Open Access Publications

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Open access publications related to sustainability research.

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Assessing Iron Complexation by Dissolved Organic Matter Using Mediated Electrochemical Oxidation
(ACS Earth and Space Chemistry, 2024-08-14) Hudson, Jeffrey M.; Luther, George W., III; Chin, Yu-Ping
FeII is an abundant reductant in the environment that participates in numerous biogeochemical cycles and pollutant attenuation. FeII in aquatic environments can exist as a complex with dissolved organic matter (DOM), where organic ligands in DOM can modulate iron’s redox potential (EH) and henceforth reactivity as a reductant. Previous studies have assessed the reactivity of FeII-complexes using probe compounds, although these compounds are limited in their ability to profile FeII oxidation across multiple thermodynamic conditions (i.e., both pH and EH) and fail to validate the EH of Fe(II)-complexes via their direct measurement. This study elucidated the redox potentials of FeII-DOM complexes via mediated electrochemical oxidation (MEO) and assessed the extent of FeII oxidation at two different applied EH and pH regimes. Furthermore, we used a Nernstian-based model calibrated with a training set between known iron-ligand thermodynamic stability constants and their respective measured potentials to indirectly determine the stability constants of both FeII and FeIII-DOM complexes as a function of EH and pH. This work highlights the versatility of MEO as an electrochemical technique and is the first to assess stability constants of Fe-complexes with aquatic DOM isolates. We also discuss linkages between speciation modeling and redox reactivity of FeII.
Burnout among public health workers during the COVID-19 response: Results from a follow-up survey
(PLOS Mental Health, 2024-08-07) Scales, Sarah Elizabeth; Kintziger, Kristina W.; Stone, Kahler W.; Jagger, Meredith A.; Horney, Jennifer A.
The public health workforce began the response to the COVID-19 pandemic with a critical workforce deficit, losing 20% of staff between 2018 and 2019. This study assesses changes in burnout among a cohort of 80 public health workers in the U.S. who completed multiple assessments during the ongoing COVID-19 response via Qualtrics. Self-reported burnout was assessed using a 5-point, validated, non-proprietary single-item measure. A binary burnout variable (1,2 = No; 3,4,5 = Yes) was created based on responses. Burnout direction (e.g., decreased, same, increased) was derived from changes in five-level work-related burnout scores. Factors indicating work-related exhaustion was higher among individuals reporting burnout in the follow-up survey compared to those without burnout. Baseline burnout, hours worked per week, and sleep quality were significant predictors of burnout at follow-up. A higher proportion of respondents reported burnout at follow-up than at the baseline survey. The ubiquitous nature of burnout among public health workers is a threat to the wellbeing of individuals in the workforce and the population’s health at large. Investments in expanding and supporting the public health workforce are needed.
El Niño and positive Indian Ocean Dipole conditions simultaneously reduce the production of multiple cereals across India
(Environmental Research Letters, 2024-09-09) Gurazada, Madhulika; McDermid, Sonali; DeFries, Ruth; Davis, Kyle F.; Singh, Jitendra; Singh, Deepti
Natural climate phenomena like El Niño Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) influence the Indian monsoon and thereby the region's agricultural systems. Understanding their influence can provide seasonal predictability of agricultural production metrics to inform decision-making and mitigate potential food security challenges. Here, we analyze the effects of ENSO and IOD on four agricultural production metrics (production, harvested area, irrigated area, and yields) for rice, maize, sorghum, pearl millet, and finger millet across India from 1968 to 2015. El Niños and positive-IODs are associated with simultaneous reductions in the production and yields of multiple crops. Impacts vary considerably by crop and geography. Maize and pearl millet experience large declines in both production and yields when compared to other grains in districts located in the northwest and southern peninsular regions. Associated with warmer and drier conditions during El Niño, >70% of all crop districts experience lower production and yields. Impacts of positive-IODs exhibit relatively more spatial variability. La Niña and negative-IODs are associated with simultaneous increases in all production metrics across the crops, particularly benefiting traditional grains. Variations in impacts of ENSO and IOD on different cereals depend on where they are grown and differences in their sensitivity to climate conditions. We compare production metrics for each crop relative to rice in overlapping rainfed districts to isolate the influence of climate conditions. Maize production and yields experience larger reductions relative to rice, while pearl millet production and yields also experience reductions relative to rice during El Niños and positive-IODs. However, sorghum experiences enhanced production and harvested areas, and finger millet experiences enhanced production and yields. These findings suggest that transitioning from maize and rice to these traditional cereals could lower interannual production variability associated with natural climate variations.
