Environmental Degradation Mechanisms Research Articles

Maladaptation in an unequal world: an evolutionary model with heterogeneous agents

Maladaptation is steadily increasing its presence in agenda and debates about climate change and its impacts. The term denotes actions undertaken, at the individual or collective level, to defend against the adverse effects of climate change or environmental degradation, but that ultimately exacerbate the underlying risk factors. In this paper, we investigate the effects of maladaptation in terms of well-being and inequality in a two-population (North–South) evolutionary model. While agents in the South often face higher vulnerability to environmental degradation and limited defense mechanisms compared to their Northern counterparts, the latter stand to endure greater economic losses, in absolute terms. Our model demonstrates that the diffusion of maladaptive choices could result in a Pareto-dominated steady state, influencing inequality levels positively or negatively based on the scale of maladaptation impacts relative to the existing environmental degradation. These findings stress the imperative of integrating environmental risk studies with maladaptive effects and dynamics. Additionally, they advocate for international discourse not only on climate change mitigation but also on adaptive measures among countries.

Study on the Direct and Indirect Photolysis of Antibacterial Florfenicol in Water Using DFT/TDDFT Method and Comparison of Its Reactivity with Hydroxyl Radical under the Effect of Metal Ions.

Florfenicol (FLO) is a widely used antibacterial drug, which is often detected in the environment. In this paper, the photolysis mechanism of FLO in water was investigated using density functional theory (DFT) and time-dependent density functional theory (TDDFT). The focus of the study is to elucidate the direct photolysis mechanism of FLO in the water environment and the indirect photolysis of free radicals (·OH, ·NO3, and ·SO4-) as active species. The effect of metal ions Ca2+/Mg2+/Zn2+ on the indirect photolysis was also investigated. The results show that the direct photolysis of FLO involves C-C/C-N/C-S bond cleavage, the C5-S7 bond cleavage is most likely to occur, and the C17-C18 cleavage reaction is not easy to occur during the direct photodegradation of FLO. The indirect photolysis of FLO is more likely to occur in the environment than direct photolysis. The main indirect photolysis involves OH-addition, NO3-addition, and SO4-addition on benzene ring. The order of difficulty in the indirect photolysis with ·OH is C2 > C3 > C4 > C5 > C6 > C1, Ca2+ can promote the indirect photolysis with ·OH, and Mg2+/Zn2+ has a dual effect on the indirect photolysis with ·OH. In other words, Mg2+ and Zn2+ can inhibit or promote the indirect photolysis with ·OH. These studies provide important information for theoretical research on the environmental behavior and degradation mechanism of drug molecules.

Pandemics and Climate Change as Systemic Risks: Law, Policy, Insurance, Physical Activity and Exercise as Mitigating Environmental Degradation Mechanisms

Climate change and the Covid-19 pandemic have been classified as systemic risks and have elaborated that such systemic risks will become the new normal. Ways to tackle the long-term effects of climate change include law and environmental policy. In addition, insurance can help mitigate the burden placed on governments when such systemic risks occur, including pandemics. In relation to the Covid-19 pandemic and the effects of long-Covid, sports and exercise are examined as a mitigating factor able to release pressure from public health and help mitigate its long-term effects. This article discusses the correlation of Covid-19 with environmental changes and climate changes and goes on to address the role of insurance, on the one hand and sports and exercise on the other hand as mitigating mechanisms to handle systemic risks such as climate change and pandemics. The article’s findings suggest and conclude that 1) outside state action (law and policy), private action such as change in lifestyle towards a more sustainable way of life, and sports and exercise can help with the long-term effects of pandemics and 2) insurance can act as a mitigating private sector mechanism. Governments should integrate law, policy, and mitigating techniques such as private insurance to tackle and respond to systemic risks. climate change, Covid-19, systemic risks, insurance, physical exercise, mitigation for climate change, mitigation, public health

Unravelling the environmental degradation mechanism of perovskite thin films

The susceptibility of these perovskites toward various atmospheric molecules under ambient conditions emphasizes its critical role in the perovskite’s structural distortion and subsequent chemical alterations.

