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51.
As bibliographical classification of published journal items affects the denominator in this equation, we investigated how
the numerator and denominator of the impact factor (IF) equation were generated for representative journals in two categories
of the Journal Citation Reports (JCR). We performed a full text search of the 1st-ranked journal in 2004 JCR category “Medicine, General and Internal” (New England Journal of Medicine, NEJM, IF = 38.570) and 61st-ranked journal (Croatian Medical Journal, CMJ, IF = 0.690), 1st-ranked journal in category “Multidisciplinary Sciences” (Nature, IF = 32.182) and journal with a relative rank of CMJ (Anais da Academia Brasileira de Ciencias, AABC, IF = 0.435). Large journals published more items categorized by Web of Science (WoS) as non-research items (editorial material,
letters, news, book reviews, bibliographical items, or corrections): 63% out of total 5,193 items in Nature and 81% out of 3,540 items in NEJM, compared with 31% out of 283 items in CMJ and only 2 (2%) out of 126 items in AABC. Some items classified by WoS as non-original contained original research data (9.5% in Nature, 7.2% in NEJM, 13.7% in CMJ and none in AABC). These items received a significant number of citations: 6.9% of total citations in Nature, 14.7% in NEJM and 18.5% in CMJ. IF decreased for all journals when only items presenting original research and citations to them were used for IF calculation.
Regardless of the journal’s size or discipline, publication of non-original research and its classification by the bibliographical
database have an effect on both numerator and denominator of the IF equation.
Preliminary results of the study were presented at the 2006 ORI Research Conference on Research Integrity, Tampa, FL, December
1–3, 2006. 相似文献
52.
Liu YF Chen HI Yu L Kuo YM Wu FS Chuang JI Liao PC Jen CJ 《Neurobiology of learning and memory》2008,90(1):81-89
Cognitive functions usually involve various synaptic proteins and neurotrophic factors in the hippocampus. However, whether treadmill exercise can improve learning and memory by upregulating some of these molecules remain unraveled. To address this question, male BALB/c mice were divided into control and exercise groups, the latter group went through 4 weeks of treadmill exercise training. At the end of exercise training period, they were either tested for passive avoidance (PA) performance or sacrificed for quantifying the hippocampal levels of brain-derived neurotrophic factor (BDNF), tropomyosin-related kinase B (TrkB, the BDNF receptor), synaptotagmin (a Ca2+-dependent synaptic vesicle protein), and SNAP-25 (a presynaptic vesicular fusion protein). Our results showed that treadmill exercise training (1) increased the retention latency without affecting the fear acquisition in the PA test, (2) transiently increased the hippocampal BDNF level at 1, 2, and 4 h after the completion of exercise training, and (3) persistently increased the hippocampal protein levels of full-length TrkB, phosphorylated TrkB and synaptotagmin, but not truncated TrkB or SNAP-25. Moreover, the protein expression level of full-length TrkB or synaptotagmin was positively correlated with PA performance in mice. Finally, inhibition of TrkB signaling by K252a abolished the exercise-facilitated PA performance and upregulation of TrkB and synaptotagmin. Taken together, these data suggest that the upregulation of TrkB and synaptotagmin in the hippocampus contributes to the exercise-facilitated aversive memory. 相似文献
53.
54.
大学生学习动机问卷的初步编制 总被引:2,自引:0,他引:2
本研究结合开放式问卷所获资料,在文献研究的基础上建构了大学生学习动机的维度,编制了大学生学习动机问卷,并将之施测于427名大学生。问卷的因素分析结果表明:(1)大学生学习动机归并为求知兴趣、能力追求、声誉获取和利他取向四个维度;(2)自编大学生学习动机问卷的信度和效度指标均达到了心理测量学要求。 相似文献
55.
低出生体重是发生成年期代谢综合征的高危因素。“代谢程序化”与“营养程序化”概念的提出对人们从多层面认识该现象的内在机制有重要指导作用。随着对发生机制研究的深入,人们终将找到预防低出生体重发生成年期代谢综合征的早期干预措施。 相似文献
56.
