scholarly journals Dynamics of tree species composition and characteristics of available space utilization in the natural forest of the National Nature Reserve Hrončokovský Grúň

2008 ◽  
Vol 54 (No. 11) ◽  
pp. 497-508 ◽  
Author(s):  
M. Saniga ◽  
M. Balanda
Keyword(s):  
Tree Species ◽  
Strong Correlation ◽  
Developmental Stages ◽  
Correlation Coefficients ◽  
Stem Volume ◽  
Total Size ◽  
Virgin Forest ◽  
Advanced Phase ◽  
Entire Height ◽  
Diameter Structure

The paper deals with changes in the diameter structure of particular tree species as well as with the selected production characteristics in the mixed virgin forest Hrončokovský Grúň. The object of the analysis was the diameter structure of particular tree species in developmental stages of virgin forest. The data were collected in the years 1972, 1982, 1992 and 2002 on permanent research plots 71.5 × 70 m (0.5 ha) in size. Diameter frequencies for particular tree species were approximated with the curves. The goal was to evaluate their mortality or vitality according to the strength of the correlation in developmental stages of the virgin forest. A strong correlation was confirmed in the advanced phase of the growth stage, whereas the strongest correlation was recorded for the ash. Beech as a virgin forest bearer had a medium strong correlation. For the advanced phase of the optimum stage lower values of the correlation coefficients were determined for all tree species. The growth vitality and thus lower mortality was characteristic of maple and ash. Beech as a structure bearer is characterized by higher mortality and therefore a weaker correlation. In the breakdown stage the highest mortality was found for the fir, which is confirmed by the lowest value of the correlation coefficient. In the advanced phase of the optimum stage the highest mortality was recorded for the beech. The analysis of growth and production relationships was conducted on the transects of 3 permanent research plots 10 × 71.5 m in size (i.e. total size of 2,145 m<sup>2</sup>). The analysis of the growth relationships between the crown and stem volume confirmed a strong correlation for beech and fir despite the fact they are present in the entire height profile of the virgin forest. The reason is that both of them are the shade-tolerant tree species. High correlation coefficients for maple and ash (<I>R</I> = 0.82 and <I>R</I> = 0.84) are the evidence of a distinctive influence of the assimilatory apparatus on the stem volume. The reason is the fact that both tree species are situated in the upper tree layer and have relatively enough space for the crown growth. The productive utilization of the crown space in the virgin forest confirmed the dominance of the beech as a structure bearer.

scholarly journals Structural diversity change and regeneration processes of the Norway spruce natural forest in Babia hora NNR in relation to altitude

2012 ◽  
Vol 52 (No. 9) ◽  
pp. 399-409 ◽  
Author(s):  
J. Vorčák ◽  
J. Merganič ◽  
M. Saniga
Keyword(s):  
Norway Spruce ◽  
Growth Stage ◽  
Dead Wood ◽  
Developmental Stages ◽  
Mineral Soil ◽  
Structural Diversity ◽  
Virgin Forest ◽  
Diameter Structure ◽  
Regeneration Processes ◽  
Diameter Differentiation

The research was focused on exploring the dynamics and forms of regeneration processes and structural diversity of the Norway spruce virgin forest in Babia hora NNR in relation to altitude. In each developmental stage <br />19 sample plots were established. The structural diversity was assessed by the indices proposed by Clark and Evans (1954), F&uuml;ldner (1995) and Jaehne and Dohrenbusch (1997). Concerning the spatial distribution of the trees in the virgin forest no tendency to their clustering with the increasing altitude was found in the zones below 1,460&nbsp;m. The influence of the altitude was confirmed in the zone above 1,461&nbsp;m where the groups of &ldquo;family spruces&rdquo; are typical. Diameter differentiation was significantly higher in the growth stage. Evaluation of this attribute in terms of the altitude detected significant diameter differentiation at an altitude below 1,260&nbsp;m in the growth stage. According to the F&uuml;ldner index the virgin forest has generally medium differentiated diameter structure. According to the complex index by Jaehne and&nbsp;Dohrenbusch (1997) the differentiation of the virgin forest decreases with the ascending altitude up to 1,460&nbsp;m, where the compact forest ends. Evaluation of the seedbed revealed that 46.2% of the naturally regenerated individuals were growing on mineral soil, 52.4% on dead wood and 1.4% on wind-thrown roots. Regarding the developmental stages 46% of the individuals were found in growth stage, 23% in optimum stage and 31% in breakdown stage.

scholarly journals Constructing single-entry stem volume models for four economically important tree species of Greece