Lateral Transport Controls the Tidally Averaged Gravitationally Driven Estuarine Circulation: Tidal Mixing Effects
(Journal of Physical Oceanography, 2024-08-01) Kukulka, Tobias; Chant, Robert J.
In classic models of the tidally averaged gravitationally driven estuarine circulation, denser salty oceanic water moves up the estuary near the bottom, while less dense riverine water flows toward the ocean near the surface. Traditionally, it is assumed that the associated pressure gradient forces and salt advection are balanced by vertical mixing. This study, however, demonstrates that lateral (across the estuary width) transport processes are essential for maintaining the estuarine circulation. This is because for realistic estuarine bathymetry, the depth-integrated salt transport up the estuary is enhanced in the deeper estuary channel. A closed salt budget then requires the lateral transport of this excess salt in the deeper channel toward the estuarine flanks. To understand how such lateral transport affects the estuarine salt and momentum balances, we devise an idealized model with explicit lateral transport focusing on tidally averaged lateral mixing effects. Solutions for the along-estuary velocity and salinity are nondimensionalized to depend only on one single nondimensional parameter, referred to as the Fischer number, which describes the relative importance of lateral to vertical tidal mixing. For relatively strong lateral tidal mixing (greater Fischer number), salinity and velocity variations are predominantly vertical. For relatively weak lateral tidal mixing (smaller Fischer number), salinity and velocity variations are predominantly lateral. Overall, lateral transport greatly affects the estuarine circulation and controls the estuarine salinity intrusion length, which is demonstrated to scale inversely with the Fischer number.
Effects of Chitin Nano-flake Fillers on the Mechanical and Barrier Properties of Polylactic Acid Biocomposite Films
(BioResources, 2024-08-16) Kwon, Soojin; Kim, Sang Yun; Oh, Kyudeok; Han, Jung Soo
Polylactic acid (PLA) is a biodegradable polymer extensively used in packaging; however, its mechanical and barrier properties require enhancement for wider applications. Chitin-derived nanoflakes (CNFL), a two-dimensionally separated nanomaterial derived from α-chitin, possess high strength and toughness, making them ideal additives for improved PLA performance. This study investigated the effect of CNFL on the properties of PLA composite films. Incorporating CNFL significantly enhanced the mechanical properties of PLA, increasing its tensile strength and stiffness while preserving flexibility. This enhancement was attributed to the nucleating effect of CNFL, which increases crystallinity. Additionally, CNFL improved the thermal stability of the composite films by mitigating thermal deformation. Notably, the oxygen barrier properties of CNFL-filled PLA composites were also enhanced, demonstrating a significant reduction in oxygen permeability at optimal CNFL concentrations due to increased tortuosity of the oxygen diffusion path. Overall, CNFL-filled PLA composites exhibit great potential as renewable packaging materials, particularly for protecting sensitive products, such as food and pharmaceuticals, from oxidative degradation, thereby extending shelf life and maintaining quality. These findings suggest that CNFL-filled PLA composites are promising materials for advanced applications, offering a combination of enhanced mechanical performance, improved thermal stability, and superior oxygen barrier properties.
Size-dependent effects of dams on river ecosystems and implications for dam removal outcomes
(Ecological Applications, 2024-08-13) Brown, Rebecca L.; Charles, Don; Horwitz, Richard J.; Pizzuto, James E.; Skalak, Katherine; Velinsky, David J.; Hart, David D.
