3,167 research outputs found

    Freshwater Pearl Mussel (Margaritifera Margaritifera) Host Choice and Behavioural Responses to Changes in Flow Regime

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    The endangered freshwater pearl mussel (Margaritifera margaritifera), one of the longest-lived invertebrates, are threatened globally. Scotland, UK, remains a stronghold, however even here the population is declining due to factors such as habitat degradation, pollution and pearl fishing. The study comprised two parts: field surveys of glochidia infection of host salmonid fish, and a novel laboratory flume based study of the mussel‟s behavioral responses to changes in flow regime. The intricate life cycle of M.margaritifera includes a parasitic stage as glochidia attached to gills of salmonids. The preferred host in Scotland is thought to be Salmo salar and Salmo trutta in the absence of S.salar. This has not, however, been empirically tested in the field. Eight rivers in NW Scotland were surveyed using standard electrofishing techniques and encysted glochidia counted. Results suggest S.trutta is the primary host fish for glochidia attachment in the rivers surveyed, which contradicts current accepted knowledge about host specificity of M.margaritifera. Mussel populations are often found in regulated rivers, however little data exists on response to changes in flow regime. The mussel's behavioral response to changes in flow were investigated in an experimental flume. Mussels buried significantly deeper in conditions of gradually increasing water velocity compared with rapid increases or where water velocity was constant. 68% of individual mussels washed out when the water velocity was rapidly increased. The findings are novel, provide initial recommendations for targeted management actions for the conservation of M.margaritifera both in Scotland and internationally, and highlight more research is required

    Inhibition of Tendon Cell Proliferation and Matrix Glycosaminoglycan Synthesis by Non-Steroidal Anti-Inflammatory Drugs in vitro

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    The purpose of this study was to investigate the effects of some commonly used non-steroidal anti-inflammatory drugs (NSAIDs) on human tendon. Explants of human digital flexor and patella tendons were cultured in medium containing pharmacological concentrations of NSAIDs. Cell proliferation was measured by incorporation of 3H-thymidine and glycosaminoglycan synthesis was measured by incorporation of 35S-Sulphate. Diclofenac and aceclofenac had no significant effect either on tendon cell proliferation or glycosaminoglycan synthesis. Indomethacin and naproxen inhibited cell proliferation in patella tendons and inhibited glycosaminoglycan synthesis in both digital flexor and patella tendons. If applicable to the in vivo situation, these NSAIDs should be used with caution in the treatment of pain after tendon injury and surgery

    Timeline analysis and wavelet multiscale analysis of the AKARI All-Sky Survey at 90 micron

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    We present a careful analysis of the point source detection limit of the AKARI All-Sky Survey in the WIDE-S 90 μ\mum band near the North Ecliptic Pole (NEP). Timeline Analysis is used to detect IRAS sources and then a conversion factor is derived to transform the peak timeline signal to the interpolated 90 μ\mum flux of a source. Combined with a robust noise measurement, the point source flux detection limit at S/N >5>5 for a single detector row is 1.1±0.11.1\pm0.1 Jy which corresponds to a point source detection limit of the survey of \sim0.4 Jy. Wavelet transform offers a multiscale representation of the Time Series Data (TSD). We calculate the continuous wavelet transform of the TSD and then search for significant wavelet coefficients considered as potential source detections. To discriminate real sources from spurious or moving objects, only sources with confirmation are selected. In our multiscale analysis, IRAS sources selected above 4σ4\sigma can be identified as the only real sources at the Point Source Scales. We also investigate the correlation between the non-IRAS sources detected in Timeline Analysis and cirrus emission using wavelet transform and contour plots of wavelet power spectrum. It is shown that the non-IRAS sources are most likely to be caused by excessive noise over a large range of spatial scales rather than real extended structures such as cirrus clouds.Comment: 16 pages, 19 figures, 5 tables, accepted for publication in MNRA

    Detection of Microbial Translocation in HIV and SIV Infection Using the Limulus Amebocyte Lysate Assay is Masked by Serum and Plasma

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    Objective: Microbial translocation (MT) is thought to be a major contributor to the pathogenesis of HIV-related immune activation, and circulating lipopolysaccharide (LPS) from Gram-negative bacteria is the principle measurement of this process. However, related research has been impeded by inconsistent LPS test results. Methods: Specimens were obtained from HIV-infected adults enrolled in the PEARLS study (ACTG A5175) and HIV-HCV co-infected participants enrolled in a study of liver disease staging using MRI elastography. Pig-tailed macaque specimens were obtained from SIV-infected and –uninfected animals. Samples were tested for LPS using the LAL assay with diazo-coupling modifications to improve sensitive detection. Results: When exogenous LPS was added to macaque plasma, >25% inhibition of LPS detection was found in 10/10 (100%) samples at 20% plasma concentration compared to control; in contrast 5/10 (50%) samples at 2% plasma concentration (p = 0.07) and 0/10 (0%) at 0.1% plasma concentration (p = 0.004) showed >25% inhibition of LPS detection. Similarly, when LPS was added to human serum, >25% inhibition of LPS detection was found in 5/12 (42%) of samples at 2% serum concentration compared to control, while 0/12 (0%) of samples in 0.1% serum showed >25% inhibition of LPS detection (p = 0.07). Likewise, LPS detection in human sera without exogenous LPS was improved by dilution: LPS was detected in 2/12 (17%) human samples in 2% serum, ranging from 3,436–4,736 pg/mL, compared to 9/12 (75%) samples in 0.1% serum, ranging from 123 pg/mL –60,131 pg/mL (p = 0.016). In a separate validation cohort of HIV-HCV co-infected participants sampled at two different times on the same day, LPS measured in 0.2% plasma and with diazo-coupling was closely correlated between the first and second samples (R = 0.66, p<0.05). Conclusions: Undiluted serum and plasma mask LPS detection. The extent of MT may be substantially underestimated
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