Ammonia Concentration Research Articles

Co-cultured of red hybrid tilapia and Gracilaria changii (Gracilariaceae: Rhodophyta): Effects on water quality, growth performance and algal density

ABSTRACT We evaluated the potential for co-cultured of red hybrid tilapia with Gracilaria changii in two different densities in zero water exchange conditions. Five treatments were performed, consisting of three monoculture systems as controls: algae at two different densities (M1 and M2 with 1 g L−1 density and 3 g L−1 density, respectively) and fish without algae (Mfish). For comparison purposes, the other two treatments were co-cultured fish with algae at densities of 1 g L−1 (P1) and 3 g L−1 (P2). The effects of different culture systems and densities on the water quality, growth performance, nutrient content and C/N ratio of the algae were determined. During the experimental period, the dissolved oxygen (DO) and pH values in the algal tanks (monoculture and co-culture) were significantly higher than those in the Mfish tank. The ammonia and nitrate concentrations in P1 and P2 were significantly lower compared to initial measurements. The water parameters indicated that the algae improved the water quality of the culture system. Compared to the fish monoculture (Mfish), the fish grew better with algae (P1 and P2) maybe due to the more favourable water conditions in the tanks. On day 20, the algae growth rates in the co-culture tanks (P1 and P2) were significantly higher than those in the monoculture tanks. Additionally, P1 and P2 improved the nutrient composition and C/N ratio of the algae. This study found that although the co-culture system resulted in better water quality and nutrient content in the alga, the algal density had no significant effect on fish or algal growth.

Investigating the Impacts of Wastewaters on Lettuce (Lactuca sativa) Seed Germination and Growth

There is an opportunity for agriculture to utilize the many different waste streams in our world and capitalize on what would otherwise be viewed as waste products. Hydrothermal liquefaction (HTL) is an emerging technology for converting wet biomass to bio-crude oil, while aquaponics is a practice tracing back to indigenous communities around the world; both technologies have the potential to sustainably provide the necessary nutrients for crop growth. Food systems worldwide are actively transitioning to address the many challenges of climate change in a sustainable and efficient manner. Urban agriculture (UA) has the potential to generate localized crops in densely populated areas year-round, but has its challenges, involving high capital requirements, especially for vertical farming and controlled-environment agriculture, and being energy intensive due to artificial lighting and fossil fuel-based synthetic fertilizers. This study investigated the potential for aquaponic and HTL effluents to be used in hydroponic systems through a seed germination screening experiment. Buttercrunch lettuce (Lactuca sativa L.) seeds were placed in Ziploc plastic bags on paper towels saturated with the wastewater treatments for 10 days while their total length of growth was routinely measured from the tip of the root to the tip of the cotyledons. The Chicago High School for Agricultural Sciences (CHSAS) aquaponic effluent with a 5.8× times higher nitrate concentration and 4.25× higher ammonia concentration outperformed the Bevier aquaponic effluent and improved any other source water it was combined with. Results also showed that seed germination was not inhibited in the presence of 2–8% solutions of hydrothermal liquefaction aqueous phase (HTL-AP), which performed on par with standard hydroponic fertilizer; solutions of a higher percentage, though, may lead to inhibitory effects in plants, and those of a lower percentage may not provide enough nutrients in the proper forms to sustain plant growth. However, the nutrient analyses revealed that there is still much to investigate regarding the combination of wastewaters to provide a complete, well-rounded, and sustainable source for hydroponic crop production.

Novel high-purity struvite crystallization method for phosphate recovery from simulated swine wastewater using activated talcum

The struvite crystallization method is considered a highly promising approach for phosphate recovery from swine wastewater. However, the utilization of chemicals like magnesium and alkali as sources for struvite crystallization substantially increases the overall cost of this technology. In this study, activated talcum powder (ATP) was used instead of chemical reagents to recover phosphate as struvite from simulated swine wastewater containing 93 mg/L phosphorus and 450 mg/L ammonia nitrogen. The results showed that 93.02 ± 1.56% phosphorus and 14.47 ± 1.89% ammonia nitrogen were removed from simulated wastewater in the continuous flow circulation system. The purity of the struvite collected is as high as 97.24%. Mineralogical analysis showed that mechanical activation destroyed the crystal structure of talcum and increased the reactivity of Mg2+ and OH−, allowing it to be released spontaneously into aqueous solution. The amount of magnesium ions dissolved was affected by factors such as contact time, talcum dose, ammonium concentration and pH. The main components of ATP residue were quartz and magnesite, which will not cause secondary pollution to the environment. The use of ATP to recover phosphate into struvite has the advantages of low chemical cost and no pollution of waste materials, holding broad application prospects.

