Die Körperzusammensetzung von Hobbygamern im Vergleich zu deutschlandweit erhobenen Referenzdaten     

Steffen C. E. Schmidt  Filip Kowal  Alexander Woll 《Sportwissenschaft》2018,48(3):438-446

About two thirds of adults in Germany are overweight or obese. While an increase in the consumption of high-calorie food is considered the main cause, the influence of various forms of sedentary activities is still controversially discussed. The aim of the present study is to compare the body composition of hobby gamers with reference data collected throughout Germany and to examine the effects of intensive use of computer games (gaming) on body composition. A total of 68 male participants of a computer game event aged 18–46 years (27.9 years; 180.1?cm; 83.5?kg; BMI 25.7) were examined for fat mass, body cell mass, extracellular mass, body water and phase angle using bioelectrical impedance analysis (BIA, Nutriguard MS type, data input). Ten test persons were retested by means of segmental 8?electrode BIA after a 24?h interval during their visit to the event. As a reference sample, data from 278 male adults of the same age (27.9 years, 179.4?cm; 78.8?kg; BMI 24.5) were collected in 168 locations throughout Germany. The hobby gamers reported on average 37.1?h screen media usage per week. Compared to the reference sample, they showed a slightly higher body cell mass index (p?<?0.01, T?=?4.07), but no differences in fat mass index (p?=?0.96, T?=?0.05) and phase angle (p?=?0.90, T?=?0.12). A significant increase in body water (T₀: 48.2?l, T₀₊₂₄?_h: 49.3?l; p?=?0.04, T?=?2.39) and decrease in the phase angle of the lower extremities (T₀:?7.40, T₀₊₂₄?_h: ?6.85; p?<?0.01, T?=?5.40) was observed in the 24?h retest. Compared to the reference data collected throughout Germany, hobby gamers show no differences in health-relevant parameters of body composition. Nevertheless, after intensive gaming, a short-term increase in the amount of extracellular water in the lower extremities was found. Due to these disturbances in the water balance, the consequent execution of movement breaks during gaming is important.  相似文献   

The Active Tradition: A Convergence of Ideas     

Alan Steffen 《Educational theory》1973,23(4):321-332

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‘Whys’ and ‘Hows’ of Using Philosophy in Mathematics Education     

Uffe Thomas Jankvist  Steffen Møllegaard Iversen 《Science & Education》2014,23(1):205-222

The article elaborates and exemplifies a potential categorization of the reasons for using philosophy, in particular the philosophy of mathematics, in mathematics education and approaches to doing so—the so-called ‘whys’ and ‘hows’. More precisely, the ‘whys’ are divided into the two categories of ‘philosophy as a tool’ for teaching and learning mathematics, and ‘philosophy as a goal’, referring to a stance of considering it a purpose in itself to teach students certain aspects regarding the philosophy of mathematics. A division of the ‘hows’ into three different categories is offered: illumination approaches; modules approaches; and philosophy-based approaches. A major part of the article is spent on providing illustrative exemplifications of each of these approaches by referring to already implemented uses of philosophy of mathematics in mathematics education as well as by suggesting new ones.  相似文献   

Exploring data management content in doctoral nursing handbooks     

Rebecca Raszewski  Abigail H. Goben  Martha Dewey Bergren  Krista Jones  Catherine Ryan  Alana Steffen  Susan C. Vonderheid 《Journal of the Medical Library Association》2021,109(2):248

Objective:While data management (DM) is an increasing responsibility of doctorally prepared nurses, little is understood about how DM education and expectations are reflected within student handbooks. The purpose of this study was to assess the inclusion of DM content within doctoral nursing student handbooks.Methods:A list of 346 doctoral programs was obtained from the American Association of Colleges of Nursing (AACN). Program websites were searched to locate program handbooks, which were downloaded for analysis. A textual review of 261 handbooks from 215 institutions was conducted to determine whether DM was mentioned and, if so, where the DM content was located. Statistical analysis was performed to compare the presence of DM guidance by type of institution, Carnegie Classification, and the type of doctoral program handbook.Results:A total of 1,382 codes were identified across data life cycle stages, most commonly in the handbooks’ project requirements section. The most frequent mention of DM was in relation to collecting and analyzing data; the least frequent related to publishing and sharing data and preservation. Significant differences in the frequency and location of codes were identified by program type and Carnegie Classification.Conclusions:Nursing doctoral program handbooks primarily address collecting and analyzing data during student projects. Findings suggest limited education about, and inclusion of, DM life cycle content, especially within DNP programs. Collaboration between nursing faculty and librarians and nursing and library professional organizations is needed to advance the adoption of DM best practices for preparing students in their future roles as clinicians and scholars.  相似文献   

Explaining Scientists’ Plans for International Mobility from a Life Course Perspective     

