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71.
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We observed fine-scale jetlike features, referred to as penumbral microjets, in chromospheres of sunspot penumbrae. The microjets were identified in image sequences of a sunspot taken through a Ca II H-line filter on the Solar Optical Telescope on board the Japanese solar physics satellite Hinode. The microjets' small width of 400 kilometers and short duration of less than 1 minute make them difficult to identify in existing observations. The microjets are possibly caused by magnetic reconnection in the complex magnetic configuration in penumbrae and have the potential to heat the corona above a sunspot.  相似文献   
73.
New routes to early memories   总被引:3,自引:0,他引:3  
Stimulation of one side of the olfactory system during training with odor-milk pairings in neonatal rats results in their ability to recall an odor memory by using the trained but not the untrained side of the brain. In 12-day-old rats, olfactory learning can be recalled by stimulation of either the trained or untrained side. The development of bilateral recall reflects the maturation of olfactory commissural pathways that provide access to the olfactory memory stored on the contralateral side. Furthermore, the commissural pathways need not be present at the time of memory formation but can establish new and specific access to already existing olfactory memories.  相似文献   
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Because of emerging economic realities of the latter half of this century, the practice of preventive medicine, as opposed to curative medicine, is becoming essential in developed and developing countries. This holds true in veterinary medicine as well as in human medicine, and as we become increasingly aware of this fact, we also recognize the increasing interdependence of both fields. To determine the extent to which veterinarians are prepared to deal with this change in emphasis, two surveys have been prepared; one directed to various specialty groups within the profession and the other directed to schools of veterinary medicine. The first survey was designed to identify areas in which veterinarians felt their training had been deficient relative to decision making in applied preventive medicine. The second survey queried the schools to determine what changes had been made in their curricula to remedy these inadequacies.  相似文献   
76.
This article describes the development and implementation of a World Wide Web page to support a team-taught introductory animal and poultry science course. The objectives were to examine the capabilities of this type of instructional resource, determine students' willingness to use this type of resource, create opportunities for interactive learning, and improve students' enthusiasm for the subject area. A variety of course materials were made available through the Internet, including the class syllabus, lecture notes, and practice questions to support and augment class lectures. Additional on-line resources included a bulletin board for instructor announcements, a list-serve for student discussions concerning administrative and educational issues arising during the semester, a class E-mail list, and a page with links to other sites of agricultural interest. Materials were accessible from a variety of computer resources, including campus computing laboratories, dial-up access, and access via other Internet service providers. Use of the materials was evaluated by analysis of log files from the server. Effectiveness of the resources was determined from surveys of students conducted before and after implementation of the on-line resource. Students indicated that the most useful components of the Web page were the class notes and practice/review questions. Effectiveness of the site was related to the amount of material available through the site, the level of interaction, whether the task was required, and the ease of access to computers and the Web site. Student evaluations indicated that this form of instructional supplement is a viable method for enhancing the learning experience in the introductory animal sciences.  相似文献   
77.
Hormonal stimulation of lactose synthetase in mammary carcinoma   总被引:2,自引:0,他引:2  
A transplantable rat mammary carcinoma (R3230AC) synthesizes significant quantities of the mammary gland enzyme lactose synthetase in the immature virgin female rat. In this hormonal environment, mammary glands do not synthesize the enzyme. Prolactin further stimulates the enzyme activity in the tumors to levels found only in mammary glands of rats in late pregnancy or during lactation.  相似文献   
78.
Malignant lymphoma involving bone and heart was diagnosed in a 4-year-old Whippet, using radiography, histologic examination, nuclear scintigraphy of the skeleton and heart, and cardiac ultrasonography.  相似文献   
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