135 research outputs found
Adolescents’ responses to the promotion and flavouring of e-cigarettes
Objectives
The purpose of the study is to examine adolescents’ awareness of e-cigarette marketing and investigate the impact of e-cigarette flavour descriptors on perceptions of product harm and user image.
Methods
Data come from the 2014 Youth Tobacco Policy Survey, a cross-sectional in-home survey conducted with 11–16 year olds across the UK (n = 1205). Adolescents’ awareness of e-cigarette promotion, brands, and flavours was assessed. Perceptions of product harm, and likely user of four examples of e-cigarette flavours was also examined.
Results
Some participants had tried e-cigarettes (12 %) but regular use was low (2 %) and confined to adolescents who had also smoked tobacco. Most were aware of at least one promotional channel (82 %) and that e-cigarettes came in different flavours (69 %). Brand awareness was low. E-cigarettes were perceived as harmful (M = 3.54, SD = 1.19) but this was moderated by product flavours. Fruit and sweet flavours were perceived as more likely to be tried by young never smokers than adult smokers trying to quit (p < 0.001).
Conclusions
There is a need to monitor the impact of future market and regulatory change on youth uptake and perceptions of e-cigarettes
Top mass dependent alpha_s^3 corrections to B-meson mixing in the MSSM
We compute the top mass dependent NLO strong interaction matching conditions
to the Delta F=2 effective Hamiltonian in the general MSSM. We study the
relevance of such corrections, comparing its size with that of previously known
NLO corrections in the limit mt->0, in scenarios with degeneracy, alignment,
and hierarchical squarks. We find that, while these corrections are generally
small, there are regions in the parameter space where the contributions to the
Wilson coefficients C1 and C4 could partially overcome the expected suppression
m_t/M_SUSY.Comment: 15 pages, 6 figure
Minimal Flavour Violation with hierarchical squark masses
In a supersymmetric model with hierarchical squark masses we analyze a
pattern of flavour symmetry breaking centered on the special role of the top
Yukawa coupling and, by extension, of the full Yukawa couplings for the up-type
quarks. For sufficiently heavy squarks of the first and second generation this
leads to effective Minimal Flavour Violation of the Flavour Changing Neutral
Current amplitudes. For this to happen we determine the bounds on the masses of
the heavy squarks with QCD corrections taken into account, properly including
previously neglected effects. We believe that the view presented in this paper
altogether strengthens the case for hierarchical sfermions.Comment: 13 pages, 1 figure. v2: an equation correcte
Protocol for Nearly Full-Length Sequencing of HIV-1 RNA from Plasma
Nearly full-length genome sequencing of HIV-1 using peripheral blood mononuclear cells (PBMC) DNA as a template for PCR is now a relatively routine laboratory procedure. However, this has not been the case when using virion RNA as the template and this has made full genome analysis of circulating viruses difficult. Therefore, a well-developed procedure for sequencing of full-length HIV-1 RNA directly from plasma was needed. Plasma from U.S. donors representing a range of viral loads (VL) was used to develop the assay. RNA was extracted from plasma and reverse-transcribed. Two or three overlapping regions were PCR amplified to cover the entire viral genome and sequenced for verification. The success of the procedure was sensitive to VL but was routinely successful for VL greater than 105 and the rate declined in proportion to the VL. While the two-amplicon strategy had an advantage of increasing the possibility of amplifying a single species of HIV-1, the three-amplicon strategy was more successful in amplifying samples with low viral loads. This protocol provides a useful tool for molecular analysis to understand the HIV epidemic and pathogenesis, as well as diagnosis, therapy and future vaccine strategies
Plantar calcaneal spurs in older people: longitudinal traction or vertical compression?
