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71.
Injected 111 male ring doves intramuscularly with dexamethasone throughout a reproductive cycle in an attempt to suppress adrenocortical secretions. Ss were tested for initiation and maintenance of incubation behavior. Treated Ss showed normal initiation of sitting when observed in their cages, but when they were tested alone in novel cages initiation of incubation tended to be disrupted. Prolonged dexamethasone treatment interfered with maintenance of incubation behavior in both test situations. The deleterious effect of dexamethasone on maintenance of home cage sitting was alleviated by concurrent treatment with prolactin or ACTH. In conclusion, adrenal secretions do not seem to be necessary for onset of incubation in males, but there are hormonal requirements for maintenance of this behavior. (35 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
72.
Daniel D. Dietrich Gordon A. Chandler Richard J. Fortner Charles J. Hailey Richard E. Stewart 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》1985,9(4):686-688
A new experimental capability has been developed at the Lawrence Berkeley Laboratory Super-HILAC to investigate questions relating to high resolution atomic spectroscopy. A key element of these measurements is a dual arm Johann spectrometer. The ion beam passes inside the Rowland circle of two curved crystals which are mounted such that diffracted X-rays have equal and opposite linear Doppler shifts. The X-ray lines are detected with high speed X-ray film mounted on the Rowland circle. The beam-crystal geometry is arranged so a spectral range θB ~ 30°–70° is detected. The spectrometer efficiency is high with useful exposures obtained with only 10 mC of beam. A wavelength calibration is obtained by simultaneously exposing the film with diffracted K and L X-rays from an X-ray tube. X-ray lines from the beam are slanted, with respect to the calibration lines, due to Doppler shifts arising from X-rays incident on the crystal at angles other than perpendicular to the diffraction plane. The slope of these lines provides an independent determination of the beam velocity, which is used to correct for the transverse Doppler shift. Typical results are presented. 相似文献
73.
Visualizing features and tracking their evolution 总被引:1,自引:0,他引:1
We describe basic algorithms to extract coherent amorphous regions (features or objects) from 2 and 3D scalar and vector fields and then track them in a series of consecutive time steps. We use a combination of techniques from computer vision, image processing, computer graphics, and computational geometry and apply them to data sets from computational fluid dynamics. We demonstrate how these techniques can reduce visual clutter and provide the first step to quantifying observable phenomena. These results can be generalized to other disciplines with continuous time-dependent scalar (and vector) fields 相似文献
74.
A method of treating completely displaced supracondylar fractures of the humerus in children by 'straight lateral traction', as originally used by John Dunlop, is recommended. The results in 26 children, selected because manipulation had failed to achieve reduction, is examined, and indicates that this treatment is satisfactory for some problem fractures, leading usually to good results in terms of resolution of complications and return of function. It also avoids the ugly deformities of the elbow which follow reliance on a single form of treatment for all supracondylar fractures. Failure of anatomical reduction by the appliance is shown to be in the plane of elbow movement, where normal physiological mechanisms correct the bone by remodelling. Where there is epiphyseal damage, deformities may occur with any form of treatment. 相似文献
75.
H.B. Silver 《Tribology International》1977,10(4):229-233
Current test methods for assessing corrosion on steel surfaces in the presence of lubricants have a number of disadvantages. This paper describes a test which requires only small quantities of fluid. Its advantages include speed, versatility, and the quantitative nature of the results 相似文献
76.
Buffer storage allows the decoupling of successive stages of large automatic production systems, which can be important when the machines sometimes fail. System designers should know how much added buffer capacity increases the hourly output of such systems. Previously available methods for predicting this increase treat systems with one machine in each stage. We present a computationally simple heuristic procedure for estimating hourly line output for two stage systems in which each stage may have several machines. 相似文献
77.
78.
Simple dense-pattern optical multipass cells 总被引:1,自引:0,他引:1
Silver JA 《Applied optics》2005,44(31):6545-6556
Multiple-pass optical cells with dense spot patterns are useful for many applications, especially when the cell volume must be minimized relative to the optical path length. Present methods to achieve these dense patterns require expensive, highly precise astigmatic mirrors and complex alignment procedures. This work describes a new, simpler, and less demanding mirror system, comprising either a pair of cylindrical mirrors or one cylindrical and one spherical mirror. 相似文献
79.
Seven patients with cardiac rupture from blunt trauma were encountered at the University Hospital, University of Alabama School of Medicine, in a 15-year period. Five of seven patients survived, including three with left atrial injuries and one each with right ventricular and left ventricular injuries. Useful diagnostic features included systolic hypotension, distended neck veins, and elevated central venous pressures. Associated injuries averaged four per patient. Successful management demands a high index of suspicion of cardiac injury, prompt diagnosis, and immediate median sternotomy. After repair of the heart the incision should usually be extended to allow exploratory laparotomy. 相似文献
80.
Aboudara Deane N. Woods C. William Silver Raymond S. Beckett John C. 《Spectrum, IEEE》1967,4(1):60-70
Similarity exists between moving large masses of people and the process industry. Both have fixed inputs, fixed outputs, predictable patterns, variables that can be measured, and corrections that can be made. Both entities respond to the principle of closed-loop regulation. From the experience gained in the San Francisco Bay Area Rapid Transit District (BARTD), a planned approach to coordinated and automated mass transportation systems is entirely feasible. Electronic controls are a major factor in providing an economic solution to the problem. 相似文献