• Journal of the Korean Society for Precision Engineering
• /
• v.27 no.1
• /
• pp.134-141
• /
• 2010

This study analyzed the regional morphological and mechanical characteristics of vertebrae by using micro-computed tomography (micro-CT) and micro finite element analysis (FEA). For the present study, the $12^{th}$ human thoracic vertebral bones (an 85-years female and a 48-years male) were used. These were scanned by using micro-CT. Structural parameters were evaluated from the acquired 20 image data for fifteen $4{\times}4mm^2$ regions (five regions in respective layers of superior, middle and inferior part) in the thoracic vertebral trabecular bones. $4{\times}4{\times}4mm^3$ cubic finite element models of each regions were created at $70{\mu}m$ voxel resolution to investigate effective modulus ($E^+$). The present study indicated that there were significant differences in morphological and elastic mechanical characteristics of each region. There are close relationship between effective modulus and structural model index (SMI) in the bone of the 48-years male and between effective modulus and bone volume fraction (BV/TV) in the bone of the 85-years female. In addition, the effective modulus of central regions is about 80% stiffer than that of lateral regions at transverse plane. These findings may be likely to explain the previous result that a change of loading distribution of the vertebral trabecular bones is caused by spinal curvature and nucleus pulpous degeneration of the intervertebral disc.

• Korean Journal of Plant Taxonomy
• /
• v.42 no.1
• /
• pp.1-12
• /
• 2012

To clarify the morphological variations of Galium, its morphological characteristics were examined using maximum parsimony analysis. The key characteristics as well as the range of variation in each characteristic were investigated at the species level and were employed to elucidate the relationships between the taxa. This study confirmed that species belonging to genus Galium formed a monophyletic group and comprised two main clades. Sect. Cymogaliae and sect. Leptogalium are polyphyly groups, and other sections are monophyletic group. This study also suggests that the fruit hairs, the types of petal apexes, and the colors of the petals are the most valuable taxonomic characteristics for differentiating different sections. The numbers of the leaves and leaf shape provide useful taxonomic characteristics for the identification of different species.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.83-83
• /
• 2017

The National Agrobiodiversity Center (NAS, RDA, Republic of Korea) has continually collected new valuable genetic resources. In this study, we regenerated conserved kidney bean (Phaseolus vulgaris L.) germplasm which couldn't be available because of seed quantity and quality, and we also surveyed their morphological characters for the sustainable utilization. A total of 431 kidney bean accessions were regenerated and 18 morphological traits were surveyed according to the characterization guideline of RDA Genebank. Among the surveyed traits, flowering time ranged from May 23 to September 4 and 73.8% of tested accessions were mainly flowering in June. The maturity time ranged from July 1 to October 15 and main flowering time was July (91.4%). For plant type, 270 accs (62.6%) were climbing type followed by medium type of 86 accs (20.0%) and dwarf type of 65 accs (15.1%). The seed coat colors were various; yellow (34.6%), white (22.3%), brown (17.9%), red (10.7%), black (5.8%), violet (11%), pink (1.4%), navy (0.9%). Principal component analysis indicated that five principal components (PCs) with Eigen values >1 accounted for more than 65.8% variability. The first PC was more related to growth habits such as growth type, flowering time, and plant type. The second and third PCs showed higher values of the pigment characters such as seed coat color, flower color, and pod color. In fourth and fifty PCs, there were the higher positive values of the pod shapes. Our results provided insight into the characteristics kidney beans, thus the utilization basis of kidney beans might be elevated for bio-industry.

• The Korean Journal of Mycology
• /
• v.48 no.3
• /
• pp.313-323
• /
• 2020

To investigate the morphological characteristics and genetic relationships among isolate of the artificially cultivated mushroom Hypsizygus marmoreus, 111 isolates were collected from Korea and other countries. Random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) and ITS rDNA sequencing were used to confirm the genetic relationships among the collected H. marmoreus isolates. As a result of RAPD analysis using universal rice primer (URP)-PCR, all isolates of H. marmoreus clustered into three groups, which showed high sequence similarity (>90%). In addition, isolates with morphological and geographical differences formed independent clusters. However, it was impossible to distinguish between brown and white strains. Sixteen strains showing morphological and geographic differences were selected, and their ITS region sequences (640 bp) were aligned and compared. The ITS region sequences belonging to these isolates showed 94.8-99.1% similarities to those of publicly available H. marmoreus strains in GenBank. In conclusion, there were differences among isolates in terms of morphology and the area from which they were collected, but all the isolates used in the experiment were classified as H. marmoreus.

• Clinical and Experimental Reproductive Medicine
• /
• v.24 no.2
• /
• pp.153-165
• /
• 1997

