scholarly journals Reliability, comparative validity and stability of dietary patterns derived from an FFQ in the Tehran Lipid and Glucose Study

2012 ◽  
Vol 108 (6) ◽  
pp. 1109-1117 ◽  
Author(s):  
Golaleh Asghari ◽  
Arezoo Rezazadeh ◽  
Firoozeh Hosseini-Esfahani ◽  
Yadollah Mehrabi ◽  
Parvin Mirmiran ◽  
...  
Keyword(s):  
Factor Analysis ◽  
Dietary Patterns ◽  
Reliability And Validity ◽  
Factor Scores ◽  
Limits Of Agreement ◽  
The Third ◽  
The Mean ◽  
The Difference ◽  
The Stability ◽  
Traditional Pattern

The aim of the present study was to assess the reliability, comparative validity and stability of dietary patterns defined by factor analysis for participants of the Tehran Lipid and Glucose Study. A total of 132 subjects, aged ≥ 20 years, completed a 168-item FFQ (FFQ1, FFQ2) twice, with a 14-month interval. Over this duration, twelve dietary recalls (DR) were collected each month. To assess the stability of the FFQ, participants completed the third FFQ (FFQ3) after 8 years. Following these, two dietary patterns – the ‘Iranian Traditional’ and the ‘Western’ – were derived from FFQ1 and FFQ2 and the mean of DR (mDR); and three dietary patterns were identified from FFQ3: the ‘Iranian Traditional’, the ‘Western’ and the ‘Combined’. The reliability correlations between factor scores of the two FFQ were 0·72 for the Iranian Traditional and 0·80 for the Western pattern; corrected month-to-month variations of DR correlations between the FFQ2 and mDR were 0·48 for the first and 0·75 for the second pattern. The 95 % limits of agreement for the difference between factor scores obtained from FFQ2 and mDR lay between − 1·58 and +1·58 for the Iranian Traditional and between − 1·33 and +1·33 for the Western pattern. The intra-class correlations between FFQ2 and FFQ3 were − 0·09 (P = 0·653) and 0·49 (P <0·001) for the ‘Iranian Traditional’ and the ‘Western’, respectively. These data indicate reasonable reliability and validity of the dietary patterns defined by factor analysis. Although the Western pattern was found to be fairly stable, the Iranian Traditional pattern was mostly unstable over the 8 years of the study period.

scholarly journals Inviscid spatial stability of a compressible mixing layer. Part 3. Effect of thermodynamics

1991 ◽  
Vol 224 ◽  
pp. 159-175 ◽  
Author(s):  
T. L. Jackson ◽  
C. E. Grosch
Keyword(s):  
Prandtl Number ◽  
Mixing Layer ◽  
Mean Flow ◽  
Temperature Relation ◽  
Compressible Mixing Layer ◽  
Spatial Stability ◽  
Mean Temperature ◽  
The Mean ◽  
The Difference ◽  
The Stability

We report the results of a comprehensive comparative study of the inviscid spatial stability of a parallel compressible mixing layer using various models for the mean flow. The models are (i) the hyperbolic tangent profile for the mean speed and the Crocco relation for the mean temperature, with the Chapman viscosity–temperature relation and a Prandtl number of one; (ii) the Lock profile for the mean speed and the Crocco relation for the mean temperature, with the Chapman viscosity-temperature relation and a Prandtl number of one; and (iii) the similarity solution for the coupled velocity and temperature equations using the Sutherland viscosity–temperature relation and arbitrary but constant Prandtl number. The purpose of this study was to determine the sensitivity of the stability characteristics of the compressible mixing layer to the assumed thermodynamic properties of the fluid. It is shown that the qualitative features of the stability characteristics are quite similar for all models but that there are quantitative differences resulting from the difference in the thermodynamic models. In particular, we show that the stability characteristics are sensitive to the value of the Prandtl number and to a particular value of the temperature ratio across the mixing layer.

On an inequality of long period in the motions of the Earth and Venus

1837 ◽  
Vol 3 ◽  
pp. 77-78
Keyword(s):  
Principal Term ◽  
The Sun ◽  
Method Of Calculation ◽  
The Third ◽  
Long Period ◽  
Mean Motion ◽  
The Earth ◽  
The Mean ◽  
The Difference

