Artículos
Permanent URI for this collectionhttps://docta.ucm.es/handle/20.500.14352/15
Browse
Recent Submissions
Item Intertextualidad y literatura comparada(Poligrafías : Revista de Literatura Comparada, 1997) Losada Goya, José ManuelItem Sex- and trait-specific contribution of individual- and population-level processes to age-related changes in multiple plumage ornaments(iScience, 2025) González-Bernardo, Enrique; Martínez-Padilla, Jesús; Camacho, Carlos; García del Castillo, Marta E.; Potti, Jaime; Canal, DavidIndividuals experience changes in multiple traits across their lifespan, often peaking before senescence-driven declines. Many species display secondary sexual traits that can vary with age due to physiological and selective processes, influencing individual fitness and sexual selection. Using 13 years of longitudinal data from a pied flycatcher (Ficedula hypoleuca) population, we analyzed age-related variation in wing and forehead patches in both sexes. Wing patch size increased with age due to both within- and between-individual effects, with sex-specific patterns. Forehead patch size showed sex-dependent age effects: quadratic in females, linear in males, with only males exhibiting within-individual changes. In females, forehead patch occurrence followed a quadratic age pattern, influenced by selective (dis)appearance and reproductive timing. These results show that age-related ornament expression arises from different processes across traits and sexes, highlighting potential trade-offs between reproduction and ornamentation. This study underscores the role of both sexes' ornaments in selection and life-history strategies.Item Role of N-glycosylation of surfactant protein SP-BN in lipid and SP-B interacting properties. Implications in disease(American Journal of Physiology-Lung Cellular and Molecular Physiology, 2025) Isasi Campillo, Miriam; Rangel-Arranz, Paula; García Ortega, Lucía; Pérez Gil, JesúsSP-BN is an independent protein derived from the precursor of pulmonary surfactant protein B (SP-B), a critical component of the pulmonary surfactant (PS), the membrane-based system that coats the alveolar air-liquid interface and is essential for both respiratory mechanics and innate defense. In humans, a single-nucleotide polymorphism (SNP) defining hSP-BN glycosylation has been associated with propensity to certain respiratory diseases, but molecular studies in this regard are scarce. Previous studies with the murine SP-BN, nonglycosylated, have suggested a role for this protein in lipid transfer during PS biogenesis. This study focuses on the structural and functional characterization of both glycosylated and nonglycosylated human SP-BN protein variants to elucidate the impact of N-glycosylation. Recombinant proteins (hSP-BN, glycosylated, and hSP-BN-T73I, nonglycosylated) were produced in Pichia pastoris and purified to homogeneity. The structural characterization confirmed the main features of hSP-BN as a member of the SAPLIP protein family: mainly α-helical, a propensity to dimerization and a high stability. Interestingly, N-glycosylation did not significantly affect hSP-BN structure. Regarding lipid interactions, both hSP-BN variants were able to bind and perturb membranes in lipid vesicles with a PS-like composition at acidic, but not neutral pH, which is relevant given the acidification during PS biogenesis. Remarkably, N-glycosylation impaired the synergistic effect of hSP-BN and mature SP-B to promote lipid mixing/transfer activity. These results support the joint action of both proteins in PS biogenesis and, more importantly, suggest that this combined activity affected with the SNP-induced glycosylation of hSP-BN could be behind certain PS defects acquired during biogenesis causing some susceptibility to respiratory diseases. NEW & NOTEWORTHY The impact of N-glycosylation on the structure and function of human SP-BN protein has been studied. Homogeneous production of glycosylated hSP-BN and nonglycosylated hSP-BN-T73I was achieved in Pichia pastoris. Structural characterization and lipid interaction properties at acidic pH revealed no significant differences due to glycosylation. N-glycosylation impairs the synergistic action of hSP-BN and SP-B in lipid transfer/mixing activity. N-glycosylation of hSP-BN could impair PS biogenesis, in agreement with its potential involvement in respiratory disease.Item Sobre la hermenéutica judía(Pensamiento y Cultura, 2002) Losada Goya, José ManuelRESUMEN: Una lectura conveniente de la Torah habrá de tener en cuenta tres aspectos: la tradición rabínica procede desde la letra hacia la vida, es inmediata con los acontecimientos narrados y respeta el principio de analogía. Son diferencias con la hermenéutica cristiana (menos contextualizada, mediata y mayormente literal). La consideración de estos aspectos asegura una correcta lectura de los textos judíos.Item La nature mythique du Graal dans "Le Conte du Graal" de Chrétien de Troyes(Cahiers