Effect of changes in moderate or vigorous physical activity on changes in health-related quality of life of elderly British women over seven years.

PURPOSE: This study investigates the effect of changes in moderate or vigorous physical activity (MVPA) on trajectories in health-related quality of life (HR-QoL) over 7 years in British elderly women. METHODS: A total of 1,926 women from the British Women's Heart and Health Study with information on MVPA and HR-QoL [measured using Euro quality of life 5 dimension (EQ-5D)] at baseline and at 7 years of follow-up were included in the analysis. Baseline and 7-year follow-up MVPA values were categorised into 3 groups, generating 9 categories of change in MVPA. Logistic regression was used to obtain odds ratios (ORs) of maintaining or improving HR-QoL according to different patterns of change in MVPA level. RESULTS: Women who remained inactive over the 7 years of follow-up had the largest reduction in their EQ-5D scores. Compared to these women, women that increased their MPVA level from "inactive" to "low" or to "moderate-high" were more likely to maintain or improve their HR-QoL over 7 years (ORs 1.65 or 2.70, respectively, p value for trend <0.001). After adjustment for baseline EQ-5D score and a wide range of potential confounders, results remained largely unchanged, though precision of the estimates generally decreased. CONCLUSIONS: Our findings suggest that relatively regular MVPA, even taken up later in life, can help older women prevent a decline in HR-QoL and even improve their enjoyment of life

Could NICE guidance on the choice of blood pressure lowering drugs be simplified?

Reecha Sofat and colleagues argue that prescribing advice needs updating in the light of recent evidence that all classes of blood pressure lowering drugs are broadly equivalen

Damage in adhesively bonded joints : sinusoidal and impact fatigue

The main aim of this research was to investigate the behaviour of adhesive joints exposed to repeated low-velocity impact i.e. impact fatigue (IF), and to compare this loading regime with standard fatigue (SF), i.e. non-impacting, constant amplitude, sinusoidal loading conditions. Two types of lap joint configuration using rubber toughened modified epoxy adhesives were used and exposed to various loading conditions in order to determine the fatigue behaviour of the joints for each load conditions. The fatigue life was investigated using bonded aluminium alloy (7075-T6) single lap joint (SLJ) specimens, where it was seen that IF is an extremely damaging load regime compared to SF. Different trends were visible in force-life plots for these two types of loading. In SF a gradual decrease in the fatigue life with increasing load was observed, whereas, in IF a significant decrease in life was seen at relatively modest levels of maximum force after relatively few cycles. Comparisons of the fatigue life show a considerably earlier failure in IF than in SF for comparable levels of force and energy. Additionally, it was demonstrated that the maximum force per cycle, loading time, stiffness and strength decreased as a result of damage generated in the sample during IF.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Effect of changes in moderate or vigorous physical activity on changes in health-related quality of life of elderly British women over seven years.

PURPOSE: This study investigates the effect of changes in moderate or vigorous physical activity (MVPA) on trajectories in health-related quality of life (HR-QoL) over 7 years in British elderly women. METHODS: A total of 1,926 women from the British Women's Heart and Health Study with information on MVPA and HR-QoL [measured using Euro quality of life 5 dimension (EQ-5D)] at baseline and at 7 years of follow-up were included in the analysis. Baseline and 7-year follow-up MVPA values were categorised into 3 groups, generating 9 categories of change in MVPA. Logistic regression was used to obtain odds ratios (ORs) of maintaining or improving HR-QoL according to different patterns of change in MVPA level. RESULTS: Women who remained inactive over the 7 years of follow-up had the largest reduction in their EQ-5D scores. Compared to these women, women that increased their MPVA level from "inactive" to "low" or to "moderate-high" were more likely to maintain or improve their HR-QoL over 7 years (ORs 1.65 or 2.70, respectively, p value for trend <0.001). After adjustment for baseline EQ-5D score and a wide range of potential confounders, results remained largely unchanged, though precision of the estimates generally decreased. CONCLUSIONS: Our findings suggest that relatively regular MVPA, even taken up later in life, can help older women prevent a decline in HR-QoL and even improve their enjoyment of life

