• Title/Summary/Keyword: hurdle effect

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Current status of research on microbial disinfection of food using ultrasound (초음파를 활용한 식품 살균 기술의 연구 현황)

  • Song, Kyung-Mo
    • Food Science and Industry
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    • v.53 no.3
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    • pp.277-283
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    • 2020
  • Microbial disinfection is essential to increase the preservation and safety of food. In general, thermal sterilization technology is most frequently used, but it often causes nutrient denaturation, and deterioration of food quality. Accordingly, non-thermal sterilization using a novel technology is emerging as an alternative technology. Among them, ultrasonic technology produces a disinfection effect by promoting the destruction of microorganisms by cavitation. Ultrasound technology alone has a low effect, so research is being actively conducted to develop an effective technology by applying as a hurdle technology with various other technologies. Ultrasound can be treated with various processes including traditional sterilization methods such as heating, high pressure, and chemical treatment, as well as novel technologies such as ultraviolet irradiation. Ultrasound assisted sterilization technology still remains at the laboratory level, requiring additional research such as the development of equipment for industrial application and establishment of an optimal process.

Nano-particle encapsulated doxorubicin as an anti-cancer chemotherapeutic agent: effect on the systemic immune response I

  • Lee, Hyun-Ah;Kim, Eui-Jin;Yu, Jeong-Jun;Shu, Soo-Won;Ko, Young-Hyeh;Baek, So-Young;Park, Jin-Hee;Lee, Hong-Gi
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.133.2-134
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    • 2003
  • The major hurdle of conventional chemotherapeutics is the toxicity to normal tissue. The possible therapeutic advantage(s) of nano-particle encapsulated chemotherapeutics (nano-molecules) may be the enhanced permeability and retention (EPR) effect. Nano-molecules with increase volume may incorporated into the tumor tissue selectively, which is composed of rather sparse structure. EPR effect may cause of increased effectiveness with lower tixicity to normal tissue of nano-chemotherapeutics. (omitted)

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Effect of Cooking Conditions on Quality Changes of Braised Kidney Beans during Storage (가열조리조건에 따른 강낭콩조림의 저장 중 품질변화)

  • Chung, Sun-Kyung;Lee, Dong-Sun;Lyu, Eun-Soon
    • Food Science and Preservation
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    • v.14 no.2
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    • pp.142-147
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    • 2007
  • We optimized braising time to improve the storage quality of braised kidney beans. The beans were prepared with different heating times between 25 and 50 min. and then stored at $10^{\circ}C$ for 20 day. Physical, chemical, microbiological, and organoleptic quality indices were monitored throughout storage. Longer braising times yielded products with lower concentrated brine coverage. Bis resulted in higher soluble contents and slightly lower water activities. Excessive heating time exposed the kidney beans to air and caused rapid microbial growth on the surfaces of the beans, which negatively affected product quality. The longest heating time of 50 min. also resulted in a large increase in product hardness. A braising time of 30 min. was best for preservation, as good sensory quality was mainatained.

Effect of control measures on the contamination and growth inhibition of Listeria monocytogenes in Flammulina velutipes (팽이버섯 재배 농가에서 Listeria monocytogenes 오염과 성장억제를 위한 관리기술 효과)

  • Lee, Ha Kyoung;Jeon, Ji Hye;Lee, Ji Soo;Yoon, Seo Young;Kim, Won Young;Yoon, Ki Sun
    • Journal of Mushroom
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    • v.20 no.2
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    • pp.78-85
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    • 2022
  • The consumption of Flammulina velutipes mushroom imported from Korea has been associated with the cases of listeriosis in the United States, Canada, and Australia. We investigated the effect of sanitizing the plastic wrapper (used in packaging F. velutipes) with slightly acidic electrolyzed water (SAEW) and ultraviolet C waterproof light-emitting diode (UVC-W-LED) on reducing the Listeria monocytogenes. Further, the effect of UVC-LED on L. monocytogenes growth in F. velutipes at different storage temperatures (2, 4, and 10℃) was determined. The combined (SAEW+UVC-W-LED) treatment for 5-10 min reduced 99.9% of bacterial population from the contaminated plastic wrapper. In addition, the UVC-LED treatment for 3 min reduced the L. monocytogenes concentration in F. velutipes by 0.47 log CFU/g. Moreover, the growth of L. monocytogenes in the treated mushrooms was slower than that of the untreated (control) ones. L. monocytogenes concentration in F. velutipes increased over 3 log CFU/g at 2℃ and 10℃ for 60 and 10 days, respectively. The growth of L. monocytogenes at the bottom of mushrooms was faster than that at the top at both the temperatures. These results indicate that the combined SAEW+UVC-W-LED treatment of plastic wrappers and the UVC-LED treatment of mushrooms can be used as potential hurdle technologies to control the risk of L. monocytogenes in mushrooms prior to packaging at farms.

