RESUMO Esta pesquisa registra o período reprodutivo de dez espécies de peixes dulcícolas dominantes na região límnica da Laguna dos Patos e Lago Guaíba (Astyanax fasciatus, Cyphocharax voga, Hoplias malabaricus, Oligosarcus jenynsii, Oligosarcus robustus, Hoplosternum littorale, Loricariichthys anus, Parapimelodus nigribarbis, Trachelyopterus lucenai, Pachyurus bonariensis). Os dados derivam de amostras mensais realizadas na Lagoa do Casamento (Nordeste da Laguna dos Patos; Nov. 2002 a Abr. 2004) e no Lago Guaíba (Jun. 2005 a Maio 2006). A reprodução de peixes foi identificada durante todos os meses do ano. Oligosarcus jenynsii iniciou a reprodução no inverno, mas prolongou a desova até a primavera (reprodução no início do ciclo de aquecimento da água). Três espécies também apresentaram reprodução durante os meses de aquecimento da água, mas começando na primavera e terminando no verão (reprodução tardia do ciclo de aquecimento da água): P. nigribarbis, T. lucenai e P. bonariensis. Três espécies apresentaram períodos de reprodução relativamente curtos no verão (reprodução concentrada em período de água quente): H. malabaricus, H. littorale e L. anus, e apenas uma espécie se reproduz quase continuamente durante águas mais quentes (reprodução de longa duração em período de água quente): A. fasciatus. Finalmente, duas outras espécies apresentaram um padrão reprodutivo muito distinto, iniciando a reprodução no final do verão, mas aumentando os valores do IGS ao longo do outono e inverno (reprodutores de longo período com águas em resfriamento): C. voga e O. robustus.

ABSTRACT This contribution records the reproductive periods of ten dominant freshwater fish species from the Patos Lagoon and Guaíba Lake (Astyanax fasciatus, Cyphocharax voga, Hoplias malabaricus, Oligosarcus jenynsii, Oligosarcus robustus, Hoplosternum littorale, Loricariichthys anus, Parapimelodus nigribarbis, Trachelyopterus lucenai, Pachyurus bonariensis). Data were derived from monthly samples in Casamento Lake (northern Patos Lagoon; Nov. 2002 to Apr. 2004) and Guaíba Lake (Jun. 2005 to May 2006). The reproductive period was determined according to the monthly variation of the gonadosomatic index (GSI). Fish reproduction was identified during all months of the year. Oligosarcus jenynsii started reproduction in winter, but extended spawning to spring (early warming-water reproduction). Three species also presented reproduction during warming water months, but beginning in spring and finishing in summer (late warm-water reproduction): P. nigribarbis, T. lucenai and P. bonariensis. Three species presented relatively short reproduction periods on summer (spotted warm-water reproduction): H. malabaricus, H. littorale and L. anus, and only one species reproduces almost continuously during warmer waters (long-season warm-water reproduction): A. fasciatus. Finally, two other species presented a very distinct reproductive pattern, starting reproduction on late summer but increasing GSI values along autumn and winter (long-season cooling-water reproducers): C. voga and O. robustus.

Resumo Introdução: o câncer de mama é a segunda causa de morte no mundo, sendo 90% dessas mortes decorrentes de metástases. A metaloprotease de matriz 2 (MMP-2) possui atividade de gelatinase capaz de degradar o principal constituinte do microambiente tumoral, o colágeno do tipo IV. Há duas proteínas bem estabelecidas utilizadas como marcadores na prática clínica para o câncer de mama, os receptores de estrógeno (RE) e de progesterona (RP). Embora a presença desses receptores tenha sido associada a um melhor prognóstico, a perda delas pode ocorrer durante a progressão do tumor, com subsequente resistência à terapia hormonal. Objetivo: analisar a correlação entre as proteínas MMP-2, RE e RP por imuno-histoquímica e estabelecer o processo metastático em tumores de mama primários. Método: amostras de tumor de mama (n=44) foram analisadas por imuno-histoquímica para MMP-2, receptor de estrógeno e progesterona. Resultados: observou-se que 90% das pacientes que tinham metástases e morreram apresentaram coloração positiva para a MMP-2 (p=0,0082 para ambos). Usando a análise de Kaplan-Meier, verificou-se que as pacientes RE negativas, também positivas para MMP-2, apresentaram sobrevida livre de doença (SLD) e sobrevida global (SG) (p=0,012 e p=0,005, respectivamente) piores quando comparadas às pacientes MMP-2 negativas. Resultados semelhantes foram encontrados em pacientes RP negativas para SLD (p=0,077) e SG (p=0,038). Conclusão: embora o número de amostras avaliadas tenha sido baixo (n=44), esses dados iniciais permitem inferir que a MMP-2 em combinação com os marcadores já bem estabelecidos poderia ajudar na previsão do surgimento de metástase e morte em pacientes com câncer de mama.

