• Title/Summary/Keyword: metacentric

Search Result 94, Processing Time 0.025 seconds

Chromosomal Studies of Eight Species of Bradybaenidae in Korea (한국산 달팽이과 (Bradybaenidae) 8종의 염색채 연구)

  • 이준상;권오길
    • The Korean Journal of Malacology
    • /
    • v.9 no.2
    • /
    • pp.30-43
    • /
    • 1993
  • The number of chronosomes and karyotypes in eight species of the family Bradybaenidae were analyzed by air-drying method using gonad. The mitotic haploid chromosome numbers of Acusta despecta sieboldiana were 29 and conisisted of 12 pairs metacentric, 17 pairs submetacentric chromosomes. The mitotic haploid chromosomes were 29 and 11 pairs metacentric and 17 pairs submetacentric and 1 pair telocentric chromosomes in Koreanohadra kurodana; 29 and 10 pairs metacentric chromosomes in K. koreana' 29 and 10 pairs metacentric and 18 pairs submetacentric, and 1 pair acrocentric chromosomes in Karaftohelix adamsi; 28and 10 pairs metacentric, and 18 pairs submetacintric chromosomes in Aegista chosenica; 28 and 14 pairs metacentric and 14 pairs submetacentric chromosomes in A.(Plectotropis) diversa; 28 and 15 pairs metacentric, 10 pairs submetacentric and 3 pairs acrocentric chromosomes in A. (p.)quelpartinsis; 29 and 12 pairs metacentric and 9 pairs submetacentric and 2 pairs telocentric chromosomes in Nesiohelix samarangae.

  • PDF

Estimation of drafts and metacentric heights of small fishing vessels according to loading conditions

  • Kim, Dong Jin;Yeo, Dong Jin
    • International Journal of Naval Architecture and Ocean Engineering
    • /
    • v.12 no.1
    • /
    • pp.199-212
    • /
    • 2020
  • A large percentage of maritime accidents in coastal seas are related to small fishing vessels. In order to investigate causes of maritime accidents, it is often necessary to carry out dynamic simulations for the estimation of trajectories and motions of vessels. Initial conditions of vessels such as main dimensions, loading conditions and hydrostatic properties are required for the accurate simulations. Small fishing vessels usually have few records of hydrostatic properties during their fishing operations. Therefore, in this study, estimation procedures for hydrostatic properties of small fishing vessels are proposed. At first, hull form characteristics of Korean small fishing vessels are investigated. Most of vessels have hard-chines and centerline skegs, they have similar hull forms. Bonjean curves of several small fishing vessels whose gross tonnages are below 10 tons are normalized with vessel breadths and depths. Representative bonjean curves are derived from normalized bonjean curves, and a representative hull plan is obtained as well. If the vessel loading conditions such as total weights and centers of gravity are given, fore and aft drafts can be calculated by using the representative bonjean curves with the constraint that weights and buoyancies are in equilibrium. Metacentric heights are also estimated by using the representative hull plan. Drafts and metacentric heights estimated by proposed iterative estimation procedures are compared with actual vessel data, estimated values are in good agreements with actual values. In addition, normalized fore and aft drafts, metacentric heights of vessels can be formulated as the linear functions of normalized total weights and centers of gravity. Empirical formulas of drafts and metacentric heights are proposed, and it is confirmed that the empirical formulas also provide reasonable results, which are similar to the results by iterative estimation procedures with representative bonjean curves and hull plan.

Karyotypes of Genus Liobagrus (Pisces : Amblycipitidae) in Korea (한국산(韓國産) 퉁가리속(屬) 어류(魚類)의 핵형(核型) 분석(分析))

  • Son, Yeong-Mok;Lee, Ji-Hyun
    • Korean Journal of Ichthyology
    • /
    • v.1 no.1_2
    • /
    • pp.64-72
    • /
    • 1989
  • Karyological characteristics were investigated in 3 species of the genus Liobagrus from Korea. The diploid chromosome number in L. andersoni was found to be 28, with 9 pairs of metacentrics and 5 pairs of submetacentric chromosomes, and arm number (AN) was 56. L. mediadiposalis was found with 2n of 42, consisting of 13 pairs of metacentrics and 8 pairs of submetacentric chromosomes (AN=84). In the case of L. obesus 2n was 20, with 20 metacentric chromosomes (AN=40), which was the lowest among the species of the order Siluriformes. Sexual dimorphism or intraspecific polymorphism of the chromosomes was not observed in any species examined.

