• Journal of the Korean Geographical Society
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• v.47 no.2
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• pp.193-207
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• 2012

This study discussed characteristics of Shindu Coastal Dune as habitat, and relationship between geodiversity and biodiversity. It was identified spatio-temporal variation of incoming nutrients depended on geomorphic differences of foredunes. The main incoming path of nutrients into coastal dune was considered as influx with movement of wind blown sands from the beach and tidal f lat. Concentrations of Na, Mg, K, Ca, and P in blown sands were compared. Concentrations of Na, Mg, and K showed high and irregular pattern in favorable condition of influx of blown sand. So these nutrients were related with geomorphic characteristics of foredunes. However, Na was also influenced by other factor such as salt spray. P was independent from effects of sea water and blown sands. In the case of Ca, a large coastal dune system rather than localized forms of foredunes made differences in the variation. Due to differences in spatio-temporal variation of nutrients, patterns of major vegetation could be inferred to appear differently. This study shows geomorphic dynamics of coastal dunes as habitat, and will provide information for coastal dune management and for understanding biological distribution and growth pattern in coastal dune.

• The Korean Journal of Mycology
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• v.27 no.5 s.92
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• pp.328-336
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• 1999

Isozyme comparisons of mycelial extracts from Pleurotus ostreatus were undertaken using isoelectric focusing. Enzyme isozyme patterns were Used to describe the extent of geographical diversity and degree of intraspecific variation in these extracts. A total of 77 bands were resolved from six different enzymes. Cluster analyses were performed using the zymograms for esterase (EST), glucose phosphate isomerase (GPI), leucine aminopeptidase (LAP), malate dehydrogenase(MDH), peroxidase (POX), and phosphoglucomutase (pGM). EST gave multiple banding patterns, while less variability was observed for GPI, MDH, and PGM. Cluster analyses demonstrated that strains of P. ostreatus from geographically different origins are genetically divergent, supporting the idea that there is little or no gene flow between these geographically distant population groups.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.3
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• pp.833-836
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• 2012

The incidence of esophageal cancer in Kazakhstan was analysed for the period of 1989-2010 years, with a focus on trends by age, gender and region. The highest rates of incidence were evident in the Western regions. The dynamics for cancer of the esophagus in the Republic demonstrated decrease, except in the Karaganda region, where a tendency for increase was noted. Considerable variation between regions pointed to differences in risk factor exposure which need to be targeted for future control efforts.

• Animal Systematics, Evolution and Diversity
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• no.nspc3
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• pp.93-100
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• 1992

Seven geographical variation types of G.sobaegensis in South Korea were reported by Kim and Lee(1977) and Lee and Kim (1980). After extensive reexamination, we considered type 4, one of the variation types collectd from various localities of Kyongsangbuk-do Pongwha-gun, as a new species This new species is named as Gammarus longisaeta and fully described and illustrated. Adding this new species, total 9 species of freshwater Gammarus are Known to Korea.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.497-498
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• 2000

The venus clam, Ruditapes philippinarum, is an aquaculture shellfish mainly distributed in an intertidal zone of East Asia including Korea, China and Japan. The morphological variation of this species is great. In fact, two of the most popular markers used in molecular evolution, mitochondrial DNA (mtDNA) and nuclear ribosomal DNA (rDNA), have quite different properties, which could translate into different consequences of mutation, drift, migration and selection on patterns of geographical variation and molecular divergence. (omitted)

• Current Research on Agriculture and Life Sciences
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• v.30 no.2
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• pp.115-123
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• 2012

Whiteflies harbor several secondary endosymbionts, which are maternally inherited from mother to offspring, that have major effects on host preferences, biology, and evolution. Here, we identified Wolbachia bacteria in sweetpotato whitefly (Bemisia tabaci) as well as whitefly popluations from other countries by comparison of 16S rDNA sequences. Wolbachia were detected in all tested indigenous B. tabaci populations (Bangladesh, Myanmar, Nepal, and the Philippines) as well as Q1 biotype of Korea, whereas they were absent from B biotype of Korea and Q biotype of China. Wolbachia were also detected in all five tested Aleurodicus dispersus populations as well as Tetraleurodes acaciae, whereas they were not detected in all seven Trialeurodes vaporariorum populatuions. In addiiton, Wolbachia were detected in parasitic wasp (Encarsia formosa) of B. tabaci as well as honeybee (Apis mellifera). Among the 19 whitefly populations from different countries, our analysis identified four phylogenetic groups of Wolbachia, thereby demonstrating the high diversity of this genus. Wolbachia phylogeny suggests a correlation of geographical range with ecological variation at the species level.

