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Phylogenomic Barcoding of Soil Seed Bank–Persistent and Wind‐Dispersed Non‐Native Plant Species in South Georgia
Get PDFClimate change and invasive species are leading drivers of biodiversity loss, with island ecosystems being especially vulnerable. South Georgia, a remote sub-Antarctic island, is 170 km long with approximately 30,000 ha of vegetated coastal areas, as snow and ice dominate the inland regions. Human activities on the island have historically introduced non-native species, resulting in 41 introduced vascular plant species compared with only 24 native ones. To address this imbalance, the South Georgia Non-Native Plant Management Strategy was implemented (2016–2020) to control non-native plant populations. We assessed emergent seedlings from South Georgia soil samples and wind-dispersed seeds to determine which species persist in the soil seed bank and contribute to dispersal. Using a molecular barcoding approach, we evaluated traditional markers (rbcL and matK) and optimized a high-throughput Angiosperms353 sequencing pipeline for accurate seedling identification. We generated a reference library covering all native and non-native species and applied this to 1,498 emergent seedlings and 737 trapped seeds. Molecular barcoding identified 21 species, including 10 non-natives and 11 natives. Strikingly, 84% of emergent seedlings were non-native, with Class III invasive species (Cerastium fontanum, Poa annua, Taraxacum officinale) dominating across most sites and in all wind traps. By contrast, Class I and II species occurred rarely and only at a few sites, indicating that management efforts have substantially reduced their spread, though viable seeds persist in the soil. These findings highlight both the continued threat from persistent seed banks of dominant invaders and the value of molecular barcoding for long-term monitoring. Our approach provides a framework for biosecurity and restoration management in South Georgia and other vulnerable ecosystems under climate change pressures
Electrocardiographic Markers for Cardiac Risk Stratification and Ventricular Dyssynchrony Assessment
No full textLas enfermedades cardiovasculares (ECVs), termino utilizado para denominar las enfermedades que afectan al corazón y los vasos sanguíneos, son la principal causa de fallecimiento en todo el mundo. La insuficiencia crónica cardiaca es una de las principales, ademas de ser una de las mas estudiadas, y puede estar debida a anormalidades estructurales o funcionales. Algunas ECVs están asociadas a la disincronía en la transmisión del impulso eléctrico a lo largo del corazón. Estas enfermedades conllevan una peor calidad de vida.El estudio y uso de diferentes biomarcadores procedentes de la señal electrocardiográfica (ECG), como de otros registros médicos disponibles, es de gran utilidad para una detección temprana de ECVs, y para determinar el riesgo de fallecer por alguna condición cardiovascular. El análisis de estos marcadores permiten tener una mayor comprensión de las interacciones complejas que existen entre las funciones cardiacas y la regulación autonómica, ofreciendo posibilidades para una mayor investigación futura y para uso en aplicaciones clínicas.El principal objetivo de esta tesis es entender mejor la influencia del sistema nervioso simpático sobre los cambios que se producen en la repolarización cardiaca, mediante el calculo de diferentes marcadores. Uno de ellos es la dinámica de repolarización periódica (PRD, Periodic Repolarization Dynamics). El marcador PRD mide las oscilaciones de baja frecuencia (menor a 0.1 Hz) de los cambios en el ángulo entre ondas T consecutivas, que se produce por la actividad simpática. Otros marcadores investigados están relacionados con los tiempos de activación (AT, activatión time) y repolarización (RT, repolarization time). Mediante el calculo de estos tiempos se consigue evaluar la disincronía ventricular en las derivaciones de los registros ECG. Los métodos usados para calcular el marcador PRD están descrito en el Capitulo 2. Los pasos realizados para medir la serie de ángulos consecutivos de las ondas T, dT◦, están detallados junto con las modificaciones hechas respecto de un método propuesto anteriormente para mejorar la robustez.Posteriormente, una vez obtenida la serie de dT◦, se presentan dos técnicas de calculo para hallar el valor de PRD. La técnica CWT (ContinuousWavelet Transform) calcula las pseudofrecuencias asociadas a cada escala de la transformada wavelet. La otra técnica, asociada con un menor coste computacional, es PRSA (Phase-Rectified Signal Averaging). En esta técnica se identifica las ventanas alrededor de los