What have we learned from the recent historiography of alchemy?

Over the last two decades a new scholarship on alchemy has emerged, leading to a fundamental reformulation of knowledge about alchemists and their activities. We now know that medieval and early modern alchemists employed experiment in concert with theory to demonstrate the existence of stable "chymical atoms," which were thought to combine with one another according to a hierarchical theory of matter. Employing laboratory-based analysis and synthesis, alchemists were among the first explicitly to enunciate the principle of mass balance and to show that materials are compounded of the ingredients into which they can be physically decomposed. Perhaps even more surprisingly, these convictions and practices arose out of the interaction of alchemical practice with scholastic Aristotelianism, long viewed by historians of the Scientific Revolution as antithetical to experiment. Thus the new historiography challenges both a long-standing marginalization of alchemy itself and a commonplace view of Aristotelianism as inimical to the early modern growth of experimental science.     

Multi-informant assessment of maltreated children: convergent and discriminant validity of the TSCC and TSCYC

OBJECTIVE: This study examined the convergent and discriminant validity of two trauma symptom measures, the Trauma Symptom Checklist for Children (TSCC) [Briere, J. (1996). Trauma Symptom Checklist for Children (TSCC). Odessa, FL: Psychological Assessment Resources] and the Trauma Symptom Checklist for Young Children (TSCYC) [Briere, J. (2005). Trauma Symptom Checklist for Young Children (TSCYC). Odessa, FL: Psychological Assessment Resources]. METHODS: Children's scores on the TSCC and their caretakers' ratings on the TSCYC were analyzed in a study of 310 children presenting to one of two child abuse treatment centers. RESULTS: TSCC and TSCYC scales generally converged in their assessment of symptomatology in maltreated children. Equivalent scales measuring anxiety, depression, anger, dissociation, and sexual concerns were generally most correlated with one another. Similarly, the Posttraumatic Stress-Intrusion (PTS-I) scale of the TSCYC correlated highest with the Posttraumatic Stress (PTS) and Anxiety (ANX) scales of the TSCC, the TSCYC Posttraumatic Stress-Arousal (PTS-AR) scale was correlated with the TSCC ANX scale, and the TSCC PTS scale was most correlated with the TSCYC ANX, PTS-I, and Sexual Concerns (SC) scales. The TSCYC Posttraumatic Stress-Avoidance scale was unrelated to any TSCC scale. Discriminant function analysis revealed that the TSCC PTS scale was the best single predictor of sexual abuse-related PTSD status as identified by the TSCYC. CONCLUSIONS: The TSCC and TSCYC display moderate convergent and discriminant validity with respect to one another, despite different information sources. Nevertheless, the relatively small association between relevant TSCC and TSCYC scales indicates that different symptom informants may have different perspectives on the child's symptomatology; an outcome that may be beneficial when both measures are administered simultaneously. PRACTICE IMPLICATIONS: These results reinforce the notion that both child- and parent/caretaker report measures should be used in the evaluation of traumatized children, so that multiple sources of information can be considered simultaneously. In the current context, administration of the TSCC to the child and the TSCYC to the caretaker, when appropriate (i.e., in children 8-12 years of age) may yield more clinical information on the child's symptomatology than either measure would alone-perhaps especially in cases when one of the two respondents under- or over-reports the child's distress.     

希腊数学的新看法：原始资料,问题及出版物

尽管残存的古希腊数学文献是有限的,它的起源和后来的发展问题却得到了人们的热切关注。的确,确凿证据的缺乏促进了再现失传成就的新方法,激发了把数学与早期希腊思想的其它方面相联系的独创性。通过对晚期希腊文注释本和中世纪的阿拉伯文及拉丁文译本的研究,再现某些从原希腊语作品中失传的重要著作已成为可能。这些进展提供了有关希腊数学所有较早(但绝非陈旧)的权威性典据。     

Recovery of conditioned fear by a single postextinction shock: Effect of similarity of shock contexts and of time following extinction

Subjects in six experimental groups (n = 16 each) received one-trial passive avoidance (PA) training in which shock was delivered upon movement from a white wooden floor compartment to a black grid compartment. Then fear was extinguished (30 min) in the black compartment. After either 24 or 168 h, all the groups were treated in a room distinctively different from the training room. At each interval, one group received a shock in an apparatus similar to the conditioning box, another received a shock in a dissimilar apparatus, and another was placed in a neutral box. A PA test trial in the training apparatus indicated reinstatement of extinguished fear in all the groups given a postextinction shock except the 24-h dissimilar group. Control groups revealed that the extinction treatment was effective and that spontaneous recovery was not evident. The results were explained in terms of classical conditioning, stimulus generalization, and the broadening (flattening) of stimulus generalization gradients with time.