399 research outputs found

    Quantum and classical localisation, the spin quantum Hall effect and generalisations

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    We consider network models for localisation problems belonging to symmetry class C. This symmetry class arises in a description of the dynamics of quasiparticles for disordered spin-singlet superconductors which have a Bogoliubov - de Gennes Hamiltonian that is invariant under spin rotations but not under time-reversal. Our models include but also generalise the one studied previously in the context of the spin quantum Hall effect. For these systems we express the disorder-averaged conductance and density of states in terms of sums over certain classical random walks, which are self-avoiding and have attractive interactions. A transition between localised and extended phases of the quantum system maps in this way to a similar transition for the classical walks. In the case of the spin quantum Hall effect, the classical walks are the hulls of percolation clusters, and our approach provides an alternative derivation of a mapping first established by Gruzberg, Read and Ludwig, Phys. Rev. Lett. 82, 4254 (1999).Comment: 11 pages, 5 figure

    Reliability of orthostatic beat-to-beat blood pressure tests: implications for population and clinical studies

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    Objective: To assess the test–retest reliability of orthostatic beat-to-beat blood pressure responses to active standing and related clinical definitions of orthostatic hypotension. Methods: A random sample of community-dwelling older adults from the pan-European Survey of Health, Ageing and Retirement in Europe, Ireland underwent a health assessment that mimicked that of the Irish Longitudinal Study on Ageing. An active stand test was performed using continuous blood pressure measurements. Participants attended a repeat assessment 4–12 weeks after the initial measurement. A mixed-effects regression model estimated the reliability and minimum detectable change while controlling for fixed observer and time of day effects. Results: A total of 125 individuals underwent repeat assessment (mean age 66.2 ± 7.5 years; 55.6% female). Mean time between visits was 84.3 ± 23.3 days. There was no significant mean difference in heart rate or blood pressure recovery variables between the first and repeat assessments. Minimum detectable change was noted for changes from resting values in systolic blood pressure (26.4 mmHg) and diastolic blood pressure (13.7 mmHg) at 110 s and for changes in heart rate (10.9 bpm) from resting values at 30 s after standing. Intra-class correlation values ranged from 0.47 for nadir values to 0.80 for heart rate and systolic blood pressure values measured 110 s after standing. Conclusion: Continuous orthostatic beat-to-beat blood pressure and related clinical definitions show low to moderate reliability and substantial natural variation over a 4–12-week period. Understanding variation in measures is essential for study design or estimating the effects of orthostatic hypotension, while clinically it can be used when evaluating longer term treatment effects

    Acute febrile illness is associated with Rickettsia spp infection in dogs

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    BACKGROUND: Rickettsia conorii is transmitted by Rhipicephalus sanguineus ticks and causes Mediterranean Spotted Fever (MSF) in humans. Although dogs are considered the natural host of the vector, the clinical and epidemiological significance of R. conorii infection in dogs remains unclear. The aim of this prospective study was to investigate whether Rickettsia infection causes febrile illness in dogs living in areas endemic for human MSF. METHODS: Dogs from southern Italy with acute fever (n = 99) were compared with case–control dogs with normal body temperatures (n = 72). Serology and real-time PCR were performed for Rickettsia spp., Ehrlichia canis, Anaplasma phagocytophilum/A. platys and Leishmania infantum. Conventional PCR was performed for Babesia spp. and Hepatozoon spp. Acute and convalescent antibodies to R. conorii, E. canis and A. phagocytophilum were determined. RESULTS: The seroprevalence rates at first visit for R. conorii, E. canis, A. phagocytophilum and L. infantum were 44.8%, 48.5%, 37.8% and 17.6%, respectively. The seroconversion rates for R. conorii, E. canis and A. phagocytophilum were 20.7%, 14.3% and 8.8%, respectively. The molecular positive rates at first visit for Rickettsia spp., E. canis, A. phagocytophilum, A. platys, L. infantum, Babesia spp. and Hepatozoon spp. were 1.8%, 4.1%, 0%, 2.3%, 11.1%, 2.3% and 0.6%, respectively. Positive PCR for E. canis (7%), Rickettsia spp. (3%), Babesia spp. (4.0%) and Hepatozoon spp. (1.0%) were found only in febrile dogs. The DNA sequences obtained from Rickettsia and Babesia PCRs positive samples were 100% identical to the R. conorii and Babesia vogeli sequences in GenBank®, respectively. Febrile illness was statistically associated with acute and convalescent positive R. conorii antibodies, seroconversion to R. conorii, E. canis positive PCR, and positivity to any tick pathogen PCRs. Fourteen febrile dogs (31.8%) were diagnosed with Rickettsia spp. infection based on seroconversion and/or PCR while only six afebrile dogs (12.5%) seroconverted (P = 0.0248). The most common clinical findings of dogs with Rickettsia infection diagnosed by seroconversion and/or PCR were fever, myalgia, lameness, elevation of C-reactive protein, thrombocytopenia and hypoalbuminemia. CONCLUSIONS: This study demonstrates acute febrile illness associated with Rickettsia infection in dogs living in endemic areas of human MSF based on seroconversion alone or in combination with PCR

