145 research outputs found
Caracterización de los clásicos del emprendimiento (1968-2016). Un análisis basado en la Web of Science
The aim of this paper is to broaden the analysis of entrepreneurship as a field of study by employing a bibliographical search of works which constitute the “classics” of entrepreneurship and by examining their underlying “knowledge base” (cited works) as well as the reasons why they are characterised as such. H-Classics methodology was applied in the selection of these classic works and a thorough analysis of documents, citing and cited authors as well as journals was carried out. The results obtained in the process help isolate the sources that may determine which works could be seen as truly representative of the discipline of entrepreneurship and, more importantly, to find out which of them are more likely to embody the paradigms required in order to make a clear definition of what constitutes entrepreneurship as a discipline.Este trabajo tiene como objetivo profundizar en el análisis del campo del emprendimiento mediante la búsqueda bibliográfica de los trabajos que se configuran como “clásicos del emprendimiento” y su caracterización, así como la del “conocimiento base” (trabajos citados) en que se apoyan los mismos. Se aplica la metodología H-Classics para seleccionar estos trabajos clásicos y se realiza un análisis en profundidad de documentos, autores citantes y citados y revistas. Los resultados alcanzados llevan a aislar las fuentes que permitirían determinar qué obras podrían constituir la disciplina del emprendimiento y lo que es más importante, cuáles cuentan con mayor “probabilidad” de mostrar aquellos paradigmas necesarios para conformarla
De la bibliometría al emprendimiento: un estudio de estudios
Bibliometric studies of entrepreneurship as a discipline have contributed fundamentally to the creation of a certain order in an apparently chaotic and contradictory literature, examining how the discipline has developed, giving a comprehensive vision of the structure of the field, observing its social networks, detecting trends, discovering knowledge gaps and helping to plan future research lines. The purpose of this article is to explore this special type of research. In terms of methodology, it uses an adaptation of the Systematic Literature Review, and a content analysis using text-mining software in order to look deeper into objectives, conclusions and limitations. Among the main findings, there is some evidence that indicates that the image presented to date about entrepreneurship has not considered the multidisciplinary nature of the field and could, therefore, be distorted. At the same time, a series of inherent problems have been detected, and it has become evident that there is a need to incorporate the latest advances in bibliometrics and to improve collaboration between experts from both fields in order to solve those mentioned issues and move towards future progress.Los estudios bibliométricos sobre emprendimiento como disciplina académica han contribuido fundamentalmente a crear orden en una literatura aparentemente caótica y contradictoria, examinan su desarrollo y dan una visión integral de la estructura del campo, observan sus redes sociales, detectan tendencias, descubren brechas de conocimiento y ayudan a planificar futuras líneas de investigación. El objetivo de este artículo es explorar este tipo especial de investigación. Desde el punto de vista metodológico se utiliza una adaptación del proceso de revisión sistemática de la literatura y un análisis de contenido a través de software de minería de textos para profundizar en objetivos, conclusiones y limitaciones de este tipo de análisis. Entre los principales hallazgos encontramos evidencias que indican que la imagen ofrecida hasta la fecha sobre el emprendimiento no ha considerado la naturaleza multidisciplinaria del campo y, por tanto, podría estar distorsionada. A su vez, se detectan una serie de problemas inherentes a su desarrollo, se hace evidente la necesidad de incorporar los últimos avances en bibliometría, mejorando la colaboración entre expertos de ambos campos para resolverlos y avanzar hacia el progreso futuro
Proton conductivity of multifunctional metal phosphonate frameworks
Metal phosphonates exhibit attractive characteristics for proton conductivity, such as tunable functionality, chemical and thermal stability and the existence of H-bond networks with acidic protons within their structure.1
In the present work, we examine the relationship between crystal structure and proton conductivity for several metal (mono-, di- and tri-valent) phosphonates containing rigid: (5-(dihydroxyphosphoryl)isophthalic acid, PiPhtA and 2-hydroxyphosphonoacetic acid, HPAA) or flexible: (hexa- or octamethylenediamine-N,N,N′,N′-tetrakis(methylenephosphonic acid, H8HDTMP or H8ODTMP) multifunctional ligands. The crystalline hybrid derivatives prepared show a great structural diversity, from 1D to 3D open-frameworks possessing hydrogen-bonded water molecules and phosphonic and carboxylic acid groups. The rigid 3D framework of Ca-PiPhtA, that exhibits a proton conductivity of 5.7•10-4 S/cm as synthesized, transforms into a layered compound upon exposure to ammonia vapors2 with increased proton conductivity (6.6•10-3 S/cm). The flexible frameworks of magnesium or lanthanide phosphonates, with 1D channels, present conductivities higher than 10-3 S/cm. Their activation energies fall in the range corresponding to a Grotthuss mechanism.3,4 For M(I)-HPAA solids conductivities up to 5.6•10-3 S/cm were measured.
