A Column Generation Approach to the Capacitated Vehicle Routing Problem with Stochastic Demands

In this article we introduce a new exact solution approach to the Capacitated Vehicle Routing Problem with Stochastic Demands (CVRPSD). In particular, we consider the case where all customer demands are distributed independently and where each customer’s demand follows a Poisson distribution. The CVRPSD can be formulated as a Set Partitioning Problem. We show that, under the above assumptions on demands, the associated column generation subproblem can be solved using a dynamic programming scheme which is similar to that used in the case of deterministic demands. To evaluate the potential of our approach we have embedded this column generation scheme in a branch-and-price algorithm. Computational experiments on a large set of test instances show promising resultsRouting; Stochastic programming; Logistics; Branch and Bound; Dynamic programming

Caries Epidemiology and Community Dentistry: Chances for Future Improvements in Caries Risk Groups. Outcomes of the ORCA Saturday Afternoon Symposium, Greifswald, 2014. Part 1

This paper reviews the first part of the outcomes of the ORCA Saturday Afternoon Symposium 2014 dealing with ‘caries epidemiology and community dentistry: chances for future improvements in caries risk groups'. After the caries decline in many countries, there are remaining pockets of higher caries levels, mostly in the primary dentition and/or linked to a low socio-economic status (SES). The review into the evidence of caries-preventive measures clearly points to the use of fluorides, especially toothbrushing with fluoridated toothpaste and collective measures such as water fluoridation. In contrast to several unsuccessful high-risk approaches, community and public health programmes seem to be able to ensure a population-wide access and compliance in risk groups. Their simple and evidence-based measures mostly combine regular plaque removal and fluoride applications via toothbrushing, at least for children and adolescents. For the future, the common risk factor approach which addresses associations between oral health, social deprivation, diet, hygiene, smoking, alcohol use and stress should lead to combined efforts with other community health and education specialists. Further engagement with public policy, community leaders and administration is needed in order to strengthen healthy choices and behaviour, e.g. in ‘healthy' schools and kindergartens. It seems advisable that these population programmes also aim at improving upstream factors

Julia Sets of Orthogonal Polynomials

For a probability measure with compact and non-polar support in the complex plane we relate dynamical properties of the associated sequence of orthogonal polynomials {P n } to properties of the support. More precisely we relate the Julia set of P n to the outer boundary of the support, the filled Julia set to the polynomial convex hull K of the support, and the Green’s function associated with P n to the Green’s function for the complement of K

Risk of incident atrial fibrillation in patients presenting with retinal artery or vein occlusion:a nationwide cohort study

Abstract Background The inter-relationships of atrial fibrillation (AF) to retinal vascular occlusions (whether retinal artery occlusion (RAO) or retinal venous occlusion (RVO)) remain unclear. It is unknown if a presentation of retinal artery or venous occlusions may indicate a new onset cardiac arrhythmia. To shed light on this association, we investigated the risk of new onset AF in patients with known RAO and RVO. Methods Patients with retinal occlusions from 1997 to 2011 were identified through Danish nationwide registries and matched 1:5 according to sex and age. Cumulative incidence and unadjusted rates of AF according to retinal vascular occlusions (i.e. RAO or RVO) were determined. Hazard ratios (HR) of AF according to retinal vascular occlusion were adjusted for hypertension, diabetes, vascular disease and prior stroke/systemic thromboembolism/transient ischemic attack. Results One thousand three hundred sixty-eight cases with retinal vascular occlusions were identified (median age 71.4 (inter quartile range (IQR); 61.2–79.8), 47.3% male). RAO constituted 706 cases (51.6%) and RVO 529 (38.7%). The rate of incident AF amongst all cases with retinal vascular occlusion was 1.74 per 100 person-years (95% confidence interval (CI), 1.47–2.06) compared to 1.22 (95% CI, 1.12–1.33) in the matched control group. The rate of AF in RAO was 2.01 (95% CI, 1.6–2.52) and 1.52 (1.15–2.01) in RVO. HRs of incident AF adjusted for cardiovascular comorbidities were 1.26 (95% CI; 1.04–1.53, p = 0.019) for any retinal vascular occlusion, 1.45 (95% CI; 1.10–1.89, p = 0.015) for RAO, and 1.02 (95% CI; 0.74–1.39, p = 0.920) for RVO. Conclusions A new diagnosis of retinal vascular occlusion in patients without prior AF was associated with increased risk of incident AF, particularly amongst patients with RAO. Awareness of AF in patients with retinal vascular occlusions is advised

Author Correction: Novel diagnostic and therapeutic techniques reveal changed metabolic profiles in recurrent focal segmental glomerulosclerosis

