High Production Potential Research Articles

Fast dehydration reduces bundle sheath conductance in C4 maize and sorghum.

In the face of anthropogenic warming, drought poses an escalating threat to food production. C4 plants offer promise in addressing this threat. C4 leaves operate a biochemical CO2 concentrating mechanism that exchanges metabolites between two partially isolated compartments (mesophyll and bundle sheath), which confers high-productivity potential in hot climates boosting water use efficiency. However, when C4 leaves experience dehydration, photosynthesis plummets. This paper explores the physiological mechanisms behind this decline. In a fast dehydration experiment, we measured the fluxes and isotopic composition of water and CO2 in the gas exchanged by leaves, and we interpreted results using a novel biochemical model and analysis of elasticity. Our findings show that, while CO2 supply to the mesophyll and to the bundle sheath persisted during dehydration, there was a decrease in CO2 conductance at the bundle sheath-mesophyll interface. We interpret this as causing a slowdown of intercellular metabolite exchange - an essential feature of C4 photosynthesis. This would impede the supply of reducing power to the bundle sheath, leading to phosphoglycerate accumulation and feedback inhibition of Rubisco carboxylation. The interplay between this rapid sensitivity and the effectiveness of coping strategies that C4 plants deploy may be an overlooked driver of their competitive performance.

Reappraisal of different agro-industrial waste for the optimization of cellulase production from Aspergillus niger ITV02 in a liquid medium using a Box-Benkhen design.

High-value metabolites, such as enzymes and biofuels, can be produced from various agro-industrial waste containing high percentages of cellulose and hemicellulose. Aspergillus niger ITV02 demonstrates high potential in cellulases production, the key enzyme for converting lignocellulosic materials into fermentable sugars to produce second-generation bioethanol (bioethanol 2G). This study evaluated five lignocellulosic residues of agricultural importance: sugarcane bagasse (SCB), sorghum bagasse (SB), corn stubble (CS), barley straw (BS) and rice husk (RH) as substrates for cellulase production. The temperature, pH and stirring conditions were optimized using a Box-Behnken design to identify the most suitable conditions for cellulase production while minimizing nitrogen concentrations. The results indicate that the best way of propagation A. niger ITV02 is through the use of spores as an inoculant, in conjunction with the use of materials with a high cellulose/lignin ratio, such as CS and SB for the generation of cellulases. These conditions promote the expression of cellulases towards β-glucosidase production, unlike materials with lower cellulose/lignin ratios like BS and RH, which exhibited lower cellulase activity. The optimal conditions for cellulase production by A. niger ITV02 were determined to be 33 °C, pH 5.3, and 200rpm, resulting in a 1.7-fold increase in Exoglucanase (FPase activity) (from 0.127 to 0.215 U/mL). These findings demonstrate the potential to enhance FPase activity by utilizing substrates with high cellulose/lignin content and implementing optimal operational conditions without the need to raise the nitrogen content of the basal medium, thus mitigating the economic impact of cellulase production.

Integrating environmental remediation with biodiesel production from toxic non-edible oil seeds (Croton bonplandianus) using a sustainable phyto-nano catalyst

In the current situation of the environmental uprising toxicology, rising global temperature, and energy-depleting urges to explore and discover more renewable and greener ecological-benefiting energy resources. Biobased renewable fuels generated by using waste products can help in waste management, climate change mitigation, and a low-carbon future. The main objective of this research is to produce environment-friendly and cost-effective biofuel. The potentiality of the novel, toxic, waste, and inedible feedstock Croton bonplandianus was evaluated for biodiesel synthesis through transesterification utilizing a Phyto-nano catalyst of potassium oxide prepared by Croton bonplandianus floral stalk's aqueous extract focusing on waste management. Phyto-nano catalyst characterization was done through innovative tools such as Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Zeta Potential (ZP), X-Ray Diffraction (XRD), Fourier Transformed Infrared spectroscopy (FTIR), and Diffuse Reflectance Spectroscopy (DRS). The characterization results revealed that the potassium oxide phyto-nanocatalyst possesses an average nanoparticle size of 44.5 nm. This size is optimal for enhanced catalytic activity, indicating significant potential for efficient catalysis. The highest yield (94 %) of biodiesel was secured at optimized reaction conditions of catalyst quantity (0.50 wt%), reaction time (180 min), methanol: oil ratio (9:1), and reaction thermal point (70 °C). Transformation of triglycerides to methyl esters was confirmed by GC/MS, NMR, and FTIR techniques. A total of 21 methyl esters were observed in Croton bonplandianus biodiesel confirmed via GC/MS results. Evaluation of fuel properties was done and matched with international fuel standards. The conclusive remarks for the conducted research are that Croton bonplandianus has a high potential for biodiesel production by applying Phyto-nanocatalysts of potassium oxide while dealing with hazardous environmental conditions and waste management. Phyto nanocatalyst of potassium oxide can be reused and gives the same yield after several cycles of reusability, this reusability of heterogenous Phyto nanocatalyst can reduce to total cost of biodiesel production and can contribute towards circular economy.