Nicolai Netz  Steffen Jaksztat 《Research in higher education》2017,58(5):497-519

We identify factors influencing young scientists’ plans for research stays abroad by embedding theories of social inequality, educational decision making, and migration into a life course framework. We test the developed model of international academic mobility by calculating a structural equation model using data from an online survey of scientists employed at German universities below the rank of full professor. We find that earlier international mobility mobilises scientists to plan a research stay abroad. This turns out to be a potential channel of social inequality reproduction, as individuals from a high social origin in particular spend time abroad in their early life course. Moreover, scientists’ research contexts play a vital role: Internationalised institutional environments and academic disciplines as well as personal international networks create opportunity structures that ease research stays abroad. Similarly, the current social context matters: Parenthood decreases the likelihood of plans for international mobility among female scientists. This may entail long-lasting gender inequalities. Finally, young scientists striving for an academic career are more likely to plan a research stay abroad than those with exit plans. Our results show that beyond the current context, both past life events and future life goals shape scientists’ decisions about international mobility.  相似文献   

King Kong,Storks and Birth Rates     

Steffen Wirth 《Teaching Statistics》2003,25(1):29-32

This article discusses the influence extreme observations can exert on linear correlation between variables. It shows that standard p‐values obtained according to ordinary least squares and median regression can be misleading. Bootstrapping can prevent underestimation of the standard error of the regression coefficient and therefore unmask the deceiving correlation.  相似文献   

Lower limb joint kinetics in the starting blocks and first stance in athletic sprinting   总被引：1，自引：1，他引：0  

Adam Brazil  Timothy Exell  Cassie Wilson  Steffen Willwacher  Ian Bezodis  Gareth Irwin 《Journal of sports sciences》2017,35(16):1629-1635

The aim of this study was to examine lower limb joint kinetics during the block and first stance phases in athletic sprinting. Ten male sprinters (100 m PB, 10.50 ± 0.27 s) performed maximal sprint starts from blocks. External force (1000 Hz) and three-dimensional kinematics (250 Hz) were recorded in both the block (utilising instrumented starting blocks) and subsequent first stance phases. Ankle, knee and hip resultant joint moment, power and work were calculated at the rear and front leg during the block phase and during first stance using inverse dynamics. Significantly (P < 0.05) greater peak moment, power and work were evident at the knee joint in the front block and during stance compared with the rear block. Ankle joint kinetic data significantly increased during stance compared with the front and rear block. The hip joint dominated leg extensor energy generation in the block phase (rear leg, 61 ± 10%; front leg, 64 ± 8%) but significantly reduced during stance (32 ± 9%), where the ankle contributed most (42 ± 6%). The current study provides novel insight into sprint start biomechanics and the contribution of the lower limb joints towards leg extensor energy generation.  相似文献   

Validity of block start performance without arm forces or by kinematics-only methods     

Mitsuo Otsuka  Wolfgang Potthast  Steffen Willwacher  Jan-Peter Goldmann  Toshiyuki Kurihara  Tadao Isaka 《Sports biomechanics / International Society of Biomechanics in Sports》2019,18(3):229-244

The purpose of this study was to validate the calculation of reaction time (RT) and normalised power in block starts without considering arm ground reaction forces (GRFs) or using two kinematics-only methods. The RT and normalised power in the action phase were calculated using four different methods: using GRFs of arms and legs by force plates (whole F-based method), which can be regarded as the most valid method, using GRFs of legs captured by force plates (legs F-based method), using position of the centre of mass of the entire body captured by high-speed cameras (whole P-based method), and using only a partial subset of segment position (partial P-based method). Bland–Altman plots demonstrated that the RT of the legs F-based method was not similar to that of the whole F-based method: the mean difference was 7.4 ms and the 95% limits of agreement was?45.1 to 59.8 ms, and it was the least valid method for the calculation among the four methods. In contrast, the normalised power was more valid in the legs F-based method, followed by whole and partial P-based methods. This information will help researchers and practitioners to decide upon their analysis methods when analysing block start performance.  相似文献   

The relationship between physical activity,fitness, physical complaints and BMI in German adults – results of a longitudinal study     

Susanne A. Tittlbach  Darko Jekauc  Steffen C. E. Schmidt  Alexander Woll  Klaus Bös 《European Journal of Sport Science》2017,17(8):1090-1099

Objectives: This study’s aims were to describe the development of physical activity, physical fitness (PF), subjective (physical complaints (PC)) and objective (Body mass index (BMI)) health measures and to examine the relationship between the development trajectories. In addition, the study also aimed to assess the influence of sociodemographic determinants (age, sex, socioeconomic status (SES)) in German adults over a period of 18 years. Methods: The longitudinal study population comprises of 721 men and women, aged 33–76 years over the study period. There was self-report of physical activity and PC and testing of physical fitness and BMI in each study year (1992, 1997, 2002 and 2010). Latent growth curve models were used to analyse the development. Results: Physical activity slightly increased while fitness, PC and BMI worsened over the course of 18 years. Sex, age and SES play important roles concerning physical activity, fitness and health. Several integrative associations could be detected between physical activity, fitness, PC and BMI as well as their trajectories. In particular, high initial levels of physical activity and fitness protect from high PC and BMI.The slope of physical activity was not significantly associated with slopes of fitness, PC and BMI. However, increase of fitness resulted in decrease of PC. Conclusions: A general positive development regarding the amount of physical activity could be detected. However, if it is only an unsystematic increase of physical activity, this is not in itself enough to achieve health benefits. The strengthening of fitness should be focused when increasing physical activity, since only then a health benefit is possible.  相似文献