• Journal of the Korean Geographical Society
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• v.39 no.4
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• pp.544-561
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• 2004

Weekly monitoring of discharge and water quality in forested and agricultural subcatchments were performed to understand the difference of water quality caused by land uses in Doegwollyong area. Correlations between water quality variables including discharge were analyzed for the same purpose. There was little variation of water Quality in forested subcatchment. On the other hand, the range of water quality variation in agricultural subcatchment was wide due to soil loss and the application of chemical fertilizers and livestock manure. Dissolved oxygen(DO) had strong negative correlation with discharge in both subcatchments. Total nitrogen(T-N) and potassium ion(K$^{+}$) had stronger positive correlation with discharge in forested subacatchment than in agricultural one. On the other hand, total suspended sediments(TSS), total phosphorus(T-P), and chemical oxygen demand(COD) had stronger correlation with discharge in agricultural subcatchment than in forested one. As water pollution of the Doam Lake, especially the increase of T-P is serious, soil conservation is very important to improve water quality. In particular, the loss of soil and nutrients from late June till early July were more serious than any other seasons, therefore it is necessary to apply environmentally sustainable methods of cultivation.n.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.sup3
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• pp.27-32
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• 2016

Stomach cancer, the fourth most common cancer and the second leading cause of cancer-related death through the world, is very common in parts of Iran. Geographic variation in the incidence of stomach cancer is due to many different factors. The aim of this study was to assess the geographical and spatial distribution of stomach cancer in Iran using data from the cancer registry program in Iran for the year 2009. The reported incidences of stomach cancer for different provinces were standardized to the world population structure. ArcGIS software was used to analyse the data. Hot spots and high risk areas were determined using spatial analysis (Getis-Ord Gi). Hot and cold spots were determined as more than or less than 2 standard deviations from the national average, respectively. A significance level of 0.10 was used for statistical judgment. In 2009, a total of 6,886 cases of stomach cancers were reported of which 4,891 were in men and 1,995 in women (standardized incidence rates of 19.2 and 10.0, respectively, per 100,000 population). The results showed that stomach cancer was concentrated mainly in northwest of the country in both men and women. In women, northwest provinces such as Ardebil, East Azerbaijan, West Azerbaijan, Gilan, and Qazvin were identified as hot spots (p<0.1). In men, all northwest provinces, Ardabil, East Azerbaijan, Gilan, Qazvin, Zanjan and Kurdistan, the incidences were higher than the national average and these were identified as hot spots (P<0.01). As stomach cancer is clustered in the northwest of the country, further epidemiological studies are needed to identify factors contributing to this concentration.

• Parasites, Hosts and Diseases
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• v.53 no.3
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• pp.345-348
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• 2015

Toxoplasma gondii is a eukaryotic parasite of the phylum Apicomplexa, which infects all warm-blood animals, including humans. In the present study, we examined sequence variation in dense granule 20 (GRA20) genes among T. gondii isolates collected from different hosts and geographical regions worldwide. The complete GRA20 genes were amplified from 16 T. gondii isolates using PCR, sequence were analyzed, and phylogenetic reconstruction was analyzed by maximum parsimony (MP) and maximum likelihood (ML) methods. The results showed that the complete GRA20 gene sequence was 1,586 bp in length among all the isolates used in this study, and the sequence variations in nucleotides were 0-7.9% among all strains. However, removing the type III strains (CTG, VEG), the sequence variations became very low, only 0-0.7%. These results indicated that the GRA20 sequence in type III was more divergence. Phylogenetic analysis of GRA20 sequences using MP and ML methods can differentiate 2 major clonal lineage types (type I and type III) into their respective clusters, indicating the GRA20 gene may represent a novel genetic marker for intraspecific phylogenetic analyses of T. gondii.

• Journal of the Korean Geographical Society
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• v.44 no.4
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• pp.429-446
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• 2009

To understand the sulfur flux and cycle in the forest catchment, the hydrological processes and chemical variation of soil solution, groundwater and stream water were analyzed at the Matsuzawa catchment located in the Kiryu Experimental Basin, Shiga Prefecture, central Japan. Unsaturated soil layer at the upper slope of catchment was the source area of ${SO_4}^{2-}$, and deep soil layer and groundwater were the sink zone of ${SO_4}^{2-}$. The vertical distribution of ${SO_4}^{2-}$ concentrations in groundwater affected seasonal variation of ${SO_4}^{2-}$ concentrations in stream water, as groundwater level changed. It is reasonable to assume that each hydrological processes in the forest catchment play an important roles in the retention and discharge of ${SO_4}^{2-}$.