5,758 research outputs found

    Associations of the lipidome with ageing, cognitive decline and exercise behaviours

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    One of the most recognisable features of ageing is a decline in brain health and cognitive dysfunction, which is associated with perturbations to regular lipid homeostasis. Although ageing is the largest risk factor for several neurodegenerative diseases such as dementia, a loss in cognitive function is commonly observed in adults over the age of 65. Despite the prevalence of normal age-related cognitive decline, there is a lack of effective methods to improve the health of the ageing brain. In light of this, exercise has shown promise for positively influencing neurocognitive health and associated lipid profiles. This review summarises age-related changes in several lipid classes that are found in the brain, including fatty acyls, glycerolipids, phospholipids, sphingolipids and sterols, and explores the consequences of age-associated pathological cognitive decline on these lipid classes. Evidence of the positive effects of exercise on the affected lipid profiles are also discussed to highlight the potential for exercise to be used therapeutically to mitigate age-related changes to lipid metabolism and prevent cognitive decline in later life

    Structure and dynamics of a model glass: influence of long-range forces

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    We vary the amplitude of the long-range Coulomb forces within a classical potential describing a model silica glass and study the consequences on the structure and dynamics of the glass, via molecular dynamics simulations. This model allows us to follow the variation of specific features such as the First Sharp Diffraction Peak and the Boson Peak in a system going continuously from a fragile (no Coulomb forces) to a strong (with Coulomb forces) glass. In particular we show that the characteristic features of a strong glass (existence of medium range order, bell-shaped ring size distribution, sharp Boson peak) appear as soon as tetrahedral units are formed.Comment: 5 pages, 4 figures. To be published in J.Phys.: C

    Sustainability and Land tenure: Who owns the floodplain in the Pantanal, Brazil?

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    In seeking to achieve poverty alleviation and environmental conservation, public policy has often centred on guaranteeing land titles to local peoples. However, such approaches have brought unintended outcomes, replacing small-scale economies and natural areas by intensive exploitation of resources with no clear improvement in local people’s wellbeing. To understand this, we go beyond a general political ecology framing to consider relations between sustainability and land tenure, focusing on the intersection of economics, ecology and anthropology to understand how land tenure, property and use play out on the ground. We draw together different concepts including bundle of rights, de facto and de jure resource use, property regimes, density-dependence and non-equilibrium theory. The significance of this three-discipline view is illustrated through a case study of the Pantanal wetland, Brazil, where conservationists, the government and the local population contest ownership of the Paraguay River floodplain. Government sought to address conflicts around tenure and access through a narrow view of property, which failed to encompass the overlapping layers of land tenure, property and use on the ground and only served to create further legal battles. This article concludes that a more complex view combining the three perspectives is needed in the case of the Pantanal, and in other cases of contested property rights, in order to resolve conflicting claims and foster sustainability. We dissect both the power plays involved between different groups competing for control of a valuable resource, and the legal frameworks which can and should provide checks and balances in the system. The more nuanced grasp that emerges of local systems of tenure and access, of how these diverge from western property concepts, and of their environmental implications favours a better understanding of local realities, allowing for better management policy and consequently contributing more effectively towards poverty alleviation and environmental protection

    The impact of living with long-term conditions in young adulthood on mental health and identity: What can help?

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    Background: It has been suggested that the mental health impacts of living with long-term conditions are greater in young adulthood compared to older adulthood, due to greater disruption to identity and routine life events. Objectives: To explore the impact of living with long-term conditions in young adulthood on mental health and identity, and what helps living well with these conditions. Methods: Fifteen in-depth interviews with young adults with various conditions were conducted and analysed thematically. Results: Themes related to the impacts on mental health and identity include: negative mood and depression; anxiety and fear for the future; identity as ‘ill’/abnormal compared to former self and ‘normal’ others. Themes related to suggestions for addressing negative impacts include: promotion of positive thinking; support reaching acceptance with altered identity and limitations (through stages of denial, anger, depression, then acceptance); and more professional mental health support. Discussion: In order to promote mental health and a positive sense of self/identity, young adults with long-term conditions should be offered advice and support on: positive thinking; the long and difficult process of reconstructing identity; and reaching acceptance. This is particularly important for young adults for whom the identity reconstruction process is more complex and psychologically damaging than for older adults; as this life stage is associated with health/vitality and illness represents a shift from a perceived normal trajectory to one that appears and feels abnormal

    Exploring young people's dignity: A qualitative approach

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    Aim: Human dignity as an important consideration in health care has been primarily investigated from an adult perspective. This paper explores young people's perceptions of dignity and how it impacts on their health-care experience. Method: A qualitative pilot study was undertaken at the Children's Hospital, Westmead in from 2010 to 2011. Semi structured interviews were conducted with five inpatients, and data were analysed using a grounded theory approach. Results: The adolescents interviewed perceived dignity as a way of protecting their personhood. Privacy and maintaining integrity were the means by which dignity could be preserved in a health-care setting. Conclusions: The study found that young people had unique perceptions of privacy and personhood with regards to dignity. Of the concepts of dignity in the existing literature, the dignity of identity was most applicable to adolescents' conceptions. This understanding of young people's views of dignity could prevent dignity violations in health care and beneficially impact their development. Keywords: adolescent; behavioural; ethic

    An investigation of children's peer trust across culture: is the composition of peer trust universal?

