2,802 research outputs found

    The association between habitual physical activity and cigarette cravings, and influence of smokers' characteristics in disadvantaged smokers not ready to quit.

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    RATIONALE: Habitual physical activity (PA) may have an important role in suppressing cigarette cravings. Systematic reviews show a strong acute effect of bouts of PA on reducing cigarette cravings, and it may be that these effects accumulate. OBJECTIVES: The aim was to investigate the relationship between habitual levels of PA and cigarette cravings in disadvantaged smokers not ready to quit by examining baseline cross-sectional data from the Exercise Assisted Reduction then Stop smoking study (EARS). METHODS: A series of linear regression models were applied to investigate the relationship between habitual PA and cigarette cravings and to identify additional predictors of cigarette cravings. The analyses were extended by including interaction terms with PA to identify potential moderators of the relationship between PA and cravings. RESULTS: A higher level of moderate intensity PA was associated with lower cravings (p = 0.033). Additional predictors were the mood and physical symptoms scale (p = 0.007; higher scores were associated with higher cravings) and alcohol consumption (p = 0.002; higher consumption was associated with lower cravings). In addition, a moderation effect of alcohol consumption was found; at higher levels of alcohol consumption, higher PA was significantly associated with higher cravings (p = 0.023). CONCLUSIONS: Overall, participation in regular PA is associated with reduced cigarette cravings; among those with heavy alcohol consumption, this participation is associated with higher cravings. These exploratory analyses suggest that further research into the relationship between PA, alcohol consumption and cigarette cravings is needed

    First record of the bacterial endosymbiont Wolbachia for phytophagous hoverflies from genus Merodon (Diptera : Syrphidae)

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    Wolbachia is a widespread bacterial endosymbiont among arthropod species. It influences the reproduction of the host species and also mitochondrial DNA diversity. Until now there were only a few studies that detected Wolbachia infections in hoverflies (Diptera: Syrphidae), and this is the first broader study with the aim of examining the incidence of Wolbachia in the hoverfly genus Merodon. The obtained results indicate an infection rate of 96% and the presence of both Wolbachia supergroup A and B, which are characteristic for most of the infected arthropod species. Additionally, the presence of multiple Wolbachia strains in the Merodon aureus group species was detected and the mitochondrial DNA COI-based relationships of the group are discussed in the light of infection. Finally, we discuss plant-mediated horizontal transmission of Wolbachia strains among the studied hoverfly species.Peer reviewe

    Molecular dynamics simulations of oscillatory Couette flows with slip boundary conditions

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    The effect of interfacial slip on steady-state and time-periodic flows of monatomic liquids is investigated using non-equilibrium molecular dynamics simulations. The fluid phase is confined between atomically smooth rigid walls, and the fluid flows are induced by moving one of the walls. In steady shear flows, the slip length increases almost linearly with shear rate. We found that the velocity profiles in oscillatory flows are well described by the Stokes flow solution with the slip length that depends on the local shear rate. Interestingly, the rate dependence of the slip length obtained in steady shear flows is recovered when the slip length in oscillatory flows is plotted as a function of the local shear rate magnitude. For both types of flows, the friction coefficient at the liquid-solid interface correlates well with the structure of the first fluid layer near the solid wall.Comment: 31 pages, 11 figure

    Crack Length Determination by Ultrasonic Methods

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    Accurate calculation of the stress intensity factor on a given component under load relies on an accurate size determination of the flaws present in the component. The challenge to the NDE community has been development of reliable techniques to provide that accurate size determination. Many research groups have investigated this problem using ultrasonic methods with summaries of their techniques and results provided by various authors [1–3]. In general, the techniques developed fall into three general categories; (1) determination of crack length from signal amplitude measurements, (2) determination of crack length from time-of-flight measurements, and (3) determination of crack length using diffracted waves. Sketches of representative techniques in each category are shown in Figure 1

    Factors associated with study attrition in a pilot randomised controlled trial to explore the role of exercise-assisted reduction to stop (EARS) smoking in disadvantaged groups.

