• Applied Microscopy
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• v.42 no.4
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• pp.186-193
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• 2012

The ultrastructure of the secretory granules of the submandibular gland was examined in the Korean spider shrew, Sorex caecutiens, lesser white-toothed shrew, Crocidura suaveolens and big white-toothed shrew, C. lasiura. The mucous and serous acinar granules of S. caecutiens with a border of the lucid corona differed from those of C. suaveolens and C. lasiurar with a dense lateral border. The mucous acinar granules of C. lasiura with several bands producing a variety of patterns in the matrix were similar to those of C. suaveolens. The serous acinar granules of C. lasiura had a homogenous pale center surrounded by minute dense specks or had an unusual substructure showing a geometric pattern according to the inclusions in the pale matrix of the granules. This is the first report of an unusual substructure showing a geometric pattern of the serous acinar granules of C. lasiura. The myelin-like body was observed in the granular duct cell of the three species of shrew. The myelin-like body of S. caecutiens with layers of unit membranes was different from that of C. suaveolens and C. lasiura with paired membranes. Therefore, the layers composing of the paired membranes of the myelin-like body might be one of the characteristics of Crocidura.

• Journal of Life Science
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• v.11 no.1
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• pp.54-61
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• 2001

The comparative morphology of epididymal spermatozoa in the lesser white-toothed shrew, Crocidura suaveolens, the Japanese white-toothed shrew, C. dsinezumi and the big white-toothed shrew, C. lasiura, belonging to the subfamily Crocidurinae was studied with the light and electron microscopes. The spermatozoa of C. lasiura and C. dsinezumi were characterized by the large acrosome, serrated inner acrosomal membrane, common apical body and fistulous proximal centriole with slightly dense electron granular materials, which are the charateristics of the Crocidurinae. The C. suaveolens, however, is distinguished from the two species mentioned above in the sperm morphology. That is, the spermatozoa possess not only the charateristic of the Crocidurinae such aw the large acrosome, but also those of the Soricinae, i.e. the smooth inner acrosomal membrane, wavy, finger-like and electron-dense apical body, and the solid proximal centriole filled with electron-dense materials. The results suggest that C. suaveolens has conserved characteristics of the Soricinae.

• Proceedings of the Zoological Society Korea Conference
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• 1997.04a
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• pp.23-24
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• 1997

No Abstract, See Full Text

• Applied Microscopy
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• v.31 no.2
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• pp.129-141
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• 2001

To investigate the spermiogenesis of the Saghalien Pygmy shrew (Sorex minutus gracillimus), the testis obtained from mature male shrew was studied by electron microscopy, and the following results obtained based on the morphological characteristics of cell differentiation of the seminiferous epithelium in the testis. According to the fine structural differentiation, spermiogenesis of S. minutus gracillimks was divided into Golgi, cap, acrosome, maturation and spermiation phases. Beside, the Golgi and cap phases were subdivided into three steps of early, middle and late phase respectively, and acrosome phase into two steps of early and late phase , and maturation and spermiation phases has only one step respectively. Thus, the spermiogenesis of S. minutus gracillimus was divided into a total of ten steps. The chromatin granules begin to be condensed in the acrosome phase, and a perfect nucleus of sperm was formed at the spermiation phase. Mancette were appeared from the late acrosome phase to the maturation phase. The formation of sperm tail began to develop in the late Golgi phase, and completed at the spermiation phase. Multivesicular bodies were appeared from the Golgi phase to the maturation phase, recognized with pale, pale and moderate, and dense at Golgi, cap and acrosomal and matulation phases respectively.

• Journal of Life Science
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• v.11 no.3
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• pp.218-229
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• 2001

The cycle of the seminiferous epithelium and spermiogenesis in three species if the genus Crocidura, the lesser white-toothed shrew, C. suaveolens, the Japanese white-toothed shrew, C. dsinezumi and the big(=Ussuri) white-toothed shrew C. lasiura, in the breeding season were studied with light and electron microscopes. The three species examined are distinguished from each other in the morphology of the seminiferous epithelium and the spermiogenesis, suggesting that these morphological characteristics are useful for the identification of the species. C. dsinezumi and C. lasiura, however, share many characteristics which are not common in C. suaveolens, as follows: In both species, 1) the cycle of the seminiferous epithelium is composed of 10 stages against 11 stages in C. suaveloens; 2) the earliest intermediated type spermatogonia is observed at stage I against stage III in C. suaveolens; 3) the spermatids of step 5 is observed during the stages V-VI against stages V-VII in C. suaveolens; 4) the acrosomal extension occurs during the stages VIII-X against tages IX-XI in C. suaveolens; 5) the condensation of the nucleus occurs simultaneously whereas it begins from the middle and along the nuclear membrane in C. suaveolens; 6) the capitular length in acrosome phase is shorter(about 2/3 of the diameter of the proximal centriole) than in C. suaveolens(longer than the diameter of proximal centriole; 7) length of the post nuclear cap is shorter(less than a half of the nucleus) than in C. suaveolens(about a half on the nucleus). Hudging from the similarities in the spermatogenesis in C. dsinezumi and C. lasiura, the relationship between them seems to be close compared to those with C. suaveolens.

