Hypoxia does not influence the response of fish to a mixture of estrogenic chemicals

The official published version can be obtained from the link below - Copyright @ 2009 American Chemical SocietyChemical risk assessment procedures assign a major role to standardized toxicity tests, in which the response of a particular organism to a single test substance is determined under otherwise constant and favorable conditions in the laboratory. This approach fails to consider the potential for chemical interactions, as well as failing to consider how the toxicological response varies, depending on the conditions of exposure. As yet, the issue of confounding factors on chemically mediated effects in wildlife has received little attention, despite the fact that a range of physicochemical parameters, including temperature, water quality, and pH, are known to modify chemical toxicity. Here, we consider how the estrogenic response of fish varies with regard to hypoxia. Fathead minnows (Pimephales promelas) were exposed to a mixture of estrogenic chemicals under hypoxic or normoxic conditions. Their estrogenic response was characterized using an in vivo assay, involving the analysis of the egg yolk protein, vitellogenin (VTG). The results revealed that there was no effect of hypoxia on the VTG response in either treatment group at the end of the exposure period. This suggests that this end point is robust and relatively insensitive to the effects of any physiological changes that arise as a result of hypoxia. The implications of these negative findings are discussed in terms of their relevance with regard to the development of risk assessment policy.This work was funded by a grant from the Natural Environment Research Council(NE/D00389X/1)

The influence of a surfactant, linear alkylbenzene sulfonate, on the estrogenic response to a mixture of (xeno)estrogens in vitro and in vivo

This is the post-print version of the final paper published in Aquatic Toxicology. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright © 2008 Elsevier B.V. All rights reserved.The effect of the presence of a surfactant on the activity of a mixture of environmental estrogens was assessed. In their natural habitat, fish are subject not only to exposure to mixtures of estrogenic compounds, as has been addressed in previous publications, but also to other confounding factors (chemical, physical and biological), which may, in theory, affect their responses to such compounds. To assess the potential for such interference, the commonly occurring surfactant, linear alkylbenzene sulfonate (LAS), was applied to the yeast estrogen screen at various concentrations, independently and together with a mixture of estrogens at constant concentrations. LAS enhanced the estrogenic activity of the mixture, an effect which became less pronounced over the course of time. This information was used to design an in vivo study to assess induction of vitellogenin in fathead minnows exposed to the same mixture of estrogens plus LAS. A similar trend was observed, that is, the response was enhanced, but the effect became less pronounced as the study progressed. However, the enhanced response in vivo occurred only at the highest concentration of LAS tested (362 μg/L), and was transient because it was no longer apparent by the end of the study. Although LAS is a significant contaminant in terms of both concentration and frequency of detection in the aquatic environment, these data do not suggest that it will have a significant impact on the response of fish to environmental estrogens

Zoning of coastal erosion in Santa Clara del Mar, Buenos Aires province

La zona de estudio comprende el área costera de la localidad de Santa Clara del Mar, ubicada en el sector sudeste de la provincia de Buenos Aires, en el partido de Mar Chiquita. El entorno natural del área de estudio ha sufrido modificaciones, producto principalmente del rápido crecimiento urbanístico y turístico, incrementando la erosión de playa y el retroceso de los acantilados de manera considerable. El objetivo del presente trabajo radica en analizar la morfodinámica y el retroceso costero entre 1958 y 1975 cuando la costa mostraba condiciones naturales, y las variaciones morfológicas registradas luego de la implementación de estructuras de protección entre los años 1975 y 2009. Las tasas de retroceso natural obtenidas entre los años 1958 y 1975, para la localidad de Santa Clara del Mar, variaron desde 1,7 m/año en el sector sur hasta 5,8 m/año en el norte. El análisis histórico de vulnerabilidad a la erosión permitió diferenciar a la costa de Santa Clara en tres sectores con distinta magnitud: alta, media y baja, correspondientes a un sector norte, central y sur, respectivamente. La tasa de acumulación de arena en la playa entre 1958 y 2009 fue de 0,9 m/año promedio para toda la costa. Entre los principales factores que modificaron las condiciones hidrodinámicas del sistema litoral en la ciudad de Santa Clara del Mar se destacan: la destrucción y degradación del campo de dunas colgado, la canalización del Arroyo Los Patos, la instalación de paredones verticales y la construcción de una serie de espigones en ´J´ a partir de la década de 1950. Por otro lado, las estructuras de protección costera ubicadas en Mar del Plata han influenciado indirectamente en la subsaturación de la deriva litoral, incrementando la erosión costera hacia el sur.The studied region includes the coastal zone of Santa Clara del Mar town, situated in the southeast of Buenos Aires province, in Mar Chiquita district. The natural environment of this area has been modified, mainly because of the fast growth of urbanization and tourism, increasing the erosion on the beach and the cliffs´s regression seriously. The aim of this paper is to analyze the morphodynamics and the coastal erosion during 1958 and 1975 when the coast showed natural conditions, and the morphological changes registered after the implementation of coastal protection structures between 1975 and 2009. The natural regression rates obtained between 1958 and 1975 in Santa Clara del Mar varied from 1,7 m/year in the south to 5,8 m/year in the north. The historical vulnerability to erosion analysis allowed us to divide Santa Clara del Mar´s coast into three sectors with different magnitude: high, moderate and low, corresponding to northern, central and southern sectors, respectively. The accumulation rate of sand in the beach between 1958 and 2009 was about 0,9 m/year for all the coast. The main factors that modified the hydrodynamic conditions of the coastal system of Santa Clara del Mar are: the destruction and degradation of perched dunes field, the channeling of Los Patos stream, the setting up of seawalls and the building of a group of breakwaters in ´J´ since 1950s. On the other hand, the coastal protection structures located in Mar del Plata have indirectly influenced on the longshore drift undersaturation, increasing the coastal erosion to the south.Fil: Bunicontro, Maria Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Basicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Basicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaFil: Marcomini, Silvia Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Basicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Basicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaFil: López, Rubén Alvaro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Basicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Basicas, Aplicadas y Ambientales de Buenos Aires; Argentin

