• Asian-Australasian Journal of Animal Sciences
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• v.22 no.8
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• pp.1102-1106
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• 2009

The Tibetan Mastiff is one of the most archaic, ferocious and the largest dogs in the world. The Kunming dog is the chief working-dog breed in China. In this study, ten microsatellite loci were used to assess the genetic diversity and evolutionary relationships in six dog breeds, including Tibetan Mastiff, Kunming dog, Belgian Malinois, Labrador Retriever, English Springer Spaniel, and German Shepherd. The highest genetic diversity was exhibited by the Tibetan Mastiff, indicating useful protection and little inbreeding in the modern Tibetan Mastiff. Higher genetic diversity was observed in European breeds, supporting the hypotheses that breeders outcross their pure breed dogs occasionally to avoid deleterious effects in Europe. Evolutionary relationships showed that English Springer Spaniel and Labrador Retriever were clustered together, then with the Tibetan Mastiff, consistent with previous cluster results. German Shepherd and Kunming dog were grouped together, coinciding with the breeding history of Kunming dog. It is the first time that Tibetan Mastiff and Kunming dog have been analyzed with microsatellites.

• Journal of Ecology and Environment
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• v.36 no.3
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• pp.205-210
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• 2013

Cicuta virosa L. (Apiaceae) is a perennial emergent plant designated as an endangered species in South Korea. According to the former records, only four natural habitats remain in South Korea. A former study suggested that three of four populations (Pyeongchang: PC, Hoengseong: HS, Gunsan: GS) would be classified as different ecotypes based on their different morphological characteristics and life cycle under different environmental conditions. To evaluate this suggestion, we estimated genetic diversity in each population and distance among three populations by random amplification of polymorphic DNA. Seven random primers generated a total of 61 different banding positions, 36 (59%) of them were polymorphic. Nei's gene diversity and the Shannon diversity index increased in the order of PC < HS < GS, which is the same order of population size. In the two-dimensional (2D) plot of first two principal components in principal component analysis with the presence of 61 loci, individuals could be grouped as three populations easily (proportion of variance = 0.6125). Nei's genetic distance for the three populations showed the same tendency with the geographical distance within three populations. And it is also similar to the result of discriminant analysis with the morphological or life-cycle factors from the previous study. From the results, we concluded that three different populations of C. virosa should be classified as ecotypes based on not only morphology and phenology but genetic differences in terms of diversity and distance as well.

• Korean Journal of Agricultural and Forest Meteorology
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• v.3 no.2
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• pp.114-120
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• 2001

Ginkgo biloba L. has been planted in the city as street trees because reported as resistant species to air pollutant. Especially, the trees planted on the street of 'Cheongro', Mt. 'Nam', and 'Jamsil' have been exposed to air pollutant for a long time. This study was conducted to examine chlorophyll contents and genetic variation of Ginkgo biloba in the areas. Chlorophyll contents measured in the above three areas were variable although the the diameter at breast height measured in 'Cheongro' and Mt. 'Nam' were constant. In addition, the result showed positive relation between chlorophyll contents and DBH in this study. Eight enzyme systems were analyzed in megagametophytes which were collected in the areas and separated to two groups based on chlorophyll contents. All the enzymes appeared to be polymorphic : Got-2, Pgi-2, Pgm, Acon, Mnr, Mdh, Skdh, and 6Pgd. The sensitive (S) groups varied from 1.253 to 2.571 in the genetic diversity and the tolerant (T) groups ranged from 1.416 to 2.825. The observed single locus heterozygosities (H$_{0}$) ranged from 0.056 to 0.611 in the S groups, and from 0.179 to 1.643 in the T groups. The expected heterozygosities (H$_{e}$) ranged from 0.208 to 0.629 in the S groups and from 0.321 to 0.658 in the T groups. In addition, the H$_{0}$ values averaged over all loci were 0.326 for the T groups and 0.299 for the S group, respectively. A difference between the two groups was 0.027. The T groups had the unique alleles and genotypes and all the parameters for genetic diversity showed that the T groups had higher genetic diversity than the S groups.s. genetic diversity than the S groups.

• Korean Journal of Plant Resources
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• v.26 no.2
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• pp.320-327
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• 2013

This study was carried out to address an efficient in vitro regeneration system from seed-derived callus of Phragmites communis, and to evaluate genetic variations of the regenerants using ISSR markers. Shoot regeneration via calli was greatly influenced by N6 medium compared with MS medium, and plant regeneration frequency was 90% in N6 supplemented with BA 0.25 mg/L and BA 0.5 mg/L. According to ISSR analysis of the thirty regenerants, out of 94 loci detected overall, 16 were identified to be polymorphic with a rate (PR) of 17.0%. The mean gene diversity (h) of different in vitro condition was 0.03 and ranged from 0.008 for N6 with BA 5 mg/L, to 0.040 for MS with IAA 0.1 mg/L+kinetin 2 mg/L. The results indicate that the regenerants have a low genetic variation, and ISSR analysis is effective to detect genetic variation of regenerants.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.1
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• pp.9-18
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• 2003

