CRITICAL BEHAVIOR AND THRESHOLD OF COEXISTENCE OF A PREDATOR-PREY STOCHASTIC MODEL IN A 2D LATTICE

We investigate the critical behavior of a stochastic lattice model describing a predator-prey system. By means of Monte Carlo procedure we simulate the model defined on a regular square lattice and determine the threshold of species coexistence, that is, the critical phase boundaries related to the transition between an active state, where both species coexist and an absorbing state where one of the species is extinct. A finite size scaling analysis is employed to determine the order parameter, order parameter fluctuations, correlation length and the critical exponents. Our numerical results for the critical exponents agree with those of the directed percolation universality class. We also check the validity of the hyperscaling relation and present the data collapse curves.

Chargino and neutralino production in the 3-3-1 supersymmetric model in e(-)e(-) scattering

The goal of this article is to derive the Feynman rules involving single charginos, neutralinos, double charged gauge bosons, and sleptons in a 3-3-1 supersymmetric model. Using these Feynman rules we calculate the production of double charged charginos with neutralinos and also the production of a pair of single charged charginos, both in an electron-electron linear collider.

Search for physics beyond the standard model in events with a Z boson, jets, and missing transverse energy in pp collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for Heavy Neutrinos and W-R Bosons with Right-Handed Couplings in a Left-Right Symmetric Model in pp Collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Nasopharyngeal colonization with methicillin-resistant staphylococcus aureus and mortality among patients in an intensive care unit

A colonização de nasofaringe por Staphylococcus aureus, resistente à meticilina (Methicillin-resistant S.aureus - MRSA), é comum em pacientes criticamente doentes, mas seu significado prognóstico não é inteiramente conhecido. Realizou-se estudo de coorte retrospectivo com 122 pacientes de uma unidade de terapia intensiva que realizaram triagem semanal para colonização por MRSA. Os desfechos de interesse foram: mortalidade geral e mortalidade por infecção. Diversas variáveis de exposição (gravidade, procedimentos, intercorrências e colonização nasofaríngea por MRSA) foram analisadas em modelos univariados e multivariados. Fatores significativamente associados à mortalidade geral ou por infecção foram: APACHE II e doença pulmonar. A colonização por MRSA não foi preditora de mortalidade geral (OR=1,02; IC95%=0,35-3; p=0,97) ou por infecção (OR=0,96; IC95%=0,33-2,89; p=0,96). Os resultados sugerem que, na ausência de fatores de gravidade, a colonização por MRSA não caracteriza pior prognóstico.

Test of the adiabatic nucleation model in SeTe and GeSnSe glasses

Se1-yTey and Ge1-ySnySe2.5 glasses, with compositions Y less than or equal to 0.5 and Y less than or equal to 0.6 respectively, are investigated. These glasses show a glass transition temperature (T-g) above the stability limit, indicated by the Adiabatic Nucleation Model (ANM). This effect has to be so because, other-wise, when cooled, these undercooled liquids would crystallize by generalized nucleation near the stability limit and no T-g could be observed. This shows that Se1-yTey glasses for Y < 0.5 are structurally stable. Limiting cases are pure Te and Se50Te50, which have T'(g)'s on the stability limit. Pure amorphous Te has to be obtained by fast quenching techniques, where the effective (fast quenching) T-g(*) is higher and Se50Te50 tends to crystallize easily. (C) 2004 Elsevier B.V. All rights reserved.

Comparative ''in vitro'' study on the susceptibility and emergence of mutants resistant to danofloxacin and ciprofloxacin among Staphylococcus aureus isolated from bovine mastitis

The antimicrobial susceptibility of danofloxacin was compared in vitro with ciprofloxacin against mastitogenic Staphylococcus aureus. Danofloxacin was more active than ciprofloxacin, showing minimal inhibitory concentrations (MIC90), minimal bactericidal concentrations (MBC90) and MBC/MIC ratio lower than those of ciprofloxacin. Ciprofloxacin-resistant mutants occurred at higher frequencies (greater than or equal to 10(-6)) than for danofloxacin (10(-9)).

