838 research outputs found

    Introduction to a generalized method for adaptive randomization in trials

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    Differential expression analysis for sequence count data

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    *Motivation:* High-throughput nucleotide sequencing provides quantitative readouts in assays for RNA expression (RNA-Seq), protein-DNA binding (ChIP-Seq) or cell counting (barcode sequencing). Statistical inference of differential signal in such data requires estimation of their variability throughout the dynamic range. When the number of replicates is small, error modelling is needed to achieve statistical power.

*Results:* We propose an error model that uses the negative binomial distribution, with variance and mean linked by local regression, to model the null distribution of the count data. The method controls type-I error and provides good detection power. 

*Availability:* A free open-source R software package, _DESeq_, is available from the Bioconductor project and from "http://www-huber.embl.de/users/anders/DESeq":http://www-huber.embl.de/users/anders/DESeq

    Developing an award program for children's settings to support healthy eating and physical activity and reduce the risk of overweight and obesity

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    <p>Abstract</p> <p>Background</p> <p>This paper aimed to identify the best way to engage, motivate and support early childhood services (ECS) and primary schools (PS) to create policy and practise changes to promote healthy eating and physical activity. This information would be used to develop a suitable program to implement within these children's settings to reduce the risk of childhood overweight and obesity.</p> <p>Methods</p> <p>The Medical Research Council's (UK) framework for the design and evaluation of complex interventions was used to guide the development of the healthy eating and physical activity program suitable for ECS and PS. Within this framework a range of evaluation methods, including stakeholder planning, in-depth interviews with ECS and PS staff and acceptability and feasibility trials in one local government area, were used to ascertain the best way to engage and support positive changes in these children's settings.</p> <p>Results</p> <p>Both ECS and PS identified that they had a role to play to improve children's healthy eating and physical activity. ECS identified their role in promoting healthy eating and physical activity as important for children's health, and instilling healthy habits for life. PS felt that these were health issues, rather than educational issues; however, schools saw the link between healthy eating and physical activity and student learning outcomes. These settings identified that a program that provides a simple guide that recognises good practise in these settings, such as an award scheme using a health promoting schools approach, as a feasible and acceptable way for them to support children's healthy eating and physical activity.</p> <p>Conclusion</p> <p>Through the process of design and evaluation a program - <it>Kids - 'Go for your life'</it>, was developed to promote and support children's healthy eating and physical activity and reduce the risk of childhood overweight and obesity. <it>Kids - 'Go for your life' </it>used an award program, based on a health promoting schools approach, which was demonstrated to be a suitable model to engage ECS and PS and was acceptable and feasible to create policy and practise changes to support healthy eating and physical activity for children.</p

    The use of caspase inhibitors in pulsed-field gel electrophoresis may improve the estimation of radiation-induced DNA repair and apoptosis

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    <p>Abstract</p> <p>Background</p> <p>Radiation-induced DNA double-strand break (DSB) repair can be tested by using pulsed-field gel electrophoresis (PFGE) in agarose-encapsulated cells. However, previous studies have reported that this assay is impaired by the spontaneous DNA breakage in this medium. We investigated the mechanisms of this fragmentation with the principal aim of eliminating it in order to improve the estimation of radiation-induced DNA repair.</p> <p>Methods</p> <p>Samples from cancer cell cultures or xenografted tumours were encapsulated in agarose plugs. The cell plugs were then irradiated, incubated to allow them to repair, and evaluated by PFGE, caspase-3, and histone H2AX activation (ÎłH2AX). In addition, apoptosis inhibition was evaluated through chemical caspase inhibitors.</p> <p>Results</p> <p>We confirmed that spontaneous DNA fragmentation was associated with the process of encapsulation, regardless of whether cells were irradiated or not. This DNA fragmentation was also correlated to apoptosis activation in a fraction of the cells encapsulated in agarose, while non-apoptotic cell fraction could rejoin DNA fragments as was measured by ÎłH2AX decrease and PFGE data. We were able to eliminate interference of apoptosis by applying specific caspase inhibitors, and improve the estimation of DNA repair, and apoptosis itself.</p> <p>Conclusions</p> <p>The estimation of radiation-induced DNA repair by PFGE may be improved by the use of apoptosis inhibitors. The ability to simultaneously determine DNA repair and apoptosis, which are involved in cell fate, provides new insights for using the PFGE methodology as functional assay.</p

    Differential modulation of corticospinal excitability during haptic sensing of 2-D patterns vs. textures

