排序方式: 共有77条查询结果,搜索用时 15 毫秒
1.
Danny Helman 《Teaching Statistics》2004,26(1):26-28
The national lottery is often portrayed as a game of pure chance with no room for strategy. This misperception seems to stem from the application of probability instead of expectancy considerations, and can be utilized to introduce the statistical concept of expectation. 相似文献
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Danny Bavli Elishai Ezra Daniel Kitsberg Margarita Vosk-Artzi Shashi K. Murthy Yaakov Nahmias 《Biomicrofluidics》2016,10(2)
Cell-cell interactions play a key role in regeneration, differentiation, and basic tissue function taking place under physiological shear forces. However, current solutions to mimic such interactions by micro-patterning cells within microfluidic devices have low resolution, high fabrication complexity, and are limited to one or two cell types. Here, we present a microfluidic platform capable of laminar patterning of any biotin-labeled peptide using streptavidin-based surface chemistry. The design permits the generation of arbitrary cell patterns from heterogeneous mixtures in microfluidic devices. We demonstrate the robust co-patterning of α-CD24, α-ASGPR-1, and α-Tie2 antibodies for rapid isolation and co-patterning of mixtures of hepatocytes and endothelial cells. In addition to one-step isolation and patterning, our design permits step-wise patterning of multiple cell types and empty spaces to create complex cellular geometries in vitro. In conclusion, we developed a microfluidic device that permits the generation of perfusable tissue-like patterns in microfluidic devices by directly injecting complex cell mixtures such as differentiated stem cells or tissue digests with minimal sample preparation. 相似文献
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Anteneh Ayanso Dipanjan Chatterjee Danny I. ChoAuthor vitae 《Government Information Quarterly》2011,28(4):522-532
E-Government has received significant attention as digital technologies transcend private businesses and serve as a basic source of transformation in government functions. One most notable project is the United Nations Public Administration Network (UNPAN) that assesses the e-Government readiness of the 192 member nations according to a quantitative composite index involving website assessment, telecommunication infrastructure, and human resource endowment. However, the UNPAN index, though rich in depth and breadth of data collection, relies on a method that is a simple mathematical average of the values of the variables measured. This paper revisits the UNPAN index and proposes alternative indices based on principal components analysis (PCA). Using the UNPAN survey data, four different versions of the index are presented and the resulting rankings of the nations are examined vis-à-vis the existing ranking. The theoretical and policy implications of the proposed methodology and its results are discussed. 相似文献
4.
This paper examines an application for a franchise license in Australia's professional rugby league competition, the National Rugby League (NRL). Frooman's (1999) typology of stakeholder influence strategies is used to analyse the negotiation of resource relationships between a Gold Coast franchise bid team and its key stakeholders. Primary data came from 12 interviews with nine key actors in the bid process; these were buttressed by secondary data. Frooman's typology provided a useful heuristic, but did not fully account for the critical role of firm legitimacy in stakeholders’ choice of influence strategies. The bid team negotiated stakeholders’ initial direct withholding strategies by creating access to the intangible resource of legitimacy. This subsequently provided access to material resources such as finance, a new stadium, and, ultimately, a franchise license. The findings are of note to practitioners and scholars interested professional sport and stakeholder theory. 相似文献
5.
Bruce Fuller Gretchen Caspary Sharon Lynn Kagan Christiane Gauthier Danny Shih-Cheng Huang Judith Carroll Jan McCarthy 《Early childhood research quarterly》2002,17(4):240
Various initiatives over the past 40 years have aimed to strengthen children’s early learning and social development. One policy theory—manifest in recent welfare reforms—postulates that requiring single mothers to work more outside the home will advance children’s well-being. We first examine whether young children’s social development is related to maternal employment among 405 women who entered welfare-to-work programs in 1998. For girls, age 24–42 months, we found that their mother’s recent employment duration was significantly associated with a lower incidence of aggressive behavior and inattentiveness, measured by two scales from the Child Behavior Checklist (CBCL 2/3). Yet these relationships with employment were weaker than more robust associations observed for proximal child-rearing practices, including the frequency of reading with the child, enforcing a regular bedtime, the propensity to spank the child, as well as levels of maternal depression. We then assess whether broader measures of the mother’s economic security help to predict these proximal determinants of development. We observed that food security and indicators of job quality consistently predicted the proximal factors. Structural equation models (SEM) provided additional evidence that these broader indicators of economic security, but not recent employment per se, operated through parenting practices and maternal depression to influence girls’ and boys’ social development. These results are consistent with recent findings from random-assignment experiments, showing that employment gains rarely affect child outcomes unless mothers’ income and broader economic security also improve. 相似文献
6.
Richard J. Viken Danny L. Moore John F. Knutson David J. Fordyce 《Learning & behavior》1982,10(2):135-140
The effects of isolation and handling on the reactivity of rats to two tactile stimuli were assessed in two experiments. In the first experiment, reactivity to more intense footshock was increased in rats raised in isolation but was not affected by handling by an experimenter. In the second experiment, increased reactivity to airpuff stimuli presented to the dorsal surface of isolation-reared rats was reduced by handling. The data suggest that the effects of handling on shock-motivated behaviors are not due to altered reactivity to shock and that the effect of housing or handling must be considered in behavioral tests in which reactivity to tactile stimulation might play a role as dependent or independent variables. 相似文献
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Danny J. Johnson 《Decision Sciences Journal of Innovative Education》2011,9(2):299-306
This hands‐on project uses a paper helicopter to teach students how to distinguish between common and special causes of variability when developing and using statistical process control charts. It allows the student to experience a process that is out‐of‐control due to imprecise or incomplete product design specifications and to discover how the process can be brought into control through the use of standardized product specifications and associated construction procedures. It also allows the student to experience common causes of variability, to distinguish these from the special causes of variability resulting from the incomplete design specifications, and to discover how standardization reduces process variability. The project has been used in both undergraduate and MBA classes and demonstrates these concepts in a way that is easy for the student to understand and remember. 相似文献
10.
For self-regulated learning to be effective, students need to be able to accurately assess their own performance on a learning task and use this assessment for the selection of a new learning task. Evidence suggests, however, that students have difficulties with accurate self-assessment and task selection, which may explain the poor learning outcomes often found with self-regulated learning. In experiment 1, the hypothesis was investigated and confirmed that observing a human model engaging in self-assessment, task selection, or both could be effective for secondary education students’ (N = 80) acquisition of self-assessment and task-selection skills. Experiment 2 investigated and confirmed the hypothesis that secondary education students’ (N = 90) acquisition of self-assessment and task-selection skills, either through examples or through practice, would enhance the effectiveness of self-regulated learning. It can be concluded that self-assessment and task-selection skills indeed play an important role in self-regulated learning and that training these skills can significantly increase the amount of knowledge students can gain from self-regulated learning in which they choose their own learning tasks. 相似文献