1,602 research outputs found
A comparative in situ decomposition study using still born piglets and leaf litter from a deciduous forest
A cadaver and dead plant organic matter, or litter, are rich energy sources that undergo a complex decomposition process, which impact the surrounding environmental microbiota. Advances in molecular microbiology techniques, with study of the 16S RNA genes, in particular, have highlighted the application of forensic ecogenomics in addressing key knowledge gaps. To investigate subsurface microbiome shifts as a novel tool to establish “postmortem microbial clock” and augment postmortem interval (PMI) and time-since-burial estimations, an in situ study with triplicate underground burials of piglets as human taphonomic proxies and Quercus robur leaf litter was monitored for 270 days. Changes in microbial community structure and composition were related directly to changes in seasonal temperature, with microbial shifts more pronounced during the summer. For example, Methylococcaceae could be used as seasonal bacterial indicators, from winter to summer, in establishing postmortem microbial clock for this site. Furthermore, Methylophilaceae (Methylophilales order) and Anaerolineaceae would differentiate for the piglet and leaf litter soils, respectively, 180 days after internment
Prompt atmospheric neutrino fluxes: perturbative QCD models and nuclear effects
We evaluate the prompt atmospheric neutrino flux at high energies using three
different frameworks for calculating the heavy quark production cross section
in QCD: NLO perturbative QCD, factorization including low-
resummation, and the dipole model including parton saturation. We use QCD
parameters, the value for the charm quark mass and the range for the
factorization and renormalization scales that provide the best description of
the total charm cross section measured at fixed target experiments, at RHIC and
at LHC. Using these parameters we calculate differential cross sections for
charm and bottom production and compare with the latest data on forward charm
meson production from LHCb at TeV and at TeV, finding good agreement
with the data. In addition, we investigate the role of nuclear shadowing by
including nuclear parton distribution functions (PDF) for the target air
nucleus using two different nuclear PDF schemes. Depending on the scheme used,
we find the reduction of the flux due to nuclear effects varies from to
at the highest energies. Finally, we compare our results with the
IceCube limit on the prompt neutrino flux, which is already providing valuable
information about some of the QCD models.Comment: 61 pages, 25 figures, 11 table
Integrating quantitative and qualitative methodologies for the assessment of health care systems: emergency medicine in post-conflict Serbia
BACKGROUND: Due to the complexity of health system reform in the post-conflict, post-disaster, and development settings, attempts to restructure health services are fraught with pitfalls that are often unanticipated because of inadequate preliminary assessments. Our proposed Integrated Multimodal Assessment – combining quantitative and qualitative methodologies – may provide a more robust mechanism for identifying programmatic priorities and critical barriers for appropriate and sustainable health system interventions. The purpose of this study is to describe this novel multimodal assessment using emergency medicine in post-conflict Serbia as a model. METHODS: Integrated quantitative and qualitative methodologies – system characterization and observation, focus group discussions, free-response questionnaires, and by-person factor analysis – were used to identify needs, problems, and potential barriers to the development of emergency medicine in Serbia. Participants included emergency and pre-hospital personnel from all emergency medical institutions in Belgrade. RESULTS: Demographic data indicate a loosely ordered network of part-time emergency departments supported by 24-hour pre-hospital services and an academic emergency center. Focus groups and questionnaires reveal significant impediments to delivery of care and suggest development priorities. By-person factor analysis subsequently divides respondents into distinctive attitudinal types, compares participant opinions, and identifies programmatic priorities. CONCLUSIONS: By combining quantitative and qualitative methodologies, our Integrated Multimodal Assessment identified critical needs and barriers to emergency medicine development in Serbia and may serve as a model for future health system assessments in post-conflict, post-disaster, and development settings
Renal impairment in a rural African antiretroviral programme
Background:
There is little knowledge regarding the prevalence and nature of renal impairment in African populations initiating antiretroviral treatment, nor evidence to inform the most cost effective methods of screening for renal impairment. With the increasing availability of the potentially nephrotixic drug, tenofovir, such information is important for the planning of antiretroviral programmes
Methods:
(i) Retrospective review of the prevalence and risk factors for impaired renal function in 2189 individuals initiating antiretroviral treatment in a rural African setting between 2004 and 2007 (ii) A prospective study of 149 consecutive patients initiating antiretrovirals to assess the utility of urine analysis for the detection of impaired renal function. Severe renal and moderately impaired renal function were defined as an estimated GFR of ≤ 30 mls/min/1.73 m2 and 30–60 mls/min/1.73 m2 respectively. Logistic regression was used to determine odds ratio (OR) of significantly impaired renal function (combining severe and moderate impairment). Co-variates for analysis were age, sex and CD4 count at initiation.
Results:
(i) There was a low prevalence of severe renal impairment (29/2189, 1.3% 95% C.I. 0.8–1.8) whereas moderate renal impairment was more frequent (287/2189, 13.1% 95% C.I. 11.6–14.5) with many patients having advanced immunosuppression at treatment initiation (median CD4 120 cells/μl). In multivariable logistic regression age over 40 (aOR 4.65, 95% C.I. 3.54–6.1), male gender (aOR 1.89, 95% C.I. 1.39–2.56) and CD4<100 cells/ul (aOR 1.4, 95% C.I. 1.07–1.82) were associated with risk of significant renal impairment (ii) In 149 consecutive patients, urine analysis had poor sensitivity and specificity for detecting impaired renal function.
