Nitrogen Ratio Research Articles

The effect of carbon source produced by modified corncob fermentation on denitrification

The advanced nitrogen removal is always limited by low carbon to nitrogen ratio (C/N), the feasibility of producing carbon source through fermenting corncob was evaluated in this study. The effect of initial pH, solid content and temperature on the production of volatile fatty acids (VFAs) by alkali pre-treated corncob were investigated, and the denitrification performance with anaerobic fermentation liquid (AFL) and sodium acetate (SA) was compared. The results showed that alkali pretreatment improved the mass transfer inside the corncob, and the solid content had a major impact on VFA production. The denitrification rate of the two systems was related to the influent NO3−-N concentration only when the C/N was 6:1 and 8:1, and the removal efficiency was bigger than 95 %. Nevertheless, the nitrite reduction of the AFL system was limited at a C/N of 4:1, and the removal efficiency of NO₃−-N was only 65.10 %. Moreover, the AFL system enriched a large number of genera involved in nitrogen removal and organic decomposition. The functional analysis showed that the denitrification activity and ability of the AFL system were slightly lower. However, the SA system enriched more pathogenic bacteria, the relative abundances of Arcobacter and Pseudomonas were 28.74 % and 11.85 %, respectively. This study provides a reference for optimizing the design and control of VFAs production by continuous fermentation from agricultural waste.

Environmental conditions in the Massif Central during the Upper Palaeolithic using stable isotope tracking (13C, 15N) of bone collagen from large herbivores

ABSTRACTThe environmental conditions experienced by hunter‐gatherers during the second part of the Upper Palaeolithic (ca. 28 000–15 000 cal bp) are poorly known in the mid‐elevation volcanic mountains of the Massif Central in southern France. The stable isotope ratios of carbon and nitrogen (13C/12C and 15N/14N expressed as δ13C and δ15N values) in bone collagen of large herbivores can track their diet and habitat, reflecting local abiotic conditions (temperature, aridity, altitude). Due to poor preservation of skeletal organic matter in the region, new radiocarbon dating was conducted on a limited number of quality‐controlled collagen samples, based on a minimum carbon content of 30%. They document three main phases of occupation corresponding to the Final Gravettian, the Badegoulian and the Magdalenian, each of which is represented in different regions of the Allier and Loire valleys. Over time, a decrease in horse δ15N values, the best documented species of large herbivores, is found between the Final Gravettian (ca. 26 700–25 600 cal bp), around the Last Glacial Maximum and the Badegoulian (ca. 21 900–19 200 cal bp), followed by an increase in δ15N and δ13C values during the Magdalenian (ca. 19 100–16 600 cal bp). During the Badegoulian, the δ15N values of the horses were lower than those of their counterparts in southwestern France, testifying to harsh climatic conditions favourable to a tundra‐like landscape, also reflected in the higher horse and reindeer δ13C values in the Allier valley compared to those in southwestern France. The relatively high δ13C and low δ15N values of a Final Gravettian wolf from the Allier valley suggests reindeer as a preferred prey, in line with their high abundance in the archaeological sites. Game access, rather than climatic conditions or lithic resources, seems to have motivated human groups to occupy the Massif Central during the Upper Palaeolithic.

Semidiurnal Non‐Migrating Tides in the Middle Thermosphere From Far Ultraviolet Observations

AbstractMuch of the longitude/local time dependence of the thermosphere is controlled by non‐migrating tides. Observations of semidiurnal (12‐hr) tides between 120 and 200 km altitude, that is, the middle thermosphere, are rare owing to the lack of systematic measurements in this region. Since late 2018, the Global‐scale Observations of the Limb and Disk (GOLD) Mission has provided unique measurements of thermospheric disk temperature and the column density ratio of atomic oxygen to molecular nitrogen ratio (ΣO/N2) from geostationary orbit. In this paper, we present an approach to deduce the strongest semidiurnal non‐migrating tides in the middle thermosphere by adapting the method of Krier et al. (2021, https://doi.org/10.1029/2021ja029563) that deduces diurnal non‐migrating tides in simultaneous observations of temperature and ΣO/N2 made by GOLD. Testing of this approach suggests that the principal sources of uncertainties in the derived semidiurnal non‐migrating tides are the limitation on the longitudes sampled, such that uncertainties are higher for tides with longer horizontal wavelength, and contamination of the local time sums by stationary planetary waves, which causes amplitudes to be overestimated. Our approach is applied to GOLD data during solstice conditions in 2019–2021. Comparison to models yield disagreements which are likely due to uncertainties intrinsic to the method and/or misrepresentation of tidal dynamics in the models. These results are the first observations of semidiurnal non‐migrating tides in the middle thermosphere from a geostationary observational platform.

