El Futuro de la Tecnología CMOS

[spa] Desde su aparación en los años sesenta, la tecnología CMOS (del inglés Complementary Metal Oxide Semidanductor) ha ido evolucionando rápida- y constantemente llegando a ser la tecnología de fabricación de circuitos más utilizada en la actualidad. Sin embargo, la drástica reducción en tamaño de los transistores MOS convencionales supondrá, en los próximos años, cambios radicales en su estructura y por lo tanto en su proceso de fabricación. Así pues, el objetivo de este artículo será exponer en mayor o menor medida estos cambios así como dar una visión general de la tecnología CMOS dentro del marco de los circuitos integrados

New design parameters for biparabolic beach profiles (SW Cadiz, Spain)

165 profiles of seventy-one beaches along the Gulf of Cadiz (SW, Spain) were studied to improve the formulation of the beach profile in tidal seas. Maritime climate, degree of energy exposure and size of the sand grains were taken into account to study the two sections of the biparabolic profile. The objective of the study was the determination of more accurate formulations of the design parameters for the equilibrium profile that involves tidal seas. These formulations were modelled and validated based on existing profiles to quantify the error existing between the real profile and the modelling. This comparative analysis was extended by considering the formulations proposed by other authors. The best results were obtained with the proposal presented herein

A Design Parameter for Reef Beach Profiles—A Methodology Applied to Cadiz, Spain

The southwestern coast of Spain is in a tidal zone (mesotidal) which causes the equilibrium profile to be developed in two different sections: the breakage section and the swash section. These two sections give rise to the typical bi-parabolic profile existing in tidal seas. The existence of areas with reefs/rocks which interrupt the normal development of the typical bi-parabolic profile causes different types of beach profiles. The objective of this article is designing an easy methodology for determining new formulations for the design parameters of the equilibrium profile of beaches with reefs in tidal seas. These formulations are applied on 16 profiles to quantify the error between the real profile data and the modelling results. A comparative analysis is extended to the formulations proposed by other authors, from which it is found that better results are obtained with the new formulations

Mechanisms of Action of Non-Canonical ECF Sigma Factors

Extracytoplasmic function (ECF) sigma factors are subunits of the RNA polymerase specialized in activating the transcription of a subset of genes responding to a specific environmental condition. The signal-transduction pathways where they participate can be activated by diverse mechanisms. The most common mechanism involves the action of a membrane-bound anti-sigma factor, which sequesters the ECF sigma factor, and releases it after the stimulus is sensed. However, despite most of these systems following this canonical regulation, there are many ECF sigma factors exhibiting a non-canonical regulatory mechanism. In this review, we aim to provide an updated and comprehensive view of the different activation mechanisms known for non-canonical ECF sigma factors, detailing their inclusion to the different phylogenetic groups and describing the mechanisms of regulation of some of their representative members such as EcfG from Rhodobacter sphaeroides, showing a partner-switch mechanism; EcfP from Vibrio parahaemolyticus, with a phosphorylation-dependent mechanism; or CorE from Myxococcus xanthus, regulated by a metal-sensing C-terminal extension.Spanish Government (PID2020-112634GB-I00)FEDER funds (grant A-BIO-126-UGR20

Development versus predation: Transcriptomic changes during the lifecycle of Myxococcus xanthus

Myxococcus xanthus is a multicellular bacterium with a complex lifecycle. It is a soil-dwelling predator that preys on a wide variety of microorganisms by using a group and collaborative epibiotic strategy. In the absence of nutrients this myxobacterium enters in a unique developmental program by using sophisticated and complex regulatory systems where more than 1,400 genes are transcriptional regulated to guide the community to aggregate into macroscopic fruiting bodies filled of environmentally resistant myxospores. Herein, we analyze the predatosome of M. xanthus, that is, the transcriptomic changes that the predator undergoes when encounters a prey. This study has been carried out using as a prey Sinorhizobium meliloti, a nitrogen fixing bacteria very important for the fertility of soils. The transcriptional changes include upregulation of genes that help the cells to detect, kill, lyse, and consume the prey, but also downregulation of genes not required for the predatory process. Our results have shown that, as expected, many genes encoding hydrolytic enzymes and enzymes involved in biosynthesis of secondary metabolites increase their expression levels. Moreover, it has been found that the predator modifies its lipid composition and overproduces siderophores to take up iron. Comparison with developmental transcriptome reveals that M. xanthus downregulates the expression of a significant number of genes coding for regulatory elements, many of which have been demonstrated to be key elements during development. This study shows for the first time a global view of the M. xanthus lifecycle from a transcriptome perspective.Grant PID2020-112634GB-I0 funded by MCIN/AEI/ 10.13039/501100011033FEDER funds (grant A-BIO-126-UGR20

Virtual resources for the improvement of teaching in the course of Port and Coastal Engineering (dregree in Civil Engineering)

