Improving graduate student performance in cognitive assessment: The saga continues.

Investigators have concluded that excessive numbers of errors in test administration and scoring are routinely committed by both graduate students and practicing psychologists. Developing new methods for teaching assessment is viewed as a major means of improving competency. Unlike previous studies, this investigation examined the impact of both lecture and laboratory interventions designed to improve graduate student performance in assessment. Interventions consisted of weekly lecture quizzes and a variety of laboratory interventions. The results suggest that the interventions used can significantly improve students' lecture and laboratory performance when compared with controls. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Radical styrene polymerization in the presence of trace levels of sulfonic acids

The bulk polymerization of styrene in the presence of the vinyl functional sulfonic acid 2‐sulfoethylmethacrylate (SEM) was found to have utility for making polystyrenes with narrow polydispersity, bimodal polydispersity, and ultrahigh molecular weight at fast polymerization rates. Narrow polydispersity polymers were made by the addition of SEM to nitroxide‐mediated polymerizations. Bimodal polydispersity polymers were made by the ultrahigh molecular weight component being made in the presence of SEM in the absence of an initiator and the low molecular weight component being made in the presence of an initiator and/or chain‐transfer agent. Ultrahigh molecular weight monomodal polystyrenes were prepared at much faster polymerization rates than possible via spontaneous polymerization in the absence of SEM. SEM was found to be more effective, by an order of magnitude, than camphor sulfonic acid on a weight basis and, because it is copolymerized into the polymer chain, should not lead to corrosion problems during fabrication of the polymer. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 869–875, 2003     

Solid-solution hardening and softening by Fe additions to NiAl

Solid-solution hardening in the case of a ternary alloy addition to a B2 compound with the triple defect structure has been investigated. The fact that the ternary element may occupy either of two sublattices or may affect the concentration of other types of point defects present in the material makes this a very interesting problem to consider. Ni-rich (40 at% Al), stoichiometric (50 at% Al), and Al-rich (52 at% Al) alloys were doped with up to 12 at% Fe. Lattice parameter, bulk density and hardness measurements were performed on samples quenched from 1000 °C. It was found that solid-solution softening actually occurs in the Ni-rich alloys, while hardening was observed in the stoichiometric and Al-rich alloys. The vacancy concentration was determined from the experimental data, and the site occupancies of the Fe atoms were estimated from a thermodynamic model. Through careful consideration of all point defect concentrations the solid-solution hardening and softening behaviors could be effectively rationalized.     

Effects of temperature on a.c. magnetostriction in grain-oriented silicon-iron

The a.c. magnetostriction of conventional grain-oriented 3 1/4% silicon-iron and more highly oriented silicon-iron has been measured from room temperature up to the Curie point using high temperature strain gauges. Curves of magnetostriction plotted against flux density showed that a definite change in the magnetization process occurred at about 300° C extending to 400° C for both types of material. This was considered to be due to the onset of magnetic annealing, considerably modified by the effect of the coating on the materials. From the experimental results the magnetostriction constant ₁₀₀ has been calculated using a predicted domain structure and was found to agree well with single crystal values apart from within the 300 to 400° C region.     

Plasma-sprayed coatings as adherend surface pretreatments

As part of the National Center for Manufacturing Sciences contract on adhesive bonding of dissimilar materials, UTRC, as a sub-contractor, is evaluating environmentally acceptable surface preparation techniques for selected metals and composites. The selected processes are automatable and capable of being transferred into the manufacturing arena. One aspect of the programme is the evaluation of plasma-sprayed, microporous, thin coatings as surface pretreatments for both resin-based composites and metals. Mechanical test results are presented which demonstrate the viability of this approach to achieve acceptable joint strengths with steel, titanium and aluminium bonded to several types of resin-matrix composite. The environmental impact, by elimination of organic primer systems and strong acid etching and anodizing solutions, will be discussed.     

Basis enrichment and solid–fluid coupling for model‐reduced fluid simulation

We present several enhancements to model‐reduced fluid simulation that allow improved simulation bases and two‐way solid–fluid coupling. Specifically, we present a basis enrichment scheme that allows us to combine data‐driven or artistically derived bases with more general analytic bases derived from Laplacian eigenfunctions. We handle two‐way solid–fluid coupling in a time‐splitting fashion—we alternately timestep the fluid and rigid body simulators, while taking into account the effects of the fluid on the rigid bodies and vice versa. We employ the vortex panel method to handle solid–fluid coupling and use dynamic pressure to compute the effect of the fluid on rigid bodies. Copyright © 2014 John Wiley & Sons, Ltd.     