Resourceful application and mechanism of oyster shell-microalgae synergistic system：Sustainable treatment of harsh low carbon nitrogen ratio actual wastewater

Microalgal technology holds great promise for both low C/N wastewater treatment and resource recovery simultaneously. Nevertheless, the advancement of microalgal technology is hindered by its reduced nitrogen removal efficiency in low C/N ratio wastewater. In this work, microalgae and waste oyster shells were combined to achieve a total inorganic nitrogen removal efficiency of 93.85% at a rate of 2.05 mg L−1 h−1 in low C/N wastewater. Notably, over four cycles of oyster shell reuse, the reactor achieved an average 85% ammonia nitrogen removal extent, with a wastewater treatment cost of only $0.092/ton. Moreover, microbial community analysis during the reuse of oyster shells revealed the critical importance of timely replacement in inhibiting the growth of non-functional bacteria (Poterioochromonas_malhamensi). The work demonstrated that the oyster shell - microalgae system provides a time- and cost-saving, environmental approach for the resourceful treatment of harsh low C/N wastewater.

The Ratio of Serum Urea Nitrogen to Albumin Is a Better Predictor of Overall Survival in Multiple Myeloma Patients than Urea Nitrogen Alone

Introduction: Multiple myeloma (MM) is a malignant proliferative disease of plasma cells. Abnormally cloned plasma cells secrete large amounts of monoclonal immunoglobulins in the bone marrow of MM patients. Serum urea nitrogen (sUN) is a byproduct of protein metabolism, and its effect on MM patients’ prognoses remains unknown. Therefore, we analyzed MM patients’ clinical data to explore the role of sUN and sUN/serum albumin (sUAR) in the baseline tumor load and MM prognosis of MM patients. Methods: We downloaded the clinical data of 762 MM patients from the MMRF database. After excluding those without baseline sUN, 452 patients were finally included in the study. Smoothed curve fitting, threshold analysis, Tamhane’s T2 test, multivariate-adjusted Cox regression analysis, Kaplan-Meier (K-M) curves, and receiver operating characteristic (ROC) analysis were applied in the study. Results: There were 452 newly diagnosed MM patients included in this study. In most patient groups, sUN and sUAR were positively linked with β2-microglobulin (β2-MG) and lactic dehydrogenase (LDH) according to smoothing curve fitting and threshold analysis. The higher the ISS stage, the greater the values of sUN and sUAR. Furthermore, smoothed curve fitting and threshold analysis showed that sUN was correlated with overall survival (OS), although sUAR had a stronger correlation with OS and could be applied to a broader group. The results of a multivariate-adjusted Cox regression analysis demonstrated that sUN and sUAR were independent prognostic factors for OS. The K-M curve confirmed the correlation between higher sUN and sUAR levels and worse OS. β2-MG and LDH are generally recognized prognostic factors of OS. ROC analysis revealed that sUN might boost β2-MG and LDH’s predictive value and sUAR had a higher predictive value. Conclusion: This retrospective study based on the MMRF database showed that high sUN and sUAR levels were positively associated with β2-MG, LDH, and ISS staging, and sUAR exhibited a stronger correlation with OS than sUN alone.

In-situ synthesis of nitrides and oxides through controlling reactive gas atmosphere during laser-powder bed fusion of Fe-12Cr-6Al

This study endeavors to investigate the feasibility of in situ synthesis of nitrides and oxides within Fe-12Cr-6Al alloys through precise modulation of reactive gas atmosphere during the Laser-Powder Bed Fusion process. A focused study on elucidating the effects of critical process parameters, such as laser power, scanning speed, and hatch distance, was undertaken to discern their impact on the material's microstructure, oxygen/nitrogen content, and hardness. Synthesis of nano-sized AlN and Al2O3 precipitates within the Fe-12Cr-6Al matrix was achieved when nitrogen was used for a process gas. A rise in laser power from 120 W to 200 W, coupled with a reduction in scanning speed from 1200 mm/s to 400 mm/s, resulted in decreased porosity and an increase in grain size. Additionally, all printed samples showed lower oxygen content compared to the initial powder, while nitrogen ratios were notably higher. A marginal increase of the Vickers hardness value, from 240 ± 4.5 to 266 ± 3 HV, was observed as the laser power increased and the scanning speed decreased. The hardness values were higher than those obtained from different production methods with identical compositions. These compelling results suggest a positive impact of nitride precipitates and oxide precipitates to improve hardness values.

