AbstractA key element contributing to deteriorating exercise capacity during physically demanding sport appears to be reduced carbohydrate availability coupled with an inability to effectively utilize alternative lipid fuel sources. Paradoxically, cognitive and physical decline associated with glycogen depletion occurs in the presence of an over-abundance of fuel stored as body fat that the athlete is apparently unable to access effectively. Current fuelling tactics that emphasize high-carbohydrate intakes before and during exercise inhibit fat utilization. The most efficient approach to accelerate the body’s ability to oxidize fat is to lower dietary carbohydrate intake to a level that results in nutritional ketosis (i.e., circulating ketone levels >0.5 mmol/L) while increasing fat intake for a period of several weeks. The coordinated set of metabolic adaptations that ensures proper interorgan fuel supply in the face of low-carbohydrate availability is referred to as keto-adaptation. Beyond simply providing a stable source of fuel for the brain, the major circulating ketone body, beta-hydroxybutyrate, has recently been shown to act as a signalling molecule capable of altering gene expression, eliciting complementary effects of keto-adaptation that could extend human physical and mental performance beyond current expectation. In this paper, we review these new findings and propose that the shift to fatty acids and ketones as primary fuels when dietary carbohydrate is restricted could be of benefit for some athletes. 相似文献
Although many newly-graduated librarians are applying for and accepting part-time library employment after graduation, little research has been done into what working part-time means for these early career librarians. This article, based on a survey of recent LIS graduates who have worked part-time, provides a snapshot of part-time library employment and the advantages and disadvantages it affords to new librarians. This information is particularly relevant in light of the difficult job market for entry-level librarians. All of the surveyed librarians have worked in at least one part-time professional or paraprofessional position in a library after receiving their degree. Many of these respondents describe holding multiple part-time positions and receiving low salaries and few, if any, employment benefits. The themes documented in the open-ended short answers of these part-time librarians will help to guide further research into the professional and personal impact of part-time employment. 相似文献
We describe how a team approach that we developed as a mentoring strategy can be used to recruit, advance, and guide students to be more interested in the interdisciplinary field of mathematical biology, and lead to success in undergraduate research in this field. Students are introduced to research in their first semester via lab rotations. Their participation in the research of four faculty members-two from biology and two from mathematics-gives them a first-hand overview of research in quantitative biology and also some initial experience in research itself. However, one of the primary goals of the lab rotation experience is that of developing teams of students and faculty that combine mathematics and statistics with biology and the life sciences, teams that subsequently mentor undergraduate research in genuine interdisciplinary environments. Thus, the team concept serves not only as a means of establishing interdisciplinary research, but also as a means of incorporating new students into existing research efforts that will then track those students into meaningful research of their own. We report how the team concept is used to support undergraduate research in mathematical biology and what types of team-building strategies have worked for us. 相似文献
Many formal policies have suggested that officers need a college degree; however, policies forced little change in practices of American police organizations. Six hundred-fifty patrol officers employed in 12 medium-sized police departments in three Midwestern states were surveyed as to their current educational attainment and job performance. The purpose of this study was to determine the relationship between educational level and police performance. 相似文献
As key elements in research and development systems, higher education institutions have been taking a leading role when it comes to communicating science and technology, but their performance has been inconsistent so far. In this critical and comparative study of the UK public engagement model and the Spanish scientific culture model, eighteen practitioners from higher education institutions across both regions were interviewed. A mixed qualitative data analysis has been performed identifying similarities and differences that unravelled the science communication management model in the two different higher education systems. This article provides evidence on how the institutionalisation of science communication is strongly influenced by key driving forces in the higher education context as well as the policies of administrations and other agents.
The swing speed of the bat is one of the most important factors affecting the hit-ball speed. Most field studies tend to focus on measuring ball speed, which is easier to measure and quantify than bat speed. For this reason, relatively little data exist describing bat motion in field conditions. The following describes a relatively large swing speed field study involving bats of the same model with nearly constant weight and varying inertia. The study was conducted using right-handed batters on a regulation outdoor field with a live pitcher. Swing speed was measured by tracking markers on the bat with two high-speed video cameras so that the bat markers could be traced in three-dimensional space. The ball motion was tracked using the same high-speed video cameras and a three-dimensional Doppler radar system. Bat swing speed was observed to be proportional to the batter skill level and the normalised swing speed increased with decreasing bat inertia. The bat centre of rotation during impact was close to the knob of the bat. The bats were tested under controlled laboratory conditions using a standardised performance test. The field and laboratory results showed good agreement including the hit-ball speed and the subtle effect of bat inertia on the maximum performance location. The vibrational response of the bats was considered using modal analysis. The maximum performance location was correlated with the node of the first vibrational mode. 相似文献
This article is based on a discussion document written for all schools in Suffolk, England by the English advisory team. It resulted from a small-scale survey of nine schools where results for National Curriculum test AT4 (Spelling) in 1994 and 1995 were particularly high. This in turn stemmed from concerns raised by monitoring local education authority results in this aspect of English and aimed to uncover common factors in these schools' approaches to teaching spelling and supporting pupils' development in this skill. The key factors indicated by the survey included the systematic teaching of both spelling patterns and phonics; the fostering of early independence in writing and reading; regular learning of spellings at home and effective partnership with parents in this; regular testing; effective short teaching sessions on spelling, and differentiation based on high expectations of all pupils. 相似文献