52 resultados para Wright, Erik Olin
Resumo:
We present a search for the lightest supersymmetric partner of the top quark in proton-antiproton collisions at a center-of-mass energy √s=1.96 TeV. This search was conducted within the framework of the R parity conserving minimal supersymmetric extension of the standard model, assuming the stop decays dominantly to a lepton, a sneutrino, and a bottom quark. We searched for events with two oppositely-charged leptons, at least one jet, and missing transverse energy in a data sample corresponding to an integrated luminosity of 1 fb-1 collected by the Collider Detector at Fermilab experiment. No significant evidence of a stop quark signal was found. Exclusion limits at 95% confidence level in the stop quark versus sneutrino mass plane are set. Stop quark masses up to 180 GeV/c2 are excluded for sneutrino masses around 45 GeV/c2, and sneutrino masses up to 116 GeV/c2 are excluded for stop quark masses around 150 GeV/c2.
Resumo:
A precision measurement of the top quark mass m_t is obtained using a sample of ttbar events from ppbar collisions at the Fermilab Tevatron with the CDF II detector. Selected events require an electron or muon, large missing transverse energy, and exactly four high-energy jets, at least one of which is tagged as coming from a b quark. A likelihood is calculated using a matrix element method with quasi-Monte Carlo integration taking into account finite detector resolution and jet mass effects. The event likelihood is a function of m_t and a parameter DJES to calibrate the jet energy scale /in situ/. Using a total of 1087 events, a value of m_t = 173.0 +/- 1.2 GeV/c^2 is measured.
Resumo:
The status of the TOTEM experiment is described as well as the prospects for the measurements in the early LHC runs. The primary goal of TOTEM is the measurement of the total p-p cross section, using a method independent of the luminosity. A final accuracy of 1% is ex- pected with dedicated β∗ = 1540 m runs, while at the beginning a 5% resolution is achievable with a β∗ = 90 m optics. Accordingly to the running scenarios TOTEM will be able to measure the elastic scattering in a wide range of t and to study the cross-sections and the topologies of diffractive events. In a later stage, physics studies will be extended to low-x and forward physics collaborating with CMS as a whole experimental apparatus.
Resumo:
We report on a search for the flavor-changing neutral-current decay D0 \to {\mu}+ {\mu}- in pp collisions at \surd s = 1.96 TeV using 360 pb-1 of integrated luminosity collected by the CDF II detector at the Fermilab Tevatron collider. A displaced vertex trigger selects long-lived D0 candidates in the {\mu}+ {\mu}-, {\pi}+{\pi}-, and K-{\pi}+ decay modes. We use the Cabibbo-favored D0 \to K-{\pi}+ channel to optimize the selection criteria in an unbiased manner, and the kinematically similar D0 \to{\pi}+ {\pi}- channel for normalization. We set an upper limit on the branching fraction (D0 --> {\mu}+ {\mu}-)
Resumo:
We present a search for the standard model Higgs boson produced with a Z boson in 4.1 fb^-1 of data collected with the CDF II detector at the Tevatron. In events consistent with the decay of the Higgs boson to a bottom-quark pair and the Z boson to electrons or muons, we set 95% credibility level upper limits on the ZH production cross section times the H -> b bbar branching ratio. Improved analysis methods enhance signal sensitivity by 20% relative to previous searches beyond the gain due to the larger data sample. At a Higgs boson mass of 115 GeV/c^2 we set a limit of 5.9 times the standard model value.
Resumo:
Les participes présents apparaissent, entre autres, dans des constructions à prédication seconde détachées : (1) Intervenant hier soir à Ankara, […], Vladimir Poutine s’est risqué à […]. (Le Figaro 7.12.2004 : 4) Même si les gérondifs, formes adverbiales du verbe (« converbes », cf. Haspelmath & König 1995), n’ont pas d’incidence nominale, contrairement aux participes présents, formes adjectivales du verbe, et ne sont donc pas toujours comptés parmi les constructions à prédication seconde (p.ex. Neveu 1998), les deux ont des emplois assez proches : dans des énoncés du type (2a-b), le participe adjoint peut être paraphrasé par un gérondif, même si son statut fonctionnel n’est pas le même (Halmøy, 2003 : 156-157) : (2a) Arrivant à Paris, Emile a proposé à Léa de [...]. (2b) En arrivant à Paris, Emile a proposé à Léa de[...]. (Halmøy, 2003 : 157) Le finnois ne connaît ni ce genre de constructions détachés ni de forme appelée ‘gérondif’, et les deux participes présents finnois (actif et passif) ne correspondent jamais à un participe présent détaché français : en plus de subordonnées, on trouve à leur place le deuxième infinitif, soit à l’inessif, soit à l’instructif, formes nominales qu’on trouve également dans la traduction des gérondifs : (3a) […] ? me demanda-t-elle sèchement en me montrant l’une des lignes incriminées. (Nothomb, p. 62) […] : hän kysyi minulta kuivakkaasti näyttäen erästä Unajin moittimaa riviä. (Suni, p. 4) (3b) L’espace d’un instant, il sourit, croyant que […] je m’étais trompée de commodités. (Nothomb, p. 138-139) Hetken hän hymyili luullen, että minä […] olin erehtynyt mukavuuslaitoksesta. (Suni, p. 94) : Dans cette communication, nous examinerons quatre traductions littéraires en nous demandant dans quels cas et de quelle manière la différence entre le participe et le gérondif a éventuellement été prise en considération.
