263 research outputs found

    Modeling and Design of Millimeter-Wave Networks for Highway Vehicular Communication

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    Connected and autonomous vehicles will play a pivotal role in future Intelligent Transportation Systems (ITSs) and smart cities, in general. High-speed and low-latency wireless communication links will allow municipalities to warn vehicles against safety hazards, as well as support cloud-driving solutions to drastically reduce traffic jams and air pollution. To achieve these goals, vehicles need to be equipped with a wide range of sensors generating and exchanging high rate data streams. Recently, millimeter wave (mmWave) techniques have been introduced as a means of fulfilling such high data rate requirements. In this paper, we model a highway communication network and characterize its fundamental link budget metrics. In particular, we specifically consider a network where vehicles are served by mmWave Base Stations (BSs) deployed alongside the road. To evaluate our highway network, we develop a new theoretical model that accounts for a typical scenario where heavy vehicles (such as buses and lorries) in slow lanes obstruct Line-of-Sight (LOS) paths of vehicles in fast lanes and, hence, act as blockages. Using tools from stochastic geometry, we derive approximations for the Signal-to-Interference-plus-Noise Ratio (SINR) outage probability, as well as the probability that a user achieves a target communication rate (rate coverage probability). Our analysis provides new design insights for mmWave highway communication networks. In considered highway scenarios, we show that reducing the horizontal beamwidth from 9090^\circ to 3030^\circ determines a minimal reduction in the SINR outage probability (namely, 41024 \cdot 10^{-2} at maximum). Also, unlike bi-dimensional mmWave cellular networks, for small BS densities (namely, one BS every 500500 m) it is still possible to achieve an SINR outage probability smaller than 0.20.2.Comment: Accepted for publication in IEEE Transactions on Vehicular Technology -- Connected Vehicles Serie

    Reproductive aging in Caenorhabditis elegans: From molecules to ecology

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    Aging animals display a broad range of progressive degenerative changes, and one of the most fascinating is the decline of female reproductive function. In the model organis

    How public health teams navigate their different roles in alcohol premises licensing:ExILEnS multistakeholder interview finding

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    Background: In England and Scotland, local governments regulate the sale of alcohol by awarding licences to premises to permit the sale of alcohol for consumption on or off the premises, under certain conditions; without such a licence, alcohol cannot be legally sold. In recent years, many local public health teams have become proactive in engaging with alcohol licensing, encouraging licensing authorities to act in ways intended to improve population health. Objective: This research aimed to explore and understand the approaches and activities of public health stakeholders (i.e. NHS staff and other public health professionals) in seeking to influence local alcohol licensing policy and decisions, and the views of licensing stakeholders (i.e. licensing officers/managers, police staff with a licensing remit, elected members and licensing lawyers/clerks) on the acceptability and effectiveness of these approaches. Participants: Local public health teams in England and Scotland were directly informed about this multisite study. Scoping calls were conducted with interested teams to explore their level of activity in alcohol licensing from 2012 across several categories. Twenty local authority areas with public health teams active in licensing matters were recruited purposively in England (n = 14) and Scotland (n = 6) to vary by region and rurality. Fifty-three in-depth telephone interviews (28 with public health stakeholders and 25 with licensing stakeholders outside health, such as local authority licensing teams/lawyers or police) were conducted. Interview transcripts were analysed thematically in NVivo 12 (QSR International, Warrington, UK) using inductive and deductive approaches. Results: Public health stakeholders’ approaches to engagement varied, falling into three main (and sometimes overlapping) types. (1) Many public health stakeholders in England and all public health stakeholders in Scotland took a ‘challenging’ approach to influencing licensing decisions and policies. Reducing health harms was felt to necessitate a focus on reducing availability and generating longer-term culture change, citing international evidence on the links between availability and alcohol-related harms. Some of these stakeholders viewed this as being a narrow, ‘nanny state’ approach, whereas others welcomed public health expertise and its evidence-based approach and input. (2) Some public health stakeholders favoured a more passive, ‘supportive’ approach, with some reporting that reducing availability was unachievable. They reported that, within the constraints of current licensing systems, alcohol availability may be contained (at least in theory) but cannot be reduced, because existing businesses cannot be closed on availability grounds. In this ‘supportive’ approach, public health stakeholders supplied licensing teams with data on request or waited for guidance from licensing teams on when and how to get involved. Therefore, public health action supported the licensing team in their aim of promoting ‘safe’ and ‘responsible’ retailing of alcohol and/or focused on short-term outcomes other than health, such as crime. (3) Some public health stakeholders favoured a ‘collaborative’ approach in which they worked in close partnership with licensing teams; this could include a focus on containing availability or responsible retail of alcohol, or both. Conclusions: In engaging with alcohol licensing, public health stakeholders adapted their approaches, sometimes resulting in a diminished focus on public health goals. Sampling did not include lower-activity areas, in which experiences might differ. The extent to which current licensing systems enable achievement of public health goals is questionable and the effectiveness of public health efforts merits quantitative evaluation

