A knowledge development lifecycle for reflective practice

Reflective practice is valuable because of its potential for continuous improvement through feedback and learning. Conventional models of knowledge practice however do not explicitly include reflection as part of the practice, nor locate it in a developmental cycle. They focus on modelling in a knowledge plane which itself is contextualised by active knowing processes, and ignore the influence of power in their activity models. Further, many models focus on either an artefact or a process view, resulting from a conceptual disconnect between knowledge and knowing, and failure to relate passive to active views. Using the idea of higher order loops that govern knowledge development processes, in this paper we propose a conceptualisation of a reflective Knowledge Development Life Cycle (KDLC). This explicitly includes the investigator and the organisation itself as dynamic components of a systemic process and is suited to either a constructivist or realist epistemological stance. We describe the stages required in the KDLC and discuss their significance. Finally we show how incorporation of reflection into process enables dynamic interplay between the knowing and the knowledge in the organisation

A steady, radiative-shock method for computing X-ray emission from colliding stellar winds in close, massive-star binaries

We present a practical, efficient, semianalytic formalism for computing steady state X-ray emission from radiative shocks between colliding stellar winds in relatively close ( orbital period up to order tens of days) massive-star, binary systems. Our simplified approach idealizes the individual wind flows as smooth and steady, ignoring the intrinsic instabilities and associated structure thought to occur in such flows. By also suppressing thin-shell instabilities for wind-collision radiative shocks, our steady state approach avoids the extensive structure and mixing that has thus far precluded reliable computation of X-ray emission spectra from time- dependent hydrodynamical simulations of close-binary, wind- collision systems; but in ignoring the unknown physical level of such mixing, the luminosity and hardness of X-ray spectra derived here represent upper limits to what is possible for a given set of wind and binary parameters. A key feature of our approach is the separation of calculations for the small-scale shock-emission from the ram-pressure-balance model for determining the large-scale, geometric form of the wind-wind interaction front. Integrating the localized shock emission over the full interaction surface and using a warm-absorber opacity to take account of attenuation by both the smooth wind and the compressed, cooled material in the interaction front, the method can predict spectra for a distant observer at any arbitrary orbital inclination and phase. We illustrate results for a sample selection of wind, stellar, and binary parameters, providing both full X-ray light curves and detailed spectra at selected orbital phases. The derived spectra typically have a broad characteristic form, and by synthetic processing with the standard XSPEC package, we demonstrate that they simply cannot be satisfactorily fitted with the usual attenuated single-or two-temperature thermal-emission models. We conclude with a summary of the advantages and limitations of our approach and outline its potential application for interpreting detailed X- ray observations from close, massive-star binary systems

Three New Food Plants and First Wisconsin Record of \u3ci\u3ePublilia Reticulata\u3c/i\u3e (Hemiptera: Membracidae)

Publilia reticulata was found feeding on the composites Silphium perfoliatum, S. integrifolium and Ambrosia trifida at eight sites in five Wisconsin counties in 1993-1995. This is the first report of P. reticulata using these plants and of its occurrence in Wisconsin

Human P450 CYP17A1: Control of Substrate Preference by Asparagine 202

CYP17A1 is a key steroidogenic enzyme known to conduct several distinct chemical transformations on multiple substrates. In its hydroxylase activity, this enzyme adds a hydroxyl group at the 17α position of both pregnenolone and progesterone at approximately equal rates. However, the subsequent 17,20 carbon–carbon scission reaction displays variable substrate specificity in the numerous CYP17A1 isozymes operating in vertebrates, manifesting as different Kd and kcat values when presented with 17α-hydroxypregnenlone (OHPREG) versus 17α-hydroxyprogesterone (OHPROG). Here we show that the identity of the residue at position 202 in human CYP17A1, thought to form a hydrogen bond with the A-ring alcohol substituent on the pregnene- nucleus, is a key driver of this enzyme’s native preference for OHPREG. Replacement of asparagine 202 with serine completely reverses the preference of CYP17A1, more than doubling the rate of turnover of the OHPROG to androstenedione reaction and substantially decreasing the rate of formation of dehydroepiandrosterone from OHPREG. In a series of resonance Raman experiments, it was observed that, in contrast with the case for the wild-type protein, in the mutant the 17α alcohol of OHPROG tends to form a H-bond with the proximal rather than terminal oxygen of the oxy–ferrous complex. When OHPREG was a substrate, the mutant enzyme was found to have a H-bonding interaction with the proximal oxygen that is substantially weaker than that of the wild type. These results demonstrate that a single-point mutation in the active site pocket of CYP17A1, even when far from the heme, has profound effects on steroidogenic selectivity in androgen biosynthesis

When is Religious Speech Outrageous?: \u3ci\u3eSnyder v. Phelps\u3c/i\u3e and the Limits of Religious Advocacy

The Constitution affords great protection to religiously motivated speech. Religious liberty would mean little if it did not mean the right to profess and practice as well as to believe. But are there limits beyond which religious speech loses its constitutional shield? Would it violate the First Amendment to subject a religious entity to tort liability if its religious profession causes emotional distress? When is religious speech outrageous? These are vexing questions, to say the least; but the United States Supreme Court will take them up next term—and it will do so in a factual context that has generated as much heat as light. On March 8, 2010, the Court granted certiorari in Snyder v. Phelps. It is a tort case brought by a family grieving the untimely death of their son. It is a free speech case, testing the boundaries of the constitutional commitment to the marketplace of ideas. It is a religious liberty case that has made unlikely allies of those on opposite sides of the political and cultural divides that make our liberal democracy such a challenging enterprise