3,774 research outputs found
Internet of Things and Their Coming Perspectives: A Real Options Approach
Internet of things is developing at a dizzying rate, and companies are forced to implement it in order to maintain their operational efficiency. The high flexibility inherent to these technologies makes it necessary to apply an appropriate measure, which properly assesses risks and rewards. Real options methodology is available as a tool which fits the conditions, both economic and strategic, under which investment in internet of things technologies is developed. The contribution of this paper is twofold. On the one hand, it offers an adequate tool to assess the strategic value of investment in internet of things technologies. On the other hand, it tries to raise awareness among managers of internet of things technologies because of their potential to contribute to economic and social progress. The results of the research described in this paper highlight the importance of taking action as quickly as possible if companies want to obtain the best possible performance. In order to enhance the understanding of internet of things technologies investment, this paper provides a methodology to assess the implementation of internet of things technologies by using the real options approach; in particular, the option to expand has been proposed for use in the decision-making process
Hazard Fear in Commodity Markets
[EN] We introduce a commodity futures return predictor related to “fear” about weather, disease, geopolitical and economic hazards that distress the commodity supply or demand. Using Google search volume data by 149 hazards as keywords, we define a commodity hazard-fear characteristic that reflects the extent and direction of its past excess returns’ comovement with the hazard-fear. Using this characteristic as trading signal in a long-short portfolio framework, we find a sizeable and significant commodity hazard-fear (CFEAR) premium. The CFEAR portfolio returns reflect some compensation for momentum, basis, skewness, basis-momentum, and illiquidity risks, but the risk-adjusted excess returns remain sizeable. Exposure to hazard-fear is strongly priced in the cross-section of individual commodity futures returns and commodity portfolios beyond known risk factors. We identify a significant role for investor sentiment in the CFEAR premia.S
Identification of asymmetric conditional heteroscedasticity in the presence of outliers
The identification of asymmetric conditional heteroscedasticity is often based on samplecross-correlations between past and squared observations. In this paper we analyse theeffects of outliers on these cross-correlations and, consequently, on the identification ofasymmetric volatilities. We show that, as expected, one isolated big outlier biases thesample cross-correlations towards zero and hence could hide true leverage effect.Unlike, the presence of two or more big consecutive outliers could lead to detectingspurious asymmetries or asymmetries of the wrong sign. We also address the problemof robust estimation of the cross-correlations by extending some popular robustestimators of pairwise correlations and autocorrelations. Their finite sample resistanceagainst outliers is compared through Monte Carlo experiments. Situations with isolatedand patchy outliers of different sizes are examined. It is shown that a modified Ramsayweightedestimator of the cross-correlations outperforms other estimators in identifyingasymmetric conditionally heteroscedastic models. Finally, the results are illustrated withan empirical applicatio
The diffusion of energy technologies. Evidence from renewable, fossil, and nuclear energy patents
Technology innovation is widely recognised as a critical means in tackling climate change and fulfilling energy
policy objectives. The objective of this paper is twofold: first, to provide a descriptive analysis of innovation in
energy technology across countries and sectors and over time; and second, to explore the determining factors of
patented knowledge diffusion of energy technologies by distinguishing between renewables and other energy
patents, i.e., fossil and nuclear patents) thorough a regression analysis. The data employed in this paper consists
of an original database on renewables and other energy patents applied by firms in the period 1990–2015 and
contained in PATSTAT. By drawing on patent citations as an indicator of knowledge diffusion and focusing on
characteristics extracted from patent documents, a set of econometric models is estimated. Our results show that
those patents containing more citations to previous scientific literature and patents attain greater diffusion. Joint
patents with other firms or universities exert a negligible effect on technology regarding renewables. Coownership
with universities has a negative effect on the diffusion of other types of energy technology. Several
policy implications can be determined from our results: for example, the justification for policies oriented towards
enhancing the incorporation of scientific knowledge and co-inventorship in energy innovation
Can We Treat Neuroinflammation in Alzheimer's Disease?
