Proyectos innovadores de formación universitaria para adultos con experiencia. Algunos casos en América latina

La educación en alternancia, muy difundida en niveles no universitarios, tiene sólo unas décadas de vida en las universidades de Europa y Norteamérica. Desde 2001, varias instituciones que demandaban una educación superior para sus profesores rurales de secundaria, promueven proyectos de formación universitaria en diversos países latinoamericanos. Los resultados son muy satisfactorios. Por un lado, la Universidad trabaja en partenariado con otros actores en una colaboración poco frecuente en el ámbito académico. Por otro, se realizan innovaciones educativas que permiten a los estudiantes–adultos con experiencia– transformar problemas de acción en proyectos de investigación. Esta ponencia se centra sólo en algunos aspectos de las experiencias: la cooperativa de producción de saber entre estudiantes y profesores; el estudiante, que pasa de ser “actor” a “investigador-autor”, como centro del sistema; y la ruptura transdisciplinar de los rígidos paradigmas clásicos universitarios mediante la puesta en marcha de una verdadera formación-accióninvestigación. Estos logros requieren un cambio cultural y competencial del profesor universitario, así como una ingeniería pedagógica compleja. Algunos cambios observados en las actitudes personales y profesionales de estudiantes y profesores, permiten proponer la alternancia como una alternativa sistémica de formacióndesarrollo cercana a los postulados de Bolonia, frente a los enfoques universitarios tipo transmisivo

Multiple supernumerary teeth not associated with complex syndromes: a retrospective study

Objectives: To determine the epidemiology and describe the clinical and radiographic characteristics, the type of treatment, and the possible delayed appearance of new supernumerary teeth in patients with non-syndromic multiple hyperdontia. Patients and Methods: We conducted a small retrospective observational study of 8 patients diagnosed with nonsyndromic multiple hyperdontia. Multiple hyperdontia not associated to complex syndromes was defined as apparently generally healthy patients with one or more supernumerary teeth in two or more areas. Results: The average patient age was 16.23 years; males predominated (3:1). Multiple hyperodontia with a minimum of 2 and a maximum of 9 supernumerary teeth was found (total: 34 mean: 4.25). The most frequent location was the upper jaw (76.47%). Eumorphic teeth were seen at lower premolar level, while the rest were all heteromorphic. There was altered eruption of the contiguous teeth of 4 of the impacted supernumerary teeth all the rest being asymptomatic. Extraction was the treatment in all patients, and in one of them the delayed appearance of 4 supernumerary teeth was detected. Conclusions: Multiple hyperodontia rarely occurs without being associated with complex syndromes. Prophylactic surgical removal of the supernumerary teeth is generally the treatment of choice

Multiple supernumerary teeth not associated with complex syndromes: a retrospective study

Objectives: To determine the epidemiology and describe the clinical and radiographic characteristics, the type of treatment, and the possible delayed appearance of new supernumerary teeth in patients with non-syndromic multiple hyperdontia.Patients and Methods: We conducted a small retrospective observational study of 8 patients diagnosed with nonsyndromic multiple hyperdontia. Multiple hyperdontia not associated to complex syndromes was defined as apparently generally healthy patients with one or more supernumerary teeth in two or more areas.Results: The average patient age was 16.23 years; males predominated (3:1). Multiple hyperodontia with a minimum of 2 and a maximum of 9 supernumerary teeth was found (total: 34 mean: 4.25). The most frequent location was the upper jaw (76.47%). Eumorphic teeth were seen at lower premolar level, while the rest were all heteromorphic.There was altered eruption of the contiguous teeth of 4 of the impacted supernumerary teeth all the rest being asymptomatic. Extraction was the treatment in all patients, and in one of them the delayed appearance of 4 supernumerary teeth was detected.Conclusions: Multiple hyperodontia rarely occurs without being associated with complex syndromes. Prophylactic surgical removal of the supernumerary teeth is generally the treatment of choice

Positioning Control System for a Large Range 2D Platform with Submicrometre Accuracy for Metrological and Manufacturing Applications

