• The Plant Pathology Journal
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• v.30 no.4
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• pp.367-374
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• 2014

Genomes contain a large number of unique genes which have not been found in other species. Although the origin of such "orphan" genes remains unclear, they are thought to be involved in species-specific adaptive processes. Here, we analyzed seven orphan genes (MoSPC1 to MoSPC7) prioritized based on in planta expressed sequence tag data in the rice blast fungus, Magnaporthe oryzae. Expression analysis using qRT-PCR confirmed the expression of four genes (MoSPC1, MoSPC2, MoSPC3 and MoSPC7) during plant infection. However, individual deletion mutants of these four genes did not differ from the wild-type strain for all phenotypes examined, including pathogenicity. The length, GC contents, codon adaptation index and expression during mycelial growth of the four genes suggest that these genes formed during the evolutionary history of M. oryzae. Synteny analyses using closely related fungal species corroborated the notion that these genes evolved de novo in the M. oryzae genome. In this report, we discuss our inability to detect phenotypic changes in the four deletion mutants. Based on these results, the four orphan genes may be products of de novo gene birth processes, and their adaptive potential is in the course of being tested for retention or extinction through natural selection.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.48.3-49
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• 2017

Interplanetary space of the solar system contains a large number of dust particles, referred to as Interplanetary Dust Particles (IDPs) cloud complex. They are observable through meteors and zodiacal lights. The relative contribution of possible sources to the IDPs cloud complex was an controversial topic, however, recent research (Yang & Ishiguro, 2015 and references therein) suggested a dominance of cometary origin. In this study, we numerically investigated the orbital evolution of cometary dust particles, with special concerns on different evolutionary tracks and its consequences according to initial orbits, size and particle shape. The effect of dust particle density and initial size-frequency distribution (SFD) were not decisive in total cloud complex mass and mass supply rate, when these physical quantities are confined by observed zodiacal light brightness and dust particle SFD at 1 au. We noticed that, if we assume the existence of fluffy aggregates discovered in the Earth's stratosphere and the coma of 67P/Churyumov-Gerasimenko, the required mass supply rate decreases significantly. We also found out that close encounters with planets (mostly Jupiter) are the dominating factor of the orbital evolution of dust particles, as the result, the lifetime of cometary dust particles are shorter than Poynting-Robertson lifetime (around 250 thousand years). As another consequence of severe close encounters, only a small fraction of cometary dust particles can be transferred into the orbit < 1 au. This effect is significant for large size particles of ${\beta}$ < 0.01. The exceptional cases are dust particles ejected from 2P/Encke and active asteroids. Because they rarely encounter with Jupiter, most dust particles ejected from those objects are governed by Poynting-Robertson effect and well transferred into the orbits of small semimajor axis. In consideration of the above effects, we directly estimated probability of mutual collisions between dust particles and concluded that mutual collisions in the IDPs cloud complex is mostly ignorable, except for the case of large sized particles from active asteroids.

• The Plant Pathology Journal
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• v.29 no.3
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• pp.260-273
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• 2013

The incidence and distribution of Tobacco mosaic virus (TMV) and related tobamoviruses was determined using an enzyme-linked immunosorbent assay on 1,926 symptomatic horticultural crops and 107 asymptomatic weed samples collected from 78 highly infected fields in the major horticultural crop-producing areas in 17 provinces throughout Iran. The results were confirmed by host range studies and reverse transcription-polymerase chain reaction. The overall incidence of infection by these viruses in symptomatic plants was 11.3%. The coat protein (CP) gene sequences of a number of isolates were determined and disclosed to be a high identity (up to 100%) among the Iranian isolates. Phylogenetic analysis of all known TMV CP genes showed three clades on the basis of nucleotide sequences with all Iranian isolates distinctly clustered in clade II. Analysis using the complete CP amino acid sequence showed one clade with two subgroups, IA and IB, with Iranian isolates in both subgroups. The nucleotide diversity within each subgroup was very low, but higher between the two clades. No correlation was found between genetic distance and geographical origin or host species of isolation. Statistical analyses suggested a negative selection and demonstrated the occurrence of gene flow from the isolates in other clades to the Iranian population.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.104.1-104.1
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• 2011

