• Title/Summary/Keyword: repeated measurements data

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A statistical analysis of the fat mass repeated measures data using mixed model (혼합모형을 이용한 체지방 반복측정자료에 대한 통계적 분석)

  • Jo, Jinnam;Chang, Un Jae
    • Journal of the Korean Data and Information Science Society
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    • v.24 no.2
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    • pp.303-310
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    • 2013
  • Forty two female students whose fat mass ratio was over 30% were participated in the experiment of fat mass loss of two treatments for 8 weeks. They kept diary for foods they ate every day, took a picture of the foods, transmitted the picture to the experimenter by the camera phone. Among those, 28 students took the picture by regular camera phone (Treatment A), and the other students used smart phone (Treatment B). Fat mass weight and its related variables had been measured repeatedly four times at an interval of two weeks during 8 weeks. It was shown from mixed model analysis of repeated measurements data that AR(1) covariance matrix was selected as the optimal covariance matrix pattern. The correlation between two successive times is highly correlated as 0.838. Based upon the AR(1) covariance matrix structure, the students using smart phones were somewhat more effective in losing fat mass weight than the students using regular camera phones. The time effect was highly significant, but the treatment-time interaction effect was insignificant. The baseline effect and total cholesterol were found to be significant, but the calories with taking foods were somewhat significant, but the waist to hip ratio was found to be insignificant.

Acyl-CoA: Cholesterol Acyltransferase Inhibitors from llex macropoda

  • Im Kyung-Ran;Jeong Tae-Sook;Kwon Byoung-Mog;Baek Nam-In;Kim Sung-Hoon;Kim Dae-Keun
    • Archives of Pharmacal Research
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    • v.29 no.3
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    • pp.191-194
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    • 2006
  • Twigs from llex macropoda were extracted with MeOH, and the concentrated extracts were partitioned with $CH_2Cl_2$, EtOAc, n-BuOH, and $H_2O$. Repeated column chromatography of the $CH_2Cl_2$ fraction ultimately resulted in the isolation of two compounds, via activity-guided fractionation, using ACAT inhibitory activity measurements. According to the physico-chemical data, the chemical structures of these isolated compounds were identified as lupeol (1) and betulin (2). Compounds 1 and 2 were shown to inhibit the activity of hACAT-1 and hACAT-2 in a dose-dependent manner, and compounds 1 and 2 inhibited hACAT-1 with $IC_{50}$ values of 48 and $83{\mu}M$, respectively.

Dynamic linear mixed models with ARMA covariance matrix

  • Han, Eun-Jeong;Lee, Keunbaik
    • Communications for Statistical Applications and Methods
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    • v.23 no.6
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    • pp.575-585
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    • 2016
  • Longitudinal studies repeatedly measure outcomes over time. Therefore, repeated measurements are serially correlated from same subject (within-subject variation) and there is also variation between subjects (between-subject variation). The serial correlation and the between-subject variation must be taken into account to make proper inference on covariate effects (Diggle et al., 2002). However, estimation of the covariance matrix is challenging because of many parameters and positive definiteness of the matrix. To overcome these limitations, we propose autoregressive moving average Cholesky decomposition (ARMACD) for the linear mixed models. The ARMACD allows a class of flexible, nonstationary, and heteroscedastic models that exploits the structure allowed by combining the AR and MA modeling of the random effects covariance matrix. We analyze a real dataset to illustrate our proposed methods.

A Practical Protocol of Zebrafish Heart Rate Measurement for High School Students

  • Cho, Jeong Hoon
    • Journal of Integrative Natural Science
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    • v.14 no.4
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    • pp.155-158
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    • 2021
  • To study the effects of hormones and neurotransmitters, zebrafish (Danio rerio) are a great substitute for water fleas (Daphnia). The zebrafish is an ideal vertebrate model because it has a transparent embryonic stage. It is easy to get consistent heart rate measurements in embryonic zebrafish when treating them with hormones and neurotransmitters. To observe the heart rate, two to three embryonic zebrafish are anesthetized with MS-222 and then transferred to a glass slide specifically designed for heart observation and easy application of various chemicals. After the heartbeats are counted for 2 minutes, apply either 100 µM epinephrine or 100 µM acetylcholine to the zebrafish. Wait 5, 10, and 20 minutes and count the heartbeats at each time point. All procedures are repeated three times. The final results are averaged and analyzed by using statistical methods. The above method which we have developed is practical enough for high school students to measure the heart rate in zebrafish under various conditions and to analyze the data set.

