ABSTRACT
We discuss the majority vote model coupled with scale-free networks and investigate its critical behavior. Previous studies point to a nonuniversal behavior of the majority vote model, where the critical exponents depend on the connectivity. At the same time, the effective dimension D_{eff} is unity for a degree distribution exponent 5/2<γ<7/2. We introduce a finite-size theory of the majority vote model for uncorrelated networks and present generalized scaling relations with good agreement with Monte Carlo simulation results. Our finite-size approach has two sources of size dependence: an external field representing the influence of the mass media on consensus formation and the scale-free network cutoff. The critical exponents are nonuniversal, dependent on the degree distribution exponent, precisely when 5/2<γ<7/2. For γ≥7/2, the model is in the same universality class as the majority vote model on Erdos-Rényi random graphs. However, for γ=7/2, the critical behavior includes additional logarithmic corrections.
ABSTRACT
We define a stochastic reaction-diffusion process that describes a consensus formation in a nonsedentary population. The process is a diffusive version of the majority-vote model, where the state update follows two stages: In the first stage, spins are allowed to jump to a random neighbor node with probabilities D_{+} and D_{-} for the respective spin orientations, and in the second stage, the spins in the same node can change its values according to the majority-vote update rule. The model presents a consensus formation phase when the concentration is greater than a threshold value and a paramagnetic phase on the converse for equal diffusion probabilities, i.e., maintaining the inversion symmetry. Setting unequal diffusion probabilities for the respective spin orientations is the same as applying an external magnetic field. The system undergoes a discontinuous phase transition for concentrations higher than the critical threshold on the external field. The individuals that diffuse more dominate the stationary collective opinion.
ABSTRACT
OBJECTIVES: In view of the lack of studies about the morphological and structural changes caused by solar radiation in young people, the aim of the present study was to evaluate the photoageing-related changes in the skin of different age groups by biophysical and imaging techniques. METHODS: Forty-four healthy female subjects were divided into two age groups: Group 1 (G1): 18-35 years old and Group 2 (G2): 40-60 years old. The skin of malar region of the face was evaluated in terms of mechanical properties, disorder in the pigmentation pattern, morphological and structural changes using the Cutometer® , Colorimeter® , Visioface® and Dermascan C® devices and reflectance confocal microscopy (Vivascope® ). RESULTS: The results showed that the main changes in the skin of G1 were related to the pigmentation pattern, the papilla format and depletion of thin collagen fibres. These alterations were also observed in the skin of G2, but with more pronounced effects. CONCLUSION: The knowledge about the skin changes caused by photoageing obtained in this study is very important for the development of dermocosmetic products for more effective treatments particularly focused on this type of skin. Finally, objective characterization of photoageing showed the importance of photoprotective habits since the first years of life in order to retard the appearance of skin changes caused by solar radiation.
OBJECTIFS: Compte tenu du manque d'études sur les modifications structurelles et morphologiques causées par le rayonnement solaire chez les jeunes gens, le but de la présente étude était d'évaluer les changements liés au photovieillissement de la peau de différents groupes d'âges grâce des techniques de biophysique et d'imagerie. MÉTHODES: Quarante-quatre sujets féminins en bonne santé ont été divisés en deux groupes d'âges : Groupe 1 (G1) : 18-35 ans et Groupe 2 (G2) : 40-60 ans. La peau des régions malaires du visage a été évaluée en termes de propriétés mécaniques, troubles du schéma de pigmentation, et changements morphologiques et structurels à l'aide des dispositifs Cutometer®, Colorimeter®, Visioface® et Dermascan C® et de la microscopie confocale par réflectance (Vivascope®). RÉSULTATS: Les résultats ont montré que les principaux changements au niveau de la peau du G1 étaient liés au schéma de pigmentation, au format papillaire et à la déplétion de fines fibres de collagène. Ces altérations ont également été observées au niveau de la peau du G2, mais avec des effets plus prononcés. CONCLUSION: Les connaissances sur les modifications cutanées causées par le photovieillissement acquises grâce à cette étude sont très importantes pour le développement de produits dermo-cosmétiques pour des traitements plus efficaces axés plus particulièrement sur ce type de peau. Et enfin, la caractérisation objective du photovieillissement a montré l'importance des habitudes photoprotectrices depuis les premières années de vie afin de retarder l'apparition de modifications cutanées causées par le rayonnement solaire.