puntos ancla que se obtienen según los cambios observables en la serie de dT◦.Los métodos de calculo para AT y RT están descritos en el Capitulo 4. El centro de masas del complejo QRS, en el caso del AT, y de la onda T,para el RT, son calculados en cada derivación precordial, V1-V6, del ECG.Adicionalmente, la dispersión de AT (o RT) se calcula como la diferencia entre la derivación que se activa (o repolariza) mas tarde y la primera derivación que se activa (o repolariza) para cada registro. La evaluación de la variabilidad del ritmo cardiaco y el algoritmo semiautomático para eliminar los estímulos cardiacos en los registros estimulados también son descritos.En el Capitulo 2 se examina la respuesta del sistema cardiaco ante la exposición durante 60 días a microgravedad artificial, por medio de un modelo de simulacion denominado Head-down bed-rest (HDBR). Los experimentos fueron llevados a cabo en las instalaciones de la Agencia Espacial Europea (ESA). Se midió la capacidad de mitigar los efectos nocivos de la microgravidad artificial en dos tipos de contramedidas. Una de las contramedidas estaba basada en actividades fisicas que realizaban los voluntarios, y la otra estaba basada en el tipo de dieta diaria que ellos recibían. En el Capitulo 3 se analiza la base de datos MUSIC (MUerte Subita en Insuficiencia Cardiaca) con pacientes de insuficiencia cardiaca que fallecieron por muerte súbita cardiaca o por fallo de bomba cardiaca. En ambos capítulos (2 y 3), el PRD fue medido y usado para evaluar la respuesta del sistema cardiovascular ante la exposición a la microgravedad y para medir su capacidad predictora de fallecer por algunas de las dos causas mencionadas. Los hallazgos del Capitulo 2 indican que existe una activación simpática significativa cuando se realiza la prueba de inclinación después de la exposición prolongada a la microgravedad artificial.Ademas, nuestros resultados muestran que las contramedidas relacionadas con actividades físicas son efectivas para contrarrestrar los efectos adversos de la microgravedad, mientras que las contramedidas alimenticias solo consiguen reducir parcialmente estos efectos. Los hallazgos del Capitulo 3 confirman que el marcador PRD es un buen predictor de riesgo de muerte súbita cardiaca en pacientes con antecedentes de fallo cardiaco. Y su capacidad de predicción mejora cuando se combina con los biomarcadores indice de alternancia promedio (index of average alternans, IAA), que cuantifica la magnitud de las alternancias de la onda T; y turbulence slope (TS), el cual refleja la ratio de incremento del intervalo RR despues de la aceleración de la frecuencia cardiaca inicial.Los Capitulos 4 y 5 se centran en comparar varios tipos de estimulación cardiaca, incluyendo estimulación de ventrículo derecho, en el apex o en el septo, estimulación del septo del ventrículo izquierdo, estimulación de rama izquierda y del haz de His, tanto selectivo como no selectivo. Los registros analizados incluyen señales de alta (1,000 Hz) y muy alta frecuencia (5,000 Hz) obtenidos en alguno de los siguientes momentos: antes, justo después, al dia siguiente o después de un ano de la intervención. El objetivo es determinar en que medida las distintas técnicas de estimulación se asemejan a las características del ritmo espontáneo en pacientes que no tienen trastornos de conducción y que requieren estimulaciín como tratamiento antibradicardia.Para ello, varias variables representativas de disincronía de activación ventricular y de irregularidades en la repolarización ventrciular se midieron. Se propusieron varios indices que cuantifican AT, RT y las dispersiones inter e intraventriculares y también se midieron el marcador PRD e indices basados en QT y en la onda T. A partir de los resultados que se obtienen, se concluye que las técnicas fisiológicas de estimulación cardiaca producen una mejor respuesta ventricular, mientras que las técnicas relacionadas con la estimulación del miocardio ventricular no consiguen una respuesta similar a la que se observa en registros espontáneos. Ademas, nuestros hallazgos confirman que la técnica de estimulación de rama izquierda es una alternativa efectiva a la estimulación del haz de His, cuando se evalúa la activación y repolarizacióndel ventíiculo izquierdo.En el Capitulo 6 se presenta las conclusiones. Las principales contibuciones de esta tesis se destacan, indicando el desarrollo de metodologías para medir las características de la depolarización y repolarización ventricular de manera eficiente y robusta a partir de registros ECG. El marcador PRD es capaz de detectar los cambios inducidos por la microgravedad en la modulación simpática de la repolarización ventricular, mediante