1,172 research outputs found
Forest Ecosystem Services: An Analysis of Worldwide Research
The relevance of forests to sustain human well-being and the serious threats they face have led to a notable increase of research works on forest ecosystem services during the last few years. This paper analyses the worldwide research dynamics on forest ecosystem services in the period from 1998 to 2017. A bibliometric analysis of 4284 articles was conducted. The results showed that the number of published research articles has especially increased during the last five years. In total, 68.63% of the articles were published in this period. This research line experiences a growing trend superior to the general publishing trend on forest research. In spite of this increase, its relative significance within the forest research is still limited. The most productive subject areas corresponded to Environmental Science, Agricultural and Biological Sciences and Social Sciences Economic topics are understudied. The scientific production is published in a wide range of journals. The three first publishing countries are United States, China and the United Kingdom. The most productive authors are attached to diverse research centres and their contributions are relatively recent. A high level of international cooperation has been observed between countries, institutions and authors. The findings of this study are useful for researchers since they give them an overview of the worldwide research trends on forest ecosystem services
Genetic analysis of microsatellites markers in two populations of Berrenda en Negro bovine breed
The Berrenda en Negro cattle breed has been used classically in the management of the fight bull and currently is found next their extinction. To contribute to the genetic conservation programs of this breed, we are characterized a sample of 32 animals with a panel of 15 microsatellites and we are provided data that permit, in a future, to compare its variability with other cattle breeds.La raza Bovina Berrenda en Negro se ha utilizado clásicamente en el manejo del toro de lidia y actualmente se encuentra próxima a su extinción. Para contribuir a los planes de recuperación genética de esta raza, se caracteriza una muestra de 32 animales con un panel de 15 microsatélites y se proporcionan datos que permitan, en un futuro, comparar su variabilidad con otras razas bovinas
Teachers’ professional identity: validation of an assessment instrument for preservice teachers
This study aims to develop and validate an instrument to analyse future Secondary Education teachers' perceptions regarding the development of Teachers' Professional Identity (TPI). The data were collected from a sample of 733 participants who were students enrolled in the Master's Degree for Secondary Education teachers. The psychometric properties of the instrument were obtained by analysing content, and comprehension validity, construct validity and reliability. A first subsample was used for an Exploratory Factor Analysis, and a second one to verify the identified factor structure via Confirmatory Factor Analysis. The instrument is made up of 31 items in four scales namely the understanding of TPI, the development of TPI at various educational levels, the development of TPI in comparison with that of other professionals and the influencing factors. The results show that it has high levels of validity and reliability. Therefore, it provides TPI research field with an instrument to assess it during the initial teacher training period in consecutive training models where it seems to occur more identity crisis
Intuición sobre el azar: análisis de una experiencia aleatoria con alumnos de Educación Primaria
El estudio del azar y la probabilidad forman parte del currículo de matemáticas en España desde la etapa de Educación primaria (6-12 años), siendo clave para la formación de los estudiantes la capacidad de hacer estimaciones sencillas basadas en la experiencia de situaciones aleatorias. En este texto se describe una experiencia de aula sobre el azar, llevada a cabo con alumnos de tercer ciclo de Educación Primaria (10-11
años). El propósito de la enseñanza es enfrentar al alumno a una experiencia aleatoria sencilla, como es el lanzamiento de una moneda, con la que puede desarrollar su razonamiento probabilístico, a la vez que
evaluar su intuición sobre el azar mediante diversas preguntas guiadas que conforman un cuestionario diseñado para la propia experiencia. Los resultados obtenidos muestran dificultades de los alumnos en el desempeño de ideas sobre el azar e intuiciones erróneas sobre el tema, principalmente al inventar una secuenciación aleatoria de resultados del lanzamiento de una moneda.The study of chance and probability takes part of the mathematics curriculum in Spain from the stage of primary education (6-12 years), being key issue in the students’ training the ability to make simple estimates based on the experience of random situations. In this text a classroom experience on chance aimed at students in the third cycle of primary education (10-11 years) is described. The purpose of this experience is to confront the student to a single random experience, as is the toss of a coin, with which to develop their probabilistic reasoning, while assessing their intuition about chance through various guided questions that make a questionnaire designed for this experience. The results show students’ difficulties in carrying out ideas about chance and erroneous intuitions about this topic, mainly when they propose a possible random sequencing of results by the toss of a coin.Proyecto EDU2013-41141-P (MEC) y Grupo FQM126 (Junta de Andalucía)info:eu-repo/semantics/publishedVersio
Study of Sound Perception Evaluation in Refrigeration Gases
