Greenhouse gas emissions from on-site sanitation systems: A systematic review and meta-analysis of emission rates, formation pathways and influencing factors.

Onsite sanitation systems (OSS) are significant sources of greenhouse gases (GHG) including carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). While a handful of studies have been conducted on GHG emissions from OSS, systematic evaluation of literature on this subject is limited. Our systematic review and meta-analysis provides state-of-the- art information on GHG emissions from OSS and identifies novel areas for investigation. The paper analyzes GHG emission rates from different OSS, the influence of various design, operational, and environmental factors on emission rates and proffers mitigation measures. Following the Preferred Reporting Items for Systematic reviews and Meta-analysis (PRISMA) guidelines, we identified 16 articles which quantified GHG emissions from OSS. Septic tanks emit substantial amounts of CO2 and CH4 ranging from 1.74 to 398.30 g CO2/cap/day and 0.06-110.13 g CH4/cap/day, respectively, but have low N2O emissions (0.01-0.06 g N2O/cap/day). CH4 emissions from pit latrines range from 0.77 to 20.30 g CH4/cap/day N2O emissions range from 0.76 to 1.20 gN2O/cap/day. We observed statistically significant correlations (p < 0.05) between temperature, biochemical oxygen demand, chemical oxygen demand, dissolved oxygen, storage period, and GHG emissions from OSS. However, no significant correlation (p > 0.05) was observed between soil volumetric water content and CO2 emissions. CH4 emissions (expressed as CO2 equivalents) from OSS estimated following Intergovernmental Panel for Climate Change (IPCC) guidelines were found to be seven times lower (90.99 g CO2e/cap/day) than in-situ field emission measurements (704.7 g CO2e/cap/day), implying that relying solely on IPCC guidelines may lead to underestimation of GHG emission from OSS. Our findings underscore the importance of considering local contexts and environmental factors when estimating GHG emissions from OSS. Plausible mitigation measures for GHG emissions from OSS include converting waste to biogas in anaerobic systems (e.g. biogas), applying biochar, and implementing mitigation policies that equally address inequalities in sanitation service access. Future research on GHG from OSS should focus on in-situ measurements of GHGs from pit latrines and other common OSS in developing countries, understanding the fate and transport of dissolved organics like CH4 in OSS effluents and impacts of microbial communities in OSS on GHG emissions. Addressing these gaps will enable more holistic and effective management of GHG emissions from OSS.

Reduction of greenhouse gas emissions from closed activated sludge- to aerobic granular sludge-based biosystems via gas circulation.

Greenhouse gas (GHG) emissions from biological treatment units are challenging wastewater treatment plants (WWTPs) due to their wide applications and global warming. This study aimed to reduce GHG emissions (especially N2O) using a gas circulation strategy in a closed sequencing-batch reactor when the biological unit varies from activated sludge (AS) to aerobic granular sludge (AGS). Results show that gas circulation lowers pH to 6.3 ± 0.2, facilitating regular granules but elevating total N2O production. From AS to AGS, N2O emission factor increased (0.07-0.86 %) due to decreasing ammonia-oxidizing rates while the emissions of CO2 (0.3 ± 0.1 kg-CO2/kg-chemical oxygen demand) and CH4 remained in the closed biosystem. The gas circulation decreased N2O emission factor by 63 ± 15 % after granulation higher than 44 ± 34 % before granulation, which is implemented by heterotrophic denitrification. This study provides a feasible strategy to enhance heterotrophic N2O elimination in the biological WWTPs.

Optimizing irrigation and nitrogen addition to balance grassland biomass production with greenhouse gas emissions: A mesocosm study.

