Effect of irrigation level on yield and bioactive amine content of American lettuce

The influence of four levels (25, 50, 75 and 100%) of Class A pan evaporation replenishment (PER) on the marketable yield and bioactive amine content of American lettuce (Lactuca sativa cv Lucy Brown) grown under greenhouse conditions and drip irrigation was investigated. Lettuce was planted in 1.20 m x 2.10 m plots in a completely randomised block design with three replications. Lowest fresh head weights and diameters were obtained at 25% PER. Highest marketable yields and fresh head weights were obtained at 100% PER; however, no significant difference was observed when using 75% PER. The fresh head diameter was smaller only when using 25% PER. Four amines were detected in lettuce grown under 100% PER, with a total content of 7.60 mg kg(-1). Spermidine was the prevalent amine, followed by putrescine, cadaverine and agmatine. Higher spermidine and cadaverine levels were observed in the outer layers of leaves than in the intermediate and inner leaves. The contents of every amine except agmatine increased with water stress; however, a significant difference was observed only between 100 and 25% PER. The concentrations of accumulated putrescine were not capable of negatively affecting the sensory quality of the lettuce. (c) 2005 Society of Chemical Industry.

Microtensile bond strength of a resin cement to feldpathic ceramic after different etching and silanization regimens in dry and aged conditions

Objectives. This study evaluated the durability of bond strength between resin cement and a feldspathic ceramic submitted to different etching regimens with and without silane coupling agent application.Methods. Thirty-two blocks (6.4 mm x 6.4 mm x 4.8 mm) were fabricated using a microparticulate feldspathic ceramic (Vita VM7), ultrasonically cleaned with water for 5 min and randomly divided into four groups, according to the type of etching agent and silanization method: method 1, etching with 10% hydrofluoric (HF) acid gel for I min + silanization; method 2, HF only; method 3, etching with 1.23% acidulated phosphate fluoride (APF) for 5 min + silanization; method 4, APF only. Conditioned blocks were positioned in their individual silicone molds and resin cement (Panavia F) was applied on the treated surfaces. Specimens were stored in distilled water (37 degrees C) for 24 h prior to sectioning. After sectioning the ceramic-cement blocks in x- and Y-axis with a bonded area of approximately 0.6 mm(2), the microsticks of each block were randomly divided into two storage conditions: Dry, immediate testing; TC, thermal cycling (12,000 times) + water storage for 150 d, yielding to eight experimental groups. Microtensile bond strength tests were performed in universal testing machine (cross-head speed: 1 mm/min) and failure types were noted. Data obtained (MPa) were analyzed with three-way ANOVA and Tukey's test (alpha = 0.05).Results. Significant influence of the use of silane (p < 0.0001), storage conditions (p = 0.0013) and surface treatment were observed (p = 0.0014). The highest bond strengths were achieved in both dry and thermocycled conditions when the ceramics were etched with HF acid gel and silanized (17.4 +/- 5.8 and 17.4 +/- 4.8 MPa, respectively). Silanization after HF acid gel and APT treatment increased the results dramatically (14.5 +/- 4.2-17.4 +/- 4.8 MPa) compared to non-silanized groups (2.6 +/- 0.8-8.9 +/- 3.1 MPa) where the failure type was exclusively (100%) adhesive between the cement and the ceramic.Significance. Silanization of the feldspathic ceramic surface after APF or HF acid etching increased the microtensile bond strength results significantly, with the latter providing higher results. Long-term thermocycling and water storage did not decrease the results in silanized groups. (C) 2006 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Temperature rise in cavities prepared by high and low torque handpieces and Er : YAG laser

