• Asian Pacific Journal of Cancer Prevention
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• 제16권6호
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• pp.2323-2326
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• 2015

It is urgently necessary to be aware of the distribution and risk areas of liver fluke, Opisthorchis viverrini, for proper allocation of prevention and control measures. This study aimed to investigate the human behavior, and environmental factors influencing the distribution in Surin Province of Thailand, and to build a model using stepwise multiple regression analysis with a geographic information system (GIS) on environment and climate data. The relationship between the human behavior, attitudes (<50%; $X_{111}$), environmental factors like population density ($148-169pop/km^2$; $X_{73}$), and land use as wetland ($X_{64}$), were correlated with the liver fluke disease distribution at 0.000, 0.034, and 0.006 levels, respectively. Multiple regression analysis, by equations OV= -0.599 + 0.005(population density ($148-169pop/km^2$); $X_{73}$) + 0.040 (human attitude (<50%); $X_{111}$) +0.022 (land used (wetland; X64), was used to predict the distribution of liver fluke. OV is the patients of liver fluke infection, R Square= 0.878, and, Adjust R Square= 0.849. By GIS analysis, we found Si Narong, Sangkha, Phanom Dong Rak, Mueang Surin, Non Narai, Samrong Thap, Chumphon Buri, and Rattanaburi to have the highest distributions in Surin province. In conclusion, the combination of GIS and statistical analysis can help simulate the spatial distribution and risk areas of liver fluke, and thus may be an important tool for future planning of prevention and control measures.

• Environmental Analysis Health and Toxicology
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• 제13권1_2호
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• pp.27-31
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• 1998

Motor vehicle exhaust is the major cause to the air contamination in Seoul. It includes many toxic chemicals to human health such as aidehyde, PAHs, benzene, xylene, toluene, benzo[a]pyrene, nickel, arsenic and cadmium in gasoline exhaust and formaldehyde, PAHs, 1,3-butadiene, benzene and particulate matter in diesel exhaust. Some chemicals out of them are classified as a human carcinogen. Many large diesel vehicles such as buses and trucks are drivened frequently in Seoul so that the air in Seoul is seriously contaminated by diesel exhaust, especially particulate matter. The amounts of particulate matter from large diesel vehicles may be estimated to be more than 50% of small dust in Seoul. The particles of particulate matter are coated with many toxic chemicals and some of these are considered as a human carcinogen. The cancer risk has to be throughly managed because the population density of Seoul is very high. Government should list hazardous air pollutants in Seoul, assess the exposure of people to toxic pollutants, especially carcinogens and manage human health risk.

• Parasites, Hosts and Diseases
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• 제39권2호
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• pp.185-192
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• 2001

To evaluate the factors that determine the transmission level of vivax malaria using vectorial capacity, entomological surveys were conducted from .lune to August, 2000. From 6 nights of human-bait collection in Paju, the human biting rate (ma) was counted as 87.5 bites/man/night. The parity of Anopheles sinensis from human baiting collections fluctuated from 41% to 71% (average 48.8%) of which the rate gradually increased as time passed on: 35.2% in Jun. ; 55.0% in July; 66.2% in Aug. From this proportion of parous, we could estimate the probability of daily survival rate of An. sinensis to be 0.79 assumed with 3 days gonotrophic cycle and the expectancy of infective life through 11 days could be defined as 0.073. Blood meal analysis was performed using ELISA to determine the blood meal source. Only 0.8% of blood meals were from human hosts. We could conclude that An. sinensis is highly zoophilic (cow 61.8%) Malaria is highly unstable (stability index < 0.5) in this area. From these data, vectorial capacity VC) was determined to be 0.081. In spite of a high human biting rate (ma), malaria transmission potential is very low due to a low human blood index. Therefore, we could conclude that malaria transmission by An. sinensis is resulted by high population density, not by high transmission potential. For this reason, we need more effort to decrease vector population and vector-human contact to eradicate malaria in Korea.