Enhancing methane production from distillers’ grains by cattle manure in solid-state anaerobic digestion: focusing on biodegradability, acidification and indigenous microorganisms

Distillers’ grains has high potential in methane production but the process is affected by the acidification in anaerobic digestion. To enhance the methane production in solid-state anaerobic digestion, distillers’ grains was co-digested with cattle manure in different proportions in this study. Compared to distillers’ grains, cattle manure performed lower biodegradability but higher alkalinity and nutrients, hence relieved acidification and drove microbial succession for methane enhancement in the co-digestion with distillers’ grains. The highest increase in total methane yield (10.67%) was observed in the co-digestion of distillers’ grains and cattle manure at the proportion of 70:30 (T3). This was the synergistic action of reduced acidification, relatively high biodegradability of feedstocks, and balanced composition of hydrolytic bacteria, syntrophic bacteria and acetoclastic methanogens. Further analysis revealed the positive effects of indigenous microorganisms derived from distillers’ grains and cattle manure in methane enhancement. The enrichment of Sedimentibacter, Desulfitibacter, Tepidanaerobacter from distiller's grains, and Eubacterium, Methanoculleus, Methanobacterium, Methanobrevibacter mainly from cattle manure synergistically promoted organics conversion and methane production in T3. This study further affirmed the potential use of distillers’ grains in solid-state anaerobic digestion and provided a favorable strategy for its better methane production.

Future pathways for green hydrogen: Analyzing the nexus of renewable energy consumption and hydrogen development in Chinese cities

Hydrogen energy offers a promising pathway for achieving zero-carbon urban energy consumption. This study quantitatively analyzes the patterns of hydrogen energy development and its linked to electricity consumption in China's urban areas. It investigates the spatial relationships between hydrogen energy expansion, the potential for green hydrogen production, and overall energy use. Utilizing a coupling coordination degree (CCD) model and a panel vector autoregressive (PVAR) model, the research explores the dynamic interactions between urban hydrogen energy development and the transition to renewable energy sources. In line with Chinese government policy, the study also conducts a scenario analysis of green hydrogen production by 2030, proposing a consumption strategy that balances environmental sustainability with economic growth. The key conclusions are as follows: (1) There is a spatial mismatch between the locations where hydrogen energy is being developed and where the potential for green hydrogen production is greatest. Cities with higher electricity consumption demonstrate stronger synergies in the coordinated development of hydrogen and renewable energy. (2) The development of hydrogen energy significantly accelerates the transition to renewable energy consumption in urban areas, with this impact being more substantial than that of the utilization capacity alone. (3) Hydrogen production in the Plan Scenario is significantly higher than in the Pessimistic Scenario, underscoring the critical importance of implementing renewable hydrogen projects in provinces with high production potential. Future trends in green hydrogen consumption at the provincial level indicate that addressing the challenges of efficient inter-provincial transportation of hydrogen energy remains essential.