Resumo:
Purpose –This paper explores and expands the roles of customers and companies in creating value by introducing a new a customer-based approach to service. The customer’s logic is examined as being the foundation of a customer-based marketing and business logic. Design/methodology/approach – The authors argue that both goods-dominant logics and service-dominant logics are provider-dominant. Contrasting the customer-dominant logic with provider-dominant logics, the paper examines the creation of service value from the perspectives of value-in-use, the customer’s own context, and the customer’s experience of service. Findings –Moving from a provider-dominant logic to a customer-dominant logic uncovered five major challenges to service marketers: Company involvement, company control in co-creation, visibility of value creation, locus of customer experience, and character of customer experience. Research limitations/implications – The paper is exploratory. It presents and discusses a conceptual model and suggests implications for research and practice. Practical implications –Awareness of the mechanisms of customer logic will provide businesses with new perspectives on the role of the company in their customer’s lives. We propose that understanding the customer’s logic should represent the starting-point for the marketer’s business logic. Originality/value – The paper increases the understanding of how the customer’s logic underpins the customer-dominant business logic. By exploring consequences of applying a customer-dominant logic, we suggest further directions for theoretical and empirical research.
Resumo:
A diffusion/replacement model for new consumer durables designed to be used as a long-term forecasting tool is developed. The model simulates new demand as well as replacement demand over time. The model is called DEMSIM and is built upon a counteractive adoption model specifying the basic forces affecting the adoption behaviour of individual consumers. These forces are the promoting forces and the resisting forces. The promoting forces are further divided into internal and external influences. These influences are operationalized within a multi-segmental diffusion model generating the adoption behaviour of the consumers in each segment as an expected value. This diffusion model is combined with a replacement model built upon the same segmental structure as the diffusion model. This model generates, in turn, the expected replacement behaviour in each segment. To be able to use DEMSIM as a forecasting tool in early stages of a diffusion process estimates of the model parameters are needed as soon as possible after product launch. However, traditional statistical techniques are not very helpful in estimating such parameters in early stages of a diffusion process. To enable early parameter calibration an optimization algorithm is developed by which the main parameters of the diffusion model can be estimated on the basis of very few sales observations. The optimization is carried out in iterative simulation runs. Empirical validations using the optimization algorithm reveal that the diffusion model performs well in early long-term sales forecasts, especially as it comes to the timing of future sales peaks.
