1,720,965 research outputs found
Physical exercise in the elderly: Its effects on the motor and endocrine system
No full textAgeing is associated with reduced maximal aerobic power, muscle strength and power; namely, reduced fitness. Based on the existing evidence concerning exercise prescription for healthy adults, in 1990, the American College of Sports Medicine (ACSM) made the following recommendations: frequency of training: 3-5 days/-week, intensity: 60-90% HRmax, or 50-85%VO2max, duration: 20-60 min of continuous aerobic activity with involvement of large muscle groups. However, the target of improving/maintaining physical fitness is inappropriate for the whole elderly population, which includes the frail. In these subjects, the achievement of a better health status is certainly the primary goal, as recently stated by the 1996 Heidelberg guidelines. Physical activity should be prescribed on the basis of an individual health/fitness gradient with different goals. Lower levels of physical activity than those recommended by the ACSM may reduce the risk for certain chronic degenerative diseases and yet may not be of sufficient quantity or quality to improve VO2max. In the wake of these considerations and the inclusion of the improvement/maintaining of health status among the goals of exercise prescription in the elderly population, in 1991, the ACSM lowered the recommended exercise intensity to as low as 35-40%VO2max. One of the most critical consequences of ageing of the motor system is muscle weakness. Several causes may be held responsible for this phenomenon; among these sarcopenia is, probably, the most common. The latter involves both a decrease in muscle fibre size and number. However, atrophy cannot alone entirely account for senile muscle weakness. As a matter of fact, the maximum force that may be generated per muscle cross-sectional area (F/CSA) is lower in elderly subjects. This phenomenon suggests that muscular or neural factors, or more likely both, are involved. Another common cause for the decrease in F/CSA is muscle activation. Recent reports show incomplete quadriceps muscle activation in very old (80+) men and women. Since almost complete (95%) muscle activation was found in a population of subjects ∼70 year old, it seems that activation capacity rapidly falls beyond the 7th decade. Therefore, taken together, the above neural factors may account for large part of the decrease in force with ageing. Hormonal changes in themselves are not the simple explanation for all of the changes associated with ageing. Studying the effects of strength training on the endocrine system is complicated by a variety of factors related to both the exercise challenge itself and the accurate measurements of hormones. The measurement of hormonal changes is complicated by the manner in which they are released, transported and interact with the target tissue. Many hormones are released in a pulsatile manner with superimposed diurnal, monthly, and seasonal rhythms. They often exist in different molecular weight fractions and are frequently transported in a bound form. From the work that has been carried out in younger people it would appear, that if sufficient high resistance exercise is carried out, then the acute hormonal response is not qualitatively different to that following a bout of endurance exercise. Exercise training programs have been suggested as possible countermeasures against involutional bone loss, being able to prevent or reverse almost 1% of bone loss per year in both lumbar spine and femoral neck for both pre- and postmenopausal women. As far as elderly people are concerned, it appears that strength training may have a more beneficial effect than aerobic training on BMD, especially in postmenopausal women, although some evidence suggests that also aerobic training may improve BMD in the elderly. To date, the effect of physical activity on bone turnover has received limited attention despite the strict dependence of bone mass on the balance between bone formation and bone resorption. The equilibrium between these two components of bone turnover is crucial for bone mass and BMD, since bone loss, or increase, results from an uncoupling of bone formation and bone resorption. During the last few years there has been a rapid development of reliable methods to measure biochemical markers of bone metabolism. Since these markers reflect the cellular events, they may provide new opportunities to elucidate the effects of physical exercise on bone metabolism
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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