Electrospun High Performance Polymer Reinforced Membranes for Exceptional Durability Fuel Cell Membrane Electrode Assemblies

Adequate material selection is one of the most important aspects in component design. Therefore, high-performance polymers have garnered significant interest for Proton Exchange Membrane Fuel Cell (PEMFC) and Water Electrolysis (WE) applications due to their exceptional mechanical, thermal, and chemical properties. This 'beginning by design' strategy requires a deep knowledge of environmental stressors and degradation mechanisms and focuses on proposing next-generation advanced materials able to withstand defined stress conditions for lightweight and heavy-duty transport applications. This presentation presents recent advances and challenges encountered in the preparation of high-performance polymer-reinforced membranes and highlights their specific properties resulting in exceptional durability of nearly 120,000 cycles when tested under combined Open Circuit Voltage (OCV) with Relative Humidity (RH) cycling.This work was supported by the Fuel Cells and Hydrogen 2 Joint Undertaking under grant agreement No 101006641 IMMORTAL. This Joint Undertaking receives support from the European Union’s Horizon 2020 research and innovation programme, Hydrogen Europe and Hydrogen Europe Research.

Editorial: Machining technology and environmental degradation mechanism of surface microstructure of special materials, volume II

Editorial: Machining technology and environmental degradation mechanism of surface microstructure of special materials, volume II

Commercial optical coatings in space

The use of commercial optical coatings for space applications for the aptly named “New Space” missions is a state-of-the-art trend. These products are generally less costly and time-consuming in their production and therefore, there is a much wider range of optical coatings available compared to custom-made products. However, the reliability of commercial manufacturing processes is a key concern. Additionally, the resistance of commercial products against space environmental degradation mechanism at operating temperatures needs to be evaluated. In this study, seven commercial products with multi-layer thin film optical coatings consisting of filters, mirrors and windows have been selected from various manufacturers and the results with regards to process verification and space environmental exposure testing are presented. The impact of space environmental effects on the optical performance of the coatings is evaluated, with particular emphasis on the performance at cryogenic temperature. Finally, guidelines and precautions for use of commercial optical coatings for space applications.

A compact environmental performance testing apparatus for ceramic matrix minicomposites

Minicomposite, as the elementary scale of the full-scale ceramic matrix composites (CMCs), has been commonly considered as the appropriate specimen type for basic research on environmental behavior of CMCs due to its simple structure, low fabrication cost and mature modeling foundation. However, its size is too small relative to the full-scale CMCs, resulting in the existing environmental performance testing equipment developed for macrocomposites not matching it in all respects. In order to fill this gap, a compact environmental performance testing apparatus, which consists mainly of a two-zone furnace, gas humidifier, control system and a pair of quartz tubes and high temperature specimen grips, has been designed and built here. Creep test of SiC fiber at elevated temperatures from 800 to 1100 °C with water vapor and oxidation test of SiC/SiC minicomposite at 1316 °C in stress-free wet oxygen environment were carried out respectively to verify the accuracy and reliability of the rig. With the apparatus, the environmental degradation mechanism of CMCs can be quantitatively analyzed, which lays a foundation for the service life prediction and environmental performance optimization of CMCs.

Insights into characteristics of white rot fungus during environmental plastics adhesion and degradation mechanism of plastics

Since the 1980s, plastic waste in the environment has been accumulating, and little is known about fungi biodegradation, especially in dry environments. Therefore, the research on plastic degradation technology is urgent. In this study, we demonstrated that Phanerochaete chrysosporium (P. chrysposporium), a typical species of white rot fungi, could react as a highly efficient biodegrader of polylactic acid (PLA), and 34.35 % of PLA degradation was obtained during 35-day incubation. A similar mass loss of 19.71 % could be achieved for polystyrene (PS) degradation. Here, we presented the visualization of the plastic deterioration process and their negative reciprocal on cell development, which may be caused by the challenge of using PS as a substrate. The RNA-seq analysis indicated that adaptations in energy metabolism and cellular defense were downregulated in the PS group, while lipid synthesis was upregulated in the PLA-treated group. Possible differentially expressed genes (DEG) of plastic degradation, such as hydrophobic proteins, lignin peroxidase (LiP), manganese peroxidase (MnP) and laccase (Lac), Cytochrome P450 (CYP450), and genes involved in styrene or benzoic acid degradation pathways have been recorded, and we proposed a PS degradation pathway.

