect and avoid toxicants. We studied the avoidance behavior of Physella columbiana, an aquatic pulmonate snail, in a pond that has been polluted with heavy metals for more than 120 years. Populations of this snail are rare at reference sites and are only robust at heavy-metal-polluted sites. We hypothesized that the snails are able to persist because they have evolved the ability to minimize their exposure to metals by actively avoiding metals in their environment. Using a Y-maze flow tank, we tested the avoidance behavior of snails to heavy-metal-polluted sediments and single-metal solutions of cadmium, zinc, or lead. We also tested the avoidance behaviors of the snails' laboratory-reared offspring raised in nonpolluted conditions. In addition, we tested the avoidance behavior of a small population of snails from a reference pond. Although all the snails we tested were able to detect low concentrations of heavy metals, we found that snails from the polluted site were the most sensitive, that their offspring were somewhat less sensitive, and that snails from the reference site were the least sensitive. This suggests that the ability of polluted-site snails to avoid heavy metals is both genetic and environmental. The concentrations of metals avoided by the snails from the polluted site were below the levels found at hot spots within their natal pond. The snails may be able to persist at this site because they decrease their exposure by moving to less-polluted sections of the pond. One application of our findings is the use of aquatic snails and our Y-maze design as an inexpensive pollution detector. Environmental pollutants such as lead, zinc, and arsenic are a problem throughout the world. People in underdeveloped countries often lack sophisticated pollution detection devices. We have developed a

  18. Interactions between the intestinal cestode Polyonchobothrium clarias (Pseudophyllidea: Ptychobothriidae) from the African sharptooth catfish Clarias gariepinus and heavy metal pollutants in an aquatic environment in Egypt.

    Science.gov (United States)

    Abdel-Gaber, R; Abdel-Ghaffar, F; Bashtar, A-R; Morsy, K; Saleh, R

    2016-11-01

    In an aquatic environment, there is a profound and inverse relationship between environmental quality and disease status of fish. Parasites are one of the most serious limiting factors in aquaculture. Therefore, the present investigation was carried out during the period of February-December 2014 to determine the parasitic infections in the African sharptooth catfish Clarias gariepinus, relative to the capability of internal parasites to accumulate heavy metals. Up to 100 catfish were examined for gastrointestinal helminths and 38% of fish were found to be infected with the cestode Polyonchobothrium clarias. The morphology of this parasite species, based on light and scanning electron microscopy, revealed that the adult worm was characterized by a rectangular scolex measuring 0.43-0.58 (0.49 ± 0.1) mm long and 0.15-0.21 (0.19 ± 0.1) mm wide, with a flat to slightly raised rostellum armed with a crown with two semicircles each bearing 13-15 hooks, followed by immature, mature and gravid proglottids which were about 29-55 (45), 16-30 (24) and 15-39 (28) in number, respectively. The mature proglottid contained a single set of genitalia in which medullary testes measured 0.09-0.13 (0.11 ± 0.01) mm long and 0.05-0.08 (0.06 ± 0.01) mm wide; a bi-lobed ovary was situated near the posterior margin of the proglottid, extending laterally up to the longitudinal excretory canals; the tubular uterus arose from the ootype up to the anterior margin of the proglottid; and vitelline follicles were cortical. The greater portion of the gravid proglottid was occupied by a uterus filled with unoperculate and embryonated eggs. Chemical analysis confirmed that the concentrations of heavy metals (Zn, Cu, Mn, Cd, Ni and Pb) accumulated in P. clarias were higher than in fish tissues and values recommended by FAO/WHO, with the exception of Zn, which was found to be higher in fish kidneys than in the cestode. This supports the hypothesis that cestodes of fish can be regarded

  19. Toward Electoral Security: Experiences from KwaZulu-Natal Höhere Sicherheit bei Wahlen: Erfahrungen aus KwaZulu-Natal

    Directory of Open Access Journals (Sweden)

    Kristine Höglund

    2011-01-01

    Full Text Available There is a growing recognition of the dangers of electoral violence. Yet, the theoretical foundation for systematic research and for adequate policy is still underdeveloped. This article aims to develop the theoretical understandings of strategies to manage and prevent electoral violence. This is accomplished by integrating research conducted within the two academic discourses on democratization and conflict management and also by drawing on the experiences from the conflict-ridden province KwaZulu-Natal in South Africa. The five strategies identified are monitoring, mediation, legal measures, law enforcement and self-regulating practices. In the article, the functions and mechanisms of the strategies are discussed. In addition, we analyse the limitations and usefulness of each of the strategies in turn and also provide suggestions on how to improve electoral security.Gewaltsame Auseinandersetzungen bei Wahlen werden zunehmend als Gefahr erkannt. Dennoch sind die theoretischen Grundlagen systematischer Forschungen zu diesem Phänomen, die zu angemessenen politischen Handlungsweisen beitragen könnten, immer noch ungenügend entwickelt. Dieser Beitrag zielt darauf ab, einen theoretischen Hintergrund für Strategien zum Umgang mit Gewalt bei Wahlen und zur Prävention zu entwickeln. Zu diesem Zweck kombinieren die Autorinnen Ergebnisse zweier Forschungsbereiche – der Demokratisierungsforschung und der Forschung zum Konfliktmanagement – und ziehen außerdem Erfahrungen aus der konfliktbeladenen südafrikanischen Provinz KwaZulu-Natal heran. Sie identifizieren fünf Strategien: Monitoring, Mediation, gesetzliche Maßnahmen, Sanktionierung und Selbsthilfepraktiken. Die Autorinnen diskutieren die Wirkungsweisen und Erfolgsaussichten, aber auch die Grenzen dieser Strategien und machen einige konkrete Vorschläge zur Erhöhung der Sicherheit bei Wahlen.

  20. [Metal poisoning].

    Science.gov (United States)

    Ferrer, A

    2003-01-01

    Metals are amongst the oldest toxic substances known to man. In today's industrialized world the sources of exposure to metals are ubiquitous both in the field of work and from polluted water, foodstuffs and the environment. Their toxicity is characterized by the metallic element in question, but this is modified by the type of compound, whether organic or inorganic, and its characteristics of hydrosolubility and liposolubility, which determines its toxicokinetics and thus the possibilities of it reaching its targets. The biomolecules most affected by metals are the proteins with enzymatic activity, which is why their pathology is multisystemic. The principal systems affected are the gastrointestinal, central and peripheral neurological, haematic and renal. Some metallic compounds are carcinogenic. Metals's treatment is conditioned by their chemical reactivity. They can be deactivated and eliminated by the administering of chelating agents that produce complex molecules, which are non-toxic and can be excreted. The principal chelating agents are: BAL (British Anti-Lewisite or dimercaprol) DMPS (2,3-Dimercapto-1-propanesulfonic Acid) and DMSA (meso-2,3-Dimercaptosuccinic or Succimer), EDTA, Penicilamine (b,b-dimethylcysteine) and Deferoxamine. Toxicokinetic characteristics, mechanism of action, clinical picture and treatment of some of the most relevant metals and metalloids: lead, mercury and arsenic, are considered.

  1. Black rhinoceros Diceros bicomis capture, transportation and boma management by the Natal Parks Board

    Directory of Open Access Journals (Sweden)

    R.R. Henwood

    1989-10-01

    Full Text Available Selected Papers from the Rhinoceros Conservation Workshop, Skukuza, Kruger National Park,31 August – 4 September 1988 The procedure used by the Natal Parks Board in the capture of black rhinoceros Diceros bicomis minor (Drummond, 1876 is outlined. It is emphasised that a successful capture operation requires careful planning and should not be attempted by the uninitiated or by parties who have little or no experience. Dosages of drugs are given, the darting and actual capture procedures highlighted, and aspects of transport and practical boma management are described.

  2. Villes et structures spatiales élémentaires du KwaZulu-Natal

    Directory of Open Access Journals (Sweden)

    Fabrice Folio

    2004-12-01

    Full Text Available However significant the legacy of former segregational policies in the spatial organisation of South African cities, it is important to include other basic spatial structures that have often been minimised. That is the aim of this paper. The towns in KwaZulu-Natal province provide a strong illustration of this point. The urban entities in the province can be differentiated by several criteria – either historical or contemporary – that are not always related to apartheid policy. The towns are underpinned by basic structures that organise the province. These structures are determined not only by racial discrimination, but also by economics. Recent developments seem to reinforce this trend.

  3. African languages as compulsory courses in KwaZulu Natal: Illusory initiative or inspired intervention?

    Directory of Open Access Journals (Sweden)

    Noleen S Turner

    2013-04-01

    Full Text Available The point of departure in this article is the call by the Minister of Higher Education and Training in 2011 to introduce compulsory indigenous African language courses at tertiary institutions. The current language policy of the University of KwaZulu-Natal and the practicalities and difficulties of introducing the compulsory course at tertiary level is examined. The current language policy of the present South African Government and the negative attitudes of potential African language learners at schools and universities are discussed and a recommendation made for a possible way forward.

  4. Rare association of hyper IgE syndrome with cervical rib and natal teeth

    Directory of Open Access Journals (Sweden)

    Roshan Anupama

    2009-01-01

    Full Text Available Hyper IgE syndrome (HIES is a rare immunodeficiency syndrome characterized by a triad of cutaneous abscesses, mostly caused by Staphylococus aureus; pneumonia; and raised IgE levels. Nonimmunological associations include course facial features, multiple bone fractures, joint hyperextensibility, and retained primary dentition. Patients require long-term antibiotic therapy. We report here a classical case of HIES with rare associations of natal teeth, bilateral cervical ribs, and conductive deafness. The patient was being treated with monteleukast and dapsone.

  5. Imagem corporal e fatores de risco em praticantes de caminhada da cidade do Natal-RN

    OpenAIRE

    Silva Filho, Lindomar da

    2009-01-01

    Imagem corporal é a figura de nossos corpos construída em nossas mentes e o grau de insatisfação geralmente está associada a fatores de risco identificados por medidas antropométricas. O objetivo desse estudo descritivo foi avaliar os fatores de risco decorrentes das variáveis morfológicas e funcionais associadas à percepção de autoimagem em 130 praticantes de caminhada de meia-idade da zona sul da cidade de Natal, subdivididos em quatro grupos em função do gênero e faixa etária. Como instrum...

  6. Hemoglobinopatias: a que casais oferecer o diagnóstico pré-natal?

    OpenAIRE

    2015-01-01

    As hemoglobinopatias (alfa-talassémia, beta-talassémia, drepanocitose e talassodrepanocitose) constituem anemias hereditárias, de transmissão autossómica recessiva, que nas suas formas mais graves são altamente incapacitantes. Dada a impossibilidade de cura, aos casais em risco de terem descendência afetada com as formas mais graves da doença deve ser disponibilizada a realização de diagnóstico pré-natal (DPN) molecular. Anteriormente à disponibilização do DPN já deve conhecer-se a alteração ...

  7. Attitude and beliefs of some nurses in government hospitals in Ibadan, Nigeria to natal/neonatal teeth in infants.

    Science.gov (United States)

    Bankole, O O; Oke, G A

    2013-09-01

    Eruption of the first deciduous teeth in children has shown much variation and occasionally may erupt prematurely at birth or within one month of life. Myths about natal/neonatal teeth abound in the Nigerian culture. Nurses are health care providers who are in constant close contact with patients and can be invaluable in helping to dispel these associated myths. However, to provide correct information they should be adequately equipped to do so. The aim of this study thus, was to assess the attitudes and beliefs of some nurses in Ibadan, Nigeria to natal/neonatal teeth in infants. A cross sectional survey was conducted among 380 nurses in the teaching, general and local government hospitals and clinics in Ibadan, Nigeria. Results revealed that 41.3% of the respondents would express shock and surprise if they assisted in delivering a baby with natal teeth. Half of the respondents (49.7%) felt that natal/neonatal teeth will be a great source of embarrassment to the family while a smaller proportion (11.8%), believed it was a curse (p = 0.01). On the advice the respondents would give to the mothers, more than a th (39.7%), would recommend immediate extraction of the teeth. A further 42 (11.1%) nurses were of the opinion that spiritual cleansing should be carried out prior to extraction. A greater proportion of the older nurses would advice immediate extraction of the teeth (p = 0.031). Regarding the perceived effect of natal/neonatal teeth on the children, (7.4%), (12.6%) and (29.2%) of the respondents believed that the children will behave strangely, will possess spiritual authority and be victims of stigmatization later in life respectively. This study has revealed that knowledge gaps about natal/neonatal teeth exist among the nurses in Ibadan, Nigeria. Health education programmes targeted at nurses are essential to correct these beliefs.

  8. A percepção dos moradores da comunidade do Passo da Pátria em Natal-RN

    OpenAIRE

    Machado, Mônica Pedrosa

    2008-01-01

    O presente trabalho intitulado: A percepção ambiental dos moradores da comunidade do Passo da Pátria em Natal-RN tem como principal objetivo investigar a percepção dos moradores em um ambiente degradado em fase de urbanização, localizado à margem do Rio Potengi. Trata-se de uma área de risco ambiental, que ao longo dos anos foi sendo negligenciada pelo poder público, mas que atraiu inúmeras pessoas pela facilidade de acesso às áreas urbanizadas da cidade de Natal e ao mesmo tempo pela riqueza...

  9. Seguimento da Hidronefrose Pré-Natal. Experiência da Consulta de Nefrologia Pediátrica do HGSA

    OpenAIRE

    Teixeira, Paulo; Madalena, Célia; Reis, Armando; de Matos, Paula

    2014-01-01

    Com este trabalho, os autores pretendem avaliar a evolução pós-natal da hidronefrose diagnosticada in útero.Entre Janeiro de 1991 e Maio de 1997 foram enviados à Consulta de Nefrologia Pediátrica do HGSA 80 crianças com o diagnóstico de hidronefrose pré-natal.Foram estudadas 57 crianças (76 rins) com hidronefrose primária. Os rins foram divididos em grupos de acordo com as dimensões do bacinete: Grupo O (bacinete 4 mm), grupo 1 (bacinete 4 - 9 mm), grupo 2 (bacinete 10 - 19 mm) e grupo 3 (bac...

  10. Die Barmhartigheidsbediening van die NG Kerk van Natal - afhanklik en eksklusief?

    Directory of Open Access Journals (Sweden)

    R. B. van Aarde

    2000-09-01

    Full Text Available The ministry of compassion of the Dutch Reformed Church in Natal - dependent and exclusive?This study highlights two major concerns in the history of the Dutch Reformed Church of Natal�s ministry of compassion. The church�s work became financially too dependent on government subsidies. The work originally started off with church finances, but was later financed by government. In principle there is nothing wrong with such a partnership, but the present financial dependency will have to make room for an independent ministry of compassion. The church�s ministry of compassion was also mainly focussed on the Afrikaner nation. In this the church supported the apartheid system of the day and started the perception that services of compassion are for the White community while missionary work is focussed on the Black communities. What history teaches us in this field of compassion and caring can help to rectify the ministry of compassion of the Dutch Reformed Church in KwaZulu/Natal and help the church to avoid the same mistakes in future

  11. The contribution of public capital towards economic growth: A KwaZulu-Natal case study

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    Clive E. Coetzee

    2017-04-01

    Aim: The way provincial or regional growth depends on infrastructure is investigated in this article and it is applied to data from KwaZulu-Natal province, as an illustration. Setting: This study investigates the extent to which infrastructure in KwaZulu-Natal province in South Africa leads towards economic growth of the province. Methods: From a theoretical framework, this article develops an endogenous growth model, which investigates the association between provincial public capital stock expenditure and economic growth. Data series for public capital formation are first developed to apply in this study and others to follow. Econometric techniques are then employed, using quarterly data between 2001 and 2015, to assess the set hypothesis that growth in expenditure on public capital leads to national economic growth. Results: The empirical results support the argument of a positive relationship between provincial capital stock and economic growth in the long-term. The findings also suggests that the long-term causality or effect fades over time, albeit slowly. Conclusion: The nature and statistical significance of the long-term equilibrium relationship seems to be ambiguous at best. Some evidence of an equilibrium relationship in the short-term was, however, also observed. In conclusion, there also seems to be some causality between provincial capital stock and provincial gross domestic product in the short-run.

  12. Core competencies of radiographers working in rural hospitals of KwaZulu-Natal, South Africa.

    Science.gov (United States)

    Mung'omba, Bernard; Botha, Annali D H

    2017-08-31

    Rural radiographers require, over and above traditional radiographic expertise, additional competencies which to a certain degree are unique however not limited to rural practice. Previous studies, however, have focused more attention primarily on other rural health professionals such as doctors and nurses leaving a research need in this field. This article focuses on the additional competencies that may be required for rural radiographers. To investigate and identify additional core competencies required by radiographers working in rural hospitals of KwaZulu-Natal in order to propose a continuous professional development strategy aimed at rural radiographers. An exploratory sequential design was utilised with qualitative (Phase I) and quantitative (Phase II) strands involving seven participants and 109 respondents, respectively. Only radiographers working in rural KwaZulu-Natal hospitals were included in the study. The four major themes and categories identified in Phase I were used to develop data collection instrument for Phase II of the study. Collectively, the results revealed that there were a number of additional core competencies such as, but not limited to, teamwork, ability to do basic obstetric ultrasound scans, leadership, management and reporting on plain radiographs, all of which are required by rural radiographers. In 2014 when these competencies were checked against a single curriculum, it was found that majority of them were either partially covered or not at all covered. The study provides additional information on context specific core competencies and, therefore, may act as a catalyst to influence the future of radiographers working in rural areas of South Africa.

  13. Coping, stress and burnout in the South African police service in Kwazulu-natal

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    L. Wiese

    2003-10-01

    Full Text Available The objective of this research was to determine the relationship between coping, stress and burnout in the South African Police Service. A survey design was used. The study population (N = 257 consisted of police personnel in Kwazulu-Natal. The COPE, Police Stress Inventory and Maslach Burnout Inventory – General Survey (MBI-GS, were used as measuring instruments. Structural equation analysis showed that job demands (as stressors are associated with exhaustion. Passive coping strategies contributed to exhaustion and cynicism, while seeking emotional support led to lower exhaustion. Exhaustion contributed to cynicism. Stress because of a lack of resources, active coping strategies and not coping passively seem to impact on professional efficacy. Opsomming Die doelstelling van hierdie navorsing was om die verband tussen coping, stres en uitbranding binne die Suid-Afrikaanse Polisiediens te ondersoek. ’n Opname-ontwerp is gebruik. Die studiepopulasie (N = 257 het bestaan uit polisiepersoneel in Kwazulu-Natal. Die COPE, die Polisiestres-Opname en die Maslach-uitbrandingsvraelys – Algemene Opname (MBI-GS is as meetinstrumente gebruik. Strukturele vergelykingsmodellering het aangetoon dat werkseise (as stressore geassosieer word met uitputting. Passiewe coping- strategieë het bygedra tot uitputting en sinisme, terwyl die soeke na emosionele ondersteuning tot laer uitputting gelei het. Uitputting het tot sinisme bygedra. Stres a.g.v. ’n tekort aan hulpbronne (invers, aktiewe coping-strategieë en passiewe coping-strategieë (invers blyk ’n uitwerking op professionele doeltreffendheid te hê.

