Cluster Analysis for Cognitive Diagnosis: Theory and Applications

Latent class models for cognitive diagnosis often begin with specification of a matrix that indicates which attributes or skills are needed for each item. Then by imposing restrictions that take this into account, along with a theory governing how subjects interact with items, parametric formulations of item response functions are derived and fitted. Cluster analysis provides an alternative approach that does not require specifying an item response model, but does require an item-by-attribute matrix. After summarizing the data with a particular vector of sum-scores, K-means cluster analysis or hierarchical agglomerative cluster analysis can be applied with the purpose of clustering subjects who possess the same skills. Asymptotic classification accuracy results are given, along with simulations comparing effects of test length and method of clustering. An application to a language examination is provided to illustrate how the methods can be implemented in practice.     

Neural correlates of Traditional Chinese Medicine induced advantageous risk-taking decision making

This fMRI study examined the neural correlates of the observed improvement in advantageous risk-taking behavior, as measured by the number of adjusted pumps in the Balloon Analogue Risk Task (BART), following a 60-day course of a Traditional Chinese Medicine (TCM) recipe, specifically designed to regulate impulsiveness in order to modulate risk-taking behavior. The 14 participants recruited for this study were randomly assigned to the experimental and control groups and the TCM recipe (Panax, 520 mg; Astragalus membranaceous Bunge, 520 mg; Masnetitum, 840 mg; Ostrea gigas Thumb, 470 mg; Thinleaf Milkwort Root Radix Polygalae, 450 mg; and Os Draconis, 470 mg) was administered, as a diet supplement, to the seven participants in the experimental group. The neural activity of the two groups was monitored by a 3T MRI scanner, before and after the 60-day treatment. Associated with the improved advantageous risk-taking behavior seen in the experimental group, significantly stronger blood oxygenation level dependent (BOLD) responses were observed in the bilateral dorsolateral prefrontal cortex (DLPFC), left putamen, left thalamus, right insula, and right anterior cingulate cortex (ACC), regions which have previously been reported as being involved in risk-taking decision making. The effect of the TCM in improving advantageous risk-taking decision making appears to have been related to the enhanced efficiency of the cognitive affective system, the PFC–ACC–insula–striatum network, which functions to inhibit impulsiveness, to sensitize reward-related information, and to allow the opportunity, during risk estimation, to evaluate potential gains and losses. The findings of this study suggest that interventions acting on factors modulating risk-taking decision making could have a beneficial effect in terms of optimizing risk-taking behavior.     

八段锦详解

八段锦是我国古代民间流行最广的导引术之一,分为两大类:坐式八段锦与立式八段锦,即文八段锦(坐式静功)和武八段锦(站式动功). 坐式八段锦主要起源于八仙之一钟离权所传之八段锦.钟离八段锦因吕洞宾手书于石壁而得以流传下来.     

朱熹与康德道德哲学契合之探寻

朱熹与康德作为中西方最重要的哲学家,对道德的思考有着一定的相似性.他们都试图通过把握一个超验概念进而展开他们的道德哲学;认为道德法则在本质上是先验、普遍与绝对的;个人的幸福和欲望应从属于普遍的道德法则,主张道德自律;坚持道义优先,拒绝对道德进行功利主义的理解.但是由于两种道德哲学的根本价值指向不同,结果也导致了两种理论的不同遭遇和命运.     

社会主义核心价值体系的基本属性

尽管学界对社会主义核心价值体系的内涵、理论框架等进行了富有成果的讨论,但对于社会主义核心价值体系的基本属性仍然存在模糊认识.社会主义核心价值体系的基本属性应体现在三个方面:普遍性与民族性、单元性与复合性、保护性与扩展性.即社会主义核心价值体系应具有普遍价值理念,民族精神的精华,道德单元构成,道德单元与道德意识、实践的复合,保护性"硬核",自我完善与不断创新等属性.     

利益集团如何用“中和之道”守护既得利益

以道家、道教的“智慧之眼”审视,利益集团应该如何用“中和之道”守护自己的既得利益？若以人之常情分析,谁不想守护住自己的既得利益？谁又不想把自己的既得利益代代相传？有谁愿意君子之泽、当世而斩？然而,既得利益集团从历史走到现在,往往却是事与愿违,眼睁睁看着自己的财富从手上丢失,为什么会如此？有没有什么路径进人可以解决这一难题？     

道教法术“家书式”考

道教法术与民间术数有着紧密的联系。道法渊源于民间术数,是民间术数的精致化、系统化。而在民间法术走向精致化、系统化的过程中,戒律传授与经篆传授是至关重要的。然而,在法术的实践中,民间的法师往往无篆可授,行法而不受篆的情况屡见不鲜。在民众的实际宗教需要中,“法”比“篆”更为重要,     

“100% of anything looks good”: The appeal of one hundred percent

People overweight certainty, even when certainty is only an illusion. A vaccine that was described as 100% effective against 70% of disease targets was preferred to one described as 70% effective against 100% of disease targets (Studies 1 and 2). The appeal of 100% extends beyond the probability attribute. In Study 2, participants preferred both of the vaccines above to normatively equivalent vaccines that were less than 100% effective toward fewer than 100% of targets. In Study 3, participants preferred a 100% discount on a cup of coffee every 10 days to other more frequent, but lower amount, discounts. This preference evaporated, however, when savings were framed as points rather than as percentage discounts. We propose that people view 100% as a salient reference point and overweight it in those domains where it cannot be exceeded (e.g., probability, discount); the overweighting is weaker in domains where 100% can be exceeded (e.g., target range, points).     

Precedence-effect-induced enhancement of prepulse inhibition in socially reared but not isolation-reared rats

Attention to a prepulse presented shortly before a startling stimulus enhances prepulse inhibition (PPI) of startle in normal people, but not in schizophrenics. Fear conditioning for the prepulse enhances PPI in socially reared, but not isolation-reared, rats. In humans, selective attention to acoustic signals against masking can be facilitated by precedence-effect-induced perceived spatial separation between the signal and the masker. This study investigated whether perceived spatial separation between a prepulse and a noise masker enhances PPI in socially reared rats and isolation-reared rats. The results show that both PPI and conditioning-induced PPI enhancement were larger in socially reared rats than in isolation-reared rats. More important, in socially reared, but not isolation-reared, rats, a further PPI enhancement was induced by precedence-effect-induced perceived separation between a prepulse and a masker only after the prepulse became fear conditioned. Thus, perceived separation facilitates normal rats’ attention to a conditioned prepulse and enhances PPI. Isolation rearing impairs rats’ ability to attend to ecologically significant acoustic events.     

Gender differences in the relationships of cardiovascular symptoms and somatosensory amplification to mortality

Symptoms of angina and dyspnea predict coronary artery disease and death less well in women than in men. Greater somatosensory amplification - a psychosocial propensity to report symptoms of physical discomfort - may lead women to report relatively high levels of angina and dyspnea for reasons unrelated to coronary disease, reducing their associations with mortality. We assessed this hypothesis in a nationally representative survey of U.S. adults. When stratified by gender, angina and dyspnea significantly predicted mortality among men, but predicted it less well among women. After adjusting for amplification, cardiovascular symptoms did not predict mortality among women, but amplification was positively associated with mortality among older women.