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        검색결과 359

        82.
        2018.10 구독 인증기관·개인회원 무료
        The eggs of Asian tiger mosquito, Aedes albopictus, possess high desiccation resistance, which contribute the rapid spread of this mosquito across the world. Melanization of eggshell appear to play a role in the resistance to desiccation. Dopachrome-conversion enzyme (DCE, Yellow) significantly accelerates the melanization of the eggshell. In this study, we demonstrated functional importance of two yellow genes, AalY-g and AalY-g2, in the chorion formation. Both genes were highly induced in the ovary at 48 h after blood meal. Injection of dsRNA for AalY-g or AalY-g2 into adult females had no effect on fecundity. However, the outermost colorless exochorion of the eggs obtained from both dsRNA-treated females was fragile and peeled off in places, and melanization of the endochorion was obviously delayed by several hours. In addition, unlike eggs from control females which acquired high desiccation resistance between 18 and 24 h after oviposition (HAO), 60-70% 24 HAO eggs from either AalY-g- or AalY-g2-deficient females were collapsed when they were moved to an air-dry condition, and the desiccation resistance was not increased in later stages of embryonic development analyzed. TEM analysis revealed that abnormal morphology and ultrastructure of the endochorion, particularly outer-endochorion, in the 24 HAO and older eggs from either AalY-g-and AalY-g2-deficient females. These results indicate that AalY-g and AalY-g2 are required for morphology and formation of the endochorion (outer-endochorion), a structure that appears to be critical for desiccation resistance of the Ae. albopictus eggs. This work was supported by NRFs (NRF-2015R1A6A3A04060323 and NRF-2018R1A2B6005106)
        83.
        2018.10 구독 인증기관·개인회원 무료
        Chitin deacetylases (CDAs) are extracellular-modifying enzymes that deacetylate chitin to produce chitosan. In insects, this modification may contribute to the affinity and/or cross-linking of chitin/chitosan-like polysaccharides for a variety of structural proteins, which may lead to diverse mechanical properties of the cuticle. We previously reported the functional importance of Group I CDAs, TcCDA1 and TcCDA2, as well as the two alternative spliced isoforms of the latter, TcCDA2a and TcCDA2b from the red flour beetle, Tribolium castaneum in molting, morphology of cuticle and movement of legs. In this study, we further analyzed protein localization, ultrastructural defects of the cuticles and leg joints after RNAi of those genes. Both proteins are mainly present in the innermost procuticle region called the “assembly zone”. Loss of function of either TcCDA1 or TcCDA2 caused disorganized chitinous horizontal laminae and vertical pore canals in both the rigid and soft cuticles. RNAi of TcCDA2b affects cuticle integrity similar to that seen in RNAi of the two alternatively spliced forms of TcCDA2. In contrast, TcCDA2a-deficient adult, like that seen in the hypomorphic phenotype produced by RNAi of TcCDA1, exhibited ruptured tendons between femur and tibia, resulting in loss of locomotion ability. These results suggest that Group I CDAs play critical roles in molting, morphology, ultrastructure and mobility in T. castaneum. This work was supported by NRFs (NRF-2015R1A6A3A04060323 and NRF-2018R1A2B6005106).
        84.
        2018.10 구독 인증기관·개인회원 무료
        농업용 무인멀티콥터를 활용한 방제면적은 수도작은 물론 밭작물에서도 방제 범위가 확대되고 있다. 밭작물은 작물의 형태가 다양하여 비행속도, 살포높이 등을 최적화하는 연구가 필요하다. 본 연구에서는 배추, 대파, 고추에서 발생하는 나방류에 대하여 무인멀티콥터의 살포 높이에 따른 방제효과를 확인하였다. 살포된 약제가 작물에 부착되는 정도를 조사한 결과, 배추는 2m, 대파는 3~4m, 고추는 모든 높이에서 비슷한 부착정도를 보였지만, 전체적으로 부착량이 적고 불균일 하였다. 살포 높이별 방제효과는 작물별로 각각 배추(9~10엽기)는 2m높이, 고추(약 1.2m)는 2~3m, 대파(약 60cm)는 2, 3, 4m 각각 비등한 방제효과를 보였다. 각각의 작물모두 경엽처리 대비 약효가 미흡하였으며, 고추는 4m높이 살포시 방제효과가 현저히 낮았다.