Understanding the relationship between a dam's size and its ecological effects is important for prioritization of river restoration efforts based on dam removal. Although much is known about the effects of large storage dams, this information may not be applicable to small dams, which represent the vast majority of dams being considered for removal. To better understand how dam effects vary with size, we conducted a multidisciplinary study of the downstream effect of dams on a range of ecological characteristics including geomorphology, water chemistry, periphyton, riparian vegetation, benthic macroinvertebrates, and fish. We related dam size variables to the downstream–upstream fractional difference in measured ecological characteristics for 16 dams in the mid-Atlantic region ranging from 0.9 to 57 m high, with hydraulic residence times (HRTs) ranging from 30 min to 1.5 years. For a range of physical attributes, larger dams had larger effects. For example, the water surface width below dams was greater below large dams. By contrast, there was no effect of dam size on sediment grain size, though the fraction of fine-grained bed material was lower below dams independently of dam size. Larger dams tended to reduce water quality more, with decreased downstream dissolved oxygen and increased temperature. Larger dams decreased inorganic nutrients (N, P, Si), but increased particulate nutrients (N, P) in downstream reaches. Aquatic organisms tended to have greater dissimilarity in species composition below larger dams (for fish and periphyton), lower taxonomic diversity (for macroinvertebrates), and greater pollution tolerance (for periphyton and macroinvertebrates). Plants responded differently below large and small dams, with fewer invasive species below large dams, but more below small dams. Overall, these results demonstrate that larger dams have much greater impact on the ecosystem components we measured, and hence their removal has the greatest potential for restoring river ecosystems.
Superstructure optimization for management of low-density polyethylene plastic waste
(Green Chemistry, 2024-08-14) Hernández, Borja; Vlachos, Dionisios G.; Ierapetritou, Marianthi G.
We introduce a systematic framework centered on superstructure optimization to identify the most efficient economic and environmentally friendly approach for managing plastic waste. Applying the proposed framework to low-density-polyethylene (LDPE) plastic waste, we determine that pyrolysis is the most profitable technology followed by hydroformylation to C4–C8 olefins, and the oligomerization of higher carbon olefins. Coupling the results with geographical information, the selected superstructure has the potential to improve the economics of plastic waste management by approximately $3 per kgLDPE in countries like the United States. On the other hand, the lowest CO2 emission plastic waste management uses solvent-based recycling only when there is significant degradation during mechanical recycling. When plastic waste can be recycled mechanically more than five times, the emissions in mechanical recycling are lower. These technologies collectively contribute to emissions reductions ranging from 1.5 and 3 kgCO2eq. per kgLDPE, for mechanical and solvent-based recycling, respectively.
Stability of marsh edge berms constructed from fine-grained dredged sediment
(Frontiers in Marine Science, 2024-08-28) Perkey, David W.; Tedesco, Lenore P.; Fall, Kelsey A.; Huff, Thomas P.; Chasten, Monica A.
Due to observed impacts of sea level rise, many sediment management strategies in coastal settings are seeking ways to beneficially use locally dredged sediment in restoration, nourishment, and construction projects. The placement of sediment in shallow, near-marsh areas is a promising application of dredged material to both increase accretion and provide protection to marshes and intertidal flats in back bay areas. However, dredged material in these areas often include fine-grained (<63 μm) sediments (FGS), that frequently raise questions concerning dispersion, stability, and environmental impact of the placement project. In 2020, approximately 30,500 m3 of FGS from the New Jersey Intracoastal Waterway (NJIWW) was placed along the southern edge of Gull Island, New Jersey to evaluate the feasibility of using FGS for beneficial use projects in near marsh environments. Gull Island was experiencing extensive marsh edge erosion through margin collapse. The placement was unconfined and resulted in the formation of two intertidal muddy berm-like features up to 0.7 m thick along more than 500 m of marsh. Bathymetric surveys showed that approximately 60-70% of the berm volume remained 36 months after placement, however maximum berm thickness reduced to ~0.5 m. Field monitoring performed during construction found that turbidity plumes were localized to within 100 m of the placement site and sediment cores collected in June 2022 did not show systemic winnowing from the berm surface. Laboratory and field observations indicated that the berm material was cohesive in nature and produced large aggregates upon erosion, limiting the dispersal of FGS. Observations of current velocities and waves in the area indicate a low energy system such that the cohesive berm was largely resistant to erosion and that reduction in berm volume was largely due to consolidation and compaction. This suggests that shallow water features can be constructed with FGS in similar low energy environments with limited dispersal during and following construction, while being robust enough to help stabilize the marsh edge and improve marsh survivability against sea level rise.
