Almost Conformal Vacua and Confinement

Dynamics of confining vacua which appear as deformed superconformal theory with a non-Abelian gauge symmetry, is studied by taking a concrete example of the sextet vacua of ${\cal N}=2$, SU(3) gauge theory with $n_f=4$, with equal quark masses. We show that the low-energy "matter" degrees of freedom of this theory consist of four magnetic monopole doublets of the low-energy effective SU(2) gauge group, one dyon doublet, and one electric doublet. We find a mechanism of cancellation of the beta function, which naturally but nontrivially generalizes that of Argyres-Douglas. Study of our SCFT theory as a limit of six colliding ${\cal N}=1$ vacua, suggests that the confinement in the present theory occurs in an essentially different manner from those vacua with dynamical Abelianization, and involves strongly interacting non-Abelian magnetic monopoles.Comment: 27 pages, 11 figures, LaTex fil

The Changing Landscape for Stroke\ua0Prevention in AF: Findings From the GLORIA-AF Registry Phase 2

Background GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation at risk of stroke. Phase 2 began when dabigatran, the first non\u2013vitamin K antagonist oral anticoagulant (NOAC), became available. Objectives This study sought to describe phase 2 baseline data and compare these with the pre-NOAC era collected during phase 1. Methods During phase 2, 15,641 consenting patients were enrolled (November 2011 to December 2014); 15,092 were eligible. This pre-specified cross-sectional analysis describes eligible patients\u2019 baseline characteristics. Atrial fibrillation disease characteristics, medical outcomes, and concomitant diseases and medications were collected. Data were analyzed using descriptive statistics. Results Of the total patients, 45.5% were female; median age was 71 (interquartile range: 64, 78) years. Patients were from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). Most had high stroke risk (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age  6575 years, Diabetes mellitus, previous Stroke, Vascular disease, Age 65 to 74 years, Sex category] score  652; 86.1%); 13.9% had moderate risk (CHA2DS2-VASc = 1). Overall, 79.9% received oral anticoagulants, of whom 47.6% received NOAC and 32.3% vitamin K antagonists (VKA); 12.1% received antiplatelet agents; 7.8% received no antithrombotic treatment. For comparison, the proportion of phase 1 patients (of N = 1,063 all eligible) prescribed VKA was 32.8%, acetylsalicylic acid 41.7%, and no therapy 20.2%. In Europe in phase 2, treatment with NOAC was more common than VKA (52.3% and 37.8%, respectively); 6.0% of patients received antiplatelet treatment; and 3.8% received no antithrombotic treatment. In North America, 52.1%, 26.2%, and 14.0% of patients received NOAC, VKA, and antiplatelet drugs, respectively; 7.5% received no antithrombotic treatment. NOAC use was less common in Asia (27.7%), where 27.5% of patients received VKA, 25.0% antiplatelet drugs, and 19.8% no antithrombotic treatment. Conclusions The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in Asia and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701

Anticoagulant selection in relation to the SAMe-TT2R2 score in patients with atrial fibrillation. the GLORIA-AF registry

Aim: The SAMe-TT2R2 score helps identify patients with atrial fibrillation (AF) likely to have poor anticoagulation control during anticoagulation with vitamin K antagonists (VKA) and those with scores >2 might be better managed with a target-specific oral anticoagulant (NOAC). We hypothesized that in clinical practice, VKAs may be prescribed less frequently to patients with AF and SAMe-TT2R2 scores >2 than to patients with lower scores. Methods and results: We analyzed the Phase III dataset of the Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation (GLORIA-AF), a large, global, prospective global registry of patients with newly diagnosed AF and ≥1 stroke risk factor. We compared baseline clinical characteristics and antithrombotic prescriptions to determine the probability of the VKA prescription among anticoagulated patients with the baseline SAMe-TT2R2 score >2 and ≤ 2. Among 17,465 anticoagulated patients with AF, 4,828 (27.6%) patients were prescribed VKA and 12,637 (72.4%) patients an NOAC: 11,884 (68.0%) patients had SAMe-TT2R2 scores 0-2 and 5,581 (32.0%) patients had scores >2. The proportion of patients prescribed VKA was 28.0% among patients with SAMe-TT2R2 scores >2 and 27.5% in those with scores ≤2. Conclusions: The lack of a clear association between the SAMe-TT2R2 score and anticoagulant selection may be attributed to the relative efficacy and safety profiles between NOACs and VKAs as well as to the absence of trial evidence that an SAMe-TT2R2-guided strategy for the selection of the type of anticoagulation in NVAF patients has an impact on clinical outcomes of efficacy and safety. The latter hypothesis is currently being tested in a randomized controlled trial. Clinical trial registration: URL: https://www.clinicaltrials.gov//Unique identifier: NCT01937377, NCT01468701, and NCT01671007

