183 research outputs found

    Gravitational microlensing of planets: the influence of planetary phase and caustic orientation

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    Recent studies have demonstrated that detailed monitoring of gravitational microlensing events can reveal the presence of planets orbiting the microlensed source stars. With the potential of probing planets in the Galactic Bulge and Magellanic Clouds, such detections greatly increase the volume over which planets can be found. This paper expands on these original studies by considering the effect of planetary phase on the form of the resultant microlensing light curve. It is found that crescent-like sources can undergo substantially more magnification than a uniformly illuminated disk, the model typically employed in studying such planets. In fact, such a circularly symmetric model is found to suffer a minimal degree of magnification when compared to the crescent models. The degree of magnification is also a strong function of the planet's orientation with respect to the microlensing caustic. The form of the magnification variability is also strongly dependent on the planetary phase and from which direction it is swept by the caustic, providing further clues to the geometry of the planetary system. As the amount of light reflected from a planet also depends on its phase, the detection of extreme crescent-like planets requires the advent of 30-m class telescopes, while light curves of planets at more moderate phases can be determined with today's 10-m telescopes.Comment: 7 pages, 7 figures, to appear in the MNRA

    Association of Urinary Bisphenol A Concentration with Heart Disease: Evidence from NHANES 2003/06

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    BACKGROUND: Bisphenol A (BPA) is a high production volume chemical widely used in food and drinks packaging. Associations have previously been reported between urinary BPA concentrations and heart disease, diabetes and liver enzymes in adult participants of the National Health and Nutrition Examination Survey (NHANES) 2003/04. We aimed to estimate associations between urinary BPA concentrations and health measures in NHANES 2005/06 and in data pooled across collection years. METHODOLOGY AND FINDINGS: A cross-sectional analysis of NHANES: subjects were n = 1455 (2003/04) and n = 1493 (2005/06) adults aged 18-74 years, representative of the general adult population of the United States. Regression models were adjusted for age, sex, race/ethnicity, education, income, smoking, BMI, waist circumference, and urinary creatinine concentration. Main outcomes were reported diagnoses of heart attack, coronary heart disease, angina and diabetes and serum liver enzyme levels. Urinary BPA concentrations in 2005/06 (geometric mean 1.79 ng/ml, 95% CI: 1.64 to 1.96) were lower than in 2003/04 (2.49 ng/ml, CI: 2.20 to 2.83, difference p-value = 0.00002). Higher BPA concentrations were associated with coronary heart disease in 2005/06 (OR per z-score increase in BPA = 1.33, 95%CI: 1.01 to 1.75, p = 0.043) and in pooled data (OR = 1.42, CI: 1.17 to 1.72, p = 0.001). Associations with diabetes did not reach significance in 2005/06, but pooled estimates remained significant (OR = 1.24, CI: 1.10 to 1.40, p = 0.001). There was no overall association with gamma glutamyl transferase concentrations, but pooled associations with alkaline phosphatase and lactate dehydrogenase remained significant. CONCLUSIONS: Higher BPA exposure, reflected in higher urinary concentrations of BPA, is consistently associated with reported heart disease in the general adult population of the USA. Studies to clarify the mechanisms of these associations are urgently needed

    Evaluation of the clinical effectiveness of a work-based mentoring programme to develop clinical reasoning on patient outcome: A stepped wedge cluster randomised controlled trial

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    BackgroundDespite persistent calls to measure the effectiveness of educational interventions on patient outcomes, few studies have been conducted. Within musculoskeletal physiotherapy, the effects of clinical mentoring on postgraduate physiotherapists have been explored, but its impact on patient outcomes is unknown. The objective of this trial was to assess the effectiveness of a work-based mentoring programme to facilitate physiotherapist clinical reasoning on patient outcomes.MethodsIn a stepped-wedge cluster RCT in the musculoskeletal physiotherapy outpatient departments of a large NHS organisation, 16 physiotherapists were randomised by cluster to receive the intervention-150 hours of mentored clinical practice-at one of 3 time periods; control was usual training. 441 patients submitted outcome measures: Patient-Specific Functional Scale (PSFS) (primary outcome measure), EQ-5D-5L, patient activation and patient satisfaction (secondary outcome measures). A further secondary outcome measure of physiotherapist performance was collected by an independent assessor observing the physiotherapists practice.Results80.0% of intervention patients achieved clinically significant PSFS scores compared with 63.8% of control patients. Binary logistic regression analysis modelling for time, cluster and patient characteristics showed strong statistical evidence for this difference (p = 0.023; odds ratio 4.24, 95%CI 1.22, 14.79). Physiotherapist performance scores improved from a mean of 47.8% (SD 3.60) pre-intervention to a mean of 56.0% (SD 4.24) (pConclusionThis is the first study that we aware of that provides patient outcomes measurement of an established educational intervention in physiotherapy, providing evidence that this type of intervention positively impacts patient outcomes and physiotherapist performance. This provides a basis for further research in education across other healthcare disciplines and outcome measures

