1,720,975 research outputs found
Approaches to the diagnosis and prevention of frailty
No full textAn individual who is living with frailty has impairments in homeostasis across several body systems and is more vulnerable to stressors that may ultimately predispose them to negative health-related outcomes, disability and increased healthcare use. Approximately a quarter of individuals aged > 85 years are living with frailty and as such the identification of those who are frail is a public health priority. Given that the syndrome of frailty is defined by progressive and gradual loss of physiological reserves there is much scope to attempt to modify the trajectory of the frailty syndrome via physical activity and nutritional interventions. In this review we give an up to date account on the identification of frailty in clinical practice and offer insights into physical activity and nutritional strategies that may be beneficial to modify or reverse the frailty syndrome
Understanding how we age: insights into inflammaging
No full textInflammaging is characterized by the upregulation of the inflammatory response that occurs with advancing age; its roots are strongly embedded in evolutionary theory.Inflammaging is believed to be a consequence of a remodelling of the innate and acquired immune system, resulting in chronic inflammatory cytokine production.Complex interrelated genetic, environmental and age-related factors determine an individual’s vulnerability or resilience to inflammaging. These factors include polymorphisms to the promoter regions of cytokines, cytokine receptors and antagonists, age-related decreases in autophagy and increased adiposity. Anti-inflammaging describes the upregulation of the hypothalamic-pituitary axis in response to inflammaging, leading to higher levels of cortisol, which in turn may be detrimental, contributing to less successful ageing and frailty. This may be countered by the adrenal steroid dehydroepiandrosterone, which itself declines with age, leaving certain individuals more vulnerable. Inflammaging and anti-inflammaging have both been linked with a number of age-related outcomes, including chronic morbidity, functional decline and mortality. This important area of research offers unique insights into the ageing process and the potential for screening and targeted interventions
Percutaneous muscle biopsy: history, methods and acceptability
Full text linkAdvances in histological, biochemical, physiological and molecular biological assays, as well as in microscopy and image analysis have allowed multiple analyses in muscle tissue. Muscle biopsy is invaluable in providing a definitive diagnosis of a wide range of myopathies (muscular dystrophies, glycogen storage diseases, inflammatory myopathies and congenital myopathies) and denervating disorders and gives important information on the course of the disease, informs treatment, disease stage as well as prognosis. Results of histopathological analyses should then be interpreted in context of the clinical history, examination and laboratory serum markers. Furthermore, access to muscle tissue provides the opportunity to assess morphological characteristics such as fibre composition, fibre cross sectional area and capillarisation (e.g. in ageing muscle) as well as mRNA, protein abundance and muscle enzyme activity . Ultrastructural analyses to gauge response to intervention can be performed as can studies of physiological characteristics of muscle such as single fibre contraction properties
Skeletal muscle morphology in sarcopenia defined using the EWGSOP criteria: findings from the Hertfordshire Sarcopenia Study (HSS).
No full textBACKGROUND: Sarcopenia is defined as the loss of muscle mass and function with age and is associated with decline in mobility, frailty, falls and mortality. There is considerable interest in understanding the underlying mechanisms. Our aim was to characterise muscle morphology changes associated with sarcopenia among community dwelling older men.METHODS: One hundred and five men aged 68-76 years were recruited to the Hertfordshire Sarcopenia Study (HSS) for detailed characterisation of muscle including measures of muscle mass, strength and function. Muscle tissue was obtained from a biopsy of the vastus lateralis for 99 men and was processed for immunohistochemical studies to determine myofibre distribution and area, capillarisation and satellite cell (SC) density.RESULTS: Six (6 %) men had sarcopenia as defined by the European Working Group on Sarcopenia in Older People (EWGSOP) criteria. These men had lower SC density (1.7 cells/mm(2) vs 3.8 cells/mm(2), p?=?0.06) and lower SC/fibre ratio (0.02 vs 0.06, p?=?0.06) than men without sarcopenia. Although men with sarcopenia tended to have smaller myofibres and lower capillary to fibre ratio, these relationships were not statistically significant.CONCLUSION: We have shown that there may be altered muscle morphology parameters in older men with sarcopenia. These results have the potential to help identify cell and molecular targets for therapeutic intervention. This work now requires extension to larger studies which also include women
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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