    Periodic Golay pairs and pairwise balanced designs

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    In this paper we exploit a relationship between certain pairwise balanced designs with v points and periodic Golay pairs of length v, to classify periodic Golay pairs of length less than 40. In particular, we construct all pairwise balanced designs with v points under specific block conditions having an assumed cyclic automorphism group, and using isomorph rejection which is compatible with equivalence of corresponding periodic Golay pairs, we complete a classification up to equivalence. This is done using the theory of orbit matrices and some compression techniques which apply to complementary sequences. We use similar tools to construct new periodic Golay pairs of lengths greater than 40 where classifications remain incomplete and demonstrate that under some extra conditions on its automorphism group, a periodic Golay pair of length 90 will not exist. Length 90 remains the smallest length for which existence of a periodic Golay pair is undecided. Some quasi-cyclic self-orthogonal codes are constructed as an added application

    How public health teams navigate their different roles in alcohol premises licensing: ExILEnS multistakeholder interview findings

    Get PDF
    Background: In England and Scotland, local governments regulate the sale of alcohol by awarding licences to premises to permit the sale of alcohol for consumption on or off the premises, under certain conditions; without such a licence, alcohol cannot be legally sold. In recent years, many local public health teams have become proactive in engaging with alcohol licensing, encouraging licensing authorities to act in ways intended to improve population health. Objective: This research aimed to explore and understand the approaches and activities of public health stakeholders (i.e. NHS staff and other public health professionals) in seeking to influence local alcohol licensing policy and decisions, and the views of licensing stakeholders (i.e. licensing officers/managers, police staff with a licensing remit, elected members and licensing lawyers/clerks) on the acceptability and effectiveness of these approaches. Participants: Local public health teams in England and Scotland were directly informed about this multisite study. Scoping calls were conducted with interested teams to explore their level of activity in alcohol licensing from 2012 across several categories. Twenty local authority areas with public health teams active in licensing matters were recruited purposively in England (n = 14) and Scotland (n = 6) to vary by region and rurality. Fifty-three in-depth telephone interviews (28 with public health stakeholders and 25 with licensing stakeholders outside health, such as local authority licensing teams/lawyers or police) were conducted. Interview transcripts were analysed thematically in NVivo 12 (QSR International, Warrington, UK) using inductive and deductive approaches. Results: Public health stakeholders’ approaches to engagement varied, falling into three main (and sometimes overlapping) types. (1) Many public health stakeholders in England and all public health stakeholders in Scotland took a ‘challenging’ approach to influencing licensing decisions and policies. Reducing health harms was felt to necessitate a focus on reducing availability and generating longerterm culture change, citing international evidence on the links between availability and alcohol-related harms. Some of these stakeholders viewed this as being a narrow, ‘nanny state’ approach, whereas others welcomed public health expertise and its evidence-based approach and input. (2) Some public health stakeholders favoured a more passive, ‘supportive’ approach, with some reporting that reducing availability was unachievable. They reported that, within the constraints of current licensing systems, alcohol availability may be contained (at least in theory) but cannot be reduced, because existing businesses cannot be closed on availability grounds. In this ‘supportive’ approach, public health stakeholders supplied licensing teams with data on request or waited for guidance from licensing teams on when and how to get involved. Therefore, public health action supported the licensing team in their aim of promoting ‘safe’ and ‘responsible’ retailing of alcohol and/or focused on short-term outcomes other than health, such as crime. (3) Some public health stakeholders favoured a ‘collaborative’ approach in which they worked in close partnership with licensing teams; this could include a focus on containing availability or responsible retail of alcohol, or both. Conclusions: In engaging with alcohol licensing, public health stakeholders adapted their approaches, sometimes resulting in a diminished focus on public health goals. Sampling did not include loweractivity areas, in which experiences might differ. The extent to which current licensing systems enable achievement of public health goals is questionable and the effectiveness of public health efforts merits quantitative evaluation. Study registration: The study is registered with the Research Registry as researchregistry6162. Funding: This project was funded by the National Institute for Health and Care Research (NIHR) Public Health Research programme and will be published in Public Health Research. See the NIHR Journals Library website for further project information

