Advanced microstructural characterization of plasma-sprayed zirconia coatings over extended length scales

Achieving control of the microstructure of plasma-sprayed thermal barrier coating (TBC) systems offers an opportunity to tailor coating properties to demanding applications. Accomplishing this requires a fundamental understanding of the correlations among processing, microstructure development, and related TBC properties. This article describes the quantitative characterization of the microstructure of plasma-sprayed partially stabilized zirconia (PSZ) coatings by means of x-ray and neutron-scattering imaging techniques. Small-angle neutron scattering, ultra-small-angle x-ray scattering, and x-ray microtomography were used to characterize and visualize the nature and structure of the features in these material systems. In addition, the influence of processing parameters on microstructure development is discussed along with thermal cycling effects on the pore morphology, and their resultant influence of the porosity on the thermal conductivity and elastic modulus of plasma-sprayed PSZ TBCs.     

An open-source,FireWire camera-based,Labview-controlled image acquisition system for automated,dynamic pupillometry and blink detection

The dynamic, accurate measurement of pupil size is extremely valuable for studying a large number of neuronal functions and dysfunctions. Despite tremendous and well-documented progress in image processing techniques for estimating pupil parameters, comparatively little work has been reported on practical hardware issues involved in designing image acquisition systems for pupil analysis. Here, we describe and validate the basic features of such a system which is based on a relatively compact, off-the-shelf, low-cost FireWire digital camera. We successfully implemented two configurable modes of video record: a continuous mode and an event-triggered mode. The interoperability of the whole system is guaranteed by a set of modular software components hosted on a personal computer and written in Labview. An offline analysis suite of image processing algorithms for automatically estimating pupillary and eyelid parameters were assessed using data obtained in human subjects. Our benchmark results show that such measurements can be done in a temporally precise way at a sampling frequency of up to 120 Hz and with an estimated maximum spatial resolution of 0.03 mm. Our software is made available free of charge to the scientific community, allowing end users to either use the software as is or modify it to suit their own needs.     

Blocking, Unblocking, and Overexpectation of Fear: A Role for Opioid Receptors in the Regulation of Pavlovian Association Formation.

Injection of the opioid receptor antagonist naloxone facilitated acquisition of fear to contextual and auditory conditioned stimuli (CSs) in Experiments 1A and 1B. Experiment 2 showed that prior conditioning to a distinctive context blocked conditioning to an auditory CS. Blocking of CS fear was prevented by administrations of naloxone or increases in footshock intensity. Blocking of CS fear was facilitated by decreases in footshock intensity in a naloxone-reversible manner. Experiment 3 showed that compound conditioning of two CSs, each previously and separately paired with shock, produced overexpectation of fear that was reversed by naloxone. These results are consistent with a role for opioid receptors controlling Pavlovian association formation by regulating the discrepancy (A--ΣV) described by R. A. Rescorla and A. R. Wagner (1972). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Classical conditioning provides paternity advantage for territorial male blue gouramis (Trichogaster trichopterus).

An irony of territorial behavior is that successful territory defense requires males to be aggressive, but highly aggressive males often inadvertently repel females, potential mates that the territory was created to attract. The authors provide empirical evidence that learning to anticipate the arrival of a female not only can overcome this well-recognized cost of territorial behavior but also can provide a significant paternity advantage. Following a short training period in which male blue gourami fish (Trichogaster trichopterus) either received classically conditioned pairings of a signal and a receptive female or received unpaired presentations of the signal and a female, male subjects were given an opportunity to mate. Signaling of female accessibility not only enabled classically conditioned males to attenuate their initial aggressive response to arriving females but, more important, classically conditioned males were able to spawn with females sooner, clasp females more often, and produce more young than males that did not have the benefit of a signal. Results provide the first demonstration of direct reproductive benefits resulting from classical conditioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Single-chain fragment variable antibody piezoimmunosensors

