In situ synchrotron radiation X-ray scattering study on the effect of a stearic sucrose ester on polymorphic behavior of a new sunflower oil variety.

The effect of the stearic sucrose ester (SE) S-170 on crystallization behavior and polymorphism of two stearins obtained from a new variety of high stearic high oleic sunflower oil was studied by pulsed nuclear magnetic resonance (p-NMR), small (SAXS) and wide (WAXS) angle X-ray scattering using synchrotron light and differential scanning calorimetry (DSC). p-NMR studies showed that there is always a crystallization temperature below which SE S-170 accelerated crystallization and above which SE S-170 delayed nucleation and growth. The effect of SE S-170 strongly depended on supercooling.

Micro-evolution in grasshoppers mediated by polymorphic Robertsonian translocations.

This review focuses on grasshoppers that are polymorphic for Robertsonian translocations because in these organisms the clarity of meiotic figures allows the study of both chiasma distribution and the orientation of trivalents and multivalents in metaphase I. Only five species of such grasshoppers were found in the literature, and all of them were from the New World: Oedaleonotus enigma (Scudder) (Orthoptera: Acrididae), Leptysma argentina Bruner, Dichroplus pratensis Bruner, Sinipta dalmani Stål, and Cornops aquaticum Bruner. A general feature of these species (except O.

Assembling Small Silicon Clusters Using Criteria of Maximum Matching of the Fukui Functions.

In this work, we present a methodology inspired by criteria of "maximum matching" between the Fukui functions to predict the best interaction between small silicon clusters to form larger ones. The model is based on the topological analysis of the Fukui functions. We tested the methodology in the formation of Si4-Si8 using a set of small Si2-Si6 clusters as building blocks in ground state structures in singlet and triplet multiplicities.

beta-carotene encapsulation in a mannitol matrix as affected by divalent cations and phosphate anion.

The effects of addition of divalent cations and phosphate buffer on the degree of beta-carotene encapsulation in a mannitol matrix during freeze-drying were analyzed. The degradation rate of encapsulated beta-carotene as a function of % RH and its relationship with the physical state of the matrix during storage at 25 degrees C was also studied. The presence of phosphate salts significantly delayed mannitol crystallization at a highly satisfactory degree during freeze-drying and, consequently, the degree of beta-carotene encapsulation increased.

Structural collapse prevents beta-carotene loss in a supercooled polymeric matrix.

The kinetics of degradation and surface color changes of beta-carotene encapsulated in a polymeric matrix (PVP-40) and its relationship with physical changes (manifested as structural collapse) of the matrix were studied during storage of samples at several water activities at constant temperature. The degradation rate constants obtained decreased with an increase in the relative humidity (RH) of the storage atmosphere. Beta-carotene losses were observed mainly at RHs below the glass transition temperature (Tg) of the corresponding systems, and the lower degradation constant rates were observed under conditions where the matrices were fully plasticized (i.

Chromosomal polymorphism, morphometric traits and mating success in Leptysma argentina Bruner (Orthoptera).

The South-American species Leptysma argentina Bruner is polymorphic for a centric fusion between chromosomal pairs 3 and 6 (fusion 3/6). Cytogenetic and morphological studies revealed that fusion 3/6 significantly increases some morphometric variables in males. A selection components study showed that the fusion is positively selected for longevity, the direct effect being exerted on thorax height.

Chromosomal polymorphism, morphological traits and male mating success in Leptysma argentina (Orthoptera).

Leptysma argentina (Acrididae: Orthoptera) is polymorphic for a centric fusion between pairs 3 and 6 of its basic chromosomal complement. With the aim of carrying out an analysis of selection components in this species, male mating success, in relation to karyotype and three morphometric traits, was assessed by using experimental contests with four males and one female per mating cage. Karyotype was assessed in terms of fused chromosome 3/6 dosage and coded as "0", "1" and "2" for unfused homozygotes, heterozygotes and fusion homozygotes, respectively.

Chromosome polymorphisms and natural selection in Leptysma argentina (Orthoptera). IV. Survival selection acts on karyotype polymorphisms at the adult stage and before.

Deviation from formal null models and the comparisons between age classes are amongst the most direct methods of demonstrating ongoing natural selection. We have sampled 207 males from a population of the grasshopper Leptysma argentina at the onset and the end of the adult life span for this species; generations are synchronical and do not overlap. The karyotypic frequencies for a fusion (F) and a supernumerary segment (s1) were examined.