  14. Robert Plant (1818–1858: A Victorian plant hunter in Natal, Zululand, Mauritius and the Seychelles

    Directory of Open Access Journals (Sweden)

    Donal P. McCracken

    2011-03-01

    Full Text Available In the 1850s Robert William Plant collected plants and other natural specimens in what is now KwaZulu-Natal. This one-time Englishman compiled a dictionary for gardeners before emigrating to Natal in 1850. There he worked as the agent for Samuel Stevens, the London dealer in ‘curiosities of natural history’. Though Plant collected mainly plants, he also sent consignments of beetles, butterflies, bird skins and shells back to Britain. He published the first scientific paper on Zululand and was requested by the Royal Botanic Gardens at Kew to write the first Flora natalensis. It was while collecting for this never-to-be-completed treatise that Plant contracted malaria in Maputaland. He died in St Lucia in 1858 and in doing so became South Africa’s martyr to botany. What emerges from this study is a picture of the difficulties faced by plant hunters in mid-19th-century South Africa, the sort of plants they collected and the necessity for them sometimes to diversify into other natural history products to survive.

  15. Spatial distribution of breeding Pied Flycatchers Ficedula hypoleuca in respect to their natal sites

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    Sokolov, L.

    2004-06-01

    Full Text Available Study of philopatry and dispersal of pied flycatchers Ficedula hypoleuca was launched on the Courish Spit (SE Baltic in 1981. Since then, ca. 9,000 nestlings were ringed at different sites in the Russian part of the Courish Spit. A total of 557 individuals ringed as pulli were recaptured in subsequent seasons in the study area. Both males and females are more often recaptured in the plots where they were ringed than in other plots. These results were interpreted in the framework of the hypothesis forwarded by Löhrl (1959 and supported by Berndt & Winkel (1979. These authors suggested that cavity nesters (pied flycatchers and collared flycatchers F. albicollis imprint their future local breeding area during the period of postfledging exploration. Birds that survive until the next spring, return to these imprinted areas to breed. A similar study done by Sokolov et al. (1984 on the Courish Spit in an open nesting species, the chaffinch Fringilla coelebs, confirmed this finding. We assumed that juvenile pied flycatchers disperse for varying distances during their postfledging movements and imprint a local area, some 1–5 kilometres in diameter. This area is the goal of their migration next spring. It is suggested that in spring, yearlings are non–randomly distributed in respect to the area they have imprinted as juveniles. Recently, Vysotsky (2000, 2001 re–analysed the same data on philopatry of pied flycatchers on the Courish Spit and forwarded an alternative hypothesis. He suggests that juveniles, both males and females, do not imprint any local area during the postfledging period, but are distributed randomly across the area of several dozens of kilometres in spring. Vysotsky was able to show that distribution of distances of natal dispersal did not differ from the random pattern the study plot which was an 8.5 km long line of nest boxes along the Courish Spit. The aim of this study was to test these two alternative hypotheses. To do so, we

  16. Post-natal growth of the gastrointestinal tract of the Siberian hamster: morphometric analysis.

    Science.gov (United States)

    Wołczuk, K; Kobak, J

    2014-12-01

    Post-natal growth of the gastrointestinal tract of the Siberian hamster was studied in newborn and 3-, 7-, 14-, 21-, 42- and 90-day-old animals. Morphometric measurements and calculations were carried out: length and internal surface of gastrointestinal tract segments, size (height, width, surface) and density of villi as well as allometric growth rate of the length and internal surface of the segments with respect to the body mass. The fastest growth rate of the gastrointestinal tract segments was noticed during the first 3 days of the post-natal life. Nevertheless, significant regional differences in their growth rate were found. The increase in the length and internal surface of the large intestine was fastest, while the smallest increase was observed in the oesophagus. All segments of the gastrointestinal tract except oesophagus exhibited a positive allometric relationship to the body mass from birth till final weaning, whereas during the post-weaning period, the increase was isometric. Thus, at birth, the gastrointestinal tract segments were relatively smaller compared with those observed in adults, but then, the gastrointestinal tract grew faster than the rest of the body and reached its adult proportions just before the transition to solid food. Most probably, reaching the adult structure of the gastrointestinal tract before the final weaning is an essential condition for the proper growth of an organism after the weaning.

  17. An overview of the eradication of Brucella melitensis from KwaZulu-Natal.

    Science.gov (United States)

    Emslie, F R; Nel, J R

    2002-06-01

    Brucella melitensis is a Gram-negative bacterium whose primary hosts are goats and sheep. Like the other BrucelIa spp., with the exception of Brucella ovis, it is not particularly host specific as it is pathogenic for a variety of other mammal species including humans. In humans the disease caused by it is rated as one of the most important zoonoses. Three outbreaks have been recorded in goats and sheep in South Africa; the first outbreak occurred in sheep in 1965 in the Mpumalanga and Northern Provinces (then both part of the Transvaal Province), the second occurred in sheep in 1989 near Pretoria, Gauteng Province, and the third and current outbreak was diagnosed in a flock of goats in northern KwaZulu-Natal in September 1994. Following the initial diagnosis of B. melitensis in north-eastern KwaZulu-Natal, a serological survey was conducted in order to identify foci of infection in the goat and sheep populations. Six positive foci were identified. In March 1996 a test-and-slaughter eradication campaign was initiated in these areas. Initial test results revealed a prevalence of between 1.23% and 4.02 %. All positive animals were identified and slaughtered. Eradication programmes were repeated between March 1996 and June 2000, in the populations at risk, and the disease prevalence was reduced in all the affected populations.

  18. Individual variation affects departure rate from the natal pond in an ephemeral pond-breeding anuran

    Science.gov (United States)

    Chelgren, N.D.; Rosenberg, D.K.; Heppell, S.S.; Gitelman, A.I.

    2008-01-01

    Frogs exhibit extreme plasticity and individual variation in growth and behavior during metamorphosis, driven by interactions of intrinsic state factors and extrinsic environmental factors. In northern red-legged frogs (Rana aurora Baird and Girard, 1852), we studied the timing of departure from the natal pond as it relates to date and size of individuals at metamorphosis in the context of environmental uncertainty. To affect body size at metamorphosis, we manipulated food availability during the larval stage for a sample (317) of 1045 uniquely marked individuals and released them at their natal ponds as newly metamorphosed frogs. We recaptured 34% of marked frogs in pitfall traps as they departed and related the timing of their initial terrestrial movements to individual properties using a time-to-event model. Median age at first capture was 4 and 9 days postmetamorphosis at two sites. The rate of departure was positively related to body size and to date of metamorphosis. Departure rate was strongly negatively related to time elapsed since rainfall, and this effect was diminished for smaller and later metamorphosing frogs. Individual variation in metamorphic traits thus affects individuals' responses to environmental variability, supporting a behavioral link with variation in survival associated with these same metamorphic traits. ?? 2008 NRC.

  19. Natality and calf mortality of the Northern Alaska Peninsula and Southern Alaska Peninsula caribou herds

    Directory of Open Access Journals (Sweden)

    Richard A. Sellers

    2003-04-01

    Full Text Available We studied natality in the Northern Alaska Peninsula (NAP and Southern Alaska Peninsula (SAP caribou (Rangifer tarandus granti herds during 1996-1999, and mortality and weights of calves during 1998 and 1999- Natality was lower in the NAP than the SAP primarily because most 3-year-old females did not produce calves in the NAP Patterns of calf mortality in the NAP and SAP differed from those in Interior Alaska primarily because neonatal (i.e., during the first 2 weeks of life mortality was relatively low, but mortality continued to be significant through August in both herds, and aggregate annual mortality was extreme (86% in the NAP Predators probably killed more neonatal calves in the SAP, primarily because a wolf den (Canis lupus was located on the calving area. Despite the relatively high density of brown bears (Ursus arctos and bald eagles (Haliaeetus leucocephalus, these predators killed surprisingly few calves. Golden eagles (Aquila chrysaetos were uncommon on the Alaska Peninsula. At least 2 calves apparently died from pneu¬monia in the range of the NAP but none were suspected to have died from disease in the range of the SAP. Heavy scav¬enging by bald eagles complicated determining cause of death of calves in both the NAP and SAP.

  20. Sexual abuse of boys in KwaZulu-Natal, South Africa: a hospital-based study.

    Science.gov (United States)

    Collings, Steven J

    2005-01-01

    Objective - The aim of the study was to determine the prevalence and factors associated with child sexual abuse in a total sample of boys referred for medico-legal assessment in a peri-urban area of KwaZulu-Natal, South Africa. Method - A retrospective analysis was undertaken of clinical and social work records for sexually abused boys presenting for medico-legal assessment at the Mahatma Gandhi Memorial Hospital (Phoenix, KwaZulu-Natal) during the period January 2001 to December 2003. Results - In the period reviewed, 131 boys reported an incident of sexual abuse with temporal trends indicating a significant increase in the incidence of reported abuse over the three year period. Most victims fell in the 4-11 year age category, anal penetration constituted the most common form of abuse (86% of cases), and perpetrators were predominantly persons who were known to the child. Conclusion - Study findings indicate that the sexual abuse of boys constitutes a sizeable and emerging problem in peri-urban communities in South Africa. Evidence suggests that increased rates of victimisation are associated with a breakdown in family support networks in the context of rapid urbanisation.

  1. Number One Reef: An overstepped segmented lagoon complex on the KwaZulu-Natal continental shelf

    Directory of Open Access Journals (Sweden)

    Godfrey Vella

    2012-07-01

    Full Text Available This study of the bathymetry of the mid-shelf of the Durban Bight, KwaZulu-Natal revealed a series of previously undocumented seafloor features. These features were mapped using a high-resolution multibeam bathymetric echosounder and a detailed map of the seafloor topography was produced. We recognised several features that closely resemble features of contemporary segmented lagoon and lake systems: semicircular seafloor depressions, arcuate ridges, cuspate spits and prograding submerged barriers. Based on the striking similarity in morphology to Kosi Bay – a segmented lagoon system from the sandy northern KwaZulu-Natal coastal plain – a similar evolutionary model is proposed. This model is of an incised valley formed following a sea level lowering to the Last Glacial Maximum at about 18 000 BP. Thereafter, continued transgressive infilling occurred to a point where an extensive lagoon and back-barrier system was established. At this point, sea levels remained static, causing the net segmentation of the system and the slow closure of the tidal basins or circular depressions. This type of seafloor topography is rarely preserved and is the result of fortuitous cementation after deposition and the later removal of sediment that would ordinarily bury such features.

  2. Laboratory Experiments on the Electrochemical Remediation of the Environment. Part 9: Microscale Recovery of a Soil Metal Pollutant and Its Extractant

    Science.gov (United States)

    Ibanez, Jorge G.; Balderas-Hernandez, Patricia; Garcia-Pintor, Elizabeth; Barba-Gonzalez, Sandy Nohemi; Doria-Serrano, Ma. del Carmen; Hernaiz-Arce, Lorena; Diaz-Perez, Armando; Lozano-Cusi, Ana

    2011-01-01

    Many soils throughout the world are contaminated with metal salts of diverse toxicity. We have developed an experiment to demonstrate the removal of a metal from an insoluble surrogate soil pollutant, CuCO[subscript 3] multiplied by Cu(OH)[subscript 2], by complexation followed by the simultaneous electrochemical recovery of the ligand (i.e.,…

  3. Laboratory Experiments on the Electrochemical Remediation of the Environment. Part 9: Microscale Recovery of a Soil Metal Pollutant and Its Extractant

    Science.gov (United States)

    Ibanez, Jorge G.; Balderas-Hernandez, Patricia; Garcia-Pintor, Elizabeth; Barba-Gonzalez, Sandy Nohemi; Doria-Serrano, Ma. del Carmen; Hernaiz-Arce, Lorena; Diaz-Perez, Armando; Lozano-Cusi, Ana

    2011-01-01

    Many soils throughout the world are contaminated with metal salts of diverse toxicity. We have developed an experiment to demonstrate the removal of a metal from an insoluble surrogate soil pollutant, CuCO[subscript 3] multiplied by Cu(OH)[subscript 2], by complexation followed by the simultaneous electrochemical recovery of the ligand (i.e.,…

  4. A comparative assessment of heavy metal accumulation in soft parts and byssus of mussels from subarctic, temperate, subtropical and tropical marine environments

    NARCIS (Netherlands)

    Szefer, P.; Fowler, S.W.; Ikuta, K.; Paez Osuna, F.; Ali, A.A.; Kim, B-S.; Fernandes, H.M.; Belzunce, M.J.; Guterstam, B.; Kunzendorf, H.; Wolowicz, M.; Hummel, H.; Deslous-Paoli, M.

    2006-01-01

    Existing data on metal concentrations in mussels from subarctic, temperate, subtropical and tropical waters were analyzed using multivariate statistics in order to assess regional variations in metal contamination. Potential errors were reduced by only analyzing data from surveys that employed the

  5. A comparative assessment of heavy metal accumulation in soft parts and byssus of mussels from subarctic, temperate, subtropical and tropical marine environments

    NARCIS (Netherlands)

    Szefer, P.; Fowler, S.W.; Ikuta, K.; Paez Osuna, F.; Ali, A.A.; Kim, B-S.; Fernandes, H.M.; Belzunce, M.J.; Guterstam, B.; Kunzendorf, H.; Wolowicz, M.; Hummel, H.; Deslous-Paoli, M.

    2006-01-01

    Existing data on metal concentrations in mussels from subarctic, temperate, subtropical and tropical waters were analyzed using multivariate statistics in order to assess regional variations in metal contamination. Potential errors were reduced by only analyzing data from surveys that employed the s

  6. Adsorption of Toxic Metals and Control of Mosquitos-borne Disease by Lysinibacillus sphaericus:Dual Benefits for Health and Environment

    Institute of Scientific and Technical Information of China (English)

    Javier Edo.Vargas; Jenny Dussán

    2016-01-01

    Objective Assessment of the bacteriumL. sphaericusas a dual-action candidate for biological control of mosquito-borne diseases and bioremediation of toxic metals. Methods Larvae of the mosquito,C. quinquefasciatus, were first evaluated for metal tolerance and then exposed to 5 ppm cadmium, chromium, arsenic, and lead in assays together with seven strains of L. sphaericus. A probit regression analysis was used to estimate the LC50 of Cd, Cr, As, and Pb toC. quinquefasciatus.An analysis of covariance and multifactorial ANOVA examined the metal biosorption and larvicidal properties of the seven strains of L. sphaericus. Results We found that L. sphaericus adsorbed the toxic metal ions and was toxic against mosquito larvae. The L. sphaericus strain Ⅲ(3)7 resulted in a larvae mortality of over 80% for all the tested metals. This strain also exhibited the capacity to adsorb 76% of arsenic, 32% of lead, 25% of chromium, and 7%of cadmium. Conclusion This study found combined metal adsorption and larval toxicity associated with three strains ofL. sphaericus[Ⅲ(3)7, OT4b.31, and CBAM5]. This suggests that a combination of these strains shows strong dual potential forbiological control of mosquitosin heavy metal-contaminated areas and remediate the heavy metal contamination as well.

  7. Natal teeth

    Science.gov (United States)

    ... 2016 Updated by: Michael Kapner, DDS, general and aesthetic dentistry, Norwalk Medical Center, Norwalk, CT. Review provided ... for EHRs For Developers U.S. National Library of Medicine 8600 Rockville Pike, Bethesda, MD 20894 U.S. Department ...

  8. The impact of auxins used in assisted phytoextraction of metals from the contaminated environment on the alterations caused by lead(II) ions in the organization of model lipid membranes.

    Science.gov (United States)

    Hąc-Wydro, Katarzyna; Sroka, Aleksandra; Jabłońska, Klaudia

    2016-07-01

    Auxins are successfully used to improve phytoextraction efficiency of metal ions from the contaminated environment, however, the mechanism of their activity in this field is not explained. Auxins are known to exert various biochemical alterations in the plant membranes and cells, but their activity involves also direct interactions with lipids leading to changes in membrane organization. Following the suggestion that the auxins-induced modifications in membrane properties alleviate toxic effect of metal ions in this paper we have undertaken the comparative studies on the effect of metal ions and metal ions/auxins mixtures on model membrane systems. The experiments were done on lipid monolayers differing in their composition spread on water subphase and on Pb(2+), Indole-3-acetic acid (IAA), 1-Naphthaleneacetic acid (NAA) and Pb(2+)/IAA and Pb(2+)/NAA water solutions. The analysis of the collected data suggests that metal ions and auxins can change fluidity of the lipid systems and weaken the interactions between monolayer components. This manifested in the increase of the mean area per molecule and the excess area per molecule values for the films on Pb(2+), auxins as well as Pb(2+)/auxin solutions as compared to the values on pure water subphase. However, the presence of auxin in the mixture with lead(II) ions makes the alterations induced by sole metal ions weaker. This effect was more pronounced for the membranes of a higher packing. Thus it was proposed that auxins may enhance phytoextraction of metal ions by weakening their destabilizing effect on membrane. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Exploration potential of Paraiba and Natal platform basins, NE Brazil; Potencial exploratorio das bacias da Paraiba e da plataforma de Natal, NE do Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Jose A. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Lima Filho, Mario; Neumann, Virginio H. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Geologia; Maranhao Neto, Jose Carneiro; Araujo, Joao A.A. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Programa de Pos Graduacao em Geociencias

    2008-07-01

    The portion of Brazilian continental margin located between the Pernambuco Shear Zone (ZCPE) and Touros High, enclosing Natal Platform and Paraiba basin, NE Brazil, presents a thin sedimentary cover represented by Neo- Cretaceous deposits, over an elevated basement. In this zone the narrow platform ends abruptly against the ocean plate, forming a scarped slope. This area corresponds to the Transverse zone of Northeast Brazil (TZN) limited by two extensive transcurrent E-W shear zones that acted as accommodation zones for the strain produced by the advance of the southern and northern rift branches. During the Aptian, the rift suffered a NE deflection and contoured the Borborema Province and the TZN. The resistance of this block to the rift advance generated a prominent and elevated region into the Atlantic gulf which resulted in the absence of rift deposition over the Brazilian margin and its deviation to the African side. The model suggested by this paper denominates this area as the 'exception zone' of the Brazilian margin, which possess a poor petroliferous potential and need to be separated from the sector corresponding to the Pernambuco basin, located to south of ZCPE, representing the last piece of margin before the rift deflection and possessing an important petroliferous potential. (author)

  10. Collective prenatal consultation: a new proposal for comprehensive health care Consulta pre-natal colectiva: una nueva propuesta para la atención integral Consulta coletiva de pré-natal: uma nova proposta para uma assistência integral

    Directory of Open Access Journals (Sweden)

    Lucia Helena Garcia Penna

    2008-02-01

    Full Text Available This article describes the Collective Prenatal Consultation as a new healthcare methodology, which is performed according to government standards, but collectively. Relaxation and sensitization techniques are used, as well as group dynamics, including a collective exam of the pregnant women. The Collective Consultation is carried out in a welcoming environment, which provides clarification and socialization of experiences and information, centered on those women. The healthcare professional records every obstetric parameter and behavior in the patient's prenatal card and history file. Priority is given to the principle of integrality and citizenship, with the aim to break the biomedical care paradigm, thus favoring humanized and comprehensive care to the women.Consiste en la descripción de la Consulta Pre-Natal Colectiva como una nueva metodología asistencial, la cual es realizada siguiendo los estándares gubernamentales, no obstante de forma colectiva. Se utilizan técnicas de relajación, sensibilización y dinámicas de grupo, incluyendo el examen colectivo de las gestantes en un lugar acogedor, informativo y socializador de experiencias e informaciones, en el cual la gestante es protagonista. En la Consulta Colectiva el profesional registra todos los parámetros y conductas obstétricas en el carnet e historia peri-natal, priorizando los principios de atención integral y ciudadanía, buscando romper con el paradigma asistencial-biomédico y favoreciendo para una atención humanizada e integral de la mujer.Este estudo consiste na descrição da Consulta Coletiva de Pré-Natal como nova metodologia assistencial, a qual é realizada seguindo os padrões governamentais, porém, coletivamente. Utilizou-se técnicas de relaxamento e de sensibilização e dinâmicas de grupo, incluindo o exame coletivo das gestantes em um espaço acolhedor, esclarecedor e socializador de experiências e informações, em que a gestante é protagonista. Na

  11. A comparative assessment of heavy metal accumulation in soft parts and byssus of mussels from subarctic, temperate, subtropical and tropical marine environments.