Achieving a balance between greenhouse gas mitigation and biomass production in grasslands necessitates optimizing irrigation frequency and nitrogen addition, which significantly influence grassland productivity and soil nitrous oxide emissions, and consequently impact the ecosystem carbon dioxide exchange. This study aimed to elucidate these influences using a controlled mesocosm experiment where bermudagrass (Cynodon dactylon L.) was cultivated under varied irrigation frequencies (daily and every 6 days) with (100 kg ha-1) or without nitrogen addition; measurements of net ecosystem carbon dioxide exchange, ecosystem respiration, soil respiration, and nitrous oxide emissions across two cutting events were performed as well. The findings revealed a critical interaction between water-filled pore space, regulated by irrigation, and nitrogen availability, with the latter exerting a more substantial influence on aboveground biomass growth and ecosystem carbon dioxide exchange than water availability. Moreover, the total dry matter was significantly higher with nitrogen addition compared to without nitrogen addition, irrespective of the irrigation frequency. In contrast, soil nitrous oxide emissions were observed to be significantly higher with increased irrigation frequency and nitrogen addition. The effects of nitrogen addition on soil respiration components appeared to depend on water availability, with autotrophic respiration seeing a significant rise with nitrogen addition under limited irrigation (5.4 ± 0.6 µmol m-2 s-1). Interestingly, the lower irrigation frequency did not result in water stress, suggesting resilience in bermudagrass. These findings highlight the importance of considering interactions between irrigation and nitrogen addition to optimize water and nitrogen input in grasslands for a synergistic balance between grassland biomass production and greenhouse gas emission mitigation.

Transformation mechanisms of ammonium and nitrate in subsurface wastewater infiltration system: Implication for reducing greenhouse gas emissions.

Subsurface wastewater infiltration system (SWIS) has been recognized as a cost-effective and environmentally friendly tool for wastewater treatment. However, there is a lack of knowledge on the transformation processes of nitrogen (N), hindering the improvement of the N removal efficiency in SWIS. Here, the migration and transformation mechanisms of ammonium (NH4+-N) and nitrate (NO3+-N) over 10 days were explored by 15N labeling technique. Over the study period, 49% of the added 15NH4+-N remained in the soil, 29% was removed via gaseous N emissions, and 14% was leaked with the effluent in the SWIS. In contrast, only 11% of the added 15NO3--N remained in the soil while 65% of the added 15NO3--N was removed via gaseous N emissions, and 12% with the effluent in the SWIS. The main pathway for N2O emission was denitrification (52-70%) followed by nitrification (15-28%) and co-denitrification (9-20%). Denitrification was also the predominant pathway for N loss as N2, accounting for 88-96% of the N2 emission. The dominant biological transformation processes were different at divergent soil depths, corresponding to nitrification zone and denitrification zone along the longitudinal continuum in SWIS, which was confirmed by the expression patterns of microbial gene abundance. Overall, our findings reveal the mechanism of N transformation in SWIS and provide a theoretical basis for establishing a pollutant management strategy and reducing greenhouse gas emissions from domestic wastewater treatment.

Computational Exploration of Minimum Energy Reaction Pathway of N2O Formation from Intermediate I of P450nor Using an Active Center Model.

P450nor is a heme-containing enzyme that catalyzes the conversion of nitric oxide (NO) to nitrous oxide (N2O). Its catalytic mechanism has attracted attention in chemistry, biology, and environmental engineering. The catalytic cycle of P450nor is proposed to consist of three major steps. The reaction mechanism for the last step, N2O generation, remains unknown. In this study, the reaction pathway of the N2O generation from the intermediate I was explored with the B3LYP calculations using an active center model after the examination of the validity of the model. In the validation, we compared the heme distortions between P450nor and other oxidoreductases, suggesting a small effect of protein environment on the N2O generation reaction in P450nor. We then evaluated the electrostatic environment effect of P450nor on the hydride affinity to the active site with quantum mechanics/molecular mechanics (QM/MM) calculations, confirming that the affinity was unchanged with or without the protein environment. The active center model for P450nor showed that the N2O generation process in the enzymatic reaction undergoes a reasonable barrier height without protein environment. Consequently, our findings strongly suggest that the N2O generation reaction from the intermediate I depends sorely on the intrinsic reactivity of the heme cofactor bound on cysteine residue.

