Prediction of dry matter intake based on ruminal degradation from milking cows grazing coast-cross grass

Dry matter intake (DMI) of coast-cross grazing by crossbred Holstein-Zebu and Zebu lactating cows was calculated using in vitro dry matter digestibility from extrusa (four esophageal fistulated cows) and fecal output estimate with mordent chromium. Pasture was rotationally grazed with three days grazing period and 27 days testing period, adopting a stocking rate of 1.6 and 3.2 cows/ha, during the dry and rainy season respectively. Voluntary DMI was estimated from degradation characteristics using different equations. Predicted coast-cross DMI varied with models. The prediction of tropical forages dry matter intake from equations based in ruminal degradation parameters needs farther investigation before being employed in practice.

Different responses in bulk density and saturated hydraulic conductivity to soil deformation by logging machinery on a Ferralsol under native forest

Ferralsols have high structural stability, although structural degradation has been observed to result from forest to tillage or pasture conversion. An experimental series of forest skidder passes in an east Amazonian natural forest was performed for testing the effects of mechanical stress during selective logging operations on a clay-rich Ferralsol under both dry and wet soil conditions. Distinct ruts formed up to 25 cm depth only under wet conditions. After nine passes the initially very low surface bulk density of between 0.69 and 0.80 g cm(-3) increased to 1.05 g cm(-3) in the wet soil and 0.92 g cm(-3) in the dry soil. Saturated hydraulic conductivities, initially > 250 mm h(-1), declined to a minimum of around 10 mm h(-1) in the wet soil after the first pass, and in the dry soil more gradually after nine passes. The contrasting response of bulk density and saturated hydraulic conductivity is explained by exposure of subsoil material at the base of the ruts where macrostructure rapidly deteriorated under wet conditions. We attribute the resultant moderately high hydraulic conductivities to the formation of stable microaggregates with fine sand to coarse silt textures. We conclude that the topsoil macrostructure of Ferralsols is subject to similar deterioration to that of Luvisols in temperate zones. The stable microstructure prevents marked compaction and decrease in hydraulic conductivity under wetter and more plastic soil conditions. However, typical tropical storms may regularly exceed the infiltration capacity of the deformed soils. In the deeper ruts water may concentrate and cause surface run-off, even in gently sloping areas. To avoid soil erosion, logging operations in sloping areas should therefore be restricted to dry soil conditions when rut formation is minimal.

From Plinthic Acrisols to Plinthosols and Gleysols: iron and groundwater dynamics in the tertiary sediments of the upper Amazon basin

Topography has been reported to be the major factor ruling the spatial distribution of Acrisols, Plinthosols and Gleysols on the seasonally flooded, low elevation plateaux of the upper Amazon basin occupied by Tertiary (Ica & Solimoes) sediments. In this study, detailed morphological and mineralogical investigations conducted in a representative 25-ha site were combined with hydro-geochemical data to relate the vertical and lateral soil differentiations observed to the hydro-geological history of that part of the basin. As a result of the uplift of the Andes, several cuts in the extensive Tertiary marshlands have formed, at first, slightly incised plateaux of low elevation. There, weathering under hot and humid climates would have generated a reddish, freely drained and bioturbated topsoil layer and the vertical differentiation in subsoil sediments of a plinthite over an iron-depleted mottled clay. The second episode of soil differentiation is linked to the replacement of the forest by a savannah under the drier climates of the late Pleistocene, which favours surface runoff and the infill of the incisions by fine particles. This infill, combined with the return to the present humid climate, has then enabled the local groundwater to rise on the plateaux and to generate episaturation at the topsoil/subsoil transition close to the depressions. Nowadays, ferrous iron is released from the partly iron-depleted topsoil weathering front at high water levels during the rainy seasons. It moves from footslope to low-lying positions and from top to bottom in the soil profile according to the groundwater dynamics. The present general trend is thus to the lateral export of iron at high water levels due to subsurface and overland flows, its vertical transfer during the recession of the groundwater and accumulation in a nodular plinthite. In the latter, ferrous iron is adsorbed onto its softest iron masses where it feeds the neoformation of ferrihydrite that rapidly dehydrates into haematite.

