ABSTRACT This work posits that under the terrible global crisis caused by the Covid-19 health crisis lies an economic-financial crisis, stemming from a continuum of multiple financial speculative practices in an asymmetrical multipolar environment and a driving force of global and local inequalities. Two important factors reviewed here are the financialization and consumerism whose causal environment has been influenced and intertwined with local and international governance and governability patterns fostered by the interests and hegemony of transnational and multinational enterprises (TM). Methodologically, we propose research that sheds light on these companies, as well as on multipolarity, governance and governability. The evidence analyzed confirms that underlying the health crisis lies a structural economic and financial crisis whose imbalances and abuses deepen the Covid-19 crisis.

RESUMEN El presente trabajo postula que bajo la crisis mundial causada por la pandemia de la Covid-19 subyace una crisis económicaca-financiera, derivada de un continuo de múltiples prácticas especulativas financieras en un entorno multipolar asimétrico y propulsor de desigualdades globales y locales. Dos importantes elementos examinados son la financiarización y el consumismo cuyo entorno causal ha estado influenciado y entreverado con los patrones de gobernanza y gobernabilidad locales e internacionales impulsados por los intereses y hegemonía e las empresas transnacionales y multinacionales (TM). Metodológicamente, proponemos una investigación explicativa sobre estas empresas, así como acerca de la multipolaridad, gobernanza y gobernabilidad. La evidencia analizada confirma que subyacente a la crisis sanitaria se encuentra una crisis económico-financiera estructural cuyos desequilibrios y abusos profundizan la crisis de la Covid-19.

RESUMEN Este artículo analiza la dependencia asimétrica de la volatilidad de los tipos de cambio entre la libra esterlina, yen japonés, euro y peso mexicano en términos del dólar americano, en un periodo que comprende episodios de calma e incerti-dumbre (1994-2018). Los modelos GARCH y TARCH se emplean para modelar la volatilidad del tipo de cambio. Una vez que la volatilidad se estima, se calcula la dependencia de la cola superior e inferior, para cada subperiodo: 1994-1999, 2000-2007, 2007-2012, 2013-2018. La dependencia bivariada de la volatilidad cambiaria muestra alta dependencia en la cola inferior y baja dependencia en la cola superior. JEL: G01, G15, F65, C58.

ABSTRACT This paper aims to analyse asymmetric volatility dependence in the exchange rate between the British Pound, Japanese Yen, Euro, and Mexican Peso compared to the U.S. dollar during different periods of turmoil and calm sub-periods between (1994-2018). GARCH and TARCH models are employed to model conditional variance. Once volatility is estimated, the Copula approach provides an upper and lower tail dependence measure for each subperiod: 1994-1999, 2000-2007, 2007-2012, 2013-2018. The empirical joint distribution of exchange rate volatility pairs displays high tail-dependence in the lower tail and low tail-dependence in the upper tail. Results have important implications in term of risk management and investment strategies. JEL: G01, G15, F65, C58.

RESUMO Este artigo analisa a dependência assimétrica da volatilidade das taxas de câmbio entre a libra esterlina, o iene japonês, o euro e o peso mexicano em relação ao dólar norte-americano, em um período que inclui episódios de calma e incerteza (1994-2018). Os modelos GARCH e TARCH são usados para modelar a volatilidade da taxa de câmbio. Uma vez que a volatilidade é estimada, calcula-se a dependência da cauda superior e inferior, para cada subperíodo: 1994-1999, 20002007, 2007-2012, 2013-2018. A dependência bivariada da volatilidade da taxa de câmbio mostra alta dependência na cauda inferior e baixa dependência na cauda superior. JEL: G01, G15, F65, C58.

Abstract This paper proposes the creation of sectorial ETFs to be listed on the Mexican market, employing data for 2018. Once, sectorial ETFs are proposed, an optimal portfolio is built with them to indicate which sector exhibits the best risk/return ratio; this sector should be the first created and offered. Findings reveal algorithm efficiency, physical replication is successful. Frequent Consumption and Materials are the sectors to start ETFs construction. The originality relies on, this kind of instrument is not listed in the Mexican market and are key to promote investment and to do investment strategies such as sectorial rotation.

