Digestive enzyme activity in juvenile Nile tilapia (Oreochromis niloticus, L) submitted to different dietary levels of shrimp protein hydrolysate

The effect of different dietary concentrations of shrimp protein hydrolysate (SPH) on digestive enzyme activity of Nile tilapia juveniles was evaluated. SPH concentrations in diets were 0, 15, 30 and 60 g kg^?1 (treatments SPH0, SPH15, SPH30 and SPH60, respectively). Hemoglobin, azocasein, BApNA (Nα-benzoyl-dl-arginine-p-nitroanilide), SApNA (Suc-Ala-Ala-Pro-Phe p-nitroanilide), aminoacyl of β-naphthylamide and starch were used as substrates for enzyme activity determinations. The activity of total alkaline protease was significantly higher (P < 0.05) in fish under SPH15 and SPH60 treatments than in the control (SPH0). However, the effect was not dose-dependent. Substrate-SDS-PAGE was also performed to evaluate changes in the profile of Nile tilapia digestive proteases caused by SPH. Substrate-SDS-PAGE revealed 12 active proteolytic bands, eight of which responded to SPH dietary incorporation. Inhibition substrate-SDS-PAGE indicated a decrease in the activity of three enzymes, with trypsin activity decreasing with the increase of SPH concentration, whereas the opposite occurred for two aminopeptidases. Distinct protease profiles were also found for each treatment, suggesting adaptability of digestive proteases from Nile tilapia to the different diets.     

Structure elucidation and anticancer activity of 7-oxostaurosporine derivatives from the Brazilian endemic tunicate Eudistoma vannamei

The present study reports the identification of two new staurosporine derivatives, 2-hydroxy-7-oxostaurosporine (1) and 3-hydroxy-7-oxostaurosporine (2), obtained from mid-polar fractions of an aqueous methanol extract of the tunicate Eudistoma vannamei, endemic to the northeast coast of Brazil. The mixture of 1 and 2 displayed IC₅₀ values in the nM range and was up to 14 times more cytotoxic than staurosporine across a panel of tumor cell lines, as evaluated using the MTT assay.     

Fatigue performance of Kevlar/epoxy composites with filled matrix by cork powder

The objective of this study is to characterize the fatigue strength of a Kevlar/epoxy laminate composite as well as the benefits obtained by using an epoxy matrix filled by cork powder. Twelve ply laminates, all in the same direction, of woven bi-directional Kevlar 292, were prepared by hand lay-up, using an SR 1500 epoxy resin. The composite sheets were produced by a vacuum moulding process. The addition of cork powder reduces the static strength, however, in terms of fatigue strength a similar behavior was found for both laminates.     

Plant and animal endemism in the eastern Andean slope: challenges to conservation

Background

The Andes-Amazon basin of Peru and Bolivia is one of the most data-poor, biologically rich, and rapidly changing areas of the world. Conservation scientists agree that this area hosts extremely high endemism, perhaps the highest in the world, yet we know little about the geographic distributions of these species and ecosystems within country boundaries. To address this need, we have developed conservation data on endemic biodiversity (~800 species of birds, mammals, amphibians, and plants) and terrestrial ecological systems (~90; groups of vegetation communities resulting from the action of ecological processes, substrates, and/or environmental gradients) with which we conduct a fine scale conservation prioritization across the Amazon watershed of Peru and Bolivia. We modelled the geographic distributions of 435 endemic plants and all 347 endemic vertebrate species, from existing museum and herbaria specimens at a regional conservation practitioner's scale (1:250,000-1:1,000,000), based on the best available tools and geographic data. We mapped ecological systems, endemic species concentrations, and irreplaceable areas with respect to national level protected areas.

Results

We found that sizes of endemic species distributions ranged widely (< 20 km² to > 200,000 km²) across the study area. Bird and mammal endemic species richness was greatest within a narrow 2500-3000 m elevation band along the length of the Andes Mountains. Endemic amphibian richness was highest at 1000-1500 m elevation and concentrated in the southern half of the study area. Geographical distribution of plant endemism was highly taxon-dependent. Irreplaceable areas, defined as locations with the highest number of species with narrow ranges, overlapped slightly with areas of high endemism, yet generally exhibited unique patterns across the study area by species group. We found that many endemic species and ecological systems are lacking national-level protection; a third of endemic species have distributions completely outside of national protected areas. Protected areas cover only 20% of areas of high endemism and 20% of irreplaceable areas. Almost 40% of the 91 ecological systems are in serious need of protection (= < 2% of their ranges protected).

Conclusions

We identify for the first time, areas of high endemic species concentrations and high irreplaceability that have only been roughly indicated in the past at the continental scale. We conclude that new complementary protected areas are needed to safeguard these endemics and ecosystems. An expansion in protected areas will be challenged by geographically isolated micro-endemics, varied endemic patterns among taxa, increasing deforestation, resource extraction, and changes in climate. Relying on pre-existing collections, publically accessible datasets and tools, this working framework is exportable to other regions plagued by incomplete conservation data.     

Genetic progress during 22 years of black bean improvement

The common bean breeding program coordinated by Embrapa Arroz e Feijão released 50 new cultivars from 1984 to 2010. The aim of the present study was to estimate genetic progress in terms of seed yield and other agronomic traits achieved by the black-type common bean breeding program in Brazil over the 22-year period from 1985 to 2006. Two types of field experiments were performed to assess genetic progress. In regard to experiments on lines, the three best breeding lines from each of 11 evaluation cycles constituted 33 treatments. These evaluations were made in 20 environments and served to estimate progress in seed yield and seed size because these were the criteria applied in selecting the elite lines. Cultivar evaluations included nine cultivars recommended by Embrapa during the period under investigation, and the evaluations were established in 21 environments. These evaluations served to estimate improvements in reaction to angular leaf spot, plant architecture and tolerance to lodging because cultivars usually exhibit superior phenotypes for such characteristics. Evaluations were performed from 2008 to 2010. Estimated improvement in seed yield was 25.2 kg ha^?1 or 1.1 % per year. Improvements were also found in tolerance to lodging (1.7 % per year) and 100-seed weight (0.65 % per year). There was no significant progress for the plant architecture and resistance to angular leaf spot traits.     

