629 research outputs found
Characterizing Critical Thinking Skills of Primary Students when Developing Collaborative Reading Activities
Este estudio de investigación tiene como objetivo caracterizar las habilidades de pensamiento crítico de los estudiantes de cuarto grado al desarrollar actividades de lectura en grupos colaborativos. Los constructos teóricos que se destacan en nuestra investigación están divididos en dos grupos: un grupo concebido con la pedagogía (pedagogía crítica y pensamiento crítico) y el otro grupo concebido con el aprendizaje (como el resultado de interacciones sociales (aprendizaje colaborativo, interacciones sociales y las interacciones sociales centradas en el estudiante). Los referentes teóricos principales fueron (Collins & O'Brien, 2003) para el aprendizaje centrado en el estudiante basado en aprendizaje colaborativo e interacciones sociales; y Paulo Freire (1921-1997) y Henry Giroux (b. 1943) para pedagogía crítica y pensamiento crítico como aspectos filosóficos del aprendizaje. Este estudio se realizó en un colegio público en Bogotá con estudiantes entre los 8 y 10 años de edad. Los resultados del estudio revelaron que los estudiantes se sienten motivados y usan una variedad de habilidades de pensamiento crítico cuando están expuestos a actividades de lectura enfocadas en la resolución de problemas. Además, fue posible identificar que el trabajo en grupos colaborativos fortalece sus habilidades de pensamiento crítico.This research study attempted to characterize fourth grader’s critical thinking skills when developing collaborative reading strategies. The theoretical constructs we based our research were grouped into two groups: a group concerned with pedagogy (critical pedagogy and critical thinking) and a group concerned with learning as the result of social interactions (collaborative learning and social interactions centered in students or learner-centeredness). The main referents were (Collins & O'Brien, 2003) for learner-centered learning based on collaborative learning and social interactions; and Paulo Freire (1921-1997) and Henry Giroux (b. 1943) for critical pedagogy and critical thinking as philosophical aspects of human learning. This study was conducted in a public school located in Bogota with students whose ages range from 8 to 10. The results of this study revealed that students feel motivated and use a variety of CT skills when they are exposed to problem solving reading activities. Moreover, it was possible to identify that collaborative groups enhance their CT skills
Dynamic Model Derivation of a 3RRR Robot Based in Screw Theory
In this article a technique to obtain a dynamic model of a 3RRR robot from its kinematic model based on screw theory is proposed, which allows to obtain the open or closed robot kinematics. First the kinematic model is obtained in a compact form and then the dynamic model is obtained from the Euler Lagrange method, with this the simplicity and compactness characteristics are transferred to the dynamic model. The dynamic model is obtained initially for the actuated joints and then for the effector coordinates through its interrelations. To prove the effectiveness of this theoretical derivation the obtained model is tested with a proportional-derivative controller (PD) because it provides a simple control strategy that can be extended later to more effective controllers
Reduction of adult hippocampal neurogenesis modifies brain functional connectivity and enhances cocaine-seeking in mice
Recently, adult hippocampal neurogenesis has been proposed as a putative neuroplastic mechanism involved in those behavioural processes. In this work, we studied the effect of the inhibition of adult hippocampal neurogenesis using the DNA alkylating agent temozolomide (TMZ), in cocaine-induced conditioned place preference (CPP) behaviour. In a first experiment, we investigated both CPP acquisition/expression and the functional brain circuits underlying CPP expression in control and neurogenesis-reduced conditions by analysing c-Fos immunoreactivity (c-Fos IR) in hippocampal and extrahippocampal addiction-related areas. A second experiment was designed to study the involvement of adult-born neurons in the extinction and cocaine-induced reinstatement of drug-seeking in the CPP model. We performed two independent studies where adult hippocampal neurogenesis was inhibited either before or after the CPP was acquired. Our results showed that TMZ treatment had no effect on the acquisition of the cocaine-induced CPP, but c-Fos IR associated to the test trial (CPP expression) revealed an increased activity in some of the analysed brain areas in the CPP-TMZ mice. Correlational and multivariate analysis revealed