Performance of the modified Becke-Johnson potential

Very recently, in the 2011 version of the Wien2K code, the long standing shortcome of the codes based on Density Functional Theory, namely, its impossibility to account for the experimental band gap value of semiconductors, was overcome. The novelty is the introduction of a new exchange and correlation potential, the modified Becke-Johnson potential (mBJLDA). In this paper, we report our detailed analysis of this recent work. We calculated using this code, the band structure of forty one semiconductors and found an important improvement in the overall agreement with experiment as Tran and Blaha [{\em Phys. Rev. Lett.} 102, 226401 (2009)] did before for a more reduced set of semiconductors. We find, nevertheless, within this enhanced set, that the deviation from the experimental gap value can reach even much more than 20%, in some cases. Furthermore, since there is no exchange and correlation energy term from which the mBJLDA potential can be deduced, a direct optimization procedure to get the lattice parameter in a consistent way is not possible as in the usual theory. These authors suggest that a LDA or a GGA optimization procedure is used previous to a band structure calculation and the resulting lattice parameter introduced into the 2011 code. This choice is important since small percentage differences in the lattice parameter can give rise to quite higher percentage deviations from experiment in the predicted band gap value.Comment: 10 pages, 2 figures, 5 Table

Histoplasmose pulmonar aguda e primeiro isolamento do Histoplasma capsulatum do solo do Rio Grande do Sul, Brasil

A case of acute pulmonary histoplasmosis, where the clinical histoiy and epidemiological data led to the identification of H. capsulatum natural source, is described. Specimens of spleen and liver, obtained after intraperitonial inoculation in mice, grew H. capsulatum in culture from the soil of rural area of General Câmara, by the first time in Rio Grande do Sul.Apresenta-se um caso de histoplasmose pulmonar aguda, onde a história clinica orientada levou a Identificação da fonte natural do Histoplasma capsulatum. O fungo foi obtido em cultivo a partir de fragmentos de baço e fígado de ratos inoculados intraperitonealmente com solo da zona rural de General Câmara, pela primeira vez no Rio Grande do Sul

Selection of rice cultivars resistant to some pathogens using seed health testing

Trinta e seis progênies de arroz (Oryza sativa L) irrigado foram testadas, em campo, objetivando-se determinar os fungos mais importantes de sementes e o desempenho das progênies com relação a esses patógenos, dando-se ênfase especial à descoloração e consequente perda de peso de sementes. Observaram-se diferenças significativas entre progênies quanto à presença de sete fungos de sementes. Entretanto, considerando-se a descoloração e a consequente perda de peso de sementes, Rhynchosporium oryzae, Phoma spp., Trichoconis padwickii e Helminthosporium oryzae se apresentaram como patógenos mais nocivos. Em todos os parâmetros analisados, sete progênies suplantaram a cultivar comercial IAC-899, usada como controle. Conclui-se que, apesar de trabalhoso, o teste de sanidade de sementes é um instrumento muito eficaz na seleção de novos germoplasmas de arroz com baixa incidência de fungos de sementes.Thirty-six lowland rice (Oryza sativa L.) progenies have been tested in yield trials aiming at determining the most important seed-borne fungi and the progeny performance as to each of the pathogens found in seeds, with special emphasis on seed discoloration and consequent seed weight loss. Significant progeny differences as to seven seed-born fungi have been found; however, as far as seed discoloration and consequent seed weight loss are concerned, Rhynchosporium oryzae, Phoma spp., Trichoconis padwickii and Helminthosporium oryzae have been the most important pathogens. Seven progenies outperformed IAC-899 (commercial variety used as control) regarding all the parameters analysed. It is concluded that seed health testing is an effective complementary 1001 in selecting rice germplasms with lower seed-borne fungal incidence