Resumen Se propone crear ETFs sectoriales, con datos de 2018, para su cotización en el mercado mexicano. Con los ETFs propuestos se conforma un portafolio óptimo, poniendo en evidencia qué sector tiene la mejor relación riesgo/rendimiento y, por tanto, debería ser el primer ETF en ofertarse. Los resultados indican que el algoritmo construido es eficiente por lo que la réplica física es exitosa. Los sectores para iniciar la construcción de ETFs son Consumo Frecuente y Materiales. La originalidad radica en que no existen ETFs sectoriales en México y son clave para promover la inversión y realizar estrategias como la de rotación sectorial.

Abstract This paper analyzes volatility contagion between exchange and stock market in Mexico and Brazil during the period January/2000- November/2020. The methodology includes univariate GARCH models under t-Student distribution: GARCH, APARCH, EGARCH and TARCH to examine the conditional volatility in each series and multivariate GARCH: DCC and ADCC to investigate volatility co-movements between exchange rate and stock market. A contagion effect is confirmed, at least during one period, for each economy. Findings suggest that, investors should apply exchange rate hedges during uncertainty periods or hold positions until the markets recover. Among the limitations, only two markets are covered, excluding the regional analysis. Originality relies on the empirical proposal, the emergent economies, scarcely analyzed, which are investigated and the value of the results in terms of diversification and hedging strategies.

Resumen Se analiza el contagio en volatilidad entre los mercados cambiarios y de valores en México y Brasil de enero/2000 a noviembre/2020. La metodología incluye modelos GARCH univariados: GARCH, APARCH, EGARCH y TARCH para el análisis de la volatilidad de las series y modelos multivariados GARCH: DCC y ADCC, para medir los co-movimientos de la volatilidad condicional del mercado de capitales y cambiario, permitiendo determinar la existencia de contagio. Se observa que, en el mercado brasileño, la correlación es más fuerte y estable que en el mercado mexicano, confirmando, al menos un periodo de contagio en cada economía. Las recomendaciones que se desprenden es que, durante periodos de inestabilidad se deben realizar estrategias de cobertura cambiaria o, mantener las posiciones hasta que haya recuperación en los mercados. Las limitaciones es que únicamente se incluyen dos economías latinoamericanas, por lo que, no se analiza el efecto regional. La originalidad radica en la propuesta empírica, el estudio de economías emergentes, que han sido escasamente analizadas, así como, en el aporte de información crucial para las estrategias de diversificación y cobertura de riesgos.

Abstract Inflationary targets can be pressured by disturbances and strong volatilities in the financial and exchange markets. Therefore, the stock market and exchange rates are fundamental in the transmission of monetary policy, given the relationships they have with aggregate demand and prices. This paper analyzes the incidence of the key monetary variables in the activity of the Mexican Stock Exchange, during the period 2008-2019, through a model that incorporates structural breaks, and an Autoregressive Vector with Regime Change (MS-VAR). Estimates verify the influence of the monetary policy rate; risk premiums of government and corporate bonds; and the exchange rate in the stock market, identifying the differentiated response to high and low volatility scenarios.

Resumen Los objetivos inflacionarios pueden verse presionados por perturbaciones y fuertes volatilidades en los mercados financieros y cambiarios. Por ello, el mercado accionario y los tipos de cambio son fundamentales en la transmisión de la política monetaria, dadas las relaciones que tienen con la demanda agregada y los precios. El presente trabajo analiza la incidencia de las variables monetarias clave en la actividad de la Bolsa Mexicana de Valores, durante el periodo 2008-2019, a través de un modelo que incorpora quiebres estructurales, y un Vector Autorregresivo con Cambio de Régimen (MS-VAR). Las estimaciones verifican la influencia de la tasa de política monetaria; las primas de riesgos de los bonos gubernamentales y corporativos; y el tipo de cambio en el mercado accionario, identificando la respuesta diferenciada ante escenarios de alta y baja volatilidad.

Abstract: The objective of this paper is to analyze and compare international diversification strategies, using traditional assets (stocks) and exchange traded fund (ETFs) from four different countries: Germany, the United Kingdom, the United States and Mexico; the study period is from January 2012 to April 2018. The hypothesis is that the investment strategy that includes ETFs is more profitable, both because of the nature of these instruments and because of the commissions that are generated through the traditional strategy, in which a greater number of assets is used, in order to diversify the risk of each local market. The methodology implemented consists of the Markowitz model, to obtain the efficient frontier, in addition to the estimation of the Value at Risk (VaR) of each portfolio (traditional vs. ETF).

