9 resultados para Teaching of Science
em Consorci de Serveis Universitaris de Catalunya (CSUC), Spain
Resumo:
El análisis de los ensayos de John Tyndall, Fragments of Science, permite identificar la teoría atómica, el principio de conservación de la energía y el evolucionismo darwinista como los elementos constitutivos del andamiaje teórico del naturalismo científico. Así, en su ensayo “On the Study of Physics” se resumen sus brillantes facetas como educador y divulgador científico, desarrolladas fundamentalmente en el seno de la Royal Institution. En la lectura “On Force”, Tyndall da por finalizada la controversia Joule- Mayer sobre la primacía del descubrimiento del principio de conservación de la energía, a la vez que plantea algunas de las claves de la lucha por el liderazgo en el seno de la comunidad científica. El discurso presidencial ante la British Association de 1874 en Belfast ejemplifica el coraje de Tyndall en su empeño por demarcar los territorios de la ciencia y la religión, a la luz de los nuevos desafíos científicos. En el trasfondo subyacen los procesos de secularización de la sociedad y de profesionalización de una comunidad científica heterogénea. El compromiso cívico que Tyndall demuestra en “The Belfast Address” es digno corolario de una vida y obra que permite situarlo como paradigma de lo que, en la terminología de Turner, se ha dado en denominar científico público.
Resumo:
The earning structure in science is known to be flat relative to the one in the private sector, which could cause a brain drain toward the private sector. In this paper, we assume that agents value both money and fame and study the role of the institution of science in the allocation of talent between the science sector and the private sector. Following works on the Sociology of Science, we model the institution of science as a mechanism distributing fame (i.e. peer recognition). We show that since the intrinsic performance is less noisy signal of talent in the science sector than in the private sector, a good institution of science can mitigate the brain drain. We also find that providing extra monetary incentives through the market might undermine the incentives provided by the institution and thereby worsen the brain drain. Finally, we study the optimal balance between monetary and non-monetary incentives in science.
Resumo:
The earning structure in science is known to be flat relative to the one in theprivate sector, which could cause a brain drain toward the private sector. In thispaper, we assume that agents value both money and fame and study the role ofthe institution of science in the allocation of talent between the science sector andthe private sector. Following works on the Sociology of Science, we model theinstitution of science as a mechanism distributing fame (i.e. peer recognition). Weshow that since the intrinsic performance is less noisy signal of talent in the sciencesector than in the private sector, a good institution of science can mitigate thebrain drain. We also find that providing extra monetary incentives through themarket might undermine the incentives provided by the institution and therebyworsen the brain drain. Finally, we study the optimal balance between monetaryand non-monetary incentives in science.
Resumo:
We study the determining factors of cience-based cooperation in the case of small and micro firms. In this research, we propose an analytical framework based on the resource-based view of the firm and we identify a set of organisational characteristics, which we classify as internal, external and structural factors. Each factor can be linked to at least one reason, from the firm¿s point of view, to cooperate with universities and public research centres. Each reason can, in turn, be used as an indicator of a firm¿s organisational needs or organisational capacities. In order to validate the theoretical model, we estimate a logistic regression that models the propensity to participate in science-based cooperation activities within a sample of 285 small and micro firms located in Barcelona. The results show the key role played by the absorptive capacity of new and small companies.
Resumo:
Los rankings de productividad científica resultan cada vez más relevantes, tanto a nivel individual como institucional. Garantizar que se basan en información confiable y exhaustiva es, por tanto, importante. Este estudio indica que la posición de los individuos en esa clase de ranking puede cambiar sustancialmente cuando se consideran diversos indicadores bibliométricos internacionalmente reconocidos. Se usa, como ilustración, el caso de los diez profesores del área de ‘Personalidad, Evaluación y Tratamiento Psicológico’ consignados en el reciente análisis de Olivas-Ávila y Musi-Lechuga (Psicothema 2010. Vol. 22, nº 4, pp. 909-916).
