Examining the effectiveness of the theory of planned behaviour in explaining exercise intention and behaviour during pregnancy: a meta-analysis

Background: Several studies have supported the efficacy and predictive utility of the Theory of Planned Behaviour (TPB; Ajzen 1991) in explaining a variety of behaviours including physical activity. However, the relative contribution of the theory’s components in describing intention and behaviour may differ depending on the context, time and population being studied. Such evidence is necessary to inform exercise advice and interventions aimed at pregnant women. Purpose: The purpose of this study was therefore to review the existing literature surrounding the application of the TPB in explaining exercise intentions and behaviour during pregnancy and to evaluate the magnitude of relationships between TPB constructs within this context. Method: Multiple search strategies yielded 99 potentially relevant studies of which 47 were assessed against the inclusion criteria. Finally, 7 studies, involving 777 pregnant women, were included in the analysis. Relationships identified among TPB constructs were subjected to a random-effects meta-analytic review using the Comprehensive Meta-Analysis (version 3.0) computer software package. Results: Results confirmed the existence of a medium to strong relationship between intention and behaviour (r = 0.44, P < 0.05, R2 = 19.36) and also supported the existence of a direct relationship between behaviour and perceived behavioural control (PBC; r = 0.45, P < 0.05, R2 = 20.25). Pregnant women’s attitude (r = 0.48, P < 0.05, R2 = 23.04) had the strongest association with their intention to be physically active. However, both PBC (r = 0.47, P < 0.05, R2 = 22.09) and subjective norm (r = 0.42, P < 0.05, R2 = 17.64) revealed similar relationships with intention. Conclusion: The study supports the TPB as a relevant conceptual framework for the investigation of exercise intentions and behaviours during pregnancy. PBC carried slightly more weight in explaining behaviour than did intention thereby suggesting that exercise during pregnancy is not a behaviour that is under women’s complete volitional control. Intention to exercise was influenced primarily by expectant mothers’ beliefs about the positive and negative consequences of doing so. Contrary to previous meta-analytic reports in the exercise domain, this study supported the relevance of subjective norm as a construct to investigate exercise intentions and behaviour in a pregnant population. The perceived social pressure to conform to other people’s opinion about physical activity during pregnancy may well be an important consideration for pregnant women. These findings present both researchers and practitioners with an opportunity for intervention and further research

Examining the effectiveness of the Theory of Planned Behaviour in predicting exercise intention and behaviour during pregnancy: Preliminary findings from a random effects meta-analysis

Several studies have supported the efficacy and predictive utility of the Theory of Planned Behaviour (TPB; Ajzen, 1991) in explaining a variety of behaviours including physical activity. However, the relative contribution of the theory’s components in describing intention and behaviour may differ depending on the context, time and population being studied. Such evidence is necessary to inform exercise advice and interventions aimed at pregnant women. The purpose of this study was therefore to review the existing literature surrounding the application of the TPB in explaining exercise intentions and behaviour during pregnancy and to evaluate the magnitude of relationships between TPB constructs within this context. Multiple search strategies yielded 99 potentially relevant studies of which 47 were assessed against the inclusion criteria. Finally, 7 studies, involving 777 pregnant women, were included in the analysis. Relationships identified among TPB constructs were subjected to a random-effects meta-analytic review using the Comprehensive Meta-Analysis (version 3.0) computer software package. Results confirmed the existence of a medium to strong relationship between intention and behaviour (r = .44, P < .05, R2 = 19.36) and also supported the existence of a direct relationship between behaviour and perceived behavioural control (PBC; r = .45, P < .05, R2 = 20.25). Pregnant women’s attitude (r = .48, P < .05, R2 = 23.04) had the strongest association with their intention to be physically active. However, both PBC (r = .47, P < .05, R2 = 22.09) and subjective norm (r = .42, P < .05, R2 = 17.64) revealed similar relationships with intention. The study supports the TPB as a relevant conceptual framework for the investigation of exercise intentions and behaviours during pregnancy. PBC carried slightly more weight in explaining behaviour than did intention thereby suggesting that exercise during pregnancy is not a behaviour that is under women’s complete volitional control. Intention to exercise was influenced primarily by expectant mothers’ beliefs about the positive and negative consequences of doing so. Contrary to previous meta-analytic reports in the exercise domain, this study supported the relevance of subjective norm as a construct to investigate exercise intentions and behaviour in a pregnant population. The perceived social pressure to conform to other people’s opinion about physical activity during pregnancy may well be an important consideration for pregnant women. These findings present both researchers and practitioners with an opportunity for intervention and further research

