International Journal of Agricultural Research, Innovation and Technology (IJARIT)
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Stable isotope geochemistry of silicon in granitoid zircon
No full textCo-auteur étrangerInternational audienceZircon is often used to study granites (sensu lato) and continental crust because it is very resistant and can be analyzed for various isotope systems that provide time and source information about their parental melts. Granites with different petrological histories have distinct bulk-rock silicon isotope compositions but it is unclear if these differences are also detectable in zircon because of superimposed fractionation effects (e.g., related to temperature, silica content, magmatic processes). The present study explores the Si isotope signatures of zircon from various granite types to constrain their isotope fractionation behavior and uses Revised Manuscript-Clean Click here to view linked Reference
Igneous rock powder identification using colour cameras: A powerful method for space exploration
No full textInternational audiencePowdered rocks are commonly present at the surface of extraterrestrial bodies and are widely analysed by in situ space probes. Moreover, a number of rovers exploring the surface of Mars are equipped with drills enabling them to access unaltered material and collect samples. During drilling operations, a cone of powder made of the drilled materials forms at the surface. These powders will be particularly large during the ESA/Roscosmos ExoMars 2022 mission since the rover Rosalind Franklin will drill to 2 m depth below the Martian surface. These fines are generally observed by the rovers' cameras after the drilling process and analysed by a limited range of instruments. In order to maximise the scientific return of planetary missions to Mars and other bodies in the solar system, we propose to use the images taken by rover cameras to identify the composition of the powdered materials. This could be particularly useful during the ExoMars 2022 mission where the CLUPI camera will take pictures during drilling and could thus document changes in the regolith composition (Josset et al., 2017). In the absence of a controlled light source, we used an image processing method called CaliPhoto that we previously developed for generic purposes. To test the ability of the method to identify volcanic rocks, more than twenty Mars-analogue samples were crushed at various grain sizes and photographed. The images were then processed via the CaliPhoto method and used to construct a database of reference images. New images were then taken under different lighting conditions, processed using the same method, and compared to the database. We show that it is possible to estimate igneous rock powder lithology with greater than 90% accuracy considering the uncertainties. Furthermore, when using images of polished and powdered samples, identification reaches 100%. We also show that the method permits precise lithological identification of samples that are not in the initial database. Finally, we demonstrate that the proposed method is extremely efficient, while at the same time very easy to implement on any in situ space probe. It could thus be used to help in identifying powdered igneous rocks during future missions to Mars or other rocky body in the solar system
Altered Ca2+ Homeostasis in Red Blood Cells of Polycythemia Vera Patients Following Disturbed Organelle Sorting during Terminal Erythropoiesis
No full textInternational audienceOver 95% of Polycythemia Vera (PV) patients carry the V617F mutation in the tyrosine kinase Janus kinase 2 (JAK2), resulting in uncontrolled erythroid proliferation and a high risk of thrombosis. Using mass spectrometry, we analyzed the RBC membrane proteome and showed elevated levels of multiple Ca2+ binding proteins as well as endoplasmic-reticulum-residing proteins in PV RBC membranes compared with RBC membranes from healthy individuals. In this study, we investigated the impact of JAK2V617F on (1) calcium homeostasis and RBC ion channel activity and (2) protein expression and sorting during terminal erythroid differentiation. Our data from automated patch-clamp show modified calcium homeostasis in PV RBCs and cell lines expressing JAK2V617F, with a functional impact on the activity of the Gárdos channel that could contribute to cellular dehydration. We show that JAK2V617F could play a role in organelle retention during the enucleation step of erythroid differentiation, resulting in modified whole cell proteome in reticulocytes and RBCs in PV patients. Given the central role that calcium plays in the regulation of signaling pathways, our study opens new perspectives to exploring the relationship between JAK2V617F, calcium homeostasis, and cellular abnormalities in myeloproliferative neoplasms, including cellular interactions in the bloodstream in relation to thrombotic events
Bridging theory and practice in ecosystem services mapping: a systematic review