In this paper, we analyzed the throughput of DS/CDMA system applying packet combining scheme combined with Type- I Hybrid ARQ scheme over AWGN channel and Nakagami fading channel with RAKE receiver. As the parameter for analysis, we used number of combined packet(L), number of diversity branch$({L_c})$, fading index(m), and length of packet(N), and used CRC-12 error detection code and (2,1,3) convolutional code. As a results, we found that throughput of system over Nakagami fading channel with RAKE receiver was superior to throughput over AWGN channel, and throughput of system decreases rapidly as channel degrades when number of combined packet(L) was increased. However throughput of system with the combining scheme was achieved even at low ${E_b}/{N_o}$. Also, we found that throughput of system was increased when fading index(m) and number of diversity branch$({L_c})$ were increased, but it was decreased when number of user(K) and length of packet(N) were increased.

• Journal of Microbiology and Biotechnology
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• v.16 no.8
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• pp.1276-1284
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• 2006

Listeria monocytogenes is a well-known high-risk foodborne pathogen that grows at refrigeration temperature and is responsible for outbreaks of listeriosis. We report here the incidence of L. monocytogenes in fresh chicken carcasses and present genetic diversity of L. monocytogenes isolates. In this study, 25 g of chicken carcasses from markets in Korea were examined according to the FDA method, and presumptive isolates were confirmed by multiplex PCR assay. L. monocytogenes isolates were analyzed by Pulsed-Field Gel Electrophoresis using restriction enzymes, ApaI and AscI, to obtain strain-specific DNA fragments profiles. Antimicrobial resistance of L. monocytogenes strains against generally used antibiotics (Penicillin G, Kanamycin, Tetracycline, Vancomycin, Cephalothin, Rifampicin, Erythromycin, Ampicillin, Gentamicin, Streptomycin, and Chloramphenicol) were analyzed by NCCLS protocols to examine the presence of antimicrobial resistance in natural L. monocytogenes. Of a total 274 chicken samples, 81 samples (29.6%) were positive for L. monocytogenes. Listeria innocua (50.1%), Listeria welshimeri (6.9%), and Listeria grayi (11.3%) were also detected. PFGE analysis, using restriction enzymes ApaI and AscI, showed 27 pulsotypes of L. monocytogenes. Antimicrobial resistance analysis confirmed the existence of antimicrobial resistance for penicillin G and tetracycline in isolated L. monocytogenes strains.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.6
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• pp.1025-1031
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• 2001

In this paper, we derive the outage probability of cellular mobile system with STTB(Space Time Transmitter Diversity) scheme where the received radio signals and interferers experience Rayleigh fading and AWGN. The new probability density function of L independent identically distributed interferers is derived using Laplace transforms. We express the probability of outage as a function of the average-signal to average-interference power ratio and the signal to noise ratio. In addition, the frequency reuse distance which is one of the key parameters in the design of cellular systems is analyzed.

• Korean Journal of Plant Taxonomy
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• v.41 no.3
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• pp.194-201
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• 2011

In order to acquire information on chloroplast DNA markers to evaluate the genetic diversity of evergreen broad leaved plants, we investigated the intraspecific variation of cpDNA in eight non-coding regions of nine species commonly distributed in East Asia. Although no variations were detected in psbA-trnH, rpoB-trnC, rpl16 and atpB-rbcL regions, a relatively large amount of intraspecific variations was detected in the psbC-trnS, rps16 and trnL-F regions. These results suggested that these three cpDNA markers are suitable to assess genetic diversity of the species investigated in this study. In contrast, intraspecific variations were detected in seven taxa except Hedera rhombea and Neolitsea aciculata. Neolitsea sericea and the taxa of Quercus had many polymorphic sites.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.7
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• pp.1787-1802
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• 1996

In this paper, the performance for FH/CPFSK system with limiter-discriminator detection and integrage-and-dump post-detection filtering under thermal noie, partial-band noise jamming and rayleigh fading have been analyzed. The method of hard-decision diversity of which the transmitter repeated L times on different hops for each data symbol in a way to mutigate the effects of the jamming has been applied, and the receiver has been combined the L chips. Also, error-correcting code have been applied for improving performance of system. The thermal noise and partial-band noise jamming, intersymbol interference for all eight of the possible adjacent bit data patterns, and FM noise click for evaluating systems have been considered. Also optimum parameters to improve performance of FH/CPFSK system have been obtained and validities have been proved through computer simulation.

• Korean Journal of Plant Taxonomy
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• v.48 no.2
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• pp.115-122
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• 2018

Two new species of Camellia (Theaceae) are described from Vietnam: Camellia vuquangensis Luong, Tran & L. T. Nguyen and Camellia hatinhensis Luong, Tran & L. T. Nguyen. The new taxa were collected from Vu Quang National Park in the center of Vietnam. The new finds are morphologically dissimilar to all known Camellia species. Recent Camellia discoveries have increased the number of species recorded in Vietnam from 50 to 75, making Vietnam a center of diversity and a crucial area for more research into the diversity and distributions of Camellia.