147 research outputs found
Cooperative Algorithms for MIMO Amplify-and-Forward Relay Networks
Interference alignment is a signaling technique that provides high
multiplexing gain in the interference channel. It can be extended to multi-hop
interference channels, where relays aid transmission between sources and
destinations. In addition to coverage extension and capacity enhancement,
relays increase the multiplexing gain in the interference channel. In this
paper, three cooperative algorithms are proposed for a multiple-antenna
amplify-and-forward (AF) relay interference channel. The algorithms design the
transmitters and relays so that interference at the receivers can be aligned
and canceled. The first algorithm minimizes the sum power of enhanced noise
from the relays and interference at the receivers. The second and third
algorithms rely on a connection between mean square error and mutual
information to solve the end-to-end sum-rate maximization problem with either
equality or inequality power constraints via matrix-weighted sum mean square
error minimization. The resulting iterative algorithms converge to stationary
points of the corresponding optimization problems. Simulations show that the
proposed algorithms achieve higher end-to-end sum-rates and multiplexing gains
that existing strategies for AF relays, decode-and-forward relays, and direct
transmission. The first algorithm outperforms the other algorithms at high
signal-to-noise ratio (SNR) but performs worse than them at low SNR. Thanks to
power control, the third algorithm outperforms the second algorithm at the cost
of overhead.Comment: submitted to IEEE Transactions on Signal Processing in December 2011,
revised in April 2012 and in September 201
apeNEXT: A multi-TFlops Computer for Simulations in Lattice Gauge Theory
We present the APE (Array Processor Experiment) project for the development
of dedicated parallel computers for numerical simulations in lattice gauge
theories. While APEmille is a production machine in today's physics simulations
at various sites in Europe, a new machine, apeNEXT, is currently being
developed to provide multi-Tflops computing performance. Like previous APE
machines, the new supercomputer is largely custom designed and specifically
optimized for simulations of Lattice QCD.Comment: Poster at the XXIII Physics in Collisions Conference (PIC03),
Zeuthen, Germany, June 2003, 3 pages, Latex. PSN FRAP15. Replaced for adding
forgotten autho
Incidence, Patterns, and Associations Between Dual-Antiplatelet Therapy Cessation and Risk for Adverse Events Among Patients With and Without Diabetes Mellitus Receiving Drug-Eluting Stents: Results From the PARIS Registry.
OBJECTIVES: The aim of this study was to examine the frequency and clinical impact of different cessation patterns of dual-antiplatelet therapy (DAPT) after percutaneous coronary intervention with drug-eluting stents among patients with and those without diabetes mellitus (DM). BACKGROUND: Early DAPT suspension after percutaneous coronary intervention increases the risk for major adverse cardiac events. However, temporal variability in risk and relation to DAPT cessation patterns among patients with DM remain unclear. METHODS: Using data from the PARIS (Patterns of Non-Adherence to Anti-Platelet Regimens in Stented Patients) registry, 1,430 patients with DM (34%) and 2,777 without DM (66%) treated with drug-eluting stents were identified. DAPT cessation modes were classified as temporary interruption (<14 days), disruption because of bleeding or poor compliance, and physician-recommended discontinuation. RESULTS: During 2-year follow-up, DM was associated with an increased risk for thrombotic events but a similar risk for bleeding. The cumulative incidence of DAPT cessation was significantly lower in patients with versus those without DM (50.1% vs. 55.4%; p < 0.01), driven largely by less frequent physician-guided discontinuation beyond 1 year. In contrast, 2-year rates of interruption and disruption were similar between groups. When DAPT was interrupted or discontinued under physician guidance, the risk for major adverse cardiac events was unchanged compared with patients with DM on uninterrupted DAPT. Conversely, when DAPT was disrupted, the risk for major adverse cardiac events increased compared with uninterrupted DAPT, regardless of diabetic status, with no evidence of statistical interaction. CONCLUSIONS: DAPT cessation patterns vary according to diabetic status, with less frequent physician-guided discontinuation among patients with DM. The presence of DM does not emerge as a modifier of cardiovascular risk after DAPT cessation
Status of the apeNEXT project
We present the current status of the apeNEXT project. Aim of this project is the development of the next generation of APE machines which will provide multi-teraflop computing power. Like previous machines, apeNEXT is based on a custom designed processor, which is specifically optimized for simulating QCD. We discuss the machine design, report on benchmarks, and give an overview on the status of the software development
Dual-Antiplatelet Therapy Cessation and Cardiovascular Risk in Relation to Age: Analysis From the PARIS Registry.