    Earlier Physical Therapy Input is Associated with a Reduced Length of Hospital Stay and Reduced Care Needs on Discharge in Frail Older Inpatients: An Observational Study

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    Background and Purpose\textbf{Background and Purpose}: Pressures on hospital bed occupancy in the English National Health Service (NHS) have focused attention on enhanced service delivery models and methods by which physical therapists might contribute to effective cost savings, while retaining a patient-centered approach. Earlier access to physical therapy may lead to better outcomes in frail older inpatients, but this has not been well studied in acute NHS hospitals. Our aim was to retrospectively study the associations between early physical therapy input and length of hospital stay (LOS), functional outcomes and care needs on discharge. Methods\textbf{Methods}: This was a retrospective observational study in a large tertiary university NHS hospital in the United Kingdom. We analyzed all admission episodes of people admitted to the Department of Medicine for the Elderly wards over 3 months in 2016. Patients were categorized into 2 groups: those examined by a physical therapist within 24 hours of admission and those examined after 24 hours of admission. The outcome variables were: LOS (days), functional measures on discharge (Elderly Mobility Scale and walking speed over 6 meters), and the requirement of formal care on discharge. Characterization variables on admission were: age, gender, existence of a formal care package, pre-admission abode, the Clinical Frailty Scale, Charlson Comorbidity Index, the Emergency Department Modified Early Warning Score, C-reactive protein level on admission, and the 4-item version of the Abbreviated Mental Test. The association between the delay to physical therapy input and LOS before discharge home was evaluated using a Cox proportional hazards regression model. Results and Discussion\textbf{Results and Discussion}: There were 1022 hospital episodes over the study period. We excluded 19 who were discharged without being examined by a physical therapist. Of the remaining 1003, 584 (58.2%) were examined within 24 hours of admission (early assessment), and 419 (41.8%) after 24 hours of admission (late assessment). The median (interquartile range: IQR) LOS of the early assessment group was 6.7 (3.1–13.7) versus 10.0 (4.2-20.1) days in the late assessment group, P < 0.001. The early assessment group was less likely to require formal care on discharge: n=110 (20.3%) versus n=105 (27.0%), P = 0.016. No other statistically significant differences were seen between the 2 groups. In the unadjusted Cox proportional hazards model, the hazard ratio for early assessment compared to late assessment was 1.29 (95% confidence interval: 1.12-1.48, P < 0.001). Early assessment was associated with a 29% higher probability of discharge to usual residence within the first 21 days after admission, compared to late assessment. Adjustment for possible confounding variables increased the hazard ratio: 1.34 (1.16 – 1.55) P < 0.001. Conclusions\textbf{Conclusions}: Early physical therapy input was associated with a shorter LOS and lower odds of needing care on discharge. This may be due to the beneficial effect of early physical therapy in preventing hospital-related deconditioning in frail older adults. However, causality cannot be inferred and further research is needed to investigate causal mechanisms

    Safety and efficacy of a feed additive consisting of pancreatin from porcine pancreas (Pan-zoot) for dogs (Almapharm GmbH + Co KG)

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    Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of a pancreatic extract (Pan-zoot) as a zootechnical additive for dogs. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) could not conclude on the safety of Pan-Zoot as a feed additive for dogs under the proposed conditions of use. The FEEDAP Panel could not conclude on the skin/eye irritancy potential of the additive or on the dermal sensitisation potential. Owing to its proteinaceous nature, the additive is considered a respiratory sensitiser. The additive may induce allergic reactions to the exposed users. The Panel concluded that there is no need for an environmental risk assessment. The FEEDAP Panel could not conclude on the efficacy of the product as a feed additive at the recommended conditions of use
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