de Civilisation Médiévale, 2009) Losada Goya, José ManuelRÉSUMÉ: Le silence de Perceval lors du passage du cortège dans le château du Roi Pêcheur dans «Le Conte du Graal» de Chrétien de Troyes ne cesse de susciter les questions de la critique. Plusieurs approches sont ici mises à contribution: la théorie structurelle du mythe selon André Jolles, par exemple, apporte un éclairage sur les questions que se pose le protagoniste; l’histoire littéraire apporte des récits issus de la tradition celte très suggestifs pour la comparaison des motifs littéraires; le thématisme et la mythocritique aident à cerner la signification originelle du ciboire; l’herméneutique de Paul Ricœur, enfin, permet d’accéder aux raisons profondes du mutisme du héros. Faisant appel à différentes méthodes d’interprétation, cet article cherche à montrer que les aventures du héros ont un rapport étroit avec la nature mythique du vase.Item An approach to discover students’ conceptions in online Computing Education: a case study of students’ understanding of virtual memory(IEEE Access, 2024) Pamplona Roche, Sonia; Bravo Agapito, Javier; Seoane, IsaacThis study presents a new approach for discovering conceptions among online computer science students. The research objectives were (1) to discover students’ conceptions of virtual memory, an important concept in operating systems, and (2) to provide a method for discovering students’ conceptions in the field of computer science. The study participants were students taking an undergraduate course on an operating system at an online university. Eleven students were enrolled in the course, and we selected all the participants who completed the course, seven students in total. We selected a qualitative case study as our methodology as we required a thorough and in-depth analysis of each student thought processes. Study data were obtained from questions on virtual memory that were included in two written evaluation tests at the beginning and end of the course. The questions assessed conceptual knowledge and meaningful learning of the concept of virtual memory. We discovered nine accepted conceptions and seven alternative conceptions related to virtual memory. We also inferred a mental model that could be the root cause of the discovered alternative conceptions. Our study has important implications for teaching and educational research in computer science. Regarding educational implications, this study makes recommendations for teaching virtual memory based on the results. Considering the implications for future research, our contributions are seven alternative conceptions of virtual memory that had not been previously identified, and a methodology for discovering conceptions that can be applied to other computing topics in both online and face-to-face environments.Item Parallel Maude-NPA for Cryptographic Protocol Analysis(IEEE Transactions on Dependable and Secure Computing, 2025) Canh Minh Do; Riesco Rodríguez, Adrián; Santiago Escobar; Kazuhiro OgataMaude-NPA is a formal verification tool for analyzing cryptographic protocols in the Dolev-Yao strand space model modulo an equational theory defining the cryptographic primitives. It starts from an attack state to find counterexamples or conclude that the attack concerned cannot be conducted by performing a backward narrowing reachability analysis. Although Maude-NPA is a powerful analyzer, its running performance can be improved by taking advantage of parallel and/or distributed computing when dealing with complex protocols whose state space is huge. This paper describes a parallel version of Maude-NPA in which the backward narrowing and the transition subsumption at each layer in Maude-NPA are conducted in parallel. A tool supporting the parallel version has been implemented in Maude with a master-worker model using meta-interpreters. We report on some experiments of various kinds of protocols that demonstrate that the tool can increase the running performance of Maude-NPA by 52% on average for complex case studies in which the number of states located at each layer is considerably large.Item Marizzi, Bernd, María Teresa Cortez y María Teresa Fuentes Morán (eds.): 'Deutschlernen in Spanien und Portugal. Eine teilkommentierte Bibliographie von 1502 bis 1975', Wiesbaden, Harrassowitz, 2018, 339 pp.