3,889 research outputs found

    The ecology of seamounts: structure, function, and human impacts.

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    In this review of seamount ecology, we address a number of key scientific issues concerning the structure and function of benthic communities, human impacts, and seamount management and conservation. We consider whether community composition and diversity differ between seamounts and continental slopes, how important dispersal capabilities are in seamount connectivity, what environmental factors drive species composition and diversity, whether seamounts are centers of enhanced biological productivity, and whether they have unique trophic architecture. We discuss how vulnerable seamount communities are to fishing and mining, and how we can balance exploitation of resources and conservation of habitat. Despite considerable advances in recent years, there remain many questions about seamount ecosystems that need closer integration of molecular, oceanographic, and ecological research

    An investigation to determine the cause of haemorrhagic enteritis in commercial pig grower units in the northern parts of South Africa

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    Necropsies were performed on 36 grower pigs that died peracutely on farms in the northern parts of South Africa. All these pigs were suffering from haemorrhagic enteritis and suspected toxaemia. Samples of the duodenum, jejunum and ileum were taken for histopathological examination and a section of ileum was collected for microbiological examination from each animal. Histological lesions characteristic of enterotoxigenic Clostridium infection were found. Large, Gram-positive bacilli were sometimes abundant in sections and mucosal smears of the intestine. However, only 40% of the cultures were positive for Clostridium perfringens

    A systematic review of the prevalence of parental concerns measured by the Parents' Evaluation of Developmental Status (PEDS) indicating developmental risk

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    © 2014 Woolfenden et al.; licensee BioMed Central Ltd. Background: Parental concerns about their children's development can be used as an indicator of developmental risk. We undertook a systematic review of the prevalence of parents' concerns as an indicator of developmental risk, measured by the Parents' Evaluation of Developmental Status (PEDS) and associated risk factors. Methods: Electronic databases, bibliographies and websites were searched and experts contacted. Studies were screened for eligibility and study characteristics were extracted independently by two authors. A summary estimate for prevalence was derived. Meta-regression examined the impact of study characteristics and quality. Meta-analysis was used to derive pooled estimates of the impact of biological and psychosocial risk factors on the odds of parental concerns indicating high developmental risk. Results: Thirty seven studies were identified with a total of 210,242 subjects. Overall 13.8% (95% CI 10.9 -16.8%) of parents had concerns indicating their child was at high developmental risk and 19.8% (95% CI 16.7-22.9%) had concerns indicating their child was at moderate developmental risk. Male gender, low birth weight, poor/fair child health rating, poor maternal mental health, lower socioeconomic status (SES), minority ethnicity, not being read to, a lack of access to health care and not having health insurance were significantly associated with parental concerns indicating a high developmental risk. Conclusions: The prevalence of parental concerns measured with the PEDS indicating developmental risk is substantial. There is increased prevalence associated with biological and psychosocial adversity. Trial Registration: PROSPERO Registration: CRD42012003215

    Cytosolic Phospholipase A2α and Eicosanoids Regulate Expression of Genes in Macrophages Involved in Host Defense and Inflammation

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    Acknowledgments: We thank Dr. Robert Barkley and Charis Uhlson for mass spectrometry analysis. Funding: This work was supported by grants from the National Institutes of Health HL34303 (to C.C.L., R.C.M. and D.L.B), DK54741 (to J.V.B.), GM5322 (to D.L.W.) and the Wellcome Trust (to N.A.R.G. and G.D.B.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

    Dynamic consent: a possible solution to improve patient confidence and trust in how electronic patient records are used in medical research

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    With one million people treated every 36 hours, routinely collected UK National Health Service (NHS) health data has huge potential for medical research. Advances in data acquisition from electronic patient records (EPRs) means such data are increasingly digital and can be anonymised for research purposes. NHS England’s care.data initiative recently sought to increase the amount and availability of such data. However, controversy and uncertainty following the care.data public awareness campaign led to a delay in rollout, indicating that the success of EPR data for medical research may be threatened by a loss of patient and public trust. The sharing of sensitive health care data can only be done through maintaining such trust in a constantly evolving ethicolegal and political landscape. We propose that a dynamic consent model, whereby patients can electronically control consent through time and receive information about the uses of their data, provides a transparent, flexible, and user-friendly means to maintain public trust. This could leverage the huge potential of the EPR for medical research and, ultimately, patient and societal benefit

    Dynamic consent: a possible solution to improve patient confidence and trust in how electronic patient records are used in medical research

    Get PDF
    With one million people treated every 36 hours, routinely collected UK National Health Service (NHS) health data has huge potential for medical research. Advances in data acquisition from electronic patient records (EPRs) means such data are increasingly digital and can be anonymised for research purposes. NHS England’s care.data initiative recently sought to increase the amount and availability of such data. However, controversy and uncertainty following the care.data public awareness campaign led to a delay in rollout, indicating that the success of EPR data for medical research may be threatened by a loss of patient and public trust. The sharing of sensitive health care data can only be done through maintaining such trust in a constantly evolving ethicolegal and political landscape. We propose that a dynamic consent model, whereby patients can electronically control consent through time and receive information about the uses of their data, provides a transparent, flexible, and user-friendly means to maintain public trust. This could leverage the huge potential of the EPR for medical research and, ultimately, patient and societal benefit