Optimized biogas production from poultry manure with respect to pH, C/N, and temperature

This study aims to identify the optimal conditions for generating biogas from poultry manure with respect to pH, C/N ratio, and temperature. The study was conducted in lab batch bioreactor having a working volume of 2 l at different conditions with respect to pH, carbon to nitrogen ratio (C/N), and temperature. A full factorial design is designed to analyze the impact of the three parameters and their interactions. Experiments are replicated four times to ensure the reproducibility of data. Results indicate that temperature is the only influencing parameter on biogas production from poultry manure within a pH range of 6–8 and a C/N ratio range of 10/1 to 40/1. Moreover, there is no interaction between the three parameters, and mesophilic conditions are found to be the optimum conditions for biogas production. The maximum biogas yield of 285 ml/g VS is found in mesophilic conditions at 37 °C with a retention time of 20 days. Biogas production kinetics are similar in mesophilic and thermophilic conditions but vary in psychrophilic conditions.

Tree and mycorrhizal fungal diversity drive intraspecific and intraindividual trait variation in temperate forests: Evidence from a tree diversity experiment

Abstract The study of tree species coexistence is crucial to understand the assembly of forest communities. In this context, trees adjust their traits in response to the interactions with other trees and, specifically, as a result of the competition for resources. Further, mycorrhizal fungal diversity and associations are important drivers of ecosystem functioning in forests, but their role as drivers of intraspecific trait variation has been disregarded. Here, we studied intraspecific trait variation of trees in response to tree and mycorrhizal fungal diversity. We sampled 3200 leaves from 640 trees belonging to 10 native, deciduous species in a tree diversity experiment in Central Germany. This experiment relies on the combination of gradients of tree richness and mycorrhizal associations. To handle large amounts of leaf samples, we acquired leaf‐level spectral data and used deep learning to predict values for five leaf traits from the leaf economics spectrum (LES): specific leaf area, leaf dry matter content, carbon to nitrogen ratio, carbon content and phosphorus content. For every tree, we calculated the mean value for every trait and two multi‐trait functional indices (functional richness and functional dispersion) based on values for individual leaves. Finally, we used sequencing‐based data to assess the richness of mycorrhizal fungi associated with the trees. We found that tree and mycorrhizal fungi richness had an effect on different leaf functional traits. Specifically, tree richness positively affected specific leaf area and, additionally, had a negative effect on the functional indicies, which revealed that the phenotypic diversity within the tree crown decreased with tree species richness. In addition, leaf carbon to nitrogen ratio decreased with increasing arbuscular mycorrhizal fungal richness in both arbuscular and ectomycorrhizal tree species. Finally, we did not find differences between arbuscular and ectomycorrhizal trees regarding their location within the LES. Our results suggest that trees modify their strategy in response to local tree diversity, not only by shifting trait values but also by shifting the variability intraindividually. In addition, higher mycorrhizal fungal diversity does not seem to lead to higher complementarity, but instead, tree and mycorrhizal fungi affect different aspects of leaf traits. Read the free Plain Language Summary for this article on the Journal blog.

Phosphate additives promote humic acid carbon and nitrogen skeleton formation by regulating precursors and composting bacterial communities

This study aimed to compare the effect of different phosphate additives including superphosphate (CP) and MP [Mg(OH)2 + H3PO4] on nitrogen conversion, humus fractions formation and bacterial community in food waste compost. The results showed the ratio of humic acid nitrogen in total nitrogen (HA-N/TN) in CP increased by 49 %. Ammonium nitrogen accumulation was increased by 75 % (CP) and 44 % (MP). Spectroscopic techniques proved that phosphate addition facilitated the formation of complex structures in HA. CP enhanced the dominance of Saccharomonospora, while Thermobifida and Bacillus were improved in MP. Structural equation modeling and network analysis demonstrated that ammonium nitrogen can be converted to HA-N and has positive effects on bacterial composition, reducing sugars and amino acids, especially in CP with more clustered network and synergic bacterial interactions. Therefore, the addition of phosphate provides a new idea to regulate the retained nitrogen toward humification in composting.

