308 research outputs found

    Force-free magnetosphere of an aligned rotator with differential rotation of open magnetic field lines

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    Here we briefly report on results of self-consistent numerical modeling of a differentially rotating force-free magnetosphere of an aligned rotator. We show that differential rotation of the open field line zone is significant for adjusting of the global structure of the magnetosphere to the current density flowing through the polar cap cascades. We argue that for most pulsars stationary cascades in the polar cap can not support stationary force-free configurations of the magnetosphere.Comment: 5 pages, 4 figures. Presented at the conference "Isolated Neutron Stars: from the Interior to the Surface", London, April 24-28, 2006; to appear in Astrophysics and Space Science. Significantly revised version, a mistake found by ourselfs in the numerical code was corrected, all presented results are obtained with the correct version of the cod

    A cohort study of post-weaning multisystemic wasting syndrome and PCV2 in 178 pigs from birth to 14 weeks on a single farm in England

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    Our hypothesis was that pigs that develop post-weaning multisystemic wasting syndrome (PMWS) are detectable from an early age with signs of weight loss and other clinical and serological abnormalities. Therefore, the objective of this study was to investigate the temporally varying and fixed events linked with the clinical incidence of PMWS by comparing affected and unaffected pigs in a cohort of 178 male piglets. Piglets were enrolled at birth and examined each week. Samples of blood were collected at regular intervals. The exposures measured were porcine circovirus type 2 (PCV2) antibody titres in all 178 and PCV2 antigen in a subset of 75 piglets. We also observed piglet health and measured their weight, and a post-mortem examination was performed by an external laboratory on all pigs between 6 and 14 weeks of age that died. From the cohort, 14 (8%) pigs died from PMWS and 4% from other causes. A further 37 pigs between 6 and 14 weeks of age died from PMWS (30) and ileitis and other causes (7). PMWS was only apparent in pigs from 1 to 2 weeks before death when they wasted rapidly. There were no other characteristic clinical signs and no obvious gross clinical lesions post-mortem. There was no strong link with PCV2 antibody throughout life but PCV2 antigen level was higher from 4 to 6 weeks of age in pigs that died from PMWS compared with pigs that died from other causes

    Wound healing and hyper-hydration - a counter intuitive model

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    Winters seminal work in the 1960s relating to providing an optimal level of moisture to aid wound healing (granulation and re-epithelialisation) has been the single most effective advance in wound care over many decades. As such the development of advanced wound dressings that manage the fluidic wound environment have provided significant benefits in terms of healing to both patient and clinician. Although moist wound healing provides the guiding management principle confusion may arise between what is deemed to be an adequate level of tissue hydration and the risk of developing maceration. In addition, the counter-intuitive model ‘hyper-hydration’ of tissue appears to frustrate the moist wound healing approach and advocate a course of intervention whereby tissue is hydrated beyond what is a normally acceptable therapeutic level. This paper discusses tissue hydration, the cause and effect of maceration and distinguishes these from hyper-hydration of tissue. The rationale is to provide the clinician with a knowledge base that allows optimisation of treatment and outcomes and explains the reasoning behind wound healing using hyper-hydration

    Definitions and standardization of a new grading scheme for eyelid contour abnormalities after trichiasis surgery

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    Background: Clear definitions of outcomes following trichiasis surgery are critical for planning program evaluations and for identifying ways to improve trichiasis surgery. Eyelid contour abnormality is an important adverse outcome of surgery; however, no standard method has been described to categorize eyelid contour abnormalities. Methodology/Principal Findings: A classification system for eyelid contour abnormalities following surgery for trachomatous trichiasis was developed. To determine whether the grading was reproducible using the classification system, six-week postoperative photographs were reviewed by two senior graders to characterize severity of contour abnormalities. Sample photographs defining each contour abnormality category were compiled and used to train four new graders. All six graders independently graded a Standardization Set of 75 eyelids, which included a roughly equal distribution across the severity scale, and weighted kappa scores were calculated. Two hundred forty six-week postoperative photographs from an ongoing clinical trial were randomly selected for evaluating agreement across graders. Two months after initial grading, one grader regraded a subset of the 240 photographs to measure longer-term intra-observer agreement. The weighted kappa for agreement between the two senior graders was 0.80 (95% CI: 0.71-0.89). Among the Standardization Set, agreement between the senior graders and the 4 new graders showed weighted kappa scores ranging from 0.60-0.80. Among 240 eyes comprising the clinical trial dataset, agreement ranged from weighted kappa 0.70-0.71. Longer-term intra-observer agreement was weighted kappa 0.86 (95% CI: 0.80-0.92). Conclusions/Significance: The standard eyelid contour grading system we developed reproducibly delineates differing levels of contour abnormality. This grading system could be useful both for helping to evaluate trichiasis surgery outcomes in clinical trials and for evaluating trichiasis surgery programs

