2,176 research outputs found

    Creep of natural rubber vulcanizates.

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    Dysregulation of Na+/K+ ATPase by amyloid in APP+PS1 transgenic mice

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    BACKGROUND: The pathology of Alzheimer's disease (AD) is comprised of extracellular amyloid plaques, intracellular tau tangles, dystrophic neurites and neurodegeneration. The mechanisms by which these various pathological features arise are under intense investigation. Here, expanding upon pilot gene expression studies, we have further analyzed the relationship between Na+/K+ ATPase and amyloid using APP+PS1 transgenic mice, a model that develops amyloid plaques and memory deficits in the absence of tangle formation and neuronal or synaptic loss. RESULTS: We report that in addition to decreased mRNA expression, there was decreased overall Na+/K+ ATPase enzyme activity in the amyloid-containing hippocampi of the APP+PS1 mice (although not in the amyloid-free cerebellum). In addition, dual immunolabeling revealed an absence of Na+/K+ ATPase staining in a zone surrounding congophilic plaques that was occupied by dystrophic neurites. We also demonstrate that cerebral Na+/K+ ATPase activity can be directly inhibited by high concentrations of soluble Aβ. CONCLUSIONS: The data suggest that the reductions in Na+/K+ ATPase activity in Alzheimer tissue may not be purely secondary to neuronal loss, but may results from direct effects of amyloid on this enzyme. This disruption of ion homeostasis and osmotic balance may interfere with normal electrotonic properties of dendrites, blocking intraneuronal signal processing, and contribute to neuritic dystrophia. These results suggest that therapies aimed at enhancing Na+/K+ ATPase activity in AD may improve symptoms and/or delay disease progression

    Using participatory and creative methods to facilitate emancipatory research with people facing multiple disadvantage: a role for health and care professionals

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    Participatory and creative research methods are a powerful tool for enabling active engagement in the research process of marginalised people. It can be particularly hard for people living with multiple disadvantage, such as disabled people from ethnic minority backgrounds, to access research projects that are relevant to their lived experience. This article argues that creative and participatory methods facilitate the co-researchers’ engagement in the research process, which thus becomes more empowering. Exploring the congruence of these methods with their professional ethos, health and care professionals can use their skills to develop them further. Both theory and practice examples are presented

    Walking as a meaningful leisure occupation: the implications for occupational therapy

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    Introduction: In response to growing interest in leisure in occupational therapy and the importance of understanding how occupations maintain, enhance and promote health and wellbeing, a qualitative phenomenological study was conducted to explore the experiences of walking for leisure. Method: Six healthy student participants, identified as regular walkers, were interviewed using a semi-structured format. Data were analysed following interpretative phenomenological analysis methodology. Findings: Participants expressed how and why walking was meaningful to them; the four main themes were social connectedness, wellbeing, connection to nature and achievement from a challenge. Findings suggest that occupational therapists could use walking and leisure occupations in intervention, and that there is scope for an occupational therapy perspective in health promotion. Conclusion: Determining the subjective meaning of engaging in walking as a leisure occupation has implications for occupational science and health promotion in helping to explain why people do what they do

    Decolonising occupational science education through learning activities based on a study from the Global South

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    If occupational science education is to become more globally relevant, it must highlight more voices and practices from diverse communities. Learning about occupational justice from the perspectives of Global South communities addresses cognitive injustice and the need to decolonise occupational science education. This paper offers some critical reflections concerning the author’s pedagogic approach, and the ways his research about olive growing in Palestine (Simaan, 2018) informed students’ learning about occupational justice. It focuses on the processes in which students and lecturers engaged within a decolonising approach to occupational science education. A learning activity based on pedagogical processes of ‘conscientization’ (Freire, 1996), critical reflexivity (Whiteford & Townsend, 2011) and intercultural translation (Santos, 2014) is discussed, and lessons learnt by lecturer and students about themselves, their communities, and occupational science are reflected upon. Selected students’ reflections, which illustrate how they positioned themselves in relation to the community studied, and how they interrogated their own reactions to learning about daily lives in Palestine, are discussed. These processes demonstrate the benefits of highlighting local knowledge on occupational justice produced by Global South groups, and how this knowledge might begin to address cognitive injustice and the need to decolonise occupational science pedagogy. More empirical and theoretical work is needed in occupational science education regarding intercultural translations concerning occupational justice, and means of doing and knowing from diverse Global South perspectives

