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A survey on daily physical activity level, energy expenditure and dietary energy intake by university students in Chungnam Province in Korea (충남지역 대학생의 신체활동수준, 에너지소비량 및 에너지섭취량 조사)

  • Kim, Sun Hyo
    • Journal of Nutrition and Health
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    • v.46 no.4
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    • pp.346-356
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    • 2013
  • This study investigated the daily physical activity level, energy expenditure, energy balance, and body composition and their relationship with university students. The participants were 130 male students ($19.5{\pm}0.5$ yrs) and 139 female students ($19.5{\pm}0.3$ yrs) at a university in Chungnam province. Physical activity level was evaluated by an equation based on 24 hr-activity record and dietary nutrient intake was evaluated using the food record method during a three-day period consisting of two week days and one weekend. Body composition was measured using Inbody 430 (Biospace Co., Cheonan, Korea). As a result, mean body mass index (BMI) of subjects indicated that they had normal weight, however mean body fat ratio was $19.1{\pm}5.4%$ for males and $28.4{\pm}5.0%$ for females, indicating that they had higher than normal weight. Daily mean physical activity level was 1.55 for males and 1.47 for females, which was regarded as 'low active', respectively. Females had more light activity than males (p<0.01). Daily mean energy expenditure was $2,803.5{\pm}788.9$ kcal/d for males and $1,915.4{\pm}510.2$ kcal/d for females (p<0.001). Daily mean dietary energy intake was $2,327.0{\pm}562.5$ kcal/d for males and $1,802.1{\pm}523.6/d$ for females (p<0.001), and daily mean energy balance was $-476.5{\pm}955.9$ kcal/d for males and $-113.3{\pm}728.1$ kcal/d for females (p<0.01). Daily mean dietary intake of protein, vitamins, and minerals, except Ca, satisfied recommended nutrient intake. Daily energy expenditure was positively related to body weight (p<0.01), BMI (p<0.01), and fat free mass ratio (p<0.05), but was negatively related to body fat ratio (p<0.01). In conclusion, subjects had a negative energy balance and low physical activity. They had a normal weight by BMI but had a more fat than normal weight by body fat ratio. This appears to be related to their low physical activity. Thus, nutrition education should be provided for university students in order to increase their physical activity for maintenance of normal weight by body composition and health promotion.

Nutrient Intake Status of Male and Female University Students in Chuncheon Area (춘천지역 남녀 대학생들의 영양소 섭취 상태)

  • Kim, Yoon-Sun;Kim, Bok-Ran
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.44 no.12
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    • pp.1856-1864
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    • 2015
  • The purpose of this study was to investigate the nutrient intake status of university students in Chuncheon area (175 males and 131 females). This study was conducted by employing a self-administered questionnaire. Dietary assessment was measured by a 24-h recall method. The average height and weight of male students were $175.2{\pm}6.2cm$ and $68.2{\pm}9.9kg$, respectively. For female students, average values were $161.7{\pm}5.2cm$ and $55.1{\pm}6.5kg$, respectively. The mean BMIs for both male and female students were 22.2 and 21.1, respectively. In both male and female students, the rate of skipping breakfast was high. Daily averages for energy, carbohydrates, protein, and fat intakes in male students were significantly higher than those of female students (P<0.001). For male students, protein, vitamin B1, P, Fe, and Na were above recommended nutrient intake and adequate intake, whereas for female students, they were protein, vitamin A, P, and Na. For male students, nutrient intakes for Ca, vitamin $B_2$, vitamin C, and vitamin $B_6$ were below the estimated average requirement (EAR) by at least 50% or more, whereas for female students, they were vitamin C, Fe, vitamin $B_6$, vitamin $B_2$, niacin, folate, and Ca. Ca was alarmingly low, with more than 75% of both male and female students showing levels below the EAR. Therefore, it is important that nutritional education be facilitated for college students to take responsibility of their own health through learning about nutrient intake as well as developing positive eating habits.

