Software complexity and its impact on software reliability

To produce reliable software, its complexity must be controlled by suitably decomposing the software system into smaller subsystems. A software complexity metric is developed that includes both the internal and external complexity of a module. This allows analysis of a software system during its development and provides a guide to system decomposition. The basis of this complexity metric is in the development of an external complexity measure that characterizes module interaction     

The Investigation of the Behavior of Microorganisms by Computerized Television

Instrumentation is described which permits, along with simultaneous subjective observation, the rapid recording and quantification of the overt behavior of motile microorganisms under varying conditions. From a chain of standard commercially available units (with the exception of a single especially designed one) there has emerged a totality which provides unique advantages to the student of overt behavior. It consists of a primary optical system through which the organisms are televised, a standard video tape recorder, a unit which we have christened the ``bugwatcher' that processes the video signal from the tape for quantification of data by a computer, and finally, a digital computer.     

Formation of silica and silicates during the solidification of Fe−Si−O alloys

Small (35 g) ingots of Fe?Si?O alloys have been solidified under controlled conditions and the form, distribution, and compositions of the oxides in the cast structures are reported. The composition of a melt was established by charging a preselected amount of silicon, 0.002 < pct Si < 0.7, and equilibrating the melt with the silica crucible at 1550° or 1650°C. The concentration of FeO and the morphology of the oxide particles in the cast structures indicate that during solidification the process of segregation causes the oxygen potential in the interdendritic liquid to increase over that in equilibrium with the silicon content of the liquid. It appears that nuclei for the formation of the oxide phases, which probably are in the liquid prior to the onset of solidification, become surrounded by solid iron and are made ineffective. It is possible at lower silicon levels that homogeneous nucleation may result by the melt becoming sufficiently supersaturated in oxygen to form FeO or an iron-silicate liquid phase.     

Use of selenite enrichment broth for the detection of Salmonella from stool: a report of one year experience at a provincial public health laboratory

Umbilical blood lead level, as an indicator for intrauterine exposure to lead, and neurobehavioral score, as an effect indicator, were determined in 101 neonates in Beijing area to explore the relationship between intrauterine lead exposure and neonatal neurobehavioral development. Results revealed that there was a negative relationship between neonatal umbilical blood lead level and their neurobehavioral score and behavioral ability. With umbilical blood lead level of 0.48 mumol/L as a cutoff value, there was a significant difference in neonatal behavioral ability score between groups of high and low blood lead levels. There also were significant differences in nonbiologically auditory and biological visual and auditory orientation reaction. It suggests that intrauterine lead exposure can cause adverse effects on neonatal neurobehavioral development, especially on their visual and auditory function.     

EUROPEAN BREWERY CONVENTION: HAZE AND FOAM GROUP. TOWARDS THE CHEMICAL PREDICTION OF SHELF LIFE

Rapid chemical methods are described for assesssing in beer the levels of “oxidizable polyphenols” and “sensitive proteins,” both of which influence non-biological shelf life. The method for oxidizable polyphenols depends on the formation of an insoluble complex with cinchonine sulphate. Freshly processed beers form only a slight haze on the addition of cinchonine sulphate, but the haze produced is greatly increased if the beers are previously oxidized. For beers stabilized by a process involving reduction of the polyphenol content, it is found that the rate of haze formation is then directly related to shelf life and is inversely proportional to it.     

Interactive effects of teaching strategy and personal locus of control on student performance and satisfaction.

Studied the relationships between personal locus of control (Rotter's Internal-External Control Scale), teaching discipline, student performance, and satisfaction. 54 undergraduates were randomly assigned to 2 teaching conditions. In the high discipline condition, Ss were exposed to a 2-hr "mini-course" on computer programming that adhered to 5 empirically derived dimensions of perceived high discipline. In the low discipline condition, Ss were handed identical computer programming materials and told to proceed at their own pace with no rules. Results show that Ss high on internal locus of control performed better under low discipline conditions, while high external control Ss performed better under high teacher discipline conditions. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chemistry of the Ammonia Pressure Process for Leaching Ni,Cu, and Co from Sherritt Gordon Sulphide Concentrates

The paper relates to the laboratory and pilot plant studies that have been carried out by Sherritt Gordon Mines Ltd., Metallurgical Research Div., in developing the ammonia pressure leach process for extracting copper, nickel, cobalt, and sulphur from high grade nickel concentrate produced from Lynn Lake ores, and describes in some detail the chemistry of the process.     

Responses of Mud Snails and Periwinkles to Environmental Odors and Disaccharide Mimics of Fish Odor

Estuarine snails, periwinkles (Littoraria irorata), and mud snails (Ilyanassa obsoleta) were tested for behavioral responses to aqueous extracts of tissue macerates, odors of living intact organisms, and to disaccharides derived from heparin. Extracts included salt-marsh cordgrass (Spartina alterniflora), pink shrimp (Penaeus duorarum), crushed periwinkles, and crushed mud snails. Odors included live periwinkles, mud snails, stone crab (Menippe mercenaria), striped hermit crab (Clibanarius vittatus), tulip snail (Fasciolaria hunteria), and mummichog (Fundulus heteroclitus). Responses were determined upon contact by snails of a ring of solution in the bottom of an otherwise dry bowl and by presenting snails in seawater with 25 l of solution on a cotton swab. In each test, the response of 30 individuals was determined. Behaviors were recorded as fed, alarm, and no response. The strongest alarm response (>80% of all snails tested) in both snails was elicited by crushed mud snails. The strongest feeding response was to shrimp and periwinkle extract for mud snails (>70%), and salt-marsh cordgrass extract attracted periwinkles. High percentages of mud snails and periwinkles fled in response to the odors of intact snail predators, stone crabs, tulip snails, and mummichogs. Mud snails and periwinkles did not flee in response to nonpredator odors, including each other's odor, as well as that of hermit crabs, shrimp, and marsh cordgrass. Heparin disaccharides were tested because other studies reported that biological activity of predatory fish odor is due to similar disaccharides originating from fish mucus. Mud snail responses to disaccharides indicate that they respond to the same kinds of molecules as crustacean larvae and that the modified amine on the disaccharide is essential for activity. The Q-tip assay is appropriate for bioassay-directed purification of alarm signals originating in fish body odor.     

Direct leaching zinc-sulfide concentrates by Sherritt Gordon

Oxidation in an autoclave with sulfuric acid has been shown to extract 95 to 99 pct of the zinc present, produce a quantitative amount of elemental sulfur, and avoid loss of zinc due to ferrite formation.