Electromagnetic form factors of light vector mesons

The electromagnetic form factors G_E(q^2), G_M(q^2), and G_Q(q^2), charge radii, magnetic and quadrupole moments, and decay widths of the light vector mesons rho^+, K^{*+} and K^{*0} are calculated in a Lorentz-covariant, Dyson-Schwinger equation based model using algebraic quark propagators that incorporate confinement, asymptotic freedom, and dynamical chiral symmetry breaking, and vector meson Bethe-Salpeter amplitudes closely related to the pseudoscalar amplitudes obtained from phenomenological studies of pi and K mesons. Calculated static properties of vector mesons include the charge radii and magnetic moments: r_{rho+} = 0.61 fm, r_{K*+} = 0.54 fm, and r^2_{K*0} = -0.048 fm^2; mu_{rho+} = 2.69, mu_{K*+} = 2.37, and mu_{K*0} = -0.40. The calculated static limits of the rho-meson form factors are similar to those obtained from light-front quantum mechanical calculations, but begin to differ above q^2 = 1 GeV^2 due to the dynamical evolution of the quark propagators in our approach.Comment: 8 pages of RevTeX, 5 eps figure

In vitro cultivation of Brosimum gaudichaudii Tréc. (Moraceae)

O objetivo desta pesquisa foi avaliar o potencial organogenético de entrenós, discos foliares, e raízes de Brosimum gaudichaudii utilizando 12 diferentes combinações dos fitorreguladores 6-benzilaminopurina e ácido naftaleno acético, em meio MS (diluído à metade), sólido (6,5 g de ágar), e com 20 g.L-1 de sacarose. Independentemente das combinações hormonais testadas verificou-se a formação de calos friáveis (2 a 20 mm de diâmetro) em 90% dos entrenós usados como explantes. No entanto, os tratamentos testados não foram capazes induzir calos ou gemas em raízes e em discos foliares. O estudo anatômico revelou a formação de meristemóides nas regiões mais externa e mais interna dos calos. Os resultados obtidos poderão servir de base para novos testes de indução de calos na espécie.The objective of this research was to evaluate the organogenic potential of internodes, leaf discs and roots of Brosimum gaudichaudii using 12 different combinations of the plant growth regulators 6-benzylaminopurine and naphthalene acetic acid in MS medium (half strength), solid medium (6.5 g agar) and sucrose medium (20 g.L-1). Regardless the hormonal combination tested, we observed the formation of friable calluses (2 - 20 mm wide) in 90% of the internode explants. However, the treatments were not able to induce callus or buds on roots and leaf discs. The anatomical analysis revealed meristemoid formation in the outer and inner regions of the calluses. The results may serve as the basis for further testing of callus induction in this species

Soil organisms in organic and conventional cropping systems.

Apesar do crescente interesse pela agricultura orgânica, são poucas as informações de pesquisa disponíveis sobre o assunto. Assim, num Argissolo Vermelho-Amarelo distrófico foram comparados os efeitos de sistemas de cultivo orgânico e convencional, para as culturas do tomate (Lycopersicum esculentum) e do milho (Zea mays), sobre a comunidade de organismos do solo e suas atividades. As populações de fungos,bactérias e actinomicetos, determinadas pela contagem de colônias em meio de cultura, foram semelhantes para os dois sistemas de produção. A atividade microbiana, avaliada pela evolução de CO2, manteve-se superior no sistema orgânico, sendo que em determinadas avaliações foi o dobro da evolução verificada no sistema convencional. O número de espécimes de minhoca foi praticamente dez vezes maior no sistema orgânico. Não foi observada diferença na taxa de decomposição de matéria orgânica entre os dois sistemas. De modo geral, o número de indivíduos de microartrópodos foi superior no sistema orgânico do que no sistema convencional, refletindo no maior índice de diversidade de Shannon. As maiores populações de insetos foram as da ordem Collembola, enquanto para os ácaros a maior população foi a da superfamília Oribatuloidea. Indivíduos dos grupos Aranae, Chilopoda, Dyplopoda, Pauropoda, Protura e Symphyla foram ocasionalmente coletados e de forma similar entre os sistemas

Unconventional particle-hole mixing in the systems with strong superconducting fluctuations

