Suitability of Daphnia similis as an alternative organism in ecotoxicological tests: implications for metal toxicity

The acute toxicity of metals to Daphnia similis was determined and compared to other daphnid species to evaluate the suitability of this organism in ecotoxicology bioassays. To verify the performance D. similis in toxicity tests, we also investigated the effect of Pseudokirchneriella subcapitata at 1 x 10(5) and 1 x 10(6) cells ml(-1) on Cd and Cr acute toxicity to the cladoceran. Daphnid neonates were exposed to a range of chromium and cadmium concentrations in the absence and presence of the algal cells. Metal speciation calculations using MINEQL(+) showed that total dissolved metal concentrations in zooplankton culture corresponded to 96.2% free Cd and 100% free Cr concentrations. Initial total dissolved metal concentrations were used for 48 h-LC(50) determination. LC(50) for D. similis was 5.15 x 10(-7) mol l(-1) dissolved Cd without algal cells, whereas with 1 x 10(5) cells ml(-1), it was significantly higher (7.15 x 10(-7) mol l(-1) dissolved Cd). For Cr, the 48 h-LC(50) value of 9.17 x 10(-7) mol l(-1) obtained for the cladoceran in tests with 1 x 10(6) cells ml(-1) of P. subcapitata was also significantly higher than that obtained in tests without algal cells (5.28 x 10(-7) mol l(-1) dissolved Cr). The presence of algal cells reduced the toxicity of metals to D. similis, as observed in other studies that investigated the effects of food on metal toxicity to standard cladocerans. Comparing our results to those of literature, we observed that D. similis is as sensitive to metals as other standardized Daphnia species and may serve as a potential test species in ecotoxicological evaluations.

Effects of interactions between algal densities and cadmium concentrations on Ceriodaphnia dubia fecundity and survival

The influence of different densities of the algae Pseudokirchneriella subcapitata on the chronic toxicity of cadmium to Ceriodaphnia dubia was investigated. The importance of algal cells as a source of metal to zooplankton was studied by exposing P. subcapitata cells to free cadmium ions and supplying the algae as food to C. dubia. The results of a bifactorial analysis (metal versus food levels) showed that metal toxicity to zooplankton was dependent on food level. Significant toxic effects on the fecundity and survival of C. dubia were observed at low metal concentrations with high algal density. Algae contaminated with Cd2+ were less toxic to cladoceran than was the Cd2+ in solution. Green algae retained cadmium and released low metal concentration in the test medium. We concluded that algal cells are an important route of exposure to metal and a factor that has an appreciable influence on the expression of metal toxicity to daphnids. (C) 2007 Elsevier Inc. All rights reserved.

Lethal effects of abamectin on the aquatic organisms Daphnia similis, Chironomus xanthus and Danio rerio

Abamectin is used as an acaricide and insecticide for fruits, vegetables and ornamental plants, as well as a parasiticide for animals. One of the major problems of applying pesticides to crops is the likelihood of contaminating aquatic ecosystems by drift or runoff. Therefore, toxicity tests in the laboratory are important tools to predict the effects of chemical substances in aquatic ecosystems. The aim of this study was to assess the potential hazards of abamectin to the freshwater biota and consequently the possible losses of ecological services in contaminated water bodies. For this purpose, we identified the toxicity of abamectin on daphnids, insects and fish. Abamectin was highly toxic, with an EC50 48 h for Daphnia similis of 5.1 ng L-1, LC50 96 h for Chironomus xanthus of 2.67 mu g L-1 and LC50 48 h for Danio rerio of 33 mu g L-1. (C) 2011 Elsevier Ltd. All rights reserved.

Straus: as duas sociologias médicas

Analisou-se o trabalho pioneiro de Robert Straus, de 1957, denominado "The nature and status of Medical Sociology". Straus, um dos fundadores da sociologia médica, trouxe contribuições fundamentais para o campo e criou o primeiro departamento de ciências do comportamento em uma escola médica. No texto analisado, Straus estabelece as diferenças entre sociologia na medicina e sociologia da medicina. São apresentados comentários sobre a perspectiva atual da sociologia médica e sobre o autor.