Objective The aim of this study was to compare intrapulpal temperature increases produced by a high-speed high-torque (speed-increasing) handpiece, a high-speed low-torque handpiece (air-turbine) and an Er: YAG (Erbium: Yttrium-Aluminum-Garnet) laser. Subject and methods Thirty bovine incisors were reduced to a dentine thickness of 2.0 mm. Class V preparations were prepared to a depth of 1.5 mm, measured with a caliper or by a mark on the burs. A thermocouple was placed inside the pulp chamber to determine temperature increases (C). Analysis was performed on the following groups (n = 10) treated with: G1, low-torque handpiece; G2, high-torque handpiece; and G3, Er: YAG laser (2.94 mu m at 250 mJ/4 Hz), all with water cooling. The temperature increases were recorded with a computer linked to the thermocouples. Results The data were submitted to ANOVA and Tukey statistical test. The average temperature rises were: 1.92 +/- 0.80 degrees C for G1, 1.34 +/- 0.86 degrees C for G2, and 0.75 +/- 0.39 degrees C for G3. There were significant statistical differences among the groups (p = 0.095). All the groups tested did not have a change of temperature that exceeds the threshold of 5.5 degrees C. Conclusion Temperature response to the low and high torque handpieces seemed to be similar, however the Er: YAG laser generated a lower temperature rise.

Degradação ruminal de silagem de capim-elefante com adição de vagem de algaroba triturada

This research was carried out to evaluate the ruminal degradation of dry matter (DM), crude protein (CP) and neutral detergent fiber (NDF) of silages of elephant grass (Pennisetum purpureum) cutting in 70; 90 and 110 days after regrowth with inclusion of 0; 5; 10 and 15% of mesquite (Prosopis juliflora) meal, based on natural matter in a completely randomized design, in split plot arrangement. Samples of silages were incubated in the rumen of two Jersey cows for 3; 6; 12; 24; 48; 72 and 96 h, and the bags at time "zero" were only washed with water to determine the soluble fraction. There was not interaction (P> 0.05) incubation time x inclusion of mesquite pods x cutting age of the grass for DM degradability, there was only interaction (P <0.05) between these factors for CP and NDF degradability. The most effective DM degradability (42.54%) was observed for 15% inclusion of mesquite pods. The effective CP degradability was higher (69.04%) for elephant grass silage with 70 days after regrowth with 15% of mesquite pods. The inclusion of mesquite pods in elephant grass silages improve DM, CP and NDF degradability, while increment of the age after regrowth result in reduction of this parameters.

Simultaneous solidification of two catalyst wastes and their effect on the early stages of cement hydration

Two catalyst wastes (RNi and RAI) from polyol production were considered as hazardous, due to their respective high concentration of nickel and aluminum contents. This article presents the study, done to avoid environmental impacts, of the simultaneous solidification/stabilization of both catalyst wastes with type II Portland cement (CP) by non-conventional differential thermal analysis (NCDTA). This technique allows one to monitor the initial stages of cement hydration to evaluate the accelerating and/or retarding effects on the process due to the presence of the wastes and to identify the steps where the changes occur. Pastes with water/cement ratio equal to 0.5 were prepared, into which different amounts of each waste were added. NCDTA has the same basic principle of Differential Thermal Analysis (DTA), but differs in the fact that there is no external heating or cooling system as in the case of DTA. The thermal effects of the cement paste hydration with and without waste presence were evaluated from the energy released during the process in real time by acquiring the temperature data of the sample and reference using thermistors with 0.03 A degrees C resolution, coupled to an analog-digital interface. In the early stages of cement hydration retarding and accelerating effects occur, respectively due to RNi and RAl presence, with significant thermal effects. During the simultaneous use of the two waste catalysts for their stabilization process by solidification in cement, there is a synergic resulting effect, which allows better hydration operating conditions than when each waste is solidified separately. Thermogravimetric (TG) and derivative thermogravimetric analysis (DTG) of 4 and 24 h pastes allow a quantitative information about the main cement hydrated phases and confirm the same accelerating or retarding effects due to the presence of wastes indicated from respective NCDTA curves.

