Purpose: This study sought to predict the reasons for skipping breakfast by adolescents aged 13-18 years using the 7th Korea National Health and Nutrition Examination Survey (KNHANES). Methods: The participants included 1,024 adolescents. The data were analyzed using a complex-sample t-test, the Rao Scott χ2-test, and the classification and regression tree (CART) algorithm for decision tree analysis with SPSS v. 27.0. The participants were divided into two groups, one regularly eating breakfast and the other skipping it. Results: A total of 579 and 445 study participants were found to be breakfast consumers and breakfast skippers respectively. Breakfast consumers were significantly younger than those who skipped breakfast. In addition, breakfast consumers had a significantly higher frequency of eating dinner, had been taught about nutrition, and had a lower frequency of eating out. The breakfast skippers did so to lose weight. Children who skipped breakfast consumed less energy, carbohydrates, proteins, fats, fiber, cholesterol, vitamin C, vitamin A, calcium, vitamin B1, vitamin B2, phosphorus, sodium, iron, potassium, and niacin than those who consumed breakfast. The best predictor of skipping breakfast was identifying adolescents who sought to control their weight by not eating meals. Other participants who had low and middle-low household incomes, ate dinner 3-4 times a week, were more than 14.5 years old, and ate out once a day showed a higher frequency of skipping breakfast. Conclusion: Based on these results, nutrition education targeted at losing weight correctly and emphasizing the importance of breakfast, especially for adolescents, is required. Moreover, nutrition educators should consider designing and implementing specific action plans to encourage adolescents to improve their breakfast-eating practices by also eating dinner regularly and reducing eating out.
Purpose: Much evidence suggests long-term cigarette smoking alters coronary vascular endothelial response. On this study, we applied nonnegative matrix factorization (NMF), an unsupervised learning algorithm, to CO-less $H_2^{15}O-PET$ to investigate coronary endothelial dysfunction caused by smoking noninvasively. Materials and methods: This study enrolled eighteen young male volunteers consisting of 9 smokers $(23.8{\pm}1.1\;yr;\;6.5{\pm}2.5$ pack-years) and 9 nonsmokers $(23.8{\pm}2.9 yr)$. They do not have any cardiovascular risk factor or disease history. Myocardial $H_2^{15}O-PET$ was performed at rest, during cold ($5^{\circ}C$) pressor stimulation and during adenosine infusion. Left ventricular blood pool and myocardium were segmented on dynamic PET data by NMF method. Myocardial blood flow (MBF) was calculated from input and tissue functions by a single compartmental model with correction of partial volume and spillover effects. Results: There were no significant difference in resting MBF between the two groups (Smokers: 1.43 0.41 ml/g/min and non-smokers: $1.37{\pm}0.41$ ml/g/min p=NS). during cold pressor stimulation, MBF in smokers was significantly lower than 4hat in non-smokers ($1.25{\pm}0.34$ ml/g/min vs $1.59{\pm}0.29$ ml/gmin; p=0.019). The difference in the ratio of cold pressor MBF to resting MBF between the two groups was also significant (p=0.024; $90{\pm}24%$ in smokers and $122{\pm}28%$ in non-smokers.). During adenosine infusion, however, hyperemic MBF did not differ significantly between smokers and non-smokers ($5.81{\pm}1.99$ ml/g/min vs $5.11{\pm}1.31$ ml/g/min ; p=NS). Conclusion: in smokers, MBF during cold pressor stimulation was significantly lower compared wi4h nonsmokers, reflecting smoking-Induced endothelial dysfunction. However, there was no significant difference in MBF during adenosine-induced hyperemia between the two groups.
