Modelling Locomotor Control: the advantages of mobile gaze

In 1958, JJ Gibson put forward proposals on the visual control of locomotion. Research in the last 50 years has served to clarify the sources of visual and nonvisual information that contribute to successful steering, but has yet to determine how this information is optimally combined under conditions of uncertainty. Here, we test the conditions under which a locomotor robot with a mobile camera can steer effectively using simple visual and extra-retinal parameters to examine how such models cope with the noisy real-world visual and motor estimates that are available to humans. This applied modeling gives us an insight into both the advantages and limitations of using active gaze to sample information when steering

The Role of the World Bank in Controlling Corruption

In 1997, Professor of Law and Political Science, Susan Rose-Ackerman of Yale University, delivered the Georgetown Law Center’s seventeenth Annual Philip A. Hart Memorial Lecture: The World Bank’s Role in Controlling Corruption. Susan Rose-Ackerman is Henry R. Luce Professor of Law and Political Science, Yale University, and Co-director of the Law School’s Center for Law, Economics, and Public Policy. She holds a Ph.D. in economics from Yale University and has held fellowships from the Guggenheim Foundation and the Fullbright Commission. She was a visiting Research Fellow at the World Bank in 1995-96 where she did research on corruption and economic development. She is the author of Corruption and Government Causes, Consequences and Reform (1999), Controlling Environmental Policy: The Limits of Public Law in Germany and the United States (1995); Rethinking the Progressive Agenda: The Reform of the American Regulatory State (1992); and Corruption: A Study in Political Economy (1978); and joint author of The Uncertain Search for Environmental Quality (1974) and The Nonprofit Enterprise in Market Economies (1986). She has published widely in law, economics, and policy journals. Her research interests include comparative regulatory law and policy, the political economy of corruption, public policy and administrative law, and law and economics. In this essay Professor Rose-Ackerman discuses how widespread corruption is a symptom that the state is functioning poorly. Ineffective states can retard and misdirect economic growth. International aid and lending organizations have begun to focus on corruption control as part of a general rethinking of their role in the post-Cold War world. Both James Wolfensohn, the President of the World Bank (Bank), and Michel Camdessus, the head of the International Monetary Fund (IMF), have put the control of corruption on their institutions\u27 agendas. Nevertheless, some argue that corruption is a political issue and is, therefore, outside the purview of the World Bank. Corruption, however, has fundamental economic impacts and is thus an appropriate area for World Bank and IMF concern. Bribes represent illegal user fees, taxes, or access charges paid to public agents. These payments influence economic decisions ranging from the size and character of public investment projects to the level of compliance with business regulations. It is difficult to see how a concern for the economic costs of corruption can be responsibly excluded from World Bank lending criteria

Generative Models for Preprocessing of Hospital Brain Scans

I will in this thesis present novel computational methods for processing routine clinical brain scans. Such scans were originally acquired for qualitative assessment by trained radiologists, and present a number of difficulties for computational models, such as those within common neuroimaging analysis software. The overarching objective of this work is to enable efficient and fully automated analysis of large neuroimaging datasets, of the type currently present in many hospitals worldwide. The methods presented are based on probabilistic, generative models of the observed imaging data, and therefore rely on informative priors and realistic forward models. The first part of the thesis will present a model for image quality improvement, whose key component is a novel prior for multimodal datasets. I will demonstrate its effectiveness for super-resolving thick-sliced clinical MR scans and for denoising CT images and MR-based, multi-parametric mapping acquisitions. I will then show how the same prior can be used for within-subject, intermodal image registration, for more robustly registering large numbers of clinical scans. The second part of the thesis focusses on improved, automatic segmentation and spatial normalisation of routine clinical brain scans. I propose two extensions to a widely used segmentation technique. First, a method for this model to handle missing data, which allows me to predict entirely missing modalities from one, or a few, MR contrasts. Second, a principled way of combining the strengths of probabilistic, generative models with the unprecedented discriminative capability of deep learning. By introducing a convolutional neural network as a Markov random field prior, I can model nonlinear class interactions and learn these using backpropagation. I show that this model is robust to sequence and scanner variability. Finally, I show examples of fitting a population-level, generative model to various neuroimaging data, which can model, e.g., CT scans with haemorrhagic lesions

