• Title/Summary/Keyword: Morphological Structure

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Description of Microscopic Morphology of Leptochiton hakodatensis (Mollusca: Polyplacophora)

  • Park, Jina;Lee, Yucheol;Kim, Yukyung;Park, Joong-Ki
    • Animal Systematics, Evolution and Diversity
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    • v.38 no.1
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    • pp.14-19
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    • 2022
  • Leptochiton Gray, 1847 is one of the most ancient chiton groups which includes more than 130 species that occur in cold and deep waters worldwide. Due to their small-sized body, they are often confused as juveniles of other chiton species. Moreover, lack of morphological information makes species identification of this group very challenging. To date, only two Leptochiton species(L. fuliginatus and L. rugatus) have been reported from Korean waters. In this study, we found L. hakodatensis(Thiele, 1909) for the first time in Korea and described microscopic morphological characters of valves (tegmentum sculpture), girdle scale, and radula using a scanning electron microscopy (SEM). Leptochiton hakodatensis is morphologically similar to L. fuliginatus and L. rugatus, but differently characterized by having dorso-ventrally rounded (not carinated) intermediate valves, girdle (perinotum) scales sculptured with 4-7 longitudinal ribs, and bicuspid major lateral teeth of radula. In addition to morphological examination, we determined the partial mitochondrial cytochrome c oxidase subunit I(cox1) as a DNA barcode sequence information. This is the first report that describes microscopic characters (tegmentum of valves, girdle structure, and radula) of L. hakodatensis using a SEM. This study provides a morphological basis for describing Leptochiton species and discovery of a "hidden" species of this genus.

The Usefulness of Selected Physicochemical Indices, Cell Membrane Integrity and Sperm Chromatin Structure in Assessments of Boar Semen Sensitivity

  • Wysokinska, A.;Kondracki, S.;Iwanina, M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.12
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    • pp.1713-1720
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    • 2015
  • The present work describes experiments undertaken to evaluate the usefulness of selected physicochemical indices of semen, cell membrane integrity and sperm chromatin structure for the assessment of boar semen sensitivity to processes connected with pre-insemination procedures. The experiments were carried out on 30 boars: including 15 regarded as providers of sensitive semen and 15 regarded as providers of semen that is little sensitive to laboratory processing. The selection of boars for both groups was based on sperm morphology analyses, assuming secondary morphological change incidence in spermatozoa as the criterion. Two ejaculates were manually collected from each boar at an interval of 3 to 4 months. The following analyses were carried out for each ejaculate: sperm motility assessment, sperm pH measurement, sperm morphology assessment, sperm chromatin structure evaluation and cell membrane integrity assessment. The analyses were performed three times. Semen storage did not cause an increase in the incidence of secondary morphological changes in the group of boars considered to provide sperm of low sensitivity. On the other hand, with continued storage there was a marked increase in the incidence of spermatozoa with secondary morphological changes in the group of boars regarded as producing more sensitive semen. Ejaculates of group I boars evaluated directly after collection had an approximately 6% smaller share of spermatozoa with undamaged cell membranes than the ejaculates of boars in group II ($p{\leq}0.05$). In the process of time the percentage of spermatozoa with undamaged cell membranes decreased. The sperm of group I boars was characterised with a lower sperm motility than the semen of group II boars. After 1 hour of storing diluted semen, the sperm motility of boars producing highly sensitive semen was already 4% lower ($p{\leq}0.05$), and after 24 hours of storage it was 6.33% lower than that of the boars that produced semen with a low sensitivity. Factors that confirm the accuracy of insemination male selection can include a low rate of sperm motility decrease during the storage of diluted semen, low and contained incidence of secondary morphological changes in spermatozoa during semen storage and a high frequency of spermatozoa with undamaged cell membranes.

A Taxonomic Study on Korean Allium L. Based on the Morphological Characters (형태학적 형질에 기초한 한국산 부추속의 분류학적 연구)

  • Choi, Hyeok-Jae;Jang, Chang-Gee;Lee, You-mi;Oh, Byoung-Un
    • Korean Journal of Plant Taxonomy
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    • v.37 no.3
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    • pp.275-308
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    • 2007
  • For 20 taxa of Korean Allium, including 16 species and 5 varieties, examined were morphological characters (i.e. sexuality, structure and shape of underground part, types and growing patterns of leaf and scape, and shapes of perianth, filament and pistil). The specialization and the evolutionary trends of taxonomic characters were inferred from morphological examination. Taxonomic relationships and system of Korean Allium were also studied. The characters showing evolutionary trends were the structure and shape of underground part including rhizome and bulb, leaf, scape, inflorescens, filament and ovary. It seemed that thin and short rhizome developed from thick and long one, and the membranous simple bulb tunic evolved into fibrous reticulate one. The presence of hyaline sheath in A. monanthum of sect. Microscordum was apomorphic. Both angular leaf blade with 2-rowed vascular bundle and flat blade with 1-rowed vascular bundle were developed from terete one with 2-rowed vascular bundle. The base of filament have differentiated from entire to toothed, and 2-ovuled ovary as well as erect scape before flowering was plesiomorphic type. In addition, sexuality, structure of underground part, the presence of hyaline sheath and cross-section structure of leaf were taxonomic characters with the level of the subgenus in this genus. Shape of rhizome, bulb, leaf, scape and pedicel discriminated each section from other ones in the subgenera easily. The shape and arrangement of perianth and filaments were the diagnostic characters for species level along with shape of ovary and stigma.