Phytochemical Combination Is More Effective than Individual Components in Reducing Stress Signaling in Rat Hippocampal Neurons and Microglia In Vitro.

Age-related decrements in the central nervous system (CNS) are thought to result from: (1) increased susceptibility to and accumulating effects of free radicals and inflammation; and (2) dysregulation in Ca2+ homeostasis, which affects numerous signaling pathways. Certain bioactive phytochemicals exhibit potent anti-inflammatory activities which may mitigate these age-related CNS decrements. This study investigated the individual and combination effects of green tea catechin (epigallocatechin gallate, EGCG), curcumin from turmeric, and broccoli sprouts which contain the isothiocyanate sulforaphane on inflammation and dysregulation in Ca2+ homeostasis to determine if the individual compounds were working synergistically and/or through independent mechanisms. Rat hippocampal neurons or highly aggressive proliferating immortalized (HAPI) microglial cells were pre-treated for a week with either the individual components or all in combination before inducing Ca2+ buffering deficits with dopamine (DA, 0.1 µM for 2 h) or inflammation using lipopolysaccharide (LPS, 100 ng/mL for 18 h), respectively. The EGCG (3 µM) and combination protected against DA-induced deficits in Ca2+ buffering (both % of cells that recovered and recovery time, p < 0.05). Additionally, the EGCG and combination reduced stress-mediated inflammation in HAPI rat microglial cells by attenuating LPS-induced nitrite release, inducible nitrous oxide synthase (iNOS) expression, and tumor necrosis factor-alpha (TNF-α) release (p < 0.05), but not cyclooxygenase-2 (COX-2) expression. Overall, broccoli sprouts (2 µM) and curcumin (1 µM) were not as effective as the EGCG or combination. Further research is needed to determine if dietary intervention with a variety of foods containing compounds such as those found in green tea, turmeric, or broccoli sprouts can play a role in reducing age-related CNS inflammation, microglial activation, and downstream signaling pathways that can lead to neuronal dysfunction.

Photocatalytic Removal of the Greenhouse Gas Nitrous Oxide by Liposomal Microreactors.

Nitrous oxide (N2 O) is a potent greenhouse and ozone-reactive gas for which emissions are growing rapidly due to increasingly intensive agriculture. Synthetic catalysts for N2 O decomposition typically contain precious metals and/or operate at elevated temperatures driving a desire for more sustainable alternatives. Here we demonstrate self-assembly of liposomal microreactors enabling catalytic reduction of N2 O to the climate neutral product N2 . Photoexcitation of graphitic N-doped carbon dots delivers electrons to encapsulated N2 O Reductase enzymes via a lipid-soluble biomolecular wire provided by the MtrCAB protein complex. Within the microreactor, electron transfer from MtrCAB to N2 O Reductase is facilitated by the general redox mediator methyl viologen. The liposomal microreactors use only earth-abundant elements to catalyze N2 O removal in ambient, aqueous conditions.

The NtrYX Two-Component System of Paracoccus denitrificans Is Required for the Maintenance of Cellular Iron Homeostasis and for a Complete Denitrification under Iron-Limited Conditions.

Denitrification consists of the sequential reduction of nitrate to nitrite, nitric oxide, nitrous oxide, and dinitrogen. Nitrous oxide escapes to the atmosphere, depending on copper availability and other environmental factors. Iron is also a key element because many proteins involved in denitrification contain iron-sulfur or heme centers. The NtrYX two-component regulatory system mediates the responses in a variety of metabolic processes, including denitrification. A quantitative proteomic analysis of a Paracoccus denitrificans NtrY mutant grown under denitrifying conditions revealed the induction of different TonB-dependent siderophore transporters and proteins related to iron homeostasis. This mutant showed lower intracellular iron content than the wild-type strain, and a reduced growth under denitrifying conditions in iron-limited media. Under iron-rich conditions, it releases higher concentrations of siderophores and displayes lower nitrous oxide reductase (NosZ) activity than the wild-type, thus leading to nitrous oxide emission. Bioinformatic and qRT-PCR analyses revealed that NtrYX is a global transcriptional regulatory system that responds to iron starvation and, in turn, controls expression of the iron-responsive regulators fur, rirA, and iscR, the denitrification regulators fnrP and narR, the nitric oxide-responsive regulator nnrS, and a wide set of genes, including the cd1-nitrite reductase NirS, nitrate/nitrite transporters and energy electron transport proteins.

