Ultrahigh strength in nanocrystalline materials under shock loading

Molecular dynamics simulations of nanocrystalline copper under shock loading show an unexpected ultrahigh strength behind the shock front, with values up to twice those at low pressure. Partial and perfect dislocations, twinning, and debris from dislocation interactions are found behind the shock front. Results are interpreted in terms of the pressure dependence of both deformation mechanisms active at these grain sizes, namely dislocation-based plasticity and grain boundary sliding. These simulations, together with new shock experiments on nanocrystalline nickel, raise the possibility of achieving ultrahard materials during and after shock loading.     

Incorporation of Buriti Endocarp Flour in Gluten-free Whole Cookies as Potential Source of Dietary Fiber

Cookies were prepared by replacing a mixture of brown rice flour (70 %) and corn starch (30 %) (BRFCS) by buriti endocarp flour (BEF) (0, 5, 10, 15 or 20 %). BEF figured as a potential source of dietary fiber (70.53 g 100 g^?1), especially of insoluble fiber (67.50 g 100 g^?1), and gluten-free whole cookies showed increased dietary fiber content by adding 5, 10, 15 and 20 % BEF (8.58 to 20.02 g 100 g^?1) when compared to control cookie (6.91 g 100 g^?1). The addition of BEF affected diameter, spread ratio, color and texture of cookies. All cookies added with BEF were darker, harder and presented smaller diameter and smaller spread ratio than the control cookie. These difference increased proportionally to level of substitution of BRFSC by BEF. Gluten-free whole cookies with up to 15 % BEF were well accepted by consumers. Therefore, the use of BEF in cookies may increase the availability of functional ingredients source of dietary fiber for celiac consumers, add economic value to buriti processing by-products and decrease environmental impacts due to the high amounts of waste generated by buriti processing industries.     

Assessing the use of erosion modeling to support payment for environmental services programs

Purpose

Payment for environmental services (PES) has assumed increasing importance in discussions about sustainable development strategies. Many of the PES programs are based on water erosion control and the corresponding environmental and economic benefits generated in the basins where they are implemented. The main objective of this study was to show how erosion susceptibility models can support PES programs.

Materials and methods

The application of the Universal Soil Loss Equation (USLE) in the Sarandi Experimental River Basin (32.7 km²), located in the Federal District, Brazil, was used as a study case. Then a scheme for organizing knowledge about ecosystem services related to erosion control and water resources was performed. Considering the generated scheme, the USLE results, the land use map, and the water use in the region, we evaluated how erosion modeling could support PES programs.

Results and discussion

The results show that a large part of the study basin (90%) presents “low” susceptibility to erosion, which is significant in terms of the use and conservation of ecosystem services, as well as being a limitation regarding the need for the implantation of PES programs for erosion control. Incentives for maintaining the natural vegetation in areas with higher erosion susceptibility have the greatest potential to justify PES programs in the study basin, and the sanitation company is the potential payer for erosion control in the Sarandi River Basin.

Conclusions

The application of the USLE in a spatially distributed form proved to be an important support tool for land management and the implementation of PES policies.     

The effects of the number,size and isolation of patches along a gradient of native vegetation cover: how can we increment habitat availability?

Habitat availability—or how much habitat species can reach at the landscape scale—depends primarily on the percentage of native cover. However, attributes of landscape configuration such as the number, size and isolation of habitat patches may have complementary effects on habitat availability, with implications for the management of landscapes. Here, we determined whether, and at which percentages of native cover, the number, size and isolation of patches contribute for habitat availability. We quantified habitat availability in 325 landscapes spread across the state of Rio de Janeiro, in the Atlantic Forest hotspot, with either high (>50 %), intermediate (50–30 %), low (30–10 %) or very low (<10 %) percentage of native cover, and for six hypothetical species differing in inter-patch dispersal ability. Above 50 % of native cover, the percentage of cover per se was the only determinant of habitat availability, but below 50 % the attributes of landscape configuration also contributed for habitat availability. The number of patches had a negative effect on habitat availability in landscapes with 50–10 % of native cover, whereas patch size had a positive effect in landscapes with <10 % of native cover. The different species generally responded to the same set of landscape attributes, although to different extents, potentially facilitating decision making for conservation. In landscapes with >50 % of native cover, conservation actions are probably sufficient to guarantee habitat availability, whereas in the remaining landscapes additional restoration efforts are needed, especially to reconnect and/or enlarge remaining habitat patches.     

