2,458 research outputs found

    Observational study of the effects of age, diabetes mellitus, cirrhosis and chronic kidney disease on sublingual microvascular flow.

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    BACKGROUND: Sidestream dark field (SDF) imaging has been used to demonstrate microcirculatory abnormalities in a variety of critical illnesses. The microcirculation is also affected by advancing age and chronic comorbidities. However, the effect of these conditions on SDF microcirculatory parameters has not been well described. METHODS: SDF images were obtained from five groups of 20 participants: healthy volunteers under the age of 25, healthy volunteers over the age of 55, and clinic patients over the age of 55 with one of diabetes mellitus, cirrhosis and stage 5 chronic kidney disease. Microcirculatory parameters between the groups were then compared for significance using analysis of variance for parametric and the Kruskal-Wallis test for non-parametric data. RESULTS: Median microvascular flow index was 2.85 (interquartile range 2.75 to 3.0) for participants aged 55, 2.88 (2.75 to 3.0) for those with diabetes mellitus, 3.0 (2.83 to 3.0) for those with cirrhosis and 3.0 (2.78 to 3.0) for those with chronic kidney disease (P for difference between groups = 0.14). Similarly, there were no significant differences in the proportion of perfused vessels and perfused vessel density between the groups. CONCLUSIONS: Older age, diabetes, and chronic kidney and liver disease need not be considered confounding factors for comparison of SDF microcirculatory parameters in the critically ill

    Fruit development is actively restricted in the absence of fertilization in Arabidopsis

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    Flowering plants usually require fertilization to form fruit and seed and to initiate floral organ abscission in structures that do not contribute to the fruit. An Arabidopsis mutant that initiates seedless fruit without fertilization (fwf) or parthenocarpy was isolated and characterized to understand the factors regulating the transition between the mature flower and the initiation of seed and fruit development. The fwf mutant is fertile and has normal plant growth and stature. It sets fertile seed following self-pollination and fertilization needs to be prevented to observe parthenocarpy. The initiation of parthenocarpic siliques (fruit) was found to be dependent upon carpel valve identity conferred by FRUITFULL but was independent of the perception of gibberellic acid, shown to stimulate parthenocarpy in Arabidopsis following exogenous application. The recessive nature of fwf is consistent with the involvement of FWF in processes that inhibit fruit growth and differentiation in the absence of fertilization. The enhanced cell division and expansion in the silique mesocarp layer, and increased lateral vascular bundle development imply FWF has roles also in modulating silique growth post-fertilization. Parthenocarpy was inhibited by the presence of other floral organs suggesting that both functional FWF activity and inter-organ communication act in concert to prevent fruit initiation in the absence of fertilization

    In search of a pan-European culture: European values, beliefs and models of selfhood in global perspective

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    What, if any, are the common cultural characteristics that distinguish European societies and groups when viewed against a backdrop of global cultural variation? We sought to identify any shared features of European cultures through secondary multilevel analyses of two large datasets that together provided measures of cultural values, beliefs and models of selfhood from samples in all inhabited continents. Although heterogeneous in many respects—including the value dimension of autonomy versus embeddedness—European samples shared two distinctive features: a decontextualized representation of personhood and a cultural model of selfhood emphasizing difference from others. Compared to samples from other regions, European samples on average also emphasized egalitarianism and harmony values, commitment to others in their models of selfhood, and an immutable concept of personhood, but not uniformly so. We interpret these findings in relation to a Durkheimian model of individualism

    Protocol for the development of guidance for stakeholder engagement in health and healthcare guideline development and implementation