Growth, hemato-biochemical, immune-antioxidant response, and gene expression in Nile tilapia (Oreochromis niloticus) received nano iron oxide-incorporated diets.

Nanotechnology has recently played a key role in tackling many aquacultures issues. Hence, the present study targets the evaluation of dietary inclusion of nano iron oxide (nFe2O3) on growth performance, hematology, immune-antioxidant responses, ionic regulation and expression of related genes in Nile tilapia (Oreochromis niloticus). Fish were fed supplementary nFe2O3 at rates of zero (control), 0.5, and 1 g/kg diet for 30 days. Obtained data demonstrated that nFe2O3 significantly (P < 0.05) augmented growth performance (final weight and length, body mass gain, specific growth rate, feed conversion ratio, and length gain rate). Hematological picture {RBCs, Hb, MCV, MCH and MCHC, and leukocytes interpretations (WBCs and monocytes)}; and biochemical indexes including (AST and ALT; total protein; and glucose, and cortisol) were significantly (P < 0.05) improved in nFe2O3 supplemented groups. Plasma ionic concentration was also altered with nFe2O3 supplementation, and 1g nFe2O3 revealed the most marked increase in plasma (Na+) potassium (K+) levels. Similarly, IgM, nitrous oxide (NO), and lysozyme activity, plus superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities showed a remarkable improvement in 1g nFe2O3 group compared to the control. Expression of Insulin-Like Growth Factor-1 (IGF-1) and interleukin 1-ß (IL-1ß) genes were significantly up-regulated in nFe2O3 supplemented groups. Briefly, dietary nFe2O3 inclusion had enhanced properties on growth; hemato-biochemical; immune, antioxidative profiles; and related genes expression of O. niloticus, with a recommended concentration of 1g nFe2O3.

Molecular interplay of an assembly machinery for nitrous oxide reductase.

Emissions of the critical ozone-depleting and greenhouse gas nitrous oxide (N2O) from soils and industrial processes have increased considerably over the last decades1-3. As the final step of bacterial denitrification, N2O is reduced to chemically inert N2 (refs. 1,4) in a reaction that is catalysed by the copper-dependent nitrous oxide reductase (N2OR) (ref. 5). The assembly of its unique [4Cu:2S] active site cluster CuZ requires both the ATP-binding-cassette (ABC) complex NosDFY and the membrane-anchored copper chaperone NosL (refs. 4,6). Here we report cryo-electron microscopy structures of Pseudomonas stutzeri NosDFY and its complexes with NosL and N2OR, respectively. We find that the periplasmic NosD protein contains a binding site for a Cu+ ion and interacts specifically with NosL in its nucleotide-free state, whereas its binding to N2OR requires a conformational change that is triggered by ATP binding. Mutually exclusive structures of NosDFY in complex with NosL and with N2OR reveal a sequential metal-trafficking and assembly pathway for a highly complex copper site. Within this pathway, NosDFY acts as a mechanical energy transducer rather than as a transporter. It links ATP hydrolysis in the cytoplasm to a conformational transition of the NosD subunit in the periplasm, which is required for NosDFY to switch its interaction partner so that copper ions are handed over from the chaperone NosL to the enzyme N2OR.

Regulation of the Emissions of the Greenhouse Gas Nitrous Oxide by the Soybean Endosymbiont Bradyrhizobium diazoefficiens.

