Access to information and degree of community awareness of preventive health measures in the face of covid-19 in Spain

[EN] The COVID-19 pandemic is posing a major health crisis. Spanish legislation establishes the mandatory use of masks and the implementation of hygienic measures such as hand washing and physical distancing. The aim of this study is to describe access to information and the level of community knowledge/adoption about the preventive measures proposed by the Spanish health authorities in response to the COVID-19 pandemic and to analyze the influence of socio-demographic factors in compliance among people over 18 years of age resident in Spain. An observational, descriptive and transversal study was conducted. Data was collected on sociodemographic variables, access to information and the degree of knowledge/adoption about the preventive measures: use of masks, hand hygiene and physical distancing. A total of 1811 people participated. The average age was 45.1 ± 15.1 years, predominantly female (69.3%), from an urban geographical area (74%), with a higher education level of 53.2%. Most of the respondents (57.5%) are or live with people at risk. The main access to information on preventive measures was from secondary sources (49.2%), with television being the main medium; 72.3% think that there are some difficulties in accessing information, while 8.7% of the participants do not consider the use of masks to be useful. As regards the choice of type of mask, the majority of people (44.8%) opt for the surgical variety; 88.5% of respondents believe that the physical distancing established is at least 1.5 m. This study confirmed that socio-demographic factors influence compliance with or the degree of knowledge/adoption of the preventive measures proposed to combat the COVID-19 pandemic and has made it possible to ascertain the sectors of the population with the greatest deficiencies in this respect. It shows the importance of implementing health information and education systems in the community, and it is advisable to promote specific programs aimed at men, people living in rural areas and people with a low level of education.S

Design Sprint: Enhancing STEAM and Engineering Education Through Agile Prototyping and Testing Ideas

[Abstract] Creating project-based learning experiences in the classroom where students learn in a team to solve complex problems and to develop creative and critical thinking is a challenge. Design Sprint (DS) is an agile methodology (implemented in 5 days) with the goal of creating innovative design based on user needs (User Experience). The objective of this work was to develop an Engineering Drawing classroom experience linked to the context of the current COVID-19 pandemic with the Design Sprint methodology. The experience had to involve the integration of theory and practice, the application of knowledge, the development of both hard and soft skills, and the empowerment of students to conduct research. 56 first-year students following three STEAM degrees at the University of A Coruña participated in this experience. The activities were designed for both face-to-face and remote learning. Microsoft Teams and Moodle were used for tutoring and for monitoring student progress. The Moodle Workshop tool was used for the evaluation of the prototypes that were developed and the projects were evaluated by video. The students defended their projects through a presentation in lightning talk format (Ignite). Evaluation rubrics were used following a triple approach: co-evaluation, hetero-evaluation and self-evaluation. The 3D design of the projects was developed with Autodesk software. A total of 18 projects were developed. Once the projects were completed, a survey was administered to evaluate the levels of student satisfaction. The survey results were very positive. The Design Sprint projects also showed positive effects on grades. The Design Sprint method has promoted an interactive learning environment. In addition to its simplicity, a further advantage of DS method is that all student dedication is planned. Students were therefore less likely to feel overloaded, all of which helps with better time management. The DS methodology is multipurpose, so it can be applied to various fields and subjects

Analysis of injection-locked pulsed waveform oscillators

The injection-locked behaviour of a high efficiency pulsed waveform oscillator is analyzed in detail. The design is based on a closed-loop configuration, loaded with a short nonlinear transmission line (NLTL). A new technique is provided to predict the effect of the circuit elements on the synchronization bandwidth, which enables an overall optimization of the oscillator design, considering efficiency, pulse width and locking interval. The phase-noise minimum in free-running conditions, obtained for particular values of the design parameters, is investigated through the use of phase sensitivity functions. The impact of this minimum on the noise spectrum in injection-locked conditions is also studied. The techniques have been applied to a pulsed-waveform oscillator at 0.9 GHz

Stability analysis of oscillators driven with multi-harmonic sources

An investigation of the synchronization behavior of oscillators driven with multi-harmonic sources is presented. The occurrence of ultra-subharmonic synchronization is demonstrated, which gives rise to a multi-resonance behavior versus the fundamental input frequency. When this frequency decreases, instabilities arise in the low amplitude intervals of the multi-resonance curve, and both flip and Hopf bifurcation may delimit the stable synchronization intervals. The study provides a generalization of the theory of fundamentally locked oscillators to the case of oscillators driven with multi-harmonic signals. It is illustrated through application to an oscillator at 5.7 GHz.This work has been supported by the Spanish Government under contract TEC2011-29264-C03-01