Summary Introduction: Breast cancer is the most cause of death, and approximately 90% of these deaths are due to metastases. Matrix metalloproteinase-2 (MMP-2) gelatinase activity is able to degrade a major constituent of the tumor microenvironment, type IV collagen. Two well-established proteins used as markers in clinical practice for breast cancer are the receptors for estrogen (ER) and progesterone (PR). Although the presence of these receptors has been associated with a better prognosis, loss of these proteins can occur during tumor progression, with subsequent resistance to hormone therapy. Objective: To study the correlation among MMP-2, ER, and PR, as well as the establishment of the metastatic process in primary breast tumors. Method: Breast cancer samples (n=44) were analyzed by immunohistochemistry for MMP-2, ER, and PR. Results: We observed that 90% of patients who had metastases and died showed positive staining for MMP-2 (p=0.0082 for both). Using Kaplan-Meier analysis, we found that negative ER patients who were also positive for MMP-2 had even worse disease-free survival (DFS) and overall survival (OS) (p= 0.012 and p=0.005, respectively). Similar results were found in PR-negative patients for DFS (a trend p=0.077) and OS (p=0.038). Conclusion: Regardless of our small sample size (n=44), the data obtained strongly suggest that MMP-2 in combination with already well-established markers could help to predict the emergence of metastases and death in patients with breast cancer.

Neste trabalho foram analisadas amostras de matéria orgânica de solos (MOS) de área de floresta nativa (SFN) e de solos de uma área vizinha, local de mineração de xisto, que vem sendo reabilitada há 30 anos (SFR). As espectroscopias de ressonância paramagnética eletrônica (RPE, banda X) e ressonância magnética nuclear (RMN) de 13C com as amostras no estado sólido foram utilizadas para avaliar a recuperação do solo reabilitado após a mineração do xisto. Estudos de correlação heteroespectral bidimensional dos resultados obtidos por RPE e RMN 13C foram utilizados para obter informações sobre a estrutura da matéria orgânica do solo e suas interações com o oxicátion paramagnético residual VO2+. As estruturas orgânicas hidrofílicas, que correlacionaram positivamente com o oxicátion metálico VO2+, são do tipo ácido urônico, determinadas por RMN 13C, e negativamente com o sinal do radical livre orgânico (RLO) associado a átomos de oxigênio (g = 2,0042). As estruturas hidrofóbicas aromáticas se correlacionaram positivamente com o sinal de RPE do RLO associado a átomos de carbono (g = 2,0022). Os dados das duas técnicas espectroscópicas magnéticas aplicadas às amostras de ambos os solos (SFN e SFR) mostram que o processo usado na recuperação dos solos de mineração vem sendo efetivo.

In this work, native forest soil (NFS) organic matter (SOM) sample and SOM samples from a neighboring forest soil area of an oil shale mine which is being rehabilitated for thirty years (RFS) were analyzed. X-band electron paramagnetic resonance (EPR) and solid-state 13C nuclear magnetic resonance (NMR) spectroscopies were used to evaluate the soil reclamation of the Brazilian oil shale mining process. Two-dimensional heterospectral correlation studies of the results obtained from EPR and 13C NMR were used to obtain information about SOM structures and their interactions with residual paramagnetic metal ion. The signal of the residual metallic oxycation, VO2+ correlated positively with uronic acid-type hydrophilic organic structures, determined from the 13C NMR spectra, and correlated negatively with the organic free radical (OFR) signal associated with oxygen atoms (g = 2.0042). The hydrophobic aromatic structures correlate positively with the EPR OFR signal associated with carbon atoms (g = 2.0022). The data from the two spectroscopic magnetic techniques show that the used recuperation process is effective.