Thermal stable NaMgLaTeO6:Dy3+ double perovskite yellow phosphors for w-LEDs and latent fingerprint visualization

The novel Dy3+-doped NaMgLaTeO6 (NaMgLaTeO6:Dy3+) phosphors were produced through a high-temperature solid-state reaction. X-ray diffraction (XRD) analysis and Rietveld refinement manifest that the pure phosphor was committed to the space group (P21/m (11)) and features the double perovskite structure. The band gap (Eg) of the direct semiconductor NaMgLaTeO6 is calculated to be 2.065 eV. Under 388 nm excitation, the 4F9/2→6H13/2 energy level transition contributes to the maximum emission peak at 572 nm. Other properties of the phosphor include optimal concentration (x = 5 mol %), high thermal stability, activation energy (Ea = 0.31 eV), and internal quantum efficiency (IQE = 31.44 %). The relevant color coordinate of the white light emitting diode (w-LED) prepared by the phosphor is (0.298, 0.311). The features of the latent fingerprint (LFP) created by NaMgLaTeO6:Dy3+ can be clearly reflected on different surfaces. In summary, NaMgLaTeO6:Dy3+ phosphor has proven high potential in w-LEDs production and LFP detection.

Vaccine Potency and Structure of Yeast-Produced Polio Type 2 Stabilized Virus-like Particles.

Poliovirus (PV) is on the brink of eradication due to global vaccination programs utilizing live-attenuated oral and inactivated polio vaccines. Recombinant PV virus-like particles (VLPs) are emerging as a safe next-generation vaccine candidate for the impending polio-free era. In this study, we investigate the production, antigenicity, thermostability, immunogenicity, and structures of VLPs derived from PV serotype 2 (PV2) wildtype strain and thermally stabilized mutant (wtVLP and sVLP, respectively). Both PV2 wtVLP and sVLP are efficiently produced in Pichia pastoris yeast. The PV2 sVLP displays higher levels of D-antigen and significantly enhanced thermostability than the wtVLP. Unlike the wtVLP, the sVLP elicits neutralizing antibodies in mice at levels comparable to those induced by inactivated polio vaccine. The addition of an aluminum hydroxide adjuvant to sVLP results in faster induction and a higher magnitude of neutralizing antibodies. Furthermore, our cryo-EM structural study of both sVLP and wtVLP reveals a native conformation for the sVLP and a non-native expanded conformation for the wtVLP. Our work not only validates the yeast-produced PV2 sVLP as a promising vaccine candidate with high production potential but also sheds light on the structural mechanisms that underpin the assembly and immunogenicity of the PV2 sVLP. These findings may expedite the development of sVLP-based PV vaccines.

Landscape and soil cover diversity in Polissia and Forest-Steppe of Ukraine

Recent research has revealed the patterns of spatial and temporal variability of crop yields for the Polissia and the Forest-Steppe regions of Ukraine. In addition, the approaches to differentiating agroeconomic and agroecological components in the variability of the productive potential of the territories were developed. Approaches have been developed to quantify the spatial and temporal variability of soil erosion for individual areas of the region. The issue of assessing the impact of erosion processes on crop yields at the regional level remains unresolved. The diversity of landscapes and soil cover in Polissia and the Forest-Steppe of Ukraine was assessed in this article. The research covered 10 administrative regions of the north and northwest of Ukraine, which are located mainly within mixed forests (Polissia) and the eastern European forest steppe (Forest-Steppe). Part of the territory is tangential to the Carpathian mountain forests and the Pontic steppe. Within the study area, 30 WRB soils were identified. The largest area is occupied by Phaeozems Albic (21.7% of the total area of the region). These soils are located mainly in the southern and central parts of the region. In the north of the region, Phaeozems Albic form an almost continuous cover, and to the north, the areas of these soils become island-like. Phaeozems Luvic cover 12.1% of the region's territory. The Phaeozems group also includes Phaeozems Gleyic (0.93%), Phaeozems Haplic (0.13%), and Phaeozems Sodic (1.78%). Albeluvisols Umbric (17.1%) occupy a significant part of the region's territory. These soils occupy the north of the region and extend south along the Dnipro River floodplain. Spatially close to these soils are Albeluvisols Gleyic (12.8%). In the western part of the region, in Prykarpattia, there are Albeluvisols Stagnic (0.82%). The organic carbon content in the soils of the administrative districts of the region in the 0-5 cm layer was 5.2±3.3% and ranged 0.5% to 23.9%. In the layers of 5–15 and 15–30 cm, this figure decreased to 1.9 ± 1.1% and 1.9 ± 1.0%, respectively. In the 30–60 cm layer, the organic carbon content was 1.4 ± 0.8% and ranged 0.1% to 6.1%. The lowest organic carbon content was observed in the north central part of the region, and the highest content was observed in the north-east and north-west of the region. In the south of the region, there was found a strip of soils with moderate organic carbon content. The lowest content of organic carbon is characteristic of Albeluvisols and Podzols, which are located in the north of the region. In turn, the highest content of organic carbon is characteristic of organogenic Histosols, which, together with Albeluvisols and Podzols, form the basis of the soil cover structure of the territories in the northeast and northwest of the region. It should be noted that the agronomic role of these soils is insignificant, and their organic carbon content cannot be considered as a traditional indicator of fertility. Nevertheless, organic carbon is a reliable indicator of the anti-erosion properties of both natural and agricultural soils. The organic carbon content of Chernozems is quite high, which is a factor in the high fertility of these soils and their importance in agricultural production. The organic carbon content of Fluvisols and Gleysols is naturally high. The importance of these hydromorphic soils is due to their high productive potential, which ensures their use in agriculture. It is also worth noting their high seed protection potential. Phaeozems cover a large area of the region and contain a high level of organic carbon. These soils form the basis of agricultural production and forestry in the region. The silt content in the region's soils measured 45.6 ± 8.5%, ranging 19.1% to 57.6%. The north of the region is represented by soils with the lowest silt content (19–41%). In the center, in the west of the region, there is a zone with the highest silt content (53–58%). In other parts of the region, there are transitional levels of silt content in the soil. The clay content in the soils was 30.7 ± 13.8% and ranged 7.4% to 36.0%. The zone with the lowest clay content in soils has been formed in the north. The highest clay content in soils is typical for the southern part in the center of the region. The sand content in soils is highest in the northern part of the region, and the lowest in the southwestern and southern parts of the region.

