2,688 research outputs found

    Resource allocation and adaptive scheduling for scalable video streaming

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    The obvious recent advances in areas such as video compression and network architectures allow for the deployment of novel video distribution applications. These have the potential to provide ubiquitous media access to end users. In recent years, applications based on audio and video streaming have turned out to be immensely popular and the Internet has become the most widely used vector for media content distribution, due to its high availability and connectivity. However, the nature of the Internet infrastructure is not adapted to the specific characteristics of multimedia traffic, which presents a certain tolerance to losses, but strict delay and high bandwidth requirements. In this thesis, our goal is to improve the efficiency of media delivery over the existing network architecture. In order to do so we consider the delivery of scalable video in three main delivery scenarios, namely one-to-one client server architectures, one-to-many broadcasting architectures, and many-to-one distributed streaming architectures. First, we propose a distributed media-friendly rate allocation algorithm for the delivery of both finely and coarsely scalable video streams. Unlike existing solutions, our algorithm explicitly takes the characteristics of media streams into consideration. As a result, it provides rate allocations that better fit the heterogeneous characteristics of media streams. We outline an implementation that is robust to random feedback delays and that permits a scalable deployment of the algorithm. The rate allocation that is computed by our algorithm achieves network stability and high bandwidth utilization. It moreover allows to maximize the average received quality for all streams that are delivered in the network. While considering the transmission of coarsely layered streams, we derive conditions on the encoding rates of the video layers. These conditions depend on the allowed end-to-end delay and on the rate allocation algorithm that controls the sending rates. They allow us to take full advantage of the allocated transmission rates. Second, we investigate the problem of jointly addressing the needs of multiple receivers that consume different versions of a layered media stream in a broadcasting scenario. We provide optimal scheduling algorithms that jointly optimize the playback delay and the buffer occupancy at all of these receivers when the used channel is known. Furthermore we analyze low complexity heuristics based optimization techniques, which provide close to optimal results when only limited channel knowledge is available. Finally, we explore the possibility to exploit the inherent network diversity that is provided by the Internet infrastructure. In particular, we consider media delivery schemes where multiple senders are available for the transmission of a scalable video stream to a single client. Such an architecture is referred to as a distributed streaming architecture. It has the benefit of aggregating multiple unreliable channels into a single more robust channel with high availability. Through the use of Fountain codes, we are able to transform the distributed streaming problem into a rate allocation problem of lower complexity. The solution to this problem is shown to depend not only on the average packet loss rate, but also on the average length of packet loss bursts that are observed on each of the available channels. The coding scheme that we suggest enables our system to adapt the streamed content to the network characteristics, as well as to the needs of the receiving client

    Subjective health status and health-related quality of life among women with Recurrent Vulvovaginal Candidosis (RVVC) in Europe and the USA

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    Abstract Background Recurrent vulvovaginal candidosis (RVVC) is a chronic condition causing discomfort and pain. Health status and health-related quality of life (HRQoL) in RVVC were never previously described using validated questionnaires. The objective of this study is to describe subjective health status and HRQoL and estimate health state utilities among women with RVVC. Methods A cross-sectional online survey was conducted among women who reported having suffered four or more yeast infections over the past 12 months, in five European countries (France, Germany, Italy, Spain and the UK) and the USA. Index scores were derived from the EQ-5D, a questionnaire providing a single index value for health status. The SF-36 questionnaire was used for HRQoL assessment. Information on disease severity, treatment patterns and productivity was also collected. Results 12,834 members of online research panels were contacted. Among them, 620 women with RVVC (5%) were selected to complete the full questionnaire. The mean EQ-5D index score was 0.70 (95% confidence interval: [0.67, 0.72]) and the difference between women with a yeast infection at the time of questionnaire completion and other respondents was 0.05 (p = 0.47). The EQ-5D index score increased significantly with the time since last infection (p \u3c 0.001). 68% of women reported depression/anxiety problems during acute episode, and 54% outside episodes, compared to less than 20% in general population (p \u3c 0.001). All SF-36 domain scores were significantly below general population norms. Mental health domains were the most affected. The impact on productivity was estimated at 33 lost work hours per year on average, corresponding to estimated costs between €266/year and €1,130/year depending on the country. Conclusions Subjective health status and HRQoL during and in between acute inflammatory episodes in women with RVVC are significantly worse than in the general population, despite the use of antifungal therapy. The average index score in women with RVVC is comparable to other diseases such as asthma or COPD and worse than diseases such as headache/migraine according to US and UK catalogs of index scores. The survey also revealed a significant loss of productivity associated with RVVC

