검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 59

        1.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Pasture formation and management are crucial to avoid yield reduction. This experiment aimed to examine the effects of tall fescue-centered mixed-seeding combinations on yield and vegetation changes in perennial pastures in the central region for two years, from September 2020 to October 2022. The treatments were arranged in three replications in a randomized block design: control (C), tall fescue-based mixture-1 (T-1), and tall fescue-based mixture-2 (T-2). The tall fescue (TF), orchard grass (OG), perennial ryegrass (PRG), Kentucky bluegrass (KBG), and white clover (WC) were used. The emergency rate of grasses (70.0 to 73.3%) did not differ among mixed seeding combinations. Overwintering rates (81.7 to 83.3%) were similar among treatments. The plant height of grasses was similar at each harvest date, with the highest height (86.2 cm) recorded in the second harvest of the first year, followed by that (58.4 cm) in the third harvest of the first year; it was least (38.9 cm) in the fourth harvest of the second year. There was no significant difference in the dry matter yield of grasses among the mixed seeding combination treatments in the first, third, or fourth harvests of the first year (p>0.05). For second-year grasses, dry matter yield was not significantly different in harvest date among the treatments (p>0.05). Based on mixed seeding ratio, orchard grass showed the highest yield at 70% in the C treatment, followed by tall fescue at 80% and 60% in the T-1 and T-2 treatments, respectively, in the first harvest after seeding. There was no significant difference in feed value between treatments (p>0.05), but a significant difference was observed between the third and fourth harvest (p<0.05). Therefore, it indicated that it is important to create perennial pastures in the central region through mixed seeding combinations centered on tall fescue.
        4,000원
        3.
        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.
        4.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We aimed to predict the Italian ryegrass (IRG) productivity change of introduced and domestic varieties based on climate factors and identify suitable areas for IRG cultivation using the RCP 8.5 scenario. The minimum mean air temperature in January showed the highest correlation with productivity. The ratio of possible and low productivity areas was high in Gangwondo, and the ratio of suitable and best suitable areas was relatively high in the central and southern regions in the past 30 years. The change in the IRG cultivation area was found to be 26.9% in the best suitable area between 1981–2010 but increased significantly to 88.9% between 2090s. In the IRG suitability comparison classes between domestic and introduced cultivars, the ratio of suitable and best suitable areas was relatively high in the domestic varieties during the past 30 years. However, there is almost no difference between the IRG domestic and introduced varieties in the IRG suitability classes after the 2050s. These results can predict changes in the IRG suitability classes between domestic and introduced cultivars according to the climate change scenario, but there are limitations in accurately predicting the productivity of IRG because the results may vary depending on other environmental factors.
        4,000원
        6.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Physical and electrochemical qualities were analyzed after KOH activation of a direct methanol fuel cell using needle coke as anode supporter. The results of research on support loaded with platinum-ruthenium suggest that an activated KOH needle coke container has the lowest onset potential and the highest degree of catalyst activity among all commercial catalysts. Through an analysis of the CO stripping voltammetry, we found that KOH activated catalysis showed a 21% higher electrochemical active surface area (ECSA), with a value of 31.37 m2/g, than the ECSA of deactivated catalyst (25.82 m2/g). The latter figure was 15% higher than the value of one specific commercial catalyst (TEC86E86).
        4,000원
        12.
        2014.10 구독 인증기관·개인회원 무료
        Insect pollinators of the endanger orchid Cypripedium japonicum were surveyed and identified during two years, as a part of a conservation project of the orchid at Jukyeup-san and Hwaak-san (Mt.), South Korea. In total 40 individuals of 16 species in 4 families were identified. The dominant family was Halictidae, and Lasioglossum exiliceps Vachal visited the most frequently C. japonicum during the surveys. The average visiting frequency was 2.5 individuals per hour and the highest 4.3, from 12:00 – 13:00 in a day. After 15:00 insects did not visit the flowers at all. However, all of the visiting insects were found to not carry a pollinium or pollens of the orchard on their bodies; pollen carryover by any of the visiting insects did not occur at all. The orchid seems to require certain pollinators in particular body thickness due to its unique pollination mechanism. The orchid has two exit route openings, around 1 cm in diametre, where the entrapped insects can exit and an anther is situated just in front of each opening. It was inferred that a pollen carrier should be around 1 cm in body thickness. Therefore, the candidate species as the proper pollen carriers can be Tetralonia nipponensis Perez, Xylocopa appendiculata circumvolans Smith and Bombus consobrinus Dahlbom among the surveyed visitors.
        13.
