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        검색결과 372

        161.
        2009.10 구독 인증기관·개인회원 무료
        Ecological changes, both man-made and natural, have changed the landscape of the Republic of Korea following the end of Japanese occupation at the end of World War II (1939-1945). During the Japanese occupation, forested hillsides were cleared and wood products shipped to Japan, leaving the hills and mountains largely covered by grasses and other shrub vegetation. Following WWII, the country of Korea was divided into North and South Koreas, with North Korea under communist powers, while South Korea was established as a democratic government. In South Korea poverty was rampant and local populations scavenged for wood for cooking and heating during the cold winters. Just as economic conditions were increasing, South Korea was attached by North Korea, beginning a long drawn-out conflict from 1950 to the summer of 1953, whereby an armistice was signed and an often uneasy peace between the two countries continues today. Again, the Republic of Korea emerged from a War as an impoverished country with treeless country sides, hills, and mountains. In the 1960’s, president Chung-Hee Park established a tree planting policy to reestablish long-ago lavish forested mountains and hillsides that make up more than 70% of the South Korean landscape. Today, mountains and hillsides are generally not used for agriculture and are completely forested, with planted groves and volunteer trees ranging in age from 10-50 years. These forested areas have led to increased protection for large and small mammals and birds, increasing the potential for zoonotic pathogens that there ectoparasites harbor to be transmitted to man during work and leisure activities. While forested areas provided an expanded habitat for some animals, agriculture expanded and modernized, resulting in short-cut grasses on banks separating much of the rice paddies, orchards, ditches, and dry-land farming that increased competition for small mammal habitat. As a result of increased surveillance of small and large animals and their ectoparasites, the increased prevalence of known pathogens and identification of new pathogens, especially those harbored by ticks, has demonstrated the presence of tick-borne encephalitis, several species of spotted fever group Rickettsia, and a host of other zoonotic diseases in wild animals, their ectoparasites, and man. As tick-borne diseases are not reportable diseases in Korea, the extent and impact on civilian and military populations is unknown as diagnoses are often likely sought for the wrong pathogen. While agriculture modernized, military training sites largely consist of unmanaged lands with tall grasses that are conducive to large and small mammal populations, which are host to a number of zoonotic diseases, e.g., hantaviruses, scrub typhus, murine typhus, leptospirosis, tick-borne encephalitis, spotted fever group rickettsial pathogens, Lyme disease, bartonellosis, etc. that impact on military populations training in those areas. The impact of training sites habitat modification has not been assessed, but for many sites is impractical. To reduce health risks of vectorborne diseases, the US Army has established better housing (tents to barracks with screened windows and air conditioning) at some field training sites, reducing the potential for the transmission of mosquito-borne pathogens (malaria and Japanese encephalitis virus). The increased use of permethrin-treated all climate uniforms (ACUs) and repellents, also reduce the potential for transmission of mosquito-, tick-, mite-, and flea-borne pathogens. However, training conditions at some field training sites remain largely unchanged, with personnel working and sleeping in tents that abut to forested areas where animals and their ectoparasites are present. While some training and maneuver sites are well planned for weapons qualifications of wheeled and tracked vehicles, others sites are in areas of unmanaged lands which are rodent infested. Increased surveillance by the 65th Medical Brigade not only provides a baseline and relative distribution for vector-borne diseases in Korea, but also provides disease trends and risk assessments that are necessary for protecting US military personnel training in Korea.
        162.
        2009.08 구독 인증기관·개인회원 무료
        The experimental work was conducted to investigate the effects of the application level of composted cattle manure (CCM) on forage productivity using whole crop barely (WCB)-whole crop rice (WCR) double cropping system for 3 years. Main plot was consisted of application level of CCM such as 150%, 200% and control plot. The total DMY of forages under WCB and WCR in treatment of CF significantly decreased as compared with that of treatment of CCM 150%. However, NDF, ADF and CP content of WCB and WCR were hardly influenced by CCM application.
        163.
        2009.08 구독 인증기관·개인회원 무료
        The experimental work was conducted to investigate the effects of the application level of composted cattle manure (CCM) on forage productivity using Italian ryegrass-WCR double cropping system for 3 years (2006~2008). Main plot was consisted of application level of CCM such as 150%, 200% and control plot. The total day matter yield (DMY) of Italian ryegrass and WCR in treatment of CCM 150% and CCM 200% significantly decreased as compared with that of treatment of chemical fertilizer (CF). However, NDF, AND and CP content of Italian rye grass and WCR were hardly influenced by CCM application.