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    Stakeholder engagement has become widely accepted as a necessary component of guideline development and implementation. While frameworks for developing guidelines express the need for those potentially affected by guideline recommendations to be involved in their development, there is a lack of consensus on how this should be done in practice. Further, there is a lack of guidance on how to equitably and meaningfully engage multiple stakeholders. We aim to develop guidance for the meaningful and equitable engagement of multiple stakeholders in guideline development and implementation. METHODS: This will be a multi-stage project. The first stage is to conduct a series of four systematic reviews. These will (1) describe existing guidance and methods for stakeholder engagement in guideline development and implementation, (2) characterize barriers and facilitators to stakeholder engagement in guideline development and implementation, (3) explore the impact of stakeholder engagement on guideline development and implementation, and (4) identify issues related to conflicts of interest when engaging multiple stakeholders in guideline development and implementation. DISCUSSION: We will collaborate with our multiple and diverse stakeholders to develop guidance for multi-stakeholder engagement in guideline development and implementation. We will use the results of the systematic reviews to develop a candidate list of draft guidance recommendations and will seek broad feedback on the draft guidance via an online survey of guideline developers and external stakeholders. An invited group of representatives from all stakeholder groups will discuss the results of the survey at a consensus meeting which will inform the development of the final guidance papers. Our overall goal is to improve the development of guidelines through meaningful and equitable multi-stakeholder engagement, and subsequently to improve health outcomes and reduce inequities in health

    Aerobiology over Antarctica – a new initiative for atmospheric ecology

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    The role of aerial dispersal in shaping patterns of biodiversity remains poorly understood, mainly due to a lack of coordinated efforts in gathering data at appropriate temporal and spatial scales. It has been long known that the rate of dispersal to an ecosystem can significantly influence ecosystem dynamics, and that aerial transport has been identified as an important source of biological input to remote locations. With the considerable effort devoted in recent decades to understanding atmospheric circulation in the south-polar region, a unique opportunity has emerged to investigate the atmospheric ecology of Antarctica, from regional to continental scales. This concept note identifies key questions in Antarctic microbial biogeography and the need for standardized sampling and analysis protocols to address such questions. A consortium of polar aerobiologists is established to bring together researchers with a common interest in the airborne dispersion of microbes and other propagules in the Antarctic, with opportunities for comparative studies in the Arctic

    Neutrino Propagation in a Strongly Magnetized Medium

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    We derive general expressions at the one-loop level for the coefficients of the covariant structure of the neutrino self-energy in the presence of a constant magnetic field. The neutrino energy spectrum and index of refraction are obtained for neutral and charged media in the strong-field limit (MWBme,T,μ,pM_{W}\gg \sqrt{B}\gg m_{e},T,\mu ,| \mathbf{p}| ) using the lowest Landau level approximation. The results found within the lowest Landau level approximation are numerically validated, summing in all Landau levels, for strong BT2B\gg T^{2} and weakly-strong BT2B \gtrsim T^{2} fields. The neutrino energy in leading order of the Fermi coupling constant is expressed as the sum of three terms: a kinetic-energy term, a term of interaction between the magnetic field and an induced neutrino magnetic moment, and a rest-energy term. The leading radiative correction to the kinetic-energy term depends linearly on the magnetic field strength and is independent of the chemical potential. The other two terms are only present in a charged medium. For strong and weakly-strong fields, it is found that the field-dependent correction to the neutrino energy in a neutral medium is much larger than the thermal one. Possible applications to cosmology and astrophysics are considered.Comment: 23 pages, 4 figures. Corrected misprints in reference

    Solution structure of a repeated unit of the ABA-1 nematode polyprotein allergen of ascaris reveals a novel fold and two discrete lipid-binding sites

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    Parasitic nematode worms cause serious health problems in humans and other animals. They can induce allergic-type immune responses, which can be harmful but may at the same time protect against the infections. Allergens are proteins that trigger allergic reactions and these parasites produce a type that is confined to nematodes, the nematode polyprotein allergens (NPAs). These are synthesized as large precursor proteins comprising repeating units of similar amino acid sequence that are subsequently cleaved into multiple copies of the allergen protein. NPAs bind small lipids such as fatty acids and retinol (Vitamin A) and probably transport these sensitive and insoluble compounds between the tissues of the worms. Nematodes cannot synthesize these lipids, so NPAs may also be crucial for extracting nutrients from their hosts. They may also be involved in altering immune responses by controlling the lipids by which the immune and inflammatory cells communicate. We describe the molecular structure of one unit of an NPA, the well-known ABA-1 allergen of Ascaris and find its structure to be of a type not previously found for lipid-binding proteins, and we describe the unusual sites where lipids bind within this structur
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