The Protein Composition of Barley Grown in South Dakota

High protein barley is preferred for feeding purposes and low or medium protein types are needed for satisfactory malting. The large variations which occur in the protein content of South Dakota barley make it difficult to plan an efficient program for production of either feed or malting barley. The present protein composition work investigating the protein fractionation of three barley varieties may be helpful toward adjustment of feeding and malting practices, making possible the better utilization of barley in the future

Nitrates in Drinking Water

Nitrate poisoning in livestock is a recurring problem. In ruminants the bacteria are able to convert nitrates (NO3) to nitrites (NO2) in the gastrointestinal tract. If nitrite is present in large amounts it converts hemoglobin to methemoglobin, which has little or no oxygen- carrying capacity. The result in severe cases is asphyxiation. It is not known what effects nitrates may have on swine. Nitrate levels as high as 700 parts per million (ppm ) have been found in water samples from South Dakota. The probable ways nitrates get into drinking water are by natural means and pollution. The purpose of this experiment was to determine the effects these nitrates in the drinking water have on the performance of growing-finishing pigs

Methionine and Related Compounds and Selenium Poisoning

The problem of selenium poisoning has been known for many years, but the mechanism by which this element exerts its toxicity has not been clarified. As a result, what control measures are now available are of an empirical nature, and they fail to the give the most desirable protection. In search of a better control mechanism, the role of compounds containing biologically active methyl groups has been studied. Some experimental work indicated that these types of compounds might indeed be involved in the metabolism of selenium. However, not all workers’ data were in agreement, and it was felt that further studies were needed

Tides in colliding galaxies

Long tails and streams of stars are the most noticeable upshots of galaxy collisions. Their origin as gravitational, tidal, disturbances has however been recognized only less than fifty years ago and more than ten years after their first observations. This Review describes how the idea of galactic tides emerged, in particular thanks to the advances in numerical simulations, from the first ones that included tens of particles to the most sophisticated ones with tens of millions of them and state-of-the-art hydrodynamical prescriptions. Theoretical aspects pertaining to the formation of tidal tails are then presented. The third part of the review turns to observations and underlines the need for collecting deep multi-wavelength data to tackle the variety of physical processes exhibited by collisional debris. Tidal tails are not just stellar structures, but turn out to contain all the components usually found in galactic disks, in particular atomic / molecular gas and dust. They host star-forming complexes and are able to form star-clusters or even second-generation dwarf galaxies. The final part of the review discusses what tidal tails can tell us (or not) about the structure and content of present-day galaxies, including their dark components, and explains how tidal tails may be used to probe the past evolution of galaxies and their mass assembly history. On-going deep wide-field surveys disclose many new low-surface brightness structures in the nearby Universe, offering great opportunities for attempting galactic archeology with tidal tails.Comment: 46 pages, 13 figures, Review to be published in "Tidal effects in Astronomy and Astrophysics", Lecture Notes in Physics. Comments are most welcom