Universidad de Sevilla
Recent publications
The small ribosomal subunit protein Rps15/uS19 is involved in early nucleolar ribosome biogenesis and subsequent nuclear export of pre-40S particles to the cytoplasm. In addition, the C-terminal tail of Rps15 was suggested to play a role in mature ribosomes, namely during translation elongation. Here, we show that Rps15 not only functions in nucleolar ribosome assembly but also in cytoplasmic pre-40S maturation, which is indicated by a strong genetic interaction between Rps15 and the 40S assembly factor Ltv1. Specifically, mutations either in the globular or C-terminal domain of Rps15 when combined with the non-essential ltv1 null allele are lethal or display a strong growth defect. However, not only rps15 ltv1 double mutants but also single rps15 C-terminal deletion mutants exhibit an accumulation of the 20S pre-rRNA in the cytoplasm, indicative of a cytoplasmic pre-40S maturation defect. Since in pre-40S particles, the C-terminal tail of Rps15 is positioned between assembly factors Rio2 and Tsr1, we further tested whether Tsr1 is genetically linked to Rps15, which indeed could be demonstrated. Thus, the integrity of the Rps15 C-terminal tail plays an important role during late pre-40S maturation, perhaps in a quality control step to ensure that only 40S ribosomal subunits with functional Rps15 C-terminal tail can efficiently enter translation. As mutations in the C-terminal tail of human RPS15 have been observed in connection with chronic lymphocytic leukaemia, it is possible that apart from defects in translation, an impaired late pre-40S maturation step in the cytoplasm could also be a reason for this disease.
Rica, se comparten bajo términos de la Licencia Creative Commons: Reconocimiento, No Comercial, Sin Obra Derivada 3.0 Costa Rica. Las autorizaciones adicionales a las aquí delimitadas se pueden obtener en el correo: educare@una.cr https://doi.org/10.15359/ree.26-1.9 https://www.revistas.una.ac.cr/index.php/educare Validación del cuestionario de Competencia Digital Docente en profesorado universitario chileno Resumen: Objetivo. En la actualidad es clave que el profesorado universitario desarrolle competencias para entregar una educación de calidad, entre ellas, la competencia digital. El objetivo de este estudio fue validar el "Cuestionario de competencia digital docente" en la escala de uso para el contexto de la educación superior en Chile. Metodología. El método es cuantitativo, un diseño ex post facto. La muestra estuvo conformada por 1 122 docentes. Resultados. Los resultados revelan que el instrumento es válido y fiable. Conclusiones. El modelo obtenido mediante análisis factorial confirmatorio indicó que el factor de mayor peso es la mantención de los dispositivos que realiza el profesorado universitario y el factor de menor peso es la utilización en la creación de contenido digital. La discusión sobre la preeminencia de la dimensión tecnológica por sobre la pedagógica busca orientar los procesos de mejora en la docencia universitaria. Palabras clave: Análisis factorial; cuestionario; docencia universitaria; tecnologías de la información y la comunicación.
En este documento desarrollo un breve ejercicio de autoevaluación de mi red personal para ilustrar algunas de las técnicas de análisis de redes personales más prácticas y eficientes. Concretamente, analizamos las funciones ejercidas por el núcleo de proveedores de apoyo, la tendencia a la homofilia en las relaciones entre diferentes subgrupos sociales o demográficos, el grado de estratificación de la red personal, y la construcción de tipologías con muestras de redes personales. El caso analizado muestra que la evaluación de la red personal permite representar los contextos de interacción en los que participa el individuo. A partir del ejemplo se sugieren dos dimensiones clave en la descripción de la red personal, a saber: el grado de cohesión estructural del conjunto y la configuración de los subgrupos que lo componen. Concluimos con una reflexión sobre los usos psicológicos que pueden derivarse de la evaluación de las redes personales.
Chiral pharmaceuticals are an important class of environmental pollutants. Monitoring studies have shown the non-racemic presence of these contaminants in wastewater, sludge and the receiving environment. This review describes the role of chirality in the environment, especially the distribution and toxicities of enantiomers of chiral pharmaceuticals. In the first part, a systematic overview of their distribution in various environmental matrices and the main application of chiral signatures as chemical markers of water contamination are discussed. Available studies mainly focus on four drug groups including NSAIDs, β-blockers, antidepressants and illicit drugs due to their environmental pseudopersistence and ecotoxicological effects. In the second part, a summary of the enantiospecific toxicity data reported for chiral pharmaceuticals is provided. These data are of high value to improve the accuracy of environmental risk assessments in future works. Enantioselective toxicity towards aquatic organisms have been established for ten out of 36 chiral pharmaceuticals measured and detected in wastewater or surface water samples. Their enantioselective biodegradation and ecotoxicity make the risk assessment process highly recommended. The results provided in this review work support the need for new approaches to more accurately determine the toxicological risks associated to the stereochemistry of environmental contaminants.
