Search for a Charged Higgs Boson Produced in the Vector-boson Fusion Mode with Decay H±→W±Z using pp Collisions at s√=8 TeV with the ATLAS Experiment

A search for a charged Higgs boson, H±, decaying to a W± boson and a Z boson is presented. The search is based on 20.3 fb−1 of proton-proton collision data at a center-of-mass energy of 8 TeV recorded with the ATLAS detector at the LHC. The H± boson is assumed to be produced via vector-boson fusion and the decays W±→qq′¯ and Z→e+e−/μ+μ− are considered. The search is performed in a range of charged Higgs boson masses from 200 to 1000 GeV. No evidence for the production of an H± boson is observed. Upper limits of 31--1020 fb at 95% CL are placed on the cross section for vector-boson fusion production of an H± boson times its branching fraction to W±Z. The limits are compared with predictions from the Georgi-Machacek Higgs Triplet Model.

Search for production of vector-like quark pairs and of four top quarks in the lepton-plus-jets final state in pp collisions at root 8=8 TeV with the ATLAS detector

A search for pair production of vector-like quarks, both up-type (T) and down-type (B), as well as for four-top-quark production, is presented. The search is based on pp collisions at s√=8 TeV recorded in 2012 with the ATLAS detector at the CERN Large Hadron Collider and corresponding to an integrated luminosity of 20.3 fb−1. Data are analysed in the lepton-plus-jets final state, characterised by an isolated electron or muon with high transverse momentum, large missing transverse momentum and multiple jets. Dedicated analyses are performed targeting three cases: a T quark with significant branching ratio to a W boson and a b-quark (TT¯→Wb+X), and both a T quark and a B quark with significant branching ratio to a Higgs boson and a third-generation quark (TT¯→Ht+X and BB¯→Hb+X respectively). No significant excess of events above the Standard Model expectation is observed, and 95% CL lower limits are derived on the masses of the vector-like T and B quarks under several branching ratio hypotheses assuming contributions from T→Wb, Zt, Ht and B→Wt, Zb, Hb decays. The 95% CL observed lower limits on the T quark mass range between 715 GeV and 950 GeV for all possible values of the branching ratios into the three decay modes, and are the most stringent constraints to date. Additionally, the most restrictive upper bounds on four-top-quark production are set in a number of new physics scenarios.

Validation of a method to measure light distortion surrounding a source of glare

Our objective was to validate a new device dedicated to measure the light disturbances surrounding bright sources of light under different sources of potential variability. Twenty subjects were involved in the study. Light distortion was measured using an experimental prototype (light distortion analyzer, CEORLab, University of Minho, Portugal) comprising twenty-four LED arrays panel at 2 m. Sources of variability included: intrasession and intersession repeated measures, pupil size (3 versus 6 mm), defocus (þ0.50) correction for the working distance, angular resolution (15 deg versus 30 deg), temporal stimuli presentation, and pupil size. Size, shape, location, and irregularity parameters have been obtained. At a low speed of presentation of the stimuli, changes in angular resolution did not have an effect on the results of the parameters measured. Results did not change with pupil size. Intensity of the central glare source significantly influenced the outcomes. Examination time was reduced by 30% when a 30 deg angular resolution was explored instead of 15 deg. Measurements were fast and repeatable under the same experimental conditions. Size and shape parameters showed the highest consistency, whereas location and irregularity parameters showed lower consistency. The system was sensitive to changes in the intensity of the central glare source but not to pupil changes in this sample of healthy subjects.

