1,885 research outputs found

    Comparison of bacterial biofilm communities using barcoded pyrosequencing and analysis to determine origin of biofilm fouling of reverse osmosis membranes in a full scale desalination system

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    Biofouling is the single most important issue in reverse osmosis sea water desalination worldwide (Ridgway et al., 1999) and may account for up to 50% of energy use. Which species are responsible and their origin is unclear. With the advent of next generation sequencing, species diversity and transience can be examined at orders of magnitude greater detail than was previously possible. We found many similarities in bacterial families across source water, prefiltration units and membranes in this study and in the few other studies available, despite disparate locations and seasons. Key groups included members of the Bacteroidetes (e. Flavobacteriaceae), Planctomycetes, Alphaproteobacteria (eg. Rhodobacteraceae, Sphingomonadales), Betaproteobacteria (eg. Burkholderia) and Gammaproteobacteria (eg. Oceanospirillales, Xanthomonadaceae). Despite similarities in families, the predominant fouling species on reverse osmosis (RO) membranes appear to differ between studies. This seems likely to reflect a common origin (seawater) but subsequent adaptation or selective pressures in different niches, particularly on RO membranes under high pressure and salt concentration. We can now select environmental isolates from our culture collection representing key bacterial groups responsible for biofouling in seawater systems. This will enable more accurate evaluation of the effectiveness of anti-fouling strategies

    Detecting respiratory bacterial communities of wild dolphins: Implications for animal health

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    Infectious diseases contribute to the vulnerable status of marine mammals, including respiratory illnesses. This study aimed to capture exhaled breath condensate (blow) for microbial identification from wild Indo-Pacific bottlenose dolphins Tursiops aduncus. Individual dolphins were sampled by holding a funnel connected to a 50 ml centrifuge tube over the blowhole of the animal near shore in Shark Bay (SB), Western Australia. Four individuals were sampled on 2 occasions along with seawater samples. Comparative blow and pool water samples were collected from 4 individual common bottlenose dolphins Tursiops truncatus housed in the National Aquarium (NA), Baltimore, Maryland, USA. Bacteria were identified using the V4 region of the 16S rRNA gene from extracted DNA. We identified bacteria independent of seawater in SB dolphins, which included the classes Alphaproteobacteria (26.1%) and Gammaproteobacteria (25.8%); the phyla Bacteroidetes (15.6%) and Fusobacteria (7.2%); and the genera Pseudomonas (11.5%), Pedomicrobium (4.5%), Streptobacillus (3.7%), Phenylobacterium (2.2%) and Sphingomonas (2.1%). There were broad similarities in phyla between SB and NA dolphins yet there were differences between lower taxonomic groups. A number of operational taxonomic units (OTUs) were shared between dolphin individuals, which may be a result of their genetic lineage (siblings or parentage), shared living and social interactions. A number of genera were observed in SB dolphins which have species known to be infectious in marine mammals such as Pseudomonas, Mycoplasma and Streptococcus. This study successfully characterised bacteria from DNA captured in blow from wild dolphins. The ability to capture these communities from individuals in the wild provides a novel health indicator

    Application of robotics In the clinical laboratory

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    The basic types of robot are explained, and the performances and costs of some commercial examples are given. The potential advantages and problems of introducing robots into clinical laboratories are identified and the specifcation of a suitable robot is developed. None of the commercially available robots meets all aspects of the specificalion, and currently the purchase of a robot is considered premature for most clinical laboratories

    Combined bezafibrate and medroxyprogesterone acetate: potential novel therapy for acute myeloid leukaemia

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    Background: The majority of acute myeloid leukaemia (AML) patients are over sixty years of age. With current treatment regimens, survival rates amongst these, and also those younger patients who relapse, remain dismal and novel therapies are urgently required. In particular, therapies that have anti-leukaemic activity but that, unlike conventional chemotherapy, do not impair normal haemopoiesis. Principal Findings: Here we demonstrate the potent anti-leukaemic activity of the combination of the lipid-regulating drug bezafibrate (BEZ) and the sex hormone medroxyprogesterone acetate (MPA) against AML cell lines and primary AML cells. The combined activity of BEZ and MPA (B/M) converged upon the increased synthesis and reduced metabolism of prostaglandin D2 (PGD2) resulting in elevated levels of the downstream highly bioactive, anti-neoplastic prostaglandin 15-deoxy Δ12,14 PGJ2 (15d-PGJ2). BEZ increased PGD2 synthesis via the generation of reactive oxygen species (ROS) and activation of the lipid peroxidation pathway. MPA directed prostaglandin synthesis towards 15d-PGJ2 by inhibiting the PGD2 11β -ketoreductase activity of the aldo-keto reductase AKR1C3, which metabolises PGD2 to 9α11β-PGF2α. B/M treatment resulted in growth arrest, apoptosis and cell differentiation in both AML cell lines and primary AML cells and these actions were recapitulated by treatment with 15d-PGJ2. Importantly, the actions of B/M had little effect on the survival of normal adult myeloid progenitors. Significance: Collectively our data demonstrate that B/M treatment of AML cells elevated ROS and delivered the anti-neoplastic actions of 15d-PGJ2. These observations provide the mechanistic rationale for the redeployment of B/M in elderly and relapsed AML

    Soffer's inequality and the transversely polarized Drell-Yan process at next-to-leading order

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    We check numerically if Soffer's inequality for quark distributions is preserved by next-to-leading order QCD evolution. Assuming that the inequality is saturated at a low hadronic scale we estimate the maximal transverse double spin asymmetry for Drell-Yan muon pair production to next-to-leading order accuracy.Comment: 20 Pages, LaTeX, 7 figures as eps file

    Longitudinally Polarized Photoproduction of Inclusive Hadrons Beyond the Leading Order

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    We present a complete next-to-leading order QCD calculation for single-inclusive large-pT hadron production in longitudinally polarized lepton-nucleon collisions, consistently including ``direct'' and ``resolved'' photon contributions. This process could be studied experimentally at a future polarized lepton-proton collider like eRHIC at BNL. We examine the sensitivity of such measurements to the so far completely unknown parton content of circularly polarized photons.Comment: 15 pages, 7 eps figure

    Transverse Double-Spin Asymmetries for Muon Pair Production in pp-Collisions

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    We calculate the rapidity dependence of the transverse double-spin asymmetry for the Drell-Yan process to next-to-leading order in the strong coupling. Input transversity distributions are obtained by saturating the Soffer inequality at a low hadronic mass scale. Results for the polarized BNL-RHIC proton-proton collider and the proposed HERA-N fixed-target experiment are presented, and the influence of the limited muon acceptance of the detectors on measurements of the asymmetry is studied in detail.Comment: 7 pages including 5 figures; significantly shortened, to be published in Phys. Rev.

    Joint system quantum descriptions arising from local quantumness

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    Bipartite correlations generated by non-signalling physical systems that admit a finite-dimensional local quantum description cannot exceed the quantum limits, i.e., they can always be interpreted as distant measurements of a bipartite quantum state. Here we consider the effect of dropping the assumption of finite dimensionality. Remarkably, we find that the same result holds provided that we relax the tensor structure of space-like separated measurements to mere commutativity. We argue why an extension of this result to tensor representations seems unlikely
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