1,673 research outputs found

    Characterisation of bacterioplankton communities in the meltwater ponds of Bratina Island, Victoria Land, Antarctica

    Get PDF
    A unique collection of Antarctic aquatic environments (meltwater ponds) lies in close proximity on the rock and sediment-covered undulating surface of the McMurdo Ice Shelf, near Bratina Island (Victoria Land, Antarctica). During the 2009–10 mid-austral summer, sets of discrete water samples were collected across the vertical geochemical gradients of five meltwater ponds (Egg, P70E, Legin, Salt and Orange) for geochemical and microbial community structure analysis. Bacterial DNA fingerprints (using Automated Ribosomal Intergenic Spacer Analysis) statistically clustered communities within ponds based on ANOSIM (R = 0.766, P = 0.001); however, one highly stratified pond (Egg) had two distinct depth-related bacterial communities (R = 0.975, P = 0.008). 454 pyrosequencing at three depths within Egg also identified phylum level shifts and increased diversity with depth, Bacteroidetes being the dominant phyla in the surface sample and Proteobacteria being dominant in the bottom two depths. BEST analysis, which attempts to link community structure and the geochemistry of a pond, identified conductivity and pH individually, and to a lesser extent Ag109, NO2 and V51 as dominant influences to the microbial community structure in these ponds. Increasing abundances of major halo-tolerant OTUs across the strong conductivity gradient reinforce it as the primary driver of community structure in this stud

    Benthic microbial communities of coastal terrestrial and ice shelf Antarctic meltwater ponds.

    Get PDF
    The numerous perennial meltwater ponds distributed throughout Antarctica represent diverse and productive ecosystems central to the ecological functioning of the surrounding ultra oligotrophic environment. The dominant taxa in the pond benthic communities have been well described however, little is known regarding their regional dispersal and local drivers to community structure. The benthic microbial communities of 12 meltwater ponds in the McMurdo Sound of Antarctica were investigated to examine variation between pond microbial communities and their biogeography. Geochemically comparable but geomorphologically distinct ponds were selected from Bratina Island (ice shelf) and Miers Valley (terrestrial) (<40 km between study sites), and community structure within ponds was compared using DNA fingerprinting and pyrosequencing of 16S rRNA gene amplicons. More than 85% of total sequence reads were shared between pooled benthic communities at different locations (OTU0.05), which in combination with favorable prevailing winds suggests aeolian regional distribution. Consistent with previous findings Proteobacteria and Bacteroidetes were the dominant phyla representing over 50% of total sequences; however, a large number of other phyla (21) were also detected in this ecosystem. Although dominant Bacteria were ubiquitous between ponds, site and local selection resulted in heterogeneous community structures and with more than 45% of diversity being pond specific. Potassium was identified as the most significant contributing factor to the cosmopolitan community structure and aluminum to the location unique community based on a BEST analysis (Spearman's correlation coefficient of 0.632 and 0.806, respectively). These results indicate that the microbial communities in meltwater ponds are easily dispersed regionally and that the local geochemical environment drives the ponds community structure

    Daptomycin versus vancomycin for osteoarticular infections due to methicillin-resistant Staphylococcus aureus (MRSA): a nested case-control study

    Get PDF
    Vancomycin is the standard antibiotic for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections. While daptomycin is approved for MRSA bacteremia, its effectiveness in osteoarticular infections (OAIs) has not been established. A 1:2 nested case-control study of adult patients with MRSA OAIs admitted to an academic center from 2005 to 2010 was carried out. Clinical outcomes and drug toxicity in patients treated with daptomycin versus vancomycin were compared. Twenty patients with MRSA OAIs treated with daptomycin were matched to 40 patients treated with vancomycin. The median age of the patients was 52 years (range, 25-90), and 40 (67 %) were male. Most patients had osteomyelitis (82 %), predominantly from a contiguous source (87 %). Forty percent were diabetics. Diabetic patients were more likely to receive vancomycin than daptomycin [20 (50 %) vs. 4 (20 %); p = 0.03]. Vancomycin was more often combined with antibiotics other than daptomycin [22 (55 %) vs. 5 (25 %); p = 0.03]. The median total antibiotic treatment duration was 48 (daptomycin) vs. 46 days (vancomycin) (p = 0.5). Ninety percent of daptomycin-treated patients had previously received vancomycin for a median of 14.5 days (range, 2-36). Clinical success rates were similar between daptomycin and vancomycin at 3 months [15 (75 %) vs. 27 (68 %); p = 0.8] and 6 months [14 (70 %) vs. 23 (58 %); p = 0.5], even after propensity score-based adjustment for antibiotic assignment. The frequency of adverse events was similar between treatment groups [1 (5 %) vs. 7 (18 %); p = 0.2]. Daptomycin and vancomycin achieved similar rates of clinical success and drug tolerability. Daptomycin is a reasonable alternative for treating MRSA OAIs, particularly in patients where therapy with vancomycin has not been well tolerated

    Shortage of Rural Veterinarians: Real or Perceived?

    Get PDF
    Concerns about lack of available jobs in rural veterinary practice (RVP) and ironically difficulties attracting new veterinarians are commonly expressed within the veterinary community. Reports on supply and demand for rural veterinarians have produced conflicting results. A 1990\u27s economic study forecasted a 3.0% increase in available veterinarians in large animal private practice and a 1.7% decrease in demand from 1997 to 2015. However, a later study forecasted a shortage of food supply veterinary medicine (FSVM) veterinarians from 2004 to 2016 ranging from 0.1% (poultry veterinarians) to 6.9% (federal animal health), with mixed food animal practice at 6.6%

    The validity of police reported accident data

    Full text link
    Information theory and signal detection theory techniques were used to assess the validity of police reported traffic accident data. The validity criteria were the data and conclusions of multi-disciplinary accident investigation teams who investigated the same traffic accidents. The results indicated that the accident level variables reported by the police with least reliability were vertical road character, accident severity, and road surface composition. The most reliably reported data were those concerned with the accident location, date, and number of drivers, passengers, and vehicles. The informativeness of the police reports with respect to driver/vehicle characteristics was practically nil, with the exception of driver age, sex and vehicle model for which the police were correct most of the time (but not errorless). It was also found that police reports provided very little information regarding the presence of different human conditions and states, vehicle defects and environmental/road deficiencies. The sensitivity of police investigators to all accident causes was low. When causes were categorized into human direct, human indirect (conditions and states) vehicle, and environmental, police were the most reliable with respect to human direct causes and the least reliable with respect to environmental and human indirect causes. Implications for improvement and use of police data are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25202/1/0000641.pd

    Localization of epigenetic markers in Leishmania chromatin

    Get PDF
    Eukaryotes use histone variants and post-translation modifications (PTMs), as well as DNA base modifications, to regulate DNA replication/repair, chromosome condensation, and gene expression. Despite the unusual organization of their protein-coding genes into large polycistronic transcription units (PTUs), trypanosomatid parasites also employ a histone code to control these processes, but the details of this epigenetic code are poorly understood. Here, we present the results of experiments designed to elucidate the distribution of histone variants and PTMs over the chromatin landscape o

    Kidney transplant graft outcomes in 379 257 recipients on 3 continents

    Full text link
    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145422/1/ajt14694_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145422/2/ajt14694.pd

    MMP-13 Selective Isonipecotamide Alpha-sulfone Hydroxamates

    Get PDF
    A series of N-aryl isonipecotamide α-sulfone hydroxamate derivatives has been prepared utilizing a combination of solution-phase and resin-bound library technologies to afford compounds that are potent and highly selective for MMP-13
    corecore