    Optimizing hatchery practices for genetic improvement of marine bivalves

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    This is the final version. Available from Wiley via the DOI in this record. Aquaculture currently accounts for approximately half of all seafood produced and is the fastest growing farmed food sector globally. Marine bivalve aquaculture, the farming of oysters, mussels and clams, represents a highly sustainable component of this industry and has major potential for global expansion via increased efficiency, and numbers of, production systems. Artificial spat propagation (i.e. settled juveniles) in hatcheries and selective breeding have the potential to offer rapid and widespread gains for molluscan aquaculture industry. However, bivalves have unique life-histories, genetic and genomic characteristics, which present significant challenges to achieving such genetic improvement. Selection pressures experienced by bivalve larvae and spat in the wild contribute to drive population structure and animal fitness. Similarly, domestication selection is likely to act on hatchery-produced spat, the full implications of which have not been fully explored. In this review, we outline the key features of these taxa and production practices applied in bivalve aquaculture, which have the potential to affect the genetic and phenotypic variability of hatchery-propagated stock. Alongside, we compare artificial and natural processes experienced by bivalves to investigate the possible consequences of hatchery propagation on stock production. In addition, we identify key areas of investigation that need to be prioritized to continue to the advancement of bivalve genetic improvement via selective breeding. The growing accessibility of next-generation sequencing technology and high-powered computational capabilities facilitate the implementation of novel genomic tools in breeding programmes of aquatic species. These emerging techniques represent an exciting opportunity for sustainably expanding the bivalve aquaculture sector.Biotechnology & Biological Sciences Research Council (BBSRC)Natural Environment Research CouncilBiotechnology and Biological Sciences Research CouncilBiotechnology and Biological Sciences Research CouncilBiotechnology and Biological Sciences Research Counci

    News media use, talk networks, and anti-elitism across geographic location: evidence from Wisconsin

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    A certain social-political geography recurs across European and North American societies: As post-industrialization and mechanization of agriculture have disrupted economies, rural and nonmetropolitan areas are aging and declining in population, leading to widening political and cultural gaps between metropolitan and rural communities. Yet political communication research tends to focus on national or cross-national levels, often emphasizing networked digital media and an implicitly global information order. We contend that geographic place still provides a powerful grounding for individuals’ lifeworld experiences, identities, and orientations to political communications and politics. Focusing on the U.S. state of Wisconsin, and presenting data gathered in 2018, this study demonstrates significant, though often small, differences between geographic locations in terms of their patterns of media consumption, political talk, and anti-elite attitudes. Importantly, television news continues to play a major role in citizens’ repertoires across locations, suggesting we must continue to pay attention to this broadcast medium. Residents of more metropolitan communities consume significantly more national and international news from prestige sources such as the New York Times, and their talk networks are more cleanly sorted by partisanship. Running against common stereotypes of news media use, residents of small towns and rural areas consume no more conservative media than other citizens, even without controlling for partisanship. Our theoretical model and empirical results call for further attention to the intersections of place and politics in understanding news consumption behaviors and the meanings citizens draw from media content

    The Effects of Combined Ocean Acidification and Nanoplastic Exposures on the Embryonic Development of Antarctic Krill