Conclusion:
In this rural African setting, significant renal impairment is uncommon in patients initiating antiretrovirals. Urine analysis alone may be inadequate for identification of those with impaired renal function where resources for biochemistry are limited
Maternal effects on anogenital distance in a wild marmot population
Peer reviewedPublisher PD
First Record of Fusarium verticillioides as an Entomopathogenic Fungus of Grasshoppers
Fusarium verticillioides (Saccardo) Nirenberg (Ascomycota: Hypocreales) is the most common fungus reported on infected corn kernels and vegetative tissues, but has not yet been documented as being entomopathogenic for grasshoppers. Grasshoppers and locusts represent a large group of insects that cause economic damage to forage and crops. Tropidacris collaris (Stoll) (Orthoptera: Acridoidea: Romaleidae) is a large and voracious grasshopper that in recent years has become an increasingly recurrent and widespread pest in progressively more greatly extended areas of some of in Argentina's northern provinces, with chemical insecticides being currently the only means of control. During February and March of 2008–09, nymphs and adults of T. collaris were collected with sweep nets in dense woodland vegetation at a site near Tres Estacas in western Chaco Province, Argentina, and kept in screened cages. F. verticillioides was isolated from insects that died within 10 days and was cultured in PGA medium. Pathogenicity tests were conducted and positive results recorded. Using traditional and molecular-biological methods, an isolate of F. verticillioides was obtained from T. collaris, and its pathogenecity in the laboratory was shown against another harmful grasshopper, Ronderosia bergi (Stål) (Acridoidea: Acrididae: Melanoplinae). The mortality caused by F. verticillioides on R. bergi reached 58 ± 6.53% by 10 days after inoculation. This is the first record of natural infection caused by F. verticillioides in grasshoppers
Nel positively regulates the genesis of retinal ganglion cells by promoting their differentiation and survival during development
Peer reviewedPublisher PD
Unique chemical parameters and microbial activity lead to increased archaeological preservation at the Roman frontier site of Vindolanda, UK.
Waterlogged burial conditions impact upon artefact preservation. One major determinant of preservation is presence and behaviour of microorganisms, however, unravelling the mechanisms, especially in waterlogged conditions is challenging. In this study, we analysed elemental composition, bacterial diversity and community structure from excavation trenches at the Roman Site of Vindolanda, Northumberland, UK, using pXRF and 16S rRNA gene amplicon sequencing. Excavation trenches provide information of different occupation periods. The results indicated that microbial communities were dominated by Firmicutes, Bacteroidetes and Proteobacteria at a phylum level. Samples which also had visible vivianite presence showed that there were marked increases in Methylophilus. Methylophilus might be associated with favourable preservation in these anaerobic conditions. More research is needed to clearly link the presence of Methylophilus with vivianite production. The study emphasises the need for further integration of chemical and microbiome approaches, especially in good preservation areas, to explore microbial and chemical degradation mechanisms
JunctionViewer: customizable annotation software for repeat-rich genomic regions
<p>Abstract</p> <p>Background</p> <p>Repeat-rich regions such as centromeres receive less attention than their gene-rich euchromatic counterparts because the former are difficult to assemble and analyze. Our objectives were to 1) map all ten centromeres onto the maize genetic map and 2) characterize the sequence features of maize centromeres, each of which spans several megabases of highly repetitive DNA. Repetitive sequences can be mapped using special molecular markers that are based on PCR with primers designed from two unique "repeat junctions". Efficient screening of large amounts of maize genome sequence data for repeat junctions, as well as key centromere sequence features required the development of specific annotation software.</p> <p>Results</p> <p>We developed JunctionViewer to automate the process of identifying and differentiating closely related centromere repeats and repeat junctions, and to generate graphical displays of these and other features within centromeric sequences. JunctionViewer generates NCBI BLAST, WU-BLAST, cross_match and MUMmer alignments, and displays the optimal alignments and additional annotation data as concise graphical representations that can be viewed directly through the graphical interface or as PostScript<sup>® </sup>output.</p> <p>This software enabled us to quickly characterize millions of nucleotides of newly sequenced DNA ranging in size from single reads to assembled BACs and megabase-sized pseudochromosome regions. It expedited the process of generating repeat junction markers that were subsequently used to anchor all 10 centromeres to the maize map. It also enabled us to efficiently identify key features in large genomic regions, providing insight into the arrangement and evolution of maize centromeric DNA.</p> <p>Conclusions</p> <p>JunctionViewer will be useful to scientists who wish to automatically generate concise graphical summaries of repeat sequences. It is particularly valuable for those needing to efficiently identify unique repeat junctions. The scalability and ability to customize homology search parameters for different classes of closely related repeat sequences make this software ideal for recurring annotation (e.g., genome projects that are in progress) of genomic regions that contain well-defined repeats, such as those in centromeres. Although originally customized for maize centromere sequence, we anticipate this software to facilitate the analysis of centromere and other repeat-rich regions in other organisms.</p
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