Realistic Neutrino Opacities for Supernova Simulations With Correlations and Weak Magnetism

Advances in neutrino transport allow realistic neutrino interactions to be incorporated into supernova simulations. We add tensor couplings to relativistic RPA calculations of neutrino opacities. Our results reproduce free-space neutrino-nucleon cross sections at low density, including weak magnetism and recoil corrections. In addition, our opacities are thermodynamically consistent with relativistic mean field equations of state. We find antineutrino mean free paths that are considerably larger then those for neutrinos. This difference depends little on density. In a supernova, this difference could lead to an average energy of $\bar\nu_\mu$ that is larger than that for $\nu_\mu$ by an amount that is comparable to the energy difference between $\nu_\mu$ and $\bar\nu_e$Comment: 15 pages, 10 figures, submitted to PRC, minor changes to figs. (9,10

Reproductive performance of a crossbreed of Cuban Creole boar with Duroc-Hampshire females

We describe in this paper the reproductive performance of Cuban Creole x (Duroc x Hampshire) cross-breed pigs. This cross-breeding system is presently under investigation for the reproductive improvement of mountain areas. Ours results have shown as these cross-breed population maintain good levels in the relation partution/fertilisation (82.74 percent) with respect to the employed pure breeds exploited in the same conditions. Litter size, birth weight, number of weaned, piglets and weaning weight were similar to the means reached by the exotic breeds, while the birth weight and the mean weaning weight were lower. In a general way, this crossbreeding can be considered as improver in Cuban mountain areas, pointing out the use of native genetic resources in its production.En este trabajo se describe el comportamiento reproductivo del cruzamiento entre cerdos Criollos Cubanos como línea paterna y hembras cruzadas Duroc x Hampshire. Esta pauta se encuentra en fase de investigación en Cuba para la mejora productiva de las áreas de montaña. Nuestros resultados han encontrado como este cruce se mantiene en unos niveles (82,74 p.100) para la relación parto/cubriciones frente a las razas puras intensamente explotadas en el mismo medio. El tamaño de la camada, el peso al nacimiento, el número de crías destetadas y el peso al destete, fueron similares a las medias de las razas exóticas, mientras que el peso al nacimiento y el peso promedio al destete fueron inferiores. En general este cruce puede considerarse mejorante para las condiciones de montaña, destacando la utilización de recursos genéticos autóctonos en su producción

Cuban creole pig in Bayamo jurisdiction

The former jurisdiction of Bayamo, as political colonial division began its way in the century XVI, after its foundation in 1513 as the second Cuban village. Currently the Bayamo village is integrated by 15 local districts, an extension of 835.12 km2 and a population 68690 inhabitants. In spite of have elapsed more than 470 years from the arrival of the first pigs from Spain, this region has maintained 6176 breeders of this native pig breed as direct descendant of the Mediterranean pigs. In this work is presented the racial, ecological and human factors, that they have permitted the maintenance of this population with origin in the Iberian pig.La antigua jurisdicción de Bayamo, como división política de la colonia comenzó su andadura en el siglo XVI, tras su fundación en 1513 como la segunda villa de Cuba. Actualmente el municipio de Bayamo lo integran 15 consejos populares, una superficie de 835,12 km2 y una población de 68690 habitantes. A pesar de haber transcurrido más de 470 años desde la llegada de los primeros cerdos desde España, esta región ha mantenido 6176 reproductores de la raza cerdo Criollo como descendiente directo de los cerdos mediterráneos. En este trabajo se presenta los factores racial, ecológico y humano, que han permitido la perdurabilidad de esta raza descendiente del cerdo Ibérico

Path planning with far-away obstacles detection under uncertainty

[Resumen] Hoy en día se están investigando robots de exploración terrestre y espacial más rápidos en respuesta a la creciente demanda de capacidades de exploración e investigación más rápidas, eficaces y rentables. Para estas plataformas móviles rápidas la identificación y evasión de obstáculos lejanos son críticas, ya que su alta velocidad implica la necesidad de tener en cuenta el mayor número posible de obstáculos cercanos y lejanos para el cálculo de la trayectoria global, evitando cualquier posible accidente debido a su velocidad y al tiempo de cálculo de los algoritmos de replanificación. Debido a su distancia, los obstáculos lejanos no se incluyen en los mapas locales, que están limitados por el alcance de las cámaras de profundidad. Por estas razones, este artículo propone el uso de técnicas de Inteligencia Artificial para detectarlos a partir de imágenes y estimar sus tamaños y posiciones con un cierto grado de incertidumbre. Los obstáculos detectados se incluirán posteriormente en los mapas globales, corrigiendo la trayectoria global en caso de colisionar con ellos.[Abstract] Nowadays faster terrestrial and space exploration robots are being investigated, in response to the growing demand for faster, more efficient, and cost-effective exploration and research apabilities. For these rapid mobile platforms, the identification and avoidance of far obstacles are critical, since their high speed implies the need to take into account as many near and far obstacles as possible for the global path computation, avoiding any possible accident due to their speed and the computation time of the replanning algorithms. Due to their distance, the far obstacles are not included within the local maps, which are limited by the range of the depth cameras. For these reasons, this paper proposes the use of Artificial Intelligence techniques to detect them from images and estimate their sizes and positions with a certain degree of uncertainty. The detected obstacles will be later included in the global maps, correcting the global path in case it collides with them

