Physical activity in England: Who is meeting the recommended level of participation through sports and exercise?

This article is available through the Brunel Open Access Publishing Fund. Copyright © 2012 Anokye et al.Background: Little is known about the correlates of meeting recommended levels of participation in physical activity (PA) and how this understanding informs public health policies on behaviour change. Objective: To analyse who meets the recommended level of participation in PA in males and females separately by applying ‘process’ modelling frameworks (single vs. sequential 2-step process). Methods: Using the Health Survey for England 2006, (n = 14 142; ≥16 years), gender-specific regression models were estimated using bivariate probit with selectivity correction and single probit models. A ‘sequential, 2-step process’ modelled participation and meeting the recommended level separately, whereas the ‘single process’ considered both participation and level together. Results: In females, meeting the recommended level was associated with degree holders [Marginal effect (ME) = 0.013] and age (ME = −0.001), whereas in males, age was a significant correlate (ME = −0.003 to −0.004). The order of importance of correlates was similar across genders, with ethnicity being the most important correlate in both males (ME = −0.060) and females (ME = −0.133). In females, the ‘sequential, 2-step process’ performed better (ρ = −0.364, P < 0.001) than that in males (ρ = 0.154). Conclusion: The degree to which people undertake the recommended level of PA through vigorous activity varies between males and females, and the process that best predicts such decisions, i.e. whether it is a sequential, 2-step process or a single-step choice, is also different for males and females. Understanding this should help to identify subgroups that are less likely to meet the recommended level of PA (and hence more likely to benefit from any PA promotion intervention).This study was funded by the Department of Health’s Policy Research Programme

Costs of publicly provided maternity services in Rosario, Argentina

This material is posted here with permission of the publishers, Instituto Nacional de Salud Pública. Internal or personal use of this material is permitted. However, permission to reprint/republish this material must be obtained from the Publisher.Objective. This study estimates the costs of maternal health services in Rosario, Argentina. Material and Methods. The rovider costs (US$1999) of antenatal care, a normal vaginal delivery and a caesarean section, were evaluated retrospectively in two municipal hospitals. The cost of an antenatal visit was evaluated in two health centres and the patient costs associated with the visit were evaluated in a hospital and a health centre. Results. The average cost per hospital day is$114.62. The average cost of a caesarean section ($525.57) is five times greater than that of a normal vaginal delivery ($105.61). A normal delivery costs less at the general hospital and a c-section less at the aternity hospital. The average cost of an antenatal visit is $31.10. The provider cost is lower at the health centre than at the hospital. Personnel accounted for 72-94$4.70. Direct costs are minimal compared to indirect costs of travel and waiting time. Conclusions. These results suggest the potential for increasing the efficiency of resource use by promoting antenatal care visits at the primary level. Women could also benefit from reduced travel and waiting time. Similar benefits could accrue to the provider by encouraging normal delivery at general hospitals, and complicated deliveries at specialised maternity hospitals.Josephine Borghi is funded by the Department for International Development through the Maternal Health Programme at the London School of Hygiene and Tropical Medicine. This project was conducted for and funded by the Human Reproduction Programme at WHO, Geneva

Formal Modeling and Analysis for Interactive Hybrid Systems

An effective strategy for discovering certain kinds of automation surprise and other problems in interactive systems is to build models of the participating (automated and human) agents and then explore all reachable states of the composed system looking for divergences between mental states and those of the automation. Various kinds of model checking provide ways to automate this approach when the agents can be modeled as discrete automata. But when some of the agents are continuous dynamical systems (e.g., airplanes), the composed model is a hybrid (i.e., mixed continuous and discrete) system and these are notoriously hard to analyze. We describe an approach for very abstract modeling of hybrid systems using relational approximations and their automated analysis using infinite bounded model checking supported by an SMT solver. When counterexamples are found, we describe how additional constraints can be supplied to direct counterexamples toward plausible scenarios that can be confirmed in high-fidelity simulation. The approach is illustrated though application to a known (and now corrected) human-automation interaction problem in Airbus aircraft