高效率学习的心理机制研究 总被引:18,自引:1,他引:18
本课题通过一系列研究,发现要实现高效率学习,应在知识呈现符合学生认识规律的情况下,具备以下五个主要心理要素:选择性注意是实现高效率学习的前提,元认知是高效率学习的监控系统,非智力因素是高效率学习的动力源泉,学习策略是实现高效率学习的保障,内隐认知,特别是内隐学习是高效率学习的特殊形式。 相似文献
57.
《大学生主观幸福感量表》的编制 总被引:10,自引:0,他引:10
根据国内外关于主观幸福感的文献和已有的研究经验,编制了大学生主观幸福感问卷。以往大多数研究认为,主观幸福感由生活满意度和情绪体验两个基本成分构成,本研究认为主观幸福感还应包括社会性行为和人际关系等成分。对376名大学生进行初测,通过探索性因素分析,表明大学生主观幸福感由自我满意、家庭满意、消极情绪、积极情绪、精力、生活满意、社会性行为和人际关系8个维度构成,共41个项目。对511名大学生施测41个项目的主观幸福感问卷,进行验证性因素分析,结果表明,上述结构是合理的。 相似文献
58.
The new correlated 8-factor measurement structure of the Child Behavior Checklist for ages 6-18 (CBCL/6-18; T. M. Achenbach & L. A. Rescorla, 2001) derived from an American sample was used as a benchmark to evaluate its generalizability to Turkish general population (N = 5,195) and clinical (N = 963) samples. Item-level confirmatory factor analysis (CFA) was used to evaluate the adequacy of the correlated 8-factor model across 3 sample conditions (general population, clinical, and combined sample whose Total Problems scores were above the Turkish national median). The results supported the generalizability of the overall measurement structure of the CBCL to the Turkish population. 相似文献
59.
《Cognitive behaviour therapy》2013,42(3):102-112
Abstract Four-hundred-and-forty-three patients with a physical illness (355 with coronary heart disease and 88 with chronic pain), 150 unemployed persons and 623 subjects from the normal population in Jämtland, Sweden were tested using the BDI (Beck Depression Inventory). The aim of the study was to investigate whether scores on both the physical and non-physical components of the BDI differed between the patients and the other groups, or whether only the physical component was significantly higher in the patient group, and in such a case whether this could be interpreted as symptomatic of physical disease and not of depression. A cutoff score of ≥ 10 to determine mild depression and two different alternative physical and non-physical components were used. Forty-three percent of the patients with coronary heart disease and 50% of patients with chronic pain were categorized as being at least mildly depressed. Factor analyses indicated that a physical component comprising five items was the most meaningful and could best discriminate the physical symptoms. The patients' scores were significantly higher than those of the other two groups on the physical component but only higher than the normal population sample on the nun-physical component. This supports the idea that the items for physical symptoms in the BDI might be confounding when determining depression in patients with physical diseases. The non-physical component seems to be the best indicator of depression and is recommended as a complement to the total BDI scale when determining the degree of depression in patients suffering from a physical disease. 相似文献
60.
Kiyoshi Ishii Yuko Yamada Yutaka Hishimura Yasuaki Haga 《The Japanese psychological research》2002,44(1):51-56
Using the conditioned taste aversion paradigm, two experiments were conducted to examine the effects of the interval between preexposure and test and that between conditioning and test on the magnitude of latent inhibition. Experiment 1 revealed that the degree of latent inhibition was attenuated when rats were given a 21‐day interval between preexposure and test. It was also found that this attenuation was more marked in subjects which were given conditioning immediately after preexposure than those which were conditioned shortly before the test. Retention interval between preexposure and test was reduced to 12 days in Experiment 2, and exactly the same pattern of results as those found in Experiment 1 was obtained. These findings suggest that the memory of conditioning as well as that of preexposure decreases its retrievability after a long retention interval, although the former is more retainable than the latter. 相似文献