OBJECTIVES: The aim of this study was to examine the association between dual-antiplatelet therapy (DAPT) cessation and cardiovascular risk after percutaneous coronary intervention in relation to age. BACKGROUND: Examination of outcomes by age after percutaneous coronary intervention is relevant given the aging population. METHODS: Two-year clinical outcomes, incidence, and effect of DAPT cessation on outcomes were compared by ages ≤55, 56 to 74, and ≥75 years from the PARIS (Patterns of Non-Adherence to Antiplatelet Regimens in Stented Patients) registry. DAPT cessation included physician-recommended discontinuation, interruption for surgery, and disruption (from noncompliance or bleeding). Clinical endpoints were major adverse cardiac events (MACE) (a composite of cardiac death, definite or probable stent thrombosis, spontaneous myocardial infarction, or clinically indicated target lesion revascularization), a secondary restrictive definition of MACE (MACE2) excluding target lesion revascularization, and bleeding. RESULTS: A total of 1,192 patients (24%) were ≤55 years, 2,869 (57%) were 56 to 74 years, and 957 (19%) were ≥75 years of age. Patients ≥75 years of age had higher DAPT cessation rates and increased risk for MACE2, death, cardiac death, and bleeding compared with younger patients. Discontinuation and interruption were not associated with increased cardiovascular risk across age groups, whereas disruption was associated with increased risk for MACE and MACE2 in younger patients but not in patients ≥75 years of age (p for trend <0.05). CONCLUSIONS: Nonadherence and outcomes vary by age, with patients ≥75 years having the highest DAPT cessation rates. We observed no association between outcomes and DAPT cessation in patients ≥75 years, whereas discontinuation was associated with lower MACE rates and disruption with increased MACE rates in patients <75 years
apeNEXT: A Multi-Tflops LQCD Computing Project
This paper is a slightly modified and reduced version of the proposal of the {\bf apeNEXT} project, which was submitted to DESY and INFN in spring 2000. .It presents the basic motivations and ideas of a next generation lattice QCD (LQCD) computing project, whose goal is the construction and operation of several large scale Multi-TFlops LQCD engines, providing an integrated peak performance of tens of TFlops, and a sustained (double precision) performance on key LQCD kernels of about 50% of peak speed
MolluscaBase – announcing a World Register of all Molluscs
Resumen de comunicaciĂłn oral en congresoThe Mollusca, second largest phylum on Earth, lack a global listing of valid names or even precise figures for the number of Recent species. The launching of MolluscaBase is intended to fill this gap, expanding the contents of the World Register of Marine Species (WoRMS) to include all marine, freshwater and terrestrial molluscs, recent and fossil. The WoRMS database, hosted at the Flanders Marine Institute (VLIZ) at Oostende, had more than 1,000,000 unique visitors in 2013 and provides the taxonomic backbone for initiatives such as Encyclopedia of Life, Catalogue of Life, and others. It currently contains more than 44,000 valid species names of Recent marine Mollusca, which are estimated to represent approximately 95% of all valid species. There is no similar global list of the freshwater and terrestrial Mollusca. It is estimated that there are about 23,000 species of land snails/slugs and about 5,000 freshwater gastropods and bivalves. The number of named fossil Mollusca is not known, but is in the same order of magnitude as that of Recent species. MolluscaBase is intended as an authoritative taxonomic database, relying only on published sources and built by taxonomic editors who are active malacologists and respond to feedback from users. Like in WoRMS, the contents should include Taxonomic hierarchy, Current name and synonymy, Literature sources, Distributions (using countries as the basic unit for land-based distributions), Fossil range (expressed in terms of the international chronostratigraphic chart) and other taxon attributes. This initiative is supported by LifeWatch, the