We present a catalog of infrared supernova remnants (SNRs) in the Large Magellanic Cloud (LMC). We have searched the Spitzer archival data for infrared counterparts to all 45 known SNRs in the LMC, and identified 21 which is 47% of the known SNRs. Seven of them are newly detected: SNR 0450-70.9, SNR in N4, N103B, DEM L241, DEM L249, DEM L316A, and DEM L316B. All newly discovered SNRs show emission at several IRAC 3.4, 4.5, 5.8, and 8.0 micron bands and/or MIPS 24 and 70 micron bands. Most SNRs show shell structures. We derive infrared fluxes of these newly detected SNRs. The catalog contains general information of each SNR such as location, age, and SN type together with AKARI and/or Spitzer fluxes. For the entire SNR sample, we examine their infrared colors and the possible correlation of the infrared fluxes with the fluxes at other wavelengths. For the newly detected SNRs except the SNR in N4, we also performed follow-up imaging observations of [Fe II] 1.644 micron line using IRIS2 mounted on the Anglo Australian Telescope. Three out of six SNRs show [Fe II] emission corresponding to their infrared shells. [Fe II] knots are also detected in N103B which show good spatial correlation to infrared emission seen at Spitzer images as well as knotty $H{\alpha}$ emission. We investigate the characteristics and origin of the infrared emission in individual SNRs, and discuss the environmental and evolutionary effects.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.3
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• pp.220-239
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• 2021

Grasses (Poaceae) belong to the biggest plant family among angiosperms and it cover around 20% of the earth's surface. The members of this family are mostly utilized as food resources by humans and animals but they are also valuable in terms of evolution and ecology. The member of the subfamily Pooideae represents, temperate grasses, and includes a number of economically important crops and belongs to the clade BOP (including the subfamilies Bambooideae, Oryzeae, and Pooideae). This subfamily is the largest among all grass families. The special features of this subfamily are cold acclimation and vernalization. The members of Pooideae subfamily with the aforementioned special features are thought to have evolved in the Cenozoic era when the temperature on earth started to cool down, which triggered the diversification of this subfamily through adaptation to cold weather. The agricultural origin of wheat, barley, oat, and rye is attributed to fertile crescent and thereafter they were domesticated through Neolithic evolution. The history of domestication of each Pooideae crop is distinct and is based on their purpose. Recently, breeding of these crops is performed differently due to the development of new technologies such as genomics and genome editing. This review article summarizes the evolutionary history of the members of the subfamily Pooideae and use of pre-existing information for future breeding efforts.

• Journal of The Korean Astronomical Society
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• v.54 no.4
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• pp.129-137
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• 2021

It has been established that the acoustic mode parameters of the Sun and Sun-like stars vary over activity cycles. Since the observed variations are not consistent with an activity-related origin, even Sun-like stars showing out-of-phase changes of mode frequencies and amplitudes need to be carefully studied using other observational quantities. In order to test whether the presumed relations between the global seismic parameters are a signature of the stellar activity cycle, we analyze the photometric light curve of HD 49933 for which the first direct detection of an asteroseismic signature for activity-induced variations in a Sun-like star was made, using observations by the CoRoT space telescope. We find that the amplitude of the envelope significantly anti-correlates with both the maximum frequency of the envelope and the width of the envelope unless superflare-like events completely contaminate the light curve. However, even though the photometric proxy for stellar magnetic activity appears to show relations with the global asteroseismic parameters, they are statistically insignificant. Therefore, we conclude that the global asteroseismic parameters can be utilized in cross-checking asteroseismic detections of activity-related variations in Sun-like stars, and that it is probably less secure and effective to construct a photometric magnetic activity proxy to indirectly correlate the global asteroseismic parameters. Finally, we seismically estimate the mass of HD 49933 based on our determination of the large separation of HD 49933 with evolutionary tracks computed by the MESA code and find a value of about 1.2M_☉ and a sub-solar metallicity of Z = 0.008, which agrees with the current consensus and with asteroseismic and non-asteroseismic data.

• Journal of the Economic Geographical Society of Korea
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• v.17 no.2
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• pp.249-263
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• 2014