Partitioning of glutenin flour of special wheat using aqueous two-phase systems

The partitioning behavior of the glutenin proteins was evaluated in aqueous two-phase systems (ATPSs) formed by sulfate salts (lithium or sodium) and poly(ethylene glycol) (PEG) with average molar mass of 1500 g mol⁻¹ or 4000 g mol⁻¹. The partition coefficients for the glutenin proteins in each ATPS were investigated as a function of the temperature (278.2 K–318.2 K), tie line length (TLL) and electrolyte nature. In all ATPS, the majority of glutenin proteins spontaneously concentrate in the polymer-rich phase (K_p > 1). The partition coefficient is very dependent on the salt nature and the ATPS formed by PEG + lithium sulfate presents higher K_p values as compared with the ATPS formed PEG + sodium sulfate. An increase of molar mass of polymer promotes a decrease of K_p. Thermodynamic parameters of transfer (Δ_trG, Δ_trH and Δ_trS) were obtained by the application of the Van’t Hoff equation (VHE). The values obtained by VHE indicate that the transfer of glutenin proteins to the polymer-rich phase has an enthalpic origin.     

Influence of Superovulatory Protocols on In Vitro Production of Nellore (Bos indicus) Embryos

There are indications in the literature that delaying the period between ovarian superestimulation and ovum pick up (OPU) would induce follicles to a condition of initial atresia, which could be beneficial to oocyte development. In this work, we compared three protocols for OPU and in vitro production (IVP) of embryos, in Nellore cattle. Nellore cows (n = 18) were randomly allocated in three groups: Group 1 (OPU), Group 2 [Follicle stimulating hormone (FSH) and OPU] and Group 3 (FSH deprivation and OPU). Three OPUs were performed, and the animals were switched to a different group each time (crossover), in such a way that at the end of the experiment all cows received the 3 protocols. At random stage of the oestrous cycle (D‐2), all follicles ≥ 6 mm were aspirated to induce a new follicular wave 2 days afterwards (D0). In Group 1, OPU was performed on D2 and oocytes were processed to IVP. In Group 2, starting on D0, cows were superstimulated (FSH, Folltropin^®, 30 mg administered daily, i.m., during three consecutive days, total dose = 180 mg), and 6 h after the last FSH dose, they received exogenous luteinizing hormone (LH) (12.5 mg, i.m., Lutropin^®, D3). The OPU was performed 6 h after LH administration, i.e. 12 h after the last dose of FSH. Animals in Group 3 received the same treatment as those in Group 2, except that LH was administered 42 h after the last dose of FSH, and OPU occurred 6 h later. Therefore, in this group, follicles were deprived of FSH at 48 h. Both cleavage and blastocyst rates were similar (p > 0.05, anova ) among oocytes from Groups 1, 2 and 3, respectively: 77.4% (144/185) and 42.70% (79/185); 75.54% (105/139) and 31.65% (44/139); 63.52% (101/159) and 33.33% (53/159). However, hatched blastocyst rate was higher (p < 0.01) in Group 1 (30.27%, 56/185) when compared with Group 2 (11.51%, 16/139) or 3 (15.72%, 25/159). It is concluded that, contrary to previous work on European breeds (Bos taurus), ovarian superstimulation associated with deprivation of FSH and OPU (Group 3) did not increase IVP of Nellore embryos (Bos indicus). On the contrary, the highest hatched blastocyst rates were observed in oocytes from non‐superstimulated cows.     

Spatial variability of soil properties and yield of a grazed alfalfa pasture in Brazil

Knowledge of the spatial variability of soil properties and of forage yield is needed for informed use of soil inputs such as variable rate technology (VRT) for lime and fertilizers. The objective of this research was to map and evaluate the spatial variability of soil properties, yield, lime and fertilizer needs and economic return of an alfalfa pasture. The study was conducted in a 5.3 ha irrigated alfalfa pasture in Sao Carlos, SP, Brazil that was directly grazed and intensively managed in a 270-paddock rotational system. Alfalfa shoot dry matter yield was evaluated before grazing. Soil samples were collected at 0–0.2 m depth, and each sample represented a group of 2 or 3 paddocks. Apparent soil electrical conductivity (ECa) was measured with a contact sensor. The cost of producing 1 ha of alfalfa was estimated from the amount of lime and fertilizer needed and was then used to estimate the total cost of production for the dairy system. The alfalfa dry matter yield was used to simulate the pasture stocking rate, milk yield, gross revenue and net profit. The spatial variability of soil properties and site-specific liming and fertilizer needs were modeled using semi-variograms with VESPER software, the soil fertility information and economic return were modeled with SPRING software. The results showed that geostatistics and GIS were effective tools for revealing soil and pasture spatial variability and supporting management strategies. Soil nutrients were used to classify the soil spatial distribution map and design site-specific lime and fertilizer application maps. Spatial variation in forage and spatial estimates of stocking and milk yield are adequate pasture management tools. Spatial analyses of needs, forage availability and economic return are management tools for avoiding economic problems, as well as potential environmental problems, caused by unbalanced nutrient supplies and over- or under-grazing.