Assessment of Acartia tonsa effect on Necora puber zoeal stages

A navalheira (Necora puber) é uma das espécies mais consumidas em Portugal, sendo que a maioria dos organismos consumidos é atualmente importada de países do Norte da Europa. Para o sucesso da sua produção em aquacultura, é indispensável a administração de presas adequadas à dimensão das fases larvares e que respondam às suas necessidades nutricionais. Os benefícios da administração de copépodes têm vindo a ser reconhecidos, uma vez que os calanóides possuem um largo espectro de tamanhos, movimentos naturais que promovem a sua captura e elevados níveis de ácidos gordos essenciais. Acartia tonsa é uma das espécies de copépodes mais recomendadas para administrar nos primeiros estágios larvares, mas os seus protocolos de cultivo em grande escala ainda requerem otimização. Neste enquadramento, o presente estudo teve como objetivo a seleção da microalga mais adequada para o cultivo de A. tonsa, possibilitando a avaliação do seu efeito no desenvolvimento larval de N. puber, quando comparado com a administração de Artemia franciscana. Inicialmente, os copépodes foram submetidos a duas dietas distintas: Rhodomonas lens e Tetraselmis chuii, a uma densidade de 1x104 cell.mL-1, tendo sido avaliadas as taxas de eclosão, sobrevivência e produção de ovos. A microalga que promoveu uma melhor performance foi administrada nos cultivos contínuos de A. tonsa. Em relação ao desenvolvimento larvar de N. puber, foram avaliadas as taxas de crescimento, percentagem de estágios ao longo do tempo, bem como a correlação entre o peso e o comprimento das larvas, quando alimentadas com A. tonsa e A. franciscana. Adicionalmente, foi avaliado o perfil de ácidos gordos de ambas as espécies de microalgas e de zooplâncton. R. lens permitiu um melhor desempenho enquanto alimento para cultivos de A. tonsa, promovendo uma taxa de eclosão perto de 90%, enquanto que, com T. chuii os copépodes apenas sobreviveram até ao oitavo dia. Tais resultados poderão dever-se à dimensão celular de R. lens, bem ao seu elevado conteúdo de DHA. Em relação ao desenvolvimento larvar de N. puber, Acartia tonsa promoveu uma taxa de sobrevivência de 89 ± 1,63% em zoea V e o encurtamento da fase larvar. Com ambas as dietas foi demonstrada uma forte correlação entre o peso o tamanho. Foi observada uma melhor performance larvar a partir de zoea II, quando as larvas foram alimentadas com A. tonsa, devido à elevada presença de C 20:5 n3 e C 22:6 n3 e movimentos naturais que promovem a sua captura. Assim, foi possível concluir que as A. tonsa é uma presa adequada para larvas de pequenas dimensões, promovendo elevadas sobrevivências e redução da fase larvar.

INTERANNUAL VARIABILITY IN TROPICAL ESTUARINE COPEPOD ASSEMBLAGES OFF NORTHEASTERN BRAZIL

We studied copepod assemblage variability among years, seasons, and tidal states in the Mucuri River estuary (Bahia State, Brazil). Zooplankton samples were collected seasonally through five years (2002-2006) at three sampling stations, one of which was sampled over a complete tidal cycle (two ebb and two flood tides). Temperature, salinity, river flux, and rainfall data were collected. Winter and summer represented dry and wet seasons, respectively. Copepod abundances ranged from 40 to 63% of the total zooplankton assemblage and comprised 46 taxa, among which, common estuarine species such as Temora turbinata (first record for the studied area), Parvocalanus crassirostris, Acartia lilljeborgi, Oithona hebes were the most abundant (euryhaline species). Interannual and seasonal variations were most marked in stenohaline species, e.g.. Notodiaptomus sp. and Thermocyclops minutus; density variations of euryhaline species, which made up the majority of the abundant taxa, were most closely related to tides. Diversity and richness also followed an intertidal pattern of variation.

