B content and Si/C ratios from cultured diatoms (Thalassiosira pseudonana and Thalassiosira weissflogii): Relationship to seawater pH and diatom carbon acquisition

AbstractDespite the importance of diatoms in regulating climate and the existence of large opal-containing sediments in key air-ocean exchange areas, most geochemical proxy records are based on carbonates. Among them, Boron (B) content and isotopic composition have been widely used to reconstruct pH from foraminifera and coral fossils. We assessed the possibility of a pH/CO2 seawater concentration control on B content in diatom opal to determine whether or not frustule B concentrations could be used as a pH proxy or to clarify algae physiological responses to acidifying pH. We cultured two well-studied diatom species, Thalassiosira pseudonana and Thalassiosira weissflogii at varying pH conditions and determined Si and C quotas. Frustule B content was measured by both laser-ablation inductively coupled mass spectrometry (LA-ICPMS) and secondary ion mass spectrometry (SIMS/ion probe). For both species, frustules grown at higher pH have higher B contents and higher Si requirements per fixed C. If this trend is representative of diatom silicification in a future more acidic ocean, it could contribute to changes in the efficiency of diatom ballasting and C export, as well as changes in the contribution of diatoms relative to other phytoplankton groups in Si-limited regions. If B enters the cell through the same transporter employed for HCO3− uptake, an increased HCO3− requirement with decreasing CO2 concentrations (higher pH), and higher B(OH)4/HCO3− ratios would explain the observed increase in frustule B content with increasing pH. The mechanism of B transport from the site of uptake to the site of silica deposition is unknown, but may occur via silicon transport vesicles, in which B(OH)4− may be imported for B detoxification and/or as part of a pH regulation strategy either though Na-dependent B(OH)4−/Cl− antiport or B(OH)4−/H+ antiport. B deposition in the silica matrix may occur via substitution of a B(OH)4− for a negatively charged SiO− formed during silicification. With the current analytical precision, B content of frustules is unlikely to resolve ocean pH with a precision of paleoceanographic interest. However, if frustule B content was controlled mainly by HCO3− uptake for photosynthesis, which appears to show a threshold behavior, then measurements of B content might reveal the varying importance of active HCO3− acquisition mechanisms of diatoms in the past

Study of the impact of an online self-assessment questionnaire for the treatment of measurement uncertainties

La correcta comprensión del origen de las incertidumbres experimentales, así como su tratamiento matemático, resulta fundamental en la formación de cualquier científico, pues permite determinar la precisión de los resultados experimentales. Por este motivo, estos conocimientos forman parte de las competencias relacionadas con las asignaturas de Física de los primeros cursos universitarios. Se ha desarrollado e implantado en la plataforma Moodle un cuestionario de autoevaluación online como actividad de autoaprendizaje enfocada al tratamiento de errores en las prácticas de laboratorio de las asignaturas de Física de primer curso en diferentes grados científico-técnicos. Concretamente, fueron puestos a disposición del alumnado de los Grados de Química y Ciencia y Tecnología de los Alimentos. Para valorar el impacto percibido por el alumnado de estos cuestionarios de autoevaluación se realizaron encuestas previas y posteriores a las actividades, cuyos resultados muestran una alta correlación entre el uso de la actividad y la percepción de su utilidad. De igual forma, se han analizado las estadísticas de uso y las calificaciones proporcionadas por la plataforma Moodle, mostrando que, pese a la positiva percepción del impacto del cuestionario en su aprendizaje, es necesario perfilar la actividad para conseguir un mayor grado de uso.The correct understanding of the origin of the experimental uncertainties and their mathematical treatment is fundamental in the formation of any scientist, since it allows to determine the precision of the experimental results. For this reason, such knowledge is usually part of the competences related to the Physics subjects of the first university courses. An online self-assessment questionnaire was developed and implemented in the Moodle platform as a self-learning activity focused on the treatment of errors in the laboratory practices of the first year Physics subjects in different scientific-technical degrees. Specifically, it was available to students from Chemistry and Food Science and Technology degrees. To assess the impact perceived by students, surveys were conducted before and after the activities. The analysis of the answers given to those surveys, used as indicators of the perceived impact of the activity, show a high correlation between the use of the activity and the perception of its usefulness. Similarly, usage statistics and the ratings provided by the Moodle platform were analyzed, showing that, despite the positive perception of the impact of the questionnaire on their learning, it is necessary to improve the activity to achieve a greater degree of use

Occurrence and size distribution study of microplastics in household water from different cities in continental Spain and the Canary Islands

