537 research outputs found
Mobilizing the genome of Lepidoptera through novel sequence gains and end creation by non-autonomous Lep1 Helitrons
Transposable elements (TEs) can affect the structure of genomes through their acquisition and transposition of novel DNA sequences. The 134-bp repetitive elements, Lep1, are conserved non-autonomous Helitrons in lepidopteran genomes that have characteristic 5\u27-CT and 3\u27-CTAY nucleotide termini, a 3\u27-terminal hairpin structure, a 5\u27- and 3\u27-subterminal inverted repeat (SIR), and integrations that occur between AT or TT nucleotides. Lep1 Helitrons have acquired and propagated sequences downstream of their 3\u27-CTAY termini that are 57-344-bp in length and have termini composed of a 3\u27-CTRR preceded by a 3\u27-hairpin structure and a region complementary to the 5\u27-SIR (3\u27-SIRb). Features of both the Lep1 Helitron and multiple acquired sequences indicate that secondary structures at the 3\u27-terminus may have a role in rolling circle replication or genome integration mechanisms, and are a prerequisite for novel end creation by Helitron-like TEs. The preferential integration of Lep1 Helitrons in proximity to gene-coding regions results in the creation of genetic novelty that is shown to impact gene structure and function through the introduction of novel exon sequence (exon shuffling). These findings are important in understanding the structural requirements of genomic DNA sequences that are acquired and transposed by Helitron-like TEs
Development of a Training Needs Assessment for an Education Scholarship Fellowship in Emergency Medicine
At the 2012 Academic Emergency Medicine consensus conference, āEducation Research in Emergency Medicine: Opportunities, Challenges, and Strategies for Success,ā a breakout session convened to discuss postgraduate fellowship training in emergency medicine ( EM ), which would focus on education research. Graduates will form a growing cadre of education scholars who conduct and publish quality education research. This proceedings article reports the consensus findings of a breakout session subgroup whose goal was to construct a needs assessment for the proposed 2āyear education scholarship fellowship. The authors describe, based on expert and participant consensus, a framework for a largeāscale, mixedāmethods needs assessment for such a fellowship.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95526/1/acem12035.pd
No Effect of a Whey Growth Factor Extract during Resistance Training on Strength, Body Composition, or Hypertrophic Gene Expression in Resistance-Trained Young Men
Growth factors can be isolated from bovine milk to form a whey growth factor extract (WGFE). This study examined whether WGFE promoted activation of the AKT/mTOR pathway enabling increased lean tissue mass and strength in resistance trained men. Forty six men with \u3e6 months of resistance training (RT) experience performed 12 weeks of RT. Participants consumed 20 g/day of whey protein and were randomised to receive either 1.6 g WGFE/day (WGFE; n = 22) or 1.6 g cellulose/day (control, CONT; n = 24). The primary outcome was leg press one-repetition maximum (LP1-RM) which was assessed at baseline, 6 and 12 weeks. At baseline and 12 weeks body composition was assessed by dual energy x-ray absorptiometry, and muscle protein synthesis and gene expression were assessed (vastus lateralis biopsy) in a sub-sample (WGFE n = 10, CONT n = 10) pre- and 3 hr post-training. RT increased LP1-RM (+34.9%) and lean tissue mass (+2.3%; p \u3c 0.05) with no difference between treatments (p \u3e 0.48, treatment x time). Post-exercise P70s6k phosphorylation increased acutely, FOXO3a phosphorylation was unaltered. There were no differences in kinase signalling or gene expression between treatments. Compared with CONT, WGFE did not result in greater increases in lean tissue mass or strength in experienced resistance trained men
Three new biological control programmes for South Africa: Brazilian pepper, Tamarix and Tradescantia
Three weed biological control (biocontrol) programmes are described, all of which are considered to be ātransfer projectsā that were initiated elsewhere, and on which South Africa has piggybacked its biocontrol efforts. Using knowledge and expertise from international collaborators, South African weed researchers are following a long tradition of transfer projects, which has been a largely successful and practical approach to biocontrol. Two Brazilian weeds, the Brazilian pepper tree Schinus terebinthifolia and the spiderwort Tradescantia fluminensis are being targeted, along with the Old-World trees Tamarix ramosissima and T. chinensis. The potential biocontrol agents are described and ranked for the two trees according to what has been discovered elsewhere, while the agent already released against T. fluminensis is rated (as poor), and other potential agents are considered. The addition of molecular techniques, climate matching and remote sensing in transfer projects can increase the chance of successful biocontrol and the inclusion of these techniques in the three new programmes is discussed. Transfer projects are a cost-effective and pragmatic way to pick winning biocontrol programmes
Willingness to participate in future HIV prevention studies among gay and bisexual men in Scotland, UK: a challenge for intervention trials
This article examines willingness to participate in future HIV prevention research among gay and bisexual men in Scotland, UK. Anonymous, self-complete questionnaires and Orasure GĆ¤Ć³ oral fluid samples were collected in commercial gay venues. 1,320 men were eligible for inclusion. 78.2% reported willingness to participate in future HIV prevention research; 64.6% for an HIV vaccine, 57.4% for a behaviour change study, and 53.0% for a rectal microbicide. In multivariate analysis, for HIV vaccine research, greater age, minority ethnicity, and not providing an oral fluid sample were associated with lower willingness; heterosexual orientation and not providing an oral fluid sample were for microbicides; higher education and greater HIV treatment optimism were for behaviour change. STI testing remained associated with being more willing to participate in microbicide research and frequent gay scene use remained associated with being more willing to participate in behaviour change research. Having an STI in the past 12 months remained significantly associated with being willing to participate in all three study types. There were no associations between sexual risk behaviour and willingness. Although most men expressed willingness to participate in future research, recruitment of high-risk men, who have the potential to benefit most, is likely to be more challenging
