Estimating the spatial distribution of soil available trace elements by combining auxiliary soil property data through the Bayesian maximum entropy technique

2021 ◽  
Author(s):  
Xufeng Fei ◽  
Zhaohan Lou ◽  
Rui Xiao ◽  
Zhouqiao Ren ◽  
Xiaonan Lv
Keyword(s):  
Trace Elements ◽  
Spatial Distribution ◽  
Maximum Entropy ◽  
Soil Property ◽  
Bayesian Maximum Entropy ◽  
Property Data ◽  
Entropy Technique

scholarly journals Improving Estimations of Spatial Distribution of Soil Respiration Using the Bayesian Maximum Entropy Algorithm and Soil Temperature as Auxiliary Data

PLoS ONE ◽  
2016 ◽  
Vol 11 (1) ◽  
pp. e0146589 ◽  
Author(s):  
Junguo Hu ◽  
Jian Zhou ◽  
Guomo Zhou ◽  
Yiqi Luo ◽  
Xiaojun Xu ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Soil Respiration ◽  
Soil Temperature ◽  
Maximum Entropy ◽  
Bayesian Maximum Entropy ◽  
Auxiliary Data

scholarly journals A Comparative Study of Various Methods of Handling Missing Data in UNSODA

Agriculture ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 727
Author(s):  
Yingpeng Fu ◽  
Hongjian Liao ◽  
Longlong Lv
Keyword(s):  
Missing Data ◽  
Missing Values ◽  
Soil Property ◽  
Particle Density ◽  
Organic Matter Content ◽  
Nonparametric Tests ◽  
Matter Content ◽  
Support Vector ◽  
Soil Database ◽  
Property Data

UNSODA, a free international soil database, is very popular and has been used in many fields. However, missing soil property data have limited the utility of this dataset, especially for data-driven models. Here, three machine learning-based methods, i.e., random forest (RF) regression, support vector (SVR) regression, and artificial neural network (ANN) regression, and two statistics-based methods, i.e., mean and multiple imputation (MI), were used to impute the missing soil property data, including pH, saturated hydraulic conductivity (SHC), organic matter content (OMC), porosity (PO), and particle density (PD). The missing upper depths (DU) and lower depths (DL) for the sampling locations were also imputed. Before imputing the missing values in UNSODA, a missing value simulation was performed and evaluated quantitatively. Next, nonparametric tests and multiple linear regression were performed to qualitatively evaluate the reliability of these five imputation methods. Results showed that RMSEs and MAEs of all features fluctuated within acceptable ranges. RF imputation and MI presented the lowest RMSEs and MAEs; both methods are good at explaining the variability of data. The standard error, coefficient of variance, and standard deviation decreased significantly after imputation, and there were no significant differences before and after imputation. Together, DU, pH, SHC, OMC, PO, and PD explained 91.0%, 63.9%, 88.5%, 59.4%, and 90.2% of the variation in BD using RF, SVR, ANN, mean, and MI, respectively; and this value was 99.8% when missing values were discarded. This study suggests that the RF and MI methods may be better for imputing the missing data in UNSODA.

scholarly journals The potential of trace elements mapping in child’s natal tooth by laser ablation-ICPMS method

2021 ◽  
Author(s):  
Aneta Olszewska ◽  
Anetta Hanć
Keyword(s):  
Trace Elements ◽  
Spatial Distribution ◽  
Quantitative Assessment ◽  
Toxic Elements ◽  
Tooth Enamel ◽  
Perinatal Period ◽  
Potentially Toxic Elements ◽  
Metal Exposure ◽  
Icp Ms ◽  
Distribution Of Trace Elements

Abstract Purpose Tooth enamel might provide past chronological metabolic, nutritional status and trace metal exposure during development. Thus, the trace elements distribution embedded in tooth tissues represents an archive of the environmental conditions. The choice of biomarker is estimated as critical to the measurement of metal exposure. Natal teeth are defined as teeth being present at birth. Methods LA-ICP-MS provides a quantitative assessment of spatial distribution of trace elements in a natal tooth. The objective of the current study was to compare concentrations of building and other elements in a rare but reliable and valid biomarker - natal tooth. Results It have been reported presence of potentially toxic elements: Pb, Cu, Mn, Cd, Ni distributed in prenatally and perinatally formed enamel and dentine. Conclusions Analyses of deciduous enamel can provide answers into individuals’ earliest development, including critical pre- and perinatal period.

scholarly journals Spatial distribution and potential sources of trace elements in PM10 monitored in urban and rural sites of Piedmont Region

Chemosphere ◽  
2016 ◽  
Vol 145 ◽  
pp. 495-507 ◽  
Author(s):  
Elio Padoan ◽  
Mery Malandrino ◽  
Agnese Giacomino ◽  
Mauro M. Grosa ◽  
Francesco Lollobrigida ◽  
...  
Keyword(s):  
Trace Elements ◽  
Spatial Distribution ◽  
Potential Sources ◽  
Rural Sites ◽  
Piedmont Region
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