IMPROVED SOFTWARE MAINTENANCE MANAGEMENT

A formal procedure for managing software maintenance—from the submission of a work order through the postimplementation review—opens a window of opportunity for the IS manager who sees systems as candidates for reverse engineering, reengineering, and restructuring. This article describes a set of procedures for improving maintenance management.     

Inhibitors of acrosin and granulocyte proteinases from human genital tract secretions

Human seminal plasma contains two acid-stable proteinase inhibitors, HUSI-II (Mr approximately 6500) and HUSI-I, (Mr approximately 11 000) with different inhibition specificities. The inhibitory activity of HUSI-II is strongly limited to trypsin and acrosin; both enzyme-inhibitor complexes are very stable (e.g. bovine trypsin-HUSI-II complex: Ki = 1 x 10(-10)M; human acrosin-HUSI-II complex: Ki = 2.7 x 10(-10)M). The inhibitor from human seminal plasma HUSI-II may therefore be seen as the natural antagonist of the sperm protease acrosin. In addition to pancreatic trypsin and alpha-chymotrypsin, HUSI-I forms strong complexes with neutral proteases of the lysosome-like granules from human granulocytes, for example, the elastase (Ki = 2.5 x 10(-9)M) and cathepsin G, the chymotrypsin like protease (Ki = 7 x 10(-8)M).     

Interrelationships in fatty acid processing

Examples are presented of the effect of each processing step on the quality, yield and throughput in the fatty acid processing scheme. These examples serve to illustrate the importance of seemingly unimportant process variables upon the economic involved in fatty acid processing.     

An Algorithm for Volume Estimation Based on Polyhedral Approxi mation

A volume algorithm is established which uses the data generated by computed tomography (CT) or ultrasound scans. The algorithm is based on a polyhedral reconstruction of an object of interest. Phantom studies indicate that the algorithm calculated volume is accurate within 3 percent. In a controlled clinical experiment on a laboratory animal, the algorithm calculated volume showed a maximum error of about 5 percent. In less controllable applications to human clinical data, volume calculations showed variations ranging up to 16 percent.     

Neural factors in experimental degenerative arteriopathy

Intermittent electrical stimulation of the lateral hypothalamus of rats performed for 30 min to 6 hr, results in hyperlipidemia and endothelial cell damage of the aorta and coronary arteries. Hyperlipidemia is related to transient biliary obstruction elicited by hypothalamic stimulation and is characterized by elevation of the cholesterol, phospholipid, and triglyceride fractions. Endothelial cell damage is observed ultrastructurally as plasma membrane degeneration with detachment and the formation of large spaces (“vacuoles”). Thus, neural factors may be implicated in inducing conditions associated with early atherogenesis. Stimulation carried out for longer time intervals would be expected to produce more advanced lesions. However, the role of neural transmission per se (i.e., without hyperlipidemia) in producing arteriopathy is not clearly defined from these experiments. In rats, the lesser splanchnic nerve forms the major innervation of the abdominal aorta. In animals fed normal diets, chronic intermittent stimulation of this nerve (up to 3 weeks) resulted in advanced arteriosclerotic changes with intimal fibrosis and calcification. On histologic examination, lipid deposits appeared to be absent from these lesions. Animals stimulated for shorter periods of time exhibited earlier changes associated with atherogenesis, such as endothelial damage, elastic reduplication, and adherent microthrombi. Thus, direct neural transmission, especially if excessive, plays a role in producing arteriopathy. Hyperlipidemia, if persistent, could modify these lesions so that they would accumulate plasma lipids. Experiments to test this hypothesis are currently in progress.     

Zur Hydroxyprolinbestimmung in Lebensmitteln

Zusammenfassung Die Farbreaktion von Pyrrol mitp-Dimethylaminobenzaldehyd ist als Ehrlichsche Reaktion die Grundlage der Hydroxyprolin-Bestimmung nach Oxydation mit Wasserstoffperoxid. Nach eingehender Untersuchung des Oxydationsverlaufes wurden die Reaktionsbedingungen der Farbbildung geprfift, die nicht quantitativ abläuft, sondern einem Gleichgewicht zustrebt.

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Determination of hydroxyproline in foods

Summary The determination of hydroxyproline after oxydation with hydrogenperoxide bases on the reaction of pyrrol with p-dimethylaminobenzaldehyde (Ehrlich-reaction). The oxydation and colour formation was tested and it was shown that finally there is no quantitative reaction but an equilibrium, which is reached.