6,177 research outputs found

    Reducing risks and seizing opportunities: integrating biodiversity into food and agriculture investments

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    This booklet explains how using the Agrobiodiversity Index, companies and governments can reduce operational and reputational risks and seize opportunities, by estimating and monitoring the agrobiodiversity impact of supply chain investments. The Agrobiodiversity Index can also help investors to screen their portfolios for companies and governments that promote agrobiodiversity, as a proxy for operational and reputational risks related to climate change and unsustainable production

    Le spectromètre de masse à temps de vol DEPIL et son utilisation pour la mesure de masses de protéines élevées dépassant 5 000 u : insuline et lyzozyme

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    Un spectromètre de masse à temps de vol a été construit à l'Institut de Physique Nucléaire d'Orsay pour mesurer des masses de molécules diverses. La gamme de masses accessibles est comprise entre 1 et 20 000 u. Nous présentons ici une description succincte de l'appareillage avec des exemples de mesures de hautes masses

    All CVD Boron Nitride Encapsulated Graphene FETs with CMOS Compatible Metal Edge Contacts

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    We report on the fabrication and characterization of field effect transistors (FETs) based on chemical vapor deposited (CVD) graphene encapsulated between few layer CVD boron nitride (BN) sheets with complementary metal oxide semiconductor (CMOS) compatible nickel edge contacts. Non-contact Tera-hertz time domain spectroscopy (THz-TDS) of large-area BN/graphene/BN (BN/G/BN) stacks reveals average sheet conductivity >1 mS/sq and average mobility of 2500 cm2^{2}/Vs. Improved output conductance is observed in direct current (DC) measurements under ambient conditions, indicating potential for radio-frequency (RF) applications. Moreover, we report a maximum voltage gain of 6 dB from a low frequency signal amplifier circuit. RF characterization of the GFETs yields an fT_{T} x Lg_{g} product of 2.64 GHzÎĽ\mum and an fMax_{Max} x Lg_{g} product of 5.88 GHzÎĽ\mum. This study presents for the first time THz-TDS usage in combination with other characterization methods for device performance assessment on BN/G/BN stacks. The results serve as a step towards scalable, all CVD 2D material-based FETs for CMOS compatible future nanoelectronic circuit architectures.Comment: 6 page

    Paleoenvironmental and ecological changes during the Eocene-Oligocene transition based on foraminifera from the Cap Bon Peninsula in North East Tunisia

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    Biostratigraphic analysis of the Eocene-Oligocene transition (E-O) at the Menzel Bou Zelfa and Jhaff composite section in the Cap Bon Peninsula (North East Tunisia) allowed us to recognize a continuous planktic foraminiferal biozonation: E14 Globigerinatheka semiinvoluta Zone, E15 Globigerinatheka index Zone, E16 Hantkenina alabamensis Zone and O1 Pseudohastigerina naguewichiensis Zone. A quantitative study of benthic and planktic foraminifera assemblages was carried out and the richness and diversity of foraminifera allowed us to reconstruct the paleoenvironmental evolution from marine to terrestrial environments. From the Eocene E14 Zone, the foraminiferal association characterizes a relatively warm climate with considerable oxygen content and a dominance of keeled and spinose planktic foraminifera, which became extinct at the E/O boundary, possibly due to cooling of the planktic environment. Nevertheless, the small benthic foraminifera do not show an extinction event at the Eocene/Oligocene (E/O) boundary, indicating that the benthic environment was not significantly affected. In the basal Oligocene O1 Zone, the benthic environment changes to a shallower setting due to cooling of the climate. These changes generated a remarkable dominance of globular forms in the planktic environment. Small benthic foraminifera apparently have a gradual extinction event, or more likely a gradual pattern of local disappearances, that could have been caused by the Oi1 glaciation

    Brazil, Ethiopia, and New Zealand lead the way on climate-smart agriculture.

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    As countries around the world face urgent agricultural challenges, the concept of ?climate-smart? agriculture (CSA) has been put forward to achieve climate change adaptation, mitigation, and food security synergistically. A new report explores how three countries are using integrated policy approaches to CSA and offers insights for how other countries can build CSA into their policy mix. Brazil has invested in research to support sustainable intensification while creating legal and enforcement mechanisms to protect forest areas as a response to unrestrained agricultural expansion driven by market demand. Ethiopia initiated innovative participatory watershed development programs, in partnership with numerous international institutions, which helped smallholder farmers to rehabilitate marginal land and break out of a poverty cycle. New Zealand has removed agricultural subsidies while partnering on research and development with the private sector as a way to ensure efficiency and resilience in an agricultural sector influenced by climate change and international trade dynamics. To assemble an integrated set of national policies that fosters CSA, governments will need context-specific assessments, strong multi-stakeholder institutions, coordination frameworks, and multi-scale information systems. Governments can select from an array of policy instruments ranging from regulatory mechanisms and economic incentives to public investments and educational campaigns. Many existing national policy goals and public programs designed to increase agricultural production, improve livelihoods, and reduce environmental risks can become important pillars of a national CSA strategy. Countries have obvious interests in fostering an agriculture sector that is climate-resilient, provides national needs for food, fiber, and fuel, and supports farm livelihoods. However, the incentives for national-level action toward reducing global greenhouse gas (GHG) levels are less clear in the absence of serious and shared international commitment. Integrated national CSA policies will be encouraged by clear, consistent signals from multilateral agencies, global donors, and international conventions and trade agreements that promote agriculture as a pathway for poverty reduction and food security

