Use of the correlation coefficient between plots in order to improve the accuracy of forest inventories

Forest inventories are usually compiled without taking into account the existing correlations between sampling units, which is debatable particularly where the calculations involve environmental variables. When the potential correlations between sampling units are overlooked, the accuracy of such inventories becomes distorted in terms of the confidence interval range for the variable of interest, which is volume in cubic meters. The magnitude and form of such distortion will vary according to the correlation intensity between sampling units. This study aimed to present an analysis of the addition of the correlation coefficient to the calculation of the variance of the mean in a systematic sampling procedure of a native forest population or area, as well as its impact on the accuracy of the resulting estimates, with the assumption of independence between sampling units and with the addition of a correlation between sampling units as suggested by Cochran. Results revealed that, where the correlation coefficient was added to the variance of the mean formula, it increased inventory accuracy by about 14.3%, leading to the conclusion that such an effect will occur in any forest inventory being compiled for any forest population or area of interest.

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ESTIMATING PRECISION OF SYSTEMATIC SAMPLING IN FOREST INVENTORIES

Ciência e Agrotecnologia ◽

10.1590/s1413-70542015000100002 ◽

2015 ◽

Vol 39 (1) ◽

pp. 15-22 ◽

Cited By ~ 3

Author(s):

José Marcio de Mello ◽

Henrique Ferraço Scolforo ◽

Marcel Régis Raimundo ◽

José Roberto Soares Scolforo ◽

Antônio Donizette de Oliveira ◽

...

Keyword(s):

Correlation Coefficient ◽

Forest Inventory ◽

Sampling Rate ◽

Sampling Technique ◽

Systematic Sampling ◽

Native Vegetation ◽

Forest Inventories ◽

Key Factor ◽

The Mean ◽

The Impact

The sampling technique commonly used in forest inventories is the systematic sampling. This study aimed to evaluate the estimator of the variance of the mean proposed by Cochran for a systematic sampling technique in forests with high and low percentages of the sampled area. The study areas comprised native vegetation in Minas Gerais. To assess the efficiency of the estimators in situations involving high sampling rates (determined as the percentage of the area sampled), a fragment where a census was conducted was used. The remaining fragments comprised situations involving low sampling rates, and for these fragments, inventory accuracy was determined using the Cochran estimator. As a result it was observed, in the fragment where the census was conducted, that the structure of the correlation coefficient proposed by Cochran remained approximately constant for the area, and to the extent that sampling rate reduced, the impact of the Cochran estimator on the inventory accuracy decreased. For the fragments with a low sampling rate, it could be inferred that the sampling rate was a key factor for the correlation proposed by Cochran to have an impact on the forest inventory accuracy. The use of this estimator is indicated for fragments with a sampling rate greater than 10% of the area.

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Impact of training on different observers in forest inventory

Banko Janakari ◽

10.3126/banko.v31i1.37338 ◽

2021 ◽

Vol 31 (1) ◽

pp. 12-22

Author(s):

P. Paudel ◽

P. Beckschäfer ◽

C. Kleinn

Keyword(s):

Forest Inventory ◽

Tree Height ◽

Measurement Procedure ◽

Horizontal Distance ◽

Limited Information ◽

Quality Of Data ◽

Height Measurement ◽

Forest Inventories ◽

The Mean ◽

Level Of Training

Observers with different experience levels are involved in the measurement of large number of sample plots during forest inventories, particularly in national forest inventories. However, limited information exist on the quality of data produced by different observers in forest inventory after certain levels of training. This study tries to evaluate the measurement error in forest inventory associated with observers' experience after initial and field-based training for measuring the most fundamental variables- DBH (cm), total tree height (m), and horizontal distance (m) together with bearing (azimuth) to tree from the plot-centre. On completing the second level of training, the mean of the differences in DBH measurement decreased for both the ‘experienced’ and ‘inexperienced’ groups. The mean of the differences in height measurement in the case of the experienced observers was very low as compared to the inexperienced ones. However, the mean of the differences in azimuth measurement showed that the experienced groups were overestimating by at least 1 degree. There was no trend in deviation of measurement for all four variables regardless of tree size. The decrease in the mean and error of differences in measurements after second training showed that field-based training with supervision and training on the use of instruments at laboratories were required for inexperienced surveyors whereas update in working and measurement procedure would be sufficient for the experienced ones.