Aids, sexualidade e atitudes de adolescentes sobre proteção contra o HIV

OBJECTIVE: To describe the role of sexual experience based on information and sociocultural contexts for the risk of HIV/AIDS transmission in adolescents. METHODS: A questionnaire was answered by 1,386 middle school students from the state of Santa Catarina, Southern Brazil, in 2000. The instrument included the following variables: personal characteristics, sexual experience, communication context and knowledge on AIDS, attitudes towards condom use, risk and protective behaviors and feelings. Data analysis comprised statistical description and relational analysis (Chi-square and mean comparison tests). RESULTS: Lack of knowledge about HIV transmission was related to peers as main information source (pOBJETIVO: Descrever o papel da experiência sexual no contexto informativo e sociocultural, para o risco de transmissão do HIV/Aids em adolescentes. MÉTODOS: Aplicou-se um questionário em 1.386 estudantes do ensino médio de Santa Catarina, em 2000. O instrumento considerou as seguintes variáveis: características pessoais, experiência sexual, contexto de comunicação e conhecimento sobre a Aids, atitudes quanto ao uso do preservativo, condutas arriscadas e protetoras, e sentimentos. A análise dos dados envolveu descrição estatística e análise relacional (qui-quadrado e testes de diferenças de médias). RESULTADOS: O desconhecimento da transmissão do HIV esteve relacionado aos amigos como fonte principal de informação (

Produção de biomassa de folhas e caules de três tipos de crajiru (Arrabidaea chica Verlot.) em função de espaçamentos, nas condições de Manaus-AM.

Avaliou-se a produção de folhas, caules e relação folha/caule em três tipos de crajiru (Arrabidaea chica Verlot.), em função de arranjos espaciais (0,5 x 0,5 m; 0,5 x 1,0 m; 1,0 x 1,0 m; 1,0 x 1,5 m e 1,5 x 1,5 m). A produção de folhas foi crescente nos Tipos 2 e 3, em função dos maiores espaçamentos. Já a produção de caules cresce em todos os tipos até o espaçamento 1,0 m x 1,0 m. Verificou-se que o tipo 1 deve ser recomendado para cultivo em espaçamentos intermediários, enquanto os demais tipos respondem melhor em espaçamentos maiores

Produção de biomassa de folhas e caules de três tipos de crajiru (Arrabidaea chica Verlot.) em função de espaçamentos, nas condições de Manaus, Brasil.

Avaliou-se a produção de folhas, caules e relação folha/caule em três tipos de crajiru, em função de arranjos espaciais (0,5 x 0,5 m; 0,5 x 1,0 m; 1,0 x 1,0 m; 1,0 x 1,5 m e 1,5 x 1,5 m)

Astrometric positions for 18 irregular satellites of giant planets from 23 years of observations

The irregular satellites of the giant planets are believed to have been captured during the evolution of the solar system. Knowing their physical parameters, such as size, density, and albedo is important for constraining where they came from and how they were captured. The best way to obtain these parameters are observations in situ by spacecrafts or from stellar occultations by the objects. Both techniques demand that the orbits are well known. We aimed to obtain good astrometric positions of irregular satellites to improve their orbits and ephemeris. We identified and reduced observations of several irregular satellites from three databases containing more than 8000 images obtained between 1992 and 2014 at three sites (Observat\'orio do Pico dos Dias, Observatoire de Haute-Provence, and European Southern Observatory - La Silla). We used the software PRAIA (Platform for Reduction of Astronomical Images Automatically) to make the astrometric reduction of the CCD frames. The UCAC4 catalog represented the International Celestial Reference System in the reductions. Identification of the satellites in the frames was done through their ephemerides as determined from the SPICE/NAIF kernels. Some procedures were followed to overcome missing or incomplete information (coordinates, date), mostly for the older images. We managed to obtain more than 6000 positions for 18 irregular satellites: 12 of Jupiter, 4 of Saturn, 1 of Uranus (Sycorax), and 1 of Neptune (Nereid). For some satellites the number of obtained positions is more than 50\% of what was used in earlier orbital numerical integrations. Comparison of our positions with recent JPL ephemeris suggests there are systematic errors in the orbits for some of the irregular satellites. The most evident case was an error in the inclination of Carme.Comment: 9 pages, with 3 being online materia

Avaliação do sedimento em áreas de produção de peixes em tanques redes no Reservatório de Furnas (MG).

