Structural insights into viral IRES-dependent translation mechanisms

© 2015 Elsevier B.V. All rights reserved. A diverse group of viruses subvert the host translational machinery to promote viral genome translation. This process often involves altering canonical translation initiation factors to repress cellular protein synthesis while viral proteins are efficiently synthesized. The discovery of this strategy in picornaviruses, which is based on the use of internal ribosome entry site (IRES) elements, opened new avenues to study alternative translational control mechanisms evolved in different groups of RNA viruses. IRESs are cis-acting RNA sequences that adopt three-dimensional structures and recruit the translation machinery assisted by a subset of translation initiation factors and various RNA binding proteins. However, IRESs present in the genome of different RNA viruses perform the same function despite lacking conservation of primary sequence and secondary RNA structure, and differing in host factor requirement to recruit the translation machinery. Evolutionary conserved motifs tend to preserve sequences impacting on RNA structure and RNA-protein interactions important for IRES function. While some motifs are found in various picornavirus IRESs, others occur only in one type reflecting specialized factor requirements. This review is focused to describe recent advances on the principles and RNA structure features of picornavirus IRESs.MINECO, and by an Institutional grant from Fundación Ramón ArecesPeer Reviewe

Caesarean section rates in immigrant and native women in Spain: the importance of geographical origin and type of hospital for delivery

El estudio se plantea con el objetivo de constatar la existencia de inequidades respecto a la calidad de la atención recibida durante el embarazo y parto, entre mujeres nativas e inmigrantes, siendo la cesárea (SC) uno de los principales indicadores para ello. Se plantea un estudio transversal mediante la explotación de los datos del Registro de Enfermedades Metabólicas de algunas regiones españolas, que de forma similar al Registro Nacional de Estadísticas Vitales, contienen el 100% de los nacimientos registrados en España. Dichos registros proporcionan, entre otros, datos sobre la terminación del parto, tipo de hospital y país de origen de la madre (autodeclarado). Se analizaron 215.379 partos únicos de mujeres españolas e inmigrantes de América Latina, Europa del Este y Magreb en 2005-06, calculando la prevalencia de SC según características maternas y neonatales por origen geográfico. Se exploraron dos asociaciones mediante análisis de regresión logística múltiple. En primer lugar, la asociación entre el origen geográfico y el riesgo de SC en hospitales públicos o privados por separado y, en segundo lugar, el riesgo de SC para mujeres del mismo origen geográfico dependiendo de si dieron a luz en hospitales públicos o privados. Se observó que en general, el riesgo de SC fue menor para las inmigrantes que para las mujeres nativas (odds ratio (OR) = 0,83, intervalo de confianza (IC) del 95% = 0,80–0,85), pero el riesgo varió notablemente según el área de origen. siendo mayor para las latinoamericanas (OR = 1,09 IC 95% = 1,05–1,13) y menor para las europeas del Este (OR = 0,61 IC 95% = 0,57–0,66) y magrebíes (OR = 0,60 IC 95% = 0,57–0,63). Además, el riesgo de SC fue mayor en los hospitales privados que en los públicos para todos los grupos. Sin embargo, el aumento del riesgo fue mayor para las inmigrantes que para las nativas.Concluimos que las mujeres inmigrantes en España son una población heterogénea en cuanto al riesgo de SC. El origen geográfico y el tipo de hospital son aspectos clave que subyacen a dicho riesgo. The study is proposed with the objective of verifying the existence of inequalities regarding the quality of care received during pregnancy and childbirth, between native and immigrant women, with cesarean section (CS) being one of the main indicators for this. A cross-sectional study is proposed by exploiting data from the Registry of Metabolic Diseases of some Spanish regions, which, similar to the National Registry of Vital Statistics, contains 100% of the births registered in Spain. These records provide, among others, data on the termination of childbirth, type of hospital and country of origin of the mother (self-declared). 215,379 singleton births of Spanish women and immigrants from Latin America, Eastern Europe and the Maghreb in 2005-06 were analyzed, calculating the prevalence of CS according to maternal and neonatal characteristics by geographical origin. Two associations were explored using multiple logistic regression analysis. Firstly, the association between geographical origin and the risk of CS in public or private hospitals separately and, secondly, the risk of CS for women of the same geographical origin depending on whether they gave birth in public or private hospitals. It was observed that in general, the risk of CS was lower for immigrant women than for native women (odds ratio (OR) = 0.83, 95% confidence interval (CI) = 0.80–0.85), but the risk varied markedly by area of origin. being higher for Latin American women (OR = 1.09 95% CI = 1.05–1.13) and lower for Eastern Europeans (OR = 0.61 95% CI = 0.57–0.66) and North African women (OR = 0.60 95% CI = 0.57–0.63). Furthermore, the risk of CS was higher in private hospitals than in public hospitals for all groups. However, the increased risk was greater for immigrants than for natives. We conclude that immigrant women in Spain are a heterogeneous population in terms of the risk of CS. Geographic origin and type of hospital are key aspects underlying this risk