        164.
        2009.08 구독 인증기관·개인회원 무료
        The experimental work was conducted to investigate the effects of the application level of composted cattle manure (CCM) on forage productivity using rye-whole crop rice (WCR) double cropping system for 3 years. Main plot was consisted of application level of CCM such as 150%, 200% and control plot. The total DMY of of rye-WCR in treatment of CCM 150% significantly decreased as compared with that of treatment of CF and CCM 200%. However, NDF, ADF and CP content of rye and WCR were hardly influenced by CCM application.
        165.
        2009.08 구독 인증기관·개인회원 무료
        In this study, we conducted to select the promising crops for both uses in the bioethanol and forage production in Korea. The result indicated t㏊t Natsukaje (guinea grass), Gwangpyeongok (corn), Jumbo (sorghum×sudangrass hybrid), SS405 (sorghum×sorghum hybrid), Millex32 (pearl millet), Jeju barnyard grass), Alamo (switch grass) and Selection75 (klein grass) showed the production of biomass from the highest to the lowest in order. However, the order of the production of quality forage was, from the highest to the lowest, Natsukaje (guinea grass), Jumbo (sorghum×sudangrass hybrid), SS405 (sorghum×sorghum hybrid), Gwangpyeongok (corn), Millex32 (pearl millet), Selection75 (klein grass), Jeju (barnyard grass), and Alamo (switch grass). We concluded the Natsukaje (guinea grass) was the best bioethanol crop, and also the Natsukaje (guinea grass) was the best for forage production.
        166.
        2009.08 구독 인증기관·개인회원 무료
        Although whole crop barley are now widely grown as a silage crop in Korea, but silage quality of the whole crop barley produced from farmer's fields have not been published. Therefore, this experiment was conducted to evaluate forage quality of whole crop barley which was participated in Korean quality contest in 2008. These data were classified by region, forage production, added inoculants, planting date and harvest date. Difference on lactic acid of barley silage was detected in the region (p<0.05), however, there no significant differences in other chemical composition. The moisture and lactic acid were significant differences in dry matter yield of barley silage. There is all the difference between silage added inoculants and control. Differences between planting dates in ash and crude protein (CP) were detected in barley silage (p<0.05). From comparison within harvest date, lactic acid ㏊d significant differences among barley silage. Differences in forage quality were observed among whole crop barley for silage. Therefore, nutritional quality as well as lactic acid is important in silage quality contest of whole crop barley.
        168.
        2009.08 구독 인증기관·개인회원 무료
        This experiment was conducted to evaluate the effect of seeding rate on the quality and yield of whole crop rice variety, "Namil". Whole crop rice variety, "Namil", was direct seeded at 25 April. The seeding rate were four level(30, 60, 90, and 120㎏/㏊). There was not found significantly difference plant height and dry matter(DM) content among seeding rate. Acid detergent fiber(ADF) and neutral detergent fiber(NDF) content was increased until 90㎏/㏊ of seeding rate. The content of TDN(total digestible nutrient) decreased also with increased seeding rate until 90㎏/㏊ seeding rate. The highest fresh and DM yield showed at 120㎏/㏊ seeding rate. But there was not found significantly difference among 60, 90 and 120㎏/㏊ seeding rate. Although high seeding rate increase the DM yield, 60㎏/㏊ seeding rate will be recommendable as proper seeding rate for whole crop rice.
        169.
        2009.08 구독 인증기관·개인회원 무료
        This experiment was carried out to find out the optimum variety of com hybrids and to find out alternative crops in the rice black-streaked dwarf virus(RBSDV) prevalent area. Productivity of 4 Korean improved and 6 introduced com hybrids and RBSDV infection rate were tested for 3 years in both Cheonan(middle part of Korea) and Gochang(southern part of Korea). Percentage of RBSDV diseased plants differed depending on the hybrid and region.
        172.
