270 research outputs found

    Phytotoxicity of lead on Lactuca sativa: effects on growth, mineral nutrition, photosynthetic activity and oxidant metabolism

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    Pb (lead) contamination in water and soils is increasing and its accumulation in plants may have serious deleterious consequences for environment and human health. Lead effects on plants still remain unclear and, therefore, a selection of Pb sensitive parameters used as biomarkers is required for improvement within the scope of Ecological Risk Assessment. In this study Lactuca sativa L. plants were exposed to Pb to contaminated irrigation solutions (12.5 mg l-1 and 125 mg l-1) for 15 days. Orthogonal analyses (time vs. Pb concentration vs. organ) were carried out after one, seven and fifteen days to elucidate about the effects of this element in plants. During exposure, plant growth, nutritional imbalance, water content, soluble protein content, lipid peroxidation (malondyaldehyde accumulation) and photosynthesis (chlorophyll contents and PSII fluorescence) were assessed in order to find the most adequated parameters for further studies in under realistic environmental conditions. Morphological and growth parameters showed decreases of root and shoot growth and alterations in root branching pattern. Biochemical parameters showed nutritional imbalance mostly concerning Pb, K (potassium) and Fe (iron) contents, changes in chlorophyll content and chlorophyll a:b ratio and malondyaldehyde accumulation. Therefore, such biochemical parameters may be used/ recommended as assessment parameters complementary to morphologic ones (e.g. shoot and root lengths) both in toxicological tests and further studies under realistic environmental conditions.publishe

    Sequential and Simultaneous Algorithms to Solve the Collision-Free Trajectory Planning Problem for Industrial Robots – Impact of Interpolation Functions and the Characteristics of the Actuators on Robot Performance

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    This paper has been possible thanks to the funding of Science and Innovation Ministry of the Spain Government by means of the Researching and Technologic Development Project DPI2010-20814-C02-01 (IDEMOV).Rubio Montoya, FJ.; Valero Chuliá, FJ.; Besa Gonzálvez, AJ.; Pedrosa Sanchez, AM. (2012). Sequential and Simultaneous Algorithms to Solve the Collision-Free Trajectory Planning Problem for Industrial Robots ¿ Impact of Interpolation Functions and the Characteristics of the Actuators on Robot Performance. En Robotic Systems - Applications, Control and Programming. InTech. 591-610. doi:10.5772/25970S59161

    Implementation of activities for the evaluation of the specific instrumental transversal competence in subjects in the area of mechanical engineering

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    [EN] Most of the higher education frameworks work and evaluate transversal competences, to achieve the excellence of graduates, not only academically but also integrating social aspects, ethics, communication, teamwork, etc. To this end, the present work studies a common methodology both in the activities, to improve the acquisition of the ¿Specific Instrumental¿ transversal competence, as well as in its evaluation. In the practical sessions, the student uses a detailed tutorial with the procedure to obtain the numerical result. The evaluation of the ¿Specific Instrumental¿ transversal competence is deficient following this structure, since it does not show whether the student acquires autonomy to solve similar problems. Therefore, an unguided alternative activity was proposed at the end of each session, which allows to see the evolution of the student in the face of a different problem without guidelines. Experience shows that it is rash to expect the student to handle the program autonomously in the first session. For this reason, the delivery deadline for tasks will be extended by a few weeks. Obviously, guarantee of authenticity is lost, but responsibility for learning is transferred to the student. Allowing the student to spend the time necessary for deep learning, without the pressure of ending the session.Authors gratefully acknowledge the financial support of the Vicerrectorado de Estudios, Calidad y Acreditación and the Vicerrectorado de Recursos Digitales y Documentación of the Universitat Politècnica de València (project PIME B/19-20/165) and the Instituto de Ciencias de la Educación of the Universitat Politècnica de València (EICE INTEGRAL).Pedrosa, AM.; Sánchez Orgaz, EM.; Lozano-Mínguez, E.; Martinez-Sanchis, S. (2020). Implementation of activities for the evaluation of the specific instrumental transversal competence in subjects in the area of mechanical engineering. IATED Academy. 597-602. https://doi.org/10.21125/iceri.2020.0197S59760

