5,278 research outputs found

    The evolution of gregariousness in parasitoid wasps

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    Data are assembled on the clutch-size strategies adopted by extant species of parasitoid wasp. These data are used to reconstruct the history of clutch-size evolution in the group using a series of plausible evolutionary assumptions. Extant families are either entirely solitary, both solitary and gregarious, or else clutch size is unknown. Parsimony analysis suggests that the ancestors of most families were solitary, a result which is robust to different phylogenetic relationships and likely data inadequacies. This implies that solitariness was ubiquitous throughout the initial radiation of the group, and that transitions to gregariousness have subsequently occurred a minimum of 43 times in several, but not all lineages. Current data suggest that species-rich and small-bodied lineages are more likely to have evolved gregariousness, and contain more species with small gregarious brood sizes. I discuss the implications of these data for clutch-size theory

    What do general practitioners know about ADHD? Attitudes and knowledge among first-contact gatekeepers: systematic narrative review

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    Background: Attention Deficit Hyperactivity Disorder (ADHD) is a common childhood disorder with international prevalence estimates of 5 % in childhood, yet significant evidence exists that far fewer children receive ADHD services. In many countries, ADHD is assessed and diagnosed in specialist mental health or neuro-developmental paediatric clinics, to which referral by General (Family) Practitioners (GPs) is required. In such ‘gatekeeper’ settings, where GPs act as a filter to diagnosis and treatment, GPs may either not recognise potential ADHD cases, or may be reluctant to refer. This study systematically reviews the literature regarding GPs’ views of ADHD in such settings. Methods: A search of nine major databases was conducted, with wide search parameters; 3776 records were initially retrieved. Studies were included if they were from settings where GPs are typically gatekeepers to ADHD services; if they addressed GPs’ ADHD attitudes and knowledge; if methods were clearly described; and if results for GPs were reported separately from those of other health professionals. Results: Few studies specifically addressed GP attitudes to ADHD. Only 11 papers (10 studies), spanning 2000–2010, met inclusion criteria, predominantly from the UK, Europe and Australia. As studies varied methodologically, findings are reported as a thematic narrative, under the following themes: Recognition rate; ADHD controversy (medicalisation, stigma, labelling); Causes of ADHD; GPs and ADHD diagnosis; GPs and ADHD treatment; GP ADHD training and sources of information; and Age, sex differences in knowledge and attitudes. Conclusions: Across times and settings, GPs practising in first-contact gatekeeper settings had mixed and often unhelpful attitudes regarding the validity of ADHD as a construct, the role of medication and how parenting contributed to presentation. A paucity of training was identified, alongside a reluctance of GPs to become involved in shared care practice. If access to services is to be improved for possible ADHD cases, there needs to be a focused and collaborative approach to training

    Photonic bandgaps for grating-coupled waveguide modes with a silver tunnel barrier

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    Copyright © 2007 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft. This is the published version of an article published in New Journal of Physics Vol. 9, article 251. DOI: 10.1088/1367-2630/9/8/251The optical properties of a periodically modulated photoresist waveguide structure has been explored using the Kretschmann–Raether configuration with a thin silver tunnel barrier. A detailed experimental study of how wavelength-scale periodic texture modifies the dispersion of the guided modes in the visible range for a wide range of azimuthal angles is presented. Fitting the observed in-plane momenta of the modes to predictions from a multilayer, multishape differential grating theory model allows the identities of each of the modes to be confirmed. In addition, the intensities obtained experimentally are compared favourably with those predicted from a theoretical model. Such a waveguide structure can produce not only the photonic bandgaps at the Brillouin zone boundary, but also bandgaps within the Brillouin zone caused by the Bragg scattered guided modes anti-crossing with the unscattered modes. All of these photonic bandgaps have potential applications controlling spontaneous emission in devices

    Moderating Effects of Immunosuppressive Medications and Risk Factors for Post-Operative Joint Infection Following Total Joint Arthroplasty in Patients with Rheumatoid Arthritis or Osteoarthritis

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    Objective—Inconclusive findings about infection risks, importantly the use of immunosuppressive medications, in patients who have undergone large-joint total joint arthroplasty challenge efforts to provide evidenced-based perioperative total joint arthroplasty recommendations to improve surgical outcomes. Thus, the aim of this study was to describe risk factors for developing a postoperative infection in patients undergoing TJA of a large joint [total hip arthroplasty, total knee arthroplasty, or total shoulder arthroplasty] by identifying clinical and demographic factors, including the use of high risk medications (i.e., prednisone and immunosuppressive medications) and diagnoses (i.e., rheumatoid arthritis [RA], osteoarthritis [OA], gout, obesity, diabetes mellitus), that are linked to infection status, controlling for length of follow-up. Methods—A retrospective, case-control study (N = 2,212) using de-identified patient health claims information from a commercially-insured, U.S. dataset representing 15 million patients annually (January 1, 2007 - December 31, 2009) was conducted. Descriptive statistics, t-test, chi-square test, Fisher\u27s exact test, and multivariate logistic regression were used. Results—Male gender (OR = 1.42; p \u3c .001), diagnosis of RA (OR = 1.47; p = .031), diabetes mellitus (OR = 1.38, p = .001), obesity (OR = 1.66, p \u3c .001) or gout (OR = 1.95; p = .001), and a prescription for prednisone (OR = 1.59; p \u3c .001) predicted a post-operative infection following total joint arthroplasty. Persons with post-operative joint infections were significantly more likely to be prescribed allopurinol (p = .002) and colchicine (p = .006; no significant difference was found for the use of specific disease modifying anti-rheumatic drugs and TNF-α inhibitors. Conclusion—High-risk, post-operative joint infection groups were identified allowing for precautionary clinical measures to be taken

