Gauge fields in a string-cigar braneworld

In this work we investigate the properties of an Abelian gauge vector field in a thin and in a smoothed string-like braneworld, the so-called string-cigar model. This thick brane scenario satisfies the regularity conditions and it can be regarded as an interior and exterior string-like solution. The source undergoes a geometric Ricci flow which is connected to a variation of the bulk cosmological constant. The Ricci flow changes the width and amplitude of the massless mode at the brane core and recover the usual thin string-like behavior at large distances. By numerical means we obtain the Kaluza-Klein (KK) spectrum for both the thin brane and the string-cigar. It turns out that both models exhibit a mass gap between the massless and the massive modes and between the high and the low mass regimes. The KK modes are smooth near the brane and their amplitude are enhanced by the string-cigar core. The analogue Schr\"odinger potential is also tuned by the geometric flow.Comment: The discussion about the Kaluza-Klein spectrum of the gauge field was improved. Numerical analysis was adapted to the conventional notation on Kaluza-Klein number. Some graphics were modified for considering other notation. Results unchanged. References added. Corrected typos. 17 pages. 6 figures. To match version to appears in Physics Letters

Metodologia para avaliação da reação de genótipos de milho à Fusarium verticillioides em casa de vegetação.

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Recomendação para o controle químico da antracnose foliar do sorgo.

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Levantamento de fungos causadores de podridões de colmo em milho na região Centro Oeste do Brasil.

As podridões de colmo estão entre as mais importantes doenças da cultura do milho. Vários são os patógenos causadores de podridões de colmo em plantas de milho, incluindo fungos e bactérias. Entre os principais, destacam-se Fusarium verticillioides, Fusarium graminearum, Colletotrichum graminicola, Stenocarpella macrospora, Stenocarpella maydis e Macrophomina phaseolina. O presente trabalho teve como objetivo realizar um levantamento da incidência de fungos causadores de podridões de colmo em milho na região Centro-Oeste do Brasil. Foram realizadas coletas de amostras nos estados de Goiás, Mato Grosso e Mato Grosso do Sul. Durante as coletas das amostras foi possível verificar uma elevada incidência de plantas apresentando sintomas de podridão de colmo em, praticamente, todas as regiões. Dentre os patógenos detectados, as maiores frequências foram verificadas para Fusarium spp. Nigrospora spp. e Stenocarpella spp., com freqüência de 45,7, 38,3 e 29,9%, respectivamente. Coletotrichum graminicola e Rhizoctonia spp. apresentaram frequência de 5,8 e 3,4%. Os demais fungos apresentaram menos de 3% de ocorrência nos isolamentos. Esses resultados demonstram a grande variabilidade de fungos envolvidos com as podridões de colmo na cultura do milho no Centro-Oeste do Brasil. Revelam, também, a elevada ocorrência de fungos do gênero Fusarium spp. e Stenocarpella spp., os quais predominaram nas amostras analisadas no presente trabalho. Os trabalhos de monitoramento da ocorrência de fungos causadores de podridões de colmo são fundamentais para o desenvolvimento e a adoção das melhores estratégias de controle desta doença na cultura do milho.bitstream/item/145936/1/bol-133.pd

Recomendações para o controle químico da mancha branca do milho.

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Identification of seminal parameters predictive of conception rates in Angus and Nelore bulls used in TAI.

The ability to predict male fertility is highly desirable for bulls used in AI. Timed artificial insemination (TAI) represents a breakthrough in the use of AI in Brazil and other countries. Numerous causes contribute to the wide range of results and/or unsatisfactory pregnancy rates in TAI programs, highlighting the factors inherent in the bovine female in addition to several factors inherent to quality of semen used. Regarding the quality of semen used in AI programs, differences reported in fertility could be attributed to variation in sperm qualitative characteristics. Consequently, the success of bovine AI programs largely depends on the use of good quality semen. When only high fertility bulls are used, better conception rates are achieved, reducing costs of reproductive programs. Thus, some authors have shown that semen used in TAI has great impact on pregnancy rates, and various biomarkers of sperm quality are required to predict the fertility of bull spermatozoa (Oliveira et al., 2013, Holden et al., 2017). Our goal is to correlate different methods of post-thaw semen evaluation with the P/AI of Nelore (zebu) cows subjected to TAI to identify the candidate predictors of conception rate.Proceedings of the international Bull Fertility Conference, 2018, Westport