Avaliação do capim-elefante (Pennisetum purpureum Schum.) cultivar taiwan A-148, ensilado com diferentes técnicas de redução de umidade

O objetivo deste trabalho foi avaliar o efeito de diferentes técnicas de redução de umidade sobre a composição química, digestibilidade in vitro da matéria seca (DIVMS) e degradação ruminal da matéria seca da silagem de capim-elefante (Pennisetum purpureum Schum.) cv. Taiwan A-148. Os tratamentos (A, Controle; B, 20,0; C, 30,0; D, 40,0% de sabugo de milho; E, emurchecimento por 12 horas; F, emurchecimento por 24 horas; e G, esmagamento + emurchecimento por 24 horas) foram distribuídos em delineamento inteiramente casualizado com três repetições. Os tratamentos da silagem B e E não foram eficientes em reduzir a umidade excessiva da forragem. O emurchecimento por 24 horas aumentou o teor de MS, sem influir no teor de PB e na DIVMS. Os tratamentos C e D favoreceram o desenvolvimento da população de clostrídeos, aumentaram a concentração de N-NH3 e reduziram a concentração de ácido lático e a DIVMS das silagens. O tratamento G aumentou o teor de MS e reduziu a concentração de N-NH3 e DIVMS. A adiçao de sabugo de milho (tratamentos B, C e D) reduziu a degradação ruminal da MS das silagens. O sabugo de milho reduziu a umidade, mas apresentou efeitos negativos na qualidade da silagem, enquanto o esmagamento e/ou emurchecimento foram procedimentos que mostraram bons resultados em relação à conservação do material ensilado.

The Pediatric Rheumatology International Trials Organization American-College-of-Rheumatology provisional criteria for the evaluation of response to therapy in juvenile systemic lupus erythematosus: Prospective validation of the definition of improvement

Objective. To use the Pediatric Rheumatology International Trials Organization (PRINTO) core set of outcome measures to develop a validated definition of improvement for the evaluation of response to therapy in juvenile systemic lupus erythematosus (SLE).Methods. Thirty-seven experienced pediatric rheumatologists from 27 countries, each of whom had specific experience in the assessment of juvenile SLE patients, achieved consensus on 128 patient profiles as being clinically improved or not improved. Using the physicians' consensus ratings as the gold standard measure, the chi-square, sensitivity, specificity, false-positive and false-negative rates, area under the receiver operating characteristic curve, and kappa level of agreement for 597 candidate definitions of improvement were calculated. Only definitions with a kappa value greater than 0.7 were retained. The top definitions were selected based on the product of the content validity score multiplied by its kappa statistic.Results. The definition of improvement with the highest final score was at least 50% improvement from baseline in any 2 of the 5 core set measures, with no more than 1 of the remaining worsening by more than 30%.Conclusion. PRINTO proposes a valid and reproducible definition of improvement that reflects well the consensus rating of experienced clinicians and that incorporates clinically meaningful change in core set measures in a composite end point for the evaluation of global response to therapy in patients with juvenile SLE. The definition is now proposed for use in juvenile SLE clinical trials and may help physicians to decide whether a child with SLE responded adequately to therapy.