The greenhouse gas nitrous oxide (N2O) has strong potential to drive climate change. Soils are a major source of N2O, with microbial nitrification and denitrification being the primary processes involved in such emissions. The soybean endosymbiont Bradyrhizobium diazoefficiens is a model microorganism to study denitrification, a process that depends on a set of reductases, encoded by the napEDABC, nirK, norCBQD, and nosRZDYFLX genes, which sequentially reduce nitrate (NO3-) to nitrite (NO2-), nitric oxide (NO), N2O, and dinitrogen (N2). In this bacterium, the regulatory network and environmental cues governing the expression of denitrification genes rely on the FixK2 and NnrR transcriptional regulators. To understand the role of FixK2 and NnrR proteins in N2O turnover, we monitored real-time kinetics of NO3-, NO2-, NO, N2O, N2, and oxygen (O2) in a fixK2 and nnrR mutant using a robotized incubation system. We confirmed that FixK2 and NnrR are regulatory determinants essential for NO3- respiration and N2O reduction. Furthermore, we demonstrated that N2O reduction by B. diazoefficiens is independent of canonical inducers of denitrification, such as the nitrogen oxide NO3-, and it is negatively affected by acidic and alkaline conditions. These findings advance the understanding of how specific environmental conditions and two single regulators modulate N2O turnover in B. diazoefficiens.

Influence of rice varieties, organic manure and water management on greenhouse gas emissions from paddy rice soils.

The study is focused on impact of manure application, rice varieties and water management on greenhouse gas (GHG) emissions from paddy rice soil in pot experiment. The objectives of this study were a) to assess the effect of different types of manure amendments and rice varieties on greenhouse gas emissions and b) to determine the optimum manure application rate to increase rice yield while mitigating GHG emissions under alternate wetting and drying irrigation in paddy rice production. The first pot experiment was conducted at the Department of Agronomy, Yezin Agricultural University, Myanmar, in the wet season from June to October 2016. Two different organic manures (compost and cow dung) and control (no manure), and two rice varieties; Manawthukha (135 days) and IR-50 (115 days), were tested. The results showed that cumulative CH4 emission from Manawthukha (1.084 g CH4 kg-1 soil) was significantly higher than that from IR-50 (0.683 g CH4 kg-1 soil) (P<0.0046) with yield increase (P<0.0164) because of the longer growth duration of the former. In contrast, higher cumulative nitrous oxide emissions were found for IR-50 (2.644 mg N2O kg-1 soil) than for Manawthukha (2.585 mg N2O kg-1 soil). However, IR-50 showed less global warming potential (GWP) than Manawthukha (P<0.0050). Although not significant, the numerically lowest CH4 and N2O emissions were observed in the cow dung manure treatment (0.808 g CH4 kg-1 soil, 2.135 mg N2O kg-1 soil) compared to those of the control and compost. To determine the effect of water management and organic manures on greenhouse gas emissions, second pot experiments were conducted in Madaya township during the dry and wet seasons from February to October 2017. Two water management practices {continuous flooding (CF) and alternate wetting and drying (AWD)} and four cow dung manure rates {(1) 0 (2) 2.5 t ha-1 (3) 5 t ha-1 (4) 7.5 t ha-1} were tested. The different cow dung manure rates did not significantly affect grain yield or greenhouse gas emissions in this experiment. Across the manure treatments, AWD irrigation significantly reduced CH4 emissions by 70% during the dry season and 66% during the wet season. Although a relative increase in N2O emissions under AWD was observed in both rice seasons, the global warming potential was significantly reduced in AWD compared to CF in both seasons (P<0.0002, P<0.0000) according to reduced emission in CH4. Therefore, AWD is the effective mitigation practice for reducing GWP without compromising rice yield while manure amendment had no significant effect on GHG emission from paddy rice field. Besides, AWD saved water about 10% in dry season and 19% in wet season.

