A Randomized Incremental Algorithm for the Hausdorff Voronoi Diagram of Non-crossing Clusters

In the Hausdorff Voronoi diagram of a family of \emph{clusters of points} in the plane, the distance between a point $t$ and a cluster $P$ is measured as the maximum distance between $t$ and any point in $P$, and the diagram is defined in a nearest-neighbor sense for the input clusters. In this paper we consider %El."non-crossing" \emph{non-crossing} clusters in the plane, for which the combinatorial complexity of the Hausdorff Voronoi diagram is linear in the total number of points, $n$, on the convex hulls of all clusters. We present a randomized incremental construction, based on point location, that computes this diagram in expected $O(n\log^2{n})$ time and expected $O(n)$ space. Our techniques efficiently handle non-standard characteristics of generalized Voronoi diagrams, such as sites of non-constant complexity, sites that are not enclosed in their Voronoi regions, and empty Voronoi regions. The diagram finds direct applications in VLSI computer-aided design.Comment: arXiv admin note: substantial text overlap with arXiv:1306.583

Quantization of Soliton Cellular Automata

A method of quantization of classical soliton cellular automata (QSCA) is put forward that provides a description of their time evolution operator by means of quantum circuits that involve quantum gates from which the associated Hamiltonian describing a quantum chain model is constructed. The intrinsic parallelism of QSCA, a phenomenon first known from quantum computers, is also emphasized.Comment: Latex, 6 pages, 1 figure in eps format included. Submitted to Journal of Nonlinear Mathematical Physics. Special Issue of Proccedings of NEEDS'9

On the hausdorff and other cluster Voronoi diagrams

The Voronoi diagram is a fundamental geometric structure that encodes proximity information. Given a set of geometric objects, called sites, their Voronoi diagram is a subdivision of the underlying space into maximal regions, such that all points within one region have the same nearest site. Problems in diverse application domains (such as VLSI CAD, robotics, facility location, etc.) demand various generalizations of this simple concept. While many generalized Voronoi diagrams have been well studied, many others still have unsettled questions. An example of the latter are cluster Voronoi diagrams, whose sites are sets (clusters) of objects rather than individual objects. In this dissertation we study certain cluster Voronoi diagrams from the perspective of their construction algorithms and algorithmic applications. Our main focus is the Hausdorff Voronoi diagram; we also study the farthest-segment Voronoi diagram, as well as certain special cases of the farthest-color Voronoi diagram. We establish a connection between cluster Voronoi diagrams and the stabbing circle problem for segments in the plane. Our results are as follows. (1) We investigate the randomized incremental construction of the Hausdorff Voronoi diagram. We consider separately the case of non-crossing clusters, when the combinatorial complexity of the diagram is O(n) where n is the total number of points in all clusters. For this case, we present two construction algorithms that require O(n log2 n) expected time. For the general case of arbitrary clusters, we present an algorithm that requires O((m + n log n) log n) expected time and O(m + n log n) expected space, where m is a parameter reflecting the number of crossings between clusters' convex hulls. (2) We present an O(n) time algorithm to construct the farthest-segment Voronoi diagram of n segments, after the sequence of its faces at infinity is known. This augments the well-known linear-time framework for Voronoi diagram of points in convex position, with the ability to handle disconnected Voronoi regions. (3) We establish a connection between the cluster Voronoi diagrams (the Hausdorff and the farthest-color Voronoi diagram) and the stabbing circle problem. This implies a new method to solve the latter problem. Our method results in a near-optimal O(n log2 n) time algorithm for a set of n parallel segments, and in an optimal O(n log n) time algorithm for a set of n segments satisfying some other special conditions. (4) We study the farthest-color Voronoi diagram in special cases considered by the stabbing circle problem. We prove O(n) bound for its combinatorial complexity and present an O(nlogn) time algorithm to construct it

The effectiveness of a stress-management intervention program in the management of overweight and obesity in childhood and adolescence

