Robust Line Planning in case of Multiple Pools and Disruptions

We consider the line planning problem in public transportation, under a robustness perspective. We present a mechanism for robust line planning in the case of multiple line pools, when the line operators have a different utility function per pool. We conduct an experimental study of our mechanism on both synthetic and real-world data that shows fast convergence to the optimum. We also explore a wide range of scenarios, varying from an arbitrary initial state (to be solved) to small disruptions in a previously optimal solution (to be recovered). Our experiments with the latter scenario show that our mechanism can be used as an online recovery scheme causing the system to re-converge to its optimum extremely fast.Comment: To appear in TAPAS 201

Hawking radiation in different coordinate settings: Complex paths approach

We apply the technique of complex paths to obtain Hawking radiation in different coordinate representations of the Schwarzschild space-time. The coordinate representations we consider do not possess a singularity at the horizon unlike the standard Schwarzschild coordinate. However, the event horizon manifests itself as a singularity in the expression for the semiclassical action. This singularity is regularized by using the method of complex paths and we find that Hawking radiation is recovered in these coordinates indicating the covariance of Hawking radiation as far as these coordinates are concerned.Comment: 18 pages, 2 figures, Uses IOP style file; final version; accepted in Class. Quant. Gra

Socio-demographic and fertility related characteristics and motivations of oocyte donors in eleven European countries

Do the socio-demographic and fertility-related characteristics and motivations of oocyte donors differ in European countries? The socio-demographic and fertility-related characteristics and motivations of oocyte donors differ considerably across countries. There have been no other international studies comparing the characteristics of oocyte donors. Regarding their motivations, most studies indicate mixed motives. The proposed study was a transversal epidemiological study. Data were collected from 63 voluntarily participating assisted reproduction technology centres practising oocyte donation in 11 European countries (Belgium, Czech Republic, Finland, France, Greece, Poland, Portugal, Russia, Spain, UK and Ukraine). The survey was conducted between September 2011 and June 2012 and ran for 16 calendar months depending on the number of cycles of oocyte donation performed at the centre. The sample size was computed in order to allow an estimate of the percentage of a relatively rare characteristic (2) with a precision (95 confidence interval) of 1. The calculation gave 1118 donors. In total, 1423 forms were obtained from oocyte donors. All consecutive donors in these centres filled out an anonymous questionnaire when they started their hormonal stimulation, asking for their socio-demographic and fertility-related characteristics, their motivations and compensation. Population characteristics were described and compared by country of donation. Motives for donation and mean amount of money were compared between countries and according to the donors characteristics. The socio-demographic and fertility-related characteristics and motivations of oocyte donors varied enormously across European countries. The number of received forms corresponded with a participation rate of 61.9 of the cycles performed by the participating centres. Mean age was 27.4 years. About 49 of donors were fully employed, 16 unemployed and 15 student. The motivation in the total group of donors was 47.8 pure altruism, 33.9 altruism and financial, 10.8 pure financial, 5.9 altruism and own treatment and finally 2 own treatment only. About 15 of the donors were egg sharers (patient donors), mainly from the UK and Poland. Women were donating for the first time in 55.4 of cases, for the second time in 20.3 and for the third time in 12.8. The motivation to donate was significantly related to being of foreign origin (P 0.01), age (P 0.001), living in couple or not (P 0.01), level of education (P 0.001) and number of donations (P 0.001). The amount of compensation differed considerably between centres and/or countries. The general donor profile in this study was a well-educated, 27-year-old woman living with her partner and child who mainly donated to help others. The selection of clinics in some countries and the limited participation rate may have led to a bias in donor characteristics. A possible effect of social desirability in the answers by the donors should be taken into account. The diversity of the donor population reflects the differences in European legislation (for example, on anonymity and payment) and economic circumstances. The differences in systems of reimbursement/payment demonstrate the need to have a thorough discussion on the specific meaning of these terms. The study was funded by the European Society for Human Reproduction and Embryology. The authors declare no conflicting interests

Superpixel quality in microscopy images: the impact of noise & denoising

Microscopy is a valuable imaging tool in various biomedical research areas. Recent developments have made high resolution acquisition possible within a relatively short time. State-of-the-art imaging equipment such as serial block-face electron microscopes acquire gigabytes of data in a matter of hours. In order to make these amounts of data manageable, a more data-efficient representation is required. A popular approach for such data efficiency are superpixels which are designed to cluster homogeneous regions without crossing object boundaries. The use of superpixels as a pre-processing step has shown significant improvements in making computationally intensive computer vision analysis algorithms more tractable on large amounts of data. However, microscopy datasets in particular can be degraded by noise and most superpixel algorithms do not take this artifact into account. In this paper, we give a quantitative and qualitative comparison of superpixels generated on original and denoised images. We show that several advanced superpixel techniques are hampered by noise artifacts and require denoising and parameter tuning as a pre-processing step. The evaluation is performed on the Berkeley segmentation dataset as well as on fluorescence and scanning electron microscopy data