2021 ◽  
Vol 48 (2) ◽  
pp. 136-146
Author(s):  
Panagiotis P. Koulelis ◽  
Kostas Ioannidis
Keyword(s):  
Tree Species ◽  
National Level ◽  
Sustainable Use ◽  
Information Criterion ◽  
Cost Effective ◽  
Volume Estimation ◽  
Stem Volume ◽  
Nonlinear Regression Models ◽  
Cubic Polynomial ◽  
Two Parameter

Abstract Three different nonlinear regression models were tested for their ability to predict stem volume for economically important native tree species in Greece. Τhe models were evaluated using adjusted R square (Adj Rsqr) root mean square error (RMSE) and Akaike information criterion (AICc), where necessary. In general, the quadratic polynomial and cubic polynomial models and the two-parameter power models fit the data well. Although the two-parameter power function fit best for fir, oak, and beech trees, the cubic polynomial model produced the best fit statistics for black pine. Making forest inventory estimates often involves predicting tree volumes from only the diameter at breast height (DBH) and merchantable height. This study covers important gaps in fast and cost-effective methods for calculating the volume of tree species at national level. However, the increasing need for reliable estimates of inventory components and volume changes requires more accurate volume estimation techniques. Especially when those estimates concern the national inventory, those models must be validated using an entire range of age/diameter and site classes of each species before their extended use across the country to promote the sustainable use of forest resources.

scholarly journals COMPATIBLE STEM VOLUME AND TAPER EQUATIONS FOR FIVE MAJOR TREE SPECIES IN NORTHEAST CHINA

2020 ◽  
Vol 18 (5) ◽  
pp. 6295-6308
Author(s):  
A. HUSSAIN ◽  
M.K. SHAHZAD ◽  
S.D. XIN ◽  
L.C. JIANG
Keyword(s):  
Tree Species ◽  
Northeast China ◽  
Stem Volume ◽  
Taper Equations

Anterior Cruciate Ligament Tibial Footprint Size as Measured on Magnetic Resonance Imaging: Does It Reliably Predict Actual Size?

2018 ◽  
Vol 46 (8) ◽  
pp. 1877-1884 ◽  
Author(s):  
Seong Hwan Kim ◽  
Han-Jun Lee ◽  
Yong-Beom Park ◽  
Han-Sol Jeong ◽  
Chul-Won Ha
Keyword(s):  
Anterior Cruciate Ligament ◽  
Magnetic Resonance ◽  
Strong Correlation ◽  
Cruciate Ligament ◽  
Correlation Coefficients ◽  
Actual Measurement ◽  
Actual Length ◽  
Tibial Footprint ◽  
Anterior Cruciate ◽  
Actual Size

Background: Measuring the size of the anterior cruciate ligament (ACL) tibial footprint on magnetic resonance image (MRI) is common for preoperative planning of ACL reconstruction. However, the accuracy of such measurement has not been well documented. Purpose: To investigate whether the actual size of the ACL tibial footprint could be predicted by its measurement on MRI and to develop equations to improve the accuracy of predicting the actual size based on MRI measurement. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: A total of 164 patients with normal visualized ACL in gross evaluation and MRI were included (mean ± SD age, 67.3 ± 8.3 years). Cases with ACL tear, severe mucoid degeneration, osteophyte around the ACL tibial insertion, or intervals >12 months between MRI and actual measurement were excluded. The ACL tibial footprint was carefully dissected and measured during total knee arthroplasty. The length of the ACL tibial footprint on MRI was measured on a sagittal image, while the width was measured on an oblique coronal image. For the ACL tibial footprint, the association between measurement on MRI and actual measurement of length and width was analyzed via univariable and multivariable regression analyses. Reliability of measurements on MRI was also evaluated. Results: The length and width of the ACL tibial footprint as measured on MRI showed strong correlation with the actual length and width (coefficients: ρ = 0.904 and ρ = 0.808, respectively). There were differences between ACL size on MRI and its actual size: length, 12.4 mm (range, 9.7-15.3 mm) vs 13.8 (10.6-17.8) ( P < .001); width, 8.8 mm (range, 7.0-12.1 mm) vs 7.2 (5.8-10.4) ( P < .001). Based on sex, there were also differences between the size per MRI and the actual size ( P < .001 for all): length in men, 12.6 mm (range, 10.9-15.3 mm) vs 14.2 (12.3-17.8); length in women, 12.4 mm (range, 9.7-14.5 mm) vs 13.7 (10.6-15.8); width in men, 9.3 mm (range, 8.0-12.1 mm) vs 7.6 (5.8-10.4); width in women, 8.7 mm (range, 7.0-10.4 mm) vs 7.2 (5.8-9.7). The actual length of the ACL tibial footprint could be predicted by its length on MRI and sex ( R2 = 0.83, P < .001). Similarly, actual width could be predicted by the width on MRI and sex ( R2 = 0.75, P < .001). All intraclass correlation coefficients were >0.8, indicating good reliability. Conclusion: Measurements of the size of the ACL tibial footprint on MRI showed strong correlation with its actual size. Prediction equations showed good concordance correlation coefficients.

