Evaluación del comportamiento productivo y reproductivo en tres hatos de la raza Cebú.

El estudio se realizó en tres hatos con ganado Cebú Brahman, en municipios del departamento de Santander (Colombia). Se orientó a evaluar el comportamiento productivo y reproductivo de la raza, relacionando los efectos de edad de la madre, mes y año del parto y el reproductor utilizado, sobre el intervalo entre partos. Utilizando 1843 observaciones, el intervalo entre partos para los 3 hatos fué de 465.7, 458.19 y 512.98 días, respectivamente. En 2 de los hatos hubo una inclinación a disminuír el intervalo entre partos en vacas de 7 a 13 años. En todos los hatos hubo efecto significativo del año del parto; se observó una tendencia a intervalos más cortos en las vacas paridas en verano. En 2 hatos hubo efecto significativo del reproductor sobre el intervalo entre partos; la disminución en el intervalo fue más marcada en los reproductores con el menor número de observaciones. Los porcentajes de natalidad tuvieron bruscas variaciones de acuerdo al año estudiado; los menores valores para cada hato fueron de 61.4 por ciento, 65.1 por ciento y 58.4 por ciento, y los máximos de 92.2 por ciento, 92.5 por ciento y 84.0 por ciento. El peso al nacimiento en el hato estudiado fué de 32.01 más o menos 1.88 kg en 574 observaciones, teniendo efecto significativo el sexo del ternero y su interacción con el padre. Se encontraron pesos superiores en los terneros nacidos en verano. De las enfermedades estudiadas, la rinotraqueitis bovina infecciosa fue la que presentó mayor cantidad de reactores (75 sueros de 139 muestras presentaron títulos positivos) Para diarrea viral bovina y parainfluenza-3, los sueros con títulos positivos correspondieron al 2.15 por ciento y 0.90 por ciento, respectivamente. De 9 muestras tomadas a los reproductores en los 3 hatos, no se detectó trichomoniasis ni campylobacteriosisMaestría en CienciasMaestrí

Collisionless collective modes of fermions in magnetic traps

We present a Random-Phase-Approximation formalism for the collective spectrum of two hyperfine species of dilute 40K atoms, magnetically trapped at zero temperature and subjected to a repulsive s-wave interaction between atoms with different spin projections. We examine the density-like and the spin-like oscillation spectra, as well as the transition density profiles created by external multipolar fields. The zero sound spectrum is always fragmented and the density and spin channels become clearly distinguishable if the trapping potentials acting on the species are identical. Although this distinction is lost when these confining fields are different, at selected excitation frequencies the transition densities may display the signature of the channel.Comment: 10 pages, 9 figure

Lyapunov Potential Description for Laser Dynamics

We describe the dynamical behavior of both class A and class B lasers in terms of a Lyapunov potential. For class A lasers we use the potential to analyze both deterministic and stochastic dynamics. In the stochastic case it is found that the phase of the electric field drifts with time in the steady state. For class B lasers, the potential obtained is valid in the absence of noise. In this case, a general expression relating the period of the relaxation oscillations to the potential is found. We have included in this expression the terms corresponding to the gain saturation and the mean value of the spontaneously emitted power, which were not considered previously. The validity of this expression is also discussed and a semi-empirical relation giving the period of the relaxation oscillations far from the stationary state is proposed and checked against numerical simulations.Comment: 13 pages (including 7 figures) LaTeX file. To appear in Phys Rev.A (June 1999

Promoting FAIRness in marine data at Centro Nacional Instituto Español de Oceanografía

