Spatial characteristics of cadmium in topsoils in a typical e-waste recycling area in southeast China and its potential threat to shallow groundwater

Informal electrical and electronic waste (e-waste) recycling often creates secondary sources of cadmium (Cd) pollution. To characterize the total Cd concentration (Cd-total) in topsoil and evaluate the threat of Cd in topsoils to shallow groundwater, 187 topsoil samples and 12 shallow groundwater samples were collected in a typical e-waste recycling area in southeast China. Soil organic matter content, soil pH and Cd-total in topsoil, pH and dissolved Cd concentration in shallow groundwater were measured. Cd-total in the topsoils showed an inverse distribution trend with soil pH in that high Cd concentrations (and low pH values) were found in the surrounding area of the metal recycling industrial park where there were many family-operated e-waste recycling facilities before the industrial park was established and with low concentrations (and high pH values) in other areas, and they had similar spatial correlation structures. Cd accumulation and acidification were synchronous in topsoils, and soil pH was significantly correlated with Cd-total in topsoils with low to moderate negative correlation coefficient (r = -024), indicating that both of them maybe correlated with informal recycling. The shallow groundwater in the surrounding area of the metal recycling industrial park was seriously contaminated by Cd, and topsoil Cd accumulation and acidification in the surrounding area of e-waste recycling sites significantly increase the risk of shallow groundwater contaminated by Cd. Action is urgently required to control Cd accumulation and acidification by improving the recycling operations of e-wastes in order to reduce the risk of Cd leaching from topsoils and shallow groundwater contamination. (C) 2013 Published by Elsevier B.V.Informal electrical and electronic waste (e-waste) recycling often creates secondary sources of cadmium (Cd) pollution. To characterize the total Cd concentration (Cd-total) in topsoil and evaluate the threat of Cd in topsoils to shallow groundwater, 187 topsoil samples and 12 shallow groundwater samples were collected in a typical e-waste recycling area in southeast China. Soil organic matter content, soil pH and Cd-total in topsoil, pH and dissolved Cd concentration in shallow groundwater were measured. Cd-total in the topsoils showed an inverse distribution trend with soil pH in that high Cd concentrations (and low pH values) were found in the surrounding area of the metal recycling industrial park where there were many family-operated e-waste recycling facilities before the industrial park was established and with low concentrations (and high pH values) in other areas, and they had similar spatial correlation structures. Cd accumulation and acidification were synchronous in topsoils, and soil pH was significantly correlated with Cd-total in topsoils with low to moderate negative correlation coefficient (r = -024), indicating that both of them maybe correlated with informal recycling. The shallow groundwater in the surrounding area of the metal recycling industrial park was seriously contaminated by Cd, and topsoil Cd accumulation and acidification in the surrounding area of e-waste recycling sites significantly increase the risk of shallow groundwater contaminated by Cd. Action is urgently required to control Cd accumulation and acidification by improving the recycling operations of e-wastes in order to reduce the risk of Cd leaching from topsoils and shallow groundwater contamination. (C) 2013 Published by Elsevier B.V

De novo SNP discovery and genetic linkage mapping in poplar using restriction site associated DNA and whole-genome sequencing technologies

Detailed information on genetic distance and linkage phase between adjacent SNP markers on the genetic linkage map of the female P. deltoides ‘I-69’. The corresponding identical SNPs identified based on the P. trichocarpa reference genome are also included. (XLS 452 kb

EM Algorithm for Mapping Quantitative Trait Loci in Multivalent Tetraploids

Multivalent tetraploids that include many plant species, such as potato, sugarcane, and rose, are of paramount importance to agricultural production and biological research. Quantitative trait locus (QTL) mapping in multivalent tetraploids is challenged by their unique cytogenetic properties, such as double reduction. We develop a statistical method for mapping multivalent tetraploid QTLs by considering these cytogenetic properties. This method is built in the mixture model-based framework and implemented with the EM algorithm. The method allows the simultaneous estimation of QTL positions, QTL effects, the chromosomal pairing factor, and the degree of double reduction as well as the assessment of the estimation precision of these parameters. We used simulated data to examine the statistical properties of the method and validate its utilization. The new method and its software will provide a useful tool for QTL mapping in multivalent tetraploids that undergo double reduction

Green synthesis of triclinic (anorthic) phase AgCoPO4nanoparticles: opticalstudies and theoretical modelling

We report the plant-mediated synthesis, structural investigation, optical properties and theoretical modelling of atriclinic (anorthic) phase AgCoPO4nanoparticles for thefirst time. As part of green chemistry, the secondarymetabolites in the leaf extract ofCanna indicawere engaged as the reducing/capping agent for the metal nano-particles. X-ray diffraction (XRD) revealed the presence of an anorthic AgCoPO4phase, crystallised in a triclinicstructure with P -1 space group. Optical studies using UV-vis spectroscopy and photoluminescence are reported.Transmission electron microscopy suggests the formation of quasi-nanocube morphology, unlike the conventionalspherically-shaped nanoparticles via plant-mediated reduction method. Elemental composition of the nanohybridwas confirmed by energy-dispersive x-ray spectroscopy (E.D.S.). Evidence of crystallinity was supported byselected area electron diffraction (SAED). Study of the dynamic anisotropy of the nanohybrid at optimised statesuggests its proposed application as optical material in colourimetric metal nanoparticles-mediated sensors

The 2021 WHO catalogue of Mycobacterium tuberculosis complex mutations associated with drug resistance: a genotypic analysis.