  • PDF

Chromosomal Study of Seven Species of Unionidae ( Bivalvia : Palaeoheterodonta ) in Korea (한국산 석패와 7종의 염색체 연구)

  • 박갑만;권오길
    • The Korean Journal of Malacology
    • /
    • v.7 no.1
    • /
    • pp.12-29
    • /
    • 1991
  • The chromosome numbers and the karyotypes of seven species in Unionidae are reported, using air drying in gonad. In seven species, the chromosome number of 38(2n) was counted. The mitotic chormosomes of A. arcaeformis flavotincta, A. woodiana and L. gottschei hd 7 pairs of metacentric and 12 pairs of submetacenrtic chromosomes, U. douglasiae had 6 pairs of metacentrics, 13 pairs of submetacentrics, U. douglasiae sinuolatus had 4 metacentric pairs and 15 submetacentric pairs, L. acrorhyncha had 5 metacentric pairs and 14 submetaacentric pairs, and S. triangularis had 5 mdtacenrtric pairs, 13 submetacentric pairs and 1 pair of subtelocentric chromosomes. The size of chromosomes of A. woodiana was the longest in length and L. gottschei was the shortest. The sexual difference of chromosomes was not observed.

  • PDF

Karyotypes on three species of Chinese mesogastropod snails, Semisulcospira libertina, S. dolichostoma and Viviparus rivularis

  • Park, Gab-Man;Kim, Jae-Jin;Chung, Pyung-Rim;Wang, Yong;Min, Duk Young
    • Parasites, Hosts and Diseases
    • /
    • v.37 no.1
    • /
    • pp.5-11
    • /
    • 1999
  • Three species of the families Viviparidae and Pleuroceridae, the first intermediate host of paragonimiasis, metagonimiasis and echinostomiasis were studied cytologically. The observed diploid chromosome number was as follows: Semisulcospira libertina 36, S. dolichostoma 34, and Viviparus rivularis 64. The mitotic chromosome complement of S. libertina has nine metacentric pairs and nine submetacentric pairs, and S. dolichostoma has three metacentric pairs and 14 submetacentric pairs of chromosomes. Viviparus rivularis showed two metacentric pairs and 30 submetacentric pairs of chromosomes.

  • PDF

Karyotypes of the Genus Pseudopungtungia (Pisces, Cyprinidae) (감돌고기속 Genus Pseudopungtungia (어강;잉어과) 어류의 핵형)

  • 김익수;심재환
    • The Korean Journal of Zoology
    • /
    • v.34 no.1
    • /
    • pp.54-58
    • /
    • 1991
  • 감돌고기속 어류에는 2종이 알려져 있으며 이들은 모두 한국고유어종이다. 감돌고기 Pseudopugtungia nigra의 핵형분석 결과 diploid chromosome number는 50이었으며, 7쌍의 metacentric, 18쌍의 $_{submeta}$telocentric chromosome으로 구성되어져 잇었다. 가는 돌고기 P. tenuicorpus의 2N은 50이었으며 10쌍의 metacentric, 15쌍의 $_{submeta}$telocentric chromosome으로 구성되어져 있었다.

  • PDF

갈겨니 (Zacco temmincki)의 進化에 관한 硏究 II: 갈겨니 2型의 核型分析

  • 이혜영;조정우;양서영
    • The Korean Journal of Zoology
    • /
    • v.29 no.3
    • /
    • pp.208-214
    • /
    • 1986
  • Comparative study of karyotypes in two allotypes $(Mdh-1^{MM} and Mdh-1^{MS})$ of the dark chub (Zacco temmincki) was examined. Both types had diploid number of 48 but the 7th chromosome was strikingly different between them. The chromosomes of $Mdh-1^{MM}$ type was consisted of 6 pairs of metacentrics, 6 pairs of submetacentrics, and 12 pairs of acrocentrics whereas the chromosomes of $Mdh-1^{MS}$ type had 7 pairs of metacentrics, 5 pairs of submetacentrics and 12 pairs of acrocentrics. No hybrid type between these two types was found in sympatric area at Tongchon River Namhae. Probable reproductive isolation between them was discussed.

