63 research outputs found

    Predictability of the Evolution of the Soil Structure using Water Flow Modeling for a Constructed Technosol

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    International audienceThis paper focuses on the rela on between the structure of a constructed Technosol and its hydraulic characteris cs during its early pedogenesis. The method is based on a 3-yr comparison of, on one hand, experimental measurements from an in situ gravita on lysimeter and, on the other hand, a modeling approach with HYDRUS-1D. The change of water fl ow pa erns with me was described. It was consistent with previous results for constructed Technosol aggrega on. Apart from seasonal varia ons, the specifi city of the hydraulic func oning of the constructed Technosol was shown to be due to the nature of its technogenic parent materials. The in situ evolu on of the hydrodynamics has been established and partly linked to external factors (climate, vegeta on). The direct modeling and the op miza on of the parameters over fi rst a 3-yr period and then three 9-mo periods accurately represented global water fl ow trends at the pedon scale. However it failed to simulate precisely the main events, such as massive leachate ou low. An evolu on with me of some of the hydraulic proper es was shown, expressing the structuring of the soil. The existence of two dis nct me-scales (slow and steady/fast and cyclic) of the evolu on of hydraulic parameters was then formulated as a new hypothesis. Abbrevia ons: Hz, horizon; TDR, me domain refl ectometry

    Nutritive value and physical and chemical deterrents of forage grass litter explain feeding performances of two soil macrodetritivores

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    Millipedes (Diplopoda) and terrestrial isopods (Isopoda) may play a significant role in soil decomposition. The present study aimed to contribute to the general understanding of feeding performances of macrodetritivores consuming grass litter by answering two questions. Q1: Are grass litter traits indicating nutritive value (i.e. chemical) and traits indicating feeding deterrents (i.e. mainly physical but not necessarily) both necessary to explain individual feeding performances of soil invertebrates consuming grass litter? Q2: Do grass physical traits indicating physical deterrents (e.g. WHC for mechanical aspects) provide more than, less than or the same amount of information about invertebrate individual performances as grass chemical traits indicating mainly chemical but also physical deterrents (e.g. lignin content directly for digestibility and indirectly for mechanical aspects)? We thus designed a laboratory experiment to assess individual feeding performances of two common macrodetritivores (Armadillidium vulgare (Latreille, 1804) and Glomeris marginata (Villiers, 1789)) in four monospecific treatments of litter from perennial forage grasses (Brachypodium pinnatum P. Beauv., Bromus erectus Huds., Festuca rubra L. and Holcus lanatus L.). A. vulgare feeding performances were correlated with nutritive values (litter N and P contents) and plant mechanical aspects (LDMC: leaf dry matter content). G. marginata performances were correlated with chemical deterrents (cellulose and lignin contents). Thus, (Q1) for grass litters, both traits indicating nutritive value (e.g. N, P) and feeding deterrents (e.g. LDMC, lignin content) are necessary to explain macroinvertebrates feeding performances. We also demonstrated the results depend on the invertebrate species considered. Also, (Q2) chemical deterrents may influence feeding performances of G. marginata the most, while physical deterrents related to mechanical aspects may influence those of A. vulgare the most. Our study shows that using grass chemical and physical traits that indicate both nutritive value and feeding deterrents can help explain feeding performances of macrodetritivores

    Lipopolysaccharide-induced apoptosis of macrophages determines the up-regulation of concentrative nucleoside transporters Cnt1 and Cnt2 through tumor necrosis factor-alpha-dependent and -independent mechanisms

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    In murine bone marrow macrophages, lipopolysaccharide (LPS) induces apoptosis through the autocrine production of tumor necrosis factor-alpha (TNF-alpha), as demonstrated by the fact that macrophages from TNF-alpha receptor I knock-out mice did not undergo early apoptosis. In these conditions LPS up-regulated the two concentrative high affinity nucleoside transporters here shown to be expressed in murine bone marrow macrophages, concentrative nucleoside transporter (CNT) 1 and 2, in a rapid manner that is nevertheless consistent with the de novo synthesis of carrier proteins. This effect was not dependent on the presence of macrophage colony-stimulating factor, although LPS blocked the macrophage colony-stimulating factor-mediated up-regulation of the equilibrative nucleoside transport system es. TNF-alpha mimicked the regulatory response of nucleoside transporters triggered by LPS, but macrophages isolated from TNF-alpha receptor I knock-out mice similarly up-regulated nucleoside transport after LPS treatment. Although NO is produced by macrophages after LPS treatment, NO is not involved in these regulatory responses because LPS up-regulated CNT1 and CNT2 transport activity and expression in macrophages from inducible nitric oxide synthase and cationic amino acid transporter (CAT) 2 knock-out mice, both of which lack inducible nitric oxide synthesis. These data indicate that the early proapoptotic responses of macrophages, involving the up-regulation of CNT transporters, follow redundant regulatory pathways in which TNF-alpha-dependent- and -independent mechanisms are involved. These observations also support a role for CNT transporters in determining extracellular nucleoside availability and modulating macrophage apoptosis

