499 research outputs found

    Detection of Invasive Lionfish (Pterois volitans and Pterois miles) in the Gulf of Mexico Using Environmental DNA Methods

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    Red Lionfish (Pterois volitans) and Devil Firefish (Pterois miles) are Indo-Pacific species introduced into the western North Atlantic Ocean in the 1980s. Their range currently extends from New York to Florida and adjacent waters of the Caribbean Sea and the Gulf of Mexico. Since the original sighting in 2010 off the Texas coast lionfish populations in the Gulf of Mexico have increased substantially and negative ecological impacts are expected. Lionfish detection relies on underwater visual surveys using divers and ROVs which are expensive and not always effective. This study seeks to employ real time polymerase chain reaction (RT PCR) to amplify aqueous environmental DNA (eDNA) as a highly sensitive alternative to detect and quantify lionfish. To minimize false positives and false negatives, highly specific primer sets targeting the mitochondrial DNA genome of lionfish were designed using ecoPrimers and ecoPCR. RT PCR on serial DNA dilutions indicated that the D-loop region was the best locus to amplify and quantify eDNA. Lionfish eDNA was successfully quantified in a series of mesocosms differing in volume at Moody Gardens Aquarium. Finally, the Red Lionfish presence was detected by assaying water samples collected from artificial reefs and the Flower Gardens Banks National Marine Sanctuary and adjacent reefs in the Gulf of Mexico

    An Observational Determination of the Proton to Electron Mass Ratio in the Early Universe

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    In an effort to resolve the discrepancy between two measurements of the fundamental constant mu, the proton to electron mass ratio, at early times in the universe we reanalyze the same data used in the earlier studies. Our analysis of the molecular hydrogen absorption lines in archival VLT/UVES spectra of the damped Lyman alpha systems in the QSOs Q0347-383 and Q0405-443 yields a combined measurement of a (Delta mu)/mu value of (-7 +/- 8) x 10^{-6}, consistent with no change in the value of mu over a time span of 11.5 gigayears. Here we define (Delta mu) as (mu_z - mu_0) where mu_z is the value of mu at a redshift of z and mu_0 is the present day value. Our null result is consistent with the recent measurements of King et al. 2009, (Delta mu)/u = (2.6 +/- 3.0) x 10^{-6}, and inconsistent with the positive detection of a change in mu by Reinhold et al. 2006. Both of the previous studies and this study are based on the same data but with differing analysis methods. Improvements in the wavelength calibration over the UVES pipeline calibration is a key element in both of the null results. This leads to the conclusion that the fundamental constant mu is unchanged to an accuracy of 10^{-5} over the last 80% of the age of the universe, well into the matter dominated epoch. This limit provides constraints on models of dark energy that invoke rolling scalar fields and also limits the parameter space of Super Symmetric or string theory models of physics. New instruments, both planned and under construction, will provide opportunities to greatly improve the accuracy of these measurements.Comment: Accepted for publication in the Astrophysical Journa

    Critical perspectives on ‘consumer involvement’ in health research: epistemological dissonance and the know-do gap

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    Researchers in the area of health and social care (both in Australia and internationally) are encouraged to involve consumers throughout the research process, often on ethical, political and methodological grounds, or simply as ‘good practice’. This paper presents findings from a qualitative study in the UK of researchers’ experiences and views of consumer involvement in health research. Two main themes are presented in the paper. Firstly, we explore the ‘know-do gap’ which relates to the tensions between researchers’ perceptions of the potential benefits of, and their actual practices in relation to, consumer involvement. Secondly, we focus on one of the reasons for this ‘know-do gap’, namely epistemological dissonance. Findings are linked to issues around consumerism in research, lay/professional knowledges, the (re)production of professional and consumer identities and the maintenance of boundaries between consumers and researchers

    Acute exacerbations of chronic obstructive pulmonary disease are associated with decreased CD4+ & CD8+ T cells and increased growth & differentiation factor-15 (GDF-15) in peripheral blood

