Distributed Rate Allocation in Inter-Session Network Coding

In this work, we propose a distributed rate allocation algorithm that minimizes the average decoding delay for multimedia clients in inter-session network coding systems. We consider a scenario where the users are organized in a mesh network and each user requests the content of one of the available sources. We propose a novel distributed algorithm where network users determine the coding operations and the packet rates to be requested from the parent nodes, such that the decoding delay is minimized for all clients. A rate allocation problem is solved by every user, which seeks the rates that minimize the average decoding delay for its children and for itself. Since this optimization problem is a priori non-convex, we introduce the concept of equivalent packet flows, which permits to estimate the expected number of packets that every user needs to collect for decoding. We then decompose our original rate allocation problem into a set of convex subproblems, which are eventually combined to obtain an effective approximate solution to the delay minimization problem. The results demonstrate that the proposed scheme eliminates the bottlenecks and reduces the decoding delay experienced by users with limited bandwidth resources. We validate the performance of our distributed rate allocation algorithm in different video streaming scenarios using the NS-3 network simulator. We show that our system is able to take benefit of inter-session network coding for simultaneous delivery of video sessions in networks with path diversity.

Validity of an automatic measure protocol in distal femur for allograft selection from a three-dimensional virtual bone bank system

Osteoarticular allograft is one possible treatment in wide surgical resections with large defects. Performing best osteoarticular allograft selection is of great relevance for optimal exploitation of the bone databank, good surgery outcome and patient’s recovery. Current approaches are, however, very time consuming hindering these points in practice. We present a validation study of a software able to perform automatic bone measurements used to automatically assess the distal femur sizes across a databank. 170 distal femur surfaces were reconstructed from CT data and measured manually using a size measure protocol taking into account the transepicondyler distance (A), anterior-posterior distance in medial condyle (B) and anterior-posterior distance in lateral condyle (C). Intra- and inter-observer studies were conducted and regarded as ground truth measurements. Manual and automatic measures were compared. For the automatic measurements, the correlation coefficients between observer one and automatic method, were of 0.99 for A measure and 0.96 for B and C measures. The average time needed to perform the measurements was of 16 h for both manual measurements, and of 3 min for the automatic method. Results demonstrate the high reliability and, most importantly, high repeatability of the proposed approach, and considerable speed-up on the planning.

High acceptance rate of hybrid allogeneic-autologous umbilical cord blood banking among actual and potential Swiss donors

Two competitive concepts of umbilical cord blood (UCB) banking are currently available: either allogeneic UCB is donated to a public bank or autologous cells are stored in a private bank. Allogeneic-autologous hybrid banking is a new concept that combines these two approaches. However, acceptance of hybrid UCB banking among potential donors is unknown to date.

European veterinary public health specialization: post-graduate training and expectations of potential employers

Residents of the European College of Veterinary Public Health (ECVPH) carried out a survey to explore the expectations and needs of potential employers of ECVPH diplomates and to assess the extent to which the ECVPH post-graduate training program meets those requirements. An online questionnaire was sent to 707 individuals working for universities, government organizations, and private companies active in the field of public health in 16 countries. Details on the structure and activities of the participants' organizations, their current knowledge of the ECVPH, and potential interest in employing veterinary public health (VPH) experts or hosting internships were collected. Participants were requested to rate 22 relevant competencies according to their importance for VPH professionals exiting the ECVPH training. A total of 138 completed questionnaires were included in the analysis. While generic skills such as "problem solving" and "broad horizon and inter-/multidisciplinary thinking" were consistently given high grades by all participants, the importance ascribed to more specialized skills was less homogeneous. The current ECVPH training more closely complies with the profile sought in academia, which may partly explain the lower employment rate of residents and diplomates within government and industry sectors. The study revealed a lack of awareness of the ECVPH among public health institutions and demonstrated the need for greater promotion of this veterinary specialization within Europe, both in terms of its training capacity and the professional skill-set of its diplomates. This study provides input for a critical revision of the ECVPH curriculum and the design of post-graduate training programs in VPH.

