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Antibacterial activity and qualitative phytochemical analysis of Vitex mollis fruit
Delgado-Vargas Francisco,Félix-Favela Fernando,Pío-León Juan,López-Angulo Gabriela
International Journal of Green Pharmacy , 2010,
Abstract: The pulp of the Vitex mollis fruit is edible and traditionally used to treat diarrