The sensitivity of the vortex filament method to different reconnection models

We present a detailed analysis on the effect of using different algorithms to model the reconnection of vortices in quantum turbulence, using the thin-filament approach. We examine differences between four main algorithms for the case of turbulence driven by a counterflow. In calculating the velocity field we use both the local induction approximation (LIA) and the full Biot-Savart integral. We show that results of Biot-Savart simulations are not sensitive to the particular reconnection method used, but LIA results are.Comment: 9 pages, 9 figure

Tree method for quantum vortex dynamics

We present a numerical method to compute the evolution of vortex filaments in superfluid helium. The method is based on a tree algorithm which considerably speeds up the calculation of Biot-Savart integrals. We show that the computational cost scales as Nlog{(N) rather than N squared, where $N$ is the number of discretization points. We test the method and its properties for a variety of vortex configurations, ranging from simple vortex rings to a counterflow vortex tangle, and compare results against the Local Induction Approximation and the exact Biot-Savart law.Comment: 12 pages, 10 figure

Patient reported barriers are associated with low physical and mental well-being in patients with co-morbid diabetes and chronic kidney disease

BACKGROUND:Little is known about how patient reported barriers to health care impact the quality of life (HRQoL) of patients with comorbid disease. We investigated patient reported barriers to health care and low physical and mental well-being among people with diabetes and chronic kidney disease (CKD). METHODS:Adults with diabetes and CKD (estimated Glomerular Filtration Rate < 60 ml/min/1.73m2) were recruited and completed a questionnaire on barriers to health care, the 12-Item HRQoL Short Form Survey and clinical assessment. Low physical and mental health status were defined as mean scores < 50. Logistic regression models were used. RESULTS:Three hundred eight participants (mean age 66.9 ± 11 years) were studied. Patient reported 'impact of the disease on family and friends' (OR 2.07; 95% CI 1.14 to 3.78), 'feeling unwell' (OR 4.23; 95% CI 1.45 to 12.3) and 'having other life stressors that make self-care a low priority' (OR 2.59; 95% CI 1.20 to 5.61), were all associated with higher odds of low physical health status. Patient reported 'feeling unwell' (OR 2.92; 95% CI 1.07 to 8.01), 'low mood' (OR 2.82; 95% CI 1.64 to 4.87) and 'unavailability of home help' (OR 1.91; 95% CI 1.57 to 2.33) were all associated with higher odds of low mental health status. The greater the number of patient reported barriers the higher the odds of low mental health but not physical health status. CONCLUSIONS:Patient reported barriers to health care were associated with lower physical and mental well-being. Interventions addressing these barriers may improve HRQoL among people with comorbid diabetes and CKD.Edward Zimbudzi, Clement Lo, Sanjeeva Ranasinha, Gregory Fulcher, Martin Gallagher, Stephen Jan, Peter G. Kerr, Helena J. Teede, Kevan R. Polkinghorne, Grant Russell, Rowan G. Walker, and Sophia Zounga

Kidney transplant recipient perspectives on telehealth during the COVID-19 pandemic

The COVID-19 pandemic has challenged the delivery of health services. Telehealth allows delivery of care without in-person contacts and minimizes the risk of vial transmission. We aimed to describe the perspectives of kidney transplant recipients on the benefits, challenges, and risks of telehealth. We conducted five online focus groups with 34 kidney transplant recipients who had experienced a telehealth appointment. Transcripts were thematically analyzed. We identified five themes: minimizing burden (convenient and easy, efficiency of appointments, reducing exposure to risk, limiting work disruptions, and alleviating financial burden); attuning to individual context (depending on stability of health, respect patient choice of care, and ensuring a conducive environment); protecting personal connection and trust (requires established rapport with clinicians, hampering honest conversations, diminished attentiveness without incidental interactions, reassurance of follow-up, and missed opportunity to share lived experience); empowerment and readiness (increased responsibility for self-management, confidence in physical assessment, mental preparedness, and forced independence); navigating technical challenges (interrupted communication, new and daunting technologies, and cognizant of patient digital literacy). Telehealth is convenient and minimizes time, financial, and overall treatment burden. Telehealth should ideally be available after the pandemic, be provided by a trusted nephrologist and supported with resources to help patients prepare for appointments.Brooke M Huuskes, Nicole Scholes-Robertson, Chandana Guha, Amanda Baumgart, Germaine Wong, John Kanellis ... et al

