• Animal Bioscience
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• v.35 no.8
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• pp.1109-1120
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• 2022

Antibiotics used to be supplemented to animal feeds as growth promoter and as an effective strategy to reduce the burden of pathogenic bacteria present in the gastro-intestinal tract. However, in-feed antibiotics also kill bacteria that may be beneficial to the animal. Secondly, unrestricted use of antibiotics enhanced the antibiotic resistance in pathogenic bacteria. To overcome above problems, scientists are taking a great deal of measures to develop alternatives of antibiotics. There is convincing evidence that probiotics could replace in-feed antibiotics in poultry production. Because they have beneficial effects on growth performance, meat quality, bone health and eggshell quality in poultry. Better immune responses, healthier intestinal microflora and morphology which help the birds to resist against disease attack were also identified with the supplementation of probiotics. Probiotics establish cross-feeding between different bacterial strains of gut ecosystem and reduce the blood cholesterol level via bile salt hydrolase activity. The action mode of probiotics was also updated according to recently published literatures, i.e antimicrobial substances generation or toxin reduction. This comprehensive review of probiotics is aimed to highlight the beneficial effects of probiotics as a potential alternative strategy to replace the antibiotics in poultry.

• Animal Bioscience
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• v.36 no.11
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• pp.1619-1631
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• 2023

The objective of this review was to provide an overview of the effects of dietary fiber (DF) on reproductive performance in gestating sows. Dietary fibers have been suggested to modulate microbiota in the intestine and the immune system of gestating sows and to improve gut health. Thus, DF may help alleviate the adverse effects of the stressful production cycle of gestating sows. These benefits may subsequently result in improved reproductive performance of sows. Previous studies have reported changes in microbiota by providing gestating sows with DF, and the responses of microbiota varied depending on the source of DF. The responses by providing DF to gestating sows were inconsistent for antioxidative capacity, hormonal response, and inflammatory response among the studies. The effects of DF on reproductive performance were also inconsistent among the previous studies. Potential reasons contributing to these inconsistent results would include variability in reproductive performance data, insufficient replication, influence of other nutrients contained in the DF diets, characteristics of DF, and experimental periods. The present meta-analysis suggests that increasing the total DF concentration by 10 percentage units (e.g., 12% to 22% as-fed basis) in gestating sow diets compared to the control group improves the litter born alive by 0.49 pigs per litter. However, based on the present review, questions remain regarding the benefits of fibers in gestating sow diets. Further research is warranted to clarify the mode of action of fibers and the association with subsequent reproductive performance in gestating sows.

• Mycobiology
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• v.44 no.1
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• pp.38-47
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• 2016

The ascomycete fungus Mycosphaerella graminicola (synonym Zymoseptoria tritici) is an important pathogen of wheat causing economically significant losses. The primary nutritional mode of this fungus is thought to be hemibiotrophic. This pathogenic lifestyle is associated with an early biotrophic stage of nutrient uptake followed by a necrotrophic stage aided possibly by production of a toxin or reactive oxygen species (ROS). In many other fungi, the genes CREA and AREA are important during the biotrophic stage of infection, while the NOXa gene product is important during necrotrophic growth. To test the hypothesis that these genes are important for pathogenicity of M. graminicola, we employed an over-expression strategy for the selected target genes CREA, AREA, and NOXa, which might function as regulators of nutrient acquisition or ROS generation. Increased expressions of CREA, AREA, and NOXa in M. graminicola were confirmed via quantitative real-time PCR and strains were subsequently assayed for pathogenicity. Among them, the NOXa over-expression strain, NO2, resulted in significantly increased virulence. Moreover, instead of the usual filamentous growth, we observed a predominance of yeast-like growth of NO2 which was correlated with ROS production. Our data indicate that ROS generation via NOXa is important to pathogenicity as well as development in M. graminicola.

• Phonetics and Speech Sciences
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• v.6 no.3
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• pp.81-89
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• 2014

Korean English learners tend to have difficulty perceiving and producing English vowels. The purpose of this study is to examine a link between perceived and produced vowel spaces of Korean learners of English. Sixteen Korean male and female participants perceived two sets of English synthetic vowels on a computer monitor and rated their naturalness. The same participants produced English vowels in a carrier sentence with high and low pitch variation in a clear speaking mode. The author compared the perceived and produced vowel spaces in terms of the pitch and gender variables. Results showed that the perceived vowel spaces were not significantly different in either variables. Korean learners perceived the vowels similarly. They did not differentiate the tense-lax vowel pairs nor the low vowels. Secondly, the produced vowel spaces of the male and female groups showed a 25% difference which may have come from their physiological differences in the vocal tract length. Thirdly, the comparison of the perceived and produced vowel spaces revealed that although the vowel space patterns of the Korean male and female learners appeared similar, which may lead to a relative link between perception and production, statistical differences existed in some vowels because of the acoustical properties of the synthetic vowels, which may lead to an independent link. The author concluded that any comparison between the perceived and produced vowel space of nonnative speakers should be made cautiously. Further studies would be desirable to examine how Koreans would perceive different sets of synthetic vowels.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.6 s.154
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• pp.916-927
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• 2006

The purpose of this study was to identify psychological and behavioral outcomes of commitment to apparel brand community by test structural equation model. Subjects of 317 members for 9 selected apparel communities responded the questionnaire in the home-page or in the attached file. The results were as follows: 1) The suggested structural equation mode was accepted by data from apparel brand communities with hish brand strength(${\chi}^2=97.42$, d.f.=89, p=0.25, GFI=0.92, AGFI=0.88, RMR=0.05, NFI=0.94). However, this model wasn't accepted by data kom apparel brand communities with low brand strength. 2) Three types of commitment to brand community(emotional, continuous and normative commitments) influenced brand identification positively and brand identification positively influenced three types of behavioral outcomes(favorable word-of-mouth, co-production and repurchase of brand). Therefore, managements need to develop marketing programs to promote each type of commitment to their's own brand community.

