543 research outputs found

    Visual responses of neurons in the middle temporal area of new World Monkeys after lesions of striate cortex

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    In primates, lesions of striate cortex (V1) result in scotomas in which only rudimentary visual abilities remain. These aspects of vision that survive V1 lesions have been attributed to direct thalamic pathways to extrastriate areas, including the middle temporal area (MT). However, studies in New World monkeys and humans have questioned this interpretation, suggesting that remnants of V1 are responsible for both the activation of MT and residual vision. We studied the visual responses of neurons in area MT in New World marmoset monkeys in the weeks after lesions of V1. The extent of the scotoma in each case was estimated by mapping the receptive fields of cells located near the lesion border and by histological reconstruction. Two response types were observed among the cells located in the part of MT that corresponds, in visuotopic coordinates, to the lesioned part of V1. Many neurons (62%) had receptive fields that were displaced relative to their expected location, so that they represented the visual field immediately surrounding the scotoma. This may be a consequence of a process analogous to the reorganization of the V1 map after retinal lesions. However, another 20% of the cells had receptive fields centered inside the scotoma. Most of these neurons were strongly direction-selective, similar to normal MT cells. These results show that MT cells differ in their responses to lesioning of V1 and that only a subpopulation of MT neurons can be reasonably linked to residual vision and blindsight

    ECOLOGIES OF SPONSORSHIP: WHAT FITBIT USERS CAN TEACH US ABOUT DIGITAL LITERACY

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    As digital technologies have expanded, so have the literacy sponsors that support and shape how those technologies are used. This project focuses on one of these growing sites of sponsorship surrounding a specific health-tracking technology: wearable Fitbit devices. While much of the work on literacy sponsorship has focused on institutional sponsors as agents, I argue that the picture becomes more complicated and interesting when we place our focus on how users—often considered the sponsored—can become agents in a system that may have marginalized, excluded, or used them. Using a combination of qualitative methods, this dissertation highlights how various literacy sponsors create possibilities and constraints, how communities of users support and resist these frameworks, and how users can become digital literacy sponsors. This research maps the ecologies of sponsorship that Fitbit users engage in as both consumers and producers. The concept of “ecologies of sponsorship” is a unique contribution of this project, which expands traditional frameworks for understanding the stakeholders in literacy development to account for digital, networked environments. In addition to typical tracking practices, this research found that significant groups of users “hack” the technology to help them work toward subversive goals. Some users reject the stated purposes of health-tracking technology, instead manipulating their data to create an illusion of health. Some of these users have shared their alternative goals and tactics in online communities, which allows them to become sponsors of metistic digital literacies. Rather than transforming Fitbit technology and ideologies of health through explicit hostility or force, this research explores how users developed metistic practices to subvert health-tracking systems from within. Though this research focuses on the development of digital literacies in extra-curricular spaces, there are important implications for writing classrooms that aim to help students develop digital literacies. This research raises questions about how our classroom practices might shift if we add metistic literacies to frameworks that already support functional, critical, and rhetorical literacies. And by considering classroom-based teaching in the context of larger ecologies of sponsorship, this research highlights a need for new pedagogical practices that account for the distributed nature of technological expertise

    A self-compassion intervention for healthy adolescents: Can it enhance self-compassion and reduce social comparison?

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    This thesis is concerned with adolescent mental health and wellbeing. It is presented in three parts. Part One: Literature Review. A systematic review of 20 studies, both cross-sectional and longitudinal, that investigated the relationship between school-related stress and depressive symptoms in adolescents. Significant positive relationships were found between school-related stress and depressive symptoms; however, the causal direction of this relationship is questionable as most studies were cross-sectional. Additionally, a number of studies found effects of moderating and mediating factors, such as gender. Further high-quality, longitudinal studies need to be conducted to assess the strength and direction of this relationship. Part Two: Empirical Paper. This consisted of an exploratory randomised control study to investigate the effectiveness of a three session self-compassion psychoeducation group with an imagery task, compared to a psychoeducation group alone or control group. It was conducted as a joint project with another UCL Clinical Psychology Doctorate student (Tweed, 2019). Improvements in self-compassion and social comparison were found in the psychoeducation group, but not the psychoeducation and imagery group. Within the imagery group there was evidence that the greater the ability of the participants to vividly imagine the imagery task, the greater the improvements they experienced. Acceptability feedback of the intervention sessions was positive, although there were questions regarding the acceptability of inter-session tasks. Part Three: Critical Appraisal. A reflection and appraisal focused on the empirical paper. This includes methodological and practical issues encountered during the study alongside consideration of wider issues relating to school-based research

    The British press and Northern Ireland : a case study in the reporting of violent political conflict.

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    The study presented here focuses on the treatment accorded to Northern Ireland by the British press since 1969. It argues that the press has failed to provide the public with an impartial or meaningful account of the conflict in the North, and explores some of the factors that have contributed to this failure. Chapter One outlines the primary functions that have been ascribed to journalists and the press in democratic society, and provides a standard against which press performance may be judged. Chapter Two evaluates a range of commentaries on the British media's reporting of Northern Ireland from Partition to the present day. The study moves on to examine the debate over the media's representation of "terrorism" and assesses the consequences of this debate for the British media's reporting of Northern Ireland. Chapter Four provides an account of the research methods employed in the study and reflects on some of the practical problems encountered during the course of the fieldwork. Chapter Five presents the findings of a content analysis of the coverage accorded to civilian assassinations by seven British and two Northern Irish newspapers during a five week period in 1972. Chapter Six outlines the development of the information services operated by the army and the police, and describes how these forces have used their strategic position as a news source to gain the edge in the propaganda war. Picking up on some of the themes and issues raised in previous chapters, Chapter Seven focuses on those involved in the production of news and presents the findings of a series of interviews undertaken with journalists in Belfast and London. The final chapter summarises the principal findings of the study and reflects on the prospects of a reversal in the present approach to the reporting of Northern Ireland by the British press

    An investigation into the synthesis and properties of some fluorinated polycarbonates

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    This thesis describes the synthesis and characterisation of several fluorinated aliphatic, aliphatic and aliphatic ether polycarbonates. The thesis is divided into four sections. In the first section the origins and motivation for the work are discussed, essentially the work forms part of a long term project concerned with the development of a predictively useful correlation between the structure of a polymer repeat unit and its glass transition temperature (Tg). In the second section the various methods for aliphatic polycarbonate synthesis are critically discussed together with the reason for selecting the method used in this work. The third section describes the progressive development of the eventually successful synthetic method and its application to the preparation of ten polycarbonates. The final section is concerned with the detailed characterisation of the polymers obtained, in particular with establishing that they were high polymers of the correct structure, and the measurement of their glass transition temperatures and thermal stabilities. The results of this work suggest that the theoretical oasis for the prediction of the glass transition temperatures of polymers is not presently particularly reliable. Part of the difficulty in developing a more predictively useful theory arises from the uncertainties associated with published values for Tg and a useful contribution of this work is to provide a further ten reliable data points for well characterised materials

    Battery Management Program for a Community with a Solid Waste Landfill

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