In the past, sound design was focused on the minimization of the emitted sound, understanding that the lower the sound, the better. Nowadays, this concept is outdated; in addition to the sound pressure level, many more aspects of the sound are considered to fulfil the subjective satisfaction of clients. Thus, a new concept called sound quality has emerged to reach more facets of the sound. In refrigeration systems, the recommendations of European Union are aimed at reducing greenhouse emissions by means of the replacement of the hydrochlorofluorocarbons gases with other less pollutant gases. The refrigeration systems are designed to be used with a specific refrigeration gas, and the noise emitted by these systems is certificated using this refrigeration gas. However, the regularizations have changed, and new refrigerant gases should be used. Considering that these new refrigeration gases work at different pressures, it is possible that the noise could be different with these gases. Moreover, the study of sound quality is very important for the manufacture as the perception and therefore the annoyance could change with the use of new gases. (2) Methods: Two different gases, R-449A and R-134A, have been studied. An acoustic camera has been used to measure and identify the sound quality in the refrigeration systems. (3) Results: The results have shown R-134A has better sound quality than R-449A. (4) Conclusions: This study shows that R-449A and R-134A could be a substitute for R-404A in terms of noise level
Interaction between Calpain 5, Peroxisome proliferator-activated receptor-gamma and Peroxisome proliferator-activated receptor-delta genes: a polygenic approach to obesity
<p>Abstract</p> <p>Context</p> <p>Obesity is a multifactorial disorder, that is, a disease determined by the combined effect of genes and environment. In this context, polygenic approaches are needed.</p> <p>Objective</p> <p>To investigate the possibility of the existence of a crosstalk between the <it>CALPAIN 10 </it>homologue <it>CALPAIN 5 </it>and nuclear receptors of the peroxisome proliferator-activated receptors family.</p> <p>Design</p> <p>Cross-sectional, genetic association study and gene-gene interaction analysis.</p> <p>Subjects</p> <p>The study sample comprise 1953 individuals, 725 obese (defined as body mass index ≥ 30) and 1228 non obese subjects.</p> <p>Results</p> <p>In the monogenic analysis, only the peroxisome proliferator-activated receptor delta (<it>PPARD</it>) gene was associated with obesity (OR = 1.43 [1.04–1.97], p = 0.027). In addition, we have found a significant interaction between <it>CAPN5 </it>and <it>PPARD </it>genes (p = 0.038) that reduces the risk for obesity in a 55%.</p> <p>Conclusion</p> <p>Our results suggest that <it>CAPN5 </it>and <it>PPARD </it>gene products may also interact in vivo.</p
Influence of proceedings papers on citation impact in seven sub-fields of sustainable energy research 2005-2011
Potential of a Two-Stage Variable Compression Ratio Downsized Spark Ignition Engine for Passenger Cars under different driving conditions
[EN] With the aim of reducing pollutant emissions from internal combustion engines (ICE), the application of stoichiometrically operated spark ignition (SI) engines, for light-duty vehicles, has been overcoming the compression ignition (CI) engines market share throughout the past years. The ability of a substantial reduction of the primary harmful emissions (HC, CO, and NOx) through the use of the simple three-way catalyst (TWC) is the main reason for that. Nonetheless, with increasing attention to CO2 emissions, the development of highly efficient downsized SI engines turn to be of enormous interest. The synergies of multiple systems such as direct injection, turbocharger, and variable valve actuation are able to lead the SI efficiencies closer to those of CI engines. However, to enable high load operation on such downsized engines, the compression ratio (CR) must be reduced due to knock limitations, reducing the partial-load operations efficiency. The implementation of two-stage variable compression ratio (VCR) systems enables the extraction of high thermal efficiency with high CR at lower loads and extended knock-free high load operation with low CR. In this study, the evaluation of a two-stage VCR system applied to a state-of-the-art downsized SI engine was made through standard driving cycle simulations. The VCR mechanism is composed of an eccentric element in the small end of the connecting rod, which is rotated to increase/decrease the effective connecting rod length, achieving the CRs of 12.11:1 and 9.56:1. The engine was run in an eddy-current dynamometer test bench throughout the essential operating range to obtain the brake specific fuel consumption (BSFC) map. The VCR mechanism CR switching delay was also experimentally characterized to derive a function of the operating conditions. The measured map was entered into the map-based driving cycle simulation with a sub-model to account for the isolated effects of the transient period encompassing the compression ratio switching. The results show that slow CR transitions lead to fuel consumption penalties, which suggests the need for optimizing the control strategies of the VCR system. Even though this penalty, once the gear up-shift speed is optimized for each driving cycle, the VCR system still enables fuel consumption reductions up to 3% on the WLTC driving cycle, up to 4% on the proposed urban driving cycles and up to 3% on highway driving cycles with respect to the fixed CR.This research has been partially funded by FEDER and the Spanish Government through project RTI2018-102025-B-I00. 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