Alleviating convergence problems in Group Support Systems

Not all Group Support Systems are identical, as is demonstrated by their software implementations. We discuss two existing implementations of group support tools and the process models underlying them. We demonstrate that fundamental to both processes is the merging or integration of individual data. Based on this and other empirical research, the Shared Context Model (SCM) of cooperative work is adopted and we show that it supports existing processes and others. We expect that groups will find merging their work easier with the SCM. This model is presented and embedded in the architecture and implementation of four group tools. Because these tools are destined to be used by dispersed groups, synchronously or asynchronously, an object-based communication and control mechanism is incorporated. Finally, as graphics and multi-tasking have been shown to be increasingly important, the tools are implemented in Microsoft Windows for personal computers attached to local area networks.     

Using internal fibre geometry to improve the performance of pin-loaded holes in composite materials

The anisotropic nature of fibre reinforced composites leads to large stress concentrations around pin-loaded holes through standard weave cloths. Proper understanding of how this anisotropic nature affects the load distribution around holes can be utilised to reduce these concentrations if sufficient thought is given to the internal fibre geometry near to the hole. Such local reinforcements need not be highly complex and can be readily produced without excessive effort, producing significant improvements in performance.     

A simple conceptual model for predicting the dissolution of phosphate rock in soils

Laboratory experimental and literature data were integrated to develop a simple, conceptual model to describe and predict the dissolution of a reactive phosphate rock (Gafsa phosphate rock, GPR) in soils. The model showed that initial solution Ca concentration strongly influences the time required for a single application of GPR (at 30 kgP ha^?1) to dissolve. The model predicts that all of the GPR will dissolve within a year of application in an unlimed, acid (pH_w 4.5) loam. However, if the soil has previously been limed to (pH_w 5.8, and contains permanent charge only, the model predicts that only about 50% of the GPR would have dissolved by the end of the second year after application. On the other hand, if a previously limed soil ((pH_w 5.8) contains variable-charge components, the model predicts that virtually all of the GPR would have dissolved in this soil by the end of the second year after application. These results emphasise that, even in the presence of a high proton supply, solution Ca has an overriding influence on the dissolution of GPR. The faster rate of GPR dissolution in the limed soil with variable charge, compared to that in the limed soil with permanent charge only, demonstrates the ability of the variable-charge component of soil to act as a sink for some of the lime-derived Ca. According to the solubility product principle, this allows more GPR to dissolve. Because of the generally stronger buffering of soil for P than for Ca, a relatively large proportion of any P removed by leaching and plant uptake is buffered by the sorbed phase. Consequently, the influence of leaching and plant uptake on GPR dissolution is attributed primarily to the removal of the relatively less-strongly buffered Ca.     

The effects of observational feedback on treatment integrity in school-based behavioral consultation.

Evaluated the effects of performance feedback on levels of treatment integrity in school-based behavioral consultation. Three teachers employed in a residential treatment community were responsible for treatment implementation. Treatment integrity was defined as the percentage of 2-min intervals during which contingent teacher reinforcement for student on-task behavior was directly observed. Teacher and child behavior were monitored across baseline, traditional consultation, and consultation with performance feedback conditions in a multiple baseline design. Following a Problem Identification Interview and Problem Analysis Interview (J. R. Bergan, 1977), mean levels of treatment integrity for the 3 teachers ranged from 9% to 37%. The addition of a performance feedback package increased treatment integrity for all 3 teachers to levels ranging from 60% to 83%. The findings contribute to a growing literature supporting the need for direct assessment of treatment integrity in school-based consultation research and practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assessment of renal osteodystrophy in dialysis patients: use of bone alkaline phosphatase, bone mineral density and parathyroid ultrasound in comparison with bone histology