Identifying patient-important outcomes in polycystic kidney disease: An international nominal group technique study

AIM: Patients with autosomal dominant polycystic kidney disease (ADPKD) are at increased risk of premature mortality, morbidities and complications, which severely impair quality of life. However, patient-centered outcomes are not consistently reported in trials in ADPKD, which can limit shared decision-making. We aimed to identify outcomes important to patients and caregivers and the reasons for their priorities. METHODS: Nominal group technique was adopted involving patients with ADPKD and caregivers who were purposively selected from eight centres across Australia, France and the Republic of Korea. Participants identified, ranked and discussed outcomes for trials in ADPKD. We calculated an importance score (0-1) for each outcome and conducted thematic analyses. RESULTS: Across 17 groups, 154 participants (121 patients, 33 caregivers) aged 19 to 78 (mean 54.5 years) identified 55 outcomes. The 10 highest ranked outcomes were: kidney function (importance score 0.36), end-stage kidney disease (0.32), survival (0.21), cyst size/growth (0.20), cyst pain/bleeding (0.18), blood pressure (0.17), ability to work (0.16), cerebral aneurysm/stroke (0.14), mobility/physical function (0.12), and fatigue (0.12). Three themes were identified: threatening semblance of normality, inability to control and making sense of diverse risks. CONCLUSION: For patients with ADPKD and their caregivers, kidney function, delayed progression to end-stage kidney disease and survival were the highest priorities, and were focused on achieving normality, and maintaining control over health and lifestyle. Implementing these patient-important outcomes may improve the meaning and relevance of trials to inform clinical care in ADPKD

Health-related quality of life among patients with comorbid diabetes and kidney disease attending a codesigned integrated model of care: a longitudinal study

OBJECTIVE:To evaluate the impact of an integrated diabetes and kidney disease model of care on health-related quality of life (HRQOL) of patients with comorbid diabetes and chronic kidney disease (CKD). RESEARCH DESIGN AND METHODS:A longitudinal study of adult patients (over 18 years) with comorbid diabetes and CKD (stage 3a or worse) who attended a new diabetes kidney disease service was conducted at a tertiary hospital. A questionnaire consisting of demographics, clinical data, and the Kidney Disease Quality of Life (KDQOL-36) was administered at baseline and after 12 months. Paired t-tests were used to compare baseline and 12-month scores. A subgroup analysis examined the effects by patient gender. Multiple regression analysis examined the factors associated with changes in scores. RESULTS:179 patients, 36% of whom were female, with baseline mean±SD age of 65.9±11.3 years, were studied. Across all subscales, HRQOL did not significantly change over time (p value for all mean differences >0.05). However, on subgroup analysis, symptom problem list and physical composite summary scores increased among women (MD=9.0, 95% CI 1.25 to 16.67; p=0.02 and MD=4.5, 95% CI 0.57 to 8.42; p=0.03 respectively) and physical composite scores decreased among men (MD=-3.35, 95% CI -6.26 to -0.44; p=0.03). CONCLUSION:The HRQOL of patients with comorbid diabetes and CKD attending a new codesigned, integrated diabetes and kidney disease model of care was maintained over 12 months. Given that HRQOL is known to deteriorate over time in this high-risk population, the impact of these findings on clinical outcomes warrants further investigation.Edward Zimbudzi, Clement Lo, Sanjeeva Ranasinha, Helena Teede, Tim Usherwood, Kevan R Polkinghorne ... et al

Dressing with Control: using integrability to generate desired solutions to Einstein's equations

21 pages, no figures21 pages, no figures21 pages, no figures21 pages, no figuresMotivated by integrability of the sine-Gordon equation, we investigate a technique for constructing desired solutions to Einstein's equations by combining a dressing technique with a control-theory approach. After reviewing classical integrability, we recall two well-known Killing field reductions of Einstein's equations, unify them using a harmonic map formulation, and state two results on the integrability of the equations and solvability of the dressing system. The resulting algorithm is then combined with an asymptotic analysis to produce constraints on the degrees of freedom arising in the solution-generation mechanism. The approach is carried out explicitly for the Einstein vacuum equations. Applications of the technique to other geometric field theories are also discussed

