University of Vigo
  • Vigo, Pontevedra, Spain
Recent publications
This paper proposes a gradient descent (GD) algorithm-based B-Spline wavelet neural network (GDB-SWNN) learning adaptive controller for linear motor (LM) systems under system uncertainties and actuator saturation constraints. A recursive least squares (RLS) algorithm-based indirect adaptive strategy is used to effectively estimate model parameters, which can guarantee they converge to true values. A novel GDBSWNN compensator is proposed to estimate the remaining complex uncertainties, where weights are updated by online GD training. An auxiliary system is integrated into the control scheme to address the saturation problem, which guarantees stability and satisfactory control performance when saturation occurs. In addition, a stability analysis is presented to prove that all signals of the closed-loop system are bounded using the Lyapunov theory. Experiments have been conducted on an LM-driven motion platform, where different controllers have been tested, demonstrating the effectiveness and advantages of the proposed approach.
Bioconversion of livestock wastes using insect larvae represents an emerging and effective strategy for waste management. However, knowledge on the role of the garden fruit chafer (Pachnoda sinuata L.) in waste recycling and influence on the diversity of microbial community in frass fertilizer is limited. Here, we determined whether and to what extent the conversion of cattle dung into insect frass fertilizer by P. sinuata influences the frass’ microbial community and its associated antibiotic resistance genes abundance. Pachnoda sinuata larvae were used to valorise cattle dung into frass fertilizer; samples were collected weekly to determine the composition of bacteria and fungi, and antibiotic resistant genes using molecular tools. Results revealed that bioconversion of cattle dung by P. sinuata larvae significantly increased the richness of beneficial bacteria in the frass fertilizer by 2.5-folds within 28 days, but fungal richness did not vary during the study. Treatment of cattle dung with P. sinuata larvae caused 2 – 3-folds decrease in the genes conferring resistance to commonly used antibiotics such as aminoglycoside, diaminopyrimidine, multidrug, sulfonamide and tetracycline within 14 days. Furthermore, the recycling cattle dung using considerably reduced the abundance of mobile genetic elements known to play critical roles in the horizontal transfer of antibiotic resistance genes between organisms. This study highlights the efficiency of saprohytic insects in recycling animal manure and suppressing manure-borne pathogens in the organic fertilizer products, opening new market opportunities for innovative and safe bio-based products and achieving efficient resource utilization in a circular and green economy.
Offshore wind energy is an important agent to fight climate change. However, it is simultaneously very sensitive to climate change. This study analyzes the future changes in wind speed of 10 m above sea surface (V10) in the North Atlantic Ocean and how these variations may affect offshore wind energy resources for three potential subregions (the United States (US) East Coast, western Iberian Peninsula, and the Caribbean Sea). Dynamic downscaling of three different future scenarios of the CESM2 global climate model (CMIP6 project) was performed using the WRF-ARW atmospheric model. V10 is expected to decrease in the winter and spring seasons but increase in summer and autumn, mainly in tropical regions up to 30 °N. Annually, it shows the maximum increase in the tropical region. For the Iberian Peninsula subregion, significant increases in summer are expected for wind power density (WPD) along the 21st century, but there is uncertainty for the other seasons. A WPD decrease in winter and increases in summer and autumn are expected along the 21st century for the US subregion. No significant changes were observed at annual scale. Finally, for the Caribbean Sea, a decrease is projected in the Yucatan Basin and considerable increases are foreseen for the Colombia and Venezuela basins.
