Observation of the rare B-s(0)->mu(+)mu(-) decay from the combined analysis of CMS and LHCb data

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Evolutionary optimization applied for fine-tuning parameter estimation in optical flow-based environments

Optical flow methods are accurate algorithms for estimating the displacement and velocity fields of objects in a wide variety of applications, being their performance dependent on the configuration of a set of parameters. Since there is a lack of research that aims to automatically tune such parameters, in this work we have proposed an evolutionary-based framework for such task, thus introducing three techniques for such purpose: Particle Swarm Optimization, Harmony Search and Social-Spider Optimization. The proposed framework has been compared against with the well-known Large Displacement Optical Flow approach, obtaining the best results in three out eight image sequences provided by a public dataset. Additionally, the proposed framework can be used with any other optimization technique.

Bell inequalities for K-0(K)over-bar(0) pairs from Phi-resonance decays

We analyze the premises of recent propositions to test local realism via the Bell inequalities using neutral kaons from φ resonance decays as entangled Einstein-Podolsky-Rosen pairs. We pay special attention to the derivation of the Bell inequalities, or related expressions, for unstable and oscillating kaon quasispin states and to the possibility of the actual identification of these states through their associated decay modes. We discuss an indirect method to extract probabilities to find these states by combining experimental information with theoretical input. However, we still find inconsistencies in previous derivations of the Bell inequalities. We show that the identification of the quasispin states via their associated decay mode does not allow the free choice to perform different tests on them, a property which is crucial to establish the validity of any Bell inequality in the context of local realism. In view of this we propose a different kind of Bell inequality in which the free choice or adjustability of the experimental setup is guaranteed. We also show that the proposed inequalities are violated by quantum mechanics. ©1999 The American Physical Society.

Algebraic solution of an anisotropic ring-shaped oscillator

Using an algebraic technique related to the SO (2, 1) group we construct the Green function for the potential ar2 + b(r sin θ)-2 + c(r cos θ)-2 + dr2 sin2θ + er2 cos2θ. The energy spectrum and the normalized wave functions are also obtained. © 1990.

Effects of mineral stress on the vegetative development of greenhouse-grown bell pepper plants

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Biochemical changes during the induction of mineral stress in plants of bell pepper cultivated in fertigation system

The greenhouse production associated with the fertigation management, have established in Brazil as economical alternative for several horticultural species. With this strategy this study had as aim to evaluate possible impacts in the metabolism of plants of bell pepper (Capsicum annuum L.; cv Elisa) in response to the increase of mineral concentration in the soil. During the experiments, the some nutrient concentrations were altered, to obtain high values of electric conductivity (EC) in the soil solution. The EC values commonly observed in the traditional fertigation system were adopted, as control. It was also verified the possibility of reduction of the mineral stress impact by the application of organic matter in the soil. Parameters of the antioxidative response system, as the superoxide dismutase (SOD) and catalase enzyme activities besides the proline content were evaluated to measure the extension of the saline stress and their effects on the plants. The increase of EC of the soil induced to the increase of the proline concentration and the SOD activity. Unexpectedly, it was verified that the saline stress inhibited the activity of the enzyme catalase. It was also concluded that the monitoring of EC of the soil is an indispensable tool to reach success in the fertigation system and that the study of the activity of the enzymes of the antioxidative response system, and the proline contents can be assumed as indicators in of the levels of stress in bell pepper plants (Capsicum annuum L.; cv Elisa).

Lucia B. Bell Papers - Accession 255

The Lucia B. Bell Papers consist of historical and family history information pertaining to the Bell family of South Carolina. Most of the material relates to the Bell Family and other allies clans such as the Gaston, Coln, and Stinson Families. The earliest dated material includes notes on the Bell family’s coat-of-arms and a listing of land grants from 1770-1848. Information on the Chester County Covenanters along with reprinted historical sketches concerning the area’s general history and a biographical sketch on Reverend William Martin, the first Chester County Covenanter preacher. A brief history of Fishing Creek Presbyterian Church is provided with listing of former church elders and deacons from 1895-1958.

Bilayer graphene on h-BN substrate: investigating the breakdown voltage and tuning the bandgap by electric field

By performing density functional theory calculations we show that it is possible to make the electronic bandgap in bilayer graphene supported on hexagonal boron nitride (h-BN) substrates tunable. We also show that, under applied electric fields, it is possible to insert states from h-BN into the bandgap, which generate a conduction channel through the substrate making the system metallic. In addition, we verify that the breakdown voltage strongly depends on the number of h-BN layers. We also show that both the breakdown voltage and the bandgap tuning are independent of the h-BN stacking order.

Hydration and anomalous solubility of the Bell-Lavis model as solvent

We address the investigation of the solvation properties of the minimal orientational model for water originally proposed by [Bell and Lavis, J. Phys. A 3, 568 (1970)]. The model presents two liquid phases separated by a critical line. The difference between the two phases is the presence of structure in the liquid of lower density, described through the orientational order of particles. We have considered the effect of a small concentration of inert solute on the solvent thermodynamic phases. Solute stabilizes the structure of solvent by the organization of solvent particles around solute particles at low temperatures. Thus, even at very high densities, the solution presents clusters of structured water particles surrounding solute inert particles, in a region in which pure solvent would be free of structure. Solute intercalates with solvent, a feature which has been suggested by experimental and atomistic simulation data. Examination of solute solubility has yielded a minimum in that property, which may be associated with the minimum found for noble gases. We have obtained a line of minimum solubility (TmS) across the phase diagram, accompanying the line of maximum density. This coincidence is easily explained for noninteracting solute and it is in agreement with earlier results in the literature. We give a simple argument which suggests that interacting solute would dislocate TmS to higher temperatures.