scholarly journals The Influence of Distance on Radiant Exposure and Degree of Conversion Using Different Light-Emitting-Diode Curing Units

2019 ◽  
Vol 44 (3) ◽  
pp. E133-E144 ◽  
Author(s):  
AO Al-Zain ◽  
GJ Eckert ◽  
JA Platt
Keyword(s):  
Strong Correlation ◽  
Light Emitting Diode ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Degree Of Conversion ◽  
Light Emitting ◽  
Radiant Exposure ◽  
Light Curing ◽  
Irradiance Data ◽  
Resin Curing

SUMMARY Objectives: To investigate the influence of curing distance on the degree of conversion (DC) of a resin-based composite (RBC) when similar radiant exposure was achieved using six different light-curing units (LCUs) and to explore the correlation among irradiance, radiant exposure, and DC. Methods and Materials: A managing accurate resin curing-resin calibrator system was used to collect irradiance data for both top and bottom specimen surfaces with a curing distance of 2 mm and 8 mm while targeting a consistent top surface radiant exposure. Square nanohybrid-dual-photoinitiator RBC specimens (5 × 5 × 2 mm) were cured at each distance (n=6/LCU/distance). Irradiance and DC (micro-Raman spectroscopy) were determined for the top and bottom surfaces. The effect of distance and LCU on irradiance, radiant exposure, and DC as well as their linear associations were analyzed using analysis of variance and Pearson correlation coefficients, respectively (α=0.05). Results: While maintaining a similar radiant exposure, each LCU exhibited distinctive patterns in decreased irradiance and increased curing time. No significant differences in DC values (63.21%-70.28%) were observed between the 2- and 8-mm distances, except for a multiple-emission peak LCU. Significant differences in DC were detected among the LCUs. As expected, irradiance and radiant exposure were significantly lower on the bottom surfaces. However, a strong correlation between irradiance and radiant exposure did not necessarily result in a strong correlation with DC. Conclusions: The RBC exhibited DC values &gt;63% when the top surface radiant exposure was maintained, although the same values were not reached for all lights. A moderate-strong correlation existed among irradiance, radiant exposure, and DC.

scholarly journals How to calculate the ASDAS based on C-reactive protein without individual questions from the BASDAI: the BASDAI-based ASDAS formula

Rheumatology ◽  
2019 ◽  
Vol 59 (7) ◽  
pp. 1545-1549 ◽  
Author(s):  
I Concepcion Aranda-Valera ◽  
Juan L Garrido-Castro ◽  
Lourdes Ladehesa-Pineda ◽  
Janitzia Vazquez-Mellado ◽  
Pedro Zarco ◽  
...  
Keyword(s):  
Disease Activity ◽  
Strong Correlation ◽  
Validation Cohort ◽  
Linear Regression Analysis ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
National Registry ◽  
Derivation Cohort ◽  
The Mean ◽  
New Equation

Abstract Objectives To develop a new equation to calculate the Ankylosing Spondylitis Disease Activity Score based on CRP (ASDAS-CRP) using only the BASDAI total score and CRP. Methods Axial SpA (axSpA) patients from the Cordoba Spondyloarthritis Registry cohort were recruited as a derivation cohort, while a retrospective sample from the Spanish Rheumatology Society National Registry of Spondyloarthropathies and Ibero American Spondyloarhtritis Registry registers was used as a validation cohort. We built a new equation based only on the BASDAI and CRP, defining a new formula: the BASDAI-based ASDAS (BASDAS). Linear regression analysis was used to determine the coefficients of the equation in the derivation cohort and it was subsequently validated in the validation cohort. Results A total of 52 axSpA patients in the derivation cohort and 3359 patients in the validation cohort were included. In the derivation cohort, the mean BASDAS [2.24 (s.d. 0.90)] was very similar to the ASDAS-CRP [2.23 (s.d. 0.95)], with a very strong correlation (r = 0.96, P &lt; 0.001). In the validation cohort, the mean BASDAS was 3.31 (s.d. 1.37) and the ASDAS-CRP was 3.19 (s.d. 1.27), which also had a very strong correlation (r = 0.95, P &lt; 0.001). Intraclass correlation coefficients were excellent in both cohorts (0.963 and 0.947, respectively). Conclusion The BASDAS performs similarly to the ASDAS-CRP and can be calculated with only the BASDAI total score and CRP, allowing evaluation of disease activity in retrospective studies where the individual items of the BASDAI are not available.