Subject(s)
Skin Aging/radiation effects , Sunlight/adverse effects , Ultraviolet Rays/adverse effects , Adolescent , Adult , Biophysical Phenomena , Brazil , Elasticity , Female , Humans , Middle Aged , Skin Physiological Phenomena , Skin Pigmentation , Viscosity , Young AdultABSTRACT
We address the study of quasiperiodic interactions on a square lattice by using an Ising model with ferromagnetic and antiferromagnetic exchange interactions following a quasiperiodic Fibonacci sequence in both directions of a square lattice. We applied the Monte Carlo method, together with the Metropolis algorithm, to calculate the thermodynamic quantities of the system. We obtained the Edwards-Anderson order parameter q_{EA}, the magnetic susceptibility χ, and the specific heat c in order to characterize the universality class of the phase transition. We also use the finite size scaling method to obtain the critical temperature of the system and the critical exponents ß,γ, and ν. In the low-temperature limit we obtained a spin-glass phase with critical temperature around T_{c}≈2.274, and the critical exponents ß,γ, and ν, indicating that the quasiperiodic order induces a change in the universality class of the system. Also, we discovered a spin-glass ordering in a two-dimensional system which is rare and, as far as we know, the unique example is an under-frustrated Ising model.
ABSTRACT
Several deleterious effects may occur when intense and exhaustive exercise (IE) is not well-planned. This study aimed to investigate the effects of a short duration IE on body chemical composition and hypothalamic-pituitary-adrenal (HPA) axis. C57Bl/6 mice were distributed into four groups (10 mice per group): control (C-4D and C-10D), 4 days (E-4D), and 10 days of IE (E-10D). IE program consisted of a daily running session at 85 % of maximum speed until the animal reached exhaustion. Body weight as well as total body water, fat and protein content were determined from animal carcasses. HPA activation was assessed by plasma corticosterone levels measured by radioimmunoassay and the weight of both the adrenal glands and thymus were measured. Plasma corticosterone levels increased by 64 % in both the E-4D and E-10D groups. The weight of the adrenal glands augmented by 74 % and 45 %, at 4 and 10 days of IE, respectively, whereas thymus weight diminished by 15 % only in the E-10D group. The total carcass fat content decreased by 20 % only at 4 days IE, whereas protein content decreased by 20 % in both E-4D and E-10D groups. A relationship between corticosterone plasma levels and loss of body protein content in both E-4D and E-10D groups was observed (R(2)=0.999). We concluded that IE may be related to HPA axis activation associated with remodeling of body chemical composition in C57BL/6 mice.
Subject(s)
Body Composition , Hypothalamo-Hypophyseal System/metabolism , Muscle Fatigue , Muscle, Skeletal/metabolism , Physical Exertion , Pituitary-Adrenal System/metabolism , Stress, Physiological , Adrenal Glands/anatomy & histology , Adrenal Glands/metabolism , Animals , Biomarkers/blood , Corticosterone/blood , Male , Mice, Inbred C57BL , Muscle, Skeletal/anatomy & histology , Organ Size , Pituitary-Adrenal System/anatomy & histology , Proteins/metabolism , Proteolysis , Running , Thymus Gland/anatomy & histology , Time FactorsABSTRACT
Em 2009 o município de São Paulo desencadeou ações inter setoriais com sociedade civil e comunidade para reduzir a vulnerabilidade social, denominada Virada Social. A Secretaria Municipal de Saúde (SMS) e a Coordenadoria Regional de Saúde Sul (CRS Sul) participaram da Jornada da Saúde propiciando o acesso aos serviços de promoção e prevenção da saúde: elaboração do cartão SUS, alimentação saudável, medidas de pressão arterial, glicemia, vacinas, prevenção de gravidez precoce e doenças sexualmente transmissíveis (DST) para adolescentes, prevenção de câncer do colo de útero, dengue, saúde bucal e outras
Subject(s)
Humans , Family Health , Health Services , Mental Health , Public Health , Organization and AdministrationABSTRACT
Em 2009 o município de São Paulo desencadeou ações inter setoriais com sociedade civil e comunidade para reduzir a vulnerabilidade social, denominada Virada Social. A Secretaria Municipal de Saúde (SMS) e a Coordenadoria Regional de Saúde Sul (CRS Sul) participaram da Jornada da Saúde propiciando o acesso aos serviços de promoção e prevenção da saúde: elaboração do cartão SUS, alimentação saudável, medidas de pressão arterial, glicemia, vacinas, prevenção de gravidez precoce e doenças sexualmente transmissíveis (DST) para adolescentes, prevenção de câncer do colo de útero, dengue, saúde bucal e outras.
Subject(s)
Humans , Family Health , Health Services , Mental Health , Public Health , Organization and AdministrationABSTRACT
Em 2009 o município de São Paulo desencadeou ações inter setoriais com sociedade civil e comunidade para reduzir a vulnerabilidade social, denominada Virada Social. A Secretaria Municipal de Saúde (SMS) e a Coordenadoria Regional de Saúde Sul (CRS Sul) participaram da Jornada da Saúde propiciando o acesso aos serviços de promoção e prevenção da saúde: elaboração do cartão SUS, alimentação saudável, medidas de pressão arterial, glicemia, vacinas, prevenção de gravidez precoce e doenças sexualmente transmissíveis (DST) para adolescentes, prevenção de câncer do colo de útero, dengue, saúde bucal e outras(AU)
Subject(s)
Humans , Public Health , Health Services , Family Health , Mental Health , Organization and AdministrationABSTRACT
We report observation of the electroweak production of single top quarks in pp[over ] collisions at sqrt[s]=1.96 TeV based on 2.3 fb(-1) of data collected by the D0 detector at the Fermilab Tevatron Collider. Using events containing an isolated electron or muon and missing transverse energy, together with jets originating from the fragmentation of b quarks, we measure a cross section of sigma(pp[over ]--> tb + X, tqb + X) = 3.94 + or - 0.88 pb. The probability to measure a cross section at this value or higher in the absence of signal is 2.5 x 10(-7), corresponding to a 5.0 standard deviation significance for the observation.