    Science.gov (United States)

    Szefer, P; Fowler, S W; Ikuta, K; Osuna, F Paez; Ali, A A; Kim, B-S; Fernandes, H M; Belzunce, M-J; Guterstam, B; Kunzendorf, H; Wołowicz, M; Hummel, H; Deslous-Paoli, M

    2006-01-01

    Existing data on metal concentrations in mussels from subarctic, temperate, subtropical and tropical waters were analyzed using multivariate statistics in order to assess regional variations in metal contamination. Potential errors were reduced by only analyzing data from surveys that employed the same protocols, analytical methodologies and analysts. Factor analysis demonstrated that mussels inhabiting extremely contaminated areas (e.g. from Japanese and Swedish metallurgy sources) could be separated from mussels from other contaminated areas, and that metals such as Cd, Pb, Cu and Zn could be used to identify heavily contaminated samples while Co, Fe, Cr and Ni concentrations were good markers for exposure to inputs from different industrial sources. Furthermore byssus, like soft tissue, selectively and sensitively reflects variations of certain metal concentrations in ambient waters and thus serves as a reliable biomonitor for these contaminants in a variety of coastal and estuarine areas.

  12. Building a Future without Gender Violence: Rural Teachers and Youth in Rural Kwazulu-Natal, South Africa, Leading Community Dialogue

    Science.gov (United States)

    de Lange, Naydene; Mitchell, Claudia

    2014-01-01

    This article advances the idea that rural youth and teachers are the key in leading community dialogue towards addressing gender-based violence (GBV) in their community through their film making. The youth voices on the realities of GBV in their school and community, in rural KwaZulu-Natal, South Africa, captured through the process of…

  13. Between the Lines: Gender in the Reception of Texts by School Children in Rural KwaZulu-Natal, South Africa.

    Science.gov (United States)

    Balfour, Robert

    2003-01-01

    Explores the interface between literature, gender, culture, and language within an educational context. Examines the responses of Zulu boys and girls to the introduction of a new curriculum that integrated language and literary study in a rural school in KwaZulu-Natal, South Africa. Specifically, it shows how reading can lead to a more complex and…

  14. A literature review of tele-dermatology programs in the South African public health sector: Kwazulu-Natal perspective

    CSIR Research Space (South Africa)

    Walters, Laticha EM

    2015-11-01

    Full Text Available of Tele-dermatology Programs in the South African Public Health Sector: KwaZulu-Natal perspective Authors: Laticha EM Walters, Maurice Mars, Richard E Scott Introduction: South Africa’s HIV/AIDS prevalence rate is 17,9%, the highest being in Kwa...

  15. Dynamics of some forests in Kwa Zulu-Natal, South Africa, based on ordinations and size-class distributions

    CSIR Research Space (South Africa)

    Everard, DA

    1995-12-01

    Full Text Available Indigenous forest in Kwa Zulu-Natal has been fairly well described, however, very little has been published on its dynamics. There is, to our knowledge, nothing published on disturbances regimes, dendrology and life histories of constituent species...

  16. Heritability of short-scale natal dispersal in a large-scale foraging bird, the wandering albatross.

    Science.gov (United States)

    Charmantier, A; Buoro, M; Gimenez, O; Weimerskirch, H

    2011-07-01

    Natal dispersal is a key life history trait for the evolution and adaptation of wild populations. Although its evolution has repeatedly been related to the social and environmental context faced by individuals, parent-offspring regressions have also highlighted a possible heritable component. In this study, we explore heritability of natal dispersal, at the scale of the sub-Antarctic Possession Island, for a large-scale foraging seabird, the Wandering albatross Diomedea exulans, exploiting a pedigree spanning over four decades and a maximum of four generations. The comparison of three different methods shows that heritability on the liability scale can vary drastically depending on the type of model (heritability from 6% to 86%), with a notable underestimation by restricted maximum likelihood animal models (6%) compared to Bayesian animal models (36%). In all cases, however, our results point to significant additive genetic variance in the individual propensity to disperse, after controlling for substantial effects of sex and natal colony. These results reveal promising evolutionary potential for short-scale natal dispersal, which could play a critical role for the long-term persistence of this species on the long run. © 2011 The Authors. Journal of Evolutionary Biology © 2011 European Society For Evolutionary Biology.

  17. Building a Future without Gender Violence: Rural Teachers and Youth in Rural Kwazulu-Natal, South Africa, Leading Community Dialogue

    Science.gov (United States)

    de Lange, Naydene; Mitchell, Claudia

    2014-01-01

    This article advances the idea that rural youth and teachers are the key in leading community dialogue towards addressing gender-based violence (GBV) in their community through their film making. The youth voices on the realities of GBV in their school and community, in rural KwaZulu-Natal, South Africa, captured through the process of…

  18. Between the Lines: Gender in the Reception of Texts by School Children in Rural KwaZulu-Natal, South Africa.

    Science.gov (United States)

    Balfour, Robert

    2003-01-01

    Explores the interface between literature, gender, culture, and language within an educational context. Examines the responses of Zulu boys and girls to the introduction of a new curriculum that integrated language and literary study in a rural school in KwaZulu-Natal, South Africa. Specifically, it shows how reading can lead to a more complex and…

  19. Mixed-Strain Mycobacterium tuberculosis Infections among Patients Dying in a Hospital in KwaZulu-Natal, South Africa▿

    OpenAIRE

    Cohen, Ted; Wilson, Douglas; Wallengren, Kristina; Samuel, Elizabeth Y.; Murray, Megan

    2010-01-01

    We performed spoligotyping and 24-locus mycobacterial interspersed repetitive-unit-variable-number tandem-repeat (MIRU-VNTR) typing on M. tuberculosis culture-positive biopsy specimens collected from adults dying in a hospital in KwaZulu-Natal. Of 56 culture-positive samples genotyped, we detected mixed strains in five (9%) and clonal heterogeneity in an additional four (7%).

  20. Role of Nanog in the maintenance of marrow stromal stem cells during post natal bone regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Bais, Manish V.; Shabin, Zabrina M.; Young, Megan; Einhorn, Thomas A. [Orthopaedic Research Laboratory, Department of Orthopedic Surgery, Boston University School of Medicine, Boston, MA 02118 (United States); Kotton, Darrell N. [Pulmonary Center, Boston University School of Medicine, Boston, MA 02118 (United States); Gerstnefeld, Louis C., E-mail: lgersten@bu.edu [Orthopaedic Research Laboratory, Department of Orthopedic Surgery, Boston University School of Medicine, Boston, MA 02118 (United States)

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer Nanog is related to marrow stromal stem cell maintenance. Black-Right-Pointing-Pointer Increasing Nanog expression is seen during post natal surgical bone repair. Black-Right-Pointing-Pointer Nanog knockdown decreases post surgical bone regeneration. -- Abstract: Post natal bone repair elicits a regenerative mechanism that restores the injured tissue to its pre-injury cellular composition and structure and is believed to recapitulate the embryological processes of bone formation. Prior studies showed that Nanog, a central epigenetic regulator associated with the maintenance of embryonic stem cells (ESC) was transiently expressed during fracture healing, Bais et al. . In this study, we show that murine bone marrow stromal cells (MSCs) before they are induced to undergo osteogenic differentiation express {approx}50 Multiplication-Sign the background levels of Nanog seen in murine embryonic fibroblasts (MEFs) and the W20-17 murine marrow stromal cell line stably expresses Nanog at {approx}80 Multiplication-Sign the MEF levels. Nanog expression in this cell line was inhibited by BMP7 treatment and Nanog lentivrial shRNA knockdown induced the expression of the terminal osteogenic gene osteocalcin. Lentivrial shRNA knockdown or lentiviral overexpression of Nanog in bone MSCs had inverse effects on proliferation, with knockdown decreasing and overexpression increasing MSC cell proliferation. Surgical marrow ablation of mouse tibia by medullary reaming led to a {approx}3-fold increase in Nanog that preceded osteogenic differentiation during intramembranous bone formation. Lentiviral shRNA knockdown of Nanog after surgical ablation led to an initial overexpression of osteogenic gene expression with no initial effect on bone formation but during subsequent remodeling of the newly formed bone a {approx}50% decrease was seen in the expression of terminal osteogenic gene expression and a {approx}50% loss in trabecular bone mass. This

  1. Rate and time trend of perinatal, infant, maternal mortality, natality and natural population growth in kosovo.

    Science.gov (United States)

    Azemi, Mehmedali; Gashi, Sanije; Berisha, Majlinda; Kolgeci, Selim; Ismaili-Jaha, Vlora

    2012-01-01

    THE AIM OF WORK HAS BEEN THE PRESENTATION OF THE RATE AND TIME TRENDS OF SOME INDICATORS OF THE HEATH CONDITION OF MOTHERS AND CHILDREN IN KOSOVO: fetal mortality, early neonatal mortality, perinatal mortality, infant mortality, natality, natural growth of population etc. The treated patients were the newborn and infants in the post neonatal period, women during their pregnancy and those 42 days before and after the delivery. THE DATA WERE TAKEN FROM: register of the patients treated in the Pediatric Clinic of Prishtina, World Health Organization, Mother and Child Health Care, Reproductive Health Care, Ministry of Health of the Republic of Kosovo, Statistical Department of Kosovo, the National Institute of Public Health and several academic texts in the field of pediatrics. Some indicators were analyzed in a period between year 1945-2010 and 1950-2010, whereas some others were analyzed in a time period between year 2000 and 2011. The perinatal mortality rate in 2000 was 29.1‰, whereas in 2011 it was 18.7‰. The fetal mortality rate was 14.5‰ during the year 2000, whereas in 2011 it was 11.0‰, in 2000 the early neonatal mortality was 14.8‰, in 2011 it was 7.5‰. The infant mortality in Kosovo was 164‰ in 1950, whereas in 2010 it was 20.5‰. The most frequent causes of infant mortality have been: lower respiratory tract infections, acute infective diarrhea, perinatal causes, congenital malformations and unclassified conditions. Maternal death rate varied during this time period. Maternal death in 2000 was 23 whereas in 2010 only two cases were reported. Regarding the natality, in 1950 it reached 46.1 ‰, whereas in 2010 it reached 14‰, natural growth of population rate in Kosovo was 29.1‰ in 1950, whereas in 2011 it was 11.0‰. Perinatal mortality rate in Kosovo is still high in comparison with other European countries (Turkey and Kyrgyzstan have the highest perinatal mortality rate), even though it is in a continuous decrease. Infant mortality

  2. Variable primary coordination environments of Cd(ɪɪ) binding to three helix bundles provide a pathway for rapid metal exchange

    DEFF Research Database (Denmark)

    Tebo, Alison G.; Hemmingsen, Lars Bo Stegeager; Pecoraro, Vincent L.

    2015-01-01

    Members of the ArsR/SmtB family of transcriptional repressors, such as CadC, regulate the intracellular levels of heavy metals like Cd(ii), Hg(ii), and Pb(ii). These metal sensing proteins bind their target metals with high specificity and affinity, however, a lack of structural information about...... these proteins makes defining the coordination sphere of the target metal difficult. Lingering questions as to the identity of Cd(ii) coordination in CadC are addressed via protein design techniques. Two designed peptides with tetrathiolate metal binding sites were prepared and characterized, revealing fast...... exchange between CdS3O and CdS4 coordination spheres. Correlation of (111m)Cd PAC spectroscopy and (113)Cd NMR spectroscopy suggests that Cd(ii) coordinated to CadC is in fast exchange between CdS3O and CdS4 forms, which may provide a mechanism for rapid sensing of heavy metal contaminants...

  3. Heavy metal concentrations in redeveloping soil of mine spoil under plantations of certain native woody species in dry tropical environment, India

    Institute of Scientific and Technical Information of China (English)

    Anand N. Singh; ZEHG De-hui; CHEN Fu-sheng

    2005-01-01

    Total concentration of heavy metals(Cd, Cr, Cu, Fe, Pb, Ni, Mn and Zn) was estimated in the redeveloping soil of mine spoil under 5-yr old plantations of four woody species namely: Albizia lebbeck, Albizia procera, Tectona grandis and Dendrocalamus strictus.The data recorded in the present study were compared with other unplanted coal mine spoil colliery, which was around to the study site and adjoining area of dry tropical forest. Among all the heavy metals, the maximum concentration was found for Fe and minimum for Cd.However, among all four species, total concentrations of these heavy metals were recorded maximally in the plantation plots of T. grandis except for Fe, while minimally in A. lebbeck except for Zn, whereas, the maximum concentration of Fe and Zn was in the plantation plots of D. strictus and A. procera. Statistical analysis revealed significant differences due to species for all the heavy metals except Cu.Among four species, A. lebbeck, A. procera and D. strictus showed more efficient for reducing heavy metal concentrations whereas T. grandis was not more effective to reduce heavy metal concentrations in redeveloping soil of mine spoil.

  4. Natal conditions alter age-specific reproduction but not survival or senescence in a long-lived bird of prey.

    Science.gov (United States)

    Millon, Alexandre; Petty, Steve J; Little, Brian; Lambin, Xavier

    2011-09-01

    1. Natal conditions and senescence are two major factors shaping life-history traits of wild animals. However, such factors have rarely been investigated together, and it remains largely unknown whether they interact to affect age-specific performance. 2. We used 27 years of longitudinal data collected on tawny owls with estimates of prey density (field voles) from Kielder Forest (UK) to investigate how prey density at birth affects ageing patterns in reproduction and survival. 3. Natal conditions experienced by tawny owls, measured in terms of vole density, dramatically varied among cohorts and explained 87% of the deviance in first-year apparent survival (annual estimates ranging from 0·07 to 0·33). 4. We found evidence for senescence in survival for females as well as for males. Model-averaged estimates showed that adult survival probability declined linearly with age for females from age 1. In contrast, male survival probability, lower on average than for female, declined after a plateau at age 1-3. 5. We also found evidence for reproductive senescence (number of offspring). For females, reproductive performance increased until age 9 then declined. Males showed an earlier decline in reproductive performance with an onset of senescence at age 3. 6. Long-lasting effects of natal environmental conditions were sex specific. Female reproductive performance was substantially related to natal conditions (difference of 0·24 fledgling per breeding event between females born in the first or third quartile of vole density), whereas male performance was not. We found no evidence for tawny owls born in years with low prey density having accelerated rates of senescence. 7. Our results, combined with previous findings, suggest the way natal environmental conditions affect senescence varies not only across species but also within species according to gender and the demographic trait considered.

  5. Effects of a teenage pregnancy prevention program in KwaZulu-Natal, South Africa.

    Science.gov (United States)

    Taylor, Myra; Jinabhai, Champak; Dlamini, Siyabonga; Sathiparsad, Reshma; Eggers, Matthijs S; De Vries, Hein

    2014-01-01

    Researchers aimed to determine the effects of a teenage pregnancy (TP) prevention program for 816 high school students attending 16 KwaZulu-Natal, South African schools through a randomized control trial. Data were collected at baseline and at the 8-month follow-up in 2009. Results were calculated using multivariate analyses of program effects employing Mplus 6, and indicated significantly healthier attitudes, including intentions to abstain from sex whilst at school, plans to communicate with partners about teenage pregnancy, and increased reports of condom use. Researchers thus provide some support for the effectiveness of a TP prevention program that should be further strengthened in a comprehensive approach that includes schools and families.

  6. Neutron star natal kicks and the long-term survival of star clusters

    CERN Document Server

    Contenta, Filippo; Heggie, Douglas C

    2015-01-01

    We investigate the dynamical evolution of a star cluster in an external tidal field by using N-body simulations, with focus on the effects of the presence or absence of neutron star natal velocity kicks.We show that, even if neutron stars typically represent less than 2% of the total bound mass of a star cluster, their primordial kinematic properties may affect the lifetime of the system by up to almost a factor of four. We interpret this result in the light of two known modes of star cluster dissolution, dominated by either early stellar evolution mass loss or two-body relaxation. The competition between these effects shapes the mass loss profile of star clusters, which may either dissolve abruptly ("jumping"), in the pre-core-collapse phase, or gradually ("skiing"), after having reached core collapse.

  7. Production of fat-1 transgenic rats using a post-natal female germline stem cell line.

    Science.gov (United States)

    Zhou, Li; Wang, Lei; Kang, Jing X; Xie, Wenhai; Li, Xiaoyong; Wu, Changqing; Xu, Bo; Wu, Ji

    2014-03-01

    Germline stem cell lines possess the abilities of self-renewal and differentiation, and have been established from both mouse and human ovaries. Here, we established a new female germline stem cell (FGSC) line from post-natal rats by immunomagnetic sorting for Fragilis, which showed a normal karyotype, high telomerase activity, and a consistent gene expression pattern of primordial germ cells after 1 year of culture. Using an in vitro differentiation system, the FGSC line could differentiate into oocytes. After liposome-based transfection with green fluorescent protein (GFP) or fat-1 vectors, the FGSCs were transplanted into the ovaries of infertile rats. The transplanted FGSCs underwent oogenesis, and the rats produced offspring carrying the GFP or fat-1 transgene after mating with wild-type male rats. The efficiency of gene transfer was 27.86-28.00%, and 2 months was needed to produce transgenic rats. These findings have implications in biomedical research and potential applications in biotechnology.

