125 research outputs found
Factors afecting educational success and continuity among Young people of Moroccan descent in Catalonia (Spain)
International reports and research emphasize the relation between the results of young immigrants in school and social integration and, in observing their school situation, indicate that in most countries they are worse than their native counterparts. This is particularly true for those groups that have a history of critical contact with host societies as in the case of young people of Moroccan origin in Catalonia. In this Autonomous Community, Morroccan students have low levels of accreditation at the end of compulsory schooling, have higher dropout rates, and their continuity in post-compulsory education is also lower than their native counterparts. This tendency, however, makes invisible the trajectories of school success and the growing social participation of a considerable part of these young people of Moroccan origin of both sexes in Catalan society.This article presents the results of a research project that, based on the reconstruction of the biographical and academic trajectories of these young people of Moroccan origin and the contribution of agents involved in their schooling, transitions to the labor market and social integration, has analyzed the central factors that allow the development of their success trajectories and the consolidation of long-term academic aspirations.We pay attention to the results obtained regarding the four trends that have emerged in the most relevant research in the construction of the success trajectories: the support received from the family, the social capital emanating from the peer group, the positive school experience and the impetus received from intra-ethnic associationism
Direct tree decomposition of geometric constraint graphs
The evolution of constraint based geometric models is tightly tied to parametric and feature-based Computer-Aided Design (CAD) systems. Since the introduction of parametric design by Pro/Engineer in the 1980's, most major CAD systems adopted constraint based geometric models as a core technology. Constraint based geometric models allowed CAD systems to provide a more powerful data model while offering an intuitive user interface. Later on, the same models also found application to fields like linkage design, chemical modeling, computer vision and dynamic geometry.
Constraint based geometric models are unevaluated models. A key problem related to constraint based geometric models is the geometric constraint based solving problem which, roughly speaking, can be stated as the problem of evaluating a constraint based model. Among the different approaches to geometric constraint solving, we are interested in graph-based Decomposition-Recombination solvers. In the graph-based constructive approach, the geometric problem is first translated into a graph whose vertices represent the set of geometric elements and whose edges are the constraints. Then the constraint problem is solved by decomposing the graph into a set of sub-problems, each sub-problem is recursively divided until reaching basic problems which are solved by a dedicated equational solver. The solution to the initial problem is computed by merging the solutions to the sub-problems.
The approach used by DR-solvers has been particularly successful when the decomposition into subproblems and subsequent recombination of solutions to these subproblems can be described by a plan generated a priori, that is, a plan generated as a preprocessing step without actually solving the subsystems. The plan output by the DR-planner remains unchanged as numerical values of parameters change. Such a plan is known as a DR-plan and the unit in the solver that generates it is the DR-planner. In this setting, the DR-plan is then used to drive the actual solving process, that is, computing specific coordinates that properly place geometric objects with respect to each other.