In nature, cells reside in tissues subject to complex cell–cell interactions, signals from extracellular molecules and niche soluble and mechanical signaling. These microenvironment interactions are responsible for cellular phenotypes and functions, especially in normal settings. However, in 2D cultures, where interactions are limited to the horizontal plane, cells are exposed uniformly to factors or drugs; therefore, this model does not reconstitute the interactions of a natural microenvironment. 3D culture systems more closely resemble the architectural and functional properties of in vivo tissues. In these 3D cultures, the cells are exposed to different concentrations of nutrients, growth factors, oxygen or cytotoxic agents depending on their localization and communication. The 3D architecture also differentially alters the physiological, biochemical, and biomechanical properties that can affect cell growth, cell survival, differentiation and morphogenesis, cell migration and EMT properties, mechanical responses and therapy resistance. This latter point may, in part, explain the failure of current therapies and affect drug discovery research. Organoids are a promising 3D culture system between 2D cultures and in vivo models that allow the manipulation of signaling pathways and genome editing of cells in a body-like environment but lack the many disadvantages of a living system. In this review, we will focus on the role of stem cells in the establishment of organoids and the possible therapeutic applications of this model, especially in the field of cancer research.
Resumen Introducción Las hernias diafragmáticas de Morgagni diagnosticadas prenatalmente son una rara entidad, con menor riesgo asociado de hipoplasia pulmonar y problemas respiratorios que las hernias diafragmáticas posteriores. Nuestro caso pone de manifiesto cómo en los casos de hernia diafragmática de Morgagni los pulmones tienden a desarrollarse completamente, a pesar del significativo derrame pericárdico o cuán disminuidos pueden aparentar. Principales síntomas y/o hallazgos clínicos Hernia diafragmática de Morgagni diagnosticada a las 14 semanas de gestación, con derrame pericárdico masivo y herniación torácica anterior del hígado. Diagnósticos principales, intervenciones terapéuticas y resultados No se identificaron otras malformaciones asociadas, se descartaron otras causas de derrame pericárdico y el cariotipo fetal analizado fue normal. A las 25 semanas, se realizó una pericardiocentesis fetal intrauterina, consiguiendo una significativa distensión pulmonar, con una adecuada vascularización. Tras el nacimiento, la recién nacida precisó soporte ventilatorio debido a una hipoxemia severa causada por la hipertensión pulmonar, corrigiéndose el defecto quirúrgicamente a los 6 días de vida. La evolución posterior fue favorable, sin presentar problemas respiratorios significativos. Conclusión La detección ecográfica de esta rara anomalía resulta útil para el manejo óptimo, y el drenaje pericárdico puede favorecer una resolución prenatal del derrame pericárdico, permitiéndonos evaluar de forma adecuada el riesgo de hipoplasia pulmonar.
This paper deals with innovative renewable energy (RE) - powered seawater reverse osmosis (SWRO) plants based on tidal range/PhotoVoltaic (PV) systems as a hybrid technology with interesting prospects to promote the RE desalination at medium to large capacity ranges. Key features to enhance solar PV with tidal range energy are the good temporary complementarity of both options and the predictable water production pattern that the tidal range plant allows, along with ensuring water production at night. Once the basic sizing of a power plant referred to a 20 MW turbine is conducted, the sensitivity analysis of main performance parameters of the hybrid solar/tidal desalination system is carried out through yearly simulations. With this analysis, an extension of the knowledge about the performance of hybrid tidal/solar desalination is gained in such a way that three useful design criteria are derived from the results: i) total investment cost per unitary water production, ii) energy consumed in desalination to total energy production, and iii) energy non-useful for desalination. Recommended designs are provided under each of these three criteria for given yearly freshwater demand with SWRO plants of 3.5 and 4.8 kWh/m³ of specific energy consumption. Results proves that off-grid SWRO desalination powered by hybrid tidal/PV systems in a favorable location achieves actual water production of one half of nominal production with adequate selection of design parameters. Recommended sizing of the energy generator for minimizing capital costs corresponds to 20 MW tidal/25–27 MWp PV per 12 MW of SWRO consumption. Additionally, in absence of realistic costs data, the recommended design criterion for the plant sizing relies on the ratio of energy used by the desalination plant to that produced by the hybrid tidal/PV generator. Results at an exemplary plant location show that 14.1 × 10⁶ m³/y of fresh water obtained with desalination consumption of 3.5 kWh/m³ needs 2.0 MW tidal/26.9 MWp PV. This energy system would produce 10 × 10⁶ m³/y considering 4.8 kWh/m³ of specific consumption.
