Reparameterizing the Birkhoff Polytope for Variational Permutation Inference

Many matching, tracking, sorting, and ranking problems require probabilistic reasoning about possible permutations, a set that grows factorially with dimension. Combinatorial optimization algorithms may enable efficient point estimation, but fully Bayesian inference poses a severe challenge in this high-dimensional, discrete space. To surmount this challenge, we start with the usual step of relaxing a discrete set (here, of permutation matrices) to its convex hull, which here is the Birkhoff polytope: the set of all doubly-stochastic matrices. We then introduce two novel transformations: first, an invertible and differentiable stick-breaking procedure that maps unconstrained space to the Birkhoff polytope; second, a map that rounds points toward the vertices of the polytope. Both transformations include a temperature parameter that, in the limit, concentrates the densities on permutation matrices. We then exploit these transformations and reparameterization gradients to introduce variational inference over permutation matrices, and we demonstrate its utility in a series of experiments

Explaining Cost Overruns of Large-Scale Transportation Infrastructure Projects using a Signalling Game

Strategic behaviour is one of the main explanations for cost overruns. It can theoretically be supported by agency theory, in which strategic behaviour is the result of asymmetric information between the principal and agent. This paper gives a formal account of this relation by a signalling game. This is a game with incomplete information which considers the way in which parties anticipate upon other parties' behaviour in choosing a course of action. The game shows how cost overruns are the result of an inappropriate signal. This makes it impossible for the principal to distinguish between the types of agents, and hence, allows for strategic behaviour. It is illustrated how cost overruns can be avoided by means of two policy measures, e.g. an accountability structure and benchmarking

Analyzing Funding Patterns and Their Evolution in Two Medical Research Topics

[EN] This paper analyzes funding patterns and their evolution in two medical research topics: breast cancer and ovarian cancer, taking into account cross-agency and cross- national co-funding. A bibliometric analysis of 355 463 papers from PubMed (273 526 on breast cancer and 81 937 on ovarian cancer) brought back 91 funding agencies involved in breast cancer and 65 in ovarian cancer. Additionally, the paper examined the evolution of medical subject headings ( MESH) funded by agencies. An analysis of patterns in funding, co-funding, MESH, and their evolution, was carried out using social network analysis (SNA) methodology. The results show the importance of the National Cancer Institute (NCI) in both breast and ovarian cancer. The NCI achieves its policy goals by co-funding its programs with both national and cross- national agencies. Moreover, the MESH agencies co-funded in the two years studied coincided; however, it must be said that the number of agencies which participated in research funding also increased.De-Miguel-Molina, B.; Cunningham, SW.; Palop Marro, FR. (2017). Analyzing Funding Patterns and Their Evolution in Two Medical Research Topics. International Journal of Innovation and Technology Management (Online). 14(2):1-39. doi:10.1142/S0219877017400107S13914

Tracing the Bipolar Outflow from Orion Source I

Using CARMA, we imaged the 87 GHz SiO v=0 J=2-1 line toward Orion-KL with 0.45 arcsec angular resolution. The maps indicate that radio source I drives a bipolar outflow into the surrounding molecular cloud along a NE--SW axis, in agreement with the model of Greenhill et al. (2004). The extended high velocity outflow from Orion-KL appears to be a continuation of this compact outflow. High velocity gas extends farthest along a NW--SE axis, suggesting that the outflow direction changes on time scales of a few hundred years.Comment: 4 pages, 4 figures; accepted for publication in Ap J Letter

Survey to identify research priorities for primary care in Scotland during and following the COVID-19 pandemic

OBJECTIVES: To identify research priorities for primary care in Scotland following the COVID-19 pandemic.DESIGN: Modified James Lind Alliance methodology; respondents completed an online survey to make research suggestions and rank research themes in order of priority.SETTING: Scotland primary care.PARTICIPANTS: Healthcare professionals in primary care in Scotland and members of primary care patient and public involvement groups. 512 respondents provided research suggestions; 8% (n=40) did not work in health or social care; of those who did work, 68.8% worked in primary care, 16.3% community care, 11.7% secondary care, 4.5% third sector, 4.2% university (respondents could select multiple options). Of those respondents who identified as healthcare professionals, 33% were in nursing and midwifery professions, 25% were in allied health professions (of whom 45% were occupational therapists and 35% were physiotherapists), 20% were in the medical profession and 10% were in the pharmacy profession.MAIN OUTCOMES: Suggestions for research for primary care made by respondents were categorised into themes and subthemes by researchers and ranked in order of priority by respondents.RESULTS: There were 1274 research suggestions which were categorised under 12 themes and 30 subthemes. The following five themes received the most suggestions for research: disease and illness (n=461 suggestions), access (n=202), workforce (n=164), multidisciplinary team (MDT; n=143) and integration (n=108). One hundred and three (20%) respondents to the survey participated in ranking the list of 12 themes in order of research priority. The five most highly ranked research priorities were disease and illness, health inequalities, access, workforce and MDTs. The disease and illness theme had the greatest number of suggestions for research and was scored the most highly in the ranking exercise. The subtheme ranked as the most important research priority in the disease and illness theme was ‘mental health’.CONCLUSIONS: The themes and subthemes identified in this study should inform research funders so that the direction of primary healthcare is informed by evidence

Survey to identify research priorities for primary care in Scotland during and following the COVID-19 pandemic.