    Relationship between immediate post-operative appearance and 6-week operative outcome in trichiasis surgery

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    Background: Surgical technique, including suture placement and tension, is believed to contribute to the outcome of bilamellar tarsal rotation surgery for trachomatous trichiasis. However, the immediate post-operative appearance that minimizes the chance of recurrence and other adverse outcomes has not been investigated. Methodology/Principal Findings: To explore whether the degree of correction immediately after surgery is predictive of surgical outcome at the 6-week post-operative visit, photographs taken immediately after surgery were used to predict surgical outcomes, including the severity of eyelid contour abnormality and trichiasis recurrence. Both eyelid contour abnormalities and recurrence were accurately predicted from the immediate post-operative photographs by an experienced oculoplastic surgeon 85% and 70% of the time, respectively. Participants with a "slight over-correction" that resulted in no eyelid contour abnormality and no recurrence were used to identify immediate post-operative contours that lead to a successful surgical outcome. Conclusions/Significance: The immediate post-operative eyelid contour is an important indicator of post-operative success of BLTR surgery. Based upon our findings, we developed a Surgery Photocard. This card illustrates some examples of immediate post-surgical appearances, which led to a successful outcome, as well as sub-optimal appearances, which led to poor surgical outcomes. The card also provides suggestions for improving the appearance by adjusting the suture placement or tension based upon standard oculoplastic principles

    Type-Decomposition of a Pseudo-Effect Algebra

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    The theory of direct decomposition of a centrally orthocomplete effect algebra into direct summands of various types utilizes the notion of a type-determining (TD) set. A pseudo-effect algebra (PEA) is a (possibly) noncommutative version of an effect algebra. In this article we develop the basic theory of centrally orthocomplete PEAs, generalize the notion of a TD set to PEAs, and show that TD sets induce decompositions of centrally orthocomplete PEAs into direct summands.Comment: 18 page

    Recent increases of rainfall and flooding from tropical cyclones (TCs) in North Carolina (USA): implications for organic matter and nutrient cycling in coastal watersheds

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    Coastal North Carolina experienced 36 tropical cyclones (TCs), including three floods of historical significance in the past two decades (Hurricanes Floyd-1999, Matthew-2016 and Florence-2018). These events caused catastrophic flooding and major alterations of water quality, fisheries habitat and ecological conditions of the Albemarle-Pamlico Sound (APS), the second largest estuarine complex in the United States. Continuous rainfall records for coastal NC since 1898 reveal a period of unprecedented high precipitation storm events since the late-1990s. Six of seven of the “wettest” storm events in this > 120-year record occurred in the past two decades, identifying a period of elevated precipitation and flooding associated with recent TCs. We examined storm-related freshwater discharge, carbon (C) and nutrient, i.e., nitrogen (N) and phosphorus (P) loadings, and evaluated contributions to total annual inputs in the Neuse River Estuary (NRE), a major sub-estuary of the APS. These contributions were highly significant, accounting for > 50% of annual loads depending on antecedent conditions and storm-related flooding. Depending on the magnitude of freshwater discharge, the NRE either acted as a “processor” to partially assimilate and metabolize the loads or acted as a “pipeline” to transport the loads to the APS and coastal Atlantic Ocean. Under base-flow, terrestrial sources dominate riverine carbon. During storm events these carbon sources are enhanced through the inundation and release of carbon from wetlands. These findings show that event-scale discharge plays an important and, at times, predominant role in C, N and P loadings. We appear to have entered a new climatic regime characterized by more frequent extreme precipitation events, with major ramifications for hydrology, cycling of C, N and P, water quality and habitat conditions in estuarine and coastal waters

