• Journal of dental hygiene science
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• v.13 no.2
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• pp.203-212
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• 2013

The tooth morphology and qualitative mineral contents on enamel surface using energy dispersive X-ray spectroscopy, (EDX) were examined in the white-toothed shrew (genus Crocidura ) Crocidura lasiura and C. suaveolens and the red-toothed shrew (genus Sorex) Sorex caecutiens. In the case of C. lasiura and C. suaveolens, dental formula was found I 3/1 C1/1 P1/1 M3/3=28. The upper 1st and 2nd molars had an unequal W-shape formed by 5 cusps on the crown. The 3rd molar was found one-third the size of those of 1st and 2nd molars. The upper 1st incisor had two different sized hook-shapes and the lower 1st incisor was even. In the case of S. caecutiens, dental formula was found to be I3/1 C1/1 P3/1 M3/3=32. The upper 1st and 2nd molars had an equal W-shape on crown. The upper 3rd molar was half the size of those of the other molars. The upper 1st incisor possessed two similar sized hook-shapes and the lower 1st incisor had an uneven and serrated form. A comparison with the dental and cranial measurements revealed C. lasiura to be the largest of the three species (p<0.001) and C. suaveolens and S. caecutiens were similar in size (p>0.05). A qualitative analysis of mineral contents on enamel surface of the lower 1st incisor and lower 1st molar using EDX revealed C, O, P, Ca and Cu in all specimens and Pb was detected in several enamel specimens. No significant differences in the mineral contents (% weight) were observed among the three species (p>0.05). Fe was only detected on enamel surface of S. caecutiens with red pigmented teeth. Therefore, Fe is responsible for the red tip of the teeth. These results suggest that tooth morphological characteristics including the color of the tooth tip might be used as the key classifying species belonging to Crocidura and Sorex.

• Journal of Ecology and Environment
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• v.35 no.3
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• pp.189-194
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• 2012

Coarse woody debris (CWD) is generally considered dead woody material in various stages of forest decomposition and has been hypothesized to be an important habitat feature for mammals in forests of the Pacific Northwest, USA. Sherman and pitfall trapping were conducted for 2 years on three paired sites with low and high amounts of CWD. Deer mice was the dominant species with a total capture of 605 (45.6%). Four species of insectivores were captured, including Sorex moncicolus, S. trowbridgii, S. vagrans, and Neurotrichus gibbsii. A Poisson regression model was used to test whether 11 CWD variables could predict insectivore captures. The volume of logs and mean decay were important variables for deer mice use of CWD. Mean distance from pieces of CWD to the capture point was significantly related to the total number of captures of trowbridge shrew (Sorex trowbridgii) and all insectivore species. Vagrant shrews (Sorex vagrans) were significantly associated with log volume. Retaining large size CWD should be part of a management plan for ground-dwelling insectivores in forests to secure their biodiversity.

• Smart Structures and Systems
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• v.19 no.4
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• pp.449-461
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• 2017

One of the most recent methods of structural damage identification is using the difference between structures responses after and before damage occurrence. To do this one can formulate the damage detection problem as an inverse optimization problem where the extents of damage in each element are considered as the optimizations variables. To optimize the objective function, heuristic methods such as GA, PSO etc. are widely utilized. In this paper, inspired by animals such as bat, dolphin, oilbird, shrew etc. that use echolocation for finding food, a new and efficient method, called Echolocation Search Algorithm (ESA), is proposed to properly identify the site and extent of multiple damage cases in structural systems. Numerical results show that the proposed method can reliably determine the location and severity of multiple damage cases in structural systems.

