A Tool for Evaluating Environmental Sustainability of Plastic Waste Reduction Innovations

Plastics and their byproducts are littering our cities, oceans, and waterways, and contributing to health problems in humans and animals. Since plastics have become significant in our economic and social activities, it is urgent and essential to make progress in plastic waste reduction. Many large investors are looking into technologies and solutions that reduce plastic waste, but a sole plastic waste reduction innovation or project does not guarantee or equate to sustainability performance. In this Master’s project, the team at the School of Environment and Sustainability (SEAS) investigated the plastics industry, with the objective of developing a framework and sustainability assessment tool for evaluating plastic reduction innovations to support investment decisions. The team reviewed sustainability assessment literature and studied plastic waste reduction strategies to determine key criteria and a process for evaluating sustainability performance of plastic waste reduction innovations. Through this work, the Plastic Waste Reduction Innovation Sustainability Evaluation Tool (PRISET) was created, setting educational guidelines around the criteria for both investors and other potential users. General guidance is presented for evaluating environmental sustainability of basic business models that focuses on the company’s mission & vision, circular economy attributes, and potential scale of the waste reduction innovation. More indepth tools for evaluating specific technology innovations include third party certifications and life cycle assessments that require expertise to conduct. Waste reduction innovations were classified into four categories: reuse & refill, alternative materials, innovative design and recycling; and specific guidance criteria in the form of questions were presented to highlight key drivers of sustainability performance in each category. Finally, we also conducted a case study to test the feasibility of the tool. Those innovations that address a wider set of criteria are expected to be more preferrable, while feedback from the assessment will also be useful for innovation companies themselves to focus efforts on those criteria they have not addressed.Master of ScienceSchool for Environment and SustainabilityUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/167287/1/Eval Env Sus of Plastic Waste Red.pd

Field test on the biodegradation of poly(butylene adipate-co-terephthalate) based mulch films in soil

The use of plastic much films has been fundamental to promoting food production in many regions of the world. However, concern is growing about the progressive accumulation of plastic residues in soil after crop harvest and its subsequent impact on soil health and potential to enter the food chain. Although biodegradable films have been developed to prevent these problems, it is still unclear whether they are environmentally benign. Here we evaluated the physical and chemical breakdown of four commercial poly(butylene adipate-co-terephthalate) based biodegradable mulch films (BMF1, BMF2, BMF3 and BMF4) in an agricultural soil over a 26-month period. Based on visual examination, degradation followed the series BMF4 > BMF1, BMF2 > BMF3. Importantly, microplastic residues (fragments <5 mm) still remained in the soil of all 4 plastic types after 2 years, suggesting that they are likely to accumulate over time if used on an annual basis. Viscosimetry, Fourier transform infrared (FTIR) spectroscopy and Thermogravimetric Analysis (TGA) were used to characterise the breakdown process. Our results indicated that the degradation of the mulch film after burial in agricultural soil may be linked to the nature of the polymer but also to its manufacturing formulation. Although the peak changes of polyester in the infrared spectrum were not distinct, the plastic films showed other signs of degradation including a reduction in intrinsic viscosity after burial in soil. The different degradation rates of BMF1 and BMF2 at the molecular level may be due to the different CaCO3 contents. In conclusion, under field conditions, we show that slight variations in the formulations of commercial biodegradable mulch films leads to very different persistence rates in soil. Further, we conclude that their slow rate of degradation will ultimately lead to their progressive accumulation in soil if used repeatedly

Climate and litter traits affect the response of litter decomposition to soil fauna

International audienceObjectives Soil fauna plays a crucial role in contributing to litter breakdown, accelerating the decomposition rate and enhancing the biogeochemical cycle in terrestrial ecosystems. Comprehending the specific fauna role of functional species in litter decomposition is challenging due to their vast numbers and diversity. Climate and litter quality are widely acknowledged as dominant drives of litter decomposition across large spatial scales. However, the pattern of climate and litter quality modulates the effect of soil fauna on litter decomposition remains largely unexplored. To address this gap, we conducted an extensive analysis using data from 81 studies to investigate how climate and litter traits affects soil fauna in the decomposition. Data description The paper describes fauna body size, climate zones (tropical, subtropical and temperate), ecosystem types (forest, grassland, wetland and farmland), soil types (sand, loam and clay), decomposed duration ( 360 days), litter initial traits, average annual temperature and precipitation. The litter traits encompass various parameters such as concentrations of carbon, nitrogen, phosphorus, potassium, lignin, cellulose, total phenol, condensed tannin, hydrolysable tannin and other nutrient traits. These comprehensive datasets provide valuable insights into the role of soil fauna on the decomposition at global scale. Furthermore, the data will give researchers keys to assess how climate, litter quality and soil fauna interact to determine decomposition rates

