1,658 research outputs found

    Ashland community survey : an economic, social and sanitary survey in Howard County, Missouri

    Get PDF
    Cover title

    Methylmercury in marine ecosystems : spatial patterns and processes of production, bioaccumulation, and biomagnification

    Get PDF
    Author Posting. © International Association for Ecology and Health, 2008. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in EcoHealth 5 (2008): 399-408, doi:10.1007/s10393-008-0201-1.The spatial variation of MeHg production, bioaccumulation and biomagnification in marine food webs is poorly characterized but critical to understanding the links between sources and higher trophic levels such as fish that are ultimately vectors of human and wildlife exposure. This paper discusses both large and local scale processes controlling Hg supply, methylation, bioaccumulation and transfer in marine ecosystems. While global estimates of Hg supply suggest important open ocean reservoirs of MeHg, only coastal processes and food webs are known sources of MeHg production, bioaccumulation, and bioadvection. The patterns observed to date suggest that not all sources and biotic receptors are spatially linked and that physical and ecological processes are important in transferring MeHg from source regions to bioaccumulation in marine food webs and from lower to higher trophic levels.Supported by NIH Grant Number P42 ESO7373 from the NIEHS, SERDP funds from the Department of Defense, the ESSRF (Environmental Science Strategic Research Fund) DFO, Canada, Woods Hole Sea Grant, Woods Hole Coastal Ocean Institute, National Science Foundation, and RI-INBRE Grant #P20RR016457 from NCRR, NIH

    Sulfur gases produced by the decomposition of sulfide minerals: Application to geochemical exploration

    Full text link
    We have evaluated the potential application of sulfur gas analysis to exploration for buried sulfide mineral deposits by: (1) calculating by use of equilibrium thermodynamics, the relative abundances of gases that should be given off by decomposing sulfide minerals; and (2) determining experimentally the abundances of gases that are actually given off. The calculations indicate that the gases that should be given off by decomposing sulfide minerals are (in order of decreasing abundance) H2S, COS, CS2, CH3SH, (CH3)2S2 or SO2 or S2 (depending on Eh and pH). In contrast, our experiments show that decomposing sulfide minerals evolve only CS2 and COS, in order of decreasing abundance. Pyrite produces the largest amounts of sulfur gas. Moist (rather than saturated) and non-sterile (rather than sterile) conditions enhance gas generation from pyrite, although no large difference appeared between sterile and non-sterile experiments for other sulfide minerals. These experiments indicate that the sulfur gases CS2 and COS could be useful indicators of buried metal sulfide deposits.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23777/1/0000015.pd

    Genome-Wide Association Study Identifies Loci for Liver Enzyme Concentrations in Mexican Americans: The GUARDIAN Consortium.

    Get PDF
    ObjectivePopulations of Mexican American ancestry are at an increased risk for nonalcoholic fatty liver disease. The objective of this study was to determine whether loci in known and novel genes were associated with variation in aspartate aminotransferase (AST) (n = 3,644), alanine aminotransferase (ALT) (n = 3,595), and gamma-glutamyl transferase (GGT) (n = 1,577) levels by conducting the first genome-wide association study (GWAS) of liver enzymes, which commonly measure liver function, in individuals of Mexican American ancestry.MethodsLevels of AST, ALT, and GGT were determined by enzymatic colorimetric assays. A multi-cohort GWAS of individuals of Mexican American ancestry was performed. Single-nucleotide polymorphisms (SNP) were tested for association with liver outcomes by multivariable linear regression using an additive genetic model. Association analyses were conducted separately in each cohort, followed by a nonparametric meta-analysis.ResultsIn the PNPLA3 gene, rs4823173 (P = 3.44 × 10-10 ), rs2896019 (P = 7.29 × 10-9 ), and rs2281135 (P = 8.73 × 10-9 ) were significantly associated with AST levels. Although not genome-wide significant, these same SNPs were the top hits for ALT (P = 7.12 × 10-8 , P = 1.98 × 10-7 , and P = 1.81 × 10-7 , respectively). The strong correlation (r2  = 1.0) for these SNPs indicated a single hit in the PNPLA3 gene. No genome-wide significant associations were found for GGT.ConclusionsPNPLA3, a locus previously identified with ALT, AST, and nonalcoholic fatty liver disease in European and Japanese GWAS, is also associated with liver enzymes in populations of Mexican American ancestry

    Comprehensive review of the evidence regarding the effectiveness of community-based primary health care in improving maternal, neonatal and child health: 8. summary and recommendations of the expert panel

