305 research outputs found

    Análisis sobre la fijación de aranceles a la importación

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    En este documento se realiza un análisis cuantitativo del margen de maniobra que El Salvador posee para aumentar los aranceles que aplica a las importaciones, al ser estos una importante herramienta de política comercial. El margen de maniobra será medido como la diferencia entre el arancel consolidado y el que efectivamente se aplica a las importaciones de los países con los cuales tiene relación comercial. Para precisar el análisis, se agregarán los montos de las importaciones según productos y países de procedencia, para estimar el impacto que ocasionaría un aumento de aranceles en la recaudación fiscal. Adicionalmente se hace un análisis de los tratados comerciales más importantes, cuya aplicación reduce el impacto de una decisión unilateral sobre la fijación arancelaria. Por último, las conclusiones dan evidencia de que si bien pareciera ser que el margen de maniobra es significativo, solo puede aplicarse al 23% de las importaciones salvadoreñas. El 77% restante está limitado por acuerdos de libre comercio bilaterales. Finalmente, un aumento de las barreras al comercio tiene fuertes implicaciones económicas para el país y perjudiciales para los consumidores locales; así como para los productores siempre que los productos importados sean materias primas o maquinaria

    Pulmonary Embolism related to COVID-19 Quarantine

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    The mandatory quarantine imposed in response to the COVID-19 pandemic has been related to an increase in cases of thromboembolism in non-COVID-19 patients. Particularly in countries like Argentina where strict quarantine was mandated, individuals were far less likely to risk being outside or observing healthy practices that would maintain the exacerbation of diseases such as thromboembolism. We report the case of a patient with pulmonary thromboembolism without usual triggering causes during the quarantine period, related to a previously undiagnosed hypercoagulable condition

    Strain localization in polycrystalline material with second phase particles: Numerical modeling with application to ice mixtures

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    We use a centimeter-scale 2-D numerical model to investigate the effect of the presence of a second phase with various volume percent, shape, and orientation on strain localization in a viscoelastic matrix. In addition, the evolution of bulk rheological behavior of aggregates during uniaxial compression is analyzed. The rheological effect of dynamic recrystallization processes in the matrix is reproduced by viscous strain softening. We show that the presence of hard particles strengthens the aggregate, but also causes strain localization and the formation of ductile shear zones in the matrix. The presence of soft particles weakens the aggregate, while strain localizes within the particles and matrix between particles. The shape and the orientation of second phases control the orientation, geometry, and connectivity of ductile shear zones. We propose an analytical scaling method that translates the bulk stress measurements of our 2-D simulations to 3-D experiments. Comparing our model to the laboratory uniaxial compression experiments on ice cylinders with hard second phases allows the analysis of transient and steady-state strain distribution in ice matrix, and strain partitioning between ice and second phases through empirical calibration of viscous softening parameters. We find that the ice matrix in two-phase aggregates accommodates more strain than the applied bulk strain, while at faster strain rates some of the load is transferred into hard particles. Our study illustrates that dynamic recrystallization processes in the matrix are markedly influenced by the presence of a second phase

    Delayed trait development and the convergent evolution of shell kinesis in turtles

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    Developmental processes are foundational to clarifying the causes of convergent evolution. Here, we show how a key convergently evolving trait is slowly “acquired” in growing turtles. Adaptive morphological change tends to originate late in turtle ontogeny, owing to design constraints imposed by the shell. We investigated this trend by examining derived patterns of shell formation associated with the multiple (≥ 8) origins of shell closure (kinesis) in smallbodied turtles. Using box turtles as a model, we demonstrate that the flexible hinge joint required for shell kinesis differentiates gradually and via extensive repatterning of shell tissue. Disproportionate changes in shell shape and size substantiate that this transformation is a delayed ontogenetic response (3-5 years post-hatching) to structural alterations that arise in embryogenesis. These findings exemplify that the translation of genotype to phenotype may reach far beyond embryonic life stages. Thus, the temporal scope for developmental origins of adaptive morphological change might be broader than generally understood. We propose that delayed trait differentiation via tissue repatterning might facilitate phenotypic diversification and innovation that otherwise would not arise due to developmental constraints

    Whistleblowing Behavior in Organizations

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    We develop a game theoretical model of whistleblowing behavior in organizations, focusing speci�fically on the role of incentives aimed at encouraging this type of behavior. We also analyze the potential impacts of whistleblowing behavior on the persistence of corruption. First, we present a static game consisting of two employees with three available strategies: honest, corrupt and whistleblowing behavior. Later, we examine the pure and mixed Nash equilibrium strategies of the game. Second, we use the concept of replicator dynamics to formally explore the local asymptotic stability of whistleblowing behavior within organizations. Our main results show that whistleblowing as a mechanism to control wrongdoing is only relevant under the existence of external monitoring (if the probability of detecting wrongdoing with an external mechanism is close to zero, then in the long term, all employees will begin to behave corruptly). We also show that whistleblowers reduce the minimum wages required to avoid corruption within an organization, making it less costly for an organization to combat corruption. Finally, we claim that whistleblowing strategies seem to be less attractive for activities with very high bribery in comparison to the rewards for whistleblowers, for example, this could be the case of manufacturing or retail, but not for �nancial services in general