  8. Classification and ordination of aquatic macrophytes in the Pongolo River Pans, Natal

    Directory of Open Access Journals (Sweden)

    C. F. Musil

    1973-09-01

    Full Text Available The physiography, soils and climate are briefly described for the Pongolo River flood plain pans situated in north-east Zululand (27 S, 32 E, Natal, South Africa. Quantitative vegetation data ob­tained from 60 stands distributed over 9 pans were summarized using a Braun-Blanquet procedure and a Principal Components Analysis (PCA. Both approaches indicated that the aquatic vegetation could be subdivided into two main groups of growth forms: the submerged and the floating and/or rooted-floating aquatic plants, each showing a distribution influenced primarily by physical factors such as exposure and depth of water. In the PCA, each of the above groups was defined by two stand noda, each nodum representing a plant community that could be observed in the field. The Braun- Blanquet analysis further subdivided the floating and/or rooted-floating aquatic plants into groups of species on the basis of chemical and substrate factors.

  9. Natal philopatry does not lead to population genetic differentiation in Buller's albatross (Thalassarche bulleri bulleri).

    Science.gov (United States)

    van Bekkum, Margo; Sagar, Paul M; Stahl, Jean-Claude; Chambers, Geoffrey K

    2006-01-01

    Genetic variability in the only two existing populations of Buller's albatross (Thalassarche bulleri bulleri) was assessed using six polymorphic microsatellite loci. Large biological samples were obtained from both the Snares (n = 99) and the Solander Islands (n = 27). Several measures of genetic differentiation including F(ST) and R(ST) and a principal coordinates analysis (PCO) suggest a complete absence of genetic structure between three breeding colonies on the Snares Islands, and between them and one breeding colony on the Solander Islands. Mark/recapture studies of recently banded albatross chicks on the Snares found high natal philopatry in T. b. bulleri, but the microsatellite DNA data suggest that sufficient gene flow still occurs between all four breeding colonies to maintain a genetically homogeneous population overall.

  10. Prematuridade tardia e o contexto da atenção pré-natal

    OpenAIRE

    Mariana Bello Porciúncula

    2013-01-01

    Considera-se prematuridade, o nascimento de uma criança antes das 37 semanas completas de idade gestacional. Estas crianças são denominadas de recém-nascidos pré-termos ou prematuros. Os prematuros tardios são aqueles nascidos com idade gestacional entre 34 e 36 semanas e 6 dias, representando em torno de 70% dos nascimentos na prematuridade. A avaliação da atenção pré-natal torna-se questão central na prevenção desses nascimentos prematuros, e prevenção da morbimortalidade tanto materna como...

  11. Coping with heat: function of the natal coat of cape fur seal (Arctocephalus Pusillus Pusillus pups in maintaining core body temperature.

    Directory of Open Access Journals (Sweden)

    Nicola Erdsack

    Full Text Available Cape fur seal (Arctocephalus pusillus pups spend the first weeks of life exclusively or mainly ashore. They are exposed to intense solar radiation and high temperatures for long time periods, which results in temperatures up to at least 80°C on their black natal coat. To test the hypothesis that the natal coat has a crucial function in coping with these extreme conditions, we investigated the insulating properties of the natal coat in six captive newborn Cape fur seals during the first 50 days after birth. The natal fur differs from the adult fur not only in colour, but also in density, structure, and water repellence. We measured temperature on the fur surface and within the fur, as well as skin and rectal temperature under varying environmental conditions, comparable to the species' habitat. Experiments were designed to not influence the spontaneous behaviour of the pups. Rectal temperature was constant as long as the pups stayed dry, even during long-lasting intense solar radiation for up to 3 h. Skin temperature remained close to rectal temperature as long as the fur was dry, while with wet fur, skin temperature was significantly reduced as well. Our results show that the natal coat provides an effective insulation against overheating. The severely reduced insulation of wet natal fur against cold supports the assumption that the natal fur is an adaptation to the pups' terrestrial phase of life.

  12. Core competencies of radiographers working in rural hospitals of KwaZulu-Natal, South Africa

    Directory of Open Access Journals (Sweden)

    Bernard Mung'omba

    2017-01-01

    Full Text Available Introduction: Rural radiographers require, over and above traditional radiographic expertise, additional competencies which to a certain degree are unique however not limited to rural practice. Previous studies, however, have focused more attention primarily on other rural health professionals such as doctors and nurses leaving a research need in this field. This article focuses on the additional competencies that may be required for rural radiographers.Aim: To investigate and identify additional core competencies required by radiographers working in rural hospitals of KwaZulu-Natal in order to propose a continuous professional development strategy aimed at rural radiographers.Methods: An exploratory sequential design was utilised with qualitative (Phase I and quantitative (Phase II strands involving seven participants and 109 respondents, respectively. Only radiographers working in rural KwaZulu-Natal hospitals were included in the study. The four major themes and categories identified in Phase I were used to develop data collection instrument for Phase II of the study.Results: Collectively, the results revealed that there were a number of additional core competencies such as, but not limited to, teamwork, ability to do basic obstetric ultrasound scans, leadership, management and reporting on plain radiographs, all of which are required by rural radiographers. In 2014 when these competencies were checked against a single curriculum, it was found that majority of them were either partially covered or not at all covered.Conclusion: The study provides additional information on context specific core competencies and, therefore, may act as a catalyst to influence the future of radiographers working in rural areas of South Africa.

  13. O discurso do risco e o aconselhamento genético pré-natal

    Directory of Open Access Journals (Sweden)

    Marilena C. D. V. Corrêa

    Full Text Available A medicalização é um fenômeno social difuso nas sociedades ocidentais que se expressa segundo um diferencial de gênero. A gravidez é um momento fortemente medicalizado, no qual as mulheres se vêem cercadas de uma rede de vigilância de seu corpo, sendo responsabilizadas não só pela própria saúde, mas também pela produção de um feto saudável. O controle dos riscos no pré-natal é proposto, entretanto, em um contexto no qual as possibilidades diagnósticas são amplamente majoritárias comparativamente às possibilidades terapêuticas. Essa defasagem é agravada pelo fato de, no Brasil, o abortamento ser ilegal. Este artigo é fruto de pesquisa empírica realizada em um ambulatório público de genética pré-natal, que constou de: observação das práticas de atendimento, revisão de prontuários e realização de entrevistas com profissionais de saúde. Discutem-se o contexto fortemente medicalizado do aconselhamento genético no Brasil e a percepção dos médicos sobre suas práticas neste contexto. É discutido também o possível impacto sobre a tomada de decisão das mulheres atendidas em relação a riscos, técnicas, exames e seus desdobramentos.

  14. KwaZulu-Natal coastal erosion events of 2006/2007 and 2011: A predictive tool?

    Directory of Open Access Journals (Sweden)

    Alan Smith

    2013-03-01

    Full Text Available Severe coastal erosion occurred along the KwaZulu-Natal coastline between mid-May and November 2011. Analysis of this erosion event and comparison with previous coastal erosion events in 2006/2007 offered the opportunity to extend the understanding of the time and place of coastal erosion strikes. The swells that drove the erosion hotspots of the 2011 erosion season were relatively low (significant wave heights were between 2 m and 4.5 m but of long duration. Although swell height was important, swell-propagation direction and particularly swell duration played a dominant role in driving the 2011 erosion event. Two erosion hotspot types were noted: sandy beaches underlain by shallow bedrock and thick sandy beaches. The former are triggered by high swells (as in March 2007 and austral winter erosion events (such as in 2006, 2007 and 2011. The latter become evident later in the austral winter erosion cycle. Both types were associated with subtidal shore-normal channels seaward of megacusps, themselves linked to megarip current heads. This 2011 coastal erosion event occurred during a year in which the lunar perigee sub-harmonic cycle (a 4.4-year cycle peaked, a pattern which appears to have recurred on the KwaZulu-Natal coast. If this pattern proves true, severe coastal erosion may be expected in 2015. Evidence indicates that coastal erosion is driven by the lunar nodal cycle peak but that adjacent lunar perigee sub-harmonic peaks can also cause severe coastal erosion. Knowing where and when coastal erosion may occur is vital for coastal managers and planners.

  15. Dietary adequacies among South African adults in rural KwaZulu-Natal.

    Directory of Open Access Journals (Sweden)

    Fariba Kolahdooz

    Full Text Available BACKGROUND: Food quality, determined by micronutrient content, is a stronger determinant of nutritional status than food quantity. Health concerns resulting from the co-existence of over-nutrition and under-nutrition in low income populations in South Africa have been fully recognized in the last two decades. This study aimed to further investigate dietary adequacy amongst adults in rural KwaZulu-Natal, by determining daily energy and nutrient intakes, and identifying the degree of satisfaction of dietary requirements. METHODS: Cross-sectional study assessing dietary adequacy from 24-hour dietary recalls of randomly selected 136 adults in Empangeni, KwaZulu-Natal, South Africa. RESULTS: Results are presented for men (n = 52 and women (n = 84 19-50 and >50 years old. Mean energy intake was greatest in women >50 years (2852 kcal/day and exceeded Dietary Reference Intake's for both men and women, regardless of age. Mean daily energy intake from carbohydrates was 69% for men and 67% for women, above the Dietary Reference Intake range of 45-65%. Sodium was also consumed in excess, and the Dietary Reference Intakes of vitamins A, B12, C, D, and E, calcium, zinc and pantothenic acid were not met by the majority of the population. CONCLUSION: Despite mandatory fortification of staple South African foods, micronutrient inadequacies are evident among adults in rural South African communities. Given the excess caloric intake and the rising prevalence of obesity and other non-communicable diseases in South Africa, a focus on diet quality may be a more effective approach to influence micronutrient status than a focus on diet quantity.

  16. Management of cryptococcal meningitis in a district hospital in KwaZulu-Natal: A clinical audit

    Directory of Open Access Journals (Sweden)

    Benjamin O. Adeyemi

    2014-01-01

    Full Text Available Background: Despite the development of context-specific guidelines, cryptococcal meningitis (CCM remains a leading cause of death amongst HIV-infected patients. Results from clinical audits in routine practice have shown critical gaps in clinicians’ adherence to recommendations regarding the management of CCM.Aim: The aim of this study was to review the acute management of CCM at an urban district hospital in KwaZulu-Natal, South Africa with a view to making recommendations for improving care.Setting: An urban district hospital in KwaZulu-Natal, South Africa.Methods: A retrospective audit was performed on clinical records of all patients (age > 13 years admitted to the hospital with a diagnosis of CCM between June 2011 and December 2012.Results: Measurement of cerebrospinal fluid opening pressure at initial lumbar puncture (LP was done rarely and only 23.4% of patients had therapeutic LPs. The majority of patients (117/127; 92.1% received amphotericin B, however, only 19 of the 117 patients (16.2% completed the 14-day treatment target. Amphotericin B-toxicity monitoring and prevention was suboptimal; however, in-patient referral for HIV counselling and testing was excellent.Conclusions: The quality of care of CCM based on selected process criteria showed gaps in routine care at the hospital despite the availability of context-specific guidelines. An action plan for improving care was developed based on stakeholders’ feedback. A repeat audit should be conducted in the future in order to evaluate the impact of this plan and to ensure that improvements are sustained.

  17. Sector switching among histopathologists in KwaZulu-Natal, South Africa: a qualitative study

    Science.gov (United States)

    2013-01-01

    Background The mobility of health care professionals from the public to private sector is prevalent in South Africa. However, literature on sector switching of clinical doctors remains limited. It is against this background that this study aims to make the labour market visible for histopathologists and identify the reasons for sector switching. Methods This study is exploratory and descriptive. It uses qualitative methods, such as in-depth interviews, with 70% (n = 16/23) of the population of histopathologists in KwaZulu-Natal, South Africa. Lee’s (1966) push-pull theory is adapted to explain the pull sector switching behaviours of histopathologists. Interviews were recorded and independently transcribed. The narratives of the participants were coded to reflect the main themes that contributed to their sector switching behaviours. Results Five key themes emerged as reasons for the mobility of histopathologists from the public to private sector in KwaZulu-Natal. The findings indicate that remuneration, working conditions, work flexibility, career pathing and autonomy of labour processes are the key drivers of this mobility. Conclusions Histopathologists provide a core function in the health care chain. However, their invisibility in academic discourse in both public health and human resources for health indicates the paucity of research undertaken on the importance of these specialists in the health care chain. This is especially significant in developing countries like South Africa, where there is a dearth of these specialists. This study, while exploratory, aims to open a dialogue to better understand their reasons for sector switching and, hopefully, inform policies on training, recruitment and retention of these specialists. PMID:23721129

  18. Density-dependent natal dispersal patterns in a leopard population recovering from over-harvest.

    Directory of Open Access Journals (Sweden)

    Julien Fattebert

    Full Text Available Natal dispersal enables population connectivity, gene flow and metapopulation dynamics. In polygynous mammals, dispersal is typically male-biased. Classically, the 'mate competition', 'resource competition' and 'resident fitness' hypotheses predict density-dependent dispersal patterns, while the 'inbreeding avoidance' hypothesis posits density-independent dispersal. In a leopard (Panthera pardus population recovering from over-harvest, we investigated the effect of sex, population density and prey biomass, on age of natal dispersal, distance dispersed, probability of emigration and dispersal success. Over an 11-year period, we tracked 35 subadult leopards using VHF and GPS telemetry. Subadult leopards initiated dispersal at 13.6 ± 0.4 months. Age at commencement of dispersal was positively density-dependent. Although males (11.0 ± 2.5 km generally dispersed further than females (2.7 ± 0.4 km, some males exhibited opportunistic philopatry when the population was below capacity. All 13 females were philopatric, while 12 of 22 males emigrated. Male dispersal distance and emigration probability followed a quadratic relationship with population density, whereas female dispersal distance was inversely density-dependent. Eight of 12 known-fate females and 5 of 12 known-fate male leopards were successful in settling. Dispersal success did not vary with population density, prey biomass, and for males, neither between dispersal strategies (philopatry vs. emigration. Females formed matrilineal kin clusters, supporting the resident fitness hypothesis. Conversely, mate competition appeared the main driver for male leopard dispersal. We demonstrate that dispersal patterns changed over time, i.e. as the leopard population density increased. We conclude that conservation interventions that facilitated local demographic recovery in the study area also restored dispersal patterns disrupted by unsustainable harvesting, and that this indirectly improved

  19. Natal Kicks and Time Delays in Merging Neutron Star Binaries: Implications for r-process Nucleosynthesis in Ultra-faint Dwarfs and in the Milky Way

    Science.gov (United States)

    Beniamini, Paz; Hotokezaka, Kenta; Piran, Tsvi

    2016-09-01

    Merging neutron star binaries are prime candidate sources for heavy r-process nucleosynthesis. The amount of heavy r-process material is consistent with the mass ejection and rates of mergers, and abundances of relic radioactive materials suggest that heavy r-process material is produced in rare events. Observations of possible macronovae provide further support for this model. Still, some concerns remain. One is the observation of heavy r-process elements in ultra-faint dwarf (UFD) galaxies. The escape velocities from UFDs are so small that the natal kicks, taking place at neutron stars’ birth, might eject such binaries from UFDs. Furthermore, the old stellar populations of UFDs require that r-process nucleosynthesis must have taken place very early on, while it may take several Gyr for compact binaries to merge. This last problem arises also within the Milky Way where heavy r-process materials have been observed in some low-metallicity stars. We show here that ≳ 0.5 of neutron star binaries form with a sufficiently small proper motion to remain bound even in a UFD. Furthermore, approximately 90% of double neutron stars with an initial separation of 1011 cm merge within 300 Myr and ≈ 15 % merge in less than 100 Myr. This population of “rapid mergers” explains the appearance of heavy r-process material in both UFDs and in the early Milky Way.

  20. Natal Kicks and Time Delays in Merging Neutron Star Binaries - Implications for r-process nucleosynthesis in Ultra Faint Dwarfs and in the Milky Way

    CERN Document Server

    Beniamini, Paz; Piran, Tsvi

    2016-01-01

    Merging neutron star binaries are prime candidate sources for heavy r-process nucleosynthesis. The amount of heavy r-process material is consistent with the mass ejection and rates of mergers, and abundances of relic radioactive materials suggest that heavy r-process material is produced in rare events. Observations of possible macronovae provide further support for this model. Still, some concerns remain. One is the observation of heavy r-process elements in Ultra Faint Dwarf (UFD) galaxies. The escape velocities from UFDs are so small that the natal kicks, taking place at neutron stars birth, might eject such binaries from UFDs. Furthermore the old stellar populations of UFDs requires that r-process nucleosynthesis must have taken place very early on, while it may take several Gyr for compact binaries to merge. This last problem arises also within the Milky Way where heavy r-process materials has been observed in some low metallicity stars. We show here that since a significant fraction of neutron star bina...

  1. Reversibilitas kalsifikasi tulang akibat kekurangan protein pre dan post natal (Reversibility of bone calcification on pre and post natal protein deficiency

    Directory of Open Access Journals (Sweden)

    Pinandi Sri Pudyani

    2005-09-01

    Full Text Available The growth and development play an important role in orthodontics mainly in bone, because it can determine the maturity of the bone. Bone maturity evaluation is very important in orthodontic treatment, because there are many individual variations in growth and development such as time, duration and velocity of the growth. Nutritional status during pregnancy and infant period will influence the growth and the development of bone. Protein diet is an important factor, which will determine the optimal calcification during bone growth and development stages. Bone calcification, in orthodontics, can be used to estimate the bone maturity for diagnosis and treatment planning. The purpose of this study was to recognize ones ability to surpass calcium and phosphor deficiency because of pre and postnatal protein deficiency. There were three groups of samples of Rattus norvegicus rats. The first group was the control group with standard diet, the second was the infant group with pre and postnatal protein deficiency, and the third group was young rat at weaning age with pre and postnatal protein deficiency supplemented with enough protein in the diet. Bone calcification stage was analyzed: 1 Histologically by measuring epiphyseal width on right femur; 2 by measuring calcium and phosphor concentration on left femur with Spectrophotometry Atomic Absorption and spectroscopy ultra light visible. The data were analyzed by one way ANOVA continued by t test. The result showed that: 1 there was significant (p < 0.01 epiphyseal width difference between group I and II, I and III (p < 0,01 but there was not significant difference between group II & III (p > 0.05; 2 there was significant calcium and phosphor concentration on bone between group I, II and III (p < 0.01. It was concluded that bone calcification damage because of pre and post natal protein deficiency was an irreversible process. Protein supplement after bone calcification could not restore the condition.

