Meta-analysis: a tool for medical and scientific discoveries.     

C L Schell  R J Rathe 《Bulletin of the Medical Library Association》1992,80(3):219-222

Medicine has made increasing use of meta-analysis, largely as a quantitative procedure for combining results of clinical trials. Meta-analysis begins with a comprehensive review of the literature. The next step is a systematic analysis of the quality and content of each study. Finally, results are combined statistically and conclusions are drawn from this new overview of the data. This paper presents a brief historical perspective on the use of meta-analysis in medicine with emphasis on the medical library. The authors conclude that in the future, medical librarians will play a significant role in the application of this useful technique.  相似文献   

Pre-season physiological characteristics of English first and second division soccer players.     

J A Davis  J Brewer  D Atkin 《Journal of sports sciences》1992,10(6):541-547

This investigation was undertaken in an effort to establish physiological characteristics of soccer players and to relate them to positional roles. A total of 135 footballers (age 24.4 +/- 4.6 years) were assessed for body mass, % body fat, haemoglobin, maximal oxygen uptake (VO2 max), leg power, anaerobic capacity and speed prior to an English league season. The sample included 13 goalkeepers, 22 full-backs, 24 centre-backs, 35 midfield players and 41 forwards. The goalkeepers were significantly heavier (86.1 +/- 5.5 kg; P < 0.01) than all groups except the centre-backs, had significantly higher estimated body fat percentages than centre-backs, forwards, midfield players (P < 0.01) or full-backs (P < 0.05), significantly lower estimated VO2 max values (56.4 +/- 3.9 ml kg-1 min-1; P < 0.01) and were slowest over 60 m (12.71 +/- 0.42 s). The midfield players had the highest predicted VO2 max values (61.4 +/- 3.4 ml kg-1 min-1), this being significantly greater (P < 0.05) than for the centre-backs. The forwards were the fastest group over 60 m (12.19 +/- 0.30 s), being significantly quicker than goalkeepers or centre-backs (P < 0.01) and full-backs (P < 0.05). Anaerobic power, as well as knee extensor torques (corrected for body mass) and extensor-flexor ratios, were similar between groups. No difference in estimated body fat percentage was observed between any of the outfield players, and haemoglobin concentrations were similar among players of all positions.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Recent changes in the educational placement of deaf students     

A Schildroth 《American annals of the deaf》1988,133(2):61-67

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Chaos theory, informational needs, and natural disasters   总被引：2，自引：0，他引：2  

Timothy L. Sellnow  Matthew W. Seeger  Robert R. Ulmer 《Journal of Applied Communication Research》2002,30(4):269-292

This study applies chaos theory to a system-wide analysis of crisis communication in a natural disaster. Specifically, we analyze crisis communication during the 1997 Red River Valley flood in Minnesota and North Dakota. This flood, among the worst in modern American history, consumed entire metropolitan areas, displacing thousands of people. The conditions and decisions leading to the disaster, and the subsequent reactions are retraced. Communication related to river crest predictions (fractals), the shock at the magnitude of the crisis (cosmology episode), novel forms of reorganizing (self-organization), and agencies that aided in establishing a renewed order (strange attractors) are evaluated. Ultimately, we argue that preexisting sensemaking structures favoring rationalized, traditional views of a complex system led officials to make inappropriately unequivocal predictions and ultimately diminished the effectiveness of the region's crisis communication and planning.  相似文献   

Book reviews     

Thomas L. Bonn  Richard W. Eiger  Peter W. Adams  Estelle Jobson 《Publishing Research Quarterly》2002,18(1):66-71

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The laser printer as an agent of change     

Barbara A. Brannon 《Publishing Research Quarterly》2002,17(4):3-8

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Using the Internet as Reference Tool: A How-To-Do-It Manual for Librarians and The Library Internet Trainer's Toolkit     

Priscilla L. Stephenson 《Journal of the Medical Library Association》2002,90(2):261-262

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冰上课教学方法与难点教学实践初探   总被引：1，自引：1，他引：0  

吕岩  王国成  关成雪 《冰雪运动》2002,(4):77-78

在教学实践中感到冰上课的难点有2个:站立和弯道技术.就冰上站立和弯道技术进行了技术和教学方法的初步探讨.在冰上首先要解决站立问题,能站立后滑行就比较容易;另一个难点就是弯道滑行,这点若也解决,冰上课就成功了.  相似文献   

Storage and retrieval of e-mail in a business environment: An exploratory guide     

Maureen L. Mackenzie 《Library & information science research》2002,24(4):611

Executives recognize the value of maintaining access to information. More managers filter their own e-mail rather than have assistants do this task. Organizing and storing data for future use are left to the personal preference of the individual manager. Is this in the best interest of the organization? Are data being stored in a manner causing them to be irretrievable in the future? Are irrelevant data being stored? This study investigates the strategies used to store and retrieve e-mail. The results revealed that the primary search strategy was a reliance on memory. The labels assigned to the e-mail folders triggered the user's memory. Although, in the short term, memory is sufficient for organizing and retrieving information, the lack of transferability and preservation of this information poses a danger. The association between the electronic file label and the stored information is unique to the manager and may lead to inaccessibility of relevant corporate knowledge in the future.  相似文献   

The Regrettable Necessity of Contingent Valuation     

Richard A. Epstein 《Journal of Cultural Economics》2003,27(3-4):259-274

Ordinary markets allow parties, not the state, to value property and projects. But they do not account for subjective value in such traditional contexts as condemnation. An awareness of these nonmarket values helps overcome any categorical opposition to the use of the contingent valuation method (CVM) to value cultural and environmental resources. But accurate CVM should measure all values, positive or negative, tononowners; it should apply generally to any substitute projects; and it should seek to account for diminishing marginal value of additional resource units. CVM should be used only to aggregate nonmarket preferences, not to skew the political debate to cultural or environmental objectives.  相似文献