(Deutschlernen in Spanien und Portugal. Eine teilkommentierte Bibliographie von 1502 bis 1975, 2020) Cañadas García, TeresaItem De “love” a “sad”: sintonía afectiva en el debate digital de las elecciones generales españolas 2023(Palabra Clave, 2025) Casas Mas, Belén; Guevara Gil, Juan Antonio; Menéndez Cóndor, Pamela Fabiola; Robles Morales, José ManuelEn este artículo, se analiza el nivel de emotivismo en el debate político digital de Facebook en las elecciones generales españolas 2023 a partir de cuentas oficiales y verificadas de partidos, líderes políticos, medios de comunicación, usuarios y usuarias. Se han descargado 34 968 mensajes de Facebook durante el periodo oficial de campaña electoral y se ha realizado una clasificación de estos en tres grupos de agentes: partidos conectivos, medios de comunicación y otros actores de acción conectiva. Se han utilizado técnicas de big data para analizar los mensajes y se ha aplicado el NRC Emotion Lexicon para medir las emociones presentes. Los hallazgos muestran la alta congruencia afectiva debido a que los mensajes tienen bajo contenido emocional. La presencia de la emoción “me divierte” en las reacciones asciende a casi la mitad. Esto puede ser un indicador de ironía y descontento de los usuarios hacia los mensajes publicados en el proceso electoral. En los casos con baja sintonía afectiva, destaca la sobredimensionalidad de la emoción “me divierte”. Estos resultados son relevantes desde el enfoque emotivista porque arrojan luz sobre la presencia de emociones en este tipo de debates que movilizan la opinión pública y, en ocasiones, otras dinámicas negativas que se alejan del ideal democrático.Item All-optical generation of structured light via microwave-field-controlled spontaneous emission(Optics Communications, 2025) Antón Revilla, Miguel Ángel; Cabrera Granado, EduardoWe propose a scheme for achieving spatially dependent spontaneous emission by using vortex light beams (OAM) in a five level atomic configuration. It consists of an upper excited level and four lower metastable levels. The excited level is simultaneously coupled to two ground levels by a coherent probe field and a vortex field, respectively. In addition, a microwave field couples two of the ground levels. The excited state is assumed to be coupled by the vacuum modes in the free space and eventually decays to a fifth metastable level. It is found that by manipulating key parameters such as the strength of the Laguerre–Gauss beams, the Rabi frequency and detuning of an external microwave field, and the initial state of the atoms, we can achieve highly tunable spontaneous emission spectra. A wide variety of spatiospectral behavior, including two-dimensional spectral-peak narrowing, spectral-peak enhancement and spontaneous emission quenching is obtained.Item Sobre la traducción : entrevista a Joaquín Garrigós(Ágora : Papeles de Arte Gramático, 2022) Garrigós Bueno, Joaquín; Diz Villanueva, Alba; Nicolau, FelixItem Selective growth of ZnO micro- and nano-structures on fs-laser processed metallic Zn substrates for large area applications(Journal of Alloys and Compounds, 2025) Ariza, R.; Urbieta Quiroga, Ana Irene; Ferreiro, A.; Rabanal, M.E.; Fernández Sánchez, Paloma; Solis, J.The synthesis of large area micro- and nano-structured ZnO surfaces has been successfully achieved through a two-step process. It involves the irradiation of Zn metal sheets with femtosecond laser pulses (350 fs at 1030 nm) at high repetition rates (100–500 kHz), and fast scanning speeds (cm/s). Subsequently, the irradiated sheets are thermally treated in an Argon flux at 380 ◦C, a temperature significantly lower than that typically required for growing micro- and nanostructures in ZnO. Fs-laser irradiation promotes the initial development of topography and the localized oxidation of the metal. This enables the further growth of micro- and nanostructures at preferential sites with good crystalline quality and luminescent properties. Analysis of the material at different processing steps shows that the initial laser-induced oxidation is crucial in defining ZnO growth mechanisms upon thermal treatment, and determining the final properties. We have tested the potential use of these structures as reusable photocalyst. The ease of catalyst recovery in photocatalysis experiments and the degree of degradation achieved may be considered as key performance indicators. Photocatalytic activity tests performed with a Rhodamine B solution showed degradation values up to 43 % over 90 min. The morphology of the simples remains unaltered after photocatalysis experiments.Item Interviu cu Joaquín Garrigós Bueno(România literară, 2022) Garrigós Bueno, Joaquín; Diz Villanueva, Alba; Nicolau, FelixItem Neuroimaging and immunofluorescence of the Pseudopus apodus brain: unraveling its structural complexity(Brain Structure and Function, 2025) Jiménez, S.; Morona Arribas, Ruth; Ruiz Fernández, María José; Fernández-Valle, E.; Castejón, D.; García Real, María Isabel; González Soriano, José Miguel; Moreno García, NereaThe present study provides an in-depth neuroanatomical characterization of the brain of Pseudopus apodus, combining magnetic resonance imaging (MRI) with histological analysis by immunofluorescence. In the telencephalon, the pallial regions showed distinct anatomical features, including a cortical structure, a dorsal ventricular ridge and the spherical nucleus, but prominent layering patterns, observable on histological slides, were not fully resolved by MRI. Subpallial structures, such as the nucleus accumbens and the basal ganglia, were delineated