    Planktic foraminiferal biostratigraphy, paleoecology and chronostratigraphy across the Eocene/Oligocene boundary in northern Tunisia

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    The biostratigraphic analysis of the Eocene-Oligocene transition of the Menzel Bou Zelfa and Jhaff sections in northeastern Tunisia (Cap Bon peninsula) allows us to identify a continuous planktic foraminiferal biozonation. The following biozones were recognized: Globigerinatheka semiinvoluta Zone (E14), Globigerinatheka index Zone (E15), (Hantkenina alabamensis Zone (E16) of the upper Eocene and Pseudohastigerina naguewichiensis Zone (O1) of the lower Oligocene. A rapid mass extinction event in planktic foraminifera occurred at the Eocene-Oligocene transition, including the extinction of the turborotalids (Turborotalia cerroazulensis, Turborotalia cocoaensis and Turborotalia cunialensis) followed by a significant size reduction of the genus Pseudohastigerina and the extinction of the hantkeninids (Hantkenina alabamensis, Hantkenina brevispina, Hantkenina nanggulanensis and Cribrohantkenina lazzarii), which mark the Eocene/Oligocene boundary. These species were tropical and subtropical surface and intermediate dwellers, with distinctive morphologies (carinate turborotalids and spinose hantkeninids), which were well adapted species of k-strategy. The surviving planktic foraminifera species were quite similar in morphology with globular chambers (globigerinids) and small planispiral (pseudohastigerinids), which were opportunistic species of r-strategy. The recognition of a 4 m thick interval, between the extinction of turborotalids and hantkeninids, indicates that the section is continuous and one of the most expanded throughout the Eocene-Oligocene transition. This section could serve as an auxiliary section (hypostratotype) for the complete definition of the Global Stratotype Section and Point for the Eocene/Oligocene boundary, which mark the base of the Rupelian Stage

    A fast ILP-based Heuristic for the robust design of Body Wireless Sensor Networks

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    We consider the problem of optimally designing a body wireless sensor network, while taking into account the uncertainty of data generation of biosensors. Since the related min-max robustness Integer Linear Programming (ILP) problem can be difficult to solve even for state-of-the-art commercial optimization solvers, we propose an original heuristic for its solution. The heuristic combines deterministic and probabilistic variable fixing strategies, guided by the information coming from strengthened linear relaxations of the ILP robust model, and includes a very large neighborhood search for reparation and improvement of generated solutions, formulated as an ILP problem solved exactly. Computational tests on realistic instances show that our heuristic finds solutions of much higher quality than a state-of-the-art solver and than an effective benchmark heuristic.Comment: This is the authors' final version of the paper published in G. Squillero and K. Sim (Eds.): EvoApplications 2017, Part I, LNCS 10199, pp. 1-17, 2017. DOI: 10.1007/978-3-319-55849-3\_16. The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-55849-3_1

    INVESTIGATION OF THE TRANSMISSION AND STOPPING OF LIGHT IONS PASSING THROUGH A PLASMA TARGET

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    Transmission and energy losses of 2 MeV/u Carbon and Sulphur beams passing through a plasma target, have been extensively investigated. A hydrogen plasma ignited by an electrical discharge was coupled to the Orsay Tandem beam accelerator. Fluctuations in beam transmission have been observed and attributed to a magnetic focusing effect generated during the plasma evolution. Energy loss measurements were performed on the basis of time of flight techniques and indicate an enhanced stopping power of the plasma relative to its cold matter equivalent

    Study of ion emission from a germanium crystal surface under impact of fast Pb ions in channeling conditions

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    International audienceA thin germanium crystal has been irradiated at GANIL by Pb beams of 29 MeV/A (charge state Qin = 56 and 72) and of 5.6 MeV/A (Qin = 28). The induced ion emission from the sample entrance surface was studied, impact per impact, as a function of Qin, velocity vin and energy loss DE in the crystal. The Pb ions transmitted through the crystal were analyzed in charge (Qout) and energy using the SPEG spectrometer. The emitted ionized species were detected and analyzed in mass by a Time of Flight multianode detector (LAG). Channeling was used to select peculiar DE in Ge and hence peculiar Pb ion trajectories close to the emitting surface. The experiment was performed in standard vacuum. No Ge emission was found. The dominating emitted species are H+ and hydrocarbon ions originating from the contamination layer on top of the crystal. The mean value of the number of detected species per incoming Pb ion (multiplicity) varies as (Qin/vin)^p, with p values in agreement with previous results. We have clearly observed an influence of the energy deposition DE in Ge on the emission from the top contamination layer. When selecting increasing values of DE, we observed a rather slow increase of . On the contrary, the probabilities of high multiplicity values, that are essentially connected to fragmentation after emission, strongly increase with DE
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