In this thesis we develop a new DR-planner algorithm for graph-constructive two dimensional DR-solvers. This DR-planner is based on the tree-decomposition of a graph. The triangle- or tree-decomposition of a graph decomposes a graph into three subgraphs such that subgraphs pairwise share one vertex. Shared vertices are called hinges. The tree-decomposition of a geometric constraint graph is in some sense the construction plan that solves the corresponding problem. The DR-planner algorithm first transforms the input graph into a simpler, planar graph. After that, an specific planar embedding is computed for the transformed graph where hinges, if any, can be straightly found. In the work we proof the soundness of the new algorithm. We also show that the worst case time performance of the resthe number of vertices of the input graph. The resulting algorithm is easy to implement and is as efficient as other known solving algorithms.L'evolució de models geomètrics basats en restriccions està fortament lligada al sistemes de Disseny Assistit per Computador (CAD) paramètrics i als basats en el paradigma de disseny per mitjà de característiques. Des de la introducció del disseny paramètric per part de Pro/Engineer en els anys 80, la major part de sistemes CAD utilitzaren com a tecnologia de base els models geomètrics basats en restriccions. Els models geomètrics basats en restriccions permeteren als sistemes CAD proporcionar un model d'informació més ampli i alhora oferir una interfície d'usuari intuitiva. Posteriorment, els mateixos models s'aplicaren en camps com el disseny de mecanismes, el modelatge químic, la visió per computador i la geometria dinàmica. Els models geomètrics basats en restriccions són models no avaluats. Un problema clau relacionat amb el models de restriccions geomètriques és el problema de la resolució de restriccions geomètriques, que es resumeix com el problema d'avaluar un model basat en restriccions. Entre els diferents enfocs de resolució de restriccions geomètriques, tractem els solvers de Descomposició-Recombinació (DR-solvers) basats en graphs. En l'enfoc constructiu basat en grafs, el problema geomètric es trasllada en un pas inicial a un graf, on els vèrtexs del graf representen el conjunt d'elements geomètrics i on les arestes corresponen a les restriccions geomètriques entre els elements. A continuació el problema de restriccions es resol descomposant el graf en un conjunt de subproblemes, cadascun dels quals es divideix recursivament fins a obtenir problemes bàsics, que sovint són operacions geomètriques realitzables, per exemple, amb regle i compàs, i que es resolen per mitjà d'un solver numèric específic. Finalment, la solució del problema inicial s'obté recombinant les solucions dels subproblemes. L'enfoc utilitzat pels DR-solvers ha esdevingut especialment interessant quan la descomposició en subproblemes i la posterior recombinació de solucions d'aquests subproblemes es pot descriure com un pla de construcció generat a priori, és a dir, un pla generat com a pas de pre-procés sense necessitat de resoldre realment els subsistemes. El pla generat pel DR-planner esdevé inalterable encara que els valors numèrics dels paràmetres canviin. Aquest pla es coneix com a DR-plan i la unitat en el solver que el genera és l'anomenat DR-planner. En aquest context, el DR-plan s'utilitza com a eina del procés de resolució en curs, és a dir, permet calcular les coordenades específiques que correctament posicionen els elements geomètrics uns respecte els altres. En aquesta tesi desenvolupem un nou algoritme que és la base del DR-planner per a DR-solvers constructius basats en grafs en l'espai bidimensional. Aquest DR-planner es basa en la descomposició en arbre d'un graf. La descomposició en triangles o arbre de descomposició d'un graf es basa en descomposar un graf en tres subgrafs tals que comparteixen un vèrtex 2 a 2. El conjunt de vèrtexs compartits s'anomenen \emph{hinges}. La descomposició en arbre d'un graf de restriccions geomètriques equival, en cert sentit, a resoldre el problema de restriccions geomètriques. L'algoritme del DR-planner en primer lloc transforma el graf proporcionat en un graf més simple i planar. A continuació, es calcula el dibuix en el pla del graf transformat, on les hinges, si n'hi ha, es calculen de manera directa. En aquest treball demostrem la correctesa del nou algoritme. Finalment, proporcionem l'estudi de la complexitat temporal de l'algoritme en cas pitjor i demostrem que és quadràtica en el nombre de vèrtexs del graf proporcionat. L'algoritme resultant és senzill d'implementar i tan eficient com altres algoritmes de resolució concret
Educación infantil y familias inmigrantes: posibilidades y limitaciones comunicativas