El objetivo del presente estudio cualitativo fue analizar los aspectos morfológicos de la anatomía cerebral interna utilizando imágenes de resonancia magnética (IRM) en dos especies de primates, El mono Araña (A. geoffroyi) y el humano (H. sapiens), tomando como base un estudio comparativo de las estructuras cerebrales de las dos especies, concentrándose primordialmente en el sistema límbico del cerebro del mono araña. Aunque es una especie común en el hemisferio occidental, es interesante para estudiar dada su organización social y funciones motoras, el mono araña (A. geoffroyi) ha sido poco estudiado en cuanto a su neuroanatomía. Las IRM fueron hechas a un mono araña utilizando un resonador General Electrics Signa 1.5 T. Esta investigación se llevo a cabo conforme a las leyes internacionales para la protección de animales en cautiverio y teniendo en cuenta todas las medidas de protección para el manejo experimental para evitar cualquier efecto residual de índole comportamental o fisiológico. Desde un punto de vista cualitativo, los cerebros del mono araña y el humano tenían estructuras similares. Con respecto a la forma, las estructuras más parecidas fueron encontradas en el sistema límbico, sin embargo la curvatura cervical, la amígdala, el hipocampo, la comisura anterior y el colículo fueron más grandes proporcionalmente en el mono araña que en el humano.

The objective of the present qualitative study was to analyze the morphological aspects of the inner cerebral anatomy of two species of primates, using magnetic resonance images (MRI): spider monkey (A. geoffroyi) and human (H. sapiens), on the basis of a comparative study of the cerebral structures of the two species, focusing upon the brain of the spider monkey and, primarily, its limbic system. In spite of being an endemic Western hemisphere species, a fact which is by its own right interesting for research due to this animal’s social organization and motor functions, the spider monkey (A. geoffroyi) has hardly been studied in regard to its neuroanatomy. MRI was carried out, in one spider monkey, employing a General Electric Signa 1.5 T scanner. This investigation was carried in accordance to international regulations for the protection of animals in captivity, taking into account all protective means utilized in experimental handling, and not leaving behind any residual effects, either physiological or behavioral. From a qualitative point of view, the brains of the spider monkey and the human were found to have similar structures. In reference to shape, the most similar structures were found in the limbic system; proportionally, however, cervi cal curvature, amygdala, hippocampus, anterior commissure and the colliculi, were larger in the spider monkey than in the human.

We have investigated the electron and hole spin dynamics in p-doped semiconductor InAs/GaAs quantum dots by time resolved photoluminescence. We observe a decay of the average electron spin polarisation down to 1/3 of its initial value with a characteristic time of T<FONT FACE=Symbol>D »</FONT> 500ps. We attribute this decay to the hyperfine interaction of the electron spin with randomly orientated nuclear spins. Magnetic field dependent studies reveal that this efficient spin relaxation mechanism can be suppressed by a field of the order of 100mT. In pump-probe like experiments we demonstrate that the resident hole spin, "written" with a first pulse, remains stable long enough to be "read" 15ns later with a second pulse.

Objectives: Health resources utilization is related to health conditions and to the population's sociodemographic characteristics. Low socioeconomic groups show increased utilization of certain resources. Emergency department utilization could also be affected by socioeconomic factors. The aim of this study was to identify differences in emergency department utilization among different socioeconomic groups. Material and methods: A population-based study was performed. Census sections of the city of Santander in Spain were grouped according to sociodemographic variables (age, educational and professional attinment). Areas of the city with similar socioeconomic characteristics were established by cluster analysis. The place of residence of patients visiting the emergency department of th Hospital Marqués de Valdecilla was identified and the utilization rate was calculated for each cluster. Results: Cluster analysis was able to identify four different groups, each with different socioeconomic characteristics, which were closely related to the districts of Santander. Comparison of clusters 1 and 4 showed that increased emergency department utilization was found amongst groups with lowest socioeconomic status and higher mean age, with an odds ratio of 1.91 (95% CI: 1.73-2.1). Patients from higher socioeconomic groups were more likely to be admitted to hospital while those from lower socioeconomic groups made more repeat visits to the emergency department. Conclusion: Emergency department utilization is affected by the sociodemographic characteristics of patients' area of residence. Patients with lower socioeconomic status show greater use of the emergency department.