Resumo:
Type 2 diabetes is a risk factor for the development of cardiovascular disease. Recently, the term diabetic cardiomyopathy has been proposed to describe the changes in the heart that occur in response to chronic hyperglycemia and insulin resistance. Ventricular remodelling in diabetic cardiomyopathy includes left ventricular hypertrophy, increased interstitial fibrosis, apoptosis and diastolic dysfunction. Mechanisms behind these changes are increased oxidative stress and renin-angiotensin system activation. The diabetic Goto-Kakizaki rat is a non-obese model of type 2 diabetes that exhibits defective insulin signalling. Recently two interconnected stress response pathways have been discovered that link insulin signalling, longevity, apoptosis and cardiomyocyte hypertrophy. The insulin-receptor PI3K/Ak pathway inhibits proapoptotic FOXO3a in response to insulin signalling and the nuclear Sirt1 deacetylase inhibits proapoptotic p53 and modulates FOXO3a in favour of survival and growth. --- Levosimendan is a calcium sensitizing agent used for the management of acute decompensated heart failure. Levosimendan acts as a positive inotrope by sensitizing cardiac troponin C to calcium and exerts vasodilation by opening mitochondrial and sarcolemmal ATP-sensitive potassium channels. Levosimendan has been described to have beneficial effects in ventricular remodelling after myocardial infarction. The aims of the study were to characterize whether diabetic cardiomyopathy associates with cardiac dysfunction, cardiomyocyte apoptosis, hypertrophy and fibrosis in spontaneously diabetic Goto-Kakizaki (GK) rats, which were used to model type 2 diabetes. Protein expression and activation of the Akt FOXO3a and Sirt1 p53 pathways were examined in the development of ventricular remodelling in GK rats with and without myocardial infarction (MI). The third and fourth studies examined the effects of levosimendan on ventricular remodelling and gene expression in post-MI GK rats. The results demonstrated that diabetic GK rats develop both modest hypertension and features similar to diabetic cardiomyopathy including cardiac dysfunction, LV hypertrophy and fibrosis and increased apoptotic signalling. MI induced a sustained increase in cardiomyocyte apoptosis in GK rats together with aggravated LV hypertrophy and fibrosis. The GK rat myocardium exhibited decreased Akt- FOXO3a phosphorylation and increased nuclear translocation of FOXO3a and overproduction of the Sirt1 protein. Treatment with levosimendan decreased cardiomyocyte apoptosis, senescence and LV hypertrophy and altered the gene expression profile in GK rat myocardium. The findings indicate that impaired cardioprotection via Akt FOXO3a and p38 MAPK is associated with increased apoptosis, whereas Sirt1 functions in counteracting apoptosis and the development of LV hypertrophy in the GK rat myocardium. Overall, levosimendan treatment protects against post-MI ventricular remodelling and alters the gene expression profile in the GK rat myocardium.
Resumo:
In the first half of the 20th century, most moral philosophers took the concept of virtue to be secondary to moral principles or emotions, though in various and mutually conflicting ways. In the early 1960s interest in the virtues was restored by the analytic philosophers Elizabeth Anscombe and Georg Henrik von Wright, the younger colleagues and friends of the late Wittgenstein. Later, Alasdair MacIntyre became a leading virtue ethicist. In 1981, MacIntyre introduced in After Virtue the concept of practices, which he based on the Aristotelian distinction between praxis and poiesis. This dissertation examines MacIntyre s characterization of the interconnectedness between practices and virtues, especially in relation to skills, education, and certain emotions. The primary position of the virtues is defended against the tendency in modern moral philosophy to overemphasize the role either of principles and rules or of emotions. The view according to which rational action and acting according to the virtues is best conceptualized as following rules or principles is criticized by arguments that are grounded by some Wittgensteinian observations, and that can be characterized as transcendental. Even if the virtues cannot be defined by, and are not based entirely on, emotions, the role of certain emotions on the learning and education of skills and virtues are studied more carefully than by MacIntyre. In the cases of resentment, indignation, and shame, the analysis of Peter Strawson is utilized, and in the case of regret, the analysis of Bernard Williams. Williams analysis of regret and moral conflict concludes in a kind of antirealism, which this study criticizes. Where education of practices and skills and the related reactive emotions are examined as conditions of learning and practicing the virtues, institutions and ideologies are examined as obstacles and threats to the virtues. This theme is studied through Karl Marx s conception of alienation and Karl Polanyi s historical and sociological research concerning the great transformation . The study includes six Finnish-published articles carrying the titles Our negative attitudes towards other persons , Authority and upbringing , Moral conflicts, regret and ethical realism , Practices and institutions , Doing justice as condition to communal action: a transcendental argument for justice as virtue , and Alienation from practices in capitalist society: Alasdair MacIntyre s Marxist Aristotelianism . The introductory essay sums up the themes of the articles and presents some central issues of virtue ethics by relating the classical Socratic questions to Aristotelian practical philosophy, as well as to current controversies in metaethics and moral psychology.
Resumo:
A measurement of the top-quark pair-production cross section in ppbar collisions at sqrt{s}=1.96 TeV using data corresponding to an integrated luminosity of 1.12/fb collected with the Collider Detector at Fermilab is presented. Decays of top-quark pairs into the final states e nu + jets and mu nu + jets are selected, and the cross section and the b-jet identification efficiency are determined using a new measurement technique which requires that the measured cross sections with exactly one and multiple identified b-quarks from the top-quark decays agree. Assuming a top-quark mass of 175 GeV/c^2, a cross section of 8.5+/-0.6(stat.)+/-0.7(syst.) pb is measured.