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        검색결과 488

        61.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate the optimal artificial insemination (AI) time with diagnostic kit at ovulation time. We already applied the patent about the protein in the cow heat mucose in external reproductive tract. And we would examine the accuracy for detection of cow heat by the kit produced with the protein. Evaluation of optimal heat detection was tried two time at 12 hrs and 24 hrs after the heat. And then, AI service also performed two times with no relation to the results of heat diagnosis by heat detection kit and pregnancy rates were checked with rectal palpation on 60th day after AI. Heat diagnostic results by kit in natural heat after 12 hrs in Hanwoo cows were showed 31.3~75.0% on positive in first heat detection and 33.3~100.0% on positve in second heat detection. In the 1st positive results were significant different (p<0.05), but 2nd positive were not. The results of heat detection showed different result on regional influence and individual cow effects. The pregnancy rates of first trial of heat detection were showed 34.4~78.7% on positive and 21.3~68.8% on negative after the diagnosis by heat detection kit. And the pregnancy rates of next trial of heat detection were showed 33.3~85.7% on positive and 14.3~66.6% on negative after the heat diagnosis. Both positive results of first trial and next trial also were showed significant different (p<0.05), but negative results were not. In positive result, first trial of total pregnancy rates was higher than the next trial of pregnancy, but there showed opposite results on negative results. In conclusion, the optimal heat detection kit is suitable to ordinary Hanwoo cows and it suggested that we have to improve the kit’s accuracy by detecting the materials like proteins related optimal AI time.
        4,000원
        62.
        2017.06 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        With emphasis on native genetic resource, Korean native chicken is one of the major native breeds in poultry in Korea. The weight-age data from 216 pullets of Korean native chicken were used to fit the growth curve using Gompertz model. Live weights have been recorded every three weeks for 36 weeks for 5 strains. All available weight data from birth to the 6 specific ages of week were used for the estimation of parameters. The variation in estimates of mature weight (A) decreased with the increase of age 21 through 36 weeks for all 5 strains studied. However, the variation of rate of maturing (k) showed a tendancy increase with the increase of age. These results indicate that the fitting of growth curve is getting more stable for asymptotic value (A) and more flexible for curve shape (k) with the increase of weight-age data range. Correlations among estimates of A and among estimates of k at various ages showed the highest range of 0.93 ~ 0.99 between 30 and 36 weeks except for the maturing rate (k) of red brown strains. The correlations between A and k tended to fluctuate and were not significant statistically at various ages. Thus, the estimates of growth curve parameters, A and k suitable for genetic studies in Korean native chicken can be derived from accumulated weight-age data after 30 weeks of age.
        4,000원
        63.
        2017.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        As emphasis has increased on English as an international language and on the globalized image of universities, the number of native English speaker teachers (NETs) has also increased in Korean universities. From the poststructuralist view, teacher identity is constructed through participation in valued activities of the community of practice, and it is not fixed but constantly negotiated through the interaction of the context (Wenger, 1998). While previous studies focused on nonnative English speaker teachers’ identity construction, little attention has been paid to NETs in the EFL context. Considering the need to explore teacher identity from recent theoretical perspectives, the present study investigates how NETs negotiate conflicting identities and construct their teacher identities in the Korean university context. The findings show the NETs constructed multiple identities of an English educator, a collaborative volunteer, a non-tenured instructor, and a cultural and linguistic outsider, and they legitimize their professor identity through their participation in the present and imagined community of competent teachers. The findings support the claim that teacher identity is embedded in the sociocultural context that interacts with the individual agency in making sense of who they are. Implications and suggestions of the study are addressed based on the findings.
        6,400원
        64.