    Cheeky Witnessing

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    Feminists witness legal worlds as they observe, document, and share nothing less than the reproduction of life itself. The world of the abortion trail, where people and things move across borders to change life’s reproduction, has generated a rich plurality of feminist witnessing. In observing how feminist activists improvise with sources, figures and objects of legal consciousness on the abortion trail, this paper seeks to contribute to critical understanding of that plurality, particularly as it emerges in diaspora space. Focusing on Murphy’s concept of immodest witnessing, with its attention to bodies, protocols and apparatuses as constituents of knowledge, the paper thinks with the diasporic feminist activist performance group, Speaking of I.M.E.L.D.A., about how they used self-examination, collective collaboration, and knowledge-sharing on the trail to repeal of Ireland’s Eighth Amendment. The paper argues that their improvisation with legal consciousness of reproductive choice enacts ‘cheeky witnessing’. Cheeky witnessing has three dynamics as a method of observation. First, it is messy and irreverent in innovating with names to display the mixed genealogies of sources of feminist knowledge. Second, cheeky witnessing generates novel subject-figures, such as migrant cleaners, who make knowing connections between different reproductive labourers as observers of the trail in diaspora space. Third, cheeky witnessing places funny objects, knickers in this instance, so as to join up particular public locations and make them more, if unevenly, comfortable for sexual and reproductive bodies. Cheeky witnessing show us how committed and partial practices play a role in speaking across interests and experiences, in stretching the legal imagination, and in sustaining the everyday grind of making a better world

    Pre-operative trichiatic eyelash pattern predicts post-operative trachomatous trichiasis

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    Importance Trichiasis surgery programs globally have faced high rates of poor surgical outcomes. Identifying correctable risk factors for improving long-term outcomes is essential for countries targeting elimination of trachoma as a public health problem. Objective To determine whether the location of trichiatic eyelashes prior to surgery influences development of post-operative trichiasis (PTT) within two years after surgery. Design Secondary data analysis of four randomized clinical trials evaluating methods to improve trichiasis surgery outcomes. These include the Surgery for Trichiasis, Antibiotics for Recurrence (STAR) trial, Partnership for Rapid Elimination of Trachoma (PRET-Surgery), absorbable versus silk sutures trial, and epilation versus surgery for minor trichiasis trial. Setting Primary trials were conducted in rural areas of Ethiopia and Tanzania Interventions or exposures Trichiasis surgery performed with either the bilamellar tarsal rotation procedure or posterior lamellar rotation procedure Main outcomes Prevalence of PTT within two years after surgery, location of trichiatic eyelashes pre-operatively and post-operatively Results 6,747 eyelids that underwent first-time trichiasis surgery were included. PTT rates varied by study, ranging from 10–40%. PTT was less severe (based on number of trichiatic eyelashes) than initial trichiasis for 72% of those developing PTT, and only 2% of eyelids were worse at follow up than pre-operatively. Eyelids with central only-trichiasis pre-operatively had lower rates of PTT than eyelids with peripheral only trichiasis in each of the three trials that included severe TT cases. 10% of eyelids with peripheral trichiasis pre-operatively that develop PTT have central TT post-operatively. Conclusions and relevance Pre-operative central trichiasis is less likely than peripheral trichiasis to be associated with subsequent PTT. Regardless of type of surgery, surgeon skill levels, or pre-operative trichiasis severity, the presence of peripheral trichiasis pre-operatively is associated with higher rates of PTT. Making an incision that extends the length of the eyelid and adequately rotating the nasal and temporal aspects of the eyelid when suturing may help to minimize the chance of developing peripheral PTT

    Intravitreal ranibizumab versus aflibercept versus bevacizumab for macular oedema due to central retinal vein occlusion: the LEAVO non-inferiority three-arm RCT

