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Karstensen Bonde posted an update 6 months ago
The efficiency of heavy metal in biofilm reactors depends on absorption process parameters, and those relationships are complicated. This study explores artificial neural networks (ANNs) feasibility to correlate the biofilm reactor process parameters with absorption efficiency. The heavy metal removal and turbidity were modeled as a function of five process parameters, namely pH, temperature(°C), feed flux(ml/min), substrate flow(ml/min), and hydraulic retention time(h). We developed a standalone ANN software for predicting and analyzing the absorption process in handling industrial wastewater. The model was tested extensively to confirm that the predictions are reasonable in the context of the absorption kinetics principles. The model predictions showed that the temperature and pH values are the most influential parameters affecting absorption efficiency and turbidity.
Pregnant women and their fetuses are exposed to multiple toxic metals that together with variations in essential element levels may alter epigenetic regulation, such as DNA methylation.
The aim of the study was to investigate the associations between gestational levels of toxic metals and essential elements and mixtures thereof, with global DNA methylation levels in pregnant women and their newborn children.
Using 631 mother-child pairs from a prospective birth cohort (The Norwegian Mother, Father and Child Cohort Study), we measured maternal blood concentration (gestation week ~18) of five toxic metals and seven essential elements. We investigated associations as individual exposures and two-way interactions, using elastic net regression, and total mixture, using quantile g-computation, with blood levels of 5-methylcytocine (5mC) and 5-hydroxymethylcytosine (5hmC) in mothers during pregnancy and their newborn children (cord blood). Multiple testing was adjusted for using the Benjamini and Hochberg fals as important candidates to investigate in future studies.
We identified few associations between gestational levels of several toxic metals and essential elements and global DNA methylation in pregnant mothers and their newborn children. As DNA methylation dysregulation might be a key mechanism in disease development and thus of high importance for public health, our results should be considered as important candidates to investigate in future studies.
Health disparities exist between urban and rural populations, yet research on rural-urban disparities in temperature-mortality relationships is limited. As inequality in the United States increases, understanding urban-rural and regional differences in the temperature-mortality association is crucial.
We examined regional and urban-rural differences of the temperature-mortality association in North Carolina (NC), USA, and investigated potential effect modifiers.
We applied time-series models allowing nonlinear temperature-mortality associations for 17 years (2000-2016) to generate heat and cold county-specific estimates. We used second-stage analysis to quantify the overall effects. We also explored potential effect modifiers (e.g. social associations, greenness) using stratified analysis. The analysis considered relative effects (comparing risks at 99th to 90th temperature percentiles based on county-specific temperature distributions for heat, and 1st to 10th percentiles for cold) and absolute effectsential segregation, higher income inequality, and higher income (e.g., Ratio of Relative Risks 1.72 (0.68, 4.35) comparing low to high education).
Results indicate cold-mortality risks in NC, with potential differences by regional, urban-rural areas, and community characteristics.
Results indicate cold-mortality risks in NC, with potential differences by regional, urban-rural areas, and community characteristics.Sulfite is a promising alternative for sulfate radical-based advanced oxidation processes (SR-AOPs). Transition metal and photocatalysis are generally considered to have a synergetic effect for S(IV) activation. However, the study shows that the synergetic effect is target specific. Herein, an ultra-small Fe2O3 clusters deposited graphitic carbon nitride is synthesized and used for S(IV) activation. For carbamazepine (CBZ) degradation, photogenerated holes can transform S(IV) into sulfate radical and photogenerated electrons can accelerate Fe(II)/Fe(III) cycle, which account for the synergetic effect. In contrast, the degradation of diclofenac (DCF) depends on the excitation of DCF rather than photocatalyst. Instead of radical precursor, S(IV) acts as the electron transfer bridge between excited DCF and photocatalyst. Thus, the deposition of Fe2O3 negatively affects DCF degradation. Density Functional Theory calculation shows that the first excited state rather than the ground state of diclofenac is more suitable for reactive site prediction, which confirms the photosensitization-like degradation mechanism. Moreover, the effects of pH and coexisted anions varies for CBZ and DCF. Carbohydrate Metabolism activator The study shed light on the synergetic effect of transition metal and photocatalysis for S(IV) activation, and also open an avenue for the study of target specific mechanisms for AOPs.In recent decades, many dragonfly species have become threatened with extinction. For example, populations of Sympetrum frequens, one of the most common dragonflies in rice paddy fields in Japan, decreased sharply around the late 1990s in many regions. Although previous studies suggested that the use of systemic insecticides (particularly fipronil) was likely a major cause of the decline, agronomic factors other than insecticide use and the combined effects of both have been not examined. Here, we developed an S. frequens population model using survival rate parameters associated with the farmland consolidation rate, midsummer drainage, area of crop rotation and abandoned rice paddies, insecticide use, and summer temperature and analyzed the effects of each factor on population dynamics by numerical simulations. Our population models substantially reproduced the past sharp population declines of the dragonfly in three regions. Numerical simulations using hypothetical parameters did not always suggest that the use of systemic insecticides is a sufficient cause of the sharp population declines, as the declines did not occur if the farmland consolidation rate remained at lower levels (before the 1980s).
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