E-Science European Infrastructure for Biodiversity and Ecosystem Research. In a first move, MolluscaBase should build on the existing WoRMS contents incorporating the contents of existing initiatives like CLEMAM (Checklist of European MArine Molusca), FreshGEN (Freshwater Gastropods of the European Neogene) and Fauna Europaea. The long term goal of filling the gaps in non-marine and fossil components of MolluscaBase needs your support! If you are a taxonomist, specializing in any group of non-marine or extinct molluscs, and wish to become a contributor to MolluscaBase, please let us know and contact the WoRMS team at [email protected], or the corresponding author, to find your possible role in MolluscaBase!Universidad de Málaga. Campus de Excelencia Internacional AndalucĂa Tech
Signa et tituli
La spécialisation de plus en plus grande et le cloisonnement de nos domaines de recherche (histoire, histoire de l’art, archéologie...) conduisent le plus souvent à étudier et à publier séparément, malgré leur complémentarité, les sources épigraphiques et les sources iconographiques. Des salles de nos musées aux rayons de nos bibliothèques, documents sculptés et documents inscrits forment des ensembles "disjoints". Or, statuaire et épigraphie, signa et tituli, étaient dans l’Antiquité des éléments conçus ensemble, comme les deux volets d’un même message, indissociables dès la première formulation. Cette conjonction d’un texte et d’une image définit précisément le monumentum si caractéristique de la pratique commémorative romaine. Cet ouvrage, centré sur la question du monumentum romain, regroupe les communications présentées lors du colloque "Signa et tituli. Monuments et espaces de représentation en Gaule méridionale sous le regard croisé de la sculpture et de l’épigraphie" (Aix-en-Provence, 26-27 novembre 2009). À la suite d’une approche méthodologique, l’ouvrage propose une série d’études sur différents lieux de la société romaine où se croisent données iconographiques et épigraphiques : les espaces civiques de représentation, les espaces et monuments funéraires, les espaces de la religion
Human Papillomavirus (HPV) seroprevalence, cervical HPV prevalence, genotype distribution and cytological lesions in solid organ transplant recipients and immunocompetent women in Sao Paulo, Brazil
INTRODUCTION: Solid organ transplant (SOT) recipients are at increased risk of Human Papillomavirus (HPV) persistent infection and disease. This study aimed to evaluate HPV seroprevalence, cervical HPV prevalence, genotype distribution, and frequency of HPV-related cervical lesions in SOT recipients in comparison to immunocompetent women. METHODS: Cross-sectional study including SOT and immunocompetent women aged 18 to 45 years who denied previous HPV-related lesions. Cervical samples were screened for HPV-DNA by a polymerase chain reaction (PCR)-based DNA microarray system (PapilloCheck®) and squamous intraepithelial lesions (SIL) by liquid-based cytology. A multiplexed pseudovirion-based serology assay (PsV-Luminex) was used to measure HPV serum antibodies. RESULTS: 125 SOT and 132 immunocompetent women were enrolled. Cervical samples were collected from 113 SOT and 127 immunocompetent women who had initiated sexual activity. HPV-DNA prevalence was higher in SOT than in immunocompetent women (29.6% vs. 20.2%, p = 0.112), but this difference was not statistically significant. High-risk (HR)-HPV was significantly more frequent in SOT than in immunocompetent women (19.4% vs. 7.9%, p = 0.014). Simultaneous infection with ≥2 HR-HPV types was found in 3.1% of SOT and 0.9% of immunocompetent women. HPV seropositivity for at least one HPV type was high in both groups: 63.8% of 105 SOT and 69.7% of 119 immunocompetent women (p = 0.524). Low-grade (LSIL) and high-grade SIL (HSIL) were significantly more frequent in SOT (9.7% and 5.3%, respectively) than in immunocompetent women (1.6% and 0.8%, respectively) (p = 0.001). CONCLUSIONS: These results may reflect the increased risk of HPV persistent infection and disease progression in SOT women due to chronic immunosuppression
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