Background: Molecular diagnostics are considered the most promising route to achievement of rapid, universal drug susceptibility testing for Mycobacterium tuberculosis complex (MTBC). We aimed to generate a WHO-endorsed catalogue of mutations to serve as a global standard for interpreting molecular information for drug resistance prediction. Methods: In this systematic analysis, we used a candidate gene approach to identify mutations associated with resistance or consistent with susceptibility for 13 WHO-endorsed antituberculosis drugs. We collected existing worldwide MTBC whole-genome sequencing data and phenotypic data from academic groups and consortia, reference laboratories, public health organisations, and published literature. We categorised phenotypes as follows: methods and critical concentrations currently endorsed by WHO (category 1); critical concentrations previously endorsed by WHO for those methods (category 2); methods or critical concentrations not currently endorsed by WHO (category 3). For each mutation, we used a contingency table of binary phenotypes and presence or absence of the mutation to compute positive predictive value, and we used Fisher's exact tests to generate odds ratios and Benjamini-Hochberg corrected p values. Mutations were graded as associated with resistance if present in at least five isolates, if the odds ratio was more than 1 with a statistically significant corrected p value, and if the lower bound of the 95% CI on the positive predictive value for phenotypic resistance was greater than 25%. A series of expert rules were applied for final confidence grading of each mutation. Findings: We analysed 41 137 MTBC isolates with phenotypic and whole-genome sequencing data from 45 countries. 38 215 MTBC isolates passed quality control steps and were included in the final analysis. 15 667 associations were computed for 13 211 unique mutations linked to one or more drugs. 1149 (7·3%) of 15 667 mutations were classified as associated with phenotypic resistance and 107 (0·7%) were deemed consistent with susceptibility. For rifampicin, isoniazid, ethambutol, fluoroquinolones, and streptomycin, the mutations' pooled sensitivity was more than 80%. Specificity was over 95% for all drugs except ethionamide (91·4%), moxifloxacin (91·6%) and ethambutol (93·3%). Only two resistance mutations were identified for bedaquiline, delamanid, clofazimine, and linezolid as prevalence of phenotypic resistance was low for these drugs. Interpretation: We present the first WHO-endorsed catalogue of molecular targets for MTBC drug susceptibility testing, which is intended to provide a global standard for resistance interpretation. The existence of this catalogue should encourage the implementation of molecular diagnostics by national tuberculosis programmes. Funding: Unitaid, Wellcome Trust, UK Medical Research Council, and Bill and Melinda Gates Foundation

Heavy metal concentrations and their possible sources in paddy soils of a modern agricultural zone, southeastern China

In a typical modern agricultural Zone of southeastern China, Haining City, 224 topsoil samples were collected from paddy fields to measure the total concentrations of copper (Cu), lead (Pb), zinc (Zn), cadmium (Cd), chromium (Cr), mercury (Hg), arsenic (As) and cobalt (Co). The total concentrations ranged from 15.30 to 78.40 mg kg(-1) for Cu, 20.10 to 41.40 mg kg(-1) for Pb, 54.98 to 224.4 mg kg(-1) for Zn, 0.04 to 0.24 mg kg(-1) for Cd, 54.90 to 197.1 mg kg(-1) for Cr, 0.03 to 0.61 mg kg(-1) for Hg, 3.44 to 15.28 mg kg(-1) for As, and 7.17 to 19.00 mg kg(-1) for Co. Chemometric techniques and geostatistics were utilized to quantify their spatial characteristics and define their possible sources. All eight metals had a moderate spatial dependency except that Pb had a strong spatial dependency. Both factor analysis and cluster analysis successfully classified the eight metals into three groups or subgroups, the first group included Cu, Zn and Cr, the second group included Cd, As and Co, and the last group included Pb and Hg. The Cu, Zn and Cr concentrations in majority samples were higher than their local background concentrations and they were highly correlated (r > 0.80), indicating that they had similar pollution source and anthropic factor controlled their spatial distribution; the Cd, As and Co concentrations in majority samples were lower than their local background concentrations, indicating that the source of these elements was mainly controlled by natural factors; the mean concentration of Pb exhibited generally low level, close to its local background concentration, the Hg concentration in about half of samples was higher than its local background concentration, and they were poor correlated with the other metals, indicating that the source of Pb and Hg was common controlled by natural factor and anthropic factor.In a typical modern agricultural Zone of southeastern China, Haining City, 224 topsoil samples were collected from paddy fields to measure the total concentrations of copper (Cu), lead (Pb), zinc (Zn), cadmium (Cd), chromium (Cr), mercury (Hg), arsenic (As) and cobalt (Co). The total concentrations ranged from 15.30 to 78.40 mg kg(-1) for Cu, 20.10 to 41.40 mg kg(-1) for Pb, 54.98 to 224.4 mg kg(-1) for Zn, 0.04 to 0.24 mg kg(-1) for Cd, 54.90 to 197.1 mg kg(-1) for Cr, 0.03 to 0.61 mg kg(-1) for Hg, 3.44 to 15.28 mg kg(-1) for As, and 7.17 to 19.00 mg kg(-1) for Co. Chemometric techniques and geostatistics were utilized to quantify their spatial characteristics and define their possible sources. All eight metals had a moderate spatial dependency except that Pb had a strong spatial dependency. Both factor analysis and cluster analysis successfully classified the eight metals into three groups or subgroups, the first group included Cu, Zn and Cr, the second group included Cd, As and Co, and the last group included Pb and Hg. The Cu, Zn and Cr concentrations in majority samples were higher than their local background concentrations and they were highly correlated (r > 0.80), indicating that they had similar pollution source and anthropic factor controlled their spatial distribution; the Cd, As and Co concentrations in majority samples were lower than their local background concentrations, indicating that the source of these elements was mainly controlled by natural factors; the mean concentration of Pb exhibited generally low level, close to its local background concentration, the Hg concentration in about half of samples was higher than its local background concentration, and they were poor correlated with the other metals, indicating that the source of Pb and Hg was common controlled by natural factor and anthropic factor

