Effect of microstructure on oxygen permeation in SrCo0.8Fe0.2O3−δ

The effect of microstructure on oxygen permeation in SrCo0.8Fe0.2O3– membranes was investigated using disc samples fabricated under different processing conditions of applied pressure and sintering temperature. The average grain size of the samples was found to remain unchanged as a function of applied pressure, but increased considerably when the sintering temperature was increased from 950 to 1200°C. This change in grain size has a strong effect on the oxygen permeation flux, which increased considerably as the grain size was decreased. The density as well as the microhardness of these samples were also measured and found to change slightly as the processing conditions were changed.     

Nonequilibrium Thermodynamics of Mesoscopic Systems

The Markovian dynamics of a Brownian particle is derived in the case that the local temperature is a stochastic variable. The isolated mesoscopic particle plus environment system is analyzed in the microcanonical ensemble by means of nonlinear-process projection methods. The ensuing generalized Kramers FokkerPlanck equation involves a thermodynamic potential of mean force that is different from the canonical free energy, and the conditional entropy (or availability) emerges as the relevant steady-state potential. By coupling the system to a heat bath, we provide a microscopic foundation for the phenomenological theory of nonisothermal activation in mesoscopic systems. In the second part of this article, we then prove the existence of an availability potential governing the nonisothermal features of a Josephson junction in a SQUID, by studying the Josephson internal energy (and entropy) for T T _c in a model of two BCS superconductors coupled by a tunneling Hamiltonian. The predicted periodic dependence of the junction's T _c as a function of the flux in the SQUID has meanwhile been confirmed experimentally.     

Assessment of long-chain polyunsaturated fatty acid nutritional supplementation on infant neurobehavioral development and visual acuity

The aims of this paper are (i) to consider how best to examine effects of long-chain polyunsaturated fatty acid nutritional supplementation or deficiency on infant neurobehavioral development, after controlling for other factors that might influence outcome, including maternal demographic, intellectual, and personality characteristics, and (ii) to present new findings on the relation between visual acuity and processing speed and the effects of prenatal alcohol exposure and visual acuity on infant information processing. The following topics are also addressed: (i) breastfeeding and intelligence, (ii) criteria for the selection and control of potential confounding variables, and (iii) new infant information processing measures.     

Cognitive–behavior therapy versus pharmacotherapy: Now that the jury's returned its verdict, it's time to present the rest of the evidence.

Recent reanalyses suggest that pharmacotherapy was superior to cognitive–behavior therapy in the acute treatment of more severely depressed outpatients in the National Institute of Mental Health Treatment of Depression Collaborative Research Program (TDCRP). At the same time, this finding was neither robust across sites within the TDCRP nor consistent with findings from other studies. D. F. Klein (1990) has argued that those other studies were inherently flawed because they did not include pill-placebo controls, an argument that he extended to drug–psychotherapy comparisons in the treatment of panic as well. It is agreed that the inclusion of such controls would have facilitated the interpretation of the findings, but it is not agreed that their omission rendered those studies uninterpretable. Cognitive–behavior therapy remains a viable alternative to pharmacotherapy in the treatment of depression and a particularly promising intervention in the treatment of panic disorder. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prospects for future comparisons between drugs and psychotherapy: Lessons from the CBT-versus-pharmacotherapy exchange.

In these concluding comments to the exchange among N. S. Jacobson and S. D. Hollon, D. F. Klein, I. Elkin et al, and R. J. McNally (see record 1996-02770-007, 1996-02770-008, 1996-02770-010, and 1996-02770-009, respectively) issues of continuing controversy are highlighted: the best ways to control for the allegiance effect, the complexities of assessing competence, and the role of pill placebos in comparisons between cognitive–behavior therapy (CBT) and pharmacotherapy. It is concluded that controlling for allegiance within site is the optimal strategy, that measures of competence must take context into account, and that pill placebo controls are optimal but not essential to comparisons between CBT and pharmacotherapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intraoperative monitoring with stimulus-evoked electromyography during placement of iliosacral screws. An initial clinical study

Cells of the innate immune system secrete cytokines early in immune responses that guide maturing T helper (Th) cells along appropriate lineages. This study investigates the role of cytokine networks, bridging the innate and acquired immune systems, in the pathogenesis of an organ specific autoimmune disease. Experimental allergic encephalomyelitis (EAE), a demyelinating disease of the central nervous system, is widely used as an animal model for multiple sclerosis. We demonstrate that interleukin (IL)-12 is essential for the generation of the autoreactive Th1 cells that induce EAE, both in the presence and absence of interferon gamma. The disease-promoting effects of IL-12 are antagonized by IL-10 produced by an antigen nonspecific CD4+ T cell which, in turn, is regulated by the endogenous production of IL-12. This unique immunoregulatory circuit appears to play a critical role in controlling Th cell differentiation and provides a mechanism by which microbial triggers of the innate immune system can modulate autoimmune disease.     

Europa's differentiated internal structure: inferences from four Galileo encounters

Radio Doppler data from four encounters of the Galileo spacecraft with the jovian moon Europa have been used to refine models of Europa's interior. Europa is most likely differentiated into a metallic core surrounded by a rock mantle and a water ice-liquid outer shell, but the data cannot eliminate the possibility of a uniform mixture of dense silicate and metal beneath the water ice-liquid shell. The size of a metallic core is uncertain because of its unknown composition, but it could be as large as about 50 percent of Europa's radius. The thickness of Europa's outer shell of water ice-liquid must lie in the range of about 80 to 170 kilometers.     

Emission characteristics of some dilute tungsten alloys

The effective work functions of nine tungsten-base alloys were measured. The second constituents were: 1) 5 pct Re, 2) 15 pct Re, 3) 2.5 pct Os, 4) 5 pct Os, 5) 1 pct Ir, 6) 2 pct Ir, 7) 5 pct Ta, 8) 10 pct Ta, and 9) 26 pct Ta. Work functions were determined from vacuum emission vehicle and thermionic emission microscope measurements. Mosaics of each surface were produced from the microscope which show the grain structure of the alloys and some anomalous emission areas. Some exceptionally high bare work functions were observed from samples with small alloy additions. For example, the work function of W1 pct Ir was 5.3 eV. DEAN LEO JACOBSON, formerly Section Manager, Electro-Optical Systems, Division of Xerox Corp., Pasadena, Calif.