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Corruption-robust offline two-player zero-sum Markov games
Get PDFWe study data corruption robustness in offline two-player zero-sum Markov games. Given a dataset of realized trajectories of two players, an adversary is allowed to modify an ε-fraction of it. The learner’s goal is to identify an approximate Nash Equilibrium policy pair from the corrupted data. We consider this problem in linear Markov games under different degrees of data coverage and corruption. We start by providing an information-theoretic lower bound on the suboptimality gap of any learner. Next, we propose robust versions of the Pessimistic Minimax Value Iteration algorithm (Zhong et al., 2022), both under coverage on the corrupted data and under coverage only on the clean data, and show that they achieve (near)-optimal suboptimality gap bounds with respect to ε. We note that we are the first to provide such a characterization of the problem of learning approximate Nash Equilibrium policies in offline two-player zero-sum Markov games under data corruption
Real analytic discrete choice models of demand : theory and implications
Get PDFWe demonstrate that a large class of discrete choice models of demand can be approximated by real analytic demand models. We obtain this result by combining (i) a novel real analytic property of the mixed logit and the mixed probit models with any distribution of random coefficients and (ii) an approximation property of finite mixtures of Gumbel and Gaussian distributions. To illustrate some of the implications of this result, we discuss how real analyticity facilitates nonparametric and semi-nonparametric identification, extrapolation to hypothetical counterfactuals, numerical implementation of demand inverses, and numerical implementation of the Maximum Likelihood Estimator
Mathematical modelling of impurity deposition during evaporation of dirty liquid in a porous material
No full textOpinion polls, turnout and the demand for safe seats
Get PDFDo opinion polls sway turnout and shape political competition in majoritarian systems? Can they strengthen the persistence of safe seats? Analysing national opinion polls during UK general elections and the perceived safeness of constituencies, we find that pre-election polls significantly affect voter turnout. Non-competitive elections predicted by national polls suppress turnout, especially in areas with low perceived electoral competition. This reinforces the advantage of trailing parties in their strongholds, potentially fuelling party demand for safe seats that may give rise to demands for gerrymandering. This can exacerbate spatial polarization of the electoral landscape, with implications for governance regarding opinion polling
Changes in the global hospitalisation burden of respiratory syncytial virus in young children during the COVID-19 pandemic : a systematic analysis
Get PDFBackground:
The COVID-19 pandemic is reported to have affected the epidemiology of respiratory syncytial virus (RSV), which could have important implications for RSV prevention and control strategies. We aimed to assess the hospitalisation burden of RSV-associated acute lower respiratory infection (ALRI) in children younger than 5 years during the pandemic period and the possible changes in RSV epidemiology from a global perspective.
Methods:
We conducted a systematic literature search for studies published between Jan 1, 2020, and June 30, 2022, in MEDLINE, Embase, Global Health, Web of Science, the WHO COVID-19 Research Database, CINAHL, LILACS, OpenGrey, CNKI, WanFang, and CqVip. We included unpublished data on RSV epidemiology shared by international collaborators. Eligible studies reported data on at least one of the following measures for children (aged <5 years) hospitalised with RSV-associated ALRI: hospital admission rates, in-hospital case fatality ratio, and the proportion of hospitalised children requiring supplemental oxygen or requiring mechanical ventilation or admission to intensive care. We used a generalised linear mixed-effects model for data synthesis to measure the changes in the incidence, age distribution, and disease severity of children hospitalised with RSV-associated ALRI during the pandemic, compared with the year 2019.
Findings:
We included 61 studies from 19 countries, of which 14 (23%) studies were from the published literature (4052 identified records) and 47 (77%) were from unpublished datasets. Most (51 [84%]) studies were from high-income countries; nine (15%) were from upper-middle-income countries, one (2%) was from a lower-middle-income country (Kenya), and none were from a low-income country. 15 studies contributed to the estimates of hospitalisation rate and 57 studies contributed to the severity analyses. Compared with 2019, the rates of RSV-associated ALRI hospitalisation in all children (aged 0–60 months) in 2020 decreased by 79·7% (325 000 cases vs 66 000 cases) in high-income countries, 13·8% (581 000 cases vs 501 000 cases) in upper-middle-income countries, and 42·3% (1 378 000 cases vs 795 000 cases) in Kenya. In high-income countries, annualised rates started to rise in 2021, and by March, 2022, had returned to a level similar to 2019 (6·0 cases per 1000 children [95% uncertainty interval 5·4–6·8] in April, 2021, to March, 2022, vs 5·0 cases per 1000 children [3·6–6·8] in 2019). By contrast, in middle-income countries, rates remained lower in the latest period with data available than in 2019 (for upper-middle-income countries, 2·1 cases [0·7–6·1] in April, 2021, to March, 2022, vs 3·4 [1·2–9·7] in 2019; for Kenya, 2·2 cases [1·8–2·7] in 2021 vs 4·1 [3·5–4·7] in 2019). Across all time periods and income regions, hospitalisation rates peaked in younger infants (aged 0 to <3 months) and decreased with increasing age. A significantly higher proportion of children aged 12–24 months were hospitalised with RSV-associated ALRI in high-income and upper-middle-income countries during the pandemic years than in 2019, with odds ratios ranging from 1·30 (95% uncertainty interval 1·07–1·59) to 2·05 (1·66–2·54). No consistent changes in disease severity were observed.
