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        검색결과 65

        22.
        2019.04 구독 인증기관·개인회원 무료
        본 조사지인 돌리네 습지보호지역은 경북 문경시 산북면 굴봉산 정상부에 위치하였으며, 물이 고이기 힘든 돌리네(doline) 지형에 형성된 희귀 습지이다. 뿐만 아니라 멸종위기종과 법적보호종이 분포하는 등 생물다양성 또한 매우 풍부한 것으로 평가되고 있다. 그러나 습지보호지역 주변으로 과수원 등 경작지가 형성되어 있어, 관리 및 보전을 위한 조사 및 대책이 필요하다. 따라서 본 조사에서는 습지보호지역의 체계적인 관리를 위하여 돌리네 습지의 곤충상을 조사하였다. 조사 방법에는 곤충의 다양한 습성과 서식환경을 고려하여, Searching, Sweeping, Pitfall trap, Bucket trap으로 총 4가지의 채집방법으로 조사를 실시하였다. 그 결과 총 11목 82과 188속 237종이 확인되었으며, 이중 딱정벌레목이 가장 많이 출현하였다. 특이사항으로 환경부지정종 51종(중복포함)이 조사되었으며, 그중 멸종위 기종 1종이 확인되었다. 본 연구를 통해 돌리네 습지보호지역의 곤충상을 파악하고 관리 및 보전에 대한 기초자료를 제공하고자 한다.
        23.
        2019.04 구독 인증기관·개인회원 무료
        알락수염노린재(Dolycoris baccarum L.)는 구북구(Palearctic region)에 널리 분포하는 다식성 곤충으로서 국내에서는 콩, 단감, 유자 등 다양한 작물의 해충이다. 이 종은 다른 노린재과(Pentatomidae) 곤충과 마찬가지로 수컷이 집합페로몬 을 방출하는 것으로 알려져 있다. 우리는 수컷의 집합페로몬 성분을 동정하기 위하여, 고상미량추출(SPME) 방법을 이용하여 수컷과 암컷 성충에서 방출되는 휘발성 물질을 포집하여 화학구조를 분석하였다. 그 결과, 수컷 특이적인 휘발물질로서 α-bisabolol, α-bergamotene, β-bisabolene을 동정하였고, 3가지 성분이 100:15:5 비율로 존재함을 밝혔다. 야외에서 알락수염노린재 수컷과 암컷 성충 모두가 주성분인 α-bisabolol을 처리한 트랩에 유인되었다. 나머지 2가지 성분(α-bergamotene과 β-bisabolene)의 경우, 그 자체로는 유인 효과가 없었으나 주성분인 α-bisabolol에 추가되면 보강효과가 발휘되었다. 곤충에서 α-bisabolol이 동정된 것은 이것이 처음이며, 이번에 밝혀진 알락수염노린재 집합페 로몬은 이 해충의 발생예찰과 친환경 방제에 유용할 것이다.
        25.
        2018.10 구독 인증기관·개인회원 무료
        블루베리혹파리(Dasineura oxycoccana)는 우리나라에서 2010년에 처음 발견된 이래로 지금은 전국의 블루베리 재배지에서 발견되고 있는 외래해충이다. 이 해충의 생태 조사와 방제 연구를 위해 효과적인 유인제 개발이 필요한 실정이다. 비록 캐나다 개체군으로부터 이 해충의 암컷 성페로몬이 이미 보고되었을지라도, 캐나다 연구자들은 이 물질의 질량 스펙트럼이 아닌 기체크로마토그래피의 머무름 시간 비교를 통해 성페로몬을 동정하고 야외 유인시험을 통해 확인하였다. 우리는 블루베리혹파리 유인제 개발의 첫 단계로서 이 종의 성페로몬을 암컷으로부터 분리하여 천연 물질의 질량 스펙트럼을 확인하는 것을 목표로 하였다. 암컷 성충 21마리의 복부 추출물을 농축한 시료 속에서 이 종의 성페로몬으로 알려진 ‘2,14-diacetoxy heptadecane’을 성공적으로 분리하였다. 한편, 암컷 성페로몬의 부성분으로 추정할 수 있는 추가적인 유사물질은 발견되지 않았다
        26.