    Whistleblowing Behavior in Organizations

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    We develop a game theoretical model of whistleblowing behavior in organizations, focusing speci�fically on the role of incentives aimed at encouraging this type of behavior. We also analyze the potential impacts of whistleblowing behavior on the persistence of corruption. First, we present a static game consisting of two employees with three available strategies: honest, corrupt and whistleblowing behavior. Later, we examine the pure and mixed Nash equilibrium strategies of the game. Second, we use the concept of replicator dynamics to formally explore the local asymptotic stability of whistleblowing behavior within organizations. Our main results show that whistleblowing as a mechanism to control wrongdoing is only relevant under the existence of external monitoring (if the probability of detecting wrongdoing with an external mechanism is close to zero, then in the long term, all employees will begin to behave corruptly). We also show that whistleblowers reduce the minimum wages required to avoid corruption within an organization, making it less costly for an organization to combat corruption. Finally, we claim that whistleblowing strategies seem to be less attractive for activities with very high bribery in comparison to the rewards for whistleblowers, for example, this could be the case of manufacturing or retail, but not for �nancial services in general

    Visualization of 4D Q2PSK and CE Q2PSK in Ideal Bandlimited Channels

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    This paper presents new visualization techniques for 4D Quadrature-Quadrature Phase Shift Keying (Q2PSK), Saha’s Constant Envelope (CE) Q2PSK, and Cartwright’s CEQ2PSK in ideal bandlimited channels. The signal diagrams analyzed are: time-signal eye patterns for 4D passband signals, 2D complex trajectory diagrams of baseband signals, and time-signal eye patterns for the 1D outputs of the baseband matched filter. These methods may be applied to other multidimensional modulation systems to obtain insight into the effects of noise, interference, and channel filtering

    Performance and Spectral Analysis of Q2PSK and CE Q2PSK Systems in Ideal Bandlimited Channels

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    The authors present theoretical performance analysis and simulation results for Quadrature-Quadrature Phase Shift Keying (Q2PSK), Constant Envelope (CE) Q2PSK, and trelliscoded 16D CEQ2PSK in ideal bandlimited channels of various bandwidths. The performance of receivers with and without channel estimation is reported. Spectral analysis is presented for each system, in addition to MSK and expanded uncoded 16D CEQ2PSK. We show that the effects of bandlimiting are most severe for Q2PSK. Knowledge of the channel information aids 4D CEQ2PSK the least. Only 6.8 dB of SNR is needed for the TCM system for a bit error rate of 10−5 for the narrowest channel bandwidth studied here, if the receiver has knowledge of the channel

    A new species of liolaemus (Iguania: Liolaemidae) of the alticolor group from La Paz, Bolivia

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    We describe a new species of Liolaemus, belonging to the alticolor group, that was previously confused with L. walkeri. The new species inhabits the inter-Andean dry valleys at two localities in the department of La Paz (Ananta and Jupapina), Bolivia. We compared the new species with 11 morphologically similar taxa classified as part of the alticolor group. Our comparisons were based on external morphology and included lepidosis, morphometry, meristic characters, and color patterns. Liolaemus sp. nov. differs from other species of the same group by unique dorsal coloration and lepidosis characteristics. © 2012 by The Herpetologists League, Inc.Fil: Ocampo Ballivian, Mauricio. Universidad Mayor de San Andrés; BoliviaFil: Aguilar Kirigin, Álvaro J.. Universidad Mayor de San Andrés; BoliviaFil: Quinteros, Andres Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; Argentin

    A Novel Expanded 16-Dimensional Constant Envelope Q2PSK Constellation

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    We introduce a 16-dimensional constant-amplitude constellation that is generated by concatenating either four constant envelope quadrature-quadrature phase shift keying (CEQ2PSK) symbols from Saha and Birdsall or four CEQ2PSK symbols recently discovered by Cartwright and also introduced here. Our new constellation doubles the number of points available for data transmission without decreasing the distance between points or increasing energy, and may therefore be used in a trellis coded modulation (TCM) system without constellation expansion penalty. Because the new constellation has constant envelope, the modulation scheme becomes very attractive for nonlinear channels such as the magnetic recording channel or the satellite channel with traveling wave tube amplifiers
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