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Comparison of Lead Levels in Human Permanent Teeth from Strasbourg, Mexico City, and Rural Zones of Alsace

Journal of Dental Research ◽

10.1177/00220345900690011601 ◽

1990 ◽

Vol 69 (1) ◽

pp. 90-93 ◽

Cited By ~ 20

Author(s):

R.M. Frank ◽

M.L. Sargentini-Maier ◽

J.C. Turlot ◽

M.J.F. Leroy

Keyword(s):

Mexico City ◽

Young Patients ◽

Fluorescence Analysis ◽

Sampling Procedure ◽

Permanent Teeth ◽

Systematic Sampling ◽

Dental Hard Tissues ◽

Hard Tissues ◽

Permanent Molars ◽

The Mean

A comparative study of the mean lead concentrations in enamel and dentin of human premolars and permanent molars was conducted by means of a systematic sampling procedure with energy-dispersive x-ray fluorescence analysis. In a first series of analyses, no significant statistical differences in mean lead concentrations at various levels of enamel and dentin were noted between young patients of Strasbourg and those of small villages of Alsace, nor between elderly patients living in these two locations, despite the fact that motor traffic was significantly lower in the rural zones. However, in both locations, a significantly higher concentration of lead was observed in enamel and dentin in relation to age. In a second series of analyses, the mean lead concentrations of both dental hard tissues of premolars and permanent molars of young individuals from Strasbourg, rural Alsace, and Mexico City were compared. Significantly higher mean lead concentrations were found in enamel and dentin samples from Mexico City. This was most evident for inner coronal dentin (5.7 and 6.1 times greater than in teeth of Strasbourg and rural zones of Alsace, respectively) and for pulpal root dentin (6.9 and 8.9 times greater than in teeth of Strasbourg and rural zones of Alsace). It is proposed that the higher lead concentrations are related to the higher lead content of motor gasoline and to more intense traffic conditions. The dental hard tissues appear to be of value for the study of environmental lead pollution.

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A sampling design for a large area forest inventory: case Tanzania

Canadian Journal of Forest Research ◽

10.1139/cjfr-2013-0490 ◽

2014 ◽

Vol 44 (8) ◽

pp. 931-948 ◽

Cited By ~ 46

Author(s):

Erkki Tomppo ◽

Rogers Malimbwi ◽

Matti Katila ◽

Kai Mäkisara ◽

Helena M. Henttonen ◽

...

Keyword(s):

Land Use ◽

Forest Inventory ◽

Sampling Design ◽

National Forest Inventory ◽

Sampling Errors ◽

Large Area ◽

Forest Inventories ◽

Food And Agriculture ◽

Area Of Interest ◽

Food And Agriculture Organization

Methods for constructing a sampling design for large area forest inventories are presented. The methods, data sets used, and the procedures are demonstrated in a real setting: constructing a sampling design for the first national forest inventory for Tanzania. The approach of the paper constructs a spatial model of forests, landscape, and land use. Sampling errors of the key parameters as well as the field measurement costs of the inventory were estimated using sampling simulation on data. Forests and land use often vary within a country or an area of interest, implying that stratified sampling is an efficient inventory design. Double sampling for stratification was taken for the statistical framework. The work was motivated by the approach used by The Food and Agriculture Organization of the United Nations (FAO) in supporting nations to establish forest inventories. The approach taken deviates significantly from the traditional FAO approaches, making it possible to calculate forest resource estimates at the subnational level without increasing the costs.