Orai1 and STIM1, molecular components of store-operated calcium entry (SOCE), have been associated with vascular smooth muscle cell (VSMC) proliferation in vascular remodeling. Nevertheless, the role of SARAF (SOCE-associated regulatory factor), a regulatory protein involved in STIM1 inhibition, in vascular remodeling has not been examined. The aim of this study is to examine the role of SARAF and Orai1 in VSMC proliferation and neointima formation after balloon injury of rat carotid arteries. Experiments were conducted in an animal model of rat carotid angioplasty to characterize neointima formation. VSMC isolated from rat coronary arteries was also used to examine cell proliferation. The formation of neointima after balloon injury of rat carotid arteries was confirmed by hematoxylin and eosin staining of tissue sections up to 3 wk after surgery. Injured arteries showed significantly higher expression of SARAF, STIM1, and Orai1 compared with control tissues, corroborating the presence of these regulatory proteins in the neointima layer. Proximity ligation and coimmunoprecipitation assays revealed that SARAF interacts with Orai1 in the neointima. Furthermore, selective silencing of SARAF and Orai1 by small interfering RNA (siRNA) inhibited IGF-1–induced VSMC proliferation. Our data suggest that SARAF interacts with Orai1 to modulate SOCE and VSMC proliferation after vascular injury.
In this short communication, a modified version of the well-established synchronverter model is proposed, introducing improved control characteristics that allow the efficient integration of converter-interfaced renewable energy sources to the electrical grid. In the proposed model, the inertial response is decoupled from the primary frequency response. Furthermore, a condition for a critically damped provision of inertial response is proposed. The improved performance of the proposed model against the variants of the synchronverter model is assessed by performing time-domain simulations and stability analysis.
Membrane contact sites are functional nodes at which organelles reorganize metabolic pathways and adapt to changing cues. In Saccharomyces cerevisiae, the nuclear envelope subdomain surrounding the nucleolus, very plastic and prone to expansion, can establish contacts with the vacuole and be remodeled in response to various metabolic stresses. While using genotoxins with unrelated purposes, we serendipitously discovered a fully new remodeling event at this nuclear subdomain: the nuclear envelope partitions into its regular contact with the vacuole and a dramatic internalization within the nucleus. This leads to the nuclear engulfment of a globular, cytoplasmic portion. In spite of how we discovered it, the phenomenon is likely DNA damage-independent. We define lipids supporting negative curvature, such as phosphatidic acid and sterols, as bona fide drivers of this event. Mechanistically, we suggest that the engulfment of the cytoplasm triggers a suction phenomenon that enhances the docking of proton pump-containing vesicles with the vacuolar membrane, which we show matches a boost in autophagy. Thus, our findings unveil an unprecedented remodeling of the nucleolus-surrounding membranes with impact on metabolic adaptation.
Hydrogen is not only considered as a cornerstone within renewable energy portfolio but it is also a key enabler for CO2 valorisation being a central resource for industrial decarbonization. This work evaluates the profitability of hydrogen production via combined biogas reforming and water–gas shift reaction, based on a real case scenario for landfill biogas plant in Seville (Spain). A techno-economic model was developed based on a process model and the discounted cash-flow method. A biogas flow of 700 m³/h (input given by the landfill biogas plant) was used as plant size and the analysis was carried out for two different cases: (1) use of already available energy sources at the industrial plant, and (2) solar energy generation to power the process. The economic outputs obtained showed that under the current circumstances, this hydrogen production route is not profitable. The main reason is the relatively low current hydrogen prices which comes from fossil fuels. A revenues analysis indicates that hydrogen from biogas selling prices between 2.9 and 5.7 €/kg would be needed to reach profitability, which are considerably higher than the current hydrogen cost (1.7 €/kg). A subsidy scheme is suggested to improve the competitiveness of this hydrogen production process in the short-medium term. A cost analysis is also performed, revealing that electricity prices and investment costs have a high impact on the total share (23–40% and 8–22%, respectively). Other potential costs reduction such as catalyst, labour and manteinance & overhead are also evaluated, showing that cutting-down production costs is mandatory to unlock the potential of hydrogen generation from biogas. Our work showcases the techno-economic challenge that green energy policies face in the path toward sustainable societies.