The Effect of Soil Acidification on the Distribution of Nutrients and Heavy metals in Forest Ecosystem near Ulsan Industrial Estate (울산(蔚山) 공단주변(工團周邊) 산림토양(山林土壤)의 산성화(酸性化)가 산림생태계(山林生態系)의 양료(養料)와 중금속(重金屬) 분포(分布)에 미치는 영향(影響))

  • Lee, Seung Woo;Lee, Soo Wook
    • Journal of Korean Society of Forest Science
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    • v.84 no.3
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    • pp.286-298
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    • 1995
  • This study was carried out to investigate the effect of forest soil acidification on the distribution of exchangeable cations($Ca^{2+}$, $Mg^{2+}$, $Al^{3+}$) and heavy metals(Cu, Zn, Mn, Pb, Cd) in soil, and to understand the relation of the soil chemical properties and the distribution of nutrients and hear metals in fine root and foliage. The results through survey on the long - term change of soil pH and the contents of nutrient and heavy metal in soil, fine root and foliage by 2 sites near Ulsan - Onsan industrial estate and 2 sites in limited development district are summarized as follows : 1. The average forest soil pH(A horizon) in Ulsan had been proceeded down to 3.73 in deciduous forest and 3.86 in coniferous forest in 1994 from 4.45 and 4.78 in 1987, respectively, which indicated serious soil acidification. As comparing soil pH among sites, Dongcheon coniferous forest(pH 4.57) in limited development district showed the highest values and Dangwol deciduous forest(pH 3.19) near Onsan industrial estate showed the lowest values in 1994. 2. Contents of exchangeable calcium in forest soils of limited development district where showed much higher soil pH than industrial estate were 3.5 times more in deciduous forest soil and 11 times more in coniferous forest soil than in industrial estate, and contents of exchangeable magnesium were also 4.5 and 5 times more in limited development district than in industrial estate, respectively. However contents of exchangeable aluminium which had been supposed more in forest soil of industrial estate were more in limited development district. 3. Contents of calcium and magnesium in fine root of deciduous trees(A hirsuta. Q. acutissima) were 3.6 and 1.7 times more in limited development district than in industrial estate, respectively, and those of coniferous trees(P. rigida, P. thunbergii) were 4.6 and 1.5 times more in Limited development district than in industrial estate, respectively. Also contents of calcium and magnesium in foliage of deciduous trees were 1.1 and 2.2 times more in limited development district than in industrial estate, respectively, and those of coniferous trees were 1.8 and 3.3 times more in limited development district, respectively. And contents of aluminium in fine root and foliage were nearly as same as in soil. 4. Ca/Al molar ratios in soil and fine root, which could be related with the dgree of soil acidification and Al toxicity on trees, were Less than 1 in all sites except Dongcheon, suggesting that the soil and fine root in the sites have high sensitivity to soil acidification and the decrease in nutrient uptake and root enlargement. The Ca/Al molar ratios in soil and fine root in coniferous forest were highly correlated with the soil pH one another. 5. Contents of Cu, Zn and Pb in soil, fine root and foliage were more in industrial estate than in limited development district in both deciduous and coniferous forests, however, oppositely contents of Mn and Cd in soil were more in limited development district than in industrial estate.

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An Analysis of Morphological Variation in Abies koreana Wilson and A. nephrolepis (Traut.) Maxim. of Korea (Pinaceae) and Their Phylogenetic Problems (한국산(韓國産) 분비나무와 구상나무의 형질분석(形質分析)과 종간유연관계(種間類緣關係))

