• Korean Journal of Environment and Ecology
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• v.29 no.6
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• pp.858-864
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• 2015

Developmental changes in the vocal signals of serotine bats (Eptesicus serotinus) during their infancy were examined in this study. The analysis was conducted on 4 infant serotine bats from 1 to 40 days after their birth. Pulse duration (PD), pulse interval (PI), peak frequency (PF), maximum frequency ($F_{MAX}$), minimum frequency ($F_{MIN}$), and bandwidth (BW) were measured. As the bats grew, their vocalizations became increasingly consistent and similar to those of adults. For infant bats, PD and PI decreased as they grew older, whereas PF, $F_{MAX}$, $F_{MIN}$, and BW increased. The greatest change in vocalizations was observed between the $10^{th}$ and $20^{th}$ days after birth. Also, PF, $F_{MAX}$, $F_{MIN}$ and BW, which describe sound frequency, increased dramatically during the period between the $10^{th}$ and the $20^{th}$ days. In contrast, the greatest change in PD occurred between the $30^{th}$ and $40^{th}$ days after birth. The results collected in this study suggest that frequency increased as the contraction ability of the muscles developed by around 20 days of age. Muscle relaxation ability, which is related to PD, was found to develop significantly at 30 to 40 days of age. According to the results of this study, although 40 day-old infant bats are not yet able to fly, their vocal signals were similar to those of adults. This indicates that vocal development and flying activity develop separately in young bats.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.4 no.1
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• pp.79-90
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• 1993

With immunohistochemical method, We have examined the distribution, the size, the number, and the morphology of somatostatin-immunoreactive neurons in the cerebral cortex of rats at the 1st. 2nd, 3rd, 4th postnatal week and the 2nd and 3rd months of age. The results are summarized as follows : 1) Strongly immunoreactive somatostatin neurons were found in the layer V and VI at the first postnatal week and then they were observed to be densely populated in the layer II and III from the 3rd postnatal week on as in the adult rat. 2) The size of the neuron was largest at the 2nd postnatal week while the number of the neurons was greatest in the 1st or 2nd postnatal week, depending on the different areas of the cortex. Overall the postnatal development of somatostatin neurons are well corresponds with the general principle of neuronal development of CNS.

• 한우개량
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• no.4 s.25
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• pp.32-36
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• 2000

육성기의 포인트 [양질조사자료의 충분한 급여] 생후 13개월령까지는 뼈나 내장이 발달하는 시기이므로 영양소의 배합이 중요하며 내장의 발달을 위하여 조사료의 다량급여가 필요

• Maxillofacial Plastic and Reconstructive Surgery
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• v.20 no.4
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• pp.305-315
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• 1998

The fibrous layer of mandibular condyle of the neonatal, 1-, 7-, 14-, 27-, 55-days and 1 year old rats were examined in the electron microscope with particular attention to the ultrastructure and diameter of collagen fibrils. In the 1-day rats, most of the cells of the fibrous layer were undifferentiated mesenchymal cells and fibroblasts with rough a little developed rough endoplasmic reticulum(RER) and golgi apparatus(GA). In 7-, 17 and 27-days old rats, most of the fibroblast showed well developed GA and RER with widely distended cisternae containing granular materials. In many of these cells contained intracytoplasmic filaments among the cytoplamic organelle. In 55-day and 1-year old rats, three types of cells were observed, ie, cells containing well developed cytoplasmic organelle presumed to be involved in the collagen fibril synthesis, cells showing well developed lysosomes, golgi apparatus, mitochondria and short cytoplasmic process presumed to be involved in the active resorption of the injured collagen fibrils or cellular debris, cells containing many intracytoplasmic filaments and a little organelle presumed to be cells of inactive state. The average diameters of collagen fibrils were similar in 1- and 7-day old rats as $38.48{\pm}3.81nm$, $38.06{\pm}3.86nm$. That was thickest in 14 days old rats as $50.21{\pm}3.93nm$ among experimental groups. They were gradually thinner in 27-, 55-day rats as $40.05{\pm}2.52nm$, $43.63{\pm}1.20nm$ and thinnest in 1-year old rats as $37.38{\pm}2.17nm$. The distribution pattern of diameters of collagen fibrils were unimordal with peak of 30-60nm in rats from 1-day to 17-day old. With aging from 27-day to 1 year old rats, collagen fibril diameters showed wide distribution pattern and percentage of thin collagen fibrils increased. These results may show the functional adaptation of fibrous layer of mandibular condyle to the increased mechanical forces with aging.