Razonamiento proporcional de futuros maestros de educación primaria

We present the findings of a study on prospective elementary teachers’ proportional reasoning. After describing some of the teachers’ performance in solving multiplicative structure problems that involve ratios and relations of direct proportionality between quantities, we were able to establish classifications of their answers according to various categories of proportional reasoning.Presentamos los resultados de un estudio sobre el razonamiento proporcional de futuros maestros de educación primaria. Describimos las actuaciones manifestadas por un grupo de estudiantes de magisterio de la Universidad de Granada al resolver problemas de estructura multiplicativa que involucran razones y relaciones de proporcionalidad directa entre cantidades. Encontramos que sus respuestas se clasifican en distintas categorías de razonamiento proporcional

The inclusion of power gyrator topologies as energy processing cells in photovoltaic solar conversion

This paper will provide a classification of high efficiency switching power-gyrator structures and their use as cells for energy processing in photovoltaic solar facilities. Having into account the properties of these topologies presented in the article, their inclusion in solar facilities allows increasing the performance of the whole installation. Therefore, the design, simulation and implementation of a G- type power gyrator are carried out throughout the text. In addition, in order to obtain the maximum power from the photovoltaic solar panel, a maximum power point tracking (MPPT) is mandatory in the energy processing path. Therefore, the practical implementation carried out includes a control loop of the power gyrator in order to track the aforementioned maximum power point of the photovoltaic solar panel.Postprint (published version

Guided activities in the teaching of analog electronics in the bachelor's degree in Industrial and Automatic Electronics

Within the offer of core courses of the Bachelor’s Degree in Industrial Electronics and Automation Engineering of the Technical University of Catalonia (UPC), which appeared as a result of the current undergraduate study program, within the European Higher Education Area (EHEA), there is a course, Analog Electronics (EAEIA), which allows the Electronic Engineering student to delve into the knowledge of this content. This paper exposes the philosophy of this course, in such a way that it analyzes the orientation that is intended to be given, especially within the new framework of courses offered at the EEBE where, in addition to the hours of lectures and laboratory sessions, there must be room for to the guided activities (GAs) that the current syllabus contemplates.Postprint (published version

Non-external capacitor LDO regulator for power management applications

This article aims to present the design of a 4.5-V, 450-mA low drop-out (LDO) voltage linear regulator based on a two-stage cascoded operational transconductance amplifier (OTA) as error amplifier. The aforementioned two-stage OTA is designed with cascoded current mirroring technique to boost up the output impedance. The proposed OTA has a DC gain of 101 dB under no load condition. The designed reference voltage included in the LDO regulator is provided by a band gap reference with the temperature coefficient (T¿) of 0.025 mV/ºC. The proposed LDO regulator has a maximum drop-out voltage of 0.5 V @ 450 mA of load current, and has the worst case power supply rejection ratio (PSRR) of [54.5 dB, 34.3 dB] @ [100 Hz, 10 kHz] in full load condition. All the proposed circuits are designed using a 0.35 µm CMOS technology. The design is checked in order to corroborate its performance for wide range of input voltage, founding that the circuit design works fine meeting all the initial specification requirements.Postprint (published version

