scholarly journals Growth of Black Spruce Trees Following Fertilization on Drained Peatland

1989 ◽  
Vol 65 (2) ◽  
pp. 102-106 ◽  
Author(s):  
Bijan Payandeh
Keyword(s):  
Black Spruce ◽  
Linear Regression Analysis ◽  
Volume Growth ◽  
Average Diameter ◽  
Multiple Linear Regression Analysis ◽  
Stepwise Multiple Linear Regression ◽  
Individual Tree ◽  
Individual Trees ◽  
Volume Equations ◽  
Tree Characteristics

Stem analyse of 67 peatland black spruce trees from previously drained experimental areas in northeastern Ontario that had been fertilized was used to examine effects on growth of individual trees. Stepwise multiple linear regression analysis was used to express pre- and post-fertilization diameter and volume growth as a function of site, stand and individual tree characteristics and amelioration treatments.Results indicated that, on average, diameter growth increased by 4% after fertilization. Standard volume equations, in comparison with sectional volume summation underestimated both inside- and outside-bark tree volumes by about 3%.

scholarly journals Comparison of muscle quality and functional capacity between Japanese and Brazilian older individuals

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243589
Author(s):  
Hiroshi Akima ◽  
Akito Yoshiko ◽  
Régis Radaelli ◽  
Madoka Ogawa ◽  
Kaori Shimizu ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Regression Analysis ◽  
Linear Regression ◽  
Multiple Linear Regression ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Muscle Quality ◽  
Older Individuals ◽  
Stepwise Multiple Linear Regression ◽  
Independent Variables

Muscle quality is well-known to decrease with aging and is a risk factor for metabolic abnormalities. However, there is a lack of information on race-associated differences in muscle quality and other neuromuscular features related to functional performance. This study aimed to compare muscle quality, function, and morphological characteristics in Japanese and Brazilian older individuals. Eighty-four participants aged 65–87 years were enrolled in the study (42 Japanese: 23 men, 19 women, mean age 70.4 years; 42 Brazilians: 23 men, 19 women, mean age 70.8 years). Echo intensity (EI) and muscle thickness (MT) of the quadriceps femoris were measured using B-mode ultrasonography. A stepwise multiple linear regression analysis with EI as a dependent variable revealed that MT was a significant variable for Japanese participants (R2 = 0.424, P = 0.001), while MT and subcutaneous adipose tissue (SCAT) thickness were significant variables for Brazilian participants (R2 = 0.490, P = 0.001). A second stepwise multiple linear regression analysis was performed after excluding MT and SCAT thickness from the independent variables. Sex and age for Japanese participants (R2 = 0.381, P = 0.001) and lean body mass and body mass index for Brazilian participants (R2 = 0.385, P = 0.001) were identified as significant independent variables. The present results suggest that MT is closely correlated with muscle quality in Japanese and Brazilian older individuals. Increases in muscle size may induce decreases in intramuscular adipose tissue and/or connective tissues, which are beneficial for reducing the risks of metabolic impairments in Japanese and Brazilian older individuals.

scholarly journals Effect of slow breathing on the blood pressure and the Valsalva ration in prehypertensive Indian students

Biologija ◽  
2019 ◽  
Vol 65 (2) ◽  
Author(s):  
Iryna Oleksandrivna Yepryntseva ◽  
Larisa Semyonovna Shchyrova ◽  
Vera Evgenievna Shekh
Keyword(s):  
Blood Pressure ◽  
Regression Analysis ◽  
Linear Regression ◽  
Linear Regression Analysis ◽  
Surrogate Marker ◽  
Multiple Linear Regression Analysis ◽  
Valsalva Manoeuvre ◽  
Stepwise Multiple Linear Regression ◽  
Slow Breathing ◽  
Indian Students

