首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   45篇
  免费   4篇
  2023年   1篇
  2021年   3篇
  2020年   1篇
  2019年   4篇
  2018年   3篇
  2017年   5篇
  2016年   3篇
  2015年   2篇
  2014年   3篇
  2013年   2篇
  2012年   2篇
  2011年   4篇
  2005年   2篇
  2001年   1篇
  1993年   1篇
  1987年   1篇
  1986年   1篇
  1982年   1篇
  1981年   2篇
  1980年   2篇
  1979年   1篇
  1978年   2篇
  1968年   2篇
排序方式: 共有49条查询结果,搜索用时 15 毫秒
31.
Childhood cognitive and test-taking abilities have long-term implications for educational achievement and health, and may be influenced by household environmental exposures and neighborhood contexts. This study evaluates whether age 5 scores on the Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI-R, administered in English) are associated with polycyclic aromatic hydrocarbon (PAH) exposure and neighborhood context variables including poverty, low educational attainment, low English language proficiency, and inadequate plumbing. The Columbia Center for Children’s Environmental Health enrolled African-American and Dominican-American New York City women during pregnancy, and conducted follow-up for subsequent childhood health outcomes including cognitive test scores. Individual outcomes were linked to data characterizing 1-km network buffers around prenatal addresses, home observations, interviews, and prenatal PAH exposure data from personal air monitors. Prenatal PAH exposure above the median predicted 3.5 point lower total WPPSI-R scores and 3.9 point lower verbal scores; the association was similar in magnitude across models with adjustments for neighborhood characteristics. Neighborhood-level low English proficiency was independently associated with 2.3 point lower mean total WPPSI-R score, 1.2 point lower verbal score, and 2.7 point lower performance score per standard deviation. Low neighborhood-level educational attainment was also associated with 2.0 point lower performance scores. In models examining effect modification, neighborhood associations were similar or diminished among the high PAH exposure group, as compared with the low PAH exposure group. Early life exposure to personal PAH exposure or selected neighborhood-level social contexts may predict lower cognitive test scores. However, these results may reflect limited geographic exposure variation and limited generalizability.  相似文献   
32.
As humans age, the amount of intra-individual variability (IIV) present in both their gait and their cognitive performance tends to increase. Both gait and cognitive IIV are associated with attentional control and with cerebrovascular disease, suggesting that the IIV in gait and cognitive function should be strongly correlated in the elderly. In this study temporal gait variability was determined from a 60-second period of walking. Cognitive variability was determined from two decision-time tasks assessing inhibition. Despite the presence of substantial amounts of gait and cognitive IIV in 71 elderly individuals, there were no significant correlations between measures of cognitive and gait IIV, suggesting that different factors drive IIV in the motor and cognitive performance of older individuals. These results are not consistent with the common cause theory of aging, which predicts that cognitive and sensorimotor performance should show related declines due to age-related disruption of a common neurological substrate.  相似文献   
33.
A simple BASIC language program allows the standard TRS-80 tape recorder to function as a voice key to control the timing or running of an experiment.  相似文献   
34.
The goal of this study was to use novel approaches that do not require the use of arbitrary cut-points (i.e., latent profile/transition analysis) to evaluate the prevalence and stability of the positive illusory bias (PIB) in young adolescents with attention-deficit/hyperactivity disorder (ADHD). Participants were 326 middle-school students diagnosed with ADHD (Mage = 12.26 years, 71% male, 77% Caucasian). The Self-Perception Profile for Children (SPPC) was completed by participants and their parents at baseline and again 12 and 18 months later. Cross-sectional results revealed four subgroups based on SPPC responses. Only a small subset (18.4%) of youth with ADHD exhibited a global PIB, across the behavioral, scholastic, and social domains, with an additional 29% displaying a PIB in the scholastic domain only. Additionally, average parent/adolescent-rated competence within each subgroup was in line with an objective measure of scholastic competence (i.e., grades). When examined longitudinally, only a PIB in the social domain was stable across the 18-month study period and only for half of the sample. These findings suggest that the PIB is not ubiquitous in youth with ADHD, with many young adolescents rating themselves accurately relative to their parents and their grades. Further, when stability across time is considered, the PIB may be specific to social functioning, as opposed to a global, cross-domain phenomenon. Implications for the future measurement of the PIB are discussed.  相似文献   
35.
