231 research outputs found
Reproductive cycle and migration of the blue shark (prionace glauca) in south atlantic ocean.
A study conducted in Southern Atlantic Ocean, between 27°S and 35°S, and researches developed by several authors propose the existence of an annual reproductive cycle for the blue shark, Prionace glauca, in the South Atlantic Ocean
Caracterização da morfologia uterina e das fases de desenvolvimento embrionário do tubarão-azul, Prionace glauca (Linnaeus, 1758).
Uma amostra de 60 fêmeas do tubarão-azul, Prionace glauca (Linnaeus, 1758), capturadas no Sul do Brasil, foi submetida a análises biométricas, sendo coletados para análises detalhadas os aparelhos reprodutores de 30 fêmeas, dentre os quais, oito gravídicos. Os úteros foram descritos e classificados em seis categorias de acordo com a fase de maturidade sexual. A fecundidade uterina variou entre 10 e 39, sem apresentar relação com o comprimento total (CT). O conteúdo dos úteros foi classificado em cinco fases de desenvolvimento desde ovos uterinos até embriões com cerca de 18 cm CT. Foi possível determinar com exatidão o sexo dos embriões a partir de 10,0 cm CT, não sendo observada a predominância de nenhum dos sexos dentro dos úteros
Transforming towards sustainable health and wellbeing systems:Eight guiding principles based on the experiences of nine Dutch Population Health Management initiatives
Introduction Population Health Management initiatives are increasingly introduced, aiming to develop towards sustainable health and wellbeing systems. Yet, little is known about which strategies to implement during this development. This study provides insights into which strategies are used, why, and when, based on the experiences of nine Dutch Population Health Management initiatives. Methods The realist evaluation approach was used to gain an understanding of the relationships between context, mechanisms and outcomes when Population Health Management strategies were implemented. Data were retrieved from three interview rounds (n = 207) in 2014, 2016 and 2017. Data was clustered into guiding principles, underpinned with strategy-context-mechanism-outcome configurations. Results The Dutch initiatives experienced different developments, varying between immediate large-scale collaborations with eventual relapse, and incremental growth towards cross-sector collaboration. Eight guiding principles for development towards health and wellbeing systems were identified, focusing on: 1. Shared commitment for a Population Health Management-vision; 2. Mutual understanding and trust; 3. Accountability; 4. Aligning politics and policy; 5. Financial incentives; 6. A learning cycle based on a data-infrastructure; 7. Community input and involvement; and 8. Stakeholder representation and leadership. Conclusion Development towards a sustainable health and wellbeing system is complex and time-consuming. Its success not only depends on the implementation of all eight guiding principles, but is also influenced by applying the right strategies at the right moment in the development
Understanding the mechanisms underlying cognitive control in psychosis
Background
Cognitive control (CC) involves a top–down mechanism to flexibly respond to complex stimuli and is impaired in schizophrenia.
Methods
This study investigated the impact of increasing complexity of CC processing in 140 subjects with psychosis and 39 healthy adults, with assessments of behavioral performance, neural regions of interest and symptom severity.
Results
The lowest level of CC (Stroop task) was impaired in all patients; the intermediate level of CC (Faces task) with explicit emotional information was most impaired in patients with first episode psychosis. Patients showed activation of distinct neural CC and reward networks, but iterative learning based on the higher-order of CC during the trust game, was most impaired in chronic schizophrenia. Subjects with first episode psychosis, and patients with lower symptom load, demonstrate flexibility of the CC network to facilitate learning, which appeared compromised in the more chronic stages of schizophrenia.
Conclusion
These data suggest optimal windows for opportunities to introduce therapeutic interventions to improve CC
Size and sex composition of two species of the genus Atlantoraja (Elasmobranchii, Rajidae) caught by the bottom trawl fisheries operating on the Uruguayan continental shelf (southwestern Atlantic Ocean)
In this work we analyzed the spatial and seasonal variation of length distribution, sexual proportion and mature dominance for Atlantoraja cyclophora and A. castelnaui, at the Uruguayan continental shelf. There were significant differences in total length (TL) composition between sexes, being females bigger than males for both species. Atlantoraja cyclophora showed a relatively uniform length distribution between inner and outer shelf. There were no major variations in the sex compositions and in the mature dominance between seasons, suggesting no temporal variation. Atlantoraja castelnaui showed a significant variation in its spatial and seasonal distribution. Individuals were smaller in inner shelf, pointing out the existence of juvenile zone in areas up to 50 m depth. A tendency to capture smaller individuals towards the end of the year was observed. In all seasons over 50% of females were caught below the estimated size at maturity, suggesting that this species is highly susceptible to exploitation.Neste trabalho foi analisada a variação espacial e temporal da distribuição de comprimento, proporções sexuais e dominância de maduros para Atlantoraja cyclophora e A. castelanui, na plataforma continental uruguaia. Houve diferenças significativas na distribução do comprimento total (TL) entre os sexos, sendo as fêmeas maiores que os machos para ambas espécies. Atlantoraja cyclophora mostrou uma distribuição relativamente uniforme de comprimento entre a prataforma interna e externa. Não houviram grandes variações nas composições do sexo e na dominância de maduros entre as estações do ano, sugerindo que não ha variação temporal. Atlantoraja castelnaui mostrou uma variação significativa na sua distribuição espacial e sazonal. Os indivíduos foram menores na plataforma interna, apontando para a existência de uma zona de juvenis em áreas de até 50 m de profundidade. A tendência para a captura de indivíduos menores no final do ano foi observada. Em todas as estações do ano mais de 50% das fêmeas foram capturadas em um comprimento menor ao tamanho estimado de maturidade observado na literatura, sugerindo que esta espécie é altamente suscetível à explotação
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