Exact relations between damage spreading and thermodynamic functions for the N-color Ashkin-Teller model

Exact results are derived relating quantities computable by the so-called damage spreading method and thermodynamic functions for the N-color Ashkin-Teller model. The results are valid for any ergodic dynamics. Since we restrict our analysis to the ferromagnetic case the results are also valid for any translational invariant lattice. The derived relations should be used in order to determine numerically the N-color Ashkin-Teller critical exponents with better accuracy and less computational efforts than standard Monte Carlo simulations.Comment: 6 pages, to be published in JSTAT (Journal of Statistical Mechanics: Theory and Experiment). The results of a computer simulation were included for N=3 as an example on how to use the analytical relations derived in the paper as a guide to obtain the critical temperature and critical exponent

On the coupling of the self-dual field to dynamical U(1) Matter and its dual theory

We consider an arbitrary U(1) charged matter non-minimally coupled to the self-dual field in $d=2+1$. The coupling includes a linear and a rather general quadratic term in the self-dual field. By using both a Lagragian gauge embedding and a master action approaches we derive the dual Maxwell Chern-Simons type model and show the classical equivalence between the two theories. At quantum level the master action approach in general requires the addition of an awkward extra term to the Maxwell Chern-Simons type theory. Only in the case of a linear coupling in the self-dual field the extra term can be dropped and we are able to establish the quantum equivalence of gauge invariant correlation functions in both theories.Comment: two citations and references corrected, 13 page

Damage Spreading in the Ising Model

We present two new results regarding damage spreading in ferromagnetic Ising models. First, we show that a damage spreading transition can occur in an Ising chain that evolves in contact with a thermal reservoir. Damage heals at low temperature and spreads for high T. The dynamic rules for the system's evolution for which such a transition is observed are as legitimate as the conventional rules (Glauber, Metropolis, heat bath). Our second result is that such transitions are not always in the directed percolation universality class.Comment: 5 pages, RevTeX, revised and extended version, including 3 postscript figure

Lorentz and CPT symmetries in commutative and noncommutative spacetime

We investigate the fermionic sector of a given theory, in which massive and charged Dirac fermions interact with an Abelian gauge field, including a non standard contribution that violates both Lorentz and CPT symmetries. We offer an explicit calculation in which the radiative corrections due to the fermions seem to generate a Chern-Simons-like effective action. Our results are obtained under the general guidance of dimensional regularization, and they show that there is no room for Lorentz and CPT violation in both commutative and noncommutative spacetime.Comment: RevTex4, 7 pages, to be published in J. Phys.

Atividade antibacteriana de Óleos Essenciais sobre Streptococcus mutans e Staphylococcus aureus

Este trabalho objetivou avaliar a ação antimicrobiana in vitro dos óleos essenciais de Ocimum basilicum (Manjericão Exótico), Thymus vulgaris (Tomilho Branco), e de Cinnamomum cassia (Canela da China) sobre cepas bacterianas de Streptococcus mutans (ATCC 25175) e Staphylococcus aureus (ATCC 25923). A atividade antibacteriana dos óleos essenciais foi determinada pela Concentração Inibitória Mínima (CIM) e a Concentração Bactericida Mínima (CBM) através da técnica de microdiluição e do esgotamento. Para a CIM, foram utilizadas placas de 96 poços e inseriu-se 100µL de caldo BHI, 100µL da diluição dos óleos essenciais no primeiro poço e 10µL da suspensão bacteriana (1,5x106 microrganismos/mL). Realizou-se a diluição seriada partindo-se da concentração inicial de 8% até 0,0625%. A CIM correspondeu à última diluição na qual não foi verificada a presença de bactérias. Para obter a CBM, realizou-se a semeadura em Ágar Miller-Hinton das diluições correspondentes a CIM, 2CIM e 4CIM. As placas foram incubadas a 37º C em estufa bacteriológica por 24 horas. Os testes foram realizados em triplicata tendo a clorexidina como controle positivo. Para S. aureus (ATCC 25923) a CIM e CBM dos óleos essenciais de C. cassia, O. basilicum e T. vulgaris foram 0,0625%, 4% e 0,0625%, respectivamente. Para S. mutans a CIM e a CBM dos óleos essenciais de C. cassia e T. vulgaris foram 0,125% e 0,25%, respectivamente. Já a CIM do O. basilicum foi 4% e não apresentou ação bactericida. Conclui-se que os óleos essenciais avaliados apresentaram ação antibacteriana frente a cepas de S. mutans e S. aureus, sendo que os menores valores de CIM e de CBM foram provenientes dos óleos de C. cassia e T. vulgaris1621372377The aim of this study is to evaluate the in vitro antimicrobial activity of essential oils of Ocimum basilicum (basil), Thymus vulgaris (thyme) and Cinnamomum cassia (Chinese cinnamon) against strains of Streptococcus mutans (ATCC 25175) and Staphylococcus aureus (ATCC 25923). The antibacterial activity of the essential oils was determined by Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). The MIC was obtained by the microdilution technique using 96-well microplates, in which we inserted: 100µL of Brain Heart Infusion broth at double concentration, 100µL of the dilution of the essential oils and 10µL of bacterial suspension (1.5 x 106 organisms / mL). The products were diluted from the initial concentration of 8% up to 0.0625%. The MIC corresponded to the last dilution in which there was no presence of bacteria or turbidity in the culture medium. The MBC was obtained by seeding, in Mueller-Hinton agar, 10µL aliquots of dilutions corresponding to the MIC and the two immediately preceding ones (2MIC and 4MIC). The plates were incubated at 37°C in a bacteriological incubator for 24 hours. The tests were performed in triplicate, and 2% Chlorhexidine Digluconate was the control product. For S. aureus, the MIC and MBC of the essential oils of C. cassia, O. basilicum and T. vulgaris were 0.0625%, 0.0625% and 4%, respectively. For S. mutans, the MIC and MBC of the essential oils of C. cassia and T. vulgaris were 0.125% and 0.25%, respectively. The MIC of O. basilicum against S. mutans was 4% and the essential oil showed no bactericidal action. Chlorhexidine Digluconate presented antibacterial activity against all organisms. The evaluated essential oils presented antibacterial activity against the strains of S. mutans and S. aureus, and we highlight the essential oils from C. cassia and T. vulgaris with the lowest MIC and MBCsem informaçã

