1,565 research outputs found
Evocative gene-environment correlation between genetic risk for schizophrenia and bullying victimization
Bullying exposure concerns over 10% of adolescents in Europe. Moreover, bullying victimization is heritable and victims are liable to psychotic symptoms, partly because of shared heritability with psychosis. The genetic component of bullying victimization has been proposed to involve the social reactions elicited by victims â a mechanism called âevocative gene-environment correlationâ.
We hypothesized that genetic risk for schizophrenia, a heritable disease also associated with social stress during childhood and adolescence, is related with social experiences during adolescence and is involved in the risk of developing psychotic symptoms. We studied 908 individuals of the TRAILS sample and found that 13-14-year-old adolescents with greater genetic risk for schizophrenia are more exposed to bullying assessed via peer nomination scores than their peers with lower genetic risk. Importantly, bullying victimization mediated the path from genetic risk to the frequency of psychotic symptoms about three years later. These findings provide evidence of a previously unreported form of gene-environment interplay that may be a mechanism of risk for psychosis and schizophrenia. To the extent that genetic risk translation into clinical symptoms is mediated by environmental risk factors, this evidence supports mental health prevention aimed at antagonizing bullying victimization in vulnerable individuals
Influence of the crack-tip hydride concentration on the fracture toughness of Zircaloy-4
International audienceThe influence of a hydrogen concentration gradient at the crack-tip and hydride platelet orientation on the fracture toughness, fracture mode and micromechanisms of a Zircaloy-4 commercial alloy was studied. Fracture toughness was measured on CT specimens and the analysis was performed in terms of J-integral resistance curves at temperatures ranging from 293 to 473 K. Fracture toughness results of specimens containing higher hydrides concentration near the crack-tip region, preferentially orientated in the crack plane, were compared to those obtained from specimens with a homogeneous hydrogen distribution and different platelet orientation; specimens were obtained by charging them in loaded and unloaded condition, respectively. Changes on both macroscopic and microscopic fracture behaviour were observed at temperatures ranging from 293 to 343 K, and the results show the relevance of both hydride concentration and platelet orientation. The existence of a ductile-to-brittle transition is discussed at the light of these new results
Design and Preliminary Performance Assessment of a PHM System for Electromechanical Flight Control Actuators
The evolution toward âmore electricâ aircraft has seen a decisive push in the last decade due to growing environmental concerns and the development of new market segments (flying taxis). Such a push has involved both the propulsion components and the aircraft systems, with the latter seeing a progressive trend in replacing traditional solutions based on hydraulic power with electrical or electromechanical devices. Flight Control Systems (FCSs) are one of the aircraft systems affected the most since the adoption of Electromechanical Actuators (EMAs) would provide several advantages over traditional electrohydraulic or mechanical solutions, but their application is still limited due to their sensitivity to certain single points of failure that can lead to mechanical jams. The development of an effective and reliable Prognostics and Health Management (PHM) system for EMAs could help in mitigating the risk of a sudden critical failure by properly recognizing and tracking the ongoing fault and anticipating its evolution, thus boosting the acceptance of EMAs as the primary flight-control actuators in commercial aircraft. The paper is focused on the results of the preliminary activities performed within the CleanSky 2/Astib research program, dedicated to the definition of the iron bird of a new regional-transport aircraft able to provide some prognostic capabilities and act as a technological demonstrator for new PHM strategies for EMAs employed in-flight control systems. The paper is organized as follows. At first, a proper introduction to the research program is provided, along with a brief description of the employed approach. Hence the simulation models adopted for the study are presented and used to build synthetic databases to inform the definition of the PHM algorithm. The prognostic framework is then presented, and a preliminary assessment of its expected performance is discussed
Recommended from our members
A Requirements-Led Approach for Specifying QoS-Aware Service Choreographies: An Experience Report.
[Context and motivation] Choreographies are a form of service composition in which partner services interact in a global scenario without a single point of control. The absence of an explicitly specified orchestration requires changes to requirements practices to recognize the need to optimize software services choreography and monitoring for satisfaction with system requirements.
[Question/problem] We developed a requirements-led approach that aims to provide tools and processes to transform requirements expressed on service-based systems to QoS-aware choreography specifications.
[Principal ideas/results] The approach is used by domain experts to specify natural language requirements on a service-based system, and by choreography designers to adapt their models to satisfy requirements more effectively. Non-functional requirements are mapped to BPMN choreography diagrams as quality properties, using the Q4BPMN notation, that support analysis and monitoring facilities. [Contribution] We report the new integrated approach and provide lessons learned from applying it to a real-world example of dynamic taxi management
O pronome "ele" estĂĄ sujeito ao princĂpio B? Uma discussĂŁo sobre resultados experimentais
Este artigo investiga se âele' estĂĄ sujeito ao princĂpio B da teoria de ligação. Para tal investigação, conduzimos dois experimentos. No primeiro, falantes adultos nativos de portuguĂȘs brasileiro (PB) permitiram a leitura localmente ligada do pronome âele' em metade das vezes. No segundo, por outro lado, os adultos nĂŁo permitiram essa leitura. Neste segundo experimento, foram testadas tambĂ©m crianças adquirindo PB: elas exibiram o mesmo comportamento que os sujeitos adultos. AtribuĂmos a diferença entre os resultados a razĂ”es metodolĂłgicas. No primeiro experimento, diferentemente do que no segundo, o referente exofĂłrico nĂŁo estava saliente o bastante para levar Ă leitura dĂȘitica do âele', forçando os sujeitos a permitir sua leitura ligada. Dados os resultados desse segundo experimento, realizado de forma mais criteriosa, concluĂmos que âele' Ă© um pronome, sujeito ao princĂpio B
Minimally invasive aortic valve surgery
Aortic valve disease is a prevalent disorder that affects approximately 2% of the general adult population. Surgical aortic valve replacement is the gold standard treatment for symptomatic patients. This treatment has demonstrably proven to be both safe and effective. Over the last few decades, in an attempt to reduce surgical trauma, different minimally invasive approaches for aortic valve replacement have been developed and are now being increasingly utilized. A narrative review of the literature was carried out to describe the surgical techniques for minimally invasive aortic valve surgery and report the results from different experienced centers. Minimally invasive aortic valve replacement is associated with low perioperative morbidity, mortality and a low conversion rate to full sternotomy. Long-term survival appears to be at least comparable to that reported for conventional full sternotomy. Minimally invasive aortic valve surgery, either with a partial upper sternotomy or a right anterior minithoracotomy provides early- and long-term benefits. Given these benefits, it may be considered the standard of care for isolated aortic valve disease
- âŠ