Resumo: A aquicultura tem apresentado um crescimento nos últimos anos consolidando-se como um setor de grande importância econômica. Diante deste crescimento, surge à necessidade de desenvolvimento de processos de monitoramento ambiental que assegurem uma correta interpretação dos possíveis impactos e a melhor forma de diminuí-los. O presente trabalho teve por objetivo avaliar a concentração de metais potencialmente tóxicos e de carbono e nitrogênio, em sedimentos coletados na área de influência direta de piscicultura em tanques rede no reservatório de Furnas. A área de coleta é composta por 4 braços do rio Grande todos no município de Guapé (MG). Em 3 dos 4 braços existem piscicultura em tanques rede e um foi utilizado como controle. Foram realizadas 3 coletas de sedimento em maio, agosto e outubro de 2013, utilizando-se draga de Ekman-Birge. No laboratório, as amostras foram secas, moídas e digeridas para a determinação elementar de Cu (cobre), Pb (chumbo) e Zn (zinco) por Espectrometria de Absorção Atômica com Chama (F-AAS). Os resultados encontrados nas três coletadas variaram de 11,6 a 36,9 mg.L-1 para o Cu, de 95,2 a 184,8 mg.L-1 para o Pb e de 12,7 a 86,3 mg.L-1 para o Zn. O carbono (C) e o nitrogênio (N) total foram determinados por combustão a seco, com resultados que variam de 0,71 a 2,34 % para o C e de 0,097 a 0,224 % para o N. Abstract: Aquaculture has growing in the last decades establishing as sector of great economic importance. The growing of the sector, inputs a necessity to develop environmental monitoring processes to ensuring a correct interpretation of the possible impacts and how the best way to reduce them. This study aimed to evaluate the concentration of potentially toxic metals and carbon and nitrogen in sediments, collected in the area of direct influence of fish farming in tanks, located in Furnas reservoir. The sampling area consists of 4 arms of the rio Grande in the city of Guape (MG). In arms 2 to 4 there are fish farming in net tanks and arm 1 was used as control. Three samples were taken in all sampling sites, during May, August and October 2013, using Ekman-Birge dredge. At the laboratory, samples were dried, ground and digested for elemental determination of Cu (copper), Pb (lead) and Zn (zinc) Spectrometry Flame Atomic Absorption (F-AAS). The results in the three collected ranged from 11.6 to 36.9 mg.L -1 of Cu, 95.2 to 184.8 mg.L -1 for Pb and 12.7 to 86.3 mg.L -1 for Zn. The carbon (C) and nitrogen (N) were determined by the total dry combustion with results ranging from 0.71 to 2.34% for C and 0.097 to 0.224% for

Full characterization of vibrational coherence in a porphyrin chromophore by two-dimensional electronic spectroscopy

In this work we present experimental and calculated two-dimensional electronic spectra for a 5,15-bisalkynyl porphyrin chromophore. The lowest energy electronic Qy transition couples mainly to a single 380 cm–1 vibrational mode. The two-dimensional electronic spectra reveal diagonal and cross peaks which oscillate as a function of population time. We analyze both the amplitude and phase distribution of this main vibronic transition as a function of excitation and detection frequencies. Even though Feynman diagrams provide a good indication of where the amplitude of the oscillating components are located in the excitation-detection plane, other factors also affect this distribution. Specifically, the oscillation corresponding to each Feynman diagram is expected to have a phase that is a function of excitation and detection frequencies. Therefore, the overall phase of the experimentally observed oscillation will reflect this phase dependence. Another consequence is that the overall oscillation amplitude can show interference patterns resulting from overlapping contributions from neighboring Feynman diagrams. These observations are consistently reproduced through simulations based on third order perturbation theory coupled to a spectral density described by a Brownian oscillator model