• Title/Summary/Keyword: Mass bias

Search Result 167, Processing Time 0.031 seconds

Accuracy of predictive equations for resting metabolic rate in Korean athletic and non-athletic adolescents

  • Kim, Jae-Hee;Kim, Myung-Hee;Kim, Gwi-Sun;Park, Ji-Sun;Kim, Eun-Kyung
    • Nutrition Research and Practice
    • /
    • v.9 no.4
    • /
    • pp.370-378
    • /
    • 2015
  • BACKGROUND/OBJECTIVES: Athletes generally desire changes in body composition in order to enhance their athletic performance. Often, athletes will practice chronic energy restrictions to attain body composition changes, altering their energy needs. Prediction of resting metabolic rates (RMR) is important in helping to determine an athlete's energy expenditure. This study compared measured RMR of athletic and non-athletic adolescents with predicted RMR from commonly used prediction equations to identify the most accurate equation applicable for adolescent athletes. SUBJECTS/METHODS: A total of 50 athletes (mean age of $16.6{\pm}1.0years$, 30 males and 20 females) and 50 non-athletes (mean age of $16.5{\pm}0.5years$, 30 males and 20 females) were enrolled in the study. The RMR of subjects was measured using indirect calorimetry. The accuracy of 11 RMR prediction equations was evaluated for bias, Pearson's correlation coefficient, and Bland-Altman analysis. RESULTS: Until more accurate prediction equations are developed, our findings recommend using the formulas by Cunningham (-29.8 kcal/day, limits of agreement -318.7 and +259.1 kcal/day) and Park (-0.842 kcal/day, limits of agreement -198.9 and +196.9 kcal/day) for prediction of RMR when studying male adolescent athletes. Among the new prediction formulas reviewed, the formula included in the fat-free mass as a variable [$RMR=730.4+15{\times}fat-free\;mass$] is paramount when examining athletes. CONCLUSIONS: The RMR prediction equation developed in this study is better in assessing the resting metabolic rate of Korean athletic adolescents.

Fundamental characteristics of non-mass separated ion beam deposition with RE sputter-type ion source (고주파 스퍼터타입 이온소스를 이용한 비질량분리형 이온빔증착법에 관한 특성연구)

  • ;Minoru Isshiki
    • Journal of the Korean Vacuum Society
    • /
    • v.12 no.2
    • /
    • pp.136-143
    • /
    • 2003
  • In this paper, high purity RF sputter-type ion source for non-mass separated ion beam deposition was evaluated. The fundamental characteristics of the ion source which is composed of an RF Cu coil and a high purity Cu target (99.9999 %) was studied, and the practical application of Cu thin films for ULSI metallization was discussed. The relationship between the DC target current and the DC target voltage at various RF power and Ar gas pressures was measured, and then preparation conditions for Cu thin films was described. As a result, it was found that the deposition conditions of the target voltage, the target current and the Ar pressure were optimized at -300 V, 240 W and 9 Pa, respectively. The resistivity of Cu films deposited at a bias voltage of -50 V showed a minimum value of 1.8 $\pm$ 0.1 $mu\Omega$cm, which is close to that of Cu bulk (1.67 $mu\Omega$cm).

The first UV fundamental plane and evidence of star formation in early-type galaxies

  • Jeong, Hyun-Jin;Yi, Suk-Young;Bureau, Martin;Davies, Roger L.
    • Bulletin of the Korean Space Science Society
    • /
    • 2009.10a
    • /
    • pp.36.2-36.2
    • /
    • 2009
  • We present GALEX (Galaxy Evolution Explorer) far (FUV) and near (NUV) ultraviolet imaging of 34 nearby early-type galaxies from the SAURON representative sample of 48 E/S0 galaxies, all of which have ground-based optical imaging from the MDM Observatory. The surface brightness profiles of nine galaxies (~26 per cent) show regions with blue UV-optical colours suggesting recent star formation. Five of these (~15 per cent) show blue integrated UV-optical colours that set them aside in the NUV integrated colour-magnitude relation. These are objects with either exceptionally intense and localised NUV fluxes or blue UV-optical colours throughout. They also have other properties confirming they have had recent star formation, in particular Hbeta absorption higher than expected for a quiescent population and a higher CO detection rate. This suggests that residual star formation is more common in early-type galaxies than we are used to believe. NUV-blue galaxies are generally drawn from the lower stellar velocity dispersion (sigma_e <200 km/s) and thus lower dynamical mass part of the sample. We have also constructed the first UV Fundamental Planes and show that NUV blue galaxies bias the slopes and increase the scatters. If they are eliminated the fits get closer to expectations from the virial theorem. Although our analysis is based on a limited sample, it seems that a dominant fraction of the tilt and scatter of the UV Fundamental Planes is due to the presence of young stars in preferentially low-mass early-type galaxies.

