EP-1245: Gated Rapidarc using KV intrafraction verification for liver stereotactic treatment

n/

Algorithm and performance of a clinical IMRT beam-angle optimization system

This paper describes the algorithm and examines the performance of an IMRT beam-angle optimization (BAO) system. In this algorithm successive sets of beam angles are selected from a set of predefined directions using a fast simulated annealing (FSA) algorithm. An IMRT beam-profile optimization is performed on each generated set of beams. The IMRT optimization is accelerated by using a fast dose calculation method that utilizes a precomputed dose kernel. A compact kernel is constructed for each of the predefined beams prior to starting the FSA algorithm. The IMRT optimizations during the BAO are then performed using these kernels in a fast dose calculation engine. This technique allows the IMRT optimization to be performed more than two orders of magnitude faster than a similar optimization that uses a convolution dose calculation engine.Comment: Final version that appeared in Phys. Med. Biol. 48 (2003) 3191-3212. Original EPS figures have been converted to PNG files due to size limi

An overview on the natural enemies of Rhynchophorus palm weevils, with focus on R. ferrugineus.

Rhynchophorus palm weevils are large insects belonging to the family Dryophthoridae. All Rhynchophorus species are polyphagous and have a similar life history but some are major pests because of the serious economic damage they cause, in particular to several species of the family Arecaceae. Here we review the natural enemies of Rhynchophorus species in both their native and introduced regions of the world, to assess the possibility of biological control of this taxon. Moreover, particular attention is paid to the well-studied and harmful species Rhynchophorus ferrugineus, about which more information is available, and to its natural enemies in the Mediterranean region, because the impact of this pest in this recently colonized area is particularly remarkable and also the recent trend in species management is looking for indigenous natural enemies. More than 50 natural enemies have been reported to attack Rhynchophorus species, even if most of them are associated to R. ferrugineus (Olivier), highlighting the lack of information on the other species of the genus. Pros and cons of all the biological control agents are then discussed: among the considered organisms, fungi are noteworthy to be considered for inclusion in integrated pest management programs. Overall, our overview underlines the need to increase knowledge on natural enemies of all the species of the genus Rhynchophorus, to isolate more virulent strains and to determine the optimum conditions for the actions of the biocontrol agents

Prevalence and Prognostic Influence of Peripheral Arterial Disease in Patients ≥40 Years Old Admitted into Hospital Following an Acute Coronary Event

AbstractObjectiveA significant proportion of patients with ischemic heart disease have associated peripheral arterial disease (PAD), but many are asymptomatic and this condition remains underdiagnosed. We aimed to study the prevalence of PAD in patients with an acute coronary syndrome (ACS) and to evaluate its influence in hospital clinical outcomes.MethodsThe PAMISCA register is a prospective, multicenter study involving patients ≥40 years old with ACS admitted to selected Spanish hospitals. All patients had their ankle-brachial index (ABI) measured between days 3 and 7 after the ischemic event.Results1410 ACS patients (71.4% male) were included. PAD determined by ABI was documented in 561 patients (39.8%). Factors independently related to PAD were age (OR: 1.04; 95% CI: 1.03–1.06; p<0.001), smoking (OR: 1.88; 95% CI: 1.41–2.49; p<0.0001), diabetes (OR: 1.30; 95% CI: 1.02–1.65; p<0.05), previous cardiac disease (OR: 1.54; 95% CI: 1.22–1.95; p<0.001) and previous cerebrovascular disease (OR: 1.90; 95% CI: 1.28–2.80; p<0.001). Following the ACS, an ABI≤0.90 was associated with increased cardiovascular mortality (OR: 5.45; 95% CI: 1.16–25.59; p<0.05) and a higher risk of cardiovascular complications.ConclusionThe prevalence of PAD in patients ≥40 years presenting with ACS is high and it is associated with increased cardiovascular risk

Surto policlonal de infecção de corrente sanguínea causada pelo complexo Burkholderia cepacia em unidades de hospital-dia de hematologia e transplante de medula óssea

