Characterization of lubricating oil using ultrasound

This paper presents an ultrasonic method to measure small concentrations of water in lubricating oil. It uses an ultrasonic measurement cell composed by a piezoceramic emitter (5 and 10 MHz), and a large aperture PVDF receiver that eliminates diffraction effects. The propagation velocity, attenuation coefficient and density of several samples of water-in-oil emulsion were measured. The concentrations of water of the samples were in the range of 0 to 5% in volume, and the results showed that these low concentrations can be discriminated within a resolution of 0.2% in the studied range, using the measurement of the propagation velocity.

Collateral cartilage ossification of the distal phalanx in the Brazilian Jumper horse

Collateral cartilage ossification of the distal phalanx in the Brazilian Jumper horse is a common finding. The objective of this study was to evaluate the prevalence and the degree of ossification of the collateral cartilages of the distal phalanx in Brazilian Jumper horses. In an analysis of 652 collateral cartilages from the front feet of 163 horses, 93% of these cartilages had collateral cartilage ossification (P < 0.005), and 7% of these cartilages did not have any type of ossification. In ossified cartilages, 86.4% had ossification beginning from the base, and 6.6% had a separate center of ossification.

Características da pulverização produzida por pontas Yamaho da série 'D'

This study evaluated the characteristics of spray produced by Yamaho nozzle tip'D'series. The droplet size of nozzle tips D3, D4, D5, D6 and D8 were evaluated at 703, 1.050, 1.406, 1.758, 2.110, 2.461 e 2.813 kPa pressures (100, 200, 250; 350, e 400 psi) by means of laser equipment, as well as the flow rate of nozzle tip at the pressures of 702, 1.125, 1.406, 1.828, 2.110, 2.532 e 2.813 kPa (100, 160, 200, 260,300; 360 e 400 psi) which were compared with values indicated by manufacturer. The droplet produced at all pressures presented a very fine spray, which in agriculture may promote losses by evaporation and drift. For all nozzle tips, except D8 in pressures 1.828, 2.532 e 2.813 kPa, the difference between the observed flow rate indicated by the manufacturer was higher than 5%. The paper demonstrates that the nozzle tip tested, in spite of not having uniform flow rate, may promote the contamination of spray operator and environment due to the droplet spectrum produced.

Temporal polyethism in workers of Ectatomma edentatum (Formicidae: Ponerinae)

In the present study, adult ants emerged from five nests kept under laboratory conditions were individually monitored in order to determine their longevity and observe their individual behavior in relation to age (temporal polyethism). Our results showed that most of the tasks related to colony maintenance were executed during the three first age intervals (comprising from 1 to 150 days of age), namely brood care, followed by grooming activities (self and allogrooming), nest maintenance activities (such as floor and nest inspection), and social related activities (antennating and food exchange among adults). Foraging activities were performed by ants in the higher age intervals.

Oxygen uptake kinetics and time to exhaustion in cycling and running: A comparison between trained and untrained subjects

The objective of the present study was to compare pulmonary gas exchange kinetics (VO 2 kinetics) and time to exhaustion (Tlim) between trained and untrained individuals during severe exercise performed on a cycle ergometer and treadmill. Eleven untrained males in running (UR) and cycling (UC), nine endurance cyclists (EC), and seven endurance runners (ER) were submitted to the following tests on separate days: (i) incremental test for determination of maximal oxygen uptake (VO 2max) and the intensity associated with the achievement of VO 2max (IVO 2max) on a mechanical braked cycle ergometer (EC and UC) and on a treadmill (ER and UR); (ii) all-out exercise bout performed at IVO 2max to determine the time to exhaustion at IVO 2max (Tlim) and the time constant of oxygen uptake kinetics (τ). The τ was significantly faster in trained group, both in cycling (EC = 28.2 ± 4.7 s; UC = 63.8 ± 25.0 s) and in running (ER = 28.5 ± 8.5 s; UR = 59.3 ± 12.0 s). Tlim of untrained was significantly lower in cycling (EC = 384.4 ± 66.6 s vs. UC; 311.1 ± 105.7 s) and higher in running (ER = 309.2 ± 176.6 s vs. UR = 439.8 ± 104.2 s). We conclude that the VO 2 kinetic response at the onset of severe exercise, carried out at the same relative intensity is sensitive to endurance training, irrespective of the exercise type. The endurance training seems to differently influence Tlim during exercise at IVO 2max in running and cycling. © 2003 Taylor & Francis Ltd.