The importance of nanotechnology in the world of Science and Technology has rapidly increased over recent decades, demanding positioning systems capable of providing accurate positioning in large working ranges. In this line of research, a nanopositioning platform, the NanoPla, has been developed at the University of Zaragoza. The NanoPla has a large working range of 50 mm × 50 mm and submicrometre accuracy. The NanoPla actuators are four Halbach linear motors and it implements planar motion. In addition, a 2D plane mirror laser interferometer system works as positioning sensor. One of the targets of the NanoPla is to implement commercial devices when possible. Therefore, a commercial control hardware designed for generic three phase motors has been selected to control and drive the Halbach linear motors.This thesis develops 2D positioning control strategy for large range accurate positioning systems and implements it in the NanoPla. The developed control system coordinates the performance of the four Halbach linear motors and integrates the 2D laser system positioning feedback. In order to improve the positioning accuracy, a self calibration procedure for the characterisation of the geometrical errors of the 2D laser system is proposed. The contributors to the final NanoPla positioning errors are analysed and the final positioning uncertainty (k=2) of the 2D control system is calculated to be ±0.5 µm. The resultant uncertainty is much lower than the NanoPla required positioning accuracy, broadening its applicability scope.<br /

Design optimization for the measurement accuracy improvement of a large range nanopositioning stage

Both an accurate machine design and an adequate metrology loop definition are critical factors when precision positioning represents a key issue for the final system performance. This article discusses the error budget methodology as an advantageous technique to improve the measurement accuracy of a 2D-long range stage during its design phase. The nanopositioning platform NanoPla is here presented. Its specifications, e.g., XY-travel range of 50 mm ˆ 50 mm and sub-micrometric accuracy; and some novel designed solutions, e.g., a three-layer and two-stage architecture are described. Once defined the prototype, an error analysis is performed to propose improvement design features. Then, the metrology loop of the system is mathematically modelled to define the propagation of the different sources. Several simplifications and design hypothesis are justified and validated, including the assumption of rigid body behavior, which is demonstrated after a finite element analysis verification. The different error sources and their estimated contributions are enumerated in order to conclude with the final error values obtained from the error budget. The measurement deviations obtained demonstrate the important influence of the working environmental conditions, the flatness error of the plane mirror reflectors and the accurate manufacture and assembly of the components forming the metrological loop. Thus, a temperature control of ¿0.1 ¿C results in an acceptable maximum positioning error for the developed NanoPla stage, i.e., 41 nm, 36 nm and 48 nm in X-, Y- and Z-axis, respectively

Preliminary Modelling and Implementation of the 2D-control for a Nanopositioning Long Range Stage

Different systems are recently developed to obtain effective positioning at nanometer scale with increased working ranges. For this purpose, a two-dimensional nanopositioning platform (NanoPla) has been design and manufactured. To assure the demanding metrological performance the drive and control system is being defined and validated. Based on four home-made linear motors as actuators, this work is focused on the study of the control-loop for 1D- and 2D-cases with the aim of the preliminary modelling and posterior implementation. The different required blocks are presented and an initial controller solution is proposed to achieve the established positioning requests

Cell immobilization of Streptomyces coelicolor : effect on differentiation and actinorhodin production

Streptomycetes are mycelium-forming bacteria that produce two thirds of the clinically relevant secondary metabolites. Despite the fact that secondary metabolite production is activated at specific developmental stages of the Streptomyces spp. life cycle, different streptomycetes show different behaviors, and fermentation conditions need to be optimized for each specific strain and secondary metabolite. Cell-encapsulation constitutes an interesting alternative to classical fermentations, which was demonstrated to be useful in Streptomyces, but development under these conditions remained unexplored. In this work, the influence of cell-encapsulation in hyphae differentiation and actinorhodin production was explored in the model Streptomyces coelicolor strain. Encapsulation led to a delay in growth and to a reduction of mycelium density and cell death. The high proportion of viable hyphae duplicated extracellular actinorhodin production in the encapsulated cultures with respect to the non-encapsulated ones. [Int Microbiol 2014; 17(2):75-80]Keywords: Streptomyces coelicolor &middot; encapsulation &middot; differentiation &middot; antibiotics &middot; cell deat

