• Korean Journal of Environment and Ecology
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• v.27 no.1
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• pp.52-63
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• 2013

Benthic macroinvertebrates were investigated in Yongdam-dam and Hapcheon-dam resions from June to October 2011, Korea. Yongdam-dam and Hapcheon-dam are geographically contiguous, but they are classified as other water system. Experiment site(YE-1, 2, 3; HE-1, 2, 3) which is thought to be affected by dam, control site(YC-1, 2; HC-1, 2) which is thought not to be affected by dam were selected. Species composition, macroinvertebrate communities, composition of the functional feeding groups, habitat orientied groups and community stability were assessed Yongdam-dam and Hapcheon-dam regions. Ten sites were selected for quantitative(Surber sampler $30cm{\times}30cm$) of benthic macroinvertebrates. As a results, a total of 6,369 individuals including 69 species, 33 families, 12 orders, 6 classes and 4 phyla were recognized in Yongdam-dam region. Also, a total of 5,728 individuals including 81 species, 44 families, 13 orders, 5 classes and 4 phyla were recognized in Hapcheon-dam region. Dominance index was 0.27~0.50(mean${\pm}$SD $0.38{\pm}0.09$), diversity index was 2.22~2.97($2.67{\pm}0.29$), evenness index was 0.63~0.76($0.72{\pm}0.06$) and richness index was 4.43~7.06($5.69{\pm}0.99$) in Yongdam-dam region. Dominance index was 0.40~0.81($0.59{\pm}0.18$), diversity index was 1.40~2.39($2.00{\pm}0.43$), evenness index was 0.38~0.68($0.56{\pm}0.13$) and richness index was 4.04~5.80($4.95{\pm}0.70$) in Hapcheon-dam region. In the functional feeding groups, filtering-collectors and gathering-collectors were the highest in the whole sites. In the habitat orientied groups, burrowers, clingers and swimmers were considerably occupied in all sites. As a result of community stability analysis, experiment sites has been identified much as species high resistance and resilience to environmental changes in Yongdam-dam. Control sites has been identified much as species low resistance and resilience to environmental changes in Hapcheon-dam. Species belonging to the Igroup is considered to be important in the river ecosystem stability of large dams downstream areas.

• Korean Journal of Environment and Ecology
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• v.30 no.5
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• pp.874-887
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• 2016

We surveyed bimonthly from April to October 2015 to understand the fish fauna and community structure in Wangpicheon. The collected species during the survey period were 40 species belonging to 15 families. Dominant species by number were Zacco koreanus (31.3%) and Rhynchocypris oxycephalus (14.7%). In biomass, the dominant species were Z. koreanus (29.2%) and Coreoperca herzi (8.6%). Also, nine endemic species (22.5%) including Squalidus multimaculatus and two endangered species (Lethenteron reissneri, Cottus koreanus) were identified. It was identified one introduced species (Oncorhynchus mykiss) from foreign countries for aquaculture. Compared with previous data, nine species were newly identified including L. reissneri, S. gracilis majimae, Pseudobagrus fulvidraco, O. mykiss, Chelon haematocheilus, Siniperca scherzeri, Acanthogobius lactipes, Luciogobius guttatus and Channa argus. Seven species (Rhodeus ocellatus, S. gracilis majimae, Hemibarbus longirostris, Pseudogobio esocinus, Microphysogobio yaluensis, Hemiculter eigenmanni and Cobitis hankugensis) introduced from other native waters in Korea were estimated. According to the analysis of the habitat characteristics of major migratory species (Tribolodon hakonensis, O. keta and Plecoglossus altivelis), O. keta was observed at station 11 and T. hakonensis at station 7, 10 and 11. These fishes have been mainly identified in the downstream. However P. altivelis was widely distributed from station 3 to 11. In the comparison of average standard length of P. altivelis at each station during the same period, populations collected from station 3 and 5 which are mid-upper area of the stream were $125.8{\pm}34.2mm$. Their growth was good compared with those collected from station 8 and 11 (mid-lower area): $80.2{\pm}16.6mm$. This difference in length comes from the artificial structures including weir, thus it is necessary to create a fishway that enables P. altivelis to pass around barriers for free movement and resource management.