    Get PDF
    Background: The contributions that community-based primary health care (CBPHC) and engaging with communities as valued partners can make to the improvement of maternal, neonatal and child health (MNCH) is not widely appreciated. This unfortunate reality is one of the reasons why so few priority countries failed to achieve the health-related Millennium Development Goals by 2015. This article provides a summary of a series of articles about the effectiveness of CBPHC in improving MNCH and offers recommendations from an Expert Panel for strengthening CBPHC that were formulated in 2008 and have been updated on the basis of more recent evidence.Methods: An Expert Panel convened to guide the review of the effectiveness of community-based primary health care (CBPHC). The Expert Panel met in 2008 in New York City with senior UNICEF staff. In 2016, following the completion of the review, the Panel considered the review\u27s findings and made recommendations. The review consisted of an analysis of 661 unique reports, including 583 peer-reviewed journal articles, 12 books/monographs, 4 book chapters, and 72 reports from the gray literature. The analysis consisted of 700 assessments since 39 were analyzed twice (once for an assessment of improvements in neonatal and/or child health and once for an assessment in maternal health).Results: The Expert Panel recommends that CBPHC should be a priority for strengthening health systems, accelerating progress in achieving universal health coverage, and ending preventable child and maternal deaths. The Panel also recommends that expenditures for CBPHC be monitored against expenditures for primary health care facilities and hospitals and reflect the importance of CBPHC for averting mortality. Governments, government health programs, and NGOs should develop health systems that respect and value communities as full partners and work collaboratively with them in building and strengthening CBPHC programs - through engagement with planning, implementation (including the full use of community-level workers), and evaluation. CBPHC programs need to reach every community and household in order to achieve universal coverage of key evidence-based interventions that can be implemented in the community outside of health facilities and assure that those most in need are reached.Conclusions: Stronger CBPHC programs that foster community engagement/empowerment with the implementation of evidence-based interventions will be essential for achieving universal coverage of health services by 2030 (as called for by the Sustainable Development Goals recently adopted by the United Nations), ending preventable child and maternal deaths by 2030 (as called for by the World Health Organization, UNICEF, and many countries around the world), and eventually achieving Health for All as envisioned at the International Conference on Primary Health Care in 1978. Stronger CBPHC programs can also create entry points and synergies for expanding the coverage of family planning services as well as for accelerating progress in the detection and treatment of HIV/AIDS, tuberculosis, malaria, hypertension, and other chronic diseases. Continued strengthening of CBPHC programs based on rigorous ongoing operations research and evaluation will be required, and this evidence will be needed to guide national and international policies and programs

    Time-Dependent Partition-Free Approach in Resonant Tunneling Systems

    Full text link
    An extended Keldysh formalism, well suited to properly take into account the initial correlations, is used in order to deal with the time-dependent current response of a resonant tunneling system. We use a \textit{partition-free} approach by Cini in which the whole system is in equilibrium before an external bias is switched on. No fictitious partitions are used. Besides the steady-state responses one can also calculate physical dynamical responses. In the noninteracting case we clarify under what circumstances a steady-state current develops and compare our result with the one obtained in the partitioned scheme. We prove a Theorem of asymptotic Equivalence between the two schemes for arbitrary time-dependent disturbances. We also show that the steady-state current is independent of the history of the external perturbation (Memory Loss Theorem). In the so called wide-band limit an analytic result for the time-dependent current is obtained. In the interacting case we propose an exact non-equilibrium Green function approach based on Time Dependent Density Functional Theory. The equations are no more difficult than an ordinary Mean Field treatment. We show how the scattering-state scheme by Lang follows from our formulation. An exact formula for the steady-state current of an arbitrary interacting resonant tunneling system is obtained. As an example the time-dependent current response is calculated in the Random Phase Approximation.Comment: final version, 18 pages, 9 figure

    Bisphenol A Is Released from Used Polycarbonate Animal Cages into Water at Room Temperature

    Get PDF
    doi:10.1289/ehp.5993Bisphenol A (BPA) is a monomer with estrogenic activity that is used in the production of food packaging, dental sealants, polycarbonate plastic, and many other products. The monomer has previously been reported to hydrolyze and leach from these products under high heat and alkaline conditions, and the amount of leaching increases as a function of use. We examined whether new and used polycarbonate animal cages passively release bioactive levels of BPA into water at room temperature and neutral pH. Purified water was incubated at room temperature in new polycarbonate and polysulfone cages and used (discolored) polycarbonate cages, as well as control (glass and used polypropylene) containers. The resulting water samples were characterized with gas chromatography/mass spectrometry (GC/MS) and tested for estrogenic activity using an MCF-7 human breast cancer cell proliferation assay. Significant estrogenic activity, identifiable as BPA by GC/MS (up to 310 µg/L), was released from used polycarbonate animal cages. Detectable levels of BPA were released from new polycarbonate cages (up to 0.3 µg/L) as well as new polysulfone cages (1.5 µg/L), whereas no BPA was detected in water incubated in glass and used polypropylene cages. Finally, BPA exposure as a result of being housed in used polycarbonate cages produced a 16% increase in uterine weight in prepubertal female mice relative to females housed in used polypropylene cages, although the difference was not statistically significant. Our findings suggest that laboratory animals maintained in polycarbonate and polysulfone cages are exposed to BPA via leaching, with exposure reaching the highest levels in old cages.Support during the preparation of this manuscript was provided by grants from the National Institutes of Health (CA50354) and the University of Missouri (VMFC0018) to W.V.W., NIH (ES08293 and ES11283) to F.v.S., and the U.S.G.S
    • …
    corecore