Tolerance response to ammonia and nitrite in hatchlings paralarvae of <Emphasis Type="Italic">Octopus vulgaris</Emphasis> and its toxic effects on prey consumption rate and chromatophores activity

Ammonia and nitrite are among the most important water quality parameters. The aim of this study was to determine the acute toxicity of unionized ammonia and nitrite on newly hatched Octopus vulgaris paralarvae. Concretely, survival, feeding and chromatophore activity were examined under different NH₃ and NO₂ ⁻ concentrations. The median lethal concentration (LC 50) determined for 24 h was 10.7 ppm for NH₃ and 19.9 ppm for NO₂ ⁻. Based on these results, a concentration range was chosen to test the effect of this environmental contaminants in feeding and chromatophore activity (range between 2.5 and 20 ppm for feeding and 10 and 30 ppm for chromatophore activity), resulting in modifications in both parameters. In fact, a significant decrease (P < 0.05) in Artemia nauplii consumption by the paralarvae was observed with an increase in NH₃ and NO₂ ⁻. Similarly, the chromatophore activity was also affected by concentration of these contaminants, with decreasing response (P < 0.05) when submitted to stressful situations, as the ammonia and nitrite concentration was increased.     

Vitellogenin of the Chilean flounder <Emphasis Type="Italic">Paralichthys adspersus</Emphasis> as a biomarker of endocrine disruption along the marine coast of the South Pacific. Part I: induction,purification, and identification

We sought to provide a useful indicator of the presence of endocrine-disrupting contaminants along the marine coast of the South Pacific using Chilean flounder (Paralichthys adspersus). In light of the lack of information on vitellogenin for this species, we induced, purified, and identified the plasma vitellogenin of Chilean flounder inhabiting the Chilean coast. Vitellogenin (Vg) from Chilean flounder was purified by size exclusion and ion-exchange chromatography using plasma from juvenile males induced by injecting 17β-estradiol. The Vg was detected by SDS–PAGE and Western blot analyses using an antibody against turbot (Scophthalmus maximus) vitellogenin. These analyses revealed a protein band of 205 kDa and three minor bands of 120, 90, and 68 kDa. These proteins were identified as Vg by means of mass spectrometry (LCQ Duo ESI-IT-MS), matching sequences of tryptic peptides to known sequences for several other fish species. The matches showed the presence of vitellogenin (VgI, VgII, Vg A and Vg B) in Chilean flounder, similar to species such as mummichog (Fundulus heteroclitus), Japanese medaka (Oryzias latipes), and white perch (Morone americana). These results are discussed in terms of identifying Vg in Paralichthys adspersus with the antibody to turbot Vg. Moreover, we compare the molecular size of Vg from Chilean flounder (large) with that of other flatfish species. Finally, we discuss the potential use of this molecule as a biomarker for the presence of xeno-estrogenic compounds along the Chilean coastline.     

Effect of diatom supplementation during the nursery rearing of Litopenaeus vannamei (Boone, 1931) in a heterotrophic culture system

Bio-floc shrimp culture systems have been investigated in an attempt to optimize water use and prevent the discharge of effluent into the environment. The importance of microalgae in maintaining water quality and nutrition of the shrimp is well known in conventional systems; however, its maintenance amid bio-flocs and its role in the shrimp performance in this system are still poorly understood. The aim of this study was to evaluate the contribution of diatoms in the performance of Litopenaeus vannamei reared during the nursery phase in intensive system with minimal water exchange. Shrimp (0.31?±?0.10?g) were reared among diatoms, bio-flocs and the combination of the two forming the mixture medium. The survival of shrimp was high in all treatments (90?C97%). However, the shrimp reared among diatoms showed higher weight gain (P?<?0.05) and feed conversion ratio significantly more efficient, reaching a value of 0.47. The results indicate the importance of diatoms in bio-floc culture systems and points out to future research in an attempt to maintain a constant presence of these microalgae in culture medium without requiring successive inoculations.     

Compiling Market and Other Financial Data on Smallholder Forestry in Leyte, the Philippines

Data collection and maintenance of databases concerning smallholder forestry presents special problems in developing countries. This paper examines forestry data collection experiences in a series of research projects in Leyte, Philippines, supported by the Australian Centre for International Agricultural Research, and the prospects for developing forestry accounting networks. A variety of financial data have been collected in relation to seedling production, plantation performance and timber marketing. Seedling production cost and revenue data have been obtained through snapshot surveys conducted in 2002 and 2008, and repeated attempts have been made to estimate financial returns from growing the most popular tree species. Diverse sources have been identified for timber market information. On the supply side, these include government records of registered plantations, obtaining inventory data from barangay (community) leaders, and reporting information about timber available for harvest on community notice boards. On the demand side, official records of registered timber merchants have been accessed, a detailed survey of timber processors has been conducted, and estimates are being made of apparent per capita timber consumption by district. Experiences in the Philippines reinforce that the potential for forestry accounting networks is limited by the resource-constrained situations of developing countries, placing greater reliance on one-off surveys. Use of pre-existing local networks and institutional structures offers potential for routine collection of forestry data, such as through barangay (village) leaders in the Philippines.