1,479 research outputs found

    Linking genebanks and farmers to urban high-value markets - The case of chili peppers in Peru and Bolivia [Poster]

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    Poster presented at Tropentag Conference. Stuttgart-Hohenheim (Germany), 17-19 Sep 201

    A holistic approach to enhance the use of neglected and underutilized species: the case of Andean grains in Bolivia and Peru

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    The IFAD-NUS project, implemented over the course of a decade in two phases, represents the first UN-supported global effort on neglected and underutilized species (NUS). This initiative, deployed and tested a holistic and innovative value chain framework using multi-stakeholder, participatory, inter-disciplinary, pro-poor gender- and nutrition-sensitive approaches. The project has been linking aspects often dealt with separately by R&D, such as genetic diversity, selection, cultivation, harvest, value addition, marketing, and final use, with the goal to contribute to conservation, better incomes, and improved nutrition and strengthened livelihood resilience. The project contributed to the greater conservation of Andean grains and their associated indigenous knowledge, through promoting wider use of their diversity by value chain actors, adoption of best cultivation practices, development of improved varieties, dissemination of high quality seed, and capacity development. Reduced drudgery in harvest and postharvest operations, and increased food safety were achieved through technological innovations. Development of innovative food products and inclusion of Andean grains in school meal programs is projected to have had a positive nutrition outcome for targeted communities. Increased income was recorded for all value chain actors, along with strengthened networking skills and self-reliance in marketing. The holistic approach taken in this study is advocated as an effective strategy to enhance the use of other neglected and underutilized species for conservation and livelihood benefits

    Magnetic Properties of a Pressure-induced Superconductor UGe2_2

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    We performed the DC-magnetization and neutron scattering experiments under pressure {\it P} for a pressure-induced superconductor UGe2_2. We found that the magnetic moment is enhanced at a characteristic temperature {\it T}∗^{*} in the ferromagnetic state, where {\it T}∗^{*} is smaller than a Curie temperature {\it T}C_{\rm C}. This enhancement becomes remarkable in the vicinity of {\it P}C∗_{\rm C}^{*} = 1.20 GPa, where {\it T}∗^{*} becomes 0 K and the superconducting transition temperature {\it T}SC_{\rm SC} shows a maximum. The characteristic temperature {\it T}∗^{*}, which decreases with increasing pressure, also depends on the magnetic field.Comment: To be published in J.Phys.Soc.Jp

    Pressure-induced Superconductivity in a Ferromagnet UGe2_2 -- Resistivity Measurements in Magnetic Field --

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    The electrical resistivity measurements in the magnetic field are carried out on the pressure-induced superconductor UGe2_2. The superconductivity is observed from 1.06 to 1.44 GPa. The upper critical field of HC2H_{C2} is anisotropic where HC2(T)H_{C2}(T) exhibits positive curvature for H//bH//b and cc-axis. The characteristic enhancement of HC2H_{C2} is reconfirmed for H//aH//a-axis. In the temperature and field dependence of resistivity at P>PCP > P_{C} where the ferromagnetic ordering disappears, it is observed that the application of the external field along the {\it a}-axis increases the coefficient of Fermi liquid behavior AT2AT^{2} correspondingly to the metamagnetic transition.Comment: To be published in the proceeding of the International Conference on High Pressure Science and Technology(AIRAPT-18),Beijing,China,23-27 July 200

    BDNF promotes target innervation of Xenopus mandibular trigeminal axons in vivo

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    <p>Abstract</p> <p>Background</p> <p>Trigeminal nerves consist of ophthalmic, maxillary, and mandibular branches that project to distinct regions of the facial epidermis. In <it>Xenopus </it>embryos, the mandibular branch of the trigeminal nerve extends toward and innervates the cement gland in the anterior facial epithelium. The cement gland has previously been proposed to provide a short-range chemoattractive signal to promote target innervation by mandibular trigeminal axons. Brain derived neurotrophic factor, BDNF is known to stimulate axon outgrowth and branching. The goal of this study is to determine whether BDNF functions as the proposed target recognition signal in the <it>Xenopus </it>cement gland.</p> <p>Results</p> <p>We found that the cement gland is enriched in BDNF mRNA transcripts compared to the other neurotrophins NT3 and NT4 during mandibular trigeminal nerve innervation. BDNF knockdown in <it>Xenopus </it>embryos or specifically in cement glands resulted in the failure of mandibular trigeminal axons to arborise or grow into the cement gland. BDNF expressed ectodermal grafts, when positioned in place of the cement gland, promoted local trigeminal axon arborisation <it>in vivo</it>.</p> <p>Conclusion</p> <p>BDNF is necessary locally to promote end stage target innervation of trigeminal axons <it>in vivo</it>, suggesting that BDNF functions as a short-range signal that stimulates mandibular trigeminal axon arborisation and growth into the cement gland.</p