Soilborne filamentous fungi in Brazil

The Atlantic Rainforest is a Brazilian ecosystem that is being rapidly being destroyed, along with the abiotic and biotic factors present in it. Among the biotic factors, the fungi are found in the soil which, besides being of major importance in terms of ecological niches, also have broad and significant applications in biotechnology. In order to assess the biodiversity of these microorganisms in this type of ecosystem, the Banhado Grande region was chosen at the Jureia-Itatins Ecology Station, in the state of São Paulo, Brazil. Within this region, two areas were delimited for study, one covered with natural (primary) vegetation and the other containing vegetation that regenerated following the planting of rice crops, referred to here as secondary. Collection of compound soil samples were taken (depth 0-15 cm) over a period of two and a half years, with the litter first being removed, during dry/cold and humid/hot periods. After sifting the samples, they were appropriately processed using the serial dilution technique to isolate the fungi from the soil. Six different culture media were used, having pHs of 4.5, 7.0 and 9.0. Altogether, 1,211 strains were isolated, divided into the following groups: Hyphomycetes, the most abundant followed by Ascomycetes, Zygomycetes, Coelomycetes, and Oomycetes. From these, 112 species were identified, 8 down to the genus level, and those that did not produce conidia were grouped as Mycelia sterilia. Among the strains, 67 were cellulolytic, 32 originated solely in soil under natural vegetation, and 26 originated solely in soil under secondary vegetation.

Adhesive Quality of Self-adhesive and Conventional Adhesive Resin Cement to Y-TZP Ceramic Before and After Aging Conditions

Purpose: This study evaluated the adhesive quality of simplified self-adhesive and conventional resin cements to Y-TZP in dry and aged conditions. Methods: Y-TZP ceramic blocks (N=192) (5 x 5 x 2 mm) were embedded in acrylic resin and randomly divided into two groups, based on surface conditioning: 96% isopropanol or chairside tribochemical silica coating and silanization. Conditioned ceramics were divided into four groups to receive the resin cements (Panavia F 2.0, Variolink II, RelyX U100 and Maxcem). After 24 hours, half of the specimens (n=12) from each group were submitted to shear bond strength testing (0.5 nun/minute). The remaining specimens were tested after 90 days of water storage at 37 degrees C and thermocycling (12,000x, 5 degrees C-55 degrees C). Failure types were then assessed. The data were analyzed using three-way ANOVA and the Tukey's test (alpha=0.05). Results: Significant effects of ceramic conditioning, cement type and storage conditions were observed (p<0.0001). The groups cleaned using alcohol only showed low bond strength values in dry conditions and the bond strength was reduced dramatically after aging. Groups conditioned using silica coating and silanization showed higher bond strengths both in dry and aged conditions. A high number of specimens failed prematurely prior to testing when they were cleaned using 96% isopropanol. Conclusion: Overall, silica coating and silanization showed higher, stable bond strengths with and without aging. The durability of resin-ceramic adhesion varied, depending on the adhesive cement type.

Aerosol and precipitation chemistry measurements in a remote site in Central Amazonia: the role of biogenic contribution

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Food and feeding habits of the neotropical river otter Lontra longicaudis (Carnivora, Mustelidae)

A study of the feeding habits of the neotropical river otter, Lontra longicaudis, based on focal analysis was carried out from July 1986 to July 1987. The study was conducted at a dam in the 'Duas Bocas' Biological Reserve near the town of Cariacica, Espirito Santo State, Brazil. This reserve spreads over an area of 2 910 ha, the surface being mainly covered by the Atlantic Rain Forest. In order to identify the fish and other animal remains found in otter fecal samples, these were compared to the homologous structures of identical species living in the dam. The results of 288 samples were expressed in numbers and frequency of occurrence. Fishes were the most important food item, being present in 281 samples (97.2 %). A species of the genus Geophagus was frequently found in spraints, eaten during all months studied and present in 88.9 % of the samples. Astyanax, Pimelodella, Hoplias, Leporinus, Rhamdia, Tilapia and two other unidentified genera were found less frequently. In decreasing order of occurrence, crustaceans, amphibia, mammals, insects and birds were also encountered. Seasonal variation was verified in the scats between the dry and rainy seasons, with a higher frequency of food items occurring in the latter. In agreement with other species of otters, fishes also are the most commonly ingested prey. Two characteristics of fishes, greater abundance and easier capture, make them the major prey of otters, implying that otters are opportunistic predators eating whatever is more available.

