Assessing the benefits and wider costs of different N fertilisers for grassland agriculture     

Alison Carswell  Rory Shaw  John Hunt  Antonio Rafael Sánchez-Rodríguez  Karen Saunders  Joseph Cotton 《Archives of Agronomy and Soil Science》2019,65(5):625-639

Fertiliser nitrogen (N) is essential for maintaining agronomic outputs for our growing population. However, the societal, economic and environmental impacts of excess reactive N from fertiliser is rarely assessed. Here the agronomic, economic and environmental efficacy of three N-fertiliser sources, ammonium-nitrate (AN), urea (U), and inhibited-urea (IU; with NPBT) were evaluated at two grassland sites. Dry matter yield and herbage quality were measured at each silage-cut. Additionally, NH₃-N and N₂O-N losses were measured and used to calculate the effective N source cost and externality costs, which account for associated environmental and societal impacts. We found no effect of different N sources on yield or herbage quality. However, NH₃-N emissions were significantly reduced under the IU treatment, by 48–65%. No significant differences in cumulative N₂O emissions were observed. Incorporating externality costs increased fertiliser prices by 1.23–2.36, 6.51–16.4, and 3.17–4.17 times the original cost, for AN, U and IU, respectively, transforming U from the cheapest, to the most expensive of the N sources examined. However, with no apparent yield differences between N-fertiliser sources there is no economic incentive for the land-manager to use the more environmentally and socially acceptable option, unless externality costs are incorporated into fertiliser prices at the point of sale.  相似文献   

Ammonia-oxidizing bacterial and archaeal communities in tropical bioaugmented zero water exchange shrimp production systems     

Nair  Ramya R.  Boobal  R.  Vrinda  S.  Bright Singh  I. S.  Valsamma  Joseph 《Journal of Soils and Sediments》2019,19(4):2126-2142

Journal of Soils and Sediments - Ammonia oxidation is an important process in the removal of ammonia generated from feed and metabolic wastes in aquaculture systems. Considering the biogeochemical...  相似文献   

A Qualitative and Quantitative Approach to Determine the Optimum Combination of Feeding Stimulants for Striped Bass Morone saxatilis Using an Agar Gel Carrier     

Elias  Papatryphon Joseph H.  Soares  Jr. 《Journal of the World Aquaculture Society》2002,33(1):23-31

A series of experiments was conducted to determine the optimum combination of previously identified feeding stimulants (FS), namely L-alanine (Ala), L-serine (Ser), inosine-5'-monophosphate (IMP), and betaine (Bet), for striped bass Morone saxatilis . Three experiments were conducted to determine the optimum combination of FS using an agar gel matrix as a carrier. In the first experiment a 2⁴ factorial experiment was conducted to test all possible combinations of the four FS at two levels, 0 and 0.1 M. Significant interactions between the FS were found, suggesting the complexity of gustatory stimulation and palatability. In the second experiment a 4 × 6 factorial design was employed to test each FS alone and at concentrations ranging from 0 to 8% in order to determine the minimum level at which maximal stimulation is achieved. The results suggest that there is no significant improvement in feed intake beyond the 1 % level of supplementation for all the FS. In addition, Ala produced a significantly greater response compared to all other FS. In the last experiment, a modified single factor method was used to estimate the optimum levels for each FS in a mixture. The range of the concentrations tested was 0–1% of the agar gel for each FS. Combining all four compounds yielded maximal stimulation. The levels of each compound in the final optimum combination of FS were: Ala, 0.4; Ser, 0.6; Bet, 0.4; and IMP, 0.3% of the agar gel.  相似文献   

Azomethines of sec-butylamine for the control of penicillium decay of oranges     

Joseph W. Eckert  Michael L. Rahm 《Pest management science》1983,14(3):220-228

Imines, synthesised by the reaction of sec-butylamine (SBA, 2-amino-butane) with pentan-2-one, heptan-2-one, octan-2-one, undecan-2-one, benzaldehyde and 2-furaldehyde, were evaluated as vapour-phase treatments to prevent the infection of oranges by Penicillium digitatum. All the imines provided decay control equivalent to SBA when they were introduced into the fruit container at a rate equivalent to 16.4 mg SBA litre^?1 air volume. The carbonyl compound component of the imines, tested alone at a five-fold higher rate, did not reduce fruit decay. All the imines were stable in the gaseous state in dry air. The imines of pentan-2-one and undecan-2-one were hydrolysed rapidly in a humid environment, indicating that their action against P. digitatum was due to the release of SBA into the atmosphere around the fruit. The instability of the imines of the aliphatic ketones makes them unsuitable as generators of SBA in packages. The imines derived from benzaldehyde and 2-furaldehyde were stable in moist air, but were hydrolysed to a significant degree on moist filter paper, especially at pH < 7. These aromatic imines were absorbed from the atmosphere by the fruit and were hydrolysed rapidly in water, and in a buffer solution that represented the environment in fresh injuries on fruit. Apparently all the imines tested generated SBA in the fruit environment, and this SBA accumulated at potential infection sites, where it prevented the development of decay.  相似文献   

Protection tests against parasitic diseases     

M Joseph 《Comparative immunology, microbiology and infectious diseases》1986,9(2-3):217-223