The author had pointed out, in a paper published in the Philosophical Transactions for 1828, on the corrections of the elements of Delambre’s Solar Tables, that the comparison of the corrections of the epochs of the sun and the sun’s perigee, given by the late observations, with the corrections given by the observations of the last century, appears to indicate the existence of some inequality not included in the arguments of those tables. As it was necessary, therefore, to seek for some inequality of long period, he commenced an examination of the mean motions of the planets, with the view of discovering one whose ratio to the mean motion of the earth could be expressed very nearly by a proportion of which the terms are small. The appearances of Venus are found to recur in very nearly the same order every eight years; some multiple, therefore, of the periodic time of Venus is nearly equal to eight years. It is easily seen that this multiple must be thirteen; and consequently eight times the mean motion of Venus is nearly equal to thirteen times the mean motion of the earth. The difference is about one 240th of the mean annual motion of the earth; and it implies the existence of an inequality of which the period is about 240 years. No term has yet been calculated whose period is so long with respect to the periodic time of the planets disturbed. The value of the principal term, calculated from the theory, was given by the author in a postscript to the paper above referred to. In the present memoir he gives an account of the method of calculation, and includes also other terms which are necessarily connected with the principal inequality. The first part treats of the perturbation of the earth’s longitude and radius victor; the second of the perturbation of the earth in latitude; and the third of the perturbations of Venus depending upon the same arguments.

scholarly journals Orthodontic treatment stability predictors: A retrospective longitudinal study

2016 ◽  
Vol 87 (2) ◽  
pp. 223-229 ◽  
Author(s):  
Paloma González-Gil de Bernabé ◽  
José María Montiel-Company ◽  
Vanessa Paredes-Gallardo ◽  
Jose Luis Gandía-Franco ◽  
Carlos Bellot-Arcís
Keyword(s):  
Longitudinal Study ◽  
Orthodontic Treatment ◽  
Protective Factor ◽  
Peer Assessment ◽  
Anterior Segment ◽  
End Of Treatment ◽  
The Mean ◽  
The Difference ◽  
The Stability

ABSTRACTObjective: To examine medium- to long-term orthodontic treatment stability and its possible association with certain variables.Materials and Methods: In a retrospective longitudinal study of 70 postretention patients, the Peer Assessment Rating (PAR) index was measured at the start (T1) and end (T2) of treatment and between 4 and 10 years afterwards (T3). The stability was considered absolute when the T2 and T3 values were identical and relative when the difference was within the ±5 range.Results: Among the 70 patients, 65.8% were female and 34.2% were male. Their mean age was 14.5 years. The mean treatment length was 2.4 years. The mean retention phase was 3.3 years. The mean pre- and posttreatment PAR scores were 29.8 (T1) and 6.3 (T2). The mean T1–T2 difference was 23.6. The mean T2–T3 difference was −0.39.Conclusions: Within the study, 7.1% presented absolute stability and 68.6% presented relative stability. Lower anterior segment alignment and overbite were the most unstable occlusal features and tended to worsen. Fixed retainer (odds ratio [OR] 0.31; 95% confidence interval [CI] 0.10–0.98) as a protective factor and years without retention (OR 1.32; 95% CI 1.03–1.68) as a risk factor are predictor variables of instability in the case of lower anterior segment alignment. The PAR value at the end of treatment (OR 1.29; 95% CI 1.08–1.54) and extractions (OR 4.76; 95% CI 1.05–21.6) before treatment are predictors for midline instability.

scholarly journals Dietary pattern and weight change in a 5-year follow-up among Chinese adults: results from the Jiangsu Nutrition Study

2010 ◽  
Vol 105 (7) ◽  
pp. 1047-1054 ◽  
Author(s):  
Zumin Shi ◽  
Baojun Yuan ◽  
Gang Hu ◽  
Yue Dai ◽  
Hui Zuo ◽  
...  
Keyword(s):  
Weight Gain ◽  
Dietary Patterns ◽  
Weight Change ◽  
Dietary Pattern ◽  
Weight Changes ◽  
Chinese Adults ◽  
Fresh Vegetables ◽  
Nutrition Study ◽  
The Mean ◽  
Traditional Pattern

The aim of the present study was to examine the association between dietary patterns and weight change prospectively. We followed up 1231 adults aged 20 years and older (mean age 49·3 years) from 2002 to 2007. Food intake was assessed at baseline by an FFQ. Factor analysis was used to identify dietary patterns. Nutrient intake was measured by food weighing plus consecutive individual 3 d food records. Body weight and height were measured. The mean 5-year weight gain among all participants was 0·8 (sd4·7) kg. The mean weight changes across quartiles of the ‘traditional’ pattern (rice, fresh vegetables, pork and wheat flour) were 2·0, 0·6, 0·6 and 0·0 kg. The corresponding values were 0·4, 0·5, 0·7 and 1·6 kg across quartiles of the ‘vegetable-rich’ pattern. No significant association between the ‘macho’ dietary pattern (meat and alcohol), the ‘sweet tooth’ pattern (drinks and cake) and weight gain was found. In multivariate linear regression, using the first quartile as the reference, participants in the highest quartile of the ‘traditional’ pattern had a β of − 2·18 (95 % CI − 2·91, − 1·45) for weight gain. However, the β from weight change of the highest quartile of the ‘vegetable-rich’ pattern was 1·00 (95 % CI 0·25, 1·74). In conclusion, the ‘traditional’ dietary pattern was negatively and the ‘vegetable-rich’ pattern was positively associated with weight gain in Chinese adults.