Application of computational fluid dynamics in optimizing microalgal photobioreactors

Developing more efficient microalgal photobioreactors (closed cultivation systems) is impelled by increasing interest in microalgal cultivation to produce high-value products. Compared to open cultivation systems closed photobioreactors (PBRs) offer several advantages, including the potential for high productivity in a small footprint, ability to maintain a controlled environment, and their scalability for commercial production. Computational Fluid Dynamics (CFD) provides a powerful tool to simulate flow conditions of microalgal cultivation systems and analyze operational parameters which may affect cultivation key factors such as light (wavelength, intensity, and period of exposure), accessibility to nutrients, and mixing. Besides, geometric modifications employing CFD can accelerate the design process and considerably reduce the need for a thorough, empirical exploration of reactor configurations and the associated costs. This paper provides a comprehensive review of recent updates on the application of CFD in various microalgal cultivation systems with special focus on different geometry optimization of flat plate photobioreactors.This review examines recent studies that have employed various multiphase and turbulence methods within the CFD framework to simulate fluid flow and turbulence within reactors, aiming to improve flow characteristics and enhance microalgal productivity. Specifically, the application of CFD in optimizing flat plate photobioreactors is explored, with researchers investigating a range of baffles and sparger configurations to enhance microalgal productivity. Additionally, the advantages of adopting CFD are discussed, and the potential future applications of CFD in microalgal cultivation are outlined.

Genetic optimization of the human gut bacterium Phocaeicola vulgatus for enhanced succinate production