Subharmonically injection-locked oscillator using a nonlinear transmission line

This work describes a first realization of an oscillator driven through a nonlinear transmission line (NLTL). In this way, the oscillator is able to synchronize to a sinusoidal injection source of much lower frequency. This can be understood as the result of two processes: high harmonic generation in the NLTL and frequency multiplication plus mixing in the oscillator device. The concept can be applicable in ultrawideband signal oscillators where synchronization should enable a fast oscillation start-up and facilitate the modulation process. As an example, it has been used here to obtain a pulsed-envelope oscillator at 6 GHz injected with a sinusoidal signal in the order of 100 MHz. The operation bands have been analyzed with a Poincaré map technique, allowing the detection of the bifurcation phenomena that delimit the stable synchronization ranges. For an understanding of the phase-noise spectrum, this spectrum is analyzed at higher injection frequencies with the conversion matrix approach. Very good results have been obtained in comparison with measurements.Spanish project TEC2011-29264-C03-01 for financial support

ALOS-2 L-band SAR backscatter data improves the estimation and temporal transferability of wildfire effects on soil properties under different post-fire vegetation responses

Remote sensing techniques are of particular interest for monitoring wildfire effects on soil properties, which may be highly context-dependent in large and heterogeneous burned landscapes. Despite the physical sense of synthetic aperture radar (SAR) backscatter data for characterizing soil spatial variability in burned areas, this approach remains completely unexplored. This study aimed to evaluate the performance of SAR backscatter data in C-band (Sentinel-1) and L-band (ALOS-2) for monitoring fire effects on soil organic carbon and nutrients (total nitrogen and available phosphorous) at short term in a heterogeneous Mediterranean landscape mosaic made of shrublands and forests that was affected by a large wildfire. The ability of SAR backscatter coefficients and several band transformations of both sensors for retrieving soil properties measured in the field in immediate post-fire situation (one month after fire) was tested through a model averaging approach. The temporal transferability of SAR-based models from one month to one year after wildfire was also evaluated, which allowed to assess short-term changes in soil properties at large scale as a function of pre-fire plant community type. The retrieval of soil properties in immediate post-fire conditions featured a higher overall fit and predictive capacity from ALOS-2 L-band SAR backscatter data than from Sentinel-1 C-band SAR data, with the absence of noticeable under and overestimation effects. The transferability of the ALOS-2 based model to one year after wildfire exhibited similar performance to that of the model calibration scenario (immediate post-fire conditions). Soil organic carbon and available phosphorous content was significantly higher one year after wildfire than immediately after the fire disturbance. Conversely, the short-term change in soil total nitrogen was ecosystem-dependent. Our results support the applicability of L-band SAR backscatter data for monitoring short-term variability of fire effects on soil properties, reducing data gathering costs within large and heterogeneous burned landscapesS

Spanish photovoltaic solar energy: institutional change, financial effects, and the business sector

Spain is a country with a high dependence on fossil fuels. For this reason, in 2007, it implemented a bonus system that aimed to encourage the production of renewable energies, particularly photovoltaic solar energy. These production bonuses, guaranteed by the Spanish government, led to an exponential increase in the number of companies in the market and, consequently, the MWh produced. However, in 2012, given the excessive budgetary burden involved in maintaining this “feed-in tariff” system and after several years of institutional instability, the aforementioned system of incentives for phoyovoltaic (PV) energy was eliminated. This paper has tried to analyze the consequences of this institutional change, a clear example of the “hold up” problem. For this purpose, a sample of 5354 companies, which was divided, geographically, into Spanish regions and, temporarily, into three different periods, has been taken, considering diverse economic and financial variables. The results show a notable weakening of the sector that, due to the effects of the regulatory change, has lost attractiveness and profitability for investors and is consequently suffering from stagnation, which has led to the disappearance of many companies in the sector.Raquel Fernández González gratefully acknowledge the financial support provided by the Xunta de Galicia under Grants ED431C2018/48 and ED431E2018/07 and the Ministry of Economy and Competitiveness under Grant RTI2018-099225-B-100. This research was funded by Regional Government of Castilla y León under the “Support Program for Recognized Research Groups of Public Universities of Castilla y León” (ORDEN EDU/667/2019) and the Spanish Ministry of Science, Innovation & Universities under the I + D + i state program “Challenges Research Projects” (Ref. RTI2018-098900-B-I00)

