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        검색결과 52

        21.
        2015.08 구독 인증기관 무료, 개인회원 유료
        In order to achieve successful in vitro production of embryo, it is necessary to establish intrauterine environment during in vitro culture. Thus, this study was investigated to establish embryo culture system using co-incubated collagen matrix gel (CM) with endometrial epithelial cells (EC). Endometrial epithelial cells were isolated from porcine endometrium at follicular phase, the cells seeded in insert dish for co-incubation with CM-coated culture dish. Then, culture media treated with/without 2.0 IU/ml hCG or 10 ng/ml IL-1β. After incubation for 24 h, the co-incubated insert dishes were removed from CM-coated culture dish before embryo culture. Embryos at 48 h after in vitro fertilization (IVF) were cultured on the dish for 120 h with porcine zygote medium. We determined PTGS-2 expression in the ECs, VEGF protein in co-incubated CM with EC and observed cleavage rate and blastocyst development of embryos at 168 h after IVF. In result, expression of PTGS-2 was higher at co-incubated EC with hCG and IL-1β groups than EC without hCG and IL-1β. The VEGF protein was detected at co-incubated CM with EC, EC treated with hCG and IL-1β groups higher than CM group. Also, cleavage rate was no significantly difference among all group, however, blastocyst development was significantly higher in co-incubated CM with EC treated with hCG group than un-treated groups (p<0.05). Therefore, we suggest that novel embryo culture system using co-incubated collagen matrix gel with endometrial epithelial cells treated with IL-1β is beneficial and useful for enhancing the production of porcine blastocysts in vitro.
        4,000원
        22.
        2015.05 구독 인증기관 무료, 개인회원 유료
        The oocyte undergoes various events during maturation and requires many substances for the maturation process. Various intracellular organelles are also involved in maturation of the oocyte. During the process glucose is essential for nuclear and cytoplasmic maturation, and adenosine triphosphate is needed for reorganization of the organelles and cytoskeleton. If mitochondrial function is lost, several developmental defects in meiotic chromosome segregation and maturation cause fertilization failure. The endoplasmic reticulum, a store for Ca2+, releases Ca2+ into the cytoplasm in response to various cellular signaling molecules. This event stimulates secretion of hormones, growth factors and antioxidants in oocyte during maturation. Also, oocyte nuclear maturation is stimulated by growth factors such as epidermal growth factor. This review summarizes roles of organelles with focus on the Golgi apparatus during maturation in oocyte.
        4,000원
        23.
        2015.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to investigate the efficiency of nicotinic acid on sperm cryosurvival and fertilization ability in frozen-thawed boar semen. Boar semen was collected by glove-hand method and was frozen using freezing solution treated to 0, 5, 10 and 20 mM of nicotinic acid. The frozen sperm for sperm characteristic analysis was thawed such as viability, acrosome reaction, and mitochondrial integrity. The frozen-thawed sperm was estimated by SYBR14/PI double staining for viability, FITC-PNA/PI double staining for acrosome reaction and Rhodamine123/PI double staining for mitochondrial integrity using a flow cytometry. The embryo was estimated in vitro development and DCFDA staining for reactive oxygen species assessment. As results, frozen-thawed sperm viability was significantly higher in 5 and 10 mM (61.1 ± 1.5%, 64.7 ± 2.0%) of nicotinic acid than other groups (0 mM, 52.1 ± 2.3%; 20 mM, 47.8 ± 5.1%, P<0.05). The live sperm with acrosome reaction was significantly higher in 5 and 10 mM of nicotinic acid (26.1 ± 1.8%, 24.9 ± 1.5%) than other groups (0 mM, 35.3 ± 0.8%; 20 mM, 36.5 ± 1.9%, P<0.05). The live sperm with mitochondrial integrity was significantly higher in 5 and 10 mM (84.2 ± 3.6%, 88.4 ± 2.3%) of nicotinic acid than other groups (0 mM, 77.3 ± 4.4%; 20 mM, 73.3 ± 3.6%, P<0.05). Blastocyst rate of in vitro development was significantly higher in 10 mM (17.0 ± 1.3%) of nicotinic acid than other groups (0 mM, 9.4 ± 0.5%; 5mM, 12.6 ± 0.8%; 20 mM, 5.0 ± 1.0%, P<0.05). Moreover, total cell number was higher in 5 and 10 mM (53.6 ± 2.9%, 57.9 ± 2.8%) of nicotinic acid than other groups (0 mM, 41.0 ± 1.4%; 20 mM, 23.2 ± 2.8%, P<0.05). Hydrogen peroxide in embryos was lower in 5 mM nicotinic acid (0.7 ± 0.1%) than other groups (0 mM, 1.0 ± 0.1%; 10mM, 0.9 ± 0.0%; 20 mM, 1.4 ± 1.0%, P<0.05). In conclusion, nicotinic acid-treated semen improves cryosurvival and quality of spermatozoa. Also, the fertilized oocytes with nicotinic acid improve quality of embryo and blastocyst formation.
