638 research outputs found

    Contribution of Vegetation to the Microbial Composition of Nearby Outdoor Air.

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    UnlabelledGiven that epiphytic microbes are often found in large population sizes on plants, we tested the hypothesis that plants are quantitatively important local sources of airborne microorganisms. The abundance of microbial communities, determined by quantifying bacterial 16S RNA genes and the fungal internal transcribed spacer (ITS) region, in air collected directly above vegetation was 2- to 10-fold higher than that in air collected simultaneously in an adjacent nonvegetated area 50 m upwind. Nonmetric multidimensional scaling revealed that the composition of airborne bacteria in upwind air samples grouped separately from that of downwind air samples, while communities on plants and downwind air could not be distinguished. In contrast, fungal taxa in air samples were more similar to each other than to the fungal epiphytes. A source-tracking algorithm revealed that up to 50% of airborne bacteria in downwind air samples were presumably of local plant origin. The difference in the proportional abundances of a given operational taxonomic unit (OTU) between downwind and upwind air when regressed against the proportional representation of this OTU on the plant yielded a positive slope for both bacteria and fungi, indicating that those taxa that were most abundant on plants proportionally contributed more to downwind air. Epiphytic fungi were less of a determinant of the microbiological distinctiveness of downwind air and upwind air than epiphytic bacteria. Emigration of epiphytic bacteria and, to a lesser extent, fungi, from plants can thus influence the microbial composition of nearby air, a finding that has important implications for surrounding ecosystems, including the built environment into which outdoor air can penetrate.ImportanceThis paper addresses the poorly understood role of bacterial and fungal epiphytes, the inhabitants of the aboveground plant parts, in the composition of airborne microbes in outdoor air. It is widely held that epiphytes contribute to atmospheric microbial assemblages, but much of what we know is limited to qualitative assessments. Elucidating the sources of microbes in outdoor air can inform basic biological processes seen in airborne communities (e.g., dispersal and biogeographical patterns). Furthermore, given the considerable contribution of outdoor air to microbial communities found within indoor environments, the understanding of plants as sources of airborne microbes in outdoor air might contribute to our understanding of indoor air quality. With an experimental design developed to minimize the likelihood of other-than-local plant sources contributing to the composition of airborne microbes, we provide direct evidence that plants are quantitatively important local sources of airborne microorganisms, with implications for the surrounding ecosystems

    Utero-placental blood flow in hypertensive pregnancy and the effect of nifedipine administration

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    Nifedipine, in a 5mg sublingual acute administration, causes a significant fall in the systolic, diastolic and mean arterial pressure in a mixed group of pregnant hypertensives. A concurrent, significant rise in the pulse rate was seen. The utero-placental blood flow index, which is a measure of utero-placental blood flow, was not significantly reduced following the administration of Nifedipine or a placebo. The utero-placental blood flow index was found to be a consistent measure of utero-placental blood flow in resting patients. In the absence of serious side-effects it can be concluded that Nifedipine is a safe therapy in the acute treatment of hypertensive states in pregnancy

    Obstetric violence: Clinical staff perceptions from a video of simulated practice

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    Objective(s) Obstetric Violence refers to professional deficiencies in maternity care. Examples include non-dignified care, discrimination and abandonment of care. Obstetric violence has been described in both low and high resource settings. The objective of this study was to assess knowledge and attitudes towards obstetric violence in a cohort of multinational obstetric nursing/midwifery staff and obstetricians at a private maternity hospital in Qatar. Study design An online survey for anonymous completion was sent to the hospital email accounts of obstetric nursing/midwifery staff and obstetricians at Sidra Medicine (n = 640). The survey incorporated a video showing a dramatized scenario of obstetric violence. The survey assessed the participant’s demographics and knowledge of the term obstetric violence. The participants scored their perceptions on the behaviors in the video using a visual analogue scale. The participants were then asked to reflect on their own practice. Comparisons of the survey responses were made between both doctors and nursing/midiwfery staff members using student’s t-test. Results 50 obstetricians and 167 obstetric nursing/midwifery staff fully completed the survey. Fifty two percent had previously heard of the term obstetric violence, and 48% could define it correctly. 136 (63%) had witnessed obstetric violence at some point in their career. Significant differences were seen when each professional group was asked to report on the behavior of the opposite professional team as depicted in the video (p = 0.01 and p < 0.001). Doctors completing the survey were also more critical of the doctors-in-training than were the midwifery/nursing staff (p = 0.06). Obstetricians and nursing/midiwfery responders identified patient dignity, privacy and patient-centred care as the leading professional deficiencies seen in the video. Obstetricians were significantly less likely to change their perceptions of how a care team should interact with a patient compared to the obstetric nursing/midwifery group (p < 0.001). Conclusions This questionnaire study demonstrates that the majority of staff in this cohort were aware of obstetric violence and able to identify negative behaviours in the video and then reflect on how this impacts care they provide. Further studies are needed to identify ways in which obstetric violence can be prevented in both low resource and high resource settings