Background: Obesity in childhood and adolescence represents a major health problem of our century, and accounts for a significant increase in morbidity and mortality in adulthood. In addition to the increased consumption of calories and lack of exercise, accumulating evidence suggests that childhood obesity is strongly associated with prolonged and excessive activation of the stress system. Aim: The aim of our study was to assess the effectiveness of a stress-management intervention program, which included progressive muscle relaxation, diaphragmatic breathing, guided imagery and cognitive restructuring, in overweight and obese children and adolescents. Methods: Forty-nine children and adolescents (mean age ± SEM: 11.15 ± 1.48 years) were prospectively recruited to participate in this randomized controlled study. Of those, 23 participants were assigned into the intervention group, while 26 participants represented the control group. Anthropometric measurements were recorded at the beginning and at the end of the study, and participants were asked to complete the Screen for Child Anxiety Related Disorders (S.C.A.R.E.D.), the Child Depression Inventory (C.D.I.), the Child Behavior Checklist (C.B.C.L.) and the Youth Self Report (Y.S.R.). Results: The applied stress-management methods resulted in a significant reduction in the body mass index (BMI) in the intervention group compared with the control group [ΔBMI=1.18 vs 0.10 kg/m2 (p˂0.001)]. In addition to BMI, these methods ameliorated depression and anxiety, and reduced the internalizing and externalizing problems in the intervention group. Conclusions: Our study demonstrated that the application of an 8-week stress management program could facilitate weight loss in Greek overweight and obese children and adolescents. Further larger studies are required to evaluate the effectiveness of stress-management methods in overweight and obese subjects

Genetic testing of Behçet’s disease using next-generation sequencing to identify monogenic mimics and HLA-B*51

Objective: Several monogenic autoinflammatory disorders and primary immunodeficiencies can present early in life with features that may be mistaken for Behçet's disease (BD). We aimed to develop a genetic analysis workflow to identify rare monogenic BD-like diseases and establish the contribution of HLA haplotype in a cohort of patients from the UK. // Methods: Patients with clinically suspected BD were recruited from four BD specialist care centres in the UK. All participants underwent whole exome sequencing (WES), and genetic analysis thereafter by 1. examining genes known to cause monogenic immunodeficiency, autoinflammation or vasculitis by virtual panel application; 2. scrutiny of variants prioritised by Exomiser using Human Phenotype Ontology (HPO); 3. identification of copy number variants using ExomeDepth; and 4. HLA-typing using OptiType. // Results: Thirty-one patients were recruited: median age 15 (4-52), and median disease onset age 5 (0-20). Nine/31 (29%) patients had monogenic disease mimicking BD: 5 cases of Haploinsufficiency of A20 with novel TNFAIP3 variants (p.T76I, p.M112Tfs*8, p.S548Dfs*128, p.C657Vfs*14, p.E661Nfs*36); 1 case of ISG15 deficiency with a novel nonsense variant (ISG15:p.Q16X) and 1p36.33 microdeletion; 1 case of Common variable immune deficiency (TNFRSF13B:p.A181E); and 2 cases of TNF receptor associated periodic syndrome (TNFRSF1A:p.R92Q). Of the remaining 22 patients, 8 (36%) were HLA-B*51 positive. // Conclusion: We describe a novel genetic workflow for BD, which can efficiently detect known and potentially novel monogenic forms of BD, whilst additionally providing HLA-typing. Our results highlight the importance of genetic testing before BD diagnosis, since this has impact on choice of therapy, prognosis, and genetic counselling

Prospective Analysis of Factors Influencing the Antibody Response to Hepatitis B Vaccine in Hemodialysis Patients

