• Title/Summary/Keyword: Beak

Search Result 696, Processing Time 0.052 seconds

Teratogenic effects of diazinon in chick embryos I. Effects of diazinon treatment on morphology and cholinergic blocking agents (Diazinon이 계배(鷄胚)의 기형 유발에 미치는 효과 I. 계배(鷄胚) 형태와 콜린성 봉쇄약물에 미치는 효과)

  • Kim, Jong-shu;Kim, Gon-sup;Kim, Yang-mi;Choi, Wong-young;Son, Sung-gi;Heo, Jung-ho;Lee, Ju-hong
    • Korean Journal of Veterinary Research
    • /
    • v.34 no.1
    • /
    • pp.49-54
    • /
    • 1994

  • Teratogenic effects of diazinon were assessed on morphology of chick embryos cholinergic blocking agents. Diazinon at doses ranging from 25 to $2000{\mu}g/egg$, was injected on Day 3 of incubation. $TD_{50S}$, were different for the various teratogenic sings such as wry neck, micromelia, abnormal feathering, abnormal beak and curled claws. The threshold dose for wry neck was higher than the threshold dose for other signs; $40{\mu}g/egg$ produced substantial micromelia, abnormal feathering, abnormal beak and curled claws, but gave no sings of wry neck. In contrast to the teratogenic doses, the $LD_{50}$ of diazinon was very high(above $2000{\mu}g/egg$). One of the characteristics of diazinon-induced teratogenesis was reduction of body weight(78.8%) and body length(73.8%). Maximal teratogenic effects, scored as sings of retarded growth, wry neck, micromelia, abnormal feathering, abnormal beak, and curled claws, were produced when the insectcide was administered on the third or fourth day. The threshold dose for type II teratogenic sings including wry neck and short neck was higher than for type I including micromelia and abnormal feathering. Morphorlogical studies, using atropine and gallamine, suggested that nicotinc but not muscarinic receptors may be involved in the mechanism of diazinon-induced type II malformations.

  • PDF

A taxanomic study on sections Foetidae, Arenariae, and Multiflorae of Carex L. in Korea(Cyperaceae) (한국산 사초속 진퍼리사초절, 까락사초절과 괭이사초절에 관한 분류학적 연구)

  • Oh, Yong Cha;Kim, Ji Hye
    • Korean Journal of Plant Taxonomy
    • /
    • v.32 no.3
    • /
    • pp.257-292
    • /
    • 2002

  • Morphological characters of sections Foetidae(one taxon), Arenariae(one taxon) and Multiflorae(six taxa) of genus Carex(Cyperaceae) were reexamined. The epidermal patterns of perigynium, achene and leaf were investigated using by a scanning electron microscope(SEM) and a light microscope(LM). Morphological characters, such as length and width of stem, leaf, leaf sheath, bract, spike, scale, perigynium and beak of perigynium, length of spike peduncle, size and frequency of stomatal complex of leaf, number of bract, shape of stem transection, scale and apex of scale, beak and base of perigynuim, achene, epidermal cell and cell wall of perigynium, achene, leaf epidermal patterns(fundamental epidermal cell and cell wall, silica body, subsidiary cell), hair, papillae present/absent of perigynium, and leaf were useful for the identification of observed eight taxa. According to the current study, examined eight taxa of sections Foetidae, Arenariae and Multiflorae were distinct from each other with respect to length and width of stem, leaf, bract, perigynium, perigynium beak, length of spike peduncle, shape of bract, scale and apex of scale, perigynium, perigynium beak, hair presence/absence of perigynium and leaf. A key based on data was presented here.

  • PDF KSCI