Hasil untuk "Environmental sciences"

C. Balazs, R. Morello-Frosch

Dong Li, Min Zhao, Hailong Zhang et al.

The inland water portion of the carbon cycle is an essential component of the global carbon cycle and is a promising direction to seek missing carbon sinks. Inland waters fix inorganic carbon to form autochthonous organic carbon (Auto-OC) and accept laterally transferred terrestrial OC. Calculating the carbon sink flux of inland water requires a quantitative estimation of the proportion of the aforementioned processes. In the current study, n-alkanes are used as biomarkers and the dual carbon isotope method (Bayesian mixing model) is applied to estimate the proportions of Auto-OC in the sediment of a simulation site comprising five shallow submerged macrophyte-dominated subsystems. The study results showed that a high proportion of Auto-OC was present in all sediment, regardless of the season or subsystem. However, the proportions were higher in the warm-humid season than in the cold-dry season. Results from a correlation analysis showed that temperature-controlled seasonal variations in the photosynthetic strength of aquatic organisms are the most likely cause of this difference. The average deposition rates of total organic carbon and Auto-OC were high (66.7 and 58.2 g C/m2/yr, respectively). Throughout the year, the weighted average percentage of Auto-OC ranged from 76% to 90%, with a mean value of 86% in the five aquatic subsystems. Establishing and maintaining submerged macrophyte-dominated systems have a potential of decreasing carbon dioxide (CO2) evasion and sequestrating more carbon (C) in headwaters. Working for clear submerged macrophyte-dominated lakes is beneficial for increasing carbon sinks.

Renan S. Nunes, Gabriela T.M. Xavier, Alessandro L. Urzedo et al.

Phosphorus uptake and recovery from sanitary wastewater have been considered a promising approach to producing more sustainable fertilizers, in addition to reducing environmental damage caused by the discharge of this nutrient into water streams. In this study, the Phosphorus adsorption/desorption dynamics exhibited by a tailored SiO2@FeOOH adsorbent, produced using quartz sand waste and Fe derived from the acid dissolution of scrap iron, were examined. The adsorbent’s behavior, robustness, and interaction with Ca2+ ions in simulated treated sanitary wastewater were systematically investigated. As a result, the behavior of the adsorbent under controlled conditions was successfully modeled, and relevant interactions between the material and Ca2+ ions were identified under simulated conditions. The performance of the adsorbent was not affected by the presence of nitrate, carbonate, sulfate, ammonium, fluoride, and humic substances in the simulated media. Additionally, the composite can adsorb humic substances and Phosphorus simultaneously, without interfering with its Phosphorus adsorption capacity. In simulated treated wastewater, the adsorption of the nutrient was enhanced in the presence of Ca2+; however, the formation of insoluble Ca/P deposits on the adsorbent surface significantly changed the adsorption dynamics and disturbed the recovery of Phosphorus using the usual alkaline desorption method. The adsorbent exhibited a robust Phosphorus adsorption capacity as high as 40 mg P/g in simulated treated wastewater, showing clear potential for Phosphorus uptake in Wastewater Treatment Plants. Based on the experimental evidence, future perspectives on the final disposal of the spent adsorbent were also discussed within a circular economy framework.

Trifonov Yuri

Using the complete Navier-Stokes equations, we investigate the linear stability of a viscous flow in a channel with various corrugated walls. We consider both the longitudinal corrugations when the main flow has two velocity components and the transversely corrugated wall when the basic flow has one velocity component. In frame of one approach and in a wide range of variations in the corrugation parameters and shapes, we analyze the neutral curves for the linear stability problem. We calculate the critical Reynolds number above which the main flow is unstable and there are disturbances growing in time. Perturbations of the velocity and pressure fields are, in general, three-dimensional with two wave numbers. We solve numerically the generalized eigenvalue problem. In the case of the transversely corrugated wall, we obtain two regions of parameters where the dependencies of the critical Reynolds number on the corrugation parameters are qualitatively different. The limits of these regions depend only on the ratio of the amplitude and period of corrugations. In the case of the longitudinal-corrugations, we find the corrugation parameters where the basic flow is unstable with respect to the periodic disturbances with the same wavelength as the corrugations wavelength and undergoes “the unavoidable transition” to a flow with more complicated behaviour in time.

Xiaoliang Shi, Jiayin Xin, Aruna Aria et al.