This paper reviews the on-going research studies and microgrid pilot projects focusing on the Spanish case because of its renewable energy potential with the objective set on highlights the main investigation drifts in the field such as the used technologies, control methods and operation challenges. That way, several smart grids have been commented and compared, finding that photovoltaic and wind power are the favourites energy generation technologies. Although batteries are the most widespread energy storage systems, green hydrogen has a strong presence, showing up in a third of the Spanish smart grids. Traditional control strategies are being displaced by advanced ones such as MPC or fuzzy logic due to its higher efficiency. The reader will have a clear view of the potential of renewable energy penetration in the form of smart grids in Spain, through the study of the equipment involved in the different facilities contribution and the main control strategies implemented, in a comparative analysis of the key aspect of this emerging technology.
Increased antibiotic use worldwide has become a major concern because of their health and environmental impacts. Since most antibiotic residues can hardly be removed from wastewater using conventional treatments, alternative methods receive great attention. Adsorption is one of the most efficient and cost-effective treatment methods for antibiotics. Among the adsorbents, clay minerals have garnered increasing attention due to their unique properties including availability, high specific surface area, low cost, cation exchange capacity, and good removal efficiency. This paper reviews the recent progress made in the use of natural and modified clay minerals for the removal of antibiotics from water. First, the sources, occurrence, removal and health effects of the antibiotics commonly encountered in water bodies are described. Antibiotic concentration levels and average removal efficiencies measured in conventional activated sludge treatment systems worldwide are also provided to better address the problem. Second, the review explores the characteristics of clay minerals as adsorbent of antibiotics and the factors affecting the adsorption. The review identifies and discusses the future trends and strategies used to increase the adsorption capacity of clay minerals by modification and combination techniques (intercalation of novel functional groups such as organocations, biopolymers and metal pillared-clay minerals, combination with biochar or thermal activation). The quantitative comparisons of clay minerals’ ability for antibiotic removal are given. Some natural clay minerals have good removal potential for antibiotics, with maximum adsorption capacities over 100 mg/g. For most other adsorbents, surface modifications and combination techniques resulted in improved adsorption properties (including higher surface area, enhanced adsorption capacity, increased stability and mechanical strength). Finally, the application of these adsorbents at pilot scale, using real wastewater samples, their reuse, economic analysis and life cycle assessment are other issues that have been considered.
The continuous monitoring of water stress will increase the accuracy of the deficit irrigation scheduling. Almonds are very sensitive to water stress conditions and an important water consumer. Recently, a novel approach to the use of trunk growth rate (TGR) data has been proposed for olive trees. These works suggested the use of TGR frequencies to evaluate water status of the trees. The aim of the current work was to compare the seasonal pattern of three different indicators derived from the daily curves of trunk diameter fluctuations with midday stem water potential. During three consecutive seasons (2017–2019), an irrigation experiment was carried out in a mature almond orchard (cv Vairo) at Dos Hermanas (Seville, Spain). Four irrigation treatments replicated in four blocks were evaluated using the daily curves of midday stem water potential and trunk diameter fluctuations. The different irrigation treatments were: Control, full irrigated conditions; RDI-1 (irrigation scheduling based on midday stem water potential with a deficit irrigation during kernel filling [values around −1.2 MPa]); RDI-2(similar to RDI-1 but with a more severe water stress [−2 MPa]) and incomplete recovery after harvest due to limitation of the seasonal amount of water (around 100 mm); SDI, sustained deficit irrigation with a seasonal applied water equal to RDI-2. Trunk diameter fluctuations were measured with a wireless band dendrometer. The daily curves were processed to obtain three different indicators. Maximum daily shrinkage (MDS) was the difference between the daily maximum and minimum. Trunk growth rate (TGR) was the difference between two consecutive daily maximums. The frequencies of several ranges of TGR were compared with the midday stem water potential. Weekly frequencies of values greater than 0.3 mm day⁻¹ decreased with the reduction of midday stem water potential, but the pattern changed greatly in different seasons. The weekly frequency of values between − 0.1 and 0 and between 0 and 0.1 mm day⁻¹ were steadier in different seasons. Differences between seasons were related to growth pattern and yield.
