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        검색결과 123

        46.
        2017.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We study the angular correlation function of bright (Ks ≤ 19.5) Extremely Red Objects (EROs) selected in the Subaru GTO 2 deg2 field. By applying the color selection criteria of R − Ks > 5.0, 5.5, and 6.0, we identify 9055, 4270, and 1777 EROs, respectively. The number density is consistent with similar studies on the optical − NIR color selected red galaxies. The angular correlation functions are derived for EROs with different limiting magnitude and different R −Ks color cut. When we assume that the angular correlation function w() follows a form of a power-law (i.e., w() = A−), the value of the amplitude A was larger for brighter EROs compared to the fainter EROs. The result suggests that the brighter, thus more massive high-redshift galaxies, are clustered more strongly compared to the less massive galaxies. Assuming that EROs have redshift distribution centered at hzi ∼ 1.1 with z = 0.15, the spatial correlation length r0 of the EROs estimated from the observed angular correlation function ranges ∼ 6-10 h−1Mpc. A comparison with the clustering of dark matter halos in numerical simulation suggests that the EROs are located in most massive dark matter halos and could be progenitors of L∗ elliptical galaxies.
        4,000원
        47.
        2016.10 구독 인증기관·개인회원 무료
        Pine wilt disease (PWD) is one of the most important forest tree diseases, especially in the East Asian countries of Japan, China, and Korea. The Japanese pine sawyer, Monochamus alternatus Hope, is the PWN vector for Japanese red pine and Japanese black pine while Monochamus saltuarius Gebler is the vector for Korean white pine. Various control methods, such as aerial pesticide applications, biological control using parasitoids and fumigant such as methyl bromide are used. But the PWD still has spread. Therefore, we were selected effective aerial insecticides. Susceptibility of M. saltuarius and M. alternatus adults were investigated using 9 insecticides which are available in the market in Korea. And then, we tested them to the Apis mellifera to vertify the environmental impact.
        48.
        2016.10 구독 인증기관·개인회원 무료
        Pseudococcus longispinus, a notorious cosmopolitan pest species of mealybugs, known to be distributed indoors in Korea since 2002, is found to be mixed with another species, Pseudococcus orchidicola. Finding P. orchidicola as a pest of tropical plants in Korea is rather unexpected because of their main distribution in Pacific area and South Asia. However, all the available information from morphology, molecule and advices on identification from mealybug specialists indicated this is best matching P. orchidicola. Morphological, molecular and some biological notes on P. orchidicola are provided with some adult and nymphal images, and compared with P. longispinus. A full discussion mainly on identity and distribution of P. orchidicola is given.
        49.
        2016.10 구독 인증기관·개인회원 무료
        Monochamus saltuarius is one of the insect vector of pine wilt disease with Monochamus alternatus. The present study aimed to investigate the dose to induce sterile and the effect of sterility according to the gender of M. saltuarius. As the electron beam irradiation dose increased, the hatchability, adult eclosion rate and longevity of the former mid and late maturation feeding stage of adults was slightly reduced. However, there was no difference between these two adults. In addition, female adults were more sensitive to the electron beam than the male adults. Hatchability of the F1 generation of ♂T × ♀N o r♀T × ♂N (T: 200 Gy electron beam irradiation, N: 0 Gy) was completely suppressed. As electron beam irradiation dose increased, the fecundity of female adults were slightly decreased. Results by comet assay showed that electron beam irradiation induced as dose increased DNA damage in M. saltuarius adults. These results suggest that SIT using electron beam may be useful for control of M. saltuarius.
        50.