Dme-Hsa Disease Database (DHDD): Conserved Human Disease-Related miRNA and Their Targeting Genes in Drosophila melanogaster

Abnormal expressions of microRNA (miRNA) can result in human diseases such as cancer and neurodegenerative diseases. MiRNA mainly exert their biological functions via repressing the expression of their target genes. Drosophila melanogaster (D. melanogaster) is an ideal model for studying the molecular mechanisms behind biological phenotypes, including human diseases. In this study, we collected human and D. melanogaster miRNA as well as known human disease-related genes. In total, we identified 136 human disease-related miRNA that are orthologous to 83 D. melanogaster miRNA by mapping &ldquo;seed sequence&rdquo;, and 677 human disease-related genes that are orthologous to 734 D. melanogaster genes using the DRSC Integrative Ortholog Prediction Tool Furthermore, we revealed the target relationship between genes and miRNA using miRTarBase database and target prediction software, including miRanda and TargetScan. In addition, we visualized interaction networks and signalling pathways for these filtered miRNA and target genes. Finally, we compiled all the above data and information to generate a database designated DHDD This is the first comprehensive collection of human disease-related miRNA and their targeting genes conserved in a D. melanogaster database. The DHDD provides a resource for easily searching human disease-related miRNA and their disease-related target genes as well as their orthologs in D. melanogaster, and conveniently identifying the regulatory relationships among them in the form of a visual network

Biocompatible Mn(II)-Enhanced N–S-Codoped Carbon Dots: A Versatile Fluorescence Sensor for Sensitive Hg²⁺ Detection in Coastal Seawater and Living Cells

Despite the promising potential of carbon dots (CDs) as a photoluminescent nanomaterial in advancing spectral analysis techniques for the detection of various harmful heavy metal ions such as Hg2+, Cu2+, Cd2+, and Pb2+, the fundamental challenge of effectively eliminating the interference of transition metal ions in multi-ion systems persists. In this study, we present straightforward, efficient, and versatile manganese(II)-enhanced nitrogen and sulfur codoped carbon dots (Mn(II)-N,SCDs) specifically designed for the highly selective and sensitive detection of Hg2+ ions. Mn(II)-N,SCDs exhibited uniform particle size (∼2.0 nm) and demonstrated excellent fluorescence performance, characterized by high fluorescence intensity and quantum yield (QY = 48.71%). The incorporation of Mn2+ not only enhances the fluorescence characteristics but also serves to effectively block the surplus transition metal ion binding sites on the surface of carbon dots, thereby leading to a heightened selective response to Hg2+. Furthermore, the synthesized Mn(II)-N,SCDs also exhibited low cytotoxicity and efficient cellular uptake, enabling fluorescence imaging of living cells. Importantly, the developed fluorescence sensor exhibited a highly specific response to Hg2+ ions even in the presence of other metal ions in phosphate-buffered solution (PBS), with a low detection limit of 0.29 nM (S/N = 3). The efficacy of the probe was successfully demonstrated through the determination of Hg2+ in live cells and natural coastal water samples

Solution-Phase Synthesis of Co-N-C Catalysts Using Alkali Metals-Induced N-C Templates with Metal Vacancy-Nx sites

