儿童青少年运动员的营养需要

1. 儿童青少年运动员应该食用多样化的食物，其中，蛋白质应占膳食总能量的12％-15％，碳水化合物至少占55％，而脂肪至多占30％。日常生活中如何吃才能满足这些要求呢？膳食指南宝塔提供了一条可行之道。2.有些营养素对热爱运动的儿童青少年运动员非常重要，要保证摄入充足，这些营养素是碳水化合物（包括纤维素）、维生素B6、维生素D、铁、钙、镁、锌、铬。科学合理、包罗各类食物的平衡膳食，对青少年运动员最大程度地全面摄取各种营养素，满足生长发育和运动训练的需要，是非常必要的。3.鼓励儿童青少年运动员在运动训练前、中、后进行补液，以避免脱水的发生。4.如果膳食合理平衡，就没必要额外补充营养品。     

Can constrained relevance feedback and display strategies help users retrieve items on mobile devices?

Searching online information resources using mobile devices is affected by small screens which can display only a fraction of ranked search results. In this paper we investigate whether the search effort can be reduced by means of a simple user feedback: for a screenful of search results the user is encouraged to indicate a single most relevant document. In our approach we exploit the fact that, for small display sizes and limited user actions, we can construct a user decision tree representing all possible outcomes of the user interaction with the system. Examining the trees we can compute an upper limit on relevance feedback performance. In this study we consider three standard feedback algorithms: Rocchio, Robertson/Sparck-Jones (RSJ) and a Bayesian algorithm. We evaluate them in conjunction with two strategies for presenting search results: a document ranking that attempts to maximize information gain from the user’s choices and the top-D ranked documents. Experimental results indicate that for RSJ feedback which involves an explicit feature selection policy, the greedy top-D display is more appropriate. For the other two algorithms, the exploratory display that maximizes information gain produces better results. We conducted a user study to compare the performance of the relevance feedback methods with real users and compare the results with the findings from the tree analysis. This comparison between the simulations and real user behaviour indicates that the Bayesian algorithm, coupled with the sampled display, is the most effective. Extended version of “Evaluating Relevance Feedback Algorithms for Searching on Small Displays, ” Vishwa Vinay, Ingemar J. Cox, Natasa Milic-Frayling, Ken Wood published in the proceedings of ECIR 2005, David E. Losada, Juan M. Fernández-Luna (Eds.), Springer 2005, ISBN 3-540-25295-9     

State of the art of expert searching: results of a Medical Library Association survey.

OBJECTIVES: Medical Library Association (MLA) members were surveyed to gather background about the current state of expert searching in institutions. The survey results were intended to guide the recommendations of the Task Force on Expert Searching for promoting the importance of expert searching and implementing those recommendations. METHODS: MLA members were surveyed, and data obtained from the survey were compiled and analyzed to answer three general questions: what is the perceived value of searching skills to the institution, how do health sciences librarians maintain and improve their searching skills, and how are searching services promoted and/or mandated in the institution. RESULTS: There were 256 responses to the survey. Over 95% of the respondents saw their expert-searching skills were of value to their institutions, primarily through performing mediated searches and search consultations. Over 83% of the respondents believed that their searching skills had improved over the past 10 years. Most indicated that continued training was very important in maintaining and improving their skills. Respondents promoted searching services most frequently through orientations, brochures, and the libraries' Web pages. No respondent's institution mandated expert searching. Less than 2% of respondents' institutions had best practice guidelines related to expert searching, and only about 8% had guidelines or policies that identified situations where expert searching was recommended. CONCLUSIONS: The survey supports the belief that health sciences librarians still play a valuable role in searching, particularly in answering questions about treatment options and in providing education. It also highlights the need for more expert searching courses. There has been minimal discussion about the perceived need for expert-searching guidelines in the institutions represented by survey respondents.     

Print Media Standardisation and Professionalism

The independence of the media under Ghana’s Fourth Republic is assessed from the perspective of standards and professionalism. Using a qualitative method, the study shows that unethical practices are evident in the print media landscape in Ghana, and argues that this can be traced to four major spheres: educational qualification, existence of several professional associations, a weak regulatory body and “money matters”. Overall, the study argues that legalities form a minimal part of the independence of the Ghanaian media but concerns about freedom seem to be self-inflicted by the very media practitioners through their actions and sometimes questionable reportage.     

Along the Write Lines: a case study exploring activities to enable creative writing in a secondary English classroom.

This article arises from a four week study of a class of 14‐15 year old students. The study explored students’ perception of themselves as writers and the effects of a variety of teaching and learning strategies on their creative writing responses. The aim of the project was to enhance the students’ creative writing, whilst ascertaining whether there were particular activities or types of writing that would lead to students perceiving more satisfactory outcomes in their writing. It answers the research question: What do I observe, and what do my students say, about the experience of different classroom based creative writing tasks?