• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.26 no.1
• /
• pp.64-74
• /
• 2016

Objectives: The purpose of this study was to investigate whether chemical exposure among workers has relevance to dyspnea using data from the $3^{rd}$ Korea Working Conditions Survey. Methods: The research subjects were 29,711 wage workers. Chemical exposures consist of four factors, (1) breathing in vapors, fumes, dust and dirt, (2) breathing in organic solvent vapors, (3) handling or touching chemicals, and (4) secondhand smoke. Multiple logistic regression analysis was performed to examine the association between chemical exposure and dyspnea in the last 12months using proc surveylogistic in SAS 9.3 statistical software excluding people who had received a diagnosis of hypertension or obesity that can affect the respiratory distress symptoms(n=27,842). Results: Chemical exposure among workers was associated with dyspnea after adjustment for demographics and job characteristics. Prevalence of dyspnea was 4.9 per 1,000 among men and 5.8 per 1,000. Compared to a total score of 0 points of chemical exposure among workers, a total score of 1, 2-3, and 4 points tended to have increased risk of dyspnea in a dose-response manner for both men (OR=1.43, 1.93, and 4.26; P-for trend=0.002) and women(OR=1.10, 2.81, and 7.70; P-for trend=0.002). Stratified analysis by duration of current job showed that the association between chemical exposure and dyspnea tended to get stronger until 15 years and then disappeared afterwards, which reflects healthy worker survivor effect. Conclusions: We observed significant association between chemical exposure and dyspnea using the data of the $3^{rd}$ Korea Working Conditions Survey. Our results warrants providing knowledge related to chemical exposure, performing prevention activities, and creating various health policies to protect workers.

• Korean Journal of Agricultural Science
• /
• v.29 no.1
• /
• pp.32-43
• /
• 2002

The peach pyralid moth (Dichocrocis punctiferalis) is reported as import ant pest insect to chestnut fruits in Asia including Korea. For seasonal occurrence of D. punctiferalis in 1996, 1998 and 1999, D. punctiferalis adults were collected by light trap and sex pheromone wing trap in the chestnut orchard. Also, damaged rate of chestnut fruits were examined each collecting site. In 1996, according to examination by using light trap at three different site in Kongju, the occurrence peak of 2nd gene ration of D. punctiferalis adults was early August. Collected individuals after September were cons ide red as 3rd generation. Damaged rate due to maturation type was 26.5% averagely. The order of damaged rate were early, late and middle maturation type as 35.04%, 19.35% and 26.03%, respectively. Using synthetic sex pheromone trap at Kongju, Cheungyang and Buyeo in 1998, occurrence peaks were occurred mid-August to 2nd generation and late September to 3nd gene ration in Kongju. However, from early-August to late-September 5 peaks were occurred sequentially in Cheungyang. Second generation adults were occurred in mid-August and 3rd ones were occurred from late-September to early-October in Buyeo. In 1999, occurrence peaks of 3rd generation were early, middle and late September in Kongju, Cheungyang and Buyeo respectively. Damaged rate were 6.8%, 6.6% and 15.3% in Kongju, Cheungyang and Buyeo, respectively. Damaged rate order due to variety were Eunki, Chukpa, Danpa, Bokpa, Wangjung, Byunggo57, Yuoma at Buyeo and were Chukpa, Dukmyung, Byunggo57 at Cheungyang in 1999. Damage rate of chestnut were different with variety. Eunki and Chukpa in Buyeo and Chukpa and Dukmyung in Cheungyang were more damaged by D. punctiferalis respectively.

• The Journal of Internal Korean Medicine
• /
• v.26 no.2
• /
• pp.320-332
• /
• 2005

