390 research outputs found

    Rigidity of compact Riemannian spin Manifolds with Boundary

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    In this article, we prove new rigidity results for compact Riemannian spin manifolds with boundary whose scalar curvature is bounded from below by a non-positive constant. In particular, we obtain generalizations of a result of Hang-Wang \cite{hangwang1} based on a conjecture of Schroeder and Strake \cite{schroeder}.Comment: English version of "G\'eom\'etrie spinorielle extrins\`eque et rigidit\'es", Corollary 6 in Section 3 added, to appear in Letters Math. Phy

    Crude incidence in two-phase designs in the presence of competing risks.

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    BackgroundIn many studies, some information might not be available for the whole cohort, some covariates, or even the outcome, might be ascertained in selected subsamples. These studies are part of a broad category termed two-phase studies. Common examples include the nested case-control and the case-cohort designs. For two-phase studies, appropriate weighted survival estimates have been derived; however, no estimator of cumulative incidence accounting for competing events has been proposed. This is relevant in the presence of multiple types of events, where estimation of event type specific quantities are needed for evaluating outcome.MethodsWe develop a non parametric estimator of the cumulative incidence function of events accounting for possible competing events. It handles a general sampling design by weights derived from the sampling probabilities. The variance is derived from the influence function of the subdistribution hazard.ResultsThe proposed method shows good performance in simulations. It is applied to estimate the crude incidence of relapse in childhood acute lymphoblastic leukemia in groups defined by a genotype not available for everyone in a cohort of nearly 2000 patients, where death due to toxicity acted as a competing event. In a second example the aim was to estimate engagement in care of a cohort of HIV patients in resource limited setting, where for some patients the outcome itself was missing due to lost to follow-up. A sampling based approach was used to identify outcome in a subsample of lost patients and to obtain a valid estimate of connection to care.ConclusionsA valid estimator for cumulative incidence of events accounting for competing risks under a general sampling design from an infinite target population is derived

    Development of a decision support tool to facilitate primary care management of patients with abnormal liver function tests without clinically apparent liver disease [HTA03/38/02]. Abnormal Liver Function Investigations Evaluation (ALFIE)

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    Liver function tests (LFTs) are routinely performed in primary care, and are often the gateway to further invasive and/or expensive investigations. Little is known of the consequences in people with an initial abnormal liver function (ALF) test in primary care and with no obvious liver disease. Further investigations may be dangerous for the patient and expensive for Health Services. The aims of this study are to determine the natural history of abnormalities in LFTs before overt liver disease presents in the population and identify those who require minimal further investigations with the potential for reduction in NHS costs

    Co-localization of activating transcription factor 3 and phosphorylated c-Jun in axotomized facial motoneurons

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    Activating transcription factor 3 (ATF3) and c-Jun play key roles in either cell death or cell survival, depending on the cellular background. To evaluate the functional significance of ATF3/c-Jun in the peripheral nervous system, we examined neuronal cell death, activation of ATF3/c-Jun, and microglial responses in facial motor nuclei up to 24 weeks after an extracranial facial nerve axotomy in adult rats. Following the axotomy, neuronal survival rate was progressively but significantly reduced to 79.1% at 16 weeks post-lesion (wpl) and to 65.2% at 24 wpl. ATF3 and phosphorylated c-Jun (pc-Jun) were detected in the majority of ipsilateral facial motoneurons with normal size and morphology during the early stage of degeneration (1-2 wpl). Thereafter, the number of facial motoneurons decreased gradually, and both ATF3 and pc-Jun were identified in degenerating neurons only. ATF3 and pc-Jun were co-localized in most cases. Additionally, a large number of activated microglia, recognized by OX6 (rat MHC II marker) and ED1 (phagocytic marker), gathered in the ipsilateral facial motor nuclei. Importantly, numerous OX6- and ED1-positive, phagocytic microglia closely surrounded and ingested pc-Jun-positive, degenerating neurons. Taken together, our results indicate that long-lasting co-localization of ATF3 and pc-Jun in axotomized facial motoneurons may be related to degenerative cascades provoked by an extracranial facial nerve axotomy

    Landmine injuries at the Emergency Management Center in Erbil, Iraq

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    <p>Abstract</p> <p>Background</p> <p>Landmines can cause death, injury and disability in addition to many indirect public health consequences. This study aimed at understanding the trends, demography and other epidemiological characteristics of hospitalized landmine injured patients in Erbil governorate.</p> <p>Methods</p> <p>The case records of landmine injured patients who had been admitted to the Emergency Management Centre in Erbil city from July 1998 to July 2007 were reviewed and descriptively analyzed.</p> <p>Results</p> <p>Two hundred eighty five landmine injured patients were admitted to the center, their mean ± SD age was 26.5 ± 13.2 years (range 6-71 years), 95.1% were males, nearly 50% were between 19 to 35 years of age and 96.8% were civilians. Around 72% of victims sustained limb amputations; 58.6% lower limb and 13.3% upper limb out of the total. The hospital mortality rate was 2.1%. The number of admissions for landmine injury was steadily decreasing between July 1998 and July 2001, followed by prominent increase between July 2002 and July 2003. The highest proportion of admissions occurred in summer (35.4%) and majority of incidents occurred along the borders with Iran and Turkey (61.8%).</p> <p>Conclusion</p> <p>Civilian male adolescents and young adults constituted the majority of hospitalized landmine victims in Erbil governorate. While a high proportion of victims sustained lower limb amputations, upper limb amputations particularly among children and injury to head and face were relatively common which might be attributed to handling explosives. This emphasizes the need to examine the reasons behind handling explosives.</p

