1,230 research outputs found
A patterning process utilizing a nanoimprint lithography for fabrication of planar perpendicular patterned magnetic media
This thesis describes the results of applied research in the area of patterned magnetic media. Current magnetic media is pushing the physical limits of magnetic bits by compressing them into very small spaces - a process that will eventually be hampered by the superparamagnetic effect. The superparamagnetic effect will require the magnetic media industry to find a modified method of storing magnetic bits. Perpendicular patterned magnetic media could be the method of choice for future generations of magnetic data storage. Patterning magnetic media allows bits to be stored in isolated magnetic islands instead of in a continuous magnetic surface, as is currently the case. Separating the bits increases signal to noise ratio and bit density at the same time. As the first step in fabricating patterned magnetic media, this research demonstrates the ability to pattern a 60 nanometer thick film of polymethyl methacrylate (PMMA) into 45 nanometer high pillars with a density correlating to 258 Gbits/in2over a 100 μm2 area
COMPARISON OF SKINFOLD AND BIOELECTRICAL IMPEDANCE ANALYSIS WITH DUAL-ENERGY X-RAY ABSORPTIOMETRY FOR BODY COMPOSITION ANALYSIS IN COLLEGE STUDENTS
Dual-energy x-ray absorptiometry (DXA) can provide precise measurement of soft tissue composition with minimal radiation exposure. However, having access to DXA is very costly and limited, and other noninvasive and more accessible techniques such as bioelectrical impedance analysis (BIA) and skinfold measurements are commonly used by clinicians. The purpose of this study was to compare body composition examined with BIA and 3-sites skinfold analysis to the results examined with DXA, and develop body fat prediction equations for BIA and skinfold measurements, using DXA data as the criterion Design: Cross sectional. Subjects: Sixty three college age students (28 male, 35 female) aged 18 to 27 participated in the study. Results: Body fat percentage measured with DXA is significantly higher than those measured with skinfold (p = .01) and BIA (p = .01). However, body fat percentage measured with DXA is highly correlated with those measured with skinfold (r = .895; p = .01) and BIA (r = .875; p = .01). The DXA criterion regression equations were created for skinfold and BIA: DXA%BF=4.65 + 0.43 * S3SF (sum of 3 site skinfold); DXA%BF=3.79 + 1.09 * BIA%BF. The new regression equations were further validated using 75/25% subjects cross validation. Conclusion: Skinfold and BIA measurements significantly underestimate body fat percentage compared to DXA in healthy college students. Adjustments are necessary to accurately predict body fat percentage when using skinfold or BIA at a clinical setting. To accommodate the higher body fat percentage measured with the gold standard such as DXA, the results from this study suggest the need for the current %BF standards and norms for healthy young adults to be adjusted upward
A multi-component assessment model for monitoring training distress among athletes
We report the initial validation of a multi-component assessment model for monitoring training distress among athletes. The model combines measures of mood disturbance with measures of perceived stress and symptom intensity. Altogether, 492 athletes completed the 10-item Perceived Stress Scale (PSS-10; Cohen et al., 1983), the 24-item Brunel Mood Scale (BRUMS; Terry et al., 2003), and a checklist of 19 symptoms associated with acute overtraining (Fry et al., 1994). Six training distress factors were identified by an exploratory factor analysis: ‘‘depressed mood’’, ‘‘perceived vigour’’, ‘‘physical symptoms’’, ‘‘sleep disturbance’’, ‘‘perceived stress’’, and ‘‘general fatigue’’. Comparisons of group means of these factors with a previously validated inventory were consistent with theoretical predictions and provided evidence of construct validity. Internal consistency of the subscales was also confirmed, with Cronbach alphas ranging from 0.72 to 0.86. Together, these findings suggest that this multi-component model provides a sound conceptual basis for the assessment of training distress among athletes.<br /
Perceptions of five-year competitive categories: Model of how relative age influences competitiveness in Masters sport
The purpose of this study was to examine the contrasting perceptions of masters swimmers related to the first and fifth constituent years of a 5-year age category. Swimmers aged between 35 and 93 years (154 male, 184 female) were surveyed at the 2008 FINA World Masters Championships. Exploratory factor analysis indicated the existence of the following five factors considered important for preparation, attendance, and success at masters competitions: awareness of advantages, expectancy, motivation, training, and physiological capacity. One sample ttests showed that masters swimmers are conscious of advantages that 5-year age categories afford to relatively-younger cohorts (i.e., those who are in the first year of any age category). They also perceive that, in the first compared to the fifth year of an age category, they have greater physiological capacity, engage in more training, have higher expectations to perform well, and are more motivated (all ps \u3c.001). Findings point to perceived psycho-social and physical factors that potentially explain why relatively younger masters athletes are more likely to perform better and to participate in masters competitions than relatively older masters athletes
