scholarly journals Measurement error of waist circumference: gaps in knowledge

2012 ◽  
Vol 16 (2) ◽  
pp. 281-288 ◽  
Author(s):  
Lisanne M Verweij ◽  
Caroline B Terwee ◽  
Karin I Proper ◽  
Carel TJ Hulshof ◽  
Willem van Mechelen
Keyword(s):  
Measurement Error ◽  
Waist Circumference ◽  
Repeated Measurements ◽  
Short Term ◽  
Relevant Change ◽  
Measurement Protocol ◽  
Large Measurement ◽  
Art Research ◽  
Definition Of ◽  
Large Measurement Error

AbstractObjectiveIt is not clear whether measuring waist circumference in clinical practice is problematic because the measurement error is unclear, as well as what constitutes a clinically relevant change. The present study aimed to summarize what is known from state-of-the-art research.DesignTo identify the magnitude of the measurement error of waist circumference measurements from the literature, a search was conducted in PubMed from 1975 to February 2011.ResultsThe measurement error may vary between 0·7 cm and 15 cm. Taking a realistic range of measurable waist circumference into account (60–135 cm), we argue that a short-term clinically relevant change in waist circumference of 5 % may lie between 3·0 and 6·8 cm and a maintained clinically relevant change of 3 % between 1·8 and 4·1 cm.ConclusionsBased on these results, we conclude it may be difficult to distinguish clinically relevant change from measurement error in individual subjects, due to the large measurement error and unclear definition of clinically relevant change. More research is needed to address these gaps in knowledge. To minimize measurement error, we recommend using a uniform measurement protocol, training and repeated measurements.

INFLUENCES OF AGGREGATION ON THE TWO-PHOTON FLUORESCENCE PROCESS

2013 ◽  
Vol 22 (01) ◽  
pp. 1350011 ◽  
Author(s):  
ZHIQIANG ZHOU ◽  
CHANGGUI LU ◽  
YIPING CUI
Keyword(s):  
Measurement Error ◽  
Cross Section ◽  
Correction Method ◽  
Photon Absorption ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Large Measurement ◽  
Two Photon Fluorescence ◽  
Photon Fluorescence ◽  
Large Measurement Error

Rhodamine B (RhB) is most often used as the reference in the two-photon induced fluorescence (TPIF) method to measure the two-photon absorption (TPA) cross-section. In this work, we investigate the influences of dimer formation, energy transfer and self-absorption on the two-photon fluorescence process. Those three effects will result in a large measurement error of the TPA cross-section. We thus provide a concentration gradient correction method by considering the above three processes to eliminate the measurement error.

scholarly journals Perhetaustan yhteys oppimistuloksiin Suomessa PISA- ja rekisteriaineistojen valossa

2020 ◽  
Author(s):  
Hannu Lehti ◽  
Markus Laaninen
Keyword(s):  
Measurement Error ◽  
Learning Outcomes ◽  
Negative Selection ◽  
Parental Education ◽  
Family Background ◽  
Occupational Status ◽  
Large Measurement ◽  
Pisa Data ◽  
School Surveys ◽  
Large Measurement Error

Aikaisempien tutkimusten mukaan oppimistulosten eriarvoisuus vanhemman taustan mukaan on kasvanut Suomessa viime vuosina. Tutkimusnäyttö perustuu vahvasti koulukyselyaineistoihin kuten PISA-aineistoon, jossa vanhempien koulutuksen ja ammattiasema on kysytty lapsilta. Tällaiset kyselyaineistot ovat alttiita vastausharhan aiheuttamalle mittausvirheelle. Tässä tutkimuksessa osoitamme, että PISA-aineistot sisältävät suurta mittausvirhettä vanhempien koulutuksen osalta. Siksi vanhemman ammattiasema on luotettavampi mittari, kun halutaan tutkia kotitaustan yhteyttä oppimistuloksiin PISA-aineistolla. Kun mittausvirhe ja negatiivinen valikoituminen vuosien välillä huomioidaan, oppimistulosten eriarvoisuus ei ole kasvanut Suomessa viime vuosina. / According to previous studies, the inequality of learning outcomes according to family background has increased in Finland in recent years. The evidence is strongly based on school surveys such as PISA data, where children are asked about their parental educational and occupation status. However, such surveys are prone to measurement error due to reporting bias. We show that the PISA data contain a large measurement error in terms of parental education. Therefore, parental occupational status is a more reliable indicator of family background when association between family background and learning outcomes are studied with PISA data. When the measurement error and the negative selection are taken into account, the results show that the inequality of learning outcomes has not increased in Finland in recent years.

