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Over the years, the combination of computational fluid dynamics (CFD) and theoretical models have critically contributed to improving our understanding of the nature of turbulent flows. In this paper, we review the role of CFD in the study of turbulence through both direct numerical simulations and the resolution of statistical multi-scale theories. With a historical perspective, we will discuss the evolution of the numerical modeling of turbulence from the first numerical experiments as proposed by Orszag and Patterson [1] to complex geophysical and plasma simulations where body forces such as Coriolis, the buoyancy force, or the Lorentz force can introduce strong anisotropies. Looking beyond the horizon, we address the future challenges for CFD and turbulence theorists with the prospect of exascale supercomputing.

Modelling the process of induced fracture initiation, propagation and interaction with natural fractures is a very challenged task. Significant progress has been made in recent years in the development of complex fracture models to address the needs for more suitable design tools than the conventional planar fracture models. However, some aspects of this complex process are not still fully understood in terms of their impact or importance to the overall fracture geometry, or the complexity of simulating them is beyond the current modelling capabilities or requires computation effort that is not practical for engineering purpose. A technique that has been developed to represent the process of fracture propagation is the Continuous Approximation of Strong Discontinuities, which introduces a special kinematics, capable of representing the process of degradation of the material. One way to implement this approximation is to introduce the effects of a very narrow band of localized deformations within the existing finite elements. In this paper was used a finite element procedure that performs numerical analysis of fluid flow in a deformable porous media in a fully coupled scheme. In this analysis the propagation of the hydraulic fracture occurs specially along the pathway of the natural fractures, due to their lower tensile strength and greater permeability.

Abstract Background For ruminants reared on grazing systems, gastrointestinal nematode (GIN) parasite infections represent the class of diseases with the greatest impact on animal health and productivity. Among the many possible strategies for controlling GIN infection, the enhancement of host resistance through the selection of resistant animals has been suggested by many authors. Because of the difficulty of routinely collecting phenotypic indicators of parasite resistance, information derived from molecular markers may be used to improve the efficiency of classical genetic breeding. Methods A total of 181 microsatellite markers evenly distributed along the 26 sheep autosomes were used in a genome scan analysis performed in a commercial population of Spanish Churra sheep to detect chromosomal regions associated with parasite resistance. Following a daughter design, we analysed 322 ewes distributed in eight half-sib families. The phenotypes studied included two faecal egg counts (LFEC0 and LFEC1), anti-Teladorsagia circumcincta LIV IgA levels (IgA) and serum pepsinogen levels (Peps). Results The regression analysis revealed one QTL at the 5% genome-wise significance level on chromosome 6 for LFEC1 within the marker interval BM4621-CSN3. This QTL was found to be segregating in three out of the eight families analysed. Four other QTL were identified at the 5% chromosome-wise level on chromosomes 1, 10 and 14. Three of these QTL influenced faecal egg count, and the other one had an effect on IgA levels. Conclusion This study has successfully identified segregating QTL for parasite resistance traits in a commercial population. For some of the QTL detected, we have identified interesting coincidences with QTL previously reported in sheep, although most of those studies have been focused on young animals. Some of these coincidences might indicate that some common underlying loci affect parasite resistance traits in different sheep breeds. The identification of new QTL may suggest the existence of complex host-parasite relationships that have unique features depending on the host-parasite combination, perhaps due to the different mechanisms underlying resistance in adult sheep (hypersensitivity reactions) and lambs (immunity). The most significant QTL identified on chromosome 6 for LFEC1 may be the target for future fine-mapping research efforts.

Entre 1660 y 1700 Luis XIV envió 24 representantes acreditados ante el rey católico, de los cuales 7 pueden considerarse embajadores residentes aunque ninguno de ellos permaneció allí más de seis años. Aunque éste no fue el único asunto que trataron allí, todos compartieron en mayor o menor grado una misma expectativa, que el rey de España muriera sin heredero legítimo, y una misma esperanza: que la corona española recayera en un candidato Borbón. A ello se refería la mayor parte de la información que sus enviados a la corte madrileña debían captar y enviar. Por ello éstos tuvieron que empeñarse en trabajar para convencer a los subditos del monarca católico de apoyar, o de no oponerse, a que Luis XIV, el Delfín o Felipe de Anjou heredaran el trono hispano de los Habsburgo. Sus negociaciones estuvieron en gran parte encaminadas al mismo fin: incorporar la corona española sin lucha.

The authors of the present article, all physicians engaged in a multidisciplinary perinatal collaboration in the Institut de puericulture de Paris-Necker-Enfants malades, propose an up to date view of the traumatic experience, for infants, parents and clinicians, inherent to prematurity, based on literature review. Their focus questions the impact and consequences of this experience over development, interactions and parenthood.

Patients with cardiovascular disease undergoing non cardiac surgery are exposed to three cardiac risks: myocardial infarction, heart failure and death. To estimate cardiac risk, clinical predictors of perioperative cardiovascular risk are classified as major, intermediate and minor and non cardiac surgery is stratified in high risk (greater than 5%), intermediate (from 1 to 5%), minor (lower than 1%) procedures. Efficient perioperative assessment of cardiac patients is obtained by teamwork and usually, indications for further cardiac investigations are the same as those in the nonoperative setting. An simplified algorithm, easier to use than original algorithm given in the guidelines of the American college of cardiology and the American heart association, may be helpful for the indication of further investigations. Five questions must be answered before using algorithm: is it an emergency surgical procedure?, was a coronary revascularization required in the past five years? has the patient had a coronary evaluation in the past two years?, are there identified clinical predictors of cardiac risk?, is it major or minor surgery? Three tests evaluate the preoperative cardiac risk: exercise testing, dipyridamole thallium scintigraphy, dobutamine stress echocardiography. Their accuracy is similar, their negative predictive value is high, their positive predictive value is low. These guidelines may be helpful to indicate further cardiac investigations which will have an impact on patient's treatment, monitoring during or after surgery and outcome.

An 81-year-old woman without any known previous disease was admitted for epigastralgia, nausea, vomiting and anorexia since 15 days. The investigations disclosed a pneumopericardium which was caused by the perforation of a gastric ulcer, situated on the collar of an hiatal hernia. A pericardial drainage and a suture of the ulcer were performed, but the patient could not be saved. Despite an optimal treatment composed of pericardial drainage, specific surgery and intensive care, the mortality rate of pneumopericardium is still around 50% proving the severity of this illness.