Adaptive evolution during an ongoing range expansion: the invasive bank vole (Myodes glareolus) in Ireland

Range expansions are extremely common, but have only recently begun to attract attention in terms of their genetic consequences. As populations expand, demes at the wave front experience strong genetic drift, which is expected to reduce genetic diversity and potentially cause ‘allele surfing’, where alleles may become fixed over a wide geographical area even if their effects are deleterious. Previous simulation models show that range expansions can generate very strong selective gradients on dispersal, reproduction, competition and immunity. To investigate the effects of range expansion on genetic diversity and adaptation, we studied the population genomics of the bank vole (Myodes glareolus) in Ireland. The bank vole was likely introduced in the late 1920s and is expanding its range at a rate of ~2.5 km/year. Using genotyping-by-sequencing, we genotyped 281 bank voles at 5979 SNP loci. Fourteen sample sites were arranged in three transects running from the introduction site to the wave front of the expansion. We found significant declines in genetic diversity along all three transects. However, there was no evidence that sites at the wave front had accumulated more deleterious mutations. We looked for outlier loci with strong correlations between allele frequency and distance from the introduction site, where the direction of correlation was the same in all three transects. Amongst these outliers, we found significant enrichment for genic SNPs, suggesting the action of selection. Candidates for selection included several genes with immunological functions and several genes that could influence behaviour.

Last interglacial temperature evolution — a model inter-comparison

There is a growing number of proxy-based reconstructions detailing the climatic changes that occurred during the last interglacial period (LIG). This period is of special interest, because large parts of the globe were characterized by a warmer-than-present-day climate, making this period an interesting test bed for climate models in light of projected global warming. However, mainly because synchronizing the different palaeoclimatic records is difficult, there is no consensus on a global picture of LIG temperature changes. Here we present the first model inter-comparison of transient simulations covering the LIG period. By comparing the different simulations, we aim at investigating the common signal in the LIG temperature evolution, investigating the main driving forces behind it and at listing the climate feedbacks which cause the most apparent inter-model differences. The model inter-comparison shows a robust Northern Hemisphere July temperature evolution characterized by a maximum between 130–125 ka BP with temperatures 0.3 to 5.3 K above present day. A Southern Hemisphere July temperature maximum, −1.3 to 2.5 K at around 128 ka BP, is only found when changes in the greenhouse gas concentrations are included. The robustness of simulated January temperatures is large in the Southern Hemisphere and the mid-latitudes of the Northern Hemisphere. For these regions maximum January temperature anomalies of respectively −1 to 1.2 K and −0.8 to 2.1 K are simulated for the period after 121 ka BP. In both hemispheres these temperature maxima are in line with the maximum in local summer insolation. In a number of specific regions, a common temperature evolution is not found amongst the models. We show that this is related to feedbacks within the climate system which largely determine the simulated LIG temperature evolution in these regions. Firstly, in the Arctic region, changes in the summer sea-ice cover control the evolution of LIG winter temperatures. Secondly, for the Atlantic region, the Southern Ocean and the North Pacific, possible changes in the characteristics of the Atlantic meridional overturning circulation are crucial. Thirdly, the presence of remnant continental ice from the preceding glacial has shown to be important when determining the timing of maximum LIG warmth in the Northern Hemisphere. Finally, the results reveal that changes in the monsoon regime exert a strong control on the evolution of LIG temperatures over parts of Africa and India. By listing these inter-model differences, we provide a starting point for future proxy-data studies and the sensitivity experiments needed to constrain the climate simulations and to further enhance our understanding of the temperature evolution of the LIG period.

Intrauterine instillation of diluted seminal plasma at oocyte pick-up does not increase the IVF pregnancy rate: a double-blind, placebo controlled, randomized study.