• Applied Microscopy
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• v.35 no.4
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• pp.91-97
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• 2005

The acinar cells and secretory granules of the parotid salivary gland were examined in the lesser white toothed shrew, Crocidura suaveolens and the big white-toothed shrew, C. lasiura. The parotid gland of both species were a serous gland having only one kind of serous acinar cells, and had conventional arrangement of acini and intercalated, granular and striated ducts. In case of C. suaveolens, serous acinar cells had well developed rER, prominent Golgi complex, several large mitochondria and abundant moderate dense secretory granules with various stages of the maturing or fusing process. Immature acinar secretory granules were only or mainly filled with fine strong dense specks and had an indistinct limiting membrane, and mature granules were filled with homogeneous pale large round center and had fine strong dense specks at the periphery of the homogeneous pale center and a distinct limiting membrane. In case of C. lasiula, serous acinar cells had well developed rER, prominent Golgi complex, several large mitochondria and abundant dense secretory granules with maturing or fusing process. Immature acinar secretory granules were only filled with pale rough specks and had an indistinct limiting membrane, and mature granules were only filled with rough dense specks and had a distinct limiting membrane. Eventually The acinar secretory granules of C. suaveolens were seen moderate at the light and ultrastuctural level, those of C. lasiura were strong dense at the light microscopic level and dense at the ultrastructural level.

• The Korean Journal of Ecology
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• v.18 no.4
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• pp.441-449
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• 1995

The abundance of coarse woody debris (CWD) has been hypothesized to increase niche for forest dwelling insectivores, concentration of nutrients, and the diversity of invertebrates. However, no abjective assessment based on replication in the field has yet been done. this study was carried out to test the relationships between invertebrate availability and the abundance of four insectivores (Sorex trowbridgii, S. vagrans, S. monticolus and Neurotrichus gibbsii) in western Washington, USA. Pitfall traps were used to determine abundance and diversity of invertebrates. Abundance of insectivores was not different between habitats except for S. vagrans which was more abundant in habitats with low amounts of CWD than in habitats with high amounts of CWD. Simpson’s diversity index computed for invertebrates did not differ between habitats. There were no significant relationships between the diversity indices of invertebrates and the abundance of shrews. Shrew abundance and the Coleoperan beetles also did not show any significant relationship. The results suggested insectivores might select a wide range of prey items in addition to surface-active invertebrates.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.7B
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• pp.592-600
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• 2008

In this paper, a Hybrid Scaling based DTW (HS-DTW) mechanism is proposed for detection of periodic shrew TCP attacks. A low-rate TCP attack which is a type of shrew DoS (Denial of Service) attacks, was reported recently, but it is difficult to detect the attack using previous flooding DoS detection mechanisms. A pattern matching method with DTW (Dynamic Time Warping) as a type of defense mechanisms was shown to be reasonable method of detecting and defending against a periodic low-rate TCP attack in an input traffic link. This method, however, has the problem that a legitimate link may be misidentified as an attack link, if the threshold of the DTW value is not reasonable. In order to effectively discriminate between attack traffic and legitimate traffic, the difference between their DTW values should be large as possible. To increase the difference, we analyze a critical problem with a previous algorithm and introduce a scaling method that increases the difference between DTW values. Four kinds of scaling methods are considered and the standard deviation of the sampling data is adopted. We can select an appropriate scaling scheme according to the standard deviation of an input signal. This is why the HS-DTW increases the difference between DTW values of legitimate and attack traffic. The result is that the determination of the threshold value for discrimination is easier and the probability of mistaking legitimate traffic for an attack is dramatically reduced.

• Applied Microscopy
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• v.34 no.3
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• pp.179-184
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• 2004

Normal and abnormal morphology of the epididymal spermatozoa in the big white-toothed shrew, Crocidura lasiura were studied with the light and electron microscopy. Normal spematozoa were observed with a few abnormal spermatozoa. This indicates that abnormal morphology is no absolute indicator of infertility. However, the existence of the abnormal spermatozoa is related to infertility. Especially abnormal morphology of the sperm head is definitely associated with infertility. The following types of abnormal head morphology of the epididymal spermatozoa in the wild healthy adults of the C. lasiura were described: 1) Nucleus with lack of condensation of the nucleoplasm 2) Destructed acrosome 3) Folded acrosome and plasma membrane 4) Separation of the acrosome from the nucleus 5) Acrosome with irregular condensation 6) Wrongly located granules of the apical body.

• Applied Microscopy
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• v.37 no.2
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• pp.103-109
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• 2007

The ultrastructure of submandibular gland was examined in the Korean spider shrew, Sorex caecutiens. The submandibular gland wat composed of acini and salivary ducts. A submadibular acinus was a mixed gland having serous demilune cells and mucous cells that were filled with well developed rER, mitochondria and large amount of dense secretory granules. Serous acinar granules were oval shape without distinct limiting membrane on the border and it had only coarse specks with various density. Mucous acinar granules were oval shape without distinct limiting membrane and had a variety pattern with several thin or transparent bands into the homogeneous dense matrix. Thus submandibular acinar granules of S. caecutiens belonging to subfamily Soricinae were distinct from the other mammalian species including Crocidurinae, because of the absence of limiting membrane of acinar granules and specific pattern of mucous acinar granules. Granular duct cells had large amount of small granular vesicles and several characteristic structures of granule which were revered with stratified limiting membranes and filled with coarse serous-like granule or homogeneous matrix.