Oxygen uptake during mini trampoline exercise in normal-weight,endurance-trained adults and in overweight-obese,inactive adults: A proof-of-concept study

Objectives: To examine cardiorespiratory exertion during mini trampoline exercises of different intensities in both endurance-trained athletes and overweight-obese adults. Methods: Physically healthy participants (Group A: normal-weight, endurance-trained athletes; Group B: inactive, overweight-obese adults) participated in two measurement appointments and three training sessions in between appointments, in which participants familiarized themselves with the use of the mini trampoline and the execution of the exercises. The primary outcome was the ?O_2peak for each of the six mini trampoline exercises relative to the ?O_2peak as established during an all-out exercise test on a bike ergometer during the first measurement appointment. Secondary outcomes were average ?O₂ as well as maximum and average heart rate. Results: The six mini trampoline exercises generated ?O_2peak values between 42% and 81% in the endurance-trained athletes and between 58% and 87% in the overweight-obese participants, both in relation to the bike ergometer ?O_2peak. Average ?O₂ values ranged from 35% to 69% (endurance-trained athletes) and from 48% to 71% (overweight-obese participants), depending on exercise. Average heart rate likewise lay in a range that can be categorized as moderate-to-vigorous aerobic exercise for both groups. A moderate-to-strong correlation (0.658 to 0.875, depending on exercise) between bike ergometer ?O_2peak and mini trampoline ?O_2peak was found for all six exercises. Conclusions: Mini trampoline exercise has the potential to produce training intensities that concur with established exercise guidelines. The exercise intensity is self-adjusting and allows for an effective and safe workout for different users with a wide range of fitness levels.     

Participation in organized sports,physical education,therapeutic exercises,and non-organized leisure-time physical activity: how does participation differ between childhood cancer outpatients and healthy peers?

Most childhood cancer survivors are insufficiently active. Researchers are focusing on strategies to increase physical activity (PA). However, a detailed understanding of participation in specific types of PA is missing, meaning current strategies may lack relevant information. Thus, our study sought to analyze participation in different types of PA commonly engaged in by children: organized sports, physical education in school (PES), therapeutic exercise, and non-organized leisure-time PA. Thirty-eight childhood cancer outpatients and 51 healthy children completed questionnaires. Compared to healthy children, childhood cancer outpatients, especially those who are shortly after cessation of inpatient treatment, participated significantly less often in organized sports and PES and significantly more often in therapeutic exercise compared to the healthy children. Considering organized sports and PES afford children unique social benefits and provide the potential to motivate lifelong activity, future efforts should be placed on ensuring children with cancer can access these types of PA. Educating parents, teachers, and coaches, exploring referral pathways to exercise professionals and providing individual support may enhance participation rates in organized PA and should be investigated.     

POLITICAL KNOWLEDGE, ATTRIBUTION, AND INFERRED INTEREST IN POLITICS: THE OPERATION OF BUFFER ITEMS

Bishop (1987) observed that being unable to answer a politicalknowledge question decreased self-reported interest in publicaffairs. This effect was unaffected by the introduction of upto 101 unrelated buffer items. In contrast, a single bufferitem that provided respondents with an external explanationfor their lack of knowledge greatly reduced the context effectin the present study. Implications for the operation of bufferitems are discussed.     

CONFIDENTIALITY ASSURANCES IN SURVEYS: REASSURANCE OR THREAT?

Over the last three decades, the public's willingness to takepart in surveys has gradually declined, and the decline hasbeen attributed in part to increasing concern about the confidentialityof the data requested. This paper reviews the early literaturebearing on confidentiality assurances and willingness to respond,and then reports on three experiments designed to investigatethe effects of confidentiality on the expectations of respondentsand on their willingness to take part in a survey. The resultsof all three experiments confirm our expectation that confidentialityassurances are not always perceived as reassuring, and do notnecessarily increase the public's willingness to respond.     

The optimum clustering framework: implementing the cluster hypothesis

Document clustering offers the potential of supporting users in interactive retrieval, especially when users have problems in specifying their information need precisely. In this paper, we present a theoretic foundation for optimum document clustering. Key idea is to base cluster analysis and evalutation on a set of queries, by defining documents as being similar if they are relevant to the same queries. Three components are essential within our optimum clustering framework, OCF: (1) a set of queries, (2) a probabilistic retrieval method, and (3) a document similarity metric. After introducing an appropriate validity measure, we define optimum clustering with respect to the estimates of the relevance probability for the query-document pairs under consideration. Moreover, we show that well-known clustering methods are implicitly based on the three components, but that they use heuristic design decisions for some of them. We argue that with our framework more targeted research for developing better document clustering methods becomes possible. Experimental results demonstrate the potential of our considerations.     

Numerical investigation of the power generation of a ducted composite material marine current turbine

In the hostile and highly corrosive marine environment,advanced composite materials can be used in marine current turbines due to their high strength-to-weight ratios and excellent resistance to corrosion.A composite material marine current turbine(CMMCT),which has significant advantages over traditional designs,has been developed and investigated numerically.A substantial improvement in turbine performance is achieved by placement of a duct to concentrate the energy.Computational fluid dynamics(CFD) results show that the extracted power of a ducted CMMCT can be three to four times the power extracted by a bare turbine of the same turbine area.The results provide an insight into the hydrodynamic design and operation of a CMMCT used to shorten the design period and improve technical performance.