A Calibration Method for the Logging Instrument Used in Harsh Environments

2013 ◽  
Vol 365-366 ◽  
pp. 708-715
Author(s):  
Zhen Huang ◽  
Li Kong ◽  
Pu Zhang ◽  
Xiao Nan Liu ◽  
Cheng Zhang
Keyword(s):  
Measurement Error ◽  
Calibration Method ◽  
Harsh Environments ◽  
Formation Water ◽  
Gain Error ◽  
Water Logging ◽  
Large Measurement ◽  
The Impact ◽  
Large Measurement Error

Due to the impact of harsh environments with temperatures higher than 150 °C, the characteristics of the amplifying circuits of logging instrument can be changed, to cause the large measurement error. Therefore, a new calibration method is proposed to obtain the gain value and offset for pre-amplifier system. This method use multiple calibration signals and based on the last square theory to complete the calibration work. At the experiment of calibration for the multi-parameter formation water logging instrument, the gain error for the pre-amplifier system by this calibration be improve to no exceed 0.15% to compare with over 1% by tradition method.

Obesity and Work-Related Injuries Among Farmers in Kentucky, Tennessee, and West Virginia

2021 ◽  
pp. 216507992110266
Author(s):  
Sharon Hunsucker ◽  
Deborah B. Reed
Keyword(s):  
Risk Factor ◽  
Waist Circumference ◽  
Occupational Health ◽  
West Virginia ◽  
Health Administration ◽  
Safety Risk ◽  
Farm Work ◽  
Work Related ◽  
Definition Of ◽  
Recurrent Injuries

Background Obesity is a recognized risk factor for work-related injuries (WRI). Despite the inherent safety hazards associated with farm work, research on obesity among farmers is limited giving little guidance to occupational health providers on obesity as a risk factor in farm WRI. This study evaluated the association between obesity and farm WRI. Methods Cross-sectional data were collected from farmers ( n = 100) in Kentucky, Tennessee, and West Virginia. Data included a survey (demographic data, farm factors, health indicators, occurrences of work-related injuries consistent with the definition of Occupational Safety and Health Administration [OSHA] recordable injuries) and direct anthropometric measures (height, weight, and waist circumference). Logistic regression was used to model any work-related injury, injuries consistent with the definition of OSHA recordables (herein called OSHA-recordable injuries), and recurrent injuries occurring during farm work performance on body mass index (BMI) and waist circumference. Findings Twenty-five percent of the participants reported any injuries, and 18% reported OSHA-recordable injuries. Farmers with a BMI ≥30 kg/m2 had 3 times the risk for OSHA-recordable injuries and 5 times the risk for recurrent injuries. No significant relationship was identified between waist circumference and farm WRI. Conclusion This study provides evidence that increased BMI is a safety risk for farmers. Prospective studies with a larger sample are needed. Occupational health nurses and providers should educate farmers on the potential safety risk of obesity and implement weight management programs addressing obesity in farmers.

scholarly journals ON THE UNIFORM CONVERGENCE OF DECONVOLUTION ESTIMATORS FROM REPEATED MEASUREMENTS

2021 ◽  
pp. 1-22
Author(s):  
Daisuke Kurisu ◽  
Taisuke Otsu
Keyword(s):  
Multivariate Analysis ◽  
Measurement Error ◽  
Uniform Convergence ◽  
Measurement Errors ◽  
Convergence Rates ◽  
Free Variable ◽  
Error Model ◽  
Repeated Measurements ◽  
Empirical Characteristic Function ◽  
Measurement Error Model

This paper studies the uniform convergence rates of Li and Vuong’s (1998, Journal of Multivariate Analysis 65, 139–165; hereafter LV) nonparametric deconvolution estimator and its regularized version by Comte and Kappus (2015, Journal of Multivariate Analysis 140, 31–46) for the classical measurement error model, where repeated noisy measurements on the error-free variable of interest are available. In contrast to LV, our assumptions allow unbounded supports for the error-free variable and measurement errors. Compared to Bonhomme and Robin (2010, Review of Economic Studies 77, 491–533) specialized to the measurement error model, our assumptions do not require existence of the moment generating functions of the square and product of repeated measurements. Furthermore, by utilizing a maximal inequality for the multivariate normalized empirical characteristic function process, we derive uniform convergence rates that are faster than the ones derived in these papers under such weaker conditions.

