Computing the Greedy Spanner in Linear Space

The greedy spanner is a high-quality spanner: its total weight, edge count and maximal degree are asymptotically optimal and in practice significantly better than for any other spanner with reasonable construction time. Unfortunately, all known algorithms that compute the greedy spanner of n points use Omega(n^2) space, which is impractical on large instances. To the best of our knowledge, the largest instance for which the greedy spanner was computed so far has about 13,000 vertices. We present a O(n)-space algorithm that computes the same spanner for points in R^d running in O(n^2 log^2 n) time for any fixed stretch factor and dimension. We discuss and evaluate a number of optimizations to its running time, which allowed us to compute the greedy spanner on a graph with a million vertices. To our knowledge, this is also the first algorithm for the greedy spanner with a near-quadratic running time guarantee that has actually been implemented

Visual Encoding of Dissimilarity Data via Topology-Preserving Map Deformation

We present an efficient technique for topology-preserving map deformation and apply it to the visualization of dissimilarity data in a geographic context. Map deformation techniques such as value-by-area cartograms are well studied. However, using deformation to highlight (dis)similarity between locations on a map in terms of their underlying data attributes is novel. We also identify an alternative way to represent dissimilarities on a map through the use of visual overlays. These overlays are complementary to deformation techniques and enable us to assess the quality of the deformation as well as to explore the design space of blending the two methods. Finally, we demonstrate how these techniques can be useful in several—quite different—applied contexts: travel-time visualization, social demographics research and understanding energy flowing in a wide-area power-grid

Distress in parents of children with first-onset steroid-sensitive nephrotic syndrome

Background:Steroid-sensitive nephrotic syndrome (SSNS) is associated with a relapsing–remitting course that can be stressful for parents. As little is known of parental distress at the first onset of SSNS, this study aims to describe parental distress and everyday problems in mothers and fathers of a child with newly diagnosed SSNS participating in a randomized controlled trial of levamisole added to corticosteroids. 'Methods: To assess distress, the Distress Thermometer for Parents (DT-P) was used, which includes questions on distress (thermometer score 0–10, ≥ 4 “clinical distress”) and presence of everyday problems in six domains: practical, social, emotional, physical, cognitive, and parenting. The DT-P was completed 4 weeks after the onset of SSNS. Total sum and individual items of everyday problems were compared with reference data from mothers and fathers of the Dutch general population. Results: There was no difference in clinically elevated parental distress between SSNS mothers (n = 37) and fathers (n = 25) and reference parents. Compared to reference fathers, fathers of a child with SSNS scored significantly higher on emotional problems (P = 0.030), while mothers experienced more parenting problems (P = 0.002). Regression analyses showed that lower parental age and having a girl with SSNS were significantly associated with more practical problems and higher distress thermometer scores, respectively. Conclusions: Four weeks after onset, SSNS mothers and fathers experience equal distress as reference parents. However, both parents endorsed significantly more everyday problems. Therefore, monitoring parental distress, even in the first weeks of the disease, could contribute to timely interventions and prevent worsening of problems. Clinical trial registry: Dutch Trial Register (https://onderzoekmetmensen.nl/en/trial/27331 ). Graphical abstract: [Figure not available: see fulltext.]</p

Hydrocortisone-induced increase of PDGF β-receptor expression in a human malignant mesothelioma cell line

The effect of hydrocortisone (HC) on PDGF β-receptor expression was studied in the human malignant mesothelioma cell line Mero-14. HC was found to induce a time- and dose-dependent increase of PDGF β-receptor mRNA. Nuclear run off analysis revealed that HC induced increased transcription of the PDGF β-receptor gene. The expression of PDGF β-receptor protein was also elevated by HC as demonstrated with an immunoblotting assay. However, the number of PDGF-BB binding sites on the cell surface of Mero-14 remained unchanged upon HC treatment. These results suggest that steroid hormones can regulate PDGF receptor expression in vivo

Health-related quality of life of children with first onset steroid-sensitive nephrotic syndrome

