Stability of exploratory multivariate data modeling in longitudinal data

Exploratory data-driven multivariate analysis provides a means of investigating underlying structure in complex data. To explore the stability of multivariate data modeling, we have applied a common method of multivariate modeling (factor analysis) to the Genetic Analysis Workshop 13 (GAW13) Framingham Heart Study data. Given the longitudinal nature of the data, multivariate models were generated independently for a number of different time points (corresponding to cross-sectional clinic visits for the two cohorts), and compared. In addition, each multivariate model was used to generate factor scores, which were then used as a quantitative trait in variance component-based linkage analysis to investigate the stability of linkage signals over time. We found surprisingly good correlation between factor models (i.e., predicted factor structures), maximum LOD scores, and locations of maximum LOD scores (0.81< ρ <0.94 for factor scores; ρ >0.99 for peak locations; and 0.67< ρ <0.93 for peak LOD scores). Furthermore, the regions implicated by linkage analysis with these factor scores have also been observed in other studies, further validating our exploratory modeling

Food consumption and economic development in Turkey and European Union countries

This study investigates the relationship between food consumption and economic development in Turkey and European Union countries. Differences in food diets are analysed by using data on per capita consumption in caloric terms based on the period from 1970 to 2000. The cluster analysis is employed to derive country grouping on the basis of similarities in dietary structure in the 1970 and 2000. Existence of a trend towards a common European diet is explored with Beta convergence. The empirical results show that per capita food consumption is becoming less responsive to changes in income and appears to be reaching a ceiling in the majority of EU countries and Turkey. However, the share of animal products in food consumption diet is low and income expenditure elasticity of animal products is higher with 0.84 values in Turkey than that in European countries in 2000. There are great differences in dietary structure between Turkey and the European Union. Differences also exist between European Union countries; however, despite these differences there is a general tendency for dietary structure to become increasingly similar across the majority of European Union countries. The result also supports the absence of a convergence towards a common diet if Turkey joins the European Union.

A Survey of Affected-Sibship Statistics for Nonparametric Linkage Analysis

We have compared the power of a large number of allele-sharing statistics for “nonparametric” linkage analysis with affected sibships. Our rationale was that there is an extensive literature comparing statistics for sibling pairs but that there has not been much guidance on how to choose statistics for studies that include sibships of various sizes. We concentrated on statistics that can be described as assigning scores to each identity-by-descent–sharing configuration that a pedigree might take on (Whittemore and Halpern 1994). We considered sibships of sizes two through five, 27 different genetic models, and varying recombination fractions between the marker and the trait locus. We tried to identify statistics whose power was robust over a wide variety of models. We found that the statistic that is probably used most often in such studies—S(all)—performs quite well, although it is not necessarily the best. We also found several other statistics (such as the R criterion, S(robdom), and the Sobel-and-Lange statistic C) that perform well in most situations, a few (such as S(-#geno) and the Feingold-and-Siegmund version of S(pairs)) that have high power only in very special situations, and a few (such as S(-#geno), the N criterion, and the Sobel-and-Lange statistic B) that seem to have low power for the majority of the trait models. For the most part, the same statistics performed well for all sibship sizes. We also used our results to give some suggestions regarding how to weight sibships of different sizes, in forming an overall statistic

Structural and vibrational investigation of 1,2-bis(3,4-dimethoxyphenyl) ethane-1,2-dione (Veratril): experimental and theoretical studies

WOS: 000257332800013The molecular and crystal structures of 1,2-bis(3,4-dimethoxyphenyl)ethane-1,2-dione (TMBZ = tetramethoxybenzil) were determined by a single-crystal X-ray diffraction, (1)H NMR, and FT-IR spectroscopy. The compound TMBZ (C(18)H(18)O(6), M (r) = 330.32) crystallized in the orthorhombic Fdd2 space group wherein: a = 39.145(4), b = 18.167(2), c = 4.3139(5) angstrom and beta = 90 degrees, Z = 8. The packing of the molecules in the crystal lattice is stabilized by intermolecular C-H center dot center dot center dot O contacts in the herringbone arrangement. The molecular geometry and harmonic frequencies of TMBZ in the ground state were calculated utilizing density functional (B3LYP) method with the 6-311++G(d, p)-basis set. The density functional theory optimized the geometric structure, and vibrational wave numbers of TMBZ in gas phase were compared with the experimental data. A complete assignment of the fundamentals was proposed based on the total energy distribution calculation

Farm-Level Feed Demand in Turkey

Using farm-level survey data from Turkey, this study provides estimates of the price responsiveness of feed demand beef, dairy, and sheep producers. In addition, the impact of feed quality on animal yields is assessed in the Turkish dairy cattle sector

Farm-Level Feed Demand in Turkey

Using farm-level survey data from Turkey, the authors provide estimates of the price responsiveness of feed demand beef, dairy, and sheep producers. In addition, the authors assess the impact of feed quality on animal yields in the Turkish dairy cattle sector.