    L’atenció primerenca a les Illes Balears

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    El treball descriu el programa d’atenció primerenca que es desenvolupa a les Illes Balears, la seva evolució, els professionals i les seves funcions en cada un dels àmbits implicats. Per altra part, també s’ofereixen dades sobre la població atesa. Els autors són professionals dels tres àmbits responsables del Pla integral d’atenció primerenca de les Illes Balears (educatiu, sanitari i social), els quals destaquen la importància de la coordinació interdisciplinària i la necessitat de disposar d’una xarxa de serveis que doni resposta a les necessitats dels infants i les seves famílies.El trabajo describe el programa de atención primaria que se desarrolla en las Islas Baleares, su evolución, los profesionales y sus funciones en cada uno de los ámbitos implicados. Por otra parte, también se ofrecen datos sobre la población atendida. Los autores son profesionales de los tres ámbitos responsables del Plan integral de atención primaria de las Islas Baleares (educativo, sanitario y social), los cuales destacan la importancia de la coordinación interdisciplinar y la necesidad de disponer de una red de servicios que den respuesta a las necesidades de los niños y sus familias

    Kahoot! as a Tool to Improve Student Academic Performance in Business Management Subjects

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    The new framework for learning requires the use of new technologies, such as m-learning or game-based learning programs. Gamification using this type of applications has been implemented in higher education contexts, enhancing students’ satisfaction, motivation, and class attendance. The present study refers to the introduction of new technologies and gamification through the use of the application Kahoot!, with the main objective being to analyze the relationship between the use of this gamification tool and the students’ learning results, which are measured by their academic marks. The results show a positive relationship between students’ results on the Kahoot! tests and the student’s final mark. Additionally, we demonstrate that students’ academic results improve when Kahoot! is used as an evaluation tool, taking into account improved student efficiency and a lower amount of failed grades.Proyecto de Innovación docente de la Universidad de Jaén “Una experiencia de gamificación en el aula: Evaluamos con Kahoot! (PID32_201819)

    A single-phase current-source converter combined with a hybrid converter for interfacing an electric vehicle and a renewable energy source

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    This paper presents a single-phase current-source converter (CSC) combined with a hybrid converter on the dc-link, allowing to interface an electric vehicle (EV) and a renewable energy source (RES). Therefore, the interface with the power grid is only performed through the CSC, which also permits the operation as shunt active power filter (SAPF), allowing to compensate power quality problems related with current and low power factor in the electrical installation. The whole system is composed by two main power stages, namely, the CSC that is responsible for compensating the current harmonics and low power factor, as well as operating as a grid-tied inverter or as an active rectifier, and the hybrid converter that is responsible for interfacing the dc-link of the CSC with the converters for the EV and the RES interfaces. As demonstrated along the paper, the CSC, combined with the hybrid converter on the dc-link, allows the operation as SAPF, as well as the operation in bidirectional mode, specifically for the EV operation, and also for injecting power from the RES. In the paper, the power electronics structure is described and the principle of operation is introduced, supported by the description of the control algorithms. The validation results show the proper operation of the CSC, combined with the hybrid converter on the dc-link, for the main conditions of operation, namely exchanging power with the power grid in bidirectional mode and operating as a SAPF.This work has been supported by FCT – Fundação para a Ciência e Tecnologia with-in the Project Scope: UIDB/00319/2020. This work has been supported by the FCT Project newERA4GRIDs PTDC/EEI-EEE/30283/2017 and the FCT Project DAIPESEV PTDC/EEI-EEE/30382/2017

    Novel capsular depolymerases-based strategy to kill multidrug-resistant pathogenic bacteria