    An exploratory randomised controlled trial of a premises-level intervention to reduce alcohol-related harm including violence in the United Kingdom

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    &lt;b&gt;Background&lt;/b&gt;&lt;p&gt;&lt;/p&gt; To assess the feasibility of a randomised controlled trial of a licensed premises intervention to reduce severe intoxication and disorder; to establish effect sizes and identify appropriate approaches to the development and maintenance of a rigorous research design and intervention implementation.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Methods&lt;/b&gt;&lt;p&gt;&lt;/p&gt; An exploratory two-armed parallel randomised controlled trial with a nested process evaluation. An audit of risk factors and a tailored action plan for high risk premises, with three month follow up audit and feedback. Thirty-two premises that had experienced at least one assault in the year prior to the intervention were recruited, match paired and randomly allocated to control or intervention group. Police violence data and data from a street survey of study premises’ customers, including measures of breath alcohol concentration and surveyor rated customer intoxication, were used to assess effect sizes for a future definitive trial. A nested process evaluation explored implementation barriers and the fidelity of the intervention with key stakeholders and senior staff in intervention premises using semi-structured interviews.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Results&lt;/b&gt;&lt;p&gt;&lt;/p&gt; The process evaluation indicated implementation barriers and low fidelity, with a reluctance to implement the intervention and to submit to a formal risk audit. Power calculations suggest the intervention effect on violence and subjective intoxication would be raised to significance with a study size of 517 premises.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Conclusions&lt;/b&gt;&lt;p&gt;&lt;/p&gt; It is methodologically feasible to conduct randomised controlled trials where licensed premises are the unit of allocation. However, lack of enthusiasm in senior premises staff indicates the need for intervention enforcement, rather than voluntary agreements, and on-going strategies to promote sustainability

    How do nurses and teachers perform breast self-examination: are they reliable sources of information?

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    <p>Abstract</p> <p>Background</p> <p>Breast cancer is the most common cause of cancer-related deaths among women worldwide. The aim of the present study was to determine and compare knowledge, behavior and attitudes among female nurses and teachers concerning breast self-examination (BSE).</p> <p>Methods</p> <p>Two-hundred and eighty nine women working in Aydin, Turkey (125 nurses and 164 teachers) were included in the study. The data were collected using a questionnaire designed to measure the knowledge, attitudes and behavior of the groups. Analysis involved percentiles, χ<sup>2 </sup>tests, <it>t </it>tests and factor analysis.</p> <p>Results</p> <p>The knowledge of nurses about BSE was higher than that of teachers (81.5% versus 45.1%; p < 0.001). BSE practice parameters (i.e. age groups, indications, frequency) were similar (p > 0.05), whereas skills in performing self-examination were higher in nurses (p < 0.001). Fear of having breast cancer is the most frequent reason for performing BSE. Among nurses, the reasons for failure to perform BSE were the absence of prominent breast problems (82%) and forgetting (56.4%). The teachers who did not perform BSE said that the reasons were lack of knowledge on how to perform self-examination (68.9%) and absence of problems (54%). Both groups had unacceptable technical errors in the performance of BSE.</p> <p>Conclusion</p> <p>We conclude that nurses and teachers should be supported with information enabling them to accomplish their roles in the community. To improve BSE practice, it is crucial to coordinate continuous and planned education.</p

    Inherited Glutathione Reductase Deficiency and Plasmodium falciparum Malaria—A Case Study

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    In Plasmodium falciparum-infected red blood cells (RBCs), the flavoenzyme glutathione reductase (GR) regenerates reduced glutathione, which is essential for antioxidant defense. GR utilizes NADPH produced in the pentose phosphate shunt by glucose-6-phosphate dehydrogenase (G6PD). Thus, conditions affecting host G6PD or GR induce increased sensitivity to oxidants. Hereditary G6PD deficiency is frequent in malaria endemic areas and provides protection against severe malaria. Furthermore, GR deficiency resulting from insufficient saturation of the enzyme with its prosthetic group FAD is common. Based on these naturally occurring phenomena, GR of malaria parasites and their host cells represent attractive antimalarial drug targets. Recently we were given the opportunity to examine invasion, growth, and drug sensitivity of three P. falciparum strains (3D7, K1, and Palo Alto) in the RBCs from three homozygous individuals with total GR deficiency resulting from mutations in the apoprotein. Invasion or growth in the GR-deficient RBCs was not impaired for any of the parasite strains tested. Drug sensitivity to chloroquine, artemisinin, and methylene blue was comparable to parasites grown in GR-sufficient RBCs and sensitivity towards paraquat and sodium nitroprusside was only slightly enhanced. In contrast, membrane deposition of hemichromes as well as the opsonizing complement C3b fragments and phagocytosis were strongly increased in ring-infected RBCs of the GR-deficient individuals compared to ring-infected normal RBCs. Also, in one of the individuals, membrane-bound autologous IgGs were significantly enhanced. Thus, based on our in vitro data, GR deficiency and drug-induced GR inhibition may protect from malaria by inducing enhanced ring stage phagocytosis rather than by impairing parasite growth directly
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