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        검색결과 26

        1.
        2023.10 구독 인증기관·개인회원 무료
        Honey bees are crucial pollinators for agricultural and natural ecosystems, but are experiencing heavy mortality in Korea due to a complex suite of factors. Extreme winter losses of honey bee colonies are a major threat to beekeeping but the combinations of factors underlying colony loss remain debatable. Finding solutions involves knowing the factors associated with high loss rates. To investigate whether loss rates are related to Varroa control and climate condition, we surveyed beekeepers in korea after wintering (2021–2022 to 2022–2023). The results show an average colony loss rate of 46%(2022) and 17%(2023), but over 40% colony loss before wintering at 2022. Beekeepers attempt to manage their honey bee colonies in ways that optimize colony health. Disentangling the impact of management from other variables affecting colony health is complicated by the diversity of practices used and difficulties handling typically complex and incomplete observational datasets. We propose a method to 1) Varroa mite population Control by several methods , and 2) Many nursing bee put in hive before wintering.
        7.
        2012.06 구독 인증기관·개인회원 무료
        The objective of this study was to investigate the effects of NEAA and leptin supplemented to in vitro culture medium on the developmental competence of porcine embryos after intracytoplasmic sperm injection (ICSI), and to modify the culture condition to improve the quality and the development of ICSI-derived porcine embryos in vitro. After ICSI, the putative zygotes were then cultured in PZM-3 medium with/without NEAA or leptin. The proportion of embryos that developed to the blastocyst stage significantly increased when 1% NEAA (24.62%) was added to the medium compared with 2% NEAA and no NEAA group (17.24% and 20.24%, respectively, p<0.05). The effect of different concentration of leptin (0, 10, 100, 500 ng/ml) was evaluated on the development of porcine ICSI embryos cultured in vitro. In case of blastocyst formation, 100 ng/ml group (27.05%) showed significantly higher rate than 10, 500 ng/ml, and control group (23.45%, 17.99%, and 19.68%, respectively, p<0.05). We also evaluated the effects of different NEAA and leptin treatment time on the development of porcine embryos after ICSI. Among groups of embryos cultured in the presence of NEAA or leptin for whole 7 days (D 1-7), first 4 days (D 1-4), the subsequent 3 days (D 5-7), both NEAA (27.13%, 21.17 %, and 17.56%, respectively, p<0.05) and leptin (25.60%, 20.61%, and 16.53%, respectively, p<0.05) showed that supplementation for whole 7 days significantly increased the blastocyst formation rate compared with the other groups of D1-4 and D5-7. We further evaluated the combination effect of 1% NEAA and 100 ng/ml leptin compared with the effect of each supplementation with 1% NEAA or 100 ng/ml leptin or no supplementation on development of embryos. For blastocyst formation, combination group of NEAA and leptin (24.78%) showed significantly higher rate than other three groups (18.37%, 20.44 %, and 13.27%, respectively, p<0.05). We further evaluated the expression of proapoptosis genes such as BAX and BAK and anti-apoptosis genes, BCL-XL and BCL-2 in blastocysts cultured in the presence of 100 ng/ml leptin. RT-PCR analysis revealed that leptin supplementation significantly decreased the expression of pro-apoptosis genes as well as increased the expression of anti-apoptosis genes. These results of present study demonstrate that NEAA and leptin could improve the in vitro development of ICSI- derived porcine embryos with optimal concentration of each reagent. Furthermore, the optimal culture condition could increase the quality of ICSI-derived embryos in vitro.
        8.
        2012.06 구독 인증기관·개인회원 무료
        True hermaphrodites are animals of equivocal sex in which both male and female gonads develop simultaneously. The frequency of true hermaphroditism is higher in pigs than in other domestic animals. Two Korean pigs were diagnosed with true hermaphroditism showing ovotestes, epididymes, penes, and uteri. Histomorphologically, the testicular tissues consisted of Sertoli cells that were devoid of spermatogenic germ cells and showed proliferation of interstitial cells. However, the uteri were of normal architecture and had well-developed uterine endometrial glands. The samples were 38, XX female karyotype without the sex-determining region Y (SRY) gene. The findings of this study could contribute to the understanding of true hermaphroditism in the Korean pig industry. * This work was supported by a grant (Code# PJ008148) from BioGreen21 Program, Rural Development Administration, Republic of Korea.