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    Abstract Background Although T cells, especially CD8+, have been implicated in chronic obstructive pulmonary disease (COPD) pathogenesis, their role during acute exacerbations (AE-COPD) is uncertain. Methods We recruited subjects with COPD and a history of previous AE-COPD and studied them quarterly to collect blood and spontaneously expectorated sputum while stable. During exacerbations (defined by a change in symptoms plus physician diagnosis and altered medications), we collected blood and sputum before administering antibiotics or steroids. We used flow cytometry to identify leukocytes in peripheral blood, plus Luminex® analysis or ELISA to determine levels of inflammatory biomarkers in serum and sputum supernatants. Results Of 33 enrolled subjects, 13 participated in multiple stable visits and had ≥1 AE-COPD visit, yielding 18 events with paired data. Flow cytometric analyses of peripheral blood demonstrated decreased CD4+ and CD8+ T cells during AE-COPD (both absolute and as a percentage of all leukocytes) and significantly increased granulocytes, all of which correlated significantly with serum C-reactive protein (CRP) concentrations. No change was observed in other leukocyte populations during AE-COPD, although the percentage of BDCA-1+ dendritic cells expressing the activation markers CD40 and CD86 increased. During AE-COPD, sICAM-1, sVCAM-1, IL-10, IL-15 and GDF-15 increased in serum, while in sputum supernatants, CRP and TIMP-2 increased and TIMP-1 decreased. Conclusions The decrease in CD4+ and CD8+ T cells (but not other lymphocyte subsets) in peripheral blood during AE-COPD may indicate T cell extravasation into inflammatory sites or organized lymphoid tissues. GDF-15, a sensitive marker of cardiopulmonary stress that in other settings independently predicts reduced long-term survival, is acutely increased in AE-COPD. These results extend the concept that AE-COPD are systemic inflammatory events to which adaptive immune mechanisms contribute. Trial registration NCT00281216 , ClinicalTrials.gov.http://deepblue.lib.umich.edu/bitstream/2027.42/112169/1/12931_2015_Article_251.pd

    Acute exacerbations of chronic obstructive pulmonary disease are associated with decreased CD4+ & CD8+ T cells and increased growth & differentiation factor-15 (GDF-15) in peripheral blood

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    Abstract Background Although T cells, especially CD8+, have been implicated in chronic obstructive pulmonary disease (COPD) pathogenesis, their role during acute exacerbations (AE-COPD) is uncertain. Methods We recruited subjects with COPD and a history of previous AE-COPD and studied them quarterly to collect blood and spontaneously expectorated sputum while stable. During exacerbations (defined by a change in symptoms plus physician diagnosis and altered medications), we collected blood and sputum before administering antibiotics or steroids. We used flow cytometry to identify leukocytes in peripheral blood, plus Luminex® analysis or ELISA to determine levels of inflammatory biomarkers in serum and sputum supernatants. Results Of 33 enrolled subjects, 13 participated in multiple stable visits and had ≥1 AE-COPD visit, yielding 18 events with paired data. Flow cytometric analyses of peripheral blood demonstrated decreased CD4+ and CD8+ T cells during AE-COPD (both absolute and as a percentage of all leukocytes) and significantly increased granulocytes, all of which correlated significantly with serum C-reactive protein (CRP) concentrations. No change was observed in other leukocyte populations during AE-COPD, although the percentage of BDCA-1+ dendritic cells expressing the activation markers CD40 and CD86 increased. During AE-COPD, sICAM-1, sVCAM-1, IL-10, IL-15 and GDF-15 increased in serum, while in sputum supernatants, CRP and TIMP-2 increased and TIMP-1 decreased. Conclusions The decrease in CD4+ and CD8+ T cells (but not other lymphocyte subsets) in peripheral blood during AE-COPD may indicate T cell extravasation into inflammatory sites or organized lymphoid tissues. GDF-15, a sensitive marker of cardiopulmonary stress that in other settings independently predicts reduced long-term survival, is acutely increased in AE-COPD. These results extend the concept that AE-COPD are systemic inflammatory events to which adaptive immune mechanisms contribute. Trial registration NCT00281216 , ClinicalTrials.gov.http://deepblue.lib.umich.edu/bitstream/2027.42/134660/1/12931_2015_Article_251.pd

    Application of functional genomics to the chimeric mouse model of HCV infection: optimization of microarray protocols and genomics analysis

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    BACKGROUND: Many model systems of human viral disease involve human-mouse chimeric tissue. One such system is the recently developed SCID-beige/Alb-uPA mouse model of hepatitis C virus (HCV) infection which involves a human-mouse chimeric liver. The use of functional genomics to study HCV infection in these chimeric tissues is complicated by the potential cross-hybridization of mouse mRNA on human oligonucleotide microarrays. To identify genes affected by mouse liver mRNA hybridization, mRNA from identical human liver samples labeled with either Cy3 or Cy5 was compared in the presence and absence of known amounts of mouse liver mRNA labeled in only one dye. RESULTS: The results indicate that hybridization of mouse mRNA to the corresponding human gene probe on Agilent Human 22 K oligonucleotide microarray does occur. The number of genes affected by such cross-hybridization was subsequently reduced to approximately 300 genes both by increasing the hybridization temperature and using liver samples which contain at least 80% human tissue. In addition, Real Time quantitative RT-PCR using human specific probes was shown to be a valid method to verify the expression level in human cells of known cross-hybridizing genes. CONCLUSION: The identification of genes affected by cross-hybridization of mouse liver RNA on human oligonucleotide microarrays makes it feasible to use functional genomics approaches to study the chimeric SCID-beige/Alb-uPA mouse model of HCV infection. This approach used to study cross-species hybridization on oligonucleotide microarrays can be adapted to other chimeric systems of viral disease to facilitate selective analysis of human gene expression