        4,000원
        24.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Objective of this study was to investigate the effect of nicotinic acid (NA) on the characteristics in fresh semen of miniature pig. We evaluated viability, acrosome reaction and mitochondrial integrity of sperm on 0, 3, 7 and 10 days during storage period with nicotinic acid. As results, the survival rate of sperm in 15 mM NA (day 3, 87.8 ± 1.2%; day 5, 84.0 ± 2.7%; day 7, 82.2 ± 0.9%) and 30 mM NA (day 3, 87.7 ± 0.3%; day 5, 84.4 ± 2.5%; day 7, 82.3 ± 0.7%) groups were higher than control and 5 mM NA groups in 3, 7 and 10 days of semen storage. The NA-treated sperm on 10 day was used day for observing acrosome integrity. The survival sperm with acrosome reaction was higher in 30 mM NA group (day 3, 2.7 ± 0.2%; day 5, 3.3 ± 0.6%; day 7, 11.4 ± 0.3%) than in the control, significantly (P<0.05). Moreover, the live sperm with mitochondrial integrity was higher in whole treatment groups of NA than control group, significantly (P<0.05). Specially, most mitochondrial integrity on 10 day of semen storage was significantly higher in 30 mM NA group (90.2 ± 1.6%) than other treatment groups (control, 81.8 ± 3.1%; 5 mM NA, 83.4 ± 3.0%; 15 mM NA, 89.1 ± 0.7%, P<0.05). In conclusion, supplement of NA in liquid semen of miniature pig can improve and maintain semen quality, such as viability, acrosome reaction, and mitochondria integrity.
        4,000원
        25.
        2014.12 구독 인증기관 무료, 개인회원 유료
        L-Carnitine is an antioxidant for the transport of fatty acids in mitochondria and breakdown of lipids for metabolic energy. Some studies have suggested that carnitine improves sperm motility in mammals. The objective of this study was to investigate the effect of L-carnitine on the characteristics in fresh semen of miniature pigs. The collected fresh semen was stored in modena B medium with L-carnitine (0, 1.0, 2.0, and 4.0 mg/ml) for 10 days at 18℃. The semen quality of viability, acrosome reaction and mitochondria integrity was analyzed on 0, 3, 7, and 10 day of semen storage. The percentages of live and dying sperm were not different among treatment groups with different concentrations of L-carnitine during the storage period. In acrosome reaction analysis, when the sperm stored for 7 day, the percentages of live sperm with acrosome reaction were significantly (p<0.05) lower in 1 (9.0±0.9%), 2 (7.6±0.2%) or 4mg/ml (7.9±0.8%) L-carnitine-treated groups than the control group (0 mg/ml L-carnitine) (11.12±0.2%). However, there were no difference in percentages of live sperm with acrosome reaction for 3 and 10 days of storage with each concentrations of L-carnitine. When sperm was stored for 3 and 10 days, the percentages of live sperm with mitochondria integrity were significantly higher in 2 mg/ml of L-carnitine-treated group than control group (p<0.05). In conclusion, the L-carnitine has a positive effect on acrosome reaction and mitochondria integrity in liquid state of fresh semen in miniature pigs.