Variability of copper availability in paddy fields in relation to selected soil properties in southeast China

Copper (Cu) is an essential nutrient element for plant growth and is a toxic heavy metal in excess concentrations. As such, its concentration and availability in soils are of great agricultural and environmental concern. Availability and spatial pattern of copper in relation to selected soil properties in surface soils were evaluated for an agricultural region in southeastern China. A total of 224 topsoil samples (0-15 cm) were collected from paddy fields in a study area of 731 km2. We measured total Cu and DTPA-extractable Cu (available Cu) concentrations, soil pH, soil organic matter content (SOM), total nitrogen, available phosphorus, available potassium, and cation exchange capacity (CEC). We estimated Cu availability by calculating the ratio of available Cu to total Cu concentration. The results of our chemical analyses indicated that both total Cu and available Cu concentrations had a wide range throughout the study area. In addition, we measured slight Cu accumulation in paddy fields of the study area in comparison to background levels at Zhejiang Province scale. Correlation analysis revealed that available Cu concentration was positively correlated with total Cu concentration, CEC and SOM as indicated by moderate to high correlation coefficients (r = 0.64-0.82), and Cu availability was directly correlated with SOM, pH and Cu concentration with moderate to high positive correlation (r = 0.47-0.82) at 0.01 level of significance. Spatial distribution maps illustrated that total Cu concentration and available Cu concentration had similar distribution trends with the highest concentrations in the northeast region and low concentrations in the southwest region of the study area. Copper availability ratio had a spatial distribution trend with high ratios in the northeast region and low ratios in the central region of the study area. Soil properties influencing the spatial distribution of Cu availability were SOM and pH, in addition to the concentration of available Cu.Copper (Cu) is an essential nutrient element for plant growth and is a toxic heavy metal in excess concentrations. As such, its concentration and availability in soils are of great agricultural and environmental concern. Availability and spatial pattern of copper in relation to selected soil properties in surface soils were evaluated for an agricultural region in southeastern China. A total of 224 topsoil samples (0-15 cm) were collected from paddy fields in a study area of 731 km(2). We measured total Cu and DTPA-extractable Cu (available Cu) concentrations, soil pH, soil organic matter content (SOM), total nitrogen, available phosphorus, available potassium, and cation exchange capacity (CEC). We estimated Cu availability by calculating the ratio of available Cu to total Cu concentration. The results of our chemical analyses indicated that both total Cu and available Cu concentrations had a wide range throughout the study area. In addition, we measured slight Cu accumulation in paddy fields of the study area in comparison to background levels at Zhejiang Province scale. Correlation analysis revealed that available Cu concentration was positively correlated with total Cu concentration, CEC and SOM as indicated by moderate to high correlation coefficients (r = 0.64-0.82), and Cu availability was directly correlated with SOM, pH and Cu concentration with moderate to high positive correlation (r = 0.47-0.82) at 0.01 level of significance. Spatial distribution maps illustrated that total Cu concentration and available Cu concentration had similar distribution trends with the highest concentrations in the northeast region and low concentrations in the southwest region of the study area. Copper availability ratio had a spatial distribution trend with high ratios in the northeast region and low ratios in the central region of the study area. Soil properties influencing the spatial distribution of Cu availability were SOM and pH, in addition to the concentration of available (C) 2010 Elsevier B.V. All rights reserved