MOEA/VAN: Multiobjective Evolutionary Algorithm based on Vector Angle Neighborhood

Natural selection favors the survival and reproduction of organisms that are best adapted to their environment. Selection mechanism in evolutionary algorithms mimics this process, aiming to create environmental conditions in which artificial organisms could evolve solving the problem at hand. This paper proposes a new selection scheme for evolutionary multiobjective optimization. The similarity measure that defines the concept of the neighborhood is a key feature of the proposed selection. Contrary to commonly used approaches, usually defined on the basis of distances between either individuals or weight vectors, it is suggested to consider the similarity and neighborhood based on the angle between individuals in the objective space. The smaller the angle, the more similar individuals. This notion is exploited during the mating and environmental selections. The convergence is ensured by minimizing distances from individuals to a reference point, whereas the diversity is preserved by maximizing angles between neighboring individuals. Experimental results reveal a highly competitive performance and useful characteristics of the proposed selection. Its strong diversity preserving ability allows to produce a significantly better performance on some problems when compared with stat-of-the-art algorithms.

Vanishing spin stiffness in the spin-1/2 Heisenberg chain for any nonzero temperature

Whether at the zero spin density m = 0 and finite temperatures T > 0 the spin stiffness of the spin-1/2 XXX chain is finite or vanishes remains an unsolved and controversial issue, as different approaches yield contradictory results. Here we explicitly compute the stiffness at m = 0 and find strong evidence that it vanishes. In particular, we derive an upper bound on the stiffness within a canonical ensemble at any fixed value of spin density m that is proportional to m2L in the thermodynamic limit of chain length L → ∞, for any finite, nonzero temperature, which implies the absence of ballistic transport for T > 0 for m = 0. Although our method relies in part on the thermodynamic Bethe ansatz (TBA), it does not evaluate the stiffness through the second derivative of the TBA energy eigenvalues relative to a uniform vector potential. Moreover, we provide strong evidence that in the thermodynamic limit the upper bounds on the spin current and stiffness used in our derivation remain valid under string deviations. Our results also provide strong evidence that in the thermodynamic limit the TBA method used by X. Zotos [Phys. Rev. Lett. 82, 1764 (1999)] leads to the exact stiffness values at finite temperature T > 0 for models whose stiffness is finite at T = 0, similar to the spin stiffness of the spin-1/2 Heisenberg chain but unlike the charge stiffness of the half-filled 1D Hubbard model.

Vector of coordinates, velocities and accelerations

This chapter describes the how the vector of coordinates are defined in the formulation of spatial multibody systems. For this purpose, the translational motion is described in terms of Cartesian coordinates, while rotational motion is specified using the technique of Euler parameters. This approach avoids the computational difficulties associated with the singularities in the case of using Euler angles or Bryant angles. Moreover, the formulation of the velocities vector and accelerations vector is presented and analyzed here. These two sets of vectors are defined in terms of translational and rotational coordinates.

Reliability of the interpretation of coronary angiography by the simple visual method

OBJECTIVE: Evaluation of inter and intraobserver reproducibility of by the visual method interpretation of cineangiogram in a clinically based context. METHODS: Five interventional cardiologists analyzed 11 segments of 8 coronary cineangiograms at a two month apart sessions. The percent luminal reduction by the lesions were analyzed by two different classifications: in one (A) the lesions were graded in 0% = absent, 1-50% = mild, 51 - 69 = moderate, and > or = 70% = severe; the other classification (B) was a dichotomic one : <70% = nonsignificant and > or = 70%=significant lesions. The agreement were measured by the kappa (k) index. RESULTS: Interobserver agreement was moderate for classification A (1st measurement, k = 0.36 -- 0.63, k m = 0.49; 2nd measurement, k = 0.39-0.68, k m = 0.52) and good for classification B (1st measurement, k = 0.55-0.73, k m = 0.63; 2nd measurement, k = 0.37-0.82, k m = 0.61). Intraobserver levels of agreement were k = 0.57-0.95 for classification A and 0.62-1.0 for classification B. CONCLUSION: The higher level of reproducibility obtained by adopting the dichotomous criteria usually considered for ischemic limits demonstrates that in the present clinical context, the reliability of the simple visual method is adequate for the identification of patients with clinically significant lesions and candidates for myocardial revascularization procedures.