This systematic study on the international research trends in carbon neutrality underscores its critical role in combating global warming and advancing sustainable development. By leveraging the “Web of Science Core Collection” databases and employing CiteSpace software for visual analysis, we examined 2223 research papers to track the influence and trends of key countries, institutions, and authors. Our results reveal a significant increase in publication volume, indicating a robust development potential for carbon neutrality research. The study also identifies environmental science, environmental research, and energy and fuel science as central interdisciplinary hubs, highlighting the importance of cross-disciplinary collaboration. Notably, China leads in publication output but has room for improvement in citation impact, suggesting a need for enhanced research quality and international visibility. The study's findings are instrumental for guiding future research directions, policy-making, and interdisciplinary cooperation, particularly in the fields of environmental science and energy, to accelerate progress towards carbon neutrality and global climate governance.

Alex T. Ford, Amruthavarshini Shankar, Sarah Reynolds et al.

Abstract The planet faces a triple crisis from climate change, biodiversity loss, and pollution. Like any country, the UK needs to attract the best available talent to become thought leaders to overcome these global challenges. Several Science, Technology, Engineering and Maths subjects in the UK face challenges with attracting ethnic minority students. As part of a wider project on diversity in UK environmental/marine science, we analysed university applications amongst 180 environmental and 88 marine science degrees in the UK between 2019–2021. We found them to be the least diverse degree subjects for ethnic minority students and Asian students were less likely to be accepted than white students on environmental science degrees. A survey of UK marine science course leaders highlights the belief that these issues impact the pipeline of diversity from higher education institutions to marine/environmental science careers. In this paper, we discuss the impacts of these findings and develop a roadmap to change.

Ho Young Lee, Dorothy J. You, Alexia Taylor-Just et al.

Abstract Background Pulmonary exposure to multi-walled carbon nanotubes (MWCNTs) has been reported to exert strong pro-inflammatory and pro-fibrotic adjuvant effects in mouse models of allergic lung disease. However, the molecular mechanisms through which MWCNTs exacerbate allergen-induced lung disease remain to be elucidated. We hypothesized that protease-activated receptor 2 (PAR2), a G-protein coupled receptor previously implicated in the pathogenesis of various diseases including pulmonary fibrosis and asthma, may play an important role in the exacerbation of house dust mite (HDM) allergen-induced lung disease by MWCNTs. Methods Wildtype (WT) male C57BL6 mice and Par2 KO mice were exposed to vehicle, MWCNTs, HDM extract, or both via oropharyngeal aspiration 6 times over a period of 3 weeks and were sacrificed 3-days after the final exposure (day 22). Bronchoalveolar lavage fluid (BALF) was harvested to measure changes in inflammatory cells, total protein, and lactate dehydrogenase (LDH). Lung protein and RNA were assayed for pro-inflammatory or profibrotic mediators, and formalin-fixed lung sections were evaluated for histopathology. Results In both WT and Par2 KO mice, co-exposure to MWCNTs synergistically increased lung inflammation assessed by histopathology, and increased BALF cellularity, primarily eosinophils, as well as BALF total protein and LDH in the presence of relatively low doses of HDM extract that alone produced little, if any, lung inflammation. In addition, both WT and par2 KO mice displayed a similar increase in lung Cc1-11 mRNA, which encodes the eosinophil chemokine CCL-11, after co-exposure to MWCNTs and HDM extract. However, Par2 KO mice displayed significantly less airway fibrosis as determined by quantitative morphometry compared to WT mice after co-exposure to MWCNTs and HDM extract. Accordingly, at both protein and mRNA levels, the pro-fibrotic mediator arginase 1 (ARG-1), was downregulated in Par2 KO mice exposed to MWCNTs and HDM. In contrast, phosphorylation of the pro-inflammatory transcription factor NF-κB and the pro-inflammatory cytokine CXCL-1 was increased in Par2 KO mice exposed to MWCNTs and HDM. Conclusions Our study indicates that PAR2 mediates airway fibrosis but not eosinophilic lung inflammation induced by co-exposure to MWCNTs and HDM allergens.

Audrey J. Gaskins, Lidia Mínguez-Alarcón, Trang VoPham et al.

Melanie H Jacobson, Miriam Woodward, Wei Bao et al.