        2016.04 구독 인증기관·개인회원 무료
        Monochamus alternatus is one of the insect vector of pine wilt disease with Monochamus saltuarius. The present study aimed to investigate the dose to induce sterile and the effect of sterility according to the gender of M. alternatus. As the electron beam irradiation dose increased, the longevity of the mid and late maturation feeding stage of adults was slightly reduced. However, there was no difference between these two adults. In addition, female adults were more sensitive to the electron beam than the male adults. Hatchability of the F1 generation of ♂T×♀N or ♀T×♂N (T: 200 Gy electron beam irradiation, N: 0 Gy) was completely suppressed. As electron beam irradiation dose increased, the fecundity of female adults were slightly decreased. Results by comet assay showed that electron beam irradiation induced as dose increased DNA damage in M. alternatus adults. These results suggest that SIT using electron beam may be useful for control of M. alternatus.
        51.
        2016.04 구독 인증기관·개인회원 무료
        Mealybugs (Hemiptera: Pseudococcidae) are major pests of a wide range of crops and ornamental plants worldwide, and represented by 56 species in Korea. Occurrence of, or damage by, the longtailed mealybug, Pseudococcus longispinus Targioni-Tozzetti has not been reported since 2002. However, for the first time in many years, P. longispinus was reported at Phalaenopsis orchids by Kim et al in 2015. Therefore, the present study aimed to investigate the distribution of P. longispinus which is usually found inside a greenhouse or a building where the host plants are. We have collected 129 mealybug samples at 254 sites from Korea. Among these, 27 of P. longispinus and 62 of an unidentified Pseudococcus species were found mainly in ornamental plants such as Heteropanax fragrans, commonly known as happy trees in Korea. Morphological characteristics of the unidentified mealybug were very similar to those of P. longispinus. However, the genetic variability in COI sequence comparison was significantly different between the two species. Further studies are needed to clarify the valid name for this unidentified species, and we are currently working on it.
        52.
        2015.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Dynamical analysis of compact groups provides important tests of models of compact group formation and evolution. By compiling 2066 redshifts from FLWO/FAST, from the literature, and from SDSS DR12 in the fields of compact groups in McConnachie et al. (2009), we construct the largest sample of compact groups with complete spectroscopic redshifts in the redshift range 0.01 < z < 0.22. This large redshift sample shows that the interloper fraction in the McConnachie et al. (2009) compact group candidates is  42%. A secure sample of 332 compact groups includes 192 groups with four or more member galaxies and 140 groups with three members. The fraction of early-type galaxies in these compact groups is 62%, higher than for the original Hickson compact groups. The velocity dispersions of early- and late-type galaxies in compact groups change little with groupcentric radius; the radii sampled are less than 100 h−1 kpc, smaller than the radii typically sampled by members of massive clusters of galaxies. The physical properties of our sample compact groups include size, number density, velocity dispersion, and local environment; these properties slightly differ from those derived for the original Hickson compact groups and for the DPOSS II compact groups. Differences result from subtle differences in the way the group candidates were originally selected. The abundance of the compact groups changes little with redshift over the range covered by this sample. The approximate constancy of the abundance for this sample is a potential constraint on the evolution of compact groups on a few Gigayear timescale.
        5,200원
        53.
        2015.12 구독 인증기관 무료, 개인회원 유료
        The antioxidant capacities, total phenolic contents (TPC), and total quercetin contents (TQC) of a red (Chenjujuck), a yellow (Sunpower), and a white (Grasier) onion cultivar were determined in this study. Onion was separated into edible portion and dry skin. In the case of edible portion, the yellow onion had the highest antioxidant activity, followed by the red onion. The white onion showed neither antioxidant activity nor quercetin compounds. On the other hand, the dry skin of the red onion showed higher antioxidant activity than yellow onion skin. The white onion skin had slight antioxidant activity, low TPC, and no quercetin compounds. In addition, the flavonoid compounds of the edible portion and dry skins of these colored onions were analyzed by UFLC(ultra-fast liquid chromatography). The major compounds were quercetin 3,4-diglucoside and quercetin 4- glucoside in yellow and red onion edible portion, whereas the major compounds in yellow and red onion skins were quercetin 4- glucoside, quercetin, and quercetin 3,4-diglucoside.
        4,000원
        56.