Grazing time and milk production of crossbred cows in a rotational area of Elephant grass and Tanzania grass

This study was carried out in January of two consecutive years. The objective was to evaluate the grazing time, the grazing rate and the milk production of crossbred cows, managed in two rotational grazing areas, one with elephant grass (Pennisetum purpureum Schum. cv. Guaçu) and another one with Tanzania grass (Panicum maximum Jacq. cv. Tanzania), both with natural shade in the rest area. The experiment was divided in two phases, the first with 12 cows that remained day and night in the paddock and were milked twice a day. In the second phase 15 cows were observed and remained 10.43 hours in the paddock during the day, and were kept in a corral during the night. Each cow was observed every 15 minutes. Grass specie had no effect on milk production in the two phases of the experiment. The grazing time was 564 and 474 minutes and the grazing rate was 28.7 and 24.4 minutes/hour for the Elephant grass and Tanzania grass, respectively, in first phase. In the second phase,the grazing time was 461 and 426 minutes and the grazing rate was 42.7 and 39.4 minutes/hour for the Elephant grass and Tanzania grass, respectively. Correlations were observed (P<0.01) between grazing rate and the minimum temperature (-0.68), the maximum temperature (-0.76), the relative humidity (0.44) and the THI (-0.76).

Bone mineralization among male adolescents: Critical years for bone mass gain

Objective: To verify the behavior of the mineral bone content and density in male adolescents according to age and secondary sexual characters. Methods: 47 healthy adolescents between 10 and 19 years old were assessed according to weight, height, body mass index, puberty stage, calcium intake, bone mineral density and content in the lumbar spine and in the proximal femur. The bone mass was measured through bone densitometries. The intake of calcium was calculated through a 3-day diet. The BMI (body mass index) was calculated with the Quetelet Index and the puberty stage was defined according to Tanner's criteria. The analysis used descriptive statistics such as average and standard deviation, and variance estimates to compare the different age groups. Moreover, the Tukey test was used to determine the significant differences. Results: It was evident that the calcium intake in the different ages assessed has not reached the minimum value of 800 mg. The bone mineral density and content showed an increase after the age of 14, as well as when the teenagers reached the sexual maturation stage G4. The mineralization parameters showed a high level when the teenagers were in the G3 stage, however, without statistical significance. Conclusion: The results indicate an important level of bone mineralization during adolescence. Maturation levels superior to G3 have shown more mineralization. This study proves that the critical years for bone mass gain start after the 14-15 years old or older. Copyright © 2004 by Sociedade Brasileira de Pediatria.

Avaliação de diferentes híbridos suínos submetidos à insensibilização elétrica e gasosa (CO 2). Parte 3 - Mensurações visuais de qualidade

Three pig genetics lineages A, B and C marketed in Brazil, were stunning with the manual electric stunning (Karl Schermer 220-230/250 volts, 45-60 Hz and 1.4 - 1.5 A) and the collective gaseous system (COMBI-BUTINA 90% CO 2). The electric stunning provided higher blood splashed levels in the areas of the inside round (0.477 and 0.26, p ≤ 0.01), shoulder/cranial (0.154 and 0.039, p ≤ 0.005), shoulder/central (0.261 e 0.052, p ≤ 0.001), shoulder/caudal (0.180 and 0.030, p ≤ 0.01), loin/central (0.185 and 0.065, p ≤ 0.01), loin/caudal (0.06 and 0.207, p ≤ 0.01) and loin/lateral external (0.061 and 0.013, p ≤ 0.05), as well as more diffuse blood splashed in the areas of the inside round (0.461 and 0.279, p ≤ 0.05), shoulder/cranial (0.154 and 0.039, p ≤ 0.001), shoulder/central (0.231 and 0.039, p ≤ 0.001) and shoulder/caudal (0.185 and 0.026, p ≤ 0.001). The electric stunning also provided higher skin damage levels in the areas of the shoulder (1.098 and 0.795, p ≤ 0.001), body (1.04 and 0.948, p ≤ 0.05) and ham (0.84 and 0.68, p ≤ 0.001), as well as higher eyelid reflex levels (11.57%) comparatively to the gaseous system (2.86%) of a total of 426 pigs. Small indexes of bone fractures and muscle bruises were found in both systems.

