The Role of Exercise-Induced Arousal and Exposure to Blue-Enriched Lighting on Vigilance.

It is currently assumed that exposure to an artificial blue-enriched light enhances human alertness and task performance, but recent research has suggested that behavioral effects are influenced by the basal state of arousal. Here, we tested whether the effect of blue-enriched lighting on vigilance performance depends on participants' arousal level. Twenty-four participants completed four sessions (blue-enriched vs. dim light × low vs. high arousal) at 10 pm on four consecutive days, following a repeated-measures design. Participants' arousal was manipulated parametrically through the execution of a cycling task at two intensities (low vs. moderate), and was checked by monitoring their heart rate. On each session, distal and proximal skin temperatures were recorded as a neuroergonomic index of vigilance, while participants performed a 20-min psychomotor vigilance task (PVT) under either blue-enriched light or dim light conditions. The Positive and Negative Affect Schedule (PANAS), Karolinska Sleepiness Scale (KSS), and Borg Rating of Perceived Exertion Scale (RPE) were used to measure subjective psychological state. The results showed that the exercise-induced manipulation of arousal produced robust alerting effects in most measures, while the lighting manipulation only attenuated subjective sleepiness and enhanced positive affect, but it did not influence behavior or physiology. Acute exposure to a blue-enriched light was practically ineffective when the arousal level was over baseline. The present research favored the use of acute physical exercise over acute exposure to blue-enriched lighting in order to boost humans' alertness when necessary, as in work settings where maintaining optimal levels of attention is difficult (shift work, night-work, vigilance tasks) and necessary to prevent human error and accidents.

Light Effects on Behavioural Performance Depend on the Individual State of Vigilance.

Research has shown that exposure to bright white light or blue-enriched light enhances alertness, but this effect is not consistently observed in tasks demanding high-level cognition (e.g., Sustained Attention to Response Task-SART, which measures inhibitory control). Individual differences in sensitivity to light effects might be mediated by variations in the basal level of arousal. We tested this hypothesis by measuring the participants' behavioural state of vigilance before light exposure, through the Psychomotor Vigilance Task. Then we compared the effects of a blue-enriched vs. dim light at nighttime on the performance of the auditory SART, by controlling for individual differences in basal arousal. The results replicated the alerting effects of blue-enriched light, as indexed by lower values of both proximal temperature and distal-proximal gradient. The main finding was that lighting effects on SART performance were highly variable across individuals and depended on their prior state of vigilance. Specifically, participants with higher levels of basal vigilance before light exposure benefited most from blue-enriched lighting, responding faster in the SART. These results highlight the importance of considering basal vigilance to define the boundary conditions of light effects on cognitive performance. Our study adds to current research delineating the complex and reciprocal interactions between lighting effects, arousal, cognitive task demands and behavioural performance.

[Waist circumference as a predictor of insulin resistance in young men]. / Circunferencia de la cintura como predictor de resistencia insulínica en varones jóvenes.

BACKGROUND AND OBJECTIVE: Waist circumference (WC) is a measure of upper body fat and so should be useful for identifying overweight and obese men at risk of developing metabolic complications. The objective was to determine the relations of WC to cardiovascular risk factors in a sample of young men and to assess the clinical relevance of WC in identifying insulin resistance. SUBJECTS AND METHOD: This study included 194 male Spanish subjects aged 26 (5) years who were divided in 3 groups according to the WC: Normal (< 94 cm), moderate risk (> or = 94 cm) and elevated risk (> or = 102 cm). Body mass index (BMI), WC, blood pressure, serum levels of total cholesterol, triglycerides (TG), HDL-cholesterol, LDL-cholesterol, glucose, uric acid and insulin were measured by standard methods. The homeostasis model assessment was applied to estimate the degree of insulin resistance (HOMAIR). RESULTS: The prevalence of overweight and obesity was 46.9% and 6.7% respectively. Men with moderate and elevated risk showed higher concentrations of glucose (p < 0.004), uric acid (p < 0.001), TG (p < 0.001), LDL-cholesterol/HDL-cholesterol index (p < 0.001), insulin (p < 0.001) and HOMAIR (p < 0.001). WC was significantly correlated with age (r = 0,282; p < 0.001), TG (r = 0.308; p < 0,001), insulin (r = 0.282; p < 0.001) and HOMAIR (r = 0.281; p < 0.001). A multivariate linear correlation analysis showed that HOMAIR was significantly associated with WC (p < 0.009) and TG (p < 0.003; r2 = 0.13). CONCLUSIONS: WC of these young men was independently associated with certain cardiovascular risk factors, in particular insulin resistance. This suggests that WC may be reasonably included in clinical practice as a simple tool that may help identify sub-groups of overweight or obese young men at higher metabolic risk.

