10,082 research outputs found
How useful are the stages of change for targeting interventions? randomized test of a brief intervention to reduce smoking
Objectives. To see whether the stages of change are useful for targeting a brief intervention to reduce smoking based on implementation intentions. A second objective was to rule out demand characteristics as an alternative explanation for the findings of intervention studies based on the transtheoretical model and implementation intentions. Design. Participants (N = 350) were randomized to a passive control condition (questionnaire only), active control condition (questionnaire-plus-instruction to plan to quit) or experimental condition (questionnaire, plan to quit, form an implementation intention). Their behavior and psychosocial orientation to quit were measured at baseline and 2-month follow-up. Main Outcome Measures. Theory of planned behavior variables, nicotine dependence and quitting. Results. Significantly more people quit smoking in the experimental condition than in the control conditions, and the planning instructions changed intention to quit and perceived control over quitting, but not behavior. Stage of change moderated these effects such that implementation intentions worked best for individuals who were in the preparation stage at baseline. Conclusion. Harnessing both motivational and volitional processes seems to enhance the effectiveness of smoking cessation programs, although further work is required to clarify inconsistencies in the literature using the stages of change.</p
Identity, environment and mental wellbeing in the veterinary profession
Mental health and career dissatisfaction are of increasing concern to the veterinary profession. The influence of identity on the psychological wellbeing of veterinarians has not been widely explored. Twelve recent veterinary graduates were enrolled in a private social media discussion group, and their identities investigated through narrative inquiry: a methodology which enables identity priorities to be extrapolated from stories of experience. Two distinct variants of the veterinary identity were identified: an academic, ‘diagnosis-focused’ identity, which prioritised definitive diagnosis and best-evidence treatment; and a broader ‘challenge-focused’ identity, where priorities additionally included engaging with the client, challenging environment or veterinary business. Contextual challenges (such as a client with limited finances or difficult interpersonal interactions) were seen as a source of frustration for those with a diagnosis-focused identity, as they obstructed the realisation of identity goals. Overcoming these challenges provided satisfaction to those with a challenge-focused identity. The employment environment of the graduates (general veterinary practice) provided more opportunities for those with a challenge-focused identity to realise identity goals, and more markers of emotional wellbeing were apparent in their stories. Markers of poor emotional health were evident in the stories of those with a diagnosis-focused identity
Predicting and explaining transtheoretical model stage transitions in relation to condom-carrying behaviour
Objectives: The stages of change component of the transtheoretical model has been applied to safe sex behaviours in cross-sectional analyses, but have not yet been subject to prospective analysis. It was predicted that: (a) cross-sectional analyses would demonstrate good discrimination between the stages of change, (b) prospective analyses would allow for the identification of predictors of stage transitions, and (c) implementation intentions would explain progression from the preparation stage.
Design: This study employed an experimental longitudinal design. Participants were randomly assigned to the experimental (implementation intention) or control conditions and completed questionnaires at baseline and at 2-months follow up.
Methods: 525 adolescents who were broadly representative of the UK population completed questionnaires at baseline and follow up (n = 393) measuring: demographic variables, stage of change, theory of planned behaviour constructs, anticipated regret and moral norm in relation to condom carrying behaviour. The experimental condition completed a self-generated implementation intention to carry condoms at the end of the baseline questionnaire.
Results: Discriminant function analyses indicated that the stages of change could be accurately discriminated from one another cross-sectionally and that, longitudinally, the measured variables were able to predict transitions between most stages. Implementation intentions caused people to progress from the preparation stage.
