• Development and Reproduction
• /
• v.17 no.2
• /
• pp.121-132
• /
• 2013

Ultrastructural characteristics of the germ cells and accessory cells in testis during spermatogenesis and taxonomic values of mature sperm morphology of Ruditapes philippinarum were investigated by the transmission electron microscope and scanning electron microscope observations. The testis is the diffuse organ that consists of branching acini containing developing germ cells and accessory cells associated with spermatogenesis. The morphology of the spermatozoon is of the primitive type and is somewhat different to those of other bivalves. The morphologies of the sperm nucleus type and the acrosome shape of this species have a cylinderical type and a modified cone shape, respectively. As some ultrastructural characteristics of the acrosomal vesicle, the peripheral parts of two basal rings show electron opaque part, while the apex part of the acrosome shows electron lucent part. These characteristics of sperm belong to the family Veneridae in the subclass Heterodonta, unlike a characteristic of the subclass Pteriomorphia showing all part of the acrosome being composed of electron opaque part. In particular, a cylinder-like nucleus of the sperm is curved. The spermatozoon is approximately $48-51{\mu}m$ in length, including a long acrosome (about $2.4{\mu}m$ in length), a curved sperm nucleus (about $3.40{\mu}m$ in length), and a tail flagellum. The axoneme of the sperm tail shows a 9+2 structure.

• Development and Reproduction
• /
• v.15 no.3
• /
• pp.239-247
• /
• 2011

Spermatogenesis and taxonomic values of mature sperm morphology of in male Septifer (Mytilisepta) virgatus were investigated by transmission electron microscope observations. The morphologies of the sperm nucleus and the acrosome of this species are the cylinder shape and cone shape, respectively. Spermatozoa are approximately 45-50 ${\mu}m$ in length including a sperm nucleus (about 1.26 ${\mu}m$ long), an acrosome (about 0.99 ${\mu}m$ long), and tail flagellum (about 45-47 ${\mu}m$). Several electron-dense proacrosomal vesicles become later the definitive acrosomal vesicle by the fusion of several Golgi-derived vesicles. The acrosome of this species has two regions of differing electron density: there is a thin, outer electron-dense opaque region (part) at the anterior end, behind which is a thicker, more electron-lucent region (part). In genus Septifer in Mytilidae, an axial rod does not find and also a mid-central line hole does not appear in the sperm nucleus. However, in genus Mytilus in Mytilidae, in subclass Pteriomorphia, an axial rod and a mid-central line hole appeared in the sperm nucleus. These morphological differences of the acrosome and sperm nucleus between the genuses Septifer and Mytilus can be used for phylogenetic and taxonomic analyses as a taxonomic key or a significant tool. The number of mitochondria in the midpiece of the sperm of this species are five, as seen in subclass Pteriomorphia.

• Journal of the Korean Wood Science and Technology
• /
• v.52 no.3
• /
• pp.276-288
• /
• 2024

This study was conducted to reproduce the woodworking process of Baekje wooden storage facilities. Green timber of Quercus spp. was processed using ancient woodworking tools, and the tool-trace formed in this process were compared with the tool-trace of actual excavated artifacts. In the tool-trace analysis, the length and shape of the tool-trace were objectively recorded using a 3D Scan, and that were difficult to confirm with photograph were confirmed through stereoscopic microscope. As a result, there were two types of adze's tool-trace. One of them is minute straight Blade-top trace line when trimming the wood surface and the other is Plucked trace that appear when strongly chop at the wood. When a chisel bat was not used, a long and wide continuous shape blade trace was produced. And when the chisel head was struck with the chisel bat, a straight blade-top trace was regularly observed. Saw-trace was identified in several layers with fine straight stripes. Through this, it was found that the tool-trace of the woodworking tools, which is estimated to have been used in each process, and the tool-trace remaining in the Baekje wooden storage facility coincide.

• Imaging Science in Dentistry
• /
• v.38 no.1
• /
• pp.49-56
• /
• 2008

Purpose: Diagnostic estimation of destruction and formation of bone has the typical limit according to capacity of x-ray generator and image detector. So the aim of this study was to find out how much it can reproduce the shape and the density of bone in the case of using recently developed dental type of cone beam computed tomography, and which image is applied by new detector and mathematic calculation. Materials and Methods: Cone beam computed tomography (PSR 9000N, Asahi Roentgen Ind. Co., Ltd., Japan) and soft x-ray radiography were executed on dry mandible that was already decalcified during 5 hours, 10 hours, 15 hours, 20 hours, and 25 hours. Estimating and comparing of those came to the following results. Results: The change of inferior border of mandible and anterior border of ramus in the region of cortical bone was observed between first 5 and 10 hours of decalcification. The reproduction of shape and density in the region of cortical bone and cancellous bone can be hardly observed at cone beam computed tomography compared with soft x-ray radiography. The difference of decrease of bone density according to hours of decalcification increase wasn't reproduced at cone beam computed tomography compared with soft x-ray radiography. Conclusion: CBCT images revealed higher spatial resolution. However, contrast resolution in region of low contrast sensitivity is the inferiority of images' property.