Physical and mental component summaries score of the SF-36 in coronary patients.

BACKGROUND: The aim of the study was to determine the clinical and sociodemographic factors related to the physical and mental components of the health-related quality of life (HRQL) in coronary patients. METHODS: We studied 132 patients diagnosed with Acute Myocardial Infarction (AMI) and unstable angina admitted to a cardiology unit over a period of 18 months. The HRQL was assessed with the Short Form 36 Health Questionnaire (SF-36) and the presence of possible mental disorders was measured using the General Health Questionnaire (GHQ-28). In order to study the variables related to both physical and mental summary components of the SF-36, two multiple linear regression models were constructed with the physical (PCS) and the mental component summary (MCS) as outcome variables. RESULTS: The GHQ-28 score > or = 6 was the variable most associated with the lowest PCS in the patients studied. Moreover in the patients with a personal history of coronary heart disease (CHD), age tended to increase the PCS of the HRQL, whereas in those with no such history, age diminished the PCS score. For the MCS, not being married, being of female sex, having GHQ-28 scores > or = 6 and being of younger age were the four variables most related to the lowest MCS score in the patients studied. CONCLUSION: Age, sex, marital status, personal history of CHD and the presence of a possible mental disorder were the factors most related to HRQL in the coronary patients studied. Focusing medical attention on these groups could contribute to improving their quality of life.

Circunferencia de la cintura como predictor de resistencia insulínica en varones jóvenes / Waist circumference as a predictor of insulin resistance in young men

Fundamento y objetivo: La circunferencia de la cintura (CC) es una medida de la grasa visceral que podría ser útil para identificar a las personas con sobrepeso u obesidad que tienen riesgo de desarrollar complicaciones metabólicas. El objetivo de este estudio fue determinar las relaciones de la CC con los factores de riesgo cardiovascular en varones jóvenes y evaluar la relevancia clínica de la CC en la identificación de resistencia a la insulina. Sujetos y método: Se estudió a 194 varones españoles jóvenes (edad media [desviación estándar] 26 [5] años) que fueron divididos en 3 grupos según la CC: normal (= 94 cm) y riesgo elevado (>= 102 cm), en los que se midieron el índice de masa corporal, la CC, la presión arterial, las concentraciones plasmáticas de colesterol total, los triglicéridos (TG), el colesterol unido a lipoproteínas de alta densidad (cHDL), el colesterol unido a lipoproteínas de baja densidad (cLDL), la glucosa, el ácido úrico y la insulina, por los métodos estandarizados. Para estimar el grado de resistencia a la insulina se aplicó el modelo homeostático (HOMAIR). Resultados: La prevalencia de sobrepeso y obesidad fue del 46,9 y 6,7% respectivamente. Los varones con riesgo moderado y elevado mostraron concentraciones plasmáticas más altas de glucosa (p < 0,004), ácido úrico (p < 0,001), TG (p < 0,001), índice cLDL-cHDL (p < 0,001), insulina (p < 0,001) y HOMAIR (p < 0,001). La CC se correlacionó significativamente con la edad (r = 0,282, p < 0,001), TG (r = 0,308; p < 0,001), insulina (r = 0,280; p < 0,001) y HOMAIR (r = 0,281; p < 0,001). El análisis de correlación linear multivariante demostró que el índice HOMAIR estaba significativamente asociado con la CC (p < 0,009) y la concentración de TG (p < 0,003; r2 = 0,13). Conclusiones: La CC estuvo asociada a ciertos factores de riesgo cardiovascular y en particular a la resistencia a la insulina, lo que indica que podría incluirse en la práctica clínica como una herramienta que ayude a identificar a subgrupos de varones jóvenes con sobrepeso u obesidad y mayor riesgo metabólico