    Host-Specific Response to HCV Infection in the Chimeric SCID-beige/Alb-uPA Mouse Model: Role of the Innate Antiviral Immune Response

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    The severe combined immunodeficiency disorder (SCID)-beige/albumin (Alb)-urokinase plasminogen activator (uPA) mouse containing a human-mouse chimeric liver is currently the only small animal model capable of supporting hepatitis C virus (HCV) infection. This model was utilized to characterize the host transcriptional response to HCV infection. The purpose of these studies was to investigate the genetic component of the host response to HCV infection and also to distinguish virus-induced gene expression changes from adaptive HCV-specific immune-mediated effects. Gene expression profiles from HCV-infected mice were also compared to those from HCV-infected patients. Analyses of the gene expression data demonstrate that host factors regulate the response to HCV infection, including the nature of the innate antiviral immune response. They also indicate that HCV mediates gene expression changes, including regulation of lipid metabolism genes, which have the potential to be directly cytopathic, indicating that liver pathology may not be exclusively mediated by HCV-specific adaptive immune responses. This effect appears to be inversely related to the activation of the innate antiviral immune response. In summary, the nature of the initial interferon response to HCV infection may determine the extent of viral-mediated effects on host gene expression

    Comparison of the Effects of Hexavalent Chromium in the Alimentary Canal of F344 Rats and B6C3F1 Mice Following Exposure in Drinking Water: Implications for Carcinogenic Modes of Action

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    Exposure to high concentrations of hexavalent chromium (Cr[VI]) in drinking water is reported to induce oral mucosa tumors in F344 rats and intestinal tumors in B6C3F1 mice. To investigate the modes of action underlying these tumors, 90-day drinking water studies (with interim necropsy at day 8) were conducted with concentrations of 0.1–182 mg/l Cr(VI), administered as 0.3–520 mg/l sodium dichromate dihydrate. Blood and tissue samples were analyzed for chromium content, oxidative stress, iron levels, and gross and microscopic lesions. Results for the F344 rats are described herein and compared with results from B6C3F1 mice published previously. After 90 days of exposure, total chromium concentrations in the rat and mouse oral mucosae were comparable, yet significant dose-dependent decreases in the reduced-to-oxidized glutathione ratio (GSH/GSSG) were observed only in rats. In the duodenum, changes in GSH/GSSG were only observed in mice. Levels of 8-hydroxydeoxyguanosine were not increased in the oral or duodenal mucosae of either species. Glutathione levels were increased in the duodenum but decreased in the jejunum of both species, indicating potential differential responses in the intestinal segments. Histiocytic infiltration was observed in the duodenum of both species, yet duodenal cytokines were repressed in mice but increased in rats. Serum and bone marrow iron levels were more decreased in rats than mice. Collectively, these data suggest that Cr(VI)-induced carcinogenesis in the rodent alimentary canal involves oxidative stress; however, differences in histopathology, cytokines, and iron status suggest potential contributions from other factors as well

    WireWall – a new approach to measuring coastal wave hazard

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    In the UK £150bn of assets and 4 million people are at risk from coastal flooding, whilst the construction of sea wall defence schemes typically cost at least £10,000 per linear meter. With reductions in public funding, rising sea level, changing storm conditions and 3200 km of coastal defences (i.e. about £3bn), cost savings are required that do not cause a reduction in flood resistance. The design of new coastal flood defences and the setting of tolerable hazard thresholds requires site-specific information of wave overtopping during storms of varying severity. By converting an existing wave measurement technology into a prototype overtopping monitoring system "WireWall", field observations of the wave-by-wave horizontal overtopping speeds and volumes were made at our case study site Crosby, in the North West of England. The new data quantify the wave overtopping conditions observed, which varied with the wind, waves and tide, allowing better understanding of how wave hazard at Crosby changes with the local conditions
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