66 research outputs found

    Modeling of the Evolution of Steppe Chernozems and Development  of the Method of Pedogenetic Chronology

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    Geoarchaeological methods were used to study chronosequences of surface soils in the steppe zone and to trace soil evolution during the Late Holocene in northwestern Crime

    Archaeological ash deposits and soils formed on ash in the south of the East European Plain

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    Ash as an anthropogenic substrate is widely found at archaeological sites in the south of the East European Plain. Investigations of archaeological ashes, the results of which are presented here, have been conducted in three regions that differ in climate and extent of forest cover (from 29 to 1.5%): 1) typical forest–steppe; 2) piedmont forest-steppe with islands of groves; 3) steppe, almost woodless landscapes. Using spectrometry and X-ray analysis, the present study investigates the chemical composition of ancient ash and ash experimentally produced from different sorts of fuel, as well as the geochemistry of soils developed on ash deposit

    Post-agrogenic evolution of soils in ancient Greek land use areas in the Herakleian peninsula, southwestern Crimea

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    The paper examines the regularities of the post-agrogenic evolution of soils of differing age in the Herakleian Peninsula (southwestern Crimea, Ukraine), which developed under conditions of the sub-Mediterranean climate and have been cultivated since ancient timesyesBelgorod State Universit

    Chemical data on ashy soils as an information basis for dating archaeological sites

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    Geochemical associations of accumulated and dis- persed elements in the upper horizon of soils of different age in relation to the original ash were determined. This makes it possible to calculate the time of biogeochemical transfor- mation of ash in the course of pedogenesis, thus offering a new dating technique for archaeologist

    Pars plana vitrectomy for diabetic macular edema. Internal limiting membrane delamination vs posterior hyaloid removal. A prospective randomized trial

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    To access publisher full text version of this article. Please click on the hyperlink in Additional Links field.BACKGROUND: Diabetes mellitus, as well as subsequent ocular complications such as cystoid macular edema (CME), are of fundametal socio-economic relevance. Therefore, we evaluated the influence of internal limiting membrane (ILM) removal on longterm morphological and functional outcome in patients with diabetes mellitus (DM) type 2 and chronic CME without evident vitreomacular traction. METHOD: Forty eyes with attached posterior hyaloid were included in this prospective trial and randomized intraoperatively. Prior focal (n = 31) or panretinal (n = 25) laser coagulation was permitted. Group I (n = 19 patients) underwent surgical induction of posterior vitreous detachment (PVD), group II (n = 20 patients) PVD and removal of the ILM. Eleven patients with detached posterior hyaloid (group III) were not randomized, and ILM removal was performed. One eye had to be excluded from further analysis. Examinations included ETDRS best-corrected visual acuity (BCVA), fluorescein angiography (FLA) and OCT at baseline, 3 and 6 months postoperatively. Main outcome measure was BCVA at 6 months, secondary was foveal thickness. RESULTS: Mean BCVA over 6 months remained unchanged in 85% of patients of group II, and decreased in 53% of patients of group I. Results were not statistically significant different [group I: mean decrease log MAR 95% CI (0.06; 0.32), group II: (-0.02; 0.11)]. OCT revealed a significantly greater reduction of foveal thickness following PVD with ILM removal [group I: mean change: 95% CI (-208.95 μm; -78.05 μm), group II: (-80.90 μm: +59.17 μm)]. CONCLUSION: Vitrectomy, PVD with or without ILM removal does not improve vision in patients with DM type 2 and cystoid diabetic macular edema without evident vitreoretinal traction. ILM delamination shows improved morphological results, and appears to be beneficial in eyes with preexisting PVD

    Elevated Non-Esterified Fatty Acid Concentrations during Bovine Oocyte Maturation Compromise Early Embryo Physiology