Capacitorless low-dropout regulator for power management applications

This article aims to present the design of a 4.5-V, 450-mA low drop-out (LDO) voltage linear regulator based on a two-stage cascoded operational transconductance amplifier (OTA) as error amplifier. The aforementioned two-stage OTA is designed with cascoded current mirroring technique to boost up the output impedance. The proposed OTA has a DC gain of 101 dB under no load condition. The designed reference voltage included in the LDO regulator is provided by a band gap reference with the temperature coefficient (T¿) of 0.025 mV/ºC. The proposed LDO regulator has a maximum drop-out voltage of 0.5 V @ 450 mA of load current, and has the worst case power supply rejection ratio (PSRR) of [54.5 dB, 34.3 dB] @ [100 Hz, 10 kHz] in full load condition. All the proposed circuits are designed using a 0.35 µm CMOS technology. The design is checked in order to corroborate its performance for wide range of input voltage, founding that the circuit design works fine meeting all the initial specification requirements.Postprint (published version

On single-input dual-output (SIDO) DC/DC multi-port converters for DC microgrid applications

This paper proposes the use of linear-assisted switching power converters in the context of single-inductor dual-output (SIDO) for microgrids (MG) applications. By combining a DC/DC ripple-controlled switching power converter with the respective voltage linear regulators at each output, improved performance in terms of load and line regulations is obtained. To achieve that aim, a current-steering switching policy is proposed, together with a resource-aware circuit implementation. The ripple-based hysteretic control results in variable switching frequency to guarantee critical conduction mode (boundary of CCM and DCM).Peer ReviewedPostprint (published version

A contribution to students’ assessment adjusts of multiple choice questionnaires with fuzzy logic

In University environment, it is common to use multiple-choice objective tests with three or four possible answers, of which only one is correct and the rest are erroneous. In this type of tests, usually the wrong answers are penalized in order to avoid the effect of the random answers. However, there are questions that hardly students answer since their difficulty is high. On the other hand, there are also questions that answer virtually all students since their difficulty is simple. While sometimes the course professor chooses to suppress these questions, it is also common to leave them as part of the calculation of the overall score. This communication proposes a way of, without suppressing any question, making a readjustment of the grades based on fuzzy logic techniques. To do this, it is considered, on the one hand, the initial grade obtained by each student and, on the other, the total difficulty index of the test. With these two variables, an approximation can be made to a system of linguistic variables that allows correcting the final grades of each student based on the objective difficulty of the test and a set of rules established by the professor. This will revert to greater “justice” in students’ mark system, since it will be a function of the difficulty of the test

Capacitorless voltage regulator devoted to power management

This article aims to present the design of a 4.5-V, 450-mA low drop-out (LDO) voltage linear regulator based on a two-stage cascoded operational transconductance amplifier (OTA) as error amplifier. The aforementioned two-stage OTA is designed with cascoded current mirroring technique to boost up the output impedance. The proposed OTA has a DC gain of 101 dB under no load condition. The designed reference voltage included in the LDO regulator is provided by a band gap reference with the temperature coefficient (T¿) of 0.025 mV/ºC. The proposed LDO regulator has a maximum drop-out voltage of 0.5 V @ 450 mA of load current, and has the worst case power supply rejection ratio (PSRR) of [54.5 dB, 34.3 dB] @ [100 Hz, 10 kHz] in full load condition. All the proposed circuits are designed using a 0.35 µm CMOS technology. The design is checked in order to corroborate its performance for wide range of input voltage, founding that the circuit design works fine meeting all the initial specification requirements.Postprint (published version