1,721,024 research outputs found
Effects of age and muscle length parameters on single- versus multiple-joint lower-body strength expression
No full textThe elderly population of 65 years or greater is continuing to grow all over the world, with the majority experiencing at least one functional limitation for performing daily tasks. Researchers have then discovered age-related changes in neuromuscular physiology leads to muscle dysfunction that causes impaired mobility, thus making strength the primary measurement tool for muscular impairment. There is much research out there on age-associated changes in strength-related capacities through the use of isolated-joint testing protocols. However, the majority of human performance is heavily based off of multi-joint movements, such as getting out of a chair or walking. It is very possible that there are greater declines in strength across the lifespan than originally perceived from single-joint testing. Not to mention, traditionally most single-joint studies evaluated the maximal joint force/torque at a single optimal joint angle whereas, muscle force production is dependent upon the length of the muscle. The purpose of this study to examine the age related differences in single joint versus multi-joint testing at different muscle lengths. Approximately 20 healthy young participants (18-30 years) and 20 apparently healthy elderly participants (65-85 years) with no regular, structured exercise routine will be recruited through the local community to came into the lab for 2 visits 48-96 hours apart. The first visit involved the following: a) participants will be thoroughly screened to ensure all inclusion criteria are met, b) completion of all paperwork/questionnaires, and c) participants undergoing practice trials of all strength assessments. The second visit had the participants only perform the experimental strengths assessments via the Biodex System 3, Biodex Medical Systems, Shirley, NY, USA, Exerbotics Squat, Exerbotics, Tulsa, OK, USA; at random. Isometric testing was preformed at 90°, 60°, and 20° using a goniometer with participants performing 2 maximal voluntary contractions for the leg flexors and extensors. Those same positions were also applied to the squat machine with once again, participants doing 2 MVCs for each. The data was then examined using a three-way mixed factorial analyses of variance. There were no significant differences in height (P = 0.886) nor in body mass (P = 0.692). For all torque values, the young were stronger than the elderly. There were no significant interactions of Age x Mode x Angle for knee extensors (P = 0.337), the knee flexors (P = .947), and combination of them both (P =. 440). However, there were also no significant interactions of Age x Mode (P = 0.39), but in Mode x Angle (P <0.001) for knee extensors. For knee flexors there was only a significant interaction between Age x Mode (P <0.001). The combination of knee flexors and knee extensors only yielded a significant interaction of Mode x Angle (P<0.001).Follow up pair wise comparisons for knee extensors showed there was a significant difference between groups (P<0.001) and modality (P<0.001), but not angle (P = 0.101). The hamstrings had significant differences in the age groups (P<0.001), modality (P<0.001), and in the angle (P<0.001). When the average leg extensors and flexors were combined there were observations made in only the age groups (P<0.001) and in the modality (P = 0.013), but not in the angle (P = 0.60). In conclusion, there were not significant differences in all angles for a given modality and type of muscle group. However, it appears that angle does play a role on strength. Further research is needed to determine the role of aging on muscular strength
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
A correlational meta-analysis of the interaction between achievement goals and self-determination theory in sport, exercise, and physical education
No full textElliot’s achievement goals and hierarchal model of approach and avoidance and Self-Determination Theory (SDT) are two constructs empirically proven to be conducive to accurately researching motivation within sport, exercise, and physical education settings both independently and when studied concurrently. The purpose of this paper was to examine the relationships between the two theories in the aforementioned settings by conducting a meta-analytic review. A literature search was first performed to find relevant studies. Data analysis was performed using Comprehensive Meta-Analysis Version 2 software to compute the effect size, using sample weighted mean correlation, for each relationship between Elliot’s achievement goals and SDT. Separate analyses were run to examine any effects of age on the relationship between the two theories of motivation. Fifteen out of eighteen hypothesized relationships were statistically significant along with an additional five unpredicted relationships. Eleven relationships had significant differences in effect sizes for people < 18 years old compared with people ˃ 18 years old. The results were largely congruent with the extant literature. This review can serve as a guide to the processes behind motivation in sport, physical education, and exercise
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
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