Enhancing nitrogen removal in constructed wetlands: The role of influent substrate concentrations in integrated vertical-flow systems

Recent advancements in constructed wetlands (CWs) have highlighted the imperative of enhancing nitrogen (N) removal efficiency. However, the variability in influent substrate concentrations presents a challenge in optimizing N removal strategies due to its impact on removal efficiency and mechanisms. Here we show the interplay between influent substrate concentration and N removal processes within integrated vertical-flow constructed wetlands (IVFCWs), using wastewaters enriched with NO3−-N and NH4+-N at varying carbon to nitrogen (C/N) ratios (1, 3, and 6). In the NO3−-N enriched systems, a positive correlation was observed between the C/N ratio and total nitrogen (TN) removal efficiency, which markedly increased from 13.46 ± 2.23% to 87.00 ± 2.37% as the C/N ratio escalated from 1 to 6. Conversely, in NH4+-N enriched systems, TN removal efficiencies in the A-6 setup (33.69 ± 4.83%) were marginally 1.25 to 1.29 times higher than those in A-3 and A-1 systems, attributed to constraints in dissolved oxygen (DO) levels and alkalinity. Microbial community analysis and metabolic pathway assessment revealed that anaerobic denitrification, microbial N assimilation, and dissimilatory nitrate reduction to ammonium (DNRA) predominated in NO3−-N systems with higher C/N ratios (C/N ≥ 3). In contrast, aerobic denitrification and microbial N assimilation were the primary pathways in NH4+-N systems and low C/N NO3−-N systems. A mass balance approach indicated denitrification and microbial N assimilation contributed 4.12–47.12% and 8.51–38.96% in NO3−-N systems, respectively, and 0.55–17.35% and 7.83–33.55% in NH4+-N systems to TN removal. To enhance N removal, strategies for NO3−-N dominated systems should address carbon source limitations and electron competition between denitrification and DNRA processes, while NH4+-N dominated systems require optimization of carbon utilization pathways, and ensuring adequate DO and alkalinity supply.

Intercropping changed the soil microbial community composition but no significant effect on alpha diversity.

Enhancing the planning of the forest-agricultural composite model and increasing the efficiency with which forest land is utilized could benefit from a thorough understanding of the impacts of intercropping between forests and agriculture on soil physicochemical properties and microbial communities. Populus cathayana × candansis cv. Xinlin No.1 and Glycine max intercrop soils, along with their corresponding monocrops, were used in this study's llumina high-throughput sequencing analysis to determine the composition and diversity of soil bacterial and fungal communities. The findings indicated that intercropping considerably raised the soil's total phosphorus content and significantly lowered the soil's carbon nitrogen ratio when compared to poplar single cropping. Furthermore, the total carbon and nitrogen content of soil was increased and the soil pH was decreased. The sequencing results showed that intercropping had no significant effect on soil alpha diversity. Intercropping could increase the composition of fungal community and decrease the composition of bacterial community in poplar soil. At the phylum level, intercropping significantly increased the relative abundance of four dominant phyla, i.e., Patescibacteria, Proteobacteria, Patescibacteria and Deinococcus-Thermus. And the relative abundances of only two dominant phyla were significantly increased. It was found that soil total phosphorus and available phosphorus content had the strongest correlation with soil bacterial community diversity, and soil pH had the strongest correlation with soil fungal community diversity. The results of this study were similar to those of previous studies. This study can serve as a theoretical foundation for the development of a poplar and black bean-based forest-agricultural complex management system in the future.

The effect of using nano and microbubbles as aeration strategies on the nitrification process, microbial community composition, and growth of Penaeus vannamei in a super-intensive biofloc system