A Compact Model of Interface-Type Memristors Linking Physical and Device Properties

Memristors are an electronic device whose resistance depends on the voltage history that has been applied to its two terminals. Despite its clear advantage as a computational element, a suitable transport model is lacking for the special class of interface-based memristors. Here, we adapt the widely-used Yakopcic compact model by including transport equations relevant to interface-type memristors. This model is able to reproduce the qualitative behaviour measured upon Nb-doped SrTiO$_3$ memristive devices. Our analysis demonstrates a direct correlation between the devices' characteristic parameters and those of our model. The model can clearly identify the charge transport mechanism in different resistive states thus facilitating evaluation of the relevant parameters pertaining to resistive switching in interface-based memristors. One clear application of our study is its ability to inform the design and fabrication of related memristive devices.Comment: 14 pages, 2 pages of Supplementary Data, 4 figures, 4 table

Self-perception but not peer reputation of bullying victimization is associated with non-clinical psychotic experiences in adolescents

Background Bullying victimization may be linked to psychosis but only self-report measures of victimization have been used so far. This study aimed (a) to investigate the differential associations of peer-nominated versus self-reported victim status with non-clinical psychotic experiences in a sample of young adolescents, and (b) to examine whether different types of self-reported victimization predict non-clinical psychotic experiences in these adolescents. Method A combination of standard self-report and peer nomination procedures was used to assess victimization. The sample (n = 724) was divided into four groups (exclusively self-reported victims, self- and peer-reported victims, exclusively peer-reported victims, and non-victims) to test for a group effect on non-clinical psychotic experiences. The relationship between types of victimization and non-clinical psychotic experiences was examined by a regression analysis. Results Self-reported victims, along with self- and peer-reported victims, scored higher than peer-reported victims and non-victims on non-clinical psychotic experiences. Self-reports of direct relational, indirect relational and physical victimization significantly improved the prediction of non-clinical psychotic experiences whereas verbal and possession-directed victimization had no significant predictive value. Conclusions The relationship between victimization and non-clinical psychotic experiences is only present for self-reported victimization, possibly indicative of an interpretation bias. The observed discrepancy between self-report and peer-report highlights the importance of implementing a combination of both measures for future research. Copyright © Cambridge University Press 2012

Valsartan Improves Adipose Tissue Function in Humans with Impaired Glucose Metabolism: A Randomized Placebo-Controlled Double-Blind Trial

<div><h3>Background</h3><p>Blockade of the renin-angiotensin system (RAS) reduces the incidence of type 2 diabetes mellitus. In rodents, it has been demonstrated that RAS blockade improved adipose tissue (AT) function and glucose homeostasis. However, the effects of long-term RAS blockade on AT function have not been investigated in humans. Therefore, we examined whether 26-wks treatment with the angiotensin II type 1 receptor blocker valsartan affects AT function in humans with impaired glucose metabolism (IGM).</p> <h3>Methodology/Principal Findings</h3><p>We performed a randomized, double-blind, placebo-controlled parallel-group study, in which 38 subjects with IGM were treated with valsartan (VAL, 320 mg/d) or placebo (PLB) for 26 weeks. Before and after treatment, an abdominal subcutaneous AT biopsy was collected for measurement of adipocyte size and AT gene/protein expression of angiogenesis/capillarization, adipogenesis, lipolytic and inflammatory cell markers. Furthermore, we evaluated fasting and postprandial AT blood flow (ATBF) (¹³³Xe wash-out), systemic inflammation and insulin sensitivity (hyperinsulinemic-euglycemic clamp). VAL treatment markedly reduced adipocyte size (<em>P</em><0.001), with a shift toward a higher proportion of small adipocytes. In addition, fasting (<em>P</em> = 0.043) and postprandial ATBF (<em>P</em> = 0.049) were increased, whereas gene expression of angiogenesis/capillarization, adipogenesis and macrophage infiltration markers in AT was significantly decreased after VAL compared with PLB treatment. Interestingly, the change in adipocyte size was associated with alterations in insulin sensitivity and reduced AT gene expression of macrophage infiltration markers. VAL did not alter plasma monocyte-chemoattractant protein (MCP)-1, TNF-α, adiponectin and leptin concentrations.</p> <h3>Conclusions/Significance</h3><p>26-wks VAL treatment markedly reduced abdominal subcutaneous adipocyte size and AT macrophage infiltration markers, and increased ATBF in IGM subjects. The VAL-induced decrease in adipocyte size was associated with reduced expression of macrophage infiltration markers in AT. Our findings suggest that interventions targeting the RAS may improve AT function, thereby contributing to a reduced risk of developing cardiovascular disease and type 2 diabetes.</p> <h3>Trial Registration</h3><p>Trialregister.nl NTR721 (ISRCTN Registry: ISRCTN<a href="http://www.controlled-trials.com/isrctn/pf/42786336">42786336</a>)</p> </div