Effects of low-fat diets differing in protein and carbohydrate content on cardiometabolic risk factors during weight loss and weight maintenance in obese adults with type 2 diabetes
Despite evidence for the benefits of higher-protein (HP) diets in weight loss, their role in type 2 diabetes mellitus (T2DM) management and weight maintenance is not clear. This randomised study compared the effects of a HP diet (38% carbohydrate, 30% protein, 29% fat) to a isocaloric higher-carbohydrate diet (HC: 53%:21%:23%) on cardiometabolic risk factors for 12 weeks in energy restriction (~30% reduction) followed by 12 weeks of energy balance whilst performing regular exercise. Outcomes were measured at baseline and the end of each phase. Sixty-one overweight/obese adults (BMI (body mass index) 34.3 Ā± 5.1 kg/m2, aged 55 Ā± 8 years) with T2DM who commenced the study were included in the intention-to-treat analysis including the 17 participants (HP n = 9, HC n = 8) who withdrew. Following weight loss (M Ā± SEM: -7.8 Ā± 0.6 kg), there were significant reductions in HbA1c (ā1.4% Ā± 0.1%, p < 0.001) and several cardiometabolic health risk factors. Improvements were sustained for 12 weeks when weight was stabilised and weight loss maintained. Both the HP and HC dietary patterns with concurrent exercise may be effective strategies for weight loss and weight maintenance in T2DM although further studies are needed to determine the longer term effects of weight maintenance
Substrate utilisation and energy metabolism in non-growing Campylobacter jejuni M1cam
Campylobacter jejuni, the major cause of bacterial foodborne illness, is also a fastidious organism that requires strict growth requirements in the laboratory. Our aim was to study substrate utilisation and energy metabolism in non-growing C. jejuni to investigate the ability of these bacteria to survive so effectively in the food chain. We integrated phenotypic microarrays and genome-scale metabolic modelling (GSM) to investigate the survival of C. jejuni on 95 substrates. We further investigated the underlying metabolic re-adjustment associated with varying energy demands on each substrate. We identified amino acids, organic acids and H2, as single substrates supporting survival without growth. We identified several different mechanisms, which were used alone or in combination, for ATP production: substrate-level phosphorylation via acetate kinase, the TCA cycle, and oxidative phosphorylation via the electron transport chain that utilised alternative electron donors and acceptors. The benefit of ATP production through each of these mechanisms was associated with the cost of enzyme investment, nutrient availability and/or O2 utilisation. C. jejuni can utilise a wide range of substrates as energy sources, including organic acids commonly used for marination or preservation of ingredients, which might contribute to the success of their survival in changing environments
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Nanoindentation analysis of oriented polypropylene: Influence of elastic properties in tension and compression
YesPolypropylene has been oriented by solid-phase deformation processing to draw ratios up to ā¼16, increasing tensile stiffness along the draw direction by factors up to 12. Nanoindentation of these materials showed that moduli obtained for indenter tip motion along the drawing direction (3) into to 1ā2 plane (axial indentation) were up to 60% higher than for indenter tip motion along the 2 direction into the 1ā3 plane (transverse indentation). In static tests, tensile and compressive determinations of elastic modulus gave results differing by factors up to ā¼5 for strain along the draw direction. A material model incorporating both orthotropic elasticity and tension/compression asymmetry was developed for use with Finite Element simulations. Elastic constants for the oriented polypropylene were obtained by combining static testing and published ultrasonic data, and used as input for nanoindentation simulations that were quantitatively successful. The significance of the tension/compression asymmetry was demonstrated by comparing these predictions with those obtained using tensile data only, which gave predictions of indentation modulus higher by up to 70%
Itās not just what you eat but when: The impact of eating a meal during simulated shift work on driving performance
Published online: 13 Oct 2016.Shiftworkers have impaired performance when driving at night and they also alter their eating patterns during nightshifts. However, it is unknown whether driving at night is influenced by the timing of eating. This study aims to explore the effects of timing of eating on simulated driving performance across four simulated nightshifts. Healthy, non-shiftworking males aged 18-35 years (n = 10) were allocated to either an eating at night (n = 5) or no eating at night (n = 5) condition. During the simulated nightshifts at 1730, 2030 and 0300 h, participants performed a 40-min driving simulation, 3-min Psychomotor Vigilance Task (PVT-B), and recorded their ratings of sleepiness on a subjective scale. Participants had a 6-h sleep opportunity during the day (1000-1600 h). Total 24-h food intake was consistent across groups; however, those in the eating at night condition ate a large meal (30% of 24-h intake) during the nightshift at 0130 h. It was found that participants in both conditions experienced increased sleepiness and PVT-B impairments at 0300 h compared to 1730 and 2030 h (p < 0.001). Further, at 0300 h, those in the eating condition displayed a significant decrease in time spent in the safe zone (p < 0.05; percentage of time within 10 km/h of the speed limit and 0.8 m of the centre of the lane) and significant increases in speed variability (p < 0.001), subjective sleepiness (p < 0.01) and number of crashes (p < 0.01) compared to those in the no eating condition. Results suggest that, for optimal performance, shiftworkers should consider restricting food intake during the night.Charlotte C. Gupta, Jill Dorrian, Crystal L. Grant, Maja Pajcin, Alison M. Coates, David J. Kennaway, Gary A. Wittert, Leonie K. Heilbronn, Chris B. Della Vedova, and Siobhan Bank
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