• Journal of Mechanical Science and Technology
• /
• v.17 no.2
• /
• pp.187-196
• /
• 2003

In this paper, a new methodology of evolutionary computations - An Adaptive Evolutionary Algorithm (AEA) is proposed. AEA uses a genetic algorithm (GA) and an evolution strategy (ES) in an adaptive manner in order to take merits of two different evolutionary computations : global search capability of GA and local search capability of ES. In the reproduction procedure, the proportions of the population by GA and ES are adaptively modulated according to the fitness. AEA is used to. designing fuzzy logic controller (FLC) for a high-angle-of-attack flight system for a super-maneuverable version of F-18 aircraft. AEA is used to determine the membership functions and scaling factors of an FLC. The computer simulation results show that the FLC has met both robustness and performance requirements.

• International Journal of CAD/CAM
• /
• v.6 no.1
• /
• pp.149-156
• /
• 2006

This paper presents a novel approach for constructing a piecewise triangular cubic polynomial surface with $C^1$ continuity around a common corner vertex. A $C^1$ continuity condition between two cubic triangular patches is first derived using mixed directional derivatives. An approach for constructing a surface with $C^1$ continuity around a corner is then developed. Our approach is easy and fast with the virtue of cubic reproduction, local shape controllability, $C^2$ continuous at the corner vertex. Some experimental results are presented to show the applicability and flexibility of the approach.

• Development and Reproduction
• /
• v.21 no.1
• /
• pp.63-69
• /
• 2017

On the 15 days after hatching, the larvae was 4.24-5.10 mm (mean $4.66{\pm}2.18mm$) in total length, and the fins of the membrane started to develop into a fan shape and the melanophore was deposited upper the alimentary canal of the abdomen and on the bladder. At 35 days after hatching, the post-larvae formed a branch-shaped melanophore on the head part with a total length of 6.98-12.5 (mean $9.35{\pm}1.71$) mm, formed on the upper and lower parts of the caudal part, formed on the upper and lower parts of the caudal part, and deposited under the head part and abdomen. At 40 days after hatching, the juvenile was 11.3-18.1 (mean $14.9{\pm}1.53$) mm in total length.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.36 no.4
• /
• pp.168-172
• /
• 2014

Bilateral coronoid hyperplasia causes painless progressive trismus, resulting from coronoid process impingement on the posterior aspect of the zygomatic bone. The etiology of coronoid hyperplasia is unclear, with various theories proposed. An endocrine stimulus, increased temporalis activity, trauma, genetic inheritance and familial occurrence have all been proposed, but no substantive evidence exists to support any of these hypotheses. Multiplanar reformatting of axial scans and 3-dimensional reconstruction permit precise reproduction of the shape and size of the coronoid and malar structures, and relationships of all structures of the temporal and infratemporal fossae. This case shows remarkably increased mouth opening by coronoidectomy in a patient who complained of trismus due to hyperplasia of coronoid process.

• Journal of the Korean Academy of Esthetic Dentistry
• /
• v.14 no.1
• /
• pp.15-18
• /
• 2005

In order to recover the esthetic of the missing anterior area, we must consider color, shape of a tooth and the functions of a prosthesis that is harmonized with the surrounding factors. When the tooth of a natural tooth is exposed, we face to challenge to restore them. several factors cause resorption of bones, in flammation, and gum trouble, and a defective prosthesis damages the aesthetics of the gingiva. There are two ways how to solve these problems. One can be done by periodontal surgery and the other can be done by prosthesis. Most patients want aesthetic restoration that is harmonized with their teeth and gingiva. So if prosthesis is fabricated to expose the root exposed, it is far from the patient's expectation.

• Microbiology and Biotechnology Letters
• /
• v.30 no.2
• /
• pp.111-115
• /
• 2002

To produce yellow pigment selectively, mutants were induced from Monascus anka Nakazawa et Sato IFO 4478 (KCCM 11832 strain), and their characteristics were evaluated. Five kinds of auxotrophic mutants which required amino acids for growth and pigmentation, were isolated through a series of mutagenic treatments. Especially, asparagine auxotroph Y7 produced high ratio of yellow pigment. This mutant showed all the morphological characteristics of Monascuceae but the shape of colony and the diameter of conidia. Mutant Y7 was propagated by sexual reproduction more often than asexual reproduction, which could be effective in production of pigments. Yellow pigment produced extracellularly by the mutant Y7 was more soluble in polar solvents such as ethanol and water than in nonpolar solvents. Its productivity of yellow pigment was 2.2 times higher in the mutant Y7 than in parents. In addition, its yellow pigment showed characteristics of maximum absorption at 373 nm. Moreover, the hue of pigment produced by the mutant Y7 was bright yellow, and it was stable through the subculture over 10 generations.