The incorporation of immigrated populations into catalan classrooms has generated an opportunity to detect weaknesses in the early childhood educational system, specifically relating to children between the ages of three to five. The article discusses the relationship between school and immigrant families throughout teacher discourse analysis. For such, methodological foundations on «video-cued multivocal ethnography» have been applied. Focus group discussions have been carried out in four early childhood education schools. Data analysis has detected three large topics of study having direct impact in the incorporation of children of immigrant origins: the pedagogical principles in early childhood education, the vehicular language of learning in a bilingual environment and the relationship between school and families. Focussing on this last topic, the article argues the need for a more collaborative culture between families (native and immigrant) and schools, entailing not only emphasis in communication but also its contents. Ethical concerns regarding permission and anonymity have been taken into consideration in the investigation
El aula de música como ambiente sonoro de aprendizaje en Educación Infantil
Se presenta una investigación de campo que parte de la creación de un ambiente sonoro de aprendizaje en una escuela de Educación Infantil y Primaria. En este entorno, a través del juego libre, se observa y analiza la interacción con el medio del educando de segundo ciclo de Educación Infantil (n=104), organizados en 10 grupos de perfil homogéneo. En segundo lugar, se comparan los resultados entre las diferentes edades de la etapa educativa. Se sigue una metodología de investigación mixta, cualitativa y cuantitativa, bajo el paradigma del diseño secuencial exploratorio. Las sesiones se grabaron en vídeo y se analizaron con una tabla de observación individual (TOIM) basándose en una categorización de los resultados preliminares. Los resultados muestran como el nuevo entorno y los objetos ofrecidos han permitido al alumnado desarrollar aprendizajes de manera global, más allá de aspectos relacionados con la exploración sonora. Se observan así mismo diferencias, de menos a más, en cómo se desarrollan estudiantes de diferentes edades, especialmente en referencia al tipo de juego, la aproximación a los objetos, la acción de producir y escuchar el sonido y en las relaciones sociales que se establece
Concepciones de madres y educadoras sobre la participación parental en un centro infantil rural ecuatoriano
In recent years, the Early Childhood Education and Care (ECEC) has increased in rural areas of Ecuador
as a result of the new educational policy that seeks to change the relationships between families and
schools. The aim of this research is to analyze the conceptions that mothers and teachers have about
parental participation in an Ecuadorian rural early childhood center. This is an ethnographic study. The
ethnographic study was carried out for 10 months in the children's center, combining participant
observation and interviews with different agents. Data on how teachers and mothers have specific and
differentiated expectations about participation in a school are presented. The discourse is distorted by the
different groups and processes, producing contradictions between the objectives established by law and
the educational practices that are developed in the early childhood center.En los últimos años, la atención y educación a la primera infancia se ha ido incrementando en las zonas
rurales de Ecuador como resultado de las nuevas políticas educativas que buscan cambiar las relaciones
entre las familias y las escuelas. El objetivo de esta investigación es analizar las concepciones que tanto
madres como educadoras manejan sobre la participación de los progenitores en un centro infantil de
educación temprana de una comuna rural en Ecuador. Esta es una investigación etnográfica que se llevó
a cabo durante diez meses de estancia, combinando la observación participante y la entrevista a
diferentes agentes. Se presentan datos sobre cómo educadoras y madres tienen expectativas específicas
y diferentes sobre la participación en la escuela. Se expone información sobre cómo el discurso de la
participación en el centro infantil es distorsionado por los diferentes colectivos y procesos, produciéndose
contradicciones entre los objetivos y prácticas educativas
Effect of zinc on oropharyngeal mucositis in children with acute leukemia undergoing chemotherapy