The purpose of this study was to evaluate the effect of slow breathing and prehypertension (PHT) on cardiovascular and HRV variables and on the Valsalva ratio (VR). ECG was recorded in 39 normotensives and 35 prehypertensives at 5 min resting and slow breathing (6 breaths/min) stages to obtain HR, LF and HF power; SBP and DBP were recorded at the end of each stage. The Valsalva manoeuvre was performed after resting and slow breathing stages. Two-way repeated MANOVA was used to test for the effects of PHT and slow breathing. Stepwise multiple linear regression analysis was used to reveal predictors of HR, SBP and DBP. The normotensives and the prehypertensives demonstrated reduction of SBP during slow breathing (117.95 ± 0.73 vs. 115.18 ± 0.91 mm Hg, P = 0.001 and 130.09 ± 0.08 vs. 125.91 ± 0.96 mm Hg, P < 0.001, respectively). At rest, the VR was lower in prehypertensives (1.69 ± 0.05 vs. 1.87 ± 0.05, P = 0.009). After slow breathing, the VR increased significantly only in prehypertensives (P = 0.008), it was no longer different from that of normotensives (1.82 ± 0.06 vs. 1.90 ± 0.06, P = 0.346). The LnLF power, interpreted according to our hypothesis described previously as sympathoinhibition, increased in both groups. Slow breathing reduced SBP in normotensives and prehypertensives as a result of an increase in sympathoinhibition in both groups and VR, considered as a surrogate marker of the baroreflex activity, in prehypertensives.

scholarly journals Estimation of the instantaneous peak flow from maximum daily flow: a comparison of three methods

2014 ◽  
Vol 46 (5) ◽  
pp. 671-688 ◽  
Author(s):  
J. Ding ◽  
U. Haberlandt ◽  
J. Dietrich
Keyword(s):  
Linear Regression ◽  
Multiple Linear Regression ◽  
Peak Flow ◽  
Linear Regression Analysis ◽  
Extreme Value Distribution ◽  
Maximum Flow ◽  
Multiple Linear Regression Analysis ◽  
Generalized Extreme Value Distribution ◽  
Stepwise Multiple Linear Regression ◽  
Scaling Properties

Three different methods are compared to estimate the instantaneous peak flow (IPF) from the corresponding maximum daily flow (MDF), as the daily data are more often available at gauges of interest and often with longer recording periods. In the first approach, simple linear regression is applied to calculate IPF from MDF values using probability weighted moments and quantile values. In the second method, the use of stepwise multiple linear regression analysis allows to identify the most important catchment descriptors of the study basin. The resulting equation can be applied to transfer MDF into IPF. With the third method, the temporal scaling properties of annual maximum flow series are investigated based on the hypothesis of piece wise simple scaling combined with the generalized extreme value distribution. The scaling formulas developed from three 15 min stations in the Aller-Leine river basin of Germany are transferred to all daily stations to estimate the IPF. The method based on stepwise multiple linear regression gives the best results compared with the other two methods. The simple regression method is the easiest to apply given sufficient peak flow data, while the scaling method is the most efficient method with regard to data use.

Stand structure and growing space efficiency following thinning in an even-aged Douglas-fir stand

1988 ◽  
Vol 18 (7) ◽  
pp. 859-866 ◽  
Author(s):  
K. L. O'Hara
Keyword(s):  
Stand Structure ◽  
Volume Growth ◽  
Basal Area ◽  
Stand Density ◽  
Douglas Fir ◽  
Stem Volume ◽  
Projection Area ◽  
Individual Tree ◽  
Space Efficiency ◽  
Individual Trees

The growth of individual trees from four thinning treatments in a 64-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stand was analyzed to determine desirable residual stand structures after thinning. Dominant and codominant trees had the highest individual tree stem volume growth rates over the previous 5 years, and accounted for most stand volume growth in thinned and unthinned stands. Two measures of growing space, crown projection area and sapwood basal area (a surrogate for leaf area), were used to measure how efficiently individual trees used their growing space. Crown classes were useful in characterizing growing space efficiency (volume growth per unit of growing space) only in the unthinned treatment. In thinned treatments, tall trees with medium-sized crowns were most efficient, while in the unthinned treatment, tall trees with relatively large crowns were most efficient. A large crown in an unthinned stand was comparable in size to a medium-sized crown in a thinned stand. Results suggest growing space is not limiting individual tree growth in thinned stands and that thinning to a particular stand structure is more appropriate than thinning to a particular level of stand density.