The desert vipers of the genus Cerastes are a small clade of medically important venomous snakes within the family Viperidae. According to published morphological and molecular studies, the group is comprised by four species: two morphologically similar and phylogenetically sister taxa, the African horned viper (Cerastes cerastes) and the Arabian horned viper (Cerastes gasperettii); a more distantly related species, the Saharan sand viper (Cerastes vipera), and the enigmatic Böhme’s sand viper (Cerastes boehmei), only known from a single specimen in captivity allegedly captured in Central Tunisia. In this study, we sequenced one mitochondrial marker (COI) as well as genome-wide data (ddRAD sequencing) from 28 and 41 samples, respectively, covering the entire distribution range of the genus to explore the population genomics, phylogenomic relationships and introgression patterns within the genus Cerastes. Additionally, and to provide insights into the mode of diversification of the group, we carried out niche overlap analyses considering climatic and habitat variables. Both nuclear phylogenomic reconstructions and population structure analyses have unveiled an unexpected evolutionary history for the genus Cerastes, which sharply contradicts the morphological similarities and previously published mitochondrial approaches. Cerastes cerastes and C. vipera are recovered as sister taxa whilst C. gasperettii is a sister taxon to the clade formed by these two species. We found a relatively high niche overlap (OI > 0.7) in both climatic and habitat variables between C. cerastes and C. vipera, contradicting a potential scenario of sympatric speciation. These results are in line with the introgression found between the northwestern African populations of C. cerastes and C. vipera. Finally, our genomic data confirms the existence of a lineage of C. cerastes in Arabia. All these results highlight the importance of genome-wide data over few genetic markers to study the evolutionary history of species.
Necrotizing soft-tissue infections (NSTIs) are infrequent but associated with a high mortality grade. An accurate diagnosis is difficult in the early stages, and a high level of suspicion is required. We present a 45-year-old male that came to the emergency room (ER) due to general malaise and extensive skin injuries in the lower right limb. He mentioned a 3-month-old injury, and self-performed cures were made. He was alert but presented generalized illness (tachycardia, tachypneic, hypotension, and fever) and functional impotence with inflammatory signs of the right inferior limb. The presence of pain, swelling, crepitation. and intense odor caught our attention. Laboratory tests provided data of infection (high procalcitonin and creatinine phosphokinase) with incipient renal failure with lactic acidosis and moderate hyponatremia. The patient was admitted to the Intensive Care Unit with a preliminary diagnosis of soft tissue septic shock. We initiated intravenous fluid therapy, norepinephrine to maintain MAP around 65 mmHg, shock dose corticosteroid, and empirical antibiotic treatment with Piperacillin-Tazobactam and Clindamycin. Simultaneously we contacted our Traumatology Team who examined the patient. A CT scan of the lower limbs was performed, and an ulcer on the sole of the foot approximately 3 cm deep with intraosseous gas was encountered. Urgent surgical intervention was decided, and a right supracondylar amputation was made. During his admission to ICU, despite the broad specter antibiotic that was changed to Meropenem, Vancomicyn, and Clindamycin, the main problem was a prolonged high fever with negative blood cultures and eventually negative tissue cultures. A tracheostomy was performed on the 28th day, and a total of 8 surgical interventions were made. Eventually, he was decannulated on the 42nd day. After 44 days of ICU admission, the patient was transferred to a standard-care hospital room and finally was discharged.
This work studies a new 90º connection system based on clamps for a square or rectangular steel profile, which can be used on existing structures without any prior or invasive operations. The main field where this connection system could be used would be in industrial plants, since it allows the reuse of industrial structures as many times as necessary, depending on each layout change, thus obtaining significant economic savings. This work aims to analyse the behaviour of this new type of connection using a 3D FEM-based numerical analysis procedure, previously validated against experimental tests. In this research, it has been possible to identify four behavioural modes, the first of which, linear behaviour, is the most suitable for the operational work of this type of connection. The distance between the bolts, one of the most important variables affecting the mechanical response, is parameterised and analysed in a numerical model. According to the results, the strength of the joint improves as the distance between the bolts increases, but this also means larger clamps and the need for more space.