Determination of Tetradifon in Brazilian Green Bell Pepper by Differential Pulse Voltammetry

Tetradifon, a potentially carcinogenic and mutagenic pesticide, can contribute to environmental and human contamination when applied to green bell pepper crops. In this context, in this work, a reliable and sensitive method for determination of tetradifon in Brazilian green bell pepper samples involving a differential pulse voltammetry (DPV) technique on a glassy carbon electrode is proposed. The electrochemical behavior of tetradifon as followed by cyclic voltammetry (CV) suggests that its reduction occurs via an irreversible five-electron transfer vs. Ag vertical bar AgCl, KCl 3 M reference electrode. Very well-resolved diffusion controlled voltammetric peaks have been obtained in a supporting electrolyte solution composed of a mixture of 40% dimethylformamide (DMF), 30% methanol, and 30% NaOH 0.3 mol L-1 at -1.43, -1.57, -1.73, -1.88, and -2.05 V. The proposed DPV method has a good linear response in the 3.00 - 10.0 mu mol L-1 range, with a limit of detection (L.O.D) of 0.756 mu mol L-1 and 0.831 mu mol L-1 in the absence and in the presence of the matrix, respectively. Moreover, improved L.O.D results (0.607 mu mol L-1) have been achieved in the absence of DMF from the supporting electrolyte solution. Recovery has been evaluated in five commercial green bell pepper samples, and recovery percentages ranging from 91.0 to 109 have been obtained for tetradifon determinations. The proposed voltammetric method has also been tested for reproducibility, repeatability, and potential interferents, and the results obtained for these three analytical parameters are satisfactory for electroanalytical purposes. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.024207jes] All rights reserved.

Revisiting the Acanthamoeba species that form star-shaped cysts (genotypes T7, T8, T9, and T17): characterization of seven new Brazilian environmental isolates and phylogenetic inferences

Free-living amoebae of the genus Acanthamoeba are the agents of both opportunistic and non-opportunistic infections and are frequently isolated from the environment. Of the 17 genotypes (T1-T17) identified thus far, 4 (T7, T8, T9, and T17) accommodate the rarely investigated species of morphological group I, those that form large, star-shaped cysts. We report the isolation and characterization of 7 new Brazilian environmental Acanthamoeba isolates, all assigned to group I. Phylogenetic analyses based on partial (similar to 1200 bp) SSU rRNA gene sequences placed the new isolates in the robustly supported clade composed of the species of morphological group I. One of the Brazilian isolates is closely related to A. comandoni (genotype T9), while the other 6, together with 2 isolates recently assigned to genotype T17, form a homogeneous, well-supported group (2-0% sequence divergence) that likely represents a new Acanthamoeba species. Thermotolerance, osmotolerance, and cytophatic effects, features often associated with pathogenic potential, were also examined. The results indicated that all 7 Brazilian isolates grow at temperatures up to 40 degrees C, and resist under hvperosmotic conditions. Additionally, media conditioned by each of the new Acanthamoeba isolates induced the disruption of SIRC and HeLa cell monolayers.

Magnetic Tuning of All-Organic Binary Alloys between Two Stable Radicals

Mixtures of 2-(4,5,6,7-tetrafluorobenzimidazol-2-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl (F4BImNN) and 2-(benzi-midazol-2-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl (BImNN.) crystallize as solid solutions (alloys) across a wide range of binary compositions. (F4BImNN)(x)(BImNN)((1-x)) with x < 0.8 gives orthorhombic unit cells, while x >= 0.9 gives monoclinic unit cells. In all crystalline samples, the dominant intermolecular packing is controlled by one-dimensional (1D) hydrogen-bonded chains that lead to quasi-1D ferromagnetic behavior. Magnetic analysis over 0.4-300 K indicates ordering with strong 1D ferromagnetic exchange along the chains (J/k = 12-22 K). Interchain exchange is estimated to be 33- to 150-fold weaker, based on antiferromagnetic ordered phase formation below Neel temperatures in the 0.4-1.2 K range for the various compositions. The ordering temperatures of the orthorhombic samples increase linearly as (1 - x) increases from 0.25 to 1.00. The variation is attributed to increased interchain distance corresponding to decreased interchain exchange, when more F4BImNN is added into the orthorhombic lattice. The monoclinic samples are not part of the same trend, due to the different interchain arrangement associated with the phase change.

Tuning Low-Spin to High-Spin Mn Pairs in 2-D ZnO by Injecting Holes

We have performed an ab initio theoretical investigation of substitutional Mn(Zn) atoms in planar structures of ZnO, viz., monolayer [(ZnO)(1)] and bilayer [(ZnO)(2)] systems. Due to the 2-D quantum confinement effects, in those Mn -doped (ZnO)(1) and (ZnO)(2) structures, the antiferromagnetic (AFM) coupling between (nearest neighbor) Mn(Zn) impurities have been strengthened when compared with the one in ZnO bulk systems. On the other hand, we find that the magnetic state of these systems can be tuned from AFM to FM by adding holes, which can be supplied by a p-type doping or even photoionization processes. Whereas, upon addition of electrons (n-type doping), the system keeps its AFM configuration.