Monadic recursion schemes: The effect of constants

When the class of monadic recursion schemes is augmented by individual constants, some of the properties change. It becomes undecidable whether “S diverges” or “S is strongly equivalent to T” for S, T schemes with individual constants. The family of value languages generated by this class of schemes is the family of recursively enumerable languages. The subclass of free schemes with constants is also investigated. It remains decidable whether “S halts” or “S diverges” for S a free scheme with individual constants, but it becomes undecidable whether “T has a strongly equivalent free scheme” for T an arbitrary scheme with individual constants.     

Comments on: “Studies on diversion cross-flow between two parallel channels communicating by a parallel slot — Part I” by A. Tapucu

Unique design techniques are needed for low activity ceramic materials in first wall/blanket regions of fusion reactors. A Weibull probabilistic design approach is used to characterize the scatter in the fracture strength and the size effect. Results indicate that ceramic first wall/blanket structures should be modular and each module should be proof tested. The ceramic materials should have high fracture strength, high Weibull modulus, and minimal strength degradation due to subcritical crack growth. The Weibull statistical analysis is coupled with finite element thermal and stress analysis and the probability of failure of ceramic first wall/blanket design concepts is predicted. The usefulness of the approach is demonstrated by optimizing the geometry of the structure to produce minimum probability of failure.     

Renal responses of the fetal lamb to fetal or maternal volume expansion

Fetal and maternal glomerular filtration rate (GFR), renal plasma flow (RPF), urine volume, sodium excretion, and fractional sodium reabsorption were measured in a chronically instrumented sheep preparation. Fetal GFR was essentially stable between 110 and 135 days of gestation (term = 147 days). There was a significant increase in GFR after 135 days. After the infusion of 50 ml of normal saline over a 30-minute period, fetal GFR and sodium excretion increased significantly. Fractional sodium reabsorption was significantly decreased. Thus, the fetus is capable of responding to volume expansion with saline with an increase in GFR and a decrease in fractional sodium reabsorption. After the infusion of 1000 ml of normal saline into the ewe in 1 hour, maternal GFR and RPF rose significantly. Sodium excretion rose 6-fold and fractional sodium reabsorption fell significantly. After the infusion of saline into the ewe, there was no change in fetal GFR, RPF, sodium excretion, urine volume, or fractional sodium reabsorption. Since there were no changes in fetal renal function after maternal volume expansion with saline there was no evidence for the transplacental passage of a natriuretic factor from ewe to fetus.     

Clustered defects in IC fabrication: Impact on process controlcharts

In IC fabrication, standard process control charts for defects often sound many false alarms, i.e. the chart incorrectly indicates that the process is out of control. It is pointed out that when non-Poisson behavior is encountered in defect data, it is necessary to determine whether this is due to an out-of-control manufacturing process or a manufacturing or data collection procedure that yields clustered defect counts. A procedure that includes the outlier removal method to discriminate between clustered defect data and a process that is out of control is proposed, and its application to two sets of real-world data is shown. One is an example from IC manufacturing where true clustering exists, and the other is a manufacturing example where persistent out-of-control conditions give the appearance of clustering. Simulation results indicate that the procedure works well within reasonable boundaries. A method for constructing defect control charts for processes that yield clustered defects is also presented     

The effect of feeding di-(2-ethylhexyl) phthalate (DEHP) on the lipid metabolism of laying hens

Di-(2-ethylhexyl)phthalate (DEHP), a commonly used plasticizer, is now seen as an environmental pollutant. DEHP has been found to inhibit lipid and sterol synthesis in rats and mice. The effects of DEHP on various aspects of lipid metabolism were examined in chickens. White Leghorn laying hens were fed either a standard laying mash control diet (C) or the control diet containing 1% DEHP (DEHP) or 1% DEHP and 5% tallow (DEHP-T) for 28 days. DEHP and DEHP-T lowered feed consumption 10% but did not significantly affect body weight. After 3 weeks on the diets, egg production was 15–20% less in DEHP-T than in C and DEHP hens. No differences were observed in egg weight, percent shell, white or yolk among the groups. DEHP and DEHP-T did not alter egg lipid or egg cholesterol concentrations. DEHP and DEHP-T lowered plasma lipid concentration about 20% and free and total cholesterol 20–30%. Liver weights increased, being 30, 34 and 39 g for C, DEHP and DEHP-T hens, respectively, after 28 days. Total liver lipid and cholesterol increased 19% and 26% in DEHP hens and 54% and 79% in DEHP-T hens when compared to controls. In contrast, the fat content of pectoralis major muscle decreased significantly in DEHP and DEHP-T hens. These results, in showing that DEHP alters plasma and tissue cholesterol but not yolk cholesterol, demonstrate again that egg cholesterol is remarkably resistant to alteration by dietary means.     

Age differences in free recall and subjective organization.

Previous studies concerned with subjective organization occurring during free-recall learning have not provided consistent evidence for a hypothesis of organizational deficiency in the elderly. To assess the role of recall conditions in this discrepancy, the free-recall learning of younger and older adults was examined under conditions where the recalled words were either visible or not visible. Also, 5 measures of subjective organization, including measures used in earlier studies, were used to assess the role of measurement factors in producing the inconsistent findings. Younger adults, regardless of recall condition, recalled more words and showed more subjective organization than did the older adults with each of the measures. List length, rather than type of recall trial or measure of subjective organization, seems to be responsible for the conflicting findings obtained by other investigators. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Teaching problem solving and structured programming in FORTRAN

This paper describes an approach to teaching problem solving in an introductory programming course using the FORTRAN language. The course is oriented around a set of problems which are used to illustrate a problem solving methodology. Three pedagogic aids (data table, flow diagram, and program system chart) and two control structure extensions to the FORTRAN language are used in order to provide a more convenient framework in which students can practice good problem solving and programming techniques. The control structure extensions facilitate structured programming in FORTRAN. The use of the control structures and the pedagogic aids is illustrated in the solution of a simple statistics problem: the benefits derived from using these aids are also discussed.     

Effect of septal and frontal ablations on species-typical behavior in the rat.

Assigned 15 male and 15 female Long-Evans rats to 3 groups: septal lesions, frontal lesions, and control. Behavioral measures were taken both pre- and postoperatively while Ss were freely interacting in a series of 5 large interconnecting chambers. Main categories of behavior observed included exploration, sleep, grooming, aggression, eating, mating, and drinking. The numerous differences found were related more often to sex and phase (pre- vs. postoperative), irrespective of lesion effects. Following behavioral observations, 2-way active-avoidance measures were obtained, and Ss with septal lesions showed the expected facilitation of avoidance behavior. The problem of comparing results derived from studies of brain damage using observational methods with those from laboratory task studies is discussed. (22 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)