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THE EFFECT OF ALTERATION OF THYROXINE BINDING CAPACITY ON THE DIALYZABLE AND ABSOLUTE FRACTIONS OF TRIIODOTHYRONINE IN CIRCULATION

Acta Endocrinologica ◽

10.1530/acta.0.0720265 ◽

1973 ◽

Vol 72 (2) ◽

pp. 265-271 ◽

Cited By ~ 6

Author(s):

J. H. Dussault ◽

D. A. Fisher ◽

J. T. Nicoloff ◽

V. V. Row ◽

R. Volpe

Keyword(s):

Correlation Coefficient ◽

Inverse Relationship ◽

Binding Capacity ◽

Hormone Concentration ◽

Thyroxine Binding Globulin ◽

Serum Thyroxine ◽

A Value ◽

The Mean ◽

Male Subjects ◽

Female Subjects

ABSTRACT In order to determine the effect of alterations in binding capacity of thyroxine binding globulin (TBG) on triiodothyronine (T3) metabolism, studies were conducted in 10 patients with idiopathically low (7 subjects) or elevated (3 subjects) TBG levels and 10 subjects given norethandrolone (7 male subjects) or oestrogen (3 female subjects). Measurements of serum thyroxine (T4) concentration, maximal T4 binding capacity, serum T3 concentration and per cent dialyzable T3 were conducted. Serum T3 was measured both by chemical and radioimmunoassay methods. In patients with idiopathically low TBG, the mean serum T4 concentration was low (2.4 μg/100 ml), the mean serum T3 level low (55 ng/100 ml), the mean per cent dialyzable T3 increased (0.52%), and the calculated free T3 concentration normal (186 pg/100 ml). In patients with idiopathically high TBG levels the mean T4 concentration was high (10.3 μg/100 ml), the mean T3 level slightly elevated (127 ng/100 ml), the% dialyzable T3 low (0.10%) and the calculated free T3 concentration low normal (123 pg/100 ml). The correlation coefficient between the per cent dialyzable T3 and maximal TBG binding capacity in the 20 subjects was 0.68, a value significant at the P < 0.01 level. Thus, alterations in binding capacity of TBG seem to influence T3 and T4 metabolism similarly; the inverse relationship between the % of dialyzable hormone and total hormone concentration tends to keep the absolue levels of free hormones stable.

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Onchocerciasis control in Ghana (1974–2016)

Parasites & Vectors ◽

10.1186/s13071-020-04507-2 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Nana-Kwadwo Biritwum ◽

Dziedzom K. de Souza ◽

Odame Asiedu ◽

Benjamin Marfo ◽

Uche Veronica Amazigo ◽

...

Keyword(s):

Confidence Interval ◽

Vector Control ◽

Control Strategy ◽

Financial Support ◽

Control Programme ◽

Ivermectin Treatment ◽

Mobile Community ◽

The Mean ◽

The Impact ◽

Onchocerciasis Control

Abstract Background The control of onchocerciasis in Ghana started in 1974 under the auspices of the Onchocerciasis Control Programme (OCP). Between 1974 and 2002, a combination of approaches including vector control, mobile community ivermectin treatment, and community-directed treatment with ivermectin (CDTI) were employed. From 1997, CDTI became the main control strategy employed by the Ghana OCP (GOCP). This review was undertaken to assess the impact of the control interventions on onchocerciasis in Ghana between 1974 and 2016, since which time the focus has changed from control to elimination. Methods In this paper, we review programme data from 1974 to 2016 to assess the impact of control activities on prevalence indicators of onchocerciasis. This review includes an evaluation of CDTI implementation, microfilaria (Mf) prevalence assessments and rapid epidemiological mapping of onchocerciasis results. Results This review indicates that the control of onchocerciasis in Ghana has been very successful, with a significant decrease in the prevalence of infection from 69.13% [95% confidence interval) CI 60.24–78.01] in 1975 to 0.72% (95% CI 0.19–1.26) in 2015. Similarly, the mean community Mf load decreased from 14.48 MF/skin snip in 1975 to 0.07 MF/skin snip (95% CI 0.00–0.19) in 2015. Between 1997 and 2016, the therapeutic coverage increased from 58.50 to 83.80%, with nearly 100 million ivermectin tablets distributed. Conclusions Despite the significant reduction in the prevalence of onchocerciasis in Ghana, there are still communities with MF prevalence above 1%. As the focus of the GOCP has changed from the control of onchocerciasis to its elimination, both guidance and financial support are required to ensure that the latter goal is met.