Phonon Band Structure and Thermal Transport Correlation in a Layered Diatomic Crystal

To elucidate the relationship between a crystal's structure, its thermal conductivity, and its phonon dispersion characteristics, an analysis is conducted on layered diatomic Lennard-Jones crystals with various mass ratios. Lattice dynamics theory and molecular dynamics simulations are used to predict the phonon dispersion curves and the thermal conductivity. The layered structure generates directionally dependent thermal conductivities lower than those predicted by density trends alone. The dispersion characteristics are quantified using a set of novel band diagram metrics, which are used to assess the contributions of acoustic phonons and optical phonons to the thermal conductivity. The thermal conductivity increases as the extent of the acoustic modes increases, and decreases as the extent of the stop bands increases. The sensitivity of the thermal conductivity to the band diagram metrics is highest at low temperatures, where there is less anharmonic scattering, indicating that dispersion plays a more prominent role in thermal transport in that regime. We propose that the dispersion metrics (i) provide an indirect measure of the relative contributions of dispersion and anharmonic scattering to the thermal transport, and (ii) uncouple the standard thermal conductivity structure-property relation to that of structure-dispersion and dispersion-property relations, providing opportunities for better understanding of the underlying physical mechanisms and a potential tool for material design.Comment: 30 pages, 10 figure

The Long Life of Birds: The Rat-Pigeon Comparison Revisited

The most studied comparison of aging and maximum lifespan potential (MLSP) among endotherms involves the 7-fold longevity difference between rats (MLSP 5y) and pigeons (MLSP 35y). A widely accepted theory explaining MLSP differences between species is the oxidative stress theory, which purports that reactive oxygen species (ROS) produced during mitochondrial respiration damage bio-molecules and eventually lead to the breakdown of regulatory systems and consequent death. Previous rat-pigeon studies compared only aspects of the oxidative stress theory and most concluded that the lower mitochondrial superoxide production of pigeons compared to rats was responsible for their much greater longevity. This conclusion is based mainly on data from one tissue (the heart) using one mitochondrial substrate (succinate). Studies on heart mitochondria using pyruvate as a mitochondrial substrate gave contradictory results. We believe the conclusion that birds produce less mitochondrial superoxide than mammals is unwarranted

A COMPREHENSIVE METRIC FOR COMPARING TIME HISTORIES IN VALIDATION OF SIMULATION MODELS WITH EMPHASIS ON VEHICLE SAFETY APPLICATIONS

ABSTRACT Computer modeling and simulation are the cornerstones of product design and development in the automotive industry. Computer-aided engineering tools have improved to the extent that virtual testing may lead to significant reduction in prototype building and testing of vehicle designs. In order to make this a reality, we need to assess our confidence in the predictive capabilities of simulation models. As a first step in this direction, this paper deals with developing a metric to compare time histories that are outputs of simulation models to time histories from experimental tests with emphasis on vehicle safety applications. We focus on quantifying discrepancy between time histories as the latter constitute the predominant form of responses of interest in vehicle safety considerations. First we evaluate popular measures used to quantify discrepancy between time histories in fields such as statistics, computational mechanics, signal processing, and data mining. Then we propose a structured combination of some of these measures and define a comprehensive metric that encapsulates the important aspects of time history comparison. The new metric classifies error components associated with three physically meaningful characteristics (phase, magnitude and topology), and utilizes norms, cross-correlation measures and algorithms such as dynamic time warping to quantify discrepancies. Two case studies demonstrate that the proposed metric seems to be more consistent than existing metrics. It is also shown how the metric can be used in conjunction with ratings from subject matter experts to build regression-based val- * Corresponding author, Phone/Fax: (734) 615-8991/647-8403 idation models

A multicentre, randomised controlled trial of PDSAFE, a physiotherapist-delivered fall prevention programme for people with Parkinson’s

