1,234 research outputs found

    Investment cost channel and monetary transmission

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    We show that a standard DSGE model with investment cost channels has important model stability and policy implications. Our analysis suggests that in economies characterized by supply side well as demand side channels of monetary transmission, policymakers may have to resort to a much more aggressive stand against inflation to obtain locally unique equilibrium. In such an environment targeting output gap may cause model instability. We also show that it is difficult to distinguish between the New Keynesian model and labor cost channel only case, while with investment cost channel differences are more significant. This result is important as it suggests that if one does not take into account the investment cost channel, one is underestimating the importance of supply side effects

    Lending relationships and monetary policy

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    Financial intermediation and bank spreads are important elements in the analysis of business cycle transmission and monetary policy. We present a simple framework that introduces lending relationships, a relevant feature of financial intermediation that has been so far neglected in the monetary economics literature, into a dynamic stochastic general equilibrium model with staggered prices and cost channels. Our main findings are: (i) banking spreads move countercyclically generating amplified output responses, (ii) spread movements are important for monetary policy making even when a standard Taylor rule is employed (iii) modifying the policy rule to include a banking spread adjustment improves stabilization of shocks and increases welfare when compared to rules that only respond to output gap and inflation, and finally (iv) the presence of strong lending relationships in the banking sector can lead to indeterminacy of equilibrium forcing the central bank to react to spread movements

    Liquidity effects and cost channels in monetary transmission

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    We study liquidity effects and cost channels within a model of nominal rigidities and imperfect competition that gives explicit role for money-credit markets and investment decisions. We find that cost channels matter for monetary transmission, amplifying the impact of supply shocks and dampening the effects of demand shocks. Liquidity effects only obtain when the policy is specified by an interest rate policy rule and money-credit conditions are determined endogenously. We also find that determinacy issues are particularly relevant when models include the cost channel and explicit money-credit markets

    Constraining the Origin of Local Positrons with HAWC TeV Gamma-Ray Observations of Two Nearby Pulsar Wind Nebulae

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    The HAWC Gamma-Ray Observatory has reported the discovery of TeV gamma-ray emission extending several degrees around the positions of Geminga and B0656+14 pulsars. Assuming these gamma rays are produced by inverse Compton scattering off low-energy photons in electron halos around the pulsars, we determine the diffusion of electrons and positrons in the local interstellar medium. We will present the morphological and spectral studies of these two VHE gamma-ray sources and the derived positron spectrum at Earth.Comment: Presented at the 35th International Cosmic Ray Conference (ICRC2017), Bexco, Busan, Korea. See arXiv:1708.02572 for all HAWC contribution

    EDGE: a code to calculate diffusion of cosmic-ray electrons and their gamma-ray emission

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    The positron excess measured by PAMELA and AMS can only be explained if there is one or several sources injecting them. Moreover, at the highest energies, it requires the presence of nearby (\simhundreds of parsecs) and middle age (maximum of \simhundreds of kyr) source. Pulsars, as factories of electrons and positrons, are one of the proposed candidates to explain the origin of this excess. To calculate the contribution of these sources to the electron and positron flux at the Earth, we developed EDGE (Electron Diffusion and Gamma rays to the Earth), a code to treat diffusion of electrons and compute their diffusion from a central source with a flexible injection spectrum. We can derive the source's gamma-ray spectrum, spatial extension, the all-electron density in space and the electron and positron flux reaching the Earth. We present in this contribution the fundamentals of the code and study how different parameters affect the gamma-ray spectrum of a source and the electron flux measured at the Earth.Comment: Presented at the 35th International Cosmic Ray Conference (ICRC2017), Bexco, Busan, Kore

    A Template-based gamma-ray Reconstruction Method for Air Shower Arrays

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    We introduce a new Monte Carlo template-based reconstruction method for air shower arrays, with a focus on shower core and energy reconstruction of γ\gamma-ray induced air showers. The algorithm fits an observed lateral amplitude distribution of an extensive air shower against an expected probability distribution using a likelihood approach. A full Monte Carlo air shower simulation in combination with the detector simulation is used to generate the expected probability distributions. The goodness of fit can be used to discriminate between γ\gamma-ray and hadron induced air showers. As an example, we apply this method to the High Altitude Water Cherenkov γ\gamma-ray Observatory and its recently installed high-energy upgrade. The performance of this method and the applicability to air shower arrays with mixed detector types makes it a promising reconstruction approach for current and future instruments

