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The cadence that maximises power output developed at the crank by an individual cyclist is conventionally determined using a laboratory test. The purpose of this study was two-fold: (i) to show that such a cadence, which we call the optimal cadence, can be determined using power output, heart-rate, and cadence measured in the field and (ii) to describe methodology to do so. For an individual cyclist's sessions, power output is related to cadence and the elicited heart-rate using a non-linear regression model. Optimal cadences are found for two riders (83 and 70 revolutions per minute, respectively); these cadences are similar to the riders’ preferred cadences (82–92?rpm and 65–75?rpm). Power output reduces by approximately 6% for cadences 20?rpm above or below optimum. Our methodology can be used by a rider to determine an optimal cadence without laboratory testing intervention: the rider will need to collect power output, heart-rate, and cadence measurements from training and racing sessions over an extended period (>6 months); ride at a range of cadences within those sessions; and calculate his/her optimal cadence using the methodology described or a software tool that implements it.  相似文献   
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We are not free to choose whether anyone will learn about death, though we have some choice about how they will learn. The author discusses the basic questions that need to be answered in planning death education at any level, and the possible goals, in terms of cognitive gain, skills, and attitudinal objectives. Some principles in regard to teaching methods and evaluation are described, with illustrations from the experiences of medical students and others. It is important that the teacher should be able to deal with the problems that such programs may arouse. Cheap emotional arousal is easy to produce, but trivial, unless creatively used for a valued purpose and adequately resolved. Death is infinitely exploitable, and the growth of death voyeurism via "education" is alarming. The capacity to recognize and avoid being exploited or exploiting others must be one of our principle educational objectives.  相似文献   
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The purpose of the study was to examine the relationship of classroom environment to attitudes toward science and achievement in science among tenth grade biology students. An attitude instrument was administered at three times during the school year to measure student attitudes toward science and the classroom environment. The classroom environment measures examined six areas: emotional climate of the science classroom, science curriculum, physical environment of the science classroom, science teacher, other students in the science classroom, and friends attitudes toward science. Student achievement in science was measured by teacher reported semester grades. The results of the study indicated: (1) student attitudes toward the classroom environment predicted between 56 to 61% of the variance in attitudes toward science, (2) student attitudes toward the classroom environment predicted between 5 to 14% of the variance in achievement in science, (3) student attitudes toward science and attitudes toward the classroom environment predicted between 8 and 18% of the variance in achievement in science.  相似文献   
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Bullying is grounded in the interactions between an individual and complex social–ecological systems. Therefore, bullying involvement is not just confined to the classroom or school. Recent research suggests that sibling aggression may be a predictor for peer-level aggression. These findings may be more relevant for students with disabilities because studies suggest that students with disabilities are disproportionately involved in the bullying dynamic. Therefore, this study explored the intersection between sibling aggression and school belonging on bullying, victimisation and fighting for 14,508 students, including 1183 students with disabilities and 13,325 students without disabilities in grades 6 through 12. As hypothesised, students with disabilities reported higher levels of victimisation, bullying and fighting. Additionally, high levels of school belonging partially buffered fighting and bullying behaviours for students with and without disabilities. These findings demonstrate the importance of establishing an inclusive and safe environment for school-aged youth.  相似文献   
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Purpose

Metalloproteinases are a key component of the pathogenesis of abdominal hernias. Obesity is considered a risk factor in herniogenesis and hernia recurrence. The aim of this study was to evaluate the serum concentrations of metalloproteinase-2 (MMP-2), MMP-9, MMP-13, and adiponectin in morbidly obese and nonoverweight controls.

Materials and methods

The participants were recruited from among patients undergoing bariatric and non-bariatric surgery and divided into two groups: I (body mass index (BMI)≥35 kg/m2, n=40) and II (BMI<25 kg/m2, n=30). Serum concentrations of MMP-2, MMP-9, MMP-13, and adiponectin were measured using enzyme-linked immunosorbent assay (ELISA).

Results

A statistically significant difference between groups was observed for MMP-2 concentration. The median MMP-9 concentration was higher in the obese group, but the difference was not statistically significant. Median MMP-13 concentrations did not differ between groups. Serum adiponectin concentration was insignificantly higher in the non-obese group.

Conclusions

The elevated serum MMP-2 and MMP-9 concentrations in obese individuals may be related to the higher incidence of incisional hernias in this population.
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