674 research outputs found
Correction to: Reducing external costs of nitrogen pollution by relocation of pig production between regions in the European Union
No full textThe article Reducing external costs of nitrogen pollution by relocation of pig production between regions in the European Union, written by Hans J. M. van Grinsven, Jan D. van Dam, Jan Peter Lesschen, Marloes H. G. Timmers, Gerard L. Velthof, Luis Lassaletta, was originally published electronically on the publisher’s internet portal (currently SpringerLink) on 28 May 2018 without open access. With the author(s)’ decision to opt for Open Choice the copyright of the article changed on April 2019
Acetylene and oxygen as inhibitors of nitrous oxide production in Nitrosomonas europaea and Nitrosospira briensis: a cautionary tale
No full textAutotrophic ammonia-oxidizing bacteria produce nitrous oxide (N2O) as a by-product of nitrification or as an intermediate of nitrifier denitrification. In soil incubations, acetylene (C2H2) and large partial pressures of oxygen (O2) are used to distinguish between these sources. C2H2 inhibits ammonia oxidation and should therefore inhibit N2O production by both nitrification and nitrifier denitrification. O2 suppresses the reduction pathway of nitrifier denitrification. However, doubts concerning the reliability of C2H2 and O2 as inhibitors have arisen recently. Therefore, in this study we tested the influence of C2H2 and large partial pressures of O2 alone and in combination on N2O production in pure cultures of the ammonia oxidizers Nitrosomonas europaea and Nitrosospira briensis. C2H2 largely inhibited nitrite production in both ammonia oxidizers and N2O production by N. europaea. Surprisingly, it did not affect the N2O production in N. briensis. The variable response of ammonia oxidizers to C2H2 might have consequences for the use of C2H2 as an inhibitor of nitrification in soils. Different partial pressures of O2 ranging from less than 10 kPa O2 to 100 kPa O2 were tested for their effectiveness in inhibiting N2O production via nitrifier denitrification. The partial pressure of 100 kPa O2 yielded minimal N2O production by both ammonia-oxidizing species and seemed to inhibit N2O emission from nitrifier denitrification to a large extent. However, a negative effect of 100 kPa O2 on ammonia oxidation itself could not be excluded. The applicability of both inhibitors in determining N2O production pathways in soils is discussed. [KEYWORDS: Nitrous oxide; Acetylene; Oxygen; Ammonia oxidizer; Nitrifier denitrification]
Trends in global nitrous oxide emissions from animal production systems
No full textWastes from animal production systems contribute as much as 30-50% to the global N2O emissions from agriculture, but relatively little attention has been given on improving the accuracy of the estimates and on developing mitigation options. This paper discusses trends and uncertainties in global N2O emission from animal waste and discusses possible mitigation strategies, on the basis of literature data and results of simple calculations. Total N2O emissions from animal production systems are estimated at 1.5 Tg. Dung and urine from grazing animals deposited in pastures (41%), indirect sources (27%), animal wastes in stables and storages (19%), application of animal wastes to land (10%) and burning of dung (3%) are the five sources distinguished. Most sensitive factors are N excretion per animal head, the emission factor for grazing animals and that for indirect emissions. Total N2O emissions are related to type and number of animals, N excretion per animal, and the management of animal wastes. Projections by FAO suggest that animal numbers will increase by 40% between 2000 and 2030. Mean N excretion per animal head will probably also increase. These trends combined suggest a strong increase in total N2O emission from animal production systems in the near future, which is opposite to the objectives of the Kyoto Protocol. Improving N use efficiency, combined with anaerobic digestion of animal wastes for bio fuel generation are the most feasible options for mitigation, but these options seem insufficient to reverse the trend of increasing N2O emission. In conclusion, animal production systems are a major and increasing source of N2O in agriculture. The uncertainties in the emission estimates are large, due to the many complexities involved and the lack of accurate data, especially about N excretion and the management of animal wastes in practice. Suggestions are made how to increase the accuracy of the emission estimates and to mitigate N2O emission from animal production systems
Gerard Mercator´s Three Astrolabes
No full textNo scientific instruments made by Gerard Mercator (1512- 1594), the great cartographer, were known to exist, though it is recorded that he made astrolabes and other brass artefacts. In early 1992, the present author identified an unsigned astrolabe in Florence as being made in Mercstor's Duisburg workshop. By 1994, the 400th anniversary of Mercator's death, two fiírther astrolabes had been identified as being by his hand. They are in museums in Augsburg and Brno. This paper describes the mcthod of identifícation of these unsigned instruments, culminating in the discovcry of Mercator's monogram on the rim of the astrolabe in Brno
Nutrient use efficiency in the food chain of China
No full text<p align="center"> Key words: Nitrogen, phosphorus, food chain, food pyramid, food system, food security, food cost, environmental impacts, nutrient cycling, nutrient management <p align="left"> Nitrogen (N) and phosphorus (P) fertilizer applications have greatly contributed to the increased global food production during the last decades, but have also contributed to decreasing N and P use efficiencies (NUE and PUE) in the food production - consumption chain, and to increased N and P losses to air and water, with major ecological implications. <p align="left"> The aim of this thesis is to increase the quantitative understanding of N and P flows and losses in the food production - consumption chain in China at regional level in the past 30 years and to develop strategies to increase NUE and PUE in the food chain. A novel ‘food chain’ approach and the NUFER model were developed to analyse N and P flows in crop production, animal production, food processing and retail, and households. Data were derived from statistical sources, literature and field surveys. <p align="left"> Between 1980 and 2005, NUE and PUE decreased in crop production, increased in the animal production and decreased in the whole food chain. Total N losses to water and atmosphere almost tripled between 1980 (14.3 Tg) and 2005 (42.8 Tg), and P losses to water systems increased from 0.5 to 3.0 Tg. There were significant regional differences in NUE, PUE, and N and P losses; regions with high N and P losses were in Beijing and Tianjin metropolitans, Pearl River Delta, and Yangzi River Delta. Urban expansion is a major driving force for change; total N losses increased 2.9 folds, and P losses increased even 37 folds during the development of Beijing metropolitan, between 1978 and 2008. Scenario analyses indicated that implementation of a package of integrated nutrient management measures, combined with diet changes and increased imports of animal food and feed, are the most effective management options for increasing NUE and PUE, and for decreasing N and P losses. <p align="left"> Application of the food chain approach and the NUFER model can help policy makers in China to plan food production - consumption chains, and thereby manage N and P flows in this chain at regional level. 
