40 resultados para INTRINSIC FLUORESCENCE
Resumo:
Contrary to the widespread belief that people are positively motivated by reward incentives, some studies have shown that performance-based extrinsic reward can actually undermine a person's intrinsic motivation to engage in a task. This “undermining effect” has timely practical implications, given the burgeoning of performance-based incentive systems in contemporary society. It also presents a theoretical challenge for economic and reinforcement learning theories, which tend to assume that monetary incentives monotonically increase motivation. Despite the practical and theoretical importance of this provocative phenomenon, however, little is known about its neural basis. Herein we induced the behavioral undermining effect using a newly developed task, and we tracked its neural correlates using functional MRI. Our results show that performance-based monetary reward indeed undermines intrinsic motivation, as assessed by the number of voluntary engagements in the task. We found that activity in the anterior striatum and the prefrontal areas decreased along with this behavioral undermining effect. These findings suggest that the corticobasal ganglia valuation system underlies the undermining effect through the integration of extrinsic reward value and intrinsic task value.
Resumo:
Sensitive optical detection of nitroaromatic vapours with diketo-pyrrolopyrrole thin films is reported for the first time and the impact of thin film crystal structure and morphology on fluorescence quenching behaviour demonstrated.
Resumo:
We introduce semiconductor quantum dot-based fluorescence imaging with approximately 2-fold increased optical resolution in three dimensions as a method that allows both studying cellular structures and spatial organization of biomolecules in membranes and subcellular organelles. Target biomolecules are labelled with quantum dots via immunocytochemistry. The resolution enhancement is achieved by three-photon absorption of quantum dots and subsequent fluorescence emission from a higher-order excitonic state. Different from conventional multiphoton microscopy, this approach can be realized on any confocal microscope without the need for pulsed excitation light. We demonstrate quantum dot triexciton imaging (QDTI) of the microtubule network of U373 cells, 3D imaging of TNF receptor 2 on the plasma membrane of HeLa cells, and multicolor 3D imaging of mitochondrial cytochrome c oxidase and actin in COS-7 cells.
Resumo:
This paper analyses the relationship between agency and Indonesian women’s well-being. The existing debate on empowerment mostly focuses on agency's instrumental value, how agency benefits development and household/women's welfare. We depart from this debate by considering the intrinsic value of agency for women using the Indonesia Family Life Survey. We measure agency based on the decisions women make within their households. We find the effects of agency are not unambiguously positive. Agency has intrinsic value, seen in its strong relationship to well-being in certain spheres, which is moderated by the 'burden of responsibility' that seems to be felt by decision-makers.
Resumo:
Understanding what makes some species more vulnerable to extinction than others is an important challenge for conservation. Many comparative analyses have addressed this issue exploring how intrinsic and extrinsic traits associate with general estimates of vulnerability. However, these general estimates do not consider the actual threats that drive species to extinction and hence, are more difficult to translate into effective management. We provide an updated description of the types and spatial distribution of threats that affect mammals globally using data from the IUCN for 5941 species of mammals. Using these data we explore the links between intrinsic species traits and specific threats in order to identify key intrinsic features associated with particular drivers of extinction. We find that families formed by small-size habitat specialists are more likely to be threatened by habitat-modifying processes; whereas, families formed by larger mammals with small litter sizes are more likely to be threatened by processes that directly affect survival. These results highlight the importance of considering the actual threatening process in comparative studies. We also discuss the need to standardize and rank threat importance in global assessments such as the IUCN Red List to improve our ability to understand what makes some species more vulnerable to extinction than others.
Resumo:
The research reported here is a retrospective case study of the recent (2010) introduction of the Masters in Teaching and Learning (MTL) as a post-graduate level programme of professional development for teachers. It contributes to the debate and research over the past two decades about the impact of post-graduate professional development and appropriate ways of delivering it. The study is located within an extensive body of literature dealing with the importance of the teaching profession with regard to the success of schools and pupils and the impact of professional development on teaching quality and of teaching quality on attainment. A further relevant context is the ongoing tension between the teaching profession and academics on the one hand and government and political actors on the other, in respect of the approaches to professional development and to the control of educational processes. The research questions which inform the study deal with the perspectives of various participants – policy makers, programme directors, coaches and teachers studying for the MTL – on the extent to which the MTL is likely to have an ameliorative effect on teaching and pupil attainment, their experiences of the process of policy development and their experiences as course participants. The study adopts a case study approach which involves elite interviews with those responsible for the development and implementation of the MTL, questionnaires completed by MTL course participants and a comparison group taking a conventional MA and in depth interviews with participants and coaches. The results revealed tensions and difficulties associated with the development of the MTL including uneasy relationships between HE institutions and government agencies, ideas about ‘producer capture’, the relevance of the MBA model and concern over the role of coaches. However, while acknowledging various difficulties and some misconceived expectations they viewed its potential to meet its expressed aims positively, given time. Course participants were positive about their experience of the MTL and felt that it had contributed to many aspects of their professional development. Most saw it as a positive experience despite the variable quality of support from their schools, particularly in the form of the school-based coach the concept of which had been heralded as the bellwether of the MTL. It was striking that the responses of the MTL participants were very similar to those of teachers taking a conventional MA. A finding which would repay further investigation is that while the great majority of course participants felt that the MTL (and the MA) had contributed to their becoming more effective teachers they were much less confident that it had contributed to increased pupil attainment.
Resumo:
In recent years, scholars have devoted increased attention to the agency of small states in International Relations. However, the conventional wisdom remains that while not completely powerful, small states are unlikely to achieve much of significance when faced by great power opposition. This argument, however, implicitly rests on resource-based and compulsory understandings of power. This article explores the implicit connections between the concept of "small state" and diverse concepts of power, asking how we should understand these states' attempts to gain influence and achieve their international political objectives. By connecting the study of small states with additional understandings of power, the article elaborates the broader avenues for influence that are open to many states but are particularly relevant for small states. The article argues that small states' power can be best understood as originating in three categories: “derivative,” collective, and particular-intrinsic. Derivative power, coined by Michael Handel, relies upon the relationship with a great power. Collective power involves building coalitions of supportive states, often through institutions. Particular-intrinsic power relies on the assets of the small state trying to do the influencing. Small states specialize in the bases and means of these types of power, which may have unconventional compulsory, institutional, structural, and productive aspects.