Initiation of soil formation in weathered sulfidic Cu-Pb-Zn tailings under subtropical and semi-arid climatic conditions

Field evidence has been scarce about soil (or technosol) formation and direct phytostabilization of base metal mine tailings under field conditions. The present study evaluated key attributes of soil formation in weathered and neutral Cu-Pb-Zn tailings subject to organic amendment (WC: woodchips) and colonization of pioneer native plant species (mixed native woody and grass plant species) in a 2.5-year field trial under subtropical and semi-arid climatic conditions. Key soil indicators of engineered soil formation process were characterized, including organic carbon fractions, aggregation, microbial community and key enzymatic activities. The majority (64-87%) of the OC was stabilized in microaggregate or organo-mineral complexes in the amended tailings. The levels of OC and water soluble OC were elevated by 2-3 folds across the treatments, with the highest level in the treatment of WC and plant colonization (WC+P). Specifically, the WC+P treatment increased the proportion of water stable macroaggregates. Plants further contributed to the N rich organic matter in the tailings, favouring organo-mineral interactions and organic stabilization. Besides, the plants played a major role in boosting microbial biomass and activities in the treated tailings. WC and plants enhanced the contents of organic carbon (OC) associated with aggregates (e.g., physically protected OC), formation of water-stable aggregates (e.g., micro and macroaggregates), chemical buffering capacity (e.g., cation exchange capacity). Microbial community and enzymatic activities were also stimulated in the amended tailings. The present results showed that the formation of functional technosol was initiated in the eco-engineered and weathered Cu-Pb-Zn tailings under field conditions for direct phytostabilization

Preparation and characterisation of manganese and iron compounds as potential control-release foliar fertilisers

Nanoscale crystals containing manganese and iron as potential foliar fertilizers have been further investigated with the experience accumulated from previous research on potential zinc foliar fertilizer. Compared to Zn(II), Mn(II) and Fe(II) are easily oxidisable in ambient environment, adding stricter criteria to compound selection to prevent oxidation. Adoption of phosphate buffer saline system and chelate have been proposed as the solution and extensively assessed in this paper. After quick co-precipitation, as-prepared crystals were characterised via XRD, FTIR, SEM, TEM, elemental analysis, and AAS to confirm the compositions and two-dimensional nanoscale morphology and assess the nutrient ion release and aqueous stability. In particular, the available Mn concentration in manganese ammonium phosphate and manganese oxalate suspensions was similar to 10 and similar to 110 mg/L, respectively. In comparison, ferrous ammonium phosphate and ferrous oxalate suspensions contained similar to 10 and similar to 30 mg/L of iron ions, respectively. Therefore, these suspensions can all be used as long-term foliar fertilizers for the correction of Mn and Fe deficiency in plants

deep c lstm neural network for epileptic seizure and tumor detection using high dimension eeg signals

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GLS as a diagnostic biomarker in breast cancer: in-silico, in-situ, and in-vitro insights

BackgroundRecently, a novel programmed cell death mechanism, Cuproptosis, has been discovered and found to play an important role in the development and progression of diverse tumors. In the present study, we comprehensively investigated the core gene of this mechanism, GLS, in breast cancer.Materials and methodsBulk RNA sequencing data were curated from the TCGA repository to investigate the aberrant expression of GLS over diverse cancer types. Then, we examined its efficacy as a diagnostic biomarker in breast cancer by Area Under Curve (AUC) of the Receiver Operative Characteristic (ROC) curve. Furthermore, by applying siRNA technique, we knocked down the GLS expression level in cancerous cell lines, measuring the corresponding effects on cell proliferation and metastasis. Afterward, we explored the potential implications of GLS expression in the tumor immune microenvironment quantitatively by using several R packages and algorithms, including ESTIMATE, CIBERSORT, etc.ResultsPan-cancer analysis suggested that GLS was aberrantly over-expressed in many cancer types, with breast cancer being typical. More in-depth analyses revealed the expression of GLS exerted a high ROC-AUC value in breast cancer diagnosis. Through the knock-down of GLS expression, it was found that GLS expression was strongly relevant to the growth and metastasis of tumor. Furthermore, it was also found to be correlated with the immune tumor microenvironment.ConclusionWe highlighted that GLS expression might be applicable as a diagnostic biomarker in breast cancer and possess significant implications in the growth and metastasis of tumor and the immune tumor microenvironment, sharing new insights into ontological and personalized medicine