        85.
        2018.10 구독 인증기관·개인회원 무료
        Gonggeom-ji is designated wetland protected area by the Ministry of Environment of Korea in 2011 because of it’s high biodiversity and historic value. It contains a reservoir, paddy and forest site which has diverse niches for insects. Three transect lines of 50m were designated. Data were collected in May, October, November in 2017 represented as seasons for spring, summer and autumn respectively. Quantitative methods were conducted along each transect line by sweeping and pitfall trap. Based on this study total of 1079 individuals of insect fauna were collected, representing 170 species in 60 families and 8 orders. The highest diversity, richness and evenness index were observed in the forest site in May(4.77, 8.6 and 0.91 respectively) and the highest dominance index was observed in the forest site in November(0.64). The highest similarity index was observed in the reservoir site in May and August(0.519).
        86.
        2018.10 구독 인증기관·개인회원 무료
        나무이는 감귤그린병, 제브라칩병과 같은 식물병원균의 매개충이 되는 경제적으로 중요한 해충그룹으로서, 귤나무이(Diaphorina citri Kuwayama)는 감귤산업에 큰 피해를 주는 감귤그린병(Citrus Huanglongbing Disease)을 매개하여 전 세계적으로 문제가 되고 있다. 최근 기후 온난화로 귤나무이가 유입될시 제주도를 비롯한 남부지방에서도 하우스 재배 감귤에는 충분히 월동 가능할 것으로 분석된다(감귤연구소, 2015).제주도지역이 경우, 묘목 수입에 의하여 전파될 가능성이 가장 클 것으로 예상된다. 이에 국내 유입 대비를 위한 예찰방법 및 동정법 개발이 필요한 실정이다. 제주도 지역을 2016년부터 현재까지 43지점을 조사한 결과, 18종의 나무이와 14종의 기주식물을 확인되었다. 또한 실내사육을 통해서 생육단계별 생태사진과 동정에 필요한 암수 생식기 표본, DNA 염기서열을 확보하였다. 현재까지 운향과를 기주로하는 나무이는 발견되지 않았으며 귤나무이 또한 발견되지 않았다.
        87.
        2018.10 구독 인증기관·개인회원 무료
        The hypopharyngeal gland (HPG) of the honeybee worker produces royal jelly (RJ) and has a developmental cycle closely related to the division of labor. In this study, we investigated to compare the HPG acini diameter of differently aged worker bees with high royal jelly producing colony (HRC) or less producing colony (LRC). Additionally, we also evaluated whether the fresh weight of the head is a reliable indicator of the developmental status of HPG. The HRC showed a significantly higher RJ production about two-times as compared with those of the LRC. We measured the HG-diameters on days 1, 3, 6, 9, 12, 15. The microscopic analysis revealed that the acini size of the HRC was significantly larger than the LRC. In addition, the acini diameter of HRC was 15% longer than the LRC on the first day after emerging. It was shown that the fastest development during 3 days which is preparing for nurse the brood. The HPG acini diameters increased in both colonies in a similar fashion until day 12 and then decreased. We also compared the fresh head weight of the experimental colonies, differences were similar to the development of HPG. Therefore, high royal jelly production may have a positive correlation between HPG acini size and the fresh head weight.
        88.
        2018.10 구독 인증기관·개인회원 무료
        Insect cuticle tanning (pigmentation and sclerotization) is a complex and vital process, which includes hydroxylation of initial amino acid, tyrosine, to DOPA and decarboxylation of DOPA to dopamine. In the pigmentation process, dopamine further undergoes two N-acylation reactions to yield N-acetyldopamine (NADA) and N-β-alanyldopamine (NBAD). In the former reaction, arylalkylamine N-acetyltransferase (AANAT1) converts dopamine to NADA, and in the later reaction, aspartate 1-decarboxylase (ADC) provides β-alanine, which is conjugated with dopamine catalyzed by NBAD synthase (Ebony) for production of NBAD. In this study, we performed functional genomics of TmAANAT1, TmADC and Tmebony to determine whether they are required for cuticle pigmentation in Tenebrio molitor adults. Loss of function of these genes by RNAi caused the significantly darker body color than that of control animals. Note that, although all phenotypes exhibited dark cuticle pigmentation, RNAi of either TmADC or Tmebony only altered brownish outer region of the cuticle to dark/black. In contrast, RNAi of TmAANAT1 had no effect on the brown hue of the outer cuticle layer, but less or no pigmented inner region of the cuticle became significantly darker than those of control adults. These results suggest that, like that seen in TcAANAT1- or TcADC-deficient Tribolium castaneum adults, NADA produced by a reaction by TmAANAT1 contributes the lighter inner cuticle layer(s), whereas NBAD appears to do the highly pigmented outer cuticle layer(s) of the cuticle of T. molitor adults. This work was supported by NRFs (NRF-2015R1A6A3A04060323 and NRF-2018R1A2B6005106).
