Influence of different attentional focus on EMG amplitude and contraction duration during the bench press at different speeds     

Joaquin Calatayud  Jonas Vinstrup  Markus D. Jakobsen  Emil Sundstrup  Juan Carlos Colado  Lars L. Andersen 《Journal of sports sciences》2018,36(10):1162-1166

The purpose of this study was to investigate whether using different focus affects electromyographic (EMG) amplitude and contraction duration during bench press performed at explosive and controlled speeds. Eighteen young male individuals were familiarized with the procedure and performed the one-maximum repetition (1RM) test in the first session. In the second session, participants performed the bench press exercise at 50% of the 1RM with 3 different attentional focuses (regular focus on moving the load vs contracting the pectoralis vs contracting the triceps) at 2 speed conditions (controlled vs maximal speed). During the controlled speed condition, focusing on using either the pectoralis or the triceps muscles increased pectoralis normalized EMG (nEMG) by 6% (95% CI 3–8%; p = 0.0001) and 4% nEMG (95% CI 1–7%; p = 0.0096), respectively, compared with the regular focus condition. Triceps activity was increased by 4% nEMG (95% CI 0–7%; p = 0.0308) at the controlled speed condition during the triceps focus. During the explosive speed condition, the use of different focuses had no effect. The different attentional focus resulted in comparable contraction duration for the measured muscles when the exercise was performed explosively. Using internal focus to increase EMG amplitude seems to function only during conditions of controlled speed.  相似文献   

Is there a specific relationship between childhood sexual and physical abuse and repeated suicidal behavior?     

Ystgaard M  Hestetun I  Loeb M  Mehlum L 《Child abuse & neglect》2004,28(8):863-875

OBJECTIVE: Studies show that childhood sexual and physical abuse predict repeated suicide attempts and self-mutilation. Little is known about the importance of sexual and physical abuse when compared to other severe childhood adversities with respect to chronic suicidal behavior. METHOD: Seventy-four subjects, 65% of whom were women, consecutively admitted to a general hospital after having made a suicide attempt, were interviewed as part of the intake interview about prior suicide attempts and self-mutilation and received DSM-IV diagnoses. Sexual abuse, physical abuse, neglect, antipathy from parents, loss of parents, and severe discord in the family before the age of 18, were covered by the Childhood Experience of Care and Abuse (CECA) interview schedule. RESULTS: The prevalence of severe sexual abuse was 35%, severe physical abuse 18%, neglect 27%, antipathy 34%, loss of caregiver 37% and exposure to family violence 31%. Physical and sexual abuse were independently associated with repeated suicide attempts when controlling for the effects of the other childhood adverse factors. No other childhood adversity was related to chronic suicidal behavior. The odds ratio of exposure to sexual or physical abuse was highest among those who both repeated suicide attempts and self-mutilated. CONCLUSION: Physical and sexual abuse are significantly and independently associated with repeated suicidal behavior.  相似文献   

The effects of search tool type and cognitive style on performance during hypermedia database searches     

Lars F. Leader  James D. Klein 《Educational technology research and development : ETR & D》1996,44(2):5-15

This study investigated the effects of search tools and learner cognitive styles on performance in searches for information within a hypermedia database. Seventy-five students in a university English as a Second Language (ESL) program were blocked for field dependence and assigned to one of four treatments: browser, index/find, map, and all tools. Subjects searched the hypermedia database, EarthQuest, for facts to answer practice and posttest questions on science topics. Results revealed a significant interaction between search tool and cognitive style. Field-independent learners performed significantly better than field-dependent learners under the index/find and map treatments. Subjects in the four treatment groups accessed information from the database differently. Furthermore, cognitive style was significantly related to achievement, tool use, and attitude. Implications for the design and instructional use of hypermedia databases are provided.  相似文献   

Learning for the professions: lessons from linking international research projects     

Madeleine Abrandt Dahlgren  Anna Reid  Lars Owe Dahlgren  Peter Petocz 《Higher Education》2008,56(2):129-148

At the core of higher education is the experience of students whose focus for learning is often directed towards their future employability. In this paper, we explore the intersections between two large international research projects involving over 500 students. Interviews with students yielded their conceptions of learning and work in specific discipline and professional areas. Analysis of the Swedish and Australian data sets showed the important interplay between students’ individual ideas about learning and future work with their workplace. A meta-analysis of the two projects highlights the utility of higher education for students’ future working life and suggests ways in which institutions and policy makers can critique current practice in a way that will incline curriculum and teaching development towards professional formation.  相似文献   

Hospital nurses’ information retrieval behaviours in relation to evidence based nursing: a literature review          下载免费PDF全文

Berit Elisabeth Alving  Janne Buck Christensen  Lars Thrysøe 《Health information and libraries journal》2018,35(1):3-23

  相似文献   

A Review of the Physics and the Building Science which Underpins Methods of Low Energy Storage of Museum and Archive Collections*     

Tim Padfield  Morten Ryhl-Svendsen  Poul Klenz Larsen  Lars Aasbjerg Jensen 《文物保护研究》2018,63(5):209-215