Fluxes of nitrogen and phosphorus in fouling communities on artificial offshore structures

The number of offshore artificial structures in the North Sea is continuously increasing. Apart from the structures that have been added to the marine environment accidentally (e.g., shipwrecks), structures are also deliberately developed to meet the increasing needs for renewable energy. These structures provide habitat for fouling organisms. The fouling communities vary in abundance and composition based on location, depth, and structure age. Most fouling species filter particles from the water column, changing phytoplankton production and affecting larval settlement success, while releasing ammonium that can fuel phytoplankton growth as well as (pseudo)faeces that enriches the seabed, changing local biogeochemical cycles.Our study used in-situ incubation chambers to investigate oxygen, nitrogen, and phosphate fluxes associated with fouling organisms to improve understanding of these changes in biogeochemical cycles. Divers used incubation chambers (domes) on shipwrecks in the southern North Sea where over 55 years mature fouling communities have established. A series of water samples was collected from each dome during deployment to measure the change in concentration of ammonium, nitrite, nitrate, and phosphate. All fauna enclosed in the domes was collected after each measurement for further analysis.The full macrofauna dataset contained 65 unique species on 4 shipwrecks (25 to 50 species per sample). Abundance ranged from 2187 to 59,427 individuals per sample (683 cm2). On average, a decrease in oxygen concentration of 126 μmol/g ash free dry weight/h was found. The sequential water samples also showed clear changes in nutrient concentration with time in all incubations. The largest changes were observed with high fouling community abundances and biomass. Ammonium, nitrite, and phosphate always increased, with 1.5-to-5-fold increases from start to end of the incubation, while for nitrate both an efflux and influx were measured. Oxygen decreased in all incubations. Mean fluxes (all in μmol per m2 per hour with standard error) were significant for ammonium (945 ± 300), nitrite (80 ± 30), phosphate (61 ± 8), and oxygen (−11,794 ± 3289), but not for nitrate (−206 ± 122). Per gram AFDW, only ammonium (12.7 ± 3.5) and oxygen (−126 ± 48) had fluxes that differed significantly from zero.Compared to average seabed (sandy bottom) oxygen demand and community fluxes from previous studies, the observed fluxes were high. Our findings resembled those from temperate biogenic reef studies. Further data collection across a larger spatial and temporal scale is needed to fully understand offshore structure effects on marine environments.

How non-equilibrium aerosol chemistry impacts particle acidity: the GMXe AERosol CHEMistry (GMXe–AERCHEM, v1.0) sub-submodel of MESSy

Abstract. Aqueous-phase chemical processes in clouds, fog, and deliquescent aerosols are known to alter atmospheric composition and acidity significantly. Traditionally, global and regional models predict aerosol composition by relying on thermodynamic equilibrium models and neglect non-equilibrium processes. Here, we present the AERosol CHEMistry (GMXe–AERCHEM, v1.0) sub-submodel developed for the Modular Earth Submodel System (MESSy) as an add-on to the thermodynamic equilibrium model (i.e. ISORROPIA-II) used by MESSy's Global Modal-aerosol eXtension (GMXe) submodel. AERCHEM allows the representation of non-equilibrium aqueous-phase chemistry of varying complexity in deliquescent fine aerosols. We perform a global simulation for the year 2010 by using the available detailed kinetic model for the chemistry of inorganic and small oxygenated organics. We evaluate AERCHEM's performance by comparing the simulated concentrations of sulfate, nitrate, ammonium, and chloride to in situ measurements of three monitoring networks. Overall, AERCHEM reproduces observed concentrations reasonably well. We find that, especially in the USA, the consideration of non-equilibrium chemistry in deliquescent aerosols reduces the model bias for sulfate, nitrate, and ammonium when compared to simulated concentrations by ISORROPIA-II. Over most continental regions, fine-aerosol acidity simulated by AERCHEM is similar to the predictions by ISORROPIA-II, but simulated aerosol acidity tends to be slightly lower in most regions. The consideration of non-equilibrium chemistry in deliquescent aerosols leads to a significantly higher aerosol acidity in the marine boundary layer, which is in line with observations and recent literature. AERCHEM allows an investigation of the global-scale impact of aerosol non-equilibrium chemistry on atmospheric composition. This will aid in the exploration of key multiphase processes and improve the model predictions for oxidation capacity and aerosols in the troposphere.