la cuantificación de la magnitud en las oscilaciones de los ángulos de ondas T consecutivas.También se ha evaluado la capacidad predectiva del marcador PRD para estratificar el riesgo de fallecer por muerte súbica cardiaca o fallo de bomba en sujetos con insuficiencia cardiaca crónica, tanto individual como en combinacióncon otros marcadores del ECG. Ademas, en esta tesis se ha comparado diferentes técnicas de estimulación cardiaca y se ha visto que las técnicas fisiológicas consiguen devolver el comportamiento ventricular espontáneo, como se muestra por la similitudes en la depolarización y repolarización del ECG, especialmente cuando nos enfocamos en el análisis del ventrículo izquierdo.Cardiovascular disease (CVD), a term used to describe conditions that affect the heart and blood vessels, is the leading cause of disease burden worldwide. Chronic heart failure (CHF) stands out as one of the most important and commonly studied diseases and may be due to structural and/or functional abnormalities. Certain cardiovascular diseases are associated with dyssynchrony in the transmission of electrical impulses throughout the heart. These diseases lead to a diminished quality of life. The study and application of various markers derived from electrocardiographic signals (ECG), as well as other available medical recordings, are highly valuable tools for the early detection of CVD and for assessing the risk of mortality associated with CVD. The analysis of these markers is crucial to advance our understanding of the complex interactions between cardiac function and autonomic regulation, offering possibilities for future research and use in medical applications. The main objective of this thesis is to better understand the influence of the sympathetic nervous system on changes in cardiac repolarization by calculating ECG markers. One of the investigated markers is called Periodic Repolarization Dynamics (PRD). PRD quantifies the low-frequency oscillations (below 0.1 Hz) of the angle between consecutive T waves, the magnitude of which is influenced by sympathetic activity. Other investigated markers are related to activation (AT) and repolarization times (RT). By calculating these times, it is possible to assess ventricular dyssynchrony in ECG leads. The methods used to calculate PRD are fully described in Chapter 2. The steps taken to measure the angle dTº between consecutive T waves are detailed together with the modifications made to a previously proposed method of computation to improve its robustness. Once the time series of the angles dTº is obtained, two techniques to measure PRD are presented. The Continuous Wavelet Transform (CWT) technique calculates the pseudo-frequencies associated with each scale of the wavelet transform. The other technique, which is associated with a lower computational cost, is called Phase-Rectified Signal Averaging (PRSA). This technique involves the identification of windows around anchor points identified according to the changes seen in the dTº series. The methods used to calculate AT and RT are fully described in Chapter 4. The center of mass of the QRS complex, in the case of AT, and of the T wave, in the case of RT, is measured for each of the precordial ECG leads V1-V6. Furthermore, the spatial dispersion of AT (RT) is calculated as the difference between the last activated (repolarized) lead and the first activated (repolarized) lead for each recording. Assessment of heart rate variability and the semiautomated algorithm to remove cardiac pacing stimuli in stimulated recordings are also described. Chapter 2 examines the response of the cardiovascular system when exposed to artificial microgravity for 60 days, using a ground-based analogue known as Head-Down Bed Rest (HDBR). The experiments were conducted at European Space Agency (ESA) facilities. The effectiveness of two types of countermeasures to mitigate the harmful effects of artificial microgravity was tested. One of the countermeasures was based on the physical activities performed by the volunteers when lying on the bed. The other countermeasure was based on diet modifications. Chapter 3 analyzes the MUSIC (MUerte Súbita en Insuficiencia Cardiaca) database, focusing specifically on heart failure patients who experienced sudden cardiac death (SCD) or pump failure death (PFD) during follow-up. In both Chapter 2 and Chapter 3, PRD was measured and used to assess the response of the cardiovascular system to microgravity exposure and predict mortality due to SCD or PFD. The findings of Chapter 2 indicate that there is significant sympathetic activation during the tilt test performed after prolonged exposure to artificial microgravity. Furthermore, our