    Lithium Treatment of APPSwDI/NOS2−/− Mice Leads to Reduced Hyperphosphorylated Tau, Increased Amyloid Deposition and Altered Inflammatory Phenotype

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    Lithium is an anti-psychotic that has been shown to prevent the hyperphosphorylation of tau protein through the inhibition of glycogen-synthase kinase 3-beta (GSK3β). We recently developed a mouse model that progresses from amyloid pathology to tau pathology and neurodegeneration due to the genetic deletion of NOS2 in an APP transgenic mouse; the APPSwDI/NOS2−/− mouse. Because this mouse develops tau pathology, amyloid pathology and neuronal loss we were interested in the effect anti-tau therapy would have on amyloid pathology, learning and memory. We administered lithium in the diets of APPSwDI/NOS2−/− mice for a period of eight months, followed by water maze testing at 12 months of age, immediately prior to sacrifice. We found that lithium significantly lowered hyperphosphorylated tau levels as measured by Western blot and immunocytochemistry. However, we found no apparent neuroprotection, no effect on spatial memory deficits and an increase in histological amyloid deposition. Aβ levels measured biochemically were unaltered. We also found that lithium significantly altered the neuroinflammatory phenotype of the brain, resulting in enhanced alternative inflammatory response while concurrently lowering the classical inflammatory response. Our data suggest that lithium may be beneficial for the treatment of tauopathies but may not be beneficial for the treatment of Alzheimer's disease

    Diverse inflammatory responses in transgenic mouse models of Alzheimer's disease and the effect of immunotherapy on these responses

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    While the presence of an inflammatory response in AD (Alzheimer's disease) is well known, the data on inflammation are conflicting, suggesting that inflammation either attenuates pathology, exacerbates it or has no effect. Our goal was to more fully characterize the inflammatory response in APP (amyloid precursor protein) transgenic mice with and without disease progression. In addition, we have examined how anti-Aβ (amyloid β-peptide) immunotherapy alters this inflammatory response. We have used quantitative RT–PCR (reverse transcription–PCR) and protein analysis to measure inflammatory responses ranging from pro-inflammatory to anti-inflammatory and repair factors in transgenic mice that develop amyloid deposits only (APPSw) and amyloid deposits with progression to tau pathology and neuron loss [APPSw/NOS2−/− (nitric oxide synthase 2−/−)]. We also examined tissues from previously published immunotherapy studies. These studies were a passive immunization study in APPSw mice and an active vaccination study in APPSw/NOS2−/− mice. Both studies have already been shown to lower amyloid load and improve cognition. We have found that amyloid deposition is associated with high expression of alternative activation and acquired deactivation genes and low expression of pro-inflammatory genes, whereas disease progression is associated with a mixed phenotype including increased levels of some classical activation factors. Immunotherapy targeting amyloid deposition in both mouse models resulted in decreased alternative inflammatory markers and, in the case of passive immunization, a transient increase in pro-inflammatory markers. Our results suggest that an alternative immune response favours retention of amyloid deposits in the brain, and switching away from this state by immunotherapy permits removal of amyloid

    Diversity of Poisonous Plants and their Antidotes, Affecting Ruminant Livestock Production on Rangelands in Ghana

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    The survival of the extensive livestock system, the practice for most farmers in the livestock industry in Ghana depends heavily on the natural pastures as forage resource. To efficiently use the rangelands, knowledge of the species composition, especially that of poisonous plants is essential. Documented knowledge in Ghana is scanty; documentation and dissemination of the knowledge resource would enable a wider access and wider benefit to stakeholders. A study was conducted in Ghana on poisonous plants with the aim to discover the existence and diversity of poisonous plants and associated antidotes affecting livestock for documentation and preservation of knowledge. 70 different items were cited; 22 were poisonous plants for which antidotes were not cited, 28 were poisonous plants with known antidotes and 32 antidotes. There were 575 citations of plants from 194 reported cases of suspected plant poisoning, categorized as poisonous plants for which no antidotes were cited (146), poisonous plants with cited antidotes (147) and antidotes (282). 50 plants species were identified and belonged to 29 plant families. Some plants were known only by local names. There was an extensive knowledge of the diversity of poisonous plants and antidotes within the ecological zones along with possible antidotes

    Can the Desiccation of Great Salt Lake be Stopped?

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    Great Salt Lake is a terminal lake, with its watershed in the Wasatch and Uinta Mountains of Utah, Wyoming and Idaho. Like all terminal lakes, the water inflows are balanced only by evaporative loss from its surface—when inflows decrease the lake shrinks until evaporation matches that inflow
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