Quantum hub and authority centrality measures for directed networks based on continuous-time quantum walks

In this article, we introduce, test and discuss three quantum methods for computing hub and authority centrality scores in directed networks. The methods are based on unitary, continuous-time quantum walks; the construction of a suitable Hermitian Hamiltonian is achieved by performing a quantum walk on the associated bipartite graph. Two methods, called CQAu and CQAw, use the same evolution operator, inspired by the classical Hyperlink-Induced Topic Search (HITS) algorithm, but with different initial states; the computation of hub and authority scores is performed simultaneously. The third method, called CQG and inspired by classical PageRank, requires instead two separate runs with different evolution operators, one for hub and one for authority scores. The methods are tested on several directed graphs with different sizes and properties; a comparison with other well-established ranking algorithms is provided. CQAw emerges as the most reliable of the three methods and yields rankings that are largely compatible with results from HITS, although CQAu and CQG also present interesting features and potential for applications

Application of a fixed-receiver Linear Fresnel Reflector in concentrating photovoltaics

Among the numerous proposals for concentrator design in concentrating photovoltaics, fixed-receiver linear Fresnel reflectors (with a fixed receiver and multiple mirror strips at ground level, rotating on multiple parallel axes) seem to have been quite neglected so far in the literature. In this work we present and discuss properties and possibilities of a fixed-receiver LFR for concentrating photovoltaics, adopting flat mirrors as primary reflectors, integrated with a simple cooling system. Thanks to their technical characteristics, fixed-receiver LFRs are especially well suited for the realization of medium/large scale CPV power plants, in view of the foreseeable use of PV as one of the main electricity sources. The annual performance in a desertic site - inclusive of the energy used for cooling - is computed from a thermal simulation of the system, and it is compared to the performance of a non-concentrating PV system. We show that the use of Fresnel concentrators is currently competitive with non-concentrating systems for medium-to-large plants in suitable locations, and could be an advantageous alternative in the case of a rise in price of PV panels, or as the effect of a price drop in mirrors and Fresnel components due to scale economy. Moreover, CPV Fresnel concentrators do not suffer from drawbacks usually associated with thermal concentrating technologies, such as high working temperatures, the need for large structures and for an external power block, and management complexity. The proposed technology is easily achievable and it is not much more complex to manage than a non-concentrating PV system

Optimization of the geometry of Fresnel linear collectors

International audienceMethods and results concerning the optical optimization of a linear Fresnel collector are presented. The variables considered in the optimization are the positions, widths and focal lengths of the mirrors; the mirrors can be of variable size and focal length, and they can be nonuniformly spaced. The target function to be optimized is the plant cost divided by the collected solar radiation in a year. The computation of the collected radiation and of its average on the year, and the optimization of the cost/radiation function are carried out via suitable mathematical methods and the choice of a plausible cost function. Four different levels of optimization (uniformly spaced identical mirrors; nonuniformly spaced identical mirrors; mirrors of the same width with uniform spacing and variable focal lengths; and finally a full optimization) are presented, with a discussion of the resulting gain on the target function (i.e. the reduction of the ratio between the plant cost and the collected radiation). The results show that the application of suitable optimization strategies can lead to an estimated gain around 12% with respect to the initial configuration (all mirrors identical and adjacent), and that a full optimization leads to a gain of 4.5% over a simple uniform optimization. This gain is due in large part to the possibility of regulating the focal lengths (the optimization of focals leads to a 2.8% gain over the uniform case), while only a minor improvement (less than 0.4%) is obtained with nonuniformly spaced identical mirrors