    Mechanisms of Mitochondria–Neurofilament Interactions

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    Mitochondria are localized to regions of the cell where ATP consumption is high and are dispersed according to changes in local energy needs. In addition to motion directed by molecular motors, mitochondrial distribution in neuronal cells appears to depend on the docking of mitochondria to microtubules and neurofilaments. We examined interactions between mitochondria and neurofilaments using fluorescence microscopy, dynamic light scattering, atomic force microscopy, and sedimentation assays. Mitochondria-neurofilament interactions depend on mitochondrial membrane potential, as revealed by staining with a membrane potential sensitive dye (JC-1) in the presence of substrates/ADP or uncouplers (valinomycin/carbonyl cyanide p-(trifluoromethoxy)phenylhydrazone) and are affected by the phosphorylation status of neurofilaments and neurofilament sidearms. Antibodies against the neurofilament heavy subunit disrupt binding between mitochondria and neurofilaments, and isolated neurofilament sidearms alone interact with mitochondria, suggesting that they mediate the interactions between the two structures. These data suggest that specific and regulated mitochondrial-neurofilament interactions occur in situ and may contribute to the dynamic distribution of these organelles within the cytoplasm of neurons

    Video Multicast in (large) local area networks

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    We consider the problem of distributing high-quality video signals over IP multicast in large Local Area Networks (LANs), under real-time delay constraints, and with software-only processing. In a large LAN (such as the network of a university campus, or the network of a large company), the source of channel heterogeneity that the video communications system must cope with is not that of different bandwidth constraints available to each receiver, but it is essentially variations in the available CPU power that each receiver will have in order to decode the incoming signal. In this paper we propose a new architecture for a video multicast system, present the design of the different components of this system, and show results obtained in a real implementation. Our feeds consist of video encoded at about 3 Mbits/sec and 16 frames/sec, capable of tolerating the loss of about 300 Kbits/sec worth of data. Decoding is performed on Linux PCs, and the quality of our reconstructed signals degrades gracefully with the speed of the CPU on which the receiver runs

    Translational Medicine and Patient Safety in Europe:TRANSFoRm - Architecture for the Learning Health System in Europe

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    The Learning Health System (LHS) describes linking routine healthcare systems directly with both research translation and knowledge translation as an extension of the evidence-based medicine paradigm, taking advantage of the ubiquitous use of electronic health record (EHR) systems. TRANSFoRm is an EU FP7 project that seeks to develop an infrastructure for the LHS in European primary care. Methods. The project is based on three clinical use cases, a genotype-phenotype study in diabetes, a randomised controlled trial with gastroesophageal reflux disease, and a diagnostic decision support system for chest pain, abdominal pain, and shortness of breath. Results. Four models were developed (clinical research, clinical data, provenance, and diagnosis) that form the basis of the projects approach to interoperability. These models are maintained as ontologies with binding of terms to define precise data elements. CDISC ODM and SDM standards are extended using an archetype approach to enable a two-level model of individual data elements, representing both research content and clinical content. Separate configurations of the TRANSFoRm tools serve each use case. Conclusions. The project has been successful in using ontologies and archetypes to develop a highly flexible solution to the problem of heterogeneity of data sources presented by the LHS

    Towards an Understanding of the Globular Cluster Over--abundance around the Central Giant Elliptical NGC 1399

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    We investigate the kinematics of a combined sample of 74 globular clusters around NGC 1399. Their high velocity dispersion, increasing with radius, supports their association with the gravitational potential of the galaxy cluster rather than with that of NGC 1399 itself. We find no evidence for rotation in the full sample, although some indication for rotation in the outer regions. The data do not allow us to detect differences between the kinematics of the blue and red sub-populations of globular clusters. A comparison between the globular cluster systems of NGC 1399 and those of NGC 1404 and NGC 1380 indicates that the globular clusters in all three galaxies are likely to have formed via similar mechanisms and at similar epochs. The only property which distinguishes the NGC 1399 globular cluster system from these others is that it is ten times more abundant. We summarize the evidence for associating these excess globulars with the galaxy cluster rather than with NGC 1399 itself, and suggest that the over-abundance can be explained by tidal stripping, at an early epoch, of neighboring galaxies and subsequent accumulation of globulars in the gravitational potential of the galaxy cluster.Comment: AJ accepted (March issue), 27 pages (6 figures included), AAS style, two columns. Also available at http://www.eso.org/~mkissle

    Biosignatures of methanogenic archaea by Confocal Raman Microspectroscopy (CRM)