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    Multidrug resistant pathogens represent one of the greatest threats to human health of the new millennium. ESKAPE bacterial pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and other Enterobacteriaceae species) are the leading group among these socalled superbugs, which rapidly acquire resistances to several (and sometimes all) available antibiotics and cause a variety of nosocomial infections (e.g. bacteraemia and wound infections). Our research has been leading an innovative approach based on bacteriophage-derived enzymes (called capsular depolymerases) against A. baumannii (see video at ref 1). Previously, we found that some bacteriophages (i.e. viruses that specifically infect bacteria) acquired the ability to infect different Acinetobacter hosts through acquisition of different capsular depolymerases (2). These enzymes located at the bacteriophage tails bind and degrade specific bacterial capsules types (2). Recently, recombinantly expressed capsular depolymerases showed to be active in several environment conditions, non-nontoxic to mammalian cells and able to make A. baumannii fully susceptible to host complement effect, namely in i) Galleria mellonella caterpillar, ii) murine and iii) human serum models (3, 4). A single intraperitoneal injection of depolymerase protect 60% of mice from dead, with significant reduction of proinflammatory cytokine profile (4). We show that capsular depolymerases fit the new trend of antimicrobials needed, as they are highly specific, stable and refractory to resistance as they do not kill bacteria per se, instead they remove bacterial surface polysaccharides, diminishing bacterial virulence and exposing them to the host immune system. This innovative antimicrobial approach can be applied to other pathogenic bacteria.info:eu-repo/semantics/publishedVersio

    Establishment and characterization of human pluripotent stem cells-derived brain organoids to model cerebellar diseases

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    Supplementary Information Te online version contains supplementary material available at https://doi.org/ 10.1038/s41598-022-16369-y.The establishment of robust human brain organoids to model cerebellar diseases is essential to study new therapeutic strategies for cerebellum-associated disorders. Machado-Joseph disease (MJD) is a cerebellar hereditary neurodegenerative disease, without therapeutic options able to prevent the disease progression. In the present work, control and MJD induced-pluripotent stem cells were used to establish human brain organoids. These organoids were characterized regarding brain development, cell type composition, and MJD-associated neuropathology markers, to evaluate their value for cerebellar diseases modeling. Our data indicate that the organoids recapitulated, to some extent, aspects of brain development, such as astroglia emerging after neurons and the presence of ventricular-like zones surrounded by glia and neurons that are found only in primate brains. Moreover, the brain organoids presented markers of neural progenitors proliferation, neuronal differentiation, inhibitory and excitatory synapses, and firing neurons. The established brain organoids also exhibited markers of cerebellar neurons progenitors and mature cerebellar neurons. Finally, MJD brain organoids showed higher ventricular-like zone numbers, an indication of lower maturation, and an increased number of ataxin-3-positive aggregates, compared with control organoids. Altogether, our data indicate that the established organoids recapitulate important characteristics of human brain development and exhibit cerebellar features, constituting a resourceful tool for testing therapeutic approaches for cerebellar diseases.This work was funded by the European Regional Development Fund (ERDF) through the Centro 2020 Regional Operational Programme under BrainHealth2020 projects (CENTRO-01-0145-FEDER-000008), through the COMPETE 2020—Operational Programme for Competitiveness and Internationalization and Portuguese national funds via FCT—Fundação para a Ciência e a Tecnologia, under projects — UIDB/04539/2020 and UIDP/04539/2020, POCI-01-0145-FEDER-030737 (NeuroStemForMJD, PTDC/BTM-ORG/30737/2017), CEEC-IND/04242/2017, PhD Scholarships 2020.04751.BD and 2020.07385.BD. It was also funded by the National Ataxia Foundation, the French Muscular Dystrophy Association (AFM-Téléthon) Trampoline Grant #20126, EU Joint Programme—Neurodegenerative Disease Research (JPND) Project JPCO FUND/0005/2015-ModelPolyQ), and the Richard Chin and Lily Lock Machado-Joseph Disease Research Fund.info:eu-repo/semantics/publishedVersio

    Assessment of the use of technical software by the students in the context of mechanical engineering

