Distribution and abundance of early life stages of squid (Illex argentinus) in the south-west Atlantic

A joint research cruise (Japan-Argentina-Uruguay) was carried out in the South-western Atlantic during August-September 1989 in order to study the winter-spawning and hatchery areas of Illex argentinus, and also the migration pattern of the juveniles towards the continental shelf. A few Rhynchoteuthion larvae were found in subtropical waters of the Brazil Current, next to the Brazil-Malvinas confluence, and in the frontal zone with shelf water, but never at temperatures below 14°C. Large numbers of juveniles found in subantarctic waters (6–10°C) on the shelf were probably migrating southward from their hatchery grounds following the zooplankton concentrations on which they were feeding

Factores que inciden en el habito de fumar de escolares de educación basica y media del Chile

INTRODUÇÃO: Considerando a indiscutível evidência dos efeitos adversos do fumo para a saúde, milhões de pessoas continuam fumando. A situação é de maior gravidade, já que muitos dos fumantes e a maioria dos novos fumantes, tanto no Chile, como em outros países, são adolescentes. Dicidiu-se realizar estudo com o objetivo de determinar a prevalência do tabagismo em escolares chilenos e quantificar o impacto de fatores socioeconômicos, socioculturais, familiares, de exposição aos meios de comunicaçao de massa, demográficos, educacionais e psicosociais. MATERIAL E MÉTODO: Foi selecionada uma amostra aleatória representativa e proporcional de 2.967 escolares de educação básica e média, na Região Metropolitana do Chile, de acordo com o grau do curso (IV, VI e VIII básico de I e IV medio), sexo, tipo de escola e área geográfica. A prevalência de tabagismo foi determinada por meio de questionário auto administrado. O nível socioeconômico (NSE) foi avaliado pelo método de Graffar modificado determinando-se além das condições familiares, a exposicião aos meios de comunicação de massa e aos fatores psicosociais. O rendimento escolar foi determinado por um teste de idiomas e de matemáticas, além de outras variáveis educacionais. A análise estatística inclui análise de variância, teste "t" de Student e teste de Scheffe para comparar os médias, correlação, regressao múltipla, teste do qui-quadrado e o método de OPS/OMS para o cálculo de risco relativo(RR). RESULTADOS: A prevalência de tabagismo (10,6%) aumentou significativamente com a idade de 1,3% nos escolares menores de 13 anos, a 15,4 a 36,9% nos adolescentes entre 13-15 anos e ³ 16 anos, respectivamente (p < 0,001), e foi maior nos escolares de sexo feminino. Os níveis de plazer (r = 0,499 p < 0,001), rebeldía (r = 0,124 p < 0,001), recreação familiar (r = -0,131 pUNTRODUCTION: Despite the harmful effects of tobacco millions of people continue to smoke. Many of these smokers, including most news smokers, are adolescents - both in Chile and in other countries. This study sought to determine the prevalence of smoking among Chilean elementary and high school children and to quantify the relative impact of socioeconomic, socio-cultural, familial, mass media exposure, demographic, educational and psychosocial factors on smoking. MATERIAL AND METHOD: A representative sample of 2,967 elementary and high school children from Chile's Metropolitan Region were chosen at random, by grade (IV, VI, and VIII elementary school grades and I and IV high school grades), sex, type of school and geographical area. Prevalence of smoking was determined through an anonymous self-administered questionnaire. Socioeconomic status (SES) was measured by means of Graffar's modified method and family conditions, mass media exposure and psychosocial factors were registered. Scholastic achievement was measured by a language and mathematics test and other educational variables were considered. Statistical procedures included analysis of variance, Student's test and Scheffe's test for comparison of means, correlation, stepwise multiple regression, chi-squared and PAHO/WHO risk approach methodology. RESULTS: Prevalence of smoking (10.6%) increased significantly with age, from 1.3% in school children aged < 13 years to 15.4% and 36.9%, in adolescent students aged 13-15 years and ;³; 16 years, respectively (p< 0.001) and was higher in females than in males. Pleasure level (r= 0.499 p < 0.001), level of rebelliousness (r= 0.124 p < 0.0001), family recreation level (r=-0.131 p < 0.0001) and the percentage of school attendance (r=-0.118 p < 0.0001) were the independent variables with the greatest explanatory power in smoking variance (r²= 0.2860), but pleasure level was the variable with the greatest explanatory power in the explained variance (89.2%) and with the greatest RR (34.3). The relative impact of the independent variables on smoking varied according to age, sex and SES. CONCLUSIONS: The result demonstrate that pleasure level, level of rebelliousness, family recreation lvel and the percentage of school attendance were the independent variables with the greatest explanatory power in smoking. These findings may be useful in the implementation of education and health policies with a view to the reduction of this serious public health risk factor.INTRODUCCIÓN: Considerando la indiscutible evidencia de los efectos adversos del tabaco, para la salud, millones de personas continúan fumando. La situación es de mayor gravedad, ya que muchos de estos fumadores y la mayoría de los nuevos fumadores, tanto en Chile, como en otros países, son adolescentes. Los objetivos de este estudio fueron determinar la prevalencia de tabaquismo en escolares chilenos y cuantificar el impacto relativo que ejercen factores socioeconómicos, socioculturales, familiares, de exposición a medios de comunicación de masas, demográficos, educacionales y psicosociales, sobre la prevalencia de tabaquismo. MATERIAL E MÉTODO: Se seleccionó una muestra aleatoria, representativa de 2.967 escolares de educación básica y media de la Región Metropolitana de Chile, proporcional de acuerdo al curso(IV, VI, y VIII año básico y I y IV año medio), sexo, tipo de colegio y área geográfica. La prevalencia de tabaquismo se determinó mediante un cuestionario autoadministrado. El nivel socioeconómico(NSE) se midió por medio del método de Graffar modificado, midiéndose además, las condiciones familiares, la exposición a medios de comunicación de masas y factores psicosociales. El rendimiento escolar se determinó mediante un test de castellano y matemáticas, al mismo tiempo que se registraron otras variables educacionales. El análisis estadístico incluyó análisis de varianza, test de la t de Student y test de Scheffe para comparación de medias, correlación, regresión múltiple stepwise, chi-cuadrado y la metodología del enfoque de riesgo de OPS/OMS, para el cálculo del riesgo relativo simple (RR). RESULTADOS: La prevalencia de tabaquismo (10,6%) aumentó significativamente con la edad, de 1,3% en los escolares menores de 13 años, a 15,4% y 36,9%, en los adolescentes entre 13-15 años y ;³; 16 años, respectivamente (p< 0,001), a la vez que fue mayor en los escolares de sexo femenino. El grado de placer(r=0,499

