• 원예과학기술지
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• 제29권4호
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• pp.293-297
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• 2011

This experiment was conducted to elucidate the effects of mulching materials and removing time of the transparent polyethylene (PE) film on the growth of garlic at Uiseong experimental field, Korea. The experimental mulching materials comprised of transparent polyethylene film (0.025 mm) and net polyethylene (NPE). Plant height and leaf number of garlic were highest at PE treatment when the PE removing date was March 18 and this treatment also promoted the no. of cloves. Length of leaf sheath and bolting rate were highest and bulb weight loss rate was lowest at PE + NPE treatment when the PE removing date was March 18. But clove number was the lowest in this treatment compared to conventional PE film treatment. Conventional mulching method accelerated secondary growth rate but bulb weight loss was vice versa. There were statistically no differences in bulb diameter among treatments but conventional treatment positively focused on bulb diameter. Whenever PE film remove can suppress weeds compared to no mulching treatment but the dry weight of weeds were increasing trends as the removal dates of PE film were delayed. Transparent PE or PE + NPE treatments can be recommended to grow best quality garlic when PE film removing date is March 18.

• 대한수의학회지
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• 제15권2호
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• pp.215-222
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• 1975

Infertility and breeding status of Korean cows which are reared in a extensive alpine ranches of Daegwanryeong area was investigated. The results obtained were summarized as follows, 1. Infertility frequency of the cows was 25.9% against a total examined number of 675 heads, and was 17.6% against a total rearing number. 2. The distributions of infertile cows 44.6% of Granular vaginitis-like syndrome, 36% of repeat breeder, 8.6% of symptom of ovary, 6.8% of symptom of uterus and 4% of other symptoms. 3. According to its age were found by 51.4% upon 2 years of age, 30.3% upon 3 years of age, 11.4% upon 4 years of age and 6.9% upon S years of age. 4. Breeding status of Korean cows showed 74.1% of conception rate in the cases of pre-treatment, while breeding status increased markedely in the cases of post-treatment by the 85.8%. 5. The conception rate by the artificial insemination mainly on the first mating was 36.1%. on the second mating 23.0% and on the third mating 18.0%. Total conception rate between first and third mating was 77.1%. 6. The therapeutic effect by treatment for granular vaginitis-like syndrome was 87.1%.

• International Journal of Industrial Entomology and Biomaterials
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• 제3권2호
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• pp.187-190
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• 2001

Inheritance pattern of resistance to Bombyx mori nuclear polyhedrosis virus (BmNPV) was studied in an Indian silkworm stock TX by single back-cross test method. The resistant parent ［TX］, susceptible parent ［HM］, their Fl, F2, and Fl progeny back-crossed to TX [BC(R)] and HM [BC(S)] were inoculated per os with a fixed concentration of BmNPV($0.5{\times}10^{th} PIB/ml$) on the first day of second stadium. The cumulative mortality was recorded until day $10^{\times}$ post-inoculation. The results show that the resistance to BmNPV in TX fellow mono Mendelian inheritance pattern. The resistance dominated over the susceptibility at Fl. At F2, the resistant and susceptible offspring segregated in 3:1 ratio whereas at BC(S), the resistant and susceptible offspring segregated in 1:1 ratio. The response of BC(R) was more or less like the resistant parent TX which confirms the involvement of a major dominant gene conferring resistance to BmNPV in TX. The possible mechanism of inheritance of resistance in TX is discussed.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제2권4호
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• pp.247-258
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• 2021

To understand restoration and conservation projects conducted in Korea for endangered freshwater fishes and amphibians/reptiles, information about Request for Protocols-related studies on restoration, breeding, and release were collected. Trends of studies were visualized via word clouds and VOSviewer program using a text mining technique. Analysis of restoration projects for endangered freshwater fishes elucidated that most research studies conducted to date were focused on genetics and release through captive breeding that could be classified into captive breeding and habitat environments. As for research projects related to amphibians/reptiles, monitoring projects had the highest number, followed by genetic, translocation, and monitoring studies. In addition, restoration projects for amphibians/reptiles included a large number of post-capture translocation projects. Thus, many projects were confirmed by public institutions rather than by the Ministry of Environment. Network analysis revealed that it was largely classified into capture, translocation, and Kaloula borealis. Based on these results, limitations, achievements, and challenges associated with projects conducted thus far are highlighted. Research directions for future restoration and conservation of endangered freshwater fishes and amphibians/reptiles in South Korea are also suggested.