9 pages, 5 figures, 1 table, supplementary materials https://doi.org/10.1016/j.watres.2023.120044.-- Data availability: Data will be made available on requestThe purpose of this study was to investigate the occurrence of microplastics (MPs) in drinking water in Spain by comparing tap water from different locations using common sampling and identification procedures. We sampled tap water from 24 points in 8 different locations from continental Spain and the Canary Islands by means of 25 μm opening size steel filters coupled to household connections. All particles were measured and spectroscopically characterized including not only MPs but also particles consisting of natural materials with evidence of industrial processing, such as dyed natural fibres, referred insofar as artificial particles (APs). The average concentration of MPs was 12.5 ± 4.9 MPs/m3 and that of anthropogenic particles 32.2 ± 12.5 APs/m3. The main synthetic polymers detected were polyamide, polyester, and polypropylene, with lower counts of other polymers including the biopolymer poly(lactic acid). Particle size and mass distributions were parameterized by means of power law distributions, which allowed performing estimations of the concentration of smaller particles provided the same scaling parameter of the power law applies. The calculated total mass concentration of the identified MPs was 45.5 ng/L. The observed size distribution of MPs allowed an estimation for the concentration of nanoplastics (< 1 µm) well below the ng/L range; higher concentrations are not consistent with scale invariant fractal fragmentation. Our findings showed that MPs in the drinking water sampled in this work do not represent a significant way of exposure to MPs and would probably pose a negligible risk for human healthThe authors acknowledge the financial support provided by Plastics Europe and that of the Spanish Government, Ministerio de Ciencia e Innovación, grants PID2020-113769RB-C21/C22.With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)Peer reviewe

A nationwide monitoring of atmospheric microplastic deposition

8 Pág.Plastic production continues to increase every year, yet it is widely acknowledged that a significant portion of this material ends up in ecosystems as microplastics (MPs). Among all the environmental compartments affected by MPs, the atmosphere remains the least well-known. Here, we conducted a one-year simultaneous monitoring of atmospheric MPs deposition in ten urban areas, each with different population sizes, economic activities, and climates. The objective was to assess the role of the atmosphere in the fate of MPs by conducting a nationwide quantification of atmospheric MP deposition. To achieve this, we deployed collectors in ten different urban areas across continental Spain and the Canary Islands. We implemented a systematic sampling methodology with rigorous quality control/quality assurance, along with particle-oriented identification and quantification of anthropogenic particle deposition, which included MPs and industrially processed natural fibres. Among the sampled MPs, polyester fibres were the most abundant, followed by acrylic polymers, polypropylene, and alkyd resins. Their equivalent sizes ranged from 22 μm to 398 μm, with a median value of 71 μm. The particle size distribution of MPs showed fewer large particles than expected from a three-dimensional fractal fragmentation pattern, which was attributed to the higher mobility of small particles, especially fibres. The atmospheric deposition rate of MPs ranged from 5.6 to 78.6 MPs m-2 day-1, with the higher values observed in densely populated areas such as Barcelona and Madrid. Additionally, we detected natural polymers, mostly cellulosic fibres with evidence of industrial processing, with a deposition rate ranging from 6.4 to 58.6 particles m-2 day-1. There was a positive correlation was found between the population of the study area and the median of atmospheric MP deposition, supporting the hypothesis that urban areas act as sources of atmospheric MPs. Our study presents a systematic methodology for monitoring atmospheric MP deposition.The authors acknowledge the support provided by Spanish Network of Plastics in the Environment, EnviroPlaNet (www.enviroplanet.net) and the financial support provided by the Spanish Government, Ministerio de Ciencia e Innovación, grants PID2020-113769RB-C21/C22. The authors would like to thank the Interdepartmental Investigation Research Service of the Universidad Autónoma de Madrid (SIDI-UAM and Segainvex) for the use of their infrastructures and their technical support. J.G.S. thanks ACIISI for the contract from the Viera y Clavijo program at the University of La Laguna (85 % co-financed by the European Social Fund).Peer reviewe

Characterization of Tajogaite volcanic plumes detected over the Iberian Peninsula from a set of satellite and ground-based remote sensing instrumentation

Three volcanic plumes were detected during the Tajogaite volcano eruptive activity (Canary Islands, Spain, September–December 2021) over the Iberian Peninsula. The spatiotemporal evolution of these events is characterised by combining passive satellite remote sensing and ground-based lidar and sun-photometer systems. The inversion algorithm GRASP is used with a suite of ground-based remote sensing instruments such as lidar/ ceilometer and sun-photometer from eight sites at different locations throughout the Iberian Peninsula. Satellite observations showed that the volcanic ash plumes remained nearby the Canary Islands covering a mean area of 120 ± 202 km2 during the whole period of eruptive activity and that sulphur dioxide plumes reached the Iberian Peninsula

Breast cancer risks associated with missense variants in breast cancer susceptibility genes