Improvement in relaxation response in corpus cavernosum from trained rats

Objectives. To evaluate the contractile and relaxing responses in rat corpus cavernosum (RCC) from rats after 8 weeks of run training, because erectile function is highly dependent on nitric oxide (NO) from nitrergic fibers or endothelium. Physical activity enhances NO production and improves endothelial function, with beneficial effects on cardiovascular disease.Methods. The training program consisted of 8 weeks of run training, 5 days/wk, and each session lasted 60 minutes. The RCC was isolated, and concentration-response curves to NO, acetylcholine, sodium nitroprusside, phenylephrine, and endothelin were obtained. The excitatory and inhibitory effects of electrical field stimulation (2 to 32 Hz) were also evaluated.Results. NO (0.1 to 100 muM) and sodium nitroprusside (0.01 to 1000 muM) produced a relaxing effect in RCC in a dose-dependent manner, with the maximal responses to NO (control 62% +/- 4%, trained 88% +/- 3%) and sodium nitroprusside (control 83% +/- 3%, trained 95% +/- 2%) significantly enhanced after 8 weeks of run training. However, acetylcholine-induced relaxations were not affected by exercise. Similarly, electrical field stimulation-induced relaxations were significantly increased in RCC from trained rats at 2 Hz (control 2.4% +/- 0.3%, trained 4.2% +/- 0.5%) and 4 Hz (control 5.3% +/- 1.2%, trained 12.5% +/- 1.7%). The contractile sensitivity of RCC to phenylephrine (0.01 to 100 AM) and endothelin (0.01 to 100 nM) was not modified by training exercise.Conclusions. Our findings suggest that run training enhances functional responses in rat RCC that involves increases in the NO-cyclic guanosine monophosphate signaling pathway by endothelium-independent mechanisms that is not accompanied by changes in contractile sensitivity. (C) 2004 Elsevier B.V.

Improvement of the dielectric and ferroelectric properties in superlattice structure of Pb(Zr,Ti)O-3 thin films grown by a chemical solution route

Making heterolayered perovskite materials constitutes an approach for the creation of better dielectric and ferroelectric properties. In the experiment reported here, heterolayered PZT40/PZT60 films were grown on Pt/Ti/SiO2/Si (100) by a chemical solution deposition. The dielectric constant of the heterolayered thin film was significantly enhanced compared with that of pure PZT40 and PZT60 thin films. A dielectric constant of 701 at 100 kHz was observed for a stacking periodicity of six layers having a total thickness of 150 nm. The heterolayered film exhibited greater remanent polarization than PZT60 and PZT40 films. The values of remanent polarization were 7.9, 18.5, and 31 muC/cm(2), respectively, for pure PZT60, PZT40, and heterolayered thin films, suggesting that the superior dielectric and ferroelectric properties of the heterolayered thin film resulted from a cooperative interaction between the ferroelectric phases made from alternating tetragonal and rhombohedral phases of PZT, simulating the morphotropic phase boundary of this system. (C) 2004 American Institute of Physics.

Use of survival analysis as a tool for the genetic improvement of age at first conception in Nellore cattle

Restricted breeding seasons in beef cattle lead to censoring of reproductive data. In this paper, age at first conception (AFC) of Nellore females exposed to the sires for the first time between 11 and 16 months of age, was studied aiming to verify the possibility of genetically advance sexual precocity using a survival model. The final data set contained 6699 records of AFC in days. Records of females that did not calve in the next year following exposure to the sire were considered censored (77.5% of total). The model used was a Weibull mixed survival model including effects of contemporary groups, period (fixed) and animal (random). The effect of the contemporary groups on AFC was important (p < 0.01). Heritabilities were 0.51 and 0.76 in logarithmic and original scales respectively. Results indicate that it is possible to genetically advance sexual precocity, using the outcome of survival analysis of AFC as selection criterion. They also suggest that improvements of the environment could advance sexual precocity too, thus an adequate pregnancy rate for farmers could quickly be achieved.

Avaliação química e microbiológica do capim-elefante, cultivar taiwan A-148, preparado para ensilagem com bagaço de cana-de-açúcar

Elephant grass (Pennisetum purpureum Schum.), was cut after nine weeks of regrowth and mixed with 10, 20, 30 and 40% of sugar cane bagasse (SCB) with the objective of reducing the moisture content of the ensiled mass. Willing of the grass for eight and twelve hours was used as a comparative treatment. Initial dry matter of the grass (13%) increased in the forage mass to 17, 23, 24 and 27% by the addition of 10, 20, 30 and 40% of the SCB respectively. Wilting for eight and twelve hours increased initial dry matter to 18 and 24% respectively. Buffering capacity of elephant grass was reduced by the addition of 40% of SCB. Clostridium spores in the ensiled mass tended to be lower due to the effect of the two pre-treatments. Initial dry matter and number of spores of Clostridium were negatively correlated although without statistic significance. The addition of SCB reduced (P < 0.0.5) soluble carbohydrates and crude protein percentages in the ensiled mass. It was concluded that wilting is more effective than the addition of SCB in the practice of ensiling elephant grass.

