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81.
82.
In 4 experiments, female White Carneaux pigeons were exposed to key-light illuminations separated from food delivery by 12–60 sec. Approach to the key light did not develop on conventional trace-conditioning arrangements but occurred consistently whenever some auditory or visual stimulus filled the CS–UCS gap (serial conditioning) or was always present except during the gap. The CS approach was strong only when the stimulus present during the intertrial interval remained on until the termination of CS; if the stimulus ended at CS onset, conditioning did not occur. Although discriminability of CS–UCS gaps from intertrial periods seemed necessary for conditioning to occur in the absence of close CS–UCS contiguity, the outcome of the final experiment indicates that such discriminability was not sufficient for conditioning. Results are discussed in terms of possible 2nd-order conditioning effects and the changes in the associative strength of the "local context" existing when the CS appears, which may lead to superconditioning of CS. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
83.
The problem of change in thermal resistance of pores and microcracks in refractories with occurrence of heterogeneous reactions and formation of gas with diffusion product transfer in the temperature gradient field is analyzed.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 34, No. 3, pp. 452–455, March, 1978.  相似文献   
84.
A new three dimensional oscillator for generating three phases of sinewaves is derived. The model is similar to the previous ones (Ref. 1 and 2) in enabling an undistorted stabilized generation of sinewaves. It possesses certain advantages in comparison to the previous models. The oscillator appears as a viable model for representing synchronous generators in a simplified manner in the simulation of power systems.  相似文献   
85.
The effect of cetylpyridinium chloride (CPC) on pathogenic fungi and Nocardia asteroides was studied. Sputa seeded with each of 11 organisms (Aspergillus flavus; Aspergillus fumigatus, Blastomyces dermatitidis, Candida albicans, Coccidioides immitis, Cryptococcus neoformans, Geotrichum candidum, Histoplasma capsulatum; Nocardia asteroides, Paracoccidioides brasiliensis, and Sporothrix schenckii) were treated with CPC and kept for 2, 5 and 9 days. The CPC reagent used (0.5% CPC and 0.5% sodium chloride) is one the Mycobacteriolgoy Branch at the Center for Disease Control added to sputa before shipping them to laboratories for recovery of mycobacteria. None of the organisms tested survived this treatment, and none was recovered on mycological or mycobacteriological media. Seeded sputa containing these organisms were also tested with a second CPC reagent (0.02% CPC and 0.5% sodium chloride) and held for 2, 5 and 9 days. A few colonies of A. flavus, A. fumigatus, and N. asteroides were recovered from these samples. Neither the morphology of the fungi nor their stainability by the fluorescent antibody method was affected by treatment with the reagent containing 0.5% CPC. However, the background material in smears from the 0.5% CPC-treated samples retained the conjugate, and this made weakly fluorescing organisms more difficult to detect. The 0.5% CPC treatment did not alter the morphology of N. asteroides or its ability to be stained with Kinyoun acid-fast stain.  相似文献   
86.
Although it is frequently stated that the frontal lobes play a significant role in memory function, research proof has been ambiguous at best. The present study investigated this problem by administering a variety of memory tests (e.g., Wechsler Memory Scale, WAIS) to 16 schizophrenic patients who had undergone prefrontal leukotomy approximately 25 yrs earlier. Ss were divided into 3 groups on the basis of recovery after surgery. Two comparison groups (5 psychiatric and 5 normal controls) were established to control for psychiatric symptomatology, years of institutionalization, age, and years of education. Results indicate that large bilateral orbitofrontal lesions may not result in amnesia; in fact, the nonoperated schizophrenic control group performed the most poorly. Proactive interference was demonstrated, however, resulting in significant impairment for all Ss with prefrontal lobe damage despite normal scores on commonly used memory tests. Ability to maintain consistent and directed attention and to overcome interference is proposed as a role of the frontal lobes in memory function. (55 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
87.
88.
The injection of a suspension of Walker 256 carcinoma cells into the carotid artery of rats produced a model of hematogenously spread cerebral metastases. Most animals died from massive extracerebral tumors of the head and jaw; brain tumors were present in only one-quarter. External carotid artery ligation prior to tumor inoculation did not increase the incidence of fatal brain tumor. When cyclophosphamide, 15 mg/kg, was injected as a single dose on the fourteenth day after tumor inoculation, most of the extracerebral tumor disappeared. Fifty percent of the animals so treated were cured of tumor, but 90% of the remainder died of large intracerebral tumors. Severe cytopathic changes resulting from cyclophosphamide were present in extracerebral or choroid plexus tumors but were mild or nonexistent in intracerebral tumors. These selective effects of cyclophosphamide suggest that water-soluble agents are less effective against tumor in the brain than against extracerebral tumors despite the fact that metastatic tumor breaks down the blood-brain barrier.  相似文献   
89.
We report an unusual case in which an apparently normal upper lobe of the right lung was supplied by major systemic arterial and pulmonary arterial vessels. The anomalous artery arose from the descending aorta. Following interruption of this vessel, the machinery-like murmur previously present disappeared.  相似文献   
90.
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