A prospective study exploring the construct and predictive validity of the COM-B model for physical activity

The final, definitive version of this paper has been published in Journal of Health Psychology, November 2017, doi: https://doi.org/10.1177/1359105317739098, published by SAGE Publishing, All rights reserved.This study examined the constructs of Capability, Opportunity, and Motivation from the COM-B model and their influence on moderate-to-vigorous physical activity (MVPA). Using a prospective survey design, 186 healthy adults completed measures representing the Theoretical Domains Framework mapped to the COM-B, and MVPA one week later. The main indicators for the COM constructs were ‘habits’ (Capability), ‘subjective norms’ (Opportunity), and ‘exercise self-identity’ (Motivation). Motivation (77%) and MVPA (50%) were strongly predicted, with Capability and Motivation as key drivers of behaviour. Motivation was a strong mediator for Capability on behaviour. Future research should consider this approach for other populations and behaviours.Peer reviewe

Aquilegia, Vol. 28 No. 1, January-February 2004: Newsletter of the Colorado Native Plant Society

https://epublications.regis.edu/aquilegia/1101/thumbnail.jp

Prospectus, September 22, 1999

https://spark.parkland.edu/prospectus_1999/1022/thumbnail.jp

Determinants of weekly sitting time: Construct validation of an initial COM-B model and comparison of its predictive validity with the Theory of Planned Behaviour

© 2020 Taylor & Francis. This is an Accepted Manuscript of an article published by Taylor & Francis in Psychology & Health on 14 May 2020, available online: https://doi.org/10.1080/08870446.2020.1763994.Objective: In relation to sitting behaviour, to investigate which theoretical domains best formed the Capability, Opportunity, and Motivation constructs of the COM-B, and compare the predictive validity to the Theory of Planned Behaviour (TPB), taking habit strength into consideration. Design: Using a prospective design, 186 adults completed measures capturing domains from the Theoretical Domains Framework for the three COM-B constructs, and habit strength, which were examined using a formative measurement model. Predictive validity was then compared to the TPB.Main Outcome Measures: Self-reported sitting behaviour. Results: Self-monitoring (behavioural regulation domain) formed Capability; subjective norm (social influences domain) formed Opportunity; intention (intentions domain), positive affect (emotion domain), and perceived behavioural control (beliefs about capabilities domain), formed Motivation. The COM-B strongly predicted sitting behaviour (27% variance explained), with Capability, Opportunity, and habit strength as key drivers. The TPB explained a large amount of variance (23%) in sitting behaviour, with intention and habit strength as key drivers. Conclusions: The behavioural regulation domain of Capability, the social influences domain of Opportunity, and habit strength were important drivers of sitting behaviour, with comparable variance predicted in the COM-B and TPB. Future research should consider this approach to conceptualise the COM-B for specific populations and behaviours.Peer reviewe

Robust signatures in the current-voltage characteristics of DNA molecules oriented between two graphene nanoribbon electrodes

In this work we numerically calculate the electric current through three kinds of DNA sequences (telomeric, \lambda-DNA, and p53-DNA) described by different heuristic models. A bias voltage is applied between two zig-zag edged graphene contacts attached to the DNA segments, while a gate terminal modulates the conductance of the molecule. The calculation of current is performed by integrating the transmission function (calculated using the lattice Green's function) over the range of energies allowed by the chemical potentials. We show that a telomeric DNA sequence, when treated as a quantum wire in the fully coherent low-temperature regime, works as an excellent semiconductor. Clear steps are apparent in the current-voltage curves of telomeric sequences and are present independent of lengths and sequence initialisation at the contacts. The current-voltage curves suggest the existence of stepped structures independent of length and sequencing initialisation at the contacts. We also find that the molecule-electrode coupling can drastically influence the magnitude of the current. The difference between telomeric DNA and other DNA, such as \lambda-DNA and DNA for the tumour suppressor p53, is particularly visible in the length dependence of the current

A review of the use of covariates in cluster randomized trials uncovers marked discrepancies between guidance and practice

Objectives: Reviews of the handling of covariates in trials have explicitly excluded cluster randomized trials (CRTs). In this study, we review the use of covariates in randomization, the reporting of covariates, and adjusted analyses in CRTs. Study Design and Setting: We reviewed a random sample of 300 CRTs published between 2000 and 2008 across 150 English language journals. Results: Fifty-eight percent of trials used covariates in randomization. Only 69 (23%) included tables of cluster- and individual-level covariates. Fifty-eight percent reported significance tests of baseline balance. Of 207 trials that reported baseline measures of the primary outcome, 155 (75%) subsequently adjusted for these in analyses. Of 174 trials that used covariates in randomization, 30 (17%) included an analysis adjusting for all those covariates. Of 219 trial reports that included an adjusted analysis of the primary outcome, only 71 (32%) reported that covariates were chosen a priori. Conclusion: There are some marked discrepancies between practice and guidance on the use of covariates in the design, analysis, and reporting of CRTs. It is essential that researchers follow guidelines on the use and reporting of covariates in CRTs, promoting the validity of trial conclusions and quality of trial reports

Geographic contrasts between pre- and postzygotic barriers are consistent with reinforcement in Heliconius butterflies.