<p>Abstract</p> <p>Background</p> <p>Plantar calcaneal spurs are common, however their pathophysiology is poorly understood. This study aimed to evaluate the prevalence and correlates of plantar calcaneal spurs in a large sample of older people.</p> <p>Methods</p> <p>Weightbearing lateral foot radiographs of 216 people (140 women and 76 men) aged 62 to 94 years (mean age 75.9, <smcaps>SD</smcaps> 6.6) were examined for plantar calcaneal and Achilles tendon spurs. Associations between the presence of spurs and sex, body mass index, radiographic measures of foot posture, self-reported co-morbidities and current or previous heel pain were then explored.</p> <p>Results</p> <p>Of the 216 participants, 119 (55%) had at least one plantar calcaneal spur and 103 (48%) had at least one Achilles tendon spur. Those with plantar calcaneal spurs were more likely to have Achilles tendon spurs (odds ratio [OR] = 2.0, 95% confidence interval [CI] 1.2 to 3.5). Prevalence of spurs did not differ according to sex. Participants with plantar calcaneal spurs were more likely to be obese (OR = 7.9, 95% CI 3.6 to 17.0), report osteoarthritis (OR = 2.6, 95% CI 1.6 to 4.8) and have current or previous heel pain (OR = 4.6, 95% CI 2.3 to 9.4). No relationship was found between the presence of calcaneal spurs and radiographic measures of foot posture.</p> <p>Conclusion</p> <p>Calcaneal spurs are common in older men and women and are related to obesity, osteoarthritis and current or previous heel pain, but are unrelated to radiographic measurements of foot posture. These findings support the theory that plantar calcaneal spurs may be an adaptive response to vertical compression of the heel rather than longitudinal traction at the calcaneal enthesis.</p
Unifying view of mechanical and functional hotspots across class A GPCRs
G protein-coupled receptors (GPCRs) are the largest superfamily of signaling proteins. Their activation process is accompanied by conformational changes that have not yet been fully uncovered. Here, we carry out a novel comparative analysis of internal structural fluctuations across a variety of receptors from class A GPCRs, which currently has the richest structural coverage. We infer the local mechanical couplings underpinning the receptors' functional dynamics and finally identify those amino acids whose virtual deletion causes a significant softening of the mechanical network. The relevance of these amino acids is demonstrated by their overlap with those known to be crucial for GPCR function, based on static structural criteria. The differences with the latter set allow us to identify those sites whose functional role is more clearly detected by considering dynamical and mechanical properties. Of these sites with a genuine mechanical/dynamical character, the top ranking is amino acid 7x52, a previously unexplored, and experimentally verifiable key site for GPCR conformational response to ligand binding. \ua9 2017 Ponzoni et al
Immaturity of the Oculomotor Saccade and Vergence Interaction in Dyslexic Children: Evidence from a Reading and Visual Search Study
Studies comparing binocular eye movements during reading and visual search in dyslexic children are, at our knowledge, inexistent. In the present study we examined ocular motor characteristics in dyslexic children versus two groups of non dyslexic children with chronological/reading age-matched. Binocular eye movements were recorded by an infrared system (mobileEBT®, e(ye)BRAIN) in twelve dyslexic children (mean age 11 years old) and a group of chronological age-matched (N = 9) and reading age-matched (N = 10) non dyslexic children. Two visual tasks were used: text reading and visual search. Independently of the task, the ocular motor behavior in dyslexic children is similar to those reported in reading age-matched non dyslexic children: many and longer fixations as well as poor quality of binocular coordination during and after the saccades. In contrast, chronological age-matched non dyslexic children showed a small number of fixations and short duration of fixations in reading task with respect to visual search task; furthermore their saccades were well yoked in both tasks. The atypical eye movement's patterns observed in dyslexic children suggest a deficiency in the visual attentional processing as well as an immaturity of the ocular motor saccade and vergence systems interaction
Co-existence of physiologically similar sulfate-reducing bacteria in a full-scale sulfidogenic bioreactor fed with a single organic electron donor