Manejo de irrigação e nitrogênio no feijoeiro comum cultivado em sistema plantio direto

With technological innovations, such as irrigation, the bean has been grown by producers who have the most varied levels of technology that, in suitable times, allows the planting great success in grain yield. The aim of this study was to evaluate the response of the dry bean to different managements of irrigation and nitrogen fertilization with no-tillage system, in Aquidauana - MS, Brazil. The experiment was conducted at the Universidade Estadual de Mato Grosso do Sul (UEMS), with the soil of the area classified as Alfisol, using the bean crop "Perola" sown on June 30, 2007. The experimental design was a randomized block split-plot consisting of three blocks and two replications within each block. The plots were composed of three management of irrigation, by the Class A pan method, using Hargreaves-Samani equation, and management by tensiometry (-40 kPa), with water replacement of 16.5 mm for all irrigation plots. The subplots consisted on four rates of nitrogen fertilization (0; 50; 100 and 150 kg ha(-1)), in which the nitrogen source was urea. It was concluded that the irrigation management through the Class A pan and Hargreaves-Samani equation conduced to higher grain yields of bean, 3031.11 and 3005.02 kg ha(-1) respectively.

Biogeography of common dolphins (genus Delphinus) in the Southwestern Atlantic Ocean

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Vermiculita como substrato para o teste de germinação de sementes de barbatimão

The objective of this research was to evaluate the use of vermiculite as a substrate for the germination test of 'barbatimao' seeds and to establish what would be the best granulometry and the best moisture intensity to germinate 'barbatimao' seeds. Four replications of 50 seeds were previously scarified with H(2)SO(4) for 60 minutes. Afterwards, the following germination substrates were evaluated: paper rolls moistened with water equivalent to 2.5 times the weight of the dry paper (control); micron, super thin, thin and average sized vermiculite moistened with 0.5, 1.0, 1.5 and 2.0 times the weight of the dry paper. The germination temperature was 30 C. The percentage of normal seedlings was obtained seven days after sowing (first count) and, then, weekly (up to 28 days). Average time and relative distribution of germination were calculated. It was concluded that the germination of 'barbatimao' seeds can be carried out with either fine vermiculite moistened with water equivalent to 2.0 times the weight of the dry paper or average sized substrate moistened with water equivalent to 0.5 to 2.0 times the weight of dry paper. These treatments resulted in higher and faster germination (21 days), similarly to the paper roll method.

Estabilidade física de péletes protegidos por diferentes produtos impermeabilizantes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of atmosphere on the sintering and grain growth of tin oxide

High purity SnO 2 powder (>99.9%) was compacted in cylindrical pellets and sintered in atmospheres of dry argon, argon with water vapor, oxygen and CO 2 using 10 °C/min up to 1200 °C or isotherms in the range of 1000 to 1200 °C. Time, temperature and sintering atmosphere have large influence on grain growth and low influence on densification of this oxide. Surface diffusion is the dominant mechanism up to 1200 °C and evaporation-condensation is dominant above 1200 °C. The maximum linear shrinkage observed was about 2.0% and attributed to structural rearrangement of particles due to high capillary stresses developed with neighboring particles. © 1999 Trans Tech Publications.

Phenology of a dioecious population of Batrachospermum delicatulum (Batrachospermales, Rhodophyta) in a stream from southeastern Brazil

The seasonal dynamics of a dioecious population of Batrachospermum delicatulum (Skuja) Necchi and Entwisle was evaluated biweekly during the growth period of the macroscopic gametophyte, from late autumn (May) to early spring (October) in a third-order stream from the northeast region of Sao Paulo State, southeastern Brazil (20°43'S, 49°13'W). The population fluctuated throughout the study period in terms of percentage cover, frequency and chlorophyll content. Percent cover and frequency showed a clear pattern with the lowest values at the initial and final stages of the growth period and the highest in July-August (winter). Gametophyte growth was associated with high illumination and low temperature, which agrees with most observations on Batrachospermales in stream environments. Relatively wide variations in reproductive characteristics were observed during the growth period, which were not correlated with percentage cover, frequency and chlorophyll content. The phenologic pattern observed in this population was characterized by a synchronic development of female/male plant ratio with the number of spermatangia per plant resulting in. (i) a higher proportion of fertilized (carposporophytic) plants associated with more male plants; (ii) higher fertilization rates during the periods with higher production of spermatangia per plant; and (iii) higher production of spermatangia per plant when the population had more male plants. These characteristics were largely associated with water temperature and ion content. In terms of reproductive success, the population studied can be regarded as highly efficient, considering the relatively low proportion of male to female plants and high fertilization rates. These data are consistent with a hypothesis to explain high fertilization rates in dioecious species in lotic habitats consisting of outcrossing among adjacent plants with intermingled male and female branches within an algal cluster. Efficient reproductive strategies have been reported in dioecious, monoecious and even mixed populations of B. delicatulum and can be interpreted as adaptations to successfully colonize streams with different characteristics.