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    Background Licensed ranibizumab (0.5 mg/0.05 ml Lucentis®; Novartis International AG, Basel, Switzerland) and aflibercept (2 mg/0.05 ml Eylea®; Bayer AG, Leverkusen, Germany) and unlicensed bevacizumab (1.25 mg/0.05 ml Avastin®; F. Hoffmann-La Roche AG, Basel, Switzerland) are used to treat macula oedema due to central retinal vein occlusion, but their relative clinical effectiveness, cost-effectiveness and impact on the UK NHS and Personal Social Services have never been directly compared over the typical disease treatment period. Objective The objective was to compare the clinical effectiveness and cost-effectiveness of three intravitreal antivascular endothelial growth factor agents for the management of macula oedema due to central retinal vein occlusion. Design This was a three-arm, double-masked, randomised controlled non-inferiority trial. Setting The trial was set in 44 UK NHS ophthalmology departments, between 2014 and 2018. Participants A total of 463 patients with visual impairment due to macula oedema secondary to central retinal vein occlusion were included in the trial. Interventions The participants were treated with repeated intravitreal injections of ranibizumab (n = 155), aflibercept (n = 154) or bevacizumab (n = 154). Main outcome measures The primary outcome was an increase in the best corrected visual acuity letter score from baseline to 100 weeks in the trial eye. The null hypothesis that aflibercept and bevacizumab are each inferior to ranibizumab was tested with a non-inferiority margin of –5 visual acuity letters over 100 weeks. Secondary outcomes included additional visual acuity, and imaging outcomes, Visual Function Questionnaire-25, EuroQol-5 Dimensions with and without a vision bolt-on, and drug side effects. Cost-effectiveness was estimated using treatment costs and Visual Function Questionnaire-Utility Index to measure quality-adjusted life-years. Results The adjusted mean changes at 100 weeks in the best corrected visual acuity letter scores were as follows – ranibizumab, 12.5 letters (standard deviation 21.1 letters); aflibercept, 15.1 letters (standard deviation 18.7 letters); and bevacizumab, 9.8 letters (standard deviation 21.4 letters). Aflibercept was non-inferior to ranibizumab in the intention-to-treat population (adjusted mean best corrected visual acuity difference 2.23 letters, 95% confidence interval –2.17 to 6.63 letters; p = 0.0006), but not superior. The study was unable to demonstrate that bevacizumab was non-inferior to ranibizumab in the intention-to-treat population (adjusted mean best corrected visual acuity difference –1.73 letters, 95% confidence interval –6.12 to 2.67 letters; p = 0.071). A post hoc analysis was unable to demonstrate that bevacizumab was non-inferior to aflibercept in the intention-to-treat population (adjusted mean best corrected visual acuity difference was –3.96 letters, 95% confidence interval –8.34 to 0.42 letters; p = 0.32). All per-protocol population results were the same. Fewer injections were required with aflibercept (10.0) than with ranibizumab (11.8) (difference in means –1.8, 95% confidence interval –2.9 to –0.8). A post hoc analysis showed that more bevacizumab than aflibercept injections were required (difference in means 1.6, 95% confidence interval 0.5 to 2.7). There were no new safety concerns. The model- and trial-based cost-effectiveness analyses estimated that bevacizumab was the most cost-effective treatment at a threshold of £20,000–30,000 per quality-adjusted life-year. Limitations The comparison of aflibercept and bevacizumab was a post hoc analysis. Conclusion The study showed aflibercept to be non-inferior to ranibizumab. However, the possibility that bevacizumab is worse than ranibizumab and aflibercept by 5 visual acuity letters cannot be ruled out. Bevacizumab is an economically attractive treatment alternative and would lead to substantial cost savings to the NHS and other health-care systems. However, uncertainty about its relative effectiveness should be discussed comprehensively with patients, their representatives and funders before treatment is considered. Future work To obtain extensive patient feedback and discuss with all stakeholders future bevacizumab NHS use. Trial registration Current Controlled Trials ISRCTN13623634. Funding This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 38. See the NIHR Journals Library website for further project information
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