The Economic and Social Implication of Count Regression Models for Married Women's Completed Fertility in Korea (우리나라 가구의 자녀수 결정요인에 관한 Count 모형 분석 및 경제적 함의)

  • Kim, Hyun-Sook
    • Korea journal of population studies
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    • v.30 no.3
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    • pp.107-135
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    • 2007
  • This paper uses a static Gamma count model, a traditional hurdle model and an endogenous switching Poisson model, respectively for determining married women's completed fertility rates in Korea. This paper analyzes the impact of household income, women's wage and education, and women's job market participation on the number of children of married women above age 40 and on the expected number of children of women aged below 40. The paper shows that a household income significantly increases the number of children for at least women aged above 40, however, this income effect is disappearing for younger generation. The empirical model suggests that women having a job tend to have fewer children for a group 39 years old and below and find that there is an endogeneity problem between child birth and labor force participation, too. The education level of married women gives a positive effect for giving a birth, itself, while it gives a negative impact on the number of children. Based on the empirical results, it concludes that Becker's Quantity-Quality theory works for Korea, too.

Effects of Combined Training on the FMS Score in Woman Rugby National Players (12주간의 복합트레이닝이 국가대표 여자럭비선수들의 FMS(Functional Movement Screen) 점수에 미치는 영향)

  • Lee, Jin-Wook;Zhang, Seok-Am;Lee, Jang-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.11
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    • pp.7439-7446
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    • 2015
  • The purpose of this study was to find the risk factors of injury by FMS and to investigate the effects of 12-weeks' combined training program on body imbalance, physical fitness, muscle strength and FMS score in woman rugby players of the national team. Fourteen subjects were woman rugby national players to participate in the 17th Incheon Asian Games. These players tested FMS and performed 12 weeks' (May~Aug, 2014) combined training program (4days, 120min${\geq}$). Statistical evaluation was undertaken using paired t-test (pre vs. post). The results of this study were as follows; Frist, the score of FMS test on Deep Squat, Hurdle Step, Active Straight Leg Raise, and Trunk Stability Push up were significantly increased after 12 weeks' combined training program (p<.05), and also Inline Lunge (p<.01) and Rotary Stability (p<.001) were significantly increased. However, Shoulder Mobility was not significantly increased(p=.104) although the tendency of increased was FMS score. Second, the sum of the entire item was significantly increased after combined training(p<.001). These results suggest that 12-weeks' combined training program has effect of improving FMS score and low-injury risk in woman rugby national players. Therefore, we consider that FMS have effect on prevention of athletic injury and improvement of athletic performance in woman rugby national players.

Signaling Effects of Government Support on Investment Attraction of Technology-based Start-ups: An Empirical Study of a Hurdle Model (기술창업기업의 투자유치에 대한 정부지원의 신호효과: 허들모형을 이용한 실증연구)

  • Bong, Kang Ho;Kwon, Jihun;Kim, Kyu-Tae
    • Korean small business review
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    • v.42 no.4
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    • pp.309-326
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    • 2020
  • There often is information asymmetry between start-ups and the investors, which is because start-up companies in the early stages do not have track records. Meanwhile, since the government grants programs go through a fair and the intense competition process, the government grants can provide a more objective information for start-ups in the early stages and perform a signal function that guarantees a company's capabilities and potential. This study confirms the quantitative relationship between government grants and investment attraction by using the hurdler model. We found that, although there is the proportionate relationship between the scale of government grants and that of external funds, more than a certain amount of government grants is required for technology-based start-ups to exceed the stage of attracting their first external funds. Our findings suggest that it is necessary to consider the hurdles structure in the study of signaling theory perspective, as the mechanisms for determining whether or not to attract external funds are different from determining the level of external funds. In addition, differentiated policy support is needed to help early-stage technology start-ups go beyond the threshold of investment attraction-the creation of a 'threshold effect'.