This study assessed HRQoL and emotional and behavioral difficulties (EBD) and associated variables in children with first onset SSNS. While relapsing steroid-sensitive nephrotic syndrome (SSNS) in children is associated with lower health-related quality of life (HRQoL), little is known about first onset. Four weeks after onset, children (2–16 years) and/or their parents who participated in a randomized placebo-controlled trial, completed the Pediatric Quality of Life Inventory 4.0 (PedsQL) and Strengths and Difficulties Questionnaire (SDQ) to measure HRQoL and EBD, respectively. Total and subscale scores and the proportion of children with impaired HRQoL (&gt; 1 SD below the mean of the reference group) or SDQ clinical scores (&lt; 10th and &gt; 90th percentile) were compared to the Dutch general population (reference group). Regression analyses were used to identify associated variables. Compared to the reference group, children 8–18 years reported significantly lower total HRQoL, and physical and emotional functioning. A large proportion (&gt; 45%) of these children had impaired HRQoL. There were no differences in HRQoL between children 2–7 years and the reference group, except for higher scores on social functioning (5–7 years). Similar proportions of SSNS and reference children scored within the clinical range of SDQ subscales. Age, sex, and steroid side-effects were negatively associated with HRQol and/or EBD. Conclusion: This study showed that HRQoL and EBD are affected in children of different ages with first onset SSNS. This calls for more awareness from healthcare providers and routinely monitoring of HRQoL and EBD in daily clinical care to prevent worsening of symptoms. Clinical trial registry: Netherlands Trial Register (https://trialsearch.who.int/ ; NTR7013), date of registration: 02 June 2018. What is Known: • Health-related quality of life (HRQoL) is lower and emotional and behavioral difficulties (EBD) is more affected in children with frequently-relapsing and steroid-dependent nephrotic syndrome. What is New: • HRQoL and EBD are affected in children with first onset steroid-sensitive nephrotic syndrome compared to a reference group of the Dutch general population. • To what extent HRQoL and EBD are affected depends on the age of the patient.</p

Insufficient protection by Neisseria meningitidis vaccination alone during eculizumab therapy

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mHealth in urology

Introduction: Smartphones are increasingly playing a role in healthcare and previous studies assessing medical applications (apps) have raised concerns about lack of expert involvement and low content accuracy. However, there are no such studies in Urology. We reviewed Urology apps with the aim of assessing the level of participation of healthcare professionals (HCP) and scientific Urology associations in their development. Material and Methods: A systematic search was performed on PubMed, Apple's App Store and Google's Play Store, for Urology apps, available in English. Apps were reviewed by three graders to determine the app's platform, target customer, developer, app type, app category, price and the participation of a HCP or a scientific Urology association in the development. Results: The search yielded 372 apps, of which 150 were specific for Urology. A fifth of all apps had no HCP involvement (20.7%) and only a third had been developed with a scientific Urology association (34.7%). The lowest percentage of HCP (13.4%) and urological association (1.9%) involvement was in apps designed for the general population. Furthermore, there was no contribution from an Urology society in "Electronic Medical Record" nor in "Patient Information" apps. A limitation of the study is that only Android and iOS apps were reviewed. Conclusions: Despite the increasing Mobile Health (mHealth) market, this is the first study that demonstrates the lack of expert participation in the design of Urology apps, particularly in apps designed for the general public. Until clear regulation is enforced, the urological community should help regulate app development. Maintaining a register of certified apps or issuing an official scientific seal of approval could improve overall app quality. We propose that urologists become stakeholders in mHealth, shaping future app design and promoting peer-review app validation

Prediction of hemorrhagic transformation after experimental ischemic stroke using MRI-based algorithms.

Estimation of hemorrhagic transformation (HT) risk is crucial for treatment decision-making after acute ischemic stroke. We aimed to determine the accuracy of multiparametric MRI-based predictive algorithms in calculating probability of HT after stroke. Spontaneously, hypertensive rats were subjected to embolic stroke and, after 3 h treated with tissue plasminogen activator (Group I: n = 6) or vehicle (Group II: n = 7). Brain MRI measurements of T2, T2*, diffusion, perfusion, and blood-brain barrier permeability were obtained at 2, 24, and 168 h post-stroke. Generalized linear model and random forest (RF) predictive algorithms were developed to calculate the probability of HT and infarction from acute MRI data. Validation against seven-day outcome on MRI and histology revealed that highest accuracy of hemorrhage prediction was achieved with a RF-based model that included spatial brain features (Group I: area under the receiver-operating characteristic curve (AUC) = 0.85 ± 0.14; Group II: AUC = 0.89 ± 0.09), with significant improvement over perfusion- or permeability-based thresholding methods. However, overlap between predicted and actual tissue outcome was significantly lower for hemorrhage prediction models (maximum Dice's Similarity Index (DSI) = 0.20 ± 0.06) than for infarct prediction models (maximum DSI = 0.81 ± 0.06). Multiparametric MRI-based predictive algorithms enable early identification of post-ischemic tissue at risk of HT and may contribute to improved treatment decision-making after acute ischemic stroke.Multivariate analysis of psychological dat