Contributions of implicit memory strategies to the rehabilitation of an amnesic patient: case report

Even severe amnesic patients usually are able to learn new information using implicit memory strategies. In the present study we describe our experience in the rehabilitation of an amnesic patient who had suffered cerebral anoxia. He was taught to use a computer text editor, enabling him to sheltered work. The training program lasted 14 weeks and was based on errorless learning and drilling practice techniques. The patient succeeded in all tasks, even though he could not remember accurately the training sessions. These results meet previous studies which point out that interaction between implicit and residual explicit memory can provide a basis new learning in amnesic patients. The domain-specific knowledge acquisition is demonstrating effectiveness in neuropsychological rehabilitation of brain injured patients.Mesmo pacientes severamente amnésticos são capazes de aprender informações novas, apoiados em estratégias de memória implícita. No presente estudo descrevemos uma experiência de reabilitação neuropsicológica, em que um paciente amnéstico, portador de lesão cerebral por anóxia, foi submetido a treino para uso de computador, visando sua capacitação semi-profissional. O treinamento teve duração de 14 semanas, e as técnicas de ensino utilizadas foram a prática repetitiva e a aprendizagem sem erros. O paciente obteve sucesso na realização das tarefas propostas, aprendendo a operar um editor de textos e mantendo o aprendizado após a passagem do tempo. Apesar disso, lembrava-se apenas vagamente da situação de aprendizagem. O presente estudo corrobora trabalhos anteriores que observam a interação entre mecanismos de memória implícita e resíduos de memória explícita operando na aquisição de conhecimentos em pacientes amnésticos. A aprendizagem de conhecimentos específicos vem se mostrando eficiente para a reabilitação de pacientes que sofreram lesões cerebrais.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de PsicobiologiaUNIFESP, EPM, Depto. de PsicobiologiaSciEL

Infancia y flexibilidad laboral en la agricultura de exportación mexicana

Desde mediados de los ochenta del siglo pasado, la reducción del gasto público destinado al campo y la eliminación de barreras comerciales pusieron en juego la competitividad del sector agrícola mexicano. Las empresas adoptaron cambios tecnológicos y de organización laboral a partir de una combinación de mano de obra calificada con fuerza de trabajo desvalorizada por razones de género, edad o etnia; esta última opera en condiciones de amplia flexibilidad laboral. El presente artículo analiza las formas de inserción del trabajo infantil migrante en la agricultura de exportación mexicana. Los datos fueron levantados en un campo de jornaleros de una de las empresas más importantes del ramo. Se aplicó una encuesta a 66 familias y se hicieron 41 entrevistas semi-estructuradas, 3 talleres con infantes y una matriz de riesgos laborales. El 94% de los niños y niñas trabajan en el corte de pepino y jitomate y el 6% restante (chicas mayores de 14 años) en labores de empaque. Las niñas presentan una doble jornada de trabajo debido a sus responsabilidades domésticas. El ingreso promedio diario es de 97 pesos mexicanos (alrededor de $9.40 dólares de los EE. UU.), que contribuye a cerca de la mitad del ingreso global de la familia. Se concluye que el derecho a la educación y a la salud de la población infantil jornalera son los más afectados, ya que dos tercios de los niños y niñas encuestados no asisten a la escuela y sus condiciones de trabajo conllevan considerables riesgos para la salud.-1. Introducción. -2. Diseño metodológico. -3. Marco conceptual: flexibilidad laboral y trabajo infantil. -4. Flexibilidad laboral y trabajo infantil jornalero. -4.1. Eventualidad en el empleo. -4.2. Jornada laboral.-4.3. Forma de contratación y pago. -4.4. Riesgos para la salud. -5. Conclusiones. -Bibliografí

Beyond the Fragmentation Threshold Hypothesis: Regime Shifts in Biodiversity Across Fragmented Landscapes

Ecological systems are vulnerable to irreversible change when key system properties are pushed over thresholds, resulting in the loss of resilience and the precipitation of a regime shift. Perhaps the most important of such properties in human-modified landscapes is the total amount of remnant native vegetation. In a seminal study Andrén proposed the existence of a fragmentation threshold in the total amount of remnant vegetation, below which landscape-scale connectivity is eroded and local species richness and abundance become dependent on patch size. Despite the fact that species patch-area effects have been a mainstay of conservation science there has yet to be a robust empirical evaluation of this hypothesis. Here we present and test a new conceptual model describing the mechanisms and consequences of biodiversity change in fragmented landscapes, identifying the fragmentation threshold as a first step in a positive feedback mechanism that has the capacity to impair ecological resilience, and drive a regime shift in biodiversity. The model considers that local extinction risk is defined by patch size, and immigration rates by landscape vegetation cover, and that the recovery from local species losses depends upon the landscape species pool. Using a unique dataset on the distribution of non-volant small mammals across replicate landscapes in the Atlantic forest of Brazil, we found strong evidence for our model predictions - that patch-area effects are evident only at intermediate levels of total forest cover, where landscape diversity is still high and opportunities for enhancing biodiversity through local management are greatest. Furthermore, high levels of forest loss can push native biota through an extinction filter, and result in the abrupt, landscape-wide loss of forest-specialist taxa, ecological resilience and management effectiveness. The proposed model links hitherto distinct theoretical approaches within a single framework, providing a powerful tool for analysing the potential effectiveness of management interventions

Hallazgo del mosquito Haemagogus equinus (Theobald, 1903) en el área metropolitana de Bucaramanga, Santander

Utilizando un sistema de vigilancia entomológica, se registra por primera vez en Colombia el hallazgo del mosquito Haemagogus equinus, eficiente vector del virus de la fiebre amarilla selvática, en criaderos artificiales (llantas). Se recolectaron 181 larvas de H. equinus en cuatro ovilarvitrampas encontradas positivas, localizadas en el área metropolitana de Bucaramanga

Nutritional status of pre-school children from low income families

<p>Abstract</p> <p>Background</p> <p>We evaluated growth and nutritional status of preschool children between 2 and 6 years old from low income families from 14 daycare centers.</p> <p>Methods</p> <p>Cross-sectional study with 1544 children from daycare centers of Santo Andre, Brazil. Body weight (W), height (H) and body mass index (BMI) were classified according to the 2000 National Center for Health Statistics (CDC/NCHS). Cutoff points for nutritional disorders: -2 z scores and 2.5 and 10 percentiles for malnutrition risk, 85 to 95 percentile for overweight and above BMI 95 percentile for obesity. Stepwise Forward Regression method was used including age, gender, birth weight, breastfeeding duration, age of mother at birth and period of time they attended the daycare center.</p> <p>Results</p> <p>Children presented mean z scores of H, W and BMI above the median of the CDC/NCHS reference. Girls were taller and heavier than boys, while we observed similar BMI between both genders. The z scores tended to rise with age. A Pearson Coefficient of Correlation of 0.89 for W, 0.93 for H and 0.95 for BMI was documented indicating positive association of age with weight, height and BMI. The frequency of children below -2 z scores was lower than expected: 1.5% for W, 1.75% for H and 0% for BMI, which suggests that there were no malnourished children. The other extremity of the distribution evidenced prevalence of overweight and obesity of 16.8% and 10.8%, respectively.</p> <p>Conclusion</p> <p>Low income preschool children are in an advanced stage of nutritional transition with a high prevalence of overweight.</p