Binding Mode and Structure–Activity Relationships around Direct Inhibitors of the Nrf2–Keap1 Complex

An X‐ray crystal structure of Kelch‐like ECH‐associated protein (Keap1) co‐crystallised with (1S,2R)‐2‐[(1S)‐1‐[(1,3‐dioxo‐2,3‐dihydro‐1H‐isoindol‐2‐yl)methyl]‐1,2,3,4‐tetrahydroisoquinolin‐2‐carbonyl]cyclohexane‐1‐carboxylic acid (compound (S,R,S)‐ 1 a ) was obtained. This X‐ray crystal structure provides breakthrough experimental evidence for the true binding mode of the hit compound (S,R,S)‐ 1 a , as the ligand orientation was found to differ from that of the initial docking model, which was available at the start of the project. Crystallographic elucidation of this binding mode helped to focus and drive the drug design process more effectively and efficiently.     

Antithrombins Wibble and Wobble (T85M/K): archetypal conformational diseases with in vivo latent-transition, thrombosis, and heparin activation

The inherent variability of conformational diseases is demonstrated by two families with different mutations of the same conserved aminoacid in antithrombin. Threonine 85 underlies the opening of the main beta-sheet of the molecule and its replacement, by the polar lysine, in antithrombin Wobble, resulted in a plasma deficiency of antithrombin with an uncharacteristically severe onset of thrombosis at 10 years of age, whereas the replacement of the same residue by a nonpolar methionine, antithrombin Wibble, gave near-normal levels of plasma antithrombin and more typical adult thromboembolic disease. Isolated antithrombin Wibble had a decreased thermal stability (Tm 56.2, normal 57.6 degreesC) but was fully stabilized by the heparin pentasaccharide (Tm 71.8, normal 71.0 degreesC), indicating that the prime abnormality is a laxity in the transition of the main sheet of the molecule from the 5- to 6-stranded form, as was confirmed by the ready conversion of antithrombin Wibble to the 6-stranded latent form on incubation. That this transition can occur in vivo was shown by the finding of nearly 10% of the proband's plasma antithrombin in the latent form and also, surprisingly, of small but definitive amounts of latent antithrombin in normal plasma. The latent transition will be predictably accelerated not only by gross mutations, as with antithrombin Wobble, to give severe episodic thrombosis, but also by milder mutations, as with antithrombin Wibble, to trigger thrombosis in the presence of other predisposing factors, including the conformational stress imposed by the raised body temperatures of fevers. Both antithrombin variants had an exceptional (25-fold) increase in heparin affinity and this, together with an increased inhibitory activity against factor Xa, provides evidence of the direct linkage of A-sheet opening to the conformational basis of heparin binding and activation.     

Fluid dynamics and flow patterns in stirred tanks with a turbine impeller

Velocity profiles were measured in a stirred tank with a turbine impeller using a three-dimensional, pitot tube probe. A tangential jet model was used to describe the flow in the region of the impeller, and two-dimensional potential flow models and a circular jet were used to describe the flow in the rest of the tank. The tangential jet model accurately predicted the measurements from this work and comparable measurements reported in the literature for water and air, for varying impeller diameter and speeds and for different tank diameters. In the rest of the tank a three-dimensional, low velocity, flow field exists; and the center of circulation is not a true stagnation point. The flow at this point is tangential. The two-dimensional models only qualitatively described the flow in this region, and a three-dimensional model would be required. It was experimentally and theoretically confirmed that standard practice of using 10% baffles effectively controls the flow in the tank.     

Latency–probability curves for sequential decision models: A comment on Weatherburn.

Discusses D. Weatherburn's (see record 1979-25180-001) mathematical argument that shows that the relationship between response latency and response probability in sensory discrimination experiments does not determine the form of an underlying sequential decision process unless the time rates for implicit events are also specified. This argument is not denied, but in many cases the expected variation of time rates is not sufficient to rule out the use of the latency–probability graph. This is particularly the case if time rate variation is directly determined by stimulus magnitude or if variations due to motivation occur only from trial to trial rather than from session to session. It is concluded that, even if such variation is large, there is a considerable amount of information to be gained from latency–probability analysis. (13 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)