  2. Evaluación de metales redox-sensitivos como proxies de paleoxigenación en un ambiente marino hipóxico del norte de Chile Redox-sensitive metals evaluation as proxis of paleoxygenation in a hypoxic marine environment of northern Chile

    Directory of Open Access Journals (Sweden)

    JORGE VALDÉS

    2004-03-01

    metales registrada entre las muestras de la parte superior de los testigos (correspondientes a antes de 1996 y las muestras superficiales (correspondientes al año 2000 y tomadas en la misma zona de los testigos, pueden ser atribuidas al efecto de El Niño 1997-1998, el cual provocó un brusco descenso en el flujo de metales (principalmente Ni y Cd hacia los sedimentos, debido a una condición más oxigenada de la columna de agua. Este trabajo muestra que de los cinco metales analizados, solo en Ni y el Cd parecen tener un potencial como indicadores de paleoxigenación en la bahía Mejillones. Sin embargo, su uso está restringido para identificar cambios extremos desde una condición anóxica a una óxica en los sedimentos de fondo de esta bahía.The distribution of molybdenum, cadmium, zinc, vanadium and nickel, all redox-sensitive metals, was analyzed under a spatial (surface sediment samples and temporal (core samples perspective, in order to identify the potential of these metals for paleoxygenation interpretations in Mejillones bay, a hypoxic environment of northern Chile. Lithogenic supply (according to aluminum was discarded. Biogenic flux is not the unique factor that controls the mechanism of metals preservation in sediments of this bay. Spatial variation of metals concentration was investigated in relation to the bottom water oxygenation in each sampling station. Results showed that only Ni and Cd present a strong correlation with dissolved oxygen, increasing their concentration toward the deepest area of the bay were an oxygen minimum zone prevails with values around 0.02 mL L-1. The temporal variation in redox-sensitive metals, recorded in three sediments core covering the last 2,000 years, showed that bottom oxygenation of the bay changed from a more oxygenated environment in the past to a less oxygenated environment at present. A biogenic flux across a very well developed oxycline, associated to an anoxic sediment-water interface, are proposed to be the

  3. Contamination of soil by heavy metals in the mining Sierra of Cartegena La Union and its environment (Southeast Spain); Contaminacion de suelos por metales pesados en la sierra minera de Cartagena La Union y su entorno (Sureste de Espana)

    Energy Technology Data Exchange (ETDEWEB)

    Belmonte Serrato, F.; Rojo Lopez, S.; Romero Diaz, A.; Moreno Brotons, J.; Alonso Sarria, F.

    2009-07-01

    This paper analyzes the metal pollution in natural, agricultural and mineral-industrial soils in the Sierra of Cartagena La Union and its adjacent area. The analysis was conducted on 52 soil samples randomly selected and 23 samples form the bed of the channels draining to the Mar Menor and the Mediterranean sea. The results indicate high concentrations of metals that exceed, in many cases, the maximum allowable by the relevant laws of various countries, including Spain. Of note is the excessive contamination by lead (Pb) and Cinz (Zn) that doubles or even triples the maximum of the most permissive laws. (Author) 9 refs.

  4. What Is It Going to Be? Pattern and Potential Function of Natal Coat Change in Sexually Dichromatic Redfronted Lemurs (Eulemur fulvus rufus)

    DEFF Research Database (Denmark)

    Barthold, Julia A; Fichtel, Claudia; Kappeler, Peter M

    2009-01-01

    their mothers, but an accepted functional explanation for natal coats is not available. Here we describe pelage coloration change in sexually dichromatic redfronted lemurs (Eulemur fulvus rufus) in Kirindy Forest, and propose a new functional hypothesis for this phenomenon. In this species, infants are born...... and female infants were found. Hypotheses about the ultimate function of natal coats focusing on enhanced infant care or reduced infanticide risk did not explain the pelage change in redfronted lemurs. The natal pelage pattern in this species may instead serve as sexual mimicry. Accordingly, female infants...

  5. The influence of ethylenediamine tetra acetic acid (EDTA) on the transformation and solubility of metallic palladium and palladium(II) oxide in the environment.

    Science.gov (United States)

    Zereini, Fathi; Wiseman, Clare L S; Vang, My; Albers, Peter; Schneider, Wolfgang; Schindl, Roland; Leopold, Kerstin

    2015-05-01

    The environmental occurrence of elevated concentrations of platinum (Pt), palladium (Pd) and rhodium (Rh) from automotive catalytic converters has been well-documented. Limited information exists regarding their chemical behavior post-emission, however, especially in the presence of commonly occurring complexing agents. The purpose of this study is to examine the influence of ethylenediamine tetra acetic acid (EDTA) on the possible environmental transformation and solubility of Pd by conducting batch experiments using metallic palladium (Pd black) and palladium(ii) oxide (PdO). Changes in the particle surface chemistry of treated samples were analyzed using X-ray Photoelectron Spectroscopy (XPS) and Transition Electron Microscopy/Energy Dispersive X-ray Spectrometry (TEM/EDX) techniques. Metallic palladium was partially transformed into PdOx (x environmental immobility of Pd, small amounts of this element emitted in metallic form are likely to be soluble in the presence of complexing agents such as EDTA.

  6. Perch and Its Parasites as Heavy Metal Biomonitors in a Freshwater Environment: The Case Study of the Ružín Water Reservoir, Slovakia

    Directory of Open Access Journals (Sweden)

    Dana Miklisová

    2012-03-01

    Full Text Available Heavy metal concentrations were determined in 43 perches (Perca fluviatilis and in two of its most common parasites, the acanthocephalan Acanthocephalus lucii and the cestode Proteocephalus percae, collected in the period 2009–2010 from Ružín, a seriously polluted water reservoir in Slovakia. Samples of muscle, liver, kidney, brain, male and female reproductive organs and adipose tissue of fish and both parasites were analyzed for As, Cd, Cr, Cu, Hg, Mn, Ni, Pb and Zn, by ICP-MS. Mean concentrations of individual heavy metals in all fish samples decreased in the order zinc > copper > manganese > mercury > arsenic > chromium > cadmium > nickel > lead. Zinc was found to be the dominant element and its antagonistic interaction with copper was confirmed. The kidney was a key target organ receiving the highest mean concentrations of all analyzed metals, but some metals showed specific affinity for particular tissues. In terms of human health, concentration of Hg in fish muscle, which exceeded more than two-times its maximum level admitted in foodstuffs in European countries, is of great importance and should be taken into account. Bioaccumulation factors (C[parasite]/C[fish tissue] calculated for all elements indicated much higher detection skills of A. lucii and P. percae parasites than fish organs and hence, present results allow proposing both parasite models as useful tools to monitor aquatic environmental quality. Acanthocephalans, however, seem to be superior for heavy metal monitoring, also demonstrated under experimental conditions. Present results also indicate the decreasing heavy metal burden of the reservoir and its gradual recovery in the course of time.

  7. Selective dissolution followed by EDDS washing of an e-waste contaminated soil: Extraction efficiency, fate of residual metals, and impact on soil environment.

    Science.gov (United States)

    Beiyuan, Jingzi; Tsang, Daniel C W; Valix, Marjorie; Zhang, Weihua; Yang, Xin; Ok, Yong Sik; Li, Xiang-Dong

    2017-01-01

    To enhance extraction of strongly bound metals from oxide minerals and organic matter, this study examined the sequential use of reductants, oxidants, alkaline solvents and organic acids followed by a biodegradable chelating agent (EDDS, [S,S]-ethylene-diamine-disuccinic-acid) in a two-stage soil washing. The soil was contaminated by Cu, Zn, and Pb at an e-waste recycling site in Qingyuan city, China. In addition to extraction efficiency, this study also examined the fate of residual metals (e.g., leachability, bioaccessibility, and distribution) and the soil quality parameters (i.e., cytotoxicity, enzyme activities, and available nutrients). The reductants (dithionite-citrate-bicarbonate and hydroxylamine hydrochloride) effectively extracted metals by mineral dissolution, but elevated the leachability and bioaccessibility of metals due to the transformation from Fe/Mn oxides to labile fractions. Subsequent EDDS washing was found necessary to mitigate the residual risks. In comparison, prior washing by oxidants (persulphate, hypochlorite, and hydrogen peroxide) was marginally useful because of limited amount of soil organic matter. Prior washing by alkaline solvents (sodium hydroxide and sodium bicarbonate) was also ineffective due to metal precipitation. In contrast, prior washing by low-molecular-weight organic acids (citrate and oxalate) improved the extraction efficiency. Compared to hydroxylamine hydrochloride, citrate and oxalate induced lower cytotoxicity (Microtox) and allowed higher enzyme activities (dehydrogenase, acid phosphatase, and urease) and soil nutrients (available nitrogen and phosphorus), which would facilitate reuse of the treated soil. Therefore, while sequential washing proved to enhance extraction efficacy, the selection of chemical agents besides EDDS should also include the consideration of effects on metal leachability/bioaccessibility and soil quality. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Perch and its parasites as heavy metal biomonitors in a freshwater environment: the case study of the Ružín water reservoir, Slovakia.

    Science.gov (United States)

    Brázová, Tímea; Torres, Jordi; Eira, Catarina; Hanzelová, Vladimíra; Miklisová, Dana; Salamún, Peter

    2012-01-01

    Heavy metal concentrations were determined in 43 perches (Perca fluviatilis) and in two of its most common parasites, the acanthocephalan Acanthocephalus lucii and the cestode Proteocephalus percae, collected in the period 2009-2010 from Ružín, a seriously polluted water reservoir in Slovakia. Samples of muscle, liver, kidney, brain, male and female reproductive organs and adipose tissue of fish and both parasites were analyzed for As, Cd, Cr, Cu, Hg, Mn, Ni, Pb and Zn, by ICP-MS. Mean concentrations of individual heavy metals in all fish samples decreased in the order zinc > copper > manganese > mercury > arsenic > chromium > cadmium > nickel > lead. Zinc was found to be the dominant element and its antagonistic interaction with copper was confirmed. The kidney was a key target organ receiving the highest mean concentrations of all analyzed metals, but some metals showed specific affinity for particular tissues. In terms of human health, concentration of Hg in fish muscle, which exceeded more than two-times its maximum level admitted in foodstuffs in European countries, is of great importance and should be taken into account. Bioaccumulation factors (C([parasite])/C([fish tissue])) calculated for all elements indicated much higher detection skills of A. lucii and P. percae parasites than fish organs and hence, present results allow proposing both parasite models as useful tools to monitor aquatic environmental quality. Acanthocephalans, however, seem to be superior for heavy metal monitoring, also demonstrated under experimental conditions. Present results also indicate the decreasing heavy metal burden of the reservoir and its gradual recovery in the course of time.

  9. "Direct" Gas-phase Metallicities, Stellar Properties, and Local Environments of Emission-line Galaxies at Redshift below 0.90

    CERN Document Server

    Ly, Chun; Nagao, Tohru; Kashikawa, Nobunari; Shimasaku, Kazuhiro; Hayashi, Masao

    2013-01-01

    Using deep narrow-band imaging and optical spectroscopy from Keck and MMT, we identify a sample of 20 emission-line galaxies at z=0.065-0.90 where the weak auroral emission line, [O III]4363, is detected at >3\\sigma. These detections allow us to determine the gas-phase metal abundances using the "direct" method. After correcting for dust attenuation using Balmer decrements, we find that 10 of these low-mass galaxies are extremely metal-poor with 12+log(O/H) 1 galaxies.

  10. Experiences of women who have lost young children to AIDS in KwaZulu-Natal, South Africa: a qualitative study

    Directory of Open Access Journals (Sweden)

    Demmer Craig

    2010-12-01

    Full Text Available Abstract Background AIDS continues to be the leading cause of death in South Africa. Little is known about the experiences of mothers who have lost a young child to AIDS. The purpose of this qualitative study was to explore the attitudes and experiences of women who had lost a young child to HIV/AIDS in KwaZulu-Natal Province, South Africa. Methods In-depth interviews were conducted with 10 women who had lost a child to AIDS. The average age of the deceased children was six years. Interviews were also conducted with 12 key informants to obtain their perspectives on working with women who had lost a child to AIDS. A thematic analysis of the transcripts was performed. Results In addition to the pain of losing a child, the women in this study had to endure multiple stresses within a harsh and sometimes hostile environment. Confronted with pervasive stigma and extreme poverty, they had few people they could rely on during their child's sickness and death. They were forced to keep their emotions to themselves since they were not likely to obtain much support from family members or people in the community. Throughout the period of caring for a sick child and watching the child die, they were essentially alone. The demands of caring for their child and subsequent grief, together with daily subsistence worries, took its toll. Key informants struggled to address the needs of these women due to several factors, including scarce resources, lack of training around bereavement issues, reluctance by people in the community to seek help with emotional issues, and poverty. Conclusions The present study offers one of the first perspectives on the experiences of mothers who have lost a young child to AIDS. Interventions that are tailored to the local context and address bereavement issues, as well as other issues that affect the daily lives of these mothers, are urgently needed. Further studies are needed to identify factors that promote resilience among these

  11. Experiences of action learning groups for public health sector managers in rural KwaZulu-Natal, South Africa.

    Science.gov (United States)

    Blanchard, Catherine P; Carpenter, Bryan

    2012-01-01

    The World Health Organisation identifies strengthening leadership and management as an essential component in scaling up health services to reach the UN's Millennium Development Goals. There is an identified need for informal, practically based management training programs, such as action learning, which allow trainees to reflect on their own work environment. Action learning, in essence, is learning by sharing real problems with others, as opposed to theoretical classroom learning. The objective of this study was to pilot an action learning group program with managers in a rural public health setting and to explore participants' experience of the program. An eleven-month action learning group program was conducted for public health sector managers in a rural health district in northern KwaZulu-Natal. On conclusion of the action learning group program, a qualitative study using focus group discussions was conducted to explore participants' experience of the action learning groups and their potential usefulness as a development opportunity. Respondents' commitment to the project was evident from the high attendance at group meetings (average of 95%). On conclusion of the program, all participants had presented a work related problem to their respective groups and all participants had developed an action plan, and provided feedback on their action plan. Ten participants were still actively working on their action plans and seven participants had completed their action plans. The main themes that emerged from the qualitative data were understandings of action learning; elements that enabled the program; perceived benefits; and reported changes over the course of the program. The major benefits reported by participants were enhanced teamwork and collaboration, and providing participants with the skills to apply action learning principles to other challenges in their working lives. From the participants' shared perspectives, although the findings cannot be generalised

  12. Global DNA methylation in earthworms: A candidate biomarker of epigenetic risks related to the presence of metals/metalloids in terrestrial environments

    Energy Technology Data Exchange (ETDEWEB)

    Maldonado Santoyo, Maria; Rodriguez Flores, Crescencio; Lopez Torres, Adolfo; Wrobel, Kazimierz [Department of Chemistry, University of Guanajuato, L de Retana No 5, 36000 Guanajuato (Mexico); Wrobel, Katarzyna, E-mail: katarzyn@quijote.ugto.mx [Department of Chemistry, University of Guanajuato, L de Retana No 5, 36000 Guanajuato (Mexico)

    2011-10-15

    In this work, possible relationships between global DNA methylation and metal/metalloid concentrations in earthworms have been explored. Direct correlation was observed between soil and tissue As, Se, Sb, Zn, Cu, Mn, Ag, Co, Hg, Pb (p < 0.05). Speciation results obtained for As and Hg hint at the capability of earthworms for conversion of inorganic element forms present in soil to methylated species. Inverse correlation was observed between the percentage of methylated DNA cytosines and total tissue As, As + Hg, As + Hg + Se + Sb ({beta} = -0.8456, p = 0.071; {beta} = -0.9406, p = 0.017; {beta} = -0.9526, p = 0.012 respectively), as well as inorganic As + Hg ({beta} = -0.8807, p = 0.049). It was concluded that earthworms would be particularly helpful as bioindicators of elements undergoing in vivo methylation and might also be used to assess the related risk of epigenetic changes in DNA methylation. - Graphical abstract: Display Omitted Highlights: > Several metals and metalloids contribute to epigenetic gene regulation. > As, Hg, Se, Sb inversely correlated with global DNA methylation in earthworms. > Biomethylation of the above elements in worms suggested. > Elements biomethylation apparently competes with DNA methylation. > DNA methylation a biomarker of epigenetic risks related to soil metals/metalloids. - Biomethylation of As, Hg in earthworms versus DNA methylation - a candidate biomarker of epigenetic risks related to the presence of metals/metalloids in soil.

  13. 'Direct' Gas-Phase Metallicities, Stellar Properties, and Local Environments of Emission-Line Galaxies at Redshifts Below 0.90

    Science.gov (United States)

    Ly, Chun; Malkan, Matthew A.; Nagao, Tohru; Kashikawa, Nobunari; Shimasaku, Kazuhiro; Hayashi, Masao

    2013-01-01

    Using deep narrow-band (NB) imaging and optical spectroscopy from the Keck telescope and the Multi Mirror Telescope (MMT), we identify a sample of 20 emission-line galaxies (ELGs) at z = 0.065-0.90 where the weak auroral emission line, [O iii] lambda4363, is detected at >=3sigma. These detections allow us to determine the gas-phase metallicity using the "direct" method. With electron temperature measurements, and dust attenuation corrections from Balmer decrements, we find that 4 of these low-mass galaxies are extremely metal-poor with 12+log(O/H) excess among star-forming galaxies at z =0.4 -- 0.85. We also find that the gas-phase metallicities for a given stellar mass and SFR lie systematically lower than the local stellar M-Z-(SFR) relation by approx. = 0.2 dex (2 sigma significance). These results are partly due to selection effects, since galaxies with strong star formation and low metallicity are more likely to yield [O iii] lambda4363 detections. Finally, the observed higher ionization parameter and high electron density suggest that they are lower redshift analogs to typical z approx. > 1 galaxies.

  14. Environment impact of heavy metals on urban soil in the vicinity of industrial area of Baoji city, P.R. China

    Science.gov (United States)

    Li, Xiaoping; Huang, Chunchang

    2007-08-01

    Heavy metals in soils are of great environmental concern, in order to evaluate heavy metal contents and their relationships in the surface soil of industrial area of Baoji city, and also to investigate their influence on the soils. Soil samples were collected from 50 sites, and the concentration of Pb, Zn, Cu, Cr, Ni heavy metals and the contents of characteristics in soil from industrial area of Baoji city were determined with X-ray fluorescence method. The concentrations of Pb, Zn, Cu, Cr and Ni in the investigated soils reached the amount of 2,682.00-76,979.42, 169.30-8,288.58, 62.24-242.36, 91.96-110.54 and 36.14-179.28 mg kg-1, respectively. The major element Pb contents of the topsoils were determined. to highlight the influence of ‘anthropic’ features on the heavy metal concentrations and their distributions. To compare, all values of elements were much higher than those of unpolluted soils in the middle of Shaanxi province that average 16.0-26.5, 67.1-120.0, 17.8-57.0, 46.9-65.6 and 24.7-34.6 mg kg-1 for Pb, Zn, Cu, Cr and Ni, respectively. An ensemble of basic and relativity analysis was performed to reduce the precipitate of Pb in soil was extremely high and greatly relativity with other elements. Meanwhile, Pb, Zn, Cu, Cr, Ni heavy metals were typical elements of anthropic activities sources, so it was easy to infer to the tracers of anthropic pollutions from the factorial analysis, which was coming from the storage battery manufactory pollutions. The pollutant distributions were constructed for the urban area which identified storage battery manufactory soot precipitate as the main source of diffuse pollution and also showed the contribution of the topsoils of industrial area of Baoji city as the source point of pollution. Consequently, the impact of heavy metals on soil was proposed and discussed. These results highlight the need for instituting a systematic and continuous monitoring of heavy metals and other forms of pollutants in Baoji city to

  15. [Spatiotemporal variation characteristics of heavy metals pollution in the water, soil and sediments environment of the Lean River-Poyang Lake Wetland].