Alzheimer’s disease (AD), considered the most common type of dementia, is characterized by a progressive loss of memory, visuospatial, language and complex cognitive abilities. In addition, patients often show comorbid depression and aggressiveness. Aging is the major factor contributing to AD; however, the initial cause that triggers the disease is yet unknown. Scientific evidence demonstrates that AD, especially the late onset of AD, is not the result of a single event, but rather it appears because of a combination of risk elements with the lack of protective ones. A major risk factor underlying the disease is neuroinflammation, which can be activated by different situations, including chronic pathogenic infections, prolonged stress and metabolic syndrome. Consequently, many therapeutic strategies against AD have been designed to reduce neuro-inflammation, with very promising results improving cognitive function in preclinical models of the disease. The literature is massive; thus, in this review we will revise the translational evidence of these early strategies focusing in anti-diabetic and anti-inflammatory molecules and discuss their therapeutic application in humans. Furthermore, we review the preclinical and clinical data of nutraceutical application against AD symptoms. Finally, we introduce new players underlying neuroinflammation in AD: the activity of the endocannabinoid system and the intestinal microbiota as neuroprotectors. This review highlights the importance of a broad multimodal approach to treat successfully the neuroinflammation underlying AD
Concepciones de los maestros sobre la enseñanza y el aprendizaje y sus prácticas educativas en clases de ciencias naturales
Se identifican las concepciones sobre la enseñanza y el aprendizaje de 80 maestros de primaria, mexicanos, y se estudian las relaciones que se establecen entre estas concepciones y sus prácticas educativas en clases de ciencias. Para estudiar las concepciones de los maestros se aplicó una entrevista de administración individual. Para estudiar las prácticas educativas se realizaron registros observacionales de las lecciones de los maestros. Un análisis cualitativo de las respuestas de los maestros a la entrevista reveló tres concepciones de la enseñanza y el aprendizaje: tradicional, de transición entre una perspectiva tradicional y una constructivista y constructivista. El análisis de las relaciones entre las concepciones de la enseñanza y el aprendizaje y las prácticas educativas mostró incongruencias. La mayoría de los maestros sostuvieron concepciones sobre la enseñanza y el aprendizaje más innovadoras que lo que realmente hicieron en el aula.This study identifies conceptions held by 80 Mexican primary school teachers regarding teaching and learning and examines the relationship between these conceptions and educational practices in science classes. To study the teachers' concepts, an individual interview was used. To study the educational practices, classroom observational measures were used. A qualitative analysis of the teachers' interview responses revealed three concepts of teaching and learning: traditional, transitional between traditional and constructivist, and constructivist. The analysis of the relationships between the concepts of teaching and learning on the one hand and the educational practices on the other displayed incongruities. The majority of the teachers maintained concepts of teaching and learning that are more innovative than what they practiced in class
Sensibilidad intercultural en la entrevista consular
Los encuentros interculturales exigen de los individuos habilidades no solo de carácter lingüístico-comunicativo sino también de carácter intercultural, donde la sensibilidad intercultural ejerce una función de suma importancia para entender el mensaje que cada interlocutor desea transmitir en la comunicación. Esta habilidad, evita los malentendidos y la visión estereotipada del otro, permite entender la diferencia y aceptarla a tal punto que logra contribuir con la creación de sociedades más justas, abiertas y pluriculturales. Dicho lo anterior, la sensibilidad intercultural se constituye en un elemento fundamental en los encuentros interculturales, ya que es a partir de ella que los seres humanos logran entender la complejidad que implican los encuentros interculturales y pueden entender y tratar la diferencia de mejor manera. Por ello, el objetivo de esta investigación es diseñar una guía práctica digital, dirigida a los funcionarios consulares de la Embajada de los Estados Unidos en Bogotá, que facilite el encuentro intercultural en el marco de la entrevista consular. El material está diseñado a partir de los conceptos teóricos que presentan Walsh (2004), Castro (2000) y Bennett (2004) al respecto de la aceptación de la diferencia y la sensibilidad intercultural. En cuanto a la metodología empleada para el desarrollo de la guía, se sigue la ruta de diseño de material presentada por Jolly & Bolitho (2004), y se enmarca el estudio en la investigación cualitativa de tipo práctico. Finalmente, se da evidencia de la relevancia del material diseñado en cuanto