ABSTRACT

The need to keep things cool for durability should be the single most powerful influence on storage design. The simplest temperature control is to moderate the outside temperature by a combination of thermal insulation and heat capacity. The low energy storage building is a lightweight, thermally insulated, airtight building put on top of an uninsulated floor slab laid directly on the ground. The thermal insulation is calculated to even out the daily temperature cycle but to allow an annual temperature cycle which is about half the amplitude, but much smoother, than the annual temperature cycle outside. The winter temperature inside will nearly always be above ambient and so will maintain a moderate RH without need for either humidification or dehumidification. The temperature inside in summer will be below ambient and thus will force dehumidification of the infiltrating air. However, the airtightness of the building allows intermittent dehumidification with low energy consumption, less than one kWh/m³ per year. There now exist enough buildings designed on this principle to reassure curators that highly valued collections can be stored in a space with a gentle temperature cycle and with an RH stability as good as air-conditioning usually achieves.  相似文献   

Stronger disciplinary identities in multidisciplinary research schools     

Lars Geschwind  Göran Melin 《Studies in Continuing Education》2016,38(1):16-28

In this study, two multidisciplinary Social Sciences and Humanities research schools in Sweden have been investigated regarding disciplinary identity-making. This study investigates the meetings between different disciplines around a common thematic area of study for Ph.D. students. The Ph.D. students navigate through a complex social and organisational landscape with obligations and loyalties towards the discipline and the research school, which may be in conflict with each other. The main finding is that a multidisciplinary environment in fact creates strong disciplinary identities, partly in contrast to the purpose with the multidisciplinary research school. Encounters with Ph.D. students from other disciplines give the Ph.D. student something to relate to and to discuss e.g. with the supervisor. Another finding is that multidisciplinary research schools extend the perspectives of students. For some, new methods and theories from neighbouring disciplines were integrated and used, while for others the empirical scope of research was affected.  相似文献   

Evaluating the Madrasa preschool programme in East Africa: a quasi‐experimental study     

Peter A.M. Mwaura  Kathy Sylva  Lars‐Erik Malmberg 《International Journal of Early Years Education》2008,16(3):237-255

This study investigated the effect of preschool experience (two types of preschool: Madrasa and non‐Madrasa) on the cognitive development of children in East Africa. In the three countries studied (Kenya, Uganda, and Tanzania/Zanzibar) preschool education is burgeoning and government standards are being set. This quasi experimental evaluation used four subscales (block building, verbal comprehension, early number concept, picture similarities) adapted from the British Ability Scale II (BAS II; discussed by Elliot, Smith and McCulloch in 1996 Elliot, C.D., Smith, P. and McCulloch, K. 1996. British Ability Scale (BAS), Berkshire, , UK: NFER‐NELSON.  [Google Scholar]), and three (verbal meaning, exclusion, closure) from the African Child Intelligence Test (ACIT; discussed by Drenth and colleagues in 1980 Drenth, P.J.D., Van der Vlier, H., Muinde, N.P., Otaala, B., Omari, I.M. and Opolot, J.A. 1980. Jaribio akili mtoto Afrika. [African child intelligence test.] [in Kiswahili], Amsterdam: Free University of Amsterdam.  [Google Scholar]). The development of 423 children was studied at pre‐test (entry to preschool) and at post‐test 18 months later. Hierarchical regression showed that children with both types of preschool experience performed better than the home (comparison) group; however, children attending Madrasa Resource Centre preschools achieved significantly higher scores overall.  相似文献   

A new device for measuring ski running surface force and pressure profiles     

Johnny Nilsson  Lars Karlöf  Vidar Jakobsen 《Sports Engineering》2013,16(1):55-59

The pressure/force acting between the running surface of a ski and the snow may indirectly change glide friction. Thus, measuring the pressure/force distribution may be important for a deeper understanding of glide in skiing. The present aim was to construct a device that allowed the pressure/force underneath the ski running surface (SRS) to be recorded. Pressure sensors were attached on top of a platform. Sheets of different materials were used to improve the interaction between the SRS and the sensors. Possible functions of the device are demonstrated in three applications that emphasized comparison of force distribution underneath skis selected for similarity, force distribution under both skis and a single ski as well as backward weight distribution. The results show that the device with the pressure sensors mapped pressure/force distribution underneath the skis in the applications presented, and the system can thus be a useful tool for further optimizing e.g., ski designs.  相似文献   

Bewegungsberatung durch Experten aus der Sportwissenschaft. Eine Public Health Strategie zur Erhöhung körperlicher Aktivität bei speziellen Zielgruppen     

Lars Gabrys  Christian Thiel  Gert Saborowski  Lutz Vogt  Winfried Banzer 《Sportwissenschaft》2013,43(1):12-19

Although sports clubs, associations and health insurance companies offer a wide range of exercise programs, several target groups, such as groups with low socioeconomic status struggle to overcome barriers for participation. The aim of this paper is to show the need for, as well as the prospects of structured physical activity counselling for specific target groups provided by exercise specialists. This successful approach to promote physical activity is described detailed in the group of long-term unemployed persons over 50 years in a job centre setting. A close cooperation with established local exercise programs is intended. Deficits and requirements of physical activity counselling in primary health care settings are adopted and transferred into the theory-based public health strategy. This approach has the potential to create a new field of work for exercise and health professionals in the field of primary prevention.  相似文献