13,197 research outputs found
An application of interactive computer graphics technology to the design of dispersal mechanisms
Interactive computer graphics technology is combined with a general purpose mechanisms computer code to study the operational behavior of three guided bomb dispersal mechanism designs. These studies illustrate the use of computer graphics techniques to discover operational anomalies, to assess the effectiveness of design improvements, to reduce the time and cost of the modeling effort, and to provide the mechanism designer with a visual understanding of the physical operation of such systems
TRIDENT 1 third stage motor separation system
The third stage engine separation system has shown through test and analysis that it can effectively and reliably perform its function. The weight of the hardware associated with this system is well within the targeted value
Processing irrelevant location information: practice and transfer effects in a Simon task.
How humans produce cognitively driven fine motor movements is a question of fundamental importance in how we interact with the world around us. For example, we are exposed to a constant stream of information and we must select the information that is most relevant by which to guide our actions. In the present study, we employed a well-known behavioral assay called the Simon task to better understand how humans are able to learn to filter out irrelevant information. We trained subjects for four days with a visual stimulus presented, alternately, in central and lateral locations. Subjects responded with one hand moving a joystick in either the left or right direction. They were instructed to ignore the irrelevant location information and respond based on color (e.g. red to the right and green to the left). On the fifth day, an additional testing session was conducted where the task changed and the subjects had to respond by shape (e.g. triangle to the right and rectangle to the left). They were instructed to ignore the color and location, and respond based solely on the task relevant shape. We found that the magnitude of the Simon effect decreases with training, however it returns in the first few trials after a break. Furthermore, task-defined associations between response direction and color did not significantly affect the Simon effect based on shape, and no significant associative learning from the specific stimulus-response features was found for the centrally located stimuli. We discuss how these results are consistent with a model involving route suppression/gating of the irrelevant location information. Much of the learning seems to be driven by subjects learning to suppress irrelevant location information, however, this seems to be an active inhibition process that requires a few trials of experience to engage
Implications of skeletal muscle loss for public health nutrition messages:a brief report
Age-related skeletal muscle loss, sarcopenia, cachexia and wider malnutrition (under nutrition) are complex in aetiology with interaction of clinical, social and economic factors. Weight loss and loss of skeletal muscle mass in older people are associated with increased morbidity and mortality with implications for increasing health and social care costs. There is insufficient evidence to identify the ideal treatment options. However, preventing weight loss and loss of skeletal muscle in older age will be keys to reducing morbidity and mortality. This will require all those coming into contact with older people to identify and address weight loss early, including through diet, improving physical activity and increasing social interaction. Public health messages on diet should, in the main, continue to focus on older people achieving current UK dietary recommendations for their age as visually depicted in the eatwell plate together with associated messages regarding dietary supplements where appropriate
Adapting to variable prismatic displacement
In each of two studies, subjects were exposed to a continuously changing prismatic displacement with a mean value of 19 prism diopters (variable displacement) and to a fixed 19-diopter displacement (fixed displacement). In Experiment 1, significant adaptation (post-pre shifts in hand-eye coordination) was found for fixed, but not for variable, displacement. Experiment 2 demonstrated that adaptation was obtained for variable displacement, but it was very fragile and is lost if the measures of adaptation are preceded by even a very brief exposure of the hand to normal or near-normal vision. Contrary to the results of some previous studies, an increase in within-S dispersion was not found of target pointing responses as a result of exposure to variable displacement
Neuromuscular control of wingbeat kinematics in Anna's hummingbirds (Calypte anna)
Hummingbirds can maintain the highest wingbeat frequencies of any flying vertebrate – a feat accomplished by the large pectoral muscles that power the wing strokes. An unusual feature of these muscles is that they are activated by one or a few spikes per cycle as revealed by electromyogram recordings (EMGs). The relatively simple nature of this activation pattern provides an opportunity to understand how motor units are recruited to modulate limb kinematics. Hummingbirds made to fly in low-density air responded by moderately increasing wingbeat frequency and substantially increasing the wing stroke amplitude as compared with flight in normal air. There was little change in the number of spikes per EMG burst in the pectoralis major muscle between flight in normal and low-density heliox (mean=1.4 spikes cycle^(–1)). However the spike amplitude, which we take to be an indication of the number of active motor units, increased in concert with the wing stroke amplitude, 1.7 times the value in air. We also challenged the hummingbirds using transient load lifting to elicit maximum burst performance. During maximum load lifting, both wing stroke amplitude and wingbeat frequency increased substantially above those values during hovering flight. The number of spikes per EMG burst increased to a mean of 3.3 per cycle, and the maximum spike amplitude increased to approximately 1.6 times those values during flight in heliox. These results suggest that hummingbirds recruit additional motor units (spatial recruitment) to regulate wing stroke amplitude but that temporal recruitment is also required to maintain maximum stroke amplitude at the highest wingbeat frequencies
Incivility in the Workplace: The Experiences of Female Sport Management Faculty in Higher Education
Access to higher education for women has dramatically increased in the United States during the past 50 years. Female college graduates have reversed the figures and gone from being outnumbered by their male counterparts 3 to 2 in the 1970s, to now outnumbering male college graduates 3 to 2. Women also graduate from masters and doctoral programs at a higher rate than men.
However, increases in the number of women obtaining college and advanced degrees has not translated to comparable representation in faculty positions or leadership roles in higher education. This lack of women in leadership positions, as well as perceived discrimination against female faculty, may be even more of a concern in sport management programs. Sport is considered a male domain, and women are often seen as intruders in this realm.
The purpose of this study was to examine the manifestation of incivility from colleagues and superiors experienced within a sample of female sport management faculty members utilizing social identity theory as a guiding framework. Incivility was conceptualized for the current study as deviant behavior that is not necessarily intended to physically harm the target (e.g., belittling others, showing disdain to someone while they are talking, engaging in outside tasks during meetings)
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The Social Science of Democracy?
Alexis de Tocqueville is surely one of the most widely cited, discussed, and celebrated political theorists in the world. Jon Elster's book, Alexis de Tocqueville: the First Social Scientist proceeds from a provocative premise: that Tocqueville's major works were lacking in “system” and were “hugely incoherent,” and that Tocqeuville himself “was not a major political thinker” (xi). Elster argues that instead Tocqueville ought to be viewed as a penetrating historical sociologist and an exemplary social scientist who might well be considered the first true social scientist. Elster's argument is important for at least two reasons: first, because it offers a striking and challenging reading of Tocqueville; and second, because it expands on Elster's own contributions in the philosophy of social science, and develops interesting understandings of “causal mechanisms,” methodological individualism, and social explanation more generally. As Elster writes in his Introduction, “the main task of this book is to argue for the relevance of Tocqueville for social science in the twenty-first century (p. 5).” The purpose of this Perspectives symposium is to assess Elster's argument in broad terms. What are the strengths and limits of Elster's reading of Tocqueville? How ought we to assess Elster's understanding of Tocqueville's deficiencies as a “political theorist?” What is the relevance of Tocqueville for contemporary social science? And, most importantly, what are the challenges and possible trajectories facing social science in the twenty-first century, and to what extent does Elster's essay point us in the right direction?—Jeffrey C. Isaac, EditorGovernmen
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