        2013.04 구독 인증기관·개인회원 무료
        The toxicity of red pine needle hydrodistillate, its constituents, and 12 structurally related compounds to third instar larvae of insecticide-susceptible Aedes aegypti and wild Aedes albopictus was examined using a direct-contact bioassay. Results were compared with those of the currently used larvicides fenthion and temephos. The red pine needle hydrodistillate constituents were identified by GC-MS and co-elution of authenticated samples following co-injection. Based on 24 h LC50 values, 3-carene (8.60–9.33 mg/L), limonene (10.34–10.77 mg/L), and thymol (10.65–11.45 mg/L) were the most toxic constituents. The moderate toxicity was produced by (1S)-(–)-α-pinene, p-cymene, geranyl acetate, myrcene, and β -caryophyllene (LC50, 27.62–38.01 and 28.61–39.52 mg/L). Overall, these compounds were less effective than either fenthion (LC50, 0.012–0.022 mg/L) or temephos (LC50, 0.010–0.015 mg/L). In the light of global efforts to reduce the level of highly toxic synthetic insecticides in the agricultural environment, red pine needle hydrodistillate and the compounds described merit further study as potential larvicides for the control of mosquito populations.
        58.
        2008.12 구독 인증기관 무료, 개인회원 유료
        Bicuculline is one of the most commonly used GABAд eceptor antagonists in electrophysiological research. Because of its poor water solubility, bicuculline quaternary ammonium salts such as bicuculline methiodide (BMI) and bicuculline methbromide are preferred. However, a number of studies have shown that BMI has non-GABAд eceptor-mediated effects. The substantia gelatinosa (SG) of the trigeminal subnucleus caudalis (Vc) is implicated in the processing of nociceptive signaling. In this study, we investigated whether BMI has non-GABA receptor-mediated activity in Vc SG neurons using a whole cell patch clamp technique. SG neurons were depolarized by application of BMI (20M) using a high Cℓ⁻ipette solution. GABA ( 30-100μM) also induced membrane depolarization of SG neuron. Although BMI is known to be a GABAд receptor antagonist, GABA-induced membrane depolarization was enhanced by co-application with BMI. However, free base bicuculline (fBIC) and picrotoxin (PTX), a GABAд and GABAс receptor antagonist, blocked the GABA-induced response. Furthermore, BMI-induced membrane depolarization persisted in the presence of PTX or an antagonist cocktail consisting of tetrodotoxin (Nα+ nnel blocker),AP-5 (NMDA receptor antagonist), CNQX (non-NMDA receptor antagonist), and strychnine (glycine receptor antagonist). Thus BMI induces membrane depolarization by directly acting on postsynaptic Vc SG neurons in a manner which is independent of GABAд receptors. These results suggest that other unknown mechanisms may be involved in BMI-induced membrane depolarization.
        4,000원
        60.
        2008.10 구독 인증기관·개인회원 무료
        In order to establish a year round indoor-rearing system for Copper butterflies; large copper butterfly, Lycaena dispar, the effect of temperature on larval development and diapause was investigated. Temperature has been suggested as an important factor regulating the developmental rate, length of life, and survival rate from insect. As temperature increased, the developmental period was gradually shorten. The developmental periods of large copper larvae had a range of 11.0 days to 28.5 days at 30℃ and 17.5℃ respectively. The highest emergence rate was 94.2% recorded at 20℃. And the low emergence rate was 72.7% under 17.5℃. We investgated the sensitive stages to diapause induction in the larger copper effect of temperature and photoperiod. The experiment involves transfer of individuals from diapause averting (LD 16:8h, 25℃) to diapause inducing condition (LD 8:16h, 20℃) at various stages. Diapause was induced in 95.2% insect transferred at hatching larvae, in 15.6% of insects transferred at 2nd stadium molt, in 0% of insects transferred at after 3rd stadium molt. Percentage diapause induction increase with the length of short days and low temperature experienced. The main stage sensitive to photoperiod and temperature induction of diapause determination is the early first larval instar. The diapause induction began 14 days and ended 20 days after hatching larvae (LD 8:16h, 20℃).
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