that, under normal conditions, the hippocampus showed widespread functional connectivity with other brain areas and strongly contributed to the functional brain network associated with CPP expression. However, mice with reduced neurogenesis showed an alternative brain circuit. The results of the second experiment revealed that mice acquiring the cocaine-induced CPP under neurogenesis-reduced conditions were delayed in extinguishing their drug seeking behaviour. However, when neurogenesis was inhibited after CPP acquisition, extinction was not affected but an enhanced long-term CPP retention was found, suggesting that the role of the adult-born neurons may differ depending on whether they are generated before or after drug-contextual associations are established. Importantly, cocaine-induced reinstatement of CPP behaviour was increased in the TMZ mice, regardless of the time of neurogenesis inhibition.Universidad de Málaga. Andalucía Tech, Campus de Excelencia Internacional. Spanish Ministry of Economy and Competitiveness (PSI2013-44901-P to L.J.S.; Subprograma RETICS Red de Trastornos Adictivos RD12/0028/0001, to F.R.F.). Author E.C-O. holds a ‘Sara Borrell’ research contract from the Spanish Carlos III Health Institute, Spanish Ministry of Economy and Competitiviness (grant number CD12/00455). Author D.L.G-M. holds a ‘FPU’ grant from the Spanish Ministry of Education, Culture and Sports (grant number FPU13/04819)
Modeling COVID-19 with Uncertainty in Granada, Spain. Intra-Hospitalary Circuit and Expectations over the Next Months
Mathematical models have been remarkable tools for knowing in advance the appropriate time to enforce population restrictions and distribute hospital resources. Here, we present a
mathematical Susceptible-Exposed-Infectious-Recovered (SEIR) model to study the transmission
dynamics of COVID-19 in Granada, Spain, taking into account the uncertainty of the phenomenon.
In the model, the patients moving throughout the hospital’s departments (intra-hospitalary circuit)
are considered in order to help to optimize the use of a hospital’s resources in the future. Two
main seasons, September–April (autumn-winter) and May–August (summer), where the hospital
pressure is significantly different, have been included. The model is calibrated and validated with
data obtained from the hospitals in Granada. Possible future scenarios have been simulated. The
model is able to capture the history of the pandemic in Granada. It provides predictions about the
intra-hospitalary COVID-19 circuit over time and shows that the number of infected is expected to
decline continuously from May without an increase next autumn–winter if population measures
continue to be satisfied. The model strongly suggests that the number of infected cases will reduce
rapidly with aggressive vaccination policies. The proposed study is being used in Granada to design
public health policies and perform wise re-distribution of hospital resources in advance.Spanish Ministerio de Economía, Industria y Competitividad (MINECO)Agencia Estatal de Investigación (AEI)Fondo Europeo de Desarrollo
Regional (FEDER UE) grant MTM2017-89664-PEuropean Union through the Operational
Program of the [European Regional Development Fund (ERDF)/European Social Fund (ESF)] of the Valencian Community 2014–2020Ramón
Areces Foundation, Madrid, Spain (CIVP18A3920)
Sistemas de evaluación flexibles como instrumento de mejora de los resultados académicos de los estudiantes
Esta comunicación continúa describiendo la experiencia de los firmantes en la aplicación de las nuevas metodologías docentes descritas en una comunicación anterior [1].
En primer lugar se recuerdan dichas nuevas metodologías y se resumen los resultados obtenidos con la aplicación de las mismas en los últimos cursos académicos.
Se ha constatado en la práctica que, tanto el aprendizaje efectivo del alumno como sus resultados académicos alcanzados, dependen fuertemente del sistema de evaluación adoptado, condicionando incluso la estrategia de estudio y seguimiento de la asignatura por parte del alumno.
En base a ello, y siguiendo las tendencias de autonomía del estudiante en su aprendizaje, auspiciadas por el Espacio Europeo de Educación Superior, se ha propuesto en el curso académico actualmente vigente (2012-2013) un nuevo sistema de evaluación más flexible que, intentando medir objetivamente el rendimiento de los estudiantes, le motive a éste a configurar de forma voluntaria las distintas actividades valorables en los distintos componentes de la evaluación.
El objetivo principal de este nuevo sistema es reducir la tasa de abandono prematuro de la asignatura por parte de los estudiantes y la consecuente mejora de sus resultados académicos en la misma.