No full textInternational audienceThe mapping and assessment of Ecosystem Services (ES) aims at better connecting environmental conservation, economic development, and human well-being. However, 60 years after the development of the ES concept, a persistent gap remains between the production of scientific knowledge on ES and its use in support of policy and management. Here, we report on a systematic review of the scientific literature that helps better understand key challenges and offers potential solutions to bridge this gap. The review considered four criteria: (1) how stakeholders participate to studies; (2) how usable ES maps are for decision-making; (3) what policy recommendations were made; and (4) what research recommendations were made. The analysis of 135 papers published between 2008 and 2020 revealed diverse technical and conceptual challenges that could prevent the effective use of ES concepts and methods outside the academic realm. The main challenges identified in the literature were the uncertainty levels of ES mapping outputs, issues of spatial scales, the understanding of ES interactions, and the need for temporal analysis. Many policies rely on mapped outcomes, creating a window of opportunity for the uptake of ES mapping into policy-making. However, it remains key to involve stakeholders early in the co-design of ES studies and to better understand their preferences and motivation to adopt ES mapping in their practices. The study shows that higher levels of learnability of ES mapping practices, further popularization to foster public awareness, and increased capacity building would facilitate the ES concept uptake into decision and policy-making
BMFPs, a versatile therapeutic tool for redirecting a preexisting Epstein-Barr virus antibody response toward defined target cells
No full textInternational audienceIndustrial production of therapeutic monoclonal antibodies is mostly performed in eukaryotic-based systems, allowing posttranslational modifications mandatory for their functional activity. The resulting elevated product cost limits therapy access to some patients. To address this limitation, we conceptualized a novel immunotherapeutic approach to redirect a preexisting polyclonal antibody response against Epstein-Barr virus (EBV) toward defined target cells. We engineered and expressed in bacteria bimodular fusion proteins (BMFPs) comprising an Fc-deficient binding moiety targeting an antigen expressed at the surface of a target cell, fused to the EBV-P18 antigen, which recruits circulating endogenous anti-P18 IgG in EBV + individuals. Opsonization of BMFP-coated targets efficiently triggered antibody-mediated clearing effector mechanisms. When assessed in a P18-primed mouse tumor model, therapy performed with an anti-huCD20 BMFP significantly led to increased survival and total cancer remission in some animals. These results indicate that BMFPs could represent potent and useful therapeutic molecules to treat a number of diseases
Nutrient Flows and Balances in Mixed Farming Systems in Madagascar
No full textInternational audienceMixed farming systems are still prevalent in sub-Saharan Africa. In these systems, the recycling of nutrients through crop-livestock integration (CLI) practices is crucial for the sustainability of soil fertility and crop production. The objective of this study was to analyze nutrient (N, P, K) flows and balances of mixed farming systems to assess CLI contribution to the performance of those systems. We hypothesized that more intensive farms had a better nutrient balance at the farm level, and that improved biomass management methods improved their nutrient balance. Nine farms in the Madagascar highlands were selected, some corresponding to poor traditional farms with only draft cattle; some small or medium-sized, more intensive farms with a dairy herd; and some of the latter with some improvement to management methods of livestock effluents (manure composting, liquid manure collection). The nutrient balance of the farming systems was determined, and performance indicators were calculated at both farming, livestock, and CLI levels. Results showed that nutrient recycling through CLI is significant in the functioning of the systems studied, contributing primarily to circulating nutrient flows (up to 76%) and leading to greater efficiency and productivity. Nutrient flows resulting from these practices mainly concerned animal feeding (higher than 60% of nutrient flows), even if manure management was central for crop fertilization and that manure remained a desired animal product of these types of farms (up to 100% of animal products). Large negative balances of N and K (up to 80% of inputs) were observed in traditional livestock systems with draft cattle. They were smaller (39–68%) in more intensive dairy farms. Composting of manure did not decrease negative balances, whereas their magnitude was significantly reduced by the collection of liquid manure (19% for N; 42% for K). Better management of biomass at the farm level, in particular the collection of liquid manure, seemed to substantially reduce nutrient losses in MFS
Reappraisal of gap analysis for effusive crises at Piton de la Fournaise