From Policy to Practice: Assessing the State Innovation Models Initiative’s Early Success in Incorporating Social Determinants of Health in ASCVD Hospitalizations in the United States
(American Journal of Epidemiology, 2024-08-27) Parekh, Tarang; Xue, Hong; Wadhera, Rishi K.; Cheskin, Lawrence J.; Cuellar, Alison E.
The study examines effects of the CMS State Innovation Models(SIM) on capturing social risk factors in adults hospitalized with Atherosclerotic Cardiovascular Disease (ASCVD). Using a difference-in-differences(DID) approach with propensity score weights, the study compared documentation of secondary diagnosis of SDOH/social factors using ICD-9 V codes (“SDOH codes”) in adults hospitalized with ASCVD as a primary diagnosis (N= 1,485,354). Data were gathered from January 1, 2010, to September 30, 2015, covering the period before and after the SIM implementation in October 2013. From January 2010 to September 2015, SDOH codes were infrequently utilized among adults with ASCVD(0.55%, 95% CI: 0.43%-0.67%). SDOH codes with ASCVD increased from pre- to post-period in SIM states(0.56% to 0.93%) and comparison states (0.46% to 0.56%). SIM implementation was associated with greater improvement in SDOH codes utilization (adjusted OR 1.30, 95%CI: 1.18-1.43) during ASCVD hospitalizations. The odds of SDOH codes utilization were 86% higher in ED admissions(AOR 1.86, 95%CI: 1.76-1.97) than in routine admissions with ASCVD. Findings were similar when limiting population to older adults(>=65 years) enrolled in Medicare(AOR 1.50, 95%CI 1.31-1.71), whereas not significant for Medicaid beneficiaries. The study points to challenges for healthcare providers in documenting SDOH in adults with ASCVD.
Biomass-derived, Target Specific, and Ecologically Safer Insecticide Active Ingredients
(Chemistry-Sustainability-Energy-Materials, 2024-08-21) Goculdas, Tejas B.; Ramirez, Maximus; Crossley, Michael; Sadula, Sunitha; Vlachos, Dionisios G.
With the continuous increase in food production to support the growing population, ensuring agricultural sustainability using crop-protecting agents, such as pesticides, is vital. Conventional pesticides pose significant environmental risks, prompting the need for eco-friendly alternatives. This study reports the synthesis of new amide-based insecticidal active ingredients from biomass-derived monomers, specifically furfural and vanillin. The process involves reductive amination followed by carbonylation. The synthesis of the furfural-based carbamate yield reaches a cumulative 88%, with catalysts Rh/Al2O3 and La(OTf)3 being recyclable at each stage. Insecticidal activity assessments reveal that the furfural carbamate exhibits competitive performance, achieving an LC50 of 6.35 μg/cm², compared to 6.27 μg/cm² for carbofuran. Ecotoxicity predictions indicate significantly lower toxicity levels toward non-target aquatic and terrestrial species. The importance of the low octanol-water partition coefficient of the biobased carbamate, attributed to the oxygen heteroatom and electron density of the furan ring, is discussed in detail. Building on these promising results, the synthesis strategy was extended to six other biobased aldehydes, resulting in a diverse portfolio of biomass-derived carbamates. A techno-economic analysis reveals a minimum selling price of 11.1$/kg, only half that of comparable carbamates, demonstrating the economic viability of these new biobased insecticides.
Sustainable Aviation Fuel Molecules from (Hemi)Cellulose: Computational Insights into Synthesis Routes, Fuel Properties, and Process Chemistry Metrics
(ACS Sustainable Chemistry and Engineering, 2024-08-13) Chang, Chin-Fei; Paragian, Kristin; Sadula, Sunitha; Rangarajan, Srinivas; Vlachos, Dionisios G.