• 한국수산과학회지
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• 제56권4호
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• pp.380-387
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• 2023

Stocking density is associated with Paralichthys olivaceus growth; thus, fish should be rapidly reared at high densities for commercial reasons. Studies have reported that high stocking density retards growth; however, few have investigated the malformations caused by stocking density stress. This study compared the growth and malformation rates of P. olivaceus at different densities and stress- and immune-related gene expression between malformed and normal fish. Forty days post-hatching, fish (total length, 1.49±0.02 cm) were reared at 800 (low density; LD), 1500 (medium density; MD), and 4000 (high density; HD) fish/m², and the growth rate was measured weekly. On day 30, RNA was extracted from the kidneys, and the expression of stress-, immune-, and malformation-related genes was analyzed using qRT-PCR. The malformation rate in the HD groups was approximately three times higher (62%) than that in the LD and MD groups (approximately 20%), and growth was lower regarding length and weight. The stress-related (HSP70 and GPX) and immune-related (PIR and IgM) genes showed higher mRNA expression in the HD group and malformed fish than in the LD group and normal fish. However, TLR3 showed the opposite results. In summary, high stocking density suppressed growth and increased malformation risk in P. olivaceus.

• Asian-Australasian Journal of Animal Sciences
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• 제20권11호
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• pp.1670-1676
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• 2007

Fifty repeat breeder (RB) Friesian cows were allocated to five groups of 10 cows each, to determine the effect of progesterone (P4) supplement on P4 concentrations and pregnancy rates during the periods of corpus luteum (CL) formation and development between days 2-7 and 7-12 following a spontaneous or $PGF_{2{\alpha}}$-induced estrus. Cows were artificially inseminated during $PGF_{2{\alpha}}$-induced (PGF-P4-d2 and PGF-P4-d7 groups) or spontaneous (S-P4-d2, S-P4-d7, and control groups) estrus. Progesterone-releasing intravaginal device (PRID) devoid of estrogen capsule were inserted either on d 2 (PGF-P4-d2 and S-P4-d2 groups) or d 7 (PGF-P4-d7 and S-P4-d7 groups) post-insemination and left in place for 5 days. Control cows did not receive any treatment. Blood samples were collected for progesterone analysis from all cows once daily for 4 days starting on the day of estrus (d 0) and once every 3 days thereafter until d 22. Progesterone treatment by day interaction accounted for higher plasma P4 in treated than non-treated control cows. Progesterone concentrations differed significantly (p<0.05) during metestrus (d 2 to d 7) but not during diestrus (d 7 to d 12). $PGF_{2{\alpha}}$ treatment, lactation number, service number or their interactions did not affect progesterone concentrations and pregnancy rates. Therefore, cows were grouped according to the day of P4 supplement irrespective of the $PGF_{2{\alpha}}$ treatment. Progesterone supplement on d 7 but not d 2 significantly increased (p<0.03) pregnancy rates in repeat breeding cows with four or more previous services but not in cows in their third service. In conclusion, post-insemination P4 supplement to repeat breeding cows with four or more previous services improved pregnancy rates and should be advocated when no specific reason for infertility is diagnosed. Further studies with larger numbers of repeat breeding cows under field conditions are needed to ascertain the findings of this study.

• 한국의류학회지
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• 제32권10호
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• pp.1559-1570
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• 2008

Since brought into from the economic life of nomads, the felt, the target of this study, has been developed in various ways of giving the functions of class symbol as well of protection against the cold and of ornamentation. Therefore, the study on how the felt was developed in Joseon Dynasty and how different culture from nomadic tribes it formed is significant in comprehensively under,;landing the economic, social and natural environmental factors in the Dynasty. The felt named "Jeon" has been constantly appearing in Korea from the ancient time, but it was not produced actively in the early part of Joseon Dynasty. That's why it was not a climatic condition suitable for sheep-breeding, and the government managed sheep-breeding but it aimed primarily at not producing clothing materials but having memorial ceremonies. Since sheep-breeding was not widely spreaded, production of Jeon was limited and some part was imported from China, so it was one of rare valuable goods. Therefore, the felt of wools named "Yangmojeon", the colored felt named "Chaejeon", etc. were used as liking items in the high-class society, and their materials and components were a little different depending on the official post. On the other hand, people in the low-class society used to wear the felt hats made of cattle feathers and miscellaneous fur, named "Jeonlip" and "Beougeoji". Since the middle of Joseon Dynasty, use of the felt was divided into two groups according to the users and the function, along with successful spreading of cotton and development of market economy. The function of Jeon to protect against the cold was replaced by cotton, but the felt hats of Beongeoji, Jeonlip, etc. were worn by common people continuously. As seen above, it is considered that the felt culture in Joseon Dynasty was formed very differently from the nomadic culture, because of its historical and sociocultural characteristics, and it had unique developing progress among all available fabrics.