        2017.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        한국 어린이들이 중국어를 배우면서 접하는 한자의 학습에 대해 아직까지 국내에서는 경험에 근 거한 교수법과 방법론 위주로 논의가 이루어지며, 무엇을, 언제, 어떻게 도입해야 하는가에 대한 논 의는 충분히 이루어지지 않고 있다. 즉 학습자의 연령 요소와 그에 따른 인지 발달과 관련된 고려가 부족한 편이다. 본고는 이에 중국 어린이의 한자 읽기에 대한 실증적 연구들을 검토함으로써 한국 어린이의 한자 교육에 어떤 시사점이 있는지 살펴보고자 하였다. 선행연구에 따르면, 알파벳 등 표 음문자를 사용하는 어린이가 발달적 읽기 장애가 있는 경우, 이들의 기억력 장애는 시각적-공간적 자극 처리 능력보다는 음운 인식 능력과 관계된 것으로 알려져 있다. 또한 중국 어린이를 대상으로 한 많은 연구들이 중국어 읽기 능력의 습득에서 작업 기억의 중요성을 조사하여, 중국어 한자 읽기 에서 음운 인식과 시각적 자극에 대한 처리의 기능을 다각도로 관찰, 조사하고 있다. 그러나 아직까 지는 어느 한쪽을 지지하는 유력하고 일관된 결과를 보이지 않는다. 다만 중국 어린이 학습자가 언 어적 환경과 인지 발달 단계에 따라 한자 읽기 습득에 있어 음운과 시각적 정보, 두 유형의 인지적 처리 기술이 서로 다른 처리 기제를 가질 수 있으며 두 가지 모두 한자 변별과 밀접한 관련이 있음 을 시사한다. 따라서 한국 어린이를 대상으로 하는 외국어로서의 중국어 교육 및 학습에서도 한자 읽기의 교수와 학습은 학습자의 인지 발달 단계를 고려하여 적절한 교수요목과 교수방식을 선택해 야 하며, 이에 대한 실증적인 연구가 필요하다.
        6,300원
        65.
        2017.05 구독 인증기관·개인회원 무료
        Alterations affecting the status of robustness and health can bring about physiological changes including hematological parameters in pigs. To identify quantitative trait loci (QTL) associated with 8 hematological phenotypes (one leukocyte trait, six erythrocyte traits, and one platelet trait), we performed a genome-wide association study using the Porcine SNP 60K BeadChip in an intercross population between Landrace and Korean native pigs. A total of 36,740 SNPs from 816 F2 offspring were analysed for each blood related traits after filtering by quality control. Data were analysed genome-wide rapid association using the mixed model and regression (GRAMMAR) approach. A total of 257 significant SNPs (P<1.36x10-6) on SSC3, 6, 8, 13, and 17 were detected for blood related traits in this study. Interestingly, the genomic region between 17.9 and 130 Mb on SSC8 was found to be significantly associated with RBC, MCV, and MCH. Our results include 5 significant SNPs within five candidate genes (KIT, IL15, TXK, ARAP2, and ERG) for hematopoiesis. Further validation of these identified SNPs could give valuable information for understanding the variation of hematological traits in swine.
        66.