Production of sustainable aviation fuels (SAFs) can significantly reduce the aviation industry’s carbon footprint. Current pathways that produce SAFs in significant volumes from ethanol and fatty acids can be costly, have a relatively high carbon intensity (CI), and impose sustainability challenges. There is a need for a diversified approach to reduce costs and utilize more sustainable feedstocks effectively. Here, we map out catalytic synthesis routes to convert furanics derived from the (hemi)cellulosic biomass to alkanes and cycloalkanes using automated network generation with RING and semiempirical thermochemistry calculations. We find >100 energy-dense C8–C16 alkane and cycloalkane SAF candidates over 300 synthesis routes; the top three are 2-methyl heptane, ethyl cyclohexane, and propyl cyclohexane, although these are relatively short. The shortest, least endothermic process chemistry involves C–C coupling, oxygen removal, and hydrogen addition, with dehydracyclization of the heterocyclic oxygens in the furan ring being the most endothermic step. The global warming potential due to hydrogen use and byproduct CO2 is typically 0.7–1 kg CO2/kg SAF product; the least CO2 emitting routes entail making larger molecules with fewer ketonization, hydrogenation, and hydrodeoxygenation steps. The large number of SAF candidates highlights the rich potential of furanics as a source of SAF molecules. However, the structural dissimilarity between reactants and target products precludes pathways with fewer than six synthetic steps, thus necessitating intensified processes, integrating multiple reaction steps in multifunctional catalytic reactors.
Cu Based Dilute Alloys for Tuning the C2+ Selectivity of Electrochemical CO2 Reduction
(Small, 2024-07-12) Crandall, Bradie S.; Qi, Zhen; Foucher, Alexandre C.; Weitzner, Stephen E.; Akhade, Sneha A.; Liu, Xin; Kashi, Ajay R.; Buckley, Aya K.; Ma, Sichao; Stach, Eric A.; Varley, Joel B.; Jiao, Feng; Biener, Juergen
Electrochemical CO2 reduction is a promising technology for replacing fossil fuel feedstocks in the chemical industry but further improvements in catalyst selectivity need to be made. So far, only copper-based catalysts have shown efficient conversion of CO2 into the desired multi-carbon (C2+) products. This work explores Cu-based dilute alloys to systematically tune the energy landscape of CO2 electrolysis toward C2+ products. Selection of the dilute alloy components is guided by grand canonical density functional theory simulations using the calculated binding energies of the reaction intermediates CO*, CHO*, and OCCO* dimer as descriptors for the selectivity toward C2+ products. A physical vapor deposition catalyst testing platform is employed to isolate the effect of alloy composition on the C2+/C1 product branching ratio without interference from catalyst morphology or catalyst integration. Six dilute alloy catalysts are prepared and tested with respect to their C2+/C1 product ratio using different electrolyzer environments including selected tests in a 100-cm2 electrolyzer. Consistent with theory, CuAl, CuB, CuGa and especially CuSc show increased selectivity toward C2+ products by making CO dimerization energetically more favorable on the dominant Cu facets, demonstrating the power of using the dilute alloy approach to tune the selectivity of CO2 electrolysis.
Universal Carbonizable Filaments for 3D Printing
(Advanced Functional Materials, 2024-06-23) Park, Soyeon; Shi, Baohui; Islam, Md Mohaiminul; He, Jinlong; Sung, Dae Han; Zhang, Chunyan; Cao, Zhang; Shang, Yuanyuan; Liu, Ling; Fu, Kelvin
Carbon additive manufacturing emerges as a powerful technique for crafting tunable 3D carbon architectures, employing multiscale arrangement and topological design for mechanical and functional applications. However, the potential of 3D carbon fabrication is constrained when utilizing state-of-the-art feedstock and manufacturing routes. To address these limitations, a 3D carbon fabrication strategy is developed named carbonizable filament technology (CAFIT). In CAFIT, the evolution of high-loaded carbon composite filaments broadens the capabilities of straightforward 3D printing technology by ensuring structural stability for subsequent post-carbonization to achieve scalable and engineered 3D carbon structures. This strategy has strengths regarding 1) simplicity, 2) applicability to a variety of carbon materials, and 3) creating nearly replicated 3D carbon structures with multiscale features. The fundamental mechanisms governing the processability of the universal filament and structural change of carbon particles throughout the process using carbon nanotubes as an example are explored. Moreover, through simulation and demonstration, the adaptability of CAFIT is illustrated by utilizing a wide range of carbon materials, including low-dimensional nano/micro carbons (carbon blacks, carbon nanotubes, and graphenes), as well as carbon fibers, to fabricate 3D architected carbon structures.