Evidence of estrogenic mixture effects on the reproductive performance of fish

The official published version can be obtained from the link below - Copyright @ 2007 American Chemical SocietyRecent research into the effects of mixtures of estrogenic chemicals has revealed the capacity for similarly acting chemicals to act in combination, according to the principles of concentration addition. This means that, collectively, they may pose a significant environmental risk, even when each component is present at a low and individually ineffective concentration. The aim of this study was to investigate the ecological significance of mixture effects at low-effect concentrations by assessing the combined effect of estrogenic chemicals on the reproductive performance of fish. Pairs of fathead minnows were exposed to five estrogenic chemicals. Endpoints analyzed included fecundity, the expression of male secondary sexual characteristics, somatic indices, and vitellogenin induction. In the first phase of the study, a concentration-response analysis was performed to investigate the relative sensitivity of these endpoints. In the second phase, mixture effects at low-effect concentrations were explored by exposing fish to each of the mixture components, individually and in combination. Data from these experiments provide evidence of mixture effects on fitness and fecundity, demonstrating the capacity for chemicals to act together to affect reproductive performance, even when each component is present belowthe threshold of detectable effects. This has important implications for hazard assessment and contributes to our understanding of mixture effects at increasing levels of biological complexity.This work was funded by the European Commission, under contract EVK1-2001-00091

Úlcera bilateral por Acanthamoeba em usuária de lentes de contato gelatinosas descartáveis: um incidente trágico ou uma conseqüência da política agressiva de venda de lentes de contato gelatinosas?

This is the report of a case of bilateral Acanthamoeba keratitis in a 19-year-old woman who bought a pair of disposable soft contact lenses in a boutique. She wore this same pair of lenses for 3 months daily without the appropriate care. This led to bilateral corneal transplantation with cataract extraction and also trabeculectomy in the right eye. When last seen, both grafts were crystal clear but the visual acuities were far from satisfactory. She also had bilateral secondary glaucoma, barely controlled by topical medication. Actually, the physical features and the wearing time characteristics of the disposable soft contact lenses created unprecedented difficulties to the medical surveillance of their wearers. Without the right assistance they tend to become careless regarding routine cleaning. They also feel free to buy less expensive lenses, to use saline instead of lens solutions, to violate the limits of wearing time and to extend the use over the sleeping period. Additionally, the aggressive marketing and the wide distribution of these lenses increase the chances that economically or educationally unprepared people will acquire them. The question that remains is: Is the present case an accidental event or an example of what is likely to happen in the future if the indiscriminate selling of disposable soft contact lenses continues to evolve?Este é o relato de uma paciente do sexo feminino, de 19 anos, com ceratite bilateral por Acanthamoeba, devido ao uso de lentes de contato descartáveis, adquiridas em uma butique. Fez uso do mesmo par de lentes durante três meses, sem os cuidados adequados. Foi submetida a transplante penetrante de córnea e facectomia bilateral, além de trabeculectomia no olho direito. Quando vista pela última vez, os enxertos estavam transparentes, mas a visão de ambos os olhos não era satisfatória. Ela também apresentava glaucoma secundário bilateral, controlado precariamente com medicação tópica. Ocorre que, as características físicas e o regime de uso das lentes de contato gelatinosas descartáveis criam dificuldades adicionais para a vigilância médica dos seus usuários. Sem a assistência correta, eles relaxam com a rotina de limpeza, compram lentes mais baratas, usam soro fisiológico ao invés das soluções adequadas, violam os limites de uso e dormem com as mesmas. Além disso, o "marketing" agressivo e a ampla distribuição dessas lentes aumentam as chances de que pessoas, não preparadas econômica e educacionalmente, venham ter acesso às mesmas. A pergunta que fica é: Seria o presente caso um evento acidental ou um exemplo do que pode acontecer no futuro caso as lentes de contato descartáveis continuem sendo vendidas indiscriminadamente