        2018.10 구독 인증기관·개인회원 무료
        과수의 주요 해충인 복숭아순나방(Grapholita molesta)을 친환경적으로 방제하기 위하여 성페로몬을 함유한 방출기를 이용한 교미교란 기술이 이용되고 있다. 그러나 방출소재가 다른 교미교란제 간 유효성분의 방출량과 방제효과에 대한 정보가 없어 효과적인 이용이 곤란한 실정이다. 우리는 튜브형과 파우치형 교미교란제의 야외 노출시기별 유효 성분(Z8-12:Ac)의 방출율을 조사하였고, 각 교미교란제의 방제효과를 트랩 유인저해율과 과실 방제효과의 비교를 통해 평가하였다. 튜브형의 연간 총 방출량은 파우치형 보다 5.7배 높았다. 튜브형은 약 4개월 후에 방출율이 급격히 감소하였던 반면, 파우치형은 처리 직후부터 방출율이 낮았고 그 비율이 6개월 동안 지속되었다. 튜브형을 처리한 과수원에서 트랩 유인저해율은 99.8%에 달하였고, 과실 방제효과는 85.3%였다. 파우치형의 경우, 트랩 유인저해율은 98.7%로 높았으나 방제효과는 64.7%에 불과하였다. 따라서 튜브형의 유효기간이 약 4개월이므로 과수 품종에 따라 교미교란제 설치시기를 조정해야 활용가치를 높일 수 있을 것으로 보인다.
        27.
        2018.10 구독 인증기관·개인회원 무료
        노린재류는 복숭아, 매실, 자두, 살구 등 핵과류 과실을 가해하는 해충으로 알려져 있다. 그러나 아직 핵과류 과원에서 과실을 가해하는 노린재 종에 대한 자세한 정보가 없어 효과적인 방제대책을 수립하기 어려운 실정이다. 우리는 2017년과 2018년에 핵과류 과실을 가해하는 노린재의 종류와 발생 밀도를 다양한 계절에 여러 지역에서 육안으로 조사하였다. 핵과류 6종(매실, 자두, 복숭아, 양앵두, 플럼코트, 살구)을 가해하는 노린재류는 총 4종으로써 썩덩나무노린재, 갈색날개노린재, 가시노린재, 알락수염노린재였다. 매실, 복숭아, 양앵두, 살구를 가해하는 우점 노린재는 썩덩나무노린재였던 반면, 자두에서는 갈색노린재의 밀도가 가장 높았다. 핵과류를 가해하는 노린재 중에서 썩덩나무노린재가 차지하는 비율은 64.2%였고, 갈색날개노린재는 23.7%를 차지하여 이 2종이 약 88%를 점유하였다. 따라서 핵과류에서 피해가 가장 큰 썩덩나무노린재의 체계적인 관리방안에 대한 연구가 필요하다.
        28.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objectives of this study was to evaluate the degradability and digestibility of crude protein (CP), rumen undegradable protein (RUP), and individual amino acids (AA) on six by-product feedstuffs (BPF) (rice bran, RB; wheat bran, WB; corn gluten feed, CGF; tofu residue, TR; spent mushroom substrate from Pleurotus ostreatus, SMSP; brewers grain, BG) as ruminants feed. Three Hanwoo steers (40 months old, 520 ± 20.20 kg of body weight) fitted with a permanent rumen cannula and T-shaped duodenal cannula were used to examine of the BPF using in situ nylon bag and mobile bag technique. The bran CGF (19.2%) and food-processing residue BG (19.7%) had the highest CP contents than other feeds. The RUP value of bran RB (39.7%) and food-processing residues SMSP (81.1%) were higher than other feeds. The intestinal digestion of CP was higher in bran RB (44.2%) and food-processing residues BG (40.5%) than other feeds. In addition, intestinal digestion of Met was higher in bran RB (55.7%) and food-processing residues BG (44.0%) than other feeds. Overall, these results suggest that RB and BG might be useful as main raw ingredients in feed for ruminants. Our results can be used as baseline data for ruminant ration formulation.
        4,000원
        29.
        2018.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Boron nitride nanotubes (BNNTs) are receiving great attention because of their unusual material properties, such as high thermal conductivity, mechanical strength, and electrical resistance. However, high-throughput and highefficiency synthesis of BNNTs has been hindered due to the high boiling point of boron (~ 4000℃) and weak interaction between boron and nitrogen. Although, hydrogen-catalyzed plasma synthesis has shown potential for scalable synthesis of BNNTs, the direct use of H2 gas as a precursor material is not strongly recommended, as it is extremely flammable. In the present study, BNNTs have been synthesized using radio-frequency inductively coupled thermal plasma (RF-ITP) catalyzed by solid-state ammonium chloride (NH4Cl), a safe catalyst materials for BNNT synthesis. Similar to BNNTs synthesized from h-BN (hexagonal boron nitride) + H2, successful fabrication of BNNTs synthesized from h-BN+NH4Cl is confirmed by their sheet-like properties, FE-SEM images, and XRD analysis. In addition, improved dispersion properties in aqueous solution are found in BNNTs synthesized from h-BN +NH4Cl.