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    Methanogenic archaea are anaerobic chemotrophic microorganisms that meet many of the metabolic and physiological requirements for survival on the martian subsurface. In particular, methanogens from Siberian permafrost are extremely resistant against different types of environmental stresses as well as simulated martian thermo-physical and subsurface conditions, making them promising model organisms for potential life on Mars. Raman spectroscopy is a vibrational spectroscopic technique that has shown a remarkable potential in microbial identification. It provides fingerprint-like information about the overall chemical composition of the samples and allows a nondestructive investigation. The biosignatures of Methanosarcina soligelidi SMA-21 were characterized by CRM during the growth phases at a single-cell level, which presented a high heterogeneity and diversity in the chemical composition of the cells and detectible subpopulation differences. This study also highlighted potential technical challenges concerning the Raman detection of methanogenic archaea (and other non-pigmented microorganisms) embedded on a mineral substrate. The biosignatures of permafrost and non-permafrost strains in the stationary phase of growth were also characterized by CRM. A cluster analysis of the spectra revealed that permafrost and non-permafrost strains have a different overall chemical composition, which has possible evolutionary implications

    Promoting ecological solutions for sustainable infrastructure

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    Sustainable infrastructure needs ecological solutions – it’s time to work together! We, the participants of the IENE 2020 International Conference, acknowledge that: 1. We are facing a significant worldwide expansion of transportation networks; this is especially the case in countries with developing economies. 2. If no action is taken, this global expansion will entail a substantial increase in greenhouse gas emissions, wildlife mortality and landscape fragmentation and change, with devastating effects on climate, biodiversity and ecosystem services. 3. Globally, ecosystem services are estimated to yield more than the Gross World Product of 2019 (https://www.worldometers.info/gdp/). 4. Despite the development and implementation of environmental impact assessment legislation, many existing transportation infrastructure networks are not environmentally friendly. These impacts are far-reaching with a debt being paid daily through unnecessary risks extendable to human health and well-being. 5.The economic, social, and ecological consequences of biodiversity loss and the role of transportation infrastructure is increasingly acknowledged worldwide: ‱Conservation and restoration of ecological connectivity is a major flagship in the preparation of the upcoming United Nations “Post-2020 Global biodiversity framework” following the recognised failure of the Aichi Targets associated with the loss and fragmentation of natural habitats (Target 5) (https://www.cbd.int/gbo5). ‱The European Green Deal and the new European Biodiversity Strategy for 2030, adopted by the European Commission in May 2020, stresses the need to develop a resilient Trans-European Nature Network supported by ecological corridors allowing the free flow of genes and individuals (https://ec.europa.eu/info/sites/info/files/communication-annex-eu-biodiversity-strategy-2030_en.pdf). ‱The Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) states that since 1970, transportation infrastructure is an important driver of land use change and associated loss of terrestrial biodiversity (https://ipbes.net/global-assessment). ‱The World Economic Forum 2020 recognised that biodiversity loss is one of the major threats with ‘plausible higher than average impact’ on Global Economies (https://www.weforum.org/reports/the-global-risks-report-2020). 6.To ahieve sustainability, infrastructure development must be decoupled from its negative effect on biodiversity. This requires immediate, stringent action and shared responsibilities from all stakeholders. 7.Regional, national, and worldwide networks of experts, including researchers, practitioners, landscape designers, and managers, address such concerns through knowledge-sharing platforms that promote effective ecological solutions. 8.The scarcity of collective and coordinated efforts, such as joint decision-making processes involving environmental, transportation, energy, policy and financing agencies, is still a major obstacle to achieve sustainability in transportation infrastructure projects.Comissão Europeia. Programa LIFE. Projeto LIFE LINES (LIFE14 NAT/PT/001081

    Local mutations:On the tentative beginnings of molecular oncology in Britain 1980–2000

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    Popular and scientific accounts of the molecularisation of cancer typically attribute it to advances in laboratory science, particularly molecular geneticists. However, historical research has indicated that clinical expertise input was often vital for advancing such work. The present paper reinforces that view. Looking in detail at British research into the molecular genetics of familial cancers during the 1980s and 1990s, it shows that that research, too, depended on crucial input from family cancer clinics. Moreover, the development of clinical services for familial cancers was in turn shaped by the demands of contributing to molecular genetic research. The paper concludes that accounts of the molecularisation of cancer that suppose a one-way transfer of knowledge and practice from laboratory to clinic misrepresent the complex interactions that were involved in molecularising familial cancers, and that were informed by the particular local and national circumstances in which they took shape

    Status of the Micro Vertex Detector of the Compressed Baryonic Matter Experiment

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    The CBM experiment will investigate heavy-ion collisions at beam energies from 8 to 45 AGeV at the future accelerator facility FAIR. The goal of the experiment is to study the QCD phase diagram in the vincinity of the QCD critical point. To do so, CBM aims at measuring rare probes among them open charm. In order to identify those rare and short lived particles despite the rich combinatorial background generated in heavy ion collisions, a micro vertex detector (MVD) providing an unprecedented combination of high rate capability and radiation hardness, very light material budget and excellent granularity is required. In this work, we will discuss the concept of this detector and summarize the status of the R&D
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