• Journal of Microbiology and Biotechnology
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• v.14 no.3
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• pp.503-508
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• 2004

The antimicrobial substance produced by Lactobacillus bulgaricus was inactivated by protease. It showed inhibitory activity against Staphylococcus aureus ATCC6538, Streptococcus agalactiae ATCC14364, some Gram-positive and Gram-negative bacteria, and characteristics of a bacteriocin. The optimal temperature and culture time for the production of bacteriocin were $30^{\circ}C$ and 10 h, respectively, in the culture of L. bulgaricus. The bacteriocin production started in the exponential phase and reached a maximum at the early stationary phase. Using Staph. aureus ATCC6538 and Strep. agalactiae ATCC14364, known as common bovine mastitis pathogens, as indicator strains for determination of the bacteriocin activity, the antimicrobial activity of the bacteriocin was found to be stable in acidic and neutral pH's (2- 7) even at lOOT, whereas it was lost at high pH (10- 11) and $100^{\circ}C$. The mode of action for the antimicrobial activity was bacteriocidal, and the molecular weight determined by SDS-PAGE and overlay method was 14 kDa.

• International Journal of Contents
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• v.18 no.1
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• pp.76-84
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• 2022

Tidal power generation plays a critical role in reducing greenhouse gas emissions. It uses a tidal force generated by gravitational force between the moon, the earth, and the sun. The change of seawater height generates the tide-generating force, and the magnitude of the change is the tide level. The tide level change has the same period as the tide-generating force twice a day, every 29.5 days, every year, and every 18.6 years. Sihwa Lake Tidal Power Station is Korea's first tidal power plant that began commercial power generation in August 2011 and has been accumulating a large volume of data on electricity production, power generation sales, sluice displacement, and tide levels. The purpose of this paper was to analyze the impact of the inefficiency factors affecting production and the tidal level change on tidal power generation and their characteristics using Sihwa Lake Tidal Power's operational performance data. Throughout this paper we show that tidal power generating operation is accurately predicting the trends of magnitude of tidal force to be periodical for each day. determining the drop to initiate the water turbine generator factoring the constraints on the operation of Sihwa Lake, and reflecting the water discharge through the floodgate and water turbine during the standby mode in the power generation plan to be in the optimal condition until the initiation of the next power generation can maximize power generation.

• Environmental Engineering Research
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• v.24 no.2
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• pp.298-308
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• 2019

This work deals with the membrane fouling mode and the unclogging in seawater ultrafiltration process. The identification of the fouling mechanism by modeling the experimental flux decline was performed using both the classical models of Hermia and the combined models of Bolton. The results show that Bolton models did not bring more precise information than the Hermia's and the flux decline can be described by one of the four Hermia's models since the backwash interval is ${\leq}60$ min. An experimental screening study has been then conducted to choose among 5 parameters (backwash interval, duration, pulses and the flow-rate or injected hypochlorite concentration) those that are the most influential on the fouling and the net water production. It has emerged that fouling is mainly affected by the backwash interval; its prolongation from 30 to 60 min engenders an increase in the reversible fouling and a decrease in the irreversible fouling. This later is also significantly reduced when the hypochlorite concentration increases from 4.5 to 10 ppm. Moreover, the net water production significantly increases with increasing the filtration duration up to 60 min and decreases with decreasing the backwash duration and backwash flow-rate from 10 to 40 s and from 15 to ${\geq}20L.min^{-1}$, respectively.

• Smart Structures and Systems
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• v.26 no.1
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• pp.117-134
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• 2020

Over recent years, the interest for vegetables and fruits in all seasons and places has much increased, from where diverse countries have directed to the commercial production in greenhouse. In this article, we propose an algorithm based on wireless sensor network technologies that monitor the microclimate inside a greenhouse and linear equations model for optimization plant production and material cost. Moreover, we also suggest a novel design of an intelligent greenhouse. We validate our algorithms with simulations on a benchmark based on experimental data made at lNRA of Montfavet in France. Finally, we calculate the statistical estimators RMSE, TSSE, MAPE, EF and R². The results obtained are promising, which shows the efficiency of our proposed system.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.2
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• pp.226-235
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• 2019

Soluble silica profiles of the East Sea were described by comparing the 1970 Japanese data with the 1999-2000 ONR-JES data set, which is the most extensive collection of data currently available. Considering the ventilation mode change happened/ongoing and the features of the soluble silica to phosphate ratio we suggest a hypothesis that a utilization of soluble silica by the primary production might be exacerbated in the future. According to the silica limitation hypothesis composition of primary producers will be altered and followed by a weaker contribution of ballast against aggregates in the export production. Since the silicate cycle is deeply intertwined with the carbon cycle whether the warmed future ocean would behave like the East Sea appears to a potentially promising study theme.