Oropharyngeal mucositis (OM) is one of the main side-effects of oncological therapy. There is no treatment to prevent its occurrence, but some zinc-based therapies have been proven to help in decreasing its intensity. The objective of this study was to determine the effect of zinc in OM in children with acute leukemia in the early stages of oncological treatment. This quasi-experimental study evaluated OM in 2 groups (control group: conventional hospital management, and experimental group: administration of 50 mg of zinc gluconate daily plus conventional hospital management). OM severity was recorded at a two-month follow-up. Forty-nine patients (26 in the control group and 23 in the experimental group) were included. The mean age of the patients was 11.1 ± 2.7 years; 65.3% had a diagnosis of pre-B acute lymphoblastic leukemia. The incidences of OM in the control group and the experimental group were 46.2% and 26.1%, respectively, but the difference was not significant. Based on a negative binomial regression model, females had, on average, 1.5 more days with OM (p = 0.002), and patients assigned to the experimental group had, on average, 2 less days with OM than the control group (p = 0.001). The pain score was higher in the control group (p = 0.0009), as was the mean score on the WHO scale (p = 0.0012). Zinc facilitated a reduction in the severity and duration of OM; further studies focusing on children are needed to confirm the effects of this trace element
Transport and distributions of naturally and anthropogenically sourced trace metals and arsenic in submarine canyons
Continental margins play a key role in the cycling of natural and anthropogenic trace metals (TMs) as pathways at the interface between landmasses and deep ocean basins but also as sinks. Knowledge of how short-lived forcings alter the export dynamics of TMs is essential for our understanding of their fate in that setting. Here we report time series of particulate metal fluxes in three submarine canyons —namely Escombreras, Almeria and the Garrucha-Almanzora system— of the South-Western Mediterranean Sea. Our research focuses on combining multi-elemental TMs (Al, Fe, Ti, Co, Cu, Mn, Ni, Pb and Zn) and As (a metalloid) contents of settling particles collected near the bottom by automated particle traps during one year, and seafloor sediment samples from below the traps. We assess the role of storms and bottom trawling in the off-shelf transport of particulate TMs and As, and the natural and anthropogenic contributions of TMs by using enrichment factors (EFs). The TM export fluxes and composition changed over the study period, from March 2015 to March 2016. TM fluxes increase in early spring 2015 in association with short-lived storm events and during calm months in the Garrucha-Almanzora Canyon system, likely due to sediment resuspension triggered by bottom trawling. In terms of composition, TMs in the sinking fluxes appear to be closely associated with lithogenic (Al, Fe and Ti) and authigenic (Mn) particles’ proxies. During storm events, the mass of settling particles in Escombreras and Almeria canyons was impoverished in Al, Fe, As, Co, Cu, Mn and Ni compared to other periods. The Garrucha-Almanzora Canyon system behaves differently as the above-described differences, are not observed there. Moreover, the TM composition of the sediments —with higher contents of Fe, Ti and several other TMs— in this canyon is barely tied to the composition of the settling particles. Finally, Cu and Zn contents, together with Pb in the northernmost Escombreras Canyon, are best explained by referring to anthropogenic sources. This work provides insights into the profound influence of the natural and anthropogenic forcings controlling the distributions and seasonal dynamics of particulate TMs and As in submarine canyons
Particle fluxes in submarine canyons along a sediment-starved continental margin and in the adjacent open slope and basin in the SW Mediterranean Sea
Investigating the transfer of particulate matter from the continental shelf to the deep basin is critical to understand the functioning of deep sea ecosystems. In this paper we present novel results on the temporal variability of particle fluxes to the deep in three physiographic domains of a 240 km long margin segment and nearby basin off Murcia and Almeria provinces in the SW Mediterranean Sea, which are submarine canyons forming a rather diverse set (namely Escombreras, Garrucha-Almanzora and Almeria), the adjacent open slope and the deep basin. This margin is located off one of the driest regions in Europe and, therefore, its study may help understanding how mainland aridity translates into the export of particles to deep margin environments. Five mooring lines equipped with currentmeters, turbidity-meters and sediment traps were deployed for one entire annual cycle, from March 2015 to March 2016. We combine oceanographic, hydrological and meteorological data with grain size and bulk elemental data (organic carbon, opal, CaCO3, lithogenic) from the collected sinking particles to understand what drives particle transfers in such an