PRODUCCIÓN ORGÁNICA DE LECHE DE OVEJA

Los sistemas de producción orgánicos se basan en procesos naturales, aprovechamiento de recursos locales y disminución en la degradación del suelo. La efectividad de la producción de leche de los sistemas orgánicos vs los sistemas de producción convenciona les es un tema abierto a debate. Son diversos los estudios en los cuales se observa un efecto positivo de los sistemas orgánicos de producción de leche de oveja en relación al bienestar y salud animal, calidad de los productos e impacto ambiental. No obsta nte, algunos autores citan rendimientos lácteos inferiores, así como mayor susceptibilidad a condiciones medioambientales comparados con los obtenidos en sistemas convencionales. Los menores rendimientos en los sistemas orgánicos de producción de leche de oveja, están relacionados con el limitado aporte nutricional, el bajo potencial genético, así como las cambiantes condiciones medioambientales. Estos sistemas ovinos son principalmente un método de producción para un mercado específico que ofrece productos con calidad Premium y elevados estándares de calidad en sus procesos de producción. Por lo que una empresa ovina orgánica de producción de leche debe ser considerada viable en la medida que presente un balance positivo a nivel de sostenibilidad global, es decir, que sea socialmente benéfica , económicamente viable y medioambientalmente responsable

Vertebral Osteonecrosis

Vertebral osteonecrosis (ON) is a rare, underdiagnosed disease, also called pseudarthrosis due to ischemia following a compression fracture (CF). The main features include the air-occupied intravertebral cleft visualized as a radiolucent shade of linear or semilunar X-ray, namely an intravertebral vacuum cleft (IVC) sign. Usually, this phenomenon shows low signal intensity with all magnetic resonance imaging (MRI) sequences. Another feature of ON of the vertebral body is the intravertebral fluid analogous to edema and fibrosis in histological sections. This appears as low signal intensity on T1-weighted MRI, with high signal intensity on T2-weighted images. The risk factors for vertebral ON are multivariate, and the pathophysiological mechanisms are still unknown with certainty

IMPLEMENTACIÓN DE UN SISTEMA PROXY DE NAVEGACION SEGURA EN EL GET DE CIENFUEGOS

El objetivo fue implementar un sistema de proxy gratuito basado en software libre para el logro de mayor seguridad y control en el Grupo de Electrónica para el Turismo de Cienfuegos (GET). Esta entidad utiliza un proxy Kerio para el control de la red, programa limitado por la compra de licencias. Se identificaron softwares y protocolos existentes para un sistema proxy de navegación segura. Se caracterizó la red de datos del GET de Cienfuegos. Se compararon los softwares existentes para el sistema. Se propuso el Squid como servidor proxy por su fortaleza y seguridad, el E2guardian como filtro web por su potencial, el Squish para el control de cuota por ser el único programa de software libre. Además, se escogieron los métodos de autenticación NTLM por ser el método más seguro entre los tres niveles de autenticación del Squid, Se implementó en una Pc corei3 con el Promox versión 4.4

DESEMPEÑO DE ALGORITMOS HEURÍSTICOS EN LA SOLUCIÓN DE PROBLEMAS CUADRÁTICOS NO CONVEXOS CON RESTRICCIONES DE CAJA

En el trabajo se proponen varios algoritmos heurísticos para resolver el problema cuadrático no convexo con restricciones de caja y se compara su rendimiento tomando en consideración la calidad de las soluciones y el tiempo de ejecución empleado. Adicionalmente, comparamos los resultados obtenidos con los algoritmos heurísticos con los algoritmos híbridos heurísticos, que consisten, una vez hallada la mejor solución del algoritmo heurístico, realizar una exploración exhaustiva de su vecindad, para determinar un mínimo local contenido en ella. Los resultados muestran un mejor desempeño de las metaheurísticas Enjambre de Partículas (PSO) y Algoritmos Genéticos (GA) en problemas de hasta 200 variables. Por último se muestra un mejor desempeño de las metaheurísticas hibridas en comparación con las no híbridas, aunque no poseen diferencias significativas entre ellas

Potential fields modeling for the Cayos Basin (Western Caribbean Plate): Implications in basin crustal structure