Phylogenetic study of East-Asia Astragalus L. based on morphological characters (형태형질에 기초한 동아시아산 황기속 식물의 계통분류)

  • Song, Il-Bae;Heo, Kweon
    • Korean Journal of Plant Taxonomy
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    • v.44 no.3
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    • pp.191-201
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    • 2014
  • In order to find useful taxonomic morphological characters, 17 taxa from East-Asia Astragalus and Oxytropis anertii were investigated. In this study, seed coat structure, fruit surface, and fruit anatomical structures were selected to classify the species in Astragalus. As a results, useful morphological and anatomical characters in East-Asia Astragalus were life cycle, leaflet shape, raceme, petal color, seed color, pod shape, absent or present of hairs in pod surface, bent degree of dorsal suture, and thickness of endocarp. Using medicinal sources in China, A. floridus, A. membranaceus, A. membranaceus var. mongholicus and A. tongolensis were formed same group. However, these were not completely consensus in the morphological characters. The other hand, A. koraiensis and A. sikokianus, which have controversial taxonomic issue, have clearly no differences morphological characters each other. Therefore, A. koraiensis, A. sikokianus, and A. bhotanensis should be conducted a comparative study on the DNA sequences and molecular cytology in order to clarify the taxonomic treatments in the near future.

Morphological Interpretation of the Transformation Process of Urban Form in Gosan-Up (형태학적 개념을 활용한 조선시대 고산현의 도시형태 변천과정 해석)

  • Lee, Kyung-Chan;Kang, In-Ae
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.32 no.4
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    • pp.37-49
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    • 2014
  • This paper aims to interpret the transformation process of town plan of Gosan-up(高山), which was provincial administrative focus town in Josun dynasty, basing on morphological viewpoint. Morphological concepts, such as morphological frame, urban plan, kernel, colonization, route system, fixation line, fringe belt, plan unit & plan division, morphological period derived from the study of Conzen, M.R.G. and Caniggia, G. epidome district, break point, broken plot, urban fallow, privatization are adopted for the interpretation of urban form. Morphological period of Gosan can be divided in four ; formation of kernel & morphological structure, disintegration & redevelopment of the kernel, augmentative development of the kernel & formation of modern epidome district, outwards expanding of urbanized area, transition & reorganization of epidome district. Especially public leading projects such as construction of new regional connection road and public facilities such as myeon(township) office, agricultural cooperatives federation office, market, are main factors of morphological transformation of townplan. In the early stage, under the Japanese imperialism, construction of the new matrix route(Gosan-ro) through the kernel and followed planned routes gave way to disintegrating traditional areal plan unit and forming small block plan units in administrative facilities area. And linear plan units with commercial buildings were formed along the new matrix route and planned route adjacent to periodical market. In the latter stage, with development of public facilities, private sectors' large circulation institution and terminal outside the kernel with planned routes formed areal block based plan units with commercial and public buildings. And part of the spatial area with the linear plan unit were turned into urban fallow. With the transformation of town plan, new roads outside the kernel have substituted for traditional fixation line of waterway with road and topographical feature. Fringe belts were made successively along the new road and around the major intersections outside of existing urbanized area. Land use in fringe belts, constituting of outer locational tendency early on formation, was gradually replaced with commercial & business buildings.

