2,352 research outputs found
Park and ride: Lessons from the UK experience
Park and Ride schemes using dedicated bus services have become particularly popular
over the last 40 years with UK policymakers. This popularity can largely be attributed
to the UK policy context and the advocating of Park and Ride to tackle increasing car
use, congestion and traffic-related emissions. The aim of this paper is to use existing
evidence on the degree to which this has been achieved and provide lessons on how
bus-based Park and Ride can be used effectively. From this, lessons are provided that
will benefit stakeholders internationally on the use of dedicated link-mode Park and
Ride schemes operating at the edge of urban areas. It is found that although Park and
Ride has been popular amongst motorists, it has also attracted users of existing public
transport services and has generated additional trips, resulting in a counter-productive
effect. It is concluded that for Park and Ride to be successful, it should be
implemented in tandem with other supply-side measures and alongside sufficiently
rigorous restraint instruments. Also, despite the use of frequent and dedicated bus-link
services providing a key feature that attracts motorists who would not otherwise use
public transport, their use needs to be carefully monitored to avoid low load-factors
decreasing levels of efficiency
Association between smoking-related attentional bias and craving measured in the clinic and in the natural environment
Previous laboratory studies have investigated associations between attentional bias and craving, but ecological momentary assessment (EMA) may provide ecologically-valid data. This study examines whether clinic-measured attentional bias is associated with noticing smoking cues, attention to smoking, and craving assessed by EMA and whether EMA-assessed cues and attention to smoking are associated with craving in a secondary analysis of data from 100 cigarette smokers attempting cessation. Two weeks before quitting, participants completed attentional bias assessments on visual probe (VP) and Stroop tasks and completed random EMA-assessments for seven weeks thereafter. Participants completed 9,271 random assessments, averaging 3.3 prompts/day. Clinic-measured attentional bias was not associated with cues seen (VP: OR = 1.00, 95% CI = [0.99, 1.01]; Stroop: OR = 1.00, 95% CI [0.99, 1.00]), attention toward smoking (VP: OR = 1.00, 95% CI [0.99, 1.02]; Stroop: OR = 1.00, 95% CI [0.99, 1.00]), or craving (VP: OR = 1.00, 95% CI [0.99, 1.02]; Stroop: OR = 1.00, 95% CI [0.99, 1.01]). EMA responses to seeing a smoking cue (OR = 1.94, 95% CI [1.74, 2.16]) and attention toward smoking (OR = 3.69, 95% CI [3.42, 3.98]) were associated with craving. Internal reliability was higher for the Stroop (α = .75) than visual probe task (α = .20). In smokers attempting cessation, clinic measures of attentional bias do not predict noticing smoking cues, focus on smoking, or craving. However, associations exist between noticing smoking cues, attention toward smoking, and craving assessed in the moment, suggesting that attentional bias may not be a stable trait. (PsycINFO Database Recor
The development and validation of a human screening model of tobacco abstinence
Introduction
Given the low efficacy of smoking cessation methods, an experimental medicine model indicating smoking abstinence would be of great benefit to the development of new treatments. Hence the sensitivity of cognitive tasks and ambulatory craving measures to smoking abstinence were investigated.
Methods
Cognitive tasks and ambulatory ratings of craving were assessed for sensitivity to acute abstinence (experiment 1), and nicotine replacement therapy administration (NRT) (experiment 2).
Results
In experiment 1 go/no-go performance was improved (Mean Difference [MD] -0.99, 95% CI: −1.90 to −0.08) and craving was lower (Regression Coefficient [RC] −33.39, 95% CI: -39.96 to -26.82) in satiated compared with abstinent smokers. There was no clear evidence that N-back (MD 0.64, 95% CI: −0.42 to 2.51), delay discounting (MD 0.01, 95% CI: 0.001 to 0.005) or dot probe performance (MD 0.61, 95% CI: −0.87 to 1.54) were sensitive to acute abstinence. In experiment 2 go/no-go performance was improved (MD 1.12, 95% CI: 0.16–2.08) and craving was lower (RC −18.59, 95% CI: −24.63 to −12.55) smokers abstinent overnight receiving NRT compared with placebo. There was no clear evidence that N-back (MD −0.25, 95% CI: −1.45 to 0.94), delay discounting (MD 0.01, 95% CI: -0.002 to 0.004) or dot probe performance (MD −0.49, 95% CI: −1.61 to −0.64) were sensitive to NRT.
