33 research outputs found

    Neutrino emission from dense matter, and neutron star thermal evolution

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    A brief review is given of neutrino emission processes in dense matter, with particular emphasis on recent developments. These include direct Urca processes for nucleons and hyperons, which can give rise to rapid energy loss from the stellar core without exotic matter, and the effect of band structure on neutrino bremsstrahlung from electrons in the crust, which results in much lower energy losses by this process than had previously been estimated

    A qualitative investigation into knowledge, beliefs, and practices surrounding mastitis in sub-Saharan Africa: what implications for vertical transmission of HIV?

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    BACKGROUND: Mastitis constitutes an important risk factor in HIV vertical transmission. Very little, however, is known on how women in sub-Saharan Africa conceptualise health problems related to breastfeeding, such as mastitis, and how they act when sick. We aimed at filling this gap in knowledge, by documenting the indigenous nosography of mastitis, health seeking behaviour, and remedies for prophylaxis and treatment in rural sub-Saharan Africa. METHODS: The study was conducted in the Nouna Health District, rural Burkina Faso. We employed a combination of in-depth individual interviews and focus group discussions reaching both women and guérisseuers. All material was transcribed, translated, and analysed inductively, applying data and analyst triangulation. RESULTS: Respondents perceived breast problems related to lactation to be highly prevalent and described a sequence of symptoms which resembles the biomedical understanding of pathologies related to breastfeeding, ranging from breast engorgement (stasis) to inflammation (mastitis) and infection (breast abscess). The aetiology of disease, however, differed from biomedical notions as both women and guerisseurs distinguished between "natural" and "unnatural" causes of health problems related to breastfeeding. To prevent and treat such pathologies, women used a combination of traditional and biomedical therapies, depending on the perceived cause of illness. In general, however, a marked preference for traditional systems of care was observed. CONCLUSION: Health problems related to breastfeeding are perceived to be very common in rural Burkina Faso. Further epidemiological research to assess the actual prevalence of such pathologies is urgently needed to inform the design of adequate control measures, especially given the impact of mastitis on HIV vertical transmission. Our investigation into local illness concepts and health care seeking behaviour is useful to ensure that such measures be culturally sensitive. Further research into the efficacy of local customs and traditional healing methods and their effect on viral load in breast milk is also urgently needed

    Human malarial disease: a consequence of inflammatory cytokine release

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    Malaria causes an acute systemic human disease that bears many similarities, both clinically and mechanistically, to those caused by bacteria, rickettsia, and viruses. Over the past few decades, a literature has emerged that argues for most of the pathology seen in all of these infectious diseases being explained by activation of the inflammatory system, with the balance between the pro and anti-inflammatory cytokines being tipped towards the onset of systemic inflammation. Although not often expressed in energy terms, there is, when reduced to biochemical essentials, wide agreement that infection with falciparum malaria is often fatal because mitochondria are unable to generate enough ATP to maintain normal cellular function. Most, however, would contend that this largely occurs because sequestered parasitized red cells prevent sufficient oxygen getting to where it is needed. This review considers the evidence that an equally or more important way ATP deficency arises in malaria, as well as these other infectious diseases, is an inability of mitochondria, through the effects of inflammatory cytokines on their function, to utilise available oxygen. This activity of these cytokines, plus their capacity to control the pathways through which oxygen supply to mitochondria are restricted (particularly through directing sequestration and driving anaemia), combine to make falciparum malaria primarily an inflammatory cytokine-driven disease

    Early breastfeeding experiences of adolescent mothers: a qualitative prospective study

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    BACKGROUND: Teen mothers face many challenges to successful breastfeeding and are less likely to breastfeed than any other population group in the U.S. Few studies have investigated this population; all prior studies are cross-sectional and collect breastfeeding data retrospectively. The purpose of our qualitative prospective study was to understand the factors that contribute to the breastfeeding decisions and practices of teen mothers. METHODS: This prospective study took place from January through December 2009 in Greensboro, North Carolina in the U.S. We followed the cohort from pregnancy until two weeks after they ceased all breastfeeding and milk expression. We conducted semi-structured interviews at baseline and follow-up, and tracked infant feeding weekly by phone. We analyzed the data to create individual life and breastfeeding journeys and then identified themes that cut across the individual journeys. RESULTS: Four of the five teenagers breastfed at the breast for nine days: in contrast, one teen breastfed exclusively for five months. Milk expression by pumping was associated with significantly longer provision of human milk. Breastfeeding practices and cessation were closely connected with their experiences as new mothers in the context of ongoing multiple roles, complex living situations, youth and dependency, and poor knowledge of the fundamentals of breastfeeding and infant development. Breastfeeding cessation was influenced by inadequate breastfeeding skill, physically unpleasant and painful early experiences they were unprepared to manage, and inadequate health care response to real problems. CONCLUSIONS: Continued breastfeeding depends on a complex interplay of multiple factors, including having made an informed choice and having the skills, support and experiences needed to sustain the belief that breastfeeding is the best choice for them and their baby given their life situation. Teenagers in the US context need to have a positive early breastfeeding experience, be able to identify and claim a reliable support system supportive of breastfeeding, and gain through their experience, a belief in their own agency and competency as mothers
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