Condition for the constancy of regression of a polynomial statistic on a sample mean

1994 ◽  
Vol 68 (4) ◽  
pp. 469-474
Author(s):  
A. A. Zinger ◽  
L. B. Klebanov
Keyword(s):  
Sample Mean ◽  
Constancy Of Regression

Periodontitis Is Related to Exercise Capacity: Two Cross-sectional Studies

2021 ◽  
pp. 002203452199542
Author(s):  
B. Holtfreter ◽  
B. Stubbe ◽  
S. Gläser ◽  
J. Trabandt ◽  
H. Völzke ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Disease Severity ◽  
Cardiorespiratory Fitness ◽  
Large Scale ◽  
Cardiopulmonary Exercise Testing ◽  
Exercise Duration ◽  
Cross Sectional ◽  
Sample Mean ◽  
Cardiometabolic Diseases ◽  
Number Of Teeth

Although a potential link between periodontitis and cardiorespiratory fitness might provide a reasonable explanation for effects of tooth-related alterations seen on cardiometabolic diseases, evidence is currently limited. Thus, we investigated the association between clinically assessed periodontitis and cardiopulmonary exercise testing (CPET). Data from 2 independent cross-sectional population-based studies (5-y follow-up of the Study of Health in Pomerania [SHIP-1; N = 1,639] and SHIP-Trend-0 [ N = 2,439]) were analyzed. Participants received a half-mouth periodontal examination, and teeth were counted. CPET was based on symptom limited-exercise tests on a bicycle ergometer. Associations of periodontitis parameters with CPET parameters were analyzed by confounder-adjusted multivariable linear regression. In the total sample, mean pocket probing depth (PPD), mean clinical attachment levels, and number of teeth were consistently associated with peak oxygen uptake (peakVO2) and exercise duration in both studies, even after restriction to cardiorespiratory healthy participants. Statistically significant associations with oxygen uptake at anaerobic threshold (VO2@AT), slope of the efficiency of ventilation in removing carbon dioxide, and peak oxygen pulse (VÉ/VCO2 slope) occurred. Further, interactions with age were identified, such that mainly older individuals with higher levels of periodontal disease severity were associated with lower peakVO2. Restricted to never smokers, associations with mean clinical attachment levels and the number of teeth mostly diminished, while associations of mean PPD with peakVO2, VO2@AT, VÉ/VCO2 slope, and exercise duration in SHIP-1 and SHIP-Trend-0 were confirmed. In SHIP-1, mean peakVO2 was 1,895 mL/min in participants with a mean PPD of 1.6 mm and 1,809 mL/min in participants with a mean PPD of 3.7 mm. To conclude, only mean PPD reflecting current disease severity was consistently linked to cardiorespiratory fitness in 2 cross-sectional samples of the general population. If confirmed in well-designed large-scale longitudinal studies, the association between periodontitis and cardiorespiratory fitness might provide a biologically plausible mechanism linking periodontitis with cardiometabolic diseases.

scholarly journals Biochemical Validation of a Self-Administered Food Frequency Questionnaire to Assess Diet Using Carotenoids and Vitamins E and D in Male Adolescents in Spain

Antioxidants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 750
Author(s):  
Leyre Notario-Barandiaran ◽  
Eva-María Navarrete-Muñoz ◽  
Desirée Valera-Gran ◽  
Elena Hernández-Álvarez ◽  
Encarnación Donoso-Navarro ◽  
...  
Keyword(s):  
Vitamin E ◽  
Food Frequency Questionnaire ◽  
Vegetable Intake ◽  
Correlation Coefficients ◽  
Fruit And Vegetable Intake ◽  
Fruit And Vegetable ◽  
Sample Mean ◽  
Food Frequency ◽  
Male Adolescents ◽  
Β Carotene

Reliable tools to evaluate diet are needed, particularly in life periods such as adolescence in which a rapid rate of growth and development occurs. We assessed the biochemical validity of a self-administered food frequency questionnaire (FFQ) in a sample of Spanish male adolescents using carotenoids and vitamin E and D data. We analyzed data from 122 male adolescents aged 15–17 years of the INMA-Granada birth cohort study. Adolescents answered a 104-item FFQ and provided a non-fasting blood sample. Mean daily nutrient intakes and serum concentration were estimated for main carotenoids (lutein-zeaxanthin, β-cryptoxanthin, lycopene, α-carotene and β-carotene), vitamins E and D and also for fruit and vegetable intake. Pearson correlation coefficients (r) and the percentage of agreement (same or adjacent quintiles) between serum vitamin concentrations and energy-adjusted intakes were estimated. Statistically significant correlation coefficients were observed for the total carotenoids (r = 0.40) and specific carotenoids, with the highest correlation observed for lutein–zeaxanthin (r = 0.42) and the lowest for β-carotene (0.23). The correlation coefficient between fruit and vegetable intake and serum carotenoids was 0.29 (higher for vegetable intake, r = 0.33 than for fruit intake, r = 0.19). Low correlations were observed for vitamin E and D. The average percentage of agreement for carotenoids was 55.8%, and lower for vitamin E and D (50% and 41%, respectively). The FFQ may be an acceptable tool for dietary assessment among male adolescents in Spain.

scholarly journals Identifying individuals with high risk of Alzheimer’s disease using polygenic risk scores

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ganna Leonenko ◽  
Emily Baker ◽  
Joshua Stevenson-Hoare ◽  
Annerieke Sierksma ◽  
Mark Fiers ◽  
...  
Keyword(s):  
High Risk ◽  
Risk Score ◽  
Genetic Risk ◽  
Prediction Accuracy ◽  
Genetic Risk Score ◽  
Low Risk ◽  
Risk Scores ◽  
Sample Mean ◽  
Polygenic Risk ◽  
Reliable Identification

AbstractPolygenic Risk Scores (PRS) for AD offer unique possibilities for reliable identification of individuals at high and low risk of AD. However, there is little agreement in the field as to what approach should be used for genetic risk score calculations, how to model the effect of APOE, what the optimal p-value threshold (pT) for SNP selection is and how to compare scores between studies and methods. We show that the best prediction accuracy is achieved with a model with two predictors (APOE and PRS excluding APOE region) with pT<0.1 for SNP selection. Prediction accuracy in a sample across different PRS approaches is similar, but individuals’ scores and their associated ranking differ. We show that standardising PRS against the population mean, as opposed to the sample mean, makes the individuals’ scores comparable between studies. Our work highlights the best strategies for polygenic profiling when assessing individuals for AD risk.

Conscious and Preconscious Influences on Recall: A Reassessment and Extension

1967 ◽  
Vol 20 (3) ◽  
pp. 963-974 ◽  
Author(s):  
Steven H. Stein ◽  
Robert H. Harrison
Keyword(s):  
Serial Position ◽  
Word List ◽  
Control Word ◽  
Personality Inventory ◽  
Primary Associate ◽  
Sample Mean ◽  
And Control

In an attempt to replicate the Spence (1964) finding that primary recall hinders the recall of primary associates, an experiment controlling for serial position and associative clustering effects was performed. Results were obtained which indicate facilitation rather than restriction of associate recall after primary recall. Spence-type results were obtained, however, with Ss whose scores were above the sample mean on the Extraversion scale of the Maudsley Personality Inventory. In addition, hypotheses based on Eysenck's theories concerning introversion-extraversion and anxiety were tested as to their efficacy in predicting the amount and pattern of primary associate (associates to the primary of a word list) and control word associate (associates related to a primary which does not appear in the word list) recall. As predicted, extraversion correlated with the degree to which S alternated between primary associates and control associates during recall. Anxiety was not related to any of the experimental measures.

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