Improvement of the Mo/TiO2-Al2O3 catalyst by the control of the sol-gel synthesis

Traditional hydrotreating catalysts are constituted by molybdenum deposited on Al2O3 promoted by nickel and phosphorous. Several studies have shown that TiO2-Al2O3 mixed oxides are excellent supports for the active phases. Results concerning the preparation, characterization and testing of molybdenum catalyst supported on titania-alumina are presented. The support was prepared by sol-gel route using titanium and aluminum isopropoxides, the titanium one chelated with acetylacetone (acac) to promote similar hydrolysis ratio for both the alcoxides. The effect of nominal molar ratio [Ti]/[Ti+Al] on the microstructural features of nanometric particles was analyzed by X-Ray Diffraction, N-2 Adsorption Isotherms and Transmission Electron Microscopy. The catalytic activity of Mo impregnated supports was evaluated using the thiophene hydrodesulfurization at different temperatures and atmospheric pressure. The pores size distribution curve moves from the micropores to the mesopores by increasing the Ti contents, allowing the fine tuning of average size from 2.5 to 6 nm. Maximal (367 m(2).g(-1)) and minimal (127 m(2).g(-1)) surface area were found for support containing [Ti]/[Ti+Al] ratio equal to 0.1 and 1, respectively. The good mesopore texture of alumina-titania support with [Ti]/[Ti+Al] molar ratio between 0.3 and 0.5 was found particularly valuable for the preparation of well dispersed MoS2 active phase, leading to HDS catalyst with somewhat higher activity than that prepared using a commercial alumina support.

Botutatu: nova cultivar de amendoim (Arachis hypogaea L.)

Botutatu is a new released peanut cultivar, selected from the Brazilian cultivar Tatu by progeny testing. It belongs to Valencia type and has similar characteristics of cultivar Tatu, differing from the late by being 23.7% superior in pod yield.

Improvement of Aspergillus niger glucoamylase thermostability by directed evolution

Directed evolution was used to improve the thermostability of Aspergillus niger glucoamylase (GA) expressed in Saccharomyces cerevisiae. A starch-plate assay developed to screen GA mutants for thermostability gave results consistent with those of irreversible thermoinactivation kinetic analysis. Several thermostable multiply-mutated GAs were isolated and characterized by DNA sequencing and kinetic analysis. Three new GA mutations, T62A, T290A and H391Y, have been identified that encode GAs that are more thermostable than wild-type GA, and that improve thermostability cumulatively. These individual mutations were combined with the previously constructed thermostable site-directed mutations D20C/A27C (forming a disulficle bond), S30P, and G137A to create a multiply-mutated GA designated THS8. THS8 GA is substantially more thermostable than wild-type GA at 8OoC, with a 5.1 kJ/mol increase in the free energy of therrnoinactivation, making it the most thermostable Aspergillus niger GA mutant characterized to date. THS8 GA and the singly-mutated GAs have specific activities and catalytic efficiencies (k(cat)/K-m) similar to those of wild-type GA.