Taking Stock of Recent Progress in Livelihood Vulnerability Assessments to Climate Change in the Developing World
(Climate, 2024-07-08) Zainab, Atoofa; Shah, Kalim U.
Over the past few decades, the use of vulnerability assessments has grown substantially to support rural communities in developing countries. These studies aim to help these communities achieve their livelihood goals, such as sustainable resource use and adaptation to global changes, by evaluating their susceptibility to climate change impacts. This systematic review critically examines the extensive body of literature on Livelihood Vulnerability Index (LVI) assessments related to climate change impacts in developing countries. By synthesizing findings from various studies, this review highlights patterns and methodologies used to understand the effects of climate change on vulnerable populations. Key focus areas include geographical distribution, methodological approaches, and the frameworks utilized in vulnerability assessments. The review identifies prominent frameworks, such as the LVI and LVI-IPCC, which integrate indicators of sensitivity, exposure, and adaptive capacity to evaluate climate risks. Findings reveal a concentration of studies in Asia and Africa, with a strong emphasis on agricultural and coastal ecosystems. Methodologically, there is a notable reliance on stratified random sampling to accurately capture community and household-level vulnerabilities. A detailed comparative analysis of the LVI, LVI-IPCC, and Sustainable Livelihood Framework (SLF) is also presented, highlighting their characteristics, benefits, and limitations. The review underscores the need for methodological refinements to better address temporal and regional variations in vulnerability. It concludes with recommendations for future research, integrating broader climate scenarios, exploring sectoral interdependencies, and adopting dynamic approaches to enhance the accuracy and applicability of vulnerability assessments.
Photofate of Tetrabromobisphenol-A in the Arctic: Role of photofluence and dissolved organic matter
(Arctic, Antarctic, and Alpine Research, 2024-08-09) O’Halloran, Robyn C.; Kerrigan, Jill; O’Connor, Lauren E.; Guerard, Jennifer J.; Hageman, Kimberly J.; Chin, Yu-Ping
Polybrominated diphenyl ethers (PBDEs) used in consumer goods and flame retardants have been replaced by alternatives such as tetrabromobisphenol A (TBBPA). TBBPA does not readily undergo global distal transport, but local sources still threaten aquatic ecosystems. We studied the photofate of TBBPA with a specific focus on how Arctic-derived dissolved organic matter (DOM) affects its reaction kinetics, degradation pathways and formation of photoproducts in artificial and natural sunlight. Our results corroborate earlier studies that reveal a pH-dependent trend in TBBPA’s direct photolysis with longer degradation times for its acidic form. DOM either plays no role or it slightly reduces TBBPA’s rate of photodegradation via inner-filter effects. Photolysis experiments conducted at our Arctic field site, Toolik Lake Field Station, revealed slower than anticipated degradation, which magnified the half-life significantly during in-lake experiments. Importantly, the composition of DOM was found to influence the type and distribution of TBBPA photoproducts formed, which suggests that different degradation pathways occur in the presence of DOM. These findings provide valuable insights into the intricate interplay of environmental variables that govern the fate of TBBPA in sunlit aquatic ecosystems globally. Graphical Abstract available at: https://doi.org/10.1080/15230430.2024.2372867
Hypoxia Triggered by Expanding River Plume on the East China Sea Inner Shelf During Flood Years
(Journal of Geophysical Research: Oceans, 2024-07-31) Li, Dewang; Chen, Jianfang; Wang, Bin; Jin, Haiyan; Shou, Lu; Lin, Hua; Miao, Yanyi; Sun, Qianwen; Jiang, Zhibing; Meng, Qicheng; Zeng, Jiangning; Zhou, Feng; Cai, Wei-Jun
The frequency of riverine floods is predicted to increase in East Asia. However, the response of coastal hypoxia (<63 μmol L−1) to floods has not been well understood. In the summer of 2020, characterized by one of the most significant Changjiang water fluxes in three decades, we conducted a cruise during the flood period on the East China Sea inner shelf. Our observations revealed severe bottom hypoxia with a maximum spatial coverage of ∼11,600 km2 and a minimum dissolved oxygen concentration (DO) of 21 μmol L−1. In the surface layer, the relationships between salinity and nitrate, dissolved inorganic carbon (DIC) indicated significant organic matter production, validated by a high-Chlorophyll-a (Chl a) patch (>5 μg L−1). Furthermore, the significant relationship between apparent oxygen utilization and DIC of deep waters reveals that the organic matter decomposition primarily drove the hypoxia during the flood period. Episodic wind events also influenced bottom DO and DIC, by transporting surface waters to the deep. Multiple-years