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    <p>Abstract</p> <p>Background</p> <p>Recently, we showed a selective enhancement in corticospinal excitability when participants actively discriminated raised 2-D symbols with the index finger. This extra-facilitation likely reflected activation in the premotor and dorsal prefrontal cortices modulating motor cortical activity during attention to haptic sensing. However, this parieto-frontal network appears to be finely modulated depending upon whether haptic sensing is directed towards material or geometric properties. To examine this issue, we contrasted changes in corticospinal excitability when young adults (n = 18) were engaged in either a roughness discrimination on two gratings with different spatial periods, or a 2-D pattern discrimination of the relative offset in the alignment of a row of small circles in the upward or downward direction.</p> <p>Results</p> <p>A significant effect of task conditions was detected on motor evoked potential amplitudes, reflecting the observation that corticospinal facilitation was, on average, ~18% greater in the pattern discrimination than in the roughness discrimination.</p> <p>Conclusions</p> <p>This differential modulation of corticospinal excitability during haptic sensing of 2-D patterns vs. roughness is consistent with the existence of preferred activation of a visuo-haptic cortical dorsal stream network including frontal motor areas during spatial vs. intensive processing of surface properties in the haptic system.</p

    Genotype x environment interactions in eggplant for fruit phenolic acid content

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    Eggplant fruit are a rich source of phenolic acids that influence fruit culinary quality and antioxidant content. We evaluated the influence of production environments and stability of diverse genotypes across environments for eggplant fruit phenolic acid content. Ten Solanum melongena accessions consisting of five F-1 hybrid cultivars, three open-pollinated cultivars and two land race accessions, plus one S. macrocarpon and one S. aethiopicum accession, were grown at two locations under greenhouse and open field environments. Twenty phenolic acid conjugates were identified in fruit flesh and assigned to six classes that included hydroxycinnamic acid amides, caffeoylquinic acid esters, hydroxycinnamoylquinic acid esters, malonylcaffeoylquinic acid esters, di-hydroxycinnamoylquinic acid esters, and other hydroxycinnamic acid conjugates. There were significant differences among accessions for total phenolic acid conjugate content and for all six classes. There were no significant differences detected among the environments for any of the variables. However, the environment x accession interaction was highly significant for all phenolic acid classes. Broad-sense heritability estimates for all six phenolic acid classes were high, ranging from 0.64 to 0.96. Stability analysis demonstrated widespread instability for phenolic acid content across environments. Stability of the predominant caffeoylquinic acid esters class positively influenced stability of total phenolic acid content for some but not all genotypes. High heritability, coupled with highly significant genotype x environment interactions suggests that stability estimates may improve the efficiency of breeding new genotypes with predictable performance across environments.Stommel, JR.; Whitaker, B.; Haynes, K.; Prohens Tomás, J. (2015). Genotype x environment interactions in eggplant for fruit phenolic acid content. 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    Search for time-dependent B0s - B0s-bar oscillations using a vertex charge dipole technique

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    We report a search for B0s - B0s-bar oscillations using a sample of 400,000 hadronic Z0 decays collected by the SLD experiment. The analysis takes advantage of the electron beam polarization as well as information from the hemisphere opposite that of the reconstructed B decay to tag the B production flavor. The excellent resolution provided by the pixel CCD vertex detector is exploited to cleanly reconstruct both B and cascade D decay vertices, and tag the B decay flavor from the charge difference between them. We exclude the following values of the B0s - B0s-bar oscillation frequency: Delta m_s < 4.9 ps-1 and 7.9 < Delta m_s < 10.3 ps-1 at the 95% confidence level.Comment: 18 pages, 3 figures, replaced by version accepted for publication in Phys.Rev.D; results differ slightly from first versio

    Lunar exploration: opening a window into the history and evolution of the inner Solar System

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    The lunar geological record contains a rich archive of the history of the inner Solar System, including information relevant to understanding the origin and evolution of the Earth-Moon system, the geological evolution of rocky planets, and our local cosmic environment. This paper provides a brief review of lunar exploration to-date, and describes how future exploration initiatives will further advance our understanding of the origin and evolution of the Moon, the Earth-Moon system, and of the Solar System more generally. It is concluded that further advances will require the placing of new scientific instruments on, and the return of additional samples from, the lunar surface. Some of these scientific objectives can be achieved robotically, for example by in situ geochemical and geophysical measurements and through carefully targeted sample return missions. However, in the longer term, we argue that lunar science would greatly benefit from renewed human operations on the surface of the Moon, such as would be facilitated by implementing the recently proposed Global Exploration Roadmap

    Autism as a disorder of neural information processing: directions for research and targets for therapy

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    The broad variation in phenotypes and severities within autism spectrum disorders suggests the involvement of multiple predisposing factors, interacting in complex ways with normal developmental courses and gradients. Identification of these factors, and the common developmental path into which theyfeed, is hampered bythe large degrees of convergence from causal factors to altered brain development, and divergence from abnormal brain development into altered cognition and behaviour. Genetic, neurochemical, neuroimaging and behavioural findings on autism, as well as studies of normal development and of genetic syndromes that share symptoms with autism, offer hypotheses as to the nature of causal factors and their possible effects on the structure and dynamics of neural systems. Such alterations in neural properties may in turn perturb activity-dependent development, giving rise to a complex behavioural syndrome many steps removed from the root causes. Animal models based on genetic, neurochemical, neurophysiological, and behavioural manipulations offer the possibility of exploring these developmental processes in detail, as do human studies addressing endophenotypes beyond the diagnosis itself
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