METHODOLOGY: MISUSE OF R2 VALUES FROM LINEAR REGRESSION IN FRACTAL ANALYSIS

Comment on the Value of R2in Regression

Comment on the Value of R2in Regression Analysis

✍ Lawrence A. Gordon 📂 Article 📅 1972 🏛 American Accounting Association 🌐 English ⚖ 219 KB

On the Value of R2in Regression Analysis

On the Value of R2in Regression Analysis: A Reply

✍ Eugene E. Comiskey 📂 Article 📅 1972 🏛 American Accounting Association 🌐 English ⚖ 359 KB

A criterion for the use of linear regres

A criterion for the use of linear regression analysis in the determination of low values of absorption coefficient using the impedance tube method

✍ L. Joffe 📂 Article 📅 1974 🏛 Elsevier Science 🌐 English ⚖ 252 KB

An assessment of two-step linear regress

An assessment of two-step linear regression and multifactor probit analysis as alternatives to acute to chronic ratios in the estimation of chronic response from acute toxicity data to derive water quality guidelines

✍ Andrew R Slaughter; Carolyn G Palmer; Wilhelmine J Muller 📂 Article 📅 2007 🏛 Society of Environmental Toxicology and Chemistry 🌐 English ⚖ 214 KB

Saliva and serum samples were collected

Saliva and serum samples were collected from eight healthy volunteers every two hours during a 26-hour period. Melatonin concentrations were measured by radioimmunoassay after chloroform extraction using radioiodinated melatonin as a tracer. Five of the subjects had high serum melatonin levels at night (peak levels higher than 75 pg/ml); in three subjects the highest serum melatonin concentration was 20-40 pg/ml. All subjects had low levels (P <0.001, was obtained for all detectable value pairs (n= 73). The regression and correlation coefficients were almost equal for the peak values of melatonin and during the rising and descending phases of the secretion patterns. However, no significant correlation was found between low daytime salivary and serum concentrations when calculated separately. In the five high-secretors the melatonin levels in saliva reflected reliably the changes in serum, but in the three low-secretors the correlation between salivary and serum melatonin was not significant. The proportion of melatonin found in saliva decreased with increasing serum melatonin levels. Circadian rhythm parameters were estimated by single cosinor analysis. The acrophases did not differ significantly within a subject in the concomitant measurements of serum and salivary melatonin. The measurements of salivary melatonin levels seem valid for studies on melatonin rhythms, but the melatonin concentrations measured in saliva do not always consistently reflect the absolute concentrations in blood.

✍ Maija-Liisa Laakso; Tarja Porkka-Heiskanen; Aino Alila; Dag Stenberg; Gunnar Joh 📂 Article 📅 1990 🏛 John Wiley and Sons 🌐 English ⚖ 622 KB