    Science.gov (United States)

    Jian, Min-Fei; Li, Ling-Yu; Xu, Peng-Fei; Chen, Pu-Qing; Xiong, Jian-Qiu; Zhou, Xue-Ling

    2014-05-01

    Overlying water, sediments, surface soils in the typical wetland areas of Lean River and Poyang Lake which were rich in non-ferrous metal mineral resources on both sides of the river, were chosen for monitoring heavy metals including copper, lead and cadmium of base flow in average season, flood season, and dry season in 2012. Statistical analysis methods were coupled to characterize the spatiotemporal variation of heavy metals pollution and identify the main sources. The results indicated that the concentrations of copper were the highest in all samples of each sampling sites in the Lean River-Poyang Lake wetland. And the content values of copper, lead and cadmium in different samples of different sampling sites also showed that the content values of copper were higher than those of lead, and the content values of lead were also higher than those of cadmium. The results also showed that the heavy metals pollution of copper, lead and cadmium in flood season was the heaviest whereas the heavy metals pollution in dry season was comparatively light. The results of the contents of the three kinds of heavy metals elements in different sampling sites of the watersheds of lean River showed that the contents of copper in the samples from the upstream sampling sites of Lean River were higher than those of other samples from other sites. And the contents of lead in the samples from the downstream sampling sites of Lean River were higher than those of other samples from other sampling sites. The contents of cadmium in the samples from the midstream sampling sites of Lean River were higher than those of other samples from other sites. The first principal component representing copper pollution explained 36. 99% of the total variance of water quality. The second principal component concerning representing lead pollution explained 30. 12% of the total variance. The correlation analysis results showed that there were significant positive correlations among the contents of copper

  16. Predictive, pre-natal and diagnostic genetic testing for Huntington's disease: the experience in Canada from 1987 to 2000.

    Science.gov (United States)

    Creighton, S; Almqvist, E W; MacGregor, D; Fernandez, B; Hogg, H; Beis, J; Welch, J P; Riddell, C; Lokkesmoe, R; Khalifa, M; MacKenzie, J; Sajoo, A; Farrell, S; Robert, F; Shugar, A; Summers, A; Meschino, W; Allingham-Hawkins, D; Chiu, T; Hunter, A; Allanson, J; Hare, H; Schween, J; Collins, L; Sanders, S; Greenberg, C; Cardwell, S; Lemire, E; MacLeod, P; Hayden, M R

    2003-06-01

    Predictive and pre-natal testing for Huntington's Disease (HD) has been available since 1987. Initially this was offered by linkage analysis, which was surpassed by the advent of the direct mutation test for HD in 1993. Direct mutation analysis provided an accurate test that not only enhanced predictive and pre-natal testing, but also permitted the diagnostic testing of symptomatic individuals. The objective of this study was to investigate the uptake, utilization, and outcome of predictive, pre-natal and diagnostic testing in Canada from 1987 to April 1, 2000. A retrospective design was used; all Canadian medical genetics centres and their affiliated laboratories offering genetic testing for HD were invited to participate. A total of 15 of 22 centres (68.2%), currently offering or ever having offered genetic testing for HD, responded, providing data on test results, demographics, and clinical history. A total of 1061 predictive tests, 15 pre-natal tests, and 626 diagnostic tests were performed. The uptake for predictive testing was approximately 18% of the estimated at-risk Canadian population, ranging from 12.5% in the Maritimes to 20.7% in British Columbia. There appears to have been a decline in the rate of testing in recent years. Of the predictive tests, 45.0% of individuals were found to have an increased risk, and a preponderance of females (60.2%) sought testing. A greater proportion of those at testing once direct CAG mutation analysis had become available (10.9% after mutation analysis vs 4.7% before mutation analysis, p = 0.0077). Very few pre-natal tests were requested. Of the 15 pre-natal tests, 12 had an increased risk, resulting in termination of pregnancy in all but one. Diagnostic testing identified 68.5% of individuals to be positive by mutation analysis, while 31.5% of those with HD-like symptoms were not found to have the HD mutation. The positive diagnostic tests included 24.5% of individuals with no known prior family history of HD.

  17. Two decades of genetic profiling yields first evidence of natal philopatry and long-term fidelity to parturition sites in sharks

    KAUST Repository

    Feldheim, Kevin Andrew

    2013-12-09

    Sharks are a globally threatened group of marine fishes that often breed in their natal region of origin. There has even been speculation that female sharks return to their exact birthplace to breed (\\'natal philopatry\\'), which would have important conservation implications. Genetic profiling of lemon sharks (Negaprion brevirostris) from 20 consecutive cohorts (1993-2012) at Bimini, Bahamas, showed that certain females faithfully gave birth at this site for nearly two decades. At least six females born in the 1993-1997 cohorts returned to give birth 14-17 years later, providing the first direct evidence of natal philopatry in the chondrichthyans. Long-term fidelity to specific nursery sites coupled with natal philopatry highlights the merits of emerging spatial and local conservation efforts for these threatened predators. © 2013 John Wiley & Sons Ltd.

  18. CD248 expression on mesenchymal stromal cells is required for post‐natal and infection‐dependent thymus remodelling and regeneration

    National Research Council Canada - National Science Library

    Lax, Siân; Ross, Ewan A; White, Andrea; Marshall, Jennifer L; Jenkinson, William E; Isacke, Clare M; Huso, David L; Cunningham, Adam F; Anderson, Graham; Buckley, Christopher D

    2012-01-01

    ...‐natal thymus development and regeneration post‐ Salmonella infection. In CD248 −/− mice the thymus is hypocellular and regeneration is poorer, with significant loss of all thymocyte populations...

  19. Diagnóstico pré-natal das genodermatoses Prenatal diagnosis of genodermatoses

    Directory of Open Access Journals (Sweden)

    Maria Carolina de Abreu Sampaio

    2007-08-01

    Full Text Available O diagnóstico pré-natal está indicado para algumas genodermatoses graves, como a epidermólise bolhosa distrófica recessiva e a epidermólise bolhosa juncional. A biópsia de pele fetal foi introduzida em 1980, mas não pode ser realizada antes da 15a semana de gestação. A análise do DNA fetal é método preciso e pode ser realizado mais precocemente na gestação. No entanto, deve-se conhecer a base molecular da genodermatose, e é essencial determinar a mutação e/ou marcadores informativos nas famílias com criança previamente afetada. O DNA fetal pode ser obtido pela biópsia da vilosidade coriônica ou amniocentese. O diagnóstico genético pré-implantação tem surgido como alternativa que dispensa a interrupção da gestação. Essa técnica, que envolve fertilização in vitro e teste genético do embrião. vem sendo realizada para genodermatoses em poucos centros de referência. A ultra-sonografia é exame não invasivo, mas tem uso limitado no diagnóstico pré-natal de genodermatoses. A ultrasonografia tridimensional geralmente estabelece o diagnóstico tardiamente na gestação, e há apenas relatos anedóticos de diagnóstico pré-natal de genodermatoses usando esse método.Prenatal diagnostic testing is indicated for some severe genodermatoses, such as recessive dystrophic epidermolysis bullosa and junctional epidermolysis bullosa. Fetal skin biopsy was introduced in 1980, but it cannot be performed before 15th gestational week. Fetal DNA analysis is a precise method and can be performed earlier in pregnancy. However, the molecular basis of the genodermatoses must be known and it is essential to determine the gene mutations and/or informative markers in the families with a previously affected child. Fetal DNA can be obtained by chorionic villus sampling or amniocentesis. Preimplantation genetic diagnosis is an alternative approach obviating the need for termination of pregnancy. It involves in vitro fertilization and

  20. Uptake of lead, zinc, cadmium, and copper by the pulmonate mollusc, Helix aspersa Muller, and its relevance to the monitoring of heavy metal contamination of the environment

    Energy Technology Data Exchange (ETDEWEB)

    Coughtrey, P.J.; Martin, M.H.

    1977-01-13

    The occurrence of lead, zinc, cadmium, and copper in individuals of Helix aspersa from two sites of varying degrees of contamination was studied. Zinc, cadmium, and copper were shown to increase in a linear fashion with animal weight. The rate of uptake for zinc and cadmium in particular was significantly greater at the more contaminated site. Statistical analysis of the data, using correlation and regression techniques, provided information on apparent intermetallic effects. It is concluded that because metal uptake and body weight show a positive linear relationship only the use of animals of similar weight and/or size can be used for monitoring purposes. Even then, different patterns of uptake into different organs and interactions between metal uptakes are such as to seriously question the use of Helix, and other molluscs, for monitoring purposes unless specific organs from comparably sized and/or aged animals are used.

  1. Bioerosion by microbial euendoliths in benthic foraminifera from heavy metal-polluted coastal environments of Portovesme (South-Western Sardinia, Italy

    Directory of Open Access Journals (Sweden)

    A. Cherchi

    2012-08-01

    Full Text Available A monitoring survey of the coastal area facing the industrial area of Portoscuso-Portovesme (South-Western Sardinia, Italy revealed intense bioerosional processes. Benthic foraminifera collected at the same depth (about 2 m but at different distances from the pollution source show extensive microbial infestation, anomalous Mg/Ca molar ratios and high levels of heavy metals in the shell associated with a decrease in foraminifera richness, population density and biodiversity with the presence of morphologically abnormal specimens. We found that carbonate dissolution induced by euendoliths is selective, depending on the Mg content and morpho-structural types of foraminiferal taxa. This study provides evidences for a connection between heavy metal dispersion, decrease in pH of the sea-water and bioerosional processes on foraminifera.

  2. Effect of Cd(2+) and Cd(2+)/auxin mixtures on lipid monolayers - Model membrane studies on the role of auxins in phytoremediation of metal ions from contaminated environment.

    Science.gov (United States)

    Hąc-Wydro, Katarzyna; Mach, Marzena; Węder, Karolina; Pająk, Katarzyna; Wydro, Paweł

    2017-03-23

    In this work Langmuir monolayer experiments were performed to analyze the effect of Cd(2+) ions and their mixtures with synthetic auxin (1-naphthaleneacetic acid - NAA) on lipid films. These investigations were motivated by the fact that auxins act effectively as the agents improving the removal of metal ions from contaminated water and soil by plants (phytoextraction), and although their mechanism of action in this area is still unclear, it was suggested that it can be membrane-related. The experiments were done for one component (1,2-dipalmitoyl-sn-glycero-3-phosphocholine - DPPC; 1,2-dioleoyl-sn-glycero-3-phosphocholine - DOPC; 1,2-dipalmitoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (sodium salt) - DPPG) monolayers and mixed (DPPG/DOPC and DPPG/DPPC) films treated as model of plant leaves membranes. The monolayer properties were analyzed based on the surface pressure-area isotherms obtained during film compression, stability measurements and Brewster angle microcopy studies. The collected results together with the data presented in literature evidenced that both metal ions and auxins modify lipid system properties and by using them in a combination it is possible to weaken the influence of sole metal ions on membrane organization. This seems to be in agreement with the hypothesis that the role of plant growth regulators in increasing phytoextraction effectiveness may be membrane-related. However, further experiments are required to find possible correlations between the type and concentration of metal ion, composition of membrane or structural elements in auxin molecule and observed alterations in membrane properties.

  3. DGT as a useful monitoring tool for radionuclides and trace metals in environments impacted by uranium mining: Case study of the Sagnes wetland in France.

    Science.gov (United States)

    Leermakers, Martine; Phrommavanh, Vannapha; Drozdzak, Jagoda; Gao, Yue; Nos, Jérémy; Descostes, Michael

    2016-07-01

    The Diffusive Gradients in Thin films (DGT) technique was used to analyse U, (226)Ra and other trace metals in stream water and soil porewater in a wetland in France impacted by uranium mining. High resolution profiles of metals in soil porewater obtained by DGT could be measured for the first time up to a depth of 75 cm by the construction of a novel DGT holder. In stream water, the DGT technique was compared to speciation carried out by filtration (0.45 μm) and ultrafiltration (UF) (500 kDa/100 kDa/10 kDa) and DGT porewater profiles were compared with piezometer data obtained in a parallel study. An increase in the trace concentrations of dissolved (0.45 μm) and particulate U, (226)Ra, and elements such as Al, Fe, Mn and Ba was observed in the stream water as it passes through the bog as a results of mobilization from the wetland. The porewater results indicate DGT labile metals species to be present in porewater and mobilization of uranium and other elements linked to the presence of enriched clays. In stream water, colloids and particles govern the behavior of U, Al and Fe, whereas Mn, Ba and Ra are essentially transported as truly dissolved metal species with DGT labile concentrations accounting for 100% of the dissolved fraction. The combined approaches of DGT and UF allow us to obtain a better understanding on the biogeochemical processes involved in the retention and mobility of U and (226)Ra in the wetland.

  4. Measuring Spatial Distribution Characteristics of Heavy Metal Contaminations in a Network-Constrained Environment: A Case Study in River Network of Daye, China

    Directory of Open Access Journals (Sweden)

    Zhensheng Wang

    2017-06-01

    Full Text Available Measuring the spatial distribution of heavy metal contaminants is the basis of pollution evaluation and risk control. Considering the cost of soil sampling and analysis, spatial interpolation methods have been widely applied to estimate the heavy metal concentrations at unsampled locations. However, traditional spatial interpolation methods assume the sample sites can be located stochastically on a plane and the spatial association between sample locations is analyzed using Euclidean distances, which may lead to biased conclusions in some circumstances. This study aims to analyze the spatial distribution characteristics of copper and lead contamination in river sediments of Daye using network spatial analysis methods. The results demonstrate that network inverse distance weighted interpolation methods are more accurate than planar interpolation methods. Furthermore, the method named local indicators of network-constrained clusters based on local Moran’ I statistic (ILINCS is applied to explore the local spatial patterns of copper and lead pollution in river sediments, which is helpful for identifying the contaminated areas and assessing heavy metal pollution of Daye.

  5. Recovery of soil properties after seedlings Inoculation with AM fungi and addition of composted olive mill waste in the regeneration of a heavy metal polluted environment

    Science.gov (United States)

    curaqueo, Gustavo; Schoebitz, Mauricio; Borie, Fernando; del Mar Alguacil, Maria; Caravaca, Fuensanta; Roldan, Antonio

    2014-05-01

    A greenhouse experiment was carried out in order to investigate the effects of arbuscular mycorrhizal (AM) fungi inoculation and the use of composted olive waste (COW) on the establishment of Tetraclinis articulata and soil properties in a heavy metal polluted soil. The higher doses of COW in combination with AM fungi increased shoot and root biomass production of T. articulata by 96% and 60% respectively. These treatments trended to improve the soils properties evaluated, highlighting the C compounds and N as well as the microbiological activities. In relation to the metal translocation in T. articulata, doses of COW applied decreased the Cr, Ni and Pb contents in shoot, as well as Cr and As in root, although the most of them reached low levels and far from phytotoxic. The COW amendment aided G-mosseae-inoculated T. articulata plants to thrive in contaminated soil, mainly through an improvement in both nutrients uptake, mainly P and soil microbial function. In addition, the combined use of AM fungi plus COW could be a feasible strategy to be incorporated in phytoremediation programs; because it promotes soil properties, a better performance of plants for supporting the stress in heavy-metal contaminated soils derived from mining process, and also can be a good way for olive mill wastes disposal.

  6. The low-metallicity QSO HE 2158-0107: A massive galaxy growing by the accretion of nearly pristine gas from its environment?

    CERN Document Server

    Husemann, B; Jahnke, K; Sánchez, S F

    2011-01-01

    [abridged] The metallicities of AGN are usually well above solar in their NLR, often reaching up to several times solar in their broad-line regions. Low-metallicity AGN are rare objects which have so far always been associated with low-mass galaxies hosting low-mass BHs (M_BH<10^6Msun). In this paper we present IFS data of the low-redshift QSO HE 2158-0107 for which we find strong evidence for sub-solar NLR metallicities associated with a massive BH (M_BH~3x10^8Msun). The QSO is surrounded by a large extended emission-line region reaching out to 30kpc from the QSO in a tail-like geometry. We present optical and near-IR images and investigate the properties of the host galaxy. The SED of the host is rather blue, indicative of a significant young age stellar population formed within the last 1Gyr. A 3sigma upper limit of L_bulge<4.5x10^10Lsun for the H band luminosity and a corresponding stellar mass upper limit of M_bulge<3.4x10^10Msun show that the host is offset from the local BH-bulge relations. Th...

  7. What is it going to be? Pattern and potential function of natal coat change in sexually dichromatic redfronted lemurs (Eulemur fulvus rufus).

    Science.gov (United States)

    Barthold, Julia; Fichtel, Claudia; Kappeler, Peter

    2009-01-01

    In some primate species, pelage colorations at birth contrast with adult colorations. The intensity of natal coats and their phylogenetic distribution is highly variable within primates. Natal coat coloration seems to change to adult coloration in most species when infants become independent from their mothers, but an accepted functional explanation for natal coats is not available. Here we describe pelage coloration change in sexually dichromatic redfronted lemurs (Eulemur fulvus rufus) in Kirindy Forest, and propose a new functional hypothesis for this phenomenon. In this species, infants are born with adult male coloration and female infants subsequently undergo a change in coloration. Using digital pictures and behavioral data collected on eight mother-offspring dyads from birth until the end of the coloration change, we 1) described timing and pattern of pelage developmentin redfronted lemur infants and 2) examined behavioral developmental correlates of the coloration change. The color change took place between 7 and 17 weeks of age and coincided with advanced physical independence; a pattern also found in monochromatic primate species with natal coats. No behavioral differences between male and female infants were found. Hypotheses about the ultimate function of natal coats focusing on enhanced infant care or reduced infanticide risk did not explain the pelage change in redfronted lemurs. The natal pelage pattern in this species may instead serve as sexual mimicry. Accordingly, female infants may mimic males during the most vulnerable developmental phase to avoid sex-specific aggression by adult females in a species with intense female-female aggression and competition.

  8. Alien trees, shrubs and creepers invading indigenous vegetation in the Hluhluwe-Umfolozi Game Reserve Complex in Natal

    OpenAIRE

    I.A.W Macdonald

    1983-01-01

    The results of a survey and monitoring programme conducted in the Hluhluwe-Umfolozi Game Reserve Complex in Natal are presented. The area consists of 900 km2  of savanna and forest vegetation. Twenty alien tree, shrub and creeper species currently invading indigenous vegetation within the Complex are listed. Herbaceous aliens were not surveyed. An analysis of the habitats being invaded by these alien plants is presented and it is concluded that riverine and forest-edge habitats are those most...