The Biocatalytic Potential of Aromatic Ammonia-Lyase from Loktanella atrilutea.

Characterization of the aromatic ammonia-lyase from Loktanella atrilutea (LaAAL) revealed reduced activity towards canonical AAL substrates: l-Phe, l-Tyr, and l-His, contrasted by its pronounced efficiency towards 3,4-dimethoxy-l-phenylalanine. Assessing the optimal conditions, LaAAL exhibited maximal activity at pH 9.5 in the ammonia elimination reaction route, distinct from the typical pH ranges of most PALs and TALs. Within the exploration of the ammonia source for the opposite, synthetically valuable ammonia addition reaction, the stability of LaAAL exhibited a positive correlation with the ammonia concentration, with the highest stability in 4 M ammonium carbamate of unadjusted pH of ~9.5. While the enzyme activity increased with rising temperatures yet, the highest operational stability and highest stationary conversions of LaAAL were observed at 30 °C. The substrate scope analysis highlighted the catalytic adaptability of LaAAL in the hydroamination of diverse cinnamic acids, especially of meta-substituted and di-/multi-substituted analogues, with structural modelling exposing steric clashes between the substrates' ortho-substituents and catalytic site residues. LaAAL showed a predilection for ammonia elimination, while classifying as a tyrosine ammonia-lyase (TAL) among the natural AAL classes. However, its distinctive attributes, such as genomic context, unique substrate specificity and catalytic fingerprint, suggest a potential natural role beyond those of known AAL classes.

Effect of Brosimum alicastrum Foliage on Intake, Kinetics of Fermentation and Passage and Microbial N Supply in Sheep Fed Megathyrsus maximus Hay.

An experiment was carried out to assess the effect of the incorporation of sun-dried foliage of Brosimum alicastrum into rations based on hay of Megathyrsus maximus on intake, rumen fermentation, kinetics of passage, microbial nitrogen supply to the small intestine, apparent digestibility in Pelibuey hair sheep. Four rations were randomly allotted to four rumen-cannulated lambs (BW = 37.4 ± 4.9 kg) using a 4 × 4 Latin square design to assess the effect of increasing levels (0, 15, 30 and 45% DM basis) of foliage of Brosimum alicastrum on a basal ration of M. maximus. Organic matter intake and water consumption increased linearly (p < 0.01) with increasing levels of B. alicastrum in the ration. The rate and potential extent of rumen fermentation of OM and CP of B. alicastrum were 10.6%/h and 86.6% and 11.4%/h and 95.2%, respectively, but no effect (p > 0.05) was found on the potential rumen degradation of DM (40.2%) or on the rate of degradation of DM (0.033%/h) of M. maximus, although a positive effect was found in the rumen degradation rate of NDF (p < 0.05). VFA and ammonia concentration in the rumen and the rate of passage of solids and liquids through the rumen (k1) increased linearly (p < 0.01) with increasing levels of B. alicastrum. Rumen pH was not affected by the incorporation of B. alicastrum (p > 0.05). Microbial nitrogen supply to the small intestine (p < 0.001), apparent digestibility of dry matter (p < 0.01) and NDF (p < 0.05) of the rations were also significantly increased as a result of the incorporation of B. alicastrum foliage. Results from this experiment suggest that the foliage of Brosimum alicastrum can be readily incorporated at around 30% of the ration of dry matter in hair sheep with beneficial effects on feed intake, rate of passage and microbial N supply to the lower tract.