Resumo:
This article suggests the study of the key concept of conflict as a means of implementing a critical and communicativecurriculum based on the study of relevant social themes. To this end we put forward the principal characteristics of thecritical/communicative curriculum. We offer a didactic proposal about conflict and explain the results of its application intwo Secondary Education classrooms
Resumo:
Purpose: To evaluate the suitability of an improved version of an automatic segmentation method based on geodesic active regions (GAR) for segmenting cerebral vasculature with aneurysms from 3D X-ray reconstruc-tion angiography (3DRA) and time of °ight magnetic resonance angiography (TOF-MRA) images available in the clinical routine.Methods: Three aspects of the GAR method have been improved: execution time, robustness to variability in imaging protocols and robustness to variability in image spatial resolutions. The improved GAR was retrospectively evaluated on images from patients containing intracranial aneurysms in the area of the Circle of Willis and imaged with two modalities: 3DRA and TOF-MRA. Images were obtained from two clinical centers, each using di®erent imaging equipment. Evaluation included qualitative and quantitative analyses ofthe segmentation results on 20 images from 10 patients. The gold standard was built from 660 cross-sections (33 per image) of vessels and aneurysms, manually measured by interventional neuroradiologists. GAR has also been compared to an interactive segmentation method: iso-intensity surface extraction (ISE). In addition, since patients had been imaged with the two modalities, we performed an inter-modality agreement analysis with respect to both the manual measurements and each of the two segmentation methods. Results: Both GAR and ISE di®ered from the gold standard within acceptable limits compared to the imaging resolution. GAR (ISE, respectively) had an average accuracy of 0.20 (0.24) mm for 3DRA and 0.27 (0.30) mm for TOF-MRA, and had a repeatability of 0.05 (0.20) mm. Compared to ISE, GAR had a lower qualitative error in the vessel region and a lower quantitative error in the aneurysm region. The repeatabilityof GAR was superior to manual measurements and ISE. The inter-modality agreement was similar between GAR and the manual measurements. Conclusions: The improved GAR method outperformed ISE qualitatively as well as quantitatively and is suitable for segmenting 3DRA and TOF-MRA images from clinical routine.
Resumo:
Purpose: The objective of this study is to investigate the feasibility of detecting and quantifying 3D cerebrovascular wall motion from a single 3D rotational x-ray angiography (3DRA) acquisition within a clinically acceptable time and computing from the estimated motion field for the further biomechanical modeling of the cerebrovascular wall. Methods: The whole motion cycle of the cerebral vasculature is modeled using a 4D B-spline transformation, which is estimated from a 4D to 2D + t image registration framework. The registration is performed by optimizing a single similarity metric between the entire 2D + t measured projection sequence and the corresponding forward projections of the deformed volume at their exact time instants. The joint use of two acceleration strategies, together with their implementation on graphics processing units, is also proposed so as to reach computation times close to clinical requirements. For further characterizing vessel wall properties, an approximation of the wall thickness changes is obtained through a strain calculation. Results: Evaluation on in silico and in vitro pulsating phantom aneurysms demonstrated an accurate estimation of wall motion curves. In general, the error was below 10% of the maximum pulsation, even in the situation when substantial inhomogeneous intensity pattern was present. Experiments on in vivo data provided realistic aneurysm and vessel wall motion estimates, whereas in regions where motion was neither visible nor anatomically possible, no motion was detected. The use of the acceleration strategies enabled completing the estimation process for one entire cycle in 5-10 min without degrading the overall performance. The strain map extracted from our motion estimation provided a realistic deformation measure of the vessel wall. Conclusions: The authors' technique has demonstrated that it can provide accurate and robust 4D estimates of cerebrovascular wall motion within a clinically acceptable time, although it has to be applied to a larger patient population prior to possible wide application to routine endovascular procedures. In particular, for the first time, this feasibility study has shown that in vivo cerebrovascular motion can be obtained intraprocedurally from a 3DRA acquisition. Results have also shown the potential of performing strain analysis using this imaging modality, thus making possible for the future modeling of biomechanical properties of the vascular wall.