35 research outputs found

    Triboson interpretations of the ATLAS diboson excess

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    The ATLAS excess in fat jet pair production is kinematically compatible with the decay of a heavy resonance into two gauge bosons plus an extra particle. This hypothesis would explain the absence of such a large excess in the analogous CMS analysis of fat dijet final states, as well as the negative results of diboson resonance searches in the semi-leptonic decay modes. If the extra particle is the Higgs boson, this hypothesis might also explain -statistical fluctuations aside- why the CMS search for WH resonances in the semi-leptonic channel finds some excess while in the fully hadronic one it does not have a significant deviation.Comment: LaTeX 17 pages. v2: Enlarged discussion to address CMS WH excess. v3: Added discussion of diboson helicities. Final version to appear in JHE

    The weakest link: competence and prestige as constraints to referral by isolated nurses in rural Niger

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    BACKGROUND: For a health district to function referral from health centres to district hospitals is critical. In many developing countries referral systems perform well below expectations. Niger is not an exception in this matter. Beyond obvious problems of cost and access this study shows to what extent the behaviour of the health worker in its interaction with the patient can be a barrier of its own. METHODS: Information was triangulated from three sources in two rural districts in Niger: first, 46 semi-structured interviews with health centre nurses; second, 42 focus group discussions with an average of 12 participants – patients, relatives of patients and others; third, 231 semi-structured interviews with referred patients. RESULTS: Passive patients without 'voice' reinforce authoritarian attitudes of health centre staff. The latter appear reluctant to refer because they see little added value in referral and fear loss of power and prestige. As a result staff communicates poorly and show little eagerness to convince reluctant patients and families to accept referral proposals. CONCLUSIONS: Diminishing referral costs and distance barriers is not enough to correct failing referral systems. There is also a need for investment in district hospitals to make referrals visibly worthwhile and for professional upgrading of the human resources at the first contact level, so as to allow for more effective referral patterns

    Immunological Basis for the Gender Differences in Murine Paracoccidioides brasiliensis Infection

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    This study aimed to investigate the immunological mechanisms involved in the gender distinct incidence of paracoccidioidomycosis (pcm), an endemic systemic mycosis in Latin America, which is at least 10 times more frequent in men than in women. Then, we compared the immune response of male and female mice to Paracoccidioides brasiliensis infection, as well as the influence in the gender differences exerted by paracoccin, a P. brasiliensis component with carbohydrate recognition property. High production of Th1 cytokines and T-bet expression have been detected in the paracoccin stimulated cultures of spleen cells from infected female mice. In contrast, in similar experimental conditions, cells from infected males produced higher levels of the Th2 cytokines and expressed GATA-3. Macrophages from male and female mice when stimulated with paracoccin displayed similar phagocytic capability, while fungicidal activity was two times more efficiently performed by macrophages from female mice, a fact that was associated with 50% higher levels of nitric oxide production. In order to evaluate the role of sexual hormones in the observed gender distinction, we have utilized mice that have been submitted to gonadectomy followed by inverse hormonal reconstitution. Spleen cells derived from castrated males reconstituted with estradiol have produced higher levels of IFN-γ (1291±15 pg/mL) and lower levels of IL-10 (494±38 pg/mL), than normal male in response to paracoccin stimulus. In contrast, spleen cells from castrated female mice that had been treated with testosterone produced more IL-10 (1284±36 pg/mL) and less IFN-γ (587±14 pg/mL) than cells from normal female. In conclusion, our results reveal that the sexual hormones had a profound effect on the biology of immune cells, and estradiol favours protective responses to P. brasiliensis infection. In addition, fungal components, such as paracoccin, may provide additional support to the gender dimorphic immunity that marks P. brasiliensis infection

    Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

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    The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference

    Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

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    In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

    Dissociação clínico-radiológica nas manifestações pulmonares da paracoccidioidomicose Clinical-radiological dissociation in lung manifestations of paracoccidioidomycosis

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    Os pulmões estão entre os principais sítios acometidos pela paracoccidioidomicose, contudo as alterações nem sempre são fáceis de serem diferenciadas de outros distúrbios respiratórios. O objetivo deste estudo foi verificar a freqüência do comprometimento pulmonar na paracoccidioidomicose e se existe associação clínico-radiológica. Foi realizado um estudo retrospectivo de março de 1996 a novembro de 2006, em pacientes com paracoccidioidomicose no Hospital Universitário Regional de Maringá, PR. No período foram confirmados 45 casos, dos quais 79,5% apresentavam alterações radiológicas em Raios-X de tórax e quatro deles tinham também tuberculose pulmonar. De 40 pacientes com paracoccidioidomicose exclusivamente, 57,5% apresentavam manifestações clínicas respiratórias e 77,5% alterações radiológicas, ficando evidente uma dissociação clínico-radiológica, o tabagismo foi declarado por 80,6% dos pacientes que apresentavam alterações radiológicas. Concluímos que as alterações morfológicas no pulmão, embora freqüentes, nem sempre correspondem a sinais e sintomas respiratórios e são difíceis de serem atribuídas exclusivamente à paracoccidioidomicose.<br>Lungs are among the main sites affected by paracoccidioidomycosis. However, the alterations are not always easy to differentiate from other respiratory disorders. The objectives of the present study were to investigate the frequency of lung impairment in paracoccidioidomycosis cases and to investigate whether any clinical-radiological association exists. A retrospective study was carried out from March 1996 to November 2006, among patients with paracoccidioidomycosis at the Regional University Hospital of Maringá, Paraná, Brazil. Over this period, 45 cases were confirmed, of which 79.5% presented radiological abnormalities on chest X-rays, and four of them also presented pulmonary tuberculosis. Out of the total of 40 patients with paracoccidioidomycosis alone, 57.5% presented respiratory clinical manifestations, whereas 77.5% presented radiological abnormalities, thus demonstrating clinical-radiological dissociation. On the other hand, 80.6% of the patients who presented radiological abnormalities said that they smoked. We concluded that although morphological abnormalities in the lungs are frequent, they do not always correspond to respiratory signs and symptoms and cannot easily be attributed exclusively to paracoccidioidomycosis
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