Modeling of two-phase flows at low Capillary number with VoF method

In this work, a modified version of the FSF (Filtered Surface Force) method is presented. The method was originally developed by Raeini et al. specifically for modeling low Capillary number multiphase flows, basing its structure on a well consolidated VoF (Volume of Fluid) CSF (Continuum Surface Force) solver in OpenFOAM (R). The numerical method proposed in this paper is a combination of the FSF and the CICSAM scheme of Ubbink, which has been translated into a TVD framework instead of its original NVD formulation. The capability of this scheme in compressing the interface numerically lets to simplify the FSF formulation, avoiding the modification of the indicator function for the computation of the surface tension forces. Moreover, a different formulation of the filter applied to the capillary forces is presented as a simplification of the original implementation. The time step is limited by capillary forces time scale and the Courant number is chosen as a compromise between the necessity of reducing the calculation time and the numerical diffusion of the advection schemes. The methodology is validated with several test cases, showing different problems of the classical CSF method and making comparisons with theoretical solutions

Relationship between cellular and whey components in buffalo milk

High somatic cell count (SCC) affects milk quality and cheesemaking, resulting in a reduction in cheese yield and quality. In dairy cows, quarter milk samples with >200 000 cells/ml are considered to have subclinical mastitis, while there is much uncertainty on the corresponding levels of SCC in buffalo milk. In this study 30 lactating water buffaloes were selected and SCC, differential somatic cell counts and several whey components were tested in quarter milk samples to assess the relationship between inflammation markers and milk quality. Overall 236 quarter milk samples were considered. To evaluate the relationship between cellular markers (SCC, polymorphonuclear leucocytes, PMN, and N-Acetyl-\u3b2-glucosaminidase, NAGase) and other milk components, three classes were defined (low, medium and high). Analysis of milk yield showed a significant reduction in the high class of each of the three markers chosen. Overall, the highest class was characterized by significant changes in milk composition and a lower milk quality. The presence of an inflammatory status of the udder was frequent after the first trimester of lactation and in buffaloes with two or more parturitions. This study showed that significant changes in milk components can be observed when SCC are >400 000 cells/ml, PMN are >50% and NAGase is >100 units. These thresholds could be suggested as levels to define udder health status in buffalo cows

Salmonella Typhimurium infection primes a nutriprive mechanism in piglets

Salmonella enterica serovar Typhimurium (S. Typhimurium) is an important cause of acute food- borne zoonoses worldwide, typically carried by pigs. It is well known that Salmonella has evolved a wide array of strategies enabling it to invade the host, but little information is available on the specific host responses to Salmonella infections. In the present study, we used an in vivo approach (involving piglets infected with a virulent or an attenuated S. Typhimurium strain) coupled to histological and proteomic analysis of the cecum mucosa, to highlight the host pathways activated during S. Typhimurium infection. We confirm the complex host-pathogen interaction. Our data showed that the metabolic and the cytoskeleton organization functions were the most significantly altered. In particular, the modifications of energy metabolic pathway could suggest a "nutriprive" mechanism, in which the host reduce its metabolic and energetic status to limit Salmonella infection. This study could represent a preliminary approach, providing information useful to better understand the host-Salmonella interaction

Salmonella Typhimurium infection primes a nutriprive mechanism in piglets

Salmonella enterica serovar Typhimurium (S. Typhimurium) is an important cause of acute food- borne zoonoses worldwide, typically carried by pigs. It is well known that Salmonella has evolved a wide array of strategies enabling it to invade the host, but little information is available on the specific host responses to Salmonella infections. In the present study, we used an in vivo approach (involving piglets infected with a virulent or an attenuated S. Typhimurium strain) coupled to histological and proteomic analysis of the cecum mucosa, to highlight the host pathways activated during S. Typhimurium infection. We confirm the complex host-pathogen interaction. Our data showed that the metabolic and the cytoskeleton organization functions were the most significantly altered. In particular, the modifications of energy metabolic pathway could suggest a "nutriprive" mechanism, in which the host reduce its metabolic and energetic status to limit Salmonella infection. This study could represent a preliminary approach, providing information useful to better understand the host-Salmonella interaction

O tratamento das superfícies arquitetônicas como problema teórico da restauração

O artigo aborda a questão das superfícies arquitetônicas e sua relação com a teoria de restauração. São examinadas com esse intuito, em linhas gerais, as transformações por que passaram as teorias de restauro. Analisam-se também as tendências contemporâneas, com o intuito de averiguar os princípios gerais que deveriam guiar as intervenções. Verificase então o que ocorre na prática de intervenções em superfícies arquitetônicas, notando-se que há uma dissociação entre teoria e prática. Neste texto, procura-se enfatizar a relevância da reflexão teórica para enfrentar os problemas em toda a sua complexidade e como meio eficiente de preservar os aspectos materiais, históricos, formais e simbólicos dos monumentos