Cardamonin Attenuates Experimental Colitis and Associated Colorectal Cancer.

Cardamonin is a naturally occurring chalcone, majorly from the Zingiberaceae family, which includes a wide range of spices from India. Herein, we investigated the anti-inflammatory property of cardamonin using different in vitro and in vivo systems. In RAW 264.7 cells, treatment with cardamonin showed a reduced nitrous oxide production without affecting the cell viability and decreased the expression of iNOS, TNF-α, and IL-6, and inhibited NF-kB signaling which emphasizes the role of cardamonin as an anti-inflammatory molecule. In a mouse model of dextran sodium sulfate (DSS)-induced colitis, cardamonin treatment protected the mice from colitis. Subsequently, we evaluated the therapeutic potential of this chalcone in a colitis-associated colon cancer model. We performed microRNA profiling in the different groups and observed that cardamonin modulates miRNA expression, thereby inhibiting tumor formation. Together, our findings indicate that cardamonin has the potential to be considered for future therapy against colorectal cancer.

Enhancement of Nitrous Oxide Emissions in Soil Microbial Consortia via Copper Competition between Proteobacterial Methanotrophs and Denitrifiers.

Unique means of copper scavenging have been identified in proteobacterial methanotrophs, particularly the use of methanobactin, a novel ribosomally synthesized, post-translationally modified polypeptide that binds copper with very high affinity. The possibility that copper sequestration strategies of methanotrophs may interfere with copper uptake of denitrifiers in situ and thereby enhance N2O emissions was examined using a suite of laboratory experiments performed with rice paddy microbial consortia. Addition of purified methanobactin from Methylosinus trichosporium OB3b to denitrifying rice paddy soil microbial consortia resulted in substantially increased N2O production, with more pronounced responses observed for soils with lower copper content. The N2O emission-enhancing effect of the soil's native mbnA-expressing Methylocystaceae methanotrophs on the native denitrifiers was then experimentally verified with a Methylocystaceae-dominant chemostat culture prepared from a rice paddy microbial consortium as the inoculum. Finally, with microcosms amended with various cell numbers of methanobactin-producing Methylosinus trichosporium OB3b before CH4 enrichment, microbiomes with different ratios of methanobactin-producing Methylocystaceae to gammaproteobacterial methanotrophs incapable of methanobactin production were simulated. Significant enhancement of N2O production from denitrification was evident in both Methylocystaceae-dominant and Methylococcaceae-dominant enrichments, albeit to a greater extent in the former, signifying the comparative potency of methanobactin-mediated copper sequestration, while implying the presence of alternative copper abstraction mechanisms for Methylococcaceae. These observations support that copper-mediated methanotrophic enhancement of N2O production from denitrification is plausible where methanotrophs and denitrifiers cohabit. IMPORTANCE Proteobacterial methanotrophs-groups of microorganisms that utilize methane as a source of energy and carbon-have been known to employ unique mechanisms to scavenge copper, namely, utilization of methanobactin, a polypeptide that binds copper with high affinity and specificity. Previously the possibility that copper sequestration by methanotrophs may lead to alteration of cuproenzyme-mediated reactions in denitrifiers and consequently increase emission of potent greenhouse gas N2O has been suggested in axenic and coculture experiments. Here, a suite of experiments with rice paddy soil slurry cultures with complex microbial compositions were performed to corroborate that such copper-mediated interplay may actually take place in environments cohabited by diverse methanotrophs and denitrifiers. As spatial and temporal heterogeneity allows for spatial coexistence of methanotrophy (aerobic) and denitrification (anaerobic) in soils, the results from this study suggest that this previously unidentified mechanism of N2O production may account for a significant proportion of N2O efflux from agricultural soils.

First field estimation of greenhouse gas release from European soil-dwelling Scarabaeidae larvae targeting the genus Melolontha.