Resumen: El presente trabajo tiene por objetivo analizar y comparar estrategias de diversificación internacional, empleando activos tradicionales (acciones) y exchange traded fund (ETFs) de cuatro diferentes países: Alemania, Reino Unido, Estados Unidos y México; el periodo de estudio es de enero de 2012 a abril del año 2018. La hipótesis es que, la estrategia de inversión que incluye ETFs es más redituable, tanto por la naturaleza de dichos instrumentos, como por las comisiones que se generan a través de la estrategia tradicional, en la cual se emplea un número mayor de activos, con el objeto de diversificar el riesgo de cada mercado local. La metodología implementada consiste en el modelo de Markowitz, para la obtención de la frontera eficiente, además de la estimación del Valor en Riesgo (VaR) de cada portafolio (tradicional vs ETF).

Abstract The objective of this paper is to analyze the pension system returns conditional volatility, as well as the volatility dynamics and structural changes that have taken place during the period studied (July 1997 to April 2018). In order to achieve this objective, the methodology used was to implement GARCH (1,1) models, and to conduct various tests to ascertain the presence of regime switching. In addition, an Auto-regresive Markov Regime-Switching Model was estimated, which allowed to distinguish between high and low volatility regimes. This paper contribution is to present a broader analysis of pension funds volatility through the detection of volatility regimen switching. It was concluded that the returns of the pension system rested in two regimes, one of high and the other of low volatility, with approximately the same probability of occurrence. Even though a deeper analysis of the investment policy is required, it is observed a volatility increment related to the investment policy flexibilization.

Resumen El presente trabajo tiene por objetivo analizar la volatilidad condicional de los rendimientos del sistema de pensiones; así como la dinámica de la volatilidad y los cambios estructurales que se han presentado durante el periodo de estudio (julio/1997-abril/2018). Para lograr dicho objetivo, la metodología utilizada fue usar modelos GARCH (1,1) y realizar distintas pruebas para comprobar la presencia de cambios de régimen. Asimismo, se estimó un modelo autorregresivo con cambio de régimen markoviano MS-AR, distinguiendo entre dos regímenes de volatilidad: alta y baja. La contribución del presente trabajo consiste en ofrecer un análisis más detallado de la volatilidad del sistema de pensiones, principalmente mediante la detección de los cambios de régimen. Se concluyó que los rendimientos del sistema pensionario se encuentran en dos regímenes, uno de alta y otro de baja volatilidad, con aproximadamente la misma probabilidad. Aun cuando es necesario realizar un análisis más detallado de la política de inversión, se manifiesta un incremento en la volatilidad relacionado con la flexibilización de esta política.

Abstract In recent years, consumer credit in Mexico has grown in significant ways. Credit cards, which represent 52% of credit in the country, grew by 19% from 2011 to 2018, while the average debt per card increased by 62%. This increase generates problems of over-indebtedness in Mexican households. Using microdata from the National Income and Expenditure Survey (NIES), this research seeks to identify the factors that affect over-indebtedness in households, and to offer an explanation of said phenomenon using a neural network methodology. The principal determinant of over-indebtedness in Mexican households is the existence of bank credit, given that this indicates a long-term transfer of family income to the financial sector.

Resumen En años recientes el crédito al consumo en México creció de manera importante. Las tarjetas de crédito, que representan 52% de los créditos en el país, crecieron 19% de 2011 a 2018; mientras que el endeudamiento promedio por tarjeta creció 62%. Dicho crecimiento genera problemas de sobreendeudamiento de los hogares mexicanos. Empleando microdatos de la Encuesta Nacional de Ingresos y Gastos en los Hogares (ENIGH), la presente investigación busca encontrar los factores del sobreendeudamiento en los hogares, y aportar una explicación del mismo para ello, se utilizó la metodología de redes neuronales. El principal determinante de sobreendeudamiento de los hogares mexicanos es la existencia de un crédito bancario, hecho que indica una transferencia de largo plazo del ingreso familiar hacia este sector financiero.