  • PDF

Study on the Chromosome Size, Number and Shape by the Centromeric Index, Arm Ratio and Relative Length in Single Comb White Leghorns (단관백색레그혼순계에 있어 중심입지수, 등완비 및 상대적길이에 의한 염색체의 형태적 특징과 수에 관한 연구)

  • 오봉국;손시환;최연호
    • Korean Journal of Poultry Science
    • /
    • v.13 no.2
    • /
    • pp.167-172
    • /
    • 1986
  • Chromosome size, number and shape were studied by the centromeric index, the arm ratio and the relative length of chromosome. The chromosomes of 50 early chick embryos which were derived from a pure line of Single Comb White Leghorns were examined. Using a colchicine, hypotonic treatment, fixation and air-drying technique, the clear prometaphase figures were obtained from the whole embryo. The results of the present investigation of chromosome pairs were as follows, 1. Pair 1 and 2; metacentric and submetacentric chromosomes which could be clearly distinguished from each other by size. 2. Pair 3 and 4: acrocentric chromosomes of similar length but the 4th pair had a distinct short arm which was not present in the 3rd. 3, Pair 5; metacentric sex chromosomes, 2 chromosome had relative 5th length but the W chromosome had slightly shorter length than 7th pair of chromosomes. 4. Pair 6; acrocentric chromosomes similar in shape to pair 3 but of little more than half the size. 5, Pair 7 and 8; acrocentric chrocentric but the 7th pairs had a definite short arm. 6. Pair 9; similar length to the 7, 8 pairs but had a medially placed centromere. 7. microchromosomes of 30 pairs ; nearly all acrocentric chromosomes which appeared as paired dots. The total number of diploid was appeared to 72-78. But a number of observations presented the total diploid number in 78 (58%). The inconstancy in number observed in this study was presumably due to the minute size of the microchromosomes. Thus, the modal numbers for the diploid chromosome was at least 78.

  • PDF

Independence of SCI patients after HALLIWICK hydrotherapy method - A Case report - (수중치료후 척수손상 환자의 독립 - 증례 보고 -)

  • Kim, Chi-Hyok;Kim, Yong-Kwon
    • Journal of Korean Physical Therapy Science
    • /
    • v.6 no.4
    • /
    • pp.241-249
    • /
    • 1999
  • One of the major purpose of rehabilitation program is for the individual to achieve independence. That means independence from family members, independence from friends, and independence from rehabilitation team. An independent attitude is essential for autonomous functioning. Unless a disabled person is motivated to function independently, he will never do so. 3) Hydrotherapy, HALLIWICK method was applied to SCI patient. Especially, metacentric effect, density, buoyancy and breathing control are very very important theory.

  • PDF

Cytogenetic Studies of Polyploidy Manipulation (배수분조작을 위한 세포유전학적 연구)

  • 손진기
    • Korean Journal of Animal Reproduction
    • /
    • v.13 no.1
    • /
    • pp.49-55
    • /
    • 1989
  • The Results of colchicine and pretreatment time have shown that the cells of Coho Salmon(Oncorhynchus Kisutch) were effectively injected 6 hours prior to the harvest at a final concentration of 10$\mu\textrm{g}$/g body weight. The cell-density from 8,000 cells/㎣ (=8${\times}$106 ml) was found as ideal. The best effect of hypotonic solution in proportion to the cell is 20 : 1 and 50 minutes. The model number of diploid chromosome in this species was 2n=60. The karyotype analysis proved that the diploid complement consisted of 19 pairs of metacentric-, 4 pairs of submetacentric- and 7 paris of acrocentric-chromosomes. The diagrammatic representation proved that the diploid complement consisted of 7 pairs of metacentric-, 2 pairs of submetacentric- and 1 pair of acrocentric-chromosomes.

  • PDF