Inter- and intra-operator variability associated with extracapsular suture tensioning

2012 ◽  
Vol 25 (06) ◽  
pp. 472-477 ◽  
Author(s):  
E. A. Buffa ◽  
A. M. Marchevsky ◽  
J. Heller ◽  
A. P. Moores ◽  
M. Farrell ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Cruciate Ligament ◽  
Mean Difference ◽  
Marked Variation ◽  
Limits Of Agreement ◽  
Cranial Cruciate Ligament ◽  
Suture Tension ◽  
Clinical Consequences ◽  
The Mean ◽  
The Difference

SummaryObjectives: To determine inter- and intra- operator variability associated with extracapsular suture tensioning as performed during lateral fabello-tibial suture placement.Study design: Ex vivo study.Methods: Fifteen Greyhound cadaveric pelvic limbs were prepared by cutting the cranial cruciate ligament and placing an extracapsular fabello-tibial suture. On two occasions, three surgeons tensioned the extracapsular suture of each stifle. Stifles were returned to 135 degrees of flexion and the suture tension was measured using a commercially available suture tensioner with inbuilt tensiometer.Statistical analysis: Intra-operator and inter-operator agreement were assessed using the limits of agreement method. A linear mixed effects model was specified to assess the effect of operator, repeated estimates and stifle order on tension applied.Results: The mean difference within the three operators ranged from 0 to 14.7N. With 95% limits of agreement, on most occasions for all three operators, the difference was between –31.7 and 41.0 N. The mean difference between the three operators ranged from 6.0 to 30.7 N. With 95% limits of agreement, on most occasions the difference between operators was between –25.6 and 62.5 N.Clinical significance: Marked variation exists in the tension applied during fabello- tibial suture application, both within and between surgeons. This variation may lead to inconsistent clinical outcomes. Further studies are required to determine the clinical consequences of this marked variation in extracapsular suture tensioning.

Evaluation of the Stability of the Subjects with Anterior Cruciate Injuries Reconstruction

2020 ◽  
Author(s):  
Hossein Akbari Aghdam ◽  
Mahsa Kavyani ◽  
Maryam Bosak ◽  
Mohammad Taghi Karimi ◽  
Mehdi Motififard
Keyword(s):  
Acl Reconstruction ◽  
Postural Stability ◽  
Center Of Pressure ◽  
Mean Value ◽  
P Value ◽  
Before And After ◽  
The Mean ◽  
The Difference ◽  
Anterior Cruciate ◽  
The Stability

AbstractAnterior cruciate ligament (ACL) is the most frequently injured ligament in the knee and is often injured during sport-related activities. ACL injuries influence the abilities of the subjects during standing and walking. Although early surgical intervention is preferred treatment for the majority of knee surgeons, the effect of this approach on postural stability of patients is not fully understood. Therefore, the aim of this study was to determine the difference between stability of ACL-reconstructed subjects before and after surgery. A group of 15 consecutive ACL injured patients participated in this study. Postural stability of the patients was evaluated 1 week before and 6 months after surgery (ACL reconstruction with hamstring autograft). A Kistler force plate was used to evaluate center of pressure (COP) sway during quiet standing. The mean values of the COP parameters were obtained in pre and postsurgery conditions. Paired sample t-test was used to evaluate the difference between the stability parameters of the two conditions. The significant point was set at 0.05. The mean value of path length of COP velocity in mediolateral (ML) direction was 1,485.57 ± 479.42 mm and 2,641.33 ± 996.26 mm before and after surgery, respectively (p-value = 0.01). Although the mean value of COP velocity in anteroposterior and ML directions increased after surgery, the difference was only significant for velocity in ML direction (p-value = 0.049). The results of this study showed that the standing stability of those with ACL reconstruction decreased significantly after ACL reconstruction, which may be due to the effects of the surgery on sensory mechanism of ACL and inability of patients to return to their previous deep sense perception and knee proprioception.

scholarly journals Agreement analysis between critical power and intensity corresponding to 50% in cycling exercise