Can we IMPROVE cardiovascular outcomes through phosphate lowering in CKD? Rationale and protocol for the IMpact of Phosphate Reduction on Vascular End-points in Chronic Kidney Disease (IMPROVE-CKD) study

Introduction: Patients with chronic kidney disease (CKD) are at heightened cardiovascular risk, which has been associated with abnormalities of bone and mineral metabolism. A deeper understanding of these abnormalities should facilitate improved treatment strategies and patient-level outcomes, but at present there are few large, randomised controlled clinical trials to guide management. Positive associations between serum phosphate and fibroblast growth factor 23 (FGF-23) and cardiovascular morbidity and mortality in both the general and CKD populations have resulted in clinical guidelines suggesting that serum phosphate be targeted towards the normal range, although few randomised and placebo-controlled studies have addressed clinical outcomes using interventions to improve phosphate control. Early preventive measures to reduce the development and progression of vascular calcification, left ventricular hypertrophy and arterial stiffness are crucial in patients with CKD. Methods and analysis: We outline the rationale and protocol for an international, multicentre, randomised parallel-group trial assessing the impact of the non-calcium-based phosphate binder, lanthanum carbonate, compared with placebo on surrogate markers of cardiovascular disease in a predialysis CKD population—the IM pact of P hosphate R eduction O n V ascular E nd-points (IMPROVE)-CKD study. The primary objective of the IMPROVE-CKD study is to determine if the use of lanthanum carbonate reduces the burden of cardiovascular disease in patients with CKD stages 3b and 4 when compared with placebo. The primary end-point of the study is change in arterial compliance measured by pulse wave velocity over a 96-week period. Secondary outcomes include change in aortic calcification and biochemical parameters of serum phosphate, parathyroid hormone and FGF-23 levels. Ethics and dissemination: Ethical approval for the IMPROVE-CKD trial was obtained by each local Institutional Ethics Committee for all 17 participating sites in Australia, New Zealand and Malaysia prior to study commencement. Results of this clinical trial will be published in peer-reviewed journals and presented at conferences.Nicole Lioufas, Nigel D Toussaint, Eugenia Pedagogos, Grahame Elder, Sunil V Badve, Elaine Pascoe, Andrea Valks, Carmel Hawley, Geoffrey A Block, Neil C Boudville, Katrina Campbell, James D Cameron, Sylvia S M Chen, Randall J Faull, Stephen G Holt, Lai S Hooi, Dana Jackson, Meg J Jardine, David W Johnson, Peter G Kerr, Kenneth K Lau, Alicia Morrish, Vlado Perkovic, Kevan R Polkinghorne, Carol A Pollock, Donna Reidlinger, Laura Robison, Edward R Smith, Robert J Walker, Angela Yee Moon Wang

Dialysis initiation, modality choice, access, and prescription: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

Globally, the number of patients undergoing maintenance dialysis is increasing, yet throughout the world there is significant variability in the practice of initiating dialysis. Factors such as availability of resources, reasons for starting dialysis, timing of dialysis initiation, patient education and preparedness, dialysis modality and access, as well as varied \u201ccountry-specific\u201d factors significantly affect patient experiences and outcomes. As the burden of end-stage kidney disease (ESKD) has increased globally, there has also been a growing recognition of the importance of patient involvement in determining the goals of care and decisions regarding treatment. In January 2018, KDIGO (Kidney Disease: Improving Global Outcomes) convened a Controversies Conference focused on dialysis initiation, including modality choice, access, and prescription. Here we present a summary of the conference discussions, including identified knowledge gaps, areas of controversy, and priorities for research. A major novel theme represented during the conference was the need to move away from a \u201cone-size-fits-all\u201d approach to dialysis and provide more individualized care that incorporates patient goals and preferences while still maintaining best practices for quality and safety. Identifying and including patient-centered goals that can be validated as quality indicators in the context of diverse health care systems to achieve equity of outcomes will require alignment of goals and incentives between patients, providers, regulators, and payers that will vary across health care jurisdictions