New experimental findings on the separation of cobalt and nickel from an ammonia-ammonium-based leach liquor using ammonium-saponified Cyanex 272

There is a need to improve cobalt and nickel recovery from industrial waste streams such as secondary leach solutions and rechargeable battery leach solutions due to the increasing economic value of these critical metals. Ammonia is an important lixiviant due to its limited environmental impact compared to acid based lixiviants, however, the subsequent selective extraction of cobalt and nickel from the leach liquor is a major challenge. This study presents new experimental findings on the treatment of a Base metal Refinery (BMR) secondary leach liquor that contains high concentrations of ammonia and ammonium sulphate, and low concentrations of cobalt (∼442 mg/L) and nickel (∼1624 mg/L) using partially saponified Cyanex 272. New knowledge that can be applied in the treatment of ammonia based leachates from various industrial wastes that contain residual cobalt and nickel is presented herein. The investigation was conducted through the determination of the optimum extraction temperature, percentage saponification, and organic to aqueous ratios. Partial saponification of Cyanex 272 increased ammonia-metal complex stability at the interphase and this limited cobalt extraction between 30 °C and 50 °C. However, a high cobalt extraction percentage, and a high separation factor of 94.07 %, and 1189.76 respectively were achieved at 60 °C, 20 % saponification, and 0.5 O/A loadings in a single contact. A second-stage batch extraction produced a nickel aqueous stream with no cobalt. Stripping of the loaded organic phase with dilute sulphuric acid produced a pure cobalt aqueous stream. Further, the extractant was successfully regenerated post stripping. Overall, partial ammonium-saponification increased the extent of cobalt extraction, and selectivity. The novel process conditions reported herein can be used to design sustainable cobalt-nickel separation processes.

Investigation of an indigenous chalcopyrite ore leaching in ammonia solution: characterization, leaching and kinetics

ABSTRACT Chalcopyrite ore is one of the most abundant and pertinent oxidized copper minerals. In this research, the dissolution kinetics of chalcopyrite in an ammonia solution was examined. During leaching, the influences of leachant concentration, temperature, and particle diameter on the extent of copper ore dissolution were investigated. However, it was affirmed that the dissolution efficiency of chalcopyrite ore increased with decreasing particle fraction and increasing reaction temperature and ammonia concentration. About 68.6% copper ore dissolution was achieved with 2.0 mol/L NH3, 75 ºC reaction temperature, and 45 μm particle diameter within 120 minutes. The dissolution reaction mechanism was found to be described by diffusion-control with a calculated activation energy of 32.26 kJ/mol. In the XRD spectra of the residual product obtained at established conditions, CuFeS2 peaks were absent, indicating the leachability of the sample. Hence, the leach residue could serve as an important by-product for some local industries.

Multiparameter gas sensor based on UV-SFR combined with wavelet transform-neural network at ppb level

Abnormal concentrations of nitric oxide (NO), ammonia (NH3), carbon disulfide (CS2) and sulphur dioxide (SO2) in exhaled breath are closely associated with diseases in specific organs of the body. Meanwhile, the above gases are also common pollutants in the atmosphere, and effective online detection of them plays a key role in disease prevention and environmental pollution prevention. This study reports a multiparameter gas sensor system based on the combination of ultraviolet segmented fitting reduction (UV-SFR) and wavelet transform-neural network (WT-NN) model for simultaneous online detection of the concentrations of NO, NH3, CS2 and SO2. Firstly, to avoid the occurrence of spectral baseline drift and absorption peak intensity reduction, a UV-SFR method is proposed for the discrete single peak type absorption spectra contained in the UV spectra. Our method can remove the slow change absorption induced by other factors, and ultimately obtain the differential absorption spectra of the gas mixtures. Then, the WT is used to denoise the differential absorption spectra of the gas mixtures. Next, for the presence of severe spectral line overlap in gas mixtures, the NN model is built based on the denoised spectral data. Finally, transfer learning is introduced into NN to improve the detection accuracy. The experimental results show that the sensor system can reliably achieve simultaneous online detection of NO, NH3, CS2, and SO2 at ppb level, and the average absolute errors of their measurements are 0.96 ppb, 1.27 ppb, 0.76 ppb and 0.97 ppb, with measurement accuracies of 3.5 %, 0.8 %, 0.5 % and 0.9 %, respectively.