        2017.05 구독 인증기관·개인회원 무료
        Previously, we reported a quantitative trait locus (QTL) that affect total teat number (TTN) on pig chromosome 7 (SSC7) in a large F2 intercross population between Landrace and Korean native pigs. The aim of this study was to refine the QTL associated with TTN and to identify positional candidate gene(s) within the refined genomic region. TTN was recorded in 1,105 F2 progeny. All experimental animals were genotyped using 998 informative single nucleotide polymorphism (SNP) markers located on SSC7. A haplotype-based linkage and association analysis using the PHASEBOOK programme was applied to perform high-resolution QTL analysis. Additionally, linear mixed-effect models were used to assess the effect of a positional candidate gene on TTN and other economically important traits [i.e., thoracic vertebrae number (THO), carcass body length (CBL) and weight (CW), back fat thickness (BFT) and intramuscular fat content (IMF) in loin muscles]. Joint linkage and association analysis refined the critical region to a 1.07 Mb region that included a novel positional candidate gene, BRMS1L, that encodes the breast cancer metastasis-suppressor 1-like protein, which could possibly be implicated in normal mammary gland development. Significant association of an SNP marker (g.-1087 G>A) in the 5’-flanking region of BRMS1L with TTN (P=1.10x10-8), THO (P=5.80x10-4), and CBL (P=0.038) was observed. Based on these data, we propose BRMS1L as a positional candidate gene for TTN in pigs. After validation of the association in other independent populations and further functional studies, these results could be useful in optimizing breeding programmes that improve TTN and other economically important traits in swine
        68.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Bovine leukemia virus (BLV) is the causative agent of enzootic bovine leukosis. This study was conducted to clarify the seroprevalence of BLV in the Republic of Korea. Blood samples were obtained from Korean native cattle farms in all provinces of South Korea except Jeju. A commercial indirect enzyme-linked immunosorbent assay with 4,498 samples to detect antibodies against BLV was conducted. The results revealed that the prevalence of BLV was dependent upon age, with increasing prevalence among cattle occurring until they were 5 years old. The highest seroprevalence in cattle was observed in Chungnam (29.6%) and the lowest was observed in Jeonnam (2.6%). The mean overall prevalence for BLV antibodies in the survey was 10.2%, indicating that BLV is widespread nationwide.
        3,000원
        69.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The seroprevalence of major infectious abortion agents was investigated in native Korean goats from Jeonnam province using ELISA. A total of 98 blood samples were collected from goats. Overall, 48 (49.0%), 11 (11.2%), and 1 (1.0%) serum samples tested positive for C. burnetii, T. gondii, and C. abortus, respectively, while none of the samples were positive for B. abortus or N. caninum. Moreover, a PCR assay conducted to detect C. burnetii antigens in goats with a history of abortion revealed 18 (38.3%) of 47 goats were C. burnetii positive by both the ELISA and PCR assay.
        4,000원
        70.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Okamura, Kana. 2017. “Korean Native Speakers’ Perception of and Responses to Interrogative Greetings”. The Sociolinguistic Journal of Korea 25(1). 143~165. This research examines (1) if native speakers of Korean perceive phrases such as “어디 가 (Where are you going)?” and “밥 먹었어 (Have you eaten)?” as questions or as greetings, and (2) how speakers respond to these phrases. Various expressions are used as greetings in Korean, but interrogative greetings in particular are considered to be widely favored because they express personal interest in the interlocutor. Previous studies claim that because the phrases function more as greetings than questions, it is enough to respond with a general answer rather than an honest or detailed answer. To verify this claim, a questionnaire was distributed to 144 native Korean speakers in their 20s. The degree of intimacy between the speakers and the circumstances of the interaction were used to investigate the perception of and responses to interrogative greetings. The statistical analysis of the questionnaire results found that while the phrases do function as greetings, they still retain their interrogative function, and as such, many native speakers give honest answers such as “응, 먹었어 (Yes, I ate).” Additionally, interlocutor intimacy and situation did indeed influence how the phrases are perceived and answered.
        6,000원
        71.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cryopreservation of germ cells from genetically proven animals could be a source of restoration tools from the risk of extinction or disappearance of wanted characteristics. Using frozen semen, the genetic gains of Korean native cattle have been increased greatly for 70 years. The preservation of genetic resources as a form of frozen semen straw has limited availability due to the numbers. To circumvent this weakness of frozen semen, we tested two re-freezing methods with different initial thawing temperatures using frozen Korean proven semen and rare breed semen from albino, black and chikso breeders. It has been known that human sperm could resist to cryo-damages by repeated freeze-thaw cycles, but not for Korean proven bulls number (KPN) or for rare breeds. Total 7 frozen semem from brindled(2), black(1), Korean Albino(2) and KPN(1) bulls were used for our research. After thawing straws under 5°C/2min or 37°C/40sec with low temperature water bath and thermo jug, spermatozoa were re-diluted with triladyl diluents after first thawing and re-frozen. Sperm motilities were compared between animals and treated groups after re-thawing. Mean values of motility and viability of refrozen/thawed sperm for expansion of the number of straws were significantly higher in 5°C than in 37°C (P< < 0.05). However, the activity of viable sperm thawed at 5°C was significantly decreased after first and second thawing. It is estimated that re-freezing of frozen semen from rare Korean native cattle is possible with resistant properties of survived spermatozoa.