Influence of Corrosion Deterioration on Lifetime Seismic Resilience of Highway Bridges

Highway bridges across the globe have demonstrated vulnerability to damage during earthquake events. While earthquakes occur infrequently, environmental degradation mechanisms such as chloride-induced corrosion deterioration are continuous and decrease the structural performance over time. There is a need to assess the performance of existing older bridges in India, taking into account the combined threats of corrosion degradation and seismic hazard. In this regard, resilience has emerged as a powerful tool to determine the bridge performance integrating the seismic vulnerability, losses, and recovery functions. This study presents a case-study for lifetime resilience assessment considering the effect of environmental and seismic hazards using a representative two-span semi-integral bridge. Finite element models of the bridge is developed at pristine and four degraded conditions considering chloride-induced corrosion. Nonlinear time-history analyses are conducted on the bridge models to develop time-dependent seismic fragility curves. Further, these fragility curves are used to estimate post-earthquake direct and indirect losses that are combined with suitable recovery models to estimate the functionality and resilience of the bridge. Results obtained from the analysis revealed a degrading trend of the resilience of the bridge as it deteriorates with age, representing the significance of lifetime seismic resilience assessment for estimating the performance of existing aging bridges.

Carboxypeptidase G and pterin deaminase metabolic pathways degrade folic acid in Variovorax sp. F1

BackgroundFolic acid (FA) is a synthetic vitamin (B9) and the oxidized form of a metabolic cofactor that is essential for life. Although the biosynthetic mechanisms of FA are established, its environmental degradation mechanism has not been fully elucidated. The present study aimed to identify bacteria in soil that degrade FA and the mechanisms involved.ResultsWe isolated the soil bacterium Variovorax sp. F1 from sampled weed rhizospheres in a grassland and investigated its FA degradation mechanism. Cultured Variovorax sp. F1 rapidly degraded FA to pteroic acid (PA), indicating that FA hydrolysis to PA and glutamate. We cloned the carboxypeptidase G (CPG) gene and found widely distributed paralogs within the Variovorax genus. Recombinant CPG preferred FA and deaminofolic acid as substrates, indicating its involvement in FA degradation by Variovorax. Prolonged culture of Variovorax sp. F1 resulted in decreased rates of deaminofolic acid (DFA) and deaminopteroic acid (DPA) accumulation. This indicated that the deamination reaction also comprised a route of FA degradation. We also identified an F1 gene that was orthologous to the pterin deaminase gene (Arad3529) of Agrobacterium radiobacter. The encoded protein deaminated FA and PA to DFA and DPA, which was consistent with the deamination activity of FA and PA in bacterial cell-free extracts.ConclusionWe discovered that the two enzymes required for FA degradation pathways in isolates of Variovorax sp. F1 comprise CPG and pterin deaminase, and that DFA and PA are intermediates in the generation of DPA.

Degrading Characterization of the Newly Isolated Nocardioides sp. N39 for 3-Amino-5-methyl-isoxazole and the Related Genomic Information.

3-amino-5-methyl-isoxazole (3A5MI) is a persistent and harmful intermediate in the degradation of antibiotic sulfamethoxazole. It was accumulated in the environments day by day and has caused great environmental risks due to its refractory characteristic. Microbial degradation is economic and environmentally friendly and a promising method to eliminate this pollutant. In this study, a bacterial strain, Nocardioides sp. N39, was isolated. N39 can grow on 3A5MI as the sole carbon, nitrogen and energy resource. The effect of different factors on 3A5MI degradation by N39 was explored, including initial 3A5MI concentration, temperature, pH value, dissolved oxygen and additional carbon or nitrogen source. The degradation ability of N39 to various 3A5MI analogs was also explored. Nevertheless, the degrading ability of N39 for 3A5MI is not permanent, and long-term storage would lead to the loss of this ability. This may result from the mobile genetic elements in the bacterium according to the genomic comparison of N39 and its degrading ability-lost strain, N40. Despite this, N39 could support a lot of useful information about the degradation of 3A5MI and highlight the importance of studies about the environmental effects and potential degradation mechanism.

Environmental Distribution, Metabolic Fate, and Degradation Mechanism of Chlorpyrifos: Recent and Future Perspectives.