• Applied Microscopy
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• v.40 no.1
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• pp.37-45
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• 2010

Captured wild specimens of the big white-toothed shrew, Crocidura lasiura were classified into three age classes by tooth wear and height of molars, and seasonal variations of breeding and reproductive organs were examined. Juveniles had not tooth wear in molars and height of the third molars were lower than the first and second molars, and had only non-breeding condition. Young adults had little tooth wear and the third molars reached to the first and second molars, and old adults had heavy tooth wear in molars, young adults and old adults had breeding or non-breeding condition according to the season. On the basis of histological examination, seasonal variations of breeding were confirmed that breeding condition of young and old adult males were continued from early February to early October although the breeding activity was the highest in April, that of females were continued from the end of March to October, males reached sexual maturity earlier than females. Whereas the breeding condition seems to cease for non-breeding season because of the deficiency of food resources, soil invertebrates. Young and old adult males of the breeding season had large testes with enlarged seminiferous tubules that were filled with numerous germ cells, and expanded caudal epididymides with a vast number of spermatozoa, and were more than 10.0 g in the body weight and 0.03 g in the testis and epididymis weight. The females of the breeding season were pregnant condition with 4~6 litters or had the Graafian follicles and the corpus lutea in the ovary, and were more than 9.6 g in the body weight.

• Applied Microscopy
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• v.40 no.3
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• pp.125-132
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• 2010

Captured specimens of the lesser white-toothed shrew, Crocidura suaveolens were classified into three age classes by tooth wear and seasonal variations of reproductive organs were investigated. Molars of juveniles had not tooth wear and the height of the third molars were lower than the first and second molars, young adults had smooth tooth wear and the third molars reached to the first and second molars, and old adults had heavy tooth wear and the third molars also reached to the first and second molars. On the basis of histological examination, seasonal variation of breeding was confirmed that breeding season of adult males was from early February to early October, having a peak of the breeding in April and July, and non-breeding season was from in the middle of October to late January. Young and old adult males of the breeding season had large testes with enlarged seminiferous tubules filling with numerous germ cells and expanded caudal epididymides with a vast number of spermatozoa, Young and old adult males of the non-breeding season had the small testes with the extremely slender seminiferous tubules filling with only spermatogonia and the reduced caudal epididymides without spermatozoa. Males weighing more than 3.9 g in the body weight and 0.013 g in the testis and epididymis weight reached sexual maturation in breeding season, and the females weighing more than 3.8 g in body weight of the breeding season were pregnant condition having 5~6 litters or had the Graafian follicles and the corpus lutea in the ovary.

• Parasites, Hosts and Diseases
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• v.47 no.3
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• pp.311-314
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• 2009

A total of 1,498 small mammals (rodents and insectivores), including Apodemus agrarius (n= 1,366), Crocidura lasiura (54), Mus musculus (32), Micronytus fortis (28), Eothenomys regulus (9), Micronys minutes (6), and Cricetulus triton (3), were live-trapped in Gyeonggi-do (Province) (Paju-si, Pocheon-gun, and Yeoncheon-gun) near the demilitarized zone (DMZ) from December 2004 to September 2005. A. agrarius was found to be infected with 3 species of echinostomes (Echinostoma hortense, Echinostoma cinetorchis, and Euparyphium murinum), while C. lasiura was infected with 1 species (Echinochasmus japonicas) of echinostome. Other mammals were free from echinostome infections. Total 16 E. hortense were detected in 7 (0.5%) mice, 9 E. cinetorchis from 5 (0.4%), and 3 E. murinum from 2 (0.1%) out of 1.366 A. agrarius examined. E. japonicus was found only in 1 (1.9%; total 3 specimens) C. lasiura. These results demonstrate that A. agrarius and C. lasiura, inhabiting near the DMZ of Gyeonggi-do serve as the natural definitive hosts for several species of echinostomes, although their infection rates are low. This is the first record of natural infections of A. agrarius with E. cinetorchis and C. lasiura with E. japonicus in the Republic of Korea.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.3 s.357
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• pp.33-40
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• 2007

In this paper, low-rate TCP attack as one of shrew attacks is considered and the scaling based dynamic time warping (S-DTW) algorithm is introduced. The low-rate TCP attack can not be detected by the detection method for the previous flooding DoS/DDoS (Denial of Service/Distirbuted Denial of Service) attacks due to its low average traffic rate. It, however, is a periodic short burst that exploits the homogeneity of the minimum retransmission timeout (RTO) of TCP flows and then some pattern matching mechanisms have been proposed to detect it among legitimate input flows. A DTW mechanism as one of detection approaches has proposed to detect attack input stream consisting of many legitimate or attack flows, and shown a depending method as well. This approach, however, has a problem that legitimate input stream may be caught as an attack one. In addition, it is difficult to decide a threshold for separation between the legitimate and the malicious. Thus, the causes of this problem are analyzed through simulation and the scaling by maximum auto-correlation value is executed before computing the DTW. We also discuss the results on applying various scaling approaches and using standard deviation of input streams monitored.