        4,000원
        72.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study was to identify quantitative trait loci (QTLs) influencing teat number traits in an F2 intercross between Landrace and Korean native pigs (KNP). Three teat number traits (left, right, and total) were measured in 1105 F2 progeny. All experimental animals were genotyped with 173 informative microsatellite markers located throughout the pig genome. We detect that seven chromosomes harbored QTLs for teat number traits: genome regions on SSC1, 3, 7, 8, 10, 11, and 13. Six of fourteen identified QTL reached genome-wide significance. In SSC7, we identified a major QTL affecting total teat number that accounted for 5.6% of the phenotypic variance, which was the highest test statistic (F-ratio = 61.1 under the additive model, nominal P = 1.3×10-14) observed in this study. In this region, QTL for left and right teat number were also detected with genome-wide significance. With exception of the QTL in SSC10, the allele from KNP in all 6 identified QTLs was associated with decreased phenotypic values. In conclusion, our study identified both previously reported and novel QTL affecting teat number traits. These results can play an important role in determining the genetic structure underlying the variation of teat number in pigs.
        4,000원
        73.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to estimate growth curve parameters by sex in Korean native Goat. Weight-age data from 148 male goats and 169 female goats raised at Animal Genetic Resources Research Center in Korea were used in this study. Growth curve parameters were estimated from nonlinear regression using Gompertz and Logistic models. Mature weight ( ) and growth rate () of male goats were 50.0 kg, and 0.0038, respectively, when Gompertz model was used. They were 47.9 kg and 0.0062, respectively, when Logistic model was used. In female goats, mature weight ( ) and growth rate () were 35.8 kg and 0.0030, respectively, when Gompertz model was used. They were 34.6 kg and 0.0046 when Logistic model was used. The goodness of fit determined by R2 was higher in the Gompertz model than that in the Logistic model. The growth curve functions estimated from the Gompertz model in Korean-native male and female goats were , respectively. The inflection point () showed that the maximum growth rate and the weight at inflection (  ) estimated from the Gompertz model were 234.8 days and 18.37 kg, respectively, in male goats. They were 235.7 days and 13.16 kg, respectively, in female goats. The growth pattern of Korean-native goats obtained from this study might be useful for determining their feeding and management plans by sex and design breeding strategies.
        4,000원
        74.
        2016.12 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Neuron-specific enolase (NSE), a brain specific isoenzyme of the glycolytic enzyme, is characterized by its consistent occurrence in the cytoplasm of mature neurons. The purpose of the present study was to investigate the expression of NSE in the developing tongue of Korean native goats. The tongues of the fetuses were removed from 2- to 4-year-old female Korean native goats by caesarean section performed under general anesthesia. The expression of NSE in the developing tongue of goat fetuses (60, 90, 120, and 150 days) was studied using immunohistochemistry. In 60-day-old fetuses, NSE-immunoreactivity (IR) exhibited weak appearance in lamina propria of the basal portion and the apical epithelia of the tongue. In 90-day-old fetuses, NSE-nerve fibers were extended in the core part of connective tissue, and primordia of the taste buds was moderately positive. In 120-day-old fetuses, NSE-IR was strongly expressed in taste buds and gustatory nerve fibers. In neonates, the taste buds of vallate papillae were strongly positive for NSE, and development of nerve fibers was synapsed with connective tissue of well innervated taste buds. These results indicate that NSE expressions were associated with the sign of nerve innervation in prenatal development of goat tongues and NSE may be a useful neuronal marker to understand the development of gustatory nerve innervations.