Established as the first science park in the world in the late 1950's, the Research Triangle Park(RTP) has not jut grown significantly but also has been successful in the transition from the exogenous development model to the endogenous development model. In this context, this paper attempts to explore the evolutionary path of the RTP by drawing upon the concept of triple-helix spaces of regional innovation. Firstly, the three research universities in the triangle area, as a knowledge space, played a fundamental role for forming the RTP. However, it is difficult to say that the regional universities, as opposed to the Silicon Valley and the Boston area, have had a significant impact on inducing the dynamics of the cluster evolution and the triple helix spaces. Secondly, it can be argued that the North Carolina's Board of Science and Technology, which was formed in 1961 but traced back to the 1950's in its origin, has been a centerpiece of a consensus space that makes a contribution to creating, sustaining and transforming the RTP as a triple-helix-based innovation cluster. Thirdly, there have been a plenty of agents to be an innovation space in the RTP. Particularly, the North Carolina Biotechnology Center(NCBC) and the Microelectronic Center of North Carolina(MCNC) have been the boundary permeable agents to make triple-helix agents interact. Today, the RTP has the triple-helix spaces with the structure that a consensus spaces is centered on out of the three, but all of those are inter-connected and influenced by each other. It can be claimed that the RTP today shows the dynamic structure of cluster evolution in a way in which the existing industry sectors have adapted to the changes in external environment and the new industry sectors have emerged at the same time.

• The Korean Journal of Mycology
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• v.27 no.6 s.93
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• pp.406-411
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• 1999

The phylogenetic relationships of black-spored basidioid taxa (mainly coprinoid taxa) and an agaric-like gastroid taxon were studied. The sequences of internal transcribed spacer regions (ITS) partially including 17S, 25S and 5.8S from 14 species (Coprinus comatus, C. atramentarius, C. micaceus, C. cinereus, C. disseminatus, C. rhizophorus, C. radians, C. echinosporus, Psathyrella candolleana, Podaxis pistillaris, Conocybe lactea, Bolbitius demangei, Agaricus balzei, and Stropharia rugosoannulata) were compared. The reciprocal homologies of ITS sequences among these species were in the range of $38.7{\sim}77.2%$. Black-spored taxa were classified into four clusters. Cluster I comprised C. micaceus, C. radians, and C. disseminata. Cluster II is consisted of C. cinereus, C. echinosporus, C. rhizophorus, and C. atramentarius. On the other hand, C. comatus is in cluster III with Agaricus balzei and Podaxis pistillaris even though this species is belonging to the section Coprinus in morphological aspect. Psathyrelloid taxon is included in cluster II. The question of the origin of secotioid (agaric-like) fungi has been taken, though largely on theoritical suggestions as to whether gastroid taxa give rise to agarics with secotioid taxa as intermediates or whether secotioid taxa are evolutionary novelities arising from many distinct groups of agarics. In this relationship, it was shown that secotioid taxon evolved from within agaric species.

• Korean Journal of Plant Taxonomy
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• v.35 no.4
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• pp.273-285
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• 2005

Genetic variation of notorious invasive plants, common ragweed (Ambrosia artemisiifolia L.) and giant ragweed (Ambrosia trifida L.) were examined using the internal transcribed spacer (ITS) sequences of nuclear ribosomal DNA. A total of 18 different ITS types were detected from 156 individuals of common ragweed sampled mainly from the southern part of Korean peninsula whereas four types were identified from 46 individuals of giant ragweed. High sequence diversity observed from common ragweed in Korean populations was interpreted as multiple introduction. Genetic recombination was suggested as possible method for the production of some of the ITS types while point mutation was mainly responsible for the origin of the sequence diversity. This study provided some of basic genetic information needed for understanding of the evolutionary process in ragweed during invasion.

• Korean Journal of Plant Taxonomy
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• v.47 no.2
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• pp.161-169
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• 2017

The genome size is one of the basic characters of an organism, and it is widely applied in various fields of biology, such as systematics, breeding biology, population biology, and evolutionary biology. This factor was recently highlighted in genome studies because choosing a representative of a plant group having the smallest genome size is important for the efficiency of a genome project. For the estimation of the genome size, flow cytometry has recently been highlighted because it is a convenient, fast, and reliable method. In this study, we report the genome sizes of 15 taxa of Lamiaceae from nine genera distributed in Korea using flow cytometry. Data pertaining to the genome size for all of our species have not been reported thus far, and the data from Agastache, Clinopodium, Elsholtzia, and Isodon are the first reported for each genus. The genome sizes of 15 genera and 39 species were reported to the Plant DNA C-values Database (http://data.kew.org/cvalues/). Scutellaria indica L. has a genome size of 0.37 pg (1C). This is the fourth smallest value among the 98 Lamiaceae taxa in the Angiosperm DNA C-value Database, indicating that this taxon can be used as a reference species in the genome studies in Lamiaceae as a native Korean species. The largest genome size observed in this study is in Phlomis umbrosa Turcz. (1C=2.60 pg), representing the possible polyploidy origin of this species in the family.