Time-periodic phases in populations of nonlinearly coupled oscillators with bimodal frequency distributions

The mean field Kuramoto model describing the synchronization of a population of phase oscillators with a bimodal frequency distribution is analyzed (by the method of multiple scales) near regions in its phase diagram corresponding to synchronization to phases with a time periodic order parameter. The richest behavior is found near the tricritical point were the incoherent, stationarily synchronized, ``traveling wave'' and ``standing wave'' phases coexist. The behavior near the tricritical point can be extrapolated to the rest of the phase diagram. Direct Brownian simulation of the model confirms our findings.Comment: Revtex,16 pag.,10 fig., submitted to Physica

The Black Creole Cuban Pig: origin, evolution and present status

The origin of the Cuban Creole Black pig is under a controversy, but the majority of authors locate their procedure in the ancient Spanish Iberian branches. Others hypothesis point out a possible influence of pre-hispanic Black Canarian pig, and also the early influence of Duroc and Hampshire breeds. Coinciding with all the Cuban farming development, this breed increase greatly their census from the beginning of the colonisation to the first half of the XVIIIth century, when their decreasing started as a consequence of the big expansion of tobacco and sugar Cain agriculture. In the present century this breed was in risk of extinction because the competence of improved foreign breeds, but presently this bred has gain god perspectives, because her role in the Cuban sustainable development.El origen del Cerdo Negro Criollo Cubano sigue siendo discutido, aunque la mayoría de los autores atribuyen su procedencia de los antiguos troncos ibéricos de España. Otras hipótesis plantean una posible influencia de los cerdos canarios prehispánicos e incluso el aporte reciente de sangre de las razas Duroc y Hampshire. Esta raza, coincidiendo con todo el desarrollo ganadero cubano, incrementó enormemente sus censos desde el inicio de la colonización hasta la primera mitad del siglo XVIII donde comenzó su declive a consecuencia de la gran expansión de la explotación tabacalera y de la caña de azúcar. En el presente siglo ha peligrado su conservación por la competencia de las razas selectas extranjeras aunque en la actualidad presenta unas excelentes perspectivas de recuperación dentro del desarrollo sostenible de Cuba

Hamiltonian Study of Improved U(1U(1 Lattice Gauge Theory in Three Dimensions

A comprehensive analysis of the Symanzik improved anisotropic three-dimensional U(1) lattice gauge theory in the Hamiltonian limit is made. Monte Carlo techniques are used to obtain numerical results for the static potential, ratio of the renormalized and bare anisotropies, the string tension, lowest glueball masses and the mass ratio. Evidence that rotational symmetry is established more accurately for the Symanzik improved anisotropic action is presented. The discretization errors in the static potential and the renormalization of the bare anisotropy are found to be only a few percent compared to errors of about 20-25% for the unimproved gauge action. Evidence of scaling in the string tension, antisymmetric mass gap and the mass ratio is observed in the weak coupling region and the behaviour is tested against analytic and numerical results obtained in various other Hamiltonian studies of the theory. We find that more accurate determination of the scaling coefficients of the string tension and the antisymmetric mass gap has been achieved, and the agreement with various other Hamiltonian studies of the theory is excellent. The improved action is found to give faster convergence to the continuum limit. Very clear evidence is obtained that in the continuum limit the glueball ratio $M_{S}/M_{A}$ approaches exactly 2, as expected in a theory of free, massive bosons.Comment: 13 pages, 15 figures, submitted to Phys. Rev.

Nonlinear analysis of a simple model of temperature evolution in a satellite

We analyse a simple model of the heat transfer to and from a small satellite orbiting round a solar system planet. Our approach considers the satellite isothermal, with external heat input from the environment and from internal energy dissipation, and output to the environment as black-body radiation. The resulting nonlinear ordinary differential equation for the satellite's temperature is analysed by qualitative, perturbation and numerical methods, which show that the temperature approaches a periodic pattern (attracting limit cycle). This approach can occur in two ways, according to the values of the parameters: (i) a slow decay towards the limit cycle over a time longer than the period, or (ii) a fast decay towards the limit cycle over a time shorter than the period. In the first case, an exactly soluble average equation is valid. We discuss the consequences of our model for the thermal stability of satellites.Comment: 13 pages, 4 figures (5 EPS files

Stability of Spatio-Temporal Structures in a Lattice Model of Pulse-Coupled Oscillators

We analyze the collective behavior of a lattice model of pulse-coupled oscillators. By studying the intrinsic dynamics of each member of the population and their mutual interactions we observe the emergence of either spatio-temporal structures or synchronized regimes. We perform a linear stability analysis of these structures.Comment: 15 pages, 2 PostScript available upon request at [email protected], Accepted in Physica