Making the Herball: John Gerard and the Fashioning of an Elizabethan Herbarist
No full textJohn Gerard (1545-1612) would not be remembered except for the fact that he wrote the Elizabethan book on plants: The Herball or Generall History of Plantes. Gathered by John Gerarde of London Master of Chirurgerie (London: John Norton, 1597). Although there are few documentary records about this barber surgeon and supervisor of the gardens of William Cecil, Lord Burghley, Gerard's Herball (1597) is itself a rich source of information about his activities and ambitions. Drawing on this material as well as the two catalogues Gerard published about his own garden of medicinal, indigenous, and exotic plants, I reconstruct five roles Gerard took on over the course of his life: surgeon, gardener, client, author, and herbarist. Applying the models of Renaissance self-fashioning and Renaissance scientist-courtier offered by Stephen J. Greenblatt and Mario Biagioli to this member of the minor gentry and London guild community allows us to see Gerard in a new light. I argue that he consciously and energetically shaped his career by finding a powerful patron and a place among the newly emerging community of early modern naturalists. This allows us to see the Herball (1597) in the context of his own expectations and the assumptions of Renaissance book culture and to give Gerard more credit for his accomplishment than previous historians have generally done
Gerard Genette Naratology on Gender Inequality from Alex L. Tobing’s Mekar Karena Memar
No full textThis research examines the gender inequality experienced by Gloria in Mekar Karena Memar\u27s novel by Alex L. Tobing from Gerard Genette\u27s narratology theory. The author is interested in studying gender inequality because, in this novel, the main character named Gloria is fighting against the gender inequality that she experiences. This makes this issue attractive to the author because women generally only received improper treatment without daring to do anything in those days. The author of the novel uses the pure narrative method, where the pure author acts like someone who is outside the novel and does not participate in the role of a character from the novel. In this study, the authors used a qualitative study method. The author collects data through literature study (documentation) and performs analysis using the Genette theory which consists of five parts: order, duration, frequency, mood, and voice. After analyzing, the writer found that the author had described the gender inequality experienced by a character named Gloria in the novel, as well as the actions Gloria had taken to overcome the gender inequality she experienced
Inter-and intra-individual differences in skin hydration and surface lipids measured with mid-infrared spectroscopy
No full textSkin health is characterized by heterogeneous system of water and lipids in upper layers providing protection from external environment and preventing loss of vital components of the body. Skin hydration (moisture) and sebum (skin surface lipids) are considered to be important factors in skin health; a right balance between these components is an indication of healthy skin and plays a central role in protecting and preserving skin integrity. In this manuscript we present inter-and intra-individual variation in skin hydration and surface lipids measured with a home-built experimental prototype based on infrared spectroscopy. Results show good agreement with measurements performed by commercially available instruments Corneometer and Sebumeter used for skin hydration and sebum measurements respectively.</p
Comparison of indices for the prediction of nitrogen mineralization after destruction of managed grassland
No full textDetection of Schistosoma haematobium using lensless imaging and flow cytometry, a proof of principle study
No full textWe present a simple method for the diagnosis of urinary schistosomiasis using an in-line lensless holographic microscope combined with flow cytometry technique. Using simple image processing algorithms and binary image classifier, our system provides automated detection of Schistosoma haematobium eggs in infected urine samples. Registered hologram is reconstructed by applying backpropagation from sensor to sample plane and reconstructed image is automatically analysed for the presence of S. haematobium eggs. Designed for use in a resource-poor laboratory setting, our proposed method has been implemented using a Raspberry Pi computer. From pre-clinical test performed with human urine samples spiked with S. haematobium eggs (approximately 200 eggs per 12 ml of urine), we achieved a sensitivity and specificity of 50.6% and 98.6% respectively. Our proposed method requires no complex sample preparation methods making the system simple to operate and useable in point-of-care diagnosis of urinary schistosomiasis.This method can be optimized to complement existing diagnostic procedures for the detection of S. haematobium eggs and can be deployed to inaccessible remote areas.Team Raf Van de PlasDesign for Sustainabilit
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