Nitrogen-coordinated metal sites (MNx) in metal- and nitrogen-co-doped carbon (M-N-C) catalysts are known for their versatile and promising electrocatalytic activity. However, the synthesis of MNx moieties with desired configuration and catalytic property is still quite challenging using the conventional high-temperature treatment approach. In this study, we demonstrate the solution-phase synthesis of Co-N-C catalysts via the formation of CoNx moieties at metal vacancy-Nx (MVNx) sites on nitrogen-doped carbon (N-C) templated by alkali metals, including sodium and potassium. The formation of CoNx sites is confirmed via a combined approach of various physical characterization techniques, elemental analysis, and electrochemical analysis. For each series of Co-N-C catalysts templated by the same alkali metal (e.g., Na or K), there is a correlation between the CoNx content and the electrocatalytic activity for the oxygen reduction reaction (ORR). Moreover, the correlation of CoNx content with ORR activity also depends on the type of sacrificial alkali metals, suggesting the role of sacrificial metals in creating MVNx sites with a diverse coordination environment. These findings may further guide the future development of M-N-C electrocatalysts with abundant and versatile MNx moieties through this solution-phase coordination approach

Genome-Wide Identification and Expression Analysis of the Dof Transcription Factor Gene Family in Gossypium hirsutum L.

Gossypium hirsutum L. is a worldwide economical crop; however, premature leaf senescence reduces its production and quality which is regulated by stresses, hormones, and genes. DNA binding with the one zinc finger (Dof) transcription factors (TFs) participate widely in plant development and responses to biotic and abiotic stresses, but there have been few reports of these TFs in cotton. Here, we perform a genome-wide study of G. Hirsutum L. Dof (GhDof) genes and analyze their phylogeny, duplication, and expression. In total, 114 GhDof genes have been identified and classified into nine subgroups (A, B1, B2.2, B2.1, C1, C2.1, C2.2, D1, and D2) based on phylogenetic analysis. An MCScanX analysis showed that the GhDof genes expanded due to segmental duplications. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis showed that GhDofD9.6 was not only differentially expressed between CCRI10 (with premature senescence) and Liao4086 (without premature senescence) but also responded to salinity stress; GhDofA5.7, GhDofA7.4, GhDofA8.2, GhDof11.1, GhDofD7.2, and GhDofD11.3 signfificantly responded to cold (4 &deg;C) stress. This work lays the foundation for further analysis of the function of GhDof genes in G. hirsutum, which will be helpful for improving the production and quality of cotton

Surface ocean nitrate-limitation in the aftermath of Marinoan snowball Earth: Evidence from the Ediacaran Doushantuo Formation in the western margin of the Yangtze Block, South China

© 2020 Elsevier B.V. Geochemical and paleontological studies suggest that a rapid rise in atmospheric O2 level in the termination of the Marinoan global glaciation (635 Ma) might have triggered the diversification of eukaryotes and caused the deep ocean oxygenation. It is proposed that the Earth\u27s surface redox condition was directly linked to the marine primary productivity, which represented the only major O2 source before the evolution of land plants. The marine primary productivity was mainly controlled by the bioavailability of macronutrients, phosphorus (P) and nitrogen (N). Thus, reconstruction of ancient P and N cycles can provide direct constraints on marine organic matter production and the redox landscape of the ocean. Previous studies of the Ediacaran Doushantuo Formation in the Yangtze Block, South China, suggested that the Ediacaran marine N cycle was highly dynamic and was characterized by dramatic fluctuations in the intensity of denitrification. However, these studies were mainly focused on sections deposited in the offshore marine environment, and little is known about the N cycle in the nearshore regions. In this study, we report high-resolution organic carbon (δ13Corg) and nitrogen (δ15NTN) isotopes of the Doushantuo Formation at the E-Shan section in the western margin of the Yangtze Block. The Doushantuo Formation at the E-Shan section is composed of alternating deposition of thin bedded sandstone and mudstone, and was deposited in a nearshore delta environment. The δ13Corg profile displays two prominent negative excursions, which are coincident with two positive excursions in δ15NTN. The positive excursion in δ15NTN implies the enhanced denitrification, resulting in the loss of N (nitrate and ammonium). In addition, there are negative correlations between δ15NTN and TOC content and between δ15NTN and δ13Corg. Such relationships suggest that the reduction of N supply would lower primary productivity and accordingly decrease the carbon isotope of dissolved inorganic carbon (δ13CDIC) in the surface ocean. In addition, this interpretation also implies that N-fixation was not active in the nearshore region. We speculate that the muted N-fixation in the nearshore regions could be attributed to the Fe limitation in oxic shallow seawater and general Mo deficiency of the Ediacaran ocean. Thus, our study indicates that the surface ocean productivity and marine redox landscape were coupled in the Ediacaran ocean