Showing papers by "National University of Cuyo published in 1987"

Effect of the chronic ingestion of chlorimipramine and desipramine on the hole board response to acute stresses in male rats

Abstract: The effect of the chronic ingestion of chlorimipramine (CI) or desipramine (DS) on the alterations of hole board behavior caused by a model stress (2 IP injections of physiological saline) and by a short restraint stress (5 min) is analyzed in this study. The experimental groups ingested about 3 mg/kg/24 hr CI or DS for 15 days. Then some experimental and control rats were assigned to control of drug effects on baseline activity. The remaining rats were submitted to saline stress (Experiment I) or restraint stress (Experiment II). The baseline scores of hole board locomotion, head dipping, grooming and defecation were not affected by DS treatment but locomotion slightly increased in the CI treated group. Saline stress impaired significantly head dipping and caused excessive grooming in control rats. The CI treatment induced almost full protection against these behavioral effects of saline stresses better than Restraint stress was found to cause a pronounced inhibition of head dipping as well as great increase of the scores of grooming in the control group. The CI treatment clearly attenuated these effects of restraint but DS treatment was not effective. The results suggest that (1) male rats treated chronically with CI tolerated both acute stresses better than untreated rats, and that (2) a similar treatment with DS did not provide protection against the effect of such stresses on hole board responding. Inasmuch as CI and DS have different relative potency at noradrenergic and serotonergic systems, it is speculated that this might be in part responsible for their differences as stress protectors.

In vitro mass tuberisation as a contribution to potato micropropagation

Abstract: Mass tuberisation was obtained on plantlets growing from nodal potato cuttings cultured in vitro on Murashige-Skoog (MS) medium under continuous light of 5000 lux at 24–25°C. Tuber formation was stimulated by transferring the plantlets to MS or White-Nitsch-Morel (WhNM) liquid or solid media supplemented with 8% sucrose, 2 mg 1−1 benzyladenine (BAP), 2 mg 1−1 naphthalenacetic acid (NAA) and/or 100 mg 1−1 (2-chloroethyl) trimethylammonium chloride (CCC). Liquid media invariably induced heavier minitubers (390–790 mg each). The process to tuberisation took only two months. Minitubers always produced normal growing plants after dormancy break.

Calculation of neutron cross sections and thermalization parameters for molecular gases using a synthetic scattering function. I.

Abstract: Based on a synthetic scattering function describing the interaction of thermal neutrons with molecular gases, we developed analytical expressions for cross sections of interest in reactor-physics calculations; these are the zero- and first-order angular moments of the double-differential cross section, ${\ensuremath{\sigma}}_{0}$(${E}_{0}$,E) and ${\ensuremath{\sigma}}_{1}$(${E}_{0}$,E), respectively, and the total scattering cross section \ensuremath{\sigma}(${E}_{0}$). The formulas presented here allow then a very fast and reliable evaluation of thermalization parameters and transport coefficients at any desired temperature of the moderating media. One of the main applications of this study is the generation of (thermal) nuclear data libraries for reactor codes, using a minimum set of input information. In the following paper, calculations based on our formulas are compared with experimental data and other theories for some commonly used moderators under different physical conditions.

Non-Markovian diffusion-like equation for transport processes with anisotropic scattering

Abstract: In order to describe particles diffusing in a medium with anisotropic scattering, we have derived a non-Markovian pseudo-diffusion equation starting from the solution of the one-dimensional persistent random walk model. The differential equation has a space-time convolution with a well-defined kernel. The analytic solution of this non-Markovian diffusion equation, in Fourier space, gives the conditional probability (essentially a renormalized Gaussian distribution) which is a function of the order parameter ( p − q ) ( p and q being the forward and backward scattering probabilities respectively). The velocity autocorrelation function has also been obtained analytically, showing the dependence with the order parameter.

Alternative approach to the Schrödinger equation: Shifting operators between Hilbert spaces

Abstract: For a given one-dimensional Hamiltonian we construct a family of Hamiltonians whose Hilbert spaces are related by shifting operators such that each level of the original Hilbert space corresponds to the ground state of another one of the family. This allows us to establish the equivalence between the Schr\"odinger equation and a sequence of Ricatti equations.

New weyl theory: geometrization of electromagnetism and gravitation: motivations and classical results

Abstract: A geometrical unified field theory of electromagnetism and gravitation is developed in a Weyl space-time. The integrability conditions of the field equations cast the laws of classical perfect fluids under electromagnetic interactions. The purely gravitational limit of the theory is Einstein's General Relativity and the purely electromagnetic case coincides with the predictions of Maxwell's theory.

Total Cross Section of Sulphur at Slow Neutron Energies

Abstract: The total cross section of elemental Sulphur was measured at neutron energies between 1.6 x 10-3 eV and 100 eV, using a pulsed neutron source and time-of-flight techniques. The data in the epithermal neutron region were used to extract the value of the bound nucleus scattering length, taking into account the neutron-electron interaction. A similar transmission experiment was also performed on elemental Bismuth.