Genetics of resistance to powdery mildew (Microsphaera diffusa) in Brazilian soybean populations

Crosses between resistant and susceptible soybean cultivars were performed and the F2 populations were obtained to study the inheritance of soybean resistance to powdery mildew and to estimate the number and action of genes related to resistance. The reaction to powdery mildew was studied in a greenhouse and pots carrying plants with symptoms were distributed among the pots carrying the genotypes to be tested as a source of inoculum. Individual plants were scored according to the method of Yorinori (1997), with modifications, and classified as resistant or susceptible. The results showed that adult soybeans plants can present resistance to powdery mildew, which is controlled by one major gene with a dominant effect.

Search schemes for random optimization algorithms that preserve the asymptotic distribution

Markovian algorithms for estimating the global maximum or minimum of real valued functions defined on some domain Omega subset of R-d are presented. Conditions on the search schemes that preserve the asymptotic distribution are derived. Global and local search schemes satisfying these conditions are analysed and shown to yield sharper confidence intervals when compared to the i.i.d. case.

Beam Search Algorithms for Minimizing Tool Switches on a Flexible Manufacturing System

In the minimization of tool switches problem we seek a sequence to process a set of jobs so that the number of tool switches required is minimized. In this work different variations of a heuristic based on partial ordered job sequences are implemented and evaluated. All variations adopt a depth first strategy of the enumeration tree. The computational test results indicate that good results can be obtained by a variation which keeps the best three branches at each node of the enumeration tree, and randomly choose, among all active nodes, the next node to branch when backtracking.

Allocation of protective devices in distribution circuits using nonlinear programming models and genetic algorithms

The optimized allocation of protective devices in strategic points of the circuit improves the quality of the energy supply and the system reliability index. This paper presents a nonlinear integer programming (NLIP) model with binary variables, to deal with the problem of protective device allocation in the main feeder and all branches of an overhead distribution circuit, to improve the reliability index and to provide customers with service of high quality and reliability. The constraints considered in the problem take into account technical and economical limitations, such as coordination problems of serial protective devices, available equipment, the importance of the feeder and the circuit topology. The use of genetic algorithms (GAs) is proposed to solve this problem, using a binary representation that does (1) or does not (0) show allocation of protective devices (reclosers, sectionalizers and fuses) in predefined points of the circuit. Results are presented for a real circuit (134 busses), with the possibility of protective device allocation in 29 points. Also the ability of the algorithm in finding good solutions while improving significantly the indicators of reliability is shown. (C) 2003 Elsevier B.V. All rights reserved.

The genetics of hypertension modifies the renal cell replication response induced by experimental diabetes

To investigate whether the genetics of hypertension modifies renal cell responses in experimental diabetes, we studied the renal cell replication and its regulation by two cyclin-dependent kinase (Cdk) inhibitors, p27(Kip1) and p21(Cip1), in prehypertensive spontaneously hypertensive rats (SUR) and their genetically normotensive counterparts, Wistar Kyoto (WKY) rats, with and without streptozotocin-induced diabetes. In diabetic SIIR, the number of proliferating glomerular (0.6 +/- 0.3 positive cells/50 glomeruli) and tubulointerstitial (2.8 +/- 0.6 positive tubulointerstitial cells/50 grid fields) cells assessed by the bromodeoxyuridine technique was significantly (P = 0.0002) lower than in control SIIR (13.2 +/- 1.7 and 48.6 +/- 9.7, respectively) and control (14.0 +/- 1.8 and 63.9 +/- 10.6) and diabetic (14.3 +/- 3.5 and 66.4 +/- 11.5) WKY rats. Proliferating cell nuclear antigen, another marker of cell proliferation, was significantly reduced in replicating glomerular (P = 0.0002) and tubulointerstitial (P < 0.0001) cells in diabetic SHR. In freshly isolated glomeruli, the level of p27(Kip1) detected by Western blotting was significantly higher In diabetic SIIR than in nondiabetic SHR (1.52 +/- 0.14 vs. 1.00 +/- 0.10% of control, P = 0.014). The expression of p21(Cip1) in isolated glomeruli did not differ among the groups of rats. In conclusion, the response of renal cell replication to diabetes differs markedly between prehypertensive SIIR and their WKY control rats. The decreased glomerular cell proliferation in prehypertensive diabetic SIIR is at least partly mediated by a higher expression of the Cdk inhibitor p27(Kip1).