        4,000원
        26.
        2014.09 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to investigate the changes of oxidative stress and antioxidant enzyme during in vitro development with washing culture oil in porcine embryos. During the culture, the four types of culture oil such as paraffin oil with or without washing and mineral oil with or without washing were examined. The oil was washed with PZM-3 during 7 days and collected oil only. The embryos were stained with CellTrackerTM Red, DC-FDA and Hoechst 33342 to confirm the effects of the oil. As a results, Cleavage rates and total cell number were no difference among the four oil groups. However, ≥16 cell embryos were significantly different in fore type oil treat-ment and blastocyst rate was significantly higher washing paraffin treatment than in other group(p<0.05). Also, the expression of free radical were lower in washing paraffin oil than in other groups (p<0.05). On the other hand, the expression of glutathione were not significant different among paraffin oil with or without washing and mineral oil with or without washing, however washing paraffin oil and washing mineral groups were higher than other treat-ment groups. In conclusion, the washing oil was expected with positive effects on in vitro development in porcine embryos.
        4,000원
        27.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 대학생을 대상으로 하여 컴포트 푸드(comfort food)의 구성요인과 종류, 그리고 희노애락의 4개 정 서에 따른 컴포트 푸드의 섭취에 성차가 존재하는가를 확인하고자 하였다. 이를 위해 대학생 425명을 연구 참가 자로 선정하여 설문조사를 실시하였다. 그 결과 첫째, 남학생과 여학생 모두에서 따뜻함과 위안을 주는 음식, 즐 거운 추억을 떠올리게 하는 음식, 맛있는 음식을 컴포트 푸드의 개념으로 가장 높게 지각하고 있었으며, 음식 외 적 요소에서 부담 없는 음식, 편리한 음식을 컴포트 푸드의 개념으로 가장 낮게 지각하고 있었다. 그러나 건강을 고려한 음식에서는 여자가 남자보다 컴포트 푸드로 더 적합하게 생각하는 것으로 나타났다. 둘째, 컴포트 푸드의 종류로 남자는 고기류, 찌개 및 백반, 술을 보고하였고, 여자는 찌개 및 백반, 과일 및 야채, 고기류를 보고하였 다. 남자가 음식종류를 선호하고 여자가 스낵 종류를 선호한다는 가설을 지지되지 않았다. 셋째, 제시된 4개의 정서에 따라 섭취하는 컴포트 푸드의 종류를 살펴본 결과, 부정적 정서를 경험하는 상황에서는 남녀 모두 주로 술, 초콜릿, 매운 음식 그리고 음료를 선호하고 있었으며, 긍정적 정서를 경험하는 상황에서는 남녀 모두 치킨이 공통적으로 선호되었으며 여학생들은 다양한 음식들을 컴포트 푸드로 선택한 것에 반해 남학생들은 술을 주요 상위권의 음식으로 선택하고 있었다. 마지막으로 본 연구의 제한점과 후속연구에 대해서 논의하였다.
        4,600원
        28.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This experiment was conducted to investigate effect of brine mineral water (BMW) on growth performance and properties of blood in weaning pigs. Treatments allotted were 0% (general water), 2%, 3% and 5% BMW. In growth trial, a total of 36 weaning pig barrows [(Landrace×Yorkshire)×Duroc] weaned after 21 days with an average initial weight of 5.38±0.89 kg were used. Each treatment had 3 replications of 3 pigs per pen in a randomized complete block design. Weaning pigs were investigated for growth performance, complete blood corpuscle count and blood biochemical assay. In results, growth performance of 2% and 3% treatment groups were significantly higher than other groups (p<0.05). In addition, high density lipoprotein cholesterol was significantly (p<0.05) higher in 2% group than other treatment groups. On the other hand, mean corpuscular volume of supplement of BMW treatment groups were significantly (p<0.05) increased than control. Therefore, this study suggests that supplementation of BMW could improve growth performance and level of red blood cell in weaning pigs.