Objectives: The aim of the experiment is to identify any anti-tumor effects of Duchesnea indica(Andr.) Focke on stomach, liver, urinary bladder, prostate and kidney cancer cells. Materials & Methods: For cancer cells, AGS stomach, Hep3B and Hep3G2 liver, HT-1197, HT-1376 urinary bladder, PC3 prostate, and A-704 kidney cancer cells, all obtained from Korean Ce 11 Line Bank, were used. The boiled extract of Duchesnea indica(Andr.) Focke (10 and 20 microliters) was injected into cultures, and the cultures were observed at 0, 6 and 12 hours, and from then on at 12 hours intervals up to 72 hours. The destruction of stomach, liver, urinary bladder, prostate and kidney cancer cells were measured through Trypan blue exclusion testing. The suppresion on viability of stomach, liver, urinary bladder, prostate and kidney cancer cells was measured via MTT assay. Anti-cancer mechanisms were assessed by analyzing the cell cycle. Results: In morphologic change, AGS, Hep3B, HepG2 showed the withdrawn and floating appearance that is typical in cellular impairment. The destruction of AGS, HT-1197, HT-1376, A-704, PC-3, Hep3B and HepG2 cancer cells in each test group was greater than that in the control group to a statistically significant degree. The suppression on viability of AGS, HT-1197 and Hep3G in each test group was greater than that in the control group to a statistically significant degree. Analysis of the cell cycle after injection of D... Focke showed inhibition of cell division in all test groups(AGS, Hep3B, HepG2, HT-1197, HT-1376, PC3, A-704). Conclusions: The results of this experiment suggest that Duchesnea indica(Andr.) Focke has statistically significant anti-tumor effects on stomach, urinary bladder, kidney, prostate and liver cancer, of which stomach and liver cancer are prominently significant. This in vitro experiment supports a role for Duchesnea indica(Andr.) Focke as a potential cancer treatment, but progressive research on Duchesnea indica(Andr.) Focke and its anti-tumor effects is needed to develop a practical application for it in cancer treatment.

• Journal of Sericultural and Entomological Science
• /
• v.43 no.1
• /
• pp.26-28
• /
• 2001

The cytotoxicity of the ethanol extracts of varietal samples of mulberry leaves and branches and silkworm feces was measured using CT-26 cells originated from murine metastatic colon cancer, using dye uptake assay in order to find potential anticancer agents. Two ethanol extracts (varietal mulberry leaves and mulberry branches) were prepared from 16 varietal mulberries and used as partial extract materials for the activity assay. Among these, the ethanol extracts from Shinkwangppong leaves showed a little anticancer activity, and those from Sugaeppong, Cheongunppong and Gumsulppong branches showed some anticancer activity as well as cytotoxicity. In contrast, ethanol extracts from freeze-dried, the 3rd day of 5th instar feces showed more potent anticancer activity than that of other mulberry leaves, mulberry branches and other 5th silkworm instar larva feces on the basis of high UV absorbance at 665 nm.

• Journal of Sericultural and Entomological Science
• /
• v.26 no.2
• /
• pp.26-31
• /
• 1984

In general, acid dyes been used for silk dyeing, but acid dyed silk shows weakness in color fastess, To improve this defect, the silk dyed with Acid Mordant Blue 13 was treated with chromes salts solution. Some mechanical properties and dyeing behaviors of the chrome mordant with dyed silk fabric were tested in this work. The tensile strength of silk fabric treated with chrome salts solution was decreased as the duration of treatment was increased. The mean rate constant (K) of photo-degradation was 1.019, and 1.047 after treated with Cr (III) and Cr (Ⅵ), respectively, whereas it was 1.304 in untreatment. The washing fastness of silk fabric also was improved by treatment with mordant and it was 3rd-4th grade and 4th grade when silk was treated with Cr (III) and Cr (Ⅵ), respectively, while untreatment gave 1st grade. The colour of dyed silk fabric was 2.5RP.3/10, but it was 5PB.4/3 and 5PB. 4/4 when the silk fabric was treated with Cr (III) for two hours and with Cr (Ⅵ) for one hour at 90$^{\circ}C$, respectively.

• Communications of the Korean Mathematical Society
• /
• v.26 no.3
• /
• pp.499-513
• /
• 2011

By using the Riccati transformation technique, we study the oscillation and asymptotic behavior for the third-order nonlinear delay dynamic equations $(c(t)(p(t)x^{\Delta}(t))^{\Delta})^{\Delta}+q(t)f(x({\tau}(t)))=0$ on a time scale T, where c(t), p(t) and q(t) are real-valued positive rd-continuous functions defined on $\mathbb{T}$. We establish some new sufficient conditions which ensure that every solution oscillates or converges to zero. Our oscillation results are essentially new. Some examples are considered to illustrate the main results.

• Journal of Fisheries and Marine Sciences Education
• /
• v.26 no.6
• /
• pp.1392-1401
• /
• 2014

This study was conducted to understand elementary school from third to sixth grade students' conceptions of evaporation and condensation to classified by grade and examples of questionnaires. For this purpose, 1606 students from 3rd grade to 6th grade were involved. They had conceptions of evaporation and condensation questionnaire. The results of this study were as the following: Firstly, students have to know about the basic conceptions to understand conceptions of evaporation and condensation. Secondly, it would appear that these ideas can sometimes be influenced in unintended ways and be not easily changed by science teaching. Thirdly, it would appear that they understood conceptions of evaporation better than that of condensation.