“Safety and health” as a criterion in the choice of tunneling method

Risk management is of paramount importance in the success of tunnelling works and is linked to the tunnelling method and to the constraints of the works. Sequencial Excavation Method (SEM) and Tun-nel Boring Machine (TBM) method have been competing for years. This article, part of a wider study on the influence of the â Safety and Healthâ criterion in the choice of method, reviews the existing literature about the criteria usually employed to choose the tunnelling method and on the criterion â Safety and Healthâ . This crite-rion is particularly important, due to the financial impacts of work accidents and occupational diseases. This article is especially useful to the scientific and technical community, since it synthesizes the relevance of each one of the choice criteria used and it shows why â Safety and Healthâ must be a criterion in the decision mak-ing process to choose the tunnelling method.

Hierarchical modelling of timber reference properties using probabilistic methods: Maximum Likelihood Method, Bayesian Methods and Probability Networks

In recent decades, an increased interest has been evidenced in the research on multi-scale hierarchical modelling in the field of mechanics, and also in the field of wood products and timber engineering. One of the main motivations for hierar-chical modelling is to understand how properties, composition and structure at lower scale levels may influence and be used to predict the material properties on a macroscopic and structural engineering scale. This chapter presents the applicability of statistic and probabilistic methods, such as the Maximum Likelihood method and Bayesian methods, in the representation of timber’s mechanical properties and its inference accounting to prior information obtained in different importance scales. These methods allow to analyse distinct timber’s reference properties, such as density, bending stiffness and strength, and hierarchically consider information obtained through different non, semi or destructive tests. The basis and fundaments of the methods are described and also recommendations and limitations are discussed. The methods may be used in several contexts, however require an expert’s knowledge to assess the correct statistic fitting and define the correlation arrangement between properties.

Determination of catalase activity and its inhibition by a simple manometric method

[Excerpt] Introduction: There has been a considerable amount of controversy about the use of manometric methods to measure catalase activity. As Maehly and Chance point out in their excellent review] the advantages of these methods is "... that they can be used for any kind of biological material, and purification of the enzyme is not required. The assay is independent of small amounts of peroxidase activity. It is fairly simple to perform, it is rapid and it can be adapted to continuous reading of the reaction". A variety of drawbacks are also listed by the same authors, viz, the inactivation of the enzyme under the experimental conditions and the time lag before a constant rate of oxygen evolution is reached. [...]

Evaluación de la interacción virus-hospedante-vector- endosimbiontes y su influencia en la transmisión del Mal de Río Cuarto en infecciones simples y mixtas con el Cereal Rhabdovirus.

