Dipòsit Digital de la Universitat de Barcelona

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El Dipòsit Digital de la Universitat de Barcelona és el repositori institucional que conté en format digital els materials derivats de l'activitat docent, investigadora i institucional de la comunitat universitària.

Enviaments recents

Modelling the epidemiological impact of diagnostic performance on malaria transmission: a multi-scale approach
(2026-06) Hernàndez Arnal, Violeta; López Codina, Daniel; Prats i Soler, Clara; Ibañes Miguez, Marta
Malaria is one of the leading causes of preventable death worldwide, yet the epidemiological impact of diagnostic performance on the transmission dynamics is poorly understood. Three models of increasing complexity are studied: a single-strain model, a two-strain model and a spatially distributed model in order to quantify how the choice of the diagnostic method and the geographical distribution of healthcare centers affect the prevalence of the disease. The results of the study show that Rapid Diagnosis Tests (RDT) present a blind spot that allows the mutated variant to circulate silently at high prevalence levels, a phenomenon suppressed when changing the diagnostic method to microscopy. The spatial analysis demonstrates that diagnostic quality has a stronger influence on endemic prevalence rather than the size of the healthcare network.
Biochar as a sustainable sorbent for the removal of lanthanides from acid mine drainage
(Elsevier Ltd., 2025-06-01) Serra Ventura, Joan; Rasero López, Sandra; Romera Miró, Marc; Vidal, Marta; Rigol Parera, Anna
The extraction and processing of ores containing lanthanides (Ln) generate significant amounts of waste that may lead to Ln-rich leachates and acid mine drainage (AMD). AMD is characterised by an acidic pH and high iron (Fe) concentrations. Due to the environmental risk of these leachates, there is a need to apply effective remediation strategies to decrease Ln concentrations in leachate-affected waters. In this scenario, biochar was investigated as a sustainable and cost-effective alternative for the treatment of these waters. This study explored the viability of two biochar materials (derived from pine branches (PB) and garden wastes (GaW)) for the removal of Ln (La, Sm and Lu) from contaminated waters, including AMD. A continuous-flow sorption technique was used to simulate a real scenario of water filtration using a biochar barrier. Initially, two Sm-spiked water matrices, double-deionised water (DD) and river freshwater (FW) were tested, revealing no statistically significant differences in the biochar sorption capacities obtained (220 and 216 meq kg−1 for PB, 459 and 392 meq kg−1 for GaW in DD vs. FW scenarios, respectively), despite the slight differences in pH, dissolved organic matter, and water-soluble cation concentrations between the matrices. For mixed Ln contamination (La + Sm + Lu), Ln appeared to be equally distributed at the biochar sorption sites, whereas the biochar showed a similar overall sorption capacity when comparing mixed Ln contamination to only Sm contamination. After the initial tests, the efficiency of the biochar materials to sorb Ln from AMD was tested in a simulated AMD matrix. Biochar materials with high buffering capacity, such as those tested in this work, were considered a suitable option for the treatment of Ln-contaminated AMD, provided that the operation times are adapted so as not to exceed the acid neutralising capacity of the material.
Criteria employed by teacher educators when reflecting upon a problem-solving activity involving robots
(Universidade Estadual Paulista, 2026) Sala Sebastià, Gemma; Breda, Adriana; Seckel Santis, María José; Farsani, Danyal
[eng] This study aims to identify the criteria employed by teacher educators and researchers in mathematics education when evaluating an activity designed to foster computational thinking through the use of the BlueBot educational robot. The proposal is targeted at pre-service early childhood education teachers, with the objective of preparing them to effectively teach this content. In recent years, several countries have incorporated computational thinking into their curricula as part of educational reforms responding to evolving social demands. The study involved twenty experts in mathematics education and teacher training who participated in a 90-minute workshop organised by the authors at a Catalan university. During the session, the participants carried out the proposed activity, reflected on their experience, and contributed to a group discussion in which they shared their evaluations. They were audio-recorded and subsequently transcribed for analysis. The data were examined using the didactic suitability criteria of the ontosemiotic approach. Although the participants were not familiar with this theoretical framework, their evaluations revealed indicators consistent with its criteria, enabling a theoretically grounded reinterpretation of their views. The findings show that the instructional activity was perceived as highly suitable from a didactic perspective, with particular emphasis on