  9. Incidence and Geographic Distribution of Extensively Drug-Resistant Tuberculosis in KwaZulu-Natal Province, South Africa

    Science.gov (United States)

    Lim, Jennifer R.; Gandhi, Neel R.; Mthiyane, Thuli; Mlisana, Koleka; Moodley, Julie; Jaglal, Prenika; Ramdin, Neeshan; Brust, James C. M.; Ismail, Nazir; Rustomjee, Roxana; Shah, N. Sarita

    2015-01-01

    South Africa is experiencing a widespread drug-resistant tuberculosis epidemic, although data are limited regarding the current situation. This study finds that the extensively drug-resistant tuberculosis (XDR-TB) incidence in KwaZulu-Natal increased to 3.5 cases/100,000 (776 cases) in 2011-2012. XDR-TB cases are widely distributed geographically, with the majority of districts experiencing a rise in incidence. PMID:26147963

  10. Improving working relationships for smallholder farmers in formal organic crop supply chains: Evidence from KwaZulu-Natal, South Africa

    OpenAIRE

    2006-01-01

    The 48 members of the Ezemvelo Farmers' Organisation (EFO) in KwaZulu-Natal, South Africa (SA), that are fully-certified as organic farmers were surveyed in October-December 2004 to assess their perceived levels of satisfaction, trust, cooperation and commitment in a formal supply chain producing amadhumbes (a traditional vegetable tuber), potatoes and sweet potatoes for a major SA supermarket group. Empirical recursive models show that a high level of satisfaction in the working relationship...

  11. An intrauterine catch-up growth regimen increases food intake and post-natal growth in rats.

    Science.gov (United States)

    Baik, M; Rajasekar, P; Lee, M S; Kim, J; Kwon, D-H; Kang, W; Nguyen, T H; Vu, T-T T

    2014-12-01

    Nutritional conditions during the intrauterine stage are an important developmental programming factor that can affect the growth and metabolic status during foetal development and permanently alter the phenotypes of newborn offspring and adults. This study was performed to examine the effects of intrauterine catch-up growth (IUCG) on food intake, post-natal body growth and the metabolic status of offspring and growing rats. Control pregnant rats were fed ad libitum during the entire gestation period. For the IUCG regimen, pregnant rats were fed 50% of the food of the controls from pregnancy days 4 through 11 (8 days), followed by ad libitum feeding from pregnancy days 12 through parturition. The birth weight of offspring was not affected by the IUCG regimen. At weaning, offspring from each treatment group were assigned to two groups and given either a normal diet or high-fat diet (HFD) for 12 weeks until 103 days of age. In the normal diet group, the IUCG offspring showed a 9.0% increase (P food intake, were 11.2% heavier (p food intake and post-natal body growth of offspring without inducing metabolic disorders such as obesity and insulin resistance. The IUCG nutritional regimen might be used to improve the food intake and post-natal body growth of domestic animals. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

  12. Post-natal myogenic and adipogenic developmental: defects and metabolic impairment upon loss of A-type lamins.

    Science.gov (United States)

    Kubben, Nard; Voncken, Jan Willem; Konings, Gonda; van Weeghel, Michel; van den Hoogenhof, Maarten Mg; Gijbels, Marion; van Erk, Arie; Schoonderwoerd, Kees; van den Bosch, Bianca; Dahlmans, Vivian; Calis, Chantal; Houten, Sander M; Misteli, Tom; Pinto, Yigal M

    2011-01-01

    A-type lamins are a major component of the nuclear lamina. Mutations in the LMNA gene, which encodes the A-type lamins A and C, cause a set of phenotypically diverse diseases collectively called laminopathies. While adult LMNA null mice show various symptoms typically associated with laminopathies, the effect of loss of lamin A/C on early post-natal development is poorly understood. Here we developed a novel LMNA null mouse (LMNA(GT-/-)) based on genetrap technology and analyzed its early post-natal development. We detect LMNA transcripts in heart, the outflow tract, dorsal aorta, liver and somites during early embryonic development. Loss of A-type lamins results in severe growth retardation and developmental defects of the heart, including impaired myocyte hypertrophy, skeletal muscle hypotrophy, decreased amounts of subcutaneous adipose tissue and impaired ex vivo adipogenic differentiation. These defects cause death at 2 to 3 weeks post partum associated with muscle weakness and metabolic complications, but without the occurrence of dilated cardiomyopathy or an obvious progeroid phenotype. Our results indicate that defective early post-natal development critically contributes to the disease phenotypes in adult laminopathies.

  13. Metal and metal oxide nanoparticle synthesis from metal organic frameworks (MOFs): finding the border of metal and metal oxides

    Science.gov (United States)

    Das, Raja; Pachfule, Pradip; Banerjee, Rahul; Poddar, Pankaj

    2012-01-01

    Herein, for the first time, we report a generalized strategy for the successful synthesis of highly crystalline metal and metal oxide nanoparticles embedded in a carbon matrix by the controlled thermolysis of metal organic frameworks (MOFs). The rationalized synthesis strategy of a broad range of metal and metal oxides nanoparticles, such as Cu/CuO, Co/Co3O4, ZnO, Mn2O3, MgO and CdS/CdO, by thermolysis of MOFs demonstrates for the first time that metal ions with a reduction potential of -0.27 volts or higher present in MOFs always form pure metal nanoparticles during thermolysis in N2, whereas metal ions with a reduction potential lower than -0.27 volts form metal oxide nanoparticles during thermolysis in N2. Another point of interest is the fact that we have found a unique relationship between the nanoparticle size and the distance between the secondary building units inside the MOF precursors. Interestingly, the crystallinity of the carbon matrix was also found to be greatly influenced by the environment (N2 and air) during thermolysis. Moreover, these nanoparticles dispersed in a carbon matrix showed promising H2 and CO2 adsorption properties depending on the environment used for the thermolysis of MOFs.Herein, for the first time, we report a generalized strategy for the successful synthesis of highly crystalline metal and metal oxide nanoparticles embedded in a carbon matrix by the controlled thermolysis of metal organic frameworks (MOFs). The rationalized synthesis strategy of a broad range of metal and metal oxides nanoparticles, such as Cu/CuO, Co/Co3O4, ZnO, Mn2O3, MgO and CdS/CdO, by thermolysis of MOFs demonstrates for the first time that metal ions with a reduction potential of -0.27 volts or higher present in MOFs always form pure metal nanoparticles during thermolysis in N2, whereas metal ions with a reduction potential lower than -0.27 volts form metal oxide nanoparticles during thermolysis in N2. Another point of interest is the fact that we have

  14. A ESCOLA DE AUXILIARES DE ENFERMAGEM DE NATAL E O HOSPITAL UNIVERSITÁRIO ONOFRE LOPES

    Directory of Open Access Journals (Sweden)

    DJAILSON JOSÉ DELGADO CARLOS

    2009-01-01

    Full Text Available Estudio con enfoque histórico y cualitativo, con el objetivo de analizar la historia de la Escuela de Enfermería de Natal y su relación con el Hospital Universitario Onofre Lopes. La investigación empírica se pautó a partir de documentos como: informes, actas, cartas, reglamentos, estatutos, Leyes, Decretos y entrevistas con personas que tienen claros recuerdos de esa historia. Se deduce que la inserción de la Escuela en el Hospital transformó lenta y progresivamente el equipo de Enfermería de la institución, a medida que incorporaba profesionales capacitados por ella. Esa valoración se acentuó, después que la Universidad do Rio Grande do Norte se tornó órgano federativo, en 1960, y la directora de la Escuela se hizo cargo también de la dirección de la Enfermería del Hospital. Esa dupla función y dupla responsabilidad convergieron y favorecieron la intensificación de la capacitación de los ayudantes en auxiliares y técnicos de Enfermería.

  15. Cultural politics and masculinities: multiple-partners in historical perspective in KwaZulu-Natal.

    Science.gov (United States)

    Hunter, Mark

    2005-05-01

    Drawing from ethnographic, archival and secondary research, this article examines multiple-sexual partners in historical perspective in KwaZulu-Natal, a South Africa province where one in three people are thought to be HIV positive. Research on masculinities, multiple partners, and AIDS has been predominantly directed towards the present day. This article stresses the importance of unraveling the antecedents of contemporary masculinities particularly the gendered cultural politics through which they have been produced. Arguing against dominant conceptions of African masculinity as being innate or static, it charts the rise and fall of the isoka, the Zulu man with multiple-sexual partners, over the last century. Showing how the isoka developed through changing conditions occasioned by capitalism, migrant labor and Christianity, it contends that an important turning point took place from the 1970s when high unemployment threatened previous expressions of manliness, notably marriage, settings up an independent household and becoming umnumzana (a household head). The high value placed on men seeking multiple-partners increasingly filled the void left by men's inability to become men through previous means. Turning to the contemporary period, the articles argues that, shaken by the huge AIDS deaths, men are betraying increasing doubts about the isoka masculinity.

  16. Antibiotic resistance of Vibrio parahaemolyticus isolated from pond-reared Litopenaeus vannamei marketed in Natal, Brazil

    Directory of Open Access Journals (Sweden)

    Ligia Maria Rodrigues de Melo

    2011-12-01

    Full Text Available Ten out of fifty fresh and refrigerated samples of shrimp (Litopenaeus vannamei collected from retailers in Natal (Rio Grande do Norte, Northeastern Brazil tested positive for Vibrio parahaemolyticus. The Kanagawa test and multiplex PCR assays were used to detect TDH and TRH hemolysins and the tdh, trh and tlh genes, respectively. All strains were Kanagawa-negative and tlh-positive. Antibiotic susceptibility testing was done for seven antibiotics by the agar diffusion technique. Five strains (50% presented multiple antibiotic resistance to ampicillin (90% and amikacin (60%, while two strains (20% displayed intermediate-level resistance to amikacin. All strains were sensitive to chloramphenicol. Intermediate-level susceptibility and/or resistance to other antibiotics ranged from 10 to 90%, with emphasis on the observed growing intermediate-level resistance to ciprofloxacin. Half our isolates yielded a multiple antibiotic resistance index above 0.2 (range: 0.14-0.29, indicating a considerable risk of propagation of antibiotic resistance throughout the food chain.

  17. Roosting habitat use and selection by northern spotted owls during natal dispersal

    Science.gov (United States)

    Sovern, Stan G.; Forsman, Eric D.; Dugger, Catherine M.; Taylor, Margaret

    2015-01-01

    We studied habitat selection by northern spotted owls (Strix occidentalis caurina) during natal dispersal in Washington State, USA, at both the roost site and landscape scales. We used logistic regression to obtain parameters for an exponential resource selection function based on vegetation attributes in roost and random plots in 76 forest stands that were used for roosting. We used a similar analysis to evaluate selection of landscape habitat attributes based on 301 radio-telemetry relocations and random points within our study area. We found no evidence of within-stand selection for any of the variables examined, but 78% of roosts were in stands with at least some large (>50 cm dbh) trees. At the landscape scale, owls selected for stands with high canopy cover (>70%). Dispersing owls selected vegetation types that were more similar to habitat selected by adult owls than habitat that would result from following guidelines previously proposed to maintain dispersal habitat. Our analysis indicates that juvenile owls select stands for roosting that have greater canopy cover than is recommended in current agency guidelines.

  18. The KwaZulu-Natal School Library Policy and its feasibility for implementation

    Directory of Open Access Journals (Sweden)

    Mariana Du Toit

    2013-03-01

    Full Text Available The research took into account accepted standards of good policy formulation to provide perspective and contextualise the study, and delineated educational challenges for the sector.The following theoretical frameworks guided the study: a constructivist approach in interpreting and  evaluating the role of school libraries within an education system based in constructivist principles, the traditional policy model to evaluate policy formulation and design, and a social constructionist view of policy in the interpreting of policy development and implementation. The epistemological basis for the main   methodology, the Delphi technique, was social constructivism.The research design comprised two phases.  Qualitative data collected from the Delphi panel's expert opinion was interpreted to analyse the policy document critically and assess its implementation strategy.  Quantitative data from an analysis of existing surveys and reports provided an overview of the current state of school  library provisioning in KwaZulu-Natal.  School library models already being implemented in the province were evaluated against this background.The research results provide guidelines for reviewing and refining the provincial policy intervention and  brought to the fore several issues that need to be resolved to facilitate school library development in South Africa.

  19. Síndrome de burnout no setor de transporte de Natal

    Directory of Open Access Journals (Sweden)

    Luciana Bezerra de Souza Gianasi

    Full Text Available Reconhecendo-se a importância que o ambiente de trabalho tem para a saúde mental, o objetivo desse estudo foi investigar a relação entre a síndrome de burnout e as fontes de desgaste físico e emocional no setor de transporte coletivo urbano da cidade de Natal. A pesquisa foi realizada com 412 motoristas e cobradores de duas empresas. Para coleta dos dados, aplicaram-se dois questionários e uma ficha sociodemográfica. O primeiro, construído e validado durante a pesquisa, investigou as fontes e o segundo, a síndrome. Entre os resultados, confirmou-se a prevalência da síndrome e que a principal fonte de desgaste físico e emocional que a prediz é o fator referente a conflitos de valores e ausência de equidade no ambiente de trabalho.

  20. Coastal dynamics on a soft coastline from serendipitous webcams: KwaZulu-Natal, South Africa

    Science.gov (United States)

    Guastella, Lisa A.; Smith, Alan M.

    2014-10-01

    Webcams have become popular means of showcasing beach conditions for a wide variety of beach users. However, webcams can also be a useful tool in assessing changes in coastal morphology and coastal processes. This information can be used by managers to assist in planning. A number of fixed-position beach webcams are freely available to the South African public via various tourism, surfing, weather and aviation websites, individual clubs and a cell-phone network provider. The advantages of these public networks are that the information is free and as the webcams are fixed, afford a consistent and comparable view of the beach. The disadvantage is that you are at the mercy of the provider: resolution is generally poor, downtime and communication are out of your control, and you have no influence over the positioning of the webcam or the discontinuity of service. Notwithstanding the above, the existing webcams can still provide valuable information. From the network of beach webcams available in South Africa we analyse imagery from three beach webcams located in the province of KwaZulu-Natal, at Umhlanga, Margate beach and lagoon, and Amanzimtoti beach and lagoon to examine the coastal dynamics. From these case studies we illustrate seasonal beach rotation and lagoon mouth dynamics, specifically why outlets migrate southwards in opposition to regional longshore drift.

  1. Women Tourism Entrepreneurs in KwaZulu-Natal, South Africa: Any Way Forward?

    Directory of Open Access Journals (Sweden)

    Sibongile Princess Tshabalala

    2016-10-01

    Full Text Available This study, done in KwaZulu-Natal, South Africa, sheds light into the challenges facing women entrepreneurs involved in tourism businesses and the opportunities they can harness in the tourism industry, with particular reference to some gender nuances. The study collected qualitative and quantitative data from respondents, and the data were analysed using content and descriptive analyses respectively. The challenges facing these women entrepreneurs, identified by this study, include lack of financial capital, low business capability, problem of size and scope, racial issues and traditional perceptions, and imperfect business location. Some opportunities for growth identified are local municipality support, internet marketing, and formation of business network for self-support and training. This study recommends business skills training for the women entrepreneurs in the areas of sourcing business funding, creating unique value proposition, product excellence, marketing capability, operational excellence and customer service. Although this study was conducted in a South African province, it has implications for women entrepreneurs in sub-Saharan Africa, and beyond.

  2. Triangulation theory applied to conflict over hormone herbicide drift in Natal, South Africa

    Science.gov (United States)

    Preston-Whyte, Robert A.; Laing, Mark D.

    1994-05-01

    Policies that arise out of conflict or collaboration between specific interest groups and government agencies are often explained by theoretical constructs that fall under the umbrella of group theory. Triangulation theory is one of these constructs and serves to explain the mutuality of interests that exist between government agencies and interest groups expressed as points linking geometric forms. Conflict tends to occur when competing interest groups are excluded from the linkage, in this case between the opponents and proponents of hormone herbicides in the Tala area in Natal, South Africa. In opposition to the use of hormone herbicides were vegetable farmers and their supporters: in linked support were agricultural interest groups who used hormone herbicides, the manufacturers of the herbicides, and the government agency responsible for agriculture. Because of the influence exerted through mutual support by the proponents of hormone herbicides, the formulation of policy decisions directed towards the resolution of the conflict was delayed. When the minister of agriculture finally intervened, the policy decisions were designed to secure the support of those opposing the use of hormone herbicides by introducing issues that cut across those maintaining the discord.

  3. [Social representation related to care in the family health program in Natal-Brazil].

    Science.gov (United States)

    Rodrigues, Maísa Paulino; de Lima, Kenio Costa; Roncalli, Angelo Giuseppe

    2008-01-01

    This study examines the core and outlying representational elements of healthcare constructed by Family Healthcare Program teams in Natal, Brazil, using the theory of social representations and the central core theory. The sample consisted of ninety healthcare practitioners working with this Program, with data collected through free word association, a questionnaire and focus groups. The core representation consists of attention/love and comfort, disclosing different understandings and showing that accumulated knowledge is supported by a view that is close to care-giving. However, traditional values and trivial connotations are maintained, hindering the implementation of more effective interventions in by this Program. The core composition indicated that any capacity-building efforts that try to modify attitudes - and thus the daily practice of these practitioners - must assign high priority to discussions on redefining these elements of attention/love and comfort. They must consider the set of mental, emotional, and practical elaborations as well as explanations arising from daily life that are introduced into the constitution of the social representations under examination, influencing choices and shaping the strategies used by practitioners to provide care.

  4. Providing mental health services to survivors: a Kwa Zulu-Natal perspective.

    Science.gov (United States)

    Pillay, B J

    2000-01-01

    The Truth and Reconciliation Commission (TRC) was established to deal with the history and future prevention of the abuse of human rights in South Africa. It aimed to restore relationships between the state and/or other perpetrators and victims of violence. Nevertheless, the process has highlighted the alarming prevalence of psychological trauma in our society. This paper reports on a study of individuals and/or families who presented their testimonies to the TRC in the Kwa Zulu-Natal and Free State Provinces of South Africa. The participants were asked to complete a semi-structured questionnaire designed by the author and a Post-traumatic Stress Disorder Checklist. Most witnesses had recognisable psychiatric disorders. The most common was post-traumatic stress disorder (chronic), followed by either anxiety and mood disorders. The results from this study point to the pervasiveness and seriousness of the sequelae of trauma experienced by individuals and communities (both victims and perpetrators) in South Africa. Health professionals in South Africa have the mammoth task and responsibility to assist in the process of healing and reparation.