Slow pyrolyzed biochars from crop residues for soil metal(loid) immobilization and microbial community abundance in contaminated agricultural soils

This study evaluated the feasibility of using biochars produced from three types of crop residues for immobilizing Pb and As and their effects on the abundance of microbial community in contaminated lowland paddy (P-soil) and upland (U-soil) agricultural soils. Biochars were produced from umbrella tree [Maesopsis eminii] wood bark [WB], cocopeat [CP], and palm kernel shell [PKS] at 500\ua0°C by slow pyrolysis at a heating rate of 10\ua0°C min-1. Soils were incubated with 5% (w\ua0w-1) biochars at 25\ua0°C and 70% water holding capacity for 45\ua0d. The biochar effects on metal immobilization were evaluated by sequential extraction of the treated soil, and the microbial community was determined by microbial fatty acid profiles and dehydrogenase activity. The addition of WB caused the largest decrease in Pb in the exchangeable fraction (P-soil: 77.7%, U-soil: 91.5%), followed by CP (P-soil: 67.1%, U-soil: 81.1%) and PKS (P-soil: 9.1%, U-soil: 20.0%) compared to that by the control. In contrast, the additions of WB and CP increased the exchangeable As in U-soil by 84.6% and 14.8%, respectively. Alkalinity and high phosphorous content of biochars might be attributed to the Pb immobilization and As mobilization, respectively. The silicon content in biochars is also an influencing factor in increasing the As mobility. However, no considerable effects of biochars on the microbial community abundance and dehydrogenase activity were found in both soils

Evaluating biochar and its modifications for the removal of ammonium, nitrate, and phosphate in water

Removal of nitrogen (N) and phosphorus (P) from water through the use of various sorbents is often considered an economically viable way for supplementing conventional methods. Biochar has been widely studied for its potential adsorption capabilities for soluble N and P, but the performance of different types of biochars can vary widely. In this review, we summarized the adsorption capacities of biochars in removing N (NH4-N and NO3-N) and P (PO4-P) based on the reported data, and discussed the possible mechanisms and influencing factors. In general, the NH4-N adsorption capacity of unmodified biochars is relatively low, at levels of less than 20 mg/g. This adsorption is mainly via ion exchange and/or interactions with oxygen-containing functional groups on biochar surfaces. The affinity is even lower for NO3-N, because of electrostatic repulsion by negatively charged biochar surfaces. Precipitation of PO4-P by metals/metal oxides in biochar is the primary mechanism for PO4-P removal. Biochars modified by metals have a significantly higher capacity to remove NH4-N, NO3-N, and PO4-P than unmodified biochar, due to the change in surface charge and the increase in metal oxides on the biochar surface. Ambient conditions in the aqueous phase, including temperature, pH, and co-existing ions, can significantly alter the adsorption of N and P by biochars, indicating the importance of optimal processing parameters for N and P removal. However, the release of endogenous N and P from biochar to water can impede its performance, and the presence of competing ions in water poses practical challenges for the use of biochar for nutrient removal. This review demonstrates that progress is needed to improve the performance of biochars and overcome challenges before the widespread field application of biochar for N and P removal is realized