        9.
        2012.06 구독 인증기관·개인회원 무료
        The aim of this study was to examine the effect of acteoside (the cyclin-dependent kinase inhibitor) on the SCNT efficiency with adult fibroblasts in dog. Canine adult fibroblasts were obtained from muscle and cell cycle of fibroblasts was synchronized by culturing to confluency, serum starvation and treating with 30 μM acteoside for 48 h. Cell cycle stages, cell cytotoxicity (apoptosis) and, prduction of reactive oxygen species (ROS) were analyzed using flow cytometry. The canine cells, prepared by confluent-cell culture or treating with 30 μM acteoside for 48 h, were injected into enucleated in vivo matured oocytes, the couplets were electrical fused and activated by calcium ionomycin. SCNT embryos using acteoside-treated fibroblasts were surgically transferred into oviducts of estrus cycle synchronized recipient dogs. In cell cycle synchronization (G0/G1), there was no significant difference between serum starvations (83.9%) and acteoside treated groups (81.3%) that were higher than confluent group (78.5%). In production of apoptosis, confluent and acteoside treated groups (4.3 and 4.5%, respectively) were generated less than serum starvation group (21.8%). In case of ROS, serum starvation group was induced a significantly higher than other groups. After synchronization of the donor cell cycle, either confluent or acteoside treated, cells were placed with enucleated in vivo-matured dog oocytes, fused by electric stimulation, activated, and transferred into naturally estrus-synchronized surrogates. Fusion and cleavage rate of acteoside treated group were 64.1 and 41.5%, which were higher than those of confluent group (53.9 and 20.6%, respectively). The reconstructed embryo development rates to 4-cell and 8-cell in acteoside treated group were 29.5 and 14.8%, respectively, while confluent group showed 11.1 and 3.2%, respectively. Total 54 SCNT embryos using acteoside-treated fibroblasts were transferred into oviducts of 2 recipient dogs and one recipient finally delivered one puppy, whereas din`t detected pregnancy on transfer of cloned embryos reconstructed with confluent cells in 6 surrogate dogs. In conclusion, the results of the current study demonstrated that canine fibroblasts could be successfully arrested at the G0/G1 stage with reduced the formation of ROS and apoptosis after acteoside treatment. This results may contribute to improve the effi-ciency of canine SCNT. * This research was supported by iPET (Grants 110056-3), Ministry for Food, Agriculture, Forestry and Fisheries, Republic of Korea.
        10.
        2012.06 구독 인증기관·개인회원 무료
        Acteoside acts as an anti-oxidative activity and anti-apoptosis in the cells. But, it has been not studied on maturation and development of porcine oocytes. The aims of the present study were to examine the effects of acteoside on the morphological progress of meiosis, developmental competence, and ROS in porcine oocytes. Oocytes were matured in tissue culture medium-199, supplemented with acteoside at various concentrations: 0 (control), 10, 30 and 50 μM. The oocytes maturation rates of groups supplemented with acteoside were no significantly different (81.13, 85.96, 82.95 and 83.68%, respectively). Level of ROS was significantly decreased in acteoside treated group. Furthermore, the parthenogenetic blastocyst rate was significantly improved in 10 μM acteoside treated group compared with control group (44.83 vs. 27.75%). And we investigated effect of acteoside on the oocytes condition represented by cytoplasmic maturation by homogeneous distribution and formation of cytoplasmic organelles and regulation of apoptosis-related genes. In the results. during IVM, 10 μM acteoside treated oocytes showed that the mitochondria and lipid droplet were smaller and homogeneous distribution in cytoplasm compare with control oocytes. And reverse transcription polymerase chain reaction (RTPCR) of parthenogenetic blstocysts revealed that acteoside increased the anti-apoptotic genes (Mcl-1, Bcl-2 and Bcl-xL), whereas reduced the expression of pro-apoptotic genes (Bax and Bak). In conclusion, based on the results, the effect of acteoside on IVM was not attractive. However, in acteoside treated group, cytoplasmic maturation seemed to be improved with morphologically uniform distribution of cytoplasmic organelles. Furthermore, embryonic development in acteoside treated group was significantly highly increased than that of non-treated group. Our results represents that addition of acteoside to the IVM medium has a beneficial effect in physiology of porcine oocytes, providing a improved method for porcine oocytes in vitro. * This work was supported by a grant (Code# PJ008148) from BioGreen21 Program, Rural Development Administration, Republic of Korea.