        2009.05 구독 인증기관·개인회원 무료
        A full genomic DNA microarray technique was employed to investigate the effects of Dongchunghacho on aortal and hepatic gene expression in apolipoprotein E knockout mice fed a high-fat/high-cholesterol diet. Male 8- week - old ApoE-/- mice were randomly divided into two groups, control(high cholesterol group; HC) and supplementation of Dongchunghacho (SD). All of the mice were fed a high-fet/high cholesterol diet with or without Dongchunghacho supplemented by 1% for 6 weeks. At first, lipid profile of the Dongchunghacho was measured by biochemical analysis. No differences were observed in serum triglyceride and total cholesterol levels between the two groups. Antigenotoxic effect of the Dongchunghacho was measured by the single cell gel electrophoresis assay (Comet assay) and quantified as % fluorescence in tail. Dongchunghacho supplementation decreased significantly leukocytic DNA damage and also there was a tendency of reduction in hepatic DNA damage in Dongchunghacho group compared with the control group. In up regulated genes in liver and aorta of the mice, genes with 0 to 2- fold difference in expression level between the two group (HD and SD) was very much more in liver than in aorta, on the contrary, those with 2-fold to 16-flod difference increased greatly rather in aorta than in liver. Also, almost the same results were observed in down regulated genes in liver and aorta between the two groups. These results suggested that supplementation of Dongchunghacho might be helpful in preventing leukocytic DNA damage induced by high fat diet, and has a more crucial roles in aortal gene expression.
        173.
        2009.05 구독 인증기관·개인회원 무료
        We assessed the environmental risk of herbicide resistant transgenic rice (Protox) on non-target herbivore, grasshoppers (Oxya japonica japonica Thunberg). We conducted life-history experiments of grasshoppers with measuring their body weight, body length, eating amount, and feces amount between non-transgenic rice (nTR; Dongjin rice) and transgenic rice (TR; Protox rice) under laboratory conditions (Temp. 25Ð, R.H. 50-70%, Photoperiod L16:D8) in 2007. The growth of grasshoppers appeared to increase at each measuring date. We also compared the growth rate of grasshoppers between nTR and TR to examine the transgenic impact on the herbivore and we found there was no statistically signifi cant difference between the two plant types (P>0.05). We found that body weight and body length for grasshoppers were highly correlated at each of the two types of plants, nTR (0.962) and TR (0.960). The correlation of eating amount and feces amount of grasshoppers were higher nTR (0.830) than TR (0.782). The energy effi ciency of the grasshopper was not a signifi cant between nTR and TR (P> 0.05). But the molt timing of the grasshoppers for TR difference was faster than for nTR. Conclusively life-history of the grasshoppers but molt timing was not a signifi cant difference between nTR and TR. Therefore, we could conclude there was not any environment risk on herbivore from our result.
        174.
        2009.05 구독 인증기관·개인회원 무료
        DNA barcode is known to be successfully applied in identification on the members of Insecta. In recent studies, however, it was known that the DNA approach may fail in several taxa with following cases: (1) very recent speciation and hybridization, (2) recent diverged groups with complex gene histories, (3) the spread of maternally transmitted bacteria, (4) adding more than one geographical race and at least one congener, (5) different levels of dispersal. In this study, we taxonomically review on the Korean Hatchiana using the morphological data and DNA barcodes. In morphology, they are distinct from each other by the characteristics of body coloration, eye, pronotum, scutellum, and aedeagus. In molecular data, however, the interspecific sequence distance ranged from 0.0-3.4%. This result is caused by H. glochidiatus, of which the sequence divergence is 0.2-2.8% in H. rosinae, 0.8-2.6% in H. baekripoensis, and 0.0-3.3% in H. jirisanensis. Also, H. glochidiatus produces mixed-clusters with H. rosinae and H. jirisanensis in NJ phenogram. Through this presentation, therefore, we discuss on why the four Korean Hatchiana species distinct by morphological characters produce mixed-clusters in DNA barcoding.
        176.
        2008.10 구독 인증기관·개인회원 무료
        Sclerodermus harmandi populations were collected from 6 Korean regions (Seoul, Gangwon, Chungcheong, Jeolla, Gyeonasang and Jeju provinces), 1 Chinese region (Nanjing) and 1 Japanese region (Tokyo). Above all was identified as the same species based on morphological characteristics. In present study, we compared the intra-specific characteristics of regional isolated populations of S. harmandi based on nucleotide and amino acid sequences of variant genomic and mitochondrial loci: the full length of internal transcribed spacer 1 and 2 (ITS1 & ITS2), the complete cytochrome oxidase subunit I and II (COI & COII) and tRNA genes for aspartate and lysine and 5'end of ATPase 8 genes. There were no significant differences among the analysed 9 populations regardless of regional segregation. The nucleotide and translated amino acid sequences similarities were significantly high, despite some sequence differences were found in same loci. This result support the report based on the morphological characteristics. However, we are conducting further study to identify whether sequence differences in specific loci are the characteristics of individual level in population or population level and to analyse the full sequences of mitochondrial DNA by regional segregation.