with histological clarity and further supported by MRI. In the hypothalamic and diencephalic regions, the dense and complex cellular composition made precise delineation of individual nuclei difficult by MRI, in contrast to the histological accuracy, however by MRI the identification of the major tracts running through these domains are clearly identifiable. Mesencephalic and rhombencephalic structures, including the optic tectum, isthmic nuclei, cerebellum, and reticular groups, were systematically described using a combination of histological and MRI techniques. In addition, immunofluorescence analysis of specific markers, such as Calretinin, ChAT, Isl1, Satb1, Serotonin and Tyrosine Hydroxylase, provided higher resolution of functional sub-regions, allowing precise identification of boundaries and facilitating comprehensive regional mapping, showing complex organizational arrangements, both in rostral regions, such as the dorsal ventricular crest, and in caudal regions, within the tegmental and posterior nuclei of the brain, including the ventral tegmental area, substantia nigra and raphe nuclei. These findings establish a robust neuroanatomical framework for Pseudopus apodus, contributing significantly to the understanding of reptile brain organization and providing valuable insights into the evolutionary adaptations underlying a limbless lizard neuroanatomy.Item Tracing the origin of the alien pest Cydia pomonella in Algeria through a worldwide comparison of the species’ DNA barcodes(Agricultural and Forest Entomology, 2024) Mahi, Tayeb; Harizia, Abdelkader; Canelo, Tara; Benguerai, Abdelkader; Bonal Andrés, RaúlDNA barcodes (i.e., gene sequences used as identifiers for species identification) constitute a very useful tool in invasive pest research. Using them, we studied, for the first time, the origin and population structure of the alien Cydia pomonella in Africa, a major apple pest. We sequenced a fragment of the mitochondrial gene Cytochrome c oxidase subunit I (COI) from C. pomonella caterpillars collected in northern Algeria and compared them with DNA barcodes from the rest of the world available at public repositories. The phylogeny built upon that COI database supports the European origin of the species: haplotypes at the base of the phylogeny were registered in this continent. In Algeria, the results suggest that this pest could have been introduced from Europe, with two unique African mutations probably favoured by C. pomonella multivoltinism and large population sizes. Population genetic analyses at three Algerian localities showed neither structure nor founder effects. However, to confirm the underlying process of the observed population patterns, it is necessary to perform analyses using genes with higher mutation rates. Compared to higher resolution markers, mitochondrial DNA barcodes are still a cost-effective tool for taxonomic determination of unknown specimens and, sometimes, may also allow a preliminary tracing of its origin. This is crucial to detect and stop the spread of invasive pests (i.e., borders). We encourage further studies including functional genes to assess whether any mutations are promoting C. pomonella adaptation to the Northern Africa environment.Item Tres niveles de protección a la libertad de expresión y producción de los científicos(Revista jurídica Pérez-Llorca, 2025) Llanes Estrada, Felipe JoséItem "The Universal Mechanic, Literary, Poetical and Prosaic Company Limited" (1892)(Diablotexto Digital, 2025) Zamora y Pérez de Urría, Rafael de, Marqués de Valero de Urría; Romero López, María DoloresItem Representation of women in executive and academic roles within scientific societies in the field of European Endodontology(International Endodontic Journal, 2025) Arias Paniagua, Ana María; Duncan, Henry F; Perez Alfayate, Ruth; Martín-González, Jenifer; Riaza, PaulaAim: To explore gender distribution within the field of Endodontology in Europe and to evaluate the representation of women in executive and academic roles within scientific societies as well as national and international conferences. Methodology: After ethical approval, an online questionnaire was developed and shared with the European Society of Endodontology and the 36 national Endodontic societies officially affiliated. The survey inquired about gender composition amongst members, executive committee roles, participation in major congresses and representation in leadership and authorship positions within scientific journals affiliated with these societies over the last 5 years. Information was also retrieved from publicly available websites. Genders of the first, last and corresponding authors from scientific journals were identified. The relative ratio of women amongst society members, executive committee roles, participation in major congresses and representation in leadership and authorship positions within scientific journals was calculated. The ratio of women in leadership