In this paper, we describe a novel nonlabeled biosensor with high diagnostic potential for rapid and sensitive detection of antigens in complex biological samples. The biosensor comprises a piezoimmunosensor (PZ) displaying a specially constructed recombinant antibody on its surface. The recombinant single-chain fragment variable (scFv) antibody contained a cysteine within the linker amino acid sequence used to join the scFv variable heavy and light chains. The presence of cysteine induced the scFv construct to self-assemble as a densely packed rigid monolayer on the gold surface of a quartz crystal microbalance. scFv molecules in this self-assembled monolayer (SAM) exhibited a defined orientation and high areal densities, with scFv-modified microbalance surfaces displaying 35 times as many variable antigen-binding sites per square centimeter as surfaces modified with whole antibody. Experimental data show that the scFv SAM PZ is superior to Fab fragment, Fab fragment containing a free sulfhydryl group (i.e., Fab-SH), and whole antibody PZs regarding sensitivity and specificity. Because of their small uniform size (MW approximately 27000) and the ease with which they can be modified using genetic engineering, scFv's have significant advantages over whole antibodies in microbalance biosensor systems. We demonstrate here that the use of scFv containing a cysteine within the scFv linker sequence (i.e., scFv-cys) for preparation of biosensor surfaces markedly increases the density of available antigen-binding sites, yielding a system that is highly selective, rapid, and capable of detecting low concentrations of antigens in complex samples.     

Attraction and repulsion by life and death in suicidal and in normal children.

Attraction and repulsion by life and death in 52 suicidal and 58 normal 6–12 yr olds were measured through responses to questions that followed fairy-tale stories. Each story represented 1 of the 4 attitudes. Parallel forms of the test were administered in a time interval of 4 wks. Analyses showed that the 4 attitudes were distinguishable from each other and that the response profile of the suicidal Ss was significantly different from that of normal Ss. Suicidal Ss, in contrast to normal Ss, showed a high degree of repulsion by life and attraction to death and a low degree of attraction to life and repulsion by death. In addition, in suicidal Ss the 4 attitudes were more distinguishable from each other but at the same time were more conflictual. The correlations between the scores of the 1st administrations indicate that 3 of the 4 attitudes have a moderate reliability for both normal and suicidal children. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Utility of the Beck Depression Inventory with psychiatrically hospitalized adolescents.

Investigated whether the Beck Depression Inventory (BDI) is a psychometrically sound instrument for measuring depressive symptomatology in 78 12–16 yr old psychiatrically disturbed adolescents. Test–retest, item-total, and coefficient alpha estimates of reliability were found to be statistically acceptable. BDI scores discriminated between patients with a hospital diagnosis of major depressive disorder and a diagnostically heterogeneous group of patients with nonaffective conditions. Results suggest that the BDI can be used profitably in clinical and treatment studies of depressive phenomena in early adolescence. (6 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An investigation into the possible occurrence of peptide-bound lanthionine in locust muscle

The amino acid composition of the protein of the wing muscle of the African migratory locust (Locusta migratoria migratorioides) was examined by qualitative and quantitative methods. the possible presence of lanthionine was investigated. Lanthionine could not be detected by two-dimensional paper chromatography nor by ion-exchange chromatography operated under three different conditions of temperature and pH. the analysis of hydrolysates prepared after a preliminary oxidation revealed no changes in composition that would arise had lanthionine been present together with other acids.     

Fractionation of plant material II.—Amino acid composition of some fractions obtained from the broad bean plant (Vicia faba L.) and chromatographic differentiation of hydroxyproline isomers

The amino acid compositions of three protein fractions obtained from broad bean leaves were estimated by ion exchange chromatography. Hydroxyproline was found present in the TCA-soluble, non-diffusible fraction and in the final residue after the further extraction with phenol-acetic acid-water (2: 1 : 1, w/v/v), but not in the extract itself. By comparison with the behaviour of four authentic isomers of hydroxyproline, under two standard conditions of chromatographic analysis, the isomer found was trans-4-hydroxy-proline. These results are discussed in relation to other reports of hydroxyproline occurring in plant material.