scholarly journals Estimation of genetic parameters for growth related traits at different stages of development in Paralichthys olivaceus (Temminck & Schlegel, 1846)

2016 ◽  
Vol 63 (3) ◽  
Author(s):  
F. Liu ◽  
S. L. Chen ◽  
L. Wang ◽  
Y. P. Zhang ◽  
Y. S. Tian ◽  
...  
Keyword(s):  
Body Weight ◽  
Growth Stage ◽  
Genetic Parameters ◽  
Developmental Stages ◽  
Growth Traits ◽  
Paralichthys Olivaceus ◽  
Correlation Coefficients ◽  
Breeding Value ◽  
Estimated Breeding Value ◽  
Estimation Of Genetic Parameters

Genetic parameters of growth traits at different growing stages of Paralichthys olivaceus (Temminck and Schlegel, 1846) were estimated using 30 families. The estimates of heritability for body weight at four developmental stages viz., 210, 450, 720 and 830 days of age, varied from 0.12 to 0.37. The heritability at 720 days of age was the lowest and that of 450 days was the highest. The maternal effect was 0.08 at 210 days, 0.03 at 450 days and almost zero (8.89 E-8 and 2.40 E-7) at 720 and 830 days. Correlation coefficients of the estimated breeding value (EBV) and phenotypic value (PV) of body weight at different developmental stages were 0.470-0.803, which were highly significant (p<0.01). Correlation of estimated breeding value (EBV) and phenotypic value (PV) was the highest at 210 days of age and the lowest at 720 days. Genetic correlation among the four stages showed large variation (0.339-0.811), which were highly significant except that of 210 and 830 days. The value and accuracy of estimating genetic parameters for growth traits at different stages was different. Therefore, the growth stage should be taken into account when designing a breeding program for growth traits in P. olivaceus.

scholarly journals Evaluation of stem rot in 339 Bornean tree species: implications of size, taxonomy, and soil-related variation for aboveground biomass estimates

2015 ◽  
Vol 12 (19) ◽  
pp. 5735-5751 ◽  
Author(s):  
K. D. Heineman ◽  
S. E. Russo ◽  
I. C. Baillie ◽  
J. D. Mamit ◽  
P. P.-K. Chai ◽  
...  
Keyword(s):  
Tropical Forests ◽  
Wood Density ◽  
Aboveground Biomass ◽  
Tree Species ◽  
Tree Size ◽  
Stem Rot ◽  
Stem Volume ◽  
Data Sets ◽  
Related Variation ◽  
Source Of Error

Abstract. Fungal decay of heart wood creates hollows and areas of reduced wood density within the stems of living trees known as stem rot. Although stem rot is acknowledged as a source of error in forest aboveground biomass (AGB) estimates, there are few data sets available to evaluate the controls over stem rot infection and severity in tropical forests. Using legacy and recent data from 3180 drilled, felled, and cored stems in mixed dipterocarp forests in Sarawak, Malaysian Borneo, we quantified the frequency and severity of stem rot in a total of 339 tree species, and related variation in stem rot with tree size, wood density, taxonomy, and species' soil association, as well as edaphic conditions. Predicted stem rot frequency for a 50 cm tree was 53 % of felled, 39 % of drilled, and 28 % of cored stems, demonstrating differences among methods in rot detection ability. The percent stem volume infected by rot, or stem rot severity, ranged widely among trees with stem rot infection (0.1–82.8 %) and averaged 9 % across all trees felled. Tree taxonomy explained the greatest proportion of variance in both stem rot frequency and severity among the predictors evaluated in our models. Stem rot frequency, but not severity, increased sharply with tree diameter, ranging from 13 % in trees 10–30 cm DBH to 54 % in stems ≥ 50 cm DBH across all data sets. The frequency of stem rot increased significantly in soils with low pH and cation concentrations in topsoil, and stem rot was more common in tree species associated with dystrophic sandy soils than with nutrient-rich clays. When scaled to forest stands, the maximum percent of stem biomass lost to stem rot varied significantly with soil properties, and we estimate that stem rot reduces total forest AGB estimates by up to 7 % relative to what would be predicted assuming all stems are composed strictly of intact wood. This study demonstrates not only that stem rot is likely to be a significant source of error in forest AGB estimation, but also that it strongly covaries with tree size, taxonomy, habitat association, and soil resources, underscoring the need to account for tree community composition and edaphic variation in estimating carbon storage in tropical forests.