Genetic diversity and population structure between natural and cultivated populations of sea lettuce, Enteromorpha prolifera, in Korea revealed by RAPD markers

  • Chang, Hyo-Jae;Huh, Man-Kyu;Huh, Hong-Wook;Lee, Bok-Kyu
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2003.05a
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    • pp.279-280
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    • 2003
  • Although it has been known though many morphological and physiological studies, its genetic diversity and population structure have not yet been investigated in this species. Therefore, detailed studies, in particular at the DNA level, on genetic diversity of natural populations of wild sea lettuce, and genetic relationships between natural sea lettuce and cultivated sea lettuce are necessary from the viewpoint of plant evolution. (omitted)

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EFFICIENT IMPLEMENTATION OF GRAYSCALE MORPHOLOGICAL OPERATORS (형태학 필터의 효과적 구현 방안에 관한 연구)

  • 고성제;이경훈
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.10
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    • pp.1861-1871
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    • 1994
  • This paper presents efficient real time software implementation methods for the grayscale morphological composite function processing (FP) system. The proposed method is based on a matrix representation of the composite FP system using a basis matrix composed of structuring elements. We propose a procedure to derive the basis matrix for composite FP systems with any grayscale structuring element (GSE). It is shown that composite FP operations including morphological opening and closing are more efficiently accomplished by a local matrix operation with the basis matrix rather than cascade operations, eliminating delays and requiring less memory storage. In the second part of this paper, a VLSI implementation architecture for grayscale morphological operators is presented. The proposed implementation architecture employs a bit-serial approach which allows grayscale morphological operations to be decomposed into bit-level binary operation unit for the p-bit grayscale singnal. It is shown that this realization is simple and modular structure and thus is suitable for VLSI implementation.

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Quantitative Morphology of High-Redshift Galaxies Using GALEX Ultraviolet Images of Nearby Galaxies

  • Yeom, Bum-Suk;Rey, Soo-Chang;Kim, Youngkwang;Lee, Youngdae;Chung, Jiwon;Kim, Suk;Lee, Woong
    • Journal of Astronomy and Space Sciences
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    • v.34 no.3
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    • pp.183-197
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    • 2017
  • We present simulations of the optical-band images of high-redshift galaxies utilizing 845 near-ultraviolet (NUV) images of nearby galaxies obtained through the Galaxy Evolution Explorer (GALEX). We compute the concentration (C), asymmetry (A), Gini (G), and $M_{20}$ parameters of the GALEX NUV/Sloan Digital Sky Survey r-band images at z ~ 0 and their artificially redshifted optical images at z = 0.9 and 1.6 in order to quantify the morphology of galaxies at local and high redshifts. The morphological properties of nearby galaxies in the NUV are presented using a combination of morphological parameters, in which early-type galaxies are well separated from late-type galaxies in the $G-M_{20}$, $C-M_{20}$, A-C, and $A-M_{20}$ planes. Based on the distribution of galaxies in the A-C and $G-M_{20}$ planes, we examine the morphological K-correction (i.e., cosmological distance effect and bandshift effect). The cosmological distance effect on the quantitative morphological parameters is found to be significant for early-type galaxies, while late-type galaxies are more greatly affected by the bandshift effect. Knowledge of the morphological K-correction will set the foundation for forthcoming studies on understanding the quantitative assessment of galaxy evolution.

Effects of Chitosan on Body Weight Gain, Growth Hormone and Intestinal Morphology in Weaned Pigs

  • Xu, Yuanqing;Shi, Binlin;Yan, Sumei;Li, Tiyu;Guo, Yiwei;Li, Junliang
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.10
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    • pp.1484-1489
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    • 2013
  • The study was conducted to determine the effects of chitosan on the concentrations of GH and IGF-I in serum and small intestinal morphological structure of piglets, in order to evaluate the regulating action of chitosan on weaned pig growth through endocrine and intestinal morphological approaches. A total of 180 weaned pigs (35 d of age; $11.56{\pm}1.61kg$ of body weight) were selected and assigned randomly to 5 dietary treatments, including 1 basal diet (control) and 4 diets with chitosan supplementation (100, 500, 1,000 and 2,000 mg/kg, respectively). Each treatment contained six replicate pens with six pigs per pen. The experiment lasted for 28 d. The results showed that the average body weight gain (BWG) of pigs was improved quadratically by dietary chitosan during the former 14 d and the later 14 d after weaned (p<0.05). Furthermore, dietary supplementation of chitosan tended to quadratically increase the concentration of serum GH on d 14 (p = 0.082) and 28 (p = 0.087). Diets supplemented with increasing levels of chitosan increased quadratically the villus height of jejunum and ileum on d 14 (p = 0.089, p<0.01) and 28 (p = 0.074, p<0.01), meanwhile, chitosan increased quadratically the ratio of villus height to crypt depth in duodenum, jejunum and ileum on d 14 (p<0.05, p = 0.055, p<0.01) and 28 (p<0.01, p<0.01, p<0.01), however, it decreased quadratically crypt depth in ileum on d 14 (p<0.05) and that in duodenum, jejunum and ileum on d 28 (p<0.01, p<0.05, p<0.05). In conclusion, these results indicated that chitosan could quadratically improve growth in weaned pigs, and the underlying mechanism may due to the increase of the serum GH concentration and improvement of the small intestines morphological structure.