• Journal of agricultural medicine and community health
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• v.33 no.1
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• pp.90-100
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• 2008

=Objectives: The aim of this study was to investigate the smoking rate and the related factors to early smoking of high school students.Methods: A questionnaire was administered to 920 students in 3 high schools in Daegu Metropolitan Results: Of total respondents, 1.8% had experience of smoking. Of those, 20.2% citied curiosity, 9.0% cited upon recommendation of friends, and 6.2% cited stress management as the main reason for their smoking. Separately, 53.1% responded habitually and 26.5% responded stress management as the main reason for continuing smoking. Of total former smokers, 68.4% said 'worry about their health' as the main reason for quitting smoking. Of those who failed to quit smoking, 58.7% cited 'weakness of will' as the main reason for their failure. Of total respondents, 10.8% were smoking currently. 'Smoking of family member'(p<0.01) and 'intent to smoke'(p<0.05) were significantly associated to early smoking of the subjects.In multivariate logistic regression analysis, 'higher levels of stress' and 'smoking of family member' were significant related factors to early smoking.Conclusions: Amid growing number of early smokers, it is imminent to identify the actual state of discourage smoking. In addition, education programs need to be developed to assist early smokers in quitting smoking and prevent smoking among youth.

• Journal of Animal Science and Technology
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• v.45 no.1
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• pp.33-40
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• 2003

The present study was undertaken to find relationships of plasma insulin-like growth factor (IGF)-I and IGF-II concentrations to litter size and lactation performance. Sixty pure-bred Landrace and Yorkshire pigs having similar farrowing weeks which had been selected from a large number of pregnant gilts and sows were divided into low- (<${\mu}$－0.5SD) and high-litter size (>${\mu}$+0.5 SD) lines under a 2 (breed)${\times}$2 (line) factorial arrange of treatments. After adjusting the litter size to nine piglets per sow at farrowing, total litter weight was measured at three weeks postpartum at weaning as an index of milk yield. Blood samples were obtained from the jugular vein at day (d)-90 pregnancy (Px) and at d-15 postpartum. The litter size or the number of piglets born during the present experiment and the average litter size during the entire parities up to the present one were greater in the high-line than in the low-line by 3.7 and 2.4 piglets, respectively (P<0.01); effect of the breed on litter size was not significant. Plasma IGF-II concentration at d-90 Px was greater in the high-line than in the low-line. Litter size and d-90 Px IGF-I concentration were negatively correlated in Landrace (r=－0.46; P<0.05) and tended to be negatively correlated in Yorkshire (r=－0.31; P=0.09), which resulted in a significant negative correlation between these two variables in total animals (r=－0.35; P<0.01). Litter weight at weaning was not different between the two breeds or lines. Relationships between the litter weight and IGF concentration were not consistent across the breed ${\times}$ physiological stage combinations. Results suggest that d-90 Px IGF concentrations may be indicative of the litter size at impending farrowing.

• Journal of Embryo Transfer
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• v.19 no.2
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• pp.155-163
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• 2004

The aims of this study are 1) to test oocytes and embryos collected from in-vitro to achieving the valuable protocol by culturing, vitrifying and thawing of oocytes/embryos, and 2) to transfer them to recipient, and finally have resulted in pregnancies from recipient females after surgical or nonsurgical transfer. In vitro maturation and fertilization were performed according to Funahashi et al (1994). Glucose-free NCSU 23 supplemented with 5 mM sodium pyruvate, 0.5 mM sodium lactate and 4 mg/ml bovine serum albumin for 2 days at $39^{\circ}C$, and 10% fetal bovine serum albumin was added to the culture medium thereafter. Embryos were treated with 7.5 ${\mu}g/ml$ cytochalasin-B for 30 min, centrifuged at 13,000 rpm for 13 min and then exposed sequentially to an ethylene glycol(EG) vitrification solution, aspirated into OPS, and plunged/thawed into/from liquid nitrogen. In vivo embryos were surgically collected from three dornors after AI for control group. Forty-nine embryos were washed 3 times in mPBS + 10% FBS, followed treatments : cultured, centrifuged, vitrified, recovered and transferred to recipients as in vitro prepared embryos. Three recipients were transferred individually with 100, 100 frozen embryos derived from abattoir and 34 fresh embryos by surgically, and another three recipients were transferred individually with 150, 150 frozen embryos and 100 fresh embryos by nonsurgically, respectively. all recipient sows exhibited delayed returns to estrus. To our knowledge, theses results suggest that required an improved techniques, more vigorous embryos preparation and substitute to gilt with cleaner uterous condition.

