Genetic Divergence Among Accessions Of Cassava (manihot Esculenta Crantz) Sampled In The Tapajós Region, State Of Pará, Using Agronomic Characters And Microsatellite Markers

The aim of this work was to estimate the genetic divergence among accessions of cassava sampled in the Tapajós region in the State of Pará, Brazil, and conserved at the Regional Germplasm Bank of Eastern Amazon, using agronomic descriptors and molecular markers. Twenty-two accessions of cassava were evaluated in the field for two successive years, based on six agronomic descriptors in twelve-months-old plants without a specific experimental design. Accessions were also evaluated with eleven microsatellite loci in an automatic DNA analyser. Descriptive and multivariate statistical analyses were applied. Based on principal components analysis, the character weight of the aerial portion of the plant contributed most to the phenotypical variation. The six traits were used in the analysis of genetic dissimilarity between accessions, and the correlation between matrices generated by morphological and molecular data was estimated. The matrices of genetic dissimilarity were used in the construction of dendrograms using the UPGMA method. We observed a high variation of agronomical descriptors and molecular markers evaluated, which were capable to separate the accessions into distinct groups. A weak positive correlation was detected among the two matrices of genetic distances, which indicates the possibility to explore the genetic diversity using crossings and accessions Amarelinha 36 and Olho roxo 13 are divergent and potentially promising for the generation of heterotic hybrids.3752989300

Predictive ability of logistic regression, auto-logistic regression and neural network models in empirical land-use change modeling: a case study

The objective of this study is to compare the abilities of logistic, auto-logistic and artificial neural network (ANN) models for quantifying the relationships between land uses and their drivers. In addition, the application of the results obtained by the three techniques is tested in a dynamic land-use change model (CLUE-s) for the Paochiao watershed region in Taiwan. Relative operating characteristic curves (ROCs), kappa statistics, multiple resolution validation and landscape metrics were used to assess the ability of the three techniques in estimating the relationship between driving factors and land use and its subsequent application in land-use change models. The validation results illustrate that for this case study ANNs constitute a powerful alternative for the use of logistic regression in empirical modeling of spatial land-use change processes. ANNs provide in this case a better fit between driving factors and land-use pattern. In addition, auto-logistic regression performs better than logistic regression and nearly as well as ANNs. Auto-logistic regression and ANNs are considered especially useful when the performance of more conventional models is not satisfactory or the underlying data relationships are unknown. The results indicate that an evaluation of alternative techniques to specify relationships between driving factors and land use can improve the performance of land-use change models

Can the Consumption–Wealth Ratio Predict Housing Returns? Evidence from OECD Countries

This is the peer reviewed version of the following article: CAPORALE, G.M., SOUSA, R.M. and WOHAR, M.E., 2016. Can the consumption-wealth ratio predict housing returns? Evidence from OECD countries. Real Estate Economics, In Press. which has been published in final form at http://dx.doi.org/10.1111/1540-6229.12135. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.©2016 American Real Estate and Urban Economics Association We use a representative consumer model to analyze the relation between the transitory deviations of consumption from its common trend with aggregate wealth and labor income, cay, and the housing risk premium. The evidence based on data for 15 OECD countries shows that, if financial and housing assets are seen as complements, investors will temporarily allow consumption to rise when they expect a rise in future housing returns. By contrast, if housing assets are treated as substitutes for financial assets, consumption will be reduced

Dipolar interactions and anisotropic magnetoresistance in metallic granular systems

We revisit the theory of magnetoresistance for a system of nanoscopic magnetic granules in metallic matrix. Using a simple model for the spin dependent perturbation potential of the granules, we solve Boltzmann equation for the spin dependent components of the non equilibrium electronic distribution function. For typical values of the geometric parameters in granular systems, we find a peculiar structure of the distribution function of conduction electrons, which is at variance with the two-current model of conduction in inhomogeneous systems. Our treatment explicitly includes the effects of dipolar correlations yielding a magnetoresistance ratio which contains, in addition to the term proportional to the square of uniform magnetization (), a weak anisotropic contribution depending on the angle between electric and magnetic fields, and arising from the anisotropic character of dipolar interactions.Comment: 9 pages, 2 figures, accepted in PR