• Genomics & Informatics
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• 제14권4호
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• pp.196-204
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• 2016

Many researchers have found that one of the most important characteristics of the structure of linkage disequilibrium is that the human genome can be divided into non-overlapping block partitions in which only a small number of haplotypes are observed. The location and distribution of haplotype blocks can be seen as a population property influenced by population genetic events such as selection, mutation, recombination and population structure. In this study, we investigate the effects of the density of markers relative to the full set of all polymorphisms in the region on the results of haplotype partitioning for five popular haplotype block partition methods: three methods in Haploview (confidence interval, four gamete test, and solid spine), MIG++ implemented in PLINK 1.9 and S-MIG++. We used several experimental datasets obtained by sampling subsets of single nucleotide polymorphism (SNP) markers of chromosome 22 region in the 1000 Genomes Project data and also the HapMap phase 3 data to compare the results of haplotype block partitions by five methods. With decreasing sampling ratio down to 20% of the original SNP markers, the total number of haplotype blocks decreases and the length of haplotype blocks increases for all algorithms. When we examined the marker-independence of the haplotype block locations constructed from the datasets of different density, the results using below 50% of the entire SNP markers were very different from the results using the entire SNP markers. We conclude that the haplotype block construction results should be used and interpreted carefully depending on the selection of markers and the purpose of the study.

• 한국멀티미디어학회논문지
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• 제23권9호
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• pp.1147-1154
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• 2020

Nowadays, one of the most common diseases is chronic mental fatigue syndrome. This can be caused by many factors, such as busy life, heavy workload, high population density, and adverse technological impact. Most office workers and students who are sitting all day long while being exposed to this kind of environments are likely to be involved in the mental illness. Therefore, to prevent the illness, it has been highly required to design a device that enables mental fatigue to be monitored continuously without human intervention. This paper proposes a linear regression method to reliably estimating the level of human mental fatigue using wearable physiological sensors, with an estimation error of 0.852. Also, this paper presents an Android application that is able to check mental health conditions in daily life.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제2권4호
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• pp.259-273
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• 2021

We conducted a study to investigate the characteristics of the carbon cycle of two streams (located in Shig a Prefecture, Japan), having similar size, namely, the Adokawa stream (length: 52 km, area: 305 km², watershed population: 8,000) and the Yasukawa stream (length: 62 km, area: 380 km², watershed population: 120,000), but with different degree of human activity. Samples were collected from these two streams at 14 (Adokawa stream) and 23 (Yasukawa stream) stations in the flowing direction. The dissolved inorganic carbon (DIC) concentration and the stable carbon isotope ratio of DIC (δ¹³C-DIC) were measured in addition to the watershed features and the chemical variables of the stream water. The δ¹³C-DIC (-9.50 ± 2.54‰), DIC concentration (249 ± 76 µM), and electric conductivity (52 ± 13 µS/cm) in Adokawa stream showed small variations from upstream to downstream. However, the δ¹³C-DIC (-8.68 ± 2.3‰) upstream of Yasukawa stream was similar to that of Adokawa stream and decreased downstream (-12.13 ± 0.43‰). DIC concentration (upstream: 272 ± 89 µM, downstream: 690 ± 37 µM) and electric conductivity (upstream: 69 ± 17 µS/cm, downstream: 193 ± 37 µS/cm) were higher downstream than upstream of Yasukawa stream. The DIC concentration of Yasukawa stream was significantly correlated with watershed environmental variables, such as, watershed population density (r = 0.8581, p<0.0001, n = 23), and forest area percentage of the watershed (r = -0.9188, p<0.0001, n = 23). δ¹³C-DIC showed significant negative correlation with the DIC concentration (r = -0.7734, p<0.0001, n = 23), electric conductivity (r = -0.5396, p = 0.0079, n = 23), and watershed population density (r = -0.6836, p = 0.0003, n = 23). Our approach using a stable carbon isotope ratio suggests that DIC concentration and δ¹³C-DIC could be used as indicators for monitoring the health of stream ecosystems with different watershed characteristics.