An analysis of two equilibrium models relating to live-beef cattle futures market

The live-beef cattle futures contract has been traded since November, 1966. As a marketing device for price stabilization, it has received relatively little theoretical attention. Ehrlich postulated that the cash-futures price spread reflects feeding costs. Several equilibrium models exist which explain the simultaneous determination of futures and cash market prices. One such model, developed by Telser, implicitly assumes that the basis must reflect the cost of storage for commodities marketed seasonally. The overall objective of this study was to determine whether the cash-futures price spreads were reflected by the cost of feeding feeder animals and whether Telser\u27s equilibrium model could be applied in the analysis of the live-beef cattle futures market and feedlot marketings. A secondary objective was to determine whether short hedgers, such as feedlot operators, have benefited from the use of this market as a hedging medium or whether the market was biased in favor of long positions. It was found that cash-futures price spreads were reflected by feeding costs but that commercial placements were inversely related to net short hedging positions. Also, a consistent bias in favor of routine long positions was evidenced since futures prices consistently under estimated distant cash prices. Although short hedgers were able to realize the returns they had locked in over and above total feeding costs at the beginning of the hedging operation, unhedged positions yielded higher returns than hedged positions. It could not be concluded that Telser\u27s equilibrium model applied to the live-beef futures market. Finally, contrary to the implications of Ehrlich\u27s analysis, it could not be determined whether the fact that cash-futures price spreads were reflected by feeding costs was a necessary condition for an equilibrium relationship between the feedlot industry and the live-beef cattle futures market

Self-tracking in Parkinson’s: The lived efforts of self-management

People living with Parkinson's disease engage in self-tracking as part of their health self-management. Whilst health technologies designed for this group have primarily focused on improving the clinical assessments of the disease, less attention has been given to how people with Parkinson's use technology to track and manage their disease in their everyday experience. We report on a qualitative study in which we systematically analysed posts from an online health community (OHC) comprising people with Parkinson's (PwP). Our findings show that PwP track a diversity of information and use a wide range of digital and non-digital tools, informed by temporal and structured practices. Using an existing framework of sensemaking for chronic disease self-management, we also identify new ways in which PwP engage in sensemaking, alongside a set of new challenges that are particular to the character of this chronic disease. We relate our findings to technologies for self-tracking offering design implications

Contracting with General Dental Services: a mixed-methods study on factors influencing responses to contracts in English general dental practice