Arthropods are a major soil fauna group, and have the potential to substantially influence the spatial and temporal variability of soil greenhouse gas (GHG) sinks and sources. The overall effect of soil-inhabiting arthropods on soil GHG fluxes still remains poorly quantified since the majority of the available data comes from laboratory experiments, is often controversial, and has been limited to a few species. The main objective of this study was to provide first insights into field-level carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) release of soil-inhabiting larvae of the Scarabaeidae family. Larvae of the genus Melolontha were excavated at various sites in west-central and southern Germany, covering a wide range of different larval developmental stages, larval activity levels, and vegetation types. Excavated larvae were immediately incubated in the field to measure their GHG production. Gaseous carbon release of individual larvae showed a large inter- and intra-site variability which was strongly correlated to larval biomass. This correlation persisted when upscaling individual CO2 and CH4 production to the plot scale. Field release estimates for Melolontha spp. were subsequently upscaled to the European level to derive the first regional GHG release estimates for members of the Scarabaeidae family. Estimates ranged between 10.42 and 409.53 kt CO2 yr-1, and 0.01 and 1.36 kt CH4 yr-1. Larval N2O release was only sporadically observed and not upscaled. For one site, a comparison of field- and laboratory-based GHG production measurements was conducted to assess potential biases introduced by transferring Scarabaeidae larvae to artificial environments. Release strength and variability of captive larvae decreased significantly within two weeks and the correlation between larval biomass and gaseous carbon production disappeared, highlighting the importance of field measurements. Overall, our data show that Scarabaeidae larvae can be significant soil GHG sources and should not be neglected in soil GHG flux research.

Mitigation of greenhouse gas emissions through optimized irrigation and nitrogen fertilization in intensively managed wheat-maize production.

In the wheat-maize rotation cultivation system in northern China, excessive irrigation and over-fertilization have depleted groundwater and increased nitrogen (N) losses. These problems can be addressed by optimized N fertilization and water-saving irrigation. We evaluated the effects of these practices on greenhouse gas emissions (GHG), net profit, and soil carbon (C) sequestration. We conducted a field experiment with flood irrigation (FN0, 0 kg N ha-1 yr-1, FN600, 600 kg N ha-1 yr-1) and drip fertigation treatments (DN0, 0 kg N ha-1 yr-1; DN420, 420 kg N ha-1 yr-1; DN600, 600 kg N ha-1 yr-1) in 2015-2017. Compared with FN600, DN600 decreased direct GHGs (N2O + CH4) emissions by 21%, and increased the net GHG balance, GHG intensity, irrigation water-use efficiency (IWUE), and soil organic C content (ΔSOC) by 13%, 12%, 88%, and 89.8%, respectively. Higher costs in DN600 (for electricity, labour, polyethylene) led to a 33.8% lower net profit than in FN600. Compared with FN600, DN420 reduced N and irrigation water by 30% and 46%, respectively, which increased partial factor productivity and IWUE (by 49% and 94%, respectively), but DN420 did not affect GHG mitigation or net profit. Because lower profit is the key factor limiting the technical extension of fertigation, financial subsidies should be made available for farmers to install fertigation technology.

Arctigenin prevents the progression of osteoarthritis by targeting PI3K/Akt/NF-κB axis: In vitro and in vivo studies.

Osteoarthritis (OA), which is principally featured by progressive joint metabolic imbalance and subsequent degeneration of articular cartilage, is a common chronic joint disease. Arctigenin (ATG), a dietary phyto-oestrogen, has been described to have potent anti-inflammatory effects. Nevertheless, its protective effects on OA have not been clearly established. The target of our following study is to evaluate the protective effects of ATG on IL-1ß-induced human OA chondrocytes and mouse OA model. Our results revealed that the ATG pre-treatment effectively decreases the level of pro-inflammatory mediators, such as prostaglandin E2 (PGE2), nitrous oxide (NO), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), IL-6 and tumour necrosis factor alpha (TNF-α) in IL-1ß-induced human chondrocytes. In addition, ATG protects against the degradation of extracellular matrix (ECM) under the stimulation of IL-1ß and the possible mechanism might be connected with the inactivation of phosphatidylinositol-3-kinase (PI3K)/Akt/nuclear factor-kappa B (NF-κB) axis. Furthermore, a powerful binding capacity between ATG and PI3K was also uncovered in our molecular docking research. Meanwhile, ATG may act as a protector on the mouse OA model. Collectively, all these findings suggest that ATG could be utilized as a promising therapeutic agent for the treatment of OA.

