• Journal of Embryo Transfer
• /
• v.27 no.4
• /
• pp.265-270
• /
• 2012

In canine, oocytes are ovulated at the GV (germinal vesicle) stage and they have to fulfill maturation phase before reaching metaphase II stage. The efficiency of in vitro maturation is still very low. Therefore, the aim of this study was to investigate the effect of in vitro maturation on nuclear changes of immature canine oocytes recovered from different reproductive stages ovaries and different culture conditions. The oocytes were cultured in TCM-199 with supplement at 5% $CO_2$ and $38.5^{\circ}C$ for 72 h. The nuclear maturation of canine oocytes was evaluated with Hoechst 33342 stain under fluorescence microscope (Fig. 1). The results of this study detected differences in in vitro maturation rate between oocytes recovered from follicle status and non-follicle status ovaries. However, these differences were not significant as indicated in Table 1 and Fig. 2. In regard to the effect of culture condition with supplements, we did not found significant differences compared with control group (Table 2, Table 3). One of the reasons for this data could be the conditions that ovaries were exposed during slaughtering process or the long distant transportation of the ovaries. Although these data have not shown clearly significant differences results compared with control, furthermore the different reproductive status ovaries was beneficial for maturation of oocytes in vitro and can be a basic part of knowledge to improve in vitro maturation of canine oocytes.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.47 no.6
• /
• pp.997-1005
• /
• 2014

We analyzed annual and seasonal variations in fish species composition and distribution patterns using both daily catch and quantitative analysis data collected from a set-net fishery over a period of two years (2011-2012) on the coast of Dapo, Geoje Island. Set-net fishing season in this area is from May to November, and the annual yield based on the daily catch data was 171,412 kg in 2011, and 102,611 kg in 2012. In total, there were 46 species (belonging to 36 families and 12 orders) in 2011, and 41 species (belonging to 25 families and 9 orders) in 2012. The dominant species in terms of numbers were Trachurus japonicus, Engraulis japonicus, Clupea pallasii, Scomber japonicus, and Sphyraena pinguis. The range in fork length for T. japonicus and E. japonicus was from 3.2 to 23.9 cm, and from 2.6 to 13.3 cm, respectively. The fork length of recruiting juveniles to the Dapo set-net fishing ground ranged from 4.6 to 7.8 cm (median) for T. japonicus, and from 4.1 to 5.0 cm (median) for E. japonicus. The fact that most of the fish caught from the two species were at immature growth stages implies that the coast of Dapo can act as a nursery area for these migratory species.

• Fisheries and Aquatic Sciences
• /
• v.1 no.2
• /
• pp.269-275
• /
• 1998

Spider crabs, Libinia emarginata, were eyestalk-ablated unilaterally and bilaterally to manipulate endogenous methyl farnesoate (MF) to increase during the embryogenesis. Endogenous MF were measured weekly over the embryogenesis of the crab, using HPLC with the aids of GC/MS and MS database (CAS 010485-70-8) for the identification of the hormone. Initial MF titers both in the hemolymph and embryos of intact control were at bottom levels and the hormone concentrations kept unchanged (p<0.05), reflecting physiological unnecessaries of the hormone in the embryogenesis. Eyestalk ablation significantly stimulated the crabs to increase endogenous MF in both tissues (p<0.0l). In the response of the embryos to the increased MF, no growth stimulations were observed, at least, in the first part of embryogenesis. The increased mortalities and immature sheddings of embryos resulted from the crabs under the influence of elevated MF in both tissues, instead, suggesting that the elevated MF against the crab's requirement blocked the normal developmental process of the crab embryos. These data can give crustacean endocrinologists some insights to understand the effects of the hormone on the crustacean reproduction studied previously in which JH analogs ambiguously affected the crustacean reproduction depending on the reproductive stages. The data also can give shrimp aquaculturists some implication of a possible generation of unfavorable shrimp seeds attributed to elevated egg MF originated from their eyestalk-ablated mother shrimp.