Synergistic Effect of Slightly Acidic Electrolyzed Water and Ultrasound at Mild Heat Temperature in Microbial Reduction and Shelf-Life Extension of Fresh-Cut Bell Pepper

  • Luo, Ke;Oh, Deog-Hwan
    • Journal of Microbiology and Biotechnology
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    • v.25 no.9
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    • pp.1502-1509
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    • 2015
  • The objectives of this study were to evaluate the effect of combined treatments (slightly acidic electrolyzed water (SAEW), ultrasound (US), or mild heat (60℃)) on the growth of Listeria monocytogenes and Salmonella enterica serovar Typhimurium in fresh-cut bell pepper, and the shelf-life and sensory quality (color and texture) were followed during storage at 4℃ and 25℃. An additional 0.65, 1.72, and 2.70 log CFU/g reduction was achieved by heat treatments at 60℃ for 1 min for DW, SAEW, and SAEW+US, respectively. Regardless of the type of pathogen, the combined treatment (SAEW+US+60℃) achieved a significantly (p < 0.05) longer lag time in all treatment groups. This combined treatment also prolonged the shelf-life of bell pepper up to 8 days and 30 h for the storage at 4℃ and 25℃, respectively. There was also no significant difference in the color and hardness of treated (SAEW+US+60℃) bell pepper from that of control during the storage. This new hurdle approach is thus expected to improve the microbial safety of bell peppers during storage and distribution.

Effect of Joule Heating and Hydrostatic Pressure on Reduction of Total Aerobes and Spores of Bacillus cereus in Sauces Prepared with Traditional Korean Fermented Foods (장류를 이용하여 제조한 소스류의 총균 및 Bacillus cereus 포자에 대한 줄가열 및 초고압 처리 효과)

  • Jo, Eun-Ji;Oh, Se-Wook;Hur, Byung-Serk;Hong, Sang-Pil
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.10
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    • pp.1619-1626
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    • 2014
  • This study was conducted to evaluate the effects of Joule heating and hydrostatic pressure on reduction of total aerobes and spores of Bacillus cereus in four kinds of sauces prepared with traditional Korean fermented foods. Total aerobes and inoculated spores of B. cereus in sauces were assayed after treatment or during storage at $30^{\circ}C$ after 4 or 8 weeks. Joule heating ($85^{\circ}C$), hydrostatic pressure (550 Mpa, 5 min), and antimicrobial additive (3% ethanol) were separately applied or combined as a hurdle technique. A 1.0~2.0 log reduction in total aerobes of Doenjang and Gochujang sauce was observed upon Joule heating at 80, 85, and $95^{\circ}C$. Significant reductions (0.92~1.21 log/0.5~1.38 log and 1.26~1.7 log/0.47~3.45 log) of total aerobes/spores of B. cereus in Doenjang and Gochujang sauce, respectively, occurred upon JA (Joule+additive), JP (Joule+hydrostatic pressure) or JAP (Joule+additive+ hydrostatic pressure). Effects of each treatments were maintained or increased during storage for 8 weeks at $30^{\circ}C$, suggesting that total aerobes and spores of B. cereus in Doenjang and Gochujang sauce can be controlled through Joule heating or hydrostatic pressure treatment.

Risk Prediction Using Genome-Wide Association Studies on Type 2 Diabetes

  • Choi, Sungkyoung;Bae, Sunghwan;Park, Taesung
    • Genomics & Informatics
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    • v.14 no.4
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    • pp.138-148
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    • 2016
  • The success of genome-wide association studies (GWASs) has enabled us to improve risk assessment and provide novel genetic variants for diagnosis, prevention, and treatment. However, most variants discovered by GWASs have been reported to have very small effect sizes on complex human diseases, which has been a big hurdle in building risk prediction models. Recently, many statistical approaches based on penalized regression have been developed to solve the "large p and small n" problem. In this report, we evaluated the performance of several statistical methods for predicting a binary trait: stepwise logistic regression (SLR), least absolute shrinkage and selection operator (LASSO), and Elastic-Net (EN). We first built a prediction model by combining variable selection and prediction methods for type 2 diabetes using Affymetrix Genome-Wide Human SNP Array 5.0 from the Korean Association Resource project. We assessed the risk prediction performance using area under the receiver operating characteristic curve (AUC) for the internal and external validation datasets. In the internal validation, SLR-LASSO and SLR-EN tended to yield more accurate predictions than other combinations. During the external validation, the SLR-SLR and SLR-EN combinations achieved the highest AUC of 0.726. We propose these combinations as a potentially powerful risk prediction model for type 2 diabetes.