Analysis of heuristic algorithms for the transportation model in static and multistage planning in network expansion systems

The usefulness of the application of heuristic algorithms in the transportation model, first proposed by Garver, is analysed in relation to planning for the expansion of transmission systems. The formulation of the mathematical model and the solution techniques proposed in the specialised literature are analysed in detail. Starting with the constructive heuristic algorithm proposed by Garver, an extension is made to the problem of multistage planning for transmission systems. The quality of the solutions found by heuristic algorithms for the transportation model is analysed, as are applications in problems of planning transmission systems.

Youth and social cohesion in Ibero-America: a model in the making. Summary

Includes bibliography

Inclusion of the European Nordic model in the debate concerning social protection reform: the long-term development of Nordic welfare systems (1890-2005) and their transferability to Latin America in the twenty-first century

Includes bibliography

Changes in the distribution of income and the New Economic Model in Colombia

Includes bibliography

Changes in the distribution of income and the New Economic Model in Jamaica

Includes bibliography

Haemonchus contortus: A multiple-resistant Brazilian isolate and the costs for its characterization and maintenance for research use

The aim of this work was to determine the resistance level of Haemonchus contortus isolated from the Santa Inês flock of the Embrapa (Brazilian government's Agricultural Research Company), Southeast Livestock Unit (CPPSE), as well as to determine costs of characterizing and maintaining this isolate in host donors. Forty-two male Santa Inês lambs were experimentally infected with 4000 H. contortus infective larvae of the field isolate of CPPSE, called Embrapa2010, and divided into six treatment groups, which received triclorfon, albendazol plus cobalt sulfate, ivermectin, moxidectin, closantel and levamisole phosphate, as well as a negative control group (water). Egg per gram (EPG) counts were performed at 0, 3, 7, 10 and 14. days post treatment when the animals were slaughtered for parasite count. The data were analyzed using the RESO statistical program, considering anthelmintic resistance under 95% of efficacy. EPG and worm count presented a linear and significant relation with 94% determination coefficient. The susceptibility results obtained by RESO through both criteria (EPG and worm count) were equal, except for closantel, showing that the isolate Embrapa2010 is resistant to benzimidazoles, macrocyclic lactones and imidazothiazoles. The need of a control group did not appear to be essential since the result for susceptibility in the analyses with or without this group was the same. Suppression in egg production after treatment did not occur in the ivermectin and moxidectin groups. In the control group, the establishment percentage was just 12.5 because of the low number of third-stage larvae, resistance (innate and infection immunity) of the animals studied plus good nutrition. Drug classes presented similar efficacy between adults and immature stages. The costs for isolate characterization were calculated for 42 animals during 60. days. The total cost based on local market rates was approximately US$ 8000. The precise identification of Brazilian isolates and their establishment in host donors would be useful for laboratorial anthelmintic resistance diagnoses through in vitro tests, which has an annual cost of approximately US$ 2500 for maintenance in host donors. © 2012 Elsevier B.V.

Search for physics beyond the standard model in events with τ leptons, jets, and large transverse momentum imbalance in pp collisions at √s = 7 TeV

A search for physics beyond the standard model is performed with events having one or more hadronically decaying τ leptons, highly energetic jets, and large transverse momentum imbalance. The data sample corresponds to an integrated luminosity of 4.98 fb-1 of proton-proton collisions at √ = 7 TeV collected with the CMS detector at the LHC in 2011. The number of observed events is consistent with predictions for standard model processes. Lower limits on the mass of the gluino in supersymmetric models are determined. © 2013 CERN for the benefit of the CMS collaboration.

A Reproducible Venous Thrombosis Model in Horses Induced by the Combination of an Endothelial Lesion and Blood Flow Stasis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)