The protein nutritional status affects hope of patients in the terminal phase of cancer

Progressive destruction of the patient’s body in the terminal phase of cancer intensifies the breakdown of muscle tissue proteins, producing neurotoxic ammonia and urea. These metabolites negatively affect the brain function and are more difficult to remove from the cancer-ravaged body than from better-nourished patients. Developing cachexia impairs the functioning of all body organs, including the excretory function of the kidneys, including the removal of neurotoxic metabolites. Elevated concentrations of ammonia and urea in the brain leads to cerebral dysfunction involving a spectrum of neuropsychiatric and neurological symptoms. This may negatively affect the perception of patient’s existential situation, and the experience of hope. Improving the protein nutritional status of patients in the terminal phase of cancer may decrease the muscle tissue breakdown, improve the functioning of internal organs and the efficiency of removing neurotoxic metabolites from the body. According to this, we hypothesize that the hope of patients in the terminal phase of cancer may significantly depend on their protein nutritional status. Patients less malnourished with protein experience greater hope and cope better with their existential situation than those more malnourished. We propose a clinical trial to investigate the relation between protein nutritional status and hope experience in patients in the terminal phase of cancer. The verification of this hypothesis may contribute to better and more holistic patients’ care, both professional and non-professional, which may improve the quality of their life in the last days.

Possibilities of Utilising Biomass Collected from Road Verges to Produce Biogas and Biodiesel

Grass collected as part of roadside maintenance is conventionally subjected to composting, which has the disadvantage of generating significant CO2 emissions. Thus, it is crucial to find an alternative method for the utilisation of grass waste. The aim of this study was to determine the specific biogas yield (SBY) from the anaerobic mono-digestion of grass from road verges and to assess the content of Fatty Acid Methyl Esters (FAMEs) in grass in relation to the time of cutting and the preservation method of the studied material. The biochemical biogas potential (BBP) test and the FAMEs content were performed on fresh and ensiled grass collected in spring, summer, and autumn. The highest biogas production was obtained from fresh grass cut in spring (715.05 ± 26.43 NL kgVS−1), while the minimum SBY was observed for fresh grass cut in summer (540.19 ± 24.32 NL kgVS−1). The methane (CH4) content in the biogas ranged between 55.0 ± 2.0% and 60.0 ± 1.0%. The contents of ammonia (NH3) and hydrogen sulphide (H2S) in biogas remained below the threshold values for these inhibitors. The highest level of total FAMEs was determined in fresh grass cut in autumn (98.08 ± 19.25 mg gDM−1), while the lowest level was detected in fresh grass cut in spring (56.37 ± 7.03 mg gDM−1). C16:0 and C18:0, which are ideal for biofuel production, were present in the largest amount (66.87 ± 15.56 mg gDM−1) in fresh grass cut in autumn. The ensiling process significantly impacted the content of total FAMEs in spring grass, leading to a reduction in total saturated fatty acids (SFAs) and an increase in total unsaturated fatty acids (USFAs). We conclude that grass biomass collected during the maintenance of road verges is a valuable feedstock for the production of both liquid and gaseous biofuels; however, generating energy from biogas appears to be more efficient than producing biodiesel.

The influence of environmental change and seasons on the sperm quality of breeding boars after relocation

This study aimed to determine the impact of relocation as a potential stress factor on the reproductive properties of breeding boars, as well as the impact of the new environment on the quantity and quality of the semen obtained during different seasons. At the beginning of spring, 16 breeding boars (Large White (n=3), German Landrace (n=4), Swedish Landrace (n=6) and Pietrain (n=3)) were relocated from old to new housing conditions and exposed to loading, transport, unloading, and rehousing in a new environment. They had the same conditions of feeding, care, sexual exploitation and keeping, before and after relocation. The health status of all breeding boars was carefully monitored and controlled. No significant differences were observed in the total and average number of doses produced between seasons. There was a significantly higher value of total ejaculate volume and density during the spring compared to the values obtained in other seasons (P&lt;0.01). Differences in the average percentage of mobility between autumn and winter were not significant (P=0.983), as in spring and summer (P=0.737). Ventilation rate, gas concentrations of ammonia, nitrous oxide and carbon dioxide in the boar enclosure were similar before and after relocation. Two days after relocation, one boar (ID 172) showed signs of illness and was treated, but his sperm was rejected due to sperm agglutination and reduced motility, so he was culled. Individual analysis of the production indicators showed that there was no significant change in the spermatogenesis of healthy boars, even though they were relocated.