The demand for sustainably produced bulk chemicals is constantly rising. Succinate serves as a fundamental component in various food, chemical, and pharmaceutical products. Succinate can be produced from sustainable raw materials using microbial fermentation and enzyme-based technologies. Bacteroides and Phocaeicola species, widely distributed and prevalent gut commensals, possess enzyme sets for the metabolization of complex plant polysaccharides and synthesize succinate as a fermentative end product. This study employed novel molecular techniques to enhance succinate yields in the natural succinate producer Phocaeicola vulgatus by directing the metabolic carbon flow toward succinate formation. The deletion of the gene encoding the methylmalonyl-CoA mutase (Δmcm, bvu_0309-0310) resulted in a 95% increase in succinate production, as metabolization to propionate was effectively blocked. Furthermore, deletion of genes encoding the lactate dehydrogenase (Δldh, bvu_2499) and the pyruvate:formate lyase (Δpfl, bvu_2880) eliminated the formation of fermentative end products lactate and formate. By overproducing the transketolase (TKT, BVU_2318) in the triple deletion mutant, succinate production increased from 3.9 mmol/g dry weight in the wild type to 10.9 mmol/g dry weight. Overall, succinate yield increased by 180% in the new mutant strain P. vulgatus Δmcm Δldh Δpfl pG106_tkt relative to the parent strain. This approach is a proof of concept, verifying the genetic accessibility of P. vulgatus, and forms the basis for targeted genetic optimization. The increase of efficiency highlights the huge potential of P. vulgatus as a succinate producer with applications in sustainable bioproduction processes.Key points• Deleting methylmalonyl-CoA mutase gene in P. vulgatus doubled succinate production• Triple deletion mutant with transketolase overexpression increased succinate yield by 180%• P. vulgatus shows high potential for sustainable bulk chemical production via genetic optimization

Investigating the Effects of Simultaneous Administration of Melatonin and Atorvastatin against High Glucose-Induced Oxidative Stress and Apoptosis in Cultured Chondrocytes.

Osteoarthritis (OA) is a prevalent joint disorder categorized into phenotypic subtypes, including those associated with age, traumatic events, and metabolic syndrome. In the aging population, type 2 diabetes mellitus (T2DM) and osteoarthritis (OA) frequently coexist. This can result in higher rates of disability and a greater financial burden. This study aimed to investigate the protective effects of melatonin and atorvastatin together against oxidative stress and apoptosis induced by high glucose in C28I2 human chondrocytes. After being pretreated for 6 hours with melatonin (10 and 100 μM) and atorvastatin (0.01 and 0.1 μM), C28I2 cells were exposed to a high concentration of D-glucose (75 mM) for 72 hours. The impact of a high D-glucose concentration (75 mM), with or without melatonin and/or atorvastatin, on cell viability, intra-cellular ROS generation, lipid peroxidation level, antioxidant activities, and the expression of proteins, including Bax, Bcl-2, and caspase-3, was analyzed. Melatonin and atorvastatin combination effectively inhibited high glucose-induced cytotoxicity, ROS production, and MDA and mitochondrial membrane potential levels. The combination of melatonin and atorvastatin was more successful in reducing ROS production compared to each of the drugs alone. Melatonin, but not atorvastatin, reversed high glucose-induced alteration in the catalase activity. Furthermore, the combination of melatonin and atorvastatin significantly enhanced the ability of each medication to lower the expression of pro-apoptotic protein Bax. The combination of melatonin and atorvastatin exerted greater protective effects against hyperglycemia-induced toxicity in chondrocytes.

Economics and Constraints of Organic Turmeric at Kakching District of Manipur

Background: As the locale of the present study has high potential for production of organic turmeric, so to take the relevant measures for best exploit the resources and to create more income and employment to the rural people. Methods: The present study is based on 200 turmeric growers drawn by adopting a multistage purposive stratified simple random sampling technique from Kakching district; based on the primary data, collected through personal interview method with the help of pre-tested and well structured questionnaire exclusively designed pertaining for the agricultural year 2020-2022. Result: The majority (93.00 per cent) of the respondents belonged to semi-medium land holding with an area of 2.01 to 3.00 ha, total gross return was highest (₹ 1,61,768.44/-) for medium farm size group and benefit-cost ratio was highest (2.64 : 1) for small farm size group. The major production constraint was lack of proper inputs, lack of training, lack of irrigation facility, lack of quality planting material etc.

Cascading valorization of defatted rice bran for lactic acid fermentation and biogas production

