471 research outputs found

    The disappearing act: a dusty wind eclipsing RW Aur

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    The authors acknowledge support from the Science and Technology Facilities Council through grants no. ST/K502339/1 and ST/M001296/1, and the Science Foundation Ireland through grant no. 10/RFP/AST2780.RW Aur is a young binary star that experienced a deep dimming in 2010-11in component A and a second even deeper dimming from summer 2014 to summer 2016. We present new unresolved multi-band photometry during the 2014-16 eclipse, new emission line spectroscopy before and during th dimming, archive infrared photometry between 2014-15, as well as an overview of literature data. Spectral observations were carried out witht he Fibre-fed RObotic Dual-beam Optical Spectrograph on the Liverpool Telescope. Photometric monitoring was done with the Las Cumbres Observatory Global Telescope Network and James Gregory Telescope. Ourphotometry shows that RW Aur dropped in brightness to R = 12.5 in March 2016. In addition to the long-term dimming trend, RW Aur is variable on time-scales as short as hours. The short-term variation is most likely due to an unstable accretion flow. This, combined with the presence of accretion-related emission lines in the spectra suggest that accretion flows in the binary system are at least partially visible during the eclipse. The equivalent width of [O I] increases by a factor of ten in 2014, coinciding with the dimming event, confirming previous reports.The blueshifted part of the Hα profile is suppressed during the eclipse. In combination with the increase in mid-infrared brightness during the eclipse reported in the literature and seen in WISE archival data, and constraints on the geometry of the disk around RW Aur A we arrive at the conclusion that the obscuring screen is part of a wind emanating from the inner disc.Publisher PDFPeer reviewe

    Graph Zeta Function and Gauge Theories

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    Along the recently trodden path of studying certain number theoretic properties of gauge theories, especially supersymmetric theories whose vacuum manifolds are non-trivial, we investigate Ihara's Graph Zeta Function for large classes of quiver theories and periodic tilings by bi-partite graphs. In particular, we examine issues such as the spectra of the adjacency and whether the gauge theory satisfies the strong and weak versions of the graph theoretical analogue of the Riemann Hypothesis.Comment: 35 pages, 7 Figure

    Multidisciplinary and multifaceted outpatient management of patients with osteoarthritis: protocol for a randomised, controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Osteoarthritis (OA) is a prevalent joint disorder with a need for efficient and evidence-based management strategies.</p> <p>Objectives</p> <p>The primary purpose of this study is to compare the effects of a multidisciplinary outpatient clinic, including a brief group-based educational programme, with a traditional individual outpatient clinic for patients with hip, knee, hand or generalized OA. A secondary purpose is to investigate the effects of a telephone follow-up call.</p> <p>Methods</p> <p>This is a pragmatic randomised single-blind controlled study with a total of 400 patients with hip, knee, hand or generalized OA between 40 and 80 years referred to an outpatient rheumatology hospital clinic. The randomisation is stratified according to the diagnostic subgroups. The experimental group is exposed to a multidisciplinary and multifaceted intervention, including a 3.5 hour group-based patient education programme about OA in addition to individual consultations with members of a multidisciplinary team. The control intervention is based on regular care with an individual outpatient consultation with a rheumatologist (treatment as usual). Primary outcomes are patient satisfaction measured at 4 months and cost-effectiveness measured at 12 months. Secondary outcomes are pain and global disease activity measured on a numeric rating scales (NRS), generic and disease specific functioning and disability using Short Form-36 (SF-36) health survey, the Western Ontario and McMaster Universities Osteoarthritis Index 3 (WOMAC), the Australian/Canadian Osteoarthritis Hand Index (AUSCAN), and a patient-generated measure of disability (Patient-Specific Functional scale, PSFS). Global perceived effect of change in health status during the study period is also reported. At 4-month follow-up, patients in both groups will be randomly allocated to a 10-minute telephone call or no follow-up ("treatment as usual"). After additional 8 months (12-month follow-up) the four groups will be compared in a secondary analysis with regard to health outcomes and health care costs.</p> <p>Discussion</p> <p>This trial will provide results on how multidisciplinary and multifaceted management of patients with OA affects health outcomes and health care costs.</p> <p>Trial registration</p> <p>Current Controlled Trials ISRCTN25778426</p

    M2-Branes and Fano 3-folds

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    A class of supersymmetric gauge theories arising from M2-branes probing Calabi-Yau 4-folds which are cones over smooth toric Fano 3-folds is investigated. For each model, the toric data of the mesonic moduli space is derived using the forward algorithm. The generators of the mesonic moduli space are determined using Hilbert series. The spectrum of scaling dimensions for chiral operators is computed.Comment: 128 pages, 39 figures, 42 table

    A transcriptomic snapshot of early molecular communication between Pasteuria penetrans and Meloidogyne incognita