The Effects of Encapsulation and Double-layer Emulsion of Peanut Oil on in vitro Rumen Degradability Rates and Fermentation Profile in Sheep

Background: Peanut oil is rich in polyunsaturated fatty acids (PUFAs) and plays an important role in human and animal health. PUFAs are generally undergo to the biohydrogenation (BH) process by the rumen microbes. The single-layer emulsion encapsulation has been used in sheep diet. However, a limited reference was found concerning double-layer techniques to protect the essential PUFAs from BH process in the rumen. Methods: EDLEPO was made with a matrix of peanut oil, whey protein isolate (WPI), microcrystalline cellulose (MCC) and maltodextrin at 40: 2.5: 7.5: 55. The first layer was the binding of WPI with peanut oil and the second layer is the binding of WPI with MCC. Moreover, the in vitro experiment was designed with 5 treatments separated by CON group (0 g/kg EDLEPO) and experimental groups which are leveled by EDLEPO inclusion (25, 50, 75 and 100 g/kg levels of EDLEPO) in the buffered sheep’s rumen. Result: Increased levels of EDLEPO inclusion reduced rumen ammonia-N concentration (P less than 0.05) by a linear response. Hence, increased levels of EDLEPO inclusion increased rumen degradability rates expressed as IVDMD and IVOMD up to 12% and 9%, respectively, by a linear response (P less than 0.05). No significant differences were found between treatments on pH value, VFAs and total gas production. However, the increased levels of EDLEPO inclusion reduced CH4 concentration expressed as CH4/IVDMD and CH4/IVOMD up to 9% and 17% (P less than 0.05). It can be concluded that the EDLEPO inclusion in the diet increased in vitro rumen degradability rates with no negative effects on the rumen fermentation profile.

Nitrogen dynamics as a function of soil types, compaction, and moisture.

In this study, the complex interactions between soil types, compaction, and moisture on nitrogen (N) transformation processes such as ammonia (NH3) volatilization, ammonification, nitrification, and denitrification were examined over a 30-day period using a simulated column approach. Two soil types: loam, and sandy loam, were subjected to three compaction treatments-control, surface, and sub-surface compaction-and two moisture regimes, dry and wet. Liquid urea ammonium nitrate (32-0-0) was used as the N fertilizer source at a rate of 200 kg N ha-1. Key indicators of N transformations were measured, including residual concentrations of ammonium (NH4-N) and nitrate (NO3-N), NO3-N leaching, NH3 volatilization, and nitrous oxide (N2O) emissions. Findings revealed that compaction significantly increased residual NH4-N concentrations in deeper soil profiles, with the highest 190.80 mg kg-1 recorded in loam soil under sub-surface compaction and dry conditions. Nitrification rates decreased across both soil types due to compaction, evidenced by elevated residual NH4-N levels. Increased NO3-N leaching was observed in loam soil (178.06 mg L-1), greater than sandy loam (81.11 mg L-1), due to initial higher residual NO3- in loam soil. The interaction of compaction and moisture most affected N2O emissions, with the highest emissions in control treatments during dry weather at 2.88 kg ha -1. Additionally, higher NH3 volatilization was noted in moist sandy loam soil under control conditions at 19.64 kg ha -1. These results highlight the necessity of considering soil texture, moisture, and compaction in implementing sustainable N management strategies in agriculture and suggest recommendations such as avoiding broadcast application in moist sandy loam and loam soil to mitigate NH3 volatilization and enhance N use efficiency, as well as advocating for readjustment of fertilizer rate based on organic matter content to reduce potential NO3-N leaching and N2O emissions, particularly in loam soil.