        4,000원
        75.
        2016.10 구독 인증기관·개인회원 무료
        Sperm recovery from epididymis in animals considered as important tools to preserve high-value or endangered species. However, there are no appropriate castrating indicators of timing for recovery of sperm which can be available to artificial reproduction technologies such as artificial insemination (AI) and in vitro fertilization (IVF), particularly in young Hanwoo bull. Therefore, this study aimed to investigate semen volume, morphology and motility of sperm in epididymis of young Hanwoo bulls at 8, 13, 14, and 15 months of age. About 2 cm of the epididymal tail only was cut and minced using blades. Minced epididymal tail tissues were mixed with semen extender (OptixCell, France, IMV technologies) and sperm were recovered with a cell strainer (100 μm nylon mesh). The number of sperm at 8 months of age was lower than that at 13, 14, 15 months of age in bulls after collection (33.6±27.2 vs. 352.4±39.2, 320.4±113.6 and 422.8±252.4×107cells respectively; P<0.05). After the frozen-thawed sperm the the percentage of abnormal head, tail and dead damaged acrosome did not differ between the ages 13, 14 and 15 months of age in bulls (P>0.05), however, the dead sperm with intact acrosome (DIA), the numbers showed that more than 15 months in 8, 13, 14 months (8.7±4.1 vs. 47.3±12.2, 34.8±14.0, 28.8±8.5, P<0.05). In addition, frozen-thawed sperm at 8 months of age showed low total motile sperm compared to those at 13, 14 and 15 months of age (26.4±8.2 vs. 45.7±29.5, 62.3±41.0, 70.4±15.9%, respectively; P<0.05). In conclusion, sperm derived from epididymal tail at 8 months of age in Hanwoo bulls showed high abnormal morphology and poor motility, which is not adequate for artificial insemination(AI) and in vitro fertilization(IVF). On the other hand, sperm derived from epididymal tail at 13, 14, 15 months of age in bull showed high normal morphology and motility, which may be available for AI and IVF. Epididymal sperm collected from bulls over 13 months is needed for further study whether to use the actual in vitro fertilization.
        76.
        2016.10 구독 인증기관·개인회원 무료
        The tyrosinase (TYR) genes have been accepted as major genes involved in the plumage pigmentation of chickens. Tyrosinase (TYR) gene is located on chromosome 1 in chicken and it is composed of five exons and four introns. TYR gene is described as a key enzyme in melanin biosynthesis. Especially, most examples of color patterns in chicken have been due to differential in the tyrosinase gene. This study was conducted to the association of feather color and sequence polymorphism in the Tyrosinase(TYR) gene was investigated using Korean native chickens(red plumage, red-line plumage, Ogol = KNC) and white leghorn(WL). From WL and KNC breed analyses, 232 differential SNPs were detected in 4th exon and 4th intron of TYR gene respectively. The genotype frequencies for 50 SNPs were compared between KCR, KCRD and KCO represented homozygous SNP types in all the analyzed SNP positions while KNC displayed various SNP types. In this study, we conclude that the variation of a wild type sequence in intron 4 of the tyrosinase gene is pigmentation of the original native chickens in korean. This work was supported by a grant from the “Livestock Preservation of Genetic Resources", Rural Development Administration, Republic of Korea.
        77.
