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Thermal expansion, electrical resistivity, magnetization, and specific heat measurements were performed on URu2-xFexSi2 single crystals for various values of Fe concentration x in both the hidden-order (HO) and large-moment antiferromagnetic (LMAFM) regions of the phase diagram. Our results show that the paramagnetic (PM) to HO and LMAFM phase transitions are manifested differently in the thermal expansion coefficient. The uniaxial pressure derivatives of the HO/LMAFM transition temperature T0 change dramatically when crossing from the HO to the LMAFM phase. The energy gap also changes consistently when crossing the phase boundary. In addition, for Fe concentrations at xc ≈ 0.1, we observe two features in the thermal expansion upon cooling, one that appears to be associated with the transition from the PM to the HO phase and another one at lower temperature that may be due to the transition from the HO to the LMAFM phase.

A prevention trial tested the efficacy of "INSIGHTS into Children's Temperament" as compared to a Read Aloud attention control condition in reducing student disruptive behavior and enhancing student competence and teacher classroom management. Participants included 116 first and second grade students, their parents, and their 42 teachers in six inner city schools. Teachers completed the Sutter-Eyberg Student Behavior Inventory (SESBI) and the Teacher's Rating Scale of Child's Actual Competence and Social Acceptance (TRS) at baseline and again upon completion of the intervention. Boys participating in "INSIGHTS," compared with those in the Read Aloud program, showed a significant decline in attentional difficulties and overt aggression toward others. Teachers in "INSIGHTS," compared to those in the attention control condition, reported significantly fewer problems managing the emotional-oppositional behavior, attentional difficulties, and covert disruptive behavior of their male students. They also perceived the boys as significantly more cognitively and physically competent. (Contains 5 tables.)

This article reexamines spontaneity as an important, albeit neglected, mechanism in collective action dynamics, and elaborates on its operation and effects in protest events and social movements. We do not presume that spontaneity is routinely at play in all collective actions. Rather, based on our grounded analysis of historical and ethnographic data, we contend that spontaneity is triggered by certain conditions: nonhierarchical organization; uncertain/ambiguous moments and events; behavioral/emotional priming; and certain ecological/spatial factors. We conclude by elaborating why the activation of spontaneous actions matters in shaping the course and character of protest events and movements, and we suggest that spontaneity be resuscitated in the study of collective action and everyday life more generally.

This article provides an analytic overview of scholarly work on the concept of collective identity by considering its conceptualization and various empirical manifestations, the analytic approaches informing its discussion and analysis, and a number of theoretical and empirical issues, including a synopsis of the symbolic means through which collective identity is expressed and asserted. Although the scholarly roots of the concept can be traced to classical sociologists such as Marx and Durkheim, and more recently to the mid-century work of scholars such as Erik Erickson and Erving Goffman, it was not until the latter quarter of the past century that the concept generated an outpouring of work invoking the concept directly or referring to it indirectly through the linkage of various collectivities and their identity interests via such concepts as identity politics, identity projects, contested identities, insurgent identities, nationalism, imagined communities, identity movements and even social movements more generally. Conceptually, the essence of collective identity resides in a shared and interactive sense of "we-ness" and "collective agency." Although the concept is distinguished analytically from both personal identity and social identity, the three types of identity clearly overlap and interact. Empirically, collective identity can surface in a variety of contexts, although the preponderance of research has focused on its connection to gender, ethnicity, religion, nationalism and particularly social movements. Analytically, collective identity has generally been discussed from a primordial, structural, and/or constructionist standpoint. Primordial and structural approaches are discussed as variants of essentialism, which is contrasted to constructionism. Among other things, constructionism focuses attention on the symbolic expression and maintenance of collective identities.