Background and aims Liver diseases play an important role in the development and progression of atrial fibrillation (AF). The Fibrosis-4 (FIB-4) index is a non-invasive score recommended for detecting liver fibrosis. Since the association between liver fibrosis and outcomes of AF patients is still not well defined, we aim to analyze prognosis impact of FIB-4 index in those patients. Methods A retrospective population-based cohort study was performed with 12,870 unselected patients from a single health area in Spain with AF from 2014 to 2019. Cox regression models were used to estimate the association of FIB-4 index with mortality. The association with ischemic stroke (IS), major bleeding (MB), acute myocardial infarction (AMI), and heart failure (HF) was assessed by competing risk analysis. Results A total of 61.1%, 22.0%, and 16.9% were classified as low, moderate and high risk of liver fibrosis according to FIB-4 index, respectively. During a mean follow-up of 4.5 ± 1.7 years, FIB-4 index was associated with mortality (adjusted HR 1.04; 95% CI 1.01–1.06; p = 0.002), MB and HF (adjusted sHR 1.03, 95% CI 1.01–1.04; p = 0.004), but not with IS or with AMI. The association between FIB-4 and MB was only found in patients treated with vitamin K antagonists, not in patients on direct oral anticoagulants. Conclusions The FIB-4 index, a non-invasive scoring method for evaluating liver fibrosis, is independently associated with all-cause mortality, MB and HF in patients with AF, suggesting that it may be useful as a risk assessment tool to identify adverse outcomes in patients with AF. Graphical abstract
Ferromagnetism in 2D materials has attracted tremendous interest from the scientific community thanks to its potential for the design of magnetic materials with unique properties. The presence of a ferromagnetic element in a 2D material can improve the existing properties and offer new ones, giving rise to the development of manifold applications. This review focuses on recent advances and perspectives of 2D materials that bear at least one ferromagnetic element (iron, cobalt, nickel) as i) structural constituent, ii) dopant atom, or iii) adjacent atom through proximity effect. By describing in detail the magnetic properties that have emerged so far, their potential to form next‐generation 2D magnets is discussed. Moreover, the contribution of such 2D materials is analyzed in various applications (electrochemical, photochemical, optical, and electronic), aiming to explore further functionalities and capabilities of ferromagnetic elements, apart from their magnetic nature. Special attention is given to gadolinium and other rare earth elements that display a ferromagnetic order even at ultra‐low temperatures and form part of 2D structured materials, with particularly appealing properties deriving from their 4f electrons.
Plexcitonic nanoparticles exhibit strong light‐matter interactions, mediated by localized surface plasmon resonances, and thereby promise potential applications in fields such as photonics, solar cells, and sensing, among others. Herein, these light‐matter interactions are investigated by UV‐visible and surface‐enhanced Raman scattering (SERS) spectroscopies, supported by finite‐difference time‐domain (FDTD) calculations. Our results reveal the importance of combining plasmonic nanomaterials and J‐aggregates with near‐zero‐refractive index. As plexcitonic nanostructures nanorattles are employed, based on J‐aggregates of the cyanine dye 5,5,6,6‐tetrachloro‐1,1‐diethyl‐3,3‐bis(4‐sulfobutyl)benzimidazolocarbocyanine (TDBC) and plasmonic silver‐coated gold nanorods, confined within mesoporous silica shells, which facilitate the adsorption of the J‐aggregates onto the metallic nanorod surface, while providing high colloidal stability. Electromagnetic simulations show that the electromagnetic field is strongly confined inside the J‐aggregate layer, at wavelengths near the upper plexcitonic mode, but it is damped toward the J‐aggregate/water interface at the lower plexcitonic mode. This behavior is ascribed to the sharp variation of dielectric properties of the J‐aggregate shell close to the plasmon resonance, which leads to a high opposite refractive index contrast between water and the TDBC shell, at the upper and the lower plexcitonic modes. This behavior is responsible for the high SERS efficiency of the plexcitonic nanorattles under both 633 nm and 532 nm laser illumination. SERS analysis showed a detection sensitivity down to the single‐nanoparticle level and, therefore, an exceptionally high average SERS intensity per particle. These findings may open new opportunities for ultrasensitive biosensing and bioimaging, as superbright and highly stable optical labels based on the strong coupling effect.