The effect of age on hematological and serum biochemical values on juvenile ring-necked pheasants (Phasianus colchicus)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Chalcopyrite and bornite differentially affect protein synthesis in planktonic cells of Acidithiobacillus ferrooxidans

Acidithiobacillus ferrooxidans is used in bioleaching industrial operations to recover metal ions from mineral sulfides. Chalcopyrite and bornite are copper sulfides that have the same elemental composition, but differ in their susceptibility to the bioleaching process. Our objective was to identify differentially expressed proteins in A. ferrooxidans LR cells exposed to chalcopyrite or bornite, as a sole energy source, for 24 hours. Compared to the control (without minerals), proteins were induced or repressed in planktonic cells after contact with chalcopyrite or bornite by 24 hours. These results demonstrated that the time of exposure to the copper minerals was enough to trigger distinct responses in the A. ferrooxidans metabolism. © 2007 Trans Tech Publications.

Tree species composition and environmental relationships in a Neotropical swamp forest in Southeastern Brazil

We examined the relationships between topography, soil properties and tree species composition in a Neotropical swamp forest in southeastern Brazil. Plots were sampled in the forest, encompassing three different soil ground water regimes along the topographical declivity. All non-climbing plant individuals with trunk height >1.3 m were sampled. A canonical correspondence analysis-CCA-of the species-environmental relationships grouped tree species according to drainage and chemical soil conditions. A total of 86 species were found, being 77 species in the inferior, 40 species in the intermediate and 35 species in the superior topographic section. Some species were among the 10 most abundant ones, both in the overall sampled area and in each topographical section, with alternation events occurring only with their abundance position. However, substantial differences in floristic composition between sections were detected in a fine spatial scale, due to higher number of species, diversity index (H′) and species unique (exclusives) in the inferior topographic section. These higher values can be attributed to its higher spatial heterogeneity that included better drained and seasonally waterlogged soils, higher soil fertility and lower acidity. The increase of the soil water saturation and the uniform conditions derived from the superficial water layer has led to a lower number of species and an increase on the palm trees abundance in the intermediate and superior sections. Our results showed that at a small spatial scale niche differentiation must be an important factor related to the increase of the local diversity. The wide distribution of the most abundant species in the studied area and the increase of local diversity corroborate the pattern of distribution of species in larger scales of swamp forests, in which the most abundant species repeat themselves in high densities in different remnants. However, the floristic composition of each remnant is strongly variable, contributing to the increase of regional diversity. © 2008 Springer Science+Business Media B.V.

Hacia una dinámica del desarrollo latinoamericano: selección

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Produtividade de cana-de-açúcar sob adubação com torta de filtro enriquecida com fosfato solúvel

Phosphorus is considered an essential element for plants and it is found in small amounts in Brazilian soils. The filter cake residue, composed of a mixture of bagasse and decanting sludge, has high levels of organic matter, phosphorus and calcium. The phosphorus present in the filter cake is organic, and its release, as it happens to the nitrogen, occurs gradually by mineralization and by microorganisms attack in the soil. This study aimed to evaluate sugarcane vegetative growth and yield under fertilization with filter cake enriched with soluble phosphate. The experiment was carried out in Presidente Prudente, São Paulo State, Brazil, by using a randomized complete block design, in a 5x4 factorial scheme, where the first factor consisted of filter cake doses (0 t ha-1, 0.5 t ha-1, 1.0 t ha-1, 2.0 t ha-1, and 4.0 t ha-1) and the second of phosphorus fertilizer doses (0 kg ha-1, 50 kg ha -1, 100 kg ha-1, and 200 kg ha-1 of P 2O5), with 4 repetitions, totalizing 80 plots. The experiment evaluated the tiller number, at 30, 60, 90, and 120 days after planting, oBrix, and yield. The stalk yield and tillering were influenced by the filter cake rates applied to the soil. Filter cake doses and their combination with phosphate did not change the juice quality (Brix) at harvest.

Development, institutional and policy aspects of international migration between Africa, Europe and Latin America and the Caribbean

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Africans in the Southern European countries: Italy, Spain and Portugal

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