Objetivos: La utilización por parte de la población de los recursos sanitarios se encuentra relacionada con los niveles de salud y con factores socioeconómicos. Los grupos de población con menor nivel socioeconómico tienen una mayor utilización de determinados recursos sanitarios; los servicios de urgencia podrían presentar un uso diferencial entre los distintos grupos de población. El presente estudio pretende identificar diferencias en el uso de los recursos de atención urgente entre grupos con diferentes características socioeconómicas. Material y métodos: Se realiza un estudio poblacional, en el que mediante el agrupamiento de las secciones censales de la ciudad de Santander, según variables sociodemográficas (edad, nivel de formación y nivel de empleo), se establecen áreas de la ciudad con similares características, mediante análisis de clusters. Se identifica el origen de los pacientes que consultan en el Servicio de Urgencias Hospitalarias (SUH) del Hospital Marqués de Valdecilla, y se calcula la tasa de demanda para cada una de las áreas sociodemográficas. Resultados: El análisis de clusters es capaz de identificar cuatro agrupaciones de diferentes características socioeconómicas que se ajustan a barrios de la ciudad de Santander. Se aprecia una mayor utilización del SUH en los grupos sociales más desfavorecidos y de mayor edad media (odds ratio [OR] = 1,91; intervalo de confianza [IC] del 95% 1,73-2,1) de la agrupación 1 con respecto a la 4. La proporción de ingresos es superior en las agrupaciones más favorecidas, mientras que el número de usuarios que realizan visitas repetidas proceden de agrupaciones con menor nivel socioeconómico. Conclusión: La utilización del SUH está condicionada por las características sociodemográficas del área de residencia, identificándose mayor uso entre los grupos de más bajo nivel socioeconómico.

Objectives: Health resources utilization is related to health conditions and to the population's sociodemographic characteristics. Low socioeconomic groups show increased utilization of certain resources. Emergency department utilization could also be affected by socioeconomic factors. The aim of this study was to identify differences in emergency department utilization among different socioeconomic groups. Material and methods: A population-based study was performed. Census sections of the city of Santander in Spain were grouped according to sociodemographic variables (age, educational and professional attinment). Areas of the city with similar socioeconomic characteristics were established by cluster analysis. The place of residence of patients visiting the emergency department of th Hospital Marqués de Valdecilla was identified and the utilization rate was calculated for each cluster. Results: Cluster analysis was able to identify four different groups, each with different socioeconomic characteristics, which were closely related to the districts of Santander. Comparison of clusters 1 and 4 showed that increased emergency department utilization was found amongst groups with lowest socioeconomic status and higher mean age, with an odds ratio of 1.91 (95% CI: 1.73-2.1). Patients from higher socioeconomic groups were more likely to be admitted to hospital while those from lower socioeconomic groups made more repeat visits to the emergency department. Conclusion: Emergency department utilization is affected by the sociodemographic characteristics of patients' area of residence. Patients with lower socioeconomic status show greater use of the emergency department.

Objetivos: La utilización por parte de la población de los recursos sanitarios se encuentra relacionada con los niveles de salud y con factores socioeconómicos. Los grupos de población con menor nivel socioeconómico tienen una mayor utilización de determinados recursos sanitarios; los servicios de urgencia podrían presentar un uso diferencial entre los distintos grupos de población. El presente estudio pretende identificar diferencias en el uso de los recursos de atención urgente entre grupos con diferentes características socioeconómicas. Material y métodos: Se realiza un estudio poblacional, en el que mediante el agrupamiento de las secciones censales de la ciudad de Santander, según variables sociodemográficas (edad, nivel de formación y nivel de empleo), se establecen áreas de la ciudad con similares características, mediante análisis de clusters. Se identifica el origen de los pacientes que consultan en el Servicio de Urgencias Hospitalarias (SUH) del Hospital Marqués de Valdecilla, y se calcula la tasa de demanda para cada una de las áreas sociodemográficas. Resultados: El análisis de clusters es capaz de identificar cuatro agrupaciones de diferentes características socioeconómicas que se ajustan a barrios de la ciudad de Santander. Se aprecia una mayor utilización del SUH en los grupos sociales más desfavorecidos y de mayor edad media (odds ratio [OR] = 1,91; intervalo de confianza [IC] del 95% 1,73-2,1) de la agrupación 1 con respecto a la 4. La proporción de ingresos es superior en las agrupaciones más favorecidas, mientras que el número de usuarios que realizan visitas repetidas proceden de agrupaciones con menor nivel socioeconómico. Conclusión: La utilización del SUH está condicionada por las características sociodemográficas del área de residencia, identificándose mayor uso entre los grupos de más bajo nivel socioeconómico.