Anomalous jumping in a double-well potential

Noise induced jumping between meta-stable states in a potential depends on the structure of the noise. For an $\alpha$-stable noise, jumping triggered by single extreme events contributes to the transition probability. This is also called Levy flights and might be of importance in triggering sudden changes in geophysical flow and perhaps even climatic changes. The steady state statistics is also influenced by the noise structure leading to a non-Gibbs distribution for an $\alpha$-stable noise.Comment: 11 pages, 7 figure

Surface tension implementation for Gensmac 2D

In the present work we describe a method which allows the incorporation of surface tension into the GENSMAC2D code. This is achieved on two scales. First on the scale of a cell, the surface tension effects are incorporated into the free surface boundary conditions through the computation of the capillary pressure. The required curvature is estimated by fitting a least square circle to the free surface using the tracking particles in the cell and in its close neighbors. On a sub-cell scale, short wavelength perturbations are filtered out using a local 4-point stencil which is mass conservative. An efficient implementation is obtained through a dual representation of the cell data, using both a matrix representation, for ease at identifying neighbouring cells, and also a tree data structure, which permits the representation of specific groups of cells with additional information pertaining to that group. The resulting code is shown to be robust, and to produce accurate results when compared with exact solutions of selected fluid dynamic problems involving surface tension

Identifying critically important vascular access outcomes for trials in haemodialysis : an international survey with patients, caregivers and health professionals

BACKGROUND: Vascular access outcomes reported across haemodialysis (HD) trials are numerous, heterogeneous and not always relevant to patients and clinicians. This study aimed to identify critically important vascular access outcomes. METHOD: Outcomes derived from a systematic review, multi-disciplinary expert panel and patient input were included in a multilanguage online survey. Participants rated the absolute importance of outcomes using a 9-point Likert scale (7-9 being critically important). The relative importance was determined by a best-worst scale using multinomial logistic regression. Open text responses were analysed thematically. RESULTS: The survey was completed by 873 participants [224 (26%) patients/caregivers and 649 (74%) health professionals] from 58 countries. Vascular access function was considered the most important outcome (mean score 7.8 for patients and caregivers/8.5 for health professionals, with 85%/95% rating it critically important, and top ranked on best-worst scale), followed by infection (mean 7.4/8.2, 79%/92% rating it critically important, second rank on best-worst scale). Health professionals rated all outcomes of equal or higher importance than patients/caregivers, except for aneurysms. We identified six themes: necessity for HD, applicability across vascular access types, frequency and severity of debilitation, minimizing the risk of hospitalization and death, optimizing technical competence and adherence to best practice and direct impact on appearance and lifestyle. CONCLUSIONS: Vascular access function was the most critically important outcome among patients/caregivers and health professionals. Consistent reporting of this outcome across trials in HD will strengthen their value in supporting vascular access practice and shared decision making in patients requiring HD

Germinação de esporos de Puccinia polysora por extratos aquosos de Mikania glomerata

Corn rust requires chemical fungicides as the main method for its control. This research aimed to evaluate the spore germination of the fungus Puccinia polysora, responsible for corn rust, using static aqueous extract of guaco (Mikania glomerata). The extract was obtained by hydrating whole leaves of guaco in distilled water and then it was kept in the refrigerator for 24 hours. Afterwards, the extract was filtered with filter paper and diluted in water until it reached the concentrations of 1, 2, 3, 4 and 5%. The control was prepared with distilled water. Aliquots of 40 µL of the extract and 40 µL of spore suspension of P. polysora (1 x 104 spores mL-1), obtained in a commercial farming area in Toledo (Paraná, Brazil), were spread over the surface of a microscope slide covered with a thin layer (1 mL) of water agar at 1%, placed in gerbox boxes and kept in the dark for 24 hours at 22 °C. Later, the percentage of germinated spores was determined by counting them under the microscope. The results were analyzed by ANAVA and regression test, and they indicated that all the concentrations inhibited the germination of spores, reaching 74% in the highest concentration tested, when compared to the control.A ferrugem polisora do milho possui como principal método de controle os fungicidas químicos. Esta pesquisa visou avaliar a germinação dos esporos do fungo Puccinia polysora, responsável pela ferrugem do milho, com extrato aquoso estático de guaco (Mikania glomerata). O extrato de guaco foi obtido por meio da hidratação das folhas inteiras em água destilada e mantido na geladeira por 24 horas. Em seguida, filtrou-se com papel filtro e diluiu-se em água até atingir as concentrações de 1, 2, 3, 4 e 5%. A testemunha foi representada com água destilada. Alíquotas de 40 µL do extrato e 40 µL da suspensão de esporos de P. polysora (1x104 esporos mL-1) obtidas em uma lavoura comercial da cidade de Toledo (PR), foram distribuídas sobre a superfície da lâmina de microscopia revestida por fina camada (1 mL) de ágar-água a 1% e acondicionadas em caixas de gerbox no escuro por 24 horas em temperatura de 22 ºC. Posteriormente, determinou-se a porcentagem de esporos germinados por contagem em microscópio. Os resultados foram analisados pela ANAVA e pelo teste de regressão e indicaram que todas as concentrações inibiram a germinação de esporos, atingindo 74% na maior concentração testada, quando comparada a testemunha