The crustacean gill (Na(+),K(+))-ATPase: Allosteric modulation of high- and low-affinity ATP-binding sites by sodium and potassium

The blue crab, Callinectes danae, tolerates exposure to a wide salinity range employing mechanisms of compensatory ion uptake when in dilute media. Although the gill (Na(+), K(+))-ATPase is vital to hyperosmoregulatory ability, the interactions occurring at the sites of ATP binding on the molecule itself are unknown. Here, we investigate the modulation by Na(+) and K(+) of homotropic interactions between the ATP-binding sites, and of phosphoenzyme formation of the (Na(+),K(+))-ATPase from the posterior gills of this euryhaline crab. The contribution of the high- and low-affinity ATP-binding sites to maximum velocity was similar for both Na(+) and K(+). However, in contrast to Na(+), a threshold K(+) concentration triggers the appearance of the high-affinity binding sites, displacing the saturation curve to lower ATP concentrations. Further, a low-affinity site for phosphorylation is present on the enzyme. These findings reveal notable differences in the catalytic mechanism of the crustacean (Na(+),K(+))-ATPase compared to the vertebrate enzyme. (C) 2008 Elsevier Inc. All rights reserved.

Crustáceos no cerrito Ariano Souza, Rio Grande, Rio Grande do Sul e distribuição de Callinectes sapidus (Brachyura, Portunidae)

While all species of the genus Callinectes Stimpson, 1860 have a continuous distribution on the Atlantic coast of the Americas, Callinectes sapidus Rathbun, 1896 is the only one with disjunct distribution. Considering that this species was introduced in Europe and Japan, it has been suggested that the occurrence of C. sapidus on the southern coast of Brazil was due to the transport by ballast water. In the archaeological site Ariano Souza, located in the estuary of the Patos Lagoon (southern Brazil), remains of crustaceans, including claws of approximately two thousand years ago, were found. A preliminary analysis of this material showed Callinectes chelae. Because this archaeological site is located inside the estuary, it has been hypothesized that these chelae belong either to C. sapidus or to C. danae Smith, 1869. A comparison between pincers collected in the archaeological and pincers of these two species (90 dactyls, 30 of each type) was performed. The analysis (ANOVA) considered the variability of seven characters of the dactyls, and demonstrated the existence of two groups. Results showed that the measured characters suffice to separate these species, and indicated that the material found in the archaeological site belongs to C. sapidus. The hypothesis of the introduction of C. sapidus in the area is rejected. The possible biogeographic history of the species is discussed.

Impact of a power plant cooling system on copepod and meroplankton survival (Bahía Blanca estuary, Argentina)

The impact of a power plant cooling system in the Bahía Blanca estuary (Argentina) on the survival of target zooplanktonic organisms (copepods and crustacean larvae) and on overall mesozooplankton abundance was evaluated over time. Mortality rates were calculated for juveniles and adults of four key species in the estuary: Acartia tonsa Dana, 1849 and Eurytemora americana Williams, 1906 (native and invading copepods), and larvae of the crab Chasmagnathus granulata Dana, 1851 and the invading cirriped Balanus glandula Darwin, 1854. Mean total mortality values were up to four times higher at the water discharge site than at intake, though for all four species, significant differences were only registered in post-capture mortality. The findings show no evidence of greater larval sensitivity. As expected, the sharpest decrease in overall mesozooplankton abundance was found in areas close to heated water discharge.

