Abstract The aim of this study was to identify and confirm the trifactorial structure of the Barratt Impulsiveness Scale (BIS-11) proposed for adults by Patton, Stanford and Barratt (1995) in a sample of children and adolescents. The sample consisted of 600 children between of 9 and 17 years old (M = 12.9, SD=2.3). For the factorial analysis the data were divided into two random samples. In the first subsample the Exploratory Factorial Analysis was performed, and three dimensions were identified. Subsequently, in the second subsample, Confirmatory Factor Analysis was performed. The factorial solution of 19 items showed adequate fit (CFI = .909, IFI = .912, RMSEA = .043 CI [.032 − .054], χ2/gl = 1.561). The total Cronbach alpha was α = .795. Each scale has acceptable coefficients: Attentional Impulsiveness α = .641, Motor Impulsiveness α = .659 and Non-planning Impulsiveness α = .727.

Resumen El objetivo de este estudio fue identificar y confirmar la estructura trifactorial de la Escala Barratt de Impulsividad (BIS-11) propuesta para adultos (Patton, Stanford y Barratt, 1995) en una muestra de 600 niños y adolescentes entre 9 y 17 años de edad (M = 12.9, DT = 2.3). Para el análisis factorial los datos fueron divididos aleatoriamente en dos. Con la primera submuestra se realizó el Análisis Factorial Exploratorio, en el que se identificaron tres dimensiones. Posteriormente, con la segunda submuestra se llevó a cabo el Análisis Factorial Confirmatorio. La solución factorial resultante de 19 ítems arroja adecuados indicadores de ajuste (CFI = .909, IFI = .912, RMSEA = .043 CI [.032 − .054], χ2/gl = 1.561). El alfa Cronbach total ha sido α = .795. Las escalas obtienen coeficientes aceptables para estas edades, Impulsividad Atencional con α = .641, Impulsividad Motora α = .659 e Impulsividad no Planificadora α = .727.

Abstract Sixteen monthly cruises were carried out at a station 6.5 km to the NW of the mouth of Magdalena Bay (Mexico) to study the temporal variability of phytoplankton biomass and primary production rates, and the response of phytoplankton to the prevailing hydrographic characteristics. During each cruise, temperature and salinity were measured in the water column, and discrete samples were collected to measure inorganic nutrient concentrations (nitrate, phosphate, and silicate) and chlorophyll a content (as a proxy for phytoplankton biomass); in addition, in situ incubations were performed to estimate primary production (PP) rates using the 14C technique. During spring and early summer (March-July), the water column at the study site was cold (14.4 ºC at 80 m depth and 17.7 ºC at the surface) and well mixed, with high nutrient concentrations (nitrate = 6.39 μM, phosphate = 0.91 μM, and silicate = 11.87 μM) at the surface, typical of intense upwelling systems. On the contrary, from August to February the water column was stratified (23.5 ± 3.2 ºC above the thermocline and 17.0 ± 1.7 ºC at 80 m depth) and had low nutrient concentrations (nitrate = 3.90 μM, phosphate = 0.47 μM, and silicate = 10.30 μM) at the surface. Phytoplankton abundance, chlorophyll a concentration, and PP rates in the euphotic zone were higher during the upwelling season, with maximum cell density of 1.7 × 106 cells·L-1 (nanoplankton fraction), integrated chlorophyll a content of 231 mg·m-2, and integrated PP rates of 553 mg Cm-2·h-1). Abundance of cells <20 μm, as determined by flow cytometry, revealed the importance of the nanoplankton and picoplankton fractions in this region. This study showed the seasonal variability of phytoplankton communities (biomass and productivity) in waters off Magdalena Bay and the coupling of phytoplankton to environmental variability. Seasonal variability was similar to that observed for other typical coastal upwelling regions, that is, higher phytoplankton abundances and PP rates in spring and summer and lower values in autumn and winter.