Validation of a core patient-reported outcome measure for fatigue in patients receiving hemodialysis: The SONG-HD fatigue instrument

Background and objectives Fatigue is a very common and debilitating symptom and identified by patients as a critically important core outcome to be included in all trials involving patients receiving hemodialysis. A valid, standardized measure for fatigue is needed to yield meaningful and relevant evidence about this outcome. This study validated a core patient-reported outcome measure for fatigue in hemodialysis. Design, setting, participants, & measurements A longitudinal cohort study was conducted to assess the validity and reliability of a new fatigue measure (Standardized Outcomes in Nephrology-Hemodialysis Fatigue [SONGHD Fatigue]). Eligible and consenting patients completed the measure at three time points: baseline, a week later, and 12 days following the second time point. Cronbach α and intraclass correlation coefficient were calculated to assess internal consistency, and Spearman rho was used to assess convergent validity. Confirmatory factor analysis was also conducted. Hemodialysis units in the United Kingdom, Australia, and Romania participated in this study. Adult patients aged 18 years and over who were English speaking and receiving maintenance hemodialysis were eligible to participate. Standardized Outcomes in Nephrology-Hemodialysis, the Visual Analog Scale for fatigue, the 12-Item Short Form Survey, and Functional Assessment of Chronic Illness Therapy–Fatigue were used. Results In total, 485 participants completed the study across the United Kingdom, Australia, and Romania. Psychometric assessment demonstrated that Standardized Outcomes in Nephrology-Hemodialysis is internally consistent (Cronbach α =0.81–0.86) and stable over a 1-week period (intraclass correlation coefficient =0.68–0.74). The measure demonstrated convergence with Functional Assessment of Chronic Illness Therapy–Fatigue and had moderate correlations with other measures that assessed related but not the same concept (the 12-Item Short Form Survey and the Visual Analog Scale). Confirmatory factor analysis supported the one-factor model. Conclusions SONG-HD Fatigue seems to be a reliable and valid measure to be used in trials involving patients receiving hemodialysis

Pattern selection in the absolutely unstable regime as a nonlinear eigenvalue problem: Taylor vortices in axial flow

A unique pattern selection in the absolutely unstable regime of a driven, nonlinear, open-flow system is analyzed: The spatiotemporal structures of rotationally symmetric vortices that propagate downstream in the annulus of the rotating Taylor-Couette system due to an externally imposed axial through-flow are investigated for two different axial boundary conditions at the in- and outlet. Unlike the stationary patterns in systems without through-flow the spatiotemporal structures of propagating vortices are independent of parameter history, initial conditions, and system's length. They do, however, depend on the axial boundary conditions, the driving rate of the inner cylinder and the through-flow rate. Our analysis of the amplitude equation shows that the pattern selection can be described by a nonlinear eigenvalue problem with the frequency being the eigenvalue. Approaching the border between absolute and convective instability the eigenvalue problem becomes effectively linear and the selection mechanism approaches that one of linear front propagation. PACS:47.54.+r,47.20.Ky,47.32.-y,47.20.FtComment: 15 pages (LateX-file), 8 figures (Postscript

Identifying critically important cardiovascular outcomes for trials in hemodialysis: an international survey with patients, caregivers and health professionals