Kim, Ju-Ock;Jung, Sung-Soo;Park, Hee-Sun;Kim, Myoung-Hoon;Kim, Sun-Young;Lee, Young-Ha
Tuberculosis and Respiratory Diseases
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v.52
no.4
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pp.317-329
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2002
Background : Immunotherapy is another treatment modality for various cancers. There is little information on the antitumor effects of immunotherapy on implanted lung cancer mouse models. Toxoplasma gondii is able to potently induce a nonspecific stimulation of the host immune system. Therefore, this study evaluated the antitumor and antimetastatic effect of nonspecific immune stimulation by T. gondii in a Lewis lung cancer mouse model. Methods : Female C57BL/6 mice were injected with either Lewis lung cancer cells ($1{\times}10^6$ per mouse) or 5 cysts from the T. gondii Me49 strain with various schedules. The number of survival days, the tumor size of the implanted muscle and the histopathological findings of each group were noted. In addition to these mice, the Toxoplasma antigen($50{\mu}g$ per mouse) or a lymphokine (0.5 ml per mouse) was added to boost the immunotherapy. Results : No mouse in the Toxoplasma-infected group had died, whereas the mice receiving only the cancer cells (cancer control) survived for $29.1{\pm}4.4$ days. Cancer cells were revealed from 1 week after cancer cell inceulation in the muscle and from 3 weeks in the lung of the cancer control, whereas cancer cells were found in both the preinfection control and coinfection control groups from 2 weeks and 4 weeks in the lung respectively. The in the number of survival days were $32.4{\pm}3.3$ in the mice receiving T. gondii 2 weeks prior to the cancer cells inoculation (preinfection control), $30.9{\pm}5.1$ in mice received both simultaneously (coinfection control), and $34.9{\pm}2.9$ in mice received T. gondii 2 weeks after cancer cells implantation (postinfection control). These 3 infection groups had significantly longer survival days and suppressed tumor growth than those of the cancer control. In addition to these mice, and injection with the Toxoplasma antigen alone or in combination with lymphokine resulted in a significant increase in the number of survival days. Conclusion : These findings suggest that an injection with T. gondii can induce the antitumor and antimetastatic effects in Lewis lung cancer mouse models. Moreover, these effects were increased with an injection of the Toxoplasma antigen alone or in combination with lymphokine. However, this therapy can not prevent the development of cancer.
This experiment was conducted to construct process models to estimate grain weight (GW) and grain nitrogen content (GN) in rice. A model was developed to describe the dynamic pattern of GW and GN during grain-filling period considering their relationships with temperature, solar radiation and growth traits such as LAI, shoot dry-weight, shoot nitrogen content, grain number during grain filling. Firstly, maximum grain weight (GWmax) and maximum grain nitrogen content (GNmax) equation was formulated in relation to Accumulated effective temperature (AET) ${\times}$ Accumulated radiation (AR) using boundary line analysis. Secondly, GW and GN equation were created by relating the difference between GW and GWmax and the difference between GN and GNmax, respectively, with growth traits. Considering the statistics such as coefficient of determination and relative root mean square of error and number of predictor variables, appropriate models for GW and GN were selected. Model for GW includes GWmax determined by AET ${\times}$ AR, shoot dry weight and grain number per unit land area as predictor variables while model for GN includes GNmax determined by AET ${\times}$ AR, shoot N content and grain number per unit land area. These models could explain the variations of GW and GN caused not only by variations of temperature and solar radiation but also by variations of growth traits due to different sowing date, nitrogen fertilization amount and row spacing with relatively high accuracy.
Journal of the Korean Society of Food Science and Nutrition
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v.43
no.1
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pp.47-54
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2014
The aim of this study is to evaluate the effects of green tea polyphenol (GTP) on anticancer treatment with cisplatin (CP), using both an in vitro cell culture model and an in vivo mouse model of established breast tumor. Mouse breast cancer cells (EMT6) were treated with or without GTP and CP followed by determination of the cell viability using an MTT assay. The relative cell viability of CP treated EMT6 cells was 96% at a 20 ${\mu}g/mL$ concentration of cisplatin; however, in combination with GTP (50 ${\mu}g/mL$), the cell viability decreased to 20% at the same concentration of CP (20 ${\mu}g/mL$). For the in vivo study, EMT6 cells were inoculated into Balb/c mice for the establishment of a tumor-bearing mice model. The tumor-bearing mice were treated with CP (5 mg/kg. i.p.) with or without dietary GTP (0.2% drinking water). Tumor growth was monitored by a measurement of tumor size using a digital caliper, and nephrotoxicity was determined by enzymatic and histological examinations. The levels of p53 and caspase-3 in tumor tissues were examined by a Western blot. In tumor-bearing mice treated with GTP plus CP, the increment of tumor volume showed a significant reduction, compared with CP or GTP alone. The levels of p53 and cleaved caspase-3 (caspase-3/p17) in tumor tissues of tumor-bearing mice were increased by CP and GTP compared to CP alone. In CP treated tumor-bearing mice, ${\gamma}$-glutamyltranspeptidase (GGT) and alkaline phosphatase (AP) activities were decreased, and marked tubular necrosis and dilatation were observed in the kidney. CP-induced enzymatic and histopathological changes in the kidney of tumor-bearing mice were reduced by combinations of GTP with CP. The results of these experiments demonstrated that dietary GTP has a potentiating effect on CP anti-tumor activity and a protective effect against CP-induced renal dysfunction. Therefore, GTP may be used as a modulator in anticancer treatment with CP.