Objectives To identify research priorities for primary care in Scotland following the COVID-19 pandemic. Design Modified James Lind Alliance methodology; respondents completed an online survey to make research suggestions and rank research themes in order of priority. Setting Scotland primary care. Participants Healthcare professionals in primary care in Scotland and members of primary care patient and public involvement groups. 512 respondents provided research suggestions; 8% (n=40) did not work in health or social care; of those who did work, 68.8% worked in primary care, 16.3% community care, 11.7% secondary care, 4.5% third sector, 4.2% university (respondents could select multiple options). Of those respondents who identified as healthcare professionals, 33% were in nursing and midwifery professions, 25% were in allied health professions (of whom 45% were occupational therapists and 35% were physiotherapists), 20% were in the medical profession and 10% were in the pharmacy profession. Main outcomes Suggestions for research for primary care made by respondents were categorised into themes and subthemes by researchers and ranked in order of priority by respondents. Results There were 1274 research suggestions which were categorised under 12 themes and 30 subthemes. The following five themes received the most suggestions for research: disease and illness (n=461 suggestions), access (n=202), workforce (n=164), multidisciplinary team (MDT; n=143) and integration (n=108). One hundred and three (20%) respondents to the survey participated in ranking the list of 12 themes in order of research priority. The five most highly ranked research priorities were disease and illness, health inequalities, access, workforce and MDTs. The disease and illness theme had the greatest number of suggestions for research and was scored the most highly in the ranking exercise. The subtheme ranked as the most important research priority in the disease and illness theme was 'mental health'. Conclusions The themes and subthemes identified in this study should inform research funders so that the direction of primary healthcare is informed by evidence

Abordaxe fisioterápico no asma infantil

[Resumen] Objetivo: analizar qué intervenciones se están llevando a cabo por parte de la fisioterapia en la patología del asma. Material y métodos: revisión de artículos en los cuales se lleven a cabo intervenciones de fisioterapia en niños asmáticos. La búsqueda se efectuó en las bases de datos Pubmed, PEDro, Web of Science y Scopus, seleccionando artículos publicados entre 2013 y 2017 en lengua inglesa, portuguesa y española. Resultados: se seleccionaron 6 artículos, la mayoría de calidad intermedia, con variabilidad en el número de sujetos en cada estudio. La población que se seleccionó comprende desde el nacimiento hasta los 18 años. Las terapias fisioterápicas empleadas son variables. Se realiza en todos los casos un tratamiento enfocado al abordaje de las capacidades físicas por medio de diferentes programas de entrenamiento que cada estudio enfocó de forma diferente. Los aspectos más evaluados han sido la función pulmonar, la calidad de vida y la disnea, medidos a través de diferentes test y pruebas funcionales. Se obtienen resultados positivos en el manejo del asma con cada uno de estos programas de entrenamiento físico. Conclusiones: existen múltiples programas de intervención fisioterápica sobre el asma. Se llevan a cabo programas de entrenamiento de la musculatura inspiratoria, entrenamiento aeróbico, anaeróbico, de fuerza y equilibrio por parte de la fisioterapia en el abordaje de esta patología y todos presentan beneficio sobre ella. Asimismo, se objetivó que el programa de tratamiento que engloba un entrenamiento basado en ejercicio aeróbico y ejercicios respiratorios presenta una mayor eficacia.[Abstract] Objective: to analyze what interventions are being carried out by physiotherapy in the pathology of asthma. Material and methods: review of articles in which physiotherapy interventions are carried out in asthmatic children. The search was carried out in the Pubmed, PEDro, Web of Science and Scopus databases, selecting articles published between 2013 and 2017 in English, Portuguese and Spanish. Results: Six articles were selected, most of intermediate quality, with variability in the number of subjects in each study. The population that was selected comprises from birth to 18 years. The physiotherapeutic therapies used are variable. In all cases, a treatment focused on addressing physical abilities is carried out through different training programs that each study focused on differently. The most evaluated aspects have been pulmonary function, quality of life and dyspnea, measured through different tests and functional tests. Positive results are obtained in the management of asthma with each of these physical training programs. Conclusions: There are multiple programs of physiotherapy intervention on asthma. Training programs for inspiratory musculature, aerobic, anaerobic, strength and balance training are carried out by physiotherapy in the approach to this pathology and all have benefit over it. Likewise, it was found that the treatment program that includes a training based on aerobic exercise and breathing exercises is more effective.[Resumo] Obxectivo: analizar que intervencións se están a facer por parte da fisioterapia na patoloxía da asma. Material e metodoloxía: revisión de artículos nos que se fagan intervencións de fisioterapia en nenos asmáticos. A búsqueda efectuouse nas bases de datos Pubmed, PEDro, Web of Science y Scopus, seleccionando artículos publicados entre 2013 y 2017 en lingua inglesa, portuguesa e española. Resultados: seleccionáronse 6 artigos, a maioría de calidade intermedia, con variabilidade no número de suxeitos en cada estudo. A poboación que se seleccionou comprende dende o nacemento ata os 18 anos. As terapias fisioterápicas empregadas son variables. Realizouse en todos os casos un tratamento enfocado á abordaxe das capacidades físicas por medio de diferentes programas de entrenamento que cada estudo enfocou de forma diferente. Os aspectos máis avaliados foron a función pulmonar, a calidade da vida e a disnea, medidos a través de diferentes test e probas funcionais. Obtéñense resultados positivos no manexo do asma con cada un destes programas de entrenamento físico. Conclusións: existen múltiples programas de intervención fisioterápica sobre a asma infantil. Lévanse a cabo programas de entrenamento da musculatura inspiratoria, entrenamiento aeróbico, anaeróbico, de forza e equilibrio por parte da fisioterapia no abordaxe desta patoloxía e todos presentan beneficio sobre ela. Así mesmo obxectivouse que o programa de tratamento que engloba un entrenamento baseado no exercicio aeróbico e exercicios respiratorios presenta unha maior eficacia.Traballo fin de grao (UDC.FCS). Fisioterapia. Curso 2017/201