Variação temporal do zooplâncton da Praia de Tramandaí, Rio Grande do Sul, com ênfase em Copepoda

Com o objetivo de conhecer a variação temporal da composição, abundância, diversidade e biomassa do zooplâncton da zona de arrebentação da Praia de Tramandaí, Rio Grande do Sul, amostragens quinzenais foram realizadas entre agosto de 2005 e agosto de 2006. Os arrastos foram efetuados com rede cilindro-cônica com 150 cm de comprimento, 50 cm de diâmetro de boca e malha de 300 µm. Dados de clorofila-a, direção do vento, corrente de deriva litorânea, salinidade, temperatura do ar e da água também foram obtidos. O grupo dos Copepoda foi responsável pela maior diversidade de espécies, sendo que Temora turbinata (Dana, 1849) apresentou maior abundância relativa e freqüência de ocorrência. Outras espécies de Copepoda também foram importantes numericamente como Acartia tonsa (Dana, 1849), Subeucalanus pileatus (Glesbrecht, 1888) e Ctenocalanus vanus (Glesbrecht, 1888). O Mysidacea Metamysidopsis elongata atlantica (Bascescu, 1968) apresentou freqüência de 58,33% e abundância relativa de 44%, sendo o pico de biomassa de mesozooplâncton (96 mg.m-3) registrado em setembro de 2005 correspondente ao máximo valor de densidade apresentado pela espécie (3.535 org.m-3). Informações sobre o zooplâncton desta região são muito escassos e os dados levantados servirão de base para o conhecimento dos processos biológicos que ocorrem na coluna d'água da Praia de Tramandaí.

¿Es relevante la culpabilidad en la Ley de Responsabilidad Penal del Menor?

Aquest treball representa la culminació d’una de les etapes més importants en la vida d’una persona, la formació universitària. Quatre anys de formació y creixement tant personal com professional finalitzen amb l’elaboració d’aquest treball y, es degut a això, la importància d’aquest. En aquest treball d’investigació tractarem la rellevància de la culpabilitat en la Llei de Responsabilitat Penal del Menor. En l’estudi d’aquesta qüestió desenvoluparem els punts fonamentals per tractar de dilucidar si es necessari o no una reforma de la Llei de Responsabilitat Penal del Menor que suposi un enduriment de les mesures que es recullen en aquesta. Per a això, partirem del conceptes més bàsics per poder entendre la qüestió a tractar, passarem pels principis fonamentals de la Llei Penal del Menor, per les reformes de les que ha estat objecte la mateixa y finalitzarem amb un estudi de casos reals.

L'evolució iconogràfica del mite de Dànae : De Gossaert a Subirachs

El fascinant mite de Dànae ha inspirat artistes de múltiples disciplines; poetes, escriptors, escultors, gravadors i pintors han quedat subjugats per aquesta història i per la seva ductilitat. En aquest document concentrarem la nostra anàlisi en l'estudi d'un conjunt representatiu i divers de pintures sobre l'escena de la pluja d'or del mite de Dànae.

Nivel de ruido y efectos en el ecosistema por uso del zumbador en la pesca de suco Paralonchurus peruanus, Pacasmayo

En Pacasmayo, Región la Libertad, se efectuaron experimentos para determinación de ondas sonoras producidas por el zumbador utilizando equipos hidroacústicos y jaulas con peces en cautiverio, para evaluar su efecto en el ambiente biótico y abiótico. Se detectó incremento de oxígeno disuelto en el agua de mar (0,20 mL/L); fragmentación de diatomeas, presencia de quistes de esporas de Chaetoceros en superficie, disminución de la abundancia relativa de Acartia tonsa, Centropages brachiatus, Paracalanus parvus y Oithona setigera. El nivel de presión acústica generado por el zumbador estuvo dentro de la amplitud de onda máxima de 145 dB//1 μBar ref 1m, que no es letal en los peces; sin embargo, estos niveles de ondas acústicas afectarían el sistema sensorial, alterando su desplazamiento, orientación y equilibrio, ocasionando que los peces queden atrapados en la red de enmalle.