Bisphenol A migration from plastic materials: direct insight of ecotoxicity in Daphnia magna

Bisphenol A (BPA) is an endocrine disrupting chemical (EDC) whose migration from food packaging is recognized worldwide. However, the real overall food contamination and related consequences are yet largely unknown. Among humans, children’s exposure to BPA has been emphasized because of the immaturity of their biological systems. The main aim of this study was to assess the reproductive impact of BPA leached from commercially available plastic containers used or related to child nutrition, performing ecotoxicological tests using the biomonitoring species Daphnia magna. Acute and chronic tests, as well as single and multigenerational tests were done. Migration of BPA from several baby bottles and other plastic containers evaluated by GC-MS indicated that a broader range of foodstuff may be contaminated when packed in plastics. Ecotoxicological test results performed using defined concentrations of BPA were in agreement with literature, although a precocious maturity of daphnids was detected at 3.0 mg/L. Curiously, an increased reproductive output (neonates per female) was observed when daphnids were bred in the polycarbonate (PC) containers (145.1±4.3 % to 264.7±3.8 %), both in single as in multigenerational tests, in comparison with the negative control group (100.3±1.6 %). A strong correlated dose-dependent ecotoxicological effect was observed, providing evidence that BPA leached from plastic food packaging materials act as functional estrogen in vivo at very low concentrations. In contrast, neonate production by daphnids cultured in polypropylene and non-PC bottles was slightly but not significantly enhanced (92.5±2.0 % to 118.8±1.8 %). Multigenerational tests also revealed magnification of the adverse effects, not only on fecundity but also on mortality, which represents a worrying trend for organisms that are chronically exposed to xenoestrogens for many generations. Two plausible explanations for the observed results could be given: a non-monotonic dose–response relationship or a mixture toxicity effect.

Avaliação da toxicidade das águas do rio Cubatão (Norte) - Joinville, SC, com base em ensaios ecotoxicológicos com Daphnia magna

Dissertação de mestrado em Ecologia

Soupirs françois redoublez, sur la paix italienne. Magna est veritas & prævalet !

[Mazarinade. 1649]

Le grand nymphée de Leptis Magna : étude historiographique, urbanistique et architecturale

RESUME en français Centrée sur le grand nymphée de Leptis Magna la recherche met en évidence l'évolution et la signification de ce monument des eaux dans l'une des plus importantes cités africaines de l'époque romaine en mettant en lumière trois thèmes principaux. L'étude historiographique permet tout d'abord d'appréhender, à l'aide des témoignages littéraires des siècles derniers et d'une abondante documentation d'archive, l'histoire de l'édifice de son ensablement à sa remise au jour, puis de suivre les différentes étapes de son dégagement et de sa restauration, mettant ainsi en relief la perception des divers observateurs à l'encontre du monument. L'étude urbanistique permet ensuite de dégager la signification de l'édifice dans la cité par rapport aux autres monuments du secteur aux différentes périodes de son histoire, ainsi que de reconstituer l'approvisionnement en eau de Leptis Magna. Enfin, l'étude architecturale s'intéresse à l'analyse détaillée des structures, permettant la mise en évidence de la conception initiale, du fonctionnement et des transformations du nymphée. Cette dernière approche, qui s'accompagne d'un catalogue circonstancié des éléments du décor, fait intervenir des considérations sur les techniques de constructions, le traitement des blocs d'ornementation et, d'une manière plus générale, sur ('économie du chantier. Cette recherche permet non seulement de reconstituer l'aspect, le rôle et l'histoire du monument et de le replacer dans la série des nymphées romains, mais aussi de percevoir son impact sur les habitants du lieu aux différents moments de son histoire, cherchant ainsi à rejoindre par l'archéologie des considérations sociologiques. THE GREAT SEVERAN NYMPHAEUM OF LEPTIS MAGNA: HISTORIOGRAPHICAL, URBANISTIC AND ARCHITECTURAL STUDY RESUME en anglais Based on the great nymphaeum of Leptis Magna, the research considers the development and significance of this water monument in one of the most important African cities of the Roman period, through three principal aspects. The historiographical study aboards the subject through literary testimony from the last centuries and an abundance of documentary archives, the history of the edifice from its burial to its reconstruction, studying the different stages of its unearthing and its restoration, thus pinpointing perspectives from various observers of the monument. The urban study divulges the significance of the edifice in the city, in comparison with other monuments in the region over different periods of its history, as well as reconstituting Leptis Magna's water supply. Finally, the architectural study undertakes a detailed analysis of the structures, which highlights the conception and the transformations of the nymphaeum, as well as its hydraulic functions. This architectural approach, which is accompanied by a detailed catalogue of the decorative elements, juxtaposes the technical considerations of construction with the ornamental treatment of the marble blocks, accounting for the economical aspects of the site of the nymphaeum. This research proposes not only a consideration of the appearance, the role and the history of the monument and situates it within the series of Roman nymphaea, but also the perception of its impact on the local inhabitants at different moments in its history, looking for accomplish by archaeology some sociological considerations.