REFERENCIAS.
[1] RODRÍGUEZ GARCÍA, E. A. CARRILLO ANDRÉS, A. SERRANO CASARES, F. DOMÍNGUEZ MUÑOZ, F. "La evaluación continua y la tutoría virtual como herramientas eficientes en el proceso de enseñanza-aprendizaje de los estudiantes”. En Actas VII Congreso Nacional de Ingeniería Termodinámica, (Bilbao 15, 16 y 17 de junio de 2011)
Immune responses following neonatal vaccination with conserved F4 fragment of VtaA proteins from virulent Glaesserella parasuis adjuvanted with CAF®01 or CDA
Glaesserella parasuis is a Gram-negative bacterium that colonizes the upper airways of swine, capable of causing a systemic infection called Glässer’s disease. This disease is more frequent in young post-weaning piglets. Current treatments against G. parasuis infection are based on the use of antimicrobials or inactivated vaccines, which promote limited cross-protection against different serovars. For this reason, there is an interest in developing novel subunit vaccines with the capacity to confer effective protection against different virulent strains. Herein, we characterize the immunogenicity and the potential benefits of neonatal immunization with two different vaccine formulations based on the F4 polypeptide, a conserved immunogenic protein fragment from the virulence-associated trimeric autotransporters of virulent G. parasuis strains. With this purpose, we immunized two groups of piglets with F4 combined with cationic adjuvant CAF®01 or cyclic dinucleotide CDA. Piglets immunized with a commercial bacterin and non-immunized animals served as control groups. The vaccinated piglets received two doses of vaccine, at 14 days old and 21 days later. The immune response induced against the F4 polypeptide varied depending on the adjuvant used. Piglets vaccinated with the F4+CDA vaccine developed specific anti-F4 IgGs, biased towards the induction of IgG1 responses, whereas no anti-F4 IgGs were de novo induced after immunization with the CAF®01 vaccine. Piglets immunized with both formulations displayed balanced memory T-cell responses, evidenced upon in vitro re-stimulation of peripheral blood mononuclear cells with F4. Interestingly, pigs immunized with F4+CAF®01 controlled more efficiently a natural nasal colonization by a virulent serovar 4 G. parasuis that spontaneously occurred during the experimental procedure. According to the results, the immunogenicity and the protection afforded by F4 depend on the adjuvant used. F4 may represent a candidate to consider for a Glässer‘s disease vaccine and could contribute to a better understanding of the mechanisms involved in protection against virulent G. parasuis colonization.This study was financially supported by the European Project TRANSVAC2–730964–INFRAIA–2016-1 of the European Vaccine Initiative funded in turn by the European Commission under the Horizon 2020 Program. Sergi López-Serrano was funded by this Project. IRTA-CReSA is also supported by the Centres de Recerca de Catalunya (CERCA) Program from the Generalitat de Catalunya.info:eu-repo/semantics/publishedVersio
Stent-induced tracheal stenosis can be predicted by IL-8 expression in rabbits
Background: bare metal stents may cause complications like fibrous encapsulation, granulation and tracheal stenosis. We investigated the behaviour of three commercially available stents in vivo (rabbits) and in vitro (coculture of those stents with epithelial and fibroblast cell lines). Also, we investigated whether development of tracheal stenosis could be predicted by any biological marker. Materials and methods: the tracheae of 30 rabbits were implanted with either nitinol stents, with or without paclitaxel elution, or a cobalt-based stent. An additional ten rabbits underwent mock implantation (controls). Serial peripheral venous blood samples were taken throughout the study, and several cytokines measured. Animals were euthanized on day 90, with immediate tracheal endoscopy and lavage performed, then necropsy. Results: rabbits with cobalt-based stent exhibited more inflammation and the highest stenosis incidence, with reduced survival. Both in vivo and in vitro, this stent induced higher IL-8 levels than nitinol stents. Most important, the presence of stent-induced tracheal stenosis was closely associated to increase in IL-8 expression in blood just 1 day after tracheal stent implantation: a 1·19-fold increase vs. baseline had 83% sensitivity, 83% specificity, 77% positive predictive value, 88%negative predictive value and 83% accuracy to predict development of stenosis. Conclusions: the cobalt-based stent had the highest incidence of tracheal inflammation and stenosis. On the other hand, the paclitaxel-eluting nitinol stent did not prevent those complications and provoked a marked reaction compared with the bare nitinol stent. Early increase in IL-8 expression in blood after stent implantation could predict development of tracheal stenosis in rabbits
Identificación de errores conceptuales comunes en estudiantes de Termodinámica Básica
Se investigan los preconceptos sobre calor y temperatura que tienen los alumnos de ingeniería antes de recibir formación en Termodinámica. El diagnóstico se realiza mediante un cuestionario, pasado a principios de curso. En esta comunicación se resumen los resultados de una prueba realizada con 206 estudiantes. Se cuantifica la frecuencia de diferentes tipos de error conceptual.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
Antipsychotic Medication Influences the Discriminative Value of Acylethanolamides as Biomarkers of Substance Use Disorder.
