Diversity and symbiotic performance of peanut rhizobia from Southeast region of Brazil.

The use of peanut as a trap-plant for obtaining rhizobia may result in a high diversity of efficient isolates. This study aimed to evaluate the diversity and symbiotic efficiency of peanut rhizobia from the Southeastern region of Brazil. The bacteria were isolated from nodules of two genotypes in soils from the States of São Paulo and Rio de Janeiro, Brazil. The bacteria were authenticated and evaluated regarding to their symbiotic capacity. The rhizobial diversity was evaluated through their culture characteristics on yeast mannitol agar (YMA) culture media and by polymerase chain reaction Box- (PCR). Two selected isolates were characterized phenotypically regarding their capacity to solubilize phosphate, to grow on media with different concentrations of NaCI, pH's and incubation temperatures. For these the 16S rRNA gene sequencing and symbiotic efficiency using non-autoclaved soils were conducted. The majority of the obtained isolates showed rapid growth and acidified the culture medium. Analysis of the isolates through the Box-PCR revealed low similarity to the reference strain indicated for the culture and a large genetic variability of the obtained isolates. The isolates AM 01 and AM 07, which clustered with Bradyrhizobium and Rhizobium genus, respectively, showed a potential for evaluations and a means to recommend new rhizobia strains for peanut

Adsorption equilibrium of fructose, glucose and sucrose for cationic resins in the sodium and potassium form

Separation of glucose from mixtures of fructose and sucrose in molasses is a major challenge in industrial sugar chromatographic separations. The efficiency of a chromatographic process is largely dependent on the adsorbent used. Sulfonated poly(styrene-co-divinylbenzene) (PS-DVB) ion exchange resins are the most frequently used for sugars separation, generally in a cationic form. The cation will complex with the hydroxyl group of the sugar leading to a selective adsorption according to the orientation of the hydroxyl group. Thus, the conformation of the sugar determines its relative affinity for the resin and its distribution coefficient. Consequently, fructose forms the more stable sugar-cation complex being preferentially adsorbed in the resin followed by glucose. Sucrose interacts very weakly with the cation and is partially or totally excluded from the resin matrix owing to its larger molecular size. The separation process is usually carried out at high temperatures. However, this implies high energy costs and an elevated level of hydrolysis. Adsorption isotherms of the sugars present in a mixture are a very important parameter for the selection of the adsorbent to be used in the chromatographic separation. Therefore, in this study, the adsorption isotherms of glucose, fructose and sucrose were determined for two resins of PS-DVB in the sodium and potassium forms. Potassium and sodium are the most recommended cations for the separation of sucrose, fructose and glucose. The sodium and potassium resins matrix used in this work consist in meshes of 500-600 μm and 290-350 μm, respectively. Solutions with single and multi-component mixtures of the three sugars were used at 25ºC and 40ºC. A static method was used to determine the equilibrium adsorptions: 3.5 mL of solutions with different sugar concentrations were added to a known amount of adsorvent. The mixture was held for 8h under agitation and a fixed temperature and a final concentration in equilibrium with resin was determined by HPLC. As expected, the results achieved showed that for all the conditions, fructose is the most adsorved sugar followed by glucose and sucrose. For both resins, the increase of temperature conducted to a decrease on the adsorption constant for all the sugars in the mono-component mixtures. Nevertheless, the adsorption in multi-component mixtures was not significantly affected by the temperature in the sodium resin, and regarding the potassium resin only a small increase in the adsorption was observed. Multi-component mixtures at 25 ºC showed a decrease in the adsorption as compared with mono-component mixtures. However, at 40ºC the adsorption observed for the multi-component mixtures was higher than the observed for the mono-component ones. The sugars that demonstrated lower selectivity values were fructose/glucose since these sugars have the same molecular weight. Sucrose/fructose selectivity showed a higher value when compared with sucrose/glucose because of the complex formed between fructose and the resin. This profile was found for both resins used, regardless of temperature. Selectivity of both resins decreased with the increase of the temperature values. Nevertheless, the selectivity obtained for the potassium resin was higher as compared to the selectivity obtained for the sodium resin. In sum, potassium resin appears to be the most suitable adsorvent and an operational temperature of 25 ºC showed the best results

Performance reprodutiva de cabras Alpinas e Saanen tratadas com gonadotrofina coriônica humana no quinto e vigésimo dia pós-serviço durante a estação de monta induzida.