This study investigated the integrated valorization of defatted rice bran (DRB) by converting it into lactic acid (LA) and subsequently utilizing the residues from LA production for biomethane generation through anaerobic digestion (AD). Processing 480 kg of DRB resulted in the production of 70 L of pure LA and generated significant waste streams, primarily consisting of 572 kg of decanted hydrolysate pellet (Pellet DEC) and 220 kg of microfiltration retentate (Retentate MF). Exceptionally high methane yields of 374‒434 LN kgVS-1 were observed for residues from LA fermentation in biochemical methane potential tests, indicating their high potential for biogas production. During long-term semi-continuous AD, varying organic loading rates (OLRs) from 0.5‒2.5 kgVS m-3 d⁻¹ demonstrated feedstock- and OLR-dependent methane production. Reactor failure at higher OLRs was attributed to the accumulation of total ammoniacal nitrogen (TAN). The co-digestion of Pellet DEC and Retentate MF proved to be more resilient, with OLRs up to 2 kgVS m-3 d-1, mitigating TAN inhibition. Methane yields, ranging from 265‒334 LN kgVS-1 before reaching inhibitory OLR levels, were higher than those found in the literature. Process integration has emerged as a promising approach because the biogas generated from residues could effectively offset the energy demands of LA production. Supported by life cycle assessment, the integrated processes showed a 67% lower environmental impact at the midpoint and a 71% lower environmental impact at the endpoint, along with an 80% reduction in energy costs compared to the standalone LA production. Results proved a significant enhancement of the sustainability and economic viability of this integrated biorefinery approach.

Long-term performance and activity study of a two-stage anaerobic EGSB reactors system treating complex and toxic industrial wastewater.

Anaerobic treatment of industrial wastewater using upflow anaerobic reactors is an extended trend due to its high efficiency and biogas production potential, but its implementation in some sectors is limited due to the complexity and toxicity of the wastewaters. In this study, a two-stage expanded granular sludge bed (EGSB) reactors system has been investigated at both bench and pilot scale for the treatment of complex and toxic real wastewater from a petrochemical industry. The effect of different operational parameters including organic loading rate (OLR), hydraulic retention time (HRT) and influent characteristics over COD removal and biogas production and composition have been studied. Additionally, biomass specific methanogenic activity (SMA) and wastewater toxicity have been evaluated after long-term operation. Optimum total HRT of 24 h has been determined resulting in total COD and SO4 2- removal of 56.30 ± 5.25% and 31.68 ± 14.71%, respectively, at pilot scale, and average biogas production of 93.47 ± 34.92 NL/day with 67.01 ± 10.23 %CH4 content and 5210.11 ± 6802.27 ppmv of H2S. SMA and toxicity tests have confirmed inhibitory and toxic effects of wastewater over anaerobic biomass with average maximum inhibition of 65.34% in the unacclimated anaerobic inoculum while chronic toxicity produced a decrease of an order of magnitude in SMA after 600 days of operation. This study demonstrates the feasibility of applying an anaerobic treatment to this wastewater using EGSB reactors between a 0.97-1.74 gCOD/L/day OLR range. Nonetheless, periodic reinoculation would be necessary for long-term operation due to chronic toxicity of the wastewater exerted on the anaerobic biomass. PRACTITIONER POINTS: A two-stage EGSB reactors system has been operated at bench and pilot scale to treat complex and toxic petrochemical wastewater. Optimal total HRT of 24 h resulted in average COD removal ranging from 40% to 60%. SMA and toxicity tests have been performed to study long-term acclimation, detecting an activity depletion of an order of magnitude.

Spatial Patterns of Productivity and Human Development Potentials for Pinus pinea L.

Pinus pinea (stone pine), a Mediterranean species, is valued for its highly nutritious pine nuts and its ability to adapt to different environmental conditions. The species has been increasingly planted in Chile, where its main ecological requirements are met across a vast area. However, new plantations are established without considering social dimensions. Policymakers can regulate private decisions on tree planting through the appropriate design of economic incentives to foster social well-being. The objective of this work was to describe spatial patterns of potential areas for the cultivation of the exotic nut-bearing conifer P. pinea in central Chile and the possible correlation of those patterns with human development indices. Spatial data layers of the municipality development index (MDI), elevation, edaphoclimatic variables, and stone pine nut’s productive potential were overlapped at the municipality scale along 1225 km in central Chile. A spatial principal component analysis (sPCA) was used to integrate multiple dimensions, summarizing covariation structures, and identifying spatial patterns in the study area. Key results showed that spatial patterns of the potential productive index (PPI) were strongly regulated by the spatial pattern of climate and soil variables, whereas the spatial pattern of MDI showed a cryptic pattern and that the three dimensions of MDI—welfare, economy, and education—showed a different spatial movement, especially education and welfare. The results allow us to recommend that public policies boost municipality development through the promotion of P. pinea plantations and should target areas with a high productive potential and low MDI to generate socio-economic improvements. These findings are useful for the strategic spatial planning of the species cropping in Chile.

