Defect analysis of Fe3(Al1– x Si x ) alloys by positron-lifetime spectroscopy

The recovery behaviour of vacancy-type defects created at 1000°C in Fe₃(Al_{1– x} Si _x ) alloys has been investigated by positron-lifetime measurements in samples cooled to room temperature by water quenching, air quenching and furnace cooling. In addition, a set of samples was aged for one week at 520°C. After water quenching, measurements reveal a high concentration of thermal vacancies, and from the decrease of the average positron lifetime it is inferred that vacancy recovery is strongly composition-dependent. Greater decreases of the positron lifetime were found for Si-rich samples, suggesting diffusion enhancement as the Si concentration increases. For the Fe₃Al alloy, the retained vacancy concentration depends strongly on the cooling rate. This is related to atomic ordering and a rebuilding of the D0₃ structure.     

La enseñanza práctica de la Psicología: una experiencia de condicionamiento instrumental

RESUMEN

n este informe se presenta una experiencia docente en la que un elevado número de estudiantes de primero de Psicología (140), trabajando en grupos de cinco personas y utilizando unos recursos limitados, consiguieron llevar a cabo un condicionamiento instrumental con ratas en la caja de Skinner, cumpliendo adecuadamente los objetivos metodológicos propuestos. Esta experiencia confirma la posibilidad de realizar prácticas en Psicología a pesar de los numerosos impedimentos que existen para ello, destacados por los autores.     

El lenguaje de los antropoides

RESUMEN

José Eugenio Ortega presenta este dossier sobre el lenguaje de los antropoides repasando algunos intentos de enseñar lenguaje a chimpancés y recordando la gran influencia del “Proyecto Washoe” en investigaciones posteriores desde distintas perspectivas. A continuación explica la clasificación de orden de los primates y las características que hacen de los chimpancés los sujetos idóneos para este tipo de estudios y aborda la polémica entre los grupos que siguen distintos procedimientos respecto a cuál es la metodología correcta, afirmando que en todos los trabajos de lenguaje de antropoides ha habido fallos en el control de variables. En la última parte explica cuatro posturas de los investigadores a la hora de interpretar los resultados de sus estudios, finalizando con algunas reflexiones en torno a las implicaciones de estos trabajos con relación a los de Darwin y manifestando que el estudio de las capacidades de simbolización de los antropoides puede aportar bastantes datos al problema de la evolución humana.     

Cultural-Related, Contextual, and Asthma-Specific Risks Associated with Asthma Morbidity in Urban Children

The objective of this study was to examine associations between specific dimensions of the multi-dimensional cumulative risk index (CRI) and asthma morbidity in urban, school-aged children from African American, Latino and Non-Latino White backgrounds. An additional goal of the study was to identify the proportion of families that qualify for high-risk status on each dimension of the CRI by ethnic group. A total of 264 children with asthma, ages 7–15 (40% female; 76% ethnic minority) and their primary caregivers completed interview-based questionnaires assessing cultural, contextual, and asthma-specific risks that can impact asthma morbidity. Higher levels of asthma-related risks were associated with more functional morbidity for all groups of children, despite ethnic group background. Contextual and cultural risk dimensions contributed to more morbidity for African-American and Latino children. Analyses by Latino ethnic subgroup revealed that contextual and cultural risks are significantly related to more functional morbidity for Puerto Rican children compared to Dominican children. Findings suggest which type of risks may more meaningfully contribute to variations in asthma morbidity for children from specific ethnic groups. These results can inform culturally sensitive clinical interventions for urban children with asthma whose health outcomes lag far behind their non-Latino White counterparts.     

Development of aptitude at altitude

Millions of people currently live at altitudes in excess of 2500 metres, where oxygen supply is limited, but very little is known about the development of brain and behavioural function under such hypoxic conditions. We describe the physiological, cognitive and behavioural profile of a large cohort of infants (6–12 months), children (6–10 years) and adolescents (13–16 years) who were born and are living at three altitude locations in Bolivia (～500 m, ～2500 m and ～3700 m). Level of haemoglobin oxygen saturation and end‐tidal carbon dioxide were significantly lower in all age groups living above 2500 metres, confirming the presence of hypoxia and hypocapnia, but without any detectable detriment to health. Infant measures of neurodevelopment and behaviour yielded comparable results across altitude groups. Neuropsychological assessment in children and adolescent groups indicated a minor reduction in psychomotor speed with increasing altitude, with no effect of age. This may result from slowing of underlying brain activity in parallel with reduced cerebral metabolism and blood flow, evidenced here by reduced cerebral blood flow velocity, particularly in the basilar artery, in children and adolescents. The proportion of European, Native American and African genetic admixture was comparable across altitude groups, suggesting that adaptation to high altitude in these children occurred in response to chronic hypoxic exposure irrespective of ethnic origin. Thus, psychomotor slowing is proposed to be an adaptive rather than a deficient trait, perhaps enabling accuracy of mental activity in hypoxic conditions.     

Critical Incidents in Multicultural Supervision: Exploring Supervisees' and Supervisors' Experiences

Reports of supervisors' and supervisees' critical incidents in multicultural supervision were used to (a) explore events in supervision that influenced supervisees' multicultural competence, (b) explore how supervision was experienced differently by supervisors and supervisees, and (c) identify recommendations for improving multicultural supervision. Implications for training and research are discussed. Los reportes de incidentes críticos en la supervisión multicultural fueron utilizados para (a) explorar los acontecimientos en la supervisión que influyeron la competencia multicultural de los supervisados (b) explorar cómo la supervisión fue experimentada diferentemente por los supervisores y los supervisados e (c) identificar recomendaciones para mejorar la supervisión multicultural. Se discuten las implicaciones para la instrucción e investigación en esta area.     

A simple IBM I/O Selectric typewriter controller

A simple inexpensive IBM I/O Selectric typewriter controller is described. The board plugs into an RS-232 port and enables letter-quality output. Computers with editing capabilities can therefore be used as word processors for as little as $35, about 8 h of labor, and the cost of the typewriter. The controller is a firmware-governed microprocessor, and as a result, it is easily tailored for special applications. Hardware and software are discussed.     

Impoverishment of psychoanalysis. On the decline of psychoanalytic education

Anyone wishing to practice the "impossible profession" must once again overcome the resistances that originally produced the insights of psychoanalysis. Training analysts and institute faculty members pass on their successful as well as their failed attempts to surmount these resistances to the next generation. Herein lies the danger that the quality of training may decline as well as the opportunity to enrich psychoanalytic knowledge.