Acute modification in plasma lipid levels in ultramarathon runners

We aimed to evaluate the effects of a 24-h ultramarathon, an aerobic test of high physical load, on lipid profile and apolipoproteins B (ApoB) and A1 (ApoA1) levels, minimally modified low-density lipoprotein (LDL), and oxidised LDL. Prospective evaluation of 16 male athletes who participated in an ultramarathon run, where the objective was to run the greatest distance possible in 24 h. Fourteen participants completed the run. The mean distance achieved was 133.1 km (maximum of 169.6 km). There was a trend in reduction of triglycerides and total cholesterol (P = 0.06 and 0.05, respectively), without significant modifications in high-density lipoprotein, LDL and ApoA1 levels (P = 0.16; 0.55 and 0.67). There was a marked reduction in ApoB levels (P < 0.001), correlated directly to the distance covered (Pearson R = 0.68). Accordingly, an increase in the LDL/ApoB ratio was observed. The stress of this physical activity was not associated to an increase in minimally modified LDL or oxidised LDL. Lipid profile levels were not acutely altered by prolonged physical activity. Similarly, there was no evidence of greater oxidation of LDL over a 24-h period of physical activity. The reduction in ApoB was directly proportional to the distance covered, suggesting an acute positive change in phenotype of LDL molecules.     

XML标记的语义

尽管 XML 文档类型定义提供了一种机器可读形式的、能够说明 XML 语言语法的机制,但目前并没有类似的机制来指定 XML 词汇表的具体语义。这意味着没办法说明 XML 标记的意义,由 XML 形式呈现的事实和关系无法清晰、全面和规范地定义。这在实践和理论上都引起了严重的后果。从积极的方面看,XML 结构能被赋予任意语义,并可用于最初的设计者无法预见的领域。从不太积极的方面来看,内容开发者和软件工程师必须依靠乏味的文档,或者更糟的情况是,只能依靠猜测标记语言设计者的意图来开展工作。这一过程既费时费力,又易出错,还无法核实验证。即便是设计者当初的建档工作做得相当完美,不如意的情况还是会发生。另外,对标记语义本质研究的匮乏也意味着属于工程应用领域的数字文档处理根本没有什么理论。尽管目前正在进行的一些工程（XML 模式、RDF、语义网）已经取得了一些成绩,但是这些工程都没有直接全面地解决XML 标记语义的核心问题。本文回顾了标记意义这个概念的发展历史,阐明了解释 XML 正式语义的动机,并介绍了一个研究语义的科研项目——BECHAMEL 标记语义计划。     

Dealing With Item Nonresponse in Large‐Scale Cognitive Assessments: The Impact of Missing Data Methods on Estimated Explanatory Relationships

Competence data from low‐stakes educational large‐scale assessment studies allow for evaluating relationships between competencies and other variables. The impact of item‐level nonresponse has not been investigated with regard to statistics that determine the size of these relationships (e.g., correlations, regression coefficients). Classical approaches such as ignoring missing values or treating them as incorrect are currently applied in many large‐scale studies, while recent model‐based approaches that can account for nonignorable nonresponse have been developed. Estimates of item and person parameters have been demonstrated to be biased for classical approaches when missing data are missing not at random (MNAR). In our study, we focus on parameter estimates of the structural model (i.e., the true regression coefficient when regressing competence on an explanatory variable), simulating data according to various missing data mechanisms. We found that model‐based approaches and ignoring missing values performed well in retrieving regression coefficients even when we induced missing data that were MNAR. Treating missing values as incorrect responses can lead to substantial bias. We demonstrate the validity of our approach empirically and discuss the relevance of our results.     

Renegotiating vocational instruction

Recent research by the author and others suggests that secondary vocational instruction may often fail to develop students' analytical and critical thinking skills. This failure, it is argued, is manifest in teacher-student negotiation as set in a complex social, economic, and institutional context. The article focuses on how vocational education might be reformed to address this problem. Discussed are the need for instruction in problem solving and decision making, more basic skill instruction, student involvement in the group management of entrepreneurial projects, development of critical thinking skills for the purpose of improving workplaces and society, revision of vocational teacher preparation, and a restructuring of the ways in which secondary vocational education is offered. Vocational education is redefined as academically integrated, experiential coursework in which a diverse group of students is educated broadly for work, learning, and life.     

The Role of Campus Traditions in Campus Life at Christian Colleges and Universities

This article presents the preliminary findings of an ongoing Traditions Research Project (TRP) study on the impact of campus traditions on campus life within the context of Christian postsecondary institutions. In this initial phase, the researchers conducted 63 interviews with faculty, student development educators, and staff members, in addition to gathering data from 12 student focus groups at three institutional members of the Council for Christian Colleges & Universities. In the future, the researchers intend to identify several additional colleges that have tradition-rich environments in order to expand the qualitative database related to this topic. The initial process of data analysis identified three major themes, along with several subthemes, regarding the role of traditions in contributing to campus life. These themes provide valuable information regarding the characteristics of campus traditions, the important role they play in creating and maintaining campus culture, and the role of these events in the lives of participants and institutions. In addition to presenting and discussing the themes and subthemes, the authors provide implications for practice that may be helpful to higher education leaders as they seek to provide meaningful campus traditions that foster students’ holistic development.