Darwin y el mar

Además de sus conocidos aportes a la geología, la paleontología y la biogeografía de ecosistemas terrestres de la región pampeana y la Patagonia (Argentina), Darwin realizó notables y poco difundidas contribuciones al conocimiento de los ambientes marinos costeros del actual territorio argentino y de los organismos que habitan en ellos. La intimidad de Darwin con el mar se advierte en toda su obra: en el Viaje y en el Origen igual que en numerosos trabajos de investigación realizados y publicados a su regreso a Inglaterra. Entre 1846 y 1854 dio a conocer una extensa obra sobre cirrípedos o cirripedios, que sentó las bases del estudio de esos crustáceos y, aún hoy, es bibliografía obligada de los taxónomos. Su trabajo sobre la estructura y distribución de los arrecifes coralinos de 1842, es considerado un documento fundacional del conocimiento sobre el origen de los atolones. Los moluscos fueron igualmente objeto de publicaciones y cartas entre 1848 y 1871. La difundida imagen de Darwin sentado ante un escritorio escribiendo sus libros lleva a olvidar que pasaba también mucho tiempo con el microscopio. En el Viaje del Beagle incluyó párrafos sobre aves marinas, lo mismo que sobre briozoos o briozoarios, y en El origen, explicó sus pensamientos acerca de la migración de los ojos en los lenguados. Dedicó especial atención a las algas gigantes o sargazos marinos de Tierra del Fuego (donde se los conoce por cachiyuyos). Se incluyen los siguientes trabajos de divulgación científica -Darwin y los briozoos; -Darwin y el desarrollo larval de crustáceos; -Sobre Cirripedios; De Darwin a los acelerómetros; -Los peces de cara torcida; -La incursión en la costa sur de Buenos Aires

GESTÃO DOS CURSOS DE PÓS-GRADUAÇÃO LATO SENSU: ESTRATÉGIAS E IMPACTOS NA AVALIAÇÃO DOCENTE DA UNIDADE BAURU DO CENTRO UNIVERSITÁRIO SENAC

O presente estudo tem como objetivo discutir a relação entre as estratégias de gestão adotadas nos cursos de pós-graduação lato sensu ofertados pela Unidade Bauru do Centro Universitário SENAC, no período compreendido entre 2011 e 2014, especificamente as voltadas à qualidade do processo ensino-aprendizagem e seus reflexos nos resultados da avaliação docente sob a ótica da percepção dos discentes, sendo esta uma das oito dimensões estabelecidas pela instituição para a sua avaliação institucional. A metodologia adotada nesta investigação foi de natureza exploratória e qualitativa, utilizando-se da pesquisa bibliográfica, entrevista e análise documental, esta última desenvolvida por meio da análise dos relatórios da avaliação institucional que é aplicada semestralmente e que foram disponibilizados pela instituição. Enquanto resultados, verifica-se no período estudado uma significativa evolução nos índices de satisfação do corpo discente em relação aos professores dos cursos. Conclui-se, portanto, que as estratégias adotadas podem estar impactando positivamente na qualidade dos cursos, se analisadas sob esta ótica, a dos discentes

The impact of environmental cues on customers' quality perception and willingness to pay and the moderating role of consumer mood and motives

