A low-tech, low-cost method to capture point-source ammonia emissions and their potential use as a nitrogen fertiliser

Rising global energy prices have led to increased costs of nitrogen (N) fertilisers for farmers, but N pollution (losses) from agricultural activities can account for over 50% of the nitrogen applied. This study assesses the feasibility of a low-cost and low-tech method of NH3 emission capture from an agricultural point source (chicken manure) using a water column bubbling technique, and its application as a fertiliser to several plant types. Solutions of i) nitric acid (HNO3), ii) calcium nitrate (Ca(NO3)2), iii) a mixture of Ca(NO3)2 and HNO3 and iv) deionised H2O were used to scrub NH3 from air pumped from a storage container containing chicken manure. We conclude that NH3 can be captured from manure using low-tech methods, and that solutions of common fertiliser compounds such as ammonium nitrate and calcium ammonium nitrate can be replicated by binding captured NH3 to solutions of nitrate. Our results suggest that dissolved calcium nitrate is just as effective at scrubbing NH3 from the atmosphere as nitric acid at low concentrations, but could do so at a near neutral pH. For use on common silage grass for livestock feed, all of the captured ammonium solutions significantly increased yields, including the ammonium only solution. However, the aquatic plants (Taxiphyllum Barbieri and Salvinia auriculata) did not respond favourably to a high ratio of NH4+ in solution, and in the case of Salvinia auriculata, the plant was significantly damaged by the ammonium only solution. In conclusion, we highlight that the capture and utilisation of NH3 emissions from point sources is possible using very basic apparatus and that if used correctly, this captured nitrogen can be stored and applied to crops in a variety of forms which could reduce reliance and cost of mineral fertiliser use.<br/

CEA systems: the means to achieve future food security and environmental sustainability?

As demand for food production continues to rise, it is clear that in order to meet the challenges of the future in terms of food security and environmental sustainability, radical changes are required throughout all levels of the global food system. Controlled Environment Agriculture (CEA) (a.k.a. indoor farming) has an advantage over conventional farming methods in that production processes can be largely separated from the natural environment, thus, production is less reliant on environmental conditions, and pollution can be better restricted and controlled. While output potential of conventional farming at a global scale is predicted to suffer due to the effects of climate change, technological advancements in this time will drastically improve both the economic and environmental performance of CEA systems. This article summarizes the current understanding and gaps in knowledge surrounding the environmental sustainability of CEA systems, and assesses whether these systems may allow for intensive and fully sustainable agriculture at a global scale. The energy requirements and subsequent carbon footprint of many systems is currently the greatest environmental hurdle to overcome. The lack of economically grown staple crops which make up the majority of calories consumed by humans is also a major limiting factor in the expansion of CEA systems to reduce the environmental impacts of food production at a global scale. This review introduces the concept of Integrated System CEA (ISCEA) in which multiple CEA systems can be deployed in an integrated localized fashion to increase efficiency and reduce environmental impacts of food production. We conclude that it is feasible that with sufficient green energy, that ISCEA systems could largely negate most forms of environmental damage associated with conventional farming at a global scale (e.g., GHGs, deforestation, nitrogen, phosphorus, pesticide use, etc.). However, while there is plenty of research being carried out into improving energy efficiency, renewable energy and crop diversification in CEA systems, the circular economy approach to waste is largely ignored. We recommend that industries begin to investigate how nutrient flows and efficiencies in systems can be better managed to improve the environmental performance of CEA systems of the future

Measurements of methane and nitrous oxide in human breath and the development of UK scale emissions

Exhaled human breath can contain small, elevated concentrations of methane (CH4) and nitrous oxide (N2O), both of which contribute to global warming. These emissions from humans are not well understood and are rarely quantified in global greenhouse gas inventories. This study investigated emissions of CH4 and N2O in human breath from 104 volunteers in the UK population, to better understand what drives these emissions and to quantify national-scale estimates. A total of 328 breath samples were collected, and age, sex, dietary preference, and smoking habits were recorded for every participant. The percentage of methane producers (MPs) identified in this study was 31%. The percentage of MPs was higher in older age groups with 25% of people under the age of 30 classified as MPs compared to 40% in the 30+ age group. Females (38%) were more likely to be MPs than males (25%), though overall concentrations emitted from both MP groups were similar. All participants were found to emit N2O in breath, though none of the factors investigated explained the differences in emissions. Dietary preference was not found to affect CH4 or N2O emissions from breath in this study. We estimate a total emission of 1.04 (0.86–1.40) Gg of CH4 and 0.069 (0.066–0.072) Gg of N2O in human breath annually in the UK, the equivalent of 53.9 (47.8–60.0) Gg of CO2. In terms of magnitude, these values are approximately 0.05% and 0.1% of the total emissions of CH4 and N2O reported in the UK national greenhouse gas inventories

