Electrophysiological correlates of performance monitoring in middle and late adolescence

The ability to monitor and evaluate the consequences of ongoing behaviors and coordinate behavioral adjustments seems to rely on networks including the anterior cingulate cortex (ACC) and phasic changes in dopamine activity. Activity (and presumably functional maturation) of the ACC may be indirectly measured using the error-related negativity (ERN), an event-related potential (ERP) component that is hypothesized to reflect activity of the automatic response monitoring system. To date, no studies have examined the measurement reliability of the ERN as a trait-like measure of response monitoring, its development in mid- and late- adolescence as well as its relation to risk-taking and empathic ability, two traits linked to dopaminergic and ACC activity. Utilizing a large sample of 15- and 18-year-old males, the present study examined the test-retest reliability of the ERN, age-related changes in the ERN and other components of the ERP associated with error monitoring (the Pe and CRN), and the relations of the error-related ERP components to personality traits of risk propensity and empathy. Results indicated good test-retest reliability of the ERN providing important validation of the ERN as a stable and possibly trait-like electrophysiological correlate of performance monitoring. Ofthe three components, only the ERN was of greater amplitude for the older adolescents suggesting that its ACC network is functionally late to mature, due to either structural or neurochemical changes with age. Finally, the ERN was smaller for those with high risk propensity and low empathy, while other components associated with error monitoring were not, which suggests that poor ACe function may be associated with the desire to engage in risky behaviors and the ERN may be influenced by the extent of individuals' concern with the outcome of events.

Secretory immunity in overweight and obese versus normal-weight early-and late-pubertal females

Obesity is a condition associated with a wide variety of health problems including hypertension, dyslipidemia, diabetes mellitus, certain forms of cancer, cardiovascular disease, and gallstones (157). TTiere is growing evidence that obesity may also be related to compromised immune function due to altered metabolic, psychological, and physical attributes (93). The aim of this study was to compare: a) immunity-related variables such as frequency of upper respiratory tract infections (URTI) and salivary secretory immunoglobulin A (sIgA) levels between overweight/obese (OB) and normal weight (NW) early-pubertal and late-pubertal girls, and b) stress-related variables such as Cortisol, melatonin, the melatonin/cortisol ratio, testosterone and the testosterone/cortisol ratio. Physical activity levels, stress indicators, and fatigue were used to explain potential differences in the dependent variables. It was hypothesized that the OB females would have lower melatonin (M) and higher Cortisol (C) and testosterone (T) levels compared with NW girls, regardless of maturity status. The altered levels of melatonin, Cortisol, and testosterone, would result in decreased M/C and T/C ratios, despite the increase in testosterone in OB females. It was hypothesized that this altered hormonal status results in a compromised immunity marked by higher frequency of upper respiratory tract infections (URTI) and decreased levels of secretory immunoglobulin A (sIgA). It was also hypothesized that OB girls would participate in less hours of physical activity than their NW counterparts and that this would relate to their stress and immunity levels. Forty (16 early- and 24 late-pubertal) overweight and obese females were compared to fifty-three (27 eariy- and 26 late-pubertal) age-matched normal-weight control subjects. Participants were categorized as early-pubertal (EP) or late-pubertal (LP) using Tanner self-staging of secondary sex characteristics. Subjects were classified into the two adiposity groups according to relative body fat (%BF), where normal weight (NW) subjects had a %BF less than 25%, and overweight and obese (OB) subjects had a %BF greater than 27.5%. Participants completed a number of questionnaires and information was collected on menstrual history, smoking history, alcohol and caffeine consumption, and medical history. Following the determination of maturity status, a complete anthropometric assessment was made including height, body mass, and body composition. All questionnaires and measurements were completed during a one-hour visit between 1 500 and 1900 hours Relative body fat was assessed using bioelectrical impedance analysis. Resting saliva samples were obtained and assayed (ELISA) for testosterone, Cortisol, melatonin and secretory immunoglobulin A. Physical activity was self-reported using the Godin- Shephard Leisure time questionnaire, and quantified using Actigraph GTIM accelerometers, which participants wore for seven consecutive days from the time they woke up in the morning, until the time they went to bed. Late-pubertal girls also completed questionnaires on their perceived stress and fatigue. Finally, all participants also filled out a one-month health log to record frequency of symptoms of upper respiratory tract infections (URTI). Significant age effects were found for testosterone, Cortisol, incidence of sickness, and sIgA when controlling for physical activity, however there were no significant effects of adiposity on any of the variables. There was a trend which neared-significance for an effect of adiposity on sIgA (p=0.01). There were no significant differences between the groups on the total selfreported leisure-time physical activity in METs per week, however EP girls recorded significantly greater levels of moderate, hard, and very hard physical activity from accelerometers. Results of the perceived stress and fatigue questionnaires in late-pubertal girls demonstrated that contrary to what was hypothesized, NW girls reported more stress and more fatigue than OB girls. Results of the present study suggest that excess adiposity in early- and latepubescent girls may not have a negative impact on immunity as hypothesized.

Being anglophone : language, place and identity in Quebec's eastern townships

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

Studies on Quasinormal Modes and Late-time Tails in Black Hole Spacetimes

This thesis Entitled Studies on Quasinormal modes and Late-time tails black hole spacetimes. In this thesis, the signature of these new theories are probed on the evolution of field perturbations on the black hole spacetimes in the theory. Chapter 1 gives a general introduction to black holes and its perturbation formalism. Various concepts in the area covered by the thesis are also elucidated in this chapter. Chapter 2 describes the evolution of massive, charged scalar field perturbations around a Reissner-Nordstrom black hole surrounded by a static and spherically symmetric quintessence. Chapter 3 comprises the evolution of massless scalar, electromagnetic and gravitational fields around spherically symmetric black hole whose asymptotes are defined by the quintessence, with special interest on the late-time behavior. Chapter 4 examines the evolution of Dirac field around a Schwarzschild black hole surrounded by quintessence. Detailed numerical simulations are done to analyze the nature of field on different surfaces of constant radius . Chapter 5is dedicated to the study of the evolution of massless fields around the black hole geometry in the HL gravity.