results show that the activity-based countermeasure is able to mitigate the adverse effects of microgravity, while the diet-based countermeasure only partially reduces these effects. The findings of Chapter 3 confirm that PRD is a strong predictor of SCD in patients with a history of heart failure. The predictive accuracy of PRD is improved when combined with ECG markers such as the Index of Average Alternans (IAA), which quantifies the magnitude of T wave alternans, and the Turbulence Slope (TS), which reflects the rate of increase of the RR interval following the initial heart rate acceleration. Chapter 4 and Chapter 5 focus on comparing different cardiac stimulation techniques, including right ventricular pacing at the apex (RVAP) or septum (RVSP), left ventricular septal pacing (LVSP), left bundle branch pacing (LBBP) and His bundle pacing (HBP), with LBBP and HBP being selective or non-selective. The analyzed ECG recordings include high-frequency (1,000 Hz) and ultra-high-frequency (5,000 Hz) recordings obtained at some of the following times: before intervention, immediately after, the day after intervention and one year after intervention. The aim is to determine to what extent the different pacing techniques resemble the characteristics of spontaneous rhythm in patients with no conduction disorders that require pacing as an antibradycardia treatment. For that, several variables representative of ventricular activation dyssynchrony and of irregularities in ventricular repolarization are measured. Indices quantifying AT and RT and their spatial interventricular and intraventricular dispersions are proposed. The PRD index and other QT-based and T-wave-based indices are also measured. Our results show that physiological stimulation techniques, such as LBBP and HBP, produce ventricular electrical responses that are close to electrical activity under spontaneous rhythm, whereas techniques based on pacing the ventricular myocardium, such as RVAP or RVSP, do not achieve comparable spontaneous responses. Furthermore, our findings confirm that LBBP offers an effective alternative to HBP when activation and repolarization of the left ventricle are evaluated. Chapter 6 presents the conclusions. The main contributions of the thesis are highlighted, indicating that the thesis develops robust and efficient methodologies to measure the characteristics of ventricular depolarization and repolarization from ECG recordings. The PRD marker is shown to reflect a microgravity-induced increase in sympathetic modulation of ventricular repolarization by quantifying the magnitude of the oscillations in the angle between consecutive T waves. Furthermore, the predictive capacity of PRD to stratify CHF patients for the risk of SCD and PFD, alone and in combination with other ECG markers, is corroborated. In addition, this thesis compares different cardiac pacing techniques and shows that physiological pacing techniques targeting the cardiac conduction system are capable of mimicking ventricular activity under spontaneous rhythm, as indicated by similarities in ECG depolarization and repolarization, particularly when focusing the analysis on the left ventricle.<br /
Percutaneous Peripheral Nerve Stimulation in Chemotherapy-Induced Neuropathy: A Case Report
Get PDFBackground and Clinical Significance: Chemotherapy-induced peripheral neuropathy (CIPN) is a frequent and limiting complication of oncological treatment, particularly in patients receiving oxaliplatin. Its onset can significantly affect the quality of life and compromise the continuity of the antineoplastic therapy. Due to the limited efficacy of available pharmacological therapies, percutaneous electrical nerve stimulation (PENS) has been proposed as a non-invasive alternative for symptom management. Case presentation: We report the case of a 75-year-old woman with colorectal adenocarcinoma who developed CIPN following oxaliplatin administration. She underwent a 12-week course of PENS targeting the median nerve, with weekly sessions conducted without interruption of chemotherapy and without adverse effects. The patient showed progressive improvement in neurosensory symptoms, as measured by the EORTC QLQ-CIPN20 questionnaire. Quantitative sensory testing revealed normalization of thermal and vibratory sensitivity and improved mechanical detection thresholds. The cumulative oxaliplatin dose was maintained throughout treatment. Conclusions: PENS may offer an effective and safe therapeutic option for managing CIPN, enabling symptom control without compromising oncological treatment. This case supports the need for controlled clinical trials to confirm efficacy and establish standardized protocols