    Chemistry in Infrared Dark Cloud Clumps: a Molecular Line Survey at 3 mm

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    We have observed 37 Infrared Dark Clouds (IRDCs), containing a total of 159 clumps, in high-density molecular tracers at 3 mm using the 22-meter ATNF Mopra Telescope located in Australia. After determining kinematic distances, we eliminated clumps that are not located in IRDCs and clumps with a separation between them of less than one Mopra beam. Our final sample consists of 92 IRDC clumps. The most commonly detected molecular lines are (detection rates higher than 8%): N2H+, HNC, HN13C, HCO+, H13CO+, HCN, C2H, HC3N, HNCO, and SiO. We investigate the behavior of the different molecular tracers and look for chemical variations as a function of an evolutionary sequence based on Spitzer IRAC and MIPS emission. We find that the molecular tracers behave differently through the evolutionary sequence and some of them can be used to yield useful relative age information. The presence of HNC and N2H+ lines do not depend on the star formation activity. On the other hand, HC3N, HNCO, and SiO are predominantly detected in later stages of evolution. Optical depth calculations show that in IRDC clumps the N2H+ line is optically thin, the C2H line is moderately optically thick, and HNC and HCO+ are optically thick. The HCN hyperfine transitions are blended, and, in addition, show self-absorbed line profiles and extended wing emission. These factors combined prevent the use of HCN hyperfine transitions for the calculation of physical parameters. Total column densities of the different molecules, except C2H, increase with the evolutionary stage of the clumps. Molecular abundances increase with the evolutionary stage for N2H+ and HCO+. The N2H+/HCO+ and N2H+/HNC abudance ratios act as chemical clocks, increasing with the evolution of the clumps.Comment: Accepted to ApJ. 29 page

    Host predisposition by endogenous Transforming Growth Factor-β1 overexpression promotes pulmonary fibrosis following bleomycin injury

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    <p>Abstract</p> <p>Background</p> <p>Idiopathic Pulmonary Fibrosis (IPF) is a progressive diffuse disease involving the lung parenchyma. Despite recent advances, the molecular mechanisms of the initiation and progression of this disease remain elusive. Previous studies have demonstrated TGFβ1 as a key effector cytokine in the development of lung fibrosis.</p> <p>Methods</p> <p>In this study we have used a transgenic mouse based strategy to identify the effect of overexpression of this key effector mediator on the development of pulmonary fibrosis in response to exogenous injury. We bred two lines (line 25 and 18) of transgenic mice (Tr+) that overexpressed active TGFβ1. Three-month old transgenic and wild type mice were subsequently wounded with intraperitoneal bleomycin. Mice were sacrificed at 6 weeks post-bleomycin and their lungs analysed histologically and biochemically.</p> <p>Results</p> <p>The severity of lung fibrosis was significantly greater in the Tr+ mice compared to the wild type mice. Using an oligonucleotide microarray based strategy we identified discrete patterns of gene expression contributing to TGFβ1 associated pulmonary fibrosis.</p> <p>Conclusion</p> <p>This data emphasises the importance of a host predisposition in the form of endogenous TGFβ1, in the development of pulmonary fibrosis in response to an exogenous injury.</p
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