Abstract P563: Prognosis Driven Definition of Carotid Near-Occlusion With Full Collapse

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Charith Cooray ◽  
Thomas Gu ◽  
Allan J Fox ◽  
Elias Johansson
Keyword(s):  
Ischemic Stroke ◽  
Carotid Stenosis ◽  
Risk Markers ◽  
Inclusion Criteria ◽  
Short Term ◽  
Residual Stenosis ◽  
Kaplan Meier ◽  
Near Occlusion ◽  
Definition Of ◽  
Distal Artery

Introduction: Carotid near-occlusion is a severe carotid stenosis causing distal artery collapse of varying degree. Near-occlusion is often divided into a “full collapse” group with a threadlike distal lumen, and the often overlooked “without full collapse” group with a normal-appearing, albeit small, distal lumen. By this division by appearance, symptomatic near-occlusion with full collapse has been reported to have worse short-term prognosis than those without full collapse, no other division has been assessed for prognosis. The aim of this study was to assess if a measurement based definition of full collapse might improve prognostic discrimination. Methods: 99 consecutive patients with symptomatic near-occlusion diagnosed on CT-angiography were included. The risk of preoperative recurrent ipsilateral ischemic stroke within 28 days of presenting event was assessed with Kaplan-Meier analysis, censoring at revascularization. We assessed residual stenosis diameter, distal ICA diameter, ICA-ratio (side-to-side), and ICA-ECA ratio as risk markers. Results: By appearance, the 28-day risk of stroke tended to be higher for full collapse (27%, 11/42) than without full collapse (11%, 6/57), p=0.054 (figure). The best new definition of full collapse was distal ICA diameter ≤2.0 mm and/or ICA ratio ≤0.47. 10 patients were reclassified by this new definition compared to appearance definition, 5 in each direction. By the new definition, 28-day risk of stroke was higher in full collapse (34%, 14/42) than without full collapse (5%, 3/57), p<0.001 (fig 1B). Conclusions: Compared to the appearance based definition, our new definition of separating near-occlusions into with and without full collapse yields similar groups sizes but better prognostic discrimination. This new definition could be used as inclusion criteria in future treatment trials.

scholarly journals Folate bioavailability from foods rich in folates assessed in a short term human study using stable isotope dilution assays

2015 ◽  
Vol 6 (1) ◽  
pp. 241-247 ◽  
Author(s):  
Sabine Mönch ◽  
Michael Netzel ◽  
Gabriele Netzel ◽  
Undine Ott ◽  
Thomas Frank ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Isotope Dilution ◽  
Human Study ◽  
Short Term ◽  
Standard Definition ◽  
Stable Isotope Dilution ◽  
Stable Isotope Dilution Assays ◽  
Folate Bioavailability ◽  
Definition Of ◽  
Different Sources

Different sources of folate may have different bioavailability and hence may impact the standard definition of folate equivalents.

scholarly journals When is a Learning Object not an Object: A first step towards a theory of learning objects

2002 ◽  
Vol 3 (2) ◽  
Author(s):  
Mike Sosteric ◽  
Susan Hesemeier
Keyword(s):  
Economies Of Scale ◽  
Learning Objects ◽  
Short Term ◽  
Object A ◽  
Smart Learning ◽  
Smart Learning Environments ◽  
Adequate Definition ◽  
Definition Of ◽  
Conceptual Confusion

<p> For some, “learning objects" are the “next big thing” in distance education promising smart learning environments, fantastic economies of scale, and the power to tap into expanding educational markets. While learning objects may be revolutionary in the long term, in the short term, definitional problems and conceptual confusion undermine our ability to understand and critically evaluate the emerging field. This article is an attempt to provide an adequate definition of learning objects by (a) jettisoning useless theoretical links hitherto invoked to theorize learning objects, and (b) reducing the definition of learning objects to the bare essentials. The article closes with suggestions for further research and further refinement of the definition of learning objects. </P>

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