Phenological aspects of flowering and fruiting at the Ecological Station of Paulo de Faria-SP-Brazil

The present work was carried out at 'Estacao Ecologica de Paulo de Faria', north of the state of Sao Paulo, southeast of Brazil (19°55'-19°58'S and 49°31'-49°32'W). The flowering and fruiting phenology of trees, shrubs, and lianas species were observed from April 1993 to December 1995. The results were compaired with those surveyed at other forests from Sao Paulo state: Santa Genebra (Campinas). Serra do Japi (Jundiai) and lianas of Mata Atlantica. The majority of species of lianas flowered from January to April and trees and shrubs between September to December. The most intense frutification period occurred during May to August. Similarly to Santa Genebra, the flowering season at 'Estacao Ecologica de Paulo de Faria' started at the beginning of the wet season while frutification during the dryest period of the year. At Serra do Japi, the flowering and frutification occurred from the end of dry and beginning of the rainy season. Considering the liana at Mata Atlantica presented two peaks of flowering, while at 'Estacao Ecologica de Paulo de Faria' occurs only one. Regarding the fruiting phenology is similar for both area, most species producing fruits during the first semestre.

Argilominerais de Coberturas Sedimentares Cenozóicas do Centro-leste do Estado de São Paulo

Clay mineral analysis contributed to the mineralogical characterization and stratigraphic setting of continental Cenozoic deposits of central-eastern portion of São Paulo State, southeastern Brazil. These deposits, often thin and discontinuous, comprise the Itaqueri Formation (Cretaceous-Paleogene), Rio Claro Formation (Pliocene) and associated Neocenozoic deposits. X-ray diffractometry provided mineralogical and semiquantitative constitution of clays, while scanning electron microscopy (SEM) provided details about mineralogical constitution, packing of microscopic grains and nature (detrital or diagenetic) of clays. These results supported interpretations about paleoenvironmental conditions during sedimentation, revealing possible links between changing climates (dry or humid) and correlative Cenozoic deposits in southeastern Brazil. In addition, SEM images showed microstructures which influence on geotechnical behaviour (erosion and collapse phenomena) of sedimentary materials.

Evaluation of naturally and artificially aged seeds of Phaseolus vulgaris L.

Seed ageing is natural phenomenon that occurs in all seeds, including those stored in dry and low temperature rooms. Phaseolus vulgaris L. cv. 'Carioca' seeds harvested in five different years were stored in at 15°C. Seed samples were germinated and evaluated according to The Brazilian Rules for Testing Seeds. The newest seed sample was submitted to artificial ageing. Small (∼1g) samples of all materials (naturally and artificially aged) were ground and proteins extracted. Equal quantities of protein were loaded onto the gels and electrophoresis carried out. Although seeds submitted to 24, 48, 72 and 96 hours of artificial ageing did not show any statistical difference (5%) in relation to unaged seeds in physiological parameters related to emergence, some statistically different parameters related to dry matter and length of shoots and roots occurred. A 24 h of artificial ageing at 41°C improved these factors. Protein patterns were changed after 72 h of artificial ageing and naturally aged seeds showed alterations after two years storage at 15°C. Aged seeds, naturally and artificially, had decreasing germination, vigour, and changes in the characteristic banding pattern of proteins. Physiological parameters and electrophoresis examination showed that for naturally aged seeds physiological parameters were more sensitive while artificially aged seeds, (41°C/100% RH), had electrophoretic profiles that were more efficient for seed lot discrimination.

Bond strength of acrylic teeth to denture base resin after various surface conditioning methods before and after thermocycling

This study aimed to evaluate the durability of adhesion between acrylic teeth and denture base acrylic resin. The base surfaces of 24 acrylic teeth were flatted and submitted to 4 surface treatment methods: SM1 (control): No SM; SM2: application of a methyl methacrylate-based bonding agent (Vitacol); SM3: air abrasion with 30-μm silicone oxide plus silane; SM4: SM3 plus SM2. A heat-polymerized acrylic resin was applied to the teeth. Thereafter, bar specimens were produced for the microtensile test at dry and thermocyled conditions (60 days water storage followed by 12,000 cycles). The results showed that bond strength was significantly affected by the SM (P < .0001) (SM4 = SM2 > SM3 > SM1) and storage regimens (P < .0001) (dry > thermocycled). The methyl methacrylate-based adhesive showed the highest bond strength.

A comparison of the film thickness of two adhesive luting agents and the effect of thermocycling on their microTBs to feldspathic ceramic.