Interactions between sulphur dioxide and soil salinity in wheat plants

Increasing sulphur dioxide (SO2) concentration in the atmosphere with expansions of electricity production and mineral processing in the world has led to numerous studies and understandings of adverse impacts of SO2 on growth and physiology of plants in Although there have been many studies on SO2 dose-response (physiology, growth, and (or) yield) relationships in plants, there is a lack of understanding of influences of environmental stress such as NaCl salinity, on plant responses to elevated SO2 concentrations in the air, which may occur in agricultural areas such as India, China and Australia with agricultural and natural ecosystems. low rainfall, or artificial irrigation and elevated SO2 levels in the air. Since stomatal conductance predominantly controls SO2 uptake and then its toxicity in leaf cells, salinity induced-stomatal closure could decrease the SO2 uptake and protect plants against SO2 toxicity. On the other hand, SO2 itself may induce changes in stomatal conductance, this may in turn, influence leaf transpiration, then salt (NaCl) uptake from the transpiration stream, and eventual salt toxicity in NaCl salinity-stressed plants, Therefore, simultaneous exposure to soil NaCl salinity and SO2 may modify each other's effects on the responses of physiology and growth in the plants. The studies in this thesis examined responses of growth and physiology in wheat plants exposed to SO2, NaCl salinity and their combination under near ambient conditions. Wheat (Triticum aestivum cv. Wilgoyne (Ciano/Gallo)) plants were exposed to factorial treatments of SO2 and NaCl salinity in fumigation chambers with rain-exclusion tops under near-ambient conditions. In experiment 1, wheat plants were exposed to a factorial combination of three levels of salinity (with high Na/Ca ratio): control, 50 and 100 mM NaCl, and three levels of SO2: < 10 (ambient), 44 and 107 nl 1-1 for 4 hours per day for up to 110 days. In experiment 2, wheat plants were exposed to a factorial combination of two levels of salinity (with low Na/Ca ratio): control and 50 mM NaCl, and three levels of SO2: < 10 (ambient), 231, and 441 nl 1-1 for 4 hours per day for up to 51 days. Low concentrations of SO2 (44 and 107 nl 1-1) stimulated vegetative growth in early growth phase, but had no effect later. Exposure to higher SO2 concentration (441 nl 1-1) significantly decreased plant growth. Low SO2 concentrations increased grain yield, but higher SO2 concentration (441 nl 1-1) decreased ear yield. Shoot to root ratios in plants were not changed by the low SO2 concentrations (44 and 107 nl 1-1), but increased by the relatively higher SO2 concentrations (231 and 441 nl 1-1). Increasing NaCl concentrations significantly reduced plant growth and grain yield. Severe NaCl salinity caused a substantial decrease in root growth, due to the effect of high Na+/Ca2+ ratio, resulting in an increase in Mild NaCl salinity initially decreased shoot growth, resulting in a decrease in shoot to root ratio, but later a shoot to root ratio. significant decrease in root growth developed, resulting in an increase in shoot to root ratio. The effects of SO2 fumigation and NaCl salinity on plant dry weights and shoot to root ratios were mostly additive, except that dry weight in plants subject to mild NaCl salinity was decreased less by 441 nl 1-1 SO2 fumigation than the nonsaline plants. Exposure to 231 nl 1-1 SO2 increased shoot to root ratio in plants with mild NaCl. To understand physiological mechanisms behind the negative growth responses to SO2 fumigation, NaCl salinity and their combinations, stomatal conductance, sulphur and salt accumulation, photosynthesis, carbohydrate concentrations, and nitrogen metabolism parameters were examined in long-term fumigation experiments under near-ambient conditions. In the long-term exposure to increased SO2 concentrations, the responses of plant growth and yield were negatively correlated with SO2 concentrations, but not with concentrations of sulphur in plant tissues. Plants exposed to low (107 nl 1-1) and relatively higher concentrations of SO2 (441 nl 1-1) had similar concentrations of sulphur in leaves. Reductions in growth and yield in plants exposed to higher concentrations of SO2 resulted from SO2 toxicity to physiological processes, such as nutritional and ionic balances, photosynthesis, and nitrogen metabolism. Exposure to 441 nl 1-1 SO2 significantly decreased stomatal conductance, net photosynthesis rate, and carbohydrate availability, which contributed an increase in shoot to root ratio. SO2 increased sulphate anion concentration which significantly disturbed ionic balance, causing increased K+ and decreased Na2 + , Ca2+ and CP concentrations and the nitrogen/sulphur balance in plant tissues. Although SO2 fumigation did not affect nitrogen uptake rate, it changed nitrogen distribution, nitrate reductase activity in leaves, soluble protein content and concentrations of total amino acids in plant tissues. Salt toxicity and secondary physiological damages contributed to growth and yield reductions in plants subject to prolonged NaCl Increasing NaCl concentrations caused excessive salt (C1-, Na+) accumulation in plant tissues, and decreases in Although net photosynthesis rates in the youngest fully expanded leaves were little affected by NaCl salinity, long-term exposure to NaCl salinity decreased nonstructural carbohydrate concentrations in plant Cumulative salt injury may have caused a significant salinity stress. concentrations of K+ and sulphate anion. tissues. photosynthetic loss in old leaves and a decrease in total carbon gain in plants. Increasing NaCl salinity also significantly disturbed nitrogen metabolism in plants, by decreasing nitrogen uptake, altering nitrogen distribution, and increasing accumulation of total amino acids. The nature of interactions between SO2 fumigation and NaCl salinity appeared to depend on their effects on the uptake and toxicity of SO2 and NaCl salt to physiological processes. Although severe NaCl salinity significantly decreased sulphur concentration in leaves of plants exposed to SO2, due to NaCl-induced increase in stomatal resistance, it decreased growth and yield in plants exposed to low SO2 concentrations and severe salinity. However, mild NaCl salinity that induced a slight increase in stomatal resistance, only slightly decreased leaf sulphur concentration in plants exposed to higher concentrations of SO2. Therefore mild NaCl salinity could not effectively protect plants against SO2 toxicity through reducing SO2 uptake in the long term, In contrast, exposure to 441 nl l-1 SO2 significantly decreased Cl' and Na+ concentrations, but increased K+ concentrations in leaves of plants subject to long-term mild salinity stress, which decreased salt toxicity to physiological processes. Fumigation with SO2 concentrations of less than 441 nl 1-1, additively affected photosynthesis, carbohydrate production, and nitrogen metabolism parameters in plants subject to long-term NaCl salinity. Exposure to 441 nl 1-1 SO2 and mild NaCl salinity had antagonistic interactions on physiological responses, such as carbohydrate concentrations and nitrogen metabolism parameters. Plant tolerance to the long-term NaCl salinity was enhanced by 441 nl 1-1 SO2 fumigation by decreasing Na+ and CF concentration and increasing K+ concentration in leaves, and salt toxicity to physiological processes, resulting in antagonistic interactions on growth and yield. It is concluded that increasing NaCl salinity could not effectively protect plants against SO2 toxicity on physiology and growth by increasing leaf stomatal resistance, in the wheat plants exposed to a long-term simultaneous SO2 fumigation under ambient conditions. The two stresses are most likely to additively affect physiological responses, growth and yield in wheat plants in the long term. However, relatively higher SO2 fumigation appeared to protect the saline plants from salt toxicity to physiological processes and eventual growth, through decreasing stomatal conductance and salt concentrations in plant tissues. The effects of SO2 fumigation, NaCl salinity and their combination on the physiological responses to eventual growth in plants are discussed in the context of conceptual models