CP^n, or, entanglement illustrated

We show that many topological and geometrical properties of complex projective space can be understood just by looking at a suitably constructed picture. The idea is to view CP^n as a set of flat tori parametrized by the positive octant of a round sphere. We pay particular attention to submanifolds of constant entanglement in CP^3 and give a few new results concerning them.Comment: 28 pages, 9 figure

Optimum Unambiguous Discrimination Between Linearly Independent Symmetric States

The quantum formalism permits one to discriminate sometimes between any set of linearly-independent pure states with certainty. We obtain the maximum probability with which a set of equally-likely, symmetric, linearly-independent states can be discriminated. The form of this bound is examined for symmetric coherent states of a harmonic oscillator or field mode.Comment: 9 pages, 2 eps figures, submitted to Physics Letters

Experimental Demonstration of Optimal Unambiguous State Discrimination

We present the first full demonstration of unambiguous state discrimination between non-orthogonal quantum states. Using a novel free space interferometer we have realised the optimum quantum measurement scheme for two non-orthogonal states of light, known as the Ivanovic-Dieks-Peres (IDP) measurement. We have for the first time gained access to all three possible outcomes of this measurement. All aspects of this generalised measurement scheme, including its superiority over a standard von Neumann measurement, have been demonstrated within 1.5% of the IDP predictions

Comparison of two unknown pure quantum states

We investigate the extent to which we can establish whether or not two quantum systems have been prepared in the same state. We investigate the possibility of universal unambiguous state comparison. We show that it is impossible to conclusively identify two pure unknown states as being identical, and construct the optimal measurement for conclusively identifying them as being different. We then derive optimal strategies for state comparison when the state of each system is one of two known states

Maximal Entanglement, Collective Coordinates and Tracking the King

Maximal entangled states (MES) provide a basis to two d-dimensional particles Hilbert space, d=prime $\ne 2$. The MES forming this basis are product states in the collective, center of mass and relative, coordinates. These states are associated (underpinned) with lines of finite geometry whose constituent points are associated with product states carrying Mutual Unbiased Bases (MUB) labels. This representation is shown to be convenient for the study of the Mean King Problem and a variant thereof, termed Tracking the King which proves to be a novel quantum communication channel. The main topics, notions used are reviewed in an attempt to have the paper self contained.Comment: 8. arXiv admin note: substantial text overlap with arXiv:1206.3884, arXiv:1206.035

Habitat of Argentine squid (Illex argentinus) paralarvae in the southwestern Atlantic

Illex argentinus is one of Argentina’s most important commercial species and sustains one of the most important cephalopod fisheries worldwide. Catches, and presumably population abundances, show strong interannual fluctuations, probably forced by processes which occur during the species’ early life history. However, knowledge of paralarvae ecology and the influence of the environment on larval survival are fragmentary and limited. In this work, we describe the habitat of I. argentinus paralarvae caught in 4 research cruises between 34° and 42° S, taking into account information on seasonal transport of paralarvae by currents, chlorophyll a concentrations, characteristics of water masses and water column structure. Argentine squid paralarvae habitat is environmentally complex. Paralarvae occur in the plankton when the biological production in the area is relatively low but offshore transport is at a minimum, thus decreasing the chances of the paralarvae being exported to places unsuitable for survival. We discuss how the synchronization of the squid reproductive cycle relates to these environmental events and may improve paralarvae survival and recruitment.Fil: Torres Alberto, María Luz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: Saraceno, Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmósfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmósfera; ArgentinaFil: Ivanovic, M.. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: Acha, Eduardo Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Subsede Instituto Nacional de Investigación y Desarrollo Pesquero; Argentina. Instituto Nacional de Investigaciones y Desarrollo Pesquero; Argentin