        2016.10 구독 인증기관·개인회원 무료
        Recently, the consumption of chickens meat has been gradually increased in Korea. However, most of the chickens breeds in Korea were imported from overseas. This study was conducted to evaluate the genetic distances and single nucleotide polymorphism by the mtDNA D-loop control analysis method for the Korean native chickens(red plumage, red-line plumage, Ogol) and white leghorn. For the initial investigation of the relationships between Korean native chickens(red plumage(KCR), red-line plumage(KCRD), Ogol(KCO)) with white leghorn breeds, the sequences from D-loop control region in mitochondrial DNA (mtDNA) was used. The results from phylogenetic analysis indicated that both KNC and white leghorn breeds were classified well with wild duck breeds. However, KCR was not discriminated well with KCRD. The haplotype analysis indicated that KCR and KCO have ten different haplotypes with nineteen SNPs. Three haplotypes (haplotype 1, 2, 3, 5, 17) were shared both in KNC(KCR, KCRD) and KCO. On the other hand, haplotype 4, 6, 7 was appeared only KCR and haplotype 13, 16, 18 were identified only in KCRD population. In addition, haplotype 8, 9, 11, 12, 14, 15, 19 was appeared only KCO. With further verifications, the results presented here can be used for the on servation and commercialization of the Korean native chickens. This work was supported by a grant from the “Livestock Preservation of Genetic Resources", Rural Development Administration, Republic of Korea.
        78.
        2016.10 구독 인증기관·개인회원 무료
        This study was conducted to evaluate the genetic distances and specific DNA makers by the randomly amplified polymorphic DNA (RAPD)-PCR method for the Korean native chickens(red plumage, red-line plumage, Ogol) and white leghorn. Genomic DNA was extracted from plumage from chickens after they were slaughtered. The extracted DNA was observed by nano-spectrometer. RAPD analysis was performed using 13 different primers. Statistical analysis was made for the estimation of the genetic distance among the chicken’s and the cluster tree was drawn by using MEGA 5.05 software. Genetic relations among them were determined by RAPD analysis. The polymorphic bands were observed 72% and the rest of 28% was monomorpic. The largest genetic distance (2.266) was found between the native chickens(red, red-line) and the ogol chickens by UPGMAP method and the closest distance was observed between the ogol in korean chickens as expected. The highest genetic distance between them was estimated 2.266 and in the dendrogram analysis, among I and II within cluster II, most of the ogol chickens were in IIB, indicating the expression of the ogol color could be due to original and the ancestral genetic crossing. Thus, this genetic distance can be useful as the differential genomic information in the normal(red plumage, red-line plumage) and ogol of korean native chickens. This work was supported by a grant from the “Livestock Preservation of Genetic Resources", Rural Development Administration, Republic of Korea.
        79.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Korean native cattle, Hanwoo, is the most popular breed of beef cattle in Korea. However, the reproductive performance data are limited although reproduction is one of the most economically and biologically important in beef production. Therefore, this study was undertaken to investigate reproductive performance parameters including calving interval, parity for life time production. Data collected from 206,827 calvings were analyzed. There were no significant differences in calving interval and gestation days as parity increased from 2nd and 13rd parity cow, from spring to winter. However, we found a dramatic increase in calving interval after year 2000. About 1 month were increased per year ( y = 30.578x + 344.45 R² = 0.9157). Interestingly, we observed that parities for life time can be affected by birth weight. Calves with 23 kg at birth showed highest parities, 3.4±2.0 times. In summary, this study provides valuable data on reproductive performance of Hanwoo and the data presented here can be used as a standard target for optimising and enhancing reproductive performance.
        4,000원
        80.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Wholesale beef price is the critical factor for determining Korean native cattle, Hanwoo, farm’s income in short-term. Wholesale beef price has seasonality due to high demand in Korean traditional holidays such as Korean thanksgiving day and lunar new year’s day. Therefore, it is important to make reproduction and marketing plans for Korean Hanwoo farmers, in order to increase their farm income. However, there is no study available on changes in the expected farm income depending on reproduction and marketing schedules. This study analyzed the expected farm income per head depending on the monthly-based marketing schedules. The analysis was conducted based on the seasonality of wholesale beef price, reproduction efficiency, operating costs, relationship between carcass grade and slaughter age. The result shows that slaughter Hanwoo at the age of 29 months-old in August and January generating the highest expected farm income per head.
        4,000원
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