The underestimation of compliance to direct help requests explained by adaptive sampling

Helping behavior is any intentional behavior that benefits another living being or group (Hogg & Vaughan, 2010). People tend to underestimate the probability that others will comply with their direct requests for help (Flynn & Lake, 2008). This implies that when they need help, they will assess the probability of getting it (De Paulo, 1982, cited in Flynn & Lake, 2008) and then they will tend to estimate one that is actually lower than the real chance, so they may not even consider worth asking for it. Existing explanations for this phenomenon attribute it to a mistaken cost computation by the help seeker, who will emphasize the instrumental cost of “saying yes”, ignoring that the potential helper also needs to take into account the social cost of saying “no”. And the truth is that, especially in face-to-face interactions, the discomfort caused by refusing to help can be very high. In short, help seekers tend to fail to realize that it might be more costly to refuse to comply with a help request rather than accepting. A similar effect has been observed when estimating trustworthiness of people. Fetchenhauer and Dunning (2010) showed that people also tend to underestimate it. This bias is reduced when, instead of asymmetric feedback (getting feedback only when deciding to trust the other person), symmetric feedback (always given) was provided. This cause could as well be applicable to help seeking as people only receive feedback when they actually make their request but not otherwise. Fazio, Shook, and Eiser (2004) studied something that could be reinforcing these outcomes: Learning asymmetries. By means of a computer game called BeanFest, they showed that people learn better about negatively valenced objects (beans in this case) than about positively valenced ones. This learning asymmetry esteemed from “information gain being contingent on approach behavior” (p. 293), which could be identified with what Fetchenhauer and Dunning mention as ‘asymmetric feedback’, and hence also with help requests. Fazio et al. also found a generalization asymmetry in favor of negative attitudes versus positive ones. They attributed it to a negativity bias that “weights resemblance to a known negative more heavily than resemblance to a positive” (p. 300). Applied to help seeking scenarios, this would mean that when facing an unknown situation, people would tend to generalize and infer that is more likely that they get a negative rather than a positive outcome from it, so, along with what it was said before, people will be more inclined to think that they will get a “no” when requesting help. Denrell and Le Mens (2011) present a different perspective when trying to explain judgment biases in general. They deviate from the classical inappropriate information processing (depicted among other by Fiske & Taylor, 2007, and Tversky & Kahneman, 1974) and explain this in terms of ‘adaptive sampling’. Adaptive sampling is a sampling mechanism in which the selection of sample items is conditioned by the values of the variable of interest previously observed (Thompson, 2011). Sampling adaptively allows individuals to safeguard themselves from experiences they went through once and turned out to lay negative outcomes. However, it also prevents them from giving a second chance to those experiences to get an updated outcome that could maybe turn into a positive one, a more positive one, or just one that regresses to the mean, whatever direction that implies. That, as Denrell and Le Mens (2011) explained, makes sense: If you go to a restaurant, and you did not like the food, you do not choose that restaurant again. This is what we think could be happening when asking for help: When we get a “no”, we stop asking. And here, we want to provide a complementary explanation for the underestimation of the probability that others comply with our direct help requests based on adaptive sampling. First, we will develop and explain a model that represents the theory. Later on, we will test it empirically by means of experiments, and will elaborate on the analysis of its results.

Inclusion and empowerment in public art and urban design

To involve citizens in developing the processes of city making is an objective that occupies part of the agenda of political parties in the context of the necessary renewal in representative democracy. This paper aims to provide some answers to the following questions: Is it possible to overcome the participatory processes based exclusively on the consultation? Is it possible to"train" residents to take an active role in decision-making? How can we manage, proactively, the relationship between public actors, technicians and politicians, in a participatory process? We analyse the process development for creating the Wall of Remembrance in the Barcelona neighbourhood of Baró de Viver, a work of public art, created and produced by its neighbours, in the context of a long participatory process focused on changing the image of the neighbourhood and the improvement of public space. This result and this process have been possible in a given context of cooperation among neighbours, local government and the research team (CR-Polis, Art, City, Society at the University of Barcelona). The development of a creative process of citizen participation between 2004 and 2011 made possible the direct management of decision making by the residents on the field of the design of public space in the neighbourhood. However, the material results of the process does not overshadow the great achievement of the project: the inclusion of a neighbourhood in taking informed decisions because of their empowerment in public space design and management of their remembrances.