El “Mal de Río Cuarto” es la enfermedad más importante del maíz en la Argentina. El agente causal es un fijivirus denominado Mal de Río Cuarto virus (MRCV). Se transmite únicamente a través de delfácidos (Hemiptera-Delphacidae) de forma persistente propagativa. Se han descripto diversas especies con demostrada capacidad vectora, entre ellos Delphacodes kuscheli Fennah y Toya propinqua Fieber. La primera es de gran importancia tanto por su abundancia en las zonas maiceras de nuestro país como por su eficiencia de transmisión mientras que T. propinqua es una especie cosmopolita que se encuentra ampliamente distribuida en toda el área productiva. Ambas especies poseen una demostrada capacidad de transmisión a cereales de grano fino, importantes epidemiológicamente por su rol como reservorios del virus y el vector en época invernal. Un aspecto que requiere especial atención es la aparición de una nueva virosis, un Cytorhabdovirus, en infecciones mixtas con MRCV en cereales de invierno en el sur de la provincia de Córdoba (región endémica del Mal de Río Cuarto). Al igual que este último el rhabdovirus se transmite por insectos delfácidos, por lo que sería relevante estudiar las posibles interacciones entre la coinfección por ambos patógenos y sus consecuencias en la transmisión del MRCV. La capacidad vectora puede estar afectada por diversos aspectos biológicos, entre los que se pueden mencionar el estadío del insecto al momento de la adquisición del virus, los niveles de concentración viral alcanzados en el organismo del vector, la existencia de barreras morfofisiológicas (como las membranas basales del intestino medio y glándulas salivales, y mecanismos de inmunidad innata) y la presencia de endosimbiontes. Se conoce que existen diferencias en la transmisión según el MRCV se adquiera como ninfa de primer o tercer estadío, por lo que se propone realizar estudios comparativos entre ambos grupos. Se plantea además evaluar el efecto de diferencias de concentración del MRCV en el organismo del insecto en la transmisión mediante RT-qPCR, en infecciones simples y mixtas. Se analizará la posible existencia de barreras morfofisiológicas observando el tropismo de las partículas virales en los tejidos del vector a través de inmunomicroscopía confocal y la activación diferencial de genes de inmunidad innata con RT-qPCR. Dado que existen antecedentes de la presencia de endosimbiontes, como Wolbachia pipientis en este grupo de insectos, se propone además estudiar la prevalencia de esta bacteria y analizar las cepas existentes en poblaciones de delfácidos del área maicera. Este objetivo es importante por dos razones. En primer lugar, W pipientis es ampliamente estudiada como potencial biocontrolador de vectores debido al fenómeno de incompatibilidad citoplasmática que expresa en sus hospedantes. En segundo lugar, esta bacteria influye en la eficiencia de transmisión de enfermedades ya que se conoce que los endosimbiontes producen proteínas denominadas simbioninas que protegen las partículas virales de la degradación enzimática durante su circulación por la hemolinfa. De este modo, la presencia de Wolbachia podría condicionar la replicación, estabilidad y persistencia de las partículas virales en insectos vectores, fenómenos comprobados para otros patosistemas. Este proyecto tiene como objetivo final profundizar los conocimientos acerca del fenómeno de la transmisión viral y establecer bases para el manejo integrado del vector y la enfermedad.

Evaluation of fish pots as a feasible fishing method in Irish waters, with specific reference to the physiological effects of common and alternate pots on the lesser spotted dogfish (Scyliorhinus canicula).

Finfish pots have emerged as a “responsible” gear, when used in combination with conservational and technical measures to sustain fisheries. Previous trials in Irish waters have offered no published reported data and so three designs tested in the current study provide new information on this gear. The most successful traps in terms of fish catch were rigid steel framed rectangular pots used to target Conger eel. Although commercial yield was low (0.2 per trap haul), potential existed for a viable pot fishery. Deployment and storage of Norwegian floating pots was conducted with relative ease but performance in the water was poor resulting in loss of gear. Catch returns were notable even though effort was restricted as mega-faunal by-catch was a problem, which lead to ending this trial. From these initial trials it was evident that catch rates were low compared to established Norwegian fisheries (3.6 cod per pot), which resulted in the utilisation of pots, already established in the crustacean fishery, to find species readily accessible to pot capture. Although fished and designed differently, these gears provided an opportunity to establish the benefits of pot fishing to fish quality and to determine the effects on by-catch. The fishing effects of three catching methods (pots, angling and trawl) and the effects of air exposure on the physiological status of a common by-catch, the lesser spotted dogfish Scyliorhinus canícula (L.) were examined using a range of physiological biomarkers (plasma catecholamine, glucose, lactate, muscle pH and muscle lactate). Physiological responses of fish to an emersion stress regime resulted in a significant metabolic disturbance in groups, but may not have weakened the overall health of these fish, as signified in the revival of some metabolites. Plasma glucose and lactate concentrations did not however recovery to baseline levels indicating that to achieve an accurate profile, responses should be determined by a suite of biomarkers. Responses did not demonstrate that samples from the pots were significantly less stressed than for the other two methods; angling and trawling, which are in contrast to many other studies. Employment of finfish potting therefore in Irish waters needs further consideration before further promotion as a more responsible method to supplement or replace established techniques.

Numerical simulations of Lamb waves in plates using a semi-analytical finite element method

Magdeburg, Univ., Fak. für Maschinenbau, Diss., 2011