Plasma acylethanolamides (NAEs), including the endocannabinoid anandamide (AEA), have been proposed as circulating biomarkers of substance use disorders. However, the concentration of these lipid transmitters might be influenced by the use of drugs prescribed for either the treatment of addiction or the associated psychiatric co-morbidities such as psychosis. As an example, neuroleptics, used for attenuation of psychotic symptoms and sedation, might theoretically interfere with the monoamine-mediated production of NAEs, obstructing the interpretation of plasma NAEs as clinical biomarkers. To solve the lack of information on the impact of neuroleptics on the concentration of NAEs, we evaluated the concentrations of NAEs in a control group and compared them to those present in (a) substance use disorders (SUD) patients that are not prescribed with neuroleptics, and (b) SUD patients (both alcohol use disorder and cocaine use disorder patients) using neuroleptics. The results demonstrate that SUD patients exhibited greater concentrations of NAEs than the control population, affecting all species with the exception of stearoylethanolamide (SEA) and palmitoleoylethanolamide (POEA). Neuroleptic treatment enhanced the concentrations of NAEs, especially those of AEA, linoleoylethanolamide (LEA), and oleoylethanolamide (OEA). This effect of neuroleptic treatment was observed independently of the drug addiction that motivated the demand for treatment (either alcohol or cocaine). This study remarks the need to control the current use of psychotropic medication as a potential confounding variable when considering the use of NAEs as biomarkers in SUDPartial funding for open access charge: Universidad de Málag
Plasma endocannabinoid alterations as a link in the comorbidity of Alzheimer's disease and type 2 diabetes mellitus.
Over the last several years, studies have suggested a role of endocannabinoids such as 2-AG and 2-OG in the impairment of β-cell function and insulin secretion, as well as in the control of lipid and glucose metabolism in the periphery. Besides, alterations in the endocannabidiome are associated with the development of dementia. Since type 2 diabetes mellitus (T2DM) is an established risk factor for late-life cognitive decline, we sought to evaluate the possible link between the alterations in plasma endocannabinoids as potential biomarkers of cognitive decline in elderly patients with T2DM.
In the present study, we evaluated the plasma levels of endocannabinoids in a cohort of elder controls and patients suffering from T2DM, with either mild cognitive impairment (MCI) or Alzheimer’s disease (AD). The cognitive performance of these patients was evaluated at the beginning of the study and their regional brain metabolic activity was assessed by PET-18FDG. We found that T2DM patients showed decreased levels of brain metabolic activity determined by PET-18FDG in the inferior parietal lobe, caudate, and thalamus, which were decreased and related to poor cognitive performance shown by both BLESSED and MMSE tests. Segregation of patients according to their cognitive status (MCI or AD) showed lower basal metabolism in the aforementioned regions, which was exacerbated in patients with AD and T2DM comorbidity. Correlation analysis showed plasma levels of the endocannabinoids 2-AG, 2-LG, and 2-OG were inversely related to brain metabolism in these areas, as well as to worse BLESSED and MMSE scores.
Our results depict that plasma endocannabinoids are potential biomarkers linking the development of cognitive decline to the occurrence of T2DM.Consejería de Universidad, Investigación e Innovación, Junta de Andalucía, grant number PI21/00291. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
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