Resumo: Objetivou-se com este estudo avaliar o efeito da administração da gonadotrofina coriônica humana (hCG) no quinto e vigésimo dia do ciclo estral sobre a taxa de gestação de cabras da raça Alpina e Saanen, durante a estação de acasalamento induzida por fotoperíodo artificial. Foram utilizados 151 animais, sendo 85 da raça Alpina e 66 da Saanen. Do total, 110 foram submetidas à monta natural e 41 à inseminação artificial. Após a identificação do estro e acasalamento ou inseminação, as fêmeas foram divididas ao acaso, em dois tratamentos:T1 = 1mL de solução salina intramuscular no quinto e vigésimo dia após a cobertura e T2 = 250 UI de hCG no mesmo esquema. A gestação foi verificada por ultra-sonografia trans-retal aos 35 dias após a cobertura. Não houve efeito da administração do hCG sobre a taxa de gestação, taxa de parição e número de fetos nascidos (P>0,05). As diferentes raças empregadas neste estudo também não influenciaram os parâmetros estudados. Independentemente da aplicação do hCG, houve decréscimo significativo na taxa de gestação quando se empregou a inseminação artificial (P0,05) of the hCG administration on gestation rate, parturition rate and number of born foetus. The difference breeds used in this study didn?t influence the studied parameters. Independently of the application of hCG, there was significant decrease in the gestation rate when the artificial insemination was used (P <0,05). Under the conditions of this study, the hCG administration in the fifth and twentieth day of the estrous cycle estral doesn?t present any effect on gestation rate of goats of the Alpine and Saanen breeds

A VSA search for the extended Sunyaev-Zel'dovich Effect in the Corona Borealis Supercluster

We present interferometric imaging at 33 GHz of the Corona Borealis supercluster, using the extended configuration of the Very Small Array. A total area of 24 deg^2 has been imaged, with an angular resolution of 11 arcmin and a sensitivity of 12 mJy/beam. The aim of these observations is to search for Sunyaev-Zel'dovich (SZ) detections from known clusters of galaxies in this supercluster and for a possible extended SZ decrement due to diffuse warm/hot gas in the intercluster medium. We measure negative flux values in the positions of the ten richest clusters in the region. Collectively, this implies a 3.0-sigma detection of the SZ effect. In the clusters A2061 and A2065 we find decrements of approximately 2-sigma. Our main result is the detection of two strong and resolved negative features at -70+-12 mJy/beam (-157+-27 microK) and -103+-10 mJy/beam (-230+-23 microK), respectively, located in a region with no known clusters, near the centre of the supercluster. We discuss their possible origins in terms of primordial CMB anisotropies and/or SZ signals related to either unknown clusters or to a diffuse extended warm/hot gas distribution. Our analyses have revealed that a primordial CMB fluctuation is a plausible explanation for the weaker feature (probability of 37.82%). For the stronger one, neither primordial CMB (probability of 0.33%) nor SZ can account alone for its size and total intensity. The most reasonable explanation, then, is a combination of both primordial CMB and SZ signal. Finally, we explore what characteristics would be required for a filamentary structure consisting of warm/hot diffuse gas in order to produce a significant contribution to such a spot taking into account the constraints set by X-ray data.Comment: 16 pages, 10 figures. Accepted in MNRA

Morphophysiological and biochemical changes in Enterolobium contortisiliquum seedlings under abiotic stresses

Among the main problems that compromise the development of forest species are water and salt stresses, especially in the early stages of development, when seedlings are more sensitive. Thus, the objective of this study was to evaluate the morphophysiological and biochemical changes in Enterolobium contortisiliquum seedlings subjected to abiotic stresses. The experimental design was randomized complete blocks (RCB), composed of fi ve treatments, with four replicates, and the experimental plot consisted of twenty plants. From the 31st day after sowing, when the seedlings reached approximately 15 cm in height, they began to receive the treatments, which consisted of different levels of electrical conductivity of irrigation water (0.3; 2; 4; 6; 8 dS m-1) for salt stress and periods of water restriction (0; 4; 8; 12 and 16 days without irrigation) for water stress. The traits evaluated were: plant height, root length, stem diameter, number of leaves, leaf area, total dry matter, Dickson quality index, height/shoot dry matter ratio, total soluble sugars, starch, total amino acids and proline. An increase in the electrical conductivity of irrigation water and days without irrigation compromised the development of E. contortisiliquum seedlings, which was intensified from 2 dS m-1 and four days without irrigation for salt and water stresses, respectively. The mechanism of survival of E. contortisiliquum to abiotic stresses involves reduction in the growth and quality of seedlings, with activation of biochemical defense mechanisms of the species

The Spectroscopic Orbit of the Planetary Companion Transiting HD209458

We report a spectroscopic orbit with period P = 3.52433 +/- 0.00027 days for the planetary companion that transits the solar-type star HD209458. For the metallicity, mass, and radius of the star we derive [Fe/H] = 0.00 +/- 0.02, M = 1.1 +/- 0.1 solar masses, and R = 1.3 +/- 0.1 solar radii. This is based on a new analysis of the iron lines in our HIRES template spectrum, and also on the absolute magnitude and color of the star, and uses isochrones from four different sets of stellar evolution models. Using these values for the stellar parameters we reanalyze the transit data and derive an orbital inclination of i = 85.2 +/- 1.4 degrees. For the planet we derive a mass of Mp = 0.69 +/- 0.05 Jupiter masses, a radius of Rp = 1.54 +/- 0.18 Jupiter radii, and a density of 0.23 +/- 0.08 grams per cubic cm.Comment: 11 pages, 1 figure, 2 tables, LaTex, aastex, accepted for publication by ApJ Letter