Idiopathic forms of Focal Segmental Glomerulosclerosis (FSGS) are caused by circulating permeability factors, which can lead to early recurrence of FSGS and kidney failure after kidney transplantation. In the past three decades, many research endeavors were undertaken to identify these unknown factors. Even though some potential candidates have been recently discussed in the literature, “the” actual factor remains elusive. Therefore, there is an increased demand in FSGS research for the use of novel technologies that allow us to study FSGS from a yet unexplored angle. Here, we report the successful treatment of recurrent FSGS in a patient after living-related kidney transplantation by removal of circulating factors with CytoSorb apheresis. Interestingly, the classical published circulating factors were all in normal range in this patient but early disease recurrence in the transplant kidney and immediate response to CytoSorb apheresis were still suggestive for pathogenic circulating factors. To proof the functional effects of the patient’s serum on podocytes and the glomerular filtration barrier we used a podocyte cell culture model and a proteinuria model in zebrafish to detect pathogenic effects on the podocytes actin cytoskeleton inducing a functional phenotype and podocyte effacement. We then performed Raman spectroscopy in the < 50 kDa serum fraction, on cultured podocytes treated with the FSGS serum and in kidney biopsies of the same patient at the time of transplantation and at the time of disease recurrence. The analysis revealed changes in podocyte metabolome induced by the FSGS serum as well as in focal glomerular and parietal epithelial cell regions in the FSGS biopsy. Several altered Raman spectra were identified in the fractionated serum and metabolome analysis by mass spectrometry detected lipid profiles in the FSGS serum, which were supported by disturbances in the Raman spectra. Our novel innovative analysis reveals changed lipid metabolome profiles associated with idiopathic FSGS that might reflect a new subtype of the disease

Novel diagnostic and therapeutic techniques reveal changed metabolic profiles in recurrent focal segmental glomerulosclerosis

Idiopathic forms of Focal Segmental Glomerulosclerosis (FSGS) are caused by circulating permeability factors, which can lead to early recurrence of FSGS and kidney failure after kidney transplantation. In the past three decades, many research endeavors were undertaken to identify these unknown factors. Even though some potential candidates have been recently discussed in the literature, “the” actual factor remains elusive. Therefore, there is an increased demand in FSGS research for the use of novel technologies that allow us to study FSGS from a yet unexplored angle. Here, we report the successful treatment of recurrent FSGS in a patient after living-related kidney transplantation by removal of circulating factors with CytoSorb apheresis. Interestingly, the classical published circulating factors were all in normal range in this patient but early disease recurrence in the transplant kidney and immediate response to CytoSorb apheresis were still suggestive for pathogenic circulating factors. To proof the functional effects of the patient’s serum on podocytes and the glomerular filtration barrier we used a podocyte cell culture model and a proteinuria model in zebrafish to detect pathogenic effects on the podocytes actin cytoskeleton inducing a functional phenotype and podocyte effacement. We then performed Raman spectroscopy in the < 50 kDa serum fraction, on cultured podocytes treated with the FSGS serum and in kidney biopsies of the same patient at the time of transplantation and at the time of disease recurrence. The analysis revealed changes in podocyte metabolome induced by the FSGS serum as well as in focal glomerular and parietal epithelial cell regions in the FSGS biopsy. Several altered Raman spectra were identified in the fractionated serum and metabolome analysis by mass spectrometry detected lipid profiles in the FSGS serum, which were supported by disturbances in the Raman spectra. Our novel innovative analysis reveals changed lipid metabolome profiles associated with idiopathic FSGS that might reflect a new subtype of the disease

Incidence rates of dilated cardiomyopathy in adult first-degree relatives versus matched controls

BACKGROUND: The incidence rates and importance of traditional risk factors in dilated cardiomyopathy among first-degree relatives are unknown. METHODS AND RESULTS: We identified all probands with dilated cardiomyopathy (n = 13,714, mean age at diagnosis 63 years) from the Danish nationwide registries between 1994 and 2017. Incidence rates among first-degree relatives (n = 29,671, mean age 38 years) and for up to 10 age- and sex-matched controls were calculated. Totally 233 (0.8%) first-degree relatives and 285 (0.1%) controls developed dilated cardiomyopathy during a median follow-up of 8.2 (Q1-Q3 4.4–13.3) years. Incidence rates (per 100,000 person-years) were 86.4 (95% confidence interval 73.9–101.0) and 111.1 (79.4–128.7) for first-degree relatives aged < 50 and ≥ 50 years, respectively, versus 7.5 (6.4–8.9) and 19.7 (16.8–23.2) for controls. Atrial fibrillation, diabetes, ischemic heart disease, and hypertension were associated with increased risks of developing dilated cardiomyopathy both in first-degree relatives and controls. Population attributable fractions for the 4 risk factors were 27.7% for first-degree relatives and 37.3% for controls aged < 50 years, and 46.4% versus 58.4% for first-degree relatives and controls among people aged ≥ 50 years, respectively. CONCLUSIONS: The absolute incidence rates of dilated cardiomyopathy in first-degree relatives to patients with dilated cardiomyopathy were low, but significantly higher than in matched controls and elevated by the presence of additional risk factors, especially atrial fibrillation. Additional investigations are warranted to assess whether aggressive treatment of risk factors translates into a reduction of dilated cardiomyopathy in first-degree relatives

The smallest eigenvalue of Hankel matrices

Let H_N=(s_{n+m}),n,m\le N denote the Hankel matrix of moments of a positive measure with moments of any order. We study the large N behaviour of the smallest eigenvalue lambda_N of H_N. It is proved that lambda_N has exponential decay to zero for any measure with compact support. For general determinate moment problems the decay to 0 of lambda_N can be arbitrarily slow or arbitrarily fast. In the indeterminate case, where lambda_N is known to be bounded below by a positive constant, we prove that the limit of the n'th smallest eigenvalue of H_N for N tending to infinity tends rapidly to infinity with n. The special case of the Stieltjes-Wigert polynomials is discussed