Conclusions: Transitions between most stages were reliably predicted thereby providing potential targets for intervention. The brief implementation intention intervention was effective and could easily be utilised and expanded to encompass a broader range of sexual health behaviours.</p
The challenges and issues of undergraduate student retention and attainment in UK veterinary medical education
Student retention and attainment has recently been identified as a key area for development in veterinary medical education enquiry. Woodfield's research on retention and attainment across the UK disciplines has yielded some unique information about the challenges and issues of students who study veterinary medicine and related subjects. The present literature review aims to expand on Woodfield's findings and explain important issues about retention and attainment across veterinary medicine. Overall, the subject of retention and attainment in undergraduate veterinary medical education needs a great deal more empirical attention, such as data on the retention and attainment of mature and widening access students, and the effects of students being placed at remote locations during their studies. Our findings also cover some unsurprising issues: the dominance of women in a profession that is principally lead by men, the underrepresentation of black and minority ethnic (BME) students in veterinary medicine, and the effects of content overload in the veterinary medical curriculum. Based on data gathered by Woodfield and our investigation of the scholarly and gray literatures, we offer an overview of gaps in current knowledge and recommendations for further research
Massive planet migration: Theoretical predictions and comparison with observations
We quantify the utility of large radial velocity surveys for constraining
theoretical models of Type II migration and protoplanetary disk physics. We
describe a theoretical model for the expected radial distribution of extrasolar
planets that combines an analytic description of migration with an empirically
calibrated disk model. The disk model includes viscous evolution and mass loss
via photoevaporation. Comparing the predicted distribution to a uniformly
selected subsample of planets from the Lick / Keck / AAT planet search
programs, we find that a simple model in which planets form in the outer disk
at a uniform rate, migrate inward according to a standard Type II prescription,
and become stranded when the gas disk is dispersed, is consistent with the
radial distribution of planets for orbital radii 0.1 AU < a < 2.5 AU and planet
masses greater than 1.65 Jupiter masses. Some variant models are disfavored by
existing data, but the significance is limited (~95%) due to the small sample
of planets suitable for statistical analysis. We show that the favored model
predicts that the planetary mass function should be almost independent of
orbital radius at distances where migration dominates the massive planet
population. We also study how the radial distribution of planets depends upon
the adopted disk model. We find that the distribution can constrain not only
changes in the power-law index of the disk viscosity, but also sharp jumps in
the efficiency of angular momentum transport that might occur at small radii.Comment: ApJ, in press. References updated to match published versio
Single-Cell Enumeration of an Uncultivated TM7 Subgroup in the
Specific oligonucleotide hybridization conditions were established for single-cell enumeration of uncultivated TM7 and IO25 bacteria by using clones expressing heterologous 16S rRNA. In situ analysis of human subgingival crevice specimens revealed that a greater proportion of samples from sites of chronic periodontitis than from healthy sites contained TM7 subgroup IO25. In addition, IO25 bacterial cells from periodontitis site samples were more abundant and fourfold longer than IO25 cells from healthy site samples
Accretion Disc Evolution in Single and Binary T Tauri Stars
We present theoretical models for the evolution of T Tauri stars surrounded
by circumstellar discs. The models include the effects of pre-main-sequence
stellar and time dependent disc evolution, and incorporate the effects of
stellar magnetic fields acting on the inner disc. For single stars, consistency
with observations in Taurus-Auriga demands that disc dispersal occurs rapidly,
on much less than the viscous timescale of the disc, at roughly the epoch when
heating by stellar radiation first dominates over internal viscous dissipation.
Applying the models to close binaries, we find that because the initial
conditions for discs in binaries are uncertain, studies of extreme mass ratio
systems are required to provide a stringent test of theoretical disc evolution
models. We also note that no correlation of the infra-red colours of T Tauri
stars with their rotation rate is observed, in apparent contradiction to the
predictions of simple magnetospheric accretion models.Comment: 11 pages, MNRAS in pres
MHD simulations of the collapsar model for GRBs
We present results from axisymmetric, time-dependent magnetohydrodynamic
(MHD) simulations of the collapsar model for gamma-ray bursts. Our main
conclusion is that, within the collapsar model, MHD effects alone are able to
launch, accelerate and sustain a strong polar outflow. We also find that the
outflow is Poynting flux-dominated, and note that this provides favorable
initial conditions for the subsequent production of a baryon-poor fireball.Comment: 4 pages, to appear in proceedings of "2003 GRB Conference" (Santa Fe,
NM, September 8-12, 2003), needs aipprocs LaTeX class, movies are available
at http://rocinante.colorado.edu/~proga
Resonant state expansion applied to planar waveguides
The resonant state expansion, a recently developed method in electrodynamics,
is generalized here to planar open optical systems with non-normal incidence of
light. The method is illustrated and verified on exactly solvable examples,
such as a dielectric slab and a Bragg reflector microcavity, for which explicit
analytic formulas are developed. This comparison demonstrates the accuracy and
convergence of the method. Interestingly, the spectral analysis of a dielectric
slab in terms of resonant states reveals an influence of waveguide modes in the
transmission. These modes, which on resonance do not couple to external light,
surprisingly do couple to external light for off-resonant excitation
Reduction of Effective Terahertz Focal Spot Size By Means Of Nested Concentric Parabolic Reflectors
An ongoing limitation of terahertz spectroscopy is that the technique is
generally limited to the study of relatively large samples of order 4 mm across
due to the generally large size of the focal beam spot. We present a nested
concentric parabolic reflector design which can reduce the terahertz focal spot
size. This parabolic reflector design takes advantage of the feature that
reflected rays experience a relative time delay which is the same for all
paths. The increase in effective optical path for reflected light is equivalent
to the aperture diameter itself. We have shown that the light throughput of an
aperture of 2 mm can be increased by a factor 15 as compared to a regular
aperture of the same size at low frequencies. This technique can potentially be
used to reduce the focal spot size in terahertz spectroscopy and enable the
study of smaller samples
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