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Can Health-Promoting Schools Contribute to Better Health Behaviors? Physical Activity, Sedentary Behavior, and Dietary Habits among Israeli Adolescents

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18031183 ◽

2021 ◽

Vol 18 (3) ◽

pp. 1183

Author(s):

Hila Beck ◽

Riki Tesler ◽

Sharon Barak ◽

Daniel Sender Moran ◽

Adilson Marques ◽

...

Keyword(s):

Physical Activity ◽

Health Behavior ◽

Confidence Interval ◽

Health Behaviors ◽

Sedentary Behavior ◽

Dietary Habits ◽

Group Differences ◽

Time Behavior ◽

Health Promoting ◽

The Mean

Schools with health-promoting school (HPS) frameworks are actively committed to enhancing healthy lifestyles. This study explored the contribution of school participation in HPS on students’ health behaviors, namely, physical activity (PA), sedentary behavior, and dieting. Data from the 2018/2019 Health Behavior in School-aged Children study on Israeli adolescents aged 11–17 years were used. Schools were selected from a sample of HPSs and non-HPSs. Between-group differences and predictions of health behavior were analyzed. No between-group differences were observed in mean number of days/week with at least 60 min of PA (HPS: 3.84 ± 2.19 days/week, 95% confidence interval of the mean = 3.02–3.34; non-HPS: 3.93 ± 2.17 days/week, 95% confidence interval of the mean = 3.13–3.38). Most children engaged in screen time behavior for >2 h/day (HPS: 60.83%; non-HPS: 63.91%). The odds of being on a diet were higher among more active children (odds ratio [OR] = 1.20), higher socio-economic status (OR = 1.23), and female (OR = 2.29). HPS did not predict any health behavior. These findings suggest that HPSs did not contribute to health behaviors more than non-HPSs. Therefore, health-promoting activities in HPSs need to be improved in order to justify their recognition as members of the HPS network and to fulfill their mission.

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Evaluating Endoscopic Ipsilateral Endonasal Corridor Approaches to the Anterolateral Wall of the Maxillary Sinus: A Computerized Tomography Study

International Archives of Otorhinolaryngology ◽

10.1055/s-0041-1724092 ◽

2021 ◽

Author(s):

Navarat Vatcharayothin ◽

Pornthep Kasemsiri ◽

Sanguansak Thanaviratananich ◽

Cattleya Thongrong

Keyword(s):

Confidence Interval ◽

Maxillary Sinus ◽

Inferior Turbinate ◽

Radial Access ◽

Sinus Wall ◽

Nasal Floor ◽

Significant Difference ◽

Anterolateral Wall ◽

The Mean ◽

Maxillary Sinuses

Abstract Introduction The endoscopic access to lesions in the anterolateral wall of the maxillary sinus is a challenging issue; therefore, the evaluation of access should be performed. Objective To assess the accessibility of three endoscopic ipsilateral endonasal corridors. Methods Three corridors were created in each of the 30 maxillary sinuses from 19 head cadavers. Accessing the anterolateral wall of the maxillary sinus was documented with a straight stereotactic navigator probe at the level of the nasal floor and of the axilla of the inferior turbinate. Results At level of the nasal floor, the prelacrimal approach, the modified endoscopic Denker approach, and the endoscopic Denker approach allowed mean radial access to the anterolateral maxillary sinus wall of 42.6 ± 7.3 (95% confidence interval [CI]: 39.9–45.3), 56.0 ± 6.1 (95%CI: 53.7–58.3), and 60.1 ± 6.2 (95%CI: 57.8–62.4), respectively. Furthermore, these approaches provided more lateral access to the maxillary sinus at the level of the axilla of the inferior turbinate, with mean radial access of 45.8 ± 6.9 (95%CI: 43.3–48.4) for the prelacrimal approach, 59.8 ± 4.7 (95% CI:58.1–61.6) for the modified endoscopic Denker approach, and 63.6 ± 5.5 (95%CI: 61.6–65.7) for the endoscopic Denker approach. The mean radial access in each corridor, either at the level of the nasal floor or the axilla of the inferior turbinate, showed a statistically significant difference in all comparison approaches (p < 0.05). Conclusions The prelacrimal approach provided a narrow radial access, which allows access to anteromedial lesions of the maxillary sinus, whereas the modified endoscopic Denker and the endoscopic Denker approaches provided more lateral radial access and improved operational feasibility on far anterolateral maxillary sinus lesions.