  5. Lubricin is Required for the Structural Integrity and Post-natal Maintenance of TMJ.

    Science.gov (United States)

    Koyama, E; Saunders, C; Salhab, I; Decker, R S; Chen, I; Um, H; Pacifici, M; Nah, H D

    2014-07-01

    The Proteoglycan 4 (Prg4) product lubricin plays essential roles in boundary lubrication and movement in limb synovial joints, but its roles in temporomandibular joint (TMJ) are unclear. Thus, we characterized the TMJ phenotype in wild-type and Prg4(-/-) mouse littermates over age. As early as 2 weeks of age, mutant mice exhibited hyperplasia in the glenoid fossa articular cartilage, articular disc, and synovial membrane. By 1 month of age, there were fewer condylar superficial tenascin-C/Col1-positive cells and more numerous apoptotic condylar apical cells, while chondroprogenitors displayed higher mitotic activity, and Sox9-, Col2-, and ColX-expressing chondrocyte zones were significantly expanded. Mutant subchondral bone contained numerous Catepsin K-expressing osteoclasts at the chondro-osseous junction, increased invasive marrow cavities, and suboptimal subchondral bone. Mutant glenoid fossa, disc, synovial cells, and condyles displayed higher Hyaluronan synthase 2 expression. Mutant discs also lost their characteristic concave shape, exhibited ectopic chondrocyte differentiation, and occasionally adhered to condylar surfaces. A fibrinoid substance of unclear origin often covered the condylar surface. By 6 months of age, mutant condyles displayed osteoarthritic degradation with apical/mid-zone separation. In sum, lubricin exerts multiple essential direct and indirect roles to preserve TMJ structural and cellular integrity over post-natal life.

  6. Secrecy, empowerment and protection: positioning PrEP in KwaZulu-Natal, South Africa.

    Science.gov (United States)

    Govender, Eliza; Mansoor, Leila; MacQueen, Kate; Abdool Karim, Quarraisha

    2017-11-01

    The release of World Health Organisation guidelines recommending the prophylactic use of daily Truvada(®) for all populations at high risk of acquiring HIV opens the way for implementation of oral pre-exposure prophylaxis (PrEP). The impact of new prevention technologies is, however, dependent on demand creation strategies such as user awareness, acceptability and access, which in turn are influenced by sociocultural and gender norms. This study was conducted in three locations in KwaZulu-Natal, urban, rural and peri-urban, with six participatory workshops. Knowledge, desirable features of a product and demand positioning for PrEP were assessed using a participatory action media research process which included art-based activities and group discussion using a semi-structured interview schedule. The data were analysed using thematic analysis. The key themes that emerged in relation to product adoption were: ability to maintain secrecy of product use; the need for agency with personal choices around HIV prevention; and an increased desire for HIV protection. Findings reaffirm the influence of user engagement in understanding the sociocultural dynamics that influence demand creation for PrEP adoption.

  7. Challenging cheap-labour theory: Natal and Transvaal coal miners, ca 1890-1950

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, P. [University of Johannesburg, Johannesburg (South Africa)

    2008-07-01

    In the first half of the twentieth century, South Africa's two main coal-producing provinces, Natal and the Transvaal, were regarded as having separate industries. Comparing the two, the article shows that their geology, markets, ownership and organization were distinctive. In contrast, the patterns of labour struggles were alike, reflecting labour processes, racial divisions, and legal and ideological frameworks that were similar. The historiography of South African mining labour has emphasized the role of black migrants, who 'oscillated' between the mines and the rural areas from where they originated and to which they retired. While structuralist analyses argued that migrancy was the bedrock of a cheap-labour system that underpinned white power, leading social historians stressed that migrants were primarily rural men. The account presented here rejects the thrust of both positions, showing that a high proportion of coal miners settled around the mines. More of them would have done so had this been permitted, and the same applies to Africans working on the gold mines. Given that cheap-labour theory strengthens the exceptionalism that runs through much South African history, rejecting it can open up new possibilities for comparative study. In passing, the article reveals that black workers participated in the militant 1913 strike by the Witwatersrand's white mine workers.

  8. Understanding Compact Object Formation and Natal Kicks. IV. The case of IC 10 X-1

    CERN Document Server

    Wong, Tsing-Wai; Ansari, Asna; Fragos, Tassos; Glebbeek, Evert; Kalogera, Vassiliki; McClintock, Jeffrey

    2013-01-01

    The extragalactic X-ray binary IC 10 X-1 has attracted attention as it is possibly the host of the most massive stellar-mass black-hole (BH) known to date. Here we consider all available observational constraints and construct its evolutionary history up to the instant just before the formation of the BH. Our analysis accounts for the simplest possible history that includes three evolutionary phases: binary orbital dynamics at core collapse, common envelope (CE) evolution, and evolution of the BH--helium star binary progenitor of the observed system. We derive the complete set of constraints on the progenitor system at various evolutionary stages. Specifically: right before the core collapse event, we find the mass of the BH immediate progenitor to be $\\gtrsim 31 M_\\sun$ (at 95% of confidence, same hereafter). The magnitude of the natal kick imparted to the BH is constrained to be $\\lesssim 130$ km/s. More significantly we obtain robust constraints on the physics of the CE event. IC 10 X-1 provides leverage i...

  9. Natal Kicks of Stellar-Mass Black Holes by Asymmetric Mass Ejection in Fallback Supernovae

    CERN Document Server

    Janka, H -Thomas

    2013-01-01

    Integrating trajectories of low-mass X-ray binaries containing black holes within the Galactic potential, Repetto, Davies & Sigurdsson recently showed that the large distances of some systems above the Galactic plane can only be explained if black holes receive appreciable natal kicks. Surprisingly, they found that the distribution of black hole kick velocities (rather than that of the momenta) should be similar to that of neutron stars. Here I argue that this result can be understood if neutron star and black hole kicks are a consequence of large-scale asymmetries created in the supernova ejecta by the explosion mechanism. The corresponding anisotropic gravitational attraction of the asymmetrically expelled matter does not only accelerate new-born neutron stars by the "gravitational tug-boat mechanism". It can also lead to delayed black-hole formation by asymmetric fallback of the slowest parts of the initial ejecta onto the transiently existing neutron star, in course of which the momentum of the black ...

  10. Natal kicks of stellar mass black holes by asymmetric mass ejection in fallback supernovae

    Science.gov (United States)

    Janka, Hans-Thomas

    2013-09-01

    Integrating trajectories of low-mass X-ray binaries containing black holes within the Galactic potential, Repetto, Davies & Sigurdsson recently showed that the large distances of some systems above the Galactic plane can only be explained if black holes receive appreciable natal kicks. Surprisingly, they found that the distribution of black hole kick velocities (rather than that of the momenta) should be similar to that of neutron stars. Here I argue that this result can be understood if neutron star and black hole kicks are a consequence of large-scale asymmetries created in the supernova ejecta by the explosion mechanism. The corresponding anisotropic gravitational attraction of the asymmetrically expelled matter does not only accelerate new-born neutron stars by the `gravitational tug-boat mechanism', but can also lead to delayed black hole formation by asymmetric fallback of the slowest parts of the initial ejecta on to the transiently existing neutron star, in course of which the momentum of the black hole can grow with the fallback mass. Black hole kick velocities will therefore not be reduced by the ratio of neutron star to black hole mass as would be expected for kicks caused by anisotropic neutrino emission of the nascent neutron star.

  11. RADIOATIVIDADE DAS AREIAS UTILIZADAS NA CONSTRUÇÃO CIVIL DA CIDADE DO NATAL/RN

    Directory of Open Access Journals (Sweden)

    Luiz Henrique Lira de Oliveria

    2012-10-01

    Full Text Available O presente trabalho tem por desígnio identificar os minerais pesados encontrados nos aluviões que abastecem o mercado da construção civil da grande Natal, bem como medir a radioatividade provinda dessas areias, nas quais as pessoas estão em constante contato, a fim de alertá-las aos possíveis perigos. Para tal, escolheu-se a localidade de Jacobina, no município de Macaíba/RN pelo fato da existência de exploração de areia nas margens do rio Potengi, onde foram realizadas medições gamaespectométricas no solo e em afloramentos com o Cintilômetro RS-125 Super-SPEC, adquirido pelo CNPq (Processo nº 550307/2010-9. A partir dos resultados obtidos, foram criadas superfícies modeladas (em meio digital através de mapas temáticos que proporcionaram uma simples interpretação das doses radioativas absorvidas.

  12. Men's moralising discourses on gender and HIV risk in rural KwaZulu-Natal, South Africa.

    Science.gov (United States)

    Mindry, Deborah L; Knight, Lucia; van Rooyen, Heidi

    2015-01-01

    Various interventions have resulted in increased rates of HIV testing. However, encouraging men to acknowledge their risk for HIV, to test and link to treatment remains a challenge. In this study, we examine men's perspectives on navigating HIV risk in rural KwaZulu-Natal, South Africa. Qualitative interviews were conducted at four intervals over a three-year time period with a baseline cohort of 126 men and women. We found that men navigated HIV risk in their sexual relationships mainly by monitoring their partner's behaviour. Men expressed concerns about female respectability, invoking discourses on hlonipha rooted in Zulu cultural ideals and Christian ideals about women staying close to home. In the post-apartheid era, these concerns were inflected by anxieties over changing gender norms and the high rates and risks of infection in the region. HIV prevention discourses on behaviour intersected with men's efforts to assert their masculinity through the monitoring and controlling of women's behaviour. The potential negative impacts of this should be addressed. Prevention efforts need to focus on men's vulnerability to infection in terms of their own behaviour as well as the contexts in which they live.

  13. Single-nucleotide variations associated with Mycobacterium tuberculosis KwaZulu-Natal strains

    Indian Academy of Sciences (India)

    Sarbashis Das; Ragothaman M Yennamalli; Anchal Vishnoi; Parul Gupta; Alok Bhattacharya

    2009-09-01

    The occurrence of drug resistance in Mycobacterium tuberculosis, the aetiological agent of tuberculosis (TB), is hampering the management and control of TB in the world. Here we present a computational analysis of recently sequenced drug-sensitive (DS), multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains of M. tuberculosis. Single-nucleotide variations (SNVs) were identified in a pair-wise manner using the anchor-based whole genome comparison (ABWGC) tool and its modified version. For this analysis, four fully sequenced genomes of different strains of M. tuberculosis were taken along with three KwaZulu-Natal (KZN) strains isolated from South Africa including one XDR and one MDR strain. KZN strains were compared with other fully sequenced strains and also among each other. The variations were analysed with respect to their biological influence as a result of either altered structure or synthesis. The results suggest that the DR phenotype may be due to changes in a number of genes. The database on KZN strains can be accessed through the website http://mirna.jnu.ac.in/mgdd/.

  14. Magnetic mapping of fly-ash pollution and heavy metals from soil samples around a point source in a dry tropical environment.

    Science.gov (United States)

    Sharma, Atul Prakash; Tripathi, B D

    2008-03-01

    The Singrauli region in the southeastern part of Uttar Pradesh, India is one of the most polluted industrial sites of Asia. It encompasses 11 open cast coal mines and six thermal power stations that generate about 7,500 MW (about 10% of India's installed generation capacity) electricity. Thermal power plants represent the main source of pollution in this region, emitting six million tonnes of fly-ash per annum. Fly-ash is deposited on soils over a large area surrounding thermal power plants. Fly-ashes have high surface concentrations of several toxic elements (heavy metals) and high atmospheric mobility. Fly ash is produced through high-temperature combustion of fossil fuel rich in ferromagnetic minerals. These contaminants can be identified using rock-magnetic methods. Magnetic susceptibility is directly linked to the concentration of ferromagnetic minerals, primarily high values of magnetite. In this study, magnetic susceptibility of top soil samples collected from surrounding areas of a bituminous-coal-fired power plant were measured to identify areas of high emission levels and to chart the spatial distribution of airborne solid particles. Sites close to the power plant have shown higher values of susceptibility that decreases with increasing distance from the source. A significant correlation between magnetic susceptibility and heavy metal content in soils is found. A comparison of the spatial distribution of magnetic susceptibility with heavy-metal concentrations in soil samples suggests that magnetic measurements can be used as a rapid and inexpensive method for proxy mapping of air borne pollution due to industrial activity.

  15. Distribution and seasonal variability in the benthic eukaryotic community of Río Tinto (SW, Spain), an acidic, high metal extreme environment.

    Science.gov (United States)

    Aguilera, Angeles; Zettler, Erik; Gómez, Felipe; Amaral-Zettler, Linda; Rodríguez, Nuria; Amils, Ricardo

    2007-11-01

    The eukaryotic community of the Río Tinto (SW, Spain) was surveyed in fall, winter and spring through the combined use of traditional microscopy and molecular approaches, including Denaturing Gradient Gel Electrophoresis (DGGE) and sequence analysis of 18S rRNA gene fragments. Eukaryotic assemblages of surface sediment biofilms collected in January, May and September 2002 were compared from 13 sampling stations along the river. Physicochemical data revealed extremely acidic conditions (the pH ranged from 0.9 to 2.5) with high concentrations of heavy metals, including up to 20 mg l(-1) Fe, 317 mg l(-1) Zn, 47 mg l(-1) As, 42 mg l(-1) Cd and 4 mg l(-1) Ni. In total, 20 taxa were identified, including members of the Bacillariophyta, Chlorophyta and Euglenophyta phyla as well as ciliates, cercomonads, amoebae, stramenopiles, fungi, heliozoans and rotifers. In general, total cell abundances were highest in fall and spring but decreased drastically in winter, and the sampling stations with the most extreme conditions showed the lowest number of cells, as well as the lowest diversity. Species diversity did not vary much during the year. Only the filamentous algae showed a dramatic seasonal change, since they almost disappeared in winter and reached the highest biomass during the summer. Principal Components Analysis (PCA) showed a high inverse correlation between pH and most of the heavy metals analyzed, as well as Dunaliella sp., while Chlamydomonas sp. was directly related to pH during May and September. Three heavy metals (Zn, Cu and Ni) remained separate from the rest and showed an inverse correlation with most of the species analyzed, except for Dunaliella sp.

  16. Perch and Its Parasites as Heavy Metal Biomonitors in a Freshwater Environment: The Case Study of the Ružín Water Reservoir, Slovakia

    OpenAIRE

    Dana Miklisová; Vladimíra Hanzelová; Catarina Eira; Jordi Torres; Tímea Brázová; Peter Šalamún

    2012-01-01

    Heavy metal concentrations were determined in 43 perches (Perca fluviatilis) and in two of its most common parasites, the acanthocephalan Acanthocephalus lucii and the cestode Proteocephalus percae, collected in the period 2009–2010 from Ružín, a seriously polluted water reservoir in Slovakia. Samples of muscle, liver, kidney, brain, male and female reproductive organs and adipose tissue of fish and both parasites were analyzed for As, Cd, Cr, Cu, Hg, Mn, Ni, Pb and Zn, by ICP-MS. Mean concen...

  17. MetalS(3), a database-mining tool for the identification of structurally similar metal sites.

    Science.gov (United States)

    Valasatava, Yana; Rosato, Antonio; Cavallaro, Gabriele; Andreini, Claudia

    2014-08-01

    We have developed a database search tool to identify metal sites having structural similarity to a query metal site structure within the MetalPDB database of minimal functional sites (MFSs) contained in metal-binding biological macromolecules. MFSs describe the local environment around the metal(s) independently of the larger context of the macromolecular structure. Such a local environment has a determinant role in tuning the chemical reactivity of the metal, ultimately contributing to the functional properties of the whole system. The database search tool, which we called MetalS(3) (Metal Sites Similarity Search), can be accessed through a Web interface at http://metalweb.cerm.unifi.it/tools/metals3/ . MetalS(3) uses a suitably adapted version of an algorithm that we previously developed to systematically compare the structure of the query metal site with each MFS in MetalPDB. For each MFS, the best superposition is kept. All these superpositions are then ranked according to the MetalS(3) scoring function and are presented to the user in tabular form. The user can interact with the output Web page to visualize the structural alignment or the sequence alignment derived from it. Options to filter the results are available. Test calculations show that the MetalS(3) output correlates well with expectations from protein homology considerations. Furthermore, we describe some usage scenarios that highlight the usefulness of MetalS(3) to obtain mechanistic and functional hints regardless of homology.

  18. Estudo comparativo de indicadores bioquímicos de concentração de ferro, em duas populações de gestantes, com e sem atendimento pré-natal A comparative study of biochemical indicators of iron concentration in two groups of pregnant women, with and without pre-natal care

    Directory of Open Access Journals (Sweden)

    Sophia Cornbluth Szarfarc

    1982-02-01

    Full Text Available Foi avaliada a influência da quantidade do atendimento pré-natal na deficiência de ferro entre gestantes com 36 e mais semanas de gravidez, em comparação com um grupo padrão. A amostra foi distribuída em 3 grupos: GP - com pré-natal de "acreditação" satisfatória (grupo padrão; CPN com pré-natal, de diferentes qualidades; SPN - sem pré-natal. Os resultados obtidos para hemoglobina mostraram que no grupo padrão (GP a prevalência e severidade de anemia são significativamente menores do que no grupo com pré-natal (CPN e este do que no sem pré-natal (SPN. Os resultados obtidos na relação hemoglobina/hematócrito, ferro sérico e capacidade total de ligação de ferro apresentaram o GP em situação significativamente melhor do que os grupos CPN e SPN que não foram estatisticamente diferentes entre si. Chamou-se a atenção para a necessidade de aumento de cobertura e uniformização na qualidade dos serviços de pré-natal, com o objetivo de diminuir a prevalência de deficiência de ferro entre gestantes.The influence of the amount of pre-natal care on the prevalence of iron-deficiency among women, 36 weeks or more pregnant, was assessed. The sample population was divided into three groups: the Standard Group (GP - with adequate assistance of the pre-natal care services from the first trimester of pregnancy onwards; those who received pre-natal assistance, but of varying adequacy and begun at different gestational ages (CPN; and those who received no pre-natal assistance at all (SPN. The results obtained from hemoglobin analysis showed that prevalence and severity of anemia increases significantly from the GP to the SPN. The analysis of the mean corpuscular hemoglobin concentration, serum iron and transferrin saturation showed no statistically significant differences between groups CPN and SPN; the GP showed better results when compared to the other two. Attention is called to the necessity of pre-natal care and the

  19. Metallated metal-organic frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Bury, Wojciech; Farha, Omar K.; Hupp, Joseph T.; Mondloch, Joseph E.

    2017-08-22

    Porous metal-organic frameworks (MOFs) and metallated porous MOFs are provided. Also provided are methods of metallating porous MOFs using atomic layer deposition and methods of using the metallated MOFs as catalysts and in remediation applications.

  20. Metallated metal-organic frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Bury, Wojciech; Farha, Omar K.; Hupp, Joseph T.; Mondloch, Joseph E.

    2017-02-07

    Porous metal-organic frameworks (MOFs) and metallated porous MOFs are provided. Also provided are methods of metallating porous MOFs using atomic layer deposition and methods of using the metallated MOFs as catalysts and in remediation applications.