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    In aquatic environments, plastic pollution occurs concomitantly with anthropogenic climate stressors such as ocean acidification. Within the Southern Ocean, Antarctic krill (Euphausia Superba) support many marine predators and play a key role in the biogeochemical cycle. Ocean acidification and plastic pollution have been acknowledged to hinder Antarctic krill development and physiology in singularity, however potential multi-stressor effects of plastic particulates coupled with ocean acidification are unexplored. Furthermore, Antarctic krill may be especially vulnerable to plastic pollution due to their close association with sea-ice, a known plastic sink. Here, we investigate the behaviour of nanoplastic [spherical, aminated (NH2), and yellow-green fluorescent polystyrene nanoparticles] in Antarctic seawater and explore the single and combined effects of nanoplastic (160 nm radius, at a concentration of 2.5 µg ml−1) and ocean acidification (pCO2 ∼900, pHT 7.7) on the embryonic development of Antarctic krill. Gravid female krill were collected in the Atlantic sector of the Southern Ocean (North Scotia Sea). Produced eggs were incubated at 0.5 ◦C in four treatments (control, nanoplastic, ocean acidification and the multi-stressor scenario of nanoplastic presence, and ocean acidification) and their embryonic development after 6 days, at the incubation endpoint, was determined. We observed that negatively charged nanoplastic particles suspended in seawater from the Scotia Sea aggregated to sizes exceeding the nanoscale after 24 h (1054.13 ± 53.49 nm). Further, we found that the proportion of embryos developing through the early stages to reach at least the limb bud stage was highest in the control treatment (21.84%) and lowest in the multi-stressor treatment (13.17%). Since the biological thresholds to any stressors can be altered by the presence of additional stressors, we propose that future nanoplastic ecotoxicology studies should consider the changing global ocean under future climate scenarios for assessments of their impact and highlight that determining the behaviour of nanoplastic particles used in incubation studies is critical to determining their toxicity

    Reproductive toxicity of the water accommodated fraction (WAF) of crude oil in the polychaetes Arenicola marina (L.) and Nereis virens (Sars).

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    addresses: School of Biosciences, Hatherley Laboratories, University of Exeter, Prince of Wales Road, Exeter EX4 4PS, UK. [email protected]: Journal Article; Research Support, Non-U.S. Gov'tCopyright © 2008 Elsevier. NOTICE: This is the author’s version of a work accepted for publication by Elsevier. Changes resulting from the publishing process, including peer review, editing, corrections, structural formatting and other quality control mechanisms, may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Aquatic Toxicology, 2008, Vol. 90, Issue 1, pp. 73 – 81 DOI: http://dx.doi.org/10.1016/j.aquatox.2008.08.001Accidental pollution incidents are common in the marine environment and are often caused by oil-related activities. Here the potential of such an incident to disrupt reproduction in two polychaete species is investigated, using an environmentally relevant preparation of weathered Forties crude oil, i.e. the water accommodated fraction (WAF). Oocytes were collected and exposed to three concentrations of WAF for 1h prior to the addition of sperm, so that fertilization took place under exposure conditions. Fertilization success was significantly reduced in both species by an exposure to WAF concentrations equivalent to 0.38 mgL(-1) PAHs, to just 26.8% in Arenicola marina compared to 76% in Nereis virens. The effects of WAF exposure on fertilization were greatly enhanced at lower sperm concentrations in N. virens, with a complete lack of fertilization reactions observed at sperm concentrations of 10(3)sperm per mL. We therefore suggest a mechanism of toxicity related to sperm swimming behaviour, resulting in reduced sperm:egg collision rates. WAF was found to reduce post-fertilization development rates and have teratogenic effects on early embryonic stages in both species, which exhibited abnormal cleavage patterns and high levels of fluctuating asymmetry. These results illustrate how the presence of crude oil in its soluble form in seawater at the time of a spawning event for either A. marina or N. virens could impact on fertilization success with implications for the fertilization ecology of these free spawning marine invertebrates

    Fit for Cancer Treatment: a prospective feasibility study of primary care initiated prehabilitation for patients with suspected cancer

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    Background Risk profile assessment and corrective interventions using optimisation of health status and prehabilitation represent an important strategy in the management of patients with a suspected cancer diagnosis. Aim To determine the feasibility of pre-treatment optimisation and prehabilitation commenced at index primary care consultation, to improve patients’ preparation for treatment by maximising the time available. Design & setting Between January 2015 and May 2016, 195 patients presenting to 12 GP practices were deemed eligible to enter the study, of which 189 (96.9%, median age 60 [21–91] years and 65 months; 124 female) were recruited and consented to the prehabilitation bundle. Method All patients were simultaneously referred to secondary care using urgent suspected cancer (USC) pathways. The primary outcome measures were definitive diagnosis and treatment plan. Results Fifteen patients (7.9%) were diagnosed with cancer (three breast, three colon, two lung, two skin [one melanoma, one sarcoma], one tonsil, one vocal cord, one pancreas, one prostate, one ependymoma) and 62 were diagnosed with other significant medical conditions (47 gastrointestinal, 13 sepsis, two respiratory) requiring secondary care assessment and treatment. Of the 15 patients with cancer, 11 (73.3%) underwent potentially curative treatment, and four (26.7%) palliative treatment. Of the total study cohort, 84 (44%) required a form of optimisation in primary care, and patients with cancer were more likely to require optimisation than others (n = 10 [63%] versus n = 74 [43%], χ2 9.384, P = 0.002). Conclusion One in 12 primary care USC patients had cancer (5.6% receiving potentially curative treatment), one in three had other systemic health issues, and overall two in five benefited from healthcare intervention. Primary care optimisation was feasible and associated with important allied health benefits

    Genotoxic damage in polychaetes: a study of species and cell-type sensitivities.