A combination of culture-dependent and independent methods was used to study the co-existence of different sulfate-reducing bacteria (SRB) in an upflow anaerobic sludge bed reactor treating sulfate-rich wastewater. The wastewater was fed with ethanol as an external electron donor. Twenty six strains of SRB were randomly picked and isolated from the highest serial dilution that showed growth (i.e. 108). Repetitive enterobacterial palindromic polymerase chain reaction and whole cell protein profiling revealed a low genetic diversity, with only two genotypes among the 26 strains obtained in the pure culture. The low genetic diversity suggests the absence of micro-niches within the reactor, which might be due to a low spatial and temporal micro-heterogeneity. The total 16S rDNA sequencing of two representative strains L3 and L7 indicated a close relatedness to the genus Desulfovibrio. The two strains differed in as many as five physiological traits, which might allow them to occupy distinct niches and thus co-exist within the same habitat. Whole cell hybridisation with fluorescently labeled oligonucleotide probes was performed to characterise the SRB community in the reactor. The isolated strains Desulfovibrio L3 and Desulfovibrio L7 were the most dominant SRB, representing 30–35% and 25–35%, respectively, of the total SRB community. Desulfobulbus-like bacteria contributed for 20–25%, and the Desulfobacca acetoxidans-specific probe targeted approximately 15–20% of the total SRB. The whole cell hybridisation results thus revealed a consortium of four different species of SRB that can be enriched and maintained on a single energy source in a full-scale sulfidogenic reactor
Unraveling the Regulatory Mechanisms Underlying Tissue-Dependent Genetic Variation of Gene Expression
It is known that genetic variants can affect gene expression, but it is not yet completely clear through what mechanisms genetic variation mediate this expression. We therefore compared the cis-effect of single nucleotide polymorphisms (SNPs) on gene expression between blood samples from 1,240 human subjects and four primary non-blood tissues (liver, subcutaneous, and visceral adipose tissue and skeletal muscle) from 85 subjects. We characterized four different mechanisms for 2,072 probes that show tissue-dependent genetic regulation between blood and non-blood tissues: on average 33.2% only showed cis-regulation in non-blood tissues; 14.5% of the eQTL probes were regulated by different, independent SNPs depending on the tissue of investigation. 47.9% showed a different effect size although they were regulated by the same SNPs. Surprisingly, we observed that 4.4% were regulated by the same SNP but with opposite allelic direction. We show here that SNPs that are located in transcriptional regulatory elements are enriched for tissue-dependent regulation, including SNPs at 3′ and 5′ untranslated regions (P = 1.84×10−5 and 4.7×10−4, respectively) and SNPs that are synonymous-coding (P = 9.9×10−4). SNPs that are associated with complex traits more often exert a tissue-dependent effect on gene expression (P = 2.6×10−10). Our study yields new insights into the genetic basis of tissue-dependent expression and suggests that complex trait associated genetic variants have even more complex regulatory effects than previously anticipated
Thermostable DNA Polymerase from a Viral Metagenome Is a Potent RT-PCR Enzyme
Viral metagenomic libraries are a promising but previously untapped source of new reagent enzymes. Deep sequencing and functional screening of viral metagenomic DNA from a near-boiling thermal pool identified clones expressing thermostable DNA polymerase (Pol) activity. Among these, 3173 Pol demonstrated both high thermostability and innate reverse transcriptase (RT) activity. We describe the biochemistry of 3173 Pol and report its use in single-enzyme reverse transcription PCR (RT-PCR). Wild-type 3173 Pol contains a proofreading 3′-5′ exonuclease domain that confers high fidelity in PCR. An easier-to-use exonuclease-deficient derivative was incorporated into a PyroScript RT-PCR master mix and compared to one-enzyme (Tth) and two-enzyme (MMLV RT/Taq) RT-PCR systems for quantitative detection of MS2 RNA, influenza A RNA, and mRNA targets. Specificity and sensitivity of 3173 Pol-based RT-PCR were higher than Tth Pol and comparable to three common two-enzyme systems. The performance and simplified set-up make this enzyme a potential alternative for research and molecular diagnostics
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