  • Chang, Chin-Sung;Jeon, Jeong Ill;Hyun, Jung Oh
    • Journal of Korean Society of Forest Science
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    • v.86 no.3
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    • pp.378-390
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    • 1997
  • Ten total populations of Korean fir (Abies koreana Wilson) and Manshurian fir [A. nephrolepis (Traut.) Maxim.] were sampled from south Korea to investigate patterns of intraspecific variation in these species and to evaluate a recognition of the two species. Principal components analysis and cluster analysis were performed both on seed-cone data and on needle morphology data. The characters that contributed most to the separation between A. koreana and A. nephrolepis along three principal components axis were leaf width, length of seed, width of seed wing, length of seed wing, cone width, width of scale, and length of bract tip, but these characters were not diagnostic because of overlap in reality. Therefore, all these characters were not reliable in distinguishing these two taxa including bract position (exerted and recurved vs. exerted and straight). The individuals of A. koreana from Mt. Chi-ri appeared quite unique probably on account of its larger cone size and longer scale tip, while those from Mt. Hal-la of A. koreana were generally distinct from others in terms of their larger seed and seed wing and longer scale width. The Mt. Duk-yu specimens of A. korecana appeared somewhat smaller but more data were needed due to the small sampling size. Generally, the gradual clinal geographic trends made evident by the position of resin ducts in leaves of A. koreana can be detected. The southern populations, Mt. Hal-la (an insular population) were generally distinct from the northern populations (Mt. Chi-ri, Mt. Ga-ya and Mt. Duk-yu) in terms of their position of resin duct (medial, within mesophyll vs marginal, close to epidermis : 100% vs 75 or 50%). Although no sharp boundary separating these two species could be detected based on cone and needle morphology, the observed clinal pattern was distinct in northern populations of A. koreana and southern population of A. nephrnlepis. In a preceding study of the flavonoids variation of 20 species in eastern Asia, flavanone (5-deoxyflavanone) was found to be characteristic of A. faxoniana Rehder et Wilson, A. georgei Orr of China and A. koreana of Korea. A. faxoniana, which is assumed to be primitive species, has position of resin duct relative to both the medial and the marginal, while A. georgei and A. koreana are identified by marginal position of resin duct. With respect of foliar flavonoids chemistry, A. koreana was distinct from A. nephrolepis : the southmost samples (Mt. Hal-la and Mt. Chi-ri) contained additional flavonoids derivatives (mainly flavanone) that were not found in the northmost samples of A. nephrolepis except a few individuals from Mts. Seo-rak and Tae-bak populations of Kwang-won province. The presence of A. koreana type flavonoids in two Chinese species suggested that position of resin duct may be a phyletic character. Abies koreana including two Chinese taxa, exhibited the most elaborate and specialized flavonoids profile within the Abies in eastern Asia. Contrary to our initial expectations, the apparent intermediates between A. nephrolepis and A. koreana in Duk-yu and Ga-ya mountains were found. The pattern of variation on position of resin duct and flavonoids chemistry in these populations of A. kareana suggested that genetic interchange or natural hybridization had occurred between these two species. The evidence needed to resolve the status of this taxon is still inconclusive in our opinion until intermediate individuals from Mts. Duk-yu and Ga-ya show indication of hybridization between the two species.

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Anastomosis Groups and Cultural Characteristics of Rhizoctonia solani Isolates from Crops in Korea (국내(國內) 작물(作物)에서 분리한 Rhizoctonia solani 균주(菌株)들의 균사융합군(菌絲融合群)과 배양적(培養的) 특성(特性))

  • Kim, Wan-Gyu;Cho, Won-Dae;Lee, Young-Hee
    • The Korean Journal of Mycology
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    • v.22 no.4
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    • pp.309-324
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    • 1994
  • A total of 2,276 isolates of Rhizoctonia solani obtained from diseased crops of 68 species was classified into anastomosis groups AG-1, AG-2-1, AG-2-2, AG-3, AG-4 and AG-5 by anastomosis test. Among the isolates, 1,091 isolates were identified as AG-1, 326 isolates as AG-2-1, 191 isolates as AG-2-2, 71 isolates as AG-3, 505 isolates as AG-4, and 92 isolates as AG-5. Among the isolates of AG-1, 791 isolates were grouped as cultural type IA, 280 isolates as cultural type IB, and the others as cultural type IC. Among the isolates of AG-2-2, 112 isolates were grouped as cultural type IIIB, and the others as cultural type IV. Cultural types IA, IB and IC of AG-1 were isolated from 7, 26 and 2 species of crops, respectively. AG-2-1 was isolated from 10 species of crops. Cultural types IIIB and IV of AG-2-2 were isolated from 7 and 3 species of crops, respectively. AG-3 was only isolated from Solanum tuberosum. AG-4 was isolated from 43 species of crops, and AG-5 from 13 species of crops. A single anastomosis group was isolated from each of 45 species of crops, but two or more than two anastomosis groups were isolated from each of the other crops. Cultural appearance of the isolates belonging to an anastomosis group or a cultural type was mostly distinct from that belonging to others, although cultural appearances of some anastomosis groups or cultural types were similar to one another. Optimum temperature for mycelial growth of AG-1, AG-2-2, AG-4 and AG-5 ranged from 26 to $30^{\circ}C$, and that of AG-2-1 and AG-3 from 22 to $26^{\circ}C$. Minimum temperature for mycelial growth of AG-2-1 was the lowest as $2{\sim}3^{\circ}C$, that of AG-1(IA) and AG-4 was the highest as $10{\sim}11^{\circ}C$, and that of the others ranged from 5 to $10^{\circ}C$. Maximum temperature for mycelial growth of AG-2-2(IIIB) was the highest as $36{\sim}37^{\circ}C$, that of AG-2-1 was the lowest as $29{\sim}30^{\circ}C$, and that of the others ranged from 31 to $36^{\circ}C$. When the mycelial growth rates at $26^{\circ}C$ were compared, AG-1(IC) grew most rapidly, followed by AG-1(IA) and AG-1(IB), and AG-2-1 grew most slowly.

