Implementing effective software metrics programs

Increasingly organisations are foregoing an ad hoc approach to metrics in favor of complete metrics programs. The authors identify consensus requirements for metric program success and examine how programs in two organisations measured up     

Interactions between nurses and patients on ventilators

Image cytometric analysis of DNA ploidy status of 40 fresh primary breast carcinomas was performed in a comparative study on cytologic preparations stained directly by the Feulgen method and smears from the same tumors Feulgen-stained after Papanicolaou staining. There was a 0.82 overall concordance in diploid and aneuploid tumor classification and a good correlation (r = 0.736, P < 0.001) between the DNA indices determined by the two methods. Discordances are probably due to tumor heterogeneity. This study demonstrates that image cytometric DNA analysis on previously routine-stained cytologic preparations is feasible and reliable for pretreatment DNA analysis and suggests potential applications in retrospective studies with cytologic material from archives.     

A comparison of neural network and fuzzy clustering techniques insegmenting magnetic resonance images of the brain

Magnetic resonance (MR) brain section images are segmented and then synthetically colored to give visual representations of the original data with three approaches: the literal and approximate fuzzy c-means unsupervised clustering algorithms, and a supervised computational neural network. Initial clinical results are presented on normal volunteers and selected patients with brain tumors surrounded by edema. Supervised and unsupervised segmentation techniques provide broadly similar results. Unsupervised fuzzy algorithms were visually observed to show better segmentation when compared with raw image data for volunteer studies. For a more complex segmentation problem with tumor/edema or cerebrospinal fluid boundary, where the tissues have similar MR relaxation behavior, inconsistency in rating among experts was observed, with fuzz-c-means approaches being slightly preferred over feedforward cascade correlation results. Various facets of both approaches, such as supervised versus unsupervised learning, time complexity, and utility for the diagnostic process, are compared     

The orphan receptors COUP-TF and HNF-4 serve as accessory factors required for induction of phosphoenolpyruvate carboxykinase gene transcription by glucocorticoids

In the present study we examined the coupling of NADPH oxidation to substrate hydroxylation and the effects of steroids on this process in reconstituted P450scc and P450c11 systems. To determine the relative rates of substrate hydroxylation vs electron leakage we assayed both the steroid product and H2O2 in the same sample. For both P450 systems the rates of steroid product and superoxide formation increased as NADPH concentration was increased. However, P450c11 was found to be more leaky. The leakage from the P450scc system was not affected by pregnenolone, the product of cholesterol side chain cleavage. In contrast, corticosterone, the product of P450c11, increased the rate of futile NADPH oxidation by the P450c11 system. We also tested a series of steroids to analyze the stereospecificity of their effects. Relative to the control without steroid, both C-19 and C-21 steroids with 11 alpha-hydroxy groups (11 alpha-OH-testosterone and 11 alpha-OH-cortisol) decreased leakage, and those with 11 beta-OH groups (11 beta-OH-testosterone and cortisol) stimulated both NADPH oxidation and electron leakage as measured by H2O2 formation. The results revealed a correlation between the effects previously observed in living cells and in our reconstituted systems. These findings provide further evidence that mitochondrial P450 systems indeed function as a significant source of oxygen radicals in steroidogenic cells.     

Spatial learning and memory in the tortoise (Geochelone carbonaria).

A single tortoise (Geochelone carbonaria) was trained in an eight-arm radial maze, with the apparatus and general procedures modeled on those used to demonstrate spatial learning in rats. The tortoise learned to perform reliably above chance, preferentially choosing baited arms, rather than returning to arms previously visited on a trial. Test sessions that examined control by olfactory cues revealed that they did not affect performance. No systematic, stereotyped response patterns were evident. In spite of differences in brain structure, the tortoise showed spatial learning abilities comparable to those observed in mammals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Routine cultures of bone marrow and peripheral stem cell harvests: clinical impact, cost analysis, and review

The American Association of Blood Banks requires routine culture of hematopoietic progenitor cells prior to bone marrow transplantation. We sought to evaluate the cost of that requirement and the incidence and clinical significance of positive cultures. We performed a retrospective analysis of transplant recipients at our institution. Of the 605 patients for whom 1,934 consecutive cultures of harvests were done between December 1992 and February 1996, 11 had positive cultures. Six patients received a culture-positive harvest with no adverse effects. The total cost of cultures was $35,660 (U.S. $). In North America and worldwide in 1995, routine culture of harvests would have prevented 7.9 and 18.9 cases of bacteremia, respectively, at a cost of $95,000 per bacteremia prevented. We conclude that routine culture of hematopoietic progenitor cells yields low rates of positivity and that infusion of contaminated harvests rarely results in clinically adverse outcomes.     

Comparing parameter schemes for propositional reasoning: An empirical study

Complete propositional reasoning is impractical as a tool in artificial intelligence, because it is computationally intractable. Most current approaches to limited propositional reasoning cannot easily be adjusted to use more (or less) time to prove more (fewer) theorems when the task requires it. This difficulty can be solved byparameterizing the reasoner: designing in a ‘power dial’ giving the user fine control over cost and performance. System designers face the significant problem of choosing the best parameter scheme to use. This paper proposes an empirical methodology for comparing parameter schemes and illustrates its use in comparing eight such schemes for a given complete, resolution-based propositional reasoner. From the data, a clear choice emerges as the most preferable of the eight.