Toward in vitro fertilization in Brachiaria spp.

Brachiaria are forage grasses widely cultivated in tropical areas. In vitro pollination was applied to accessions of Brachiaria spp. by placing pollen of non-dehiscent anthers on a solid medium near isolated ovaries. Viability and in vitro germination were tested in order to establish good conditions for pollen development. Comparing sexual to apomictic plants, apomictic pollen has more abortion after meiosis during the microspore stage and a lower viability and, of both types, only some plants have sufficient germination in a high sugar concentration. Using in vitro pollination with the sexual plant, the pollen tube penetrates into the nucellus and micropyle, but the embryo sac degenerates and collapses. In the apomictic B. decumbens, in vitro pollination leads to the transfer of the sperm nuclei into the egg cell and the central cell. The results are discussed according to normal fertilization and barriers in sexual and apomictic plants

Adsorption Of Cadmium And Copper In Representative Soils Of Eastern Amazonia, Brazil

Studies of heavy metals adsorption in soil play a key role in predicting environmental susceptibility to contamination by toxic elements. The objective of this study was to evaluate cadmium (Cd) and copper (Cu) adsorption in surface and subsurface soil. Samples of six soils: Xanthic Hapludox (XH1 and XH2), Typic Hapludox (TH), Typic Rhodudalf (TR), Typic Fluvaquent (TF), and Amazonian dark earths (ADE) from Eastern Amazonian, Brazil. The soils were selected for chemical, physical and mineralogical characterization and to determine the adsorption by Langmuir and Freundlich isotherms. All soils characterized as kaolinitic, and among them, XH1 and XH2 showed the lowest fertility. The Langmuir and Freundlich isotherms revealed a higher Cu (H curve) than Cd (L curve) adsorption. Parameters of Langmuir and Freundlich isotherms indicate that soils TR, TF and ADE has the greatest capacity and affinity for metal adsorption. Correlation between the curve adsorption parameters and the soil attributes indicates that the pH, CEC, OM and MnO variables had the best influence on metal retention. The Langmuir and Freundlich isotherms satisfactorily described Cu and Cd soil adsorption, where TR, TF and ADE has a lower vulnerability to metal input to the environment. Besides the pH, CEC and OM the MnO had a significant effect on Cu and Cd adsorption in Amazon soils.3753005301

Coró pequeno da soja.

Aspectos biologicos e comportamento; Controle.bitstream/item/53940/1/51.pd

A review of Corrosion Resistance Nanocomposite Coatings

The deterioration of materials, particularly metals, under the influence of electrochemical corrosion is a high cost problem faced by nearly all industries. The reduction of corrosion processes and the prevention of future problems require a detailed knowledge of these processes and of the strategies to avoid them. In this context, it is essential to use methodologies that may prevent the electrochemical deterioration of materials as well as monitor their performance in aggressive environments. Among them, it is possible to cite the use of functional coatings, particularly nanocomposite coatings. Therefore, this chapter proposes a review concerning the production of nanocomposite coatings with anticorrosive application obtained by electrodeposition technique (electrochemical codeposition). The production of such coatings is in agreement with the current needs of innovation, which drives a requirement for scientific advancement and the need for fundamental research. In this context, nanocomposite coatings with anticorrosive properties promote changes in metal surfaces, creating new materials with improved characteristics compared to those originally observed and maintaining the integrity of these surfaces

Feeding And Oviposition Preference Of Phyllophaga Cuyabana (moser) (coleoptera: Melolonthidae) On Several Crops