• Korean Journal of Environment and Ecology
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• v.24 no.2
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• pp.202-208
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• 2010

This study reports developmental changes in the vocal signals produced by infant or young Pipistrellus abramus. In contrast to adult bats, infant bats of the P. abramus emitted calls characterized by multi harmonics and variable signal patterns. Infants at two day of age emitted a irregular signal and showed gentle FM signals between 10 and 20 days. After about 40 days of age, the young bats emitted similar signals to the echolocation calls of adults. As the infant bats growing up, vocal signals trend showen a decrease in pulse duration(p<0.001), pulse interval(p<0.001) and number of harmonic(p<0.001). And the peak frequency(p<0.001), starting frequency(p<0.001) and ending frequency(p<0.001) in infant bats increased with the age. The largest change in pulse interval occurred in 5 days. And the pulse duration, peak frequency, starting frequency and ending frequency of the bat's sounds changed most dramatically in 25 days of age.

• 건강소식
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• v.19 no.6 s.199
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• pp.62-65
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• 1995

• 건강소식
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• v.19 no.7 s.200
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• pp.60-63
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• 1995

• 건강소식
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• v.19 no.5 s.198
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• pp.60-63
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• 1995

• Development and Reproduction
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• v.8 no.1
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• pp.57-64
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• 2004

This study was carried out to examine the expression of the circadian clock genes in the mouse ovary and testis at different developmental stages. Expression of Period1(Per 1), Period2(Per2), Period3(Per3), Cryptochrome1(Cry1), Cyptochrome2(Cry2), Clock Small and Prokineticin1 and Prokineticin2 receptor(Prok1r, Prok2r) genes in mouse ovary was explored by semiquantitative reverse transcription Polymerase chain reaction(RT-PCR) according to the developmental stage(post partum day; ppd 1, 7, 10, 21 and 35). Immunohistochemistry using PER1 antibody was also analyzed. The differential expression pattern of clock genes was presented according to stages of the mouse ovarian development (ppd 1, 7, 10, 21 and 35). In the cases of ovaries, at the starting point of follicle growth at ppd 7 and 10, the clock gene expression patterns were changed vastly. According to the developmental stages, the clock genes were highly expressed at ppd 7 and 10 in mouse testis also. Receptors for Prok2, the circadian output molecule of SCN, were also expressed in ovary at ppd 7 and in testis at ppd 1 and 7, respectively. Immnunohistochemical analysis of PER1 showed positive signals in the cytoplasm of oocytes and granulosa cells. The level or PER1 expression was increased in cells at the spermatogonia and the condensing spermatids. The expression pattern of Perl and localization of PER1 were showed similar patterns according to the developmental stages in ovary and testis. Taken together, it could be observed that the expression of clock genes was highly correlated with gonadal development and germ cell differentiation in mice. Therefore, in this study, circadian programming of the genes in the ovary and testis is strongly imposed across a wide range of core reproductive cycles and normal development of gametes. Although the existence of circadian genes is clearly investigated, further studies on the direct evidence is required for the understanding of the relationship between circadian genes and regulation of gonadal differentiation and germ cell development.

• Clinical and Experimental Pediatrics
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• v.52 no.1
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• pp.28-35
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• 2009

Purpose : We compared body growth, blood cell counts, and chemistry among infants receiving soy-based formula (SF), breast milk (BM), and casein-based formula (CF). Methods : Full-term neonates delivered at our hospital from June 2001 to August 2003 were recruited and divided into 3 feeding groups (BM=20, SF=19, CF=12 ) according to the parents wishes. Breast feeding or artificial formulae were given during the initial 3 months of age; thereafter, weaning foods were added freely. Height, weight, head circumference, skin-fold thickness, and mid-arm circumference were measured at birth and 1, 2, 4, 5, 12, and 36 months of age. Cell counts and blood chemistry were analyzed at 5, 12, and 36 months of age. Result : At 5 months of age, body weight was the lowest in the SF group; the height was similar among all groups. Thereafter, there were no differences in height or weight among the groups until 36 months of age. Hemoglobin was the lowest in the BM group at 5 and 12 months of age (P< 0.05 ). At 5 months of age, serum cholesterol, BUN, phosphates, and K+ were significantly lower in the SF group; thereafter, all chemical parameters were similar until 36 months of age. Conclusion : Infants fed with SF showed normal growth during the first 3 years of life as compared to infants fed with BM and CF. Low values of serum phosphates and K+ at 5 months of age in the SF group, despite the high mineral content, suggest that further investigation is needed for effective mineral absorption.