The aim of this study was to evaluate the effect of using nano and microbubbles as aeration strategies on the nitrification process, microbial community composition of water and biofilm, microbial flocs proximate composition, and growth of Penaeus vannamei in a pilot scale super-intensive system with biofloc technology. A grow-out (stocking density: 450 shrimp m−3) was carried out for 74 days in a greenhouse with nine 35 m3 tanks, using the following treatments: T1: nanobubbles, T2: microbubbles, T3: mixed (nano + microbubbles). The nanobubbles were generated by nozzle-type air injectors and the microbubbles were generated by microperforated hoses. Artificial substrates, with an area equivalent to 200% of the lateral surface, were used into the experimental units. Molasses was used as an organic carbon source at a carbon:nitrogen ratio of 15:1. The main morphotypes of bacteria in the water and in the biofilm were analyzed using direct counting and a profile of the bacterial composition of the water was performed using metagenomic analysis. Control of total ammonia nitrogen (TAN) was better in treatments T2 and T3 than in T1. At the end of the experiment, treatment T3 showed a higher total abundance of bacteria in the water than T1 and T2. Bacillus abundance in the biofilm was higher in the T3 treatment than in T1 and T2. The relative abundance of nitrifying bacteria was <1% in all treatments. Treatment T1 had a higher relative abundance of nitrite-oxidizing bacteria than the others. However, the T3 treatment had a better distribution of nitrifying bacteria species. T3 treatment showed a higher diversity and evenness of operational taxonomic units. The microbial flocs in the T2 had a higher crude protein content than in the T1. These results indicate that the use of a mixed aeration system promotes a higher load of microorganisms, which has proven to improve water quality and can influence shrimp growth. The shrimp final weight was higher in T1 (12.57 g) and T3 (12.54 g) than in T2 (11.70 g), survival was higher in T3 (97.17%) than in T1 (80.33%), and yield was higher in T3 (4.61 Kg m−3) than in T1 (4.06 Kg m−3) and T2 (4.21 Kg m−3). The treatment that used nano and microbubble as aeration strategy (T3) proved to be the best as it provided better TAN control, higher abundance of bacillus bacteria in the biofilm, higher diversity and evenness of bacteria, and even higher shrimp growth and survival.

Mineral protection mediates soil carbon temperature sensitivity of nine old-growth temperate forests across the latitude transect

Temperature sensitivity (Q10) of soil microbial respiration serves as a crucial indicator for assessing the response of soil organic carbon (SOC) to global warming. However, the biogeographic variation in Q10 remains inconsistent. In this study, we examined Q10 and its potential drivers in nine old-growth mixed broad-leaved Korean pine (Pinus koraiensis Sieb. et Zucc.) forests (the climax community of Asian temperate mixed forest) under a wide range of climatic conditions. We found that stand characteristics (arbuscular mycorrhizal tree basal area to ectomycorrhizal tree basal area ratio and root to shoot ratio) contributed to soil C sequestration by facilitating the accumulation of soil recalcitrant C components. Contrary to the C quality-temperature hypothesis, Q10 was not correlated with C quality (soil C to nitrogen ratio and recalcitrant C to labile C ratio). Soil mineral protection parameters (Fe/Al oxides) had negative effect on Q10 because they inhibited microbial activities by decreasing substrate accessibility. Additionally, soils with high microbial biomass C and microbial biomass C to soil organic C ratio had high Q10. Overall, understanding the complex relationships among Q10, mineral protection, and microbial attributes on a spatial scale is essential for accurately predicting soil C cycling in forest ecosystems.

Effect of a Dietary Intervention on Insulin Requirements and Glycemic Control in Type 1 Diabetes: A 12-Week Randomized Clinical Trial.

This study compared the effects of a low-fat vegan diet to those of a portion-controlled diet in people with type 1 diabetes. Over 12 weeks, the average total daily dose of insulin decreased significantly and insulin sensitivity increased significantly in the vegan group, while no significant changes were observed in the group receiving the portion-controlled diet. Total and LDL cholesterol decreased in the vegan group, as did the ratio of blood urea nitrogen to creatinine. A1C decreased in both groups. These findings suggest that a low-fat vegan diet may yield improvements in insulin sensitivity, insulin requirements, glycemic control, and markers of cardiovascular and renal health compared with a portion-controlled diet in people with type 1 diabetes.