Evidence of phloem boron transport in response to interrupted boron supply in white lupin (Lupinus albus L. cv. Kiev Mutant) at the reproductive stage

The present study investigates whether previously acquired boron (B) in mature leaves in white lupin can be retranslocated into the rapidly growing young reproductive organs, in response to short-term (3 d) interrupted B supply. In a preliminary experiment with white lupin in soil culture, B concentrations in phloem exudates remained at 300-500 μM, which were substantially higher than those in the xylem sap (10-30 μM). The high ratios of B concentrations in phloem exudates to those in the xylem sap were close to values published for potassium in lupin plants. To differentiate 'old' B in the shoot from 'new' B in the root, an experiment was carried out in which the plants were first supplied with 20 μM 11B (99.34% by weight) in nutrient solution for 48 d after germination (DAG) until early flowering and then transferred into either 0.2 μM or 20 μM 10B (99.47% by weight) for 3 d. Regardless of the 10B treatments, significant levels of 11B were found in the phloem exudates (200-300 μM in 20 μM 10B and 430 μM in 0.2 μM 10B treatment) and xylem sap over the three days even without 11B supply to the root. In response to the 0.2 μM 10B treatment, the translocation of previously acquired 11B in the young (the uppermost three leaves), matured, and old leaves was enhanced, coinciding with the rise of 11B in the xylem sap (to >15 μM) and phloem exudates (430 μM). The evidence supports the hypothesis that previously acquired B in the shoot was recirculated to the root via the phloem, transferred into the xylem in the root, and transported in the xylem to the shoot. In addition, some previously acquired 11B in the leaves may have been translocated into the rapidly growing inflorescence. Phloem B transport resulted in the continued net increment of 11B in the flowers over 3 d without 11B supply. However, it is still uncertain whether the amount of B available for recirculation is adequate to support reproductive growth until seed maturation