This is the author accepted manuscript. The final version is available from BMJ Publishing Group via the DOI in this record.Objective: To estimate the effect of a physiotherapist-delivered fall-prevention programme for people with Parkinson’s (PwP). Methods: People at risk of falls with confirmed Parkinson’s were recruited to this multi-centre, pragmatic, investigator blind, individually randomised controlled trial with pre-specified sub-group analyses. 474 PwP (Hoehn and Yahr 1-4) were randomised: 238 allocated to a physiotherapy programme and 236 to control. All participants had routine care; the control group received a DVD about Parkinson’s and single advice session at trial completion. The intervention group (PDSAFE) had an individually tailored, progressive home-based fall-avoidance strategy training programme with balance and strengthening exercises. The primary outcome was risk of repeat-falling, collected by self-report monthly diaries, 0 to 6 months post-randomisation. Secondary outcomes included, Mini-BESTest for balance, chair stand test, Falls Efficacy, freezing of gait, health related quality of life (Euroqol EQ-5D), Geriatric Depression Scale, Physical Activity Scale for the Elderly and Parkinson’s disease Questionnaire, fractures and rate of near-falling. Results: Average age, 72 years and 266 (56%) were men. By 6 months 116 (55%) of the control group, and 125 (61.5%) of the intervention group reported repeat falls (controlled odds ratio 1.21, 95% confidence interval 0.74 to 1.98, P=0.447). Secondary sub-group analyses suggested a different response to the intervention between moderate and severe disease severity groups. Balance, falls efficacy and chair stand time improved with near-falls reduced in the intervention arm. Conclusion: PDSAFE did not reduce falling in this pragmatic trial of PwP. Other functional tasks improved and reduced fall rates were apparent among those with moderate disease.Department of HealthNational Institute for Health Research (NIHR

Prevalence of mastitis for cows of different genotypes milked for two consecutive seasons

Extending the calving interval from the traditional 12-month to a 24-month calving interval has been suggested as a practical solution for maximizing lactation yield per calving. Somatic cell count (SCC) and the incidence of mastitis were examined in New Zealand (NZ) and overseas (OS) Holstein-Friesian cows fed on pasture alone or supplemented with 3 or 6 kg DM maize/barley concentrates/cow/day during an extended lactation of up to 21 months. Average cow SCC was three-fold higher (P<0.001) in the extended or second season of the lactation compared with the first season, with NZ cows having a slightly higher SCC (P<0.01) in the second season compared to OS cows (191,000 and 115,000 cells/ml respectively). The SCC elevations occurred regardless of infection status of the udder. Although OS cows tended to have twice as many cases of clinical mastitis (P=0.01) in the first season compared to the NZ cows, affecting 59% and 27% of cows respectively, there was no difference in infection status between genotypes in the second season (20% and 18% respectively). Results showed that although cows experienced less mastitis during the second spring of the lactation, the average cow SCC was higher during the extended part of the lactation

Self-energy of image states on copper surfaces

We report extensive calculations of the imaginary part of the electron self-energy in the vicinity of the (100) and (111) surfaces of Cu. The quasiparticle self-energy is computed by going beyond a free-electron description of the metal surface, either within the GW approximation of many-body theory or with inclusion, within the GW$\Gamma$ approximation, of short-range exchange-correlation effects. Calculations of the decay rate of the first three image states on Cu(100) and the first image state on Cu(111) are also reported, and the impact of both band structure and many-body effects on the electron relaxation process is discussed.Comment: 8 pages, 5 figures, to appear in Phys. Rev.

Anorgasmia in women

This article reports on the etiology and treatment of anorgasmia. Etiological factors include childhood and adolescent experiences, current individual attitudes, and lifestyle factors, as well as the quality and dynamics of past and present committed relationships. It is important to assess the nature of each of the previously mentioned factors in determining the nature of the orgasmic dysfunction as well as assisting in the development of a treatment plan. Treatment approaches for anorgasmia need to address individual factors (e.g., performance anxiety, poor body image) as well as interpersonal problems. A systemic treatment framework would appear to be the most useful approach to treat this sexual dysfunction, as this type of strategy identifies and treats the difficulties experienced by the anorgasmic woman within the total context of her life. Of course, this approach necessitates the involvement of the partner in therapy, and treatment is unlikely to be effective unless the problems experienced by both the woman and her partner are addressed. Limitations of past research in terms of inadequate evaluation of treatment, low sample sizes, and poorly defined interventions are discussed. Finally, directions for future research to advance our understanding of the most effective treatments for anorgasmia are considered. <br /

Museum object handling: a health promoting community-based activity for dementia care

In a quasi-experimental design (N = 80), this study examined the wellbeing impact of handling museum artefacts, by testing for differences across domain, time, gender and stages of dementia. Results indicated people with early and moderate impairment showed positive increases in wellbeing, regardless of the type of dementia but those with early stage dementia showed larger positive increases in wellbeing. We can feel confident that for most people with early to middle stage dementia, handling museum objects in a supportive group environment, increases subjective wellbeing and should be considered part of a health promotion strategy in dementia care