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The Absorption and Purification of Air Pollutants and Heavy Metals by Selected Trees in Kwangju (광주지역(光州地域)에서 주요(主要) 수목(樹木)의 대기오염물질(大氣汚染物質)과 중금속(重金屬) 흡수(吸收) 정화기능(淨化機能)에 관(關)한 연구(硏究))

  • Cho, Hi Doo
    • Journal of Korean Society of Forest Science
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    • v.88 no.4
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    • pp.510-522
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    • 1999
  • The air pollutants ; $SO_2$, $SO{_4}^{-2}$, $NO{_3}^-$, $Cl^-$ are absorbed into soils through falling with dusts and rain from the atmosphere. The sources of heavy metal contaminants in the environments are agricultural and horticultural materials, sewage sludges, fossil fuel combustion, metallurgical industries, electronics and waste disposal etc.. The soils and hydrosphere can be polluted on the way of the circulation of these heavy metals. Studied pollutant anions are $SO{_4}^{-2}$, $NO{_3}^-$ and $Cl^-$ and heavy metals are Se, Mo, Zn, Cd, Pb, Mn, Cr, Co, V, As, Cu and Ni which are the elements to be concerned with the essentials for plants, with animal and human health. This study is with the aim of selecting the species of roadside trees and green space trees which have excellent absorption of air pollutants and heavy metals from the atmosphere and the soils in the urban area. Two areas are designated to carry out this study : urban area ; Kwangju city and rural area ; the yard of Forest Environment Institute of Chollanam-do, at Sanje-ri, Sampo-myum, Naju city, Chollanam-do (23km away from Kwangju). This study is carried out to understand the movement of anions and heavy metals from the soils to the trees in both areas, the absorption of anions and heavy metals from atmosphere into leaves and the amounts of anions and heavy metals in leaves and fine roots(< 1mm dia.) of roadside trees and green space trees in Kwangju and trees in the yard of Forest Environment Institute of Chollanam-do. The tree species selected for this study in both areas are Ginkgo biloba, Quercus acutissima, Cedrus deodara, Platanus occidentalis, Robinia pseudoacacia, Alnus japonica. Metasequoia glyptostroboides. Zekova serrata. Prunus serrulata var. spontanea, and Pinus densiflora. The results of the study are as follows : 1. $SO{_4}^{-2}$, $NO{_3}^-$ and $Cl^-$ concentrations are higher in the soils of the urban area than in those of the rural area, and $NO{_3}^-$ and $SO{_4}^{-2}$ are higher in the leaves than in the roots due to the absorption of the these pollutants through the stomata. 2. Ginkgo biloba, Robinia pseudoacacia. Zekova serrata, Quercus acutissima, and Platanus occidentalis can be adequated to the roadside trees and the environmental trees due to their good absorption of $NO{_3}^-$ and $SO{_4}^{-2}$. 3. Heavy metals in the soils of both areas are in the order of Mn > Zn > V > Cr > Pb > Ni > Cu > Mo> Cd, and in the leaves and roots of the trees in the both areas are in the order of Mn>Zn>Cr>Cu>V>Ni. Both orders are similar ones except V. There are more in the urban soils than in the rural soils in amount of Mn, Zn, Pb, V, Cu. 4. It is supposed that there is no antagonism between Mn and Zn in this study. 5. Se, Co and As are not detected in the soils, the leaves and the roots in both areas. Sn, Mo, Cd and Pb are also not detected in the leaves and roots in spite of considerable amount in the soils of both areas.

