Showing papers by "State University of Campinas published in 1971"
52 citations
TL;DR: In this article, the results of some atomic calculations as affected by the Coulomb correlation were compared with the approximations proposed by Slater, Gaspar, Kohn and Sham, and Liberman.
Abstract: In this paper we present the results of some atomic calculations as affected by the Coulomb correlation. We deal with atoms and ions with and without spin polarization. Thus we are able to compare calculated energy eigenvalues and hyperfine fields of contact with the experimental ionization energies and fields. Our approximation for the mass operator (exchange plus correlation) can thus be compared with the approximations proposed by Slater, Gaspar, Kohn and Sham, and Liberman. A broad evaluation of the results implies that our approximation for exchange and correlation is correct. Furthermore, when neglecting the correlation effects, we noticed that the results become poorer. Thus, this paper favors a single-particle description of many-body systems based on an effective-wave equation with the mass operator instead of the simpler exchange operator of the Hartree-Fock theory.
37 citations
TL;DR: Nymphal Malpighian tubes of Triatoma infestans Klug have polyploid nuclei, however, these nuclei show heterochromatic bodies which have the number of replication steps not always in accordance with the euchromatin ones, in what they are similar to the Diptera.
Abstract: Nymphal Malpighian tubes of Triatoma infestans Klug have polyploid nuclei, as other insect groups. These nuclei, however, show heterochromatic bodies which have the number of replication steps not always in accordance with the euchromatin ones, in what they are similar to the Diptera. The nuclear volume does not follow the same increase in the DNA content per nucleus.
24 citations
TL;DR: In this paper, the reaction between hydrated lanthanide bromides and N,N-dimethylacetamide (DMA) was studied and the molar conductance of the compounds in DMA and nitromethane was determined.
14 citations
TL;DR: The following evidence indicates that this protein present in the secretion of the silk glands of Melipona quadrifasciata is not collagen: the optical sign of its birefringence does not become reversed after von Ebner's reaction, and its secretion can be detected when the cell nucleus attains a ploidy degree optimal for secretory activity.
Abstract: Acid and neutral polysaccharides exist in the secretion of the silk glands of Melipona quadrifasciata during the entire functional stage, except in the late 5th instar. However, only from the 3rd instar on is a molecularly oriented structural protein present. The following evidence indicates that this protein is not collagen: (1) the optical sign of its birefringence does not become reversed after von Ebner's reaction, and (2) its secretion can be detected when the cell nucleus attains a ploidy degree optimal for secretory activity. This is at first observed in the distal part of the glands and then throughout the organ.
8 citations
2 citations
TL;DR: The analyses of the data allow to conclude that both DLI and API, which have been used to evaluate the obliquity of the main lines and the distal crease of the palm, should not be considered as depending upon an important genetic component.
Abstract: The heritability of two main line indexes (DLI and TLI), a palm crease index (API), and an ulnarity index (UI) were investigated by using twin pair methodology for quantitative traits. The analyses of the data allow to conclude that both DLI and API, which have been used to evaluate the obliquity of the main lines and the distal crease of the palm, should not be considered as depending upon an important genetic component. Otherwise, data on TLI and UI, while showing inconsistencies with the theoretical expectations, may be considered as genetic traits.
1 citations