AbstractBisphenol A (BPA) has been recognized as an endocrine disrupting chemical and identified as an obesogen. Although once ubiquitous, human exposure to BPA has been declining owing to its substitution with other bisphenols. Two structurally similar substitutes, bisphenol S (BPS) and bisphenol F (BPF), have raised similar concerns, although fewer studies have been conducted on these newer derivatives. We used data from the US National Health and Nutrition Examination Surveys from 2013 to 2016 to evaluate associations between BPA, BPS, and BPF and body mass outcomes among children and adolescents aged 6 to 19 years. Concentrations of BPA, BPS, and BPF were measured in spot urine samples using HPLC with tandem mass spectrometry. General obesity was defined as ≥95th percentile of the age- and sex-standardized body mass index (BMI) z-scores according to the 2000 US norms. Abdominal obesity was defined as a waist circumference/height ratio of ≥0.5. BPA, BPS, and BPF were detected in 97.5%, 87.8%, and 55.2% of urine samples, respectively. Log-transformed urinary BPS concentrations were associated with an increased prevalence of general obesity (OR, 1.16; 95% CI, 1.02 to 1.32) and abdominal obesity (OR, 1.13; 95% CI, 1.02 to 1.27). BPF detection (vs not detected) was associated with an increased prevalence of abdominal obesity (OR, 1.29; 95% CI, 1.01 to 1.64) and continuous BMI z-score (β = 0.10; 95% CI, 0.01 to 0.20). BPA and total bisphenols were not statistically significantly associated with general obesity, abdominal obesity, or any body mass outcome. These results suggest that BPA substitute chemicals are correlated with obesity in contemporary children.

M. Stafoggia, S. Breitner, Regina Hampel et al.

A. Khouz, A. Khouz, A. Khouz et al.

<p>In recent decades, multiple researchers have produced landslide susceptibility maps using different techniques and models, including the information value method, which is a statistical model that is widely applied to various coastal environments. This study aimed to evaluate susceptibility to landslides in the Essaouira coastal area using bivariate statistical methods. In this study, 588 distinct landslides were identified, inventoried, and mapped. Landslides are performed by means of observation and interpretation of different data sources, namely high-resolution satellite images, aerial photographs, topographic maps, and extensive field surveys. The rocky coastal system of Essaouira is located in the middle of the Atlantic coast of Morocco. The study area was split into 1534 cliff terrain units that were 50 m in width. For training and validation purposes, the landslide inventory was divided into two independent groups: 70 % for training and 30 % for validation. Twenty-two layers of landslide conditioning factors were prepared – namely, elevation, slope angle, slope aspect, plan curvature, profile curvature, cliff height, topographic wetness index, topographic position index, slope over area ratio, solar radiation, presence of faulting, lithological units, toe lithology, presence and type of cliff toe protection, layer tilt, rainfall, streams, land-use patterns, normalised difference vegetation index, lithological material grain size, and presence of springs. The statistical relationship between the conditioning factors and the different landslide types was calculated using the bivariate information value method in a pixel-based model and in the elementary terrain units-based model. Coastal landside susceptibility maps were validated using landslide training group partitions. The receiver operating characteristic curve and area under the curve were used to assess the accuracy and prediction capacity of the different coastal landslide susceptibility models. Two methodologies, considering a pixel-based approach and using coastal terrain units, were adopted to evaluate coastal landslide susceptibility. The results allowed for the classification of 38 % of the rocky coast subsystem as having high susceptibility to landslides, which were mostly located in the southern part of the Essaouira coastal area. These susceptibility maps will be useful for future planned development activities as well as for environmental protection.</p>

Xianhui Zhao, Oluwafemi Oyedeji, Erin Webb et al.

Owing to its low cost and sustainable nature, lignocellulosic biomass has been utilized for reinforcing polymers, but it is crucial to understand the impact of high-ash concentrations in biomass on composite strength and processing. Biomass is not only desirable for biofuel production but could also have a strong market, if high-ash biomass is acceptable, for biocomposites. In this work, natural fibers (switchgrass and corn stover) were used to reinforce polylactic acid (PLA) to produce biocomposites. Natural fibers were pretreated to obtain fibers that contain different percentages of ash. The mechanical properties (such as Young's modulus, tensile strength, failure strain, storage modulus) of corn stover/PLA composites remained largely unaffected by the ash concentration of the biomass fibers, despite the large range of ash contents (2.2–11.9 wt%). However, the tensile strengths of switchgrass/PLA composites were slightly negatively affected by the ash concentration of the switchgrass fibers (0.7–2.1 wt%). Both the switchgrass/PLA and the corn stover/PLA composites exhibited a high-enough tensile strength (49–57 MPa) and suitable complex viscosity (2.0−7.0 kPa·s at the frequency of 3.2 rad/s). They are expected to be 3D-printable through an extrusion-based additive manufacturing process.

Gursewak Singh, Brian Ward, Amnon Levi et al.