    The LDBC Social Network Benchmark

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    The Linked Data Benchmark Council's Social Network Benchmark (LDBC SNB) is an effort intended to test various functionalities of systems used for graph-like data management. For this, LDBC SNB uses the recognizable scenario of operating a social network, characterized by its graph-shaped data. LDBC SNB consists of two workloads that focus on different functionalities: the Interactive workload (interactive transactional queries) and the Business Intelligence workload (analytical queries). This document contains the definition of the Interactive Workload and the first draft of the Business Intelligence Workload. This includes a detailed explanation of the data used in the LDBC SNB benchmark, a detailed description for all queries, and instructions on how to generate the data and run the benchmark with the provided software.Comment: For the repository containing the source code of this technical report, see https://github.com/ldbc/ldbc_snb_doc

    Accelerated surgery versus standard care in hip fracture (HIP ATTACK): an international, randomised, controlled trial

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    The James Webb Space Telescope Mission

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    Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least 4m4m. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the 6.5m6.5m James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

    Soil macrofauna communities in Brazilian land-use systems

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    Soil animal communities include more than 40 higher-order taxa, representing over 23% of all described species. These animals have a wide range of feeding sources and contribute to several important soil functions and ecosystem services. Although many studies have assessed macroinvertebrate communities in Brazil, few of them have been published in journals and even fewer have made the data openly available for consultation and further use. As part of ongoing efforts to synthesise the global soil macrofauna communities and to increase the amount of openly-accessible data in GBIF and other repositories related to soil biodiversity, the present paper provides links to 29 soil macroinvertebrate datasets covering 42 soil fauna taxa, collected in various land-use systems in Brazil. A total of 83,085 georeferenced occurrences of these taxa are presented, based on quantitative estimates performed using a standardised sampling method commonly adopted worldwide to collect soil macrofauna populations, i.e. the TSBF (Tropical Soil Biology and Fertility Programme) protocol. This consists of digging soil monoliths of 25 x 25 cm area, with handsorting of the macroinvertebrates visible to the naked eye from the surface litter and from within the soil, typically in the upper 0-20 cm layer (but sometimes shallower, i.e. top 0-10 cm or deeper to 0-40 cm, depending on the site). The land-use systems included anthropogenic sites managed with agricultural systems (e.g. pastures, annual and perennial crops, agroforestry), as well as planted forests and native vegetation located mostly in the southern Brazilian State of ParanĂĄ (96 sites), with a few additional sites in the neighbouring states of SĂŁo Paulo (21 sites) and Santa Catarina (five sites). Important metadata on soil properties, particularly soil chemical parameters (mainly pH, C, P, Ca, K, Mg, Al contents, exchangeable acidity, Cation Exchange Capacity, Base Saturation and, infrequently, total N), particle size distribution (mainly % sand, silt and clay) and, infrequently, soil moisture and bulk density, as well as on human management practices (land use and vegetation cover) are provided. These data will be particularly useful for those interested in estimating land-use change impacts on soil biodiversity and its implications for below-ground foodwebs, ecosystem functioning and ecosystem service delivery.Quantitative estimates are provided for 42 soil animal taxa, for two biodiversity hotspots: the Brazilian Atlantic Forest and Cerrado biomes. Data are provided at the individual monolith level, representing sampling events ranging from February 2001 up to September 2016 in 122 sampling sites and over 1800 samples, for a total of 83,085 ocurrences

    Contribution de la faune du sol au fonctionnement et Ă  l'Ă©volution des Technosols