Nitrogen-doped carbon nano-onions/polypyrrole nanocomposite based low-cost flexible sensor for room temperature ammonia detection

One of the frontier research areas in the field of gas sensing is high-performance room temperature-based novel sensing materials, and new family of low-cost and eco-friendly carbon nanomaterials with a unique structure has attracted significant attention. In this work, we propose a novel low-cost flexible room temperature ammonia gas sensor based on nitrogen-doped carbon nano-onions/polypyrrole (NCNO-PPy) composite material mounted low-cost membrane substrate was synthesized by combining hydrothermal and in-situ chemical polymerization methods. The proposed flexible sensor revealed high sensing performance when employed as the sensing material for ammonia detection at room temperature. The NCNO-PPy ammonia sensor exhibited 17.32% response for 100 ppm ammonia concentration with a low response time of 26 s. The NCNO-PPy based flexible sensor displays high selectivity, good repeatability, and long-term durability with 1 ppm as the lower detection limit. The proposed flexible sensor also demonstrated remarkable mechanical robustness under extreme bending conditions, i.e., up to 90° bending angle and 500 bending cycles. This enhanced sensing performance can be related to the potential bonding and synergistic interaction between nitrogen-doped CNOs and PPy, the formation of defects from nitrogen doping, and the presence of high reactive sites on the surface of NCNO-PPy composites. Additionally, the computational study was performed on optimized NCNO-PPy nanocomposite for both with and without NH3 interaction. A deeper understanding of the sensing phenomena was proposed by the computation of several electronic characteristics, such as band gap, electron affinity, and ionization potential, for the optimized composite.

A multi-spatial scale assessment of land-use stress on water quality in headwater streams in the Platinum Belt, South Africa

River water quality is affected by various stressors (land-uses) operating at different hydrological spatial scales. Few studies have employed a multi-scaled analyses to differentiate effects of natural grasslands and woodlands, agriculture, impoundments, urban and mining stressors on headwater streams. Using a multi-scaled modeling approach, this study disentangled the distinct spatial signatures and mechanistic effects of specific stressors and topographic drivers on individual water quality parameters in tributaries of the Gwathle River Catchment in the Platinum Belt of South Africa. Water samples were collected on six occasions from 15 sites on three rivers over 12-months. Physio-chemical parameters as well as major anions, cations and metals were measured. Five key water quality parameters were identified using principal components analysis: sulfate, ammonium, copper, turbidity, and pH to characterise catchment water quality conditions. Using class-level composition (PLAND) and connectedness (COHESION) metrics together with topographic data, generalized linear mixed models were developed at multiple scales (sub-basin, cumulative catchment, riparian buffers) to identify the most parsimonious model with the dominant drivers of each water quality parameter. Ammonium concentrations were best explained by urban stress, Cu increased with mining and agriculture, turbidity increased with elevation heterogeneity, agriculture, urbanisation and fallow lands all at the sub-basin scale. River pH was positively predicted by slope heterogeneity, mining cover and impoundment connectivity at the catchment scale. Sulfate increased with mining and agriculture composition in the 100 m riparian buffer. Hierarchical cluster analysis of water quality and scale-dependent parsimonious drivers separated the river sites into three distinct groups distinguishing pristine, moderately impacted, and heavily mined sites. By demonstrating stressor- and scale-dependent water quality responses, this multi-scale nested modeling approach reveals the importance of developing adaptive, targeted management plans at hydrologically meaningful scales to sustain water quality amid intensifying land use.

