• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.32 no.4
• /
• pp.317-326
• /
• 2006

Purpose : The aim of this study was to evaluate the effect of recombinant human bone morphogenetic protein-7 (rhBMP-7) injected on the rate of new-bone formation for distraction osteogenesis on dogs. Materials & Methods : Twelve adult dogs were randomly selected into two groups of six dogs on each. Unilateral osteotomies were performed on the body of the mandible and an intraoral distractor was mounted to the mandible on dogs. One group was treated with injection of rhBMP-7 and the other group served as the control. RhBMP-7 was administered on the day of surgery by single injection into the medullary bone at the osteotomy gap. Distraction was performed five days after osteotomy as a rate of 0.5 mm twice per day for 10 days. The animals were then sacrificed at 2, 4, and 8 weeks after completion of the distraction. Two dogs in each group, totaling four dogs, were killed at 2 weeks, 4 weeks, and 8 weeks after completion of distraction, respectively. The lengthened mandibles were harvested and processed for radiographic and histological examinations. In addition, immunohistochemical examination using osteocalcin expression was studied. Results : Radiographs showed accelerated regenerate ossification with maturation of new bone in the rhBMP-7 group comparing with the control group at the 4 weeks of the consolidation. There was no significant difference in the radiographic findings at the 2 weeks and 8 weeks of the consolidation period. Histological findings demonstrated increased bone healing pattern in the rhBMP-7-treated group during all observation period. The expression of osteocalcin immunoreactivity was hardly detected in the normal mandible of dog, but the expression was detected in all experimental rhBMP-7 treated specimens. There were also significant increasing in number of positive immunostaining cells and staining intensity of osteocalcin expression in the rhBMP-7 treated group compared with those of the control group on 2-weeks and 4-weeks. There was a significant decreasing in staining intenstiy of all both two groups on 8 weeks of consolidation period, but significant differences of immunostaining was not seen in two groups. Conclusions : A single injection of rhBMP-7 at the time of osteotomy may stimulate the rate of regenerate ossification and increase callus maturation during distraction osteogenesis. In addition, it may shorten the distraction osteogenesis procedure and decrease the prevalence of complications associated with mandibular distraction osteogenesis.

• Analyses & Alternatives
• /
• v.7 no.2
• /
• pp.35-77
• /
• 2023

This study aims to solve the entangled loop between demographic transition (DT) and economic growth by analyzing cross-country data. We undertake a national-level group analysis to verify the compressed transition of demographic variables over time. Assuming that the LA (latecomer advantage) on DT over time exists, we verify that the DT of the latecomer is compressed by providing a formal proof of LA on DT over income. As a DT has the double-kinked functions of income, we check them in multiple aspects: early maturation, leftward threshold, and steeper descent under a contour map and econometric methods. We find that the developing countries (the latecomer) have speedy DT (CDT, compressed DT) as well as speedy income such that DT of the latecomers starts at lower levels of income, lasts for a shorter period, and finishes at the earlier stage of economic development compared to that of developed countries (the early mover). To check the balance of DT, we classify countries into four groups of DT---balanced, slow, unilateral, and rapid transition countries. We identify that the main causes of rapid transition are due to the strong family planning programs of the government. Finally, we check the effect of latecomer's CDT on economic growth inversely: we undertake the simulation of the CDT effect on economic growth and the aging process for the latecomer. A worrying result is that the CDT of the latecomer shows a sharp upturn of the working-age population, followed by a sharp downturn in a short period. Compared to early-mover countries, the latecomer countries cannot buy more time to accommodate the workable population for the period of demographic bonus and prepare their aging societies for demographic onus. Thus, we conclude that CDT is not necessarily advantageous to developing countries. These outcomes of the latecomer's CDT can be re-interpreted as follows. Developing countries need power sources to pump up economic development, such as the following production factors: labor, physical and financial capital, and economic systems. As for labor, the properties of early maturation and leftward thresholds on DTs of the latecomer mean that demographic movement occurs at an unusually early stage of economic development; this is similar to a plane that leaks fuel before or just before take-off, with the result that it no longer flies higher or farther. What is worse, the property of steeper descent represents the falling speed of a plane so that it cannot be sustained at higher levels, and then plummets to all-time lows.