Wastewater treatment plant effluents increase the global warming potential in a subtropical urbanized river

Rivers play a pivotal role in global carbon (C) and nitrogen (N) biogeochemical cycles. Urbanized rivers are significant hotspots of greenhouse gases (GHGs, N2O, CO2 and CH4) emissions. This study examined the GHGs distributions in the Guanxun River, an effluents-receiving subtropical urbanized river, as well as the key environmental factors and processes affecting the pattern and emission characteristics of GHGs. Dissolved N2O, CO2, and CH4 concentrations reached 228.0 nmol L–1, 0.44 mmol L–1, and 5.2 μmol L–1 during the wet period, and 929.8 nmol L–1, 0.7 mmol L–1, and 4.6 μmol L–1 during the dry period, respectively. Effluents inputs increased C and N loadings, reduced C/N ratios, and promoted further methanogenesis and N2O production dominated by incomplete denitrification after the outfall. Increased urbanization in the far downstream, high hydraulic residence time, low DO and high organic C environment promoted methanogenesis. The strong CH4 oxidation and methanogenic reactions inhibited by the effluents combined to suppress CH4 emissions in downstream near the outfall, and the process also contributed to CO2 production. The carbon fixation downstream from the outfall were inhibited by effluents. Ultimately, it promoted CO2 emissions downstream from the outfall. The continuous C, N, and chlorine inputs maintained the high saturation and production potential of GHGs, and altered microbial community structure and functional genes abundance. Ultimately, the global warming potential downstream increased by 186 % and 84 % during wet and dry periods on the 20-year scale, and increased by 91 % and 49 % during wet and dry periods on the 100-year scale, respectively, compared with upstream from the outfall. In urbanized rivers with sufficient C and N source supply from WWTP effluents, the large effluent equivalently transformed the natural water within the channel into a subsequent "reactor". Furthermore, the IPCC recommended EF5r values appear to underestimate the N2O emission potential of urbanized rivers with high pollution loading that receiving WWTP effluents. The findings of this study might aid the development of effective strategies for mitigating global climate change.

Enhanced photocatalytic performance of CdZnS nanoparticles and attapulgite/carbon nitride composites by carbon quantum dots mediated facilitated charge separation/transfer: Cr(VI) reduction and H2O2 production

In this work, CdZnS@carbon quantum dots/amino-modified attapulgite/carbon nitride (CdZnS@CQDs/M-ATP/PCN), function as Z-scheme heterojunction photocatalysts, have been successfully prepared by the hydrothermal method. CdZnS@CQDs-1/M-ATP/PCN-1 was optimized toward reduction of Cr(VI) and production of H2O2 under visible light, showing significantly improved photocatalytic performance. After coupling of M-ATP/PCN-1 with CdZnS and a moderate addition of CQDs, the synergistic formation of Z-scheme heterojunctions photocatalytic system effectively enhanced the photocatalytic properties of the composites. The results revealed that the CdZnS@CQDs/M-ATP/PCN catalysts contain rich active centers and suitable energy band structures, which enable them to produce more OH and O2−. Additionally, they also absorb visible light strongly and thus effectively improves the photocatalytic activity. Specifically, the reduction of Cr(VI) by CdZnS@CQDs-1/M-ATP/PCN-1 catalyst was achieved greater than 97.6 %, along with the production of 719.32 μmol·L−1 H2O2. Combining density functional theory (DFT) calculations, experimental test results and characterizations, we find that the excellent photocatalytic performance is attributed to the incorporation of CQDs and the formation of Z-scheme heterojunctions. We have developed a non-precious metal-based efficient Z-scheme photocatalytic system using simple hydrothermal synthesis method, which has a very high potential for energy production, environmentally sustainable remediation, and water purification.