        4,000원
        29.
        2014.04 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to investigate the relationship between fertility and protein pattern change using in vitro fertilization, analysis of sperm characteristics and two-dimensional gel electrophoresis in different pig types. In results, the viability and mitochondria integrity of sperm were higher significantly (p<0.05) but the portions of ac-rosome reaction was lower significantly (p<0.05) in Duroc and F1 (potbellied×PWG miniature pig) than PWG minia-ture. On in vitro fertilization to investigate fertility, the fertility of F1 semen war higher significantly (p<0.05) than in Duroc and PWG miniature pig. On the other hand, protein patterns showed similar function among the different boar semen. Especially, the heat shock 70 kDa 1-like and G patch domain-containing protein 4 were significantly (p<0.05) higher expressed in F1 than in Duroc and PWG miniature pig. The proteins associated with mitochondria in Duroc were significantly (p<0.05) higher expressed than in F1 and PWG miniature pig. The developmental rates to blastocyst stage of oocytes fertilized with sperm of F1 pig were significantly (p<0.05) higher than in PWG miniature pig. However, phosphoglycerate kinase 2 and zinc finger protein 431 were significantly (p<0.05) higher expressed in PWG miniature pig than in F1 and Duroc pigs. In conclusion, the results of the present study indicate that different proteins were expressed in different pig types, and were associated with a sperm functions and embryo develop-ment.
        4,000원
        30.
        2014.04 구독 인증기관 무료, 개인회원 유료
        Artificial insemination technique has been contributed immensely for production of livestock worldwide as a critical assisted reproductive technique to preserve and propagate excellent genes in domestic animal industry. In the past decade, methods for semen preservation have been improved mostly in liquid preservation method for boar semen and freezing method for bull semen. Among many factors affecting semen quality during preservation, reactive oxy-gen species, produced by aerobic respiration in sperm for survival and motility, are unfavorable to sperm physiology. In mammalian cell as well as in the sperm, antioxidant system plays a role in degradation of reactive oxygen species. Magnetized water forms smaller stabilizing water clusters, resulting in high absorption and permeability of the cell for water, implicating its application for semen preservation. Therefore, this review focuses on preservation methods of boar and bull semen with respect to improvement of extender and reduction of reactive oxygen species by using magnetized water and supplementation of antioxidants.
        4,000원
        31.
        2014.04 구독 인증기관·개인회원 무료
        Dynamics of predator-prey systems are strongly affected by the strategic behavior of both predator and prey. Thus, understanding the relationship between the strategic behavior and the species survival is necessary to comprehend the system resilience and stability. In the present study, we constructed a spatially explicit lattice model to simulate integrative predator (wolf)-prey (two rabbit species)-plant relationships. Wolves have only the hunting strategy, while rabbits have the hunting-escaping strategy. When a rabbit simultaneously encounters its predator (wolves) and prey (plant), either hunting or escaping should take priority. Hunting priority is referred to as hunting preferred strategy (HPS), while escape priority is referred to as escape preferred strategy (EPS). These strategies are associated with some degree of willingness to either hunt (H) or escape (E). One rabbit species takes HPS (HPS-rabbit) and the other rabbit species takes EPS (EPS-rabbit). We investigated the changes in predicted population density for wolves, rabbits, and plant with changes in the value of H and E. Simulation results indicated that EPS-rabbit had a greater chance for survival than HPS-rabbit regardless of the initial density of EPS-rabbit, and the chance was optimized at the appropriate values of E and H. In addition, we briefly discussed the development of our model as a tool for understanding behavioral strategies in specific predatorprey interactions.