    Foliar lead uptake by lettuce exposed to atmospheric fallouts

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    Metal uptake by plants occurs by soil−root transfer but also by direct transfer of contaminants from the atmosphere to the shoots. This second pathway may be particularly important in kitchen gardens near industrial plants. The mechanisms of foliar uptake of lead by lettuce (Lactuca sativa) exposed to the atmospheric fallouts of a lead-recycling plant were studied. After 43 days of exposure, the thoroughly washed leaves contained 335 ± 50 mg Pb kg−1 (dry weight). Micro-X-ray fluorescence mappings evidenced Pb-rich spots of a few hundreds of micrometers in diameter located in necrotic zones. These spots were more abundant at the base of the central nervure. Environmental scanning electron microscopy coupled with energy dispersive X-ray microanalysis showed that smaller particles (a few micrometers in diameter) were also present in other regions of the leaves, often located beneath the leaf surface. In addition, submicrometric particles were observed inside stomatal openings. Raman microspectrometry analyses of the leaves identified smelter-originated Pb minerals but also secondary phases likely resulting from the weathering of original particles. On the basis of these observations, several pathways for foliar lead uptake are discussed. A better understanding of these mechanisms may be of interest for risk assessment of population exposure to atmospheric metal contamination

    Lessons learned from the ATLAS performance studies of the Iberian Cloud for the first LHC running period

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    In this contribution we describe the performance of the Iberian (Spain and Portugal) ATLAS cloud during the first LHC running period (March 2010-January 2013) in the context of the GRID Computing and Data Distribution Model. The evolution of the resources for CPU, disk and tape in the Iberian Tier-1 and Tier-2s is summarized. The data distribution over all ATLAS destinations is shown, focusing on the number of files transferred and the size of the data. The status and distribution of simulation and analysis jobs within the cloud are discussed. The Distributed Analysis tools used to perform physics analysis are explained as well. Cloud performance in terms of the availability and reliability of its sites is discussed. The effect of the changes in the ATLAS Computing Model on the cloud is analyzed. Finally, the readiness of the Iberian Cloud towards the first Long Shutdown (LS1) is evaluated and an outline of the foreseen actions to take in the coming years is given. The shutdown will be a good opportunity to improve and evolve the ATLAS Distributed Computing system to prepare for the future challenges of the LHC operation.Peer Reviewe

    Photonic mode dispersion of a two-dimensional distributed feedback polymer laser

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    G. A. Turnbull, P. Andrew, William L. Barnes, and I. D. W. Samuel, Physical Review B, Vol. 67, article 165107 (2003). "Copyright © 2003 by the American Physical Society."We present an analysis of the photonic mode dispersion of a two-dimensional (2D) distributed feedback polymer laser based on the conjugated polymer poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylene vinylene]. We use a combination of a simple model, together with experimental measurements of the photonic mode dispersion in transmission and emission, to explain the operating characteristics of the laser. The laser was found to oscillate at 636 nm on one edge of a photonic stop band in the photonic dispersion. A 2D coupling of modes traveling perpendicular to the orthogonal gratings was found to lead to a low divergence laser emission normal to the waveguide. At pump energies well above the oscillation threshold for this mode, a divergent, cross-shaped far-field emission was observed, resulting from a distributed feedback occurring over a wide range of wave vectors in one band of the photonic dispersion

    Hadron therapy information sharing prototype

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    The European PARTNER project developed a prototypical system for sharing hadron therapy data. This system allows doctors and patients to record and report treatment-related events during and after hadron therapy. It presents doctors and statisticians with an integrated view of adverse events across institutions, using open-source components for data federation, semantics, and analysis. There is a particular emphasis upon semantic consistency, achieved through intelligent, annotated form designs. The system as presented is ready for use in a clinical setting, and amenable to further customization. The essential contribution of the work reported here lies in the novel data integration and reporting methods, as well as the approach to software sustainability achieved through the use of community-supported open-source components

    Two chemically distinct root lignin barriers control solute and water balance.

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    Lignin is a complex polymer deposited in the cell wall of specialised plant cells, where it provides essential cellular functions. Plants coordinate timing, location, abundance and composition of lignin deposition in response to endogenous and exogenous cues. In roots, a fine band of lignin, the Casparian strip encircles endodermal cells. This forms an extracellular barrier to solutes and water and plays a critical role in maintaining nutrient homeostasis. A signalling pathway senses the integrity of this diffusion barrier and can induce over-lignification to compensate for barrier defects. Here, we report that activation of this endodermal sensing mechanism triggers a transcriptional reprogramming strongly inducing the phenylpropanoid pathway and immune signaling. This leads to deposition of compensatory lignin that is chemically distinct from Casparian strip lignin. We also report that a complete loss of endodermal lignification drastically impacts mineral nutrients homeostasis and plant growth
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