its epistemic, cognitive, and ecological suitability. These results underscore the need to design and implement teacher training programmes – both pre-service and in-service – that support the development of mathematical thinking through computational thinking, with a strong focus on reflective practice. [spa] El objetivo de este trabajo es identificar los criterios que utilizan formadores de docentes e investigadores en Didáctica de las Matemáticas para valorar una actividad orientada al desarrollo del pensamiento computacional, mediante el uso del robot educativo BlueBot. La propuesta se dirige a la formación de futuros maestros de Educación Infantil, con el fin de formarlos para enseñar este contenido, recientemente incorporado en diversos países a través de reformas curriculares que responden a las demandas sociales actuales. Participaron en el estudio veinte expertos en Didáctica de las Matemáticas y formación del profesorado, quienes asistieron a un taller de 90 minutos organizado por los autores en una universidad catalana. Los participantes realizaron la actividad, reflexionaron sobre ella y, en una puesta en común, compartieron sus valoraciones, las cuales fueron grabadas y transcritas. El análisis de estas intervenciones se llevó a cabo mediante la herramienta de los Criterios de Idoneidad Didáctica del Enfoque Ontosemiótico. Aunque los participantes no estaban familiarizados con dicho marco teórico, sus valoraciones permitieron identificar indicadores alineados con estos criterios, posibilitando su reinterpretación fundamentada. Los resultados evidencian que la actividad fue valorada como altamente idónea desde una perspectiva didáctica, destacándose, especialmente, la idoneidad epistémica, la cognitiva y la ecológica. Finalmente, es necesario diseñar e implementar programas de formación para orientar a las futuras maestras y a los maestros y maestras en activo, con el fin de promover el desarrollo del Pensamiento Matemático a través del Pensamiento Computacional, donde la reflexión sobre la práctica educativa toma un papel primordial.
Vine-pruning waste derived catalyst for ibuprofen degradation from water through ozonation
(Elsevier Ltd., 2025-06-01) Nieto-Sandoval, Julia; Cavalcante, R.P.; Bayarri Ferrer, Bernardí; Sans Mazón, Carme
This work aimed to valorize vine shoots, for water treatment applications by investigating hydrochar materials in catalytic ozonation. For this purpose, a vine-pruning waste derived catalyst was synthesized via hydrothermal treatment at 200 °C, previous a cobalt impregnation step. The catalytic ozonation of the pharmaceutical ibuprofen showed 47 % higher degradation rate than single ozonation. However, the catalytic efficiency was reduced increasing the catalyst dose due to dissolved organic matter released during reaction. To address this issue, several chemical post-treatments were tested without effectiveness. Nevertheless, in the presence of a post-treated pyrolyzed catalyst at 550 °C (0.25 g/L), 86 % ibuprofen removal within just 1 min was achieved using 5 mg/L of ozone. The increase in BET surface area and the adsorption of ibuprofen on the material observed suggest a synergistic effect of both processes. Additionally, the effectiveness of the system was confirmed in a real aqueous matrix.
Traits of creativity in the initial training of mathematics teachers: assessment with didactic suitability criteria
(Springer Nature Switzerland, 2026-08-04) Calle, Eulalia; Breda, Adriana; Farsani, Danyal; Seckel Santis, María José
The objective of this research is to analyze the relationship between the most outstanding aspects of creativity considered by future mathematics teachers in Ecuador and the characteristics of the assessment of the final reports of the pre-professional practice, referring to creativity in their professional training process, in order to establish a tool that promotes and values mathematical creativity. A qualitatively driven mixed-methods approach was adopted. First, a content analysis of institutional assessment instruments and practice reports was conducted using the didactic suitability criteria of the Onto-Semiotic Approach as analytical categories. These included Forms 3, 4, and 8, completed during the March–August 2024 academic period by 30 pre-service teachers in advanced stages of training. Second, a validated questionnaire combining Likert-type and open-ended questions was administered to 27 participants to explore their conceptions of creativity. Descriptive statistics (percentages) were used as a complementary resource, while open responses were analyzed through content analysis based on the same theoretical framework. Finally, we work on the relationship between the results of the two types of questions. It is evident that most future teachers are not fully aware of the importance and need to incorporate creativity into their training process, addressing it in a very superficial way. In conclusion, it is essential to use the didactic suitability criteria tool that contributes to the reflection of teaching practice, taking into account the incorporation of creative activities proposed by teachers.