The aim of the present study was to evaluate the effect of thermocycling (TC) on the microtensile bond strength (microTBS) of two luting agents to feldspathic ceramic and to measure their film thickness (FT). For the microTBS test, sixteen blocks (6.4 x 6.4 x 4.8 mm) were fabricated using a feldspathic ceramic, etched with 10% hydrofluoric acid, rinsed and treated with the silane agent. The ceramic blocks were divided into two groups (n= 8): Gr1: dual-cured resin cement and Gr2: flowable resin. The luting agents were applied on the treated surfaces. Microsticks (1 +/-0. 1mm2) were prepared and stored under two conditions: dry, specimens immediately submitted to the microTBS test, and TC (6,000 cycles; 5 degrees C-55 degrees C). The microTBS was evaluated using a universal testing machine (1 mm/min). The microTBS data (MPa) were submitted to two-way ANOVA and Tukey' test (5%). For the FT test (ISO 4049), 0.05 ml of each luting agent (n=8) was pressed between two Mylar-covered glass plates (150 N) for 180 seconds and light polymerized. FT was measured using a digital paquimeter (Model 727-2001). The data (mm) were submitted to one-way ANOVA. The luting cement did not influence the microTBS results (p= 0.4467). Higher microtensile bond values were found after TC (20.5 +/- 8.6 MPa) compared to the dry condition (13.9 +/- 4. 7MPa), for both luting agents. The luting agents presented similar film thicknesses: Gr1- 0.052 +/- 0.016 mm; Gr2-0.041 +/- 0.003 mm. The luting agents presented similar film thickness and microTBS values, in dry and TC conditions and TC increased the bond strength regardless of the luting agent.

Pre-harvest sugarcane burning: Determination of emission factors through laboratory measurements

Sugarcane is an important crop for the Brazilian economy and roughly 50% of its production is used to produce ethanol. However, the common practice of pre-harvest burning of sugarcane straw emits particulate material, greenhouse gases, and tropospheric ozone precursors to the atmosphere. Even with policies to eliminate the practice of pre-harvest sugarcane burning in the near future, there is still significant environmental damage. Thus, the generation of reliable inventories of emissions due to this activity is crucial in order to assess their environmental impact. Nevertheless, the official Brazilian emissions inventory does not presently include the contribution from pre-harvest sugarcane burning. In this context, this work aims to determine sugarcane straw burning emission factors for some trace gases and particulate material smaller than 2.5μm in the laboratory. Excess mixing ratios for CO2, CO, NOX, UHC (unburned hydrocarbons), and PM2.5 were measured, allowing the estimation of their respective emission factors. Average estimated values for emission factors (g kg-1 of burned dry biomass) were 1,303 ± 218 for CO2, 65 ± 14 for CO, 1.5 ± 0.4 for NOX, 16 ± 6 for UHC, and 2.6 ± 1.6 for PM2.5. These emission factors can be used to generate more realistic emission inventories and therefore improve the results of air quality models. © 2012 by the authors; licensee MDPI, Basel, Switzerland.

Effects of cement-curing mode and light-curing unit on the bond durability of ceramic cemented to dentin

The aim of this study was to evaluate the effects of different light-curing units and resin cement curing types on the bond durability of a feldspathic ceramic bonded to dentin. The crowns of 40 human molars were sectioned, exposing the dentin. Forty ceramic blocks of VITA VM7 were produced according to the manufacturer's recommendations. The ceramic surface was etched with 10% hydrofluoric acid/60s and silanized. The dentin was treated with37% phosphoric acid/15s, and the adhesive was applied. The ceramic blocks were divided and cemented to dentin according to resin cement/RC curing type(dual-and photocured), light-curing unit (halogen light/QTH and LED), and storage conditions (dry and storage/150 days + 12,000 cycles/thermocycling). All blocks were stored in distilled water (37°C/24h) and sectioned (n = 10): G1-QTH + RC Photo, G2-QTH + RC Dual, G3-LED + RC Photo, G4-LED + RC Dual. Groups G5, G6, G7, and G8 were obtained exactly as G1 through G4, respectively, and then stored and thermocycled. Microtensile bond strength tests were performed (EMIC), and data were statistically analyzed by ANOVA and Tukey's test (5%). The bond strength values (MPa) were: G1-12.95 (6.40)ab; G2-12.02 (4.59)ab; G3-13.09 (5.62)ab; G4-15.96 (6.32)a; G5-6.22 (5.90)c; G6-9.48 (5.99)bc; G7-12.78 (11.30)ab; and G8-8.34 (5.98)bc. The same superscript letters indicate no significant differences. Different light-curing units affected the bond strength betweenceramic cemented to dentin when the photocured cement was used, and only after aging (LED>QTH). There was no difference between the effects of dual-and photo-cured resin-luting agents on the microtensile bond strength of the cement used in this study.