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Warning signals in chemically defended organisms are critical components of predator-prey interactions, often requiring multiple coordinated display components for effective communication. When threatened by a predator, venomous coral snakes (genus Micrurus) display a vigorous, non-locomotory thrashing behavior that has previously been qualitatively described. Given the high contrast and colorful banding patterns of these snakes, this thrashing display is hypothesized to be a key component of a complex aposematic signal under strong stabilizing selection across species in a mimicry system. By experimentally testing snake response across simulated predator cues, we analyzed variation in the presence and expression of a thrashing display across five species of South American coral snakes. Although the major features of the thrash display were conserved across species, we found that predator cue type, snake body size, and species identity predict significant inter- and intraspecific variation in the propensity to perform a display, the duration of thrashing, and the curvature of snake bodies. We also found an interaction between curve magnitude and body location that clearly shows which parts of the display vary most across individuals and species. Our results suggest that contrary to the assumption that all Micrurus species and individuals perform the same display, a high degree of variation exists despite presumably strong selection to conserve a common signal. This quantitative behavioral characterization presents a new framework for analyzing the non-locomotory motions displayed by snakes in a broader ecological context, especially for signaling systems with complex interaction across multiple modalities.

Un análisis cuantitativo de las serpientes coral (Genero: Micrurus) revela una variación inesperada de los comportamientos anti-depredadores estereotipados dentro de un sistema de mímicoLas señales de advertencia en organismos con defensas químicas son componentes críticos de las interacciones depredador-presa, que a menudo requieren múltiples componentes de visualización coordinados para una comunicación efectiva. Cuando son amenazadas por un depredador, las serpientes de coral venenosas (género Micrurus) muestran un comportamiento vigoroso de coletazos, no locomotor, que solo se ha descrito cualitativamente. Dado el alto contraste y los patrones de bandas coloridas de estas serpientes, se supone que este comportamiento de coletazos es un componente clave de una señal aposemática compleja bajo una fuerte selección estabilizadora entre especies en un sistema de mímica. Al probar experimentalmente la respuesta de las serpientes a través de señales simuladas de depredadores, analizamos la variación en la presencia y la expresión de coletazos en cinco especies de serpientes de coral de América del Sur. Aunque las principales características de la muestra se conservaron en todas las especies, encontramos que el tipo de señal de depredación, el tamaño del cuerpo de la serpiente y la especie en si predicen una variación significativa inter e intraespecífica en la probabilidad a realizar la conducta, la duración del coletazo y la curvatura del cuerpo de las serpientes. También encontramos una interacción entre la magnitud de la curva y la ubicación del cuerpo que muestra claramente qué partes del cuerpo varían más entre individuos y especies. Nuestros resultados sugieren que, contrariamente a la suposición de que todas las especies e individuos realizan el mismo comportamiento, persiste un alto grado de variación en el comportamiento de coletazos exhibido por las serpientes de coral Micrurus a pesar de una selección presumiblemente fuerte para converger en una señal común. Esta caracterización cuantitativa del comportamiento presenta un nuevo marco para analizar los movimientos no locomotores mostrados por las serpientes en un contexto ecológico más amplio, especialmente para los sistemas de señalización con interacción compleja a través de múltiples modalidades. Translated to Spanish by YE Jimenez (yordano_jimenez@brown.edu).

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This paper reports the conceptual design, analysis, and modeling of the electromechanical behavior of dome actuators. The geometric parameters of the actuator (dome thickness, width, radius, and depth), poling direction, electric field, and material properties (elastic compliance, piezoelectric constants, and dielectric permittivity) have been taken into account in the modeling work. The results of the analysis indicate that a dome actuator with a tangentially alternating poling direction and electric field (Case C) exhibits much larger displacement and force responses than dome actuators with other poling directions and electric fields. The first mode of natural frequency of the Case C dome actuator also was investigated, and its predicted performance was compared with that of moonie and rainbow actuators. The findings of this research clearly demonstrate the merit of design optimization of electromechanical devices.

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A sample of speech acts in everyday discourse referring to persons or events having to do with the term mental retardation was analyzed in order to investigate the belief that language use both constructs and reflects cultural norms that define the social roles of persons reduced to object status through categorical membership. Speech acts gathered suggest four emergent themes: the discourse of category membership, the dichotomy of normal and abnormal, issues of place and space, and fear. These themes were explicated from a social constructionist perspective, displaying the way speech acts construct mental retardation and subvert individuals with the label into demeaned and ridiculed objects of cultural fear.

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BRIDGE (Being Responsive to Individual Differences in General Education) is a partnership between university faculty and two elementary schools, focusing on the collaborative practices and programs in general and special education. University faculty have adopted new roles as facilitators, rather than "experts," in working side by side with teachers seeking to increase their sense of professional efficacy. Teachers at the two sites collaborate with university faculty and each other in acquiring new information and practices within four initiative areas. The four initiatives, designed generally to support professional development toward meeting the needs of struggling students, are (a) collaboration between special and general education, (b) family liaisons, (c) teacher research, and (d) teacher education. University student teachers at these two schools receive their clinical education in settings ripe with teacher inquiry, collaboration, and ongoing development of new and creative strategies.

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Modern and postmodern versions of hope as they apply to services for persons labeled as having mental retardation were examined. Proponents of modernism construct hope as relying on an ever-improving science to accurately comprehend mental retardation and other disabilities and the effectiveness of professional interventions. This myth of scientific progress is traced in various forms through American intellectual history to the development of special education as interventionist social science. Advocates of postmodernism cast doubt upon the grand narrative of modernism and critique modern social science as perpetuating stigmatized "mentally retarded" identities through the exercise of power. A rhetorical analysis of the current controversy over facilitated communication demonstrates the utilization of the language of modern science for its power effects in special education discourse.

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PURPOSE: Candida is the most common cause of opportunistic mucosal infections in human immunodeficiency virus (HIV)-positive women. We had observed an apparent correlation between the severity of immunodeficiency and the site of mucosal candida infection. The current study was designed to determine whether significant correlations existed between the sites of mucosal candida infection and the degree of immunodeficiency, as determined by subsets of lymphocyte populations. PATIENTS AND METHODS: The subjects in this study are 66 HIV-seropositive women evaluated by members of the Brown University Acquired Immunodeficiency Syndrome (AIDS) Program during the 3-year period, September 1, 1986, through August 30, 1989. All patients had thorough clinical evaluations and relevant laboratory studies at defined intervals. All patients with CD4 lymphocyte counts below 0.2 X 10(9)/L received zidovudine therapy as soon as it became available. After July 1988, all patients with CD4 counts below 0.2 X 10(9)/L received prophylaxis against Pneumocystis carinii pneumonia. All patients were counseled about HIV infection, its modes of transmission, and the early symptoms of opportunistic infections. RESULTS: The longitudinal data demonstrated that candida often infected vaginal mucosa when there was no significant reduction in CD4 lymphocyte counts. Candida infection of the oropharyngeal mucosa was associated with highly significant reductions in CD4 lymphocyte counts. Esophageal candidiasis occurred only with advanced immunodeficiency associated with CD4 counts below 0.1 X 10(9)/L. CONCLUSIONS: Candida mucosal infections occur in a hierarchical pattern in women with HIV infection. Determination of the basis for the differences in susceptibility to candida of the vaginal, oropharyngeal, and esophageal mucosal surfaces will require further studies.

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