Environmental cues and constraints affecting the seasonality of dominant calanoid copepods in brackish, coastal waters: a case study of Acartia, Temora and Eurytemora species in the south-west Baltic

Information on physiological rates and tolerances helps one gain a cause-and-effect understanding of the role that some environmental (bottom–up) factors play in regulating the seasonality and productivity of key species. We combined the results of laboratory experiments on reproductive success and field time series data on adult abundance to explore factors controlling the seasonality of Acartia spp., Eurytemora affinis and Temora longicornis, key copepods of brackish, coastal and temperate environments. Patterns in laboratory and field data were discussed using a metabolic framework that included the effects of ‘controlling’, ‘masking’ and ‘directive’ environmental factors. Over a 5-year period, changes in adult abundance within two south-west Baltic field sites (Kiel Fjord Pier, 54°19′89N, 10°09′06E, 12–21 psu, and North/Baltic Sea Canal NOK, 54°20′45N, 9°57′02E, 4–10 psu) were evaluated with respect to changes in temperature, salinity, day length and chlorophyll a concentration. Acartia spp. dominated the copepod assemblage at both sites (up to 16,764 and 21,771 females m−3 at NOK and Pier) and was 4 to 10 times more abundant than E. affinis (to 2,939 m−3 at NOK) and T. longicornis (to 1,959 m−3 at Pier), respectively. Species-specific salinity tolerance explains differences in adult abundance between sampling sites whereas phenological differences among species are best explained by the influence of species-specific thermal windows and prey requirements supporting survival and egg production. Multiple intrinsic and extrinsic (environmental) factors influence the production of different egg types (normal and resting), regulate life-history strategies and influence match–mismatch dynamics

Survey of CT radiation doses and iodinated contrast medium administration: an international multicentric study

ObjectiveTo assess the relationship between intravenous iodinated contrast media (ICM) administration usage and radiation doses for contrast-enhanced (CE) CT of head, chest, and abdomen-pelvis (AP) in international, multicenter settings. MethodsOur international (n = 16 countries), multicenter (n = 43 sites), and cross-sectional (ConRad) study had two parts. Part 1: Redcap survey with questions on information related to CT and ICM manufacturer/brand and respective protocols. Part 2: Information on 3,258 patients (18-96 years; M:F 1654:1604) who underwent CECT for a routine head (n = 456), chest (n = 528), AP (n = 599), head CT angiography (n = 539), pulmonary embolism (n = 599), and liver CT examinations (n = 537) at 43 sites across five continents. The following information was recorded: hospital name, patient age, gender, body mass index [BMI], clinical indications, scan parameters (number of scan phases, kV), IV-contrast information (concentration, volume, flow rate, and delay), and dose indices (CTDIvol and DLP). ResultsMost routine chest (58.4%) and AP (68.7%) CECT exams were performed with 2-4 scan phases with fixed scan delay (chest 71.4%; AP 79.8%, liver CECT 50.7%) following ICM administration. Most sites did not change kV across different patients and scan phases; most CECT protocols were performed at 120-140 kV (83%, 1979/2685). There were no significant differences between radiation doses for non-contrast (CTDIvol 24 [16-30] mGy; DLP 633 [414-702] mGycm) and post-contrast phases (22 [19-27] mGy; 648 [392-694] mGycm) (p = 0.142). Sites that used bolus tracking for chest and AP CECT had lower CTDIvol than sites with fixed scan delays (p < 0.001). There was no correlation between BMI and CTDIvol (r2 <= - 0.1 to 0.1, p = 0.931). ConclusionOur study demonstrates up to ten-fold variability in ICM injection protocols and radiation doses across different CT protocols. The study emphasizes the need for optimizing CT scanning and contrast protocols to reduce unnecessary contrast and radiation exposure to patients. Clinical relevance statementThe wide variability and lack of standardization of ICM media and radiation doses in CT protocols suggest the need for education and optimization of contrast usage and scan factors for optimizing image quality in CECT