STUDY QUESTION Does intrauterine application of diluted seminal plasma (SP) at the time of ovum pick-up improve the pregnancy rate by ≥14% in IVF treatment? SUMMARY ANSWER Intrauterine instillation of diluted SP at the time of ovum pick-up is unlikely to increase the pregnancy rate by ≥14% in IVF. WHAT IS KNOWN ALREADY SP modulates endometrial function, and sexual intercourse around the time of embryo transfer has been suggested to increase the likelihood of pregnancy. A previous randomized double-blind pilot study demonstrated a strong trend towards increased pregnancy rates following the intracervical application of undiluted SP. As this study was not conclusive and as the finding could have been confounded by sexual intercourse, the intrauterine application of diluted SP was investigated in the present trial. STUDY DESIGN, SIZE, DURATION A single-centre, prospective, double-blind, placebo-controlled, randomized, superiority trial on women undergoing IVF was conducted from April 2007 until February 2012 at the University Department of Gynaecological Endocrinology and Reproductive Medicine, Heidelberg, Germany. PARTICIPANTS/MATERIALS, SETTING, METHODS The study was powered to detect an 14% increase in the clinical pregnancy rate and two sequential tests were planned using the Pocock spending function. At the first interim analysis, 279 women had been randomly assigned to intrauterine diluted SP (20% SP in saline from the patients' partner) (n = 138) or placebo (n = 141) at the time of ovum pick-up. MAIN RESULTS AND THE ROLE OF CHANCE The clinical pregnancy rate per randomized patient was 37/138 (26.8%) in the SP group and 41/141 (29.1%) in the placebo group (difference: -2.3%, 95% confidence interval of the difference: -12.7 to +8.2%; P = 0.69). The live birth rate per randomized patient was 28/138 (20.3%) in the SP group and 33/141 (23.4%) in the placebo group (difference: -3.1%, 95% confidence interval of the difference: -12.7 to +6.6%; P = 0.56). It was decided to terminate the trial due to futility at the first interim analysis, at a conditional power of 62%. LIMITATIONS, REASONS FOR CAUTION The confidence interval of the difference remains wide, thus clinically relevant differences cannot reliably be excluded based on this single study. WIDER IMPLICATIONS OF THE FINDINGS The results of this study cast doubt on the validity of the concept that SP increases endometrial receptivity and thus implantation in humans. STUDY FUNDING/COMPETING INTEREST(S) Funding was provided by the department's own research facilities. TRIAL REGISTRATION NUMBER DRKS00004615.

Decoding Delay Minimization in Inter-Session Network Coding

Intra-session network coding has been shown to offer significant gains in terms of achievable throughput and delay in settings where one source multicasts data to several clients. In this paper, we consider a more general scenario where multiple sources transmit data to sets of clients over a wireline overlay network. We propose a novel framework for efficient rate allocation in networks where intermediate network nodes have the opportunity to combine packets from different sources using randomized network coding. We formulate the problem as the minimization of the average decoding delay in the client population and solve it with a gradient-based stochastic algorithm. Our optimized inter-session network coding solution is evaluated in different network topologies and is compared with basic intra-session network coding solutions. Our results show the benefits of proper coding decisions and effective rate allocation for lowering the decoding delay when the network is used by concurrent multicast sessions.

Evaluation of an inventory for the assessment of critical incidents involving football fans

Introduction: Fan violence is a frequent occurrence in Swiss football (Bundesamt für Polizei, 2015) leading to high costs for prevention and control (Mensch & Maurer, 2014). Various theories put forward an explanation of fan violence, such as the Elaborated Social Identity Model (Drury & Reicher, 2000)and the Aggravation Mitigation Model (Hylander & Guvå, 2010). Important observations from these theories are the multi-dimensional understanding of fan violence and the Dynamics occurring in the fan group. Nevertheless, none of them deal with critical incidents (CIs) which involve a tense atmosphere combined with a higher risk of fan violence. Schumacher Dimech, Brechbühl and Seiler (2015) tackled this gap in research and explored CIs where 43 defining criteria were identified and compiled in an integrated model of CIs. The defining criteria were categorised in four higher-order themes “antecedents” (e.g. a documented history of fan rivalry), “triggers” (e.g. the arrest of a fan), “reactions” (e.g. fans masking themselves) and “consequences” (e.g. fans avoiding communication with fan social workers). Methods: An inventory based on this model is being developed including these 43 criteria. In an exploratory phase, this inventory was presented as an online questionnaire and was completed by 143 individuals. Three main questions are examined: Firstly, the individual items are tested using descriptive analyses. An item analysis is conducted to test reliability, item difficulty and discriminatory power. Secondly, the model’s four higher-order themes are tested using exploratory factor analysis (EFA). Thirdly, differences between sub -groups are explored, such as gender and age-related differences. Results: Respondents rated the items’ importance as high and the quota of incomplete responses was not systematic. Two items were removed from the inventory because of low mean or a high rate of “don’t know”-responses. EFA produced a six-factor solution grouping items into match-related factors, repressive measures, fans’ delinquent behaviour, intra-group behaviour, communication and control and inter-group factors. The item “fans consume alcohol” could not be ordered into any category but was retained since literature accentuates this factor’s influence on fan violence. Analyses examining possible differences between groups are underway. Discussion: Results exploring the adequacy of this inventory assessing defining criteria of CIs in football are promising and thus further evaluative investigation is recommended. This inventory can be used in two ways: as a standardised instrument of assessment for experts evaluating specific CIs and as an instrument for exploring differences in perception and assessment of a CI e.g. gender and age differences, differences between interest groups and stakeholders.