    Critical properties and Bose Einstein Condensation in dimer spin systems

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    We analyze the spin relaxation time 1/T11/T_1 for a system made of weakly coupled one dimensional ladders.This system allows to probe the dimensional crossover between a Luttinger liquid and a Bose-Einstein condensateof magnons. We obtain the temperature dependence of 1/T11/T_1 in the various dimensional regimes, and discuss the experimental consequences.Comment: 4 pages, RevTeX 4, 3 EPS figure

    Multi-Triplet Magnons in SrCu2_2(BO3_3)2_2 Studied by Thermal Conductivity Measurements in Magnetic Fields

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    We have measured the thermal conductivity parallel to the a-axis of the Zn-free and 1% Zn-substituted SrCu2−x_{2-x}Znx_x(BO3_3)2_2 in magnetic fields up to 14 T, in order to examine the thermal conductivity due to the multi-triplet magnons. It has been found that the thermal conductivity peak observed in the spin gap state is suppressed by the substitution of Zn for Cu in high magnetic fields above 6 T, while it is not changed in low magnetic fields below 6 T. The results suggest that the thermal conductivity peak in the spin-gap state of SrCu2_2(BO3_3)2_2 is composed of not only thermal conductivity due to phonons but also that due to the multi-triplet magnons in high fields above 6 T.Comment: 7 pages, 2 figure

    Signatures of Planets in Spatially Unresolved Disks

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    Main sequence stars are commonly surrounded by debris disks, composed of cold dust continuously replenished by a reservoir of undetected dust-producing planetesimals. In a planetary system with a belt of planetesimals (like the Solar System's Kuiper Belt) and one or more interior giant planets, the trapping of dust particles in the mean motion resonances with the planets can create structure in the dust disk, as the particles accumulate at certain semimajor axes. Sufficiently massive planets may also scatter and eject dust particles out of a planetary system, creating a dust depleted region inside the orbit of the planet. In anticipation of future observations of spatially unresolved debris disks with the Spitzer Space Telescope, we are interested in studying how the structure carved by planets affects the shape of the disk's spectral energy distribution (SED), and consequently if the SED can be used to infer the presence of planets. We numerically calculate the equilibrium spatial density distributions and SEDs of dust disks originated by a belt of planetesimals in the presence of interior giant planets in different planetary configurations, and for a representative sample of chemical compositions. The dynamical models are necessary to estimate the enhancement of particles near the mean motion resonances with the planets, and to determine how many particles drift inside the planet's orbit. Based on the SEDs and predicted Spitzer\it{Spitzer} colors we discuss what types of planetary systems can be distinguishable from one another and the main parameter degeneracies in the model SEDs.Comment: 40 pages (pre-print form), including 16 figures. Published in ApJ 200

    Gridless optical networking field trial: flexible spectrum switching, defragmentation and transport of 10G/40G/100G/555G over 620-km field fiber

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    We report the first gridless networking field trial with flexible spectrum switching nodes over 620 km field fibre links. Successful transport, spectrum switching and defragmentation achieved for mixed line signals including 555G and coherent 100G

    Going with the ”Flow: Reinterpreting Energy Input in Organic Synthesis

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    The popularity of microflow chemistry has skyrocketed in the last 20 years, more and more chemists are switching from macro-batch reactors to miniaturized flow devices. As a result, microfluidics is paving its way into the future by consolidating its position in organic chemistry not only as a trend but as a new, effective, and sustainable way of conducting chemistry, that clearly will continue to grow and evolve. This perspective highlights the most relevant examples of innovative enhancing technologies applied to microflow reactors aimed to improve and intensify chemical processes. The extensive applicability of microflow chemistry is further illustrated by briefly discussing examples of complex integrated microsystems and scale-up technologies, demonstrating ultimately that microflow chemistry has the potential to become the ideal technology for the future
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