Background: Independent contractor status of NHS general dental practitioners (GDPs) and general medical practitioners (GMPs) has meant that both groups have commercial as well as professional identities. Their relationship with the state is governed by a NHS contract, the terms of which have been the focus of much negotiation and struggle in recent years. Previous study of dental contracting has taken a classical economics perspective, viewing practitioners’ behaviour as a fully rational search for contract loopholes. We apply institutional theory to this context for the first time, where individuals’ behaviour is understood as being influenced by wider institutional forces such as growing consumer demands, commercial pressures and challenges to medical professionalism. Practitioners hold values and beliefs, and carry out routines and practices which are consistent with the field’s institutional logics. By identifying institutional logics in the dental practice organisational field, we expose where tensions exist, helping to explain why contracting appears as a continual cycle of reform and resistance. Aims: To identify the factors which facilitate and hinder the use of contractual processes to manage and strategically develop General Dental Services, using a comparison with medical practice to highlight factors which are particular to NHS dental practice. Methods: Following a systematic review of health-care contracting theory and interviews with stakeholders, we undertook case studies of 16 dental and six medical practices. Case study data collection involved interviews, observation and documentary evidence; 120 interviews were undertaken in all. We tested and refined our findings using a questionnaire to GDPs and further interviews with commissioners. Results: We found that, for all three sets of actors (GDPs, GMPs, commissioners), multiple logics exist. These were interacting and sometimes in competition. We found an emergent logic of population health managerialism in dental practice, which is less compatible than the other dental practice logics of ownership responsibility, professional clinical values and entrepreneurialism. This was in contrast to medical practice, where we found a more ready acceptance of external accountability and notions of the delivery of ‘cost-effective’ care. Our quantitative work enabled us to refine and test our conceptualisations of dental practice logics. We identified that population health managerialism comprised both a logic of managerialism and a public goods logic, and that practitioners might be resistant to one and not the other. We also linked individual practitioners’ behaviour to wider institutional forces by showing that logics were predictive of responses to NHS dental contracts at the dental chair-side (the micro level), as well as predictive of approaches to wider contractual relationships with commissioners (the macro level) . Conclusions: Responses to contracts can be shaped by environmental forces and not just determined at the level of the individual. In NHS medical practice, goals are more closely aligned with commissioning goals than in general dental practice. The optimal contractual agreement between GDPs and commissioners, therefore, will be one which aims at the ‘satisfactory’ rather than the ‘ideal’; and a ‘successful’ NHS dental contract is likely to be one where neither party promotes its self-interest above the other. Future work on opportunism in health care should widen its focus beyond the self-interest of providers and look at the contribution of contextual factors such as the relationship between the government and professional bodies, the role of the media, and providers’ social and professional networks. Funding: The National Institute for Health Research Health Services and Delivery Research programme

Today was a Good Day: The Daily Life of Software Developers

What is a good workday for a software developer? What is a typical workday? We seek to answer these two questions to learn how to make good days typical. Concretely, answering these questions will help to optimize development processes and select tools that increase job satisfaction and productivity. Our work adds to a large body of research on how software developers spend their time. We report the results from 5971 responses of professional developers at Microsoft, who reflected about what made their workdays good and typical, and self-reported about how they spent their time on various activities at work. We developed conceptual frameworks to help define and characterize developer workdays from two new perspectives: good and typical. Our analysis confirms some findings in previous work, including the fact that developers actually spend little time on development and developers' aversion for meetings and interruptions. It also discovered new findings, such as that only 1.7% of survey responses mentioned emails as a reason for a bad workday, and that meetings and interruptions are only unproductive during development phases; during phases of planning, specification and release, they are common and constructive. One key finding is the importance of agency, developers' control over their workday and whether it goes as planned or is disrupted by external factors. We present actionable recommendations for researchers and managers to prioritize process and tool improvements that make good workdays typical. For instance, in light of our finding on the importance of agency, we recommend that, where possible, managers empower developers to choose their tools and tasks