        32.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study was to establish a three dimensional (3D) culture system of endometrial cells and to examine the plasminogen activators (PAs) activity in porcine uterine. The 3D culture system in porcine endometrial cells was composed to mixture 3D gel, stromal cells and epithelial cells. The 3D culture system was used to identify normal structure search as uterine tissue and PAs expression in this study. In results, porcine endometrium epithelial cells forming a top monolayer and endometrium stromal cells developed as fibroblast-like within 3D matrix scaffold. Expression of urokinase-type PA (uPA) and tissue-type PA (tPA) were observed during the 3D culture using immunofluorescence. PA activity in 3D-cultured endometrial cells was no significant difference between the tissue type, but 2D culture system were significantly lower than in 3D-cultured endometrial cells (P<0.05). Therefore, basic system and functional aspect of 3D culture could be established with similar system of endometrium tissue. We suggest that this study was assumed applicable as baseline data to investigate mechanism between porcine uterus cells in vitro.
        4,000원
        33.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The endometrium undergoes a cyclic growth and tissue remodeling as changes of epithelial cells, and plasminogen activators (PAs) are related to endometrium tissue remodeling. This study was to evulate expression of urokinase-type plasminogen activator (uPA) and tissue-type plasminogen activator (tPA) in porcine uterine epithelial cells. In results, the uPA and tPA were expressed in uterine tissue, epithelium and secretory glands in porcine endometrial cell. In addition, the uPA and tPA were expressed in cultured epithelial cells, and it were mainly expressed in cytoplasm. In porcine uterine tissue and epithelial cells, uPA activity was higher than activity in tPA. In PAs mRNA expression levels, uPA mRNA level was significantly higher than tPA mRNA level (P<0.05). The fluorescence intensity of uPA protein was also higher than fluorescence intensity of tPA protein, and uPA protein expression was significantly higher than in tPA protein expression (P<0.05). Therefore, we suggest that a physiological function in porcine uterine epithelial cells should be more influenced by uPA than in tPA during pre-ovulatory phase. The endometrium undergoes a cyclic growth and tissue remodeling as changes of epithelial cells, and plasminogen activators (PAs) are related to endometrium tissue remodeling. This study was to evulate expression of urokinase-type plasminogen activator (uPA) and tissue-type plasminogen activator (tPA) in porcine uterine epithelial cells. In results, the uPA and tPA were expressed in uterine tissue, epithelium and secretory glands in porcine endometrial cell. In addition, the uPA and tPA were expressed in cultured epithelial cells, and it were mainly expressed in cytoplasm. In porcine uterine tissue and epithelial cells, uPA activity was higher than activity in tPA. In PAs mRNA expression levels, uPA mRNA level was significantly higher than tPA mRNA level (P<0.05). The fluorescence intensity of uPA protein was also higher than fluorescence intensity of tPA protein, and uPA protein expression was significantly higher than in tPA protein expression (P<0.05). Therefore, we suggest that a physiological function in porcine uterine epithelial cells should be more influenced by uPA than in tPA during pre-ovulatory phase.
        4,000원
        34.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was designed to evaluate the effect of L-cysteine on sperm characteristics and oocyte cleavage in vitro in Korean native cattle. For this study, the freezing of diluted semen were added with Triladyl containing 20% eggyolk and/or 0, 5, 10 and 20 mM L-cysteine before cryopreservation. The viability in frozen-thawed sperm were estimated by SYBR14/PI double stain, acrosome damage with FITC-PNA, mitochondria intact with Rhodamin123 and hydrogen peroxide(H2O2) level with carboxy-DCFDA by flow-cytometry. The developmental capacity was also assessed with cleavage rates in oocytes fertilized in vitro by frozen-thawed sperm. In results, the sperm viability was significantly increased in 10 mM and 20 mM concentrations of L-cysteine than other groups (p<0.05). In addition, acrosome damage was significantly decreased in 10 mM and 20 mM concentrations of L-cysteine than other groups (p<0.05). The mitochondria intact was also significantly increased in 10 mM and 20 mM concentrations of L-cysteine than other groups (p<0.05). On the other hand, the cleavage rates were significantly increased in 0 mM, 5 mM and 10 mM groups than 20 mM concentration of L-cysteine (p<0.05). The oocyte degeneration of oocytes were significantly decreased in 0 mM, 5 mM and 10 mM groups than in 20 mM L-cysteine group (P<0.05). However, there are no significantly differences among the L-cysteine treatment groups. We suggest that concentration of 10 mM L-cysteine have beneficial impact for sperm cryopreserved in Korean native cattle. This result also could be recommended for artificial insemination program if supported by an improvement in the fertility results and required further study.