Light pollution is one of the fastest growing environmental problems in recent years, mainly affecting urbanized areas worldwide. It goes beyond the difficulty of the astronomical observation, causing a deep impact on the balance of ecosystems, wildlife and human health. To deal with this complex situation, it is necessary to increase public awareness and to demand from all implicated stakeholders efficient technical solutions to stop and mitigate unwanted light pollution effects. A continous monitoring of light pollution levels is also mandatory. In this context, we propose a new device called FreeDSM, an IoT based photometer to measure the quality of the dark sky at night. FreeDSM will be easy-to-use and easy-to-build, so every interested citizen can create their own and collaborate with the project. The main component of the photometer is an ESP32C3 microcontroller, a cheap, small, low consumption and powerful chip. Also, a TSL2591 optical sensor, of high sensitivity and large dynamic range, is included. Thanks to the proposed design, additional positioning or ambiance sensors could be incorporated. To handle all these components, the ESP32 firmware is implemented through Tasmota, an open-source home assistant solution for most of commercial sensors. And all the information to be gathered by the FreeDSM devices will be made public via a platform built using FIWARE, an open framework for IoT solutions. By doing so, this solution aims to standarization of IoT collected data, easing users own new applications development and public awareness increase of the problem. Our proposed approach is expected to empower individuals to take action against unnecessary outdoor lightning.
Radiocommunications in the mmWave band present strong free-space attenuation, which requires power maximization at the receiver. A code division multiple access (CDMA) modulation system increases the receiver’s ability to detect the transmitted signal by means of spectrum spreading. The main benefit of direct sequence spread spectrum for mmWaves is the increase in coverage due to the process gain. The main drawback of its use in high-speed communications is bandwidth reduction. Fortunately, this can be compensated for by the huge bandwidth available at mmWave frequencies. However, most of the codes available for CDMA have mutual interference. The zero correlation zone (ZCZ) codes are orthogonal to each other, but only under the condition that no multipath far echoes are received. This condition is fulfilled in mmWave radio communications, owing to strong propagation attenuation and also because of the beamforming that radio links usually do at this frequency. In this study, a field experiment is carried out consisting of data reception at 28 GHz from many different users who are simultaneously transmitting using CDMA on BPSK modulation and then comparing the performance of conventional maximal pseudorandom (PR) codes versus ZCZ codes. It is verified that the latter are received with the same process gain but no mutual interference, approximately resulting in a 12 dB improvement on the modulation error ratio (MER).
This study aimed to systematically revise the available evidence on the effects of physical exercise training programmes on people with hypothyroidism. Comparative studies were searched in six electronic databases until April 2023. The Physiotherapy Evidence Database and the Methodological Index for Non-Randomized Studies were used to determine the methodological quality of the randomized controlled trials and comparative studies respectively. A total of 10 studies were found showing a low to moderate methodological quality. Most of them were performed in women with subclinical hypothyroidism. Exercise seemed to be safe, with aerobic and resistance training leading to improvements in outcomes related to physical and mental health. The performed meta-analysis with data from 120 participants indicated that exercise showed a non-significant trend towards reducing thyroid-stimulating hormone levels (Hedges'g -0.96; 95% CI -2.71; 0.79, p = 0.160; I2 = 92%). When the analysis was performed by comparing the experimental, and control groups with data from 180 participants the results remained non-significant (SMD -1.09; CI 95% -2.88; 0.70, p = 0.23; I2 = 95%). Similar findings were obtained when pooling data for FT3 and FT4 levels. Exercise does not have a significant impact on thyroid function, although its practice can lead to secondary outcomes related to physical and mental health.