This paper presents a novel method to investigate the dynamics between the interconnected rigid and very flexible bodies of a deep-sea ROV-TMS with highly coupled dynamics. The aim is to develop an accurate yet effective system model, which is applicable to a wide range of deep-sea working-class ROV applications. The use of different sets of generalized coordinates in rigid-flexible multibody system usually leads to complex forms of constraints Jacobian and quadratic velocity vector when the interconnected rigid and flexible bodies share highly coupled dynamics. Thus, the compatibility of the formulations used in modelling is pivotal to a correct representation of the dynamics of an underwater multibody system with highly coupled dynamics. To this end, a mixed formulation, which is fully-based on absolute coordinates, is presented in modelling the dynamics of underwater tethered vehicle system. The development of system model of a basic ROV-TMS and theoretical implementations are presented in this paper. The applicability of the presented model is assessed through numerical simulations for the realistic scenarios during the deep-sea ROV operations. The numerical studies show that the proposed model is able to capture the nonlinear dynamics of cable and cable drum, and the nonlinear coupling dynamics between the tether cable and the ROV.
We present a new procedure to determine the growth function of a homogeneous Garside monoid, with respect to the finite generating set formed by the atoms. In particular, we present a formula for the growth function of each Artin–Tits monoid of spherical type (hence of each braid monoid) with respect to the standard generators, as the inverse of the determinant of a very simple matrix. Using this approach, we show that the exponential growth rates of the Artin–Tits monoids of type An (positive braid monoids) tend to 3.233636… as n tends to infinity. This number is well-known, as it is the growth rate of the coefficients of the only formal power series x0(y)=−(1+y+2y2+4y3+9y4+⋯) which is the leading root of the classical partial theta function. We also describe the sequence 1,1,2,4,9,… formed by the coefficients of −x0(y), by showing that its kth term (the coefficient of yk) is equal to the number of braids of length k, in the positive braid monoid A∞ on an infinite number of strands, whose maximal lexicographic representative starts with the first generator a1. This is an unexpected connection between the partial theta function and the theory of braids.
In this paper, the asymptotic behavior of a semilinear heat equation with long time memory and non-local diffusion is analyzed in the usual set-up for dynamical systems generated by differential equations with delay terms. This approach is different from ones used in the previous published literature on the long time behavior of heat equations with memory, which is carried out by the Dafermos transformation. As a consequence, the obtained results provide complete information about the attracting sets for the original problem, instead of the transformed one. In particular, the proved results also generalize and complete previous literature in the local case.
An interlaboratory comparison was done for the analysis of carotenoids in freeze-dried mango. The study was performed from July to September 2018. Mango fruit was freeze-dried, homogenized, and packaged under vacuum conditions in portions of 6 g (test sample). Two test samples were sent to the participating laboratories for analysis. Laboratory results were rated using Z-scores in accordance with ISO 13528 and ISO 17043. The standard deviation for proficiency assessment (also called target standard deviation) was determined using a modified Horwitz function and varied between 10 and 25%, depending on the analyte. Out of 14 laboratories from 10 different countries, 9 laboratories (64%) obtained a satisfactory performance (Z ≤ 2) for the analysis of β-carotene. While for 7 laboratories that analyzed α-carotene, (9Z)-β-carotene, β-cryptoxanthin, and zeaxanthin, 4 laboratories (57%) obtained a satisfactory performance. However, only 2 laboratories out of 7 (29%) obtained a satisfactory performance for lutein. Based on the comparability of the analytical results, this study concludes that freeze-dried mango pulp can be used as a reference material for the analysis of α and β-carotene, (9Z)-β-carotene, β-cryptoxanthin, and zeaxanthin by applying different analytical procedures for their extraction and quantification.
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David Leon
  • Plant Biology and Ecology
Manuel Pérez-Ruiz
  • Aerospace Engineering and Fluid Mechanics
Isidoro Caraballo
  • Pharmacy and Pharmaceutical Technology
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