University of Arkansas

About: University of Arkansas is a education organization based out in Fayetteville, Arkansas, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 17225 authors who have published 33329 publications receiving 941102 citations. The organization is also known as: Arkansas & UA.

Environmental and Soil Factors Affecting Micronutrient Deficiencies and Toxicities

Abstract: The availability of the essential micro nutrients B, Cu, Fe, Mn, Mo, and Zn to plants is often poorly related to the total quantity of the particular element in the soil. Soil properties such as pH, redox potential, organic matter content, nutrient interactions, the type of plant or variety, and environmental factors, such as soil water content, temperature and light, greatly influence the likelihood that a plant will exhibit micronutrient-deficiency or -toxicity symptoms. Changes in the environment often have a greater effect on micronutrient than on macro nutrient nutrition of plants. This chapter emphasizes advances in knowledge since Lucas and Knezek's (1972) review in the first edition of this book. In addition, greater emphasis than is customary will be placed on the role of the environment on micronutrient nutrition. Other general references that contain material on this topic are available (Adriano, 1986; Bergmann, 1988; Marschner, 1986; Mengel & Kirkby, 1987; Weber, 1971; and Wild, 1988). Some excellent reference sources include the specific contributions of Keren and Bingham (1985) and Fleming (1980) on B, of Loneragan et al. (1981) on Cu, of Jones (1982, 1984, 1986, and 1988) on Fe, of Graham et al. (1988) on Mn, of Gupta and Lipsett (1981) on Mo, and of Adriano (1986) on Zn. The comprehensive study of Sillanpaa (1982) provides much useful information concerning micronutrient uptake by plants and selected soil properties.

Fight or Flight? Defending against Sequential Attacks in the Game of Siege

Abstract: This article examines theory and behavior in a two-player game of siege, sequential attack and defense. The attacker’s objective is to successfully win at least one battle, while the defender’s objective is to win every battle. Theoretically, the defender either folds immediately or, if his valuation is sufficiently high and the number of battles is sufficiently small, then he has a constant incentive to fight in each battle. Attackers respond to defense with diminishing assaults over time. Consistent with theoretical predictions, the authors’ experimental results indicate that the probability of successful defense increases in the defenders valuation and it decreases in the overall number of battles in the contest. However, the defender engages in the contest significantly more often than predicted and the aggregate expenditures by both parties exceed predicted levels. Moreover, both defenders and attackers actually increase the intensity of the fight as they approach the end of the contest.

Software process improvement: it's a journey, not a destination

Abstract: Realizing the benefits of continuous software process improvement.

Kinetics of gramicidin channel formation in lipid bilayers: transmembrane monomer association.

Abstract: Conducting gramicidin channels form predominantly by the transmembrane association of monomers, one from each side of a lipid bilayer. In single-channel experiments in planar bilayers the two gramicidin analogs, [Val1]gramicidin A (gA) and [4,4,4-F3-Val1]gramicidin A (F3gA), form dimeric channels that are structurally equivalent and have characteristically different conductances. When these gramicidins were added asymmetrically, one to each side of a preformed bilayer, the predominant channel type was the hybrid channel, formed between two chemically dissimilar monomers. These channels formed by the association of monomers residing in each half of the membrane. These results also indicate that the hydrophobic gramicidins are surprisingly membrane impermeant, a conclusion that was confirmed in experiments in which gA was added asymmetrically and symmetrically to preformed bilayers.