    Two new endemic species of Monstera (Araceae: Monsteroideae: Monstereae) from Golfito in southern Costa Rica

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    Monstera croatii M.Cedeño & A.Hay and M. gambensis M.Cedeño & M.A.Blanco (Araceae: Monsteroideae: Monstereae) are newly described and illustrated from cantón Golfito in the Pacific lowlands of southern Costa Rica. Notes are provided on how they can be differentiated from similar species. Monstera croatii is unique in the genus because it reaches its adult vegetative morphology while growing as a terrestrial plant on the forest floor, and climbs only to a very limited height before flowering. Monstera gambensis is one of the smallest species in the genus.Universidad de Costa Rica/[]/UCR/Costa RicaMissouri Botanical Garden/[]//Estados UnidosSociety of Systematic Biologists/[]/SSB/InglaterraUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Jardín Botánico Lankester (JBL)UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de BiologíaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Biodiversidad y Ecología Tropical (CIBET

    Generic realignments in Maxillariinae (Orchidaceae)

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    Un reciente análisis filogenético de cuatro regiones de ADN para ca. 354 especies de la subtribu Maxillariinae indican fuertemente que el género Maxillaria, en su circunscripción tradicional, es altamente polifilético. Presentamos una nueva clasificación filogenética para Maxillariinae que reconoce 17 géneros. Los cambios necesarios incluyen: 1) la resurrección de los géneros Camaridium, Heterotaxis, y Ornithidium; 2) el reconocimiento de los recientes segregados genéricos Brasiliorchis (=Maxillaria sección Repentes), Christensonella (=Maxillaria sección Urceolatae), Nitidobulbon (en prensa), y una Sauvetrea recircunscrita (=Maxillaria sección Trigonae); 3) la adopción de los nuevos géneros Inti (=Maxillaria sección Polyphyllae), Mapinguari, Maxillariella (=Maxillaria secciones Ebulbes y Erectae), y Rhetinantha; 4) transferencias de Maxillaria sección Reflexae a Ornithidium, y Maxillaria sección Rufescens a Mormolyca; y 5) puesta en sinonimia de los géneros Adamanthus, Pseudomaxillaria, Psittacoglossum y Sepalosaccus (bajo Camaridium), Anthosiphon (bajo Cryptocentrum), Chrysocycnis (bajo Mormolyca), Dicrypta, Marsupiaria y Pentulops (bajo Heterotaxis), y Laricorchis, Neo-Urbania, y Siagonanthus (bajo Ornithidium). Algunos sinónimos nuevos al nivel de especie también son presentados.A recent phylogenetic analysis of four DNA regions for ca. 354 species of core Maxillariinae strongly indicate that the genus Maxillaria, as traditionally circumscribed, is grossly polyphyletic. We present a new phylogenetic classification for core Maxillariinae that recognizes 17 genera. Necessary realignments include: 1) resurrection of the genera Camaridium, Heterotaxis, and Ornithidium; 2) recognition of the recent segregates Brasiliorchis (=Maxillaria sect. Repentes), Christensonella (=Maxillaria sect. Urceolatae), Nitidobulbon (in press), and a recircumscribed Sauvetrea (=Maxillaria sect. Trigonae); 3) adoption of the new genera Inti (=Maxillaria sect. Polyphyllae), Mapinguari, Maxillariella (=Maxillaria sections Ebulbes and Erectae), and Rhetinantha; 4) transfers from Maxillaria sect. Reflexae to Ornithidium, and Maxillaria sect. Rufescens to Mormolyca; and 5) synonymizing of the genera Adamanthus, Pseudomaxillaria, Psittacoglossum, and Sepalosaccus (under Camaridium), Anthosiphon (under Cryptocentrum), Chrysocycnis (under Mormolyca), Dicrypta, Marsupiaria, and Pentulops (under Heterotaxis), and Laricorchis, Neo-urbania, and Siagonanthus (under Ornithidium). Some new synonyms at the specific level are also presented.National Science Foundation/[DEB-0234064]/NSF/Estados UnidosFundação de Amparo à Pesquisa do Estado de São Paulo/[01/08958-1]/FAPESP/BrasilConsejo Nacional de Ciencia y Tecnología/[]/CONACYT/MéxicoRoyal Botanic Gardens, Kew/[]//InglaterraAmerican Orchid Society/[]/AOS/Estados UnidosUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Jardín Botánico Lankester (JBL
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