        4,000원
        35.
        2013.09 구독 인증기관 무료, 개인회원 유료
        The aim of this study was to evaluate the changes of protein patterns in granulosa cells and corpus luteum in ovaries during the estrus cycle in cows. The estrus cycle was devided into five steps of follicular, ovulatory, early-luteal, mid-luteal and late-luteal phases. In results, 61 spots of total 85 spots were repeated on follicular phase and 51 spots of total 114 spots were repeated on ovulatory phase. The 40 spots of total 129 spots were repeated on early-luteal phase and 49 spots of total 104 spots were repeated on mid-luteal phase. Also 41 spots of total 60 spots were repeated on late-luteal phase. On the other hands, the 16 spots were indicated difference in follicular phase and ovulation phase had a difference 10 spots. It was showed difference No. 103 spot in ovulation phase, No. 135 spot in early-luteal phase and No. 175 and 176 spots in mid-luteal phase. Also, the 11 spots were expressed specifically in mid-luteal phase and No. 178 and 179 spots were difference of expression in late-luteal phase. We confirmed that there were 7 spots for ovulation, 4 spots for luteinization and 2 spots for luteolysis. Spot No. 89~93 in ovulation phase were transferrin, and spot No.94~98 were HSP60. Spot No. 103 was Dusty PK, spot No. 135 was OGDC- E2, and spot No. 175 and 176 were Rab GDI beta from luteinization. Spot No. 178 and 179 in luteolysis were vimentin. This results suggest that will be help to basic data about infertility.
        4,000원
        36.
        2013.09 구독 인증기관 무료, 개인회원 유료
        An uterus is female reproductive tract organ that affected estrus cycle. During a various changes occur at uterus in estrus cycle, one of them is body fluids secretion be called uterine fluid. Therefore, the objective of this study was to investigate the changes of protein patterns using two-dimensional gel electrophoresis in uterus fluids during the follicular and luteal phases in estrus cycle of pigs. In changes of protein spots were confirmed during the follicular and luteal phases. The 136 spots were expressed in follicular phase, the 57 spots of them showed reproducibility. On the other hand, the 140 spots were expressed in luteal phase, the 73 spots of them showed reproducibility. Also, spots expressed in follicular phase were number 69 and 94 spots and spots expressed in luteal phase only were number 156, 157, 184~187, 190 and 191 spots. The spots which of higher expression levels in the luteal phase than in follicular phase were number 76 and 79 spots. In conclusion, the spots expressed in follicular and luteal phases were confirmed with difference levels and these differences are function of RNA resolving, protein synthesis and cytoskeletal architecture.
        4,000원
        37.
        2013.09 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to develop of semen transport system for cryopreservation and fertility in bull sperm. The ejaculated semen were diluted with Triladyl containing 20% egg-yolk for transportation. Diluted semen was transported by three methods that there were wrapping tissue (Tissue), sinking under 30℃ water (Water) and sinking between warm water and air (Air) methods. Semen was transported within 2 hours in 0.3℃. For this study, the freezing of diluted semen were added with Triladyl containing 20% egg-yolk. And frozen-thawed sperm were estimated with SYBR14/PI double stain for viability, FITC-PNA/PI double stain for acrosome reaction analysis and Rhodamine123 double stain for mitochondrial intact assessment. In results, live sperm (SYBR+/PI-) in Air treatment group (43.3±4.7%) was significantly (p<0.05) higher than other treatment groups (Tissue: 16.3±2.7% and Water: 27.5± 3.1%), dying sperm (SYBR+/PI+) in Air treatment group (55.6±4.7%) was significantly lower than other treatment groups (Tissue: 77.6±3.2% and Water: 67.6±3.3%) (p<0.05). Acrosome reaction in Air treatment group (0.2±0.1%) within live sperm (PI negative region) was significantly (p<0.05) lower than other treatment groups (Tissue: 0.7±0.2% and Water: 0.5±0.1%), the acrosome reaction in Air treatment group (28.6±2.8%) within all sperm also was significantly lower than other treatment groups (Tissue: 44.2±1.8% and Water: 36.2±2.0%) (p<0.05). And mitochondrial intact in Air treatment group within live (97.1±0.4%) and all (61.9±3.3%) sperm were significantly higher than other treatment groups (Tissue: 85.2±3.3%, Water: 87.8±2.9% within live sperm and Tissue: 49.28±3.7%, Water: 42.0±3.1% within all sperm) (p<0.05). Therefore, we suggest that transportation by sinking method between warm water and air was beneficial to improvement of fertility in frozen-thawed in bull semen.
