577 research outputs found

    Permutrees

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    We introduce permutrees, a unified model for permutations, binary trees, Cambrian trees and binary sequences. On the combinatorial side, we study the rotation lattices on permutrees and their lattice homomorphisms, unifying the weak order, Tamari, Cambrian and boolean lattices and the classical maps between them. On the geometric side, we provide both the vertex and facet descriptions of a polytope realizing the rotation lattice, specializing to the permutahedron, the associahedra, and certain graphical zonotopes. On the algebraic side, we construct a Hopf algebra on permutrees containing the known Hopf algebraic structures on permutations, binary trees, Cambrian trees, and binary sequences.Comment: 43 pages, 25 figures; Version 2: minor correction

    Happiness on Tap: Piped Water Adoption in Urban Morocco

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    We study the demand for household water connections in urban Morocco, and the effect of such connections on household welfare. In the northern city of Tangiers, among homeowners without a private connection to the city’s water grid, a random subset was offered a simplified procedure to purchase a household connection on credit (at a zero percent interest rate). Take-up was high, at 69%. Because all households in our sample had access to the water grid through free public taps (often located fairly close to their homes), household connections did not lead to any improvement in the quality of the water households consumed; and despite significant increase in the quantity of water consumed, we find no change in the incidence of waterborne illnesses. Nevertheless, we find that households are willing to pay a substantial amount of money to have a private tap at home. Being connected generates important time gains, which are used for leisure and social activities, rather than productive activities. Because water is often a source of tension between households, household connections improve social integration and reduce conflict. Overall, within 6 months, self-reported well-being improved substantially among households in the treatment group, despite the financial cost of the connection. Our results suggest that facilitating access to credit for households to finance lump sum quality-of-life investments can significantly increase welfare, even if those investments do not result in income or health gains.

    New Therapeutic Avenues of mCSF for Brain Diseases and Injuries

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    Macrophage colony-stimulating factor (mCSF) is a cytokine known to promote the recruitment of macrophages inducing the release of CCL2, a chemokine mobilizing monocytes to sites of inflammation. Additionally, it induces microglia/macrophage proliferation and the polarization of these cells towards a M2-like phenotype, impairing their ability to release pro-inflammatory factors and toxic mediators, while favoring the release of mediators promoting tissue repair. Another important player is the mCSF receptor CSFR1, which is highly expressed in monocytes, macrophages and microglia. Here, we discuss the new interesting therapeutic avenue of the mCSF/CSFR1 axis on brain diseases. More specifically, mCSF cascade might stimulate the survival/proliferation of oligodendrocytes, enhance the immune response as well as modulate the release of growth factors and the phagocytic activity of immune cells to remove myelin debris and toxic proteins from the brain

    Gender Differences in COVID-19 Related Attitudes and Behavior: Evidence from a Panel Survey in Eight OECD Countries

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    Using original data from two waves of a survey conducted in March and April 2020 in eight OECD countries (N = 21,649), we show that women are more likely to see COVID-19 as a very serious health problem, to agree with restraining public policy measures adopted in response to it, and to comply with them. Gender differences in attitudes and behavior are substantial in all countries, robust to controlling for a large set of sociodemographic, employment, psychological, and behavioral factors, and only partially mitigated for individuals who cohabit or have direct exposure to COVID-19. The results are not driven by differential social desirability bias. They carry important implications for the spread of the pandemic and may contribute to explain gender differences in vulnerability to it

    Experimental and Numerical Study of the Influence of String Mismatch on the Yield of PV Modules Augmented By Static Planar Reflectors

