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   15篇
  免费   0篇
  2014年   1篇
  2013年   4篇
  2012年   1篇
  2009年   1篇
  2001年   2篇
  2000年   2篇
  1997年   1篇
  1994年   1篇
  1985年   1篇
  1973年   1篇
排序方式: 共有15条查询结果,搜索用时 15 毫秒
1.
Although a significant amount of research has focused on traditional media choice and use, and even on some ‘new’ media, these studies have either neglected the Internet and World Wide Web or were conducted prior to their recent popularity. This study offers a novel exploration of individuals' use of three Internet functions (information retrieval, information giving, and conversation capabilities) in the context of the use of other communication media. Data from 684 individuals demonstrate that the Internet is a multidimensional technology used in a manner similar to other, more traditional media. Specifically, conversation features of the Internet align with mediated interpersonal technologies (the telephone and electronic mail), whereas the Internet's information‐retrieval and information‐giving features are used in ways similar to mass media channels (newspapers, television, and books and magazines). In addition, needs fulfilled by these channels cluster in ways consistent with past research, regardless of the technologies employed to meet them.  相似文献   
2.
Public goods theories highlight an incentive system that rewards ‘free riding’ on the contributions of early contributors toward collective actions. However, because such theories focus on creation of the good, they may underestimate returns that accrue to early contributors subsequent to the good's realization. The concept of formative investment is introduced here to describe the extent to which organizations help to create public goods such as interorganizational linkages like participatory federations. Data from the CEOs of 48 organizations involved in a participatory federation were used to assess how an organization's level of formative investment is related to later patterns of dependency and interaction among federation members. Findings suggest that from a long‐term perspective, and for goods that involve communication and interaction, the incentive structure may not be so favorable for free riders. To the extent that organizations with high formative investment have the capability to envision the future and communicate that vision to potential federation partners, they may be able to both reduce free riding and secure for themselves advantageous positions in the subsequent network of relations.  相似文献   
3.
Molecular sequence data, made available in the last 15 years or so, have led to the classification of living cells into three phylogenetic domains: Bacteria, Archaea, and Eucarya. All the organisms that have been tested belonging to either domain were capable of mounting a stress response with essentially the same characteristics, regardless of the stressor. The protagonists in the cell's stress response are the stress genes and their protein products. Some of the latter are molecular chaperones. Under physiological conditions, these chaperones aid other cellular proteins to fold properly and achieve a native -functional- configuration, and to translocate from the place of synthesis to the cell's locale in which they will operate. In a stressed cell, the stress proteins that are chaperones protect other molecules from denaturation and help those partially damaged to regain a functional configuration. Thus, cell death is avoided and recovery is enhanced. The study of stress genes and proteins has progressed considerably in organisms belonging to the domains Bacteria and Eucarya. Less is known about the archaeal stress genes. Here, research with an organism from the Archaea is discussed, focusing on the stress genes of the hsp70 (dnaK) locus. Future perspectives for basic and applied research within the health sciences and biotechnology industries are presented.  相似文献   
4.
Although children born preterm or low birth weight (PT LBW) are more likely to exhibit behavior problems compared to children born at term, developmental and family processes associated with these problems are unclear. We examined trajectories of maternal depressive symptoms in relation to toddler compliance and behavior problems in families with PT LBW infants. A total of 177 infants (93 boys, 84 girls) and their mothers enrolled in the study during the infant's NICU stay. Data were collected at five time points across 2 years. Assessments of maternal depressive symptoms were conducted at all time points, and toddler compliance and opposition to maternal requests and behavior problems were assessed at 2 years. Toddlers born earlier with more health problems to mothers whose depressive symptoms increased over time exhibited the most opposition to maternal requests during a cleanup task at 24 months, consistent with multiple risk models. Mothers with elevated depression symptoms reported more behavior problems in their toddlers. The study has implications for family‐based early intervention programs seeking to identify PT LBW infants at highest risk for problem behaviors.  相似文献   
5.
When a moving target is tracked visually, spatial and temporal predictions are used to circumvent the neural delay required for the visuomotor processing. In particular, the internally generated predictions must be synchronized with the external stimulus during continuous tracking. We examined the utility of a circular visual-tracking paradigm for assessment of predictive timing, using normal human subjects. Disruptions of gaze–target synchronization were associated with anticipatory saccades that caused the gaze to be temporarily ahead of the target along the circular trajectory. These anticipatory saccades indicated preserved spatial prediction but suggested impaired predictive timing. We quantified gaze–target synchronization with several indices, whose distributions across subjects were such that instances of extremely poor performance were identifiable outside the margin of error determined by test–retest measures. Because predictive timing is an important element of attention functioning, the visual-tracking paradigm and dynamic synchronization indices described here may be useful for attention assessment.  相似文献   
6.
Initiatives and legislation by the Clinton/Gore Administration and Congress, specifically, the National Research and Education Network and the National Information Infrastructure Act, form the basis for current information infrastructure projects in both the public and private sector. This paper discusses legislative initiatives for networking and telecommunications services, and the political, technological and community infrastructures necessary to develop and support those services. Also assessed are the strategies of major infrastructure participants including the National Science Foundation, cable television and regional and long distance telecommunications companies, educational institutions and the Internet community, and community groups and local governments. where he teaches and administers courses in information systems management and telecommunications for mid-career information technology and network professionals at Northern California high-technology corporations.  相似文献   
7.
8.
Innovation adoption research has demonstrated that organizational features and perceived benefits of innovations play significant roles in explaining organizational‐level decisions to adopt new technologies. Beyond such motivations, however, social pressures operating at the interorganizational level have been proposed to influence the decision to adopt innovations, even without regard to any proven or anticipated benefit from the innovation itself. To empirically determine the influence of organizational features, perceived benefits, and social pressures on organizations' innovation adoption decisions, this study examined the decisions of 288 organizations to adopt Internet websites. Organizational social pressures were found to be the most significant discriminators of adopters and non adopters, although they were not particularly important in predicting the likelihood of future adoption for those organizations currently without websites. This finding suggests that social pressures are significant in innovation adoption, but that they may have their strongest effect during the early phases of innovation diffusion. Organizational features and perceived benefits were also reasonable discriminators of adopters and nonadopters as well as effective predictors of the likelihood of adoption for nonadopters. To a lesser degree, these factors were also predictive of the stage of adoption for those organizations that have already adopted websites.  相似文献   
9.
The aim of this work was to study the effects of valence and age on visual image recognition memory. The International Affective Picture System (IAPS) battery was used, and response time data were analyzed using analysis of variance, as well as an ex‐Gaussian fit method. Older participants were slower and more variable in their reaction times. Response times were longer for negative valence pictures, however this was statistically significant only for young participants. This suggests that negative emotional valence has a strong effect on recognition memory in young but not in old participants. The τ parameter, often related to attention in the literature, was smaller for young than old participants in an ex‐Gaussian fit. Differences on the τ parameter might suggest poorer attentional performance in old participants.  相似文献   
10.
Three general issues emerge from the preceding papers: a confusion between judgement and related activities such as decision making, problem solving, and attitudes; differences in the underlying assumptions about the nature of judgement; and different approaches for testing the adequacy of theories human judgement. The implications of these issues for studying human judgement processes and for future research priorities in this area are briefly discussed.  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