Optimal eigenvalues estimate for the Dirac operator on domains with boundary

We give a lower bound for the eigenvalues of the Dirac operator on a compact domain of a Riemannian spin manifold under the \MIT bag boundary condition. The limiting case is characterized by the existence of an imaginary Killing spinor.Comment: 10 page

Anthropological utopia of the new kingdom of San Francisco: Fray Marcos de Niza and the american dream

La topografía y cartografía del septentrión novohispano sedujeron a exploradores, navegantes y evangelizadores dispuestos a hallar su bagaje y propensiones en un terreno desconocido, en el actual norte de México. Fray Marcos de Niza sobresale de entre sus coetáneos, ya que su expedición recoge mitos y leyendas de ciudades maravillosas sobre las que la administración virreinal requería certificaciones y juramentos. La experiencia del franciscano en ambos polos continentales y, sobre todo, su formación religiosa de raigambre medieval sustentan un viaje que vislumbró, paradójicamente, las ultimidades de la historia en el Nuevo Mundo. Su “Relación”, muchas veces leída como un falso testimonio, guarda entre líneas un correlato místico cifrado en el Apocalipsis. Fray Marcos entrevió un Nuevo Reino de San Francisco poblado por tribus que parecían coincidir con las profecías de san Juan. Esta voluntad reduccionista devino en una utopía propicia para la diplomacia entre naciones y la conversión al catolicismo. El sueño americano del misionero debe enmarcarse bajo la ilusión de una metrópoli que vaticinaba la parusía de Cristo en la antesala de un nuevo milenio.The Northern Novohispanic topography and cartography seduced explorers, sailors and missionaries willing to find their background and inclinations over an unknown land that nowadays is the north of Mexico. Fray Marcos de Niza stands out among his contemporaries due to his expedition, which gathers myths and legends from marvelous cities that the Viceregal administration required certifications and oaths. The Franciscan vast experience in both continental poles and especially his medieval religious roots, sustained a journey that paradoxically took a glimpse of the last period of the History of the New World. His Relation, though many times taken as a false testimony, preserves scattered between lines a mystical correlate encoded in the Apocalypse. Fray Marcos distinguished a New Kingdom of San Francisco inhabited by tribes that seemed to concur with Saint John’s prophecies. This reductionist willingness resulted in a utopia that was suitable for the diplomacy between nations and the conversion to Catholicism. The missionary’s American dream must be demarcated under the illusion of a metropolis that predicted the Parousia of Christ just before the arrival of a new millennium

Greece’s Three-Act Tragedy:A Simple Model of Grexit vs. Staying Afloat inside the Single Currency Area

Against the backdrop of the Greek three-act tragedy, we present a theoretical framework for studying Greece’s recent debt and currency crisis. The model is built on two essential blocks: first, erratic macroeconomic policymaking in Greece is described using a stochastic regimeswitching model; second, the euro area governments’ responses to uncertain macroeconomic policies in Greece are considered. The model’s mechanism and assumptions allow either for a Grexit from the euro area or, conversely, the avoidance of Greece’s default against its creditors. The model also offers useful guidance to understand key drivers of the long-winded negotiations between the Syiza government and the euro area governments

Structural VARs And The Monetary Transmission Mechanism In Low-Income African Countries

Structural Vector Autoregression (SVAR) methods suggest the monetary transmission mechanism may be weak and unreliable in many low-income African countries. But are structural VARs identified via short-run restrictions capable of detecting a transmission mechanism when one exists, under research conditions typical of low-income countries (LICs)? Using a small DSGE as our data-generating process, we assess the impact on VAR-based inference of short data samples, measurement error, high-frequency supply shocks, and other features of the LIC environment. The impact of these features on finite-sample bias appears to be relatively modest when identification is valid—a strong caveat, especially in LICs. Nonetheless many of these features undermine the precision of estimated impulse responses to monetary policy shocks, and cumulatively they suggest that statistically and economically insignificant results can be expected even when the underlying transmission mechanism is strong. These data features not only undermine the efficacy of the SVAR methodology for research and policy-making, but are also severe enough to motivate a continued search for monetary policy rules that are robust to these limitations

Effect of confinement of horse heart cytochrome c and formate dehydrogenase from Candida boidinii on mesoporous carbons on their catalytic activity

This study reports the immobilization of two biocatalysts (e.g., cytochrome c—Cyt c—and the non-metalloenzyme formate dehydrogenase from Candida boidinii–cbFDH) on a series of mesoporous carbons with controlled pore sizes. The catalytic activity of the nanoconfined proteins was correlated with the pore size distribution of the carbon materials used as supports. The electrochemical behaviour of nanoconfined Cyt c showed direct electron transfer electroactivity in pore sizes matching tightly the protein dimension. The pseudo-peroxidase activity towards H2O2 reduction was enhanced at pH 4.0, due to the protein conformational changes. For cbFDH, the reduction of CO2 towards formic acid was evaluated for the nanoconfined protein, in the presence of nicotinamide adenine dinucleotide (NADH). The carbons displayed different cbFDH uptake capacity, governed by the dimensions of the main mesopore cavities and their accessibility through narrow pore necks. The catalytic activity of nanoconfined cbFDH was largely improved, compared to its performance in free solution. Regardless of the carbon support used, the production of formic acid was higher upon immobilization with lower nominal cbFDH:NADH ratios.NHI. VM and JI thank MINICINN, Spain (projects CTQ2013-48280-C3-3-R and CTQ2016-76231-C2-2-R) for financial support. COA thanks the financial support of the European Research Council through a Consolidator Grant (PHOROSOL 684161)

Structural VARs And The Monetary Transmission Mechanism In Low-Income African Countries

Structural Vector Autoregression (SVAR) methods suggest the monetary transmission mechanism may be weak and unreliable in many low-income African countries. But are structural VARs identified via short-run restrictions capable of detecting a transmission mechanism when one exists, under research conditions typical of low-income countries (LICs)? Using a small DSGE as our data-generating process, we assess the impact on VAR-based inference of short data samples, measurement error, high-frequency supply shocks, and other features of the LIC environment. The impact of these features on finite-sample bias appears to be relatively modest when identification is valid—a strong caveat, especially in LICs. Nonetheless many of these features undermine the precision of estimated impulse responses to monetary policy shocks, and cumulatively they suggest that statistically and economically insignificant results can be expected even when the underlying transmission mechanism is strong. These data features not only undermine the efficacy of the SVAR methodology for research and policy-making, but are also severe enough to motivate a continued search for monetary policy rules that are robust to these limitations

Have historical land use/land cover changes triggered a fire regime shift in central Spain?

Fire is one of the main disturbance factors shaping the landscape, and landscape is a key driver of fire behavior. Considering the role played by land use and land cover (LULC) changes as the main driver of landscape dynamics, the aim of this study was to calculate and analyze (i) the real impact of fire on LULC changes and (ii) how these LULC changes were influencing the fire regime. We used methods of historical geography and socio-spatial systemic analysis for reconstructing and assessing the LULC change and fire history in six case studies in the Central Mountain System (Spain) from archival documentary sources and historical cartography. The main result is an accurate dataset of fire records from 1497 to 2013 and a set of LULC maps for three time points (1890s–1930s, 1956–1957, and the 2000s). We have shown the nonlinear evolution of the fire regime and the importance of the local scale when assessing the interaction of landscape dynamics and fire regime variation. Our findings suggest that LULC trends have been the main influencing factor of fire regime variation in Central Spain since the mid-19th centuryinfo:eu-repo/semantics/publishedVersio