Improvement of the ferroelectric properties of ABO(3) (A= Pb, Ca, Ba; B=Ti, Zr) films

High-quality ABO(3)/LaNiO3 (A = Ph, Ca, Ba; B = Ti, Zr) hetero structures have been grown on LaAlO3 (1 0 0) substrate by the chemical solution deposition method and crystallized by a microwave oven technique. The structural, morphological and electric properties were characterized by means of X-ray diffraction (XRD), atomic force microscope (AFM), and dielectric and ferroelectric measurements. XRD patterns revealed single-phase polycrystalline and oriented thin films whose feature depends on the composition of the films. The AFM surface morphologies showed a smooth and crack-free surface with the average grain size ranging from 116 to 300 nm for both LaNiO3 electrode and the ferroelectric films. Dielectric measurements on these samples revealed dielectric constants as high as 1800 at frequency of 100 KHz. Such results showed that the combination of the chemical solution method with the microwave process provides a promising technique to grow high-quality thin films with good dielectric and ferroelectric properties. (c) 2005 Elsevier Ltd. All rights reserved.

Improvement of the chemical resistance of zirconium fluoride glasses coated with a Tiron (R) modified tin oxide layer prepared by the sol-gel process

In order to improve the chemical resistance of zirconium fluoride glass a protective transparent SnO2 layer was deposited by the solgel dip-coating process in the presence of Tiron (R) as particle surface modifier agent. After water immersion for different periods of time, both coated and non-coated fluoride glasses were analyzed by scanning electron microscopy, mass loss evaluation, infrared spectroscopy and X-ray photoelectron spectroscopy. In contrast to the effects occurring for non-coated glass, where the surface undergoes a rapid selective dissolution of the most soluble species, the results for the SnO2-coated glass showed that the filling of the film nanopores by dissolved glass material results in a hermetic barrier protecting the glass surface. The selective glass dissolution was confirmed by liquid chromatography measurements of the etching solution after each exposure time. (c) 2006 Elsevier B.V. All rights reserved.

A novel technique to produce polygenic resistance to anthracnose in Stylosanthes capitata

An improved cultivar, based on 17 genotypes of S. capitata and six of S.macrocephala, was developed at the wEmbrapa Beef Cattle Research Center, Campo Grande, Brazil. The aim was to create durable, race non-specific resistance to anthracnose controlled by polygenic factors. A mass hybridisation technique was employed to produce a high degree of genetic diversity and sizeable quantities of seed of hybrid-derived progenies of Brazilian and Venezuelan genotypes of S. capitata. Outcrossing resulted in a significant improvement in the forage production of progeny of Venezuelan accessions. The multicross was evaluated in multilocational trials, each representing a large tract of country in the Cerrados ecosystem along a north-south transect from lat.6degrees S to 20degrees S. The genetic shift that occurred in S. capitata was a key element in the formation of the new cultivar. It is a complex mixture of two species, and a recombination of much desired forage traits of Brazilian x Venezuelan genotypes, high forage and seed yields coupled with anthracnose resistance. The new cultivar with its diverse genetic make-up has a wide application in the acid-soil savannas of tropical America. It was released by Embrapa for the Cerrados in 2000.

Density improvement of the sol-gel dip-coated SnO2 films by chemical surface modification

We compare the effect of organic (Tiron (R)) and inorganic (Mn(11)) additives on the low temperature (< 600 degrees C) densification of the sol-gel dip-coated SnO2 films. The structural and compositional properties of the samples were investigated by X-ray reflectometry (XRR), X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS). The results suggest that the replacement of hydroxyl groups at the particle surface by Tiron (R) reduces the level of agglomeration of the sol, increasing the particles packing and the apparent density of the coatings. Undoped and Mn-doped films drawn from a Tiron (R) containing suspension show after firing at 500 degrees C a porosity reduction of 12 and 8.6%, respectively. The porosity decrease is less pronounced (4.3%) for the film without additives. Both XAS and XPS data show the presence of trivalent manganese. The formation of a non-homogeneous solid solution characterised by the presence of Mn(111) replacing tin atom near to the crystallite surface was evidenced by XAS. Additionally, XPS results reveal the presence of metallic Sn at the surface of films containing Tirono. (c) 2005 Elsevier Ltd. All rights reserved.