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    [EN] In the framework of the European Higher Education area, university teaching has focused in recent years on adapting Master's and Bachelor's degrees to the demands of the professional sector. To do this, the training and development of the generic and specific skills recommended for the incorporation of students into the job market have been priority objectives in the approach to study plans. However, there is no consensus on the methodologies for evaluating these skills, especially regarding how to separate the acquisition and / or improvement of the skills from the specific knowledge and skills of the subjects. Due to the lack of time, teaching staff seek methodologies that do not involve additional tests for the evaluation of competences, which would increase the number of tests to a non-realistic number with the corresponding assessment duties for the professors. In order to make a contribution in this regard, this work presents an approach for evaluating the ability to handle specific software applied to problems in the area of mechanical engineering. This work proposes a methodology for acquiring the required skills and an evaluation system to grade the degree of expertise in the manipulation of the software. In our University, this skill is called the Specific Instrumental Skill, which measures the ability of the students for using the tools in engineering, like, in this case, the use of software to run structural numerical simulations as ANSYS®. The methodology proposed is based on an a priori training. This training is based on 2 hours weekly sessions where the students should solve, in groups of 2 or 3 students, a set of labs with the help of the professor. The students do not need to deliver any report to the professor since the objective of the sessions is the training of the students. Therefore, the pressure over the student is low and the professor avoid to mark a high number of student¿s reports, allowing him to focus only on the learning process of the students and not on the evaluation during the training sessions. These labs increase the difficulty along a number of sessions. The last session consists in an exam in which the students must solve a lab similar to those already solved during the training sessions. This time, each student will work individually without the help of the professor and with a control of the time. Finally, the performance of the methodology is checked by a cross-test for the same students who are part of the group of students of another subject (control subject) where the same tool (ANSYS®) is used. The collected data showed that the students following this methodology acquire the sufficient expertise for handling the software and their skills outperform those of the students of the control subject who did not follow the proposed methodology. As a conclusion, the methodology proposed in this work guarantees a good level of expertise for the students, as shown by the results. Since the results in the final lab exam and the results of the cross-test coincides, the use of the final test exam could be interpreted as a good indicator of the degree of expertise in the use of the software. Additionally, the proposed methodology reduces the work load for the professor as it only requires assessing 1 report per student (instead of several reports for each group of 2 or 3 students in each of the session) while ensuring the authorship of the report.Authors gratefully acknowledge the financial support of the Vicerrectorado de Estudios, Calidad y Acreditación and the Vicerrectorado de Recursos Digitales y Documentación of the Universitat Politècnica de València (project PIME B/19-20/165) and the Instituto de Ciencias de la Educación of the Universitat Politècnica de València (EICE INTEGRAL).Nadal, E.; Rupérez Moreno, MJ.; Giner Navarro, J.; Rovira, A.; Ródenas, JJ.; Martínez Casas, J.; Pedrosa, AM. (2020). Assessment of the use of technical software by the students in the context of mechanical engineering. IATED Academy. 3344-3348. https://doi.org/10.21125/iceri.2020.0756S3344334

    Beyond the limits of oxygen: effects of hypoxia in a hormone-independent prostate cancer cell line

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    Prostate cancer (PCa) has a high incidence worldwide. One of the major causes of PCa resistance is intratumoral hypoxia. In solid tumors, hypoxia is strongly associated with malignant progression and resistance to therapy, which is an indicator of poor prognosis. The antiproliferative effect and induced death caused by doxorubicin, epirubicin, cisplatin, and flutamide in a hormone-independent PCa cell line will be evaluated. The hypoxia effect on drug resistance to these drugs, as well as cell proliferation and migration, will be also analyzed. All drugs induced an antiproliferative effect and also cell death in the cell line under study. Hypoxia made the cells more resistant to all drugs. Moreover, our results reveal that long time cell exposure to hypoxia decreases cellular proliferation and migration. Hypoxia can influence cellular resistance, proliferation, and migration. This study shows that hypoxia may be a key factor in the regulation of PCa.info:eu-repo/semantics/publishedVersio
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