Developing Reflective Practice in Information Systems Development: Further Progress on the Gestation of an Evaluative Framework

It is argued in this paper that evaluative activities in relation to systems development have traditionally focussed on the financial worth of the product. This approach has excluded the appraisal of important issues such as the process for building the product, the performance of the systems development team, the methods used and the organisational impact of the implemented System. In response to the traditional approach, which is skewed towards quantification techniques, a three stage framework is proposed. The three stages are iterative. The first being concerned with establishing an appropriate focus and resolution level for the evaluation, the second uses a control model to identify relevant outputs, appropriate sensors and comparators and performance criteria. The third is about selecting more sophisticated paradigms for assessing processes and their outputs. It is contended that although the specific focus of this paper is systems development, the framework could be used in any organisational context where products and services are developed and produced.     

Segmentation in the vertebrate nervous system

Although there is good evidence that growing axons can be guided by specific cues during the development of the vertebrate peripheral nervous system, little is known about the cellular mechanisms involved. We describe here an example where axons make a clear choice between two neighbouring groups of cells. Zinc iodide-osmium tetroxide staining of chick embryos reveals that motor and sensory axons grow from the neural tube region through the anterior (rostral) half of each successive somite. 180 degrees antero-posterior rotation of a portion of the neural tube relative to the somites does not alter this relationship, showing that neural segmentation is not intrinsic to the neural tube. Furthermore, if the somitic mesoderm is rotated 180 degrees about an antero-posterior axis, before somite segmentation, axons grow through the posterior (original anterior) half of each somite. Some difference therefore exists between anterior and posterior cells of the somite, undisturbed by rotation, which determines the position of axon outgrowth. It is widespread among the various vertebrate classes.     

Comparison of human adult and fetal hemoglobin: Aminophenol-induced methemoglobin formation

Summary Human fetal hemoglobin was more susceptible to methemoglobin formation in the presence of aminophenols than was adult hemoglobin. This was due to the intrinsic properties of the proteins rather than the presence of methemoglobin reductases.This work was supported by a grant from the National Institute of General Medical Sciences GM-17184.     

Effect of fatty acids on fetal rat bone in culture

Zusammenfassung Nachweis, dass Fettsäuren (Palmitin-, Stearin- und Ölsäuren) in sehr niedrigen Konzentrationen die Kalziumabgabe und die Knochenresorption in fötalen Ratten in vitro fördern.

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The studies were supported by USPHS grant No. AM 11262. The albumin monomer was kindly supplied by Drs.J. Brand andL. Raisz.