        11.
        2012.06 구독 인증기관·개인회원 무료
        The objective of the current study was to describe in vitro embryo production in Hanwoo, analyzing oocytes yield and embryo production. The effects of oocytes production and the number of OPU procedures per animal on embryo production were also evaluated. OPU was done every 3~4 days during experimental period and collected oocytes were fertilized in vitro in both OPU and needle puncture groups. First, we compared the recovery rate of oocytes based on OPU session (Experiment 1). The average of collected oocytes was calculated from every 10 session. The average number of total oocytes recovered per animalonsessionwas 5.16 (mean). Second, we compared the recovery rate base on collection period of OPU (Experiment 2). The following results show the difference of the number of recovered oocytes in every month during the procedure between the months of session. Every animal shows the constant number of recovered oocytes for the first 5 months. However, the recovery rate of oocytes was decreased from month 6 to 8. Third, we compared the developmental rate to blastocyst in two groups (Experiment 3). Oocytes by needle puncture were fertilized with frozen-thawing semen; the cleavage rate 24~48 h after in vitro fertilization (IVF) was 75.8% and blastocyst development rate was 18.8% in needle puncture group. Even though there is lower cleavage rate after IVF in OPU group (61.1%), blastocyst development rate was higher compared with needle puncture group (28.4%). In conclusion, Blastocyst developmental rate could be increased by OPU than classical method of needle puncture. Improvement of bio- technique in collecting oocytes could be applied to understand the reproductive physiology in cattle, expecially Hanwoo. Therefore, further investigation should be done to clarify the efficiency and advantage of OPU involved in reproduction in animals and human being.
        12.
        2012.03 구독 인증기관 무료, 개인회원 유료
        Cytokines are known to function as regulatory molecules that can be produced by virtually every nucleated cell type in the body, including lymphocytes, monocytes/macrophages, epithelial cells, fibroblasts, and many others. Cytokines include lymphocyte-derived factors (lymphokines), monocyte-derived factors (monokines), hematopoietic factors (colony-stimulating factors), connective tissue/ growth factors, and chemotactic chemokines. Cytokines released in response to infection can affect tumor development in different ways. When exposed to infectious agents, cytokines are secreted by sentinel cells, such as macrophages and dendritic cells. These cytokines include interleukin 1 (IL-1) and tumor necrosis factor-α, as well as others, such as IL-6, IL-12, and IL-18. When released in sufficient quantities, these molecules can cause inflammation. Chronic inflammation is highly associated with tumor initiation, promotion, and progression. In this article, we review the roles and mechanisms of cytokines in tumor development.
        4,300원
        13.
        2011.10 구독 인증기관·개인회원 무료
        The objective of this study was to evaluate in vitro production of bovine embryos in Hanwoo. Oocytes were collected by ovum pick up (OPU) from ovaries of genetically high-value Hanwoo or by needle puncture from ovaries of slaughtered cattle. OPU was done every 3 4 days duing experimental period and collected oocytes were fertilized in vitro in both OPU and needle puncture groups. First, We compared the in vitro maturation rate in two groups (Experiment 1). 545 oocytes were recoverd from 4 females by 32 trials of OPU and then 433 oocytes were shown MⅡ stage after in vitro maturation (79.4%). In case of needle puncture group, 1905 oocytes were collected and then 1420 oocytes were matured to MⅡ stage during in vitro culture(74.5%). Second, we compared the developmental rate to blastocyst in two groups (Experiment 2). 1420 oocyte by needle puncture were fertilized with frozen-thawing semen; the cleavage rate 24 48 h after in vitro fertilization (IVF) was 88.6% and blastocyst development rate was 20.5% in needle puncture group. Even though there is lower cleavage rate after IVF in OPU group (84.8%), blastocyst development rate was higher compared with needle puncture group (26.4%). In conclusion, Blastocyst developmental rate could be increased by OPU than classical method of needle puncture. Improvement of bio-technique in collecting oocytes could be applied to understand the reproductive physiology in cattle, expecially Hanwoo. Therefore, further investigation should be done to clarify the efficiency and advantage of OPU involved in reproduction in animals and human being. This research was suppoted by Imsil-gun agricultural technology service center.