• Korean Journal of Environment and Ecology
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• v.32 no.3
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• pp.342-350
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• 2018

The purpose of this study was to identify the environmental factors that affect the beginning and end of calling by Hyalessa fuscata and Cryptotympana atrata, which are dominant cicada species in the central urban areas of Korea. The study area was Banpo Apartments in Seoul. The research period included two months, being from the end of July to the end of August 2015. We analyzed the start and end time of cicada calling, and on average H. fuscata started calling at 5:21 am and C. atrata started at 7:40 am. The average end time of calling was 6:31 pm for H. fuscata and 7:51 pm for C. atrata. From the scatter plot and box plot results, H. fuscata started calling at 05:00 am, whereas C. atrata consistently stopped calling at 20:00 pm compared to H. fuscata. Multiple regression analysis of the start and end time of cicada calling showed that sunrise time was a factor affecting the start of H. fuscata calling. The end time of H. fuscata calling was affected by sunset time and total cloud cover. The starting time of C. atrata calling was mostly affected by temperature and sunrise time. The effect of temperature was greater than that of sunrise time. The end time of C. atrata calling was strongly affected by sunset time, whereas peak temperature was also shown to affect the end time. From the above results, sunrise and sunset are thought to be the critical factor affecting the start and end time of H. fuscata calling. Therefore, H. fuscata started calling with sunrise, and the end time was also affected by sunset. Temperature was the factor most affecting the start of C. atrata calling and sunset was identified as the factor affecting the end time. Therefore, the start time of C. atrata calling shows variation with daily temperature changes, and C. atrata stop calling simultaneously with sunset.

• Korean Journal of Ichthyology
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• v.6 no.2
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• pp.237-243
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• 1994

This work was conducted to study sex differentiation in the black sea bream, Acanthopagrus schlegeli (Bleeker), using a histological method for the appearance of primordial germ cell, formation of primitive gonads, differentiation of female and male from newly hatched larva to the ovotestis stage of fish. The 3~4 primordial germ cells of $6.8{\sim}7.2\;{\mu}m$ in size, which were buried under fibrous mesenchymal tissue between gut duct and notochord of pre-larva with a total length (T.L.) of 2.4 mm at 3 days after hatching. The proto-gonial cells were located in the epithelium of the coelom attached with pigment cells of juvenile with 6.4 mm in T.L. at 21 days after hatching. In juvenile of 20.8 mm in T.L. at 59 days after hatching, the proto-gonial cells were migrated to the retro-peritoneum through the lineshaped primitive gonad composed of fibrous mesenchymal tissue. In juvenile of 7.8 em in T.L. at 186 days after hatching, the mitotic division of proto-gonial cell appeared in the lineshaped primitive gonad having many eosinophilic granule cells and abundant fibrous connective tissue. In juvenile of 9.5 em in T.L. at 254 days after hatching, the gonad was occupied by abundant fibrous connective tissue, bundles of spermatocyte and spermatid. In juvenile of 10.5 cm in T.L. at 13 months after hatching, the gonad was divided into cortical layer and medullary layer. The former was composed of bundles of a few spermatocytes and proto-gonial cells, the latter was filled with the fibrous mesenchymal tissue and a few proto-gonial cells. In juvenile of 14.7 em in T.L. at 16 months after hatching, the gonad was separated into ovarian part and testicular part by the fibrous connective tissue. The ovarian part is consisted of ovarian cavity and oocytes of perinucleolus stage. The testicular part was occupied by spermatogonia in the cyst.

• Korean Journal of Ichthyology
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• v.23 no.2
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• pp.87-94
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• 2011

To find the preliminary environmental conditions for a short-time transport of living olive flounder, Paralichthys olivaceus, the stress response and physiological metabolic activity of the cultured fish to feed deprivation and slow temperature descending ($15.8^{\circ}C{\rightarrow}13.3^{\circ}C$) were monitored for 8 days. The monitored variables were the plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), glucose (GLU), total protein (TP), electrolytes ($Na^+$, $K^+$, $Cl^-$) and thyroid hormones ($TT_4$, $TT_3$, $FT_4$ and $FT_3$). In food deprivation experiment for 8 days, we did not find any statistical change of level in AST, ALT and electrolytes ($Na^+$, $K^+$, $Cl^-$), but found a significant decrease in TP and GLU. In thyroid hormones, the levels of four hormones in plasma were all showing a tendency to decrease. Especially, $FT_4$ and $TT_3$ were significantly decreased, indicating a withering of physiologic activity. In the temperature test, although no any significant change in AST, TP and electrolytes ($Na^+$, $K^+$, $Cl^-$), we observed a significant decrease of ALT and GLU following to temperature descending from $15.8^{\circ}C$ to $13.3^{\circ}C$ (P<0.05). In the levels of thyroid hormones, any significant change was not observed for experimental period. We conclude that the stress response and physiological activity of olive flounder were more influenced by feed deprivation than slow temperature descending at a transport of living fish, and plasma GLU appears to be sensitive factor to physiological metabolic activity, indicating that it could be used as a monitering mark or index for a health inspection of the fish.