Weeds negatively affect organic vegetable crop growth and profitability. Weed management is the greatest challenge for vegetable organic growers since control options are limited for organic vegetable production. Anaerobic soil disinfestation (ASD) is a novel non-chemical pest management technique that creates anoxic conditions in the topsoil layer for a limited time. ASD is primarily based on the addition of labile carbon sources to topsoil to promote anaerobic conditions driven by microorganisms in moist soil mulched with polyethylene film (polyfim). Field studies were conducted in the summer–fall of 2020 and 2021 to determine the efficacy of warm season cover crops used as carbon sources for ASD and their role in weed management. The study used a factorial experimental design with four cover crop residue treatments (sorghum-sudangrass, sunn hemp, both, or none) in two soil aeration conditions (aerated or non-aerated). Cover crops were grown for 75 days, incorporated into the soil, and sealed with totally impermeable film (TIF) clear mulch, followed by a 4-week ASD process. All incorporated cover crop treatments in non-aerated conditions generated moderate to higher anaerobic conditions (0–150 mV) and provided significantly higher (<i>p</i> < 0.05) weed control than all the other treatments tested or controls. Tomato plants transplanted in non-aerated, cover crops incorporated plots were more vigorous and produced higher yields than aerated plots. No phytotoxicity was observed on tomato plants following ASD treatment in any of the treatments tested. This study demonstrated that warm season cover crops could potentially serve as a carbon source for ASD in organic tomato production.

Gianni Betti, Gian Piero Cervellera, Francesca Gagliardi et al.

An energy transition is needed in order to meet the European pledge of reaching climate neutrality by 2050. This transition cannot ignore the renewable resources available from 70% of the Earth (namely, the oceans and seas). This concept is fundamental for the planet, especially for the Mediterranean area. Marine renewable energies are still under-deployed in the Mediterranean area for many reasons, including legislative constraints, lower energy availability, and technological readiness. An appropriate participatory process including all actors (e.g., policymakers, firms, citizens, and researchers) is necessary for a correct path toward decarbonization. The BLUE DEAL project was conceived and implemented by 12 Mediterranean partners to tackle these issues and set the route for blue energy deployment in the Mediterranean area. Activities already conducted include a survey to probe the perceptions and attitudes of citizens toward blue energy. The survey targeted about 3,000 persons in 12 Mediterranean sites with the aim of bringing citizens into the discussion on future technologies. The results showed that although blue energy is still relatively unknown to the general public (only 42% of respondents were aware of these technologies), there was a general willingness (70%) to host one or more such installations in their areas. Here, we describe our survey method and some empirical results with suggestions for replicability and recommendations on how to use it for policymaking purposes.

Qing Liu, Limin Zhang, Erik L. Allman et al.

Claudia Patricia Camacho-Rozo, Nicolás Urbina-Cardona

The study of tadpole assemblages allows inferring habitat availability and using their occupation as a means of proxy for the effective reproduction of the species, contributing to complementary information for the study of their adult forms. Environmental variables, represented by abiotic variables, vegetation structure, matrix management, and landscape elements, affect species having reproductive modes associated with oviposition and development in bodies of water. In the Orinoco region, most amphibians have complex life cycles and deposit their eggs in highly dynamic lentic bodies of water. Therefore, it is important to know how larval assemblages change over short periods of water accumulation and their relationship with environmental variables. Fieldwork was conducted during 9 weeks of larval sampling, from the beginning of the rainy season. We evaluate changes in anuran assemblages associated with water accumulation in five temporary water bodies of anthropogenic (road or pasture) and natural (savanna or gallery forest) origin. Twenty environmental variables were evaluated and measured in the center of each water body. Of these, nine landscape variables were measured only once during the study. The other eleven variables, representing management practices, physicochemical and structural characteristics of the water bodies, were measured weekly during the 3 months of sampling. We explored differences in the structure and diversity of larval-stage anuran assemblages using statistical tests suitable for small sample sizes (i.e., permutational multivariate analysis of variance PERMANOVA and the distance-based linear modeling DistLM). Of the 14 species found, two species had remarkedly high abundances from which Rhinella humboldti (19% of the total tadpole abundance) was a generalist inhabiting the natural and anthropogenic water bodies, while Leptodactylus insularum (18% of the total tadpole abundance) was a specialist at a natural pond in the savanna. The natural water bodies contained the highest number of species (between 10 and 12) and a total abundance of larvae (between 847 and 485 individuals). In contrast, the anthropogenic water body tracks generated by tractors were only occupied by two species with 50 individuals in total, while the water body generated by the trampling of cattle in pastures had three species with 474 individuals. These three species that inhabited the anthropogenic puddles were also found in the natural ponds and none of the eight species of hylids inhabited the puddles. In each field trip, all the tadpoles were collected from the sampled bodies of water. However, a week later, we found that each of the water bodies had been recolonized by four species (Leptodactylus fuscus, Leptodactylus fragilis, Elachistocleis ovalis, and R. humbolti). The variables with the highest explanatory power on the variation of anuran assemblage structure throughout all the water bodies were height of plants, number of cattle, distance to the nearest native forest edge, distance to an anthropic lentic body of water, distance to a natural lentic body of water, and pH. The bodies of water immersed in the natural cover were more diverse and had a greater degree of spatial and temporal species turnover. Our study calls for the importance of understanding the turnover of larval stage anurans over short periods, associated with water accumulation, in highly dynamic systems such as natural ponds and anthropogenic puddles. The importance of species traits and local processes is also highlighted, from environmental variables to human management activities, in the conservation of amphibian assemblages.