ABSTRACT
We present a search for a narrow resonance in the inclusive diphoton final state using approximately 2.7 fb(-1) of data collected with the D0 detector at the Fermilab Tevatron pp Collider. We observe good agreement between the data and the background prediction, and set the first 95% C.L. upper limits on the production cross section times the branching ratio for decay into a pair of photons for resonance masses between 100 and 150 GeV. This search is also interpreted in the context of several models of electroweak symmetry breaking with a Higgs boson decaying into two photons.
ABSTRACT
We present a search for direct CP violation in B(+/-)-->J/psiK(+/-)(pi(+/-)) decays. The event sample is selected from 2.8 fb(-1) of pp collisions recorded by D0 experiment in run II of the Fermilab Tevatron Collider. The charge asymmetry A_(CP)(B(+)-->J/psiK(+))= + 0.0075 +/- 0.0061(stat)+/-0.0030(syst) is obtained using a sample of approximately 40, 000 B(+/-)-->J/psiK(+/-) decays. The achieved precision is of the same level as the expected deviation predicted by some extensions of the standard model. We also measured the charge asymmetry A(CP)(B(+)-->J/psipi(+))=-0.09+/-0.08(stat)+/-0.03(syst).
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We search for the production of a heavy W' gauge boson that decays to third generation quarks in 0.9 fb-1 of pp collisions at square root(s)=1.96 TeV, collected with the D0 detector at the Fermilab Tevatron collider. We find no significant excess in the final-state invariant mass distribution and set upper limits on the production cross section times branching fraction. For a left-handed W' boson with SM couplings, we set a lower mass limit of 731 GeV. For right-handed W' bosons, we set lower mass limits of 739 GeV if the W' boson decays to both leptons and quarks and 768 GeV if the W' boson decays only to quarks. We also set limits on the coupling of the W' boson to fermions as a function of its mass.
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We present a search for associated Higgs boson production in the process pp-->WH-->WWW*-->l;+/-nul'+/-nu'+X in final states containing two like-sign isolated electrons or muons (e+/-e;+/-, e+/-micro+/-, or micro+/-micro+/-). The search is based on D0 run II data samples corresponding to integrated luminosities of 360-380 pb-1. No excess is observed over the predicted standard model background. We set 95% C.L. upper limits on sigma(pp-->WH)xBr(H-->WW*) between 3.2 and 2.8 pb for Higgs boson masses from 115 to 175 GeV.
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A search for associated production of charginos and neutralinos is performed using data recorded with the D0 detector at a pp center-of-mass energy of 1.96 TeV at the Fermilab Tevatron Collider. This analysis considers final states with missing transverse energy and three charged leptons, of which at least two are electrons or muons. No evidence for supersymmetry is found in a data set corresponding to an integrated luminosity of 320 pb-1. Limits on the product of the production cross section and leptonic branching fraction are set. For the minimal supergravity model, a chargino lower mass limit of 117 GeV at the 95% C.L. is derived in regions of parameter space with enhanced leptonic branching fractions.
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We have performed a search for neutral Higgs bosons produced in association with bottom quarks in pp collisions, using 260 pb-1 of data collected with the D0 detector in Run II of the Fermilab Tevatron Collider. The cross sections for these processes are enhanced in many extensions of the standard model (SM), such as in its minimal supersymmetric extension at large tanbeta. The results of our analysis agree with expectations from the SM, and we use our measurements to set upper limits on the production of neutral Higgs bosons in the mass range of 90 to 150 GeV.
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The D0 Collaboration has measured the inclusive jet cross section in barpp collisions at square root of s = 630 GeV. The results for pseudorapidities (eta)<0.5 are combined with our previous results at square root of s = 1800 GeV to form a ratio of cross sections with smaller uncertainties than either individual measurement. Next-to-leading-order QCD predictions show excellent agreement with the measurement at 630 GeV; agreement is also satisfactory for the ratio. Specifically, despite a 10% to 15% difference in the absolute magnitude, the dependence of the ratio on jet transverse momentum is very similar for data and theory.
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We report a search for effects of large extra spatial dimensions in pp collisions at a center-of-mass energy of 1.8 TeV with the D0 detector, using events containing a pair of electrons or photons. The data are in good agreement with the expected background and do not exhibit evidence for large extra dimensions. We set the most restrictive lower limits to date, at the 95% C.L. on the effective Planck scale between 1.0 and 1.4 TeV for several formalisms and numbers of extra dimensions.