References
1. P. Ramaswamy, N.E. Wong, G.K.H. Shimizu, Chem. Soc. Rev. 43 (2014) 5913.
2. M. Bazaga-García, R.M.P. Colodrero, M. Papadaki, P. Garczarek, J. Zoń, P. Olivera-Pastor, E.R. Losilla, L. León-Reina, M.A.G. Aranda, D. Choquesillo-Lazarte, K.D. Demadis, A. Cabeza, J. Amer. Chem. Soc. 136 (2014) 5731.
3. R.M.P. Colodrero, P. Olivera-Pastor, E.R. Losilla, D. Hernández-Alonso, M.A.G. Aranda, L. Leon-Reina, J. Rius, K.D. Demadis, B. Moreau, D. Villemin, M. Palomino, F. Rey, A. Cabeza, Inorg. Chem. 51 (2012) 7689.
4. R.M.P. Colodrero, P. Olivera-Pastor, E.R. Losilla, M.A.G. Aranda, L. Leon-Reina, M. Papadaki, A.C. McKinlay, R.E. Morris, K.D. Demadis, A. Cabeza, Dalton Trans. 41 (2012) 4045.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Junta de Andalucía, Proyecto Excelencia FQM-1656. Ministerio de Economía y Competitividad, MAT2013-41836-
Mejorando la IOT con el Dispositivo Airtraq®. Descripción de la maniobra "KET"
La vía aérea difícil (VAD) es la primera causa de morbi-mortalidad anestésica. Representa el 50% de las complicaciones severas no fatales y el 30% de las muertes de causa anestésica. Uno de cada tres casos de VAD son imprevistos.
Dentro del algoritmo de manejo de la VAD no conocida cada vez toman más importancia los dispositivos ópticos como el Airtraq®, ya que mejoran la visibilidad de la glotis respecto al laringoscopio convencional.
El Airtraq® es un dispositivo de fácil utilización y aprendizaje, que posee pocas limitaciones: apertura bucal < 20 mm, macroglosia, distancia tiromentoniana reducida, etc...
Presentamos un caso clínico en el que explicamos cómo resolvemos en nuestro hospital aquellas situaciones en las que no es posible avanzar el tubo endotraqueal (TET) usando el laringoscopio Airtraq®
Independence in CLP Languages
Studying independence of goals has proven very useful in the context of logic programming. In particular, it has provided a formal basis for powerful automatic parallelization tools, since independence ensures that two goals may be evaluated in parallel while preserving correctness and eciency. We extend the concept of independence to constraint logic programs (CLP) and
prove that it also ensures the correctness and eciency of the parallel evaluation of independent goals. Independence for CLP languages is more complex than for logic programming as search space preservation is necessary but no longer sucient for ensuring correctness and eciency. Two
additional issues arise. The rst is that the cost of constraint solving may depend upon the order constraints are encountered. The second is the need to handle dynamic scheduling. We clarify these issues by proposing various types of search independence and constraint solver independence, and show how they can be combined to allow dierent optimizations, from parallelism to intelligent
backtracking. Sucient conditions for independence which can be evaluated \a priori" at run-time are also proposed. Our study also yields new insights into independence in logic programming languages. In particular, we show that search space preservation is not only a sucient but also a necessary condition for ensuring correctness and eciency of parallel execution
Structure and absolute growth of a population of <em>Hippolyte inermis</em> Leach 1815 (Decapoda: Caridea) from <em>Zostera marina</em> (L.) meadows (Malaga, southern Spain)
Automatic parallelization of irregular and pointer-based computations: perspectives from logic and constraint programming
Irregular computations pose some of the most interesting and
challenging problems in automatic parallelization. Irregularity appears in certain kinds of numerical problems and is pervasive in symbolic applications. Such computations often use dynamic data structures which make heavy use of pointers. This complicates all the steps of a parallelizing compiler, from independence detection to task partitioning and placement. In the past decade there has been significant progress in the development of parallelizing compilers for logic programming and, more recently, constraint programming. The typical applications of these paradigms frequently involve irregular computations, which arguably makes the techniques used in these compilers potentially interesting. In this paper we
introduce in a tutorial way some of the problems faced by parallelizing compilers for logic and constraint programs. These include the need for inter-procedural pointer aliasing analysis for independence detection and having to manage speculative and irregular computations through task
granularity control and dynamic task allocation. We also provide pointers to some of the progress made in these áreas. In the associated talk we demónstrate representatives of several generations of these parallelizing compilers
Acyloxylation of Cyclic Enones: Synthesis of Densely Oxygenated Guaianolides
The α′-acyloxylation of cyclic enones with linear carboxylic acids is described. The reaction is promoted by KMnO4 in the presence of a carboxylic acid and its corresponding carboxylic anhydride. The optimization of the reaction has been carried out using the statistical methodology known as design of experiments. The optimized reaction conditions have been evaluated in terms of substrate scope and compatibility with different functional groups. The methodology has been applied to the synthesis of densely oxygenated guaianes and guaianolides
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