An Equation for Estimating Total Volume of Both Stands and Single Trees of Black Spruce

1983 ◽  
Vol 59 (1) ◽  
pp. 26-29 ◽  
Author(s):  
F. Evert
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Direct Reference ◽  
Individual Tree ◽  
Stand Volume ◽  
Volume Equation ◽  
The Individual ◽  
Individual Trees

A stand volume equation is presented for black spruce (Picea mariana (Mill.)B.S.P.), based on a sample of 785 felled trees. To ensure that the equation will provide accurate estimates of the volume of both variously stocked stands and of individual trees, stand volume was expressed as the sum of individual tree volumes without direct reference to the size of the area that the trees occupy. The equation will reduce the problem of forecasting stand volume to the simpler problem of forecasting separately the individual components in the stand-volume equation.

scholarly journals Optimized Surgical Strategy for Adult Spinal Deformity: Quantitative Lordosis Correction versus Lordosis Morphology

2021 ◽  
Vol 10 (9) ◽  
pp. 1867
Author(s):  
Sang-Kyu Im ◽  
Ki Young Lee ◽  
Hae Seong Lim ◽  
Dong Uk Suh ◽  
Jung-Hee Lee
Keyword(s):  
Regression Analysis ◽  
Linear Regression ◽  
Correlation Analysis ◽  
Sagittal Alignment ◽  
Adult Spinal Deformity ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Optimal Alignment ◽  
Stepwise Multiple Linear Regression

Background: In surgical correction of adult spinal deformity (ASD), pelvic incidence (PI)-lumbar lordosis (LL) plays a key role to restore normal sagittal alignment. Recently, it has been found that postoperative lordosis morphology act as an important factor in preventing mechanical complications. However, there have been no studies on the effect of postoperative lordosis morphology on the restoration of sagittal alignment. The primary objective of this study was to evaluate the effect of postoperative lordosis morphology on achievement of optimal sagittal alignment. The secondary objective was to find out which radiographic or morphologic parameter affects sagittal alignment in surgical correction of ASD. Methods: 228 consecutive patients with lumbar degenerative kyphosis who underwent deformity correction and long-segment fixation from T10 to S1 with sacropelvic fixation and follow-up over 2 years were enrolled. Patients were divided according to whether optimal alignment was achieved (balanced group) or not (non-balanced group) at last follow-up. We analyzed the differences of postoperative radiographic parameters and morphologic parameters between two groups. Correlation analysis and stepwise multiple linear regression analysis was performed to predict the effect of PI-LL and morphologic parameters on the sagittal vertical axis (SVA). Results: Of 228 patients, 195 (85.5%) achieved optimal alignment at last follow-up. Two groups significantly differed in postoperative and last follow-up LL (p < 0.001 and p = 0.028, respectively) and postoperative and last follow-up PI-LL (p < 0.001 and p = 0.001, respectively). Morphologic parameters did not significantly differ between the two groups except lower lordosis arc angle (=postoperative sacral slope). In correlation analysis and stepwise multiple linear regression analysis, postoperative PI-LL was the only parameter which had significant association with last follow-up SVA (R2 = 0.134, p < 0.001). Morphologic parameters did not have any association with last follow-up SVA. Conclusions: When planning spine reconstruction surgery, although considering postoperative lordosis morphology is necessary, it is still very important considering proportional lordosis correction based on individual spinopelvic alignment (PI-LL) to achieve optimal sagittal alignment.

scholarly journals A Comparative Study of the Peak Expiratory Flow Rate of Indian and Nepalese Young Adults in a Teaching Institute