• Korean Journal of Plant Resources
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• v.36 no.1
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• pp.62-90
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• 2023

This study was conducted to study the vascular plants of Balbaeksan, located on the border between Gyeongsan-si and Cheongdo-gun, Gyeongsangbuk-do. It was performed 13 times from September 2020 to November 2021, and the investigated vascular plants were identified as a total of 93 families, 302 genera, 485 species, 10 subspecies, 40 varieties, 13 varieties, and 545 taxa. Endemic plants were investigated in 18 taxa, 9 taxa of rare plants; Vulnerable (VU) 5 taxa, Least concerned (LC) 3 taxa, Data Deficient (DD) 1 taxa, Red List plants 5 taxa; 3 taxa of least concerned (LC), 2 taxa of Not Evaluated (NE), 183 taxa of biological resources subject to export approval, 78 taxa of specific taxonomy; There were 9 taxa of grade IV, 20 taxa of grade III, 20 taxa of grade II, and 28 taxa of grade I. 4 taxa of plants subject to climate change adaptation; 2 taxa of endemic plants, 1 taxa of southern plants, 1 taxa of northern plants, 4 taxa of climate change biomarker species, 2 taxa of candidate species of climate change biomarker, 65 taxa of exotic plants, and 3 taxa of ecosystem disturbance species. Plants 235 taxa (43.1%), medicinal plants 257 taxa (47.2%), ornamental plants 148 taxa (27.2%), woody plants 54 taxa (9.9%), herbaceous plants 37 taxa (6.8%), industrial plants 15 Taxa (2.8%), 11 taxa (2.0%) of fiber-bearing plants, and plants of unknown use were identified as 73 taxa (13.4%). The flora of Mt. Balbaek was investigated for the first time, and plants to be preserved in order to secure useful plant resources and biological sovereignty were identified. So continuous monitoring is necessary to prevent the introduction of foreign plants that may be caused by the recent increase in the number of people coming and going.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.545-545
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• 2015