No full textInternational audienceEffective and rapid effusive crisis response is necessary to mitigate the risks associated with lava flows that could threaten or inundate inhabited or visited areas. At Piton de la Fournaise (La Réunion, France), well-established protocols between Observatoire Volcanologique du Piton de la Fournaise – Institut de Physique du Globe de Paris (OVPF-IPGP) and civil protection, and between scientists of a multinational array of institutes, allow effective tracking of eruptive crises and hazard management embracing all stakeholders. To assess the outstanding needs for such responses Tsang and Lindsay (J Appl Volcanol 9:9, 2020) applied a gap analysis to assess research gaps in terms of preparedness, response and recovery at 11 effusive centers, including Piton de la Fournaise. For Piton de la Fournaise, their gap analysis implied widespread gaps in the state of knowledge. However, their work relied on incomplete and erroneous data and methods, resulting in a gap analysis that significantly underrepresented this state of knowledge. We thus here re-build a correct database for Piton de la Fournaise, properly define the scope of an appropriate gap analysis, and provide a robust gap analysis, finding that there are, actually, very few gaps for Piton de la Fournaise. This is a result of the existence of a great quantity of published work in the peer-reviewed literature, as well as frequent reports documenting event impact in the local press and observatory reports. At Piton de la Fournaise, this latter (observatory-based) resource is largely due to the efforts of OVPF-IPGP who have a wealth of experience having responded to 81 eruptions since its creation in 1979 through the end of September 2021
Shallow magma convection evidenced by excess degassing and thermal radiation during the dome-forming Sabancaya eruption (2012–2020)
No full textInternational audienceWe used a large set of satellite-(visible, infrared, and radar images from Planetscope, MODIS, VIIRS, Sentinel2, Landsat 8, and Sentinel 1) and ground-based data (optical images, SO 2 flux, shallow seismicity) to describe and characterize the activity of the Sabancaya volcano during the unrest and eruption phases that occurred between 2012 and 2020. The unrest phase (2012-2016) was characterized by increasing gas and thermal flux, sourced by a convective magma column rising along with the remnants of a buried plug still permeable to fluid flow. Conversely, a new conduit, adjacent to the previous one, fed the eruptive phase (2016-2020) which was instead characterized by a discontinuous extrusive activity, with phases of dome growth (at rates from 0.04 to 0.75 m 3 s −1) and collapse. The extrusive activity was accompanied by fluctuating thermal anomalies (0.5-25 MW), by irregular SO 2 degassing (700-7000 tons day −1), and by variable explosive activity (4-100 events d −1) producing repeated vulcanian ash plumes (500-5000 m above the crater). Magma budget calculation during the eruptive phase indicates a large excess of degassing, with the volume of degassed magma (0.25-1.28 km 3) much higher than the volume of erupted magma (< 0.01 km 3). Similarly, the thermal energy radiated by the eruption was much higher than that sourced by the dome itself, an unbalance that, by analogy with the degassing, we define as "excess thermal radiation". Both of these unbalances are consistent with the presence of shallow magma convection that fed the extrusive and explosive activity of the Sabancaya dome
Mathematical modelling of a pest in an age-structured crop model: The coffee berry borer case
No full textInternational audienceCoffee production is an important agriculture activity which contributes significantly to the economic growth of many countries in the world. One of the major constraints to coffee production throughout the world is the damage caused by the coffee berry borer (CBB), Hypothenemus hampei (Coleoptera: Scolytidae). It is the most damaging insect pest to coffee production in the world. These insects infest coffee berries, preferably mature berries, and spend most of their life cycle inside the berries, which make them quite difficult to control. In this work, we introduce and analyse a berry age-structured model describing the infestation dynamics of coffee berries by CBB. Using the semigroup theory in the case of Lipschitz perturbation, we show that the model has a unique nonnegative and bounded solution. We derive an explicit formula of the basic reproduction number, R0, using the next generation approach and the biological interpretation of this threshold in a specific case. Numerical simulations are carried out to illustrate the theoretical results
The Zero Effect of Income Tax on the Timing of Birth: Some Evidence on French Data
No full textInternational audienceThe present paper investigates the correlation between the French tax rebate triggered by the birth of a child and the probability to bring forward childbirth from late December to early January. Using administrative tax data from 2010 to 2016, I precisely simulate the corresponding tax rebate for households in which a child was born from December 24 to January 7. Contrary to prior research, I do not find clear evidence of a significant link between the tax rebate brought about by a supplementary dependent child on the tax return and the probability of a late December birth. Either the amount of the incentive may not be large enough or households may not correctly anticipate the corresponding tax rebate. Nevertheless, a small learning effect is present. According to my results, a significant correlation between the tax rebate and the probability of having a child in December is observed among the wealthiest half of households with at least two children already claimed that also benefit from a relatively large tax rebate. However, this seems to be due to a spurious correlation. Instead, the results could reflect the willingness of parents to avoid childbirth on a public holiday