Circular Economy Assessment of Biochar-Enhanced Compost in Viticulture Using Ecocanvas
Get PDFThis study evaluates the application of circular economy principles in the wine sector through a demonstrative case developed within the LIFE Climawin project. The initiative focuses on the local valorization of vineyard residues by producing biochar from vine pruning and using it to enrich compost derived from winemaking by-products and sheep manure. The combined application of these soil amendments aims to improve soil structure, enhance carbon sequestration, and reduce reliance on synthetic fertilizers. A systemic evaluation was conducted using the Ecocanvas methodology—a conceptual framework for mapping circular business models across environmental, economic, and social dimensions. The analysis integrated a targeted literature review, examination of technical data, direct field observations of composting and biochar production, and semi-structured interviews with key stakeholders. Results indicate multiple benefits from localized residue valorization, including improved compost quality, reduced greenhouse gas emissions, potential contributions to long-term soil health, and enhanced resource efficiency. The analysis also highlights economic opportunities, such as reduced dependency on external inputs, and social value creation through local stakeholder engagement. Furthermore, the study identifies factors that enable or constrain the replication and scaling of this model. These findings contribute to frameworks for advancing circular, economically viable, and socially inclusive climate-resilient agricultural systems
Deep Learning in Spanish University Students: The Role of Digital Literacy and Critical Thinking
Get PDFUniversity students use the Internet regularly for study, socialising, and entertainment; moreover, in adolescents and young adults, Internet use increases with age. More than ever before, the wide availability of online information requires critical thinking coupled with skills for evaluating online information, such as verifying the reliability of information and netiquette. These competencies might influence deep learning; however, few studies have analysed all these variables together. In addition, there is an ongoing academic debate as to whether using smartphones at an early age is beneficial for learning. Our study aimed to analyse, according to the age of the first smartphone, to what extent students’ critical thinking disposition, netiquette, and evaluation of the reliability of online information predict their capacity for deep learning. Our sample comprised 415 Spanish university students aged 18–36 (M = 19.98 and SD = 4.18). The instruments used were, for the assessment of Deep Learning, the Subscale of the questionnaire Attitudes towards learning of university students CEVAPU (to measure the Critical Thinking Disposition, we used the CTDS scale (Spanish adaptation of Bravo et al., 2020 and also the Competence Scale Evaluation of the reliability of online information (e-CEI) (Denoni & Cebollero-Salinas, 2025; and, finally, to assess Netiquette, the subscale of the questionnaire Evaluation of the quality of cyberbehavior “EsCaCiber” Multiple linear regression results indicated that in those participants who indicated they had acquired a smartphone before the age of thirteen, the two competencies of netiquette and evaluation of online information reliability were more strongly predictive of deep learning than in the group of participants who had their first smartphone when they were thirteen or older. Our study confirms that critical thinking disposition is a factor that favours deep learning in both groups (i.e., smartphone acquisition before and after 13 years old). The social and educational implications are along the lines of fostering a disposition to critical thinking, educating in digital literacy, especially in verifying the reliability of information, and communicating with netiquette for deep learning. Our findings indicate a potential association between critical thinking disposition and a greater propensity for deep learning in both groups (i.e., smartphone acquisition before and after 13 years old). A relevant educational implication of the results seems to indicate that a possible way to achieve deep university learning is to encourage critical thinking, to educate in digital literacy, especially in the verification of the reliability of information and to communicate with netiquette. Some of the limitations of the research design are the use of self-reports, convenience sampling and a cross-sectional design
Discursive Interpersonality: Engaging audiences in digital feature articles.