금호강은 포항시 북구 죽장면에서 발원하여 낙동강으로 합류하는 낙동강 제1지류로 유로연장은 114.6km이며, 영천과 경산지역의 생활 및 공업용수, 대구지역의 공업용수로 사용된다. 금호강의 평균 BOD는 1983년 191.2mg/L로 하수도나 산업폐수 처리 전 원수 정도의 수준이었으나, 2014년에는 3.6mg/L로 낮아져 수질개선율이 98.1%를 나타냈다. 이를 위해서 하 폐수 처리장 건설과 아울러 포항철강산업단지의 공업용수 공급을 위한 영천댐에 임하댐과 도수터널 52km를 연결하여 2001년부터 금호강에 하천유지용수로 $3.463m^3/s$를 공급하였다. 금호강 유역에서 오염총량제 목표수질은 금호B 지점이 BOD 3.8mg/L, TP 0.236mg/L이며, 금호C 지점은 BOD 4.0mg/L, TP 0.254mg/L이다. 분석기간인 2013년에서 2014년의 평균 수질은 모두 기준을 만족하고 있으나, 수질악화시에 금호B 지점에서 최대 BOD 8.6mg/L, TP 0.511mg/L, 금호C 지점에서 최대 BOD 8.5mg/L, TP 0.449mg/L을 나타내었다. 이에 영천댐의 탄력적인 유량방류로 수질악화시에 추가 방류를 수행하여 수질을 안정화시키고, 물공급의 안정화가 필요한 상황이다. 본 연구에서는 갈수기 및 이수기에 영천댐에서 하천유지용수보다 많은 유량을 탄력적으로 방류하는 가상조건을 설정하여, 하천유지유량과 목표수질을 만족하는 유량분석을 수행하였다. 이를 위해 QUALKO2 모형을 적용하였으며, 상류단 경계조건을 영천댐으로 설정하고 낙동강에 합류하기까지 약 86km 구간에 대해서 유량과 수질모의를 수행하였다. 모형적용을 위해서는 23개의 reach와 86개 element를 사용하였으며, 주요지류로는 신령천, 청통천, 부기천, 오목천, 남천, 동화천, 신천, 팔거천, 달서천, 이언천를 적용하고, 주요 하 폐수 처리시설을 점오염원으로 입력하였다. 실측자료는 2013년과 2014년의 월자료를 사용하였으며, 유량시나리오는 상류단 영천댐 방류량 조건을 반영하여, 실방류량 조건과 하천유지용수 방류조건, 유지용수 외 추가 25%, 50% 방류조건, 목표수질을 달성하는 방류조건으로 총 5가지의 시나리오를 수행하였다. 상류단 유량이 증가하면 금호강 전반적으로 수질이 개선되나 수질 악화시에는 과도한 방류량을 요구하게 되어, 수질 악화시를 위한 구조적 비구조적 대책도 필요한 상황으로 분석된다.

• Korean Journal of Food Science and Technology
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• v.26 no.2
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• pp.141-146
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• 1994

As a foundational study for processing persimmon leaves tea, the physico-chemical characters were investigated in persimmon leaves from Chungdo Bansi, Sagoksi, Kyungsan Bansi and Hiratanenasi during growth. Flesh weights increased rapidly until the middle of May and then decreased slightly. Moisture contents decreased continuously from $79{\sim}81%$ at the beginning of May during growth. Water soluble tannin contents reached $1.55{\sim}2.25%$, maximum values at the middle of May and at the beginning of June, and increased again at the middle of July and then decreased. Contents of catechins, precursor of condensed tannin, indicated $12{\sim}27\;mg%$ at the middle of May and reached $17{\sim}34\;mg%$, maximum values at the middle of June. Contents of catechin were low in order of (+)-catechin, (-)-epicatechin, (-)-epicallocatechingallate, (-)-epigallocatechin and (-)-epicatechingallate. Sugars present in persimmon leaves were composed of sucrose, glucose, fructose, raffinose and mannitol. Sucrose increased continuously, glucose and fructose decreased during growth. Raffinose content was less than 0.1%. Glucose and fructose took more than 90% until the beginning of May, and then sucrose took up $60{\sim}80%$ of total sugar contents. Total vitamin C contents indicated maximum values at the middle of May and at the beginning of June in Chungdo Bansi, Sagoksi and Kyungsan Bansi, maximum vaule at the middle of July in Hiratanenasi. From the basis of these data It was suggested that proper period for picking persimmon leaves prior to processing persimmon leaves tea was from the middle of May to the beginning of June. Since maximum values for most of chemical components occurred at the middle of May and at the beginning of June and persimmon leaves thicken after the middle of June.

• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.3
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• pp.124-131
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• 2012

This study was carried out to evaluate a possible change in freeze risk for 'Changhowon Hwangdo' peach buds in three major peach growing areas under the future climate projected by RCP8.5 emission scenario. Mean values of the monthly temperature data for the present decade (2000s) and the future decades (2020s, 2050s, 2080s) were extracted for farm lands in Icheon, Chungju, and Yeongcheon-Gyeongsan region at 1km resolution and 30 sets of daily temperature data were generated randomly by a stochastic process for each decade. The daily data were used to calculate a thermal time-based dormancy depth index which is closely related to the cold tolerance of peach buds. Combined with daily minimum temperature, dormancy depth can be used to estimate the potential risk of freezing damage on peach buds. When the freeze risk was calculated daily for the winter period (from 1 November to 15 March) in the present decade, Icheon and Chungju regions had high values across the whole period, but Yeongcheon-Gyeongsan regions had low values from mid-December to the end of January. In the future decades, the frequency of freezing damage would be reduced in all 3 regions and the reduction rate could be as high as 75 to 90% by 2080's. However, the severe class risk (over 80% damage) will not disappear in the future and most occurrences will be limited to December to early January according to the calculation. This phenomenon might be explained by shortened cold hardiness period caused by winter warming as well as sudden cold waves resulting from the higher inter-annual climate variability projected by the RCP8.5 scenario.