3.6 and 4.5 μ\mum Spitzer{\it Spitzer} Phase Curves of the Highly-Irradiated Hot Jupiters WASP-19b and HAT-P-7b

We analyze full-orbit phase curve observations of the transiting hot Jupiters WASP-19b and HAT-P-7b at 3.6 and 4.5 $\mu$m obtained using the Spitzer Space Telescope. For WASP-19b, we measure secondary eclipse depths of $0.485\%\pm 0.024\%$ and $0.584\%\pm 0.029\%$ at 3.6 and 4.5 $\mu$m, which are consistent with a single blackbody with effective temperature $2372 \pm 60$ K. The measured 3.6 and 4.5 $\mu$m secondary eclipse depths for HAT-P-7b are $0.156\%\pm 0.009\%$ and $0.190\%\pm 0.006\%$, which are well-described by a single blackbody with effective temperature $2667\pm 57$ K. Comparing the phase curves to the predictions of one-dimensional and three-dimensional atmospheric models, we find that WASP-19b's dayside emission is consistent with a model atmosphere with no dayside thermal inversion and moderately efficient day-night circulation. We also detect an eastward-shifted hotspot, suggesting the presence of a superrotating equatorial jet. In contrast, HAT-P-7b's dayside emission suggests a dayside thermal inversion and relatively inefficient day-night circulation; no hotspot shift is detected. For both planets, these same models do not agree with the measured nightside emission. The discrepancies in the model-data comparisons for WASP-19b might be explained by high-altitude silicate clouds on the nightside and/or high atmospheric metallicity, while the very low 3.6 $\mu$m nightside planetary brightness for HAT-P-7b may be indicative of an enhanced global C/O ratio. We compute Bond albedos of 0 ($<0.08$ at $1\sigma$) and $0.38\pm 0.06$ for WASP-19b and HAT-P-7b, respectively. In the context of other planets with thermal phase curve measurements, we show that WASP-19b and HAT-P-7b fit the general trend of decreasing day-night heat recirculation with increasing irradiation.Comment: 22 pages, 29 figures, accepted by Ap

Immunological consequences of antihelminthic treatment in preschool children exposed to urogenital schistosome infection

Urogenital schistosomiasis, due to Schistosoma haematobium, is endemic in sub-Saharan Africa. Control is by targeted treatment with praziquantel but preschool age children are excluded from control programs. Immunological studies on the effect of treatment at this young age are scarce. In light of studies in older individuals showing that praziquantel alters antischistosome immune responses and responses to bystander antigens, this study aims to investigate how these responses would be affected by treatment at this young age. Antibody responses directed against schistosome antigens, Plasmodium falciparum crude and recombinant antigens, and the allergen house dust mite were measured in children aged 3 to 5 years before and 6 weeks after treatment. The change in serological recognition of schistosome proteins was also investigated. Treatment augmented antischistosome IgM and IgE responses. The increase in IgE responses directed against adult worm antigens was accompanied by enhanced antigen recognition by sera from the children. Antibody responses directed against Plasmodium antigens were not significantly affected by praziquantel treatment nor were levels of allergen specific responses. Overall, praziquantel treatment enhanced, quantitatively and qualitatively, the antiworm responses associated with protective immunity but did not alter Plasmodium-specific responses or allergen-specific responses which mediate pathology in allergic disease

Osteoprotegerin-Mediated Homeostasis of Rank+ Thymic Epithelial Cells Does Not Limit Foxp3+ Regulatory T Cell Development

