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Site-specific Factors (site-specific + factor)
Selected AbstractsSuggested Methods to Mitigate Bias from Nondissolved Petroleum in Ground Water Samples Collected from the Smear ZoneGROUND WATER MONITORING & REMEDIATION, Issue 3 2009Dawn A. Zemo This article provides actual site data that confirm that turbid ground water samples collected from within the smear zone at petroleum release sites can be significantly biased high by the inclusion of a nondissolved component that is an artifact of the sampling process. Side-by-side comparisons show that reducing sample turbidity can result in significant reductions of reported concentrations for the ground water samples and that the lower turbidity results are more representative of the petroleum actually dissolved in the ground water. Depending on site-specific factors, ground water sample turbidity can be reduced by four field-based and two laboratory-based methods. These methods should be used routinely at sites where turbid samples with a nondissolved component are being collected. [source] Single-molecule analysis of chromatin: Changing the view of genomes one molecule at a timeJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2008Santhi Pondugula Abstract Wrapping DNA into chromatin provides a wealth of regulatory mechanisms that ensure normal growth and development in eukaryotes. Our understanding of chromatin structure, including nucleosomes and non-histone protein,DNA interactions, has benefited immensely from nuclease and chemical digestion techniques. DNA-bound proteins, such as histones or site-specific factors, protect DNA against nuclease cleavage and generate large nucleosomal or small regulatory factor footprints. Chromatin subject to distinct modes of regulation often coincides with sites of nuclease hypersensitivity or nucleosome positioning. An inherent limitation of cleavage-based analyses has been the inability to reliably analyze regions of interest when levels of digestion depart from single-hit kinetics. Moreover, cleavage-based techniques provide views that are averaged over all the molecules in a sample population. Therefore, in cases of occupancy of multiple regulatory elements by factors, one cannot define whether the factors are bound to the same or different molecules in the population. The recent development of DNA methyltransferase-based, single-molecule MAP-IT technology overcomes limitations of ensemble approaches and has opened numerous new avenues in chromatin research. Here, we review the strengths, limitations, applications and future prospects of MAP-IT ranging from structural issues to mechanistic questions in eukaryotic chromatin regulation. J. Cell. Biochem. 105: 330,337, 2008. © 2008 Wiley-Liss, Inc. [source] Dispersal abilities of adult click beetles in arable land revealed by analysis of carbon stable isotopesAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 3 2009Nikolaus Schallhart Abstract 1,The dispersal abilities of agrioted beetles, serious pests on a variety of crops, are poorly known under natural conditions. This hampers their control. We used, for the first time, a stable isotope approach to assess dispersal of adult Agriotes obscurus in arable land. 2,After a diet switch from a C3- to a C4-plant, carbon isotope ratios of A. obscurus larvae significantly changed towards the isotopic signature of the new diet. Moreover, the larval ,13C signatures were transferred to the wing covers of the adult beetles with little distortion. 3,To assess the dispersal abilities under natural conditions, pheromone traps, lured for Agriotes sp., were installed at two study sites in Western Austria. Each site comprised a maize field (= C4-plant) and adjacent C3-grasslands with traps established along a transect of increasing distance to the maize. 4,,13C signatures of wing covers revealed that adult male A. obscurus were able to migrate at least 80 m, which was the maximum distance that dispersal could be traced in the present study. The dispersal behaviour might have been influenced by site-specific factors. 5,The results obtained demonstrate a higher potential of adult male Agriotes to disperse than previously assumed. Moreover, the combination of pheromone trapping and stable isotope analysis proved to be an effective approach to study insect movement and dispersal in arable systems harbouring C3- and C4-crops. [source] Post-translational modifications, but not transcriptional regulation, of major chloroplast RNA-binding proteins are related to Arabidopsis seedling developmentPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 8 2006Bai-Chen Wang Abstract Chloroplast RNA-binding proteins are involved in stabilizing stored chloroplast mRNAs and in recruiting site-specific factors that mediate RNA metabolism. In the present study, we characterized two major chloroplast RNA-binding proteins, cp29A and cp29B, by MALDI-TOF MS, N-terminal sequencing, and ESI-MS/MS following 2D-PAGE separation. Polypeptides derived from cp29A were recovered with free N-terminus or with N-terminal acetylation. In addition to the two isoforms found for cp29A, an isoform derived from cp29B was also observed to have five amino acids cleaved from its N-terminus. Results of quantitative real-time RT-PCR indicate that both genes reached maximal rates of transcription 96,h after commencement of germination and maintained relatively high levels throughout the whole life cycle. Transcription of cp29A and cp29B did not vary significantly under light or dark conditions, although production of the acetylated and N-terminally cleaved protein isoforms exhibited light dependence. Exposure of etiolated Arabidopsis seedlings to light conditions for as short as 9,h restored the modified isoforms to levels similar to those found in green plants. Identification of post-translational modifications in major chloroplast RNA-binding proteins may help elucidate their roles in seedling development and in plant RNA stabilization during the greening process. [source] Daubenton's bat distribution along rivers , developing and testing a predictive modelAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue S1 2010Steve D. Langton Abstract 1.This study aimed to develop and test a predictive model of Daubenton's bat Myotis daubentonii distribution and abundance at waterway sites in England and Wales. 2.A preliminary ,core' model to predict Daubenton's bat distribution, developed in 2003 and containing terms relating to biological water quality, waterway width, mean annual discharge and the presence of trees, was re-fitted to more comprehensive datasets. A ,data mining' exercise was conducted after testing the core model, in order to investigate other important variables and to suggest alternative models, with the overall aim of improving the confidence and utility of the results. 3.On average, Daubenton's bat activity was higher on larger waterways with abundant woodland nearby. There was, however, considerable variation in the levels of activity predicted by the models, possibly due to site-specific factors. 4.Daubenton's bat activity was significantly related to aquatic macroinvertebrate diversity, demonstrating the potential relevance of this species as an indicator of a pollution-sensitive biodiversity group. High aquatic macroinvertebrate diversity was associated with good chemical water quality. 5.The analysis demonstrates that Daubenton's bat activity on rivers can be predicted from habitat and water quality data, although the precision of these predictions is low. Where practical, field surveys yield better information. Copyright © 2009 John Wiley & Sons, Ltd. [source] Nomenclature and Definitions for Emergency Department Human Immunodeficiency Virus (HIV) Testing: Report from the 2007 Conference of the National Emergency Department HIV Testing ConsortiumACADEMIC EMERGENCY MEDICINE, Issue 2 2009Michael S. Lyons MD Abstract Early diagnosis of persons infected with human immunodeficiency virus (HIV) through diagnostic testing and screening is a critical priority for individual and public health. Emergency departments (EDs) have an important role in this effort. As EDs gain experience in HIV testing, it is increasingly apparent that implementing testing is conceptually and operationally complex. A wide variety of HIV testing practice and research models have emerged, each reflecting adaptations to site-specific factors and the needs of local populations. The diversity and complexity inherent in nascent ED HIV testing practice and research are associated with the risk that findings will not be described according to a common lexicon. This article presents a comprehensive set of terms and definitions that can be used to describe ED-based HIV testing programs, developed by consensus opinion from the inaugural meeting of the National ED HIV Testing Consortium. These definitions are designed to facilitate discussion, increase comparability of future reports, and potentially accelerate wider implementation of ED HIV testing. [source] | ||||||||||