data set shows that the average Changjiang nitrate flux during flood years is about 1.4 times that during non-flood years. The flood waters mix with estuarine waters, forming the high-nutrient plume waters, which expanded farther offshore during the flood period. While high turbidity remained confined to the inner estuary. Consequently, the high-Chl a area significantly expanded, which significantly exacerbated the hypoxia. Key Points - We observed a maximum hypoxia area of ∼11,600 km2, and a minimum dissolved oxygen of 21 μmol L−1 during the flood period in 2020 - Significant nitrate removal and surface Chlorophyll a exceeding 29 μg L−1 suggested intense biological production during the flood period - The expansion of high-Chl a plume area during flood periods surpasses that of non-flood periods, contributing to hypoxia area increase Plain Language Summary Coastal waters are severely threatened by hypoxia, which impacts the growth, reproduction, and migration of marine organisms. Nutrient inputs from river basins are one of the major controlling factors of hypoxia in coastal oceans. The frequency and intensity of floods in river basins are projected to increase in the context of global warming in East Asia. However, the relationship between floods and coastal hypoxia is not well documented. The year 2020 witnessed lots of riverine flood events across Asian countries, which provided us with an excellent opportunity to reveal the influences of flood on hypoxia development on the shelf. In 2020, the August nitrate flux of Changjiang was 1.5 times higher compared to that in non-flood years. We observed maximum hypoxic waters covering 11,600 km2 with a minimum DO of 21 μmol L−1 on the East China Sea inner shelf. Historical data showed that the floods led to the expansion of the high-nutrient plume area, resulting in high biological production in the plume, and a nearly doubling of the hypoxia extent in the bottom waters. With the growing risk of intensive floods, hypoxia is likely to aggravate in coastal waters.
The source and accumulation of anthropogenic carbon in the U.S. East Coast
(Science Advances, 2024-08-09) Li, Xinyu; Wu, Zelun; Ouyang, Zhangxian; Cai, Wei-Jun
The ocean has absorbed anthropogenic carbon dioxide (Canthro) from the atmosphere and played an important role in mitigating global warming. However, how much Canthro is accumulated in coastal oceans and where it comes from have rarely been addressed with observational data. Here, we use a high-quality carbonate dataset (1996–2018) in the U.S. East Coast to address these questions. Our work shows that the offshore slope waters have the highest Canthro accumulation changes (ΔCanthro) consistent with water mass age and properties. From offshore to nearshore, ΔCanthro decreases with salinity to near zero in the subsurface, indicating no net increase in the export of Canthro from estuaries and wetlands. Excesses over the conservative mixing baseline also reveal an uptake of Canthro from the atmosphere within the shelf. Our analysis suggests that the continental shelf exports most of its absorbed Canthro from the atmosphere to the open ocean and acts as an essential pathway for global ocean Canthro storage and acidification.
Plant extract mediated synthesis of gold nanoparticles and its application to treatment of cancer
(World Journal of Advanced Engineering Technology and Sciences, 2024-07-28) Onivefu, Asishana Paul; Adekunle, Adewale Philip; Okebugwu, Joseph Chibuike; Benibo, Paul Gberiye; Aibor, Lucky Ehimen; Raji-Ayoola, Jumoke Ayodele; Latinwo, Opeyemi Olaoluwa; Onyedum, Nwamaka Nneka; Amoo, Ayosunkanmi Damilola; Ukem, David Effiong
Plant extract-mediated synthesis of gold nanoparticles is a promising research area with potential applications in various fields including medicine-cancer research, catalysis, and nanoelectronics. Gold nanoparticles have gained serious attention in recent years as a potential cancer treatment due to their unique optical and physical properties. Plant-mediated synthesis of gold nanoparticles is a promising method to produce biocompatible and non-toxic gold nanoparticles (Au-NPs). This study focuses on the current research on the plant-mediated synthesis of gold nanoparticles and their potential treatment for cancer. It also discussed the latest advancement in nanobot technology. The study will also describe the type of plants used for the synthesis of gold nanoparticles, the mechanisms involved in the synthesis, the advantages of using plant-mediated synthesis, and the disadvantages. Additionally, this study will discuss the efficacy of gold nanoparticles as cancer therapeutics and the instrumentation involved in characterizing the gold nanoparticles (Au-NPs), the opportunities for the use of gold nanoparticles (Au-NPs) in cancer treatment and future possible research in the use of nanotechnology in the fight against cancer. Overall, plant-mediated synthesis of gold nanoparticles holds promise as a safe and effective method for cancer treatment.