In male reproducible health, fertility and IVF (in-vitro fertilization), semen analysis has been most important. Semen analysis can be divided into concentration, motional and morphological analysis of sperm. The existing method which was developed earlier to analyze semen concentrated on the sperm motility analysis. To provide more useful and precise solutions for clinical problems such as infertility, semen analysis must include sperm morphological analysis. But the traditional tools for semen analysis are subjective, imprecise, inaccurate, difficult to standardize, and difficult to reproduce. Therefore, with the help of development of microcomputers and image processing techniques, we developed a new sperm morphology analyzer to overcome these problems. In this study the agreement on percent normal morphology was studied between different observers and a computerized sperm morphology analyzer on a slide-by-slide basis using strict criteria. Slides from 30 different patients from the SNUH andrology laboratory were selected randomly. Microscopic fields and sperm cells were chosen randomly and percent normal morphology was recorded. The ability of sperm morphology analyzer to repeat the same reading for normal and abnormal cells was studied. The results showed that there was no significant bias between two experienced observers. The limits of agreement were 4.1%${\sim}$-3.8%. The Pearson correlation coefficient between readers was 0.79. Between the manual and sperm morphology analyzer, the same findings were reported. In this experiments the slides were stained by two different methods, PAP and Diff-Quik staining methods. The limits of agreement were 7.2%${\sim}$-5.7% and 6.0%${\sim}$-6.3%, respectively. The Pearson correlation coefficients ware 0.76 and 0.91, respectively. The limits of agreement was tighter below 20% normal forms. In the experiments of repeatability, 52 cells stained by PAP and Diff-Quik staining methods were analyzed three times in succession. Estimating pairwise agreement, the kappa statistic for the pairs were 0.76, 0.81, 0.86, and 0.75, 0.88, 0.88 respectively. In this study it was shown that there was good agreement between manual and computerized assessment of normal and abnormal cells. The repeatability and agreement per slide of computerized sperm morphology analyzer was excellent. The computer's ability to classify normal morphology per slide is promising. Based on results obtained, this system can be of clinical value both in andrology laboratories and IVF units.

• Proceedings of the Korean Society for Language and Information Conference
• /
• 1996.02a
• /
• pp.229-236
• /
• 1996

• Molecules and Cells
• /
• v.25 no.2
• /
• pp.163-171
• /
• 2008

The genus Cynodon comprises ten species. The objective of this study was to evaluate the genetic diversity of Korean bermudagrasses at the morphological, cytological and molecular levels. Morphological parameters, the nuclear DNA content and ploidy levels were observed in 43 bermudagrass ecotypes. AFLP markers were evaluated to define the genetic diversity, and chromosome counts were made to confirm the inferred cytotypes. Nuclear DNA contents were in the ranges 1.42-1.56, 1.94-2.19, 2.54, and 2.77-2.85 pg/2C for the triploid, tetraploid, pentaploid, and hexaploid accessions, respectively. The inferred cytotypes were triploid (2n = 3x = 27), tetraploid (2n = 4x = 36), pentaploid (2n = 5x = 45), and hexaploid (2n = 6x = 54), but the majority of the collections were tetraploid (81%). Mitotic chromosome counts verified the corresponding ploidy levels. The fast growing fine-textured ecotypes had lower ploidy levels, while the pentaploids and hexaploids were coarse types. The genetic similarity ranged from 0.42 to 0.94 with an average of 0.64. UPGMA cluster analysis and principle coordinate analysis separated the ecotypes into 6 distinct groups. The genetic similarity suggests natural hybridization between the different cytotypes, which could be useful resources for future breeding and genetic studies.

• The Korean Journal of Zoology
• /
• v.30 no.4
• /
• pp.417-431
• /
• 1987

Isozyme analysis, morphometric comparison, and artificial hybridization test wereperformed to elucidate the patterns of genic variation, morphological differentiation, genetic incompatibility, and a probable path in speciation between two MDH allelotypes (MM type and MS type) of the Dark Chub Zacco temmincki, a fresh water fish inhabiting in Korean waters. The degree of genic variation of MS type(HD=.023, HG=.021) was twofold higher than that of MM type (HD=.013, HG=.014) but both allelotypes were far less than the average genic variation of fresh water Bish in general. The average genetic similarities among 7 populations of MM type and 6 Populations of MS type were S=.947 and S=.966 respectively, whereas the value between two allelotypes was S=.853. Presumed divergent time of two allelotypes was estimated to be about 700 thousand years ago. Discriminant function analysis based on 18 morphometric characters of 302 specimens representing 12 populations revealed no morphological difference between two allelotypes. Artificial hybridization test indicates that there is an obvious genetic incogpatibility between two allelotypes and therefore it is assumed that isolating mechanism is completed.

• Animal Systematics, Evolution and Diversity
• /
• v.34 no.4
• /
• pp.208-214
• /
• 2018

The genus Luidia belongs to the family Luidiidae in the order Paxillosida. It is a common littoral taxon, and the depth range of the Korean fauna is generally 0-100 m. However, specimens of Luidia were collected from Jeju Island in Korea at 150-160 m depth and identified as Luidia sagamina sagamina $D{\ddot{o}}derlein$, 1920. This species is determined by morphological characteristics and mitochondrial cytochrome c oxidase subunit I sequence analysis. Luidia sagamina sagamina is a very rare sea star in worldwide and it only collected previously from Sagami Bay, Japan, and is newly reported in Korea. Four species of Luidia, including L. s. sagamina, are recorded in the Korean fauna.

• The Korean Journal of Mycology
• /
• v.49 no.3
• /
• pp.363-371
• /
• 2021

Several species of Gyromitra are highly poisonous when consumed raw the presence of gyromitrin. In this study, Gyromitra specimens deposited in the Korea National Arboretum were re-examined and subjected to molecular sequence analysis. G. gigas, G. aff. perlata, and G. tianshanensis were identified based on their morphological features and molecular phylogenetic analysis for the first time in Korea. Furthermore, internal transcribed spacer and 28S rRNA sequences of G. esculenta and G. infula were analyzed to confirm their phylogeny.