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261.
Large impact loading with abnormal muscle activity and motion patterns may contribute to lower extremity injuries in ballet dancers. Yet, few studies investigated the influence of injury on the ballet movement. The purpose of this study was to find the neuromuscular and biomechanical characteristics in dancers with and without ankle injury during a jump-landing Sissonne Fermée task. Twenty-two ballet dancers were recruited and divided into the injured group (n = 11) and the uninjured group (n = 11). They performed a ballet movement called "Sissonne Fermée" with reflective markers and electrodes attached to their lower extremities. Ground reaction force, joint kinematics, and muscle activity were measured. The injured dancers had greater peak ankle eversion but smaller hindfoot-to-tibial eversion angles. Also, the injured dancers had greater activity of the hamstring of the dominant leg and tibialis anterior of the non-dominant leg during the pre-landing phase. The injured dancers had greater tibialis anterior activity of the dominant leg but less muscle activity in the medial gastrocnemius of the non-dominant leg during the post-landing phase. The injured dancers had a greater co-contraction index in the non-dominant ankle and a lower loading rate. The higher co-contraction indices showed that the injured dancers required more muscle effort to control ankle stability. Furthermore, the injured dancers used a "load avoidance strategy" to protect themselves from re-injury. Neuromuscular control training of the ankle joint for ballet dancers to prevent injury is necessary.  相似文献   
262.
In this study, we examined National Board certified physical education teachers' (NBCPETs) perceptions of change as a result of certification. Randomly selected NBCPETs (65; women = 53, men = 12) were interviewed. Analysis was done through the lens of Lawson's (1989) Model of the interactive factors Influencing workplace conditions for the Physical Education Teacher Several themes connected to teachers' views of themselves as NBCPETs surfaced. In particular more teaching reflection and a greater focus on student learning and assessment, including an increased emphasis on individualizing teaching were described. An elevation in their perceived status and credibility and expanded opportunities within the educational community also emerged. Alternatively, several NBCPETs explained that the certification process had little or no effect on their teaching  相似文献   
263.
In recent years, more and more point-to-point communication systems involve simultaneous transmission of multiple sources of human perceptual data over a single communication medium. For example, in a teleoperation system or a telerobotic system, streams of video, audio, and haptic data need to be sent from a field place to a remote human operator. Each type of data demands a certain range of transmission rate. This creates conflicts among these data when the available bandwidth is limited.In this paper we study the bandwidth allocation for multiple sources of human perceptual data transmitted over a rate-limited communication channel. We aim to maximize the overall user satisfaction in the data transmission, and formulate an optimization problem for the bandwidth allocation. Using either the logarithmic or exponential form of human perceptual satisfaction function, we are able to derive closed-form solutions for the optimization problem. We show that the optimal bandwidth allocation for each type of data is piecewise linear with respect to the total available bandwidth.  相似文献   
264.
The purposes of this study were (1) to determine the functional swing plane (FSP) of the clubhead and the motion planes (MPs) of the shoulder/arm points and (2) to assess planarity of the golf swing based on the FSP and the MPs. The swing motions of 14 male skilled golfers (mean handicap = -0.5 +/- 2.0) using three different clubs (driver, 5-iron, and pitching wedge) were captured by an optical motion capture system (250Hz). The FSP and MPs along with their slope/relative inclination and direction/direction of inclination were obtained using a new trajectory-plane fitting method. The slope and direction of the FSP revealed a significant club effect (p < 0.001). The relative inclination and direction of inclination of the MP showed significant point (p < 0.001) and club (p < 0.001) effects and interaction (p < 0.001). Maximum deviations of the points from the FSP revealed a significant point effect (p < 0.001) and point-club interaction (p < 0.001). It was concluded that skilled golfers exhibited well-defined and consistent FSP and MPs, and the shoulder/arm points moved on vastly different MPs and exhibited large deviations from the FSP. Skilled golfers in general exhibited semi-planar downswings with two distinct phases: a transition phase and a planar execution phase.  相似文献   
265.
It is a challenge to confirm chronic mesenteric ischemia (CMI) as a cause of gastrointestinal (Gl) symptoms such as postprandial epigastric bloating,anorexia,and debilitating weight loss.Endovascular intervention for CMI has been gaining popularity because of the high morbidity associated with surgical revascularization.However,in EVI for superior mesenteric artery (SMA) occlusion,the transfemoral approach is limited by difficulty in coaxial alignment of the guiding catheter,which leads to insufficient back-up support.Herein,we report on a 58-year-old male patient with chronic total occlusion of the SMA,which was successfully revascularized by endovascular intervention via the left radial artery.Transradial endovascutar therapy may be another treatment option for the treatment of CMI.  相似文献   
266.
Cancer metastasis to the thyroid is extremely rare. The more commonly reported primary sites for metastasis to the thyroid are the kidney, breast, lung, colon, esophagus, and uterus. Thyroid metastasis from the stomach has only been reported in three cases. Herein, we report a 71-year-old man presenting with bilateral thyroid multinodular lesions. Bilateral near-total thyroidectomy was performed due to airway compression with related symptoms. Wedge resection of a suspicious pulmonary nodule, detected on CT, was performed for diagnosis. Polypoid lesions in the stomach were examined by trans-scopic biopsy. Poorly differentiated adenocarcinomas with the same histological profiles were noted at these three sites. The immunohistochemical staining for thyroglobulin of these specimens was negative. We conclude that a new thyroid mass appearing in a patient with present or prior malignancies should raise the concern of metastatic disease.  相似文献   
267.
Seventy-six librarians participated in a series of focus groups in support of research exploring the skills, knowledge and attributes required by the contemporary library and information professional in a world of ever changing technology. The project was funded by the Australian Learning and Teaching Council. Text mining data analysis revealed three main thematic clusters (libraries, people, jobs) and one minor thematic cluster (community). Library 2.0 was broadly viewed by participants as being about change whilst librarian 2.0 was perceived by participants as not a new creation but just about good librarian practices. Participants expressed the general belief that personality traits, not just qualifications, were critical to be a successful librarian or information worker in the future.  相似文献   
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There is limited research on quantitative differences between men and women’s experiences in doctoral programs. We aim to fill that gap by sharing findings from a web-based exploratory survey of perceived gender differences on quality mentoring in educational leadership doctoral programs. According to survey results, there is limited statistical significance in terms of gender differences in programmatic supports and scholarly progress. However, women experience feelings of self-doubt due to negative experiences with advising and mentoring, including difficulties making connections to a quality mentor. Furthermore, both female and male participants shared common definitions of what constitutes quality mentorship and believed mentorship was important, but lacking in varying degrees. Finally, all participants agreed that their educational leadership preparation programs should provide additional support in terms of writing and research development. Participants also shared important recommendations for strengthening mentoring experiences as well as future research methods and foci.  相似文献   
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