• Communications for Statistical Applications and Methods
• /
• v.26 no.1
• /
• pp.11-25
• /
• 2019

The present paper utilizes auxiliary information to neutralize the effect of non-response for estimating the population mean. Improved ratio type estimators for population mean have been proposed and their properties are studied. These estimators are suggested for both single phase sampling and two phase sampling in presence of non-response. Empirical studies are conducted to validate the theoretical results and demonstrate the performance of the proposed estimators. The proposed estimators are shown to perform better than those used by Cochran (Sampling Techniques (3rd ed), John Wiley & Sons, 1977), Khare and Srivastava (In Proceedings-National Academy Science, India, Section A, 65, 195-203, 1995), Rao (Randomization Approach in Incomplete Data in Sample Surveys, Academic Press, 1983; Survey Methodology 12, 217-230, 1986), and Singh and Kumar (Australian & New Zealand Journal of Statistics, 50, 395-408, 2008; Statistical Papers, 51, 559-582, 2010) under the derived optimality condition. Suitable recommendations are put forward for survey practitioners.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.26 no.2
• /
• pp.74-80
• /
• 2013

Three new Multi ${\times}$ Bi combinations M.Con.4 ${\times}$ (SK6 ${\times}$ SK7), M.Con.4 ${\times}$ NB4D2 and Nistari ${\times}$ (SK6 ${\times}$ SK7) were studied in five seasons i.e. during the period of $18^{th}$ June - $12^{th}$ July, $30^{th}$ August - $23^{rd}$ September, $3^{rd}$ November - $2^{nd}$ December, $29^{th}$ January- $2^{nd}$ March and $30^{th}$ March-$25^{th}$ April with one control Nistari ${\times}$ NB4D2 considering nine reeling characteristics along with shell percent and cocoon yield per 100 disease free layings (DFLs) to establish the seasonal effect on all the parameters. Results reveal that all the characters performed well in November-December. Highest yield per 100 DFLs was recorded during November-December in all combinations showing >60 kg yield. Higher correlation of yield/100 DFLs with filament length, non-breakable filament length, denier, raw silk percent, reelability percent and recovery percent was recorded in all combinations of Multi ${\times}$ Bi considered in this study. Variability observed among four combinations indicates the effect of different temperature and humidity of different seasons on expression of different traits. The results indicate that there is significant relationship of raw silk percent with reelability percent, recovery percent and evenness. Reelability percent showed higher correlation with recovery percent. It was observed that neatness was positively correlated with evenness. The overall performance of the newly evolved combinations with regard to productivity and reeling characteristics is discussed emphasizing their utilization at commercial level.

• The Journal of Pediatrics of Korean Medicine
• /
• v.26 no.4
• /
• pp.38-43
• /
• 2012

Objectives: The purpose of this study was to investigate the relations between mother's temperament and child's and parenting attitude. Methods: One hundred twenty healthy mothers (above 20 ys) who has a child (7-11 ys) participated after informed consent. The temperament of the children was analyzed by the Junior Temperament and Character Inventory 7-11 (JTCI 7-11) by their mothers. The temperament of the mothers was analyzed by the Temperament and Character Inventory-Revised Short (TCI-RS) and the parenting attitude of the mothers was analyzed by the Parenting Attitude Test (PAT). The relations between mother and child temperament and parenting attitude were assessed using the Pearson correlation coefficient. Results: There were some significant correlations between maternal temperaments and child's temperaments and maternal parenting attitude. Maternal temperament and parenting attitude: Novelty seeking (NS) of mother had low positive correlations with punishment, high expectation and inconsistency. Harm avoidance (HA) had low positive correlations with high involvement and high expectation, and had weak negative correlations with supportive expression and rational explanation. Reward dependence (RD) had low positive correlation with rational explanation. Persistence (P) had low positive correlations with supportive expression, rational explanation and superintendence, and weak negative correlation with high expectation. Child's temperament and parenting attitude: NS of child had low positive correlations with achievement press, high involvement, punishment, high expectation and inconsistency. Low positive correlations were found in many sets such as HA and high expectation, RD and supportive expression and rational explanation, P and supportive expression and rational explanation. Conclusions: These results suggest that there are significant relations between mother and child temperament and parenting attitude the temperament of mother and child.