Conclusions
Findings from two experiments converge to suggest that abstinence in smokers reliably increases ambulatory craving assessments and, to a lesser extent, decreases go/no-go task performance. These findings can be utilized in the development of an experimental medicine model to test novel treatments for smoking cessation
Physical activity when young provides lifelong benefits to cortical bone size and strength in men
The skeleton shows greatest plasticity to physical activity-related mechanical loads during youth but is more at risk for failure during aging. Do the skeletal benefits of physical activity during youth persist with aging? To address this question, we used a uniquely controlled cross-sectional study design in which we compared the throwing-to-nonthrowing arm differences in humeral diaphysis bone properties in professional baseball players at different stages of their careers (n = 103) with dominant-to-nondominant arm differences in controls (n = 94). Throwing-related physical activity introduced extreme loading to the humeral diaphysis and nearly doubled its strength. Once throwing activities ceased, the cortical bone mass, area, and thickness benefits of physical activity during youth were gradually lost because of greater medullary expansion and cortical trabecularization. However, half of the bone size (total cross-sectional area) and one-third of the bone strength (polar moment of inertia) benefits of throwing-related physical activity during youth were maintained lifelong. In players who continued throwing during aging, some cortical bone mass and more strength benefits of the physical activity during youth were maintained as a result of less medullary expansion and cortical trabecularization. These data indicate that the old adage of “use it or lose it” is not entirely applicable to the skeleton and that physical activity during youth should be encouraged for lifelong bone health, with the focus being optimization of bone size and strength rather than the current paradigm of increasing mass. The data also indicate that physical activity should be encouraged during aging to reduce skeletal structural decay
Does physical activity counselling enhance the effects of a pedometer-based intervention over the long-term : 12-month findings from the Walking for Wellbeing in the West study
Peer reviewedPublisher PD
Effects of the pattern of glucocorticoid replacement on neural processing, emotional reactivity and well-being in healthy male individuals:study protocol for a randomised controlled trial
BACKGROUND: Deviation from the physiological glucocorticoid dynamics (circadian and underlying ultradian rhythmicity) is a common characteristic of various neuropsychiatric and endocrine disorders as well as glucocorticoid-based therapeutics. These states may be accompanied by neuropsychiatric symptomatology, suggesting continuous dynamic glucocorticoid equilibrium is essential for brain homeostasis. METHODS/DESIGN: The study consists of two parts. The preliminary stage of the study aims to validate (technically and pharmacologically) and optimise three different patterns of systemic cortisol administration in man. These patterns are based on the combinatory administration of metyrapone, to suppress endogenous cortisol production, and concurrent hydrocortisone replacement. The second, subsequent, core part of the study is a randomised, double-blinded, placebo-controlled, crossover study, where participants (healthy male individuals aged 18–60 years) will undergo all three hydrocortisone replacement schemes. During these infusion regimes, we plan a number of neurobehavioural tests and imaging of the brain to assess neural processing, emotional reactivity and perception, mood and self-perceived well-being. The psychological tests include: ecological momentary assessment, P1vital Oxford Emotional Test Battery and Emotional Potentiated Startle Test, Leeds Sleep Evaluation Questionnaire and the visual working memory task (n-back). The neuroimaging protocol combines magnetic resonance sequences that capture data related to the functional and perfusion status of the brain. DISCUSSION: Results of this clinical trial are designed to evaluate the impact (with possible mechanistic insights) of different patterns of daily glucocorticoid dynamics on neural processing and reactivity related to emotional perception and mood. This evidence should contribute to the optimisation of the clinical application of glucocorticoid-based therapeutics. TRIAL REGISTRATION: UK Clinical Research Network, IRAS Ref: 106181, UKCRN-ID-15236 (23 October 2013
Social comparison based relaying in device-to-device networks