scholarly journals Comparison of practical methods in clinical sites for estimating cerebral blood flow during balloon test occlusion

2019 ◽  
Vol 131 (5) ◽  
pp. 1430-1436 ◽  
Author(s):  
Shoichi Tani ◽  
Hirotoshi Imamura ◽  
Katsunori Asai ◽  
Kampei Shimizu ◽  
Hidemitsu Adachi ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Strong Correlation ◽  
Sagittal Plane ◽  
Correlation Coefficients ◽  
Trend Line ◽  
Time To Peak ◽  
Balloon Test Occlusion ◽  
Perfusion Studies ◽  
Spatial Positioning

OBJECTIVEThe authors sought to compare methods of measurement for venous phase delay (VPD) or mean stump pressure (MSTP) to rank their potential to predict ischemic tolerance during balloon test occlusion in the internal carotid artery, exploring a more correlative and convenient way to measure cerebral blood flow (CBF) that could be utilized even in the acute phase or in institutions not adequately equipped to measure CBF during the test.METHODSX-ray angiography perfusion analysis using diagnostic digital subtraction angiography (DSA) equipment enables 1-step examination (without any room-to-room transfer of patients) to measure CBF, VPD, and MSTP completely simultaneously, which has not been accomplished by any previous perfusion studies.RESULTSThis analysis was applied to 17 patients and resulted in successful estimation of all 3 parameters in each case. The average VPD of several cortical veins had a strong correlation with relative CBF (rCBF) between bilateral hemispheres with a correlation coefficient of 0.89443, a correlation as strong as that (0.90357) of the “approximate VPD,” which is interpreted based on the trend line of the scatterplot of the time to peak contrast opacification in cortical veins and their spatial positioning from the median sagittal plane. MSTP and classic visual determination of VPD have weaker correlation coefficients with rCBF (0.56119 and 0.70048, respectively). Overall, subjective visual determination in combination with the calculation of the trend line to estimate VPD provided a considerably strong correlation with rCBF (R = 0.86660) without any dedicated software or hardware.CONCLUSIONSVPD has a stronger correlation with rCBF than MSTP. rCBF could be successfully predicted on common DSA equipment, even by visual determination without expensive software, if the trend line is adopted for processing to estimate VPD.

Postgraduate publishing output in pediatric neurosurgery: correlation with fellowship site and individual scholars

2019 ◽  
Vol 24 (3) ◽  
pp. 343-351 ◽  
Author(s):  
Sonia Ajmera ◽  
Ryan P. Lee ◽  
Andrew Schultz ◽  
David S. Hersh ◽  
Jacob Lepard ◽  
...  
Keyword(s):  
Strong Correlation ◽  
Pearson Correlation ◽  
Publication Output ◽  
Correlation Coefficients ◽  
Pediatric Neurosurgery ◽  
Fellowship Training ◽  
Academic Productivity ◽  
Hirsch Index ◽  
Citation Data ◽  
Fellowship Program

OBJECTIVEThe objective of this study was to analyze the publication output of postgraduate pediatric neurosurgery fellows for a 10-year period as well as identify 25 individual highly productive pediatric neurosurgeons. The correlation between academic productivity and the site of fellowship training was studied.METHODSPrograms certified by the Accreditation Council for Pediatric Neurosurgery Fellowships that had 5 or more graduating fellows from 2006 to 2015 were included for analysis. Fellows were queried using Scopus for publications during those 10 years with citation data through 2017. Pearson correlation coefficients were calculated, comparing program rankings of faculty against fellows using the revised Hirsch index (r-index; primary) and Hirsch index (h-index; secondary). A list of 25 highly accomplished individual academicians and their fellowship training locations was compiled.RESULTSSixteen programs qualified with 152 fellows from 2006 to 2015; 136 of these surgeons published a total of 2009 articles with 23,735 citations. Most publications were pediatric-specific (66.7%) clinical articles (93.1%), with middle authorship (55%). Co-investigators were more likely from residency than fellowship. There was a clustering of the top 7 programs each having total publications of around 120 or greater, publications per fellow greater than 12, more than 1200 citations, and adjusted ir10 (revised 10-year institutional h-index) and ih10 (10-year institutional h-index) values of approximately 2 or higher. Correlating faculty and fellowship program rankings yielded correlation coefficients ranging from 0.53 to 0.80. Fifteen individuals (60%) in the top 25 (by r5 index) list completed their fellowship at 1 of these 7 institutions.CONCLUSIONSApproximately 90% of fellowship-trained pediatric neurosurgeons have 1 or more publications, but the spectrum of output is broad. There is a strong correlation between where surgeons complete their fellowships and postgraduate publications.

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