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    © The Author(s). 2018Background: Southern root-knot nematode Meloidogyne incognita (Kofoid and White, 1919), Chitwood, 1949 is a key pest of agricultural crops. Pasteuria penetrans is a hyperparasitic bacterium capable of suppressing the nematode reproduction, and represents a typical coevolved pathogen-hyperparasite system. Attachment of Pasteuria endospores to the cuticle of second-stage nematode juveniles is the first and pivotal step in the bacterial infection. RNA-Seq was used to understand the early transcriptional response of the root-knot nematode at 8 h post Pasteuria endospore attachment. Results: A total of 52,485 transcripts were assembled from the high quality (HQ) reads, out of which 582 transcripts were found differentially expressed in the Pasteuria endospore encumbered J2 s, of which 229 were up-regulated and 353 were down-regulated. Pasteuria infection caused a suppression of the protein synthesis machinery of the nematode. Several of the differentially expressed transcripts were putatively involved in nematode innate immunity, signaling, stress responses, endospore attachment process and post-attachment behavioral modification of the juveniles. The expression profiles of fifteen selected transcripts were validated to be true by the qRT PCR. RNAi based silencing of transcripts coding for fructose bisphosphate aldolase and glucosyl transferase caused a reduction in endospore attachment as compared to the controls, whereas, silencing of aspartic protease and ubiquitin coding transcripts resulted in higher incidence of endospore attachment on the nematode cuticle. Conclusions: Here we provide evidence of an early transcriptional response by the nematode upon infection by Pasteuria prior to root invasion. We found that adhesion of Pasteuria endospores to the cuticle induced a down-regulated protein response in the nematode. In addition, we show that fructose bisphosphate aldolase, glucosyl transferase, aspartic protease and ubiquitin coding transcripts are involved in modulating the endospore attachment on the nematode cuticle. Our results add new and significant information to the existing knowledge on early molecular interaction between M. incognita and P. penetrans.Peer reviewedFinal Published versio

    Successful Stepwise Development of Patient Research Partnership: 14 years’ experience of actions and consequences in Outcome Measures in Rheumatology (OMERACT)

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    There is increasing interest in making patient participation an integral component of medical research. However, practical guidance on optimizing this engagement in healthcare is scarce. Since 2002, patient involvement has been one of the key features of the Outcome Measures in Rheumatology (OMERACT) international consensus effort. Based on a review of cumulative data from qualitative studies and internal surveys among OMERACT participants, we explored the potential benefits and challenges of involving patient research partners in conferences and working group activities. We supplemented our review with personal experiences and reflections regarding patient participation in the OMERACT process. We found that between 2002 and 2016, 67 patients have attended OMERACT conferences, of whom 28 had sustained involvement; many other patients contributed to OMERACT working groups. Their participation provided face validity to the OMERACT process and expanded the research agenda. Essential facilitators have been the financial commitment to guarantee sustainable involvement of patients at these conferences, procedures for recruitment, selection and support, and dedicated time allocated in the program for patient issues. Current challenges include the representativeness of the patient panel, risk of pseudo-professionalization, and disparity in patients’ and researchers’ perception of involvement. In conclusion, OMERACT has embedded long-term patient involvement in the consensus-building process on the measurement of core health outcomes. This integrative process continues to evolve iteratively. We believe that the practical points raised here can improve participatory research implementation

    Making Friends in the Rainforest: Negrito Adaptation to Risk and Uncertainty

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    The so-called negritos adapt not just to a tropical forest environment but also to an environment characterized by perturbations and fluctuations. As with other hunter-gatherers in the region and, indeed, throughout the world, they use both social and ecological methods to enhance their chances of survival in this changing environment: socially, they have developed networks of trading and marriage partners; ecologically, they maintain patches of key resources that are available for future harvesting. As evidenced in the case of the Batek (Orang Asli), patterns of forest structure and composition are sometimes direct outcomes of intentional resource concentration and enrichment strategies. While little of the above is controversial anthropologically, what has drawn some debate is the nature of the relationship with partner societies. Conventional wisdom posits relations of inequality between foragers and others : foragers and farmers are often construed as hierarchical dyads where foragers supply products or labor to farmers in exchange for agricultural harvests and other trade goods. This kind of adaptation appears to be one of divergent specialization. However, there are cases, such as in the relationship between Batek and Semaq Beri, where both societies follow a roughly similar mode of adaptation, and specialization has not materialized. In sum, while not denying that hierarchy and inequality exist, I suggest that they have to be contextualized within a larger strand of relationships that includes both hierarchy and egality. Further, such relationships are part of the general portfolio of risk reduction strategies, following which access to widely scattered environmental resources, and passage from one location to another, is enhanced not by competing with and displacing neighbors but by maintaining a flexible regime of friendly exchange partners

    Epidemics and the Politics of Knowledge: Contested Narratives in Egypt's H1N1 Response

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    This article explores the politics of knowledge involved in understanding and responding to epidemics in an era of global health governance and biosecurity. It develops and applies an approach focused on how multiple, competing narratives about epidemics are constructed, mobilised and interact, and selectively justify pathways of intervention and response. A detailed ethnographic case study of national and local responses to H1N1 influenza, so-called ‘swine flu’, in Egypt reveals how global narratives were reworked by powerful actors in a particular political context, suppressing and delegitimizing the alternative narratives of the Zabaleen (Coptic Christian) people whose lives and livelihoods centred on raising pigs and working with them to control urban waste. The case study illustrates important ways in which geographies and politics of blame around epidemics emerge and are justified, their political contexts and consequences, and how they may feed back to shape the dynamics of disease itself.ESR
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