Measured greenhouse gas budgets challenge emission savings from palm-oil biodiesel.

The potential of palm-oil biofuels to reduce greenhouse gas (GHG) emissions compared with fossil fuels is increasingly questioned. So far, no measurement-based GHG budgets were available, and plantation age was ignored in Life Cycle Analyses (LCA). Here, we conduct LCA based on measured CO2, CH4 and N2O fluxes in young and mature Indonesian oil palm plantations. CO2 dominates the on-site GHG budgets. The young plantation is a carbon source (1012 ± 51 gC m-2 yr-1), the mature plantation a sink (-754 ± 38 gC m-2 yr-1). LCA considering the measured fluxes shows higher GHG emissions for palm-oil biodiesel than traditional LCA assuming carbon neutrality. Plantation rotation-cycle extension and earlier-yielding varieties potentially decrease GHG emissions. Due to the high emissions associated with forest conversion to oil palm, our results indicate that only biodiesel from second rotation-cycle plantations or plantations established on degraded land has the potential for pronounced GHG emission savings.

Greenhouse gas emissions resulting from conversion of peat swamp forest to oil palm plantation.

Conversion of tropical peat swamp forest to drainage-based agriculture alters greenhouse gas (GHG) production, but the magnitude of these changes remains highly uncertain. Current emissions factors for oil palm grown on drained peat do not account for temporal variation over the plantation cycle and only consider CO2 emissions. Here, we present direct measurements of GHGs emitted during the conversion from peat swamp forest to oil palm plantation, accounting for CH4 and N2O as well as CO2. Our results demonstrate that emissions factors for converted peat swamp forest is in the range 70-117 t CO2 eq ha-1 yr-1 (95% confidence interval, CI), with CO2 and N2O responsible for ca. 60 and ca. 40% of this value, respectively. These GHG emissions suggest that conversion of Southeast Asian peat swamp forest is contributing between 16.6 and 27.9% (95% CI) of combined total national GHG emissions from Malaysia and Indonesia or 0.44 and 0.74% (95% CI) of annual global emissions.

The Possible Role of Interleukin (IL)-18 and Nitrous Oxide and Their Relation to Oxidative Stress in the Development and Progression of Breast Cancer.

Background: Cancer breast is the most common malignant tumor in females globally. Mechanisms linking inflammatory cytokines and tumour growth and progression have not been established. Interleukin (IL)-18 has a modifying role in the immune defense against tumor cells. It induces production of IFN-γ. It also increases the immune cells cytotoxic activity and enhances the production of other proinflammatory cytokine. Nitric oxide (NO) has both promoting and inhibiting effects on tumorigenesis. Oxidative stress is a phenomenon that leads to oxidative damage of biomolecules, mutagenesis and carcinogenesis. Objective: The purpose of this research is to identify the potential role of IL18 and NO and their relation to oxidative stress in the development of cancer breast. Patients and Methods: This study included 120 women split into two groups ; control group and patient groups that divided into: group B (30 patients with benign breast tumors), group N (30newly diagnosed cancer breast patients) ; and group M (30 metastatic cancer breast patients). Results: Serum total anti-oxidant capacity was significant high in both cancer breast groups. Total oxidative capacity was significantly higher level in metastatic group. NO levels were significantly higher values in the three cancer breast patients groups compared to control group.IL18 was significantly high in the metastatic group. Conclusions: Serum IL-18 and NO activity can be used as a marker for evaluating disease activity in patients with cancer breast.