Resumen El presente artículo tiene por objetivo analizar la dependencia condicional entre los mercados de valores de Estados Unidos, México y Canadá durante el período 2003-2018. Las Cópulas Arquimedianas y Elípticas, así como los modelos GARCH y TARCH son utilizados para realizar la modelación en tres subperíodos: antes, durante y después de la crisis financiera global. Los resultados evidencian un incremento promedio de 38 % de la dependencia condicional en la crisis financiera, con respecto al período previo; asimismo, existe una leve disminución del parámetro de dependencia al modelar la asimetría en la volatilidad de las series. JEL Classification: G15; C58; D53

Abstract This article aims to analyze conditional dependence between the Mexican, American and Canadian stock markets during the period 2003-2018. Archimedean and elliptical Copulas and GARCH and TARCH models are employed to estimate conditional dependence in three subperiods: pre-crisis, crisis and pos- global financial crisis. Results reveal a 38% rise in conditional dependence during the crisis period, in relation to the previous period. On the other hand, the conditional dependence parameter diminishes when asymmetry is included. JEL Classification: G15; C58; D53

Microstructure, structure and electrical and dielectric properties of ZnO-doped K0.5Na0.5NbO3 (KNN) ceramics were investigated. Powders were obtained by the conventional solid-state method. Samples doped with 0 to 1 mol% of ZnO were sintered at 1125 °C for 2 h. Through XRD spectra, the perovskite structure was detected, in addition to small peaks corresponding to secondary phases. It was also observed that zinc changed the microstructure and grain size of KNN ceramics. The addition of 0.5 mol% of Zn2+ produced a softening effect in the ferroelectric properties of the material, and increased its final density. Conversely, the addition of 1 mol% of Zn2+ reduced the sample densification.

In this paper the influence of Cu on dielectric and piezoelectric properties of K1/2Na1/2NbO3 (KNN) was evaluated. Samples were obtained by solid state reaction doping with CuO (0 to 2 mol%). The obtained samples were characterized by the Archimedes method, X-Ray diffraction, Raman spectroscopy, Scanning Electron Microscopy, polarization curves, piezoelectric constant (d33) and impedance spectroscopy at room temperature. In general, it was observed that doping does not improve dielectric and piezoelectric properties. Small amounts of CuO (0.5 mol%) slightly affected the densification process, while high concentrations increased the porosity of the samples. Also, low concentrations of CuO drastically reduced d33 values, presumably due to the hardening effect of the additive.

Con el objetivo de evaluar la influencia del Cu sobre las propiedades dieléctricas y piezoeléctricas del K1/2Na1/2NbO3 (KNN) se sintetizó, por reacción en estado sólido, KNN dopado con diferentes concentraciones de CuO (0 a 2% mol). El análisis del material se realizó empleando mediciones de densidad por el método de Arquímedes, difracción de rayos X (DRX), espectroscopía Raman, microscopía electrónica de barrido (SEM), curvas de polarización, constante piezoeléctrica (d33) y espectroscopía de impedancia a temperatura ambiente. En general, se observó que el aditivo no logró mejorar las propiedades dieléctricas o piezoeléctricas. Pequeñas cantidades de CuO (0,5%mol) afectaron ligeramente el proceso de densificación, mientras que altas concentraciones incrementaron la porosidad. Asimismo, bajas concentraciones de CuO redujeron drásticamente los valores de d33, presumiblemente debido al efecto endurecedor del aditivo.

Barium titanate particles (100-300 nm) synthesized by hydrothermal method were dispersed in both polyvinyl alcohol (PVA) and ethylcellulose (EC) solutions. These suspensions were processed by electrospinning. When no particles were added, homogeneous polymeric nanofibers were obtained. Under certain conditions, polymeric suspensions of barium titanate particles were electrospun generating polymeric fibers with BT particles. The effect of a surfactant was also assessed over the formation of nanofibers. The BaTiO3 particles synthesized by hydrothermal method were characterized by X-Ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and Raman spectroscopy. Fibers were characterized by scanning electron microscopy (SEM).

O presente trabalho descreve as atividades antibacterianas e antifúngicas de diversas chalconas obtidas diretamente através da condensação aldólica tipo Claisen-Schmidt das quais se determinou a concentração inibitória mínima frente a diferentes microrganismos (bactérias Gram-positivas e Gram-negativas e fungos). Estruturas no estado sólido cristalino de sete chalconas foram determinadas por análise de difração de raios X (XRD). Estudos quimiométricos foram realizados com intuito de identificar uma potencial relação entre estrutura e atividade.