    Foliar lead uptake by lettuce exposed to atmospheric fallouts

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    Metal uptake by plants occurs by soil−root transfer but also by direct transfer of contaminants from the atmosphere to the shoots. This second pathway may be particularly important in kitchen gardens near industrial plants. The mechanisms of foliar uptake of lead by lettuce (Lactuca sativa) exposed to the atmospheric fallouts of a lead-recycling plant were studied. After 43 days of exposure, the thoroughly washed leaves contained 335 ± 50 mg Pb kg−1 (dry weight). Micro-X-ray fluorescence mappings evidenced Pb-rich spots of a few hundreds of micrometers in diameter located in necrotic zones. These spots were more abundant at the base of the central nervure. Environmental scanning electron microscopy coupled with energy dispersive X-ray microanalysis showed that smaller particles (a few micrometers in diameter) were also present in other regions of the leaves, often located beneath the leaf surface. In addition, submicrometric particles were observed inside stomatal openings. Raman microspectrometry analyses of the leaves identified smelter-originated Pb minerals but also secondary phases likely resulting from the weathering of original particles. On the basis of these observations, several pathways for foliar lead uptake are discussed. A better understanding of these mechanisms may be of interest for risk assessment of population exposure to atmospheric metal contamination

    miRMaid: a unified programming interface for microRNA data resources

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    <p>Abstract</p> <p>Background</p> <p>MicroRNAs (miRNAs) are endogenous small RNAs that play a key role in post-transcriptional regulation of gene expression in animals and plants. The number of known miRNAs has increased rapidly over the years. The current release (version 14.0) of miRBase, the central online repository for miRNA annotation, comprises over 10.000 miRNA precursors from 115 different species. Furthermore, a large number of decentralized online resources are now available, each contributing with important miRNA annotation and information.</p> <p>Results</p> <p>We have developed a software framework, designated here as miRMaid, with the goal of integrating miRNA data resources in a uniform web service interface that can be accessed and queried by researchers and, most importantly, by computers. miRMaid is built around data from miRBase and is designed to follow the official miRBase data releases. It exposes miRBase data as inter-connected web services. Third-party miRNA data resources can be modularly integrated as miRMaid plugins or they can loosely couple with miRMaid as individual entities in the World Wide Web. miRMaid is available as a public web service but is also easily installed as a local application. The software framework is freely available under the LGPL open source license for academic and commercial use.</p> <p>Conclusion</p> <p>miRMaid is an intuitive and modular software platform designed to unify miRBase and independent miRNA data resources. It enables miRNA researchers to computationally address complex questions involving the multitude of miRNA data resources. Furthermore, miRMaid constitutes a basic framework for further programming in which microRNA-interested bioinformaticians can readily develop their own tools and data sources.</p

    Therapeutic silencing of microRNA-122 in primates with chronic hepatitis

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    Hepatitis C virus (HCV) infection is a leading cause of liver disease worldwide with over 170 million infected individuals who are at greatly increased risk of developing liver failure and hepatocellular carcinoma. The current standard anti-HCV therapy, which combines pegylated interferon-α (IFN-α) with ribavirin provides sustained clearance of HCV in only about 50% of patients and is often associated with serious side effects (1, 2). Therapies that target essential host functions for HCV may provide a high barrier to resistance and, thus, could present an effective approach for the development of new HCV antiviral drugs. MicroRNA-122 (miR-122) is a highly abundant, liver-expressed microRNA, which binds to two closely spaced target sites in the 5&apos; non-coding region (NCR) of the HCV genome, resulting in upregulation of viral RNA levels (3, 4). Interaction of miR-122 with the HCV genome is essential for accumulation of viral RNA in cultured liver cells and both target sites are required for modulation of HCV RNA abundance (3-5). Previously, we reported on potent and specific miR-122 silencing in vivo using a LNA-modified phosphorothioate oligonucleotide (SPC3649) complementary to the 5&apos;-end of miR-122 leading to long-lasting decrease of serum cholesterol in mice and African green monkeys (6). Here, we investigated the potential of miR-122 antagonism by SPC3649 as a new anti-HCV therapy in chronically infected chimpanzees (genotype 1). Baseline measurements were obtained from four chimpanzees for four weeks, the last two of which included an intravenous (i.v.) placebo dose of saline. Two animals each were assigned to the high and low dose groups, 5 and 1 mg kg -1 , respectively, and were treated with i.v. injections of SPC3649 on a weekly basis for 12 week
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