Aim: Understanding the roles of deterministic and stochastic processes in community assembly is essential for gaining insights into species biogeographical patterns. However, the way community assembly processes operate is still not fully understood, especially in oceanic islands. In this study, we examine the importance of assembly processes in shaping diatom communities in islands and continents, while also investigating the influence of climate and local water chemistry variables on species distributions. Location: Global. Taxon: Stream benthic diatoms. Methods: We used diatom datasets from five continents and 19 islands and applied beta diversity analyses with a null model approach and hierarchical joint species distribution modelling. Additionally, we used continental area equivalents (CAEs) to facilitate analyses in continents, as these subsets have comparable areas and contain the same number of study sites as their corresponding islands. Results: We found that homogeneous selection dominated the assembly process within islands whereas stochastic processes tended to be more important within continents. In addition, assembly processes were influenced by study scale and island isolation. Climatic variables showed a greater influence on species distribution than local factors. When focusing on taxa unique to islands, local environmental variables had a greater impact on their distributions, compared to non-unique species. Main conclusions: We observed that the assembly processes of diatom communities are complex and influenced by a combination of deterministic and stochastic forces, which vary across spatial scales. In islands, our results suggest that there is no universal pattern of assembly processes acting on a global scale, as their influence depends on abiotic conditions such as area, isolation, and environmental heterogeneity. In addition, the sensitivity of species occurring uniquely in islands to local environmental variables suggests that they are perhaps less vulnerable to climatic changes but are more influenced by changes in local physicochemistry.
Motion control for flexible link manipulators will have a great influence on their overall performance. Conventional control systems have the problem that they cannot compensate for the presence of uncertainty due to a variety of factors such as a change in the system itself-payload variations-, degradation and modelling uncertainty. In addition, the underdamped structure of these systems entails motion-induced transient deflection and residual vibration. On the contrary, adaptive control, in particular Model Reference Adaptive Control (MRAC), has therefore been proposed to handle problems of this type dealing with other systems such as cranes, steering stability control for ground vehicles, airplanes and so on. This study presents a review and discussion on the MRAC and some individual issues of MRAC for these flexible link manipulators are addressed to specify: the state tracking error, the limitation of the adaptation values corresponding to the control gains and the control effort. Dealing with the last one, this work proves that shaping the command input to a Model Reference Adaptive Control (IS-MRAC) reduces the control effort necessary for the plant to follow the reference model and also mitigates the detrimental effects of flexibility. The IS-MRAC is implemented in a Single-Link Flexible Manipulator whose natural frequencies, experimentally and analytically estimated using the Transfer Matrix Method plus symbolic computation, vary significantly depending on payload mass and position. To this structured or parametric uncertainty, the proposed Lyapunov control law using the states associated with the low mode is designed for asymptotic stability and accommodates correctly. The state tracking, vibration suppression, and control effort reduction performances of the proposed IS-MRAC combined controller are analysed via numerical simulations and experiments.
We consider a scenario where inequality levels originate harmful effects on society. To alleviate this negative externality, we introduce tradable consumption licenses within a general equilibrium framework to obtain efficient outcomes, reduce inequality, and improve social welfare. This mechanism would be easily implementable with the necessary support of the law.
This study analyses the role of the main Spanish political groups in the polarisation of public opinion and the promotion of the culture of disinformation through Twitter (now Platform X). The study carries out an analysis of issues associated with tweets and retweets in Spanish of the total published (n = 33,506 messages out of a total of 49,288 messages), which are contrasted with 2,730 disinformation publications identified by the two most relevant fact-checking projects in Spain (Maldita.es and Newtral.es). Based on the applied methodology, a political-communicative context is observed on Platform X characterised by a high level of self-promotion and polarisation, facilitated by the communication strategy of specific topics, applied by the actors analysed. The results show how these political actors can play an active and differentiated role in the promotion of disinformation content identified by the Maldita.es and Newtral.es data verification projects. This may contribute to the polarisation of Spanish public opinion on Platform X by delegitimising the opinions of their opponents on issues of interest to the public.