Aristotelis ethica, iconomica (61), politica (65), retorica 135). - Boetius, de disciplina scolarium 181). - Magna moralia (191).

Jacobins de la rue Saint-Jacques.

Intervalos de referência para o volume da cisterna magna fetal por meio do método bidimensional usando o modo multiplanar da ultrassonografia tridimensional

Objetivo:Determinar intervalos de referência para o volume da cisterna magna fetal por meio do método bidimensional (2D) usando o modo multiplanar da ultrassonografia tridimensional.Materiais e Métodos:Estudo de corte transversal com 224 gestantes normais entre a 17ª e 29ª semanas. O volume foi obtido automaticamente pela multiplicação dos três maiores eixos nos planos axial e sagital pela constante 0,52. Regressão polinomial foi realizada para obter correlação entre o volume 2D da cisterna magna e a idade gestacional, sendo os ajustes realizados pelo coeficiente de determinação (R2). Confiabilidade e concordância foram obtidas pelo coeficiente de correlação intraclasse (CCI) e limites de concordância.Resultados:A média do volume da cisterna magna 2D variou de 0,71 ± 0,19 cm3 para 4,18 ± 0,75 cm3 entre a 17ª e 29ª semanas, respectivamente. Observou-se boa correlação do volume da cisterna magna fetal 2D e a idade gestacional (R2 = 0,67). Observou-se excelente confiabilidade e concordância intraobservador com CCI = 0,89 e limites de concordância 95% (-52,0; 51,8), respectivamente. Observou-se baixa confiabilidade e concordância interobservador com CCI = 0,64 e limites de concordância 95% (-110,1; 84,6), respectivamente.Conclusão:Intervalos de referência para o volume 2D da cisterna magna fetal usando o modo multiplanar da ultrassonografia tridimensional foram determinados e apresentaram excelente confiabilidade e concordância intraobservador.

Avaliação da ocorrência do refluxo venoso da safena magna pela ultrassonografia com doppler colorido após tratamento cirúrgico da insuficiência da junção safeno-femoral

OBJETIVO: avaliar a ocorrência do refluxo da safena magna através da ultrassonografia com Doppler colorido em sujeitos submetidos ao tratamento da insuficiência da junção safeno-femoral por ligadura simples ou por ligadura com secção da crossa. MÉTODOS: foram realizadas 60 operações (45 sujeitos) de varizes com insuficiência da junção safeno-femoral (JSF), pertencentes à classificação clínica do CEAP 2 a 5, que foram distribuídos aleatoriamente em dois grupos. Um grupo denominado C, com ligadura e secção da crossa, e um grupo denominado L, com ligadura simples sem secção da crossa da veia safena magna. Foi então pesquisada a ocorrência do refluxo da safena magna nos grupos C e L através da ultrassonografia doppler colorida após o tratamento cirúrgico com intervalos de seis meses a um ano. RESULTADOS: dos 60 membros submetidos à abordagem da crossa da safena magna, 57 foram avaliados pela ultrassonografia doppler pós-operatório, pois dois sujeitos (três membros) não retornaram e foram excluídos do estudo. A média de idade foi 54 anos, 93% do sexo feminino e predominância da classificação (CEAP) C2 de 60,5%. Das 57 operações para o tratamento do refluxo da crossa da safena, 43,9% apresentaram refluxo no pós-operatório, sendo 14,1% do grupo C e 29,8% no grupo L (p<0,05). O risco relativo de apresentar refluxo da crossa da safena no grupo L foi 2,03 vezes maior em comparação com o grupo C. CONCLUSÃO: a secção da crossa da safena magna apresenta menos refluxo pós-operatório do que a ligadura simples no tratamento da insuficiência da crossa da veia safena magna.

Magna Germnia [i. e. Germania]

Julkaisussa: Cosmographia : impressum Ulme opera et expensis justi de Albano de Venetiis per provisorem

Magna Germnia

Julkaisussa: Cosmographia : Claudii Ptolomei viri Alexandrini cosmographie octavus et ultimus liber explicit