Suchergebnisse

In her dedicated promotion of feminism and pacifism, especially during the 1930s, Vera Brittain (1893–1970) was strongly influenced by Ber­trand Russell's writings, especially Marriage and Morals (1929) and Which Way to Peace? (1936). Both were members of the Peace Pledge Union, and she continued as a sponsor after Russell abandoned his pac­ifism soon after the beginning of the Second World War. She admired his political and social activism in the aftermath of that war, endorsing it as much as her family situation allowed; and, as chairman of the Peace News board, Brittain intervened in Russell's support when a dispute broke out between him and the editor. Although their rela­tionship was personally limited, Russell's influence on her opinions and actions was profound.

Until the 1970s, the conventional wisdom in educational circles was that mathematics was culture-free knowledge. However, recent anthropological & historical research demonstrates that mathematics, like other forms of knowledge, is humanly & socially constructed. Western mathematics, imbued with values associated with rationalism, universalism, & technological development, has provided a covert & effective instrument of Western cultural imperialism, although its strength is now being lessened by educational developments that emphasize the relative nature of mathematics as cultural knowledge. The possibilities of alternative mathematical curricula are considered. Modified AA

We have examined the dynamical behavior of the kink solutions of the one-dimensional sineGordon equation in the presence of a spatially periodic parametric perturbation. Our study clarifies and extends the currently available knowledge on this and related nonlinear problems in four directions. First, we present the results of a numerical simulation program that are not compatible with the existence of a radiative threshold predicted by earlier calculations. Second, we carry out a perturbative calculation that helps interpr~t those previous predictions, enabling us to understand in depth our numerical results. Third, we apply the collective coordinate formalism to this system and demonstrate numerically that it reproduces accurately the observed kink dynamics. Fourth, we report on the occurrence of length-scale competition in this system and show how it can be understood by means of linear stability analysis. Finally, we conclude by summarizing the general physical framework that arises from our study. ; A.S. is supported by the Ministerio de Educaci6n y Ciencia (Spain) and the Fulbright Fund, by Direcci6n General de Investigaci6n Cientffica y Tecnica (Spain) through Project No. PB92-0378, and by the European Union (Network on Nonlinear Spatio-Temporal Structures in Semiconductor, Fluids, and Oscillator Ensembles). He also thanks the Los Alamos National Laboratory for warm hospitality and a productive atmosphere. Work at Los Alamos is performed under the auspices of the U.S. Department of Energy. ; Publicado

Critical Issues in Mathematics Education presents the significant contributions of Professor Alan Bishop within the mathematics education research community. Six critical issues, each of which have had paramount importance in the development of mathematics education research, are reviewed and include a discussion of current developments in each area. Teacher decision making, spatial/visualizing geometry, teachers and research, cultural/social aspects of mathematics education, socio political issues, and values serve as the basic issues discussed in this examination of mathematics education over the last fifty years during which Professor Bishop has been active in the field. A comprehensive discussion of each of these topics is realized by offering the reader a classic research contribution of Professor Bishop's together with commentary and invited chapters from leading experts in the field of mathematics education. Critical Issues in Mathematics Education will make an invaluable contribution to the ongoing reflection of mathematic education researchers worldwide, but also to policy makers and teacher educators who wish to understand some of the key issues with which mathematics education has been and still is concerned, and the context within which Professor Bishop's key contributions to these research issues were made.

We study the possibility of kink motion induced by pure ac driving in damped nonlinear lattices, focusing on the Frenkel-Kontorova and Toda models. Numerical simulations of the Frenkel-Kontorova model show no evidence for steady kink motion. We point out that momentum-balance in addition to energy-balance arguments are needed to understand the translation of the collective excitation. Finally, our result is discussed in view of related theoretical predictions and numerical simulations. ; Support from a MEC/Fulbright grant, from DGICyT (Spain) under Project No. PB92-0248, and from the European Union Network ERBCHRXCT930413. Work at Zaragoza was supported by DGICyT (Spain) under Project No. PB92-0361, and by the European Union (NETWORK on Nonlinear Approaches to Coherent and Fluctuating Processes in Condensed Matter and Optical Physics). Work at Los Alamos was performed under the auspices of the U.S. Department of Energy. ; Publicado

A model of surface growth given by a two-dimensional discrete, driven, damped sine-Gordon equation is studied using Langevin dynamics. Our large-scale simulations show that the equilibrium Kosterlitz-Thouless roughening transition splits into two crossovers (or transitions) under the external force of, e.g., vapor-surface chemical potential difference. Three different regimes are characterized in terms of roughness, growth rate, and height-height correlations-the onset of a rough phase is accompanied by the suppresion of oscillatory growth. Our results are interpreted consistently within a renormalization group framework. We discuss the generality of our conclusions and propose specific comparisons with experiments ; Partially supported by DGICyT (Spain) Grant No. PB92-0248, by MEC (Spain)/Fulbright, and by the European Union Network ERBCHRXCT930413. Work at Los Alamos is performed under the auspices of the U.S. DOE. ; Publicado

On December 6, the Department of Justice submitted a written Declaration claiming that Pentagon compliance with a Court's order to allow transgender candidates to apply for enlistment as of January 1 would "impose extraordinary burdens" on a military that "would not be adequately and properly prepared to begin processing transgender applicants." The Declaration, however, rewrites the history of transgender military policy and distorts the evidence, disregarding that the Court's order did not create new military policy, but only directed the military to return to its own policy on transgender enlistment as defined by the current Secretary of Defense. Three former Service Secretaries and one former Acting Under Secretary of Defense for Personnel and Readiness have confirmed that the military had already completed many of the necessary preparations for the lifting of the enlistment ban by the time of the Presidential transition in January, 2017. The Declaration's assertion that implementing the Court's order will impose "extraordinary burdens" because the military "would not be adequately and properly prepared" is incorrect. The Declaration's assertion that transgender applicants for military service are uniquely complicated and difficult to evaluate is incorrect. The Declaration's assertions that recruiters will not understand government identification documents that reflect changes in gender, and are not prepared to obtain supporting medical documents, are incorrect. The Declaration's assertion that the Court's order will result in transgender applicants not receiving "the appropriate medical and administrative accession screening" is incorrect. The Declaration's assertion that "key personnel" have "rotated" into different duties, therefore setting back the pace of implementation and requiring more time, is not a reason for delay.