Impact fatigue in adhesive joints

One of the forms of a vibro-impact effect in engineering components is impact fatigue (IF) caused by a cyclic repetition of low energy, low-velocity impacts, for instance, in aerospace structures. It can have a highly detrimental impact on performance and reliability of such components, exacerbated by the fact that in many cases it is disguised in loading histories by non-impact loading cycles with higher amplitudes. Since the latter are traditionally considered as most dangerous in standard fatigue, IF has not yet received deserved attention; it is less studied and practically unknown to specialists in structural integrity. Though there is a broad understanding of the danger of high-energy single impacts, repetitive impacting of components has been predominantly studied for very short series. This paper aims at the analysis of IF of adhesively bonded joints, which are becoming more broadly used in aerospace applications. The study is implemented for two types of typical adherends – an aluminium alloy and a carbon-fibre reinforced composite – and an industry-relevant epoxy adhesive. Various stages of fatigue crack development in adhesively bonded joints are studied for the conditions of standard and IF. The results obtained – in terms of crack growth rates, fatigue lives, and microstructures of fracture surfaces – are compared for the two regimes in order to find similarities and specific features

Delamination in adhesively bonded CFRP joints : standard fatigue, impact-fatigue and intermittent impact

The response of adhesive joints to three fatigue regimes, namely; constant amplitude sinusoidal loading (standard fatigue, SF), cyclic in-plane impacts (impact fatigue, IF) and a combination of the two (CSIF), has been investigated. The samples used in this study were carbon fibre reinforced polymer (CFRP) lap-strap joints (LSJs) bonded with a rubber modified epoxy adhesive. It was observed that fatigue fracture at very low load amplitudes occurred in IF. Two main patterns of failure were observed in SF; cohesive failure in the adhesive, which was linked to slow fatigue crack growth behaviour, and a mixed-mode failure, involving failure in both the adhesive and the CFRP. In addition, it was observed that the transition from cohesive to mixed mode failure was accompanied by crack growth acceleration. In IF it was seen that all failure was of a mixed-mechanism nature. In the combined standard and impact fatigue it was seen that the introduction of a relatively small number of impacts between SF blocks drastically changed the dynamics of fatigue crack propagation, increasing the crack rate. A further observation was that cavitation of rubber particles in the adhesive, which is seen as evidence of active toughening, was affected by the addition of impact loading

Damage in adhesively bonded CFRP joints : sinusoidal and impact-fatigue

The main aim of this paper is to investigate the behaviour of adhesively bonded CFRP joints subjected to cyclic low-velocity impacts and to compare this with fracture in specimens tested in standard fatigue (i.e. non-impacting, constant amplitude, sinusoidal fatigue). It is seen that the accumulated energy associated with damage in impact-fatigue is significantly lower than that associated with similar damage in standard fatigue and that the mechanisms of failure are very different for the two loading regimes. For both types of loading, fracture initiates in the adhesive layer and then propagates into the 0º ply of the composite adjacent to the adhesive layer. However, the fracture surfaces after impact-fatigue are generally less uniform and exhibit more signs of high rate/brittle fracture than seen in the fracture surfaces after standard fatigue testing. Various parameters are proposed to characterise damage in standard and impact-fatigue and it is shown that crack velocity, accumulated absorbed energy and normalised maximum force are all useful parameters for characterising damage evolution

Applying Prolog to Develop Distributed Systems

Development of distributed systems is a difficult task. Declarative programming techniques hold a promising potential for effectively supporting programmer in this challenge. While Datalog-based languages have been actively explored for programming distributed systems, Prolog received relatively little attention in this application area so far. In this paper we present a Prolog-based programming system, called DAHL, for the declarative development of distributed systems. DAHL extends Prolog with an event-driven control mechanism and built-in networking procedures. Our experimental evaluation using a distributed hash-table data structure, a protocol for achieving Byzantine fault tolerance, and a distributed software model checker - all implemented in DAHL - indicates the viability of the approach