翻訳と辞書 Words near each other ・ Clinopodium ashei ・ Clinopodium brownei ・ Clinopodium chandleri ・ Clinopodium dentatum ・ Clinopodium fasciculatum ・ Clinopodium glabellum ・ Clinopodium mimuloides ・ Clinopodium mutabile ・ Clinopodium vulgare ・ Clinoporus biporosus ・ Clinoptilolite ・ Clinopyroxene thermobarometry ・ Clinosperma ・ Clinosperma bractealis ・ Clinosperma macrocarpa ・ Clinostat ・ Clinostigma ・ Clinostigma exorrhizum ・ Clinostigma haerestigma ・ Clinostigma harlandii ・ Clinostigma samoense ・ Clinostigma savoryanum ・ Clinostomum marginatum ・ Clinostomus ・ Clinostomus funduloides ・ Clinotaenia ・ Clinotanypodini ・ Clinotanypus ・ Clinotarsus ・ Clinotarsus alticola Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Clinostat ： ウィキペディア英語版 Clinostat A clinostat is a device which uses rotation to negate the effects of gravitational pull on plant growth (gravitropism) and development (gravimorphism). It has also been used to study the effects of microgravity on cell cultures and animal embryos. ==Description== A single axis (or horizontal) clinostat consists of a disc attached to a motor. They were originally clockwork but nowadays an electric motor is used. The disc is held vertically and the motor rotates it slowly at rates in the order of one revolution per minute. A plant is attached to the disc so that it is held horizontally. The slow rotation means that the plant experiences a gravitational pull that is averaged over 360 degrees, thus approximating a weightless environment. Clinostats have also been used to cancel out effects of sunlight and other stimuli besides gravity. This type of clinostat must be exactly horizontal to simulate absence of gravity. If the clinostat is at an angle from horizontal, a net gravity vector is perceived, the magnitude of which depends on the angle. This can be used to simulate lunar gravity (ca. 1/6 g) which requires an angle from the horizontal of ca. 10 deg., i.e. sin−1(1/6). A plant only reacts to gravity if the gravistimulation is maintained for longer than a critical amount of time, called the minimal presentation time (MPT). For many plant organs the MPT lies somewhere between 10 and 200 seconds, and therefore a clinostat should rotate on a comparable timescale in order to avoid a gravitropic response. However, presentation time is cumulative, and if a clinostat's rotation is repeatedly stopped at a single position, even for periods as short as 0.5 s, a gravitropic response can result.〔B.G. Pickard (1973) Geotropic response patterns of the Avena coleoptile. I. Dependence on angle and duration of stimulation. Can. J. Bot. 51: 1003-1021〕 The presentation time for animals is one or two orders of magnitude faster than this, thus precluding the use of the slow rotation clinostat for most animal studies. However the fast rotation clinostat can be, and is, used for the study of animal cell cultures and embryos. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Clinostat」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.