Development of the STM and ARPES spectroscopies enabled to reach the resolution level sufficient for detecting the particle-hole entanglement in superconducting materials. On a quantitative level one can characterize such entanglement in terms of the, so called, Bogoliubov angle which determines to what extent the particles and holes constitute the spatially or momentum resolved excitation spectra. In classical superconductors, where the phase transition is related to formation of the Cooper pairs almost simultaneously accompanied by onset of their long-range phase coherence, the Bogoliubov angle is slanted all the way up to the critical temperature Tc. In the high temperature superconductors and in superfluid ultracold fermion atoms near the Feshbach resonance the situation is different because of the preformed pairs which exist above Tc albeit loosing coherence due to the strong quantum fluctuations. We discuss a generic temperature dependence of the Bogoliubov angle in such pseudogap state indicating a novel, non-BCS behavior. For quantitative analysis we use a two-component model describing the pairs coexisting with single fermions and study their mutual feedback effects by the selfconsistent procedure originating from the renormalization group approach.Comment: 4 pages, 4 figure

Low energy collective modes, Ginzburg-Landau theory, and pseudogap behavior in superconductors with long-range pairing interactions

We study the superconducting instability in systems with long but finite ranged, attractive, pairing interactions. We show that such long-ranged superconductors exhibit a new class of fluctuations in which the internal structure of the Cooper pair wave function is soft, and thus lead to "pseudogap" behavior in which the actual transition temperature is greatly depressed from its mean field value. These fluctuations are {\it not} phase fluctuations of the standard superconducting order parameter, and lead to a highly unusual Ginzburg-Landau description. We suggest that the crossover between the BCS limit of a short-ranged attraction and our problem is of interest in the context of superconductivity in the underdoped cuprates.Comment: 20 pages with one embedded ps figure. Minor revisions to the text and references. Final version to appear in PRB on Nov. 1st, 200

Survival of patients with AIDS and association with level of education level and race/skin color in South and Southeast Brazil: a cohort study, 1998-1999

Analisar a sobrevida de pessoas com aids e sua associação com escolaridade e raça/cor da pele. Coorte de diagnosticados entre 1998 e 1999, nas regiões Sul e Sudeste do Brasil, com análise de sobrevida (método de Kaplan--Meier), estratificada por escolaridade e raça/cor da pele; a análise multivariada foi realizada mediante regressão de Cox. Foram incluídas 2.091 pessoas com sobrevida em 60 meses, a percentuais de 65% entre brancos e 62% entre pretos/pardos; o uso irregular de antirretrovirais (HR=11,2 - IC95%8,8;14,2) e a idade ≥60 anos (HR=2,5 - IC95%1,4;4,4) foram relacionados com menor sobrevida; escolaridade >8 anos (HR=0,4 - IC95%0,3;0,6) e sexo feminino (HR=0,6 - IC95%0,5;0,8) relacionaram-se positivamente com sobrevida; os menos escolarizados tiveram sobrevida menor. Menor escolaridade sobrepôs-se às diferenças de raça/cor da pele, quando relacionada à sobrevida; tais desigualdades explicaram as diferenças observadas, mesmo com políticas de acesso universal aos antirretrovirais. Síndrome da Imunodeficiência Adquirida; Sobrevivência (Saúde Pública); Análise de Sobrevida; Escolaridade; Origem Étnica e Saúde281To analyze the survival of people with AIDS and association with schooling and race/skin color. METHODS: this was a retrospective cohort study of people diagnosed with AIDS between 1998 and 1999, in the South and Southeast regions of Brazil. We used survival analysis (Kaplan-Meier method), stratified by schooling and race/skin color and multivariate analysis was performed using Cox regression. RESULTS: the study included 2,091 people who had survived at 60 months, with 65% survival among White participants and 62% among Black/brown participants. Irregular use of antiretroviral (HR=11.2 - 95%CI8.8;14.2), and age ≥60 years (HR=2.5 - 95%CI1.4;4.4) were related to lower survival; schooling >8 years (HR=0.4 - 95%CI0.3;0.6) and being female (HR=0.6 - 95%CI0.5;0.8) were positively related to survival; those with less schooling had lower survival. CONCLUSION: lower schooling levels overlap race/skin color differences in relation to survival; these inequalities explain the differences found, despite the policies on universal access to antiretroviral.OBJETIVO: analisar a sobrevida de pessoas com aids e sua associação com escolaridade e raça/cor da pele. MÉTODOS: coorte de diagnosticados entre 1998 e 1999, nas regiões Sul e Sudeste do Brasil, com análise de sobrevida (método de Kaplan--Meier), estratificada por escolaridade e raça/cor da pele; a análise multivariada foi realizada mediante regressão de Cox. RESULTADOS: foram incluídas 2.091 pessoas com sobrevida em 60 meses, a percentuais de 65% entre brancos e 62% entre pretos/pardos; o uso irregular de antirretrovirais (HR=11,2 - IC95%8,8;14,2) e a idade ≥60 anos (HR=2,5 - IC95%1,4;4,4) foram relacionados com menor sobrevida; escolaridade >8 anos (HR=0,4 - IC95%0,3;0,6) e sexo feminino (HR=0,6 - IC95%0,5;0,8) relacionaram-se positivamente com sobrevida; os menos escolarizados tiveram sobrevida menor. CONCLUSÃO: menor escolaridade sobrepôs-se às diferenças de raça/cor da pele, quando relacionada à sobrevida; tais desigualdades explicaram as diferenças observadas, mesmo com políticas de acesso universal aos antirretrovirais.OBJETIVO: analizar la sobrevida de personas con sida y su asociación con escolaridad y raza/color de la piel. MÉTODOS: cohorte de diagnosticados entre 1998 y 1999, en las regiones Sur y Sudeste de Brasil, con análisis de supervivencia (Kaplan-Meier), estratificados por educación y raza/color de la piel; el análisis multivariante se realizó con regresión de Cox. RESULTADOS: fueron incluidas 2.091 personas con sobrevida de 60 meses, a porcentuales de 65% entre blancos y 62% entre negros/pardos; el uso irregular de antirretrovirales (HR=11,2 - IC95%8,8;14,2) y la edad ≥60 años (HR=2,5 - IC95%1,4;4,4) se relacionaron con una menor sobrevida; escolaridad >8 años (HR=0,4 - IC95%0,3;0,6) y sexo femenino (HR=0,6 - IC95%0,5;0,8) se relacionaron positivamente con sobrevida; los menos escolarizados tuvieron sobrevida menor. CONCLUSIÓN: menor escolaridad se superpuso a las diferencias de raza/color de la piel referida, cuando relacionada a la supervivencia; tales desigualdades explicaron las diferencias observadas, aún con políticas de acceso universal a antirretrovirales