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Purchasing Status and Supplier Performance Evaluation of School Foodservice in Chanwon, Korea (창원시 학교급식 식재료 구매 실태 및 공급업체 수행도 평가)

  • Jung, Hoi-Jung;Kim, Hyun-Ah
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.41 no.6
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    • pp.861-869
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    • 2012
  • This study was conducted to investigate the purchasing status and to compare supplier performance evaluations between competitive bidding and negotiated contracts in school foodservice in Changwon, Korea. A total of 190 questionnaires were distributed and 167 (return rate 87.9%) were collected from June 29 to September 28, 2010, and then a total of 151 (analysis rate 79.5%) were used for the final analysis. First, 91.4% of food product purchases for school meals were contracted through competitive bidding, especially limited competitive bidding. It mainly consisted of agricultural products, processed food, and eco-friendly agricultural products (fruit). Second, 78.8% of schools purchased food products by negotiated contracts, while single negotiation accounted for 59.7%. Food products by negotiated contract consisted of meat, kimchi, and fish. Third, the purchase status of competitive bidding and negotiated contracts showed a significant difference in agricultural products (p<0.001), fish (p<0.001), meats (p<0.001), poultry (p<0.001), antibiotic-free poultry (p<0.001), eco-friendly grain (p<0.001), eco-friendly agricultural products (fruit) (p<0.001), eco-friendly processed food (p<0.001), processed products (p<0.001), milk (p<0.001) and general grain (p<0.001) except for kimchi. Fourth, comparative analysis of supplier performance evaluation (on a 5-point Likert scale) of school foodservice showed that price of product of competitive bidding (3.73) was significantly higher than that of negotiated contract (2.95) (p<0.001), and the overall performance level of the negotiated contract (3.85) was significantly higher than that of competitive bidding (3.61) (p<0.01). The supplier performance evaluation levels of product packaging (p<0.01), product quality at the time of delivery (p<0.001), hygiene of products (p<0.001), consistency to specification (p<0.001), swiftness of return and exchange (p<0.001), emergency delivery (p<0.001), service of delivery staff (p<0.05), and handling of complaints (p<0.001) of negotiated contracts were significantly higher than those of competitive bidding of school foodservice. In conclusion, school foodservice selected food suppliers both by adopting competitive bidding and negotiated contracts. And there was a significant difference of school foodservice supplier performance between competitive bidding and negotiated contracts in Changwon, Korea.

In vitro Antioxidant and Anti-Inflammatory Activities of Ethanol Extract and Sequential Fractions of Flowers of Prunus persica in LPS-Stimulated RAW 264.7 Macrophages (복숭아꽃 에탄올 추출물과 분획물의 in vitro 항산화 효과 및 RAW 264.7 대식세포에서의 항염증 효과)