Kai-Ruei Yang, Ming-Fong Tsai, Chwen-Jen Shieh et al.

Chondroitin sulfate (ChS) is usually used as an oral nutraceutical supplement, and has been popular in Asia, Europe, and United States for many years. In this study, a potential and sustainable source of ChS from jumbo squid (<i>Dosidicus gigas</i>) cartilage was explored; ultrasound-assisted extraction (UAE) was used to extract ChS from jumbo squid cartilage. The result of mass transfer coefficients based on Fick’s law showed that UAE had higher mass transfer efficacy. The response surface methodology (RSM) combined with Box–Behnken design (BBD) was employed to evaluate the effects of the extraction parameters. The optimal conditions were extraction temperature of 52 °C, extraction time of 46 min, and NaOH concentration of 4.15%. The crude extract was precipitated by 50% ethanol, which obtained a purified ChS with 23.7% yield and 82.3% purity. The purified ChS measured by energy-dispersive X-ray spectroscopy (EDX) had a carbon to sulfur molar ratio of approximately 14:1. The FTIR, ¹H, and ¹³C NMR confirmed jumbo squid ChS were present in the form of chondroitin-4-sulfate and chondroitin-6-sulfate, with a 4S/6S ratio of 1.62. The results of this study provide an efficient process for production and purification of ChS, and are significant for the development and utilization of ChS from jumbo squid cartilage in the nutrient food or pharmaceutical industries.

Beata Dąbrowska-Bouta, Grzegorz Sulkowski, Jolanta Orzelska-Górka et al.

The increasing production and use of silver nanoparticles (AgNPs) as antimicrobial agents in medicinal and commercial products creates a substantial risk of exposure, especially for infants and children. Our current knowledge concerning the impact of AgNPs on developing brain is insufficient. Therefore we investigated the temporal profile of transcriptional changes in cellular components of the neurovascular unit in immature rats exposed to a low dose of AgNPs. The behavior of animals under these conditions was also monitored. Significant deposition of AgNPs in brain of exposed rats was identified and found to persist over the post-exposure time. Substantial changes were noted in the transcriptional profile of tight junction proteins such as occludin and claudin-5, and pericyte-related molecules such as angiopoietin-1. Moreover, downregulation of platelet-derived growth factor (PDGFβ) and its receptor (PDGFβR) which constitute the main signaling pathway between endothelial cells and pericytes was observed. These were long-lasting effects, accompanied by overexpression of astroglial-specific GFAP mRNA and endothelial cell adhesion molecule, ICAM-1, involved in the pathomechanism of neuroinflammation. The profile of changes indicates that even low doses of AgNPs administered during the early stage of life induce dysregulation of neurovascular unit constituents which may lead to disintegration of the blood-brain barrier. This was confirmed by ultrastructural analysis that revealed enhanced permeability of cerebral microvessels resulting in perivascular edema. Changes in the behavior of exposed rats indicating pro-depressive and anti-anxiety impacts were also identified. The results show a high risk of using AgNPs in medical and consumer products dedicated for infants and children.

Robert M. Sargis, Jerrold J. Heindel, Vasantha Padmanabhan

Wang Ping, Zhu Zhiqiang, Zhang Shuang

Energy, which accounts for two-thirds of today’s greenhouse gas emissions, is the key to reducing greenhouse gas emissions and slowing global warming. In this paper, the IPCC-recommended reference approach and scenario analysis were applied to evaluate dynamic change of the energy supply and energy-related carbon dioxide emissions within the period of 2000-2025 in Northern China (NC). The results show that energy importing reliance reached 85% in 2015 and the energy structure has become more diversified in NC. In addition, the per-capita CO2 emission is significantly higher while carbon intensity is lower than those of the national average. Under the LC scenario, CO2 emissions begin to fall for the first time in 2022. Hence, if Energy-Saving and Emission-Reduction strategy and regional planning for NC are implemented fully, NC will achieve the national emission reduction targets in 2025 and will have a large CO2 mitigation potential in the future.