BACKGROUND: Protein truncating variants in ATM, BRCA1, BRCA2, CHEK2, and PALB2 are associated with increased breast cancer risk, but risks associated with missense variants in these genes are uncertain. METHODS: We analyzed data on 59,639 breast cancer cases and 53,165 controls from studies participating in the Breast Cancer Association Consortium BRIDGES project. We sampled training (80%) and validation (20%) sets to analyze rare missense variants in ATM (1146 training variants), BRCA1 (644), BRCA2 (1425), CHEK2 (325), and PALB2 (472). We evaluated breast cancer risks according to five in silico prediction-of-deleteriousness algorithms, functional protein domain, and frequency, using logistic regression models and also mixture models in which a subset of variants was assumed to be risk-associated. RESULTS: The most predictive in silico algorithms were Helix (BRCA1, BRCA2 and CHEK2) and CADD (ATM). Increased risks appeared restricted to functional protein domains for ATM (FAT and PIK domains) and BRCA1 (RING and BRCT domains). For ATM, BRCA1, and BRCA2, data were compatible with small subsets (approximately 7%, 2%, and 0.6%, respectively) of rare missense variants giving similar risk to those of protein truncating variants in the same gene. For CHEK2, data were more consistent with a large fraction (approximately 60%) of rare missense variants giving a lower risk (OR 1.75, 95% CI (1.47-2.08)) than CHEK2 protein truncating variants. There was little evidence for an association with risk for missense variants in PALB2. The best fitting models were well calibrated in the validation set. CONCLUSIONS: These results will inform risk prediction models and the selection of candidate variants for functional assays and could contribute to the clinical reporting of gene panel testing for breast cancer susceptibility

Transformando enseñanzas presenciales en semipresenciales: un ejemplo, la especialidad de Formación y Orientación Laboral en el Máster en Formación del Profesorado. Protocolo de actuación, evaluación y nuevos diseños para la docencia universitaria

Fac. de Ciencias Políticas y SociologíaFALSEsubmitte

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at root s(NN)=2.76TeV

Peer reviewe

Citotoxicidad diferencial según el régimen de quimioterapia contra las células madre del cáncer de páncreas: estudio preliminar in vitro

Introduction: Pancreatic cancer treatment in advanced stages is based on different chemotherapy regimens. Cancer stem cells are responsible for tumor chemoresistance and recurrence in adjuvant and metastatic settings. The objective of this article was to evaluate how these chemotherapeutic regimens affect the proportion of cancer stem cells and the expression of stemness markers. Method: We used the pancreatic adenocarcinoma cell line PANC-1 as a model to apply different chemotherapeutic protocols (monotherapy and combined therapy) using 5-Fluorouracil, Oxaliplatin, Irinotecan, Gemcitabine and Abraxane. Results: After analyzing different tumor stem cell markers (SOX2, OCT4, CD133, CD44 and CD24) in pancreatic cancer cells treated with different chemotherapeutic protocols by means of RT-qPCR, Oxaliplatin and Gemcitabine in monotherapy were the chemotherapies that selected the most cancer stem cells while the FOLFIRI protocol decreased them. Conclusions: Regarding the selection of markers, it has been much higher in the case of Gemcitabine alone. In conclusion, these findings could improve and personalize pancreatic cancer therapy.Introducción: El tratamiento del cáncer de páncreas en estadios avanzados se basa en diferentes regímenes de quimioterapia. Las células madre cancerosas son responsables de la quimiorresistencia tumoral y la recurrencia tras tratamientos en etapa adyuvante y metastásica. El objetivo de este artículo fue evaluar cómo estos regímenes quimioterapéuticos afectan a la proporción de células madre cancerosas y la expresión de sus marcadores. Método: Utilizamos la línea celular de adenocarcinoma pancreático PANC-1 como modelo para aplicar diferentes protocolos quimioterapéuticos (monoterapia y terapia combinada) utilizando 5-Fluorouracilo, Oxaliplatino, Irinotecán, Gemcitabina y Abraxane. Resultados: Tras analizar mediante RT-qPCR diferentes marcadores de células madre tumorales (SOX2, OCT4, CD133, CD44 y CD24) en células de cáncer de páncreas tratadas con diferentes protocolos quimioterapéuticos, el Oxaliplatino y la Gemcitabina en monoterapia fueron los quimioterápicos que seleccionaron en mayor medida las células madre cancerosas mientras que el protocolo FOLFIRI las disminuyó. Conclusiones: En cuanto a la selección de marcadores, ha sido mucho mayor en el caso de Gemcitabina en monoterapia. En conclusión, estos hallazgos podrían mejorar y personalizar la terapia del cáncer de páncreas