2009 ◽  
Vol 47 (169) ◽  
Author(s):  
Parthasarathi Debray ◽  
B M Shreevatsa ◽  
R B MG ◽  
T K Sen ◽  
S Roy ◽  
...  
Keyword(s):  
Young Adults ◽  
Linear Regression ◽  
Multiple Linear Regression ◽  
Adult Population ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Prediction Equation ◽  
Regression Equation ◽  
Stepwise Multiple Linear Regression ◽  
The Mean

Peak expiratory fl ow rate (PEFR) measurement is the easiest and cheapest method to evaluaterespiratory functions. So, the study was carried out to evaluate PEFR of healthy Nepalese adults andcompare their values with healthy Indian counterparts to know whether Indian prediction equationsfor PEFR can be used for Nepalese adult population or not.One hundred twenty-three healthy, young, non smoker adult Indian (64: 28 Males, 36 Females) andNepalese (59: 32 Males, 27 Females) medical students of 18 to 20 years of age participated in the study.The mean PEFR of Indian (male: 490.4 liter/min, female: 386.0 liter/min) and Nepalese (male: 485.9liter/min, Female: 365.2 liter/min) young adults were found to have no signifi cant differences.As there is no signifi cant difference in the mean PEFR of Indian and Nepalese young adults, predictionequations made for Indian adults can be used to predict PEFR of Nepalese subjects. Therefore, anattempt has been made to formulate a regression equation from the combined Indian and Nepalesesubjects. A stepwise, multiple, linear, regression analysis was performed for this purpose. The analysisshowed that height is the best predictor for PEFR in the present study. The regression equation basedon height for the combined Indian and Nepalese young adults is calculated as: PEFR = 5.687 × Height(cm) – 495.787. However, a stepwise, multiple, linear, regression equation with residual analysisfor the best fi t model was performed to formulate prediction equation for PEFR and this showed achange of the earlier regression equation to PEFR = 5.930 × Height (cm) – 536.131.Keywords: Peak expiratory fl ow rate, peak fl ow meter, prediction equation, spirometry, youngadults

scholarly journals Empowering Forest Owners with Simple Volume Equations for Poplar Plantations in the Órbigo River Basin (NW Spain)

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 124
Author(s):  
Roberto Blanco ◽  
Juan A. Blanco
Keyword(s):  
River Basin ◽  
Hybrid Poplar ◽  
Volume Growth ◽  
Forest Owners ◽  
Individual Tree ◽  
Average Growth ◽  
Volume Increment ◽  
Annual Volume ◽  
Poplar Plantations ◽  
Volume Equations

Hybrid poplar plantations are becoming increasingly important as a source of income for farmers in northwestern Spain, as rural depopulation and farmers aging prevent landowners from planting other labor-intensive crops. However, plantation owners, usually elderly and without formal forestry background, lack of simple tools to estimate the size and volume of their plantations by themselves. Therefore, farmers are usually forced to rely on the estimates made by the timber companies that are buying their trees. With the objective of providing a simple, but empowering, tool for these forest owners, simple equations based only on diameter were developed to estimate individual tree volume for the Órbigo River basin. To do so, height and diameter growth were measured for 10 years (2009–2019) in 404 trees growing in three poplar plantations in Leon province. An average growth per tree of 1.66 cm year−1 in diameter, 1.52 m year−1 in height, and 0.03 m3 year−1 in volume was estimated, which translated into annual volume increment of 13.02 m3 ha−1 year−1. However, annual volume increment was different among plots due to their fertility, with two plots reaching maximum volume growth around 11 years since planting and another at 13 years, encompassing the typical productivity range in plantations in this region. Such data allowed developing simple but representative linear, polynomial and power equations to estimate volume explaining 93%–98% of the observed variability. Such equations can be easily implemented in any cellphone with a calculator, allowing forest owners to accurately estimate their timber existences by using only a regular measuring tape to measure tree diameter. However, models for height were less successful, explaining only 75%–76% of observed variance. Our approach to generate simplified volume equations has shown to be viable for poplar, but it could be applied to any species for which several volume equations are available.

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