  • Kwak, Chung Shil;Choi, Hye-In
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.44 no.10
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    • pp.1439-1449
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    • 2015
  • Prunus persica Flos (PPF) were investigated for their antioxidant and anti-inflammatory activities to find a natural functional food resource preventing degenerative diseases associated with excessive oxidative stress and chronic inflammation. PPF was extracted using ethanol (EtOH) and then sequentially fractioned by hexane (Hx), dichloromethane (DM), ethyl acetate (EA), n-butanol (BtOH), and water (DW). Contents of total phenolics and flavonoids, as well as 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities were measured. Anti-inflammatory effects in terms of nitric oxide (NO), prostaglandin (PG) E2, and pro-inflammatory cytokines such as interleukin (IL)-6 and tumor necrosis factor (TNF)-${\alpha}$ production were also measured using LPS-treated RAW 264.7 macrophages. EtOH extract showed relatively high antioxidant activity with high total phenolic (78.1 mg tannic acid/g) and flavonoid contents (55.3 mg rutin/g). EA fraction contained the highest total phenolic and flavonoid contents (394.6 mg tannic acid/g, 253.7 mg rutin/g), followed by BtOH (128.3 mg tannic acid/g, 93.1 mg rutin/g). EA and BtOH fractions and EtOH extract showed higher DPPH radical and ABTS radical scavenging activities than the others (P<0.05). In LPS-treated RAW 264.7 macrophages, EtOH extract ($200{\mu}g/mL$) showed significantly reduced (P<0.05) NO, PGE2, and TNF-${\alpha}$ production levels to 38.5%, 32.3%, and 48.9% of the control, respectively, as well as reduced iNOS and COX-2 protein expression. DM fraction ($50{\mu}g/mL$) showed significantly reduced (P<0.05) NO, PGE2, IL-6, and TNF-${\alpha}$ production levels to 43.5%, 13.3%, 38.7%, and 41.3% of the control, respectively, and EA fraction ($50{\mu}g/mL$) showed significantly reduced NO, PGE2, IL-6, and TNF-${\alpha}$ production levels to 44.8%, 22.4%, 45.7%, and 62.0% of the control, respectively. Taken together, EtOH extract of PPF showed potent antioxidant and anti-inflammatory activities, and EA and BtOH fractions showed comparatively stronger antioxidant activities while DM and EA fractions showed stronger anti-inflammatory activities. It can be concluded that EtOH extract of PPF and its fractions are good candidates as natural resources for the development of anti-oxidative and anti-inflammatory functional food products.

Motives for Writing After-Purchase Consumer Reviews in Online Stores and Classification of Online Store Shoppers (인터넷 점포에서의 구매후기 작성 동기 및 점포 고객 유형화)

  • Hong, Hee-Sook;Ryu, Sung-Min
    • Journal of Distribution Research
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    • v.17 no.3
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    • pp.25-57
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    • 2012
  • This study identified motives for writing apparel product reviews in online stores, and determined what motives increase the behavior of writing reviews. It also classified store customers based on the type of writing motives, and clarified the characteristics of internet purchase behavior and of a demographic profile. Data were collected from 252 females aged 20s' and 30s' who have experience of reading and writing reviews on online shopping. The five types of writing motives were altruistic information sharing, remedying of a grievance and vengeance, economic incentives, helping new product development, and the expression of satisfaction feelings. Among five motives, altruistic information sharing, economic incentives, and helping new product development stimulate writing reviews. Store customers who write reviews were classified into three groups based on their writing motive types: Other consumer advocates(29.8%), self-interested shoppers(40.5%) and shoppers with moderate motives(29.8%). There were significant differences among three groups in writing behavior (the frequency of writing reviews, writing intent of reviews, duration of writing reviews, and frequency of online shopping) and age. Based on results, managerial implications were suggested. Long Abstract : The purpose of present study is to identify the types of writing motives on online shopping, and to clarify the motives affecting the behavior of writing reviews. This study also classifies online shoppers based on the motive types, and identifies the characteristics of the classified groups in terms of writing behavior, frequency of online shopping, and demographics. Use and Gratification Theory was adopted in this study. Qualitative research (focus group interview) and quantitative research were used. Korean women(20 to 39 years old) who reported experience with purchasing clothing online, and reading and writing reviews were selected as samples(n=252). Most of the respondents were relatively young (20-34yrs., 86.1%,), single (61.1%), employed(61.1%) and residents living in big cities(50.9%). About 69.8% of respondents read and 40.5% write apparel reviews frequently or very frequently. 24.6% of the respondents indicated an "average" in their writing frequency. Based on the qualitative result of focus group interviews and previous studies on motives for online community activities, measurement items of motives for writing after-purchase reviews were developed. All items were used a five-point Likert scale with endpoints 1 (strongly disagree) and 5 (strongly agree). The degree of writing behavior was measured by items concerning experience of writing reviews, frequency of writing reviews, amount of writing reviews, and intention of writing reviews. A five-point scale(strongly disagree-strongly agree) was employed. SPSS 18.0 was used for exploratory factor analysis, K-means cluster analysis, one-way ANOVA(Scheffe test) and ${\chi}^2$-test. Confirmatory factor analysis and path model analysis were conducted by AMOS 18.0. By conducting principal components factor analysis (varimax rotation, extracting factors with eigenvalues above 1.0) on the measurement items, five factors were identified: Altruistic information sharing, remedying of a grievance and vengeance, economic incentives, helping new product development, and expression of satisfaction feelings(see Table 1). The measurement model including these final items was analyzed by confirmatory factor analysis. The measurement model had good fit indices(GFI=.918, AGFI=.884, RMR=.070, RMSEA=.054, TLI=.941) except for the probability value associated with the ${\chi}^2$ test(${\chi}^2$=189.078, df=109, p=.00). Convergent validities of all variables were confirmed using composite reliability. All SMC values were found to be lower than AVEs confirming discriminant validity. The path model's goodness-of-fit was greater than the recommended limits based on several indices(GFI=.905, AGFI=.872, RMR=.070, RMSEA=.052, TLI=.935; ${\chi}^2$=260.433, df=155, p=.00). Table 2 shows that motives of altruistic information sharing, economic incentives and helping new product development significantly increased the degree of writing product reviews of online shopping. In particular, the effect of altruistic information sharing and pursuit of economic incentives on the behavior of writing reviews were larger than the effect of helping new product development. As shown in table 3, online store shoppers were classified into three groups: Other consumer advocates (29.8%), self-interested shoppers (40.5%), and moderate shoppers (29.8%). There were significant differences among the three groups in the degree of writing reviews (experience of writing reviews, frequency of writing reviews, amount of writing reviews, intention of writing reviews, and duration of writing reviews, frequency of online shopping) and age. For five aspects of writing behavior, the group of other consumer advocates who is mainly comprised of 20s had higher scores than the other two groups. There were not any significant differences between self-interested group and moderate group regarding writing behavior and demographics.