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    Elevated concentrations of serum non-esterified fatty acids (NEFA), associated with maternal disorders such as obesity and type II diabetes, alter the ovarian follicular micro-environment and have been associated with subfertility arising from reduced oocyte developmental competence. We have asked whether elevated NEFA concentrations during oocyte maturation affect the development and physiology of zygotes formed from such oocytes, using the cow as a model. The zygotes were grown to blastocysts, which were evaluated for their quality in terms of cell number, apoptosis, expression of key genes, amino acid turnover and oxidative metabolism. Oocyte maturation under elevated NEFA concentrations resulted in blastocysts with significantly lower cell number, increased apoptotic cell ratio and altered mRNA abundance of DNMT3A, IGF2R and SLC2A1. In addition, the blastocysts displayed reduced oxygen, pyruvate and glucose consumption, up-regulated lactate consumption and higher amino acid metabolism. These data indicate that exposure of maturing oocytes to elevated NEFA concentrations has a negative impact on fertility not only through a reduction in oocyte developmental capacity but through compromised early embryo quality, viability and metabolism

    A Protocol for the Secure Linking of Registries for HPV Surveillance

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    In order to monitor the effectiveness of HPV vaccination in Canada the linkage of multiple data registries may be required. These registries may not always be managed by the same organization and, furthermore, privacy legislation or practices may restrict any data linkages of records that can actually be done among registries. The objective of this study was to develop a secure protocol for linking data from different registries and to allow on-going monitoring of HPV vaccine effectiveness.A secure linking protocol, using commutative hash functions and secure multi-party computation techniques was developed. This protocol allows for the exact matching of records among registries and the computation of statistics on the linked data while meeting five practical requirements to ensure patient confidentiality and privacy. The statistics considered were: odds ratio and its confidence interval, chi-square test, and relative risk and its confidence interval. Additional statistics on contingency tables, such as other measures of association, can be added using the same principles presented. The computation time performance of this protocol was evaluated.The protocol has acceptable computation time and scales linearly with the size of the data set and the size of the contingency table. The worse case computation time for up to 100,000 patients returned by each query and a 16 cell contingency table is less than 4 hours for basic statistics, and the best case is under 3 hours.A computationally practical protocol for the secure linking of data from multiple registries has been demonstrated in the context of HPV vaccine initiative impact assessment. The basic protocol can be generalized to the surveillance of other conditions, diseases, or vaccination programs

    Urinary bisphenol A concentrations in girls from rural and urban Egypt: a pilot study

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    Abstract Background Exposure to endocrine active compounds, including bisphenol A (BPA), remains poorly characterized in developing countries despite the fact that behavioral practices related to westernization have the potential to influence exposure. BPA is a high production volume chemical that has been associated with metabolic dysfunction as well as behavioral and developmental effects in people, including children. In this pilot study, we evaluate BPA exposure and assess likely pathways of exposure among girls from urban and rural Egypt. Methods We measured urinary concentrations of total (free plus conjugated) species of BPA in spot samples in urban (N = 30) and rural (N = 30) Egyptian girls, and compared these concentrations to preexisting data from age-matched American girls (N = 47) from the U.S. National Health and Nutrition Examination Survey (NHANES). We also collected anthropometric and questionnaire data regarding food storage behaviors to assess potential routes of exposure. Results Urban and rural Egyptian girls exhibited similar concentrations of urinary total BPA, with median unadjusted values of 1.00 and 0.60 ng/mL, respectively. Concentrations of urinary BPA in this group of Egyptian girls (median unadjusted: 0.70 ng/mL) were significantly lower compared to age-matched American girls (median unadjusted: 2.60 ng/mL) according to NHANES 2009-2010 data. Reported storage of food in plastic containers was a significant predictor of increasing concentrations of urinary BPA. Conclusions Despite the relatively low urinary BPA concentrations within this Egyptian cohort, the significant association between food storage behaviors and increasing urinary BPA concentration highlights the need to understand food and consumer product patterns that may be closing the gap between urban and rural lifestyles.http://deepblue.lib.umich.edu/bitstream/2027.42/112495/1/12940_2011_Article_523.pd
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