• Horticultural Science & Technology
• /
• v.30 no.4
• /
• pp.345-356
• /
• 2012

We investigated the changes of fruit quality parameters, polysaccharide contents and cell wall components during maturation and ripening of two Korean pear cultivar 'Hanareum' and 'Manpungbae' compared with 'Niitaka' pear (Pyrus pyrifolia Nakai) which showed different physiological maturity based on days after full bloom (DAFB). Flesh firmness decreased continuously with fruit development and maturation, reaching a final level of 29.4, 33.5, and 27.4N at maturity in 'Hanareum' (127 DAFB), 'Manpungbae' (163 DAFB), and 'Niitaka' (170 DAFB), respectively. The level of ethylene production was very low in early season 'Hanareum' pear which showed at most 0.39 ${\mu}L{\cdot}L^{-1}$ at maturity and no ethylene was detected in 'Manpungbae' and 'Niitaka' at maturity. Fructose was the most abundant soluble sugar during fruit maturation in the pears tested and an increase of sucrose was observed during fruit ripening in the Asian pears commonly. Ethanol insoluble solids (EIS) content decreased gradually with different levels among the pear cultivars as fruit ripens consisted of 10.79, 12.72, and 12.75 $mg{\cdot}g^{-1}$ FW. The amount of total soluble polyuronides was higher in early season cultivars 'Hanareum' than those of mid-season cultivar 'Manpungbae' and 'Niitaka'. In 'Niitaka' which harvested most late season, the level of 4% KOH soluble hemicelluloses was lower than 'Hanareum' and 'Manpungbae' and maintained constantly during fruit ripening period. Cellulosic residues were determined high level in 'Niitaka' which showed 612.33 ${\mu}g{\cdot}mg^{-1}$ EIS at maturity when compared with 'Hanareum' (408.0 ${\mu}g{\cdot}mg^{-1}$ EIS) and 'Manpungbae' (538.67 ${\mu}g{\cdot}mg^{-1}$ EIS). The main constituents of cell wall neutral sugars which consisted of arabinose, xylose, galactose, and glucose were decreased gradually with onset of fruit ripening regardless of cultivar. Arabinose which was predominant in 'Hanareum' pear decreased at the last stage of ripening, but the changes of cell wall neutral sugar during ripening were not occurred in 'Niitaka' pear. The change of molecular mass distribution in water soluble pectin observed dominantly at the early stage of fruit development. Depolymerization of 4% KOH-soluble hemicelluloses and degradation of xyloglucan showed in early-season cultivar 'Hanareum' during fruit maturation, and degradation of those fractions were detected only at the early stage fruit development in mid-season cultivar 'Manpungbae' and 'Niitaka'. The molecular mass profile of CDTA soluble pectin, $Na_2CO_3$-SP and 24% KOH soluble hemicelluloses showed no significant change during fruit maturation regardless of cultivar.