a que permite reflexionar sobre la importancia de desarrollar la sensibilidad intercultural y sus implicaciones en el contexto particular en el cual se desarrolla la presente investigación. Los resultados de los evaluadores expertos mostraron que el material diseñado sí responde a las necesidades evidenciadas en la población a la cual está dirigida la guía que aquí se presenta. Por ejemplo, las pautas hacen reflexionar al funcionario sobre los estereotipos y prejuicios que tiene acerca de los colombianos y que ser consciente de esto puede crear un cambio en el comportamiento que mejorará la experiencia de la entrevista. Asimismo, se considera que la guía es pertinente en cuanto fue diseñada para una población específica y evidentemente tuvo en cuenta sus necesidades particulares y las situaciones determinadas en las cuales los usuarios requerirán este conocimiento.Intercultural encounters require from individuals linguistic-communicative skills and intercultural abilities, where intercultural sensitivity plays a very important role in understanding the message that each speaker wishes to transmit. These skills prevent misunderstandings and stereotypes, allowing speakers to understand differences and accept them, which can lead to more just, open and multicultural societies. Having said this, intercultural sensitivity constitutes a key element in intercultural exchanges, since from it, human beings are not only able to understand complexities that are implicit in intercultural encounters, but they can also better understand and deal with differences. Therefore, the aim of this research is to design a practical digital guide, addressed to consular officials at the US Embassy in Bogotá, to facilitate intercultural meetings within the framework of consular interviews. The material is designed based on Walsh (2004), Castro (2000) and Bennett’s (2004) theoretical concepts on the acceptance of differences and intercultural sensibilities. Regarding the methodology used to create the guide, the material design follows Jolly & Bolitho’s (2004) model and employs practical qualitative research. Finally, evidence is given of the relevance of the material designed as it allows for reflection on the importance of developing intercultural sensitivity and its implications in the particular context in which this research is developed. The results of the expert evaluators showed that the material designed does in fact respond to the needs of the population to which the guide is presented. For example, the guidelines do not only force the official to reflect on his/her stereotypes and prejudices about Colombians but also make them conscious of it, which may in turn create a change of behaviour that will improve the interview experience. Moreover, it is considered that the guide is relevant in the sense that it was designed for a specific population, and evidently took into account the particular needs of this group, as well as the specific situations in which the users would possess knowledge.Magíster en Lingüística Aplicada del Español como Lengua ExtranjeraMaestrí
Validación de un cuestionario para evaluar el funcionamiento de las bibliotecas escolares
The school library has acquired a new prominence in recent years, becoming a fundamental learning space for the teaching of different areas and subjects and the promotion of skills in students.The objective of this work is to validate a questionnaire designed ad hoc to evaluate the functioning and the forms of use and incorporation of the school library to the daily pedagogical activity. To this purpose, the questionnaire was applied to a random sampling of 4,177 students from 358 centers of Primary, Secondary and Post-Compulsory Education, reliability was calculated using the Cronbach's Alpha test and an exploratory factor analysis was carried out. The results show that the Students Questionnaire to Evaluate the Operation of the School Library has acceptable levels of reliability and validity, so that it offers guarantees enough to evaluate the functioning of the school library
Features and Origin of Red Clays in Castafiar Cave: A Touch of Colour
In Castaiiar Cave (Caceres, Spain), coatings of red clays cover the walls
of the chambers, coexisting with diverse speleothems of aragonite, calcite, huntite
and dolomite. The mineralogy of the clays is mainly illite, chlorite, kaolinite, smectite,
quartz and Fe oxides and hydroxides such as goethite. They can be transported
into the cave by infiltration waters or form by in situ alteration of the host rock: layers
of dolomite rich in Fe and magnesite interbedded with greywackes and shales.
Present-day hydrological conditions in the cave and conditions during the formation
of speleothems have determined that the clays have not been transported by any
flooding or seepage, but mostly staying in situ, and not included into carbonate crystal
forms . Thus, most of the well-preserved speleothems are white and not stained,
conforming an interesting chromatic contrast with the red clays that represent an
additional attraction in this show cave
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