        14.
        2011.06 구독 인증기관 무료, 개인회원 유료
        Substantia gelatinosa (SG) neurons receive synaptic inputs from primary afferent Aδ- and C-fibers, where nociceptive information is integrated and modulated by numerous neurotransmitters or neuromodulators. A number of studies were dedicated to the molecular mechanism underlying the modulation of excitability or synaptic plasticity in SG neurons and revealed that second messengers, such as cAMP and cGMP, play an important role. Recently, cAMP and cGMP were shown to downregulate each other in heart muscle cells. However, involvement of the crosstalk between cAMP and cGMP in neurons is yet to be addressed. Therefore, we investigated whether interaction between cAMP and cGMP modulates synaptic plasticity in SG neurons using slice patchclamp recording from rats. Synaptic activity was measured by excitatory post-synaptic currents (EPSCs) elicited by stimulation onto dorsal root entry zone. Application of 1 mM of 8- bromoadenosine 3,5-cyclic monophosphate (8-Br-cAMP) or 8-bromoguanosine 3,5-cyclic monophosphate (8-Br-cGMP) for 15 minutes increased EPSCs, which were maintained for 30 minutes. However, simultaneous application of 8-BrcAMP and 8-Br-cGMP failed to increase EPSCs, which suggested antagonistic cross-talk between two second messengers. Application of 3-isobutyl-1-methylxanthine (IBMX) that prevents degradation of cAMP and cGMP by blocking phosphodiesterase (PDE) increased EPSCs. Co-application of cAMP/cGMP along with IBMX induced additional increase in EPSCs. These results suggest that second messengers, cAMP and cGMP, might contribute to development of chronic pain through the mutual regulation of the signal transduction.
        4,000원
        15.
        2006.09 구독 인증기관 무료, 개인회원 유료
        Schwann cells play an important role in peripheral nerve regeneration. Upon nerve injury, Schwann cells are activated and produce various proinflammatory mediators including IL-6, LIF and MCP-1, which result in the recruitment of macrophages and phagocytosis of myelin debris. However, it is unclear how the nerve injury induces Schwann cell activation. Recently, it was reported that necrotic cells induce immune cell activation via toll-like receptors (TLRs). This suggests that the TLRs expressed on Schwann cells may recognize nerve damage by binding to the endogenous ligands secreted by the damaged nerve, thereby inducing Schwann cell activation. To explore the possibility, we stimulated iSC, a rat Schwann cell line, with damaged neuronal cell extracts (DNCE). The stimulation of iSC with DNCE induced the expression of various inflammatory mediators including IL-6, LIF, MCP-1 and iNOS. Studies on the signaling pathway indicate that NF-xB, p38 and JNK activation are required for the DNCE-induced inflammatory gene expression. Furthermore, treatment of either anti-TLR3 neutralizing antibody or ribonuclease inhibited the DNCE-induced proinflammatory gene expression in iSC. In summary, these results suggest that damaged neuronal cells induce inflammatory Schwann cell activation via TLR3, which might be involved in the Wallerian degeneration after a peripheral nerve injury.
        4,000원
        18.
