Estimativa de duração do período de molhamento foliar no estado de São Paulo.

A duração de período de molhamento (DPM) foliar é considerada um dos principais fatores para a ocorrência de doenças de planta. Embora importante, esse parâmetro climático não é geralmente registrado sistematicamente nas estações meteorológicas. Desta forma, procurase estimar a DPM por meio de modelos matemáticos. Foi obtido neste trabalho o modelo empírico para estimar DPM, utilizando dados diários de umidade relativa de 10 estações meteorológicas do IAC e de 6 anos específicos. Foi obtida a equação de regressão exponencial (R 2 = 0,7533) para estimativa da DPM média mensal (horas/dia) em função da umidade relativa. Foram obtidos mapas de umidade relativa e de DPM mensais para o estado de São Paulo. A DPM variou entre as regiões do estado e nas estações do ano. A equação de regressão obtida, associada ao emprego do Sistema de Informações Geográficas, permitiu obter as informações de DPM distribuídas espacialmente e identificar diferentes áreas em função da DPM

Estimativa da severidade do míldio da videira (Plasmopara viticola) no estado de São Paulo utilizando sistema de informações geográficas.

Foi estimada a severidade do míldio (Plasmopara viticola ) da videira no estado de São Paulo, utilizando um modelo de desenvolvimento, baseado em parâmetros climáticos (temperatura e duração do período de molhamento foliar). Foram avaliados três municípios (Jales, Jundiaí e São Miguel Arcanjo), representativos de dois importantes pólos vitícolas do estado. Utilizando as ferramentas do Sistema de Informações Geográficas foram confeccionados os mapas de severidade do míldio nos meses de setembro a abril. Foram observadas diferenças na severidade entre as regiões, bem como diferenças sazonais. A metodologia adotada permitiu caracterizar o estado quanto à susceptibilidade das regiões ao míldio da videira, diferenciando o município de Jales e os municípios de Jundiaí e São Miguel Arcanjo

Orbit determination of Transneptunian objects and Centaurs for the prediction of stellar occultations

The prediction of stellar occultations by Transneptunian objects and Centaurs is a difficult challenge that requires accuracy both in the occulted star position as for the object ephemeris. Until now, the most used method of prediction involving tens of TNOs/Centaurs was to consider a constant offset for the right ascension and for the declination with respect to a reference ephemeris. This offset is determined as the difference between the most recent observations of the TNO and the reference ephemeris. This method can be successfully applied when the offset remains constant with time. This paper presents an alternative method of prediction based on a new accurate orbit determination procedure, which uses all the available positions of the TNO from the Minor Planet Center database plus sets of new astrometric positions from unpublished observations. The orbit determination is performed through a numerical integration procedure (NIMA), in which we develop a specific weighting scheme. The NIMA method was applied for 51 selected TNOs/Centaurs. For this purpose, we have performed about 2900 new observations during 2007-2014. Using NIMA, we succeed in predicting the stellar occultations of 10 TNOs and 3 Centaurs between 2013 and 2015. By comparing the NIMA and JPL ephemerides, we highlighted the variation of the offset between them with time. Giving examples, we show that the constant offset method could not accurately predict 6 out of the 13 observed positive occultations successfully predicted by NIMA. The results indicate that NIMA is capable of efficiently refine the orbits of these bodies. Finally, we show that the astrometric positions given by positive occultations can help to further refine the orbit of the TNO and consequently the future predictions. We also provide the unpublished observations of the 51 selected TNOs and their ephemeris in a usable format by the SPICE library.Comment: 12 pages, 9 figures, accepted in A&

Degradabilidade ruminal da fibra em detergente neutro e do nitrogênio insolúvel em detergente neutro da silagem de milho e do farelo de soja, em bovinos da Raça Nelore.

Empregou-se a técnica da degradação in situ, utilizando-se quatro animais Nelores com peso vivo médio de 520k e 36 meses de idade

Comparação de sistemas de avaliação de dietas para bovinos no modelo de produção intensiva de carne. Suplementação do pasto para vacas na estação seca.

Escanea

RAPD and ISSR markers in the evaluation of genetic divergence among accessions of elephant grass.

Considering the expected genetic variability of elephant grass (Pennisetum purpureum), due to its cultivation in different continents, we characterized and estimated the genetic divergences between 46 accessions of elephant grass with different edaphoclimatic adaptations, using RAPD and ISSR markers. We evaluated, comparatively, the consistency of the information achieved with these markers. Twenty-six RAPD and 25 ISSR primers were employed. The RAPD markers produced 185 bands, 72% of which were polymorphic, with a mean of 5.11 polymorphic bands per primer. The 25 ISSR starters produced 216 bands; 76% were polymorphic, with a mean of 6.56 polymorphic bands per primer. The correlation between the genetic distances achieved by the RAPD and ISSR markers was 0.76, which is highly significant by the Mantel test. Based on UPGMA grouping, considering the point of sudden change, five and six groups were formed for the data from the RAPD and ISSR markers, respectively. These markers provided partially concordant groups, indicating that these techniques can provide consistent information and consequently could be used in studies of genetic diversity among accessions

Protein synthesis and degradation gene SNPs related to feed intake, feed efficiency, growth, and ultrasound carcass traits in Nellore cattle.

We looked for possible associations of SNPs in genes related to protein turnover, with growth, feed efficiency and carcass traits in feedlot Nellore cattle. Purebred Nellore bulls and steers (N = 290; 378 ± 42 kg body weight, 23 months ± 42 days old) were evaluated for daily feed intake, body weight gain (BWG), gross feed efficiency, feed conversion ratio, partial efficiency of growth, residual feed intake (RFI), ultrasound backfat, rump fat, and ribeye area

Results of two multi-chord stellar occultations by dwarf planet (1) Ceres

We report the results of two multi-chord stellar occultations by the dwarf planet (1) Ceres that were observed from Brazil on 2010 August 17, and from the USA on 2013 October 25. Four positive detections were obtained for the 2010 occultation, and nine for the 2013 occultation. Elliptical models were adjusted to the observed chords to obtain Ceres' size and shape. Two limb fitting solutions were studied for each event. The first one is a nominal solution with an indeterminate polar aspect angle. The second one was constrained by the pole coordinates as given by Drummond et al. Assuming a Maclaurin spheroid, we determine an equatorial diameter of 972 $\pm$ 6 km and an apparent oblateness of 0.08 $\pm$ 0.03 as our best solution. These results are compared to all available size and shape determinations for Ceres made so far, and shall be confirmed by the NASA's Dawn space mission.Comment: 9 pages, 6 figures. Accepted for publication in MNRA

The first observed stellar occultations by the irregular satellite Phoebe (Saturn IX) and improved rotational period

peer reviewedWe report six stellar occultations by Phoebe (Saturn IX), an irregular satellite of Saturn, obtained between mid-2017 and mid-2019. The 2017 July 6 event was the first stellar occultation by an irregular satellite ever observed. The occultation chords were compared to a 3D shape model of the satellite obtained from Cassini observations. The rotation period available in the literature led to a sub-observer point at the moment of the observed occultations where the chords could not fit the 3D model. A procedure was developed to identify the correct sub-observer longitude. It allowed us to obtain the rotation period with improved precision compared to the currently known value from literature. We show that the difference between the observed and the predicted sub-observer longitude suggests two possible solutions for the rotation period. By comparing these values with recently observed rotational light curves and single- chord stellar occultations, we can identify the best solution for Phoebe's rotational period as 9.27365 ± 0.00002 h. From the stellar occultations, we also obtained six geocentric astrometric positions in the ICRS as realized by the Gaia DR2 with uncertainties at the 1-mas level