• Reproductive and Developmental Biology
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• v.37 no.1
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• pp.29-33
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• 2013

The objective of this work was to analyze the concentrations of progesterone (P4) and estrogen (E2) hormones changed during estrus synchronization in dairy heifers. Estrus synchronization was carried out with CIDR$^{(R)}$ (Controlled Intravaginal Drug Release) devices. Corpus luteum (CL) was classified into three grades based on its size and palpable characteristics. The concentrations of P4 and E2 were measured by enzyme-amplified chemiluminescence. Serum P4 concentration was markedly low at the estrus stage (36 hrs after removal of CIDR) compared to other stages, while E2 concentration was kept high during estrus stage. The serum P4 concentration was highest in the CL classified into grade I. These results indicate that P4 concentration could be used as a criteria for determining recipients for artificial insemination or embryo transfer in dairy cattle.

• Microbiology and Biotechnology Letters
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• v.34 no.2
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• pp.94-100
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• 2006

To isolate a bacterium that produces plant growth promoting hormone, a total of 29 bacteria were obtained from the soil in Gyeongsan, Korea. Among these, 14 strains were selected by their positive reaction on Salkowski to produce auxin. All of these were then tested for their property to produce siderophore using CAS (chrome azurol S) blue agar, and one was chosen for its ability to produce both, auxin and siderophore. This strain, denoted, AHl8, showed 1.5 times higher adventitious root induction rates than controls, using mung-beans. The strain also showed efficient biocontrol properties towards Fusarium-wilt of tomatoes in artificial pot assays. The strain was identified as Bacillus subtilis by 16s rDNA comparison and Biolog analyses. Growth and media conditions for Bacillus subtilis AH1 8 to highly produce siderophore were also investigated.

• Restorative Dentistry and Endodontics
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• v.28 no.5
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• pp.363-368
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• 2003

The purpose of this study is to evaluate the effect of additional enamel etching with phosphoric acid on the microleakage of the adhesion of self-etching primer system. Class V cavity($4mm{\times}3mm{\times}1.5mm$) preparations with all margins in enamel were prepared on buccal surface of 42 extracted human upper central incisor teeth. Prepared teeth were randomly divided into 3 groups. Group 1：no additional pretreatment with 37% phosphoric acid (NE). Group 2：additional pretreatment with 37% phosphoric acid for 10 seconds (E10s). Group 3：additional pretreatment with 37% phosphoric acid for 20 seconds (E20s). The adhesives(Clearfil SE $Bond^{\circledR}$, Kuraray, Osaka, Japan) and composite resins(Clearfil $AP-X^{\circledR}$, Osaka, Kuraray, Japan) were applied following the manufacturer's instructions. All the specimens were finished with the polishing disc(3M dental product, St Paul, MN, USA), thermocycled for 500 cycles between $5^{\circ}C$ and $55^{\circ}C$ and resected apical 3-mm root. 0.028 stainless steel wire was inserted apically into the pulp chamber of each tooth and sealed into position with sticky wax. Surrounding tooth surface was covered with a nail varnish 2 times except areas 1mm far from all the margins. After drying for one day, soaked the samples in the distilled water. Microleakage was assessed by electrochemical method(System 6514, $Electrometer^{\circledR}$), Keithley, USA) in the distilled water. In this study, the microleakage was the lowest in group 1 (NE) and the highest in group 3(E20s)(NE