• Proceedings of the Botanical Society of Korea Conference
• /
• 1999.07a
• /
• pp.85-89
• /
• 1999

Somatic embryogendesis is one of good examples of the basic research for plant embryo development as well as an important technique for plant biotechnology. This paper describes the direct somatic embryogenesis from zygotic embryos of Panax ginseng is reversely related to normal axis growth of zygotic embryos by the experiment of various chemical treatments. Under the normal growth condition, the apical tips of embryo axis produced an agar-diffusible substance, which suppressed somatic embryo development from cotyledons. Although the cells of zygotic embryos were released from the restraint of embryo axis, various factors were still involved for somatic embryo development. Electron microscopic observation revealed that the ultrastructure of cells of cotyledon epidermis markedly changed before initiation of embryonic cell division, probably indicating reprogramming events into the cells embryogenically determined state. Polar accumulation of endogenous auxin or cell-cell isolation by plasmolysis pre-treatment is the strong inducer for the somatic embryo development. The cells for the process of somatic embryogenesis might be determined by the physiological conditions fo explants and medium compositions. Direct somatic embryos from cotyledons fo ginseng were originated eithrer from single or multiple cells. The different cellular origin of somatic embryos was originated either from single or multiple cell. The different cellular origin of somatic embryos was depended on various developmental stages of cotyledons. Immature meristematic cotyledons produced multiple cell-derived somatic embryos, which developed into multiple embryos. While fully mature cotyledons produced single cell-derived single embryos with independent state. Plasmolysis pretreatment of cotyledons strongly enhanced single cell-derived somatic embryogenesis. Single embryos were converted into normal plantlets with shoot and roots, while multiple embryos were converted into only multiple shoots. GA3 or a chilling treatment was prerequisite for germination and plant conversion. Low concentration of ammonium ion in medium was necessary for balanced growth of root and shoot of plantlets. Therefore, using above procedures, successful plant regeneration of ginseng was accomplished through direct single embryogenesis, which makes it possible to produce genetically transformed ginseng efficently.

• Journal of Forest and Environmental Science
• /
• v.10 no.1
• /
• pp.32-37
• /
• 1994

This study was carried out to clarify the primary hosts of Tetrastichus sp. and its host relationship, development and reproductive capacity. Protopulvinaria mangiferae was parasitized by Aneristus ceroplastae, Microterys flavus, Coccophagus hawaiiensis. All of these primary parasitoid were attecked by the hyperparasite Tetrastichus sp.. Tetrastichus sp. was bound to be a solitary ectoparasite. Eggs were laid on the pupa of the primary host or attached to the inner surface of the integument of the scale insect. Threshold of the development and thermal constants for completion of immature stages were $9.8^{\circ}C$ and 272 day-degrees, respectively. At $25^{\circ}C$ the life span of both sexes without any food or with water were very short as compared with that with honey. After a pre-oviposition periods of about one day they laid on overage 220 eggs each, almost all during the first half of their life. The value of the net reproduction(Ro), the mean length of a generation(T) and the intrinsic rate of natural increase(r) were calculated as 99.6, 32days and 0.142 per female per day respectively.

• Clinical and Experimental Reproductive Medicine
• /
• v.13 no.2
• /
• pp.121-127
• /
• 1986

We have reviewed 59 cases of patients amoung 65 cases who underwent IVF and ET with reasonable indications irom 1984 and the results as follows. 1. Major indications for IVF and ET were tubal factor (40.7%), unexplained infertility (25.4%), endometriosis (15.3%), failed AID and AIH (10.1 %), and sperm abnormality (8.5%). 2. For superovulation of human oocytes, l00mg of clomiphene citrate and 75 IU of HMG used. The monitoring of oocyte maturation was bone by ultrasound examination and serum 17-${\beta}$ estradiol, LH values. The peak $E_2$ value was 956.36${\pm}$702.13 pg/ml. 3. The oocytes were obtained by laparoscopy 24-36 hours after the injection of HCG. 4. The mean numbers of follicles at laparoscopy was 3.06 and the successful rate of laparoscopy was 79.7%. 5. And 165 follicles were aspirated from which 98 oocytes were recovered, 59.4% of all follicles had at least one oocyte aspirated. 21.4% of the eggs were mature, 52.0% were moderate, 26.5%. were immature. 6. 67.3% of oocytes were cleaved and were transferred at 4-6 cell stages. 7. Four pregnancies including one chemical pregnancy and one spontaneous abortion were established by ${\beta}$-subunit, u-hCG and ultrasound examinations.