Efficacy of Bacillus subtilis probiotic in preventing necrotic enteritis in broilers: a systematic review and meta-analysis
(Avian Pathology, 2024-07-03) Ghimire, Shweta; Subedi, Keshab; Zhangb, Xinwen; Wu, Changqing
Probiotics can enhance broiler chicken health by improving intestinal microbiota, potentially replacing antibiotics. They protect against bacterial diseases like necrotic enteritis (NE) in poultry. Understanding their role is crucial for managing bacterial diseases, including NE. This study conducted a meta-analysis to assess the effects of Bacillus subtilis probiotic supplementation on feed conversion ratio (FCR), NE lesion score, and mortality. Additionally, a systematic review analysed gut microbiota changes in broilers challenged with Clostridium perfringens with or without the probiotic supplementation. Effect sizes from the studies were estimated in terms of standardized mean difference (SMD). Random effect models were fitted to estimate the pooled effect size and 95% confidence interval (CI) of the pooled effect size between the control [probiotic-free + C. perfringens] and the treatment [Bacillus subtilis supplemented + C. perfringens] groups. Overall variance was computed by heterogeneity (Q). The meta-analysis showed that Bacillus subtilis probiotic supplementation significantly improved FCR and reduced NE lesion score but had no effect on mortality rates. The estimated overall effects of probiotic supplementation on FCR, NE lesion score and mortality percentage in terms of SMD were −0.91 (CI = −1.34, −0.49; P < 0.001*); −0.67 (CI = −1.11, −0.22; P = 0.006*), and −0.32 (CI = −0.70, 0.06; P = 0.08), respectively. Heterogeneity analysis indicated significant variations across studies for FCR (Q = 69.66; P < 0.001*) and NE lesion score (Q = 42.35; P < 0.001*) while heterogeneity was not significant for mortality (Q = 2.72; P = 0.74). Bacillus subtilis probiotic supplementation enriched specific gut microbiota including Streptococcus, Butyricicoccus, Faecalibacterium, and Ruminococcus. These microbiotas were found to upregulate expression of various genes such as TJ proteins occluding, ZO-1, junctional adhesion 2 (JAM2), interferon gamma, IL12-β and transforming growth factor-β4. Moreover, downregulated mucin-2 expression was involved in restoring the intestinal physical barrier, reducing intestinal inflammation, and recovering the physiological functions of damaged intestines. These findings highlight the potential benefits of probiotic supplementation in poultry management, particularly in combating bacterial diseases and promoting intestinal health.
Water-Energy-Food (WEF) Nexus and the SDGs in Central and South Asia
(Springer, Cham, 2024-08-04) Akram, Humayoun Akram; Mohazzam, Sardar; Ali, Saleem H.
The international research community has been attracted to the concept of a “water-energy-food” nexus as an approach for more integrated planning for global environmental change. The Sustainable Development Goals may well be approached using such a nexus approach for data gathering and for holistic policy implementation. This chapter considers how Central and South Asia might adopt this approach, particularly in the context of rapid development which is taking place across the region. We focus on energy efficiency and public-private partnerships as two key areas where robust metrics for such a nexus being realized hold promise. We also consider some of the criticism of the nexus approach in terms of research depth and policy implementation and the use of tools such as the Water Energy Food Nexus Index in the context of this region. Overall, we find the concept is appropriate for use in this region, particularly as a means of cross-border and regional development planning.

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