Aim: The objective was to describe an outbreak of bloodstream infections by Burkholderia cepacia complex (Bcc) in bone marrow transplant and hematology outpatients. Methods: On February 15, 2008 a Bcc outbreak was suspected. 24 cases were identified. Demographic and clinical data were evaluated. Environment and healthcare workers' (HCW) hands were cultured. Species were determined and typed. Reinforcement of hand hygiene, central venous catheter (CVC) care, infusion therapy, and maintenance of laminar flow cabinet were undertaken. 16 different HCWs had cared for the CVCs. Multi-dose heparin and saline were prepared on counter common to both units. Findings: 14 patients had B. multivorans (one patient had also B. cenopacia), six non-multivorans Bcc and one did not belong to Bcc. Clone A B. multivorans occurred in 12 patients (from Hematology); in 10 their CVC had been used on February 11/12. Environmental and HCW cultures were negative. All patients were treated with meropenem, and ceftazidime lock-therapy. Eight patients (30%) were hospitalized. No deaths occurred. After control measures (multidose vial for single patient; CVC lock with ceftazidime; cleaning of laminar flow cabinet; hand hygiene improvement; use of cabinet to store prepared medication), no new cases occurred. Conclusions: This polyclonal outbreak may be explained by a common source containing multiple species of Bcc, maybe the laminar flow cabinet common to both units. There may have been contamination by B. multivorans (clone A) of multi-dose vials.O objetivo foi descrever um surto de infecções da corrente sanguínea por complexo B. cepacia (Bcc) nos ambulatórios de hematologia e transplante de medula óssea. Métodos: Em 15/02/2008, um surto de Bcc foi suspeitado. 24 casos foram identificados. Os dados demográficos e clínicos foram avaliados. Mãos de profissionais da saúde e ambiente foram cultivadas. Espécies foram determinadas e tipadas. Reforço da higiene das mãos, cuidados com cateteres, terapia de infusão e manutenção da câmara de fluxo laminar foram realizadas. 16 profissionais de saúde (PS) diferentes manipularam os cateteres. Heparina multidoses e soro eram preparadas em um balcão comum a ambas as unidades. Resultados: 14 pacientes tiveram B. multivorans (um paciente teve também B. cenopacia), 6 Bcc não-multivorans e um teve um agente não pertencente a Bcc. Clone A de B. multivorans ocorreu em 12 pacientes (da Hematologia), em 10 o cateter havia sido utilizado nos dias 11 ou 12 de fevereiro. Culturas ambientais e de PS foram negativos. Todos os pacientes foram tratados com meropenem e selo de ceftazidima. Oito pacientes (30%) foram hospitalizados. Não ocorreram mortes. Após as medidas de controle, nenhum novo caso ocorreu. Conclusões: Este surto policlonal pode ser explicado por uma fonte comum contendo várias espécies de Bcc, talvez a câmara de fluxo laminar comum a ambas as unidades. Pode ter havido contaminação por B. multivorans (clone A) de frascos multi-dose

Interação social entre agentes em ambientes de recursos limitados

Trabalho final de Mestrado para obtenção do grau de Mestre em Engenharia de Redes de Comunicação e MultimédiaO estudo da interação social entre agentes inteligentes é cada vez mais um tema central da investigação em inteligência artificial. Atualmente inseridos numa realidade onde veículos navegam autonomamente, não é difícil imaginar cenários onde estas máquinas poderão trabalhar em conjunto, maximizando as suas capacidades e tornando-se mais eficientes na utilização de recursos e na concretização dos respetivos objetivos. Devido à elevada complexidade computacional dos seus processos internos, ainda é difícil, sobretudo para máquinas com locomoção autónoma no mundo, desenvolver raciocínio social de forma complexa, pelo que este trabalho pretende contribuir com uma abordagem que aproxime a investigação de uma solução viável para cenários reais onde um sistema multi-agente, limitado pelos seus recursos, tem de produzir soluções em tempo real. Este trabalho integra-se na área dos agentes inteligentes, sendo desenvolvido o tema da interação social em arquiteturas de agentes com limitação de recursos. É apresentado um estudo sobre as arquiteturas de agentes reativas e deliberativas e as respetivas potencialidades na constituição de sistemas multi-agente num contexto de limitação de recursos. É feito o estudo do problema da delegação de tarefas numa abordagem de limitação de recursos, onde se propõe um modelo de coordenação com base em mecanismos emocionais para a sua solução.Abstract: The study of social interaction between intelligent agents is increasingly becoming a central topic of research in artificial intelligence. Living in a reality where vehicles navigate autonomously, it is not hard to imagine scenarios in which these machines could work together, maximizing their skills, making better use of their resources and being more eficient on the achievement of objectives. Due to the high computational complexity of the internal processes, it is still dificult, especially for machines with autonomous locomotion, to develop complex social reasoning, so this work aims to contribute to an approach that approximates the research to a viable solution for real scenarios where a multi-agent system, limited by its resources, has to produce solutions in real-time. This work is part of the area of intelligent agents, developing the theme of social interaction on agent architectures working with bounded-resources. It is presented a study about the reactive and deliberative architectures and their potential in the formation of multi-agent systems in a boundedresources context. It is also made a study about the task delegation problema from the resource-bounded point of view, proposing a coordenation model, based on emotional mechanisms

Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

Standalone vertex finding in the ATLAS muon spectrometer

A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011

Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ γ, H → Z Z∗ →4l and H →W W∗ →lνlν. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson