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71.
Communication researchers and social scientists are quickly discovering the value of data that exists in the postings of members of Internet e-mail, Usenet, and real-time groups. The ability to communicate with one's peers, no matter how esoteric the interests, is causing an explosion in the number of new virtual communities. The interpersonal dynamics of these groups are increasingly coming under the scrutiny of academic research. The publicly available archived records of Internet virtual communities are being analyzed for a wide variety of research interests. The ability to do naturalistic observations of group dynamics, as they are exhibited in these exchanges of text, has captured the attention of many researchers. The institutional review boards of major universities are granting researchers exempt or expedited (exempt from full review) status for this work, due to the public nature of the notes being analyzed. These studies often involve the lack of informed consent, where the group members under study are unaware they are being monitored. There is a potential for psychological harm to the members of these groups, depending on the way results are reported. This article explores the ethical considerations that must be taken into account to protect cyberspace participants. The guidelines proposed are based on the American Psychological Association ethical guidelines for use of human subjects in research. An explanation is offered as to how such guidelines can best be applied to the study of Internet communities. The constructs of Group Accessibility (the public/private nature of the actual cyberspace occupied by a group) and Perceived Privacy (the level of privacy that group members assume they have) are defined and proposed as two dimensions by which individual Internet communities may be evaluated in order to assure the ethical reporting of research findings.  相似文献   
72.

Objective

We sought to determine the incidence, clinical features, and demographic profile of head injury secondary to suspected child maltreatment (abuse or neglect) in Canada to help inform the development and evaluation of prevention programs for abusive head injuries.

Methods

From March 1, 2005 to February 28, 2008, an average of 2,545 paediatricians and paediatric subspecialists were surveyed monthly through the established network of the Canadian Paediatric Surveillance Program. We calculated incidence rates using the number of confirmed cases over the product of the duration of the study (3 years) and population estimates by age group.

Results

There were 220 confirmed cases of head injury from suspected child maltreatment. The annual incidence rate was 14.1 per 100,000 for children less than 1 year of age and 1.4 per 100,000 for those less than 15 years. Seventy three percent (141) of cases involved infants less than 12 months of age and 52% (100) of cases involved infants less than 6 months of age. Seventy-five percent (165) of cases presented to the emergency room. With regard to outcome, 12% (27) of cases resulted in death and 45% (75) of survivors had neurological sequelae at discharge. Thirty percent (67) of all cases, as well as 30% (8) of deaths were previously known to child welfare authorities.

Conclusion

This study provides an estimate of the rate of head injury secondary to suspected child maltreatment in Canada. The young age and poor medical outcomes of those involved highlights the need for prevention efforts that are implemented early in life. Given that a significant percentage of injured infants and children were already known to child welfare authorities, the study also highlights the need to establish and evaluate additional preventive efforts for parents and caregivers already in the child welfare system.  相似文献   
73.
Research on categories and markets suggests that audiences rely on categorical distinctions to make sense of market offerings. Market offerings that deviate from category norms risk devaluation. Although literature in this area has led to valuable insights, scholars have begun to question whether there has been an overemphasis on conformity, leaving existing theories ill-equipped to account for innovation. Within this context, we argue that research on authenticity in cultural sociology offers a useful platform for theorizing. We draw on the work of Peterson (1997), who underscores the importance of signals in evaluation. Objective features of market offerings (e.g., quality) matter, but particularly for innovations, these features are not readily visible. Because authentic producers are typically thought to be more committed, capable, and intrinsically motivated, when visibility of such objective features is lacking, authenticity may serve as an alternative indicator of value. Appearing authentic requires signaling believability with respect to category norms, while also being distinctive. Using data on 684 firms from five high technology sectors, we explore the relationship between authenticity and investor perceptions of value. Focusing on three different proxies for signals of authenticity—networks, governance, and narratives—we find a curvilinear association between conformity/distinctiveness and Tobin's q. Consistent with our view of authenticity as a signal, we also find that this relationship flattens as firms gain better track records and face stiffer competition.  相似文献   
74.
A subject-specific angle-driven computer model of a tennis player, combined with a forward dynamics, equipment-specific computer model of tennis ball-racket impacts, was developed to determine the effect of ball-racket impacts on loading at the elbow for one-handed backhand groundstrokes. Matching subject-specific computer simulations of a typical topspin/slice one-handed backhand groundstroke performed by an elite tennis player were done with root mean square differences between performance and matching simulations of < 0.5 degrees over a 50 ms period starting from ball impact. Simulation results suggest that for similar ball-racket impact conditions, the difference in elbow loading for a topspin and slice one-handed backhand groundstroke is relatively small. In this study, the relatively small differences in elbow loading may be due to comparable angle-time histories at the wrist and elbow joints with the major kinematic differences occurring at the shoulder. Using a subject-specific angle-driven computer model combined with a forward dynamics, equipment-specific computer model of tennis ball-racket impacts allows peak internal loading, net impulse, and shock due to ball-racket impact to be calculated which would not otherwise be possible without impractical invasive techniques. This study provides a basis for further investigation of the factors that may increase elbow loading during tennis strokes.  相似文献   
75.
This paper presents a novel sensor technology to deduce the dynamics of a bowling ball. The sensor, a miniature wireless inertial measurement unit (IMU), incorporates MEMS accelerometers and angular rate gyros, a microcontroller, a low power RF transceiver, and a rechargeable battery. When embedded in a bowling ball, the IMU transmits the acceleration and angular velocity data that define the dynamics of the ball starting with the bowler’s delivery and its motion in the lane. Example results from professional bowlers illustrate how this technology can be used to assess bowler skill and ball performance. For instance, the IMU accurately measures the spin dynamics of the ball which are crucial to develop the ball “hook.” An analysis of ball dynamics in the lane is distilled to a measurable “hook potential” metric for further assessing bowler skill. Finally, the sensor presented herein is believed to be the world’s smallest, wireless IMU. This highly miniaturized and wireless design will enable parallel training systems for many sports, including basketball, baseball, crew, cricket, golf, fly fishing, soccer, softball, tennis, rowing, among others.  相似文献   
76.
罗素·麦金龙 《游泳》2011,(6):I0024-I0025
女子水球半决赛之后,马欢欢倒在游泳池边上。所有人都在想在上海举行的决赛上会不会缺席这位最出色的选手。但是,尽管处于昏迷的边缘,马欢欢仍然努力去控制痛苦与喜悦。她的两次进球和巨大贡献,为中国赢得了参加决赛的资格,也使自己成为世锦赛上最有价值的选手。  相似文献   
77.
When using a driver, the centre of pressure of a golfer shows a pattern that is characteristic of one of two distinct swing styles: the "front foot" style or the "reverse" style. The aim of this study was to establish whether these two swing styles are also evident when using other clubs, and if so, to determine whether golfers use the same swing style when using different clubs. Forty-six professional, amateur, and recreational golfers performed swings to hit a ball into a net placed 3 m away. Ten swings were performed for each of the driver, 3-iron, and 7-iron while standing on two force plates. The position of the golfer's centre of pressure parallel with the line of shot and relative to the feet was quantified at eight swing events that were identified from 200-Hz video. Cluster analysis confirmed that the front foot and reverse styles were evident in all three clubs, and most of the golfers (96%) used the same swing style for all three clubs. Golfers that used the reverse swing positioned their centre of pressure nearer to their toes at ball contact compared with golfers that used the front foot swing.  相似文献   
78.
This paper describes 3 language learning approaches common in many urban and rural Ojibwe communities, as well as the ideologies of endangerment that drive and sustain them. Drawing from collaborative language revitalization work with teachers, learners, and community leaders, we analyze some of the teaching and learning practices that lead to the common mismatch between language learner goals and expectations, on the one hand, and the outcomes of language learning, on the other. We outline how these 3 approaches to language learning relate to cultural identities and place-based notions of authenticity as well as to current findings in the field of second language acquisition. We then profile 2 speakers who have learned Ojibwe successfully as adults to illustrate how their success was possible largely because they were able to engage with the Ojibwe language in interactive ways that run counter to common language learning approaches. We suggest that for language revitalization efforts, and individual learners, to experience higher levels of success, greater attention needs to be paid to how ideologies of endangerment impact language learning approaches.  相似文献   
79.
Instructors of sexual health courses in rural areas face unique challenges as they are often forced to use school-based prevention curricula field-tested in urban areas. Research has yet to consider what future sex educators’ regional expectations are for their profession and how those expectations might have an impact on the classroom. Drawing from interviews with 26 sex-educators-in-training, we find that future educators tended to expect that rural communities would be less diverse, more conservative, and less informed about sexual health matters, even though research demonstrates that today's rural communities inconsistently align with those perceptions.  相似文献   
80.
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