        4,000원
        31.
        2018.04 구독 인증기관·개인회원 무료
        The ambrosia beetle, Xyleborinus saxesenii Ratzeburg, infests physiologically stressed apple and peach trees in Korea. Dispersing females utilize the degradation product ethanol and host-related volatiles to locate and colonize new host trees. We examined the extent to which 12 chemicals emitted from fruit trees act synergistically with ethanol to attract X. saxesenii. The addition of benzaldehyde to ethanol significantly increased beetle attraction, although benzaldehyde was not attractive by itself. The addition of α-pinene, ethyl butyrate, ethyl isovalerate, limonene, 3-methyl-1-butanol, ethyl tiglate, aromadendrene, vanillin, 2-butanol, styrene, or ethyl 3,3-dimethylacrylate to ethanol had no effect on beetle attraction. In a dose-response test, the addition of 5–50% benzaldehyde doses synergistically increased the number of beetle captures; however, trap catches did not increase as the benzaldehyde dosage increased. The synergistic influence of benzaldehyde on beetle response to ethanol was lower in early spring than in late summer to early fall, probably because synthetic benzaldehyde emissions from field lures were overwhelmed by background levels of natural benzaldehyde emitted from peach twigs in the flowering stage.
        32.
        2018.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To elucidate the effect of cellular phone electromagnetic wave (EMW) exposure on the developing cerebellar cortex of neonatal Sprague-Dawley rats, animals were exposed to cellular phone electromagnetic waves for 1 hr per day for 3 weeks. At the end of the experimental period, animals were sacrificed by cardiac perfusion, after which histological samples were prepared and observed microscopically. In the EMW exposure group, external granule cells were remained partially in the external granular layer without migrating into the internal granular layer. In addition, dark stained shrunken Purkinje cells with pyknotic nuclei increased and the outline of cells became irregular and showed degenerative signs, such as mitochondrial swelling and disrupted cristae. Moreover, the cisternae of rough endoplasmic reticula and Golgi complex were severely swollen. Bergmann glial cells adjacent to the dark stained Purkinje cells were swollen and cytoplasmic organelles were scant. Dark stained shrunken granule cells were also observed and the outline of cells was irregular. The results of the present study suggest that cellular phone EMW exposure to neonatal Sprague-Dawley rats leads to a partial delay of early migration of cerebellar cortical cells and degenerative changes in Purkinje cells, Bergmann glial cells and granule cells.
        4,000원
        33.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Even though klotho deficiency in mice exhibits multiple aging-like phenotypes, studies using large animal models such as pigs, which have many similarities to humans, have been limited due to the absence of cell lines or animal models. The objective of this study was to generate homozygous klotho knockout porcine cell lines and cloned embryos. A CRISPR sgRNA specific for the klotho gene was designed and sgRNA (targeting exon 3 of klotho) and Cas9 RNPs were transfected into porcine fibroblasts. The transfected fibroblasts were then used for single cell colony formation and 9 single cell–derived colonies were established. In a T7 endonuclease I mutation assay, 5 colonies (#3, #4, #5, #7 and #9) were confirmed as mutated. These 5 colonies were subsequently analyzed by deep sequencing for determination of homozygous mutated colonies and 4 (#3, #4, #5 and #9) from 5 colonies contained homozygous modifications. Somatic cell nuclear transfer was performed to generate homozygous klotho knockout cloned embryos by using one homozygous mutation colony (#9); the cleavage and blastocyst formation rates were 72.0% and 8.3%, respectively. Two cloned embryos derived from a homozygous klotho knockout cell line (#9) were subjected to deep sequencing and they showed the same mutation pattern as the donor cell line. In conclusion, we produced homozygous klotho knockout porcine embryos cloned from genome-edited porcine fibroblasts.
        4,000원
        37.
        2013.04 구독 인증기관·개인회원 무료
        Repellency of 20 plant essential oils to malaria main vector in the Republic of Korea (ROK), Anopheles kleini, was evaluated using skin direct contact bioassay. Anopheles kleini showed the highest repellency to Pelargonium graveolens with EC50 value of 0.244 mg/cm2, followed by Pinus sylvestris and Cinnamomum camphora with EC50 values of 0.484 mg/cm2 and 0.862 mg/cm2. The lowest repellency of An. kleini was revealed from Clary sage oil with EC50 value of 4.665 mg/cm2. Anopheles kleini did not demonstrated any repellency to Lemon, Orange, Neem, Coconut and Olive oil over 20 mg/cm2. Major repellent constituents of Geranium, Pine and Camphora oil were analyzed and identified using Mass-data, GC and GC-Mass. Major constituent of Geranium were β-citronellol (37.0%) and Camphora, 1,8-cineole (35.8%) and Pine, α-terpineol (39.5%). Anopheles kleini showed higher repellency to β-citronellol and 1,8-cineole than to DEET and IR3535 and did not showed any repellency to sabinene and γ-eudesmol over 20 mg/cm2. Residual repellent time of 1,8-cineole and β-citronellol were 26 and 41 min, respectively and DEET, 84 min and IR3535, 102 min. In the light of global efforts to reduce the level of highly toxic synthetic repellents, the three essential oils and their major constituents described merit further study as potential biorepellents for the control of An. kleini populations
        38.