• Asian-Australasian Journal of Animal Sciences
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• 제27권5호
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• pp.683-689
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• 2014

This study examined carcass and meat quality parameters in growing/finishing pigs fed unconventionally versus the concentrate-based system. Ninety-six, 12 wk old pigs ($34{\pm}SD0.3kg$) were randomly divided into three groups, assigned to one of the three dietary treatments: standard complete concentrate mixture, conventional (C diet); unconventional, steamed potato-green forage-concentrate based diet (U diet), and unconventional basal diet+herbage mix (UH diet). Pigs fed U diet showed lower dressing percentage, meatiness, loin eye area, and weight of pork neck ($p{\leq}0.05$), but their carcasses were significantly ($p{\leq}0.05$) longer and had increased backfat depth ($p{\leq}0.05$). There was no impact of the diet on the meat content of dry matter, crude ash, acidity, and colour parameters of m. longissimus. Unconventional feeding significantly ($p{\leq}0.05$) elevated water the holding capacity of m. longissimus and slightly improved the sensory attributes analysis of meat. The addition of herbs resulted in increased loin eye area ($p{\leq}0.05$), decreased fat content ($p{\leq}0.05$) in m. longissimus, and tended to improve some sensory attributes of meat. There were significant gender differences in response to all diets. There were significant diet${\times}$sex interactions for some measured variables, but there were no clearly identifiable trends with regard to any specific carcass or meat parameters. Feeding unconventional diet to pigs may offer better culinary attributes of the meat, and improve some technologically important characteristics of pig carcass, but may negatively affect some carcass or meat parameters.

• 한국환경과학회지
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• 제21권5호
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• pp.647-654
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• 2012

The goal of this study was to investigate the distribution chart of management and satisfaction through Hanwoo education program and to provide fundamental data and development conformity available on the management and educational program to managers. In this study, we chose 75 managers taking part in Hanwoo education program as pre-test and applied satisfaction for education program to 33 managers randomly selected as post-test. The results of this study are as follows: First, age and academic career had a significant (P<0.05) effect on breeding size, breeding career, sales, and management methods. This may be due to the fact that managers in Hanwoo industry tended to raise academic standards and the age group moved towards young age rather than middle and old ages. However, an academic career was unaffected by sale and management methods. Second, managers who randomly selected the education program showed higher satisfaction about the program and lower or usual interest and intention in the educational environment, incidental facilities, and reviews. In conclusion, to equip the constituent parts of education program with entire propriety and an effective running system, information on breeding size and breeding career for managers in Hanwoo Industry with respect to age and academic career had to be clearly premeditated. It also needed the educational program to look at it from the standpoint of the managers.

• 식물조직배양학회지
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• 제26권4호
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• pp.229-233
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• 1999

본 연구에서는 낙엽송 배발생조직의 장기저장을 위한 가능성에 대하여 조사하였다. 0.4M혹은 20% PEG로 24시간 전 처리하여 -0.33$^{\circ}C$/min의 동결온도 하강율로 초저온시켰을 때 높은 조직생중량을 보인 반면 -0.5 혹은 -1.$0^{\circ}C$/min의 경우 초저온 후 조직의 생중량이 저조한 것으로 나타났다. 1, 7, 및 28일간 초저온보존된 조직을 회수하여 재생장시킨 다음 PCR을 이용하여 변이분석을 한 결과 초저온보존 기간에 관계없이 DNA변이는 전혀 나타나지 않았다. 초저온보존된 배발생 조직으로부터 체세포배 유도 및 식물체 재분화를 유도할 수 `있었다.