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    addresses: School of Biosciences, Hatherley Laboratories, University of Exeter, Prince of Wales Road, Exeter EX4 4PS, UK. [email protected]: Journal Article; Research Support, Non-U.S. Gov'tCopyright © 2008 Elsevier. NOTICE: This is the author’s version of a work accepted for publication by Elsevier. Changes resulting from the publishing process, including peer review, editing, corrections, structural formatting and other quality control mechanisms, may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Mutation Research - Genetic Toxicology and Environmental Mutagenesis, 2008, Vol. 654, Issue 1, pp. 69 – 75 DOI: http://dx.doi.org/10.1016/j.mrgentox.2008.05.008The marine environment is becoming increasingly contaminated by environmental pollutants with the potential to damage DNA, with marine sediments acting as a sink for many of these contaminants. Understanding genotoxic responses in sediment-dwelling marine organisms, such as polychaetes, is therefore of increasing importance. This study is an exploration of species-specific and cell-specific differences in cell sensitivities to DNA-damaging agents in polychaete worms, aimed at increasing fundamental knowledge of their responses to genotoxic damage. The sensitivities of coelomocytes from three polychaetes species of high ecological relevance, i.e. the lugworm Arenicola marina, the harbour ragworm Nereis diversicolor and the king ragworm Nereis virens to genotoxic damage are compared, and differences in sensitivities of their different coelomic cell types determined by use of the comet assay. A. marina was found to be the most sensitive to genotoxic damage induced by the direct-acting mutagen methyl methanesulfonate (MMS), and showed dose-dependent responses to MMS and the polycyclic aromatic hydrocarbon benzo(a)pyrene. Significant differences in sensitivity were also measured for the different types of coelomocyte. Eleocytes were more sensitive to induction of DNA damage than amoebocytes in both N. virens and N. diversicolor. Spermatozoa from A. marina showed significant DNA damage following in vitro exposure to MMS, but were less sensitive to DNA damage than coelomocytes. This investigation has clearly demonstrated that different cell types within the same species and different species within the polychaetes show significantly different responses to genotoxic insult. These findings are discussed in terms of the relationship between cell function and sensitivity and their implications for the use of polychaetes in environmental genotoxicity studies

    Impact of sympathetic nervous system activity on post-exercise flow-mediated dilatation in humans

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    Transient reduction in vascular function following systemic large muscle group exercise has previously been reported in humans. The mechanisms responsible are currently unknown. We hypothesised that sympathetic nervous system activation, induced by cycle ergometer exercise, would contribute to post-exercise reductions in flow-mediated dilatation (FMD). Ten healthy male subjects (28 ± 5 years) undertook two 30 min sessions of cycle exercise at 75% HRmax. Prior to exercise, individuals ingested either a placebo or an α1-adrenoreceptor blocker (prazosin; 0.05 mg kg−1). Central haemodynamics, brachial artery shear rate (SR) and blood flow profiles were assessed throughout each exercise bout and in response to brachial artery FMD, measured prior to, immediately after and 60 min after exercise. Cycle exercise increased both mean and antegrade SR (P < 0.001) with retrograde SR also elevated under both conditions (P < 0.001). Pre-exercise FMD was similar on both occasions, and was significantly reduced (27%) immediately following exercise in the placebo condition (t-test, P = 0.03). In contrast, FMD increased (37%) immediately following exercise in the prazosin condition (t-test, P = 0.004, interaction effect P = 0.01). Post-exercise FMD remained different between conditions after correction for baseline diameters preceding cuff deflation and also post-deflation SR. No differences in FMD or other variables were evident 60 min following recovery. Our results indicate that sympathetic vasoconstriction competes with endothelium-dependent dilator activity to determine post-exercise arterial function. These findings have implications for understanding the chronic impacts of interventions, such as exercise training, which affect both sympathetic activity and arterial shear stress
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