System-level Non-interference for Constant-time Cryptography

International audienceCache-based attacks are a class of side-channel attacks that are particularly effective in virtualized or cloud-based en-vironments, where they have been used to recover secret keys from cryptographic implementations. One common ap-proach to thwart cache-based attacks is to use constant-time implementations, i.e. which do not branch on secrets and do not perform memory accesses that depend on secrets. How-ever, there is no rigorous proof that constant-time implemen-tations are protected against concurrent cache-attacks in virtualization platforms with shared cache; moreover, many prominent implementations are not constant-time. An alter-native approach is to rely on system-level mechanisms. One recent such mechanism is stealth memory, which provisions a small amount of private cache for programs to carry po-tentially leaking computations securely. Stealth memory in-duces a weak form of constant-time, called S-constant-time, which encompasses some widely used cryptographic imple-mentations. However, there is no rigorous analysis of stealth memory and S-constant-time, and no tool support for check-ing if applications are S-constant-time. We propose a new information-flow analysis that checks if an x86 application executes in constant-time, or in S-constant-time. Moreover, we prove that constant-time (resp. S-constant-time) programs do not leak confidential infor-mation through the cache to other operating systems exe-cuting concurrently on virtualization platforms (resp. plat-forms supporting stealth memory). The soundness proofs are based on new theorems of independent interest, includ-ing isolation theorems for virtualization platforms (resp. plat-forms supporting stealth memory), and proofs that constant-time implementations (resp. S-constant-time implementa-tions) are non-interfering with respect to a strict information flow policy which disallows that control flow and memory ac-cesses depend on secrets. We formalize our results using the Coq proof assistant and we demonstrate the effectiveness of our analyses on cryptographic implementations, including PolarSSL AES, DES and RC4, SHA256 and Salsa20

Formal Verification of a Rover Anti-collision System

In this paper, we integrate inductive proof, bounded model checking, test case generation and equivalence proof techniques to verify an embedded system. This approach is implemented using Systerel Smart Solver (S3) toolset. It is applied to verify properties at system, software, and code levels. The verification process is illustrated on an anti-collision system (ARP for Automatic Rover Protection) implemented on-board a rover. Focus is placed on the verification of safety and functional properties and the proof of equivalence between the design model and the generated code

An exploration of demand for physical activity

The aim of this thesis is to contribute to the understanding of demand for physical activity. Given the government‟s target to increase the proportion of the population who are physically active, we need to know the determinants of demand for physical activity in order to identify target areas for policy. The relevant components of the demand function for physical activity, which were identified from reviews of theoretical and empirical literature on physical activity behaviour, established the need to account for costs (i.e. time and money costs) and perceived benefits among other factors in explaining physical activity behaviour. To date, there is a paucity of studies looking at this issue particularly from an economic perspective, mainly due to the lack of such data. This thesis therefore focussed on fitting varied econometric models (sample selection, count, linear, and probit) to understand how costs and perceived benefits explain indicators of physical activity behaviour (total time spent, number of days, and meeting the recommended level of participation or not); controlling for socio-economic, demographic and psychological variables. Data was sourced from the Health Survey for England (2006), Health Education Authority National Survey of Activity and Health (1991), and face-face interviews conducted in 2008 using a purposive sample. The findings suggest that time and money prices (costs per occasion of participation) of physical activity are inversely correlated with physical activity, and this is mitigated where the perceived benefits of physical activity, both health and non-health, are high. Indicators of demand were price inelastic except for meeting the recommended level of participation, which was highly responsive to changes in time price. Based on the findings, various policies including the use of economic instruments such as subsidies, particularly at the point of consumption, and mass media campaigns to increase awareness about the benefits of physical activity are discussed.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Social technologies for online learning: theoretical and contextual issues

Three exemplars are presented of social technologies deployed in educational contexts: wikis; a photo-sharing environment; and a social bookmarking tool. Students were found to engage with the technologies selectively, sometimes rejecting them, in the light of their prior conceptions of education. Some students (a minority in all the studies) were unsympathetic to the educational philosophy underpinning the technology’s adoption. The paper demonstrates, through an examination of in-context use, the importance of socio-cultural factors in relation to education, and the non-deterministic nature of educational technology. The academic study of technology has increasingly called into question the deterministic views which are so pervasive in popular discourse and among policy makers. Instead, socio-cultural factors play a crucial role in shaping and defining technology and educational technology is no exception, as the examples in the paper show. The paper concludes by drawing out some implications of the examples for the use of social technologies in education

The play's the thing

For very understandable reasons phenomenological approaches predominate in the field of sensory urbanism. This paper does not seek to add to that particular discourse. Rather it takes Rorty’s postmodernized Pragmatism as its starting point and develops a position on the role of multi-modal design representation in the design process as a means of admitting many voices and managing multidisciplinary collaboration. This paper will interrogate some of the concepts underpinning the Sensory Urbanism project to help define the scope of interest in multi-modal representations. It will then explore a range of techniques and approaches developed by artists and designers during the past fifty years or so and comment on how they might inform the question of multi-modal representation. In conclusion I will argue that we should develop a heterogeneous tool kit that adopts, adapts and re-invents existing methods because this will better serve our purposes during the exploratory phase(s) of any design project that deals with complexity