Search results for "Laboratory"
showing 10 items of 923 documents
Natural polyphenols in cancer therapy.
2011
Natural polyphenols are secondary metabolites of plants involved in defense against different types of stress. Extracts containing these compounds have been used for thousands of years in traditional eastern medicine. Polyphenols act on multiple targets in pathways and mechanisms related to carcinogenesis, tumor cell proliferation and death, inflammation, metastatic spread, angiogenesis, or drug and radiation resistance. Nevertheless, reported effects claimed for polyphenols are controversial, since correlations between in vitro effects and in vivo evidence are poorly established. The main discrepancy between health claims versus clinical observations is the frequent use of nonphysiological…
Learning about Dynamic Problems with Computer Simulators: A Case of System Dynamics Simulation Models
2008
A vast body of research shows that people by and large fail to understand and manage dynamic environments. Given the increasing complexity of our world, there is an urgent need to develop more effective ways to present dynamic problems. Many studies propose computer simulators as virtual learning environments to help people understand and manage complex problems. Still, experimental data show that simulators often carry problems from reality into the virtual laboratory. An analysis from the perspective of cognitive load theory suggests that learning about complex problems could be improved by enhancing descriptions with simulation elements that would facilitate interactive exploration of th…
Special Issue on New perspectives and approaches in plant growth-promoting rhizobacteria research : Foreword
2007
Non-thermal processes in coronae and beyond
2012
This contribution summarizes the splinter session "Non-thermal processes in coronae and beyond" held at the Cool Stars 17 workshop in Barcelona in 2012. It covers new developments in high energy non-thermal effects in the Earth's exosphere, solar and stellar flares, the diffuse emission in star forming regions and reviews the state and the challenges of the underlying atomic databases.
Advances in Kernel Machines for Image Classification and Biophysical Parameter Retrieval
2017
Remote sensing data analysis is knowing an unprecedented upswing fostered by the activities of the public and private sectors of geospatial and environmental data analysis. Modern imaging sensors offer the necessary spatial and spectral information to tackle a wide range problems through Earth Observation, such as land cover and use updating, urban dynamics, or vegetation and crop monitoring. In the upcoming years even richer information will be available: more sophisticated hyperspectral sensors with high spectral resolution, multispectral sensors with sub-metric spatial detail or drones that can be deployed in very short time lapses. Besides such opportunities, these new and wealthy infor…
"Facta non verba" : an experiment on pledging and giving
2015
International audience; We design an experiment to investigate whether asking people to state how much they will donate to a charity (i.e., to pledge) increases their actual donation. Individuals’ endowment is either certain or a random variable. We study different types of pledges, namely, private, public and irrevocable, which differ in terms of the cost to the individual for not keeping the promise. We show that in absence of endowment uncertainty, private and public pledges are associated with lower donations as compared to donations in the no-pledge case: private pledges slightly reduce donations and public pledges reduce them more significantly. Donations increase with uncertainty (in…
The Consistency of Fairness Rules: An Experimental Study
2010
In the last two decades, experimental papers on distributive justice have abounded. Two main results have been replicated. Firstly, there is a multiplicity of fairness rules. Secondly, fairness decisions differ depending on the context. This paper studies individual consistency in the use of fairness rules, as well as the structural factors that lead people to be inconsistent. We use a within-subject design, which allows us to compare individual behavior when the context changes. In line with the literature, we find a multiplicity of fairness rules. However, when we control for consistency, the set of fairness rules is considerably smaller. Only selfishness and strict egalitarianism seem to…
The role of «perceived loss» aversion on credit screening: an experiment
2013
A major characteristic of credit markets is information asymmetry.To combat its problems, as credit rationing, principals can use a menu of contracts to screen clients with different risk level. We conduct a laboratory experiment to address an important question for such settings —does the framing of the offered menu of contracts interfere with the self-selection mechanism? The answer is yes. We find subjects' choices shift when the same (positive) outcomes of the same menu of contracts are presented in two different frames. Subjects exhibit loss aversion in their perception of the positive outcomes below the reference point, and self-selection fails to occur. Uno de los mayores problemas a…
Temptation and commitment in the laboratory
2010
Temptation and self-control in intertemporal choice environments are receiving increasing attention in the theoretical economics literature. Nevertheless, there remains a scarcity of empirical evidence from controlled environments informing behavior under repeated temptations. This is unfortunate in light of the fact that in many natural environments, the same temptation must be repeatedly resisted. This paper fills that gap by reporting data from a novel laboratory study of economic decisions under repeat temptations. Subjects are repeatedly offered an option with instantaneous benefit that also entails a substantial reduction to overall earnings. We show that this option is "tempting" in …
Application of 5E model for learning Mechanics through inquiry in secondary education
2018
En este trabajo se examina el proceso de resolución de una actividad de indagación sobre las leyes de Newton que consiste en diseñar un montaje con el cuál averiguar qué superficie es la más adecuada para arrastrar cajas de ropa en un almacén. Los participantes son 23 estudiantes de 4º de ESO. Para la toma de datos se recogen sus respuestas escritas relativas al diseño del dispositivo, a la toma de datos, interpretación de resultados y establecimiento de conclusiones. Para el análisis se examinan utilizando como herramienta el modelo de instrucción 5E. Los resultados principales apuntan a ciertas dificultades en los desempeños del alumnado relativos a la elaboración del montaje y a la expli…