Port and Coastal Engineering is a subject included in the third year of the degree in Civil Engineering (Civil Constructions and Hydrology specialty) taught at the Polytechnic School of Algeciras. As this is a subject with a very specific syllabus, there is no textbook (or even appropriate references) that contemplates all the related topics of the whole course. Moreover, there are many students who, for different reasons (repeaters, Erasmus, labour obligations, ...), cannot attend the regular classes. This lack of attendance has been leading to another problem: this kind of students have been leaving the subject for several years. In addition, understanding of the basic concepts becomes even more complicated for Erasmus students enrolled in the subject because of the language barrier. In order to solve this problem, a project of teaching innovation has been launched which consists of the creation of a set of evaluable tasks for the different topics addressed to be performed by the students. In this way, the students are motivated to keep up-to-date the course contents. A comparison of the last year results with those of the preceding five years is provided. Finally, an analysis of the significance of the improvement is also presented

Diseño y fabricación de un filtro pasabanda pasivo con líneas acopladas

[spa] Las señales electromagnéticas que ocupan la banda de frecuencias de radio (RF) se transmiten por líneas de transmisión, que son estructuras materiales capaces de dirigir la energía de un punto a otro del circuito. Debido al campo electromagnético generado por una señal RF, dos líneas de transmisión próximas pueden propagar parte de la energía que circula de una a la otra. Aprovechando estas propiedades de acoplamiento capacitivo e inductivo entre líneas, se ha diseñado, simulado y fabricado un filtro pasabanda pasivo realizado con líneas de transmisión

Increase in the Erosion Rate Due to the Impact of Climate Change on Sea Level Rise: Victoria Beach, a Case Study

This article provides a general methodology for calculating the retreat of the coastline and the volume of sand necessary to renourish a beach due to sea level rise (SLR) in the medium-long term. An example is presented, Victoria Beach, and a projection is made for the years 2030, 2040, 2050, and 2100. The results obtained take into account global sea level rise (GSLR), which is worldwide, and local sea level rise (LSLR), which considers climate variability and vertical land movements. Regarding GSLR, data were provided by the projections from IPCC (Intergovernmental Panel on Climate Change) scenarios and empirical models, such as Rahmstorf and Pfeffer. The LSLR data came from the tide gauge station located in Cadiz. Finally, the results obtained showed that global warming impacts erosive effects and the subsequent volume of sand required to renourish beaches. The total sea level rise (TSLR) projections indicated for Victoria Beach are relatively higher than the GSLR projections. Even in the best IPCC scenario (RCP 2.6), Victoria Beach presents a significant erosion of 52 m, requiring a volume of sand of 1.0 Mm3 to supply renourishment.14 página

Use of the ANKI Software in Coastal Engineering Courses: Methodology and Results

Many people believe that engineering subjects require only mathematical and physical abilities as well as space perception. However, some aspects of the syllabus, must be memorized to achieve optimal academic results. The pandemic situation has meant a reduction in face-to-face classes, which has made it difficult to highlight (through repetition by teachers) those concepts that must be learnt by heart due to their importance. As is well known, the Notecard Question and Answer Technique (NQAT, based on Leitner’s system) helps students to learn those important ideas that must be kept in the long term memory to remember when needed. Therefore, an educational project is presented here that contemplates the creation of a database of question-answer cards to facilitate the memorization of concepts, formulas and key values of different parameters essential for understanding coastal engineering problems. The methodology was experimented in different courses, related to Coastal and Port Engineering. These courses are included in the third year of the Marine Sciences and Civil Engineering Bachelor degrees as well as in the MSc degree in the University of Cadiz. The program chosen was the ANKI, of broad application, easy to use and free to access. As a collateral advantage, students became familiar with this software and were able to use it in other subjects. Through a selective distribution of the different topics, all the students participated in the task of preparing the cards. Their use was encouraged by a series of online tests and a “supplementary bonus” to the final examination. The results obtained between the current course (with flash cards) and the previous one (without flash cards) did not show any substantial change in the number of students who pass the subject. However, students reported that it took less time to memorize formulations and key concepts

Differential microfluidic sensors based on dumbbell-shaped defect ground structures in microstrip technology : analysis, optimization, and applications

A microstrip defect ground structure (DGS) based on a pair of dumbbell-shaped slots is used for sensing. The device is a differential sensor consisting of a pair of mirrored lines loaded with a dumbbell-shaped DGS, and the output variable is the cross-mode transmission coefficient. Such a variable is very sensitive to asymmetries in the line pair, e.g., caused by an asymmetric dielectric load in the dumbbell-shaped DGSs. Therefore, the sensor is of special interest for the dielectric characterization of solids and liquids, or for the measurement of variables related to complex permittivity changes. It is shown in this work that by adding fluidic channels on top of the dumbbell-shaped DGSs, the device is useful for liquid characterization, particularly for the measurement of solute concentration in very diluted solutions. A sensitivity analysis useful for sensor design is carried out in this paper