Soil Ecoenzymatic Stoichiometry Reveals Microbial Metabolic Limitations in Apple Orchards with Cover Crop and Organic Fertilizer Incorporation

Understanding the stoichiometry of extracellular enzymes in soil, particularly in relation to nutrient acquisition (e.g., carbon, nitrogen, phosphorus), provides valuable insights into microorganisms’ resource requirements. This study investigates the metabolic constraints of soil microorganisms in response to different growth stages of apple trees under various soil management practices. A 14-year long-term experiment with a split-plot design was conducted, where the main plots received different cover crop treatments (bare vs. cover crop), and subplots were subjected to four fertilizer treatments (CK, M, NPK, MNPK). The significant main and interactive effects of cover crops, fertilizer treatment, and growth period on soil nutrients were observed (p &lt; 0.001). Both cover crop and fertilizer treatments significantly increased the soil organic matter content, with implications for orchard resilience to drought. However, the cover factor alone did not notably influence soil carbon–nitrogen ratios or microbial communities. Microbial carbon limitations were driven by soil water dynamics and microbial biomass, while microbial phosphorus limitations were closely linked to total nitrogen levels. The results underscore the combination of cover crops and MNPK fertilizer-enhanced soil nutrient levels and enzyme activities, mitigating microbial carbon and phosphorus limitations. These findings suggest practical strategies for optimizing fertilization practices to improve soil fertility and address nutrient constraints in orchard ecosystems.

Spatial heterogeneity of sedimentary organic matter sources in the Yangtze River estuary: Implications from fatty acid biomarkers

This study investigated the sources of sedimentary organic matter (OM) in the Yangtze River estuary (YRE), using multiple biomarkers. The results of stable carbon isotope (δ13C) and total organic carbon to nitrogen ratio (TOC/TN) suggests the contribution of marine-derived OM significantly increased seawards, while fatty acid (FA) composition provides more specific information on OM sources. In total, 30 components of FAs were identified at the studied 17 sites, which mainly composed of phytoplankton FA, followed by ubiquitous FA and bacterial FA, while terrestrial FA contributed less to the total FAs. Under the strong impacts of the large physicochemical gradients in the YRE, TOC, TN and FA components showed higher concentrations in the estuary mixing zone (especially within the turbidity maximum zone), attributing to their strong binding with OM-enriched fine particles. The spatial heterogeneity of sedimentary OM sources was highly impacted by salinity and Chl-a, as well as bacteria-mediated OM degradation.

Nutrient enrichment alters phytoplankton biomass and composition via silicon limitation

Despite management efforts, anthropogenic nutrient enrichments continue to enhance phytoplankton blooms worldwide. Release of nitrogen and phosphorus compounds not only provides surplus of nutrients but also disbalances their stoichiometry. Declines in the relative availability of dissolved silicon might induce limitation in diatoms, major primary producers with silicified shells. We studied experimentally how nutrient enrichment and resulting decline in dissolved silicon to nitrogen ratios (Si:N) affect the structure and functioning of natural plankton communities. Nitrate was added to create a range of Si:N ratios and phosphate was supplied in Redfield ratio to nitrogen. We also manipulated copepod abundance to understand the top-down effects on communities experiencing nutrient enrichment. Nitrogen and phosphorus additions resulted in a steep phytoplankton biomass increase, followed by a post-bloom decline. Phytoplankton bloom biomass was higher in high nitrogen treatments but during the post-bloom period this trend switched. Biomass was sustained longer in high Si:N treatments, indicating that silicon limitation terminates the bloom. Many diatom species did not benefit from nitrogen and phosphorus enrichment and diatom dominance ceased below Si:N of 0.4:1. Under high grazing pressure, silicate was taken up faster suggesting that silicification is important in diatom defense. Copepods shaped plankton communities via feeding on dinoflagellates, chlorophytes and the diatom Skeletonema costatum but there was no significant effect of nitrogen and phosphorus enrichment on copepod abundance. Our results, combined with previous studies, show that while nutrient concentrations define the total phytoplankton bloom biomass, resource ratios are important in sustaining biomass and determining community structure and composition.

A native plant species cover crop positively impacted vineyard water dynamics, soil health, and vine vigor

