97 research outputs found

    Paleophysical Oceanography with an Emphasis on Transport Rates

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    Paleophysical oceanography is the study of the behavior of the fluid ocean of the past, with a specific emphasis on its climate implications, leading to a focus on the general circulation. Even if the circulation is not of primary concern, heavy reliance on deep-sea cores for past climate information means that knowledge of the oceanic state when the sediments were laid down is a necessity. Like the modern problem, paleoceanography depends heavily on observations, and central difficulties lie with the very limited data types and coverage that are, and perhaps ever will be, available. An approximate separation can be made into static descriptors of the circulation (e.g., its water-mass properties and volumes) and the more difficult problem of determining transport rates of mass and other properties. Determination of the circulation of the Last Glacial Maximum is used to outline some of the main challenges to progress. Apart from sampling issues, major difficulties lie with physical interpretation of the proxies, transferring core depths to an accurate timescale (the “age-model problem”), and understanding the accuracy of time-stepping oceanic or coupled-climate models when run unconstrained by observations. Despite the existence of many plausible explanatory scenarios, few features of the paleocirculation in any period are yet known with certainty.National Science Foundation (U.S.) (grant OCE-0645936

    Reclaiming feminist futures : co-opted and progressive politics in a neoliberal age

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    This article engages with the influential narrative about the co-optation of feminism in conditions of neoliberalism put forward by prominent feminist thinkers Nancy Fraser, Hester Eisenstein and Angela McRobbie. After drawing out the twin visions of 'progressive' feminist politics that undergird this narrative — cached out in terms of either the retrieval of past socialist feminist glories or personal reinvention — we subject to critical scrutiny both the substantive claims made and the conceptual scaffolding invoked. We argue that the proleptic imaginings of all three authors, in different ways, are highly circumscribed in terms of the recommended agent, agenda and practices of progressive politics, and clouded by conceptual muddle over the meanings of 'left', 'radical' and 'progressive'. Taken together, these problems render the conclusions of Fraser, Eisenstein and McRobbie at best unconvincing and at worst dismissive of contemporary feminist efforts to challenge neoliberalism. We end the paper by disentangling and redefining left, radical and progressive and by sketching a contrasting substantive vision of progressive feminist politics enabled by this reconceptualisation

    Impairment of circulating endothelial progenitors in Down syndrome

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    <p>Abstract</p> <p>Background</p> <p>Pathological angiogenesis represents a critical issue in the progression of many diseases. Down syndrome is postulated to be a systemic anti-angiogenesis disease model, possibly due to increased expression of anti-angiogenic regulators on chromosome 21. The aim of our study was to elucidate some features of circulating endothelial progenitor cells in the context of this syndrome.</p> <p>Methods</p> <p>Circulating endothelial progenitors of Down syndrome affected individuals were isolated, <it>in vitro </it>cultured and analyzed by confocal and transmission electron microscopy. ELISA was performed to measure SDF-1α plasma levels in Down syndrome and euploid individuals. Moreover, qRT-PCR was used to quantify expression levels of <it>CXCL12 </it>gene and of its receptor in progenitor cells. The functional impairment of Down progenitors was evaluated through their susceptibility to hydroperoxide-induced oxidative stress with BODIPY assay and the major vulnerability to the infection with human pathogens. The differential expression of crucial genes in Down progenitor cells was evaluated by microarray analysis.</p> <p>Results</p> <p>We detected a marked decrease of progenitors' number in young Down individuals compared to euploid, cell size increase and some major detrimental morphological changes. Moreover, Down syndrome patients also exhibited decreased SDF-1α plasma levels and their progenitors had a reduced expression of SDF-1α encoding gene and of its membrane receptor. We further demonstrated that their progenitor cells are more susceptible to hydroperoxide-induced oxidative stress and infection with Bartonella henselae. Further, we observed that most of the differentially expressed genes belong to angiogenesis, immune response and inflammation pathways, and that infected progenitors with trisomy 21 have a more pronounced perturbation of immune response genes than infected euploid cells.</p> <p>Conclusions</p> <p>Our data provide evidences for a reduced number and altered morphology of endothelial progenitor cells in Down syndrome, also showing the higher susceptibility to oxidative stress and to pathogen infection compared to euploid cells, thereby confirming the angiogenesis and immune response deficit observed in Down syndrome individuals.</p

    Mudança organizacional: uma abordagem preliminar

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    Cancer diagnosed by emergency admission in England: an observational study using the general practice research database.

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    BACKGROUND: Patients diagnosed with cancer by the emergency route often have more advanced diseases and poorer outcomes. Rates of cancer diagnosed through unplanned admissions vary within and between countries, suggesting potential inconsistencies in the quality of care. To reduce diagnoses by this route and improve patient outcomes, high risk patient groups must be identified. This cross-sectional observational study determined the incidence of first-ever diagnoses of cancer by emergency (unplanned) admission and identified patient-level risk factors for these diagnoses in England. METHODS: Data for 74,763 randomly selected patients at 457 general practices between 1999 and 2008 were obtained from the General Practice Research Database (GPRD), including integrated Hospital Episode Statistics (HES) data and Office for National Statistics (ONS) mortality data. The proportion of first-ever diagnoses by emergency admission out of all recorded first cancer diagnoses by any route was analysed by patient characteristics. RESULTS: Diagnosis by emergency admission was recorded in 13.9% of patients diagnosed with cancer for the first time (n = 817/5870). The incidence of first cases by the emergency route was 2.51 patients per 10,000 person years. In adjusted regression analyses, patients of older age (p < 0.0001), living in the most deprived areas (RR 1.93, 95% CI 1.51 to 2.47; p < 0.0001) or who had a total Charlson score of 1 compared to 0 (RR 1.34, 95% CI 1.06 to 1.69; p = 0.014) were most at risk of diagnosis by emergency admission. Patients with more prior (all-cause) emergency admissions were less at risk of subsequent diagnosis by the emergency route (RR 0.31 per prior emergency admission, 95% CI 0.20 to 0.46; p < 0.0001). CONCLUSIONS: A much lower incidence of first-ever cancer diagnoses by emergency admission was found compared with previous studies. Identified high risk groups may benefit from interventions to reduce delayed diagnosis. Further studies should include screening and cancer staging data to improve understanding of delayed or untimely diagnosis and patient care pathways

    Testing of Fibrous Particles : Short-Term Assays and Strategies

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