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    International audiencePhotovoltaic (PV) modules are generally installed by the application of empirical rules aimed at reducing shadows during the periods of high solar irradiation. A traditional installation on a horizontal surface results in largely spaced rows of modules with a relatively low tilt angle. The addition of inter-row reflectors results in more direct and diffuse flux transmitted to the cells. The " Aleph " (Amélioration de l'Efficacité Photovoltašque) project aims to define clear rules for optimal settings of systems of PV module rows with fixed inter-row planar reflectors in a given location and under a given climate. Two PV technologies are tested for performance with this type of system: amorphous silicon (a-Si) and polycrystalline silicon (p-Si). This work combines experiments on panel behavior in an outdoor environment on the SIRTA (Site Instrumental de Recherche par Télédétection Atmosphérique) meteorology platform and a multiphysics numerical model used to couple all the important physical phenomena and accurately describe the system behavior. The model includes a ray tracing radiation/optics module based on the Monte-Carlo method, as well as an electrical module simulated in SPICE. This work presents the influence of the string mismatch losses, present at periods of heterogeneous illumination, on the yield of PV modules augmented by static planar reflectors

    RĂ©gionales 2015 : une projection du 1er tour au niveau des communes

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    Comment apprĂ©cier la situation Ă©lectorale de la France Ă  quelques jours du premier tour des Ă©lections rĂ©gionales 2015 ? Nombreuses sont les enquĂȘtes d’opinion ayant annoncĂ© des intentions de vote national ou par rĂ©gion. En revanche, ces sondages ne permettent pas d’y voir plus clair sur la gĂ©ographie Ă©lectorale au soir du dimanche 6 dĂ©cembre 2015. C’est Ă  cet exercice de projections que Martial Foucault et Vincent Pons ont rĂ©pondu par une mĂ©thode originale de correspondance entre les rĂ©sultats de la premiĂšre vague de l’EnquĂȘte Ă©lectorale française du CEVIPOF auprĂšs de 24 200 Français et les caractĂ©ristiques sociodĂ©mographiques (genre, Ăąge et catĂ©gories socio-professionnelles) des communes françaises

    Happiness on Tap: Piped Water Adoption in Urban Morocco

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    We study the demand for household water connections in urban Morocco, and the effect of such connections on household welfare. In the northern city of Tangiers, among homeowners without a private connection to the city’s water grid, a random subset was offered a simplified procedure to purchase a household connection on credit (at a zero percent interest rate). Take-up was high, at 69%. Because all households in our sample had access to the water grid through free public taps (often located fairly close to their homes), household connections did not lead to any improvement in the quality of the water households consumed; and despite significant increase in the quantity of water consumed, we find no change in the incidence of waterborne illnesses. Nevertheless, we find that households are willing to pay a substantial amount of money to have a private tap at home. Being connected generates important time gains, which are used for leisure and social activities, rather than productive activities. Because water is often a source of tension between households, household connections improve social integration and reduce conflict. Overall, within 6 months, self-reported well-being improved substantially among households in the treatment group, despite the financial cost of the connection. Our results suggest that facilitating access to credit for households to finance lump sum quality-of-life investments can significantly increase welfare, even if those investments do not result in income or health gains

    Permutree sorting

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    LIF Mediates Proinvasive Activation of Stromal Fibroblasts in Cancer

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    SummarySignaling crosstalk between tumor cells and fibroblasts confers proinvasive properties to the tumor microenvironment. Here, we identify leukemia inhibitory factor (LIF) as a tumor promoter that mediates proinvasive activation of stromal fibroblasts independent of alpha-smooth muscle actin (α-SMA) expression. We demonstrate that a pulse of transforming growth factor ÎČ (TGF-ÎČ) establishes stable proinvasive fibroblast activation by inducing LIF production in both fibroblasts and tumor cells. In fibroblasts, LIF mediates TGF-ÎČ-dependent actomyosin contractility and extracellular matrix remodeling, which results in collective carcinoma cell invasion in vitro and in vivo. Accordingly, carcinomas from multiple origins and melanomas display strong LIF upregulation, which correlates with dense collagen fiber organization, cancer cell collective invasion, and poor clinical outcome. Blockade of JAK activity by Ruxolitinib (JAK inhibitor) counteracts fibroblast-dependent carcinoma cell invasion in vitro and in vivo. These findings establish LIF as a proinvasive fibroblast producer independent of α-SMA and may open novel therapeutic perspectives for patients with aggressive primary tumors
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