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    Technosols are soils whose properties and pedogenesis are influenced by technical materials which take part in their constitution. The experimental model used here is a constructed Technosol which is deliberately composed of technical materials in a soil profile. The scientific objective is to evaluate the contribution of soil fauna to processes implied in soil functioning and evolution. Experiments in laboratory (cosms) and in climatic conditions (lysimeters, field) are conducted from ultrastructural scale to soil profile scale. Results indicate that (i) constructed Technosol can support soil fauna, (ii) the model of ecosystem engineer: Lumbricus terrestris, by macroporosity and by stables biogenic structures, contribute to the structuration, the aggregation and the decomposition of organic matter of the Technosol, (iii) when several groups of organisms implied in differents soil functions are used, effects are observed on organic matter decomposition. The huge availability of resources in the Technosol allow the presence of soil fauna but its effects and reduce soil fauna interactions which can have effects on soil functioning. A model whose objective is to evaluate effect of Lumbricus terrestris on macroporosity is proposed. In terms of soil engineering, a project of decision support model results of scientific experiences. Soil fauna inoculation in soil engineering could contribute to initiate and accelerate mechanisms of Technosol evolutionLes Technosols ont des propriétés et une pédogenÚse influencées par des matériaux technogéniques qui les constituent. Le modÚle expérimental de Technosol construit a été choisi et résulte de l'utilisation délibérée de matériaux technogéniques au sein d'un profil. L'objectif scientifique est d'évaluer la contribution de la faune du sol aux processus impliqués dans le fonctionnement et l'évolution des Technosols. Des expérimentations en laboratoire (cosmes) et en conditions climatiques réelles (lysimÚtres, parcelles) ont été menées de l'échelle ultrastructurale à celle du pédon. Les résultats indiquent que (i) le Technosol construit est un support de vie de la faune, (ii) le modÚle d'ingénieur de l'écosystÚme : Lumbricus terrestris, par la création de macroporosité et par ses structures biogéniques contribue à sa structuration, son agrégation et à la décomposition de sa matiÚre organique, (iii) lorsque plusieurs groupes d'organismes assurant des fonctions différentes sont associés, des effets sont mesurés majoritairement sur la décomposition de la matiÚre organique. La forte disponibilité des ressources du Technosol autorise la présence de la faune mais masquent en partie ses effets et inhibent les interactions faunistiques qui auront un effet sur les fonctions des sols. Un modÚle d'évaluation de l'effet de Lumbricus terrestris sur la macroporosité est proposé. En termes de génie pédologique, un projet de modÚle d'aide à la décision résulte des acquis scientifiques. L'inoculation de la faune contribuerait ainsi à initier des mécanismes d'évolution des sols et à les accélére

    Contribution of soil fauna to the functioning and the evolution of Technosols

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    Les Technosols ont des propriĂ©tĂ©s et une pĂ©dogenĂšse influencĂ©es par des matĂ©riaux technogĂ©niques qui les constituent. Le modĂšle expĂ©rimental de Technosol construit a Ă©tĂ© choisi et rĂ©sulte de l’utilisation dĂ©libĂ©rĂ©e de matĂ©riaux technogĂ©niques au sein d’un profil. L’objectif scientifique est d’évaluer la contribution de la faune du sol aux processus impliquĂ©s dans le fonctionnement et l’évolution des Technosols. Des expĂ©rimentations en laboratoire (cosmes) et en conditions climatiques rĂ©elles (lysimĂštres, parcelles) ont Ă©tĂ© menĂ©es de l’échelle ultrastructurale Ă  celle du pĂ©don. Les rĂ©sultats indiquent que (i) le Technosol construit est un support de vie de la faune, (ii) le modĂšle d’ingĂ©nieur de l’écosystĂšme : Lumbricus terrestris, par la crĂ©ation de macroporositĂ© et par ses structures biogĂ©niques contribue Ă  sa structuration, son agrĂ©gation et Ă  la dĂ©composition de sa matiĂšre organique, (iii) lorsque plusieurs groupes d’organismes assurant des fonctions diffĂ©rentes sont associĂ©s, des effets sont mesurĂ©s majoritairement sur la dĂ©composition de la matiĂšre organique. La forte disponibilitĂ© des ressources du Technosol autorise la prĂ©sence de la faune mais masquent en partie ses effets et inhibent les interactions faunistiques qui auront un effet sur les fonctions des sols. Un modĂšle d’évaluation de l’effet de Lumbricus terrestris sur la macroporositĂ© est proposĂ©. En termes de gĂ©nie pĂ©dologique, un projet de modĂšle d’aide Ă  la dĂ©cision rĂ©sulte des acquis scientifiques. L’inoculation de la faune contribuerait ainsi Ă  initier des mĂ©canismes d’évolution des sols et Ă  les accĂ©lĂ©rerTechnosols are soils whose properties and pedogenesis are influenced by technical materials which take part in their constitution. The experimental model used here is a constructed Technosol which is deliberately composed of technical materials in a soil profile. The scientific objective is to evaluate the contribution of soil fauna to processes implied in soil functioning and evolution. Experiments in laboratory (cosms) and in climatic conditions (lysimeters, field) are conducted from ultrastructural scale to soil profile scale. Results indicate that (i) constructed Technosol can support soil fauna, (ii) the model of ecosystem engineer: Lumbricus terrestris, by macroporosity and by stables biogenic structures, contribute to the structuration, the aggregation and the decomposition of organic matter of the Technosol, (iii) when several groups of organisms implied in differents soil functions are used, effects are observed on organic matter decomposition. The huge availability of resources in the Technosol allow the presence of soil fauna but its effects and reduce soil fauna interactions which can have effects on soil functioning. A model whose objective is to evaluate effect of Lumbricus terrestris on macroporosity is proposed. In terms of soil engineering, a project of decision support model results of scientific experiences. Soil fauna inoculation in soil engineering could contribute to initiate and accelerate mechanisms of Technosol evolutio
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