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On the error of estimates from successive forest inventories with SPR

Canadian Journal of Forest Research ◽

10.1139/x87-076 ◽

1987 ◽

Vol 17 (5) ◽

pp. 442-447

Author(s):

Tiberius Cunia

Keyword(s):

Forest Inventory ◽

Random Sampling ◽

Regression Coefficients ◽

Partial Replacement ◽

Forest Inventories ◽

Continuous Forest ◽

Regression Functions ◽

The Given ◽

Linear Regressions ◽

Continuous Forest Inventory

The approach used by Cunia to combine the error from sample plots with the error from volume or biomass tables when Continuous Forest Inventory (CFI) estimates of current values and growth are calculated is extended to the CFI systems using Sampling with Partial Replacement (SPR). The formulae are derived for the case of SPR on two measurement occasions when (i) volume or biomass tables are constructed from linear regressions for which an estimate of the covariance matrix of the regression coefficients is known, and (ii) the sample plots or points are selected by random sampling independently of the given volume or biomass regression functions.

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Effect of Posterior Tibial Slope Change on Postoperative Range of Motion and Clinical Outcomes after Posterior Cruciate-Substituting Total Knee Arthroplasty

The Journal of Knee Surgery ◽

10.1055/s-0041-1729967 ◽

2021 ◽

Author(s):

O-Sung Lee ◽

Jangyun Lee ◽

Myung Chul Lee ◽

Hyuk-Soo Han

Keyword(s):

Total Knee Arthroplasty ◽

Range Of Motion ◽

Correlation Coefficient ◽

Knee Arthroplasty ◽

Tibial Slope ◽

Posterior Tibial Slope ◽

Posterior Tibial ◽

Clinical Scores ◽

Total Knee ◽

The Mean

AbstractThe posterior tibial slope (PTS) is usually adjusted by less than 5 degrees, without considering its individual difference, during posterior cruciate-substituting (PS) total knee arthroplasty (TKA). The effect of these individual changes of PTS would be important because clinical results depending on postoperative PTS were reported conflictingly. We investigated the effect of the change in PTS on the postoperative range of motion (ROM) and clinical scores after PS TKA. We retrospectively reviewed 164 knees from 107 patients who underwent PS TKA with a 2-year follow-up. We analyzed the preoperative and postoperative PTS, ROM, visual analog scale pain scale, Western Ontario and McMaster University Index (WOMAC), Hospital for Special Surgery Knee Score, Knee Society Score, and Forgotten Joint Score (FJS). The association of the absolute change in PTS with ROM and clinical scores was analyzed using correlation analysis and multiple regression analysis. As a result, the mean PTS and mean ROM changed from 9.6 ± 3.4 and 120.1 ± 15.4 degrees preoperatively to 2.0 ± 1.3 and 128.4 ± 9.3 degrees postoperatively, and the mean PTS change was 7.6 ± 3.5 degrees. The PTS change had no statistically significant association with the postoperative ROM and clinical scoring systems, although it did have a weak positive correlation with WOMAC function, No 10 (difficulty in rising from sitting) (correlation coefficient = 0.342, p = 0.041), and moderate positive correlation with the FJS, No. 6 (awareness when climbing stairs) (correlation coefficient = 0.470, p = 0.001). The authors concluded that the amount of change in PTS did not affect the postoperative ROM and clinical scores, although proximal tibial resection with a constant target of PTS resulted in individually different changes in the PTS after PS TKA,

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