Selection for yield in elephant-grass forage genotypes using GGE Biplot analysis

Elephant grass is among the most used forages in intensive animal production systems due to its high productive potential, carrying capacity and nutritional quality. Because of the existing interaction between genotypes and environments, it is essential to select and develop materials that are not only high-yielding but also adaptable and stable. In this context, this study was developed to analyze the performance and select genotypes of elephant grass simultaneously for dry matter yield, performance stability and adaptability. Fifty-three elephant grass genotypes with forage potential were evaluated in four environments (rainy and dry seasons in years 1 and 2), defined according to the time at which the harvests occurred. A randomized-block design with two replicates was adopted. Dry matter yield (t.ha-1) was measured at each assessment (harvest). Adaptability and genotypic stability were evaluated using the GGE biplot methodology and R software. In the overall classification, genotypes 53, 22, 29, 17 and 33 showed the best average performance. Regarding dry matter yield, adaptability and phenotypic stability, genotype 53 was classified as the ideotype.

Shallow soils in dryland ecosystems: Drivers of C accumulation and land management implications

Shallow soils (i.e., Lithic Entisols) cover about 20% of Brazilian drylands. Inherent soil characteristics (i.e., shallow depths) and water scarcity restrict plant growth and carbon (C) inputs in these soils. In such a sensitive ecosystem, sustainable land management options are key to promoting socio-economic development and ensuring food security. Here, we use a dataset of 50 Lithic Entisol profiles distributed within the Brazilian drylands (northeastern region) to: (i) investigate the effects of land-use (cropland, grassland, and native forest), climate (semi-arid and dry sub-humid), and slope classes (0–3%, 3–8%, 8–20% and 20–45%) on soil C accumulation; and (ii) evaluate how understanding multiple drivers C accumulation can support the identification of sustainable land management options. The results suggested that land use does not affect C stock and C/N ratio, nevertheless, they were affected by climate. Under dry sub-humid climate conditions, C stocks were 41.7 Mg ha−1, 44% higher than under semi-arid climate (28.9 Mg ha−1), a result that reflects the effect of higher biomass production in wetter environments. Under slopes of 20–45%, C stocks were 54.3 Mg ha−1, 172% higher than under slopes of 0–3% (19.9 Mg ha−1), because of the higher altitudes and wetter conditions under steeper slopes. Our results showed that areas under lower slopes have lower C stocks and lower aridity index. These drier conditions reduce the productive potential of annual crops and grasslands but enable the cultivation of high-yielding Crassulacean Acid Metabolism (CAM) crops, such as Agave spp, which have a high potential for biofuel production. Furthermore, the possibility of reintroducing organic residues from ethanol production can promote an increase in C stocks, contributing to climate change mitigation. Ultimately, our study provides insights from a holistic view of SOC accumulation drivers, supporting land use planning of highly sensitive environments in tropical drylands around the world.

Determinants of Adoption of Improved Sorghum Varieties by Small-Scale Farmers in Selected Districts of Western Oromia

Achieving national food security and diversifying export earnings from agricultural products is one of the major challenges currently facing developing countries like Ethiopia. Ethiopia is the largest producer of sorghum in Africa, contributing to ensuring food security in the country. Despite the high production potential and the economic importance of the crop, the adoption, and dissemination of improved sorghum varieties are constrained by various factors. To this end, this study aimed to identify determinants of adoption of improved sorghum varieties in selected districts of Western Oromia Region, Ethiopia with the specific objectives of identifying factors affecting adoption and assessing factors hindering the production of improved sorghum varieties. The study was based on cross-sectional data from 154 randomly selected sorghum-producing farmers. Descriptive and econometric analyses were used to analyze data. The results show that about 14.94% and 85.06% were adopters and non-adopters of the crop respectively. Probit model results showed that education and extension service affected the probability of adoption of improved sorghum varieties positively and significantly while TLU affected it negatively and significantly. Untimely availability of improved seed, Price of seed, Quality of improved seed, unavailability of credit to buy seed, Untimely availability of fertilizer, High price of fertilizer, Access to market information, Low grain price, and Pests and disease are the major constraints that affect sorghum production in the study area. This study suggests the high importance of institutional and government support in education, Extension service, and improved cows than a large number of local breeds. Therefore, policy and development interventions should give emphasis on the improvement of such institutional support systems so as to achieve the adoption practice which increases the production and productivity of small-scale farmers.