El diseño del suelo y la imagen de la ciudad: la calçada portuguesa

Desde el s. XVIII todas las ciudades se plantean uno de los cambios fundamentales en la estructura de su paisaje. El aumento de población y de actividad económica conlleva la desaparición de las calles térreas y su sustitución por las calles que segregan la acera, convertida en la estructura de soporte de los servicios, de la calzada como espacio de circulación rodada. En Lisboa se extiende la pavimentación de la calzad a según el 'systema Portuguez' con piedras irregulares de basalto sobre arena y ya en 1834, se configura el 'Pelouro das Calçadas' responsable de experimentar, primero, el sistema 'macadam' (c. 1839) y, posterior y paulatinamente, de introducir el asfalto. º La acera, es tratada con losas de calcáreo que, sobre todo, a partir del último tercio de siglo serán substituidas por el 'empedrado ordinario á portuguesa' en piedra calcárea. Una derivación será el 'empedrado dito de mosaico'. Experimentado por Eusebio Pinheiro Furtado en el Castillo de São Jorge (1842), va a extenderse por la ciudad, especialmente, desde la pavimentación del 'Mar Largo' en el Rossio (1848). Así, con ocasión de la ampliación de las aceras del largo de Camões, Augusto César dos Santos, Inspector da Admistração das Calçadas expresa la política de substitución del enlosado por el empedrado 'O sistema a empregar no empedramento destos passeios, deverá ser mozaico, não só pela beleza que apresenta, como por ser uma especialidade nesta cidade, beleza que se pode levar ao efeito escolhendose um padrão simples que pela sua importância não exceda os 500‐600$ o metro superficial' (Cesar dos Santos 1869). Finalmente, en 1895 la Câmara Municipal decretará el uso del 'empedrado á portuguesa' en toda nueva pavimentación y reconstrucción de las aceras. Los sitios representativos de la ciudad se cualifican artísticamente con este modo de hacer tan característico e identitario, no en vano lo podríamos entender como una de las primeras producciones de arte público en el sentido contemporáneo del término. Este sistema de pavimentación se extiende por Portugal y se internacionaliza en España, cuando Júlio César Augusto Cordeiro patenta en Madrid (1895) el 'mosaico portugués' que cristalizará en las aceras laterales del Paseo de San Juan en Barcelona (1896) -antes de la Exposición de París de 1900, de la praça de São Sebastião de Manaus, de las avenidas Rio Branco y Atlántica de Río de Janeiro- llegando a convivir con las farolas modernitas que Pere Falqués diseñó para el 'Cincd'oros' barcelonés. La calçada á portuguesa forma parte de la identidad de Lisboa y afecta a la imagen de marca de la ciudad. Sin embargo, a pesar de su valor identitario y artístico, la calçada está en peligro de muerte. El pavimento -forma entre ellos la 'calçada-forma' está en la base de algunas de las operaciones emblemáticas de construcción de la imagen de la ciudad (La Habana, 1928; Alicante, 1957; las Ramblas de Barcelona, 1969; la reforma de la Avenida Atlántica de Río por Burle Marx, 1970). Sin embargo, estas mismas operaciones demuestran que la 'forma-calçada' no responde a muchos de los requisitos de economía, seguridad o accesibilidad universal que exige la ciudad contemporánea. En el artículo planteamos analizar los motivos y razones que planean sobre la muerte anunciada de la calçada á portuguesa.