• Parasites, Hosts and Diseases
• /
• v.56 no.6
• /
• pp.589-596
• /
• 2018

Ticks are the vectors of various pathogens, threatening human health and animal production across the globe. Here, for the first time we detected Ricketssia spp., Borrelia spp. and protozoan in ticks from Poyang Lake region in Jiangxi Province of eastern China. In 3 habitat categories and on 12 host species, 311 ticks from 11 species were collected. Haemaphysalis longicornis was the predominant species, accounting for 55.63%, followed by Rhipicephalus microplus, Haemaphysalis flava and Ixodes granulatus. Of the collected ticks, 7.07% were positive for tick-borne pathogens, and H. longicornis and H. flava were found to be co-infected with Ricketssia spp. and protozoan. H. flava was the most detected positive for tick-borne pathogens, whereas H. longicornis had the lowest infection rate, and the difference in infection rates between tick species was significant (${\chi}^2=61.24$, P<0.001). Furthermore, adult ticks demonstrated remarkably greater infection rate than immature ticks (${\chi}^2=10.12$, P=0.018), meanwhile ticks on Erinaceidae showed significantly higher positivity than ticks collected on other host species (${\chi}^2=108.44$, P<0.001). Genetic fragment sequencing and analyses showed at least 4 pathogen species presence in ticks, namely Borrelia yangtzensis, Rickettsia slovaca or Rickettsia raoultii related genospecies, Babesia vogeli and Hepatozoon canis or Hepatozoon felis related genospecies. The finding indicates that the abundant ticks can carry diverse pathogens in Poyang Lake region, and pathogen infection is highly related to species, vertebrate hosts and life stages of ticks.

• Journal of Digital Convergence
• /
• v.19 no.4
• /
• pp.89-101
• /
• 2021

Scale-up of ICT startups is not easy because of limited capabilities, lack of resources, and immature networks for the business. Therefore, this research selected a representative startup succeeded in scale-up and applied the ERIS model in analyzing their scale-up process in the initial stages of scale-up. Analysis of qualitative data collected revealed that the entrepreneurs' experience, convergence of knowledge between diverse industries, participation in public-sector-led R&D, management of communication channels between customers and businesses, and utilization of project-oriented campaigns are found to be critical success factors in scaling up ICT startups. Academically, this study validates the utility of ERIS model in analyzing the scale-up process. For practitioners, this study will be used as a reference for strategic development in seucring the competitiveness of the initial market of ICT startups and scale-up.

• Korean journal of applied entomology
• /
• v.25 no.1 s.66
• /
• pp.37-40
• /
• 1986

We surveyed the IRRI farm to determine the extent of parasitization of yellow stemborer egg masses. The egg masses were randomly collected at weekly intervals from July to October 1984 from rice fields, 15-20 days after transplanting, and brought to the laboratory for collection of emerging parasites. Three species of hymenopterous parasitoids-Tetrasticus schoenobii, Telenomus rowani, and Trichogramma japonicum-were found from 700 egg masses. We introduced a method to calculate percent parasitism as based on parasite biology and behaviour. Among the three species, the combination of T. rowani and T. japonicum was the highest multiparasitization of yellow stem borer egg masses, and T. rowani, a solitary parasite had the highest number based on immature and adult stages counted. However, T. schoenobii may be the most efficient parasite because two to four host eggs are needed to complete the larval period, and it took $10{\sim}14$ days for one generation.

• Korean journal of applied entomology
• /
• v.47 no.4
• /
• pp.435-445
• /
• 2008

Due to internal feeding behavior, the oriental tobacco budworm, Helicoverpa assulta ($Guen\acute{e}e$), infesting hot pepper has been regarded to be effectively controlled by targeting egg and neonate larval stages just before entering the fruits. This study aimed to develop an efficient biological control method focusing on these susceptible stages of H. assulta. An egg parasitoid wasp, Trichogramma evanescens Westwood, was confirmed to parasitize the eggs of H. assulta. A mixture of Gram-positive soil bacterium, Bacillus thuringiensis subsp. kurstaki, and Gram-negative entomopathogenic bacterium, Xenorhabdus nematophila ANU101, could effectively kill neonate larvae of H. assulta. A sex pheromone trap monitored the occurrence of field H. assulta adults. The microbial insecticide mixture was proved to give no detrimental effects on immature development and adult survival of the wasp by both feeding and contact toxicity tests. A combined treatment of egg parasitoid and microbial pesticide was applied to hot pepper fields infested by H. assulta. The mixture treatment of both biological control agents significantly decreased the fruit damage, which was comparable to the chemical insecticide treatment, though either single biological control agent did not show any significant control efficacy. This study also provides morphological and genetic characters of T. evanescens.