Pesticides play a significant role in crop production and have become an inevitable part of the modern environment due to their extensive distribution throughout the soil ecosystem. Prophylactic applications of chlorpyrifos (CP) affect soil fertility, modify soil microbial community structure, and pose potential health risks to the nontarget organisms. Bioremediation through microbial metabolism is found to be an ecofriendly and cheaper process for CP removal from the environment. So far, various bacterial and fungal communities have been reported for CP and its metabolites degradation. Organophosphorus hydrolase (OPH) and methyl parathion hydrolase (MPH) are crucial bacterial enzymes for CP degradation as they efficiently hydrolyze the unbreakable P-O and P = S bond. This review discusses the prospects of toxicity level, persistency, and harmful effects of CP on the environment. CP degradation mechanisms, metabolic pathways, and key enzymes, along with their structural details, are also featured. The highlights on molecular docking with OPH and MPH enzyme for CP show the best binding affinity with OPH; hence, it is an essential part of CP degradation. Simultaneously, metagenomic analysis of soil from contaminated agricultural lands and wastewater was analyzed with the goal to identify the dominant CP degraders and enzymes. The identification of potent degraders, key enzymes, and evaluation of microbial community dynamics upon pesticide exposure can be used as a warning for its dissemination and biomagnification into the food chain.

Insights into Characteristics of White Rot Fungus During Environmental Plastics Adhesion and Degradation Mechanism of Plastics

Insights into Characteristics of White Rot Fungus During Environmental Plastics Adhesion and Degradation Mechanism of Plastics

Insights into Characteristics of White Rot Fungus During Environmental Plastics Adhesion and Degradation Mechanism of Plastics

Insights into Characteristics of White Rot Fungus During Environmental Plastics Adhesion and Degradation Mechanism of Plastics

Environmental Occurrence, Toxicity Concerns, and Degradation of Diazinon Using a Microbial System.

Diazinon is an organophosphorus pesticide widely used to control cabbage insects, cotton aphids and underground pests. The continuous application of diazinon in agricultural activities has caused both ecological risk and biological hazards in the environment. Diazinon can be degraded via physical and chemical methods such as photocatalysis, adsorption and advanced oxidation. The microbial degradation of diazinon is found to be more effective than physicochemical methods for its complete clean-up from contaminated soil and water environments. The microbial strains belonging to Ochrobactrum sp., Stenotrophomonas sp., Lactobacillus brevis, Serratia marcescens, Aspergillus niger, Rhodotorula glutinis, and Rhodotorula rubra were found to be very promising for the ecofriendly removal of diazinon. The degradation pathways of diazinon and the fate of several metabolites were investigated. In addition, a variety of diazinon-degrading enzymes, such as hydrolase, acid phosphatase, laccase, cytochrome P450, and flavin monooxygenase were also discovered to play a crucial role in the biodegradation of diazinon. However, many unanswered questions still exist regarding the environmental fate and degradation mechanisms of this pesticide. The catalytic mechanisms responsible for enzymatic degradation remain unexplained, and ecotechnological techniques need to be applied to gain a comprehensive understanding of these issues. Hence, this review article provides in-depth information about the impact and toxicity of diazinon in living systems and discusses the developed ecotechnological remedial methods used for the effective biodegradation of diazinon in a contaminated environment.

Biodegradation of fipronil: current state of mechanisms of biodegradation and future perspectives.

Fipronil is a broad-spectrum phenyl-pyrazole insecticide that is widely used in agriculture. However, in the environment, its residues are toxic to aquatic animals, crustaceans, bees, termites, rabbits, lizards, and humans, and it has been classified as a C carcinogen. Due to its residual environmental hazards, various effective approaches, such as adsorption, ozone oxidation, catalyst coupling, inorganic plasma degradation, and microbial degradation, have been developed. Biodegradation is deemed to be the most effective and environmentally friendly method, and several pure cultures of bacteria and fungi capable of degrading fipronil have been isolated and identified, including Streptomyces rochei, Paracoccus sp., Bacillus firmus, Bacillus thuringiensis, Bacillus spp., Stenotrophomonas acidaminiphila, and Aspergillus glaucus. The metabolic reactions of fipronil degradation appear to be the same in different bacteria and are mainly oxidation, reduction, photolysis, and hydrolysis. However, the enzymes and genes responsible for the degradation are somewhat different. The ligninolytic enzyme MnP, the cytochrome P450 enzyme, and esterase play key roles in different strains of bacteria and fungal. Many unanswered questions exist regarding the environmental fate and degradation mechanisms of this pesticide. The genes and enzymes responsible for biodegradation remain largely unexplained, and biomolecular techniques need to be applied in order to gain a comprehensive understanding of these issues. In this review, we summarize the literature on the degradation of fipronil, focusing on biodegradation pathways and identifying the main knowledge gaps that currently exist in order to inform future research. KEY POINTS: • Biodegradation is a powerful tool for the removal of fipronil. • Oxidation, reduction, photolysis, and hydrolysis play key roles in the degradation of fipronil. • Possible biochemical pathways of fipronil in the environment are described.