• Journal of agricultural medicine and community health
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• v.31 no.3
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• pp.275-284
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• 2006

Objectives: This investigation was carried out to understand the status of the urinary incontinence (UI) and overactive bladder (OABs) syndrome of women in a rural region. Methods: The authors conducted a questionnaire survey among the 322 females who voluntarily participated in a health examination, from 16 to 18 August 2001. Using by definition of UI and OABs, we calculated the proportion of UI, OABs I, and OABs II. The data collected was evaluated using the SPSS 12.0 statistical package, and the differences of symptoms and problems related to daily life between UI, OABs patients and the others were analyzed using a Chi-square test or Fisher's exact test. Results: The overall proportion of UI was 35.4%, and stress UI (32.9%) is more common than urgency UI (17.4%) and mixed UI (14.9%). The proportion of OABs I and OABs II were respectively 36.0%, 14.0%. Symptoms related to UI or OABs were nocturia (35.1%), frequency (23.9%), urgency (21.4%) etc. Of the incontinence cases, 27.2% had experienced UI for a period of one to three years. The proportion of OABs increased significantly by age (p<0.05), UI didn't. The most frequent symptoms in UI and OABs were respectively 'slow stream', 'urgency'. The most frequent problem of daily life in UI and OABs was 'seeking toilet firstly at stranger place'. Conclusions: The proportion of UI and OABs in our study were respectively 35.4%, 14.0%. UI and OABs must be very significant health problems in women, especially rural region. Systemic and profound interventions for UI and OABs need to administer to women in Korea.

• Journal of agricultural medicine and community health
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• v.26 no.1
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• pp.65-79
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• 2001

Cerebrovascular disease(CVD) is one of the major causes of death in Korea as well as most countries in the world and the disease gives great burden to humans socio-economically due to its high fatality and common occurrence of disability as the sequelae. This study was performed to investigate the utilization of western hospital(WH) or oriental hospital(OH) due to CVD and compare the type and the clinical characteristics of patients with CVD between WH and OH located in Kwangju City, Chonnam Province and Chonbuk Province. We reviewed the medical records of 1,070 patients who were discharged from 12 WIT and 6 OH from January to March, 2000 and confirmed for the diagnosis of CVD. Fifty-one percent of the subjects were treated at WH and forty-nine percent at OH. Females were more prevalent than males. As well, the most common age group among these subjects was found to be 70 years and older. About 92% in W~H and 80% in OH received brain imaging diagnostic procedures such as CT or MRI. The cerebral infarction was the most common type of CVD when compared by the kind of utilized hospitals, sex, age group except patient Group who was treated at WH and whose age was lower than 50 years old. The cerebral hemorrhage was more frequent than cerebral infarction among this group. The proportion of cerebral hemorrhage was decreasing and that of cerebral infarction was increasing with age. The most common clinical manifestations of undetermined type of CVD was paralysis of lower extremity in WIT and paralysis of upper extremity in OH. In cerebral hemorrhage loss of consciousness in WIT and dysarthria in OH were most frequently manifested, while in the case of cerebral infarction hemiplegia in WIT and dysarthria in OH were the most common complaints. The interval from the onset of disease to admission to the hospital was 5.5 days in WH arid 31.4 days in OH and the difference was statistically significant. Average admission duration of patients at OH was longer than WH, but it was not statistically significant. In conclusion these results suggest that the effort for systematic and efficient management of CVD patients was necessary for close co-operation and role arrangement between WH and OH considering the positive and negative points of western and oriental medicines.