Genotype by environment interaction for 450-day weight of Nelore cattle analyzed by reaction norm models

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Using Amino Acid Correlation and Community Detection Algorithms to Identify Functional Determinants in Protein Families

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

Genetics of neotropical fish: from chromosomes to populations

The Neotropical freshwater fish fauna is very rich-according to the most recent catalogue 71 families and 4,475 species have been described. However, only a small amount of general information is available on the composition of Neotropical marine fishes. In Brazil, 1,298 marine species have been recorded. General analysis of available cytogenetic and population genetic data clearly indicates research has been mainly concentrated on freshwater fishes. Thus, today, cytogenetic information is available for 475 species of Characiformes, 318 species of Siluriformes, 48 species of Gymnotiformes, 199 freshwater species that do not belong to the superorder Ostariophysi, and only 109 species of marine fishes. For the species studied, only about 6% have sex chromosomes and about 5% have supernumerary or B chromosomes. A review of the cytogenetic studies shows that these data have provided valuable information about the relationships between fish groups, the occurrence of cryptic species and species complexes, the mechanism of sex determination and sex chromosome evolution, the distribution of nucleolus organizer regions, the existence supernumerary chromosomes, and the relationship between polyploidy and evolution. In relation to populations in Neotropical marine waters, the studies have shown the presence of cryptic species, which has important implications for fishery management. Different levels of genetic structuring can be found among Neotropical freshwater migratory fish species. This raises important implications for fish population genetic diversity and consequently its sustainable utilization in inland fisheries and aquaculture, specifically for conservation of ichthyo-diversity and survival.

The influence of landscape characteristics and home-range size on the quantification of landscape-genetics relationships

A common approach used to estimate landscape resistance involves comparing correlations of ecological and genetic distances calculated among individuals of a species. However, the location of sampled individuals may contain some degree of spatial uncertainty due to the natural variation of animals moving through their home range or measurement error in plant or animal locations. In this study, we evaluate the ways that spatial uncertainty, landscape characteristics, and genetic stochasticity interact to influence the strength and variability of conclusions about landscape-genetics relationships. We used a neutral landscape model to generate 45 landscapes composed of habitat and non-habitat, varying in percent habitat, aggregation, and structural connectivity (patch cohesion). We created true and alternate locations for 500 individuals, calculated ecological distances (least-cost paths), and simulated genetic distances among individuals. We compared correlations between ecological distances for true and alternate locations. We then simulated genotypes at 15 neutral loci and investigated whether the same influences could be detected in simple Mantel tests and while controlling for the effects of isolation-by distance using the partial Mantel test. Spatial uncertainty interacted with the percentage of habitat in the landscape, but led to only small reductions in correlations. Furthermore, the strongest correlations occurred with low percent habitat, high aggregation, and low to intermediate levels of cohesion. Overall genetic stochasticity was relatively low and was influenced by landscape characteristics.

Use of genetic algorithms and solvation potential to study peptides structure

In this work, genetic algorithms concepts along with a rotamer library for proteins side chains and implicit solvation potential are used to optimize the tertiary structure of peptides. We starting from the known PDB structure of its backbone which is kept fixed while the side chains allowed adopting the conformations present in the rotamer library. It was used rotamer library independent of backbone and a implicit solvation potential. The structure of Mastoporan-X was predicted using several force fields with a growing complexity; we started it with a field where the only present interaction was Lennard-Jones. We added the Coulombian term and we considered the solvation effects through a term proportional to the solvent accessible area. This paper present good and interesting results obtained using the potential with solvation term and rotamer library. Hence, the algorithm (called YODA) presented here can be a good tool to the prediction problem. (c) 2007 Elsevier B.V. All rights reserved.

Mating system in Myracrodruon urundeuva (Anarcadiaceae): implications for conservation genetics

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

Genetics of resistance to soybean cyst nematode, Heterodera glycines ichione (Race 3), in a brazilian soybean population

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

Genetics of anthracnose panel canker disease resistance and its relationship with yield and growth characters in half-sib progenies of rubber tree (Hevea brasiliensis)

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