Nanoparticles of La1-xSrxMnO3 compounds

A nanoparticles of La1-xSrxMnO3 were synthesized using homogenous coprecipitation method. The precipate was washed with water and dried at 80 °C. The samples were characterized by X-ray powder diffraction, transmission electron microscopy (TEM) and electrical resistivity as a function of temperature. The TEM results show that the particle size is in the nanometer scale.

Glutathione S-transferase activity in acetochlor, atrazine and oxyfluorfen metabolization in maize (Zea mays L.), sorghum (Sorghum bicolor L.) and wheat (Triticum aestivum L.) (Poaceae)

This experiment was conducted to evaluate the acetochlor, atrazine and oxyfluorfen herbicides plant selectivity, in relation to glutathione S-transferase activity (GST) in maize (Zea mays L.), sorghum (Sorghum bicolor L.) and wheat (Triticum aestivum L) (Poaceae) plants. GST activity was detected 24, 48 and 72 hours after treatment applications. The experiment's treatments consisted of spraying plants with water (control), acetochlor (3 L.ha -1), atrazine (4 L.ha -1) and oxyfluorfen (1 L.ha -1). The highest GST activities were observed in presence of acetochlor, mainly at 48 hours after treatment. These increments were 105, 148 and 118% when compared to maize, sorghum and wheat control groups, respectively. It is suggested that the GST may have a role in acetochlor degradation and it may be a reason for this herbicide's selectivity in these crops.

Use of 37% carbamide peroxide in the walking bleach technique: A case report

Dental bleaching represents an effective, conservative, and relatively low-cost method for improving the appearance of discolored pulpless teeth. Among the bleaching techniques, the walking bleach technique with sodium perborate associated with water or hydrogen peroxide stands out because of its esthetic results and safety. A modified walking bleach technique with the use of 37% carbamide peroxide as the bleaching agent is presented. Additionally, the adverse effects of dental bleaching in the following restorative procedures are discussed, showing the advantages with the use of 37% carbamide peroxide.

Optimization of neutral hydrolysis reaction of post-consumer PET for chemical recycling

The neutral hydrolysis reaction of post-consumer poly(ethylene terephthalate) in solid state was studied through the reaction of the polymer with water at the molar ratio 1:91 with autogenous pressure. Two sizes of post-consumer PET flakes and temperatures of 135 °C, 170°C and 205°C with pressures of 4.0 atm, 7.5 atm and 13.5 atm, respectively, were considered. With reaction time equal to 6h, the method reached 99% depolymerization at 205°C, 8.2% at 170 °C and 1.7% at 135°C. The reaction extension was measured by separating the terephthalic acid formed in the process and calculating by gravimetry how much material could still be reacted. Through the viscosimetry of diluted, solutions and the counting of carboxylic end groups in the remaining material from the gravimetric assay, it was possible to suggest that the reaction occurs randomly and in the whole volume of the polymeric particle and not solely on the surface. The terephthalic acid obtained and then purified was characterized by elemental analysis, magnetic nuclear resonance, size and panicle size distribution and spectrophotometry in the visible spectrum, and it was similar to the petrochemical equivalent, with purity recorded in carbon base equal to 99.9%.