Response to instruction, English language learners and disproportionate representation : The role of assessment

Resumen tomado de la publicaci??n

Language learning and MUDs : an overview. 'Aprendizaje de idiomas y MUDs : una visión general'.

La traducción literal de MUD es Mazmorra o Calabozo multiusuario o Dimensión multiusuario. Un MUD es un juego de rol en línea que es ejecutado en un servidor. El artículo incluye direcciones de varios MUDs

Second lives and newer islands : language, culture and identity through migration literature. 'Second lives and newer islands : lengua, cultura e identidad a trav??s de la literatura de migraci??n'

Resumen en espa??ol

Form-focused instruction in second language teaching and learning : theoretical proposals and research findings.

El artículo revisar diferentes propuestas de investigación y teóricas sobre el aprendizaje y enseñanza de la segunda lengua.

Supporting children with speech and language impairment and associated difficulties : suggestions for supporting the development of language, listening, behavior and co-ordination skills.

Este recurso describe cómo una proporción significativa de niños en edad escolar tienen dificultades en el habla y cómo éstas afectan negativamente en su aprendizaje, tanto en entornos especializados como en generales. En él se esbozan las principales áreas de dificultad para los alumnos, y sugiere cómo los profesores pueden hacer que el programa sea más accesible para facilitar el aprendizaje. Se tratan el lenguaje expresivo, el lenguaje receptivo, el uso social del lenguaje y dificultades en el desarrollo de la coordinación, así como temas específicos como el plan de estudios de inglés, matemáticas y ciencias. A lo largo de la publicación hay información e ideas para apoyar a estos alumnos, y una amplia selección de sugerencias de buenas prácticas. Se incluye un programa de habilidades motoras, rimas para la producción del habla, trabajo de memoria, y páginas fotocopiables de diccionario.

Practice tests for IGCSE English as a second language : reading and writing book 1.

El libro contiene 4 test prácticos completos con formato de examen para los ejercicios 1 y 2 de la prueba Cambridge IGCSE (International General Certificate of Secondary Education) de inglés como segundo idioma. Los test permiten desarrollar las técnicas de examen de los alumnos familiarizándose con el formato de los ejercicios de lectura y redacción, y con el tipo de temas y textos que pueden encontrar en el examen oficial. El nivel de la prueba es intermedio e intermedio-alto.

Practice tests for IGCSE English as a second language : reading and writing book 1 with key.

El libro contiene 4 test prácticos completos con formato de examen para los ejercicios 1 y 2 de la prueba Cambridge IGCSE (International General Certificate of Secondary Education) de inglés como segundo idioma. Los test permiten desarrollar las técnicas de examen de los alumnos familiarizándose con el formato de los ejercicios de lectura y redacción, y con el tipo de temas y textos que pueden encontrar en el examen oficial. El nivel de la prueba es intermedio e intermedio-alto. Incluye respuestas y redacciones de ejemplo.

Practice tests for IGCSE English as a second language : listening and speaking.

El libro contiene 4 test prácticos completos con formato de examen para los ejercicios 3, 4 y 5 de la prueba Cambridge IGCSE (International General Certificate of Secondary Education) de inglés como segundo idioma. Los test permiten desarrollar las técnicas de examen de los alumnos familiarizándose con el formato de los ejercicios de comprensión y pruebas orales, y con el tipo de temas que pueden encontrar en el examen oficial. El nivel de la prueba es intermedio e intermedio-alto.

Practice tests for IGCSE English as a second language : listening and speaking book 2.

El libro contiene test prácticos con formato de examen para los ejercicios 4 y 5 de la prueba Cambridge IGCSE (International General Certificate of Secondary Education) de inglés como segundo idioma. Incluye cuatro tests de comprensión auditiva de nivel alto y veinte prácticas orales. Los test permiten desarrollar las técnicas de examen de los alumnos familiarizándose con el formato de los ejercicios de comprensión y pruebas orales, y con el tipo de temas que pueden encontrar en el examen oficial. El nivel de la prueba es intermedio e intermedio-alto.

Practice tests for IGCSE English as a second language : listening and speaking book 2 with key.

El libro contiene test prácticos con formato de examen para los ejercicios 4 y 5 de la prueba Cambridge IGCSE (International General Certificate of Secondary Education) de inglés como segundo idioma. Contiene cuatro tests de comprensión auditiva de nivel alto y veinte prácticas orales. Los test permiten desarrollar las técnicas de examen de los alumnos familiarizándose con el formato de los ejercicios de comprensión y pruebas orales, y con el tipo de temas que pueden encontrar en el examen oficial. El nivel de la prueba es intermedio e intermedio-alto. Incluye la trascripción completa de los audios y las respuestas de los test de compresión auditiva.

Practice tests for IGCSE English as a second language : listening and speaking book 1 with key.

El libro contiene cuatro tests prácticos completos con formato de examen para los ejercicios 3, 4 y 5 de la prueba Cambridge IGCSE (International General Certificate of Secondary Education) de inglés como segundo idioma. Los test permiten desarrollar las técnicas de examen de los alumnos familiarizándose con el formato de los ejercicios de comprensión y pruebas orales, y con el tipo de temas que pueden encontrar en el examen oficial. El nivel de la prueba es intermedio e intermedio-alto. Incluye la trascripción completa de los audios y las respuestas de los tests de compresión auditiva.