The mechanical degradation mechanism of CFRP/Al double-lap bolted joints (with and without corrosion protections) after seawater ageing

Dual effects of environmental and mechanical loadings complicate mechanical behaviors of CFRP/Al joints, which significantly influence their reliable applications. This paper aims to reveal the mechanical degradation mechanism of CFRP/Al double-lap bolted joints with two kinds of corrosion protections (epoxy coating and PVC film) after seawater aging. All joints were exposed in the artificial marine environment with 3.5% sodium chloride solution at 30 ℃ for 0–8 weeks. Double-lap bearing tests and material analysis experiments with micro-CT and step profiler were conducted to reveal the environmental damage and mechanical degradation mechanism of aged joints. The results show that compared to epoxy coating, PVC film can better suppress galvanic-corrosion but degrades more the load-bearing capacity of joints due to the reduction of friction coefficient between CFRP and Al. The failure modes of unprotected joints and joints protected with PVC film evolve both from squeezing/shear-out to delamination/cleavage with ageing time, while squeezing is almost the only primary failure mode of joints protected with epoxy-coating. Joints protected with PVC films show more serious failure damage than the ones protected with epoxy-coating, since the epoxy-coating has better protective effect on CFRP laminate and therefore inhibits the deterioration of damage.

Biodegradation of the pyridinecarboxamide insecticide flonicamid by Microvirga flocculans and characterization of two novel amidases involved

Flonicamid (N-cyanomethyl-4-trifluoromethylnicotinamide, FLO) is a new type of pyridinecarboxamide insecticide that exhibits particularly good efficacy in pest control. However, the extensive use of FLO in agricultural production poses environmental risks. Hence, its environmental behavior and degradation mechanism have received increasing attention. Microvirga flocculans CGMCC 1.16731 rapidly degrades FLO to produce the intermediate N-(4-trifluoromethylnicotinoyl) glycinamide (TFNG-AM) and the end acid metabolite 4-(trifluoromethyl) nicotinol glycine (TFNG). This bioconversion is mediated by the nitrile hydratase/amidase system; however, the amidase that is responsible for the conversion of TFNG-AM to TFNG has not yet been reported. Here, gene cloning, overexpression in Escherichia coli and characterization of pure enzymes showed that two amidases—AmiA and AmiB—hydrolyzed TFNG-AM to TFNG. AmiA and AmiB showed only 20–30% identity to experimentally characterized amidase signature family members, and represent novel amidases. Compared with AmiA, AmiB was more sensitive to silver and copper ions but more resistant to organic solvents. Both enzymes demonstrated good pH tolerance and exhibited broad amide substrate specificity. Homology modeling suggested that residues Asp191 and Ser195 may strongly affect the catalytic activity of AmiA and AmiB, respectively. The present study furthers our understanding of the enzymatic mechanisms of biodegradation of nitrile-containing insecticides and may aid in the development of a bioremediation agent for FLO.

Analysis of environmental degradation mechanism in the nexus among energy consumption and poverty in Pakistan.

The study aims to analyze the mediating role of environmental degradation (ED) in the association between energy consumption (EC) and poverty (POV) in Pakistan. For this purpose, data are collected from different sources such as the global economy and World Bank ranging from 1985 to 2017. Augmented Dickey-Fuller (ADF) test is used for testing the stationarity of data. Results of ADF depict that data are stationary at the level and first difference; so this study adopts the autoregressive distributive lag (ARDL) model bound test for analyzing the long-run and short-run relationship among the modeled variables. The study follows the steps of Baron and Kenny's (1986) method to test the mediation of environmental degradation between energy consumption and poverty. The study utilized the Sobel test and VAF to confirm the mediation. The results indicate a negative and significant impact of energy consumption on poverty. The findings revealed that ED partially mediates the long-run relationship between EC and POV. The study suggests that the government makes the energy accessible to the people to fulfill their basic needs which ultimately reduces poverty. Moreover, the government should make policies to improve the environment as the study found that environmental degradation significantly contributes to poverty.