• 대한수학회보
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• 제48권4호
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• pp.697-704
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• 2011

By using the method of differential subordinations, we derive some sufficient conditions for strongly starlike functions associated with a linear operator. All these results presented here are sharp.

• 한국보건간호학회지
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• 제30권3호
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• pp.495-511
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• 2016

Purpose: The present study was performed to describe the prevalence of various types of smoking statuses and to identify factors associated with different types among Korean wageworkers. Methods: The prevalence of hardcore smoking, daily smoking, and intermittent smoking was assessed in 2,126 wage workers from the Sixth Korea National Health and Nutrition Examination Survey. The associations of these three types of smoking statuses with sociodemographic characteristics, health conditions, and occupation-related characteristics were also examined in a multinomial logistic regression. Results: In men, the prevalence of hardcore smoking and daily smoking were 11.4% and 30.2%, respectively; and in women, the daily smoking prevalence was 5.6%. The education level was strongly associated with men's hardcore smoking and women's daily smoking. The household income and marital status were associated with women's daily smoking. Among occupation-related characteristics, the regularity of work and night work were associated with men's intermittent smoking. Night work was also associated with women's daily smoking. Employment condition was associated with women's intermittent smoking. Conclusion: The socioeconomic status and health conditions, compared with occupation-related factors, were found to have more influence on smoking. Therefore, antismoking programs that focus on individual characteristics should be developed for Korean wageworkers.

• ALGAE
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• 제33권2호
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• pp.181-189
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• 2018

Emiliania huxleyi (a haptophyte) is the most abundant coccolithophore species that produces delicate calcite scales called coccoliths. In this study, we identified several candidate genes associated with coccolith production by comparing the transcriptomes of the calcifying (CCMP 371) and non-calcifying (CCMP 2090) strains of E. huxleyi. Among the candidates, genes highly expressed in CCMP 371 were identified. To confirm whether these genes are associated with calcification, we modulated coccolith production in CCMP 371 by culturing it at different calcium concentrations. At an ambient (10 mM) concentration of calcium in the growth medium, CCMP 371 sustained its calcifying ability. However, at a low (0.1 mM) concentration or absence of calcium, there was no calcite formation, demonstrating that calcium-limiting conditions negatively affect calcification. We also evaluated the expression patterns of the putative genes in cells grown at different calcium concentrations by quantitative reverse transcription polymerase chain reaction. In addition, we showed that the growth rate of cells cultured under calcium-limiting conditions does not differ from that under ambient conditions. Further studies are required to investigate the roles of the putative calcification-associated genes at the molecular level.

• Journal of the Korean Statistical Society
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• 제21권2호
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• pp.127-137
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• 1992

In this paper we investigate scaling limits for associated random measures satisfying some moment conditions. No stationarity is required. Our results imply an improvement of a central limit theorem of Cox and Grimmett to associated random measure and an extension to the nonstationary case of scaling limits of Burton and Waymire. Also we prove an invariance principle for associated random measures which is an extension of the Birkel's invariance principle for associated process.

• Journal of Microbiology and Biotechnology
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• 제29권1호
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• pp.79-90
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• 2019

Lichens are generally known as self-sufficient, symbiotic life-forms between fungi and algae/cyanobacteria, and they also provide shelter for a wide range of beneficial bacteria. Currently, bacterial-derived biodegradable polyhydroxyalkanoate (PHA) is grabbing the attention of many researchers as a promising alternative to non-degradable plastics. This study was conducted to develop a new method of PHA production using unexplored lichen-associated bacteria, which can simultaneously degrade two ubiquitous industrial toxins, anthracene and naphthalene. Here, 49 lichen-associated bacteria were isolated and tested for PHA synthesis. During the GC-MS analysis, a potential strain of EL19 was found to be a 3-hydroxyhexanoate (3-HHx) accumulator and identified as Pseudomonas sp. based on the 16S rRNA sequencing. GC analysis revealed that EL19 was capable of accumulating 30.62% and 19.63% of 3-HHx from naphthalene and anthracene, respectively, resulting in significant degradation of 98% and 96% of naphthalene and anthracene, respectively, within seven days. Moreover, the highly expressed phaC gene verified the genetic basis of $PHA_{mcl}$ production under nitrogen starvation conditions. Thus, this study strongly supports the hypothesis that lichen-associated bacteria can detoxify naphthalene and anthracene, store energy for extreme conditions, and probably help the associated lichen to live in extreme conditions. So far, this is the first investigation of lichen-associated bacteria that might utilize harmful toxins as feasible supplements and convert anthracene and naphthalene into eco-friendly 3-HHx. Implementation of the developed method would reduce the production cost of $PHA_{mcl}$ while removing harmful waste products from the environment.