Bone biopsies were studied in 73 patients to determine if a two-site radioimmunometric assay for serum bone alkaline phosphatase (BAP), total serum alkaline phosphatase (ALP), serum intact parathyroid hormone (iPTH), hand X-rays, regional bone mineral density (BMD) measurements and parathyroid enlargement detected by ultrasonography could accurately predict renal osteodystrophy. In the patients studied 57 had hyperparathyroid bone disease, 4 mixed renal osteodystrophy, 3 adynamic bone disease, 1 osteomalacia and 8 normal histology. Serum BAP, ALP and iPTH correlated positively with mineral apposition rate, osteoblastic, osteoid and eroded surface. In the diagnosis of hyperparathyroid bone disease serum iPTH was the most sensitive investigation, detecting 81% of patients at a level > 100 pg/ml but with a specificity of only 66%. Serum BAP was more sensitive, 70% at a level of > 10 ng/ml, than serum total ALP, 30% at a level of 300 IU/l, with similar specificities, 92 and 100%, respectively. Ultrasound detection of an enlarged parathyroid gland had a sensitivity of 64% and a specificity of 100% for the diagnosis of hyperparathyroid bone disease. Hand X-rays had a poor sensitivity, 47%, but a high specificity, 92%, for the detection of hyperparathyroid bone disease. The majority of patients had regional BMD values within the normal reference range and this test was of poor discriminatory value. The non-invasive markers were unable to distinguish between patients with low turnover, mild hyperparathyroidism and patients with normal histology. In conclusion the measurement of serum iPTH is a useful screening tool for the detection of hyperparathyroid bone disease which can be confirmed by the finding of a raised serum BAP or parathyroid enlargement. For definitive diagnosis, however, the gold standard remains bone biopsy and at present one cannot recommend any non-invasive method as an adequate substitute.     

Quenched BODIPY dye-labeled casein substrates for the assay of protease activity by direct fluorescence measurement

We have prepared casein conjugates of two BODIPY dyes for use as fluorogenic protease substrates in homogeneous assays. Both conjugates are labeled to such an extent that the dyes are efficiently quenched in the protein, yielding virtually nonfluorescent substrate molecules. These fluorogenic substrates release highly fluorescent BODIPY dye-labeled peptides upon protease digestion, with fluorescence increases proportional to enzyme activity. These quenched substrates are suitable for the continuous assay of enzymatic activity using standard fluorometers, filter fluorometers, or fluorescence microplate readers using either fluorescein excitation and emission wavelengths to measure BODIPY FL casein hydrolysis or Texas Red wavelengths to detect proteolysis of BODIPY TR-X casein. Most current techniques for detecting protease activity, such as the fluorescein thiocarbamoyl casein (FTC-casein) protease assay, require extensive manipulation, including separation steps, and are therefore labor intensive and error-prone. In comparison, we found the BODIPY dye-labeled casein protease assays to be simple and precise and to have greater sensitivity and a broader dynamic range of detection than the FTC-casein assay. We were able to sensitively detect the activities of a wide variety of enzymes with these new substrates, including serine, acid, sulfhydryl, and metalloproteases. We also found the assay suitable for quantitating protease inhibitor concentrations and for real-time analysis of proteolysis.     

What is driving health system change?

Socially amoral economic forces now drive health system change. The authors, assisted by a panel of experts on employers, health plans, providers, and consumers, discuss current drivers such as (1) employers' price-focused purchasing, without good quality/value measures; (2) health plans' growing successes and market clout; (3) providers declining prospects and fears about their future; and (4) consumers' worries about less choice. Future influences will include Medicare reforms, better information, and pro-consumer regulation of managed care, as well as rising social distress. The health system's future is now open for resolution in an evolving, imperfect market.     

Vector characterization of photodetectors, photoreceivers, andoptical pulse sources by time-domain pulse response measurements

Deconvolution of measurement system effects from pulse response measurements is demonstrated to yield reproducible, accurate characterization of the impulse response (and vector frequency response) of a photodetector or photoreceiver, as well as the intensity waveform of an optical pulse. Calibration is based on a <3-ps FWHM (full width at half maximum) optical pulse and a 50-GHz 3-dB bandwidth electrical sampling system. Vector characterization of a photodetector/photoreceiver to >40 GHz and an optical pulse source to >30 GHz are demonstrated. Calibration and effects of noise are discussed     

Foucault, Habermas and Evaluation

Educational evaluation may be understood in terms of what Michel Foucault describes as 'discursive practice', yet this perspective may lead to a kind of despair if evaluation technologies are seen as no more than an expression of 'the will to power'. The issue of evaluation technologies as 'machines' is not new to the evaluation literature, as the author's autobiographical reflections on his evaluation training and experience suggest. The Foucauldian view is counterposed here with the Habermasian notion of a 'science of social action', and explorations of the potential of Habermas's ideas in educational evaluation by the author and his colleagues. It is argued that Habermas's theory of communicative action offers humane, convivial and rational resources for the further development of the theory and practice of educational evaluation.