under-studied setting, and to quantify the resulting fluxes and assess their spatio-temporal variability. Weighted total mass fluxes in canyons range from 1.64 g m−2 d−1 in Almeria Canyon to 7.33 g m−2 d−1 in Garrucha-Almanzora Canyon system, which are rather low values compared to other submarine canyons in the Western Mediterranean Sea. This results from the absence of extreme wind-storm events during the investigated time period combined with the reduced sediment input to the inner shelf by river systems in the study area. Our results also show that wind-storms are the main trigger for off-shelf particle transport to the deep margin, both within submarine canyons and over the open slope. The most significant transfer period is associated to a set of north-eastern storms in early spring 2015, when the off-shelf transport likely was promoted by storm-induced downwelling. However, the prevailing oceanographic conditions restricts the advection of water down the canyon heads to a few hundred meters, thus promoting a bottom-detached transport of particles seaward. Overall physiography, canyon head incision into the continental shelf and the distance of the canyon head to the shoreline (e.g. very short in Garrucha Canyon) play a key role in particle trapping capability and, therefore, in easing downslope particle transport. Further, bottom trawling activities around the Garrucha-Almanzora Canyon system, feed a nepheloid layer at depths in excess of 400 m, subsequently enhancing particle fluxes throughout the study period. In contrast, maximum particle fluxes in the deep basin respond to seasonal phytoplankton blooms. Our study shows that particle export from the shallow inner margin to the deep outer margin in sediment-starved settings, even if limited, does occur as dominated by atmosphere and ocean driven short-lived events. However, that export does not reach too far as at several tens of kilometres from the shelf edge advective fluxes are replaced by vertical ones impelled by phytoplankton dynamics
Lung Myofibroblasts Are Characterized by DownRegulated Cyclooxygenase-2 and Its Main Metabolite, Prostaglandin E2
Background: Prostaglandin E2 (PGE(2)), the main metabolite of cyclooxygenase (COX), is a well-known anti-fibrotic agent. Moreover, myofibroblasts expressing alpha-smooth muscle actin (alpha-SMA), fibroblast expansion and epithelial-mesenchymal transition (EMT) are critical to the pathogenesis of idiopathic pulmonary fibrosis (IPF). Our aim was to investigate the expression of COX-2 and PGE(2) in human lung myofibroblasts and establish whether fibroblast-myofibroblast transition (FMT) and EMT are associated with COX-2 and PGE(2) down-regulation. Methods: Fibroblasts obtained from IPF patients (n = 6) and patients undergoing spontaneous pneumothorax (control, n = 6) and alveolar epithelial cell line A549 were incubated with TGF-beta 1 and FMT and EMT markers were evaluated. COX-2 and alpha-SMA expression, PGE(2) secretion and cell proliferation were measured after IL-1 beta and PGE(2) incubation. Results: Myofibroblasts from both control and IPF fibroblast cultures stimulated with IL-1 beta showed no COX-2 expression. IPF fibroblasts showed increased myofibroblast population and reduced COX-2 expression in response to IL-1 beta. TGF-beta 1 increased the number of myofibroblasts in a time-dependent manner. In contrast, TGF-beta 1 induced slight COX-2 expression at 4 h (without increase in myofibroblasts) and 24 h, but not at 72 h. Both IPF and control cultures incubated with TGF-beta 1 for 72 h showed diminished COX-2 induction, PGE(2) secretion and alpha-SMA expression after IL-1 beta addition. The latter decreased proliferation in fibroblasts but not in myofibroblasts. A549 cells incubated with TGF-beta 1 for 72 h showed down-regulated COX-2 expression and low basal PGE(2) secretion in response to IL-1 beta. Immuno-histochemical analysis of IPF lung tissue showed no COX-2 immuno-reactivity in myofibroblast foci. Conclusions: Myofibroblasts are associated with COX-2 down-regulation and reduced PGE(2) production, which could be crucial in IPF development and progression
Child–robot interactions using educational robots: an ethical and inclusive perspective
This research was funded by the Spanish Ministerio de Ciencia e Innovación under Grant FECYT FCT-20-15626, Line of action 2. Education and scientific vocations (2nd place out of 120 awarded).Peer ReviewedObjectius de Desenvolupament Sostenible::5 - Igualtat de GènereObjectius de Desenvolupament Sostenible::9 - Indústria, Innovació i InfraestructuraObjectius de Desenvolupament Sostenible::4 - Educació de QualitatObjectius de Desenvolupament Sostenible::10 - Reducció de les DesigualtatsPostprint (published version
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