Background and objective: Waist circumference (WC) is a measure of upper body fat and so should be useful for identifying overweight and obese men at risk of developing metabolic complications. The objective was to determine the relations of WC to cardiovascular risk factors in a sample of young men and to assess the clinical relevance of WC in identifying insulin resistance. Subjects and method: This study included 194 male Spanish subjects aged 26 (5) years who were divided in 3 groups according to the WC: Normal (= 94 cm) and elevated risk (>= 102 cm). Body mass index (BMI), WC, blood pressure, serum levels of total cholesterol, triglycerides (TG), HDL-cholesterol, LDL-cholesterol, glucose, uric acid and insulin were measured by standard methods. The homeostasis model assessment was applied to estimate the degree of insulin resistance (HOMAIR). Results: The prevalence of overweight and obesity was 46.9% and 6.7% respectively. Men with moderate and elevated risk showed higher concentrations of glucose (p < 0.004), uric acid (p < 0.001), TG (p < 0.001), LDL-cholesterol/HDL-cholesterol index (p < 0.001), insulin (p < 0.001) and HOMAIR (p < 0.001). WC was significantly correlated with age (r = 0,282; p < 0.001), TG (r = 0.308; p < 0,001), insulin (r = 0.282; p < 0.001) and HOMAIR (r = 0.281; p < 0.001). A multivariate linear correlation analysis showed that HOMAIR was significantly associated with WC (p < 0.009) and TG (p < 0.003; r2 = 0.13). Conclusions: WC of these young men was independently associated with certain cardiovascular risk factors, in particular insulin resistance. This suggests that WC may be reasonably included in clinical practice as a simple tool that may help identify sub-groups of overweight or obese young men at higher metabolic risk

Estado, seguridad social y marginalidad / State, social security and marginality

Estudio acerca del papel que desempeña el Estado al otorgar bienestar social a la población y brinda además una visión acerca de la situación económica y social de América Latina, así como los retos con los que actualmente se enfrenta. El documento contiene los siguientes capítulos: I. Estado y democracia de bienestar II. Economía y sociedad en América Latina III. Nuevos retos de la seguridad social IV. Marginalidad social en América Latina V. Marginalidad y seguridad social VI. Notas

Normas fundamentales de la seguridad social internacional / Fundamental standards in international social security

Presenta los resultados del Seminario relativo a la Norma Mínima de Seguridad Social, de la Organización Internacional del Trabajo (OIT), así como las resoluciones de la Conferencia Interamericana de Seguridad Social, y el proyecto de Código Iberoamericano de Seguridad Social, los cuales tienen gran impacto en la seguridad social nacional en busca de mejores condiciones de vida para el ser humano. En el primer capítulo se menciona a los hombres que realizaron la consolidación de la seguridad social para lograr una humanidad sin límites ni fronteras. En el segundo capítulo se dan resoluciones a algunos problemas de seguridad social. En el tercer capítulo se proporciona resumen de la evolución de la Seguridad Social Europea a partir de la Segunda Guerra Mundial. En el cuarto capítulo se reafirma el papel de los sistemas de seguridad social y el quinto capítulo da un panorama de la seguridad social internacional

Atención primaria de la salud y seguridad social en América / Primary health care and social security in America

Investigación que muestra la situación actual de la atención primaria de la salud y los programas desarrollados en América Latina en favor de la salud, a través de los siguientes puntos: I. Presentación II. Introducción III. Salud para todos. Todos para la salud IV. Atención primaria y estrategias de salud en la seguridad social en América Latina V. Tercera Consulta Técnica Regional sobre estrategias para el desarrollo de los programas de salud de la seguridad social VI. La atención primaria a la salud y su desconcentración mediante estrategias