        89.
        2018.10 구독 인증기관·개인회원 무료
        상주는 귀농 도시이자 농업 중심 도시로써 농업기술원을 유치할 만큼 생태학적 연구가치가 있는 친환경 도시이다. 특히 경천섬은 낙동강 본류에 있는 상주보 인근에 위치하고 있어 낙동강 생태 환경 연구의 중요 지역 중 하나이다. 하지만, 아직 경천섬에 대한 생물다양성 연구가 부족한 상태이다. 섬과 산지의 생태환경이 다르기 때문에 생물의 다양성도 다를 것이라 간주하고, 경천섬 주변의 생태학적 가치를 재조명할 기초자료를 조사하고자 한다. 이에 경천섬과 인근에 위치한 청룡사 길목 산지에 서식하는 곤충 채집을 통해 생물다양성을 조사하여 비교분석하는 것을 목적으로 한다. 채집방법은 직접잡기, 쓸어잡기, 함정트랩, 흡충관을 이용하였으며, 함정트랩에 사용된 유인제는 소주1.8ℓ와 빙초산350㎖를 혼합하여 사용하였다. 2018년 4월~8월 중 3회 채집과정을 수행하여 목표개체수를 확보하였고, 채집된 곤충은 에탄올을 채운 conical tube에 넣어 냉동실에 보관하여 보존성을 높였다. 채집과정에서 잡은 곤충들을 건조시키고 유사종끼리 분류하고 동정하는 과정을 거쳐 다양도지수, 우점도지수, 종풍부도지수, 종균등도지수, 유사도지수를 계산할 것이다. 기존에 알려지지 않았던 경천섬 일대의 생물다양성을 세세하게 분석하는 과정을 통해 경천섬의 생태학적 가치를 드러내고, 경천섬 일대의 자연환경관리와 보존에 필요한 정보나 체계적인 관리체계를 구축할 기초자료를 제공하고자 한다.
        90.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Acinetospora asiatica and Botrytella reinboldii are reported as two new records from S. Korea based on morphological studies and molecular analyses. A. asiatica is mainly characterized by the presence of sparsely branched uniseriate filaments with diffused meristematic zones, the formation of crampons at right angles, and the formation of plurilocular sporangia on both prostrate and erect filaments. B. reinboldii is characterized by the presence of irregularly alternating branched uniseriate filaments attached by rhizoids, and single or clustered plurilocular sporangia with a single opening. Molecular analyses of rbcL gene revealed that A. asiatica and B. reinboldii are placed within each clade of Acinetospora and Botrytella, respectively.
        4,000원
        91.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present study was conducted to evaluate the effects of high levels of nutrients on the growth performance, blood metabolites and carcass characteristics of Hanwoo cattle. Eighteen Hanwoo steers were fed two types of diets: 1) Nine animals were fed the conventional diet including typical levels of crude protein (CP) and total digestive nutrients (TDN), and 2) Nine animals were fed the treatment diet including high levels of CP and TDN. The average body weight (BW) and dry matter intake (DMI) were greater (P < 0.05) in the treatment group than in the conventional group at early and late fattening stages. Also, in the treatment group, the average daily gain (ADG) was greater (P < 0.05) at the late fattening stage. The serum total lipid and cholesterol levels were higher (P < 0.05) in the late fattening stage of treatment group. The carcass weight, total fat weight, longissimus muscle area and the grade of meat quality were also greater (P < 0.05) in the treatment group than the conventional diet group. This study demonstrates that high levels of CP and TDN exhibit a positive effect on the growth performance and carcass characteristics, indicating that high levels of CP and TDN can be used as a cost-effective feeding program for Hanwoo cattle by shortening the feeding period.