BACKGROUND: Cardiovascular disease (CVD) is a major contributor to morbidity and mortality in people on hemodialysis (HD). Cardiovascular outcomes are reported infrequently and inconsistently across trials in HD. This study aimed to identify the priorities of patients/caregivers and health professionals (HPs) for CVD outcomes to be incorporated into a core outcome set reported in all HD trials. METHODS: In an international online survey, participants rated the absolute importance of 10 cardiovascular outcomes (derived from a systematic review) on a 9-point Likert scale, with 7-9 being critically important. The relative importance was determined using a best-worst scale. Likert means, medians and proportions and best-worst preference scores were calculated for each outcome. Comments were thematically analyzed. RESULTS: Participants included 127 (19%) patients/caregivers and 549 (81%) HPs from 53 countries, of whom 530 (78%) completed the survey in English and 146 (22%) in Chinese. All but one cardiovascular outcome ('valve replacement') was rated as critically important (Likert 7-9) by all participants; 'sudden cardiac death', 'heart attack', 'stroke' and 'heart failure' were all rated at the top by patients/caregivers (median Likert score 9). Patients/caregivers ranked the same four outcomes as the most important outcomes with mean preference scores of 6.2 (95% confidence interval 4.8-7.5), 5.9 (4.6-7.2), 5.3 (4.0-6.6) and 4.9 (3.6-6.3), respectively. The same four outcomes were ranked most highly by HPs. We identified five themes underpinning the prioritization of outcomes: 'clinical equipoise and potential for intervention', 'specific or attributable to HD', 'severity or impact on the quality of life', 'strengthen knowledge and education', and 'inextricably linked burden and risk'. CONCLUSIONS: Patients and HPs believe that all cardiovascular outcomes are of critical importance but consistently identify sudden cardiac death, myocardial infarction, stroke and heart failure as the most important outcomes to be measured in all HD trials

‘A sword of Damocles’ : patient and caregiver beliefs, attitudes and perspectives on presymptomatic testing for autosomal dominant polycystic kidney disease: a focus group study

Background and objectives: Presymptomatic testing is available for early diagnosis of hereditary autosomal dominant polycystic kidney disease (ADPKD). However, the complex ethical and psychosocial implications can make decision-making challenging and require an understanding of patients’ values, goals and priorities. This study aims to describe patient and caregiver beliefs and expectations regarding presymptomatic testing for ADPKD. Design, setting and participants: 154 participants (120 patients and 34 caregivers) aged 18 years and over from eight centres in Australia, France and Korea participated in 17 focus groups. Transcripts were analysed thematically. Results: We identified five themes: avoiding financial disadvantage (insecurity in the inability to obtain life insurance, limited work opportunities, financial burden); futility in uncertainty (erratic and diverse manifestations of disease limiting utility, taking preventive actions in vain, daunted by perplexity of results, unaware of risk of inheriting ADPKD); lacking autonomy and support in decisions (overwhelmed by ambiguous information, medicalising family planning, family pressures); seizing control of well-being (gaining confidence in early detection, allowing preparation for the future, reassurance in family resilience); and anticipating impact on quality of life (reassured by lack of symptoms, judging value of life with ADPKD). Conclusions: For patients with ADPKD, presymptomatic testing provides an opportunity to take ownership of their health through family planning and preventive measures. However, these decisions can be wrought with tensions and uncertainty about prognostic implications, and the psychosocial and financial burden of testing. Healthcare professionals should focus on genetic counselling, mental health and providing education to patients’ families to support informed decision-making. Policymakers should consider the cost burden and risk of discrimination when informing government policies. Finally, patients are recommended to focus on self-care from an early age

Core Outcome Measures for Trials in People with Coronavirus Disease 2019: Respiratory Failure, Multiorgan Failure, Shortness of Breath, and Recovery

OBJECTIVES: Respiratory failure, multiple organ failure, shortness of breath, recovery, and mortality have been identified as critically important core outcomes by more than 9300 patients, health professionals, and the public from 111 countries in the global coronavirus disease 2019 core outcome set initiative. The aim of this project was to establish the core outcome measures for these domains for trials in coronavirus disease 2019. DESIGN: Three online consensus workshops were convened to establish outcome measures for the four core domains of respiratory failure, multiple organ failure, shortness of breath, and recovery. SETTING: International. PATIENTS: About 130 participants (patients, public, and health professionals) from 17 countries attended the three workshops. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Respiratory failure, assessed by the need for respiratory support based on the World Health Organization Clinical Progression Scale, was considered pragmatic, objective, and with broad applicability to various clinical scenarios. The Sequential Organ Failure Assessment was recommended for multiple organ failure, because it was routinely used in trials and clinical care, well validated, and feasible. The Modified Medical Research Council measure for shortness of breath, with minor adaptations (recall period of 24 hr to capture daily fluctuations and inclusion of activities to ensure relevance and to capture the extreme severity of shortness of breath in people with coronavirus disease 2019), was regarded as fit for purpose for this indication. The recovery measure was developed de novo and defined as the absence of symptoms, resumption of usual daily activities, and return to the previous state of health prior to the illness, using a 5-point Likert scale, and was endorsed. CONCLUSIONS: The coronavirus disease 2019 core outcome set recommended core outcome measures have content validity and are considered the most feasible and acceptable among existing measures. Implementation of the core outcome measures in trials in coronavirus disease 2019 will ensure consistency and relevance of the evidence to inform decision-making and care of patients with coronavirus disease 2019