• Applied Microscopy
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• v.37 no.3
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• pp.185-198
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• 2007

Spermiogenesis in Japanese white-toothed shrew. Crocidura dsinezumi was investigated by transmission electron microscope. Spermiogenesis was divided into 12 phases 14 steps, based on the morphological features of the nucleus and change of organelles in cytoplasm. The nucleus of spermatids in Golgi (step $1{\sim}2$) phase were spherical; however, they were changed into oval in the cap (step $3{\sim}6$) phase. Flagellum appeared in the middle of acrosomal phase; on the other hand, slender and long spermatid head was formed in maturation phase. The head of spermatids faced the lumen in step 1 to step 6 (from Golgi to cap phase), but, in step 7 to step 14 (from acrosomal to spermiation phase), it turned its head to the basal lamina of the seminiferous epithelium. The nucleus and acrosome were elongated maximally in step 10. The condensation of chromatin started in late acrosomal (step 10) phase, and it was completely finished and homogenized in the middle of maturation (step 12) phase. Multivesicular body appeared near the acrosomal vacuole during the middle cap (step 5) phase, and a large number of them were observed near the Golgi apparatus in the late cap (step 6) phase. Considering all the results, the spermiogenesis might be useful information to analyse the differentiation of spermatogenic fells.

• Applied Microscopy
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• v.35 no.2
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• pp.65-72
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• 2005

The ultrastructure of submandibular gland was examined in the lesser white-toothed shrew, Crocidura suaveolens. The submandibular gland of C. suaveolens was a mixed gland composed of serous and mucous acinar cells. Secretory granules from the acini were discharged through the salivary ducts into the oral cavity. Serous and mucous acinar cells had well developed rough endoplasmic reticulum and mitochondria and large amount of granules. In case of serous acinar granules, an immature granule was formless and had only dense specks, and a matured granule was a complete round type delimiting by a single membrane and had a homogeneous dense center with dense specks on the border. In case of mucous acinar granules, while an immature granule was a round type and had an only homogeneous matrix and an indistinct limiting membrane, a mature granule was an even round type having a variety of pattern with several dense bands into the homogeneous matrix and had a distinct membrane. Therefore, a mature mucous acinar granule of C. suaveolens was not only distinct from those of the other mammalian species to have a variety of pattern but also from those of C. lasiura to have an even round type. A great serous-like secretory granules and Myelin-like body were observed in the cytoplasm and lumen of granular duct cells. Myelin-like body, a characteristic structure only reported in salivary gland of three shrews, was discharged from secretory cell into lumen by the manner of exocytosis which has little differences from discharging manner of secretory granules.

• Applied Microscopy
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• v.35 no.2
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• pp.57-64
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• 2005

The ultrastructure and histochemical characteristics of the submandibular gland was examined in the big white-toothed shrew, Crocidura lasiura. A submandibular gland of Crocidura lasiura was a mixed gland composed of serous and mucous acinar cells. Secretory granules from the acini were discharged through the intercalated duct, the granular duct and the striated duct into the oral cavity. Serous and mucous acinar cells and granular duct cells had large amount of rough endoplasmic reticulum, free ribosome and prominent Golgi apparatus at the basal cytoplasm of the cell, and many granules at the apical cytoplasm. Oval type serous granules had a homogeneously pale round shape of bead at the center. Mucous granules were distinct from those of the other mammalian species having variety patterns with several dense bands into homogeneous pale matrix. A serous-like secretory granules and myelin-like body were observed in the cytoplasm and the lumen of granular duct cells. The myelin-like body is a characteristic structure only reported in the salivary glands of two shrews, Suncus murinus and C. dsinezumi. Striated duct cell had numerous well-developed mitochondria but secretory granule was not shown at all.