Microcausality and quantization of the fermionic Myers-Pospelov model

We study the fermionic sector of the Myers and Pospelov theory with a general background $n$. The spacelike case without temporal component is well defined and no new ingredients came about, apart from the explicit Lorentz invariance violation. The lightlike case is ill defined and physically discarded. However, the other case where a nonvanishing temporal component of the background is present, the theory is physically consistent. We show that new modes appear as a consequence of higher time derivatives. We quantize the timelike theory and calculate the microcausality violation which turns out to occur near the light cone.Comment: 9 pages and 3 figures, new version accepted in EPJC, Volume 72, Issue 9, includes lee-wick review, microcausalit

Epidemics and the Politics of Knowledge: Contested Narratives in Egypt's H1N1 Response

This article explores the politics of knowledge involved in understanding and responding to epidemics in an era of global health governance and biosecurity. It develops and applies an approach focused on how multiple, competing narratives about epidemics are constructed, mobilised and interact, and selectively justify pathways of intervention and response. A detailed ethnographic case study of national and local responses to H1N1 influenza, so-called ‘swine flu’, in Egypt reveals how global narratives were reworked by powerful actors in a particular political context, suppressing and delegitimizing the alternative narratives of the Zabaleen (Coptic Christian) people whose lives and livelihoods centred on raising pigs and working with them to control urban waste. The case study illustrates important ways in which geographies and politics of blame around epidemics emerge and are justified, their political contexts and consequences, and how they may feed back to shape the dynamics of disease itself.ESR

Características agronômicas de indutores de haploidia adaptados ao ambiente tropical.

A metodologia de linhagens duplo-haploides permite obtenção de linhagens em até três gerações, via cruzamento de plantas de milho com indutores de haploidia, e posterior seleção com base na presença ou ausência de coloração púrpura no embrião, caráter expressado pelo gene R1-navajo. A maioria dos indutores de haploidia em milho é de origem temperada, tendo desempenho inferior em condições tropicais, o que tem incentivado programas de melhoramento a adaptar indutores de haploidia via retrocruzamento com genótipos tropicais. O objetivo deste trabalho foi avaliar o potencial germinativo e caracterizar indutores de haploidia tropicalizados com base em atributos agronômicos. Para tanto, dois experimentos foram implantados na Embrapa Milho e Sorgo, em Sete Lagoas-MG, entre novembro de 2014 e setembro de 2015. O potencial germinativo foi avaliado com base no total de plantas germinadas, total de plântulas anormais ou mortas, comprimento de parte aérea e raiz, e massa fresca e seca de plântulas. Em outro experimento, os indutores foram comparados com base em 30 características morfoagronômicas demandadas pelo Ministério da Agricultura para testes de distinguibilidade, homogeneidade e estabilidade em milho comum. Foram avaliados os indutores Stock 6, W23, Tail P1, Tail P2, Tail P1 x Tail P2; 90109igig, 91202igig e 91207 igig. Observaram-se diferenças significativas entre genótipos para características ligadas à qualidade fisiológica das sementes, com valores de coeficiente de determinação genotípico acima de 77,8, denotando a predominância de efeitos genéticos. Com relação à caracterização agronômica dos indutores, verificou-se alta expressão do marcador fenotípico R1-navajo em todos os indutores avaliados, característica de grande importância para a seleção de haploides em milho, e ciclo superprecoce, com destaque para o híbrido Tail P1 x Tail P2, com 48 dias para o florescimento masculino. Os resultados indicam necessidade de multiplicação frequente dos indutores de haploidia, visando manter a qualidade fisiológica das sementes, e de escalonamento do plantio dos indutores para sincronização do florescimento com as populações-fonte, considerando-se também as condições climáticas e o sistema de manejo adotado, para favorecer o máximo de polinização, e, consequentemente, de produção de sementes haploides.bitstream/item/172642/1/bol-161-2.pd