Laboratory and greenhouse experiments were carried out to study food and oviposition preference by Phyllophaga cuyabana (Moser) on different plant species as Cajanus cajan L. (pigeon pea), Crotalaria juncea L. (sun hemp), Crotalaria spectabilis Roth (showy crotalaria), Crotalaria ochroleuca G. Don (slenderleaf rattlebox), Glycine max [L.] Merrill (soybean), Gossypium hirsutum L. (cotton), Helianthus annuus L. (sunflower), Stizolobium aterrimum [Mucuna aterrima] Piper & Tracey (velvetbean) and Zea mays L. (mayze). In no-choice experiments, the number of eggs layed in sunflower, C. juncea and soybean was larger compared to cotton. Despite the fact that the adults did not discriminate among plants, in dual-choice test, the proportion of eggs layed and leaf consumption by P. cuyabana adults in soybean were significantly higher than in C. spectabilis. The larval distribution in the soil was at random in multiple-choice, withouth any trend of preference, but in dual-choice, when soybean was the control, larvae always preferred to feed on its roots. P. cuyabana adults had preference for more suitable hosts and that could stand their offspring survival. This behaviour can be usefully exploited in an integrated management program for this pest.365759764Craig, T.P., Itami, J.K., Price, P.W., A strong relationship between oviposition preference and larval performance in a shoot-galling sawfly (1989) Ecology, 70, pp. 1691-1699Diagne, A. 2004. Seasonal occurrence of Phyllophaga species and biological studies of Phyllophaga ephilida (Say) on sweet potato, Ipomoea batatas (1) Lam, in Louisiana. PhD thesis, Louisiana State University and Agricultural and Mechanical College, Baton Rouge, 101pMoron, M.A., (1986) El genero Phyllophaga en México: Morfología, distribución y sistematica supraespecifica, , México, Instituto de Ecología, 341pOliveira, L.J., B. Santos, J.R.P. Parra & C.B. Hoffmann-Campo. 2004. Coró-da-soja, p.151-176. In J.R. Salvadori, C.J. Ávila & M.T.B. da Silva (org.), Pragas de solo no Brasil. Passo Fundo, Embrapa Trigo, Embrapa Agropecuária Oeste, Fundacep, 541pOliveira, L.J., Garcia, M.A., Flight, feeding and reproductive behaviour of Phyllophaga cuyabana (Moser) (Coleoptera: Melolonthidae) adults (2003) Pesq. Agropec. Bras, 38, pp. 179-186Potter, D.A., Held, D.W., Biology and management of the Japanese beetle (2002) Annu. Rev. Entomol, 47, pp. 175-205Silva, M.T.B. da & J.R. Salvadori. 2004. Coró-das-pastagens, p.191-210. In J.R. Salvadori, C.J. Ávila & M.T.B. da Silva (org.), Pragas de solo no Brasil. Passo Fundo, Embrapa Trigo, Embrapa Agropecuária Oeste, Fundacep, 541pSilva, da, M.T.B., Tarragó, M.F.S., Link, D., Costa, E.C., Preferência de oviposição de Diloboderus abderus (Sturm) por restos de culturas em solo com plantio direto (1996) An. Soc. Entomol. Brasil, 25, pp. 83-87Rausher, M.D., Alteration of oviposition behaviour by Battus philenor butterflies in response to variation in host-plant density (1983) Ecology, 64, pp. 1028-1034Thompson, H.N., Evolutionary ecology of the relationship between oviposition preference and performance of offspring in phytophagous insects (1988) Entomol. Exp. Appl, 47, pp. 3-14Travis, B.V., Habits of the June beetle, Phyllophaga lanceolata (Say), in Iowa (1939) J. Econ. Entomol, 32, pp. 690-69

Simultaneous alignment and folding of protein sequences

Accurate comparative analysis tools for low-homology proteins remains a difficult challenge in computational biology, especially sequence alignment and consensus folding problems. We presentpartiFold-Align, the first algorithm for simultaneous alignment and consensus folding of unaligned protein sequences; the algorithm’s complexity is polynomial in time and space. Algorithmically,partiFold-Align exploits sparsity in the set of super-secondary structure pairings and alignment candidates to achieve an effectively cubic running time for simultaneous pairwise alignment and folding. We demonstrate the efficacy of these techniques on transmembrane β-barrel proteins, an important yet difficult class of proteins with few known three-dimensional structures. Testing against structurally derived sequence alignments,partiFold-Align significantly outperforms state-of-the-art pairwise sequence alignment tools in the most difficult low sequence homology case and improves secondary structure prediction where current approaches fail. Importantly, partiFold-Align requires no prior training. These general techniques are widely applicable to many more protein families. partiFold-Align is available at http://partiFold.csail.mit.edu

Towards Reliable Automatic Protein Structure Alignment

A variety of methods have been proposed for structure similarity calculation, which are called structure alignment or superposition. One major shortcoming in current structure alignment algorithms is in their inherent design, which is based on local structure similarity. In this work, we propose a method to incorporate global information in obtaining optimal alignments and superpositions. Our method, when applied to optimizing the TM-score and the GDT score, produces significantly better results than current state-of-the-art protein structure alignment tools. Specifically, if the highest TM-score found by TMalign is lower than (0.6) and the highest TM-score found by one of the tested methods is higher than (0.5), there is a probability of (42%) that TMalign failed to find TM-scores higher than (0.5), while the same probability is reduced to (2%) if our method is used. This could significantly improve the accuracy of fold detection if the cutoff TM-score of (0.5) is used. In addition, existing structure alignment algorithms focus on structure similarity alone and simply ignore other important similarities, such as sequence similarity. Our approach has the capacity to incorporate multiple similarities into the scoring function. Results show that sequence similarity aids in finding high quality protein structure alignments that are more consistent with eye-examined alignments in HOMSTRAD. Even when structure similarity itself fails to find alignments with any consistency with eye-examined alignments, our method remains capable of finding alignments highly similar to, or even identical to, eye-examined alignments.Comment: Peer-reviewed and presented as part of the 13th Workshop on Algorithms in Bioinformatics (WABI2013