Assessing the repeatability of reflection seismic data in the presence of complex near-surface conditions CO2CRC Otway Project, Victoria, Australia (복잡한 천부구조하에서 반사법 탄성파자료의 반복성에 대한 평가, 호주, 빅토리아, CO2CRC Otway 프로젝트)

  • Al-Jabri, Yousuf;Urosevic, Milovan
    • Geophysics and Geophysical Exploration
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    • v.13 no.1
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    • pp.24-30
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    • 2010
  • This study utilises repeated numerical tests to understand the effects of variable near-surface conditions on time-lapse seismic surveys. The numerical tests were aimed at reproducing the significant scattering observed in field experiments conducted at the Naylor site in the Otway Basin for the purpose of $CO_2$ sequestration. In particular, the variation of elastic properties of both the top soil and the deeper rugose clay/limestone interface as a function of varying water saturation were investigated. Such tests simulate the measurements conducted in dry and wet seasons and to evaluate the contribution of these seasonal variations to seismic measurements in terms of non-repeatability. Full elastic pre-stack modelling experiments were carried out to quantify these effects and evaluate their individual contributions. The results show that the relatively simple scattering effects of the corrugated near-surface clay/limestone interface can have a profound effect on time-lapse surveys. The experiments also show that the changes in top soil saturation could potentially affect seismic signature even more than the corrugated deeper surface. Overall agreement between numerically predicted and in situ measured normalised root-mean-square (NRMS) differences between repeated (time-lapse) 2D seismic surveys warrant further investigation. Future field studies will include in situ measurements of the elastic properties of the weathered zone through the use of 'micro Vertical Seismic Profiling (VSP)' arrays and very dense refraction surveys. The results of this work may impact on other areas not associated with $CO_2$ sequestration, such as imaging oil production over areas where producing fields suffer from a karstic topography, such as in the Middle East and Australia.

Assessment of Validity and Reliability of Plantar Pressure in Smart Insole (스마트 인솔의 족저압 측정 결과에 대한 타당도 및 신뢰도 평가)

  • Kang, Ho Won;An, Yae Lynn;Kim, Dae-Yoo;Lee, Dong-Oh;Park, Gil Young;Lee, Dong Yeon
    • Journal of Korean Foot and Ankle Society
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    • v.26 no.3
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    • pp.130-135
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    • 2022
  • Purpose: Smart insoles are wearable devices that are inserted into shoes. Smart insoles with built-in pressure and acceleration sensors can measure the plantar pressure, stride length, and walking speed. This study evaluated the validity and reliability of the plantar pressure measurements of smart insoles during walking on flat ground. Materials and Methods: Twenty one subjects were included in this study. After wearing smart insoles, I-SOL® (Gilon, Seongnam, Korea), the subjects walked a 10 m corridor six times at a rate of 100 steps/min, and the middle three steps, free from direction changes, were chosen for data analysis. The same protocol was repeated after wearing Pedar-X (Novel Corporation, Munich, Germany), an insoletype plantar pressure measurement equipment with proven validity. The average maximum pressure (Ppeak, kPa) and the time at which Ppeak appeared (Ptime, %stride) were calculated for each device. The validity of smart insoles was evaluated by using the interclass correlation coefficient (ICC) of Ppeak and Ptime between the two instruments, and Cronbach's alpha was obtained from the Ppeak values to evaluate the reliability. Results: The ICC of Ppeak was 0.651 (good) in the hallux, 0.744 (good) in the medial forefoot, 0.839 (excellent) in the lateral forefoot, and 0.854 (excellent) in the hindfoot. The ICC of Ptime showed 0.868 (excellent) in the hallux, 0.892 (excellent) in the medial forefoot, 0.721 (good) in the lateral forefoot, and 0.832 (excellent) in the hindfoot. All ICC values showed good or excellent results. The Cronbach's alpha of Ppeak measured in the smart insoles was 0.990 in the hallux, 0.961 in the medial forefoot, 0.973 in the lateral forefoot, and 0.995 in the hindfoot; all indicated excellent reliability in all areas. Conclusion: The plantar pressure measurements of smart insoles during walking on a flat ground showed validity compared to Pedar-X, and high reliability after repeated measurements.

The Effect of Five Different Trunk Stabilization Exercise on Thickness of Abdominal Muscle Using an Ultrasonography Imaging in Normal People (정상인에서 5가지 체간 안정화 운동자세가 초음파 영상을 이용한 복부근 두께에 미치는 영향)

  • Kang, Jung-Hyun;Shim, Jae-Hun;Chon, Seung-Chul
    • Physical Therapy Korea
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    • v.19 no.3
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    • pp.1-10
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    • 2012
  • The aim of this study is to compare measurements of abdominal muscle thickness using ultrasonography imaging (USI) to those using a special transducer head device, during five different trunk stabilization exercises, ultimately to determine which exercise led to the greatest muscle thickness. Thirty eight healthy subjects participated in this cross-sectional study. The five types of trunk stabilization - i.e., a sit-up on the supine, an upper and lower extremity raise with quadruped on the prone, a leg raise in sitting on the ball, trunk rolling on the ball, and balance using sling on the prone position - were each performed with an abdominal draw. The thickness of the abdominal muscle - including the transverse abdominal (TrA), internal oblique (IO), and external oblique (EO) - was measured by USI with a special transducer head device, at rest and then at contraction in each position. Data were analyzed using one-way repeated ANOVA with the level of significance set at ${\alpha}$=.05. The results were as follows: 1) the TrA thickness was statistically significant (p<.05), whereas the IO and EO thicknesses were not (p>.05); 2) among the five types of trunk stabilization, TrA thickness significantly increased with the balance using a sling in the prone position, (p<.05), whereas no significant difference was noted for the four types of trunk stabilization (p>.05); 3) reliability data showed that there was a high degree of consistency among the measurements taken using the special transducer head device (ICC=.92). In conclusion, the balance using a sling in the prone position was more effective than any of the four other types of trunk stabilization in increasing TrA thickness in healthy subjects.

