326 research outputs found
Lethal Parasites in Oysters from Coastal Georgia with Discussion of Disease and Management Implications
Extensive mortalities of oysters, Crassostrea virginica, occurred from 1985 through 1987 in coastal waters of Georgia. Fluid thioglycolate cultures of oysters collected from 16 of 17 locations revealed infections by the apicomplexan parasite Perkinsus marinus. An ascetosporan parasite, Haplosporidium nelsoni, was also observed in histopathological examination of oysters from 4 of the locations. While the range of H. nelsoni currently is recognized as the east coast of the United States from Maine to Florida, this is the first report of the parasite in Georgia waters. This paper documents the occurrence of these two lethal parasites in oysters from coastal waters of Georgia, along with potential disease and management implications. Results of an earlier independent and previously unpublished survey are also discussed which document the presence of P. marinus in Georgia as early as 1966
Primary health care services for the aged in the United Arab Emirates: a comparison of two models of care
Aim: To compare the quality of aged care provided by two different models of primary health care services in the United Arab Emirates.
Methods: Cross sectional survey by chart review of 200 consecutive people aged 65 years and over attending two primary health care centers located in adjacent suburbs and serving populations with similar characteristics; a resource intensive center (RIC) and the other a resource thrifty center (RTC). Quality indicators were blood pressure levels in hypertensives and glycosylated hemoglobin (HbA1c) levels in diabetics.
Results: There was no variation in age, sex or number of visits per year between the clinics. Osteoarthritis,
hypertension, and diabetes were the most common diagnoses at both. The people attending the RIC had a substantially higher level of comorbidity (RIC=1.19±1.18, RTC=0.63 ± 0.68, p < 0.001), the average systolic and diastolic blood pressure for those diagnosed with hypertension was in the normal range at the RIC (138.5 ± 19.8/77.1 ± 9.9), whereas it was significantly higher and in the elevated range at the RTC (149.5 ± 17.7/85.2 ± 9.1, p < 0.001) and the HbA1c was significantly lower at the RIC (7.7 ± 1.4) than at the RTC (9.5 ± 2.0, p < 0.001). Conclusions:The quality of health outcomes for the two chronic diseases, hypertension and diabetes, appeared significantly higher at the RIC, when compared with the RTC. However, there may have
been significant selection bias. Further studies are needed to determine if the RIC improves quality measures in other aspects of chronic disease care and provides a more cost effective health care service
Limited effects of long-term daily cranberry consumption on the gut microbiome in a placebo-controlled study of women with recurrent urinary tract infections
Background: Urinary tract infections (UTIs) affect 15 million women each year in the United States, with > 20% experiencing frequent recurrent UTIs. A recent placebo-controlled clinical trial found a 39% reduction in UTI symptoms among recurrent UTI sufferers who consumed a daily cranberry beverage for 24 weeks. Using metagenomic sequencing of stool from a subset of these trial participants, we assessed the impact of cranberry consumption on the gut microbiota, a reservoir for UTI-causing pathogens such as Escherichia coli, which causes > 80% of UTIs.
Results: The overall taxonomic composition, community diversity, carriage of functional pathways and gene families, and relative abundances of the vast majority of observed bacterial taxa, including E. coli, were not changed significantly by cranberry consumption. However, one unnamed Flavonifractor species (OTU41), which represented ≤1% of the overall metagenome, was significantly less abundant in cranberry consumers compared to placebo at trial completion. Given Flavonifractor’s association with negative human health effects, we sought to determine OTU41 characteristic genes that may explain its differential abundance and/or relationship to key host functions. Using comparative genomic and metagenomic techniques, we identified genes in OTU41 related to transport and metabolism of various compounds, including tryptophan and cobalamin, which have been shown to play roles in host-microbe interactions.
Conclusion: While our results indicated that cranberry juice consumption had little impact on global measures of the microbiome, we found one unnamed Flavonifractor species differed significantly between study arms. This suggests further studies are needed to assess the role of cranberry consumption and Flavonifractor in health and wellbeing in the context of recurrent UTI.