Resumen En el periodo de la primavera de 2013 al verano de 2014 se llevaron a cabo 16 muestreos mensuales a 6.5 km al noroeste de la boca de bahía Magdalena (México) con el propósito de estudiar la variabilidad temporal de la biomasa y las tasas de producción primaria del fitoplancton y la respuesta del mismo a las características hidrográficas predominantes. En cada muestreo se midieron la temperatura y salinidad en la columna de agua y se determinaron las concentraciones de nutrientes inorgánicos (nitrato, fosfato y silicato) y el contenido de clorofila a (como proxy de la biomasa del fitoplancton); además, se hicieron incubaciones in situ para estimar la producción primaria (PP) con el método de 14C. En primavera y principios de verano (marzo-julio), el sitio presentó, en promedio, una columna de agua fría (14.4 ºC a 80 m de profundidad y 17.7 ºC en superficie) y mezclada con concentraciones de nutrientes altas en superficie (nitrato = 6.39 µM, fosfato = 0.91 µM y silicato = 11.87µM; valores característicos de zonas de afloramiento intenso). Por el contrario, de agosto a febrero se observó una columna de agua estratificada (23.5 ± 3.2 ºC arriba de la termoclina y 17.0 ± 1.7 ºC a 80 m de profundidad) con menor contenido de nutrientes en superficie (nitrato = 3.90 µM, fosfato = 0.47 µM y silicato = 10.30 µM). La abundancia del fitoplancton, la concentración de clorofila a y las tasas de PP en la zona eufótica fueron mayores en la temporada de surgencias, con densidad celular máxima de 1.7 × 106 cél·L-1 (fracción del nanoplancton), contenido de clorofila a integrada de 231 mg·m-2 y tasa de producción integrada de 553 mg C·m-2·h-1. Las abundancias de células <20 µm determinadas por citometría de flujo mostraron la importancia de las fracciones del nano y picoplancton en la región. Este estudio mostró la variabilidad estacional de las comunidades del fitoplancton (biomasa y productividad) en las aguas frente a bahía Magdalena y su acoplamiento al cambio ambiental. La variabilidad estacional fue similar a la observada en otras regiones características de afloramientos costeros, esto es, mayores abundancias y tasas de PP en primavera y verano y valores menores en otoño e invierno.

Este trabalho visa à análise comparativa entre as poeiras de basalto e gnaisse em empresas produtoras de brita nas regiões de Londrina e Curitiba, no estado do Paraná, através de avaliações ambientais apoiadas por análises químicas, petrográficas e morfoscópicas das rochas e das poeiras. Utilizou-se bomba de amostragem individual, munida com filtros de PVC, para coleta de partículas respiráveis nos trabalhadores e posterior análise por difração de raios-X para determinação de sílica livre cristalizada. As análises químicas e petrográficas foram feitas com amostras de rochas das frentes de lavra. Efetuou-se análise da morfologia e do tamanho das partículas na poeira com imagens obtidas no microscópio eletrônico de varredura. A concentração de poeira respirável apresentou valores consideráveis comparados à legislação. A porcentagem de SiO2 para o basalto ficou entre 1,0% e 5,4% e acima de 10% no gnaisse. O gnaisse mostrou-se 15% acima do basalto para partículas entre 0,5µm e 3,0µm, com formas mais irregulares e fibrosas. Conclui-se que o gnaisse apresenta maior risco de formação de nódulos silicóticos (silicose clássica) e que o basalto apresenta maior probabilidade de provocar pneumoconioses por poeiras mistas.

The purpose of this study is to make a comparative analysis of the basalt and gneiss dust yielded by crushed-stone production in companies located in Londrina and Curitiba, two cities located in the State of Paraná, by carrying out environmental assessments backed by chemical, petrography and morphological analyses of rocks and dusts samples. An individual sampling pump fitted with PVC filters was attached to the workers' lapel to collect the breathable particles, which were later analyzed by X-ray diffraction to determine free crystallized silica. Samples collected at blasting site work-fronts were analyzed chemically and petrographically. The morphological analysis of dust particle size was performed with a sweeping electronic microscope. Breathable dust concentrations were high compared to the acceptable limits set by the environmental legislation. The rate of SiO2 for basalt ranged from 1.0 to 5,4% and over 10% for gneiss. The rate of gneiss was 15% higher than the rate of basalt for particles ranging from 0.5 to 3.0µm, where particles are more irregular in shape and more fibrous. The study showed that gneiss-exposed workers are more prone to silicosis nodule formations (classical silicosis), while basalt is more conducive to mixed dust pneumoconiosis.