A Step Beyond Univision Evaluations Using a Systems Model of Performance Improvement

The article examines three views of performance improvement-scientific management, instructional design, and systems thinking, Each provides a unique view of performance improvement and specific roles for evaluation. Envisioning performance improvement from a single view may be insufficient for evaluating the performance improvement situations found in today's dynamic organisations. The articie provides an integrated definition of performance and a synthesis, model, the Systems Model of Performance.     

Information Retrieval Systems and Learning

In the past, systems of instruction and retrieval have delivered different information, have served different functions, and have varied in content coverage, control, interaction, and amount of monitoring and guidance provided. However, technological trends that increase the amount and kind of information available on-line and that increase the speed and ease with which it can be searched are eroding these differences. It is now possible to put more primary information online in more varied forms and to make it more easily accessible to those who lack knowledge of computers or retrieval systems. Consequently, retrieval systems are becoming an alternative to instruction as a way to learn. In certain circumstances, letting people learn from information retrieval systems might be preferable to more formal approaches to instruction. Cognitive psychology provides clues about when to use retrieval systems to teach and train. Using retrieval systems or instructional systems is not an all-or-nothing decision. New instructional designs like hypermedia and “parallel systems” are appearing that integrate formal instruction and information retrieval.     

The concurrent validity of the peabody individual achievement test and woodcock reading mastery tests among students with mild learning problems

Previous research has revealed moderate to high validity coefficients between the Peabody Individual Achievement Test and the Woodcock Reading Mastery Tests. However, the same research has indicated rather consistently that the latter instrument provides significantly lower means than do several screening tests currently being used in the field. This investigation replicated and extended previous research by comparing the two instruments across three grade clusters in order to determine whether the lower Woodcock scores are equally robust for each level. As in prior research, validity coefficients were moderate to high in magnitude. However, the differences between the means of two instruments were found to decrease in size from earlier to later grades. That is, seven of the eight significantly different means were found to occur in grades 1 through 4. Only one significant difference was found for grades 5 through 8. Discussion sought to explain the results in terms of the representativeness of the Woodcock norms and the novel method that Woodcock used to estimate sample means and standard deviations.     

Surface patterning of bonded microfluidic channels

Microfluidic channels in which multiple chemical and biological processes can be integrated into a single chip have provided a suitable platform for high throughput screening, chemical synthesis, detection, and alike. These microchips generally exhibit a homogeneous surface chemistry, which limits their functionality. Localized surface modification of microchannels can be challenging due to the nonplanar geometries involved. However, chip bonding remains the main hurdle, with many methods involving thermal or plasma treatment that, in most cases, neutralizes the desired chemical functionality. Postbonding modification of microchannels is subject to many limitations, some of which have been recently overcome. Novel techniques include solution-based modification using laminar or capillary flow, while conventional techniques such as photolithography remain popular. Nonetheless, new methods, including localized microplasma treatment, are emerging as effective postbonding alternatives. This Review focuses on postbonding methods for surface patterning of microchannels.     

The cognitive levels test: Its relationship with reading and mathematics achievement

Any instrument designed to measure broad cognitive ability is expected to correlate substantially with valid measures of academic achievement. This report describes an investigation designed to evaluate the relationship between the Cognitive Levels Test, a newly available instrument, and two tests of academic achievement that have been widely used for nearly two decades: the Woodcock Reading Mastery Tests and the KeyMath Diagnostic Arithmetic Test. The study included children in grades K-2 who were enrolled in a remedial summer school program. The results showed the Cognitive Levels Test (Cognitive Index) to be rather highly correlated with the KeyMath Diagnostic Arithmetic Test Total score (r=.72) and moderately correlated with the Woodcock Reading Mastery Tests Total Reading score (r=.55). A repeated measures analysis of variance comparing standard scores for the Cognitive Levels Test with those of the Woodcock Reading Mastery Tests indicated few mean differences between the two sets of scores. Implications concerning the validity of the Cognitive Levels Test were discussed.     

A microfluidic membrane device to mimic critical components of the vascular microenvironment

Vascular function, homeostasis, and pathological development are regulated by the endothelial cells that line blood vessels. Endothelial function is influenced by the integrated effects of multiple factors, including hemodynamic conditions, soluble and insoluble biochemical signals, and interactions with other cell types. Here, we present a membrane microfluidic device that recapitulates key components of the vascular microenvironment, including hemodynamic shear stress, circulating cytokines, extracellular matrix proteins, and multiple interacting cells. The utility of the device was demonstrated by measuring monocyte adhesion to and transmigration through a porcine aortic endothelial cell monolayer. Endothelial cells grown in the membrane microchannels and subjected to 20 dynes∕cm(2) shear stress remained viable, attached, and confluent for several days. Consistent with the data from macroscale systems, 25 ng∕ml tumor necrosis factor (TNF)-α significantly increased RAW264.7 monocyte adhesion. Preconditioning endothelial cells for 24 h under static or 20 dynes∕cm(2) shear stress conditions did not influence TNF-α-induced monocyte attachment. In contrast, simultaneous application of TNF-α and 20 dynes∕cm(2) shear stress caused increased monocyte adhesion compared with endothelial cells treated with TNF-α under static conditions. THP-1 monocytic cells migrated across an activated endothelium, with increased diapedesis in response to monocyte chemoattractant protein (MCP)-1 in the lower channel of the device. This microfluidic platform can be used to study complex cell-matrix and cell-cell interactions in environments that mimic those in native and tissue engineered blood vessels, and offers the potential for parallelization and increased throughput over conventional macroscale systems.