Cell immobilization of Streptomyces coelicolor : effect on differentiation and actinorhodin production

Streptomycetes are mycelium-forming bacteria that produce two thirds of the clinically relevant secondary metabolites. Despite the fact that secondary metabolite production is activated at specific developmental stages of the Streptomyces spp. life cycle, different streptomycetes show different behaviors, and fermentation conditions need to be optimized for each specific strain and secondary metabolite. Cell-encapsulation constitutes an interesting alternative to classical fermentations, which was demonstrated to be useful in Streptomyces, but development under these conditions remained unexplored. In this work, the influence of cell-encapsulation in hyphae differentiation and actinorhodin production was explored in the model Streptomyces coelicolor strain. Encapsulation led to a delay in growth and to a reduction of mycelium density and cell death. The high proportion of viable hyphae duplicated extracellular actinorhodin production in the encapsulated cultures with respect to the non-encapsulated ones. [Int Microbiol 2014; 17(2):75-80]Keywords: Streptomyces coelicolor &middot; encapsulation &middot; differentiation &middot; antibiotics &middot; cell deat

Els vertebrats de la Formació Argiles de Morella (Aptià inferior, Cretaci Inferior)

La Formació Argiles de Morella és una de les formacions del Cretaci Inferior peninsular que més registre fòssil de vertebrats està aportant. La seva condició de medis deposicionals, generalment continentals, però també de vegades transicionals amb influències mareals, fa que les restes de la fauna de vertebrats que s’ha localitzat als diversos nivells d’aquesta Formació, siguin principalment d’origen terrestre però també d’origen marí. Així entre la fauna terrestre destaquen per damunt de tot les restes de diversos grups de dinosaures mentre que, de la fauna marina, podríem destacar sobretot materials fòssils que pertanyen al grup dels plesiosaures. No obstant la varietat faunística recuperada és més ampla, amb peixos, amfibis, tortugues, escamosos, cocodrils i pterosaures. Tots junts generen un conjunt de vertebrats que representen una gran part dels tàxons que s’han descrit fins ara en la biota terrestre de l’Aptià inferior, no sols de la Península Ibèrica, sinó de la resta del continent europeu. The vertebrates from Argiles de Morella Formation (Early aptian, Early Cretaceous) One of the most relevant Iberian Lower Cretaceous Formations is the Argiles de Morella Formation. Most of the vertebrate fauna recorded from the distinct beds of this Formation are related with continental environments, but some remains are close related with marine environments. Among the continental fauna highlights the remains of a great variety of dinosaurian groups, whereas plesiosaurian are the most common among marine fauna. Nevertheless, a great variety of other vertebrates such as fishes, amphib·ians, turtles, lizards, crocodiles and pterosaurs have been recorded in beds of this Formation too. This assemblage of vertebrate remains represents one of the most complete records of early Aptian terrestrial biota from Europ

Treatment of oral mucocele - scalpel versus C02 laser

Objective: To compare the results obtained after oral mucocele resection with the scalpel versus the CO2 laser, based on the complications and recurrences after surgery Patients and Methods: Of the 68 patients we studied who have mucocele, 38 were resected with a scalpel and the remaining 30 with the CO2 laser (5-7 W). Patient sex and age were documented, along with location of the lesion as well as size, symptoms, duration, etiological factors, type of treatment, complications and recurrences after surgical removal.Results: The sample comprised 40 males and 28 females, aged between 6-65 years. The histological diagnosis was extravasation mucocele in 95% of the cases. The most frequent location was the lower lip (73.5%). The mean lesion diameter was 9 mm , and in most cases no evident etiological factor was recorded. The mean duration of the lesion was 4 months. Among the cases of conventional surgical removal of mucocele, recurrence was recorded in 8.8% of the cases, and 13.2% of the patients suffered postoperative complications - the most frequent being the presence of fibrous scars. There were no complications or relapses after a minimum follow-up of 12 months in the cases subjected to CO2 laser treatment.Conclusions: Oral mucocele ablation with the CO2 laser offers more predictable results and fewer complications and recurrences than conventional resection with the scalpel