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    The components of children's trust in same-gender peers (trust beliefs, ascribed trustworthiness, and dyadic reciprocal trust) were examined in samples of 8- to 11-year-olds from the UK, Italy, and Japan. Trust was assessed by children's ratings of the extent to which same-gender classmates kept promises and kept secrets. Social relations analyses confirmed that children from each country showed significant: (a) actor variance demonstrating reliable individual differences in trust beliefs, (b) partner variance demonstrating reliable individual differences in ascribed trustworthiness, and (c ) relationship variance demonstrating unique relationships between interaction partners. Cultural differences in trust beliefs and ascribed trustworthiness also emerged and these differences were attributed to the tendency for children from cultures that value societal goals to share personal information with the peer group

    Anatomy of autoantibody production: Dominant localization of antibody-producing cells to T cell zones in fas-deficient mice

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    AbstractThe goal of this study was to examine the in vivo site of autoantibody production in normal and autoimmune-prone mice. B cells were identified in tissue sections with IgM- and IgG2a-specific riboprobes that readily distinguished resting cells from antibody-forming cells (AFC). In normal mice, the few identifiable IgG2a-secreting cells were found in the red pulp. By contrast, in Ipr mice exceedingly high numbers of IgG2a and autoantibody-producing cells were found deep within the T cell-rich periarteriolar lymphoid sheaths (PALS). This unusual anatomic location of autoantibody-secreting B cells is unique to Fas dysregulated strains, since IgG2a-producing cells in MRL/+ and (SWR × NZB)F1 mice were found predominantly in the red pulp or outer PALS, similar to normal mice. Furthermore, analysis of spleens from Ipr and non-Ipr anti-DNA immunoglobulin transgenic mice revealed dramatic accumulation of Tg+ cells in the inner PALS only in Ipr mice. These data suggest that in the absence of Fas, autoreactive B cells accumulate in T cell-rich zones, and this anatomic feature may contribute to autoantibody production

    Direct reaction measurements with a 132Sn radioactive ion beam

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    The (d,p) neutron transfer and (d,d) elastic scattering reactions were measured in inverse kinematics using a radioactive ion beam of 132Sn at 630 MeV. The elastic scattering data were taken in a region where Rutherford scattering dominated the reaction, and nuclear effects account for less than 8% of the cross section. The magnitude of the nuclear effects was found to be independent of the optical potential used, allowing the transfer data to be normalized in a reliable manner. The neutron-transfer reaction populated a previously unmeasured state at 1363 keV, which is most likely the single-particle 3p1/2 state expected above the N=82 shell closure. The data were analyzed using finite range adiabatic wave calculations and the results compared with the previous analysis using the distorted wave Born approximation. Angular distributions for the ground and first excited states are consistent with the previous tentative spin and parity assignments. Spectroscopic factors extracted from the differential cross sections are similar to those found for the one neutron states beyond the benchmark doubly-magic nucleus 208Pb.Comment: 22 pages, 7 figure

    Depleted uranium is not toxic to rat brain endothelial (RBE4) cells

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    Abstract: Studies on Gulf War veterans with depleted uranium (DU) fragments embedded in their soft tissues have led to suggestions of possible DU-induced neurotoxicity. We investigated DU uptake into cultured rat brain endothelial cells (RBE4). Following the determination that DU readily enters RBE4 cells, cytotoxic effects were analyzed using assays for cell volume increase, heat shock protein 90 (Hsp90) expression, 3-[4,5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) reduction, and lactate dehydrogenase (LDH) activity. The results of these studies show that uptake of the U 3 O 8 uranyl chloride form of DU into RBE4 cells is efficient, but there are little or no resulting cytotoxic effects on these cells as detected by common biomarkers. Thus, the present experimental paradigm is rather reassuring and provides no indication for overt cytotoxicity in endothelial cells exposed to DU. Index Entries: Depleted uranium (DU); heavey metal toxicity; blood-brain barrier; endothelium. Article: INTRODUCTION Depleted uranium (DU) is a component of military munitions and is therefore the subject of important toxicity studies. Specifically, the possibility of DU neurotoxicity is under investigation. DU is a dense heavy metal used without reserve in many military applications. Chemically similar to natural uranium, but depleted of much of the radioactivity of the 235 U and 234 U isotopes, DU is a low-specific-activity metal that has several advantages for use as weapons material. Neurotoxicity could potentially arise from the chemical or radioactive properties of DU, and the level of neurotoxicity is as yet undetermined (1-3). Gulf War veterans with DU fragments embedded in their soft tissues were studied and the results suggested that there might be DU-associated effects on behavior and cognition (1-4). Rats embedded with DU fragments accumulated uranium in a range of tissues, with early levels highest in the kidney and a gradual increase in bone accumulation. Brain tissues were found to have far lower levels, with the hippocampus showing high levels among the brain regions following physiologically relevant exposures and cerebellum accumulating the highest levels upon extremely high exposure levels For a blood-borne contaminant to cause neurotoxicity, it must first cross the blood-brain barrier (BBB). This barrier protects the central nervous system (CNS) from toxicants in the blood, and its ability to protect against metal neurotoxicity was reviewed by Zheng et al. (7). The capillaries of the brain are lined with endothelial cells acting as the first line of defense in the BBB. The high degree of tightness of the junctions that link the endothelial cells virtually prevents any paracellular passage from occurring in physiological conditions. In addition, several transport proteins can increase the brain-to-blood efflux of various compounds (e.g., Pglycoproteins or multidrug resistance proteins [MDR] of the ATP-binding cassette [ABC]) (7). The molecula
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