        2019.12 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to determine the number of days required to break a plant’s dormancy and promote subsequent crop growth in new varieties of Gomchwi through the 4℃ treatment. Three new varieties of Gomchwi namely, ‘Sammany’, ‘Gommany’, and ‘Damogy’ were observed in this study. The rate of leaf emergence of ‘Sammany’ after 15-day of 4℃ treatment was 100%, while ‘Gommany’, and ‘Damogy’ took 20-days and 10-days, respectively to reach to 97.9% rate of leaf emergence. After 10-days of 4℃ treatment, ‘Damogy’ grew faster than the other varieties. and Harvest time for ‘Damogy’ was on January 18th, after 5-days of 4℃ treatment and yield was observed to be the highest at 15-days of 4℃ treatment. ‘Sammany’ was next with a minimum of 10-days of 4℃ treatment, although 15-days is more preferred for better harvest. ‘Gommany’ on the other hand, did not grow enough for harvest by January 18th, and its harvest time was delayed to January 31st. It needed a minimum of 15-days and preferentially 20-days of 4℃ treatment to grow normally and be ready for harvest. The plant height, leaf length and leaf petiole length appeared to grow better by extending duration of the 4℃ treatment. The number of leaves of ‘Sammany’ and ‘Gommany’ varieties was three leaves for the 5-days treatment which may be due to the incomplete breaking of dormancy. Regarding the yield per plant, ‘Sammany’ yielded 112.3 grams (g) in 15-days treatment, and ‘Gommany’ yielded 106.5 g in 25-days treatment. In the case of ‘Damogy’, it yielded 123.5 g and 183 g in the 10-days and 25-days treatment respectively. It is concluded that ‘Damogy’, ‘Sammany’ and ‘Gommany requires 10, 15, and 20 days of 4℃ treatment to break the plant’s dormancy and promote better plant growth.
        19.
        2016.10 서비스 종료(열람 제한)
        Background : Despite the presence of various bioactive compounds in ginseng, there is lack of study on the variations of bioactive compounds in ginseng according to the cultivation of soil and the applied fertilizer types (or amount). Therefore, this study aims to examine the variations of 37 fatty acids (FA) and 8 vitamin E (Vit-E) vitamers in 6-year-old ginseng root cultivated in different soil types with different fertilizers regimes. Methods and Results : The profiling of 37 FAs and 8 Vit-E vitamers in 6-year-old ginseng roots was measured by gas chromatography coupled with a flame ionization detector, and then these results were statistically analyzed with chemometrics. The FA and Vit-E content in ginseng roots varied significantly with respect to soil cultivation conditions due to organic fertilizer types and amounts used. Unsaturated FA in ginseng is approximately 2.7 fold higher than the saturated FA. Linoleic, palmitic, and oleic acids were the most abundant FAs found in the ginseng roots. Also, the major Vit-E vitamer found in ginseng root is α -tocopherol. In particular, the application of rice straw compost or food waste fertilizer was increased to create nutritionally-desirable FAs and bioactive Vit-E in ginseng root. In addition, phytonutrient profiling coupled with chemometrics can be used to discriminate the cultivation conditions of ginseng. Conclusion : This preliminary study extends our understanding about the variations of FA and Vit-E in ginseng root depending on cultivation conditions. Hence, these results can be useful as basic information for reliable ginseng production containing high amounts of phytonutrients in a paddy-converted field.
        20.
        2016.05 서비스 종료(열람 제한)
        Background : An important feature of the nutrient solution is that they affect not only the growth but also quality of crops by changing nutrient uptake, especially due to changes of EC in nutrient solution. This study was carried out to investigate effect of EC in nutrient solution on growth and ginsenoside of ginseng. Methods and Results : EC in nutrient solution was controlled with 0.68, 0.84, 1.23, 1.41 dS/m. The root weight of ginseng treated by low EC levels in nutrient solution was higher during the initial of growth. However, the higher EC levels, the more increased the change rate of root weight from the initial to the middle of growth. The highest amount of ginsenoside was changed by growth period. Although the total amount of ginsenoside in root is highest treated by EC 0.68 dS/m at 45 days after treatment. the total amount of ginsenoside in root is highest treated by EC 1.23 dS/m at 135 days after treatment. Conclusions : EC in nutrient solution should to be controlled depending on the stage of growth and the part of use, i.e. root and leaves, when ginseng is cultivated through nutri-culture.
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