The literature shows that shopping environment has an impact on various consumer behaviors, and that an elegant environment is associated with higher customer’ quality perception and willingness to pay. I investigated and found that this is true only when consumers are in a positive mood. When they are in a negative mood, consumers infer higher quality from a discount-looking shop. A between-design experimental survey has been conducted to analyze the impact of shopping environment, mood and shopping motivation on customers’ perception of quality and willingness to pay. Two mood conditions (positive/negative) have been created and induced to respondents at the beginning of the survey, along with two shopping environment conditions (upscale-looking/discount-looking) based on design, scent and sales personnel factors. Results show that shopping environment does not impact significantly the dependent variables but it interacts significantly with mood to determine quality perception; shopping motivation impacts significantly both quality perception and willingness to pay.A literatura existente mostra que o ambiente do local onde se realizam compras impactua o comportamento do consumidor e que certos elementos favoráveis presentes neste local, estão associados a uma maior perceção de qualidade e uma maior disposição para comprar por parte dos consumidores. A autora investigou e descobriu que esta afirmação apenas se confirma quando os consumidores estão com bom-humor. Se em contrapartida, os consumidores estiverem com mau-humor, são os próprios que inferem uma maior qualidade aos produtos que sejam comprados numa loja de descontos. Realizou-se um questionário experimental para analisar o impacto do ambiente do local de compras, humor e motivação na perceção de qualidade e na disposição para comprar dos consumidores. Duas condições de humor (positivas / negativas) foram criadas e induzidas aos inquiridos no início do questionário, juntamente com duas condições de ambiente de compras (de alto nível / com desconto) baseadas em fatores como o design do espaço, o aroma e os empregados do local. Os resultados mostram que o ambiente do local de compras não afeta significativamente as variáveis dependentes, mas interage significativamente com o humor para determinar a perceção de qualidade dos produtos por parte dos consumidores. Por outro lado, a motivação para comprar afeta claramente tanto a perceção quanto a disposição para comprar

Sea bass (Dicentrarchus labrax) as a potential bioindicator of estrogenic contamination in marine surface waters

Resumo apresentado sob poster apresentado ao 5th International Symposium on Fish Endocrinology, September, 2004, Castellon, Spain.Exposure of aquatic wildlife in surface waters to (xeno-)estrogens is known to cause reproductive dysfunction. Estrogenic responses in fish are the net result of complex chains of events that will depend on a number of factors, such as bioavailability, bioconcentration/bioaccumulation, and biotransformation. Most of known estrogenic chemicals are lipophilic and hydrophobic and therefore have a strong potential to accumulate in aquatic biota. Therefore, determining environmental exposures may be very difficult and not be particularly meaningful. As test organism the sea bass (Dicentrarchus labrax) was selected, a common species in European marine systems. This work is part of a study focusing on the combination effects of mixtures of estrogenic chemicals in marine and freshwater organisms. Juvenile sea bass were used in order to analyse the bioconcentration and distribution among different tissues of the chemical residues of a set of reference estrogenic chemicals such as 17ß-estradiol (E2), ethynylestradiol (EE2), nonylphenol (NP), octylphenol (OP), bisphenol-A (BPA). Fish were exposed for a period of two weeks to environmentally relevant levels of these compounds, after which liver, bile, muscle, gill and kidney were collected and analyzed. Actual concentrations of E2, EE2 and BPA seawater in the tanks were determined by either gas chromatography with ion trap detection or HPLC coupled to diode array detection. In bile, levels of BPA were determined according to a method presented earlier by Houtman et al. (13th Annual Meeting SETAC Europe, 2003). Actual NP and OP concentrations in both water and tissues were determined by HPLC-ESI-MS according to recently developed methods by Pojana et al. (J. Anal. Chem., in press). Bioconcentration and distribution of residual compounds in tissues were correlated to the levels of plasma vitellogenin (results are presented also at this conference) and to actual exposure concentrations. The general suitability of the sea bass as a bioindicator of estrogenic contamination in the marine environment is discussed.Comissão Europeia (CE) - ACE, EVK1-CT-2001-100

The ACE Project: a synopsis of in vivo studies to predict estrogenic mixture effects in freshwater and marine fish

Society of Environmental Toxicology and Chemistry - SETAC Europe 15th Annual Meeting, Lille, France, May 2005.This work is part of the ACE project (ACE, EVK1-CT-2001-100) which aim is to investigate multi-component mixtures of estrogenic compounds in aquatic ecosystems. Here we present a synopsis of in vivo data related with the joint estrogenic action of five estrogenic compounds (17ß-estradiol, ethynylestradiol, nonylphenol, octylphenol and bisphenol-A) on vitellogenesis in fathead minnow (Pimephales promelas) and sea bass (Dicentrarchus labrax). The studies were conducted with freshwater adult males and marine juveniles under flow through exposure conditions for two weeks. In the first step, fish were exposed to the five compounds individually in order to generate concentration- response curves. Therefore mixture effects were predicted on the basis of the potency of each compound by using the model of concentration addition (CA). Finally, the compounds were tested as a mixture at equipotent concentrations, and the observed mixture effects were compared to the predictions. The mixture studies showed an good agreement between observed and predicted effects and provided evidence that CA can be used as a predictive tool for the effect assessment of mixtures of (xeno)estrogens in freshwater or marine ecosystems. The differences/limitations of running in vivo mixture studies with freshwater and marine species will be discussed.Comissão Europeia (CE) - ACE project - ACE, EVK1-CT-2001-100