• Korean Journal of Animal Reproduction
• /
• v.26 no.1
• /
• pp.1-7
• /
• 2002

The present study was carried out to investigate the effects of maturation media on penetrability of pig oocytes by liquid boar sperm coincubated with different sperm concentrations in a modified Tris­buffered medium (mTBM). Follicular oocytes collected from ovaries of prepubertal gilts were matured in a modified TCM-199 (mTCM-199) medium, modified Waymouth MB 752/1 (mWaymouth MB 752/1) medium or NCSU-23 medium. Oocytes (30~40) were transferred into each well of a Nunc 4-well multidish containing 0.5 $m\ell$ maturation medium. The sperm­ich portion of ejaculates with greater than 90% motile sperm were used in the experiment. The semen was cooled 22 to 24$^{\circ}C$ over 2 h period. The semen was diluted with Beltsville Thawing Solution (BTS) extender at room temperature to give 2$\times$10$^{8}$ sperm/$m\ell$ in 100 $m\ell$ plastic bottle. Liquid boar semen of 30 $m\ell$ in 100 $m\ell$ plastic bottle was kept at 17$^{\circ}C$ far 5 days. The sperm with greater than 70% motility after day 5 of storage were used for in-vitro fertilization (IVF). After 44 h maturation of immature oocytes in 5% $CO_2$in air at 38.5$^{\circ}C$, cumulus cells were removed and oocytes (30~40) were coincubated for 6 h in 0.5 $m\ell$ mTBM fertilization medium with five different (1$\times$10$^{6}$ , 2$\times$10$^{6}$ , 4$\times$10$^{6}$ , 6$\times$10$^{6}$, 10$\times$10$^{6}$ $m\ell$) sperm concentrations. At 6 h after IVF, oocytes were transferred into 0.5 $m\ell$ NCSU-23 culture medium fur further culture of 6 h. At 12 h after IVF, sperm penetration, polyspermy and male pronuclear formation of oocytes were evaluated. Oocytes of NCSU-23 maturation medium decreased polyspermy and increased male pronuclear formation compared to those of mTCM­199 and mWaymouth MB 752/1 maturation media. Of oocytes matured in NCSU-23 medium and inseminated in mTBM medium with 2~4$\times$10$^{6}$ $m\ell$ sperm concentrations, 50.8~50.9% showed sperm penetration, 13.3~19.5% polyspermy and 43.9~45.4% male pronuclear formation. In conclusion, we found out that oocytes matured in NCSU­23 medium and inseminated in mTBM medium showed superior in­vitro fertilization compared to those matured in mTCM­199 and mWaymouth MB 752/1 maturation media and inseminated in mTBM medium. The optimum sperm concentrations for in-vitro fertilization of oocytes matured in NCSU-23 medium by liquid boar semen stored at 17$^{\circ}C$ for 5 days were 2~4$\times$10$^{6}$ $m\ell$.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.5
• /
• pp.637-642
• /
• 2002

Thirty Holstein calves were used to determine effects of age, environment and sex on blood metabolite concentrations during 1 to 90 d of age. Calves were weaned at 75 d of age. Environmental effects are grouped by the difference in month at birth and site of feeding. Blood samples were obtained every 2 or 3 d. The mean metabolite concentration every 3 d was used for the statistical analysis. Dairy bodyweight gain was not affected by environmental group and sex effect. Concentrations of plasma glucose, nonesterified fatty acids (NEFA), triglyceride, total cholesterol and total ketone changed with growth. These developmental changes in metabolite levels would be caused by ruminal maturation with increment of grain intake. Levels of plasma urea nitrogen, glucose, NEFA, triglyceride and total cholesterol drastically changed during a few weeks after birth, indicating that the physiological state in calves greatly changed during that time. Effects of the environmental group and sex were significant in almost all metabolites. Temperature influenced plasma metabolite concentrations. The plasma metabolite concentrations were affected more intensely by heat stress in the infant period than in the neonatal period.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.49 no.3
• /
• pp.404-409
• /
• 2016

We investigated the maturation and spawning of Sebastes thompsoni in the coastal waters off Ulleungdo, based on samples collected by gill net from March 2013 to February 2014. We analyzed monthly changes in maturity stage, gonadosomatic index (GSI), egg diameter, fecundity, and total length (TL) at 50% group maturity. The average TLs of female and male S. thompsoni were 22.6 cm and 22.5 cm, respectively. The main parturition period of females was during March and April. The GSI of females began to increase in January, and reached a maximum in March. The GSI of male reached a maximum between January and February. The spawning period of males was shorter than that of females. The egg diameter during gestation stage was 1.4±2.1 mm. The TL of females at 50% group maturity was 22.3 cm.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.53 no.1
• /
• pp.1-8
• /
• 2020

The reproductive biology of largehead hairtail Trichiurus japonicus, from near Jeju Island, Korea was investigated based on 4,384 individuals collected by commercial vessel from November 2016 to October 2019. There were more female specimens than male specimens (2.64:1). T. japonicus preanal lengths (PL) ranged from 10.5 to 53.5 cm; the relationships between PL and body weight (BW) were BW=0.0103PL^3.1293 for females and BW=0.0106PL^3.1251 for males. Monthly changes in gonadosomatic index were analyzed to estimate spawning season. The spawning period ranged from June to November. The size-frequency distribution of eggs suggested that T. japonicus exhibits multiple-spawning during a spawning period. The minimum size of females at maturity was 18.2 cm, while the size at sexual maturity was 25.0 cm.