Reactive oxygen species and male reproductive hormones

Reports of the increasing incidence of male infertility paired with decreasing semen quality have triggered studies on the effects of lifestyle and environmental factors on the male reproductive potential. There are numerous exogenous and endogenous factors that are able to induce excessive production of reactive oxygen species (ROS) beyond that of cellular antioxidant capacity, thus causing oxidative stress. In turn, oxidative stress negatively affects male reproductive functions and may induce infertility either directly or indirectly by affecting the hypothalamus-pituitary-gonadal (HPG) axis and/or disrupting its crosstalk with other hormonal axes. This review discusses the important exogenous and endogenous factors leading to the generation of ROS in different parts of the male reproductive tract. It also highlights the negative impact of oxidative stress on the regulation and cross-talk between the reproductive hormones. It further describes the mechanism of ROS-induced derangement of male reproductive hormonal profiles that could ultimately lead to male infertility. An understanding of the disruptive effects of ROS on male reproductive hormones would encourage further investigations directed towards the prevention of ROS-mediated hormonal imbalances, which in turn could help in the management of male infertility

Análise de conteúdo em pesquisas de Psicologia

The study focuses the application of the content analysis method in empirical research in psychology, according to the technical procedures identified under that methodology. It presents in the first place a brief discussion on the variations in CA and an analysis of the scientific validation criteria that support the method practice. Then it describes the most frequent modes of uses of the CA, extracted from a review conducted in 83 articles published between 2004 and 2009 in six psychology journals in Brazil. The selected journals were classified as A1 and A2 in a triennial assessment for the CAPES periodicals (2007- 2009), and were retrieved from the Scielo base of journals. The final discussion highlights the evaluation assessment of methodological rigor accuracy associated to the practice of the method, suggesting clear information about the CA approach, implementation of the CA and careful explanation of the steps and technical procedures adopted in data analysis.O estudo enfoca as aplicações do método análise de conteúdo (AC) em pesquisas empíricas de Psicologia, de acordo com os procedimentos técnicos identificados sob essa denominação. Apresenta, primeiramente, uma breve discussão sobre as variações de AC e uma análise dos critérios de validação científica que embasam a prática do método. Em seguida, descreve os modos mais recorrentes de utilização da AC, a partir de revisão realizada junto a 83 artigos publicados entre 2004 e 2009 em seis periódicos de Psicologia no Brasil. Os periódicos selecionados foram classificados dentro do extrato A1 e A2 na avaliação trienal de periódicos da CAPES (2007-2009), e acessados através da base de periódicos Scielo. A discussão final foi encaminhada para a avaliação do rigor metodológico vinculado à prática do método, sugerindo informações claras sobre o tipo de abordagem de AC, de execução da AC e explanação criteriosa dos passos e procedimentos técnicos adotados na análise dos dados.El estudio enfoca las aplicaciones del método Análisis de Contenido (AC) en investigaciones empíricas de psicología, con arreglo a los procedimientos técnicos identificados bajo esa denominación. Presenta, primeramente, una breve discusión acerca de las variaciones de AC y un análisis de los criterios de validación científica que dan base a la práctica del método. Enseguida, describe los modos más recurrentes de utilización del AC, a partir de revisión llevada a cabo junto a 83 artículos publicados entre 2004 y 2009 en seis periódicos de Psicología en Brasil. Los periódicos seleccionados han sido clasificados dentro del estrato A1 y A2 en la evaluación trienal de periódicos de la CAPES (2007 - 2009), y accedidos a través de la base de periódicos Scielo. La discusión final se ha destinado a la evaluación del rigor metodológico vinculado a la práctica del método, sugiriendo informaciones claras acerca del tipo de abordaje de AC, de ejecución del AC y explanación criteriosa de los pasos y procedimientos técnicos adoptados en el análisis de los datos