        2013.10 구독 인증기관·개인회원 무료
        Most traditional genome sequencing projects involving infectious viruses include culturing and purification of the virus. This can present difficulties as an analysis of multiple populations from multiple locations may be required to acquire sufficient amount of high-quality DNA for sequence analysis. The electrophoretic method provides a strategy whereby the genomic DNA sequences of the Korean isolate of Pieris rapae granulovirus (PiraGV-K) were analyzed by purifying it from host DNA by pulsed-field gel electrophoresis, thus simplifying sampling and labor time. The genomic DNA of infected P. rapae was embedded in agarose plugs, digested with a restriction nuclease and methylase, and pulsed-field gel electrophoresis (PFGE) was used to separate PiraGV-K DNA from the DNA of P. rapae, followed by mapping of fosmid clones of the separated viral DNA. The double-stranded circular genome of PiraGV-K encodes 120 open reading frames (ORFs), covering 92% of the sequenced genome. BLAST and ORF arrangement showed the presence of 78 homologs to other genes in the database. The mean overall amino acid identity of PiraGV-K ORFs was highest with the Chinese isolate of PiraGV (~99%), followed up with Choristoneura occidentalis ORFs at 58%. PiraGV-K ORFs were grouped, according to function, into 10 genes involved in transcription, 11 involved in replication, 25 structural protein genes, and 15 auxiliary genes. Genes for Chitinase (ORF 10) and cathepsin (ORF11), involved in the liquefaction of the host, were found in the genome. The recovery of PiraGV-K DNA genome by pulse-field electrophoretic separation from host genomic DNA had several advantages, compared with its isolation from particles harvested as virions or inclusions from the P. rapae host. We have sequenced and analyzed the 108,658 bp PiraGV-K genome purified by the pulsed field electrophoretic method. The method appears to be applicable to the analysis of genomes of large viruses. The chitinase, identified by PiraGV-K genome sequence, was functionally characterized by quantitative PCR, Western blot analysis, immunohistochemistry and transmission electron microscopy.
        14.
        2013.10 구독 인증기관·개인회원 무료
        Apolipophorin III (apoLp-III) is a well-known hemolymph protein having a functional role in lipid transport and immune response of insects. We cloned full-length cDNA encoding putative apoLp-III from larvae of the coleopteran beetle, Tenebrio molitor (TmapoLp-III), by identification of clones corresponding to the partial sequence of TmapoLp-III, subsequently followed with full length sequencing by a clone-by-clone primer walking method. The complete cDNA consists of 890 nucleotides, including an ORF encoding 196 amino acid residues. Excluding a putative signal peptide of the first 20 amino acid residues, the 176-residue mature apoLp-III has a calculated molecular mass of 19,146 Da. Genomic sequence analysis with respect to its cDNA showed that TmapoLp-III was organized into four exons interrupted by three introns. Several immune-related transcription factor binding sites were discovered in the putative 5’-flanking region. BLAST and phylogenetic analysis reveals that TmapoLp-III has high sequence identity (88%) with Tribolium castaneum apoLp-III but shares little sequence homologies (<26%) with other apoLp-IIIs. Homology modeling of Tm apoLp-III shows a bundle of five amphipathic helices, including a short helix 3’. The ‘helix-short helix-helix’ motif was predicted to be implicated in lipid binding interactions, through reversible conformational changes and accommodating the hydrophobic residues to the exterior for stability. Highest level of TmapoLp-III mRNA was detected at late pupal stages, albeit it is expressed in the larval and adult stages at lower levels. The tissue specific expression of the transcripts showed significantly higher numbers in larval fat body and adult integument. In addition, TmapoLp-III mRNA was found to be highly up-regulated in late stages of L. monocytogenes or E. coli challenge. These results indicate that TmapoLp-III may play an important role in innate immune responses against bacterial pathogens in T. molitor.
        15.
        2009.10 구독 인증기관·개인회원 무료
        14-3-3 proteins are known to play a pivotal role in a diverse array of cellular events such as cell survival, apoptosis, and signal transduction. Numerous 14-3-3 ζ have been cloned and characterized from a host of eukaryotic organisms including human, plants, yeast, fruit fly and silkworm. However, no study on Spodoptera exigua 14-3-3ζ in conjunction with virus infection has so far been reported in insects. It appears that expression of Se14-3-3ζ was decreased starting 24 h post-SeNPV infection as SeNPV titers seemed to increase as evidenced by intense bands of SeNPV IAP3. Interestingly, confocal microscopic analysis revealed that Se14-3-3ζ is expressed at the apical side of the NPV-uninfected gut cells, whereas it was detected mainly in the nucleus of the NPV-infected cells. Thus, despite the biological significance of Se14-3-3ζ in S. exigua in conjunction with molecular interactions between SeNPV and S. exigua is unclear now, our data suggest that Se14-3-3 ζ protein plays a role to protect S. exigua from the infection or inhibit replication of SeNPV.
        16.
        2009.10 구독 인증기관·개인회원 무료
        Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway is known to play a pivotal role in various cellular events and antiviral responses in both vertebrates and insects. In an attempt to elucidate the potential involvement of STAT on S. exigua-SeNPV interactions, the full length cDNA of SeSTAT was cloned from S. exigua. Analysis of temporal expression patterns shows that SeSTAT is expressed in all stages of life cycle such as larvae, pupae, and adult. Spatial expression analysis shows that it is highly expressed in fat body and Malpighian tubule. Interestingly, SeSTAT is induced at 24 h in response to either laminarin or LTA injection in larvae. Electrophoretic mobility shift assay (EMSA) shows that the binding of nuclear extracts from fat body cells immune-challenged with LTA to STAT5 probe was observed. In addition, SeSTAT was nuclear-translocalized in both fat body and gut cells that were challenged with LTA and laminarin, respectively. Finally, gene silencing of SeSTAT shows that SeNPV number appears to be increased. It suggests that SeSTAT may act as a negative regulator against SeNPV in midgut.
        1 2 3