Cover cropping is associated with multiple ecosystem and agronomic benefits. However, in irrigated orchards and vineyards of the dry, Western United States, cover crop adoption rates are low, often owing to concerns over their uptake of critical soil water. Regional concerns, such as this, must be addressed to identify sustainable agricultural practices that meet unique needs of diverse growing regions. A two-year study was conducted to determine the impacts of cover crops on soil water dynamics, soil health, and crop growth during the establishment of an Autumn King table grape vineyard in a semi-arid, Mediterranean climate, specifically the Central Valley of California. Phacelia (Phacelia tanacetifolia), a plant species native to the region, and an introduced species, rye (Secale cereale L. ‘Merced’), were planted as cool season cover crops in the interrow spaces of the grapevines and compared to a standard management practice of no cover crop interrow spaces. The cover crop treatments differentially impacted soil microbial biomass and soil aggregate stability, with the phacelia treatment enhancing both metrics from the first season. The phacelia treatment plots resulted in higher soil moisture beneath the vines in both years, while the rye treatment showed similar benefits only after two consecutive years of cover cropping. Vine vigor was also higher in the phacelia treatment, which was likely consequential of enhanced soil moisture in the rows. Compared to the rye, the phacelia had lower plant tissue carbon to nitrogen ratio and higher above ground plant biomass, which may underpin the soil health benefits associated with the phacelia, although variances in soil total carbon and nitrogen and ammonium and nitrate were not determined for any treatment. Altogether, we present information on cover crop plant traits that show quicker return on investment with regards to soil health improvements and water savings. Further, we demonstrate that cool season cover crops offered benefits for vineyard water productivity. In summary, for Mediterranean vineyards, cover crops can promote vineyard soil quality and be a component of sustainable water management.

Novel three-sludge municipal wastewater treatment process coupling denitrifying phosphorus removal with anaerobic ammonium oxidation

The two-sludge anoxic dephosphation (DEPHANOX) process frequently encounters the challenge of elevated effluent ammonia levels in practical applications. In this study, the anaerobic ammonium oxidation (anammox) biofilm was introduced into the DEPHANOX system, transforming it into a three-sludge system, enabling synchronous nitrogen and phosphorus elimination, particularly targeting ammonia. Despite a chemical oxygen demand/total nitrogen ratio of 4.3 ± 0.8 in the actual municipal wastewater and 4.5 h of aeration, the effluent total nitrogen was 13.7 mg/L, lower than the parallel wastewater treatment plant. Additionally, the effluent ammonia reduced to 5.1 ± 2.5 mg/L. Notably, denitrifying phosphorus removal and anammox were coupled in the anoxic zone, yielding 74.5 % nitrogen and 87.8 % phosphorus removal. 16S rRNA gene sequencing identified denitrifying phosphorus-accumulating organisms primarily in floc sludge (Saprospiraceae 7.07 %, Anaerolineaceae 1.95 %, Tetrasphaera 1.57 %), while anammox bacteria inhabited the biofilm (Candidatus Brocadia 4.00 %). This study presents a novel process for efficiently treating municipal wastewater.

Shrouded in history: Unveiling the ways of life of an early Muslim population in Santarém, Portugal (8th- 10th century AD).

In around 716 AD, the city of Santarém, Portugal, was conquered by the Berber and Arab armies that swept the Iberian Peninsula and went on to rule the region until the 12th century. Archaeological excavations in 2007/08 discovered an Islamic necropolis (Avenida 5 de Outubro #2-8) that appears to contain the remains of an early Muslim population in Santarém (8th- 10th century). In this study, skeletal material from 58 adult individuals was analysed for stable carbon (δ13Ccol; δ13Cap), nitrogen (δ15N) and sulphur (δ34S) isotope ratios in bones, and stable oxygen (δ18O), carbon (δ13Cen) and radiogenic strontium (87Sr/86Sr) isotopes in tooth enamel. The results of this study revealed a dietary pattern of predominantly C3-plant and domestic C3-fed herbivore consumption during adulthood (δ13Ccol and δ15N, respectively) but a higher proportion of C4-plant input during childhood (δ13Cen) for some individuals-interpreted as possible childhood consumption of millet porridge, a common practice in North Africa-in those with unorthodox burial types (Groups 1 and 2) that was not practiced in the individuals with canonical burials (Group 3). In this first mobility study of a medieval Muslim population in Portugal, δ18ODW values revealed greater heterogeneity in Groups 1 and 2, consistent with diverse origins, some in more humid regions than Santarém when compared to regional precipitation δ18O data, contrasting the more homogenous Group 3, consistent with the local precipitation δ18O range. Ancient DNA analysis conducted on three individuals revealed maternal (mtDNA) and paternal (Y-chromosome) lineages compatible with a North African origin for (at least) some of the individuals. Additionally, mobility of females in this population was higher than males, potentially resulting from a patrilocal social system, practiced in Berber and Arab communities. These results serve to offer a more detailed insight into the ancestry and cultural practices of early Muslim populations in Iberia.