The Spanish Institute of Oceanography is responsible, among other aspects, for scienti c and technical advice for the Government's sheries policy as well as for the protection and sustainability of the marine environment. In this task, it generates a large amount of oceanographic data characterized by its spatial dispersion during acquisition as well as by its di erent typology. The purpose of both the National Oceanographic Data Center and the GIS team is to safeguard data and to disclose what data exists and where, how and when it has been acquired and, in addition, to provide access to that data through the collaboration with di erent international data infrastructures like EMODnet or SeaDataNet. To this end, the data and metadata are subjected to quality control and formatted for integration into a national Spatial Data Infrastructure (SDI). This SDI has a GeoNetwork catalogue with ~ 1750 oceanographic campaigns, together with (meta)data and services that are continuously being revised and incorporated. All this with the ultimate goal of making the data increasingly FAIR

Ordering and finite-size effects in the dynamics of one-dimensional transient patterns

We introduce and analyze a general one-dimensional model for the description of transient patterns which occur in the evolution between two spatially homogeneous states. This phenomenon occurs, for example, during the Freedericksz transition in nematic liquid crystals.The dynamics leads to the emergence of finite domains which are locally periodic and independent of each other. This picture is substantiated by a finite-size scaling law for the structure factor. The mechanism of evolution towards the final homogeneous state is by local roll destruction and associated reduction of local wavenumber. The scaling law breaks down for systems of size comparable to the size of the locally periodic domains. For systems of this size or smaller, an apparent nonlinear selection of a global wavelength holds, giving rise to long lived periodic configurations which do not occur for large systems. We also make explicit the unsuitability of a description of transient pattern dynamics in terms of a few Fourier mode amplitudes, even for small systems with a few linearly unstable modes.Comment: 18 pages (REVTEX) + 10 postscript figures appende

Barrier effects on the collective excitations of split Bose-Einstein condensates

We investigate the collective excitations of a single-species Bose gas at T=0 in a harmonic trap where the confinement undergoes some splitting along one spatial direction. We mostly consider onedimensional potentials consisting of two harmonic wells separated a distance 2 z_0, since they essentially contain all the barrier effects that one may visualize in the 3D situation. We find, within a hydrodynamic approximation, that regardless the dimensionality of the system, pairs of levels in the excitation spectrum, corresponding to neighbouring even and odd excitations, merge together as one increases the barrier height up to the current value of the chemical potential. The excitation spectra computed in the hydrodynamical or Thomas-Fermi limit are compared with the results of exactly solving the time-dependent Gross-Pitaevskii equation. We analyze as well the characteristics of the spatial pattern of excitations of threedimensional boson systems according to the amount of splitting of the condensate.Comment: RevTeX, 12 pages, 13 ps figure

Participación comunitaria y procesos de comunicación en la implementación de programas de reasentamiento de familias dentro del contexto del desarrollo urbano en Barranquilla (Colombia)

Planning processes of development and growth of the city of Barranquilla have required the relocation of the population living in areas of intervention actions. As part of the implementation of the New Management Plan Territorial (POT), the city plans to revitalize an area around the Magdalena River with a view to improving the quality of life of citizens and to increase competitiveness of the city. The revitalization project is known as project “La Loma “. Under the current Land Use Plan of Barranquilla (POT), the urban development project “La Loma” includes, among other activities, the transfer of a large number of people currently living in this area. For this reason, this article aims to review the current POT and documents from City Council and the Mayor’s office associated with the POT and “La Loma” project, in order to identify and analyze the component of community participation and communication related to the implementation of this project. The results of the documents revealed the presence of regulatory elements associated with community participation. The results also showed potentially useful spaces for the implementation of inclusive communication processes. Therefore, this article proposes a guide for the formulation of a strategic communication plan with a focus on participatory communication and dialogue facilitator to be used during the execution of urban projects that include the relocation of families. © 2016, Universidad del Norte. All rights reserved

Survival and residence times in disordered chains with bias

We present a unified framework for first-passage time and residence time of random walks in finite one-dimensional disordered biased systems. The derivation is based on exact expansion of the backward master equation in cumulants. The dependence on initial condition, system size, and bias strength is explicitly studied for models with weak and strong disorder. Application to thermally activated processes is also developed.Comment: 13 pages with 2 figures, RevTeX4; v2:minor grammatical changes, typos correcte