Early diagnosis of disorders based on behavioural shifts and biomedical signals

There are many disorders that directly affect people’s behaviour. The people that are suffering from such a disorder are not aware of their situation, and too often the disorders are identified by relatives or co-workers because they notice behavioural shifts. However, when these changes become noticeable, it is often too late and irreversible damages have already been produced. Early detection is the key to prevent severe health-related damages and healthcare costs, as well as to improve people’s quality of life. Nowadays, in full swing of ubiquitous computing paradigm, users’ behaviour patterns can be unobtrusively monitored by means of interactions with many electronic devices. The application of this technology for the problem at hand would lead to the development of systems that are able to monitor disorders’ onset and progress in an ubiquitous and unobtrusive way, thus enabling their early detection. Some attempts for the detection of specific disorders based on these technologies have been proposed, but a global methodology that could be useful for the early detection of a wide range of disorders is still missing. This thesis aims to fill that gap by presenting as main contribution a global screening methodology for the early detection of disorders based on unobtrusive monitoring of physiological and behavioural data. The proposed methodology is the result of a cross-case analysis between two individual validation scenarios: stress in the workplace and Alzheimer’s Disease (AD) at home, from which conclusions that contribute to each of the two research fields have been drawn. The analysis of similarities and differences between the two case studies has led to a complete and generalized definition of the steps to be taken for the detection of a new disorder based on ubiquitous computing.Jendearen portaeran eragin zuzena duten gaixotasun ugari daude. Hala ere, askotan, gaixotasuna pairatzen duten pertsonak ez dira euren egoerataz ohartzen, eta familiarteko edo lankideek identifikatu ohi dute berau jokabide aldaketetaz ohartzean. Portaera aldaketa hauek nabarmentzean, ordea, beranduegi izan ohi da eta atzerazeinak diren kalteak eraginda egon ohi dira. Osasun kalte larriak eta gehiegizko kostuak ekiditeko eta gaixoen bizi kalitatea hobetzeko gakoa, gaixotasuna garaiz detektatzea da. Gaur egun, etengabe zabaltzen ari den Nonahiko Konputazioaren paradigmari esker, erabiltzaileen portaera ereduak era diskretu batean monitorizatu daitezke, gailu teknologikoekin izandako interakzioari esker. Eskuartean dugun arazoari konponbidea emateko teknologi hau erabiltzeak gaixotasunen sorrera eta aurrerapena nonahi eta era diskretu batean monitorizatzeko gai diren sistemak garatzea ekarriko luke, hauek garaiz hautematea ahalbidetuz. Gaixotasun konkretu batzuentzat soluzioak proposatu izan dira teknologi honetan oinarrituz, baina metodologia orokor bat, gaixotasun sorta zabal baten detekzio goiztiarrerako erabilgarria izango dena, oraindik ez da aurkeztu. Tesi honek hutsune hori betetzea du helburu, mota honetako gaixotasunak garaiz hautemateko, era diskretu batean atzitutako datu fisiologiko eta konportamentalen erabileran oinarritzen den behaketa sistema orokor bat proposatuz. Proposatutako metodologia bi balidazio egoera desberdinen arteko analisi gurutzatu baten emaitza da: estresa lantokian eta Alzheimerra etxean, balidazio egoera bakoitzari dagozkion ekarpenak ere ondorioztatu ahal izan direlarik. Bi kasuen arteko antzekotasun eta desberdintasunen analisiak, gaixotasun berri bat nonahiko konputazioan oinarrituta detektatzeko jarraitu beharreko pausoak bere osotasunean eta era orokor batean definitzea ahalbidetu du

Dynamic properties of language anxiety

This article begins by examining previous empirical studies to demonstrate that language anxiety, or the negative emotional reaction learners experience when using a second language (MacIntyre & Gardner, 1999), is a dynamic individual difference learner variable. I show that it forms part of an interconnected, constantly-in-flux system that changes unpredictably over multiple time scales. While at certain times this system might settle into an attractor state that accommodates contradictory conditions, perturbations that arise may lead to development and change with the curious possibility that minor disruptions generate large effects while major alterations go unnoticed. In essence, language anxiety (LA) is part of a continuous complex system in which each state evolves from a previous one. After I establish LA as a dynamic variable using the aforementioned criteria, I outline the implications and challenges for researching LA using a dynamic paradigm, which include focusing on individuals, transforming LA research questions, designing interventions and re-thinking data gathering methodologies. I conclude with implications for language teaching that emphasize: 1) raising awareness of the importance of decoding nonverbal behavior to identify moment-by-moment shifts in learner emotion; 2) remaining vigilant concerning variables that are interacting with LA that make this factor part of a cyclical process; 3) understanding that anxiety co-exists with positive emotions to varying degrees and that language tasks are not unanimously enjoyed or universally anxiety-provoking; and 4) incorporating positive psychology activities that proactively encourage buoyancy and resilience for moment-by-moment daily perturbations as well as debilitating disruptions that result in long-lasting influences