Evaluation of an inventory for the assessment of critical incidents involving football fans

Introduction: Fan violence is a frequent occurrence in Swiss football (Bundesamt für Polizei, 2015) leading to high costs for prevention and control (Mensch & Maurer, 2014). Various theories put forward an explanation of fan violence, such as the Elaborated Social Identity Model (Drury & Reicher, 2000) and the Aggravation Mitigation Model (Hylander & Guvå, 2010). Important observations from these theories are the multi-dimensional understanding of fan violence and the dynamics occurring in the fan group. Nevertheless, none of them deal with critical incidents (CIs) which involve a tense atmosphere combined with a higher risk of fan violence. Schumacher Dimech, Brechbühl and Seiler (2015) tackled this gap in research and explored CIs where 43 defining criteria were identified and compiled in an integrated model of CIs. The defining criteria were categorised in four higher-order themes “antecedents” (e.g. a documented history of fan rivalry), “triggers” (e.g. the arrest of a fan), “reactions” (e.g. fans masking themselves) and “consequences” (e.g. fans avoiding communication with fan social workers). Methods: An inventory based on this model is being developed including these 43 criteria. In an exploratory phase, this inventory was presented as an online questionnaire and was completed by 143 individuals. Three main questions are examined: Firstly, the individual items are tested using descriptive analyses. An item analysis is conducted to test reliability, item difficulty and discriminatory power. Secondly, the model’s four higher-order themes are tested using exploratory factor analysis (EFA). Thirdly, differences between sub-groups are explored, such as gender and agerelated differences. Results: Respondents rated the items’ importance as high and the quota of incomplete responses was not systematic. Two items were removed from the inventory because of low mean or a high rate of “don’t know”-responses. EFA produced a six-factor solution grouping items into match-related factors, repressive measures, fans’ delinquent behaviour, intra-group behaviour, communication and control and inter-group factors. The item “fans consume alcohol” could not be ordered into any category but was retained since literature accentuates this factor’s influence on fan violence. Analyses examining possible differences between groups are underway. Discussion: Results exploring the adequacy of this inventory assessing defining criteria of CIs in football are promising and thus further evaluative investigation is recommended. This inventory can be used in two ways: as a standardised instrument of assessment for experts evaluating specific CIs and as an instrument for exploring differences in perception and assessment of a CI e.g. gender and age differences, differences between interest groups and stakeholders. References: Bundesamt für Polizei. (2015). Jahresbericht 2014. Kriminalitätsbekämpfung Bund. Lage, Massnahmen und Mittel [Electronic Version]. Drury, J., & Reicher, S. (2000). Collective action and psychological change. The emergence of new social identities. British Journal of Social Psychology, 39, 579-604. Hylander, I., & Guvå, G. (2010). Misunderstanding of out-group behaviour: Different interpretations of the same crowd events among police officers and demonstrators. Nordic Psychology, 62, 25-47. Schumacher-Dimech, A., Brechbühl, A. &, Seiler, R. (2016). Dynamics of critical incidents with potentially violent outcomes involving ultra fans: an explorative study. Sport in Society. Advance online publication. doi: 10.1080/17430437.2015.1133597

Measurement of the electron neutrino charged-current interaction rate on water with the T2K ND280 π0 detector

This paper presents a measurement of the charged current interaction rate of the electron neutrino beam component of the beam above 1.5 GeV using the large fiducial mass of the T2K π0 detector. The predominant portion of the νe flux (∼85%) at these energies comes from kaon decays. The measured ratio of the observed beam interaction rate to the predicted rate in the detector with water targets filled is 0.89 ± 0.08 (stat.) ± 0.11 (sys.), and with the water targets emptied is 0.90 ± 0.09 (stat.) ± 0.13 (sys.). The ratio obtained for the interactions on water only from an event subtraction method is 0.87 ± 0.33 (stat.) ± 0.21 (sys.). This is the first measurement of the interaction rate of electron neutrinos on water, which is particularly of interest to experiments with water Cherenkov detectors.