    Albedos and diameters of three Mars Trojan asteroids

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    We observed the Mars Trojan asteroids (5261) Eureka and (101429) 1998 VF31 and the candidate Mars Trojan 2001 FR127 at 11.2 and 18.1 microns using Michelle on the Gemini North telescope. We derive diameters of 1.28, 0.78, and <0.52 km, respectively, with corresponding geometric visible albedos of 0.39, 0.32, and >0.14. The albedos for Eureka and 1998 VF31 are consistent with the taxonomic classes and compositions (S(I)/angritic and S(VII)/achrondritic, respectively) and implied histories presented in a companion paper by Rivkin et al. Eureka's surface likely has a relatively high thermal inertia, implying a thin regolith that is consistent with predictions and the small size that we derive.Comment: Icarus, in press. See companion paper 0709.1925 by Rivkin et al; two minor typos fixe

    Adrenaline modulates the global transcriptional profile of Salmonella revealing a role in the antimicrobial peptide and oxidative stress resistance responses

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    <p>Abstract</p> <p>Background</p> <p>The successful interaction of bacterial pathogens with host tissues requires the sensing of specific chemical and physical cues. The human gut contains a huge number of neurons involved in the secretion and sensing of a class of neuroendocrine hormones called catecholamines. Recently, in <it>Escherichia coli </it>O157:H7, the catecholamines adrenaline and noradrenaline were shown to act synergistically with a bacterial quorum sensing molecule, autoinducer 3 (AI-3), to affect bacterial virulence and motility. We wished to investigate the impact of adrenaline on the biology of <it>Salmonella </it>spp.</p> <p>Results</p> <p>We have determined the effect of adrenaline on the transcriptome of the gut pathogen <it>Salmonella enterica </it>serovar Typhimurium. Addition of adrenaline led to an induction of key metal transport systems within 30 minutes of treatment. The oxidative stress responses employing manganese internalisation were also elicited. Cells lacking the key oxidative stress regulator OxyR showed reduced survival in the presence of adrenaline and complete restoration of growth upon addition of manganese. A significant reduction in the expression of the <it>pmrHFIJKLM </it>antimicrobial peptide resistance operon reduced the ability of <it>Salmonella </it>to survive polymyxin B following addition of adrenaline. Notably, both phenotypes were reversed by the addition of the β-adrenergic blocker propranolol. Our data suggest that the BasSR two component signal transduction system is the likely adrenaline sensor mediating the antimicrobial peptide response.</p> <p>Conclusion</p> <p><it>Salmonella </it>are able to sense adrenaline and downregulate the antimicrobial peptide resistance <it>pmr </it>locus through the BasSR two component signalling system. Through iron transport, adrenaline may affect the oxidative stress balance of the cell requiring OxyR for normal growth. Both adrenaline effects can be inhibited by the addition of the β-adrenergic blocker propranolol. Adrenaline sensing may provide an environmental cue for the induction of the <it>Salmonella </it>stress response in anticipation of imminent host-derived oxidative stress. However, adrenaline may also serve in favour of the host defences by lowering antimicrobial peptide resistance and hence documenting for the first time such a function for a hormone.</p

    A New Framework for Modelling Fine Sediment Transport in Rivers Includes Flocculation to Inform Reservoir Management in Wildfire Impacted Watersheds

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    Fine-grained cohesive sediment is the primary vector for nutrient and contaminant redistribution through aquatic systems and is a critical indicator of land disturbance. A critical limitation of most existing sediment transport models is that they assume that the transport characteristics of fine sediment can be described using the same approaches that are used for coarse-grained non-cohesive sediment, thereby ignoring the tendency of fine sediment to flocculate. Here, a modelling framework to simulate flow and fine sediment transport in the Crowsnest River, the Castle River, the Oldman River and the Oldman Reservoir after the 2003 Lost Creek wildfire in Alberta, Canada was developed and validated. It is the first to include explicit description of fine sediment deposition/erosion processes as a function of bed shear stress and the flocculation process. This framework integrates four existing numerical models: MOBED, RIVFLOC, RMA2 and RMA4 using river geometry, flow, fine suspended sediment characteristics and bathymetry data. Sediment concentration and particle size distributions computed by RIVFLOC were used as the upstream boundary condition for the reservoir dispersion model RMA4. The predicted particle size distributions and mass of fine river sediment deposited within various sections of the reservoir indicate that most of the fine sediment generated by the upstream disturbance deposits in the reservoir. Deposition patterns of sediment from wildfire-impacted landscapes were different than those from unburned landscapes because of differences in settling behaviour. These differences may lead to zones of relatively increased internal loading of phosphorus to reservoir water columns, thereby increasing the potential for algae proliferation. In light of the growing threats to water resources globally from wildfire, the generic framework described herein can be used to model propagation of fine river sediment and associated nutrients or contaminants to reservoirs under different flow conditions and land use scenarios. The framework is thereby a valuable tool to support decision making for water resources management and catchment planning
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