• Imaging Science in Dentistry
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• 제53권4호
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• pp.303-312
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• 2023

Purpose: This study investigated the prevalence of developmental and acquired pathologic conditions associated with impacted third molars (3Ms) in a Southern Brazilian population and evaluated whether demographic and tooth characteristics were correlated with the presence of bone or tooth lesions. Materials and Methods: Panoramic radiographs were assessed for developmental (bone-related) or acquired (tooth-related) pathoses associated with impacted upper or lower 3Ms. Data on tooth positioning, tooth development, and patient demographics were collected. A trained, calibrated postgraduate student evaluated all images. Binary and multivariate logistic regression models were used to assess associations between outcomes and the demographic and radiographic variables. The threshold for statistical significance was set at 5% (P<0.05). Results: The sample comprised panoramic radiographs from 2054 patients, predominantly female (59.2%), with a mean age of 27.2±11.5 years. Overall, 4066 impacted 3Ms were evaluated, revealing 471 (11.6%) developmental and 710 (17.5%) acquired pathoses. Among the developmental pathoses, 460 (95.2%) were indicative of dentigerous cysts. Male sex, lower 3M location, vertical or distoangular positioning, and incomplete root formation were associated with an elevated likelihood of developmental pathology. Lower tooth position, complete root formation, and partial eruption were linked to an increased probability of an acquired pathology in the third or second molar. Conclusion: The prevalence of pathologic conditions associated with impacted 3Ms was low. Male sex, lower 3M placement, horizontal or distoangular positioning, and incomplete root formation were associated with developmental pathoses, while lower tooth position, complete root formation, and partial eruption were related to acquired pathoses.

• 복식문화연구
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• 제31권4호
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• pp.489-503
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• 2023

This study utilized the unified theory of acceptance and use of technology 2 (UTAUT2) to examine usage intentions associated with virtual fitting services. Six independent variables were examined: performance expectancy, effort expectancy, social influence, facilitating conditions, hedonic motivation, and habit. The study collected responses from 445 participants who had utilized virtual fitting services. Regarding factors related to usage intentions associated with these services, performance expectancy and social influence were found to significantly influence the usage intentions associated with photo-based virtual fitting services. Furthermore, performance expectancy, social influence, and habit significantly influenced the usage intention of avatar-based virtual fitting services. This suggests that higher levels of performance expectancy and social influence positively impact the usage intentions associated with both types of virtual fitting services, while habit influences only avatar-based virtual fitting services. Moreover, the findings confirm that effort expectancy, facilitating conditions, and hedonic motivation from UTAUT2 do not significantly influence usage intentions associated with virtual fitting services. By analyzing factors influencing potential customers' virtual fitting service usage intentions, this study can suggest effective strategies to increase usage intentions for companies providing virtual fitting services. Additionally, these findings can be utilized in the formulation of virtual fitting service marketing strategies.

• Biotechnology and Bioprocess Engineering:BBE
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• 제8권6호
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• pp.338-348
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• 2003

In the past decade, considerable progress has been made in developing the appropriate biotechnology for microalgal mass cultivation aimed at establishing a new agro-industry. This review points out the main biological constraints affecting algal biotechnology outdoors and the requirements for making this biotechnology economically viable. One of them is the availability of a wide variety of algal species and improved strains that favorably respond to varying environmental conditions existing outdoors. It is thus just a matter of time and effort before a new methodology like genetic engineering can and will be applied in this field as well. The study of stress physiology and adaptation of microalgae has also an important application in further development of the biotechnology for mass culturing of microalgae. In outdoor cultures, cells are exposed to severe changes in light and temperature much faster than the time scale re-quired for the cells to acclimate. A better understanding of those parameters and the ability to rapidly monitor those conditions will provide the growers with a better knowledge on how to optimize growth and productivity. Induction of accumulation of high value products is associated with stress conditions. Understanding the physiological response may help in providing a better production system for the desired product and, at a later stage, give an insight of the potential for genetic modification of desired strains. The potential use of microalgae as part of a biological system for bioremediation/detoxification and wastewater treatment is also associated with growing the cells under stress conditions. Important developments in monitoring and feedback control of the culture behavior through application of on-line chlorophyll fluorescence technique are in progress. Understanding the process associated with those unique environmental conditions may help in choosing the right culture conditions as well as selecting strains in order to improve the efficiency of the biological process.

• Safety and Health at Work
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• 제2권4호
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• pp.313-320
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• 2011

Objectives: To analyze the association between changes in perceived physical and psychosocial working conditions and change of sickness absence days in younger and older (< 50 and ${\geq}50$ years) food industry employees. Methods: This was a follow up study of 679 employees, who completed working conditions survey questionnaires in 2005 and 2009 and for whom the requisite sickness absence data were available for the years 2004 and 2008. Results: Sickness absence increased and working conditions improved during follow-up. However, the change of increased sickness absence days were associated with the change of increased poor working postures and the change of deteriorated team spirit and reactivity (especially among < 50 years). No other changes in working conditions were associated with the changes in sickness absence. Conclusion: Sickness absence is affected by many factors other than working conditions. Nevertheless, according to this study improving team spirit and reactivity and preventing poor working postures are important in decreasing sickness absence.

• 수면정신생리
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• 제30권1호
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• pp.3-8
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• 2023

Periodic limb movement disorder (PLMD) is a sleep-related movement disorder characterized by involuntary, rhythmic limb movements during sleep. While PLMD itself is not considered life-threatening, its association with certain underlying health conditions raises concerns about mortality risks. PLMD has been found to be associated with cardiovascular diseases such as hypertension and cardiovascular disease. The fragmented sleep caused by the repetitive limb movements and associated arousals may contribute to sympathetic activation, chronic sleep disruption, sleep deprivation, and subsequent cardiovascular problems, which can increase mortality risks. The comorbidities and health factors commonly associated with PLMD, such as obesity, diabetes, and chronic kidney disease, may also contribute to increased mortality risks. PLMD is often observed alongside other neurological disorders, including restless legs syndrome (RLS) and Parkinson's disease. The presence of PLMD in these conditions may exacerbate the underlying health issues and potentially contribute to higher mortality rates. Further research is needed to elucidate the specific mechanisms linking PLMD to mortality risks and to develop targeted interventions that address these risks.