Internet commerce has been growing at a rapid pace for the last decade. Many firms try to reach wider consumer markets by adding the Internet channel to the existing traditional channels. Despite the various benefits of the Internet channel, a significant number of firms failed in managing the new type of channel. Previous studies could not cleary explain these conflicting results associated with the Internet channel. One of the major reasons is most of the previous studies conducted analyses under a specific market condition and claimed that as the impact of Internet channel introduction. Therefore, their results are strongly influenced by the specific market settings. However, firms face various market conditions in the real worlddensity and disutility of using the Internet. The purpose of this study is to investigate the impact of various market environments on a firm's optimal channel strategy by employing a flexible game theory model. We capture various market conditions with consumer density and disutility of using the Internet.
shows the channel structures analyzed in this study. Before the Internet channel is introduced, a monopoly manufacturer sells its products through an independent physical store. From this structure, the manufacturer could introduce its own Internet channel (MI). The independent physical store could also introduce its own Internet channel and coordinate it with the existing physical store (RI). An independent Internet retailer such as Amazon could enter this market (II). In this case, two types of independent retailers compete with each other. In this model, consumers are uniformly distributed on the two dimensional space. Consumer heterogeneity is captured by a consumer's geographical location (ci) and his disutility of using the Internet channel (${\delta}_{N_i}$).
shows various market conditions captured by the two consumer heterogeneities.
(a) illustrates a market with symmetric consumer distributions. The model captures explicitly the asymmetric distributions of consumer disutility in a market as well. In a market like that is represented in
(c), the average consumer disutility of using an Internet store is relatively smaller than that of using a physical store. For example, this case represents the market in which 1) the product is suitable for Internet transactions (e.g., books) or 2) the level of E-Commerce readiness is high such as in Denmark or Finland. On the other hand, the average consumer disutility when using an Internet store is relatively greater than that of using a physical store in a market like (b). Countries like Ukraine and Bulgaria, or the market for "experience goods" such as shoes, could be examples of this market condition.
summarizes the various scenarios of consumer distributions analyzed in this study. The range for disutility of using the Internet (${\delta}_{N_i}$) is held constant, while the range of consumer distribution (${\chi}_i$) varies from -25 to 25, from -50 to 50, from -100 to 100, from -150 to 150, and from -200 to 200.
summarizes the analysis results. As the average travel cost in a market decreases while the average disutility of Internet use remains the same, average retail price, total quantity sold, physical store profit, monopoly manufacturer profit, and thus, total channel profit increase. On the other hand, the quantity sold through the Internet and the profit of the Internet store decrease with a decreasing average travel cost relative to the average disutility of Internet use. We find that a channel that has an advantage over the other kind of channel serves a larger portion of the market. In a market with a high average travel cost, in which the Internet store has a relative advantage over the physical store, for example, the Internet store becomes a mass-retailer serving a larger portion of the market. This result implies that the Internet becomes a more significant distribution channel in those markets characterized by greater geographical dispersion of buyers, or as consumers become more proficient in Internet usage. The results indicate that the degree of price discrimination also varies depending on the distribution of consumer disutility in a market. The manufacturer in a market in which the average travel cost is higher than the average disutility of using the Internet has a stronger incentive for price discrimination than the manufacturer in a market where the average travel cost is relatively lower. We also find that the manufacturer has a stronger incentive to maintain a high price level when the average travel cost in a market is relatively low. Additionally, the retail competition effect due to Internet channel introduction strengthens as average travel cost in a market decreases. This result indicates that a manufacturer's channel power relative to that of the independent physical retailer becomes stronger with a decreasing average travel cost. This implication is counter-intuitive, because it is widely believed that the negative impact of Internet channel introduction on a competing physical retailer is more significant in a market like Russia, where consumers are more geographically dispersed, than in a market like Hong Kong, that has a condensed geographic distribution of consumers.