A Process-oriented Measure Of Habit Strength For Moderate-to-vigorous Physical Activity
Habitual action is an important aspect of health behaviour, but the relevance of various habit strength indicators continues to be debated. This study focused specifically on moderate-to-vigorous physical activity (MVPA) and evaluated the construct validity of a framework emphasizing patterned action, stimulus-response bonding, automaticity, and negative consequences for nonperformance as indicators of habit strength for this form of exercise. Methods: Upper-level undergraduates (N = 124) provided demographic information and responded to questionnaire items assessing historical MVPA involvement, current MVPA involvement, and the four proposed habit strength dimensions. Factor analyses were used to examine the latent structure of the habit strength indicators, and the model’s construct validity was evaluated via an examination of relationships with repetition history and current behaviour. Results: At a measurement level, findings indicated that the proposed four-component model possessed psychometric integrity as a coherent set of factors. Criterion-related validity was also demonstrated via significant changes in three of the four factors as a function of past involvement in MVPA and significant correlations with the frequency, duration, and intensity of current MVPA. Conclusions: These findings support the construct validity of this exercise habit strength model and suggest that it could provide a template for future research on how MVPA habits are developed and maintained
Stressors, Recovery Processes, and Manifestations of Training Distress in Dance
Abstract Dancers are expected to maintain consistently high levels of performance capability and to perform on demand. To meet these expectations, they subject their bodies to long hours of intensive physical training. Such training regimens are often combined with tight rehearsal and performance schedules, which over time, can lead to persistent fatigue, psychological distress, performance decrements, and injury. A similar process has been observed as a consequence of high-intensity training in many different sports, and considerable sport-related research has been devoted to identifying the antecedents, the symptoms that are experienced, and the most cost-effective ways of monitoring symptom development. This paper presents a general heuristic framework for understanding this “training distress process” and discusses the framework with specific reference to dance
Suspended sediment regimes in contrasting reference-condition freshwater ecosystems:Implications for water quality guidelines and management
Tillage and Subsoiling Effects on Soil Compaction and Yield of Burley Tobacco
Historically, tobacco producers have relied heavily on surface tillage to prepare fields for transplanting. This typically involved moldboard plowing, followed by several secondary tillage operations, such as discing then leveling with a soil finisher. Transplanter developments and modifications in the late 1990’s, coupled with new chemicals for weed control, made no-till (NT) tobacco a viable option for tobacco producers in Kentucky (KY)
An Experimental Reef Program to Test Designs of an Artificial Reef for Kelp Mitigation
An artificial reef is being planned to mitigate alleged losses of giant kelp and the invertebrate and fish communities associated with a kelp bed. The project\u27s first step was to initiate comprehensive siting and design studies. A 25-yr time series of kelp surface canopy maps for a 100 km reach of coastline was entered into a GIS database and analyzed in conjunction with geotechnical and human-use information to define ecologically favorable and acceptable sites in the general area. A site was chosen near an area that appeared most promising in the primary study area. This study\u27s field work determined that the design of the mitigation reef will not be straightforward and that an experimental phase to test various designs needs to be performed. We recommend that a low relief (0.5-1.5 m) reef with relatively high exposure to sand scour and occasional, partial burial be constructed in order to promote the establishment of kelp. Scattered rock and broken concrete at three different density spreads (17, 34, and 67%) on the bottom will be tested. This study has revealed that existing artificial reefs have not typically sustained a persistent kelp bed. This fact, therefore, makes the Phase I experiment even more critical than originally thought
Account-making: A model for understanding and resolving distressful reactions to retirement from sport
In this paper, we examine the account-making model of Harvey, Weber, and Orbuch(1990) as a framework for understanding negative reactions to retirement from competitive sport. Theoretical aspects of the model are first summarized, and a case study is then presented to illustrate the central role of account-making in the adjustment process for an Olympic gold medallist. We conclude by suggesting ways that sport psychology consultants can facilitate account-making and thereby help athletes to cope with distressful reactions to retirement
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