3,709 research outputs found

    Sudakov Logarithm Resummation in Transverse Momentum Space for Electroweak Boson Production at Hadron Colliders

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    A complete description of W and Z boson production at high-energy hadron colliders requires the resummation of large Sudakov double logarithms which dominate the transverse momentum (q_T) distribution at small q_T. We compare different prescriptions for performing this resummation, in particular implicit impact parameter space resummation versus explicit transverse momentum space resummation. We argue that the latter method can be formulated so as to retain the advantages of the former, while at the same time allowing a smooth transition to finite order dominance at high q_T.Comment: 32 pages, Latex, epsfig, 17 figure

    Investigating the information-seeking behaviour of academic lawyers: From Ellis's model to design.

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    Information-seeking is important for lawyers, who have access to many dedicated electronic resources.However there is considerable scope for improving the design of these resources to better support information-seeking. One way of informing design is to use information-seeking models as theoretical lenses to analyse users’ behaviour with existing systems. However many models, including those informed by studying lawyers, analyse information-seeking at a high level of abstraction and are only likely to lead to broad-scoped design insights. We illustrate that one potentially useful (and lowerlevel) model is Ellis’s - by using it as a lens to analyse and make design suggestions based on the information-seeking behaviour of twenty-seven academic lawyers, who were asked to think aloud whilst using electronic legal resources to find information for their work. We identify similar information-seeking behaviours to those originally found by Ellis and his colleagues in scientific domains, along with several that were not identified in previous studies such as ‘updating’ (which we believe is particularly pertinent to legal information-seeking). We also present a refinement of Ellis’s model based on the identification of several levels that the behaviours were found to operate at and the identification of sets of mutually exclusive subtypes of behaviours

    Exaggerated CpH methylation in the autism-affected brain.

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    BackgroundThe etiology of autism, a complex, heritable, neurodevelopmental disorder, remains largely unexplained. Given the unexplained risk and recent evidence supporting a role for epigenetic mechanisms in the development of autism, we explored the role of CpG and CpH (H = A, C, or T) methylation within the autism-affected cortical brain tissue.MethodsReduced representation bisulfite sequencing (RRBS) was completed, and analysis was carried out in 63 post-mortem cortical brain samples (Brodmann area 19) from 29 autism-affected and 34 control individuals. Analyses to identify single sites that were differentially methylated and to identify any global methylation alterations at either CpG or CpH sites throughout the genome were carried out.ResultsWe report that while no individual site or region of methylation was significantly associated with autism after multi-test correction, methylated CpH dinucleotides were markedly enriched in autism-affected brains (~2-fold enrichment at p < 0.05 cutoff, p = 0.002).ConclusionsThese results further implicate epigenetic alterations in pathobiological mechanisms that underlie autism

    Affordances of distractors and compatibility effects: a study with the computational model TRoPICALS

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    Seeing an object activates in the brain both visual and action codes. Crucial evidence supporting this view is offered by compatibility effect experiments (Ellis et al. (2007). J Exp Psychol: Hum Percept Perform): perception of an object can facilitate or interfere with the execution of an action (e.g. grasping) even when the viewer has no intention of interacting with the object. TRoPICALS (Caligiore et al. (2010). Psychol Rev) is a computational model developed to study compatibility effects. It provides a general hypothesis about the brain mechanisms underlying compatibility effects, suggesting that the top-down bias from prefrontal cortex (PFC), and its agreement or disagreement with the affordances of objects, plays a key role in such phenomena. Compatibility effects have been investigated in the presence of a distractor object in (Ellis et al. (2007). J Exp Psychol: Hum Percept Perform). The reaction times (RTs) results confirmed compatibility effects found in previous experiments without the distractor. Interestingly, results also showed an unexpected effect of the distractor: responding to a target with a grip compatible with the size of the distractor produced slower RTs in comparison to the incompatible case. Here we present an enhanced version of TRoPICALS that reproduces and explains these new results. This explanation is based on the idea according to which PFC might play a double role in its top-down guidance of action selection producing: (a) a positive bias in favor of the action requested by the experimental task; (b) a negative bias directed to inhibiting the action evoked by the distractor. The model also provides two testable predictions on the possible consequences on compatibilities effects of the target and distractor objects in Parkinsonian disease patients with damages of inhibitory circuits

    Living through unsuccessful conception attempts: : a grounded theory of resilience among women undergoing fertility treatment

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    This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Reproductive and Infant Psychology on 6 May 2017, available online: https://doi.org/10.1080/02646838.2017.1320366.Objective: To provide a model of resilience among women undergoing fertility treatments, who experience repeated unsuccessful conception attempts. Background: Assisted reproductive treatment is emotionally and physically challenging. Women undergoing such treatments report experiencing high levels of anxiety and depression. There continues to be a lack of understanding of the process women go through to adapt to the challenges associated with fertility treatment, in order to continue to pursue their goal of pregnancy. Method: The study employed a qualitative Grounded Theory design. Eleven women aged between 24 and 42 years took part in individual semi-structured interviews around their experiences of living through unsuccessful fertility treatment attempts. Results: Three core categories were identified: ‘Appraisal’; ‘Stepping away from treatment’; and ‘Building self up for the next attempt’. Following the failure of treatment, participants appraised their ability to carry on with further treatment attempts. Those who felt they had depleted their resources through the cycle of attempting pregnancy had taken a step back from the treatment cycle to reconnect with themselves and gather sufficient resources to attempt treatment again. During preparation for the next treatment, participants demonstrated their resilience by taking steps to build up their resources, such as nurturing their strength and taking control of their fertility experience. Conclusions: Women undergoing fertility treatment demonstrate their resilience through a variety of actions that enable them to continue to pursue their pregnancy goal. Clinical staff should be mindful of their clients’ need to withdraw from the treatment cycle and offer support to enable them to do this.Peer reviewe

    An external evaluation of Phat Pak process and structure: Volume 2: Appendices

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    An evaluation was conducted by the 510 Evaluation Research Group 2007 after receiving a request from the Phat Pak Governance Group (PPGG). The evaluation focused on four areas identified in the Phat Pak service specification plan attached to it’s Ministry of Health contract (Youth participation, Communication Strategies, Decision making Processes and Skills Development)

    Leptogenesis in the minimal supersymmetric triplet seesaw model

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    In the supersymmetric triplet (type-II) seesaw model, in which a single SU(2)_L-triplet couples to leptons, the high-energy neutrino flavour structure can be directly determined from the low-energy neutrino data. We show that even with such a minimal triplet content, leptogenesis can be naturally accommodated thanks to the resonant interference between superpotential and soft supersymmetry breaking terms.Comment: References added, discussion expanded, to appear in PL
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