Device-to-device (D2D) communications are recognized as a key component of future wireless networks which will help to improve spectral efficiency and network densification simultaneously. In order to guarantee a quality of service (QoS) to the cellular links, the transmit power of the D2D nodes needs to be restricted, which has lead to a poor link quality over D2D transmission. One viable option to improve the D2D link quality is incorporating cooperative relays into D2D networks. However most of the existing published work in relay assisted D2D networks has assumed that relay nodes cooperate spontaneously. This cannot always be guaranteed and we take this into account by considering a fundamental model on which donation-based cooperation depends. In par- ticular we model relay cooperation as a donation game based on social comparison and characterize cooperation probability in an evolutionary context. When applying this model we evaluate the outage and capacity of relay assisted D2D network using a stochastic geometric framework
The HIPASS Catalogue - II. Completeness, Reliability, and Parameter Accuracy
The HI Parkes All Sky Survey (HIPASS) is a blind extragalactic HI 21-cm
emission line survey covering the whole southern sky from declination -90 to
+25. The HIPASS catalogue (HICAT), containing 4315 HI-selected galaxies from
the region south of declination +2, is presented in Meyer et al. (2004a, Paper
I). This paper describes in detail the completeness and reliability of HICAT,
which are calculated from the recovery rate of synthetic sources and follow-up
observations, respectively. HICAT is found to be 99 per cent complete at a peak
flux of 84 mJy and an integrated flux of 9.4 Jy km/s. The overall reliability
is 95 per cent, but rises to 99 per cent for sources with peak fluxes >58 mJy
or integrated flux > 8.2 Jy km/s. Expressions are derived for the uncertainties
on the most important HICAT parameters: peak flux, integrated flux, velocity
width, and recessional velocity. The errors on HICAT parameters are dominated
by the noise in the HIPASS data, rather than by the parametrization procedure.Comment: Accepted for publication in MNRAS. 12 pages, 11 figures. Paper with
higher resolution figures can be downloaded from http://hipass.aus-vo.or
Using observational data to estimate an upper bound on the reduction in cancer mortality due to periodic screening
BACKGROUND: Because randomized cancer screening trials are very expensive, observational cancer screening studies can play an important role in the early phases of screening evaluation. Periodic screening evaluation (PSE) is a methodology for estimating the reduction in population cancer mortality from data on subjects who receive regularly scheduled screens. Although PSE does not require assumptions about natural history of cancer it requires other assumptions, particularly progressive detection – the assumption that once a cancer is detected by a screening test, it will always be detected by the screening test. METHODS: We formulate a simple version of PSE and show that it leads to an upper bound on screening efficacy if the progressive detection assumption does not hold (and any effect of birth cohort is minimal) To determine if the upper bound is reasonable, for three randomized screening trials, we compared PSE estimates based only on screened subjects with PSE estimates based on all subjects. RESULTS: In the three randomized screening trials, PSE estimates based on screened subjects gave fairly close results to PSE estimates based on all subjects. CONCLUSION: PSE has promise for obtaining an upper bound on the reduction in population cancer mortality rates based on observational screening data. If the upper bound estimate is found to be small and any birth cohort effects are likely minimal, then a definitive randomized trial would not be warranted
Superconductivity in Weyl Semimetal Candidate MoTe2
In recent years, layered transition-metal dichalcogenides (TMDs) have
attracted considerable attention because of their rich physics; for example,
these materials exhibit superconductivity, charge density waves, and the valley
Hall effect. As a result, TMDs have promising potential applications in
electronics, catalysis, and spintronics. Despite the fact that the majority of
related research focuses on semiconducting TMDs (e.g., MoS2), the
characteristics of WTe2 are provoking strong interest in semimetallic TMDs with
extremely large magnetoresistance, pressure-driven superconductivity, and the
predicted Weyl semimetal (WSM) state. In this work, we investigate the sister
compound of WTe2, MoTe2, which is also predicted to be a WSM and a quantum spin
Hall insulator in bulk and monolayer form, respectively. We find that MoTe2
exhibits superconductivity with a resistive transition temperature Tc of 0.1 K.
The application of a small pressure (such as 0.4 GPa) is shown to dramatically
enhance the Tc, with a maximum value of 8.2 K being obtained at 11.7 GPa (a
more than 80-fold increase in Tc). This yields a dome-shaped superconducting
phase diagram. Further explorations into the nature of the superconductivity in
this system may provide insights into the interplay between strong correlations
and topological physics.Comment: 20 pages, 5 figure
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