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1.
Rats given access to a 32% sucrose solution and then downshifted to a 4% solution exhibit less contact with the sipper tube than unshifted controls always given access to 4% solution. This phenomenon, called consummatory successive negative contrast, was facilitated in Experiment 1 by a posttrial injection of corticosterone (3 mg/kg) administered immediately after the first downshift trial. Experiment 2 demonstrated that this facilitatory effect of posttrial corticosterone does not occur when administered 3 hr after the first downshift trial. These results support the hypothesis that corticosterone strengthens an aversive emotional component elicited by the surprising downshift in reward magnitude during the initial downshift trial. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
2.
The problem of finding a variable ordering to minimise the size of a reduced ordered binary decision diagrams (ROBDD) is considered for functions possessing disjunctive decompositions. An example is presented showing that the best ordering for a function with a disjunctive decomposition cannot always be directly determined from the best orderings for the component functions  相似文献   
3.
In this paper, we consider the evaluation of the safety of a self-checking circuit with combinational logic. Since the circuit is tested under normal operation, it may stay in different states such as a perfect state in which any erroneous output can be detected, unstable states in which an erroneous output may be detected or may not, a safe-state when the erroneous output has been caught, and a fail-state because the erroneous output is undetected, as time goes on. Consequently, we propose a fail-safe evaluation, using a Markov model to describe the state transitions and predicate the probability of the circuit not being in the fail-state.We include a comparison with existing evaluation methods, the proposed approach being more practical because it estimates the safety of the circuit, which is reducing as time goes on, instead of giving a constant probability measure.This work was supported in part by Research Grant No. 5711 from the Natural Sciences and Engineering Research Council of Canada and by an equipment loan from the Canadian Microelectronics Corporation.  相似文献   
4.
It is well known that only n+1 spectral coefficients, the Chow or modified-Chow parameters, are necessary to uniquely define any given linearly separable (threshold) function. It is here shown that n+1 coefficients only are necessary to define a much wider class of Boolean functions, namely all Boolean functions which can be realised from a threshold-logic core function with pre- and postlinear-translation operations. The use of n+1 spectral coefficients as a fault signature for all such functions is therefore possible.  相似文献   
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BACKGROUND: Catenins belong to a family of proteins that mediate the binding between intracytoplasmic domain of cadherins and cytoskeleton. Few data on distribution of beta and gamma catenins in non-neoplastic tissues are available from current literature. This study aims to evaluate distribution of beta and gamma catenins in oral epithelium. METHODS: Nine formalin-fixed and paraffin-embedded samples of oral epithelium were retrieved from files of Department of Oral Pathology of the University of Naples "Federico II". These samples were tested with anti-beta and anti-gamma monoclonal antibodies revealed by standard streptavidin-biotin-peroxidase technique. Sections have been evaluated by two observers by optical microscope using a 40X objective. The number of positive cells has been evaluated using a semi-quantitative method. RESULTS: The results of this study show that beta and gamma catenins were mostly distributed in the upper two-thirds of oral epithelial thickness, except for keratinized areas which appear negative. Basal layer is positive except for the basal side of basal cells. Keratinized layers are negative for beta and gamma catenins. CONCLUSIONS: In physiologic conditions staining pattern for beta and gamma catenins is almost exclusively membranous, sometimes cytoplasmic but never nuclear. This staining is well-represented even in conditions of chronic inflammation and leucoplakia.  相似文献   
7.
Zirconium oxide regulates RNA interfering of osteoblast-like cells   总被引:1,自引:0,他引:1  
Zirconium oxide (ZO) has outstanding mechanical properties, high biocompatibility and high resistance to scratching. Since dental implants are made with ZO and the genetic effects of ZO on osteoblasts are incompletely understood, we used microRNA microarray techniques to investigate the translation process in osteoblasts exposed to ZO. By using miRNA microarrays containing 329 probes designed from Human miRNA sequences, we identified in osteoblast-like cells line (MG-63) cultured on ZO disks several miRNA whose expression was significantly modified. The most notable regulated genes acting on osteoblasts are: NOG, SHOX, IGF1, BMP1 and FGFR1. The data reported below represent the first study on translation regulation in osteoblasts exposed to zirconium and one in which the effect of ZO on bone formation has been detected.  相似文献   
8.
Thermal finite element models are used to simulate the temperature distribution of a body under a certain set of boundary conditions. When short calculation times are necessary (i.e., for parametric study, active control loops, temperature monitoring algorithms, etc.) detailed FE models cannot be used and reduced-order models must be developed. Reduced-order models may have both generalized and physical degrees of freedom (dofs), according to the scope of the reduction. The use of generalized dofs is more suitable to simulate full-field temperature distribution of the body, while inclusion of physical dofs can be advantageous when temperature must be only computed at a small number of locations. In this paper a new reduction technique is proposed for applications where only a small set of temperatures must be computed; it is based on the Guyan reduction method and overcomes the limitations of the original Guyan reduction when applied to thermal models with a fluid network, characterized by non-symmetric matrices. The new technique is applied to a case study, consisting of a dummy turbine disk and its secondary air system in order to show the improvement with respect to the original Guyan approach.  相似文献   
9.
Conjugated linoleic acid (CLA) is thought to have anti-proliferative and anti-inflammatory properties, but its effect on cancer cachexia is unknown. Two effects were here investigated: that of CLA on inflammatory mediator production in human lung cancer cells, and that of reduced mediators on the myogenic differentiation of murine muscle C2C12 cells. The latter cells were grown in medium conditioned by human lung cancer A427 cells, with or without CLA, to mimic only the effect of molecules released from the tumor “in vivo”, excluding the effect of host-produced cachectic factors. The results obtained show that CLA was found to reduce the production of tumor necrosis factor-α, interleukin (IL)-1β and prostaglandin E2 (PGE2), but had no effect on IL-6 production. The mechanisms underlying the effect of CLA on cytokine or PGE2 release in A427 cells are probably mediated by activation of peroxisome proliferator-activated receptor (PPAR)α, which increased at 24 h CLA treatment. In turn, the reduced content of inflammatory mediators in medium conditioned by A427 cells, in the presence of CLA, allowed muscle cells to proliferate, again by inducing PPAR. The involvement of PPARα was demonstrated by treatment with the antagonist MK-886. The findings demonstrate the anti-inflammatory and myogenic action of CLA and point to its possible application as a novel dietary supplement and therapeutic agent in inflammatory disease states, such as cachexia.  相似文献   
10.
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