Challenges in enriching milk fat with polyunsaturated fatty acids

Milk fatty acid composition is determined by several factors including diet. The milk fatty acid profile of dairy cows is low in polyunsaturated fatty acids, especially those of the n-3 series. Efforts to change and influence fatty acid profile with longer chain polyunsaturated fatty acids have proven challenging. Several barriers prevent easy transfer of dietary polyunsaturated fatty acids to milk fat including rumen biohydrogenation and fatty acid esterification. The potential for cellular uptake and differences in fatty acid incorporation into milk fat might also have an effect, though this has received less research effort. Given physiological impediments to enriching milk fat with polyunsaturated fatty acids, manipulating the genome of the cow might provide a greater increase than diet alone, but this too may be challenged by the physiology of the cow

High-speed flow in an annular cascade with tip clearance: Numerical investigation

The high-speed flow in an annular cascade with two tip clearance sizes is numerically modeled using a Navier-Stokes solver and the high-Reynolds-number k-ε turbulence model. The numerical predictions should be regarded as complementary to the experimental work conducted in the NTUA annular cascade facility, designed for studying tip-clearance effects in compressor cascades. In the numerically simulated experiment, the stationary blades are mounted on the casing and the tip clearance is formed between them and the spinning hub. The purpose of the present paper is to scrutinize flow trends identified during the measurements and elucidate the flow patterns in the blade passage for rotating and stationary hub.</jats:p

Use of marine fauna and tool stones in the south of Buenos Aires Province (Argentina) during the Middle and Late Holocene

The exploitation of coastal and marine resources by hunter-gatherers in the south of Buenos Aires Province (Argentina) during the Mid-Late Holocene was examined through the analysis of faunal and lithic evidence in the following archaeological sites: El Americano II and Barrio Las Dunas (Mid-Late Holocene), both located in coastal sand dunes, Puente de Fierro (Late Holocene), located in a wetland distant 7 km from the seashore, Paso Vanoli, located 13 km from the seashore, and Paso Mayor YI S1 (Mid-Late Holocene), located in a fluvial environment 41 km from the seashore. The evidence suggests that, during the Mid-Holocene, in the coastal sites, hunter-gatherers used several marine vertebrates (e.g. pinnipeds and fishes—Pogonias cromis-), whereas in the inland sites, they only transported mollusks and coastal pebbles. In the Late Holocene, in the sites located a few kilometers from the coast, hunter-gatherers carried only selected parts of pinnipeds as well as mollusks and coastal pebbles. Pinnipeds represented a low proportion of the faunal remains. In contrast, in sites far away from the Atlantic coast, hunter-gatherers carried only stones and mollusks. We propose that although the Atlantic coast in the study area was regularly visited by hunter-gatherers all along the Holocene, the importance of marine food decreased during the Late Holocene, whereas the importance of coastal tool stones and mollusks continued.Fil: Frontini, Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Humanidades; ArgentinaFil: Bayón, María Cristina. Universidad Nacional del Sur. Departamento de Humanidades; Argentin