This paper explores the phenomenon of green prosumption with a view to theorising the phenomenon and highlighting the challenges and opportunities this particular subculture creates for marketers of green commodities. Narratives of young green prosumers were gathered from 18 phenomenological in‐depth interviews. Capturing green prosumer experiences and subjective meanings, three thematic categories of green prosumption practices, (a) contraction, (b) control, and (c) creation, are postulated in the study. It also highlights several unforeseen challenges as well as a vast array of opportunities emerging from the three green prosumer segments identified in the study: semi‐green prosumers, empowered green prosumers, and liberated green prosumers. This study provides green commodity marketers with a set of recommendations to exploit opportunities in these largely untapped market segments.  相似文献   
36.
The purchase and maintenance of new and used mini- and microcomputers require knowledge of the comparative advantages and disadvantages of available systems, sources of discounted and used computers, and a set of strategies and techniques for maintaining the operation of the computers throughout their useful life. This paper addresses each of these areas and suggests sources of additional information.  相似文献   
37.
Visually handicapped students learn tape-recorded materials in PSI format while a minicomputer interfaced to the student-operated, tape playback mechanisms collects data on independent study activities. The minicomputer hardware and software system is described and typical learning data are discussed.  相似文献   
38.
Microcomputers such as the TRS-80, when equipped with a simple digital input-output interface, become capable of completely controlling laboratory experiments. BASIC language software has been developed that allows simplified programming of experiments using the “state” concepts of the SKED system.  相似文献   
39.
Walk ratio, defined as step length divided by cadence, indicates the coordination of gait. During free walking, deviation from the preferential walk ratio may reveal abnormalities of walking patterns. The purpose of this study was to examine the impact of rhythmic auditory cueing (metronome) on the neuromotor control of gait at different walking speeds. Forty adults (mean age 26.6 ± 6.0 years) participated in the study. Gait characteristics were collected using a computerized walkway. In the preferred walking speed, there was no significant difference in walk ratio between uncued (walk ratio = .0064 ± .0007 m/steps/min) and metronome-cued walking (walk ratio = .0064 ± .0007 m/steps/min; p = .791). A higher value of walk ratio at the slower speed was observed with metronome-cued (walk ratio = .0071 ± .0008 m/steps/min) compared to uncued walking (walk ratio = .0068 ± .0007 m/steps/min; p < .001). The walk ratio was less at faster speed with metronome-cued (walk ratio = .0060 ± .0009 m/steps/min) compared to uncued walking (walk ratio = .0062 ± .0009 m/steps/min; p = .005). In healthy adults, the metronome cues may become an attentional demanding task, and thereby disrupt the spatial and temporal integration of gait at nonpreferred speeds.  相似文献   
40.
Fish live in three-dimensional environments, through which they swim with three translational and three rotational degrees of freedom. Navigating through such environments is recognised as a difficult problem, yet fish, and other animals that swim and fly, achieve this regularly. Despite this, the vast majority of research has considered how animals navigate horizontally from place to place and has ignored the vertical component. Here, we test the importance of the vertical axis of space for fish solving a three-dimensional spatial cognition task. We trained banded tetras (Astyanax fasciatus) to learn the route towards a goal in a rotating Y-maze in which the arms led either up and left or down and right in an environment that allowed access to visual landmarks providing horizontal and vertical information. Our results revealed that the landmarks increased navigational efficiency during training. However, these landmarks were ignored when the horizontal and vertical components were placed in conflict with each other by rotating the maze 90° during testing. From this surprising result, we conclude that the cues that are present in the vertical axis (presumably hydrostatic pressure) override landmark cues that have been shown to be salient in experiments that only consider the horizontal component of space.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号