Trial registration: Clinical trial registration number: ClinicalTrials.govNCT01776021
Genome Evolution of Wolbachia Strain wPip from the Culex pipiens Group
The obligate intracellular bacterium Wolbachia pipientis strain wPip induces cytoplasmic incompatibility (CI), patterns of crossing sterility, in the Culex pipiens group of mosquitoes. The complete sequence is presented of the 1.48-Mbp genome of wPip which encodes 1386 coding sequences (CDSs), representing the first genome sequence of a B-supergroup Wolbachia. Comparisons were made with the smaller genomes of Wolbachia strains wMel of Drosophila melanogaster, an A-supergroup Wolbachia that is also a CI inducer, and wBm, a mutualist of Brugia malayi nematodes that belongs to the D-supergroup of Wolbachia. Despite extensive gene order rearrangement, a core set of Wolbachia genes shared between the 3 genomes can be identified and contrasts with a flexible gene pool where rapid evolution has taken place. There are much more extensive prophage and ankyrin repeat encoding (ANK) gene components of the wPip genome compared with wMel and wBm, and both are likely to be of considerable importance in wPip biology. Five WO-B–like prophage regions are present and contain some genes that are identical or highly similar in multiple prophage copies, whereas other genes are unique, and it is likely that extensive recombination, duplication, and insertion have occurred between copies. A much larger number of genes encode ankyrin repeat (ANK) proteins in wPip, with 60 present compared with 23 in wMel, many of which are within or close to the prophage regions. It is likely that this pattern is partly a result of expansions in the wPip lineage, due for example to gene duplication, but their presence is in some cases more ancient. The wPip genome underlines the considerable evolutionary flexibility of Wolbachia, providing clear evidence for the rapid evolution of ANK-encoding genes and of prophage regions. This host–Wolbachia system, with its complex patterns of sterility induced between populations, now provides an excellent model for unraveling the molecular systems underlying host reproductive manipulation
Active Galactic Nuclei Jets and Multiple Oblique Shock Acceleration: Starved Spectra
Shocks in jets and hot spots of Active Galactic Nuclei (AGN) are one
prominent class of possible sources of very high energy cosmic ray particles
(above 10^18eV). Extrapolating their spectrum to their plausible injection
energy from some shock, implies an enormous hidden energy for a spectrum of
index ~-2. Some analyzes suggest the particles' injection spectrum at source to
be as steep as -2.4 to -2.7, making the problem much worse, by a factor of
order 10^6. Nevertheless, it seems implausible that more than at the very best
1/3 of the jet energy, goes into the required flux of energetic particles thus,
one would need to allow for the possibility that there is an energy problem,
which we would like to address in this work. Sequences of consecutive oblique
shock features, or conical shocks, have been theorized and eventually observed
in many AGN jets. Based on that, we use by analogy the 'Comptonisation' effect
and we propose a scenario of a single injection of particles which are
accelerated consecutively by several oblique shocks along the axis of an AGN
jet. We use detailed test-particle approximation Monte Carlo simulations in
order to calculate particle spectra by acceleration at such a shock pattern
while monitoring the efficiency of acceleration, calculating differential
spectra. We find that the first shock of a sequence of oblique shocks,
establishes a low energy power-law spectrum with ~E^-2.7. The consecutive
shocks push the spectrum up in energy, rendering flatter distributions with
steep cut-offs and characteristic depletion at low energies, an effect which
could explain the puzzling apparent extra source power as well as the flat or
inverted spectra from distant flaring sources.Comment: 14 pages, submitted to A&
Assessing the Quality of Care for Pneumonia in Integrated Community Case Management: A Cross-Sectional Mixed Methods Study
Background Pneumonia is the leading infectious cause of mortality in children under five worldwide. Community-level interventions, such as integrated community case management, have great potential to reduce the burden of pneumonia, as well as other diseases, especially in remote populations. However, there are still questions as to whether community health workers (CHW) are able to accurately assess symptoms of pneumonia and prescribe appropriate treatment. This research addresses limitations of previous studies using innovative methodology to assess the accuracy of respiratory rate measurement by CHWs and provides new evidence on the quality of care given for children with symptoms of pneumonia. It is one of few that assesses CHW performance in their usual setting, with independent re-examination by experts, following a considerable period of time post-training of CHWs. Methods In this cross-sectional mixed methods study, 1,497 CHW consultations, conducted by 90 CHWs in two districts of Luapula province, Zambia, were directly observed, with measurement of respiratory rate for children with suspected pneumonia recorded by video. Using the video footage, a retrospective reference standard assessment of respiratory rate was conducted by experts. Counts taken by CHWs were compared against the reference standard and appropriateness of the treatment prescribed by CHWs was assessed. To supplement observational findings, three focus group discussions and nine in depth interviews with CHWs were conducted. Results and Conclusion The findings support existing literature that CHWs are capable of measuring respiratory rates and providing appropriate treatment, with 81% and 78% agreement, respectively, between CHWs and experts. Accuracy in diagnosis could be strengthened through further training and the development of improved diagnostic tools appropriate for resource-poor settings
SoDaH: the SOils DAta Harmonization database, an open-source synthesis of soil data from research networks, version 1.0
Data collected from research networks present opportunities to test theories and develop models about factors responsible for the long-term persistence and vulnerability of soil organic matter (SOM). Synthesizing datasets collected by different research networks presents opportunities to expand the ecological gradients and scientific breadth of information available for inquiry. Synthesizing these data is challenging, especially considering the legacy of soil data that have already been collected and an expansion of new network science initiatives. To facilitate this effort, here we present the SOils DAta Harmonization database (SoDaH; https://lter.github.io/som-website, last access: 22 December 2020), a flexible database designed to harmonize diverse SOM datasets from multiple research networks. SoDaH is built on several network science efforts in the United States, but the tools built for SoDaH aim to provide an open-access resource to facilitate synthesis of soil carbon data. Moreover, SoDaH allows for individual locations to contribute results from experimental manipulations, repeated measurements from long-term studies, and local- to regional-scale gradients across ecosystems or landscapes. Finally, we also provide data visualization and analysis tools that can be used to query and analyze the aggregated database. The SoDaH v1.0 dataset is archived and available at https://doi.org/10.6073/pasta/9733f6b6d2ffd12bf126dc36a763e0b4 (Wieder et al., 2020)
Preexisting and de novo humoral immunity to SARS-CoV-2 in humans
Zoonotic introduction of novel coronaviruses may encounter preexisting immunity in humans. Using diverse assays for antibodies recognizing SARS-CoV-2 proteins, we detect preexisting humoral immunity. SARS-CoV-2 spike glycoprotein (S)-reactive antibodies were detectable by a flow cytometry-based method in SARS-CoV-2-uninfected individuals and were particularly prevalent in children and adolescents. They were predominantly of the IgG class and targeted the S2 subunit. By contrast, SARS-CoV-2 infection induced higher titers of SARS-CoV-2 S-reactive IgG antibodies, targeting both the S1 and S2 subunits, and concomitant IgM and IgA antibodies, lasting throughout the observation period. Notably, SARS-CoV-2-uninfected donor sera exhibited specific neutralizing activity against SARS-CoV-2 and SARS-CoV-2 S pseudotypes. Distinguishing preexisting and de novo immunity will be critical for our understanding of susceptibility to and the natural course of SARS-CoV-2 infection
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