Segmenting colour images on the basis of a fuzzy hierarchical approach

In this paper we deal with two problems related to imprecision in colour image segmentation processes: to decide whether a set of pixels verify the property "to be homogeneously coloured", and to represent the set of possible segmentations of an image at different precision levels. In order to solve the first problem we introduce a measure of distance between colours in the CIE L*a*b* space, that allows us to measure the degree of homogeneity of two pixels p and q on the basis of the maximum distance between the colours of consecutive pairs of pixels in any path linking p and q . Since homogeneity is a matter of degree, we define a (fuzzy) segmentation of an image as a set of fuzzy regions, each of them being a fuzzy subset of pixels, that we obtain by using a region growing technique. The membership degree of each pixel to each region is calculated on the basis of our homogeneity measure. The second problem is solved by introducing a fuzzy similarity relation between the fuzzy regions in this initial segmentation. The different α-cuts of the similarity relation define the set of precision levels, from which a nested hierarchy of fuzzy segmentations is finally obtained

Optoelectronic properties of Ag2S/graphene and FeS2/ graphene nanostructures and interfaces: A density functional study including dispersion forces

The optoelectronic properties of several Ag2S/graphene and FeS2/graphene nanostructures are examined through density functional theory calculations including dispersion forces. First, we analyzed the electronic structure of Ag2S and FeS2 nanocluster models, as prototypes of quantum dots, focusing on the electronic structure and absorption spectra. In the case of FeS2 nanoparticle, both ferro- and antiferromagnetic arrangements were considered. Then, Ag2S and FeS2 nanoclusters were adsorbed on top of both graphite and graphene slab models to study the stability of the systems as well as the effect of the nanocluster–surface interaction in the electronic structure, including an insight into the electron injection mechanisms in these systems. Finally, interface models, consisting of Ag2S or FeS2 thin films adsorbed on a graphene layer, were built and their optoelectronic properties examined. Overall, the results obtained in this work, support the suitability of these systems for their usage in solar cells.Ministerio de Ciencia e Innovación and EU-FEDER PID2019-106871GB-I00Junta de Andalucía-FEDER, US-138141

Physiological and Regenerative Plant Traits Explain Vegetation Regeneration under Different Severity Levels in Mediterranean Fire-Prone Ecosystems

15 p.In Mediterranean fire-prone ecosystems, plant functional traits and burn severity have decisive roles in post-fire vegetation recovery. These traits may reflect plant fitness to fire regimes in the Mediterranean Basin. The aim of this study was to evaluate the effect of burn severity on post-fire vegetation regeneration through plant functional (physiological and regenerative) traits in two Mediterranean ecosystems: one more humid and colder (Cabrera in León province, NW Spain), and another characterized by a longer summer drought (Gátova in Valencia province, SE Spain). A total of 384 and 80 field plots (2 m 2 m) were fixed in Cabrera and Gátova, respectively. In each burned plot, we quantified burn severity by means of the composite burn index (CBI), differentiating three severity levels (low, moderate, and high), and evaluated post-fire vegetation regeneration one and two years after wildfires. We measured the percentage cover of each species and classified them according to physiological (specific leaf area and N2-fixing capacity) and regenerative traits (reproductive strategy, bud bank location, and heat-stimulated germination). The main results showed that in Cabrera, burn severity had significant effects on vegetation cover independently of plant functional traits. In Gátova, burn severity effects differed among functional traits. In this site, the cover of plants with low specific leaf area and without heat-stimulation and N2-fixing capacity was negatively related to burn severity. On the contrary, the cover of N2-fixers and species with resprouting ability and heat-stimulated germination rose with increasing burn severity. In general, vegetation cover showed a more pronounced increased over time in the more humid area, mainly under the effect of high severity. The results of this research highlighted the importance of the use of plant functional traits as a driver to understand the response of different ecosystems to current fire regimes, which could be relevant for pre- and post-fire management.S