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    BACKGROUND: Study attrition has the potential to compromise a trial's internal and external validity. The aim of the present study was to identify factors associated with participant attrition in a pilot trial of the effectiveness of a novel behavioural support intervention focused on increasing physical activity to reduce smoking, to inform the methods to reduce attrition in a definitive trial. METHODS: Disadvantaged smokers who wanted to reduce but not quit were randomised (N = 99), of whom 61 (62 %) completed follow-up assessments at 16 weeks. Univariable logistic regression was conducted to determine the effects of intervention arm, method of recruitment, and participant characteristics (sociodemographic factors, and lifestyle, behavioural and attitudinal characteristics) on attrition, followed by multivariable logistic regression on those factors found to be related to attrition. RESULTS: Participants with low confidence to quit, and who were undertaking less than 150 mins of moderate and vigorous physical activity per week at baseline were less likely to complete the 16-week follow-up assessment. Exploratory analysis revealed that those who were lost to follow-up early in the trial (i.e., by 4 weeks), compared with those completing the study, were younger, had smoked for fewer years and had lower confidence to quit in the next 6 months. Participants who recorded a higher expired air carbon monoxide reading at baseline were more likely to drop out late in the study, as were those recruited via follow-up telephone calls. Multivariable analyses showed that only completing less than 150 mins of physical activity retained any confidence in predicting attrition in the presence of other variables. CONCLUSIONS: The findings indicate that those who take more effort to be recruited, are younger, are heavier smokers, have less confidence to quit, and are less physically active are more likely to withdraw or be lost to follow-up

    Extreme dimensionality reduction with quantum modeling

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    Effective and efficient forecasting relies on identification of the relevant information contained in past observations—the predictive features—and isolating it from the rest. When the future of a process bears a strong dependence on its behavior far into the past, there are many such features to store, necessitating complex models with extensive memories. Here, we highlight a family of stochastic processes whose minimal classical models must devote unboundedly many bits to tracking the past. For this family, we identify quantum models of equal accuracy that can store all relevant information within a single two-dimensional quantum system (qubit). This represents the ultimate limit of quantum compression and highlights an immense practical advantage of quantum technologies for the forecasting and simulation of complex systems

    An Exploratory Analysis of the Smoking and Physical Activity Outcomes From a Pilot Randomized Controlled Trial of an Exercise Assisted Reduction to Stop Smoking Intervention in Disadvantaged Groups.

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    INTRODUCTION: Economically disadvantaged smokers not intending to stop may benefit from interventions aimed at reducing their smoking. This study assessed the effects of a behavioral intervention promoting an increase in physical activity versus usual care in a pilot randomized controlled trial. METHODS: Disadvantaged smokers who wanted to reduce but not quit were randomized to either a counseling intervention of up to 12 weeks to support smoking reduction and increased physical activity (n = 49) or usual care (n = 50). Data at 16 weeks were collected for various smoking and physical activity outcomes. Primary analyses consisted of an intention to treat analysis based on complete case data. Secondary analyses explored the impact of handling missing data. RESULTS: Compared with controls, intervention smokers were more likely to initiate a quit attempt (36 vs. 10%; odds ratio 5.05, [95% CI: 1.10; 23.15]), and a greater proportion achieved at least 50% reduction in cigarettes smoked (63 vs. 32%; 4.21 [1.32; 13.39]). Postquit abstinence measured by exhaled carbon monoxide at 4-week follow-up showed promising differences between groups (23% vs. 6%; 4.91 [0.80; 30.24]). No benefit of intervention on physical activity was found. Secondary analyses suggested that the standard missing data assumption of "missing" being equivalent to "smoking" may be conservative resulting in a reduced intervention effect. CONCLUSIONS: A smoking reduction intervention for economically disadvantaged smokers which involved personal support to increase physical activity appears to be more effective than usual care in achieving reduction and may promote cessation. The effect does not appear to be influenced by an increase in physical activity

    A pilot randomised trial to assess the methods and procedures for evaluating the clinical effectiveness and cost-effectiveness of Exercise Assisted Reduction then Stop (EARS) among disadvantaged smokers