Rehabilitation of biological characteristics in mine tailings

Mining and extraction of economic minerals inevitably cause land degradation/destruction and the loss of biological properties required for sustainable land use post mining. Australia is a leading producer of minerals, producing at least 19 minerals (in significant amounts), and the production of copper (Cu), black coal, lead (Pb), zinc (Zn), and iron (Fe) ores has increased markedly over the last decade (Mudd 2010; Sutton and Dick 1987). From the mid-1800s to 2008, cumulative Cu, Pb, and Zn production (kt) in Australia reached 20,473; 37,945; and 48,465, respectively, in which their production in Queensland accounted for 50%-60% (Mudd 2010). Intensive mining and processing activities generate vast volumes of tailings that have been deposited in the environment. Within mined landscapes, mine wastes (e.g., tailings) represent the extremity of negative environmental impacts on the land, regardless of mining methods (e.g., opencut or underground mining). As a result, the present chapter has focused on biological characteristics of metal mine tailings and ecological engineering inputs required to rehabilitate soil-like biological properties and conditions, which underpin soil formation in the tailings for sustainable phytostabilization with native plant communities. The biological properties discussed here have mainly focused on key aspects of microbial communities and rhizosphere biology, and the processes associated with the development of key physical and chemical conditions in the tailings, which are closely coupled with biological properties

Physiological responses of plants to low boron

This review focuses on physiological responses in higher plants to B deficiency at the whole plant and organ level. Plants respond to decreasing B supply in soil solutions by slowing down or ceasing growth. Boron deficiency inhibits root elongation through limiting cell enlargement and cell division in the growing zone of root tips. In the case of severe B deficiency, the root cap, quiescent centre and protoderm of root tips disappear and root growth ceases, leading to the death of root tips. Although vascular bundles are weakly developed in B-deficient roots, early effects of B deficiency on their initiation and differentiation is poorly understood. Inhibited leaf expansion by low B indirectly decreases the photosynthetic capacity of plants, though exact roles of B in photosynthesis remain to be explored. The early inhibition of root growth, compared to shoot growth, increases the shoot:root ratio. It is hypothesised that this may enhance the susceptibility of plants to environmental stresses such as marginally deficient supplies of other nutrients and water deficit in soil. In the field, sexual reproduction is often more sensitive to low soil B than vegetative growth, and marked seed yield reductions can occur without symptoms being expressed during prior vegetative growth. In flowers, low B reduces male fertility primarily by impairing microsporogenesis and pollen tube growth. Post-fertilisation effects include impaired embryogenesis, resulting in seed abortion or the formation of incomplete or damaged embryos, and malformed fruit. However, there is a great diversity of effects of low B on reproductive growth among species, and within the same species between sites and seasons. Much of this diversity is not explained by the current literature. Key processes in reproductive development which may be impaired under B deficiency are proposed and discussed. These include the formation of a diverse array of cell wall types, the supply of carbohydrates for growth and storage reserves, and the production of flavonols. Inflorescence architecture, floral morphology, canopy structure and prevailing weather conditions are suggested as being important for xylem B delivery into flowers because of their impact on transpiration. The extent of phloem translocation of B into reproductive organs has yet to be fully assessed. The timing of B sensitive stages in reproduction of most crop plants need defining in order to facilitate appropriate timing of corrective B treatments. As most container studies have imposed B deficiency by withholding B, much of the data on severely B-deficient plants requires re-evaluation. Further studies are warranted to understand the effects of realistically low levels of B in solution on the growth of meristematic tissues and floral organs. A B-buffered solution culture system is recommended for some of this work