Identifying the traits causing reproductive isolation and the order in which they evolve isfundamental to understanding speciation. Here, we quantify prezygotic and intrinsicpostzygotic isolation between allopatric, parapatric and sympatric populations of thebutterflies Heliconius elevatus and Heliconius pardalinus. Sympatric populations from theAmazon (H. elevatus and H. p. butleri) exhibit strong prezygotic isolation and rarely mate incaptivity; however, hybrids are fertile. Allopatric populations from the Amazon(H. p. butleri) and Andes (H. p. sergestus) mate freely when brought together in captivity, butthe female F1 hybrids are sterile. Parapatric populations (H. elevatus and H. p. sergestus)exhibit both assortative mating and sterility of female F1s. Assortative mating in sympatricpopulations is consistent with reinforcement in the face of gene flow, where the driving force,selection against hybrids, is due to disruption of mimicry and other ecological traits ratherthan hybrid sterility. In contrast, the lack of assortative mating and hybrid sterility observedin allopatric populations suggests that geographic isolation enables the evolution of intrinsicpostzygotic reproductive isolation. Our results show how the types of reproductive barriersthat evolve between species may depend on geography

In Vitro and In Vivo Neurotoxicity of Prion Protein Oligomers

The mechanisms underlying prion-linked neurodegeneration remain to be elucidated, despite several recent advances in this field. Herein, we show that soluble, low molecular weight oligomers of the full-length prion protein (PrP), which possess characteristics of PrP to PrPsc conversion intermediates such as partial protease resistance, are neurotoxic in vitro on primary cultures of neurons and in vivo after subcortical stereotaxic injection. Monomeric PrP was not toxic. Insoluble, fibrillar forms of PrP exhibited no toxicity in vitro and were less toxic than their oligomeric counterparts in vivo. The toxicity was independent of PrP expression in the neurons both in vitro and in vivo for the PrP oligomers and in vivo for the PrP fibrils. Rescue experiments with antibodies showed that the exposure of the hydrophobic stretch of PrP at the oligomeric surface was necessary for toxicity. This study identifies toxic PrP species in vivo. It shows that PrP-induced neurodegeneration shares common mechanisms with other brain amyloidoses like Alzheimer disease and opens new avenues for neuroprotective intervention strategies of prion diseases targeting PrP oligomers

The Optical Orbital Light Curve of the Low-mass X-ray Binary V1408 Aquilae (= 4U 1957+115)

V1408 Aql (= 4U 1957+115) is a low-mass X-ray binary with an orbital period near 9.3 hr, whose compact star is a black hole candidate. The system shows a large-amplitude orbital photometric modulation at optical wavelengths. We have obtained new optical photometry of V1408 Aql from which we derive the orbital light curve and an improved orbital ephemeris. We show that the orbital light curve can be reproduced by a model in which the accretion disk around the compact star is thin, axisymmetric, and uneclipsed. The secondary star is heated by X-rays from the compact star and the accretion disk. The orbital modulation is produced entirely by the changing aspect of the irradiated secondary star with orbital phase. Because the system does not eclipse, the fits of the model light curves are insensitive to the orbital parameters, allowing a wide range of orbital inclinations and mass ratios.Comment: 26 pages, 9 figures (3 in color), To appear as ApJ, 730, 43, 201

Endorsement of the CONSORT Statement by High-Impact Medical Journals in China: A Survey of Instructions for Authors and Published Papers

The CONSORT Statement is a reporting guideline for authors when reporting randomized controlled trials (RCTs). It offers a standard way for authors to prepare RCT reports. It has been endorsed by many high-impact medical journals and by international editorial groups. This study was conducted to assess the endorsement of the CONSORT Statement by high-impact medical journals in China by reviewing their instructions for authors.A total of 200 medical journals were selected according to the Chinese Science and Technology Journal Citation Reports, 195 of which publish clinical research papers. Their instructions for authors were reviewed and all texts mentioning the CONSORT Statement or CONSORT extension papers were extracted. Any mention of the Uniform Requirements for Manuscripts Submitted to Biomedical Journals (URM) developed by the International Committee of Medical Journal Editors (ICMJE) or ‘clinical trial registration’ was also extracted. For journals endorsing the CONSORT Statement, their most recently published RCT reports were retrieved and evaluated to assess whether the journals have followed what the CONSORT Statement required. Out of the 195 medical journals publishing clinical research papers, only six (6/195, 3.08%) mentioned ‘CONSORT’ in their instructions for authors; out of the 200 medical journals surveyed, only 14 (14/200, 7.00%) mentioned ‘ICMJE’ or ‘URM’ in their instructions for authors, and another five journals stated in their instructions for authors that clinical trials should have trial registration numbers and that priority would be given to clinical trials which had been registered. Among the 62 RCT reports published in the six journals endorsing the CONSORT Statement, 20 (20/62, 32.26%) contained flow diagrams and only three (3/62, 4.84%) provided trial registration information.Medical journals in China endorsing either the CONSORT Statement or the ICMJE's URM constituted a small percentage of the total; all of these journals used ambiguous language regarding what was expected of authors