positions was statistically compared with the mean relative ratio of women amongst society members using a one-sample t-test. The current proportion of women in individual roles was compared with the general proportion of women members using the Binomial test. Results: Women account for 44% of members in endodontic societies. No significant discrepancy was observed in the overall representation of women as members in executive or editorial committees or in authorship positions within scientific journals in relation to the mean relative ratio of female society members but are significantly underrepresented in key positions such as society presidents, treasurers and scientific event organizers (p < .05). Additionally, women were significantly underrepresented at scientific events, both as lecturers and workshop leaders, at major congresses of national/international societies (p < .05). Few initiatives have been implemented to address these inequities; only three societies reported programmes aimed at promoting women in leadership or scientific roles. Conclusions: Within the limitations of this study, women appear to be fairly represented as members of executive and editorial committees in national endodontic societies and the ESE, as well as in authorship positions within scientific journals, but underrepresentation of women in positions of power and scientific forums persists. Some countries have begun implementing strategic measures to promote gender equity.Item The tumor suppressor HNRNPK induces p53-dependent nucleolar stress to drive ribosomopathies.(The Journal of Clinical Investigation, 2025) Aguilar Garrido, Pedro; Velasco Estévez, María; Navarro Aguadero, Miguel Ángel; Otero Sobrino, Álvaro; Ibáñez Navarro, Marta; Marugal, Miguel Ángel; Hernández Sánchez, María; Malaney, Prerna; Rodriguez, Ashley; Benitez, Oscar; Zhang, Xiaroui; Aitken, Marisa Jl; Ortiz Ruiz, Alejandra; Megías, Diego; Pérez, Manuel; Mata, Gadea; Gomez, Jesús; Lafarga, Miguel; Domínguez, Orlando; Graña-Castro, Osvaldo; Caleiras, Eduardo; Ximénez-Embun, Pilar; Isasa, Marta; Andrés Gamazo, Paloma Jimena de; Rodríguez Perales, Sandra; Torres Ruiz, Raúl; Revilla, Enrique; García Martín, Rosa María; Azorín, Daniel; Zubicaray, Josune; Sevilla, Julián; Sirozh, Oleksandra; Lafarga, Vanesa; Martínez López, Joaquín; Post, Sean M; Gallardo, MiguelThe nucleolus is a membraneless organelle and an excellent stress sensor. Any changes in its architecture or composition lead to nucleolar stress, resulting in cell cycle arrest and interruption of ribosomal activity, critical factors in aging and cancer. In this study, we identified and described the pivotal role of the RNA-binding protein HNRNPK in ribosome and nucleolar dynamics. We developed an in vitro model of endogenous HNRNPK overexpression and an in vivo mouse model of ubiquitous HNRNPK overexpression. These models showed disruptions in translation as the HNRNPK overexpression caused alterations in the nucleolar structure, resulting in p53-dependent nucleolar stress, cell cycle arrest, senescence, and bone marrow failure phenotype, similar to what is observed in patients with ribosomopathies. Together, our findings identify HNRNPK as a master regulator of ribosome biogenesis and nucleolar homeostasis through p53, providing what we believe to be a new perspective on the orchestration of nucleolar integrity, ribosome function and cellular senescence.Item Dosimetric evaluation of 6 MV photon beams in small fields using PRIMO-penEasy Monte Carlo(Radiation Physics and Chemistry, 2025) Díaz, Nataly; Villa Abaunza, Amaia; Muñoz, Jorge; Udías Moinelo, José Manuel; Ibáñez García, Paula BeatrizDosimetric validation of clinical radiotherapy plans for small fields requires high-precision instrumentation to ensure accuracy and spatial resolution. This study proposes a combination of PRIMO and penEasy Monte Carlo simulators to address scenarios where direct measurements are impractical, challenging, or yield inconsistent results due to detector limitations. We compared three dosimetric tools: A Semiflex ionization chamber PTW (model 31010) within a water-filled acrylic tank; EBT3 radiochromic films positioned between solid water layers; and PRIMO-PenEasy simulations. Experiments were performed at San Ignacio University Hospital in Bogota, Colombia, with dose measurements in two small fields and one conventional field for an Axesse-type linear accelerator. Results indicate that EBT3 radiochromic film show better agreement with MC simulation than the Semiflex ionization chamber, likely due to the chamber dose averaging effect across its detection volume. Additionally, variations in off-axis ratios were noted in both crossplane and inplane directions with more pronounced discrepancies observed in small fields compared to the conventional field. Overall, PRIMO-PenEasy MC simulations demonstrated accurate dose distributions and can be used as a viable for dosimetric validation in small photon fields.