This paper revisits Coase’s ideas on property rights in a scenario where the law allows the establishment of mandatory limits - caps- to specific harmful effects of economic activity such as air pollution or traffic congestion. We propose a general equilibrium model with a cap-and-trade mechanism where agents suffering the harm share a portfolio of Coasian rights designed according to the caps. Equilibrium allocations must comply with the cap, reducing polluting emissions or switching from private to public transport. In addition, the monetary transfers that result from the sale of rights to polluters yield compensation to the harmed population, increasing the non-polluters income.
Purpose Untreated HCV mono and HCV/HIV coinfected women have lower degrees of liver fibrosis (LF) compared to men. Direct acting antiviral (DAA) therapy attains viral eradication in > 90% of patients with progressive LF decline in parallel. Gender-related differences in LF regression in the long term assessed by non-invasive liver fibrosis markers (NILFM) in HCV mono and HCV/HIV coinfected after DAA treatment have not been explored so far Patients and Methods 374 HCV-infected adult patients, of them 214 HCV-HIV coinfected, were followed-up for 24 months after starting DAA therapy. LF was assessed by NILFM: transient elastometry (TE) and several biochemical indexes (APRI, Forns, FIB-4). Results Men had significantly more advanced LF at baseline than women assessed by NILFM. No LF differences at baseline in age, HIV coinfection course (CD4, HIV viral load), and HCV features (HCV viral load, genotype) were detected. No significant gender differences in LF decline after comparing 24-month and baseline LF values were observed. LF changes after DAA therapy were similar in HCV mono and HCV/HIV coinfected patients and in both sexes. Gender did not influence the course of LF decline after DAA assessed by NILFM: TE (p = 0.8), APRI (P = 0.9)), Forns (P = 0.4) and FIB-4 (P = 0. 7) by multivariate analysis. Conclusions No gender differences in the 24 month LF decline after DAA with independence of having HCV mono or HCV/HIV coinfection were found.
Motivation One of the main causes hampering predictability during the model identification and automated design of gene circuits in synthetic biology is the effect of molecular noise. Stochasticity may significantly impact the dynamics and function of gene circuits, specially in bacteria and yeast due to low mRNA copy numbers. Standard stochastic simulation methods are too computationally costly in realistic scenarios to be applied to optimization-based design or parameter estimation. Results In this work, we present IDESS (Identification and automated Design of Stochastic gene circuitS), a software toolbox for optimization-based design and model identification of gene regulatory circuits in the stochastic regime. This software incorporates an efficient approximation of the Chemical Master Equation as well as a stochastic simulation algorithm—both with GPU and CPU implementations—combined with global optimization algorithms capable of solving Mixed Integer Nonlinear Programming problems. The toolbox efficiently addresses two types of problems relevant in systems and synthetic biology: the automated design of stochastic synthetic gene circuits, and the parameter estimation for model identification of stochastic gene regulatory networks. Availability and implementation IDESS runs under the MATLAB environment and it is available under GPLv3 license at https://doi.org/10.5281/zenodo.7788692.
Institution pages aggregate content on ResearchGate related to an institution. The members listed on this page have self-identified as being affiliated with this institution. Publications listed on this page were identified by our algorithms as relating to this institution. This page was not created or approved by the institution. If you represent an institution and have questions about these pages or wish to report inaccurate content, you can contact us here.
4,642 members
Pedro Pablo Gallego
  • Department of Plant Biology and Soil Sciences
Juan Carlos Burguillo
  • Department of Telematics Engineering
Ana Rey Cao
  • Department of Special Didactics
Ana María Cao-Paz
  • Department of Electronics Technology
R. González Rodríguez
  • Department of Applied Mathematics II
Information
Address
Calle Maxwell s/n, 36310, Vigo, Pontevedra, Spain
Head of institution
Manuel Reigosa Roger
Website
www.uvigo.es
Phone
+34986812000