Get PDFEngaging audiences is widely regarded as essential for science communicators aiming to bridge the gap between the expert knowledge they convey and their target audience's presumed lack of expertise. Drawing on the concept of discursive interpersonality (Suau et al., 2021), this study explores a corpus of 30 digital feature articles from the SciDis Corpus (Pascual and Sancho-Ortiz, 2024) in order to identify and analyse pragmatic strategies and their associated (meta)discursive features used by science communicators to make expert knowledge accessible and engaging for lay audiences. Results show that writers deploy a range of strategies and resources, including not only interactional metadiscourse features, as expected, but also strategic resources adapted from journalistic and narrative discourses. In sum, the study shows that audience-oriented pragmatic strategies (Lorés, 2024b) extend beyond traditional metadiscourse (Hyland, 2005b). Further conclusions point to editorial and disciplinary differences in the use of pragmatic and (meta)discursive engaging strategies
Food waste heterogeneity among Spanish households: a quantile regression approach
Get PDFFood waste is a global systemic issue that poses major threats in economic, social, and environmental sustainability. Recent policy efforts have primarily targeted households, as they are responsible for most food wasted. However, for these policies to be effective, they must account for household heterogeneity, recognizing that certain socioeconomic characteristics may influence differently depending on their level of waste. This study investigates the heterogeneous impact of socioeconomic characteristics on Spanish household food waste over the period 2018–2022, analysing households from minimal to substantial waste ratios. A quantile regression approach is applied to estimate the effects across the entire distribution of food waste, rather than focusing only on average effects. Results indicate that household characteristics influence food waste in a significant different way depending on their waste level. Moreover, product-level heterogeneity is also addressed, highlighting perishable products (fish and vegetables) as critical targets. Our findings point to the need for designing highly precise interventions, focusing on specific products and socioeconomic groups that contribute most to food waste
Identification of ShgH as a dual histidine/glutamine transporter component essential for Streptococcus suis virulence and biofilm modulation
Get PDFStreptococcus suis is a zoonotic pathogen that affects pigs and humans. In this study, we characterised ShgH, a predicted substrate-binding component of an ABC transporter. Immunoassays confirmed that ShgH is expressed, secreted and surface-exposed in S. suis, in agreement with its proposed transporter function. Isothermal titration calorimetry demonstrated that ShgH binds glutamine and histidine, with a higher affinity for histidine. Deletion of the shgH gene significantly impaired uptake of both radiolabelled amino acids confirming its role as part of a transporter. Functional analysis revealed that shgH deletion results in a marked reduction in virulence in a murine infection model, while host colonization remained unaffected. ShgH contributes to infection by facilitating evasion of phagocytosis and resistance to oxidative stress through impaired nutrient acquisition and reduced capsule production. In addition, ShgH regulates biofilm formation and architecture. Notably, ShgH is highly conserved among pathogenic streptococci, suggesting a broader functional relevance. Altogether, our findings identify ShgH as a dual glutamine/histidine- binding protein essential for nutrient uptake and virulence in S. suis, and a promising target for future therapeutic interventions
Restituir desde el silencio
Get PDFEste artículo analiza Nela, 1979, de Juan Trejo, como un caso paradigmático del relato de filiación en el marco de las literaturas transicionales. A partir de una microhistoria familiar atravesada por el silencio, la adicción y la pérdida, se examinan los modos en que el autor reconstruye la figura ausente de su hermana mayor, fallecida en 1979, como parte de un ejercicio posmemorial. La obra de Trejo se inserta en una tradición narrativa que, a través del archivo, la investigación subjetiva y la reescritura del trauma, busca reconstituir no solo una historia individual sino también las tensiones latentes en la Transición democrática española. El análisis sitúa esta crónica en el cruce entre autoficción, testimonio y escritura documental, y en diálogo con los marcos conceptuales de la posmemoria, la narrativa de filiación y la melancolía política postdictatorial