The present work describes the antibacterial and antifungal activities of several chalcones obtained by a straight Claisen-Schmidt aldol condensation determined by the minimal inhibitory concentration against different microorganisms (Gram-positive and Gram-negative bacteria and fungi). Solid state crystal structures of seven chalcones were determined by X-ray diffraction (XRD) analysis. Chemometric studies were carried out in order to identify a potential structure-activity relationship.

Objectivos: Determinar a proporção de infecções das vias aéreas superiores (IVAS) tratadas com antibiótico numa Unidade de Saúde Familiar (USF); verificar quais os antibióticos mais prescritos nas IVAS; avaliar se existe relação entre a prescrição de antibióticos e a idade e o sexo do doente; avaliar se existe relação entre o antibiótico prescrito e a idade do doente. Tipo de estudo: observacional, analítico e transversal. Local: Unidade de Saúde Familiar (USF) Serpa Pinto, no Porto. População: Utentes inscritos na USF com pelo menos um contacto médico codificado como IVAS. Métodos: Recolheu-se a informação a partir dos sistemas MedicineOne® e SAM® e incluíram-se as consultas classificadas, segundo a International Classification of Primary Care-2, como: R21; R72; R74; R75; R76. Resultados: Das 299 consultas estudadas, 61,2% foram realizadas a mulheres. A média de idades foi de 26,4 anos (± 22,3). Os diagnósticos mais frequentes foram R76 (48,1%) e R74 (38,7%). Foi prescrito antibiótico em 68,2% das consultas, sendo a classe das penicilinas a mais prescrita (90,6%). Não existiu relação entre a prescrição de antibióticos e o sexo ou a idade do doente. Verificou-se uma diferença estatisticamente significativa entre a idade e a classe de antibiótico prescrita: penicilinas (25,1 anos ± 22,1) vs restantes classes (39,7 anos ± 20,1) (p < 0,001). Conclusões: A classe dos beta-lactâmicos foi a mais usada para o tratamento de IVAS, com uma maior proporção de penicilinas prescritas, em relação a outros estudos. Por outro lado, verificou-se existir relação entre a idade e a classe terapêutica de antiótico prescrita

Objectives: To determine the proportion of upper respiratory tract infections (URTI) treated with antibiotics in a primary care unit, to identify the most prescribed antibiotics for the treatment of URTI, to test the association between antibiotic prescription and the age and gender of the patient, and to test the association between patient age and the antibiotic selected. Study design: cross-sectional. Setting: Serpa Pinto Family Health Unit (USF Serpa Pinto), Porto, Portugal. Population: Patients registered in the Family Health Unit with at least one diagnosis of upper respiratory tract infection recorded. Methods: information was collected from MedicineOne® and SAM® software using International Classification of Primary Care-2 codes R21, R72, R74, R75, R76. Results: Of the 299 patients identified, 61.2% were women. The average age was 26.4 years (± 22.3). The most common diagnoses were R76 (48.1%) and R74 (38.7%). Antibiotics were prescribed in 68.2% of visits, and penicillins were the most commonly prescribed antibiotics (90.6%). There was no association between the prescription of antibiotics and the gender or age of the patient. There was a statistically significant association between patient age and the class of antibiotics prescribed. Penicillins were prescribed more to younger patients (mean age 25.1 years ± 22.1) compared to other antibiotics (mean age 39.7 years ± 20.1, p < 0.001). Conclusions: Beta-lactam antibiotics were the most commonly prescribed antibiotics for treatment of URTI, with a higher proportion of penicillins prescribed here than that found in other studies. There was an association found between age and the therapeutic class of antibiotics prescribed

Very little research has been conducted on the swimming capacity of Neotropical fish. The few studies available have focused on large migratory species. The present study used fixed and increasing velocity tests to determine prolonged and sustained speeds of the "pequira", Bryconamericus stramineus Eigenmann, 1908, a small, abundant species found in fish passages implemented at the Paraná basin, Brazil. The results of increasing velocity tests showed significant relationships between critical speeds, total and standard lengths, and body weight. When compared with other Neotropical fish, the "pequira" is able to swim faster than individuals of other species of similar length. The point of change from sustained to prolonged swimming was found to occur at an approximate speed of 8.7 lengths per second. These data provide guidance and criteria for design and proper maintenance of structures such as fishways, fish screens and other systems that aim to facilitate or avoid upstream passages as part of management strategies.