• Journal of agricultural medicine and community health
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• v.28 no.1
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• pp.39-51
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• 2003

Objectives: The oriental medical care has been getting popular in community health centers because of uniqueness, changing of disease patterns, and increasing of elderly population. From 1998, oriental medical doctors has been working in several rural community health centers for their military obligations. At this point of time, it is necessary to evaluate the oriental public health doctors system. This study was performed to investigate the utilization patterns, the degree of satisfactions, needs of oriental medical care service provided by community health center in a designated Gun area. This study focused on the need for extending over Myun area of community health center's oriental medical care services. Methods: Person-to-person interview survey method through a structured questionnaire was done by a personnel at a oriental medical care service room in a Gun community health center. The major statistical method used for the analysis were the t-test, ANOVA, and logistic analysis. Results: The total number of responded subjects in this study was 163 residents. Among these 65.0% were aged 61 or over, and only 13.5% recognized themselves were healthy. 73.7% of the respondents demanded establishment of more oriental medical care services provided by community health center to other Myun area. Factors affecting the need for enlargement of oriental medical care service room were education level, subjective awareness of access to community health center, and cost satisfaction of oriental medical service provided by community health center. Thus, a resident who had graduation of middle school achievement or above(OR=3.35), had a long way to center(OR=2.47), satisfied with oriental medical service cost(OR=2.78) had demonstrated increased chance of need by logistic regression analysis.

• Journal of agricultural medicine and community health
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• v.29 no.2
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• pp.303-314
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• 2004

Objectives: This study was carried out to assess exposure levels of organic dusts and ammonia in poultry farms in Korea. Methods: A total of six poultry farms were investigated. The farms were located in Namwon, Chonlabuk-do and in Kae-San, Chungchongbuk-do. This study consisted of a questionnaire and measuring organic dusts and ammonia. The questionnaire included the characteristics of the farms, work patterns and the tasks of the poultry farms. Results and Conclusions: The farmers raised the chickens 45 times a year and the average number of years in the poultry farm were eight years ranging from 2 to 12 years. They worked for seven days per week and the average hours spent caring the chickens are 6.3 hours per day. The duration of staying in the confinement buildings was 3.3 hours per day. The work time in summer was longest. The feed and the water supply systems were automatic and the control of ventilation windows used "winch curtain" was semiautomatic. They used mechanical ventilation system in winter and used dilution ventilation system in the other seasons. The geometric mean concentration of total and respirable dust sampled in the poultry confinement buildings was 4.0 mg/$m^3$and 0.9 mg/$m^3$ respectively. The ratio of respirable to total dusts range from 9 to 49 percent. There was no sample exceeding the criteria 10 mg/$m^3$ for total dust and 3 mg/$m^3$ for respirable dust in farms. The criteria have been recommended by Korean Ministry of Labor and American Conference of Governmental Industrial Hygienist. The personal respirable dusts measured during a circle work averaged geometric mean concentration 1.4 mg/$m^3$ Two personal samples were exceeded the threshold 3 mg/$m^3$. There was a positive relation between an index and the personal samples of respirable dusts($R^2$=0.98). The index is calculated by multipling the total number of chickens in the farm by the age of the chickens and then dividing by the volume of the confinement building. The geometric mean concentration of area and personal ammonia samples was 23.3 ppm and 22.2 ppm, respectively. Some of the ammonia samples, both area and personal samples, exceeded the short term exposure limit value 35 ppm.

• Journal of agricultural medicine and community health
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• v.29 no.2
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• pp.265-285
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• 2004

Objectives: The acute toxic effects of pesticide are well known. Concern has also been expressed that long-term exposure may result in damage to the central nervous system. This study was conducted to test the hypothesis that central nervous system symptoms might occur due to pesticide exposure. Methods: In a cross-sectional study, first, cumulative exposure index (CEI) was estimated. Neurologic symptoms (Q-16 questionnaire) for 541 farmers (exposed to pesticides) were compared with 119 non-exposed persons in spraying season nine rural areas in Korea. Results: The pesticides poisoning rates for last 3 months were 67.2% for orchard farmers, 55.3%for dry field farmers, and 20.5% for husbandry farmers, respectively, showing significant difference (p<0.001). Compared with non-exposure group, exposure groups (especially, orchard farmers) reported significantly more neurologic symptoms and had a higher overall neurological symptoms score (p<0.001). Factors related to the positive neurological symptoms (answers "yes" to six or more of Q-16 questionnaire) adjusted for age, sex, education level, smoking and alcohol drinking were type of farming (OR 3.08, 95% CI 1.50-6.30 in orchard farmers vs non-exposure group), CEI (OR 2.75, 95% CI 1.12-6.78 in Q3 vs Q1), past poisoning (OR 1.97, 95% CI 1.21-3.20 vs normal), current mild poisoning (OR 3.03, 9500 CI 1.47-6.22 vs normal) and current moderate poisoning (OR 6.34, 95% CI 3.03-13.25 vs normal), respectively. Conclusions: These results suggest that long-term exposure to pesticides appears to be associated with subtle changes in the central nervous system.