        4,000원
        92.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Pesticide application in agriculture provides significant benefits such as protection from disease, prevention of harmful insects, and increased crop yields. However, accurate toxicological tests and risk assessments are necessary because of many related adverse effects associated with pesticide use. In this review, we discuss and analyze residual pesticides contained in livestock feed in Korea. A pesticide residue tolerance standard for livestock feed has not been precisely established; so, risk assessments are required to ensure safety. Standards and approaches for animal criteria and appropriate methods for evaluating residual pesticides are discussed and analyzed based on technology related to animal product safety in Korea. The safety of livestock feed containing pesticides is assessed to establish maximum residue limits relative to pesticides. Analysis of residual pesticides in milk, muscle, brain, and fat was performed with a livestock residue test and safety evaluation of the detected pesticide was performed. Efficacy of organic solvent extraction and clean-up of feed was verified, and suitability of the instrument was examined to establish if they are effective, rapid, and safe. This review discussed extensively how pesticide residue tolerance in livestock feed and hazard evaluation may be applied in future studies.
        4,000원
        93.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Acute vascular rejection has been known as a main barrier occurring in a xenograted tissue of alpha 1,3-galactosyltransferase knock-out (GalT KO) pig into a non-human primate (NHP). Adenosine which is a final metabolite following sequential hydrolysis of nucleotide by ecto-nucleotidases such as CD39 and CD73, act as a regulator of coagulation, and inflammation. Thus xenotransplantation of CD39 and CD73 expressing pig under the GalT KO background could lead to enhanced survival of recipient NHP. We constructed a human CD39 and CD73 expression cassette designed for endothelial cell-specific expression using porcine Icam2 promoter (pIcam2-hCD39/hCD73). We performed isolation of endothelial cells (pAEC) from aorta of 4 week-old GalT KO and membrane cofactor protein expressing pig (GalT-MCP/-MCP). We were able to verify that isolated cells were endothelial-like cells using immunofluorescence staining analysis with von Willebrand factor antibody, which is well known as an endothelial maker, and tubal formation assay. To find optimal condition for efficient transfection into pAEC, we performed transfection with GFP expression vector using four programs of nucleofection, M-003, U-023, W-023 and Y-022. We were able find that the program W-023 was optimal for pAEC with regard to viability and transfection efficiency by flow cytometry and fluorescent microscopy analyses. Finally, we were able to obtain GalT-MCP/-MCP/CD39/CD73 pAEC expressing CD39 and CD73 at levels of 33.3% and 26.8%, respectively. We suggested that pACE isolated from GalT-MCP/-MCP pig might be provided as a basic resource to understand biochemical and molecular mechanisms of the rejections and as an alternative donor cells to generate GalT-MCP/-MCP/CD39/CD73 pig expressing CD39 and CD73 at endothelial cells.
        4,000원
        94.
        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
        96.
        2018.05 구독 인증기관·개인회원 무료
        In recent years, pavement distresses have been caused by diverse factors such as spalling, deterioration of repaired sections, blow-up, and alkali aggregate reaction due to changing climate environment of a concrete pavement and its construction and maintenance conditions (supply of materials, increase in use of de-icers, etc,). As a leading repair method for deteriorated concrete pavements, partial-depth repair is implemented in accordance with guidelines of material properties for joints of a concrete pavement and field application evaluation systems, but still some of the repaired sections become deteriorated again at an early stage due to poor construction quality and failure of response to environmental impacts. Distresses that can be corrected with partial-depth repairs are largely divided into those of repair materials and of the existing pavement bonded to repair materials, and combined distress of repair materials and the existing pavement. Although re-repair methods should be different by distress type and scale than conventional pavement repair methods, appropriate repair methods and guidance for re-repairs have not been in place so far, and therefore currently, re-repair practices follow the existing manual of partial depth repairs. Therefore, this study evaluated concrete bond characteristics by removing method and repair scope for an experimental section of frequently distressed pavements to determine a re-repair scope and method for deteriorated partial depth repair sections of concrete pavement, the number of which has increased over time.