The Cayos Basin is an offshore basin located in the Colombian Caribbean Sea and forms part of the Lower Nicaraguan Rise, a geological province of the western region of the Caribbean Plate. Until now, the origin of the province is still being debated. Advanced research in the study area regarding its composition and structure, from land outcrops, petrology and geochemistry of drilled cores and dredged samples, and geophysical investigations, indicates a volcanic origin for this geological province, and a close relationship to the formation of the Caribbean Large Igneous Province. On the contrary, other studies suggest that the Lower Nicaraguan Rise may be part of the continental Chortis block. In this paper, we present and discuss alternative scenarios for the nature of the underlying crust below the sedimentary sequences in the Cayos Basin. We characterize the basin through the interpretation of magnetic and gravity anomaly grids, and 2D forward modeling, constructed based on three sections, by considering restriction seismic data from previous works. The results show that the Cayos Basin is underlain by geological bodies with high density and higher magnetization. From the gravity and magnetic forward modeling, we estimated the depth to the basement is about 2-6 km, and the Moho discontinuity to have an average of 18 km below, the Cayos Basin. Our investigation implies that, at least, the Cayos Basin is in the oceanic crust domain and shows no evidence of a continental source of the Chortis block

Study of several interpolation schemes to provide ionospheric corrections for navigation

Since the development of space based geodesic techniques, the increasing of the positioning accuracy has been a major goal. In this context, the effect of the ionosphere has been a key issue to be taken into account to improve the navigation results obtained using several types of receivers: from dual frequency phase receivers at distances greater than tens of kilometres of the nearest fixed site to single frequency code receivers. To overcome this problem, it is necessary either an accurate modelling of the ionosphere at the fixed stations and an optimum interpolation scheme for the rover receiver. This approach is either valid for single frequency users or rovers using dual frequency phase receiver. The current work studies the performance of different interpolation schemes such as linear interpolation and kriging, which can be implemented in a rover receiver in order to interpolate either the Slant Total Electron Content (from now on STEC) or the Double Differenced STEC from the transmitted corrections that are computed at the fixed stations.Peer Reviewe

Resonances and Exceptional Broadcasting Conditions

Many technologies have been developed to improve the quality of broadcasting, but persist with the problem that avoids the continuity of communications when the physical conditions of the media change. However, loss of signal propagation cannot be avoided because the refractive index of propagation media changes at the same time as magnetization, electromagnetic potential and other local parameters. That is, there is neither a device nor theories that take into account the effect of the sign of the refractive index under the broadcasting process. Simultaneously with the change of refractive index, conventional waves may find travel conditions inaccessible to the desired destination. In this chapter, we proposed that a sudden change in conditions is due to a resonant behavior of the media naturally described by a homogeneous integral equation of Fredholm. In addition, we propose a method to avoid the loss of the signal due to drastic changes in the broadcasting regime

Main and Minor Types of Collagens in the Articular Cartilage: The Role of Collagens in Repair Tissue Evaluation in Chondral Defects

Several collagen subtypes have been identified in hyaline articular cartilage. The main and most abundant collagens are type II, IX and XI collagens. The minor and less abundant collagens are type III, IV, V, VI, X, XII, XIV, XVI, XXII, and XXVII collagens. All these collagens have been found to play a key role in healthy cartilage, regardless of whether they are more or less abundant. Additionally, an exhaustive evaluation of collagen fibrils in a repaired cartilage tissue after a chondral lesion is necessary to determine the quality of the repaired tissue and even whether or not this repaired tissue is considered hyaline cartilage. Therefore, this review aims to describe in depth all the collagen types found in the normal articular cartilage structure, and based on this, establish the parameters that allow one to consider a repaired cartilage tissue as a hyaline cartilage

Does Progressive Introduction of Benznidazole Reduce the Chance of Adverse Events in the Treatment of Chagas Disease?

In this retrospective cohort study, we aimed to assess whether introducing benznidazole at escalating doses reduces the probability of adverse events or treatment discontinuation compared with a full-dose scheme. We collected data from patients who had chronic " - " infection and underwent treatment from July 2008 to January 2017 in a referral center in Madrid. Dose was adjusted to body weight (5 mg/kg/day), with treatment introduction with full dose or escalating dose according to local consensus and protocols. Among the 62 patients treated, benznidazole was introduced at full dose in 28 patients and on escalating dose in the remaining 34. We found no statistical differences in the number of adverse events, treatment discontinuations, days of treatment, or sociodemographic profiles. There is insufficient evidence to support escalating dose as a strategy for reducing the adverse effects of benznidazole. Further research is needed to evaluate this strategy