In the thymus, medullary thymic epithelial cells (mTEC) regulate T cell tolerance via negative selection and Foxp3(+) regulatory T cell (Treg) development, and alterations in the mTEC compartment can lead to tolerance breakdown and autoimmunity. Both the receptor activator for NF-κB (RANK)/RANK ligand (RANKL)/osteoprotegerin (OPG) axis and expression of the transcriptional regulator Aire are involved in the regulation of thymus medullary microenvironments. However, their impact on the mechanisms controlling mTEC homeostasis is poorly understood, as are the processes that enable the thymus medulla to support the balanced production of mTEC-dependent Foxp3(+) Treg. In this study, we have investigated the control of mTEC homeostasis and examined how this process impacts the efficacy of Foxp3(+) Treg development. Using newly generated RANK Venus reporter mice, we identify distinct RANK(+) subsets that reside within both the mTEC(hi) and mTEC(lo) compartments and that represent direct targets of OPG-mediated control. Moreover, by mapping OPG expression to a subset of Aire(+) mTEC, our data show how cis- and trans-acting mechanisms are able to control the thymus medulla by operating on multiple mTEC targets. Finally, we show that whereas the increase in mTEC availability in OPG-deficient (Tnfrsf11b(−/−)) mice impacts the intrathymic Foxp3(+) Treg pool by enhancing peripheral Treg recirculation back to the thymus, it does not alter the number of de novo Rag2pGFP(+)Foxp3(+) Treg that are generated. Collectively, our study defines patterns of RANK expression within the thymus medulla, and it shows that mTEC homeostasis is not a rate-limiting step in intrathymic Foxp3(+) Treg production

Integration of algae treatment with hydroponic crop waste to reduce impact of nutrient waste streams

•Introduction: Controlled environment agriculture (CEA) is expanding globally, but little is known about nutrient losses within these systems, or how to reduce subsequent pollution. This experiment investigates the potential to treat wastewater from hydroponically produced lettuce via the application of algae. •Materials and Methods: A total of 132 heads of lettuce were produced in the 4-layer nutrient film technique (NFT) vertical farming rack. Waste from the hydroponic system was used to cultivate naturally occurring algae. Nitrogen (N), phosphorus (P) and other trace elements (Ca, Co, Cu, Fe, K, Mg, Mn, Mo, Ni and Zn) were measured at each stage of production. •Results: Overall the nutrient use efficiency (NUE) of applied mineral nitrogen (N) and phosphorus (P) was 88.7% and 59.4%. After algae treatment of waste streams the full system NUE of N and P was 99.5% and 95.0% respectively, thus significantly reducing waste heading for sewage. It was found that the crops consumed large quantities of Ca, Cu, Fe and Zn from the rooting sponges used in this experiment, which may have become available due to mineralization and the presence of slightly acidic fertiliser solution. The overall waste produced by the rooting sponge is of concern regarding the full NUE of the system, accounting for approximately 53% and 6% of the total N and P input into the system. •Conclusions: This study highlights that treating wastewater streams from controlled environment agriculture (CEA) methods such as hydroponics with algae is successful and easy to achieve with little effort. Future efforts by researchers and the CEA industry to better manage nutrient streams is recommended to improve the environmental credentials of developing CEA systems

Matrix Rigidity Regulates Cancer Cell Growth by Modulating Cellular Metabolism and Protein Synthesis

Background: Tumor cells in vivo encounter diverse types of microenvironments both at the site of the primary tumor and at sites of distant metastases. Understanding how the various mechanical properties of these microenvironments affect the biology of tumor cells during disease progression is critical in identifying molecular targets for cancer therapy. Methodology/Principal Findings: This study uses flexible polyacrylamide gels as substrates for cell growth in conjunction with a novel proteomic approach to identify the properties of rigidity-dependent cancer cell lines that contribute to their differential growth on soft and rigid substrates. Compared to cells growing on more rigid/stiff substrates (>10,000 Pa), cells on soft substrates (150–300 Pa) exhibited a longer cell cycle, due predominantly to an extension of the G1 phase of the cell cycle, and were metabolically less active, showing decreased levels of intracellular ATP and a marked reduction in protein synthesis. Using stable isotope labeling of amino acids in culture (SILAC) and mass spectrometry, we measured the rates of protein synthesis of over 1200 cellular proteins under growth conditions on soft and rigid/stiff substrates. We identified cellular proteins whose syntheses were either preferentially inhibited or preserved on soft matrices. The former category included proteins that regulate cytoskeletal structures (e.g., tubulins) and glycolysis (e.g., phosphofructokinase-1), whereas the latter category included proteins that regulate key metabolic pathways required for survival, e.g., nicotinamide phosphoribosyltransferase, a regulator of the NAD salvage pathway. Conclusions/Significance: The cellular properties of rigidity-dependent cancer cells growing on soft matrices are reminiscent of the properties of dormant cancer cells, e.g., slow growth rate and reduced metabolism. We suggest that the use of relatively soft gels as cell culture substrates would allow molecular pathways to be studied under conditions that reflect the different mechanical environments encountered by cancer cells upon metastasis to distant sites