• The Korean Journal of Ecology
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• 제7권3호
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• pp.109-118
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• 1983

Near future dynamics of water qualities (nutrient concentration) of the Han River was predicted, based on a mathematical model representing the relationship between the nutrient concentration in th river wagter and environmental factors (population density, land-use types, rock compositions and nutrient accumulation) in the basin. The population density and land-use types were forecasted to change distinctly in the downstream area, especially in Seoul City area in 1985~1990 whereas any environmental factor was not expected to change its level significantly in both upstream and middle reaches areas. It was indicated by the model that the nutrients concentration in the up- and mid-streams would keep its level in future as it was, but it would increase drastially in the downstream area. For the preservation of the water qualities in the downstream at least to keep its level as it was in 1980, practical countermeasures were proposed, based on the assessment of the contribution of each environmental factor to the water qualities.

• The Korean Journal of Ecology
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• 제23권2호
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• pp.181-185
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• 2000

This study was carried out to see whether Gastrophysa viridula (Degeer) (Coleoptera : Chrysomelidae) could be used as a biological control agent for Rumex obtusifolius L., with human manipulation of the beetle population. The study was consisted of three experimental sets : Wet-Dry experiment (the wet weight Vs dry weight relationship of Rumex obtusifolius L.), Greenhouse feeding experiment, and Field experiment. There was a significant correlation between the total wet and dry weight of Rumex obtusifolius as follows : Total dry weight : -0.23542+ (0.17514${\times}$Total wet weight) ($R^2$=0.9317, p=0.047, T=16.927 (dF=21)). In the Greenhouse feeding experiment, the result was very promising. The relationship between the density unit of the beetles and the growth of the plant is given below (20 day) : Plant growth =105.8+(-34.4${\times}$Density unit) ($R^2$=0.76, p=0.13). A repeated introduction of the beetle population into the field vegetation of R. obtusifolius from April to October is suggested to see the beetle's grazing ability on the plant. This study shows that the potential grazing power of the beetle on Rumex obtusifolius was enough to defoliate the plants, but it was able to recover from its root reserves. The practical question remains as to whether repeated additions (by man) of the beetles to Rumex obtusifolius could eliminate them.

• 한국물환경학회지
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• 제25권3호
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• pp.394-403
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• 2009

A total of 52 sampling sites were selected in the stream network of the upper Paldang watershed (e.g. Kyonan, Gapyeong, Jojong, Chengmi, Bockha, Yanghwa and Heuk streams). Over the time period of April 2007-February 2008, 1820 samples were collected and analyzed for physico-chemical variables of the upper watershed in order to investigate spatio-temporal water quality variation in particular the relationship with land use. Although temporal variations of water quality in each stream were similar and were significantly influenced by flow, spatial variations in each stream varied as physico-chemical characteristics of upper watershed. As a result of regression analysis, Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Nitrogen (T-N), and Total phosphorus (T-P) concentration were the most significantly and positively associated with people population density. It is necessary to manage not only water quality but also land use of upper watershed and flow flux.

• Toxicological Research
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• 제19권3호
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• pp.205-210
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• 2003

The aim of this study was to estimate the influence of 37 bp insertion/deletion (I/O) poly-morphism of the low density lipoprotein receptor-related protein-associated protein 1 (LRPAP1) gene on anthropometrical or biochemical parameters in korean general population. To determine the frequency of the genotype, we analyzed 244 samples of Korean origin. The frequency of the I allele was 0.55 in men and 0.56 in women, which were significantly higher than the frequency (0.26) that was reported in Czech population of Caucasian origin. In addition, the I allele of this polymorphism was significantly associated with higher value of body mass index (BMI) in our subjects by ANOVA test (P<0.05), and this association was maintained after controlling for age and gender by ANCOVA test (P<0.05). Thus, our results suggest that the I/O polymorphism of the LRPAP1 gene may be useful as a genetic marker for obesity in Korean general population.