243 research outputs found

    Confounding factors in diagnosing brain death: a case report

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    BACKGROUND: Brain death is strictly defined medically and legally. This diagnosis depends on three cardinal neurological features: coma, absent brainstem reflexes, and apnea. The diagnosis can only be made, however, in the absence of intoxication, hypothermia, or certain medical illnesses. CASE PRESENTATION: A patient with severe hypoxic-ischemic brain injury met the three cardinal neurological features of brain death but concurrent profound hypothyroidism precluded the diagnosis. Our clinical and ethical decisions were further challenged by another facet of this complex case. Although her brain damage indicated a hopeless prognosis, we could not discontinue care based on futility because the only known surrogate was mentally retarded and unable to participate in medical planning. CONCLUSION: The presence of certain medical conditions prohibits a diagnosis of brain death, which is a medicolegal diagnosis of death, not a prediction or forecast of future outcome. While prognostication is important in deciding to withdraw care, it is not a component in diagnosing brain death

    Brief Report: AIP Mutation in Pituitary Adenomas in the 18th Century and Today

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    From New England Journal of Medicine, Volume 364, issue 1, p.43-50. Copyright © (2011) Massachusetts Medical Society. Reprinted with permission.Gigantism results when a growth hormone–secreting pituitary adenoma is present before epiphyseal fusion. In 1909, when Harvey Cushing examined the skeleton of an Irish patient who lived from 1761 to 1783,1-3 he noted an enlarged pituitary fossa. We extracted DNA from the patient’s teeth and identified a germline mutation in the aryl hydrocarbon–interacting protein gene (AIP). Four contemporary Northern Irish families who presented with gigantism, acromegaly, or prolactinoma have the same mutation and haplotype associated with the mutated gene. Using coalescent theory, we infer that these persons share a common ancestor who lived about 57 to 66 generations earlier

    Evolutionary relationships between Rhynchosporium lolii sp. nov. and other Rhynchosporium species on grass.

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    Copyright: 2013 King et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedThe fungal genus Rhynchosporium (causative agent of leaf blotch) contains several host-specialised species, including R. commune (colonising barley and brome-grass), R. agropyri (couch-grass), R. secalis (rye and triticale) and the more distantly related R. orthosporum (cocksfoot). This study used molecular fingerprinting, multilocus DNA sequence data, conidial morphology, host range tests and scanning electron microscopy to investigate the relationship between Rhynchosporium species on ryegrasses, both economically important forage grasses and common wild grasses in many cereal growing areas, and other plant species. Two different types of Rhynchosporium were found on ryegrasses in the UK. Firstly, there were isolates of R. commune that were pathogenic to both barley and Italian ryegrass. Secondly, there were isolates of a new species, here named R. lolii, that were pathogenic only to ryegrass species. R. lolii was most closely related to R. orthosporum, but exhibited clear molecular, morphological and host range differences. The species was estimated to have diverged from R. orthosporum ca. 5735 years before the present. The colonisation strategy of all of the different Rhynchosporium species involved extensive hyphal growth in the sub-cuticular regions of the leaves. Finally, new species-specific PCR diagnostic tests were developed that could distinguish between these five closely related Rhynchosporium species.Peer reviewedFinal Published versio

    Carbohydrate mouth rinse: does it improve endurance exercise performance?

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    It is well known that carbohydrate (CHO) supplementation can improve performance in endurance exercises through several mechanisms such as maintenance of glycemia and sparing endogenous glycogen as well as the possibility of a central nervous-system action. Some studies have emerged in recent years in order to test the hypothesis of ergogenic action via central nervous system. Recent studies have demonstrated that CHO mouth rinse can lead to improved performance of cyclists, and this may be associated with the activation of brain areas linked to motivation and reward. These findings have already been replicated in other endurance modalities, such as running. This alternative seems to be an attractive nutritional tool to improve endurance exercise performance

    Understanding the (non-)Use of Societal Wellbeing Indicators in National Policy Development : What Can We Learn from Civil Servants? A UK Case Study

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    Gross Domestic Product is often used as a proxy for societal well-being in the context of policy development. Its shortcomings in this context are, however, well documented, and numerous alternative indicator sets have been developed. Despite this, there is limited evidence of widespread use of these alternative indicator sets by people working in policy areas relevant to societal wellbeing. Civil servants are an important group of indicator end-users. Better understanding their views concerning measuring societal wellbeing can support wider discussions about what factors determine indicator use and influence in policy decision-making. Taking the UK as a case study, we ask what views exist among civil servants in the UK about measuring societal well-being? To answer this question, we used a bootstrapped Q methodology, interviewing 20 civil servants to elicit their views about measuring societal well-being. Three distinct discourses emerged from our analysis: one that was concerned about the consequences of ignoring natural, social and human capital in decision making; one that emphasised opportunity and autonomy as key determinants of well-being; and one that focused on the technical aspects of measuring societal well-being. Each of these discourses has direct implications for the way that we integrate societal wellbeing into policy making and highlights the potential benefits of including end-users in indicator development and strategy

    Horizontal Transfer of a Nitrate Assimilation Gene Cluster and Ecological Transitions in Fungi: A Phylogenetic Study

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    High affinity nitrate assimilation genes in fungi occur in a cluster (fHANT-AC) that can be coordinately regulated. The clustered genes include nrt2, which codes for a high affinity nitrate transporter; euknr, which codes for nitrate reductase; and NAD(P)H-nir, which codes for nitrite reductase. Homologs of genes in the fHANT-AC occur in other eukaryotes and prokaryotes, but they have only been found clustered in the oomycete Phytophthora (heterokonts). We performed independent and concatenated phylogenetic analyses of homologs of all three genes in the fHANT-AC. Phylogenetic analyses limited to fungal sequences suggest that the fHANT-AC has been transferred horizontally from a basidiomycete (mushrooms and smuts) to an ancestor of the ascomycetous mold Trichoderma reesei. Phylogenetic analyses of sequences from diverse eukaryotes and eubacteria, and cluster structure, are consistent with a hypothesis that the fHANT-AC was assembled in a lineage leading to the oomycetes and was subsequently transferred to the Dikarya (Ascomycota+Basidiomycota), which is a derived fungal clade that includes the vast majority of terrestrial fungi. We propose that the acquisition of high affinity nitrate assimilation contributed to the success of Dikarya on land by allowing exploitation of nitrate in aerobic soils, and the subsequent transfer of a complete assimilation cluster improved the fitness of T. reesei in a new niche. Horizontal transmission of this cluster of functionally integrated genes supports the “selfish operon” hypothesis for maintenance of gene clusters

    Win-stay, lose-switch and public information strategies for patch fidelity of songbirds with rare extra-pair paternity

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    Determining where organisms breed and understanding why they breed in particular locations are fundamental biological questions with conservation implications. Breeding-site fidelity is common in migratory, territorial songbirds and is typically thought to occur following reproductive success with a social mate and success of nearby conspecifics. It is currently unknown if frequency of extra-pair paternity in a population influences use of information about reproductive success of nearby conspecifics for site fidelity decisions. We investigated patch fidelity of white-eyed vireos (Vireo griseus) based on reproductive success and quantified frequency of extra-pair paternity. We found support only for females making patch fidelity decisions following reproductive success with a social mate. Patch fidelity of males was not associated with reproductive success of nearby conspecifics, suggesting males may not use this information when extra-pair paternity is infrequent or the association is non-existent in this species
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