  • PDF

Comparison of Blood Lead Concentration Using Graphite Furnace Atomic Absorption Spectrometry (GF-AAs) and Inductively Coupled Plasma-mass Spectrometry (ICP-MS) (흑연로 원자 흡광 광도법과 유도 결합 플라즈마 질량 분석법을 이용한 혈중 납 농도 비교)

  • Kang, Min-Kyung;Kwon, Jung-Yeon;Kim, Byoung-Gwon;Lim, Hyoun-Ju;Seo, Jeong-Wook;Kim, Yu-Mi;Hong, Young-Seoub
    • Journal of Environmental Health Sciences
    • /
    • v.45 no.3
    • /
    • pp.258-266
    • /
    • 2019
  • Objectives: In this study, blood lead was analyzed using graphite furnace atomic absorption spectrometry (GF-AAs) and inductively coupled plasma mass spectrometry (ICP-MS). We tried to examine the difference and consistency of the analytical values and the applicability of the analytical method. Methods: We selected 57 people who agreed to participate in this study. After confirming the linearity of the calibration standard curves in GF-AAs and ICP-MS, the concentrations of lead in quality control material and samples were measured, and the degree of agreement was compared. Results: The detection limit of the ICP-MS was lower than that of GF-AAs. The coefficient of variation of reference materials was shown to be stable in the ICP-MS and GF-AAs. When the correspondence between the two equipments was verified by bias of the analysis values, a concordance was shown, and approximately 98% of the ideal reference lines were present within ${\pm}40%$ of the deflection. Conclusion: GF-AAs showed high sensitivity to single heavy metal analysis, but it took much time and showed higher detection limit than ICP-MS. Therefore, it would be considered necessary to switch to ICP-MS analysis method, considering that the level of lead exposure is gradually decreasing.

Association Between Dental Implants and Cognitive Function in Community-dwelling Older Adults in Korea

  • Ki, Seungkook;Yun, Jihye;Kim, Jinhee;Lee, Yunhwan
    • Journal of Preventive Medicine and Public Health
    • /
    • v.52 no.5
    • /
    • pp.333-343
    • /
    • 2019
  • Objectives: This study aimed to evaluate the association between dental implants and cognitive function in community-dwelling older adults. Methods: Data were collected from the baseline survey (2016-2017) of the Korean Frailty and Aging Cohort Study. The study sample comprised 1115 community-dwelling people aged 70 years to 84 years who had 0-19 natural teeth. Dental implants and natural teeth were identified by panoramic radiography, while the cognitive function was assessed by the Korean version of the Mini-Mental State Examination (MMSE-KC). The association between dental implants and cognitive function was analyzed by multiple linear regression. Sensitivity analysis was performed to test for potential bias. Results: The mean number of natural teeth in the study population was 9.50 (standard deviation [SD], 6.42), and the mean MMSE-KC score was 24.93 (SD, 3.55). In the simple univariate analysis, tooth replacement, age, sex, smoking status, alcohol consumption, body mass index, osteoporosis, number of natural teeth, periodontitis, chewing discomfort, tooth-brushing frequency, education level, monthly household income, participation in economic activity, living alone, and marital status had a significant impact on the association. After adjusting for confounders, the association between dental implants and cognitive function remained significant (B, 0.85; standard error, 0.40; p<0.05). Age, body mass index, periodontitis, tooth-brushing frequency, and education level were also significantly associated with cognitive function. The results of the sensitivity analyses were consistent with those of the primary analysis. Conclusions: Dental implants were associated with cognitive function in older adults living in the community. Dental implants as tooth replacements may play a role in preserving cognitive function.