2016 ◽  
Vol 18 (2) ◽  
pp. 197 ◽  
Author(s):  
Kristopher Mendes de Souza ◽  
Ricardo Dantas de Lucas ◽  
Paulo Cesar do Nascimento Salvador ◽  
Lucas Crescenti Abdalla Saad Helal ◽  
Luiz Guilherme Antonacci Guglielmo ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Lactate Threshold ◽  
Critical Power ◽  
Limits Of Agreement ◽  
Cycling Exercise ◽  
Significant Difference ◽  
The Mean ◽  
The Difference ◽  
Male Subjects ◽  
Level Of Agreement

DOI: http://dx.doi.org/10.5007/1980-0037.2016v18n2p197 The purpose of this study was to determine the level of agreement between critical power (CP) and intensity corresponding to 50% of the difference (50% Δ) between oxygen uptake (VO2) at lactate threshold (LT) and maximal oxygen uptake (VO2max) in untrained subjects during cycling exercise. Fifteen healthy male subjects (age: 26.0 ± 3.5 years; body weight: 76.6 ± 10.4 kg; height: 178.2 ± 7.6 cm) volunteered to participate in the study. Each subject performed a series of tests to determine LT, VO2LT, CP, VO2CP, 50% Δ, VO250% Δ, and VO2max. The values of LT, VO2LT, CP, VO2CP, 50% Δ, VO250% Δ and VO2max were 109 ± 15 W, 1.84 ± 0.23 L.min-1, 207 ± 17 W, 2.78 ± 0.27 L.min-1, 206 ± 19 W, 2.77 ± 0.29 L.min-1, and 3.71 ± 0.49 L.min-1, respectively. No significant difference was found between CP and 50% Δ (t = 0.16; p = 0.87) or between VO2CP and VO250% Δ (t = 0.12; p = 0.90). However, the bias ± 95% limits of agreement for comparison between CP and 50% Δ and between VO2CP and VO250% Δ were 1 ± 27 W (0.3 ± 14.1%) and 0.01 ± 0.24 L.min-1 (0.2 ± 8.9%), respectively. In summary, the mean CP and 50% Δ values were not significantly different. However, considering the limits of agreement between the two intensities, CP estimated based on 50% Δ might result in a remarkable error when the absolute variability of individual differences is taken into account

scholarly journals The equivalence of hydration status measured by the Fresenius BCM and the Cella Bioimpedance Spectroscopy devices on hemodialysis patients

2021 ◽  
Author(s):  
Jim Matthie ◽  
Borut Baricevic ◽  
Vlasta Malnaric Marentic ◽  
Boris Krajacic
Keyword(s):  
Statistical Power ◽  
Fluid Management ◽  
Hydration Status ◽  
P Value ◽  
Bioimpedance Spectroscopy ◽  
Promising Technique ◽  
Limits Of Agreement ◽  
Body Composition Monitor ◽  
The Mean ◽  
The Difference

AbstractBackgroundFluid management is a serious challenge for patients undergoing hemodialysis therapy (HD). Bioimpedance spectroscopy (BIS) is a promising technique to help with clinical hydration (HYD) assessment. The Fresenius Medical Care (FMC) Body Composition Monitor (BCM) is the standard but is large and expensive. Cella Medical has introduced a small wireless BIS device. This study compared the HYD status predicted by the two devices.MethodsFollowing the FMC BCM device manual guidelines, measurements of BIS were made wrist-ankle using typical ECG electrodes on the non-fistula side of HD patients pre dialysis while in their normal supine position. As usual, patients were measured before their normal time of therapy with the BCM. The Cella measurements were then performed within two minutes.ResultsForty-two HD patients (M=64%, age=64±30 yrs.), were measured. One patient data was removed. The mean BCM HYD status was 1.86 l, SD 1.46 l, and SEM 0.22 l. Cella was 1.806 l, SD 1.36 l, and the SEM 0.21 l. The 95% difference confidence interval (CI) was -0.66 to 0.55 l. The Pearson’s correlation (r) was r^2 = 0.85 (p<0.00001). There was no proportional bias: the offset was -0.056 l, and K=1.010. The limits of agreement (LOA) analysis showed a mean difference of 0.56 l, and limits d ±2SD = (−1.192 l, 1.081 l), indicating 95% of the difference will lie within these limits. To evaluate equivalence, we performed two one-sided t-tests (TOST). When the bounds were reduced to the limit =0.47 l and -0.59 l, we obtained a 0.046 p-value (alpha =0.05), at 80% statistical power. For 26% of the subjects, the difference was <0.1 l, for 43% <0.25 l, for 71% <0.5 l, for 83% <0.75 l, for 90% <1.0 l, and for 9.5% (4 patients) more than 1 l. Only two cases (4.8%) were just over the ±2SD limit.ConclusionThis study suggests the BCM and Cella devices can be used interchangeably.

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