High turnover in electro-oxidation of alcohols and ethers with a glassy carbon-supported phenanthroimidazole mediator.

Glassy carbon electrodes covalently modified with a phenanthroimidazole mediator promote electrochemical alcohol and ether oxidation: three orders of magnitude increase in TON, to ∼15 000 in each case, was observed compared with homogeneous mediated reactions. We propose the deactivation pathways in homogeneous solution are prevented by the immobilization: modified electrode reversibility is increased for a one-electron oxidation reaction. The modified electrodes were used to catalytically oxidize p-anisyl alcohol and 1-((benzyloxy)methyl)-4-methoxybenzene, selectively, to the corresponding benzaldehyde and benzyl ester, respectively

Increasing the Receptor Tyrosine Kinase EphB2 Prevents Amyloid-β-induced Depletion of Cell Surface Glutamate Receptors by a Mechanism That Requires the PDZ-binding Motif of EphB2 and Neuronal Activity.

Diverse lines of evidence suggest that amyloid-β (Aβ) peptides causally contribute to the pathogenesis of Alzheimer disease (AD), the most frequent neurodegenerative disorder. However, the mechanisms by which Aβ impairs neuronal functions remain to be fully elucidated. Previous studies showed that soluble Aβ oligomers interfere with synaptic functions by depleting NMDA-type glutamate receptors (NMDARs) from the neuronal surface and that overexpression of the receptor tyrosine kinase EphB2 can counteract this process. Through pharmacological treatments and biochemical analyses of primary neuronal cultures expressing wild-type or mutant forms of EphB2, we demonstrate that this protective effect of EphB2 depends on its PDZ-binding motif and the presence of neuronal activity but not on its kinase activity. We further present evidence that the protective effect of EphB2 may be mediated by the AMPA-type glutamate receptor subunit GluA2, which can become associated with the PDZ-binding motif of EphB2 through PDZ domain-containing proteins and can promote the retention of NMDARs in the membrane. In addition, we show that the Aβ-induced depletion of surface NMDARs does not depend on several factors that have been implicated in the pathogenesis of Aβ-induced neuronal dysfunction, including aberrant neuronal activity, tau, prion protein (PrP(C)), and EphB2 itself. Thus, although EphB2 does not appear to be directly involved in the Aβ-induced depletion of NMDARs, increasing its expression may counteract this pathogenic process through a neuronal activity- and PDZ-dependent regulation of AMPA-type glutamate receptors

Effects of Selection Systems on Job Search Decisions

On the basis of Gilliland\u27s (1993) model of selection system fairness, the present study investigated the relationships between selection procedures, perceived selection system fairness, and job search decisions in both hypothetical and actual organizations. We conducted two studies to test the model. In Study 1, we used an experimental method to examine job seekers\u27 perceptions of, and reactions to, five widely used selection procedures. Results suggested that applicants viewed employment interviews and cognitive ability tests as more job related than biographical inventories (biodata), personality tests, and drug tests, and that job relatedness significantly affected fairness perceptions, which in turn affected job search decisions. Study 2 examined the hypothesized relationships between the selection systems and job seekers\u27 pursuit of actual, relevant organizations. Results from both studies offer support for the hypothesized model, suggesting that selection tests have differential effects on perceived selection system validity and fairness, which affect subsequent job search decisions

High Stakes Behavior with Low Payoffs: Inducing Preferences with Holt-Laury Gambles

A continuing goal of experiments is to understand risky decisions when the decisions are important. Often a decision’s importance is related to the magnitude of the associated monetary stake. Khaneman and Tversky (1979) argue that risky decisions in high stakes environments can be informed using questionnaires with hypothetical choices (since subjects have no incentive to answer questions falsely.) However, results reported by Holt and Laury (2002, henceforth HL), as well as replications by Harrison (2005) suggest that decisions in “high” monetary payoff environments are not well-predicted by questionnaire responses. Thus, a potential implication of the HL results is that studying decisions in high stakes environments requires using high stakes. Here we describe and implement a procedure for studying high-stakes behavior in a low-stakes environment. We use the binary-lottery reward technique (introduced by Berg, et al (1986)) to induce preferences in a way that is consistent with the decisions reported by HL under a variety of stake sizes. The resulting decisions, all of which were made in a low-stakes environment, reflect surprisingly well the noisy choice behavior reported by HL’s subjects even in their highstakes environment. This finding is important because inducing preferences evidently requires substantially less cost than paying people to participate in extremely high-stakes games.

Effects of non-universal large scales on conditional structure functions in turbulence

We report measurements of conditional Eulerian and Lagrangian structure functions in order to assess the effects of non-universal properties of the large scales on the small scales in turbulence. We study a 1m $\times$ 1m $\times$ 1.5m flow between oscillating grids which produces $R_\lambda=285$ while containing regions of nearly homogeneous and highly inhomogeneous turbulence. Large data sets of three-dimensional tracer particle velocities have been collected using stereoscopic high speed cameras with real-time image compression technology. Eulerian and Lagrangian structure functions are measured in both homogeneous and inhomogeneous regions of the flow. We condition the structure functions on the instantaneous large scale velocity or on the grid phase. At all scales, the structure functions depend strongly on the large scale velocity, but are independent of the grid phase. We see clear signatures of inhomogeneity near the oscillating grids, but even in the homogeneous region in the center we see a surprisingly strong dependence on the large scale velocity that remains at all scales. Previous work has shown that similar correlations extend to very high Reynolds numbers. Comprehensive measurements of these effects in a laboratory flow provide a powerful tool for assessing the effects of shear, inhomogeneity and intermittency of the large scales on the small scales in turbulence