• Animal cells and systems
• /
• v.1 no.1
• /
• pp.53-61
• /
• 1997

Seasonal variation of the population structure and the reproductive pattern of the Korean striped field mouse, Apodemus agrarius, were investigated. High capture ratios in juveniles, young adult, and old adult mice were found during the period from October to November, from November to March, and from May to September, respectively, and extremely low capture ratios of old adults during the period from November to February were characteristic. It seemed that the young adults that survived during the winter might become older by summer and have been counted as the old adults. The breeding in the mice began earlier in males (from mid February or early March to late October) than in females (from mid March to late October), having a peak in August and September, and both the male and female mice weighing more than 20 g generally reached sexual maturation in general. In the breeding season, both young and old adult males had large testes with enlarged seminiferous tubules filled with numerous germ and Sertoli cells, and expanded caudal epididymides with a vast number of spermatozoa; the females had many Graafian follicles and corpora lutea in large ovaries, and developed uterine glands in the thick endometria. The lower ratios of the testis weight to the body weight in July and August in 1994 compared to 1995 seemed due to the extreme drought and considerably higher temperature in 1994, but the decrease in the ratio in mid-summer, only in the old mice, in both years might be explained partially by aging.

• Ocean and Polar Research
• /
• v.40 no.1
• /
• pp.15-22
• /
• 2018

In the present study, we investigated temporal variation in the reproductive effort and biochemical contents in adult Manila clam Ruditapes philippinarum at Shi-Heung-Ri beach on the east coast of Jeju Island. Gonad-somatic index (GSI), a ratio of the egg mass to the total biomass determined using ELISA increased dramatically from late May to June (7.1% to 19.5%). In mid-July, GSI dropped to 15.1%, indicating spawning on a small scale during this period. GSI also declined dramatically from late August (15.5%) to September (4.3%), suggesting that massive spawning occurred during this period. A positive correlation was observed between clam size and potential fecundity, while potential fecundity ranged between 1.19-8.40 million eggs/clam. Total proteins and lipids in the tissue increased from late spring to mid-summer, coinciding with an increase in GSI. Protein, lipid and carbohydrate contents in the tissue were lowest in January, indicating that clams were suffering from poor nutritional circumstances, which may be associated with poor food supply from the environment. Monthly increase and/or decrease in the body weight were closely related to gonad maturation and subsequent spawning, which was also linked to temporal changes in the contents of protein, lipid and carbohydrates in the tissue.

• Development and Reproduction
• /
• v.27 no.3
• /
• pp.101-115
• /
• 2023

Environmental factors impact oyster growth, condition, and gonadal development, which is linked to gamete characteristics observed through histology. The reproductive cycle of bivalves is related to energy storage and utilization. Therefore, in this study, the year-round growth change and gonadal development of oysters were observed using histological analysis, and the biochemical composition changes were confirmed. The oysters used in this study are being nurtured in Gadeok-do, and 40 oysters were randomly sampled monthly from March 2021 to February 2022. Result of histological analysis of gonads, oysters were showed early development from December to February, late development from March and April, mature and ripe from May to July, spawned from August to October, and spent from November to December. Condition index values of oysters decreased in summer and autumn and increased again when entered the spent after spawning. The protein content of oysters was high in May, the maturity period, and the lipid content decreased during the spawning period. In addition, EPA and DHA, the major fatty acids of oysters, were low during the spawning period and high during the maturation period. As a result, this study suggested a close relationship between changes in oyster growth, biochemical composition, and the reproductive cycle.