Lesson with Students Generated Questions: Based on a Department of Health Science (학습자 질문 중심 교수법의 효과: 보건학부를 중심으로)

  • Ahn, Youngmi;Hwang, Sujin
    • The Journal of Korean Academic Society of Nursing Education
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    • v.21 no.2
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    • pp.266-275
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    • 2015
  • Purpose: The aim of this study was to evaluate the effect of student question-centered lessons for bi-directional faculty-student communication. Methods: This study performed one-group pretest-posttest design; participants were university students majoring in health science (nursing 58, physical therapy 45) in city C. Data was collected and the program was conducted from March 3 to June 14, 2014. Measurements employed were the ARCS model of motivational design, self-assertiveness, learning satisfaction, and interpersonal relationship. Data was analyzed through frequency statistics, descriptive statistics, and repeated measurement of one-way analysis of variance with the SPSS 19.0 program. Results: In this student question-centered lesson participants exhibited significant enhanced satisfaction in terms of learning motivation, learning satisfaction, self-assertiveness, behavioral assertiveness, general assertiveness, and sensibility regarding interpersonal relationships. Conclusion: The results suggest that student question-centered lessons are applicable to a variety of subjects. Also, for comparative purposes, a faculty-centered lesson will be undertaken.

The Effects of Nebulizer Therapy with Normal Saline on Postoperative Thirst and Sore Throat (생리식염수를 이용한 흡입요법이 수술 후 갈증과 인후통에 미치는 효과)

  • No, Hyejin;Eun, Young;Park, Hyunwoo;Cheon, Mihee
    • Journal of Korean Biological Nursing Science
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    • v.22 no.3
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    • pp.204-212
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    • 2020
  • Purpose: The purpose of this study was to examine the effect of nebulizer therapy with normal saline on thirst and sore throat among postoperative patients. Methods: A quasi-experimental nonequivalent control group, pretest-posttest design was used with 50 participants. The experimental group received nebulizer therapy with normal saline every two hours for 10 minutes three times and wet gauze (n= 25), and the control group received only wet gauze (n= 25). Data were collected using the Numeral Rating Scale for Thirst and Sore Throat. Measurements were calculated before applying nebulizer therapy and total five times for 12 hours after treatment. Data were analyzed using the repeated measured ANOVA. Results: Thirst for the experimental group using the nebulizer therapy with normal saline improved more than for the control group (F= 3.06, p= .043). Sore throat was not significantly different between the two groups (F= 0.63, p= .565). Conclusion: Study results indicate that using nebulizer therapy with normal saline can reduced thirst for postoperative patients. So nurses can apply nebulizer therapy with normal saline to reduce thirst and to improve comfort for postoperative patients.

Effect of a Mentoring Program as a Strategy for Retention of Clinical Nurses (임상간호사 유지 전략으로서 멘토링 프로그램의 효과)

  • Lee, Byoung-Sook;Park, Jeong-Sook;Lee, Jeong-Hee;Hong, Sun-Nam
    • Journal of Korean Academy of Nursing Administration
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    • v.16 no.1
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    • pp.48-58
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    • 2010
  • Purpose: The purpose of this study was to identify the effect of a mentoring program as a strategy for the retention of clinical nurses. Method: Research subjects were 20 mentors, 20 mentees and 22 clinical nurses for a control group of mentees. A mentoring program was developed by an expert committee and applied to the experimental group for six months. Data were collected at three and six months after the application of the program from September, 2008 to March, 2009. Data were analyzed using $x^$-test, t-test, Repeated Measures ANOVA, One-way ANOVA in SPSS/Win 15.0 Program. Results: Job satisfaction, organizational commitment, empowerment, and carrier commitment in the mentees of the experimental group were significantly higher than the nurses of the control group. Intention of resignation in mentees of the experimental group were significantly lower than the nurses of the control group. Also, there were significant interaction between the groups and the times of measurements in all variables. Conclusion: The mentoring program showed positive impact on the variables for maintenance of clinical nurses. Recommendation: Based on these findings, retention strategies using mentoring programs were recommended to reduce clinical nurses' resignation and improve the competency of clinical nurses that leads to the productivity of nursing organizations.