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    types: Journal Article; Research Support, Non-U.S. Gov'tPlease cite the published version which is available via the DOI link in this record.There have been few rigorous studies on the effects of behavioural support for helping smokers to reduce who do not immediately wish to quit. While reduction may not have the health benefits of quitting, it may lead smokers to want to quit. Physical activity (PA) helps to reduce cravings and withdrawal symptoms, and also reduces weight gain after quitting, but smokers may be less inclined to exercise. There is scope to develop and determine the effectiveness of interventions to support smoking reduction and increase physical activity, for those not ready to quit.NIHR Health Technology Assessment programm

    Anchored enrichment dataset for true flies (order Diptera) reveals insights into the phylogeny of flower flies (family Syrphidae)

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    Background: Anchored hybrid enrichment is a form of next-generation sequencing that uses oligonucleotide probes to target conserved regions of the genome flanked by less conserved regions in order to acquire data useful for phylogenetic inference from a broad range of taxa. Once a probe kit is developed, anchored hybrid enrichment is superior to traditional PCR-based Sanger sequencing in terms of both the amount of genomic data that can be recovered and effective cost. Due to their incredibly diverse nature, importance as pollinators, and historical instability with regard to subfamilial and tribal classification, Syrphidae (flower flies or hoverflies) are an ideal candidate for anchored hybrid enrichment-based phylogenetics, especially since recent molecular phylogenies of the syrphids using only a few markers have resulted in highly unresolved topologies. Over 6200 syrphids are currently known and uncovering their phylogeny will help us to understand how these species have diversified, providing insight into an array of ecological processes, from the development of adult mimicry, the origin of adult migration, to pollination patterns and the evolution of larval resource utilization. Results: We present the first use of anchored hybrid enrichment in insect phylogenetics on a dataset containing 30 flower fly species from across all four subfamilies and 11 tribes out of 15. To produce a phylogenetic hypothesis, 559 loci were sampled to produce a final dataset containing 217,702 sites. We recovered a well resolved topology with bootstrap support values that were almost universally >95 %. The subfamily Eristalinae is recovered as paraphyletic, with the strongest support for this hypothesis to date. The ant predators in the Microdontinae are sister to all other syrphids. Syrphinae and Pipizinae are monophyletic and sister to each other. Larval predation on soft-bodied hemipterans evolved only once in this family. Conclusions: Anchored hybrid enrichment was successful in producing a robustly supported phylogenetic hypothesis for the syrphids. Subfamilial reconstruction is concordant with recent phylogenetic hypotheses, but with much higher support values. With the newly designed probe kit this analysis could be rapidly expanded with further sampling, opening the door to more comprehensive analyses targeting problem areas in syrphid phylogenetics and ecology.Peer reviewe

    Alginate inhibits iron absorption from ferrous gluconate in a randomized controlled trial and reduces iron uptake into Caco-2 cells

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    Previous in vitro results indicated that alginate beads might be a useful vehicle for food iron fortification. A human study was undertaken to test the hypothesis that alginate enhances iron absorption. A randomised, single blinded, cross-over trial was carried out in which iron absorption was measured from serum iron appearance after a test meal. Overnight-fasted volunteers (n=15) were given a test meal of 200g cola-flavoured jelly plus 21 mg iron as ferrous gluconate, either in alginate beads mixed into the jelly or in a capsule. Iron absorption was lower from the alginate beads than from ferrous gluconate (8.5% and 12.6% respectively, p=0.003). Sub-group B (n=9) consumed the test meals together with 600 mg calcium to determine whether alginate modified the inhibitory effect of calcium. Calcium reduced iron absorption from ferrous gluconate by 51%, from 11.5% to 5.6% (p=0.014), and from alginate beads by 37%, from 8.3% to 5.2% (p=0.009). In vitro studies using Caco-2 cells were designed to explore the reasons for the difference between the previous in vitro findings and the human study; confirmed the inhibitory effect of alginate. Beads similar to those used in the human study were subjected to simulated gastrointestinal digestion, with and without cola jelly, and the digestate applied to Caco-2 cells. Both alginate and cola jelly significantly reduced iron uptake into the cells, by 34% (p=0.009) and 35% (p=0.003) respectively. The combination of cola jelly and calcium produced a very low ferritin response, 16.5% (p<0.001) of that observed with ferrous gluconate alone. The results of these studies demonstrate that alginate beads are not a useful delivery system for soluble salts of iron for the purpose of food fortification
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