The development of parasite immunology during the last decade has been highly beneficial to our understanding of immune processes against parasites, and recent research has been devoted to the target antigens of effector mechanisms, especially those localized on the surfaces of the pathogens. In this context, define antigenic structures have been identified, which induced significant degree of protection. In malaria, circumsporozoite and merozoite proteins, with large repetitive sequences, have been isolated from various species of Plasmodium and cloned. Monoclonal antibodies produced against these antigens inhibited the invasion of host cells by living parasites. Some results have also been obtained in protective immunity against Leishmania and Toxoplasma. In schistosomiasis, the main characteristic of defence processes is the narrow association between cellular and humoral immunity in antibody-dependent cell-mediated cytotoxic mechanisms. Eosinophils, macrophages, and platelets efficiently killed schistosome larvae when activated by specific antibody of anaphylactic classes, especially IgE. Some of the target antigens have been characterized and cloned. The transfer to normal animals of monoclonal antibodies, and, in one case, of an anti-idiotype antibody, has induced a significant protection against challenge infestations. Optimistic perspectives can therefore be opened concerning an efficacious immunoprophylaxis of an increasing number of parasitic diseases. An adequate conjunction between potentially protective antigens and selective immunomodulators and adjuvants should lead to vaccination. Such an aim nowadays appears as more than a hope.  相似文献   

Influence of oxygen,carbon dioxide and carbon monoxide levels on decay of head lettuce after harvest     

Joseph K. Stewart 《Scientia Horticulturae》1978,9(3):207-213

Lettuces, Lactuca sativa L. var. capitata, half of which were inoculated with Botrytis cinerea Pers. ex Fr., were stored for 14 days at 7.5°C in all combinations of the following gases: 5 and 21% O₂, 0 and 3% CO₂, 0 and 1% CO. Decay was inhibited by 5% O₂ and 3% CO₂, and a combination of these was the most effective mixture. CO at 1% had no effect on decay. The results were similar for lettuces from the coastal or desert areas of California, but more decay occurred in the former than in the latter.  相似文献   

Photodecomposition of piperazine in water by ‘sunlight’ ultraviolet radiation     

Jean Rouchaud  Chantal Moons  Jacques R. Decallonne  Joseph A. Meyer 《Pest management science》1978,9(4):305-309

A solution of piperazine in water was photochemically oxidised by the dissolved oxygen when irradiated with ‘sunlight’ ultraviolet radiation obtained with a Hanau Q-300 lamp, or with RUL-300 nm lamps. Sensitisers (riboflavin, acetone and benzophenone) did not increase the rate of the oxidation induced by the RUL-300 nm lamps; however, they (especially riboflavin) accelerated the oxidation induced by the Hanau Q-300 lamp. A large number of products were observed in the sensitised oxidation but they were not analysed further. The irradiation mixture of the non-sensitised photo-oxidation, when 65% of the initial piperazine had been transformed, contained piperazine (35%), glycine (approximately 25%) and three unidentified compounds in equal amounts (approximately 13% each); the same products were obtained with both irradiation systems. The photo-oxidation of piperazine, a metabolite of the fungicide triforine, 1,4-bis(2,2,2-trichloro-l-formamidoethyl)piperaerazine, could thus be a way for the latter's biodegradation at a surface, or in plant tissues, this biodegradation having already been observed.  相似文献   

Die S-, R- und M-Formen und die Veränderlichkeit der enteropathogenen E. coli.     

Joseph Parnas  Arne Dam 《Zoonoses and public health》1973,20(10):783-797

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Über den in-vitro-Einfluß der Toxine von enteropathogenen Escherichia Coli auf die Motorik der Darmsegmente     

Joseph Parnas  N. Gyrd-Hansen  Arne Dam 《Zoonoses and public health》1975,22(10):856-859

The in vitro effect of toxins of enteropathogenetic Escherichia coli on the motility of gut segments In vitro experiments on the motility of segments of the jejunum and ileum of rabbits and pigs showed that the differentiation of the toxins of enteropathogenic E. coli by this technique was very doubtful. The enteropathogenic strains 0149: K 91 H 10 and 0138: K 81 were compared with the non-pathogenic strain 07 and with acetylcholine.  相似文献   

The nature of bound residues derived from triforine in barley plants     

Jean Rouchaud  Jacques R. Decallonne  Joseph A. Meyer 《Pest management science》1978,9(1):74-78

The shoots of barley plants root-treated with [³H]-triforine fungicide (uniformly labelled in the piperazine ring) were analysed 30 days after treatment. Methanol extraction left a solid plant residue which contained 33% of the total ³H which had been incorporated into the shoots. Methanol acidified with hydrochloric acid extracted a further 18% of the triforine-derived bound residues as N-[2,2,2-trichloro-1-(piperazin-1-yl)ethyl]formamide (8%), and piperazine (10%). In the plants, these compounds had thus been complexed to plant constituents. Hot dimethyl sulphoxide (DMSO) extracted a further 13% of the total ³H, leaving a solid residue (mainly cellulose) which contained 2% of ³H, perhaps incorporated into the cellulose. Evaporation of the solvent from the DMSO extract gave a solid, the radioactivity of which (13%) could not be extracted by methanol. A part (7%) of this radioactivity could be released by successive hydrolysis with amyloglucosidase and β-glucosidase, which generated a complex mixture of polar and water soluble unknown radioactive compounds not including piperazine. These latter compounds would be the products of extensive metabolism of triforine (and its metabolite piperazine) bound to, or incorporated into starch. Most (11%) of the radioactivity of this solid could be released by hydrochloric acid hydrolysis, which also generated a complex mixture of polar and water soluble unknown radioactive compounds not including piperazine; a part (4%) of them could have been associated with lignin in the plant.  相似文献