        97.
        2018.04 구독 인증기관·개인회원 무료
        참나무와 서어나무는 온대지역에 걸쳐 넓게 분포하고 있으며, 다양한 초식곤충의 먹이원이 되는 것으로 알려져 있다. 이 연구에서는 지리산국립공원 온대림에서 참나무림(반선)과 서어나무림(상선암)에서 초식곤충 활동량을 알고자 하였다. 각 조사지역에 0.1ha의 방형구를 설치하여 참나무와 서어나무의 분포를 확인 한 뒤 개체별로 초식곤충의 활동량인 잎 손상 지수를 측정하였다. 잎 손상 지수는 손상 퍼센트로 환산하여 분석하였다. 측정결과 전체 4,413장의 잎을 관찰하였으며, 참나무림에서는 2,683장, 서어나무림에서는 1,730장의 잎이 조사되었다. 초식곤충의 활동량은 참나무림과 서어나무림에서 각각 차이를 보였으며 서어나무림인 상선암에서 참나무의 식흔량과 서어나무의 식흔량 이 참나무림인 반선보다 모두 높게 나타났다. 이 연구결과를 바탕으로 온대림 우점 수종인 참나무와 서어나무에서 초식곤충의 활동량을 정량적으로 추정할 수 있을 것으로 생각된다.
        98.
        2018.04 구독 인증기관·개인회원 무료
        감귤그린병(Citrus Huanglongbing Disease)은 전 세계적으로 감귤산업에 가장 큰 피해를 주는 병해로 국내 미분포종인 귤나무이(Diaphorina citri Kuwayama)가 매개충으로 알려져 있다. 바이러스에 감염된 나무는 5~12년내에 대부분 고사하며 열매는 크지 못하고 색이 들지 않는 증상을 보여 상품성을 저해시킨다. 현재 접목, 묘목, 매개충등의 유입으로 전 세계적으로 확산되고 있는 실정이다. 귤나무이의 국내 분포가능성이 꾸준히 제시되면서 유입 대비를 위한 예찰방법 및 동정법 개발이 필요한 실정이다. 제주도에는 총 33종이 분포하는 것으로 알려져 있으며(권, 1983; Cho & burckhardt, 2017) 2016년부터 지금까지의 조사로 11종의 나무이와 10종의 기주식물을 확인되었다. 귤나무가 속해있는 운향과를 기주로 하는 나무이는 발견되지 않았다.
        99.
        2018.04 구독 인증기관·개인회원 무료
        Insect structural cuticular proteins (CPs) play a major role in determining the diverse physical properties of the cuticle as a result of interactions/cross-linking among themselves and with chitin. CP genes compose a large gene family and have been classified more than ten distinct families based on the presence of unique amino acid sequence motifs. In this study, we performed RNAi-based functional analysis of eleven genes (TcCPLCP1-11) in Tribolium castaneum, which belong to CPLCP (Cuticular Proteins of Low Complexity, Proline rich) cuticular protein family. RNAi for TcCPLCP7-11 caused lethal pupal-adult molting defects and/or abnormal cuticle morphology in the resulting adults. Ultrastructural defects of the cuticles from TcCPLCP7-11-deficient insects by TEM are also discussed.
        100.
        2018.04 구독 인증기관·개인회원 무료
        Eggs from the mosquito genus Aedes exhibit high desiccation resistance that likely facilitate spreading some of them as a vector of human disease throughout the world. However, molecular mechanism underlying the embryonic resistant to desiccation has not well understood. In this study, we performed functional study of two ovary-specific yellow genes, AalY-g and AalY-g2, in the Asian tiger mosquito, Aedes albopictus. The eggs obtained from AalY-g or AalY-g2 RNAi females showed poor desiccation resistance. TEM analysis revealed that, unlike that seen in the dsEGFP-control eggs, no high electron-dense outer-endochorion was evident in the eggs from AalY-g- or AalY-g2-deficient females. These results suggest that both yellow genes at least play roles in the chorion formation, which appears to be critical for integrity and desiccation resistance in Ae. albopictus eggs.
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