958 research outputs found

    Interference-Aware Deployment for Maximizing User Satisfaction in Multi-UAV Wireless Networks

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    In this letter, we study the deployment of Unmanned Aerial Vehicle mounted Base Stations (UAV-BSs) in multi-UAV cellular networks. We model the multi-UAV deployment problem as a user satisfaction maximization problem, that is, maximizing the proportion of served ground users (GUs) that meet a given minimum data rate requirement. We propose an interference-aware deployment (IAD) algorithm for serving arbitrarily distributed outdoor GUs. The proposed algorithm can alleviate the problem of overlapping coverage between adjacent UAV-BSs to minimize inter-cell interference. Therefore, reducing co-channel interference between UAV-BSs will improve user satisfaction and ensure that most GUs can achieve the minimum data rate requirement. Simulation results show that our proposed IAD outperforms comparative methods by more than 10% in user satisfaction in high-density environments.Comment: 5 pages, 3 figures, to appear in IEEE Wireless Communications Letter

    Bacteremic pneumonia caused by extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae: Appropriateness of empirical treatment matters

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    BackgroundClinical information about bacteremic pneumonia caused by extended-spectrum beta-lactamase (ESBL)-producing organism is limited.MethodsA retrospective study was conducted at two medical centers in Taiwan. From May 2002 to August 2010, clinical information and outcome of adults with bacteremic pneumonia caused by ESBL-producing Escherichia coli and Klebsiella pneumoniae were analyzed. The primary outcome is the 30-day mortality.ResultsA total of 111 patients with bacteremic pneumonia caused by E. coli (37 patients, 33.3%) and K. pneumoniae (74, 66.7%) were identified. Their mean age was 69.2 years and 51.4% were male patients. Fifty-seven (51.3%) episodes were classified as hospital-acquired infections, 19 (17.1%) as health-care-associated infections, and four (3.6%) as community-acquired infections. Fifty-one (45.9%) patients received appropriate empiric antimicrobial therapy. The 30-day mortality rate was 40.5% (45 patients). In the multivariate analysis, several independent risk factors, including rapidly fatal underlying disease [odds ratio (OR), 5.75; 95% confidence interval (CI), 1.54–21.48; p = 0.009], severe sepsis (OR, 4.84; 95% CI, 1.55–15.14; p = 0.007), critical illness (OR, 4.28; 95% CI, 1.35–13.57; p = 0.013), and receipt of appropriate empirical therapy (OR, 0.19; 95% CI, 0.07–0.55; p = 0.002), were associated with 30-day mortality. The survival analysis consistently found that individuals with appropriate empiric therapy had a higher survival rate (log-rank test, p < 0.001).ConclusionESBL-producing bacteremic pneumonia, especially health-care-associated infections, often occurred in adults with comorbidities. Appropriate empirical therapy was associated with a favorable outcome

    Predictors of intra-abdominal coagulopathic hemorrhage after living donor liver transplantation

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    AbstractBackgroundResults of preoperative conventional coagulation assays are a poor predictor of hemorrhage after liver transplantation. In this study, we evaluated the factors that are predictive of intra-abdominal coagulopathic hemorrhage after living donor liver transplantation surgery.MethodsDuring the period from January 2009 to December 2012, 118 adults underwent living donor liver transplantation (LDLT) in our institution. Of those patients, 18 (15.3%) developed intra-abdominal coagulopathic hemorrhage (n = 7) or hemorrhage due to non-coagulopathic causes (n = 11) that required emergency medical, radiological, or surgical intervention within the first month after LDLT. Possible predictors of postoperative coagulopathic hemorrhage included donor-related factors, age, body mass index, MELD score, INR value, intra-operative blood transfusion, graft/recipient weight ratio, anhepatic phase, cold ischemia time, operative time, APACHE II score, onset of re-bleeding, and hemoglobin levels during rebleeding episodes.ResultsThere were no differences in any of the variables between the two groups (coagulopathic and noncoagulopathic hemorrhage) except for cold ischemia time. We found that cold ischemia time was significantly longer in patients with postoperative coagulopathic hemorrhage (160.50 ± 45.02 min) than in patients with hemorrhage due to non-coagulopathic causes (113.55 ± 29.31 min; P = 0.027).ConclusionProlonged cold ischemia time is associated with postoperative intra-abdominal coagulopathic hemorrhage in patients after LDLT. It is, therefore, necessary to shorten the cold ischemia time in order to reduce the risk of postoperative intra-abdominal hemorrhage due to coagulopathic causes

    Mineralization of Progenitor Cells with Different Implant Topographies

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    AbstractThe major challenge for dental implants is achieving an optimal osteoregeneration. Different levels of roughness processed through sand-blasting/ acid-etching (SLA) then further treated with silane and peptide were measured. Peptide bonded with silane on the SLA and machine ground titanium (Ti) surface were used as a culture substitute. The sample properties on the osteogenic abilities were compared by testing the interaction with mesenchymal stem cells (MSCs, D1). When comparing to the SLA only group, the silane treated Ti surface with peptide bonded had smaller wetting angle and the cell proliferative ability did differ with statistical significance (p<0.05). A rougher surface binding with peptide provided higher hydrophilic ability and had the potential ability to enhance the proliferation and mineralization of the progenitor cell D1. Accordingly, a novel implant surface treatment method having tissues integrated was obtained through the supplement of peptide on the surfaces through SLA treatment of titanium

    Nationwide epidemiological study of severe gallstone disease in Taiwan

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    <p>Abstract</p> <p>Background</p> <p>Our study aimed to assess the nationwide trends in the incidence of severe gallstone disease in Taiwan among adults aged ≥20.</p> <p>Methods</p> <p>A retrospective longitudinal study was conducted using Taiwan National Health Insurance Research Database collected during 1997–2005. Patients with incident severe gallstone disease (acute cholecystitis, biliary pancreatitis, acute cholangitis) and gallstone-related procedures (elective and non-elective cholecystectomy, endoscopic retrograde cholangiopancreatography [ERCP]) that led to hospital admission were identified using ICD-9-CM diagnostic and procedure codes. Annual incidence rates of gallstone-related complications and procedures were calculated and their 95% confidence intervals (CI) were estimated assuming a Poisson distribution.</p> <p>Results</p> <p>The hospital admission rate for severe gallstone disease increased with advancing age and the age-standardized rate (95% CI) per 1000 population was 0.60 (0.59–0.60) for men and 0.59 (0.59–0.60) for women. Men had a higher rate of acute cholecystitis, probably due to the substantially lower rate of elective cholecystectomy among men than women. For those aged 20–39, hospital admissions for all gallstone-related complications and procedures increased significantly. For those aged ≥60, incidences of biliary pancreatitis, acute cholangitis, and hospital admission for gallstone receiving ERCP increased significantly without substantial change in the incidence of acute cholecystitis and despite a decreased rate of elective cholecystectomy.</p> <p>Conclusion</p> <p>This population-based study found a substantial increase in the rate of admission for severe gallstone disease among those aged 20–39. Concurrently, the incidences of biliary pancreatitis and acute cholangitis have risen among those aged ≥60.</p

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

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    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

    Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

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    One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI

    Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

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    This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good
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