Climate driven changes in temperature, pH and food quality : effects on copepod reproduction

Increased emissions of greenhouse gases into the atmosphere are causing an anthropogenic climate change. The resulting global warming challenges the ability of organisms to adapt to the new temperature conditions. However, warming is not the only major threat. In marine environments, dissolution of carbon dioxide from the atmosphere causes a decrease in surface water pH, the so called ocean acidification. The temperature and acidification effects can interact, and create even larger problems for the marine flora and fauna than either of the effects would cause alone. I have used Baltic calanoid copepods (crustacean zooplankton) as my research object and studied their growth and stress responses using climate predictions projected for the next century. I have studied both direct temperature and pH effects on copepods, and indirect effects via their food: the changing phytoplankton spring bloom composition and toxic cyanobacterium. The main aims of my thesis were: 1) to find out how warming and acidification combined with a toxic cyanobacterium affect copepod reproductive success (egg production, egg viability, egg hatching success, offspring development) and oxidative balance (antioxidant capacity, oxidative damage), and 2) to reveal the possible food quality effects of spring phytoplankton bloom composition dominated by diatoms or dinoflagellates on reproducing copepods (egg production, egg hatching, RNA:DNA ratio). The two copepod genera used, Acartia sp. and Eurytemora affinis are the dominating mesozooplankton taxa (0.2 – 2 mm) in my study area the Gulf of Finland. The 20°C temperature seems to be within the tolerance limits of Acartia spp., because copepods can adapt to the temperature phenotypically by adjusting their body size. Copepods are also able to tolerate a pH decrease of 0.4 from present values, but the combination of warm water and decreased pH causes problems for them. In my studies, the copepod oxidative balance was negatively influenced by the interaction of these two environmental factors, and egg and nauplii production were lower at 20°C and lower pH, than at 20°C and ambient pH. However, presence of toxic cyanobacterium Nodularia spumigena improved the copepod oxidative balance and helped to resist the environmental stress, in question. In addition, adaptive maternal effects seem to be an important adaptation mechanism in a changing environment, but it depends on the condition of the female copepod and her diet how much she can invest in her offspring. I did not find systematic food quality difference between diatoms and dinoflagellates. There are both good and bad diatom and dinoflagellate species. Instead, the dominating species in the phytoplankton bloom composition has a central role in determining the food quality, although copepods aim at obtaining as a balanced diet as possible by foraging on several species. If the dominating species is of poor quality it can cause stress when ingested, or lead to non-optimal foraging if rejected. My thesis demonstrates that climate change induced water temperature and pH changes can cause problems to Baltic Sea copepod communities. However, their resilience depends substantially on their diet, and therefore the response of phytoplankton to the environmental changes. As copepods are an important link in pelagic food webs, their future success can have far reaching consequences, for example on fish stocks.

Investigação dos teores de metais pesados em espécies de siris azuis do gênero Callinectes sp.

A ocorrência de metais pesados em sistemas aquáticos, usualmente, é resultante de processos naturais geoquímicos. Entretanto, a presença destes elementos químicos tem aumentado consideravelmente nas últimas décadas, como no caso da bacia do rio Cubatão, em conseqüência das atividades humanas na região. Neste trabalho, foi realizada uma análise quantitativa do conteúdo de Pb, Cd, Cr, Zn e Cu, em quatro espécies de siris azuis do gênero Callinectes sp., coletadas ao longo do rio Cubatão, utilizando a técnica da espectrometria de absorção atômica por chama (FAAS). Foram analisadas 144 amostras de siris azuis das seguintes espécies: C. danae (63%); C. sapidus (23%); C. bocourti (10.5%); e C. ornatus (3.5%). A espécie C. Sapidus foi a que apresentou os maiores níveis de concentração para os metais estudados. Com exceção do Cu, cuja concentração média obtida foi 40% maior para as fêmeas (p < 0,05), não houve qualquer variação significativa para os teores de metais pesados em relação tanto ao sexo quanto ao tamanho dos animais. Para o Cr, o intervalo de valores médios obtidos para as 4 espécies ficou acima do limite permitido pela legislação brasileira para qualquer tipo de alimento. Todos os outros resultados estiveram abaixo dos valores máximos recomendados pelas agências de saúde.