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The Effect of TGF-{\beta}_1 on Cellular Activity of Periodontal Ligament Cells activated by PDGF-BB (PDGF-BB에 의한 치주인대세포활성에 대한 TGF-{\beta}의 효과)

  • Baek, Sang-Churl;Park, Jin-Woo;Suh, Jo-Young
    • Journal of Periodontal and Implant Science
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    • v.32 no.3
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    • pp.457-473
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    • 2002
  • The purposes of this study is to evaluate the combination effects of TGF-${\beta}_1$ and PDGF-BB on the periodontal ligament cells to use as a regeneration promoting agent of periodontal tissue. Human periodontal ligament cells were prepared from the first premolar tooth extracted for the orthodontic treatment and were cultured in DMEM/100% FBS at the $37^{\circ}C$, 5% $CO_2$ incubator. Authors measured the DNA synthesis, total protein, collagen and noncollagenous protein synthesis according to the concentration of TGF-${\beta}_1$,(1,5ng/ml) and PDGF-BB (1,10 ng/ml) in combination. To explore further this delayed effect of TGF-${\beta}_1$, we preincubated human periodontal ligament cells with TGF-${\beta}_1$ for 4 or 24 hours before PDGF-BB stimulation. The results were as follows: The DNA synthetic activity was increased dose dependently by TGF-${\beta}_1$, PDGF-BB. The combination of TGF-${\beta}_1$ and PDGF-BB consistently enhanced the DNA synthetic activity to PDGF-BB alone. The ability of TGF-${\beta}_1$ to enhance DNA synthetic activity in PDGF-BB treated periodontal ligament cells was dose dependent. The maximum mitogenic effect was at the 5ng/ml of TGF-${\beta}_1$ and l0ng/ml of PDGF-BB. Preincubation of cell with TGF-${\beta}_1$ resulted in significantly greater response to PDGF-BB at all TGF-${\beta}_1$ concentration studied, and may be useful for clinical application in periodontal regenerative procedures. The total protein, collagen and noncollagen synthesis was increased dose pendently by TGF-${\beta}_1$, PDGF-BB. The % of collagen was slightly decreased according to the concentration of TGF-${\beta}_1$, PDGF-BB. The effect of TGF-${\beta}_1$, PDGF-BB were not specific for collagen synthesis since it also increased noncollagenous protein synthesis. This study demonstrates that PDGF-BB is major mitogens for human periodontal ligament cells in vitro, and supports a role for TGF-${\beta}_1$ as a regulation of the mitogenic and total protein formation to PDGF-BB in these cells.