        2012.05 구독 인증기관·개인회원 무료
        Toxicities of 10 insecticides were examined against late third instars of Culex tritaeniorhynchus using the direct-contact mortality bioassay. Six geospatially distant field mosquitoes were collected from Chuncheon-si (designated CC-CT), Hwaseong (HS-CT), Seosan (SS-CT) Jeonju (JJ-CT), Daegu (DG-CT), and Busan (BS-CT) in the Republic of Korea (ROK). Marked regional variations of insecticide susceptibility were observed. Field populations of SS-CT, JJ-CT and DG-CT from agricultural areas showed higher to extremely higher insecticide susceptibility to pyrethroids than those of CC-CT, HS-CT and BS-CT strains from none agricultural areas. Extremely high to low levels of susceptibility were measured: bifenthrin, susceptible ratio (SR) = 2.7–896.3; β-cyfluthrin, SR = 1.8–633.3; α-cypermethrin, SR = 1.2–1,051.9; deltamethrin, SR = 1.3–711.1; permethrin, SR = 1.5–1,053.4 etofenprox, SR = 2.2–29.3; chlorfenapyr, SR = 5.1–103.6; chlorpyrifos, SR = 2.3–337.0; fenitrothion, SR = 2.0–142.3 and fenthion, SR = 1.4–186.2. Culex tritaeniorhynchus populations from rice paddies had been under heavy selection pressure due to the agricultural insecticides and that’s why the mosquito species demonstrated high resistance to pyrethroids which were used for a long time to control agricultural pests in the localities. These results indicate that careful selection and rotational use of these insecticides mayresult in continued satisfactory control against field populations of Japanese encephalitis vector mosquitoes.
        39.
        2011.10 구독 인증기관·개인회원 무료
        Despite of the presence of estradiol-17β (E2) in ovarian follicles, its role(s) in in vitro maturation (IVM) is still largely unknown, especially in pigs. Thus, the current study was conducted to investigate the effect of E2 on in vitro maturation (IVM) of porcine oocytes and subsequent preimplantation development using in vitro fertilization (IVF)- or somatic cell nuclear transfer (SCNT)-derived embryos. To define the effects of E2 on IVM and early embryogenesis, porcine oocytes were matured in the presence or absence of E2, fertilized in vitro and cultivated to blastocyst stage. Compared to control group, the production of MII oocytes was significantly increased by treatment with E2, accompanying with the increase in MPF content and ERK phosphorylation, and monospermic fertilization and blastocyst development rates were also greatly elevated in the E2-treated oocytes. In addition, the advantageous role of E2 was also found in blastomere survival, which was further evidenced by both elevation of anti-apoptotic transcript Bcl-XL and decrease of pro-apoptotic transcript Bax. Furthremore, these positive effects of E2 were highly reproducible in early development of SCNT embryos. Collectively, the current study strongly suggests that E2 can be used as a efficient IVM supplement leading to successful nuclear/cytoplasmic maturatioin in pigs.
        40.
        2011.10 구독 인증기관·개인회원 무료
        Successful early embryogenesis of somatic cell nuclear transfer (SCNT) embryos is very important to produce cloned animals. However, poor preimplantation development of SCNT embryos has been a major obstacle to the generation of cloned animals due to a lack of understanding of developmental events and underlying mechanism(s). In the current study, we show that production of SCNT embryos with high developmental competence is dependent on the fusion method. Electrofusion causes spontaneous egg activation, accompanied by an increase in intracellular Ca2+ and improper nuclear remodeling, whereas Sendai virus (SV)-mediated fusion greatly reduces these events. In addition, SV-SCNT increased the blastocyst development rate and trophectoderm cell number compared to electrofusion-mediated SCNT (E-SCNT). In particular, expression of ER stress-associated genes and blastomere apoptosis were significantly increased in E-SCNT embryos, which could be alleviated by inhibition of ER stress or by using the SV-mediated fusion method. Taken together, these results strongly suggest that SV is a useful fusion material for improvement of preimplantation development of SCNT embryos through reduction of ER stress-associated apoptosis.
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