        4,000원
        38.
        2013.04 구독 인증기관·개인회원 무료
        Subterranean termites build extensive underground galleries consisting of elaborate tunnels and channels to forage food resources. Diverse soil conditions surrounding the tunnels, such as soil density, may cause irregularities in the size and shape of the tunnels, and termites are likely to encounter a number of tunnel irregularities while traveling. Considering the tunnel length, how termites respond to an irregularity is likely to affect their movement efficiency, and this in turn is directly correlated to their foraging efficiency. To understand the response of termites, we designed an artificial linear tunnel with rectangular irregularities in a 2-D arena. The tunnel widths, W, were 3 and 4 mm. The rectangular irregularities were 2 mm in width and of varying heights H (2, 1, 0, -1, and -2 mm). The positive and negative sign of H represents a convex and concave structure, respectively. We systematically observed the movement of termites, Coptotermes formosanus Shiraki, at the irregularity and quantified the time needed, τ, for a termite to pass the irregularity. The time τ was shorter for (W, H) = (3, 0) and (3, -1) than for (W, H) = (3, 1), (3, 2), and (3, -2). The time τ was longer for (W, H) = (4, -1), and (4, -2), than for (W, H) = (4, 0), (4, 1) and (4, 2). Four types of behaviors explained the response to the irregularity. The implications of these findings are briefly discussed in relation to termite foraging efficiency.
        39.
        2013.04 구독 인증기관·개인회원 무료
        In the real world, most of biological systems that follow Markov process have internal states which are unobservable, so called hidden states. However, although the states could not be directly observed, events emitted under any hidden states would often be observable. It infers that a lot of biological systems might be simulated by hidden Markov model (HMM). To date, many studies tried to apply the HMM for monitoring and describing of animal behaviors. In this study, we attempted to build a HMM that emulates the traveling behavior of subterranean termites in the artificial tunnels with varying width and curvature, based on the empirical data obtained from our previous study that explored the relationship between subterranean termite's movement efficiency and the geometric pattern of their tunnels.
        40.
        2013.04 구독 인증기관·개인회원 무료
        Understanding the predator-prey dynamics is essential to comprehend the ecosystem resilience and stability because ecosystems consist of dynamically interacting subsystems with predator-prey relationship. The relationship is likely to be of the predator and prey hunting-escaping strategy. Thus, to better understand the ecosystems, we should comprehend how the hunting and the escaping strategy affect the ecosystems. To do so, we constructed a spatially explicit lattice model to simulate the integrative predator-prey-plant relationships. When an individual simultaneously encounters its predator and/or prey, the individual should take priority between the two strategies. When the hunting (or escaping) strategy takes priority, we call it hunting preferred strategy, HPS, (or escaping preferred strategy, EPS). Each strategy was characterized by the willingness for each strategy. The degree of willingness was represented as H (for hunting) and E (for escaping). Higher value of H (or E) means stronger willingness for hunting (or escaping). We investigated the population density of each species for different values of H and E for HPS and EPS. The main conclusion that emerges from this study was that HPS plays a positive role in the ecosystem stability. In addition, we briefly discussed the development of the present model to be used to understand the predator-prey interaction in specific species.
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