• Title/Summary/Keyword: functionally blocked area

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A Study of Determinants of Regulatory Policy of Air Traffic Management and Airspace Utility (항공교통관리와 국가공역의 규제정책 결정요인의 고찰)

  • Shin, Hyun-Sam
    • The Korean Journal of Air & Space Law and Policy
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    • v.20 no.1
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    • pp.255-272
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    • 2005
  • This study was conducted to present the adaquate guidelines necessary in decision making processes regarding air traffic management as well as airspace management in the national airspace system. It encompasses the overall advanced air traffic management initiatives, domestic air traffic congestion and resolution method as well.

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Cholinergic Mechanisms on Cardiovascular Regulation in the Ventrolateral Medulla of the Rat (흰쥐 복외측 연수에서 심혈관 조절에 대한 Choline성 기전)

  • Kim, Seong-Yun;Koh, Taek-Lip;Lee, Sang-Bok
    • The Korean Journal of Pharmacology
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    • v.23 no.2
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    • pp.77-85
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    • 1987
  • This study was carried out to determine the role of cholinoceptors in the ventrolateral medulla on central control of blood pressure (BP) and heart rate (HR). In rats anesthetized with urethane and paralyzed, microinjections of the neuroexcitatory amino acid L-glutamate (300 ng/site) were performed to functionally identity the vasopressor area (VLPA) and the vasodepressor area (VLDA) in the ventrolateral medulla oblongata. 1. The bilateral microinjection of carbachol (300 ng/site) into the VLPA produced significantly an increase in BP and HR which was not blocked by bilateral pretreatment of hexamethoium ($4\;{\mu}g/site$). 2. The bilateral microinjection of physostigmine (200 ng/site) and oxotremorine (300 ng/site) into the VLPA produced significantly an increase in BP respectively. 3. The bilateral microinjection of atropine ($4\;{\mu}g/site$) into the VLPA produced significantly a decrease in BP and HR. 4. The bilateral micro injection of acetylcholine (500 ng/site) and dimethylphenylpiperazinium (500 ng/site) into the VLDA produced significantly a decrease in BP and HR respectively. 5. The depressor and bradycardiac responses elicited by the bilateral microinjection of acetylcholine (500 ng/site) into the VLDA were blocked by bilateral pretreatment of hexamethonium ($4\;{\mu}g/site$). The results suggest that the activation of cholinoceptors in VLPA produce hypertensive and tachycardiac responses which may be mediated by muscarinic receptors, and the activation of cholinoceptors in VLDA produce hypotensive and bradycardiac responses which may be mediated by nicotinic receptors.

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