Simulation and techno-economic optimization of the supercritical CO2 extraction of Eucalyptus globulus bark at industrial scale

This work addresses economic and process aspects of the supercritical fluid extraction (SFE) of Eucalyptus globulus bark at industrial scale. Broken plus intact cells (BIC) model was applied to existing data and new SFE curves were simulated. Then, statistical optimization was performed with Response Surface Methodology (RSM) involving of 5 factors (pressure, temperature, cosolvent content, solvent flow rate and extraction time), and four responses: Total Yield (ηTotal), Productivity, Cost of Manufacturing (COM) and Process Energy. The design and simulation of the industrial process (Aspen Plus® software) was performed including the employment of cosolvent in the system. The best COM scored 28.1 € kgextract-1, where ηTotal was 0.84-0.96 wt.%, Productivity reached 311–362 tonextractyear-1, and Process Energy scored 1.46– 2.10 GJ kgextract-1. These results underline that SFE provides an extended margin for trade-offs, and arguments towards the integration of SFE technology to biorefine the bark of E. globulus in pulp mills.publishe

Search for First Harmonic Modulation in the Right Ascension Distribution of Cosmic Rays Detected at the Pierre Auger Observatory

We present the results of searches for dipolar-type anisotropies in different energy ranges above $2.5\times 10^{17}$ eV with the surface detector array of the Pierre Auger Observatory, reporting on both the phase and the amplitude measurements of the first harmonic modulation in the right-ascension distribution. Upper limits on the amplitudes are obtained, which provide the most stringent bounds at present, being below 2% at 99% $C.L.$ for EeV energies. We also compare our results to those of previous experiments as well as with some theoretical expectations.Comment: 28 pages, 11 figure

Supercritical CO2 extraction of V. vinifera leaves: influence of cosolvents and particle size on removal kinetics and selectivity to target compounds

Leaves from Vitis vinifera L. contain potential bioactive compounds, namely: long chain aliphatic alcohols (e.g., 1-hexacosanol, 1-octacosanol and 1-triacontanol), α-tocopherol, β-sitosterol, and the triterpenes β-amyrin and lupeol. Supercritical fluid extraction (SFE) runs were measured at lab scale using: crushed and ground biomass; pure CO2 at 300 bar and 40−80 °C; and CO2 modified with 5 and 10 wt.% of ethanol or ethyl acetate. Total SFE yields ranged from 1.86 to 7.52 wt.%. The broken plus intact cells model (BICM), provided a good fitting of the SFE curves with 4.06 % error for total yield and 1.98–5.49 % for the individual yields of the said compounds. The BICM results revealed that the SFE is limited by intraparticle diffusion. Remarkable experimental and calculated selectivities were obtained for triterpenes (lupeol and β-amyrin), starting with a score of 1.7 and increasing along time to 10−100.publishe