Gastrointestinal response to the early administration of antimicrobial agents in growing turkeys infected with Escherichia coli

This study investigated the effects of the early administration of enrofloxacin (E) or doxycycline (D) for the first 5 consecutive days of life, or the continuous administration of the coccidiostat monensin (M) throughout the rearing period on gastrointestinal function in turkeys infected with avian pathogenic Escherichia coli (APEC) in an early or later stage of rearing. Experiment 1 lasted 21 d, and turkeys in groups E, D, and M were infected with APEC on d 15. Experiment 2 lasted 56 d, and it had a factorial arrangement of treatments where birds in groups E, D, and M were infected with APEC on d 15 or d 50. In both experiments, control groups (C) consisted of infected and uninfected birds without antibiotic or coccidiostat administration. On d 21 (Experiment 1) and d 56 (Experiment 2), 8 birds from each subgroup were killed, and the ileal and cecal digesta were sampled to analyze the activity of bacterial enzymes and the concentrations of short-chain fatty acids (SCFA). The experimental treatments did not affect the final body weight or body weight gain of birds. Both experiments demonstrated that APEC contributed to an increase in ammonia levels of the cecal digesta (means from 2 experiments: 0.311 vs. 0.225 mg/g in uninfected birds) and ileal pH (6.79 vs. 6.00) and viscosity (2.43 vs. 1.83 mPa⋅s). Moreover, the E. coli challenge enhanced the extracellular activity of several cecal bacterial enzymes, especially in older turkeys infected with APEC in a later stage of life. The continuous administration of monensin throughout the rearing period resulted in a weaker gastrointestinal response in older birds, compared with the other 2 antibiotics administered for the first 5 d of life. The results of the study are inconclusive as both desirable and undesirable effects of preventive early short-term antibiotic therapy were observed in turkeys, including normalization of ileal viscosity and cecal ammonia concentration (positive effect), and disruption in cecal SCFA production (negative effect).

Ammonia measurement in human breath of subjects with Helicobacter pylori using photoacoustic spectroscopy.

Helicobacter pylori (H. pylori) is a type of bacteria that infects the stomach. The detection of H. pylori is an essential part of current clinical practices because this disease can cause peptic ulcers, chronic inflammation of the stomach lining but also stomach cancer. Helicobacter pylori has a naturally occurring enzyme that hydrolyzes urea into ammonium carbonate called urease. Many methods exist for the detection of H. pylori infection, but an innovative approach is to detect the ammonia in the breath (ABT, Ammonia Breath Test). In this research study, using photoacoustic spectroscopy method, the ammonia concentration in the breathing zone of people with H. pylori were measured and were compared with ammonia concentration from the respiration of healthy people. From the ABT determinations of this study, the ammonia was established to be increased with 498 ppb at people with H. pylori when we compare with ABT of healthy people.

Integrated rice-yellow catfish farming resulting in variations in the agricultural environment, rice growth performance, and soil bacterial communities.

Different rice production patterns exert varying comprehensive impacts on the agricultural environment. Integrated rice-fish farming, an advanced and rapidly developing agricultural production pattern, aims to improve resource utilization efficiency and enhance food productivity. To unravel the responses and internal interactions of the agricultural ecological environment to integrated rice-fish farming, we assessed and compared environmental factor, rice growth performance, and soil microbiome in both integrated rice-yellow catfish farming (IRYF) and rice monoculture (RM) systems. Our results revealed significant increases in the total nitrogen and ammonia concentrations in the paddy water and soil induced by the IRYF. Rice growth performance in the IRYF group surpassed that in the RM group. IRYF obviously impacted almost all dominant bacterial phyla, genera, and functional groups (top ten most abundant), enhancing the ability of bacteria to degrade and utilize organic matter. Additionally, IRYF led to noticeable reductions in the Shannon, Simpson, Chao 1, and Pielou_J indices. IRYF strengthened the interconnections between various taxonomic units in bacterial co-occurrence network, resulting in increased complexity, stability, and disturbance resistance in the soil bacterial community. IRYF notably facilitated the transition from a community assembly dominated by stochastic processes to one dominated by deterministic processes for the soil bacterial community. The deterministic process driving this transition was variable selection. All the environmental factors, except for soil nitrate, demonstrated relatively high contributions to alterations in soil bacterial communities, with environmental variables significantly positively correlated with the soil bacterial community in the IRYF group. Alterations in functionality, composition, and diversity of the soil bacterial community were clearly associated with most environmental variables and rice growth performance indices. Our research contributed to understanding the comprehensive impacts of integrated rice-fish farming on agricultural ecosystems and provide theoretical support for achieving the sustainable agricultural production and optimizing the rice production patterns.