Análisis sobre la fijación de aranceles a la importación

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

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

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

Development of a mechanism and an accurate and simple mathematical model for the description of drug release: Application to a relevant example of acetazolamide-controlled release from a bio-inspired elastin-based hydrogel

Producción CientíficaTransversality between mathematical modeling, pharmacology, and materials science is essential in order to achieve controlled-release systems with advanced properties. In this regard, the area of biomaterials provides a platform for the development of depots that are able to achieve controlled release of a drug, whereas pharmacology strives to find new therapeutic molecules and mathematical models have a connecting function, providing a rational understanding by modeling the parameters that influence the release observed. Herein we present a mechanism which, based on reasonable assumptions, explains the experimental data obtained very well. In addition, we have developed a simple and accurate “lumped” kinetics model to correctly fit the experimentally observed drug release behavior. This lumped model allows us to have simple analytic solutions for the mass and rate of drug release as a function of time without limitations of time or mass of drug released, which represents an important step-forward in the area of in vitro drug delivery when compared to the current state of the art in mathematical modeling. As an example, we applied the mechanism and model to the release data for acetazolamide from a recombinant polymer. Both materials were selected because of a need to develop a suitable ophthalmic formulation for the treatment of glaucoma. The in vitro release model proposed herein provides a valuable predictive tool for ensuring product performance and batch-to-batch reproducibility, thus paving the way for the development of further pharmaceutical devices.Este trabajo forma parte de los Proyectos de Investigación financiados por la Comisión Europea a través del Fondo Social Europeo (FSE) y de la Consejería de Educación mediante el Fondo Europeo de Desarrollo Regional (ERDF), el MINECO (Proyectos MAT2013-41723-R, MAT2013-42473-R, PRI−PIBAR-2011-1403 y MAT2012-38043), la Junta de Castilla y León (Proyectos VA155A12, VA152A12, and VA244U13), el CIBER-BBN y el Instituto de Salud Carlos III mediante el Centro de Medicina Regenerativa y Terapia Celular de Castilla y León

An alternative method in distinguishing cattle transferrin phenotypes

A modification of the method described by Kristjansson (1963) allows easier distinction of the components and position of every major cattle transferrin phenotype. The modification is based on increasing the percentage of starch (15%) and reducing the pH of the gel buffer to 6.8. In all the experiments, when a voltage of 350 was applied, a tray of ice was placed over the starch gel for the remainder of the electrophoresis. Different cattle transferrin phenotypes from our modified electrophoresis method are composed as follows: Type A, 4 bands; D1, 4 bands; D1D2, 4 bands; D2, 4 bands; E, 4 bands; AD1, 6 bands; AD2, 6 bands; AE, 8 bands and sometimes 9 bands; D1E, 6 bands and sometimes 7 bands; and D2E, 6 bands. The position of the fourth D band is distinctly different in D1 vs. D2 types.Universidad Nacional de La Plat

Pulmonary Embolism related to COVID-19 Quarantine

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

Multiparametric determination of genes and their point mutations for identification of beta-lactamases

More than half of all currently used antibiotics belong to the beta-lactam group, but their clinical effectiveness is severely limited by antibiotic resistance of microorganisms that are the causative agents of infectious diseases. Several mechanisms for the resistance of Enterobacteriaceae have been established, but the main one is the enzymatic hydrolysis of the antibiotic by specific enzymes called beta-lactamases. Beta-lactamases represent a large group of genetically and functionally different enzymes of which extended-spectrum beta-lactamases (ESBLs) pose the greatest threat. Due to the plasmid localization of the encoded genes, the distribution of these enzymes among the pathogens increases every year. Among ESBLs the most widespread and clinically relevant are class A ESBLs of TEM, SHV, and CTX-M types. TEM and SHV type ESBLs are derived from penicillinases TEM-1, TEM-2, and SHV-1 and are characterized by several single amino acid substitutions. The extended spectrum of substrate specificity for CTX-M beta-lactamases is also associated with the emergence of single mutations in the coding genes. The present review describes various molecular-biological methods used to identify determinants of antibiotic resistance. Particular attention is given to the method of hybridization analysis on microarrays, which allows simultaneous multiparametric determination of many genes and point mutations in them. A separate chapter deals with the use of hybridization analysis on microarrays for genotyping of the major clinically significant ESBLs. Specificity of mutation detection by means of hybridization analysis with different detection techniques is compared

Whistleblowing Behavior in Organizations

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

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

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

Whistleblowing Behavior in Organizations

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