Abstract Background. Patients on maintenance hemodialysis typically show a suboptimal immune response to hepatitis B (HB) virus vaccination compared to the non-uremic population. The aim or our study was the identification of factors implicated in the vaccine response of our hemodialysis patients. Methods. We studied prospectively 63 hemodialysis patients who were seronegative for HB (37 males, 26 females). Their mean age was 62.2±11.28 years (range 35-80) and hemodialysis. Duration 55.96±50.1 months (range 6-225) fourteen of them (22.2%) were diabetics. Our patients followed a four-dose vaccination schedule (0, 1, 2 and 6 months) with 40 μg of a recombinant DNA HB vaccine. The antibody response was determined 1 month after the fourth dose of vaccination by assessing the titre of antiHBs antibodies (ab). Immune response was defined as sufficient when the antiHBs ab level was ≥ 12 mIU/ml. During the 6-month vaccination period we also monitored monthly and time-averaged Kt/V, residual renal function (RRF), BMI, serum creatinine, albumin, transferrin, ferritin, CRP, iPTH and the dose of erythropoietin and Vitamin D that they received. Results. An optimal immune response was achieved in 34 patients (54%, responders) (antiHBs: 295.95±341.67 mIU/ml), whereas 29 patients (46%, non-responders) showed a suboptimal response (antiHBs: 1.98±2.92 mIU/ml) (p=1.75x10 -5 ). There was a statistically significant negative correlation between the antiHBs ab titre and BMI (r=-0.28, p=0.024). A significant difference was also found between the BMI of responders and non-responders as groups (24.8±5.5 vs. 27.2±4.5, p=0.02). Grouping our patients according to the existence of diabetes, age (cut off 60 years), and hemodialysis efficiency (Kt/V≥1.2) we found a statistically significant difference in the antiHBs ab titre between diabetics and non-diabetics (8.43±12.3 vs. 200.2±317.7 mIU/ml, p=0.03), younger and older patients (262±365.09 vs. 84.36±189.1 mIU/ml, p=0.0145) and patients with efficient and inefficient hemodialysis (234.71±337.1 vs. 79.14±200.99 mIU/ml, p=0.032). Treatment with vitamin D analogues, RRF and hypoalbuminemia were not found to be implicated in the immune response of our patients

The Eurasian Modern Pollen Database (EMPD), version 2

The Eurasian (née European) Modern Pollen Database (EMPD) was established in 2013 to provide a public database of high-quality modern pollen surface samples to help support studies of past climate, land cover, and land use using fossil pollen. The EMPD is part of, and complementary to, the European Pollen Database (EPD) which contains data on fossil pollen found in Late Quaternary sedimentary archives throughout the Eurasian region. The EPD is in turn part of the rapidly growing Neotoma database, which is now the primary home for global palaeoecological data. This paper describes version 2 of the EMPD in which the number of samples held in the database has been increased by 60 % from 4826 to 8134. Much of the improvement in data coverage has come from northern Asia, and the database has consequently been renamed the Eurasian Modern Pollen Database to reflect this geographical enlargement. The EMPD can be viewed online using a dedicated map-based viewer at https://empd2.github.io and downloaded in a variety of file formats at https://doi.pangaea.de/10.1594/PANGAEA.909130 (Chevalier et al., 2019)Swiss National Science Foundation | Ref. 200021_16959

The Eurasian Modern Pollen Database (EMPD), version 2

The Eurasian (nee European) Modern Pollen Database (EMPD) was established in 2013 to provide a public database of high-quality modern pollen surface samples to help support studies of past climate, land cover, and land use using fossil pollen. The EMPD is part of, and complementary to, the European Pollen Database (EPD) which contains data on fossil pollen found in Late Quaternary sedimentary archives throughout the Eurasian region. The EPD is in turn part of the rapidly growing Neotoma database, which is now the primary home for global palaeoecological data. This paper describes version 2 of the EMPD in which the number of samples held in the database has been increased by 60% from 4826 to 8134. Much of the improvement in data coverage has come from northern Asia, and the database has consequently been renamed the Eurasian Modern Pollen Database to reflect this geographical enlargement. The EMPD can be viewed online using a dedicated map-based viewer at https://empd2.github.io and downloaded in a variety of file formats at https://doi.pangaea.de/10.1594/PANGAEA.909130 (Chevalier et al., 2019).Peer reviewe