Interpretation:
The hospitalisation burden of RSV-associated ALRI in children younger than 5 years was significantly reduced during the first year of the COVID-19 pandemic. The rebound in hospitalisation rates to pre-pandemic rates observed in the high-income region but not in the middle-income region by March, 2022, suggests a persistent negative impact of the pandemic on health-care systems and health-care access in the middle-income region. RSV surveillance needs to be established (or re-established) to monitor changes in RSV epidemiology, particularly in low-income and lower-middle-income countries.
Funding:
EU Innovative Medicines Initiative Preparing for RSV Immunisation and Surveillance in Europe (PROMISE), Bill & Melinda Gates Foundation, and WHO
"The god of criminals is their belly" : diet, prisoner health, and prison medical officers in mid-nineteenth-century English and Irish prisons
Get PDFExisting scholarship on prison diets has emphasised the role of food and its restriction as a key aspect of the deterrent system of prison discipline introduced in the 1860s. Here we suggest that a strong emphasis was placed on dietary regulation after the establishment of the reformist, but also ‘testing’, separate system of confinement in the mid-nineteenth century. While the impact of diet on the physical health of prisoners was a major concern, we argue that the psychological impact of food was also stressed, and some prison administrators and doctors argued that diet had an important protective function in preserving inmates’ mental wellbeing. Drawing on a wide range of prison archives and official reports, this article explores the crucial role of prison medical officers in England and Ireland in implementing prison dietaries. It highlights the importance and high level of individual adaptations to dietary scales laid down centrally, as a means of utilising diet as a tool of discipline or as an intervention to improve prisoners’ health. It examines the forays of some prison doctors into dietary experiments, as they investigated the impact of different dietaries or made more quotidian adjustments to food intake, based on local conditions and food supplies. The article concludes that, despite central policies geared to establishing uniformity and interest in new scientific discourses on nutrition, a wide range of practices were pursued in individual prisons, mostly shaped by practical rather than scientific factors, with many prison medical officers asserting their autonomy in making dietary adjustments
Childhood obesity prevention in general practice : supporting implementation through co-ideation
Get PDFBackground Childhood obesity is associated with physical and psychological complications thus the prevention of excess weight gain in childhood is an important health goal. Relevant to the prevention of childhood obesity, Australian general practice-specific, preventive care guidelines recommend General Practitioners (GPs) conduct growth monitoring and promote a number of healthy behaviours. However, challenges to providing preventive care in general practice may impact implementation. In October and November, 2022, a series of three workshops focusing on the prevention of childhood obesity were held with a group of Australian GPs and academics. The objective of the workshops was to determine practical ways that GPs can be supported to address barriers to the incorporation of obesity-related prevention activities into their clinical practice, for children with a healthy weight. Methods This paper describes workshop proceedings, specifically the outcomes of co-ideation activities that included idea generation, expansion of the ideas to possible interventions, and the preliminary assessment of these concepts. The ecological levels of the individual, interpersonal, and organisation were considered. Results Possible opportunities to support childhood obesity prevention were identified at multiple ecological levels within the clinic. The preliminary list of proposed interventions to facilitate action included GP education and training, clinical audit facilitation, readily accessible clinical guidelines with linked resources, a repository of resources, and provision of adequate growth monitoring tools in general practice. Conclusions Co-ideation with GPs resulted in a number of proposed interventions, informed by day-to-day practicalities, to support both guideline implementation and childhood obesity prevention in general practice
Health care professionals' knowledge and attitudes towards antibiotic prescribing for the treatment of urinary tract infections : a systematic review
Get PDFPurpose: Previous models identify knowledge and attitudes that influence prescribing behaviour. The present study focuses on antibiotic prescribing for urinary tract infections (UTIs) to describe levels of health care professionals' knowledge and attitude factors in this area and how those levels are assessed. Methods: A systematic search was conducted to identify studies assessing the identified knowledge or attitude factors influencing health care professionals' antibiotic prescribing for urinary tract infections up to September 2022. Study quality was assessed using the Newcastle–Ottawa scale. Data were extracted about the types of factors assessed, the levels indicated and how those levels were assessed. Data were synthesized using counts, and levels were categorized as ‘poor’, ‘moderate’, ‘high’ or ‘very high’. Results: Seven studies were identified, six of which relied entirely on closed‐ended items. Levels of knowledge factors assessed were poor, for example, their ‘knowledge of condition’ and ‘knowledge of task environment’ were poor. Levels of the attitude factors assessed varied, for example, while health care professionals expressed moderate confidence in providing optimal patient care and appropriate attitude of fear towards the problem of antibiotic resistance, they expressed a poor attitude of complacency by giving into patient pressure to prescribe an antibiotic. Conclusions: Present evidence suggests that clinicians have poor levels of knowledge and varying levels of attitudes about antibiotic prescribing for UTIs. However, few studies were identified, and assessments were largely limited to closed‐ended types of questions. Future studies that assess more factors and employ open‐ended question types could better inform future interventions to optimize antibiotic prescribing
A framework for understanding transformational FDI
Get PDFThis paper was commissioned by the Office for Investment and the Department for Business and Trade to aid their developing strategy on how inward investment promotion can contribute to so called levelling up. The purpose of this paper is there to explore the potential for inward investment into the UK to contribute to reducing regional inequality. We present a framework which explores how inward investment can be used to “move the dial” in lagging nations and regions of the UK, not merely offering more of the same in terms of output, productivity and employment opportunities, or alternatively not simply attracting activity that is subsequently rather divorced from the rest of the local economy