Minor alleles in the FTO SNPs contributed to the increased risk of obesity among Korean adults: meta-analysis from nationwide big data-based studies

  • Oh Yoen Kim;Jihyun Park;Jounghee Lee;Cheongmin Sohn;Mi Ock Yoon;Myoungsook Lee
    • Nutrition Research and Practice
    • /
    • v.17 no.1
    • /
    • pp.62-72
    • /
    • 2023
  • BACKGROUND/OBJECTIVES: Many studies have revealed an association between fat mass and the obesity-related gene (FTO) and obesity. On the other hand, no meta-analysis was conducted with data from only Koreans. Therefore, this study performed a meta-analysis using Korean data to provide evidence for the association between FTO single nucleotide polymorphisms (SNPs) and the risk of obesity among Korean adults. SUBJECT/METHODS: Meta-analysis was finally conducted with data extracted from seven datasets of four studies performed on Korean adults after the screening passed. Five kinds of FTO SNPs (rs9939609, rs7193144, rs9940128, rs8050136, and rs9926289) were included, and the relationship between FTO SNPs and body mass index (BMI) was investigated using linear regression with an additive model adjusted for covariants, such as age, sex, and area. RESULTS: The minor alleles of FTO SNPs were associated with increased BMI (odds ratio [OR], 1.31; 95% confidence interval [CI], 1.21-1.42). In sub-group analysis, FTO rs9939609 T>A was significantly associated with BMI (OR, 1.23; 95% CI, 1.06-1.42). The other FTO SNPs together were significantly associated with BMI (OR, 1.37; 95% CI, 1.25-1.49). The publication bias was not observed based on Egger's test. CONCLUSIONS: This meta-analysis showed that minor alleles in the FTO SNPs were significantly associated with an increased BMI among Korean adults. This meta-analysis is the first to demonstrate that minor alleles in the FTO SNPs contribute significantly to the increased risk of obesity among Korean adults using data from a Korean population.

The KALION Automated Aerosol Type Classification and Mass Concentration Calculation Algorithm (한반도 에어로졸 라이다 네트워크(KALION)의 에어로졸 유형 구분 및 질량 농도 산출 알고리즘)

  • Yeo, Huidong;Kim, Sang-Woo;Lee, Chulkyu;Kim, Dukhyeon;Kim, Byung-Gon;Kim, Sewon;Nam, Hyoung-Gu;Noh, Young Min;Park, Soojin;Park, Chan Bong;Seo, Kwangsuk;Choi, Jin-Young;Lee, Myong-In;Lee, Eun hye
    • Korean Journal of Remote Sensing
    • /
    • v.32 no.2
    • /
    • pp.119-131
    • /
    • 2016
  • Descriptions are provided of the automated aerosol-type classification and mass concentration calculation algorithm for real-time data processing and aerosol products in Korea Aerosol Lidar Observation Network (KALION, http://www.kalion.kr). The KALION algorithm provides aerosol-cloud classification and three aerosol types (clean continental, dust, and polluted continental/urban pollution aerosols). It also generates vertically resolved distributions of aerosol extinction coefficient and mass concentration. An extinction-to-backscatter ratio (lidar ratio) of 63.31 sr and aerosol mass extinction efficiency of $3.36m^2g^{-1}$ ($1.39m^2g^{-1}$ for dust), determined from co-located sky radiometer and $PM_{10}$ mass concentration measurements in Seoul from June 2006 to December 2015, are deployed in the algorithm. To assess the robustness of the algorithm, we investigate the pollution and dust events in Seoul on 28-30 March, 2015. The aerosol-type identification, especially for dust particles, is agreed with the official Asian dust report by Korean Meteorological Administration. The lidar-derived mass concentrations also well match with $PM_{10}$ mass concentrations. Mean bias difference between $PM_{10}$ and lidar-derived mass concentrations estimated from June 2006 to December 2015 in Seoul is about $3{\mu}g\;m^{-3}$. Lidar ratio and aerosol mass extinction efficiency for each aerosol types will be developed and implemented into the KALION algorithm. More products, such as ice and water-droplet cloud discrimination, cloud base height, and boundary layer height will be produced by the KALION algorithm.

A Exploratory Study on Press Fairness Concept Held by Ordinary People (언론 수용자의 공정성 개념에 대한 탐색적 연구)

  • Moon, Jong-Dae;Ahn, Cha-Soo;Jin, Hyun-Seong;Ahn, Soon-Tae
    • Korean journal of communication and information
    • /
    • v.38
    • /
    • pp.183-210
    • /
    • 2007
  • The study tried to explore ordinary people's press fairness concept being neglected by the mainstream of fairness research thus far. With empirical standpoint, this study first investigated (un)fairness concept held by general audience, and then compared it with existing ones long suggested by experts such as scholars and media workers. Also, the study examined audience's concept construct in terms of its characteristics and implications. A systematic sample of 300 adults in Seoul was interviewed and their answers (instances of press unfairness) were analyzed and categorized. The most serious problem in fairness, they pointed, was that the press's not neutral. Also, truth and balance were importantly raised as a press problem with regard to fairness. The result showed press ethics and commercial morals could be a significant element for people's view on press fairness. These elements are new to the literature and heuristic regarding how to approach toward fairness issue in our society. The study also discusses the implications of other findings.

  • PDF

Simultaneous Determination and Occurrences of Pharmaceuticals by Solid-Phase Extraction and Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) in Environmental Aqueous Samples

  • Koo, So-Hyun;Jo, Cheon-Ho;Shin, Sun-Kyoung;Myung, Seung-Woon
    • Bulletin of the Korean Chemical Society
    • /
    • v.31 no.5
    • /
    • pp.1192-1198
    • /
    • 2010
  • Pharmaceuticals and personal care products (PPCPs) are emerging contaminants in the aquatic environment. Many pharmaceuticals are not completely removed during wastewater treatment, leading to their presence in wastewater treatment effluents, rivers, lakes, and ground water. Here, we developed analytical methods for monitoring ten pharmaceuticals from surface water by LC/ESI-MS/MS. For sample clean-up and extraction, MCX (mixed cation exchange) and HLB (hydrophilic-lipophilic balance) solid-phase extraction (SPE) cartridges were used. The limits of detection (LOD) in distilled water and the blank surface water were in the range of 0.006 - 0.65 and 1.66 - 45.05 pg/mL, respectively. The limits of quantitation (LOQ) for the distilled water and the blank surface water were in the range of 0.02 - 2.17 and 5.52 - 150.15 pg/mL, respectively. The absolute recoveries for fortified water samples were between 62.1% and 125.4%. Intra-day precision and accuracy for the blank surface water were 2.9% - 24.1% (R.S.D.) and -16.3% - 16.3% (bias), respectively. In surface wastewater near rivers, chlortetracycline and acetylsalicylic acid were detected frequently in the range of 0.017 - 5.404 and 0.029 - 0.269 ng/mL, respectively. Surface water near rivers had higher levels than surface water of domestic treatment plants.

플라즈마 도핑 후 급속열처리법을 이용한 n+/p 얕은 접합 형성

  • Do, Seung-U;Seo, Yeong-Ho;Lee, Jae-Seong;Lee, Yong-Hyeon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2009.11a
    • /
    • pp.50-50
    • /
    • 2009
  • In this paper, the plasma doping is performed on p-type wafers using $PH_3$ gas(10 %) diluted with He gas(90 %). The wafer is placed in the plasma generated with 200 W and a negative DC bias (1 kV) is applied to the substrate for 60 sec under no substrate heating. the flow rate of the diluted $PH_3$ gas and the process pressure are 100 sccm and 10 mTorr, respectively. In order to diffuse and activate the dopant, annealing process such as rapid thermal annealing (RTA) is performed. RTA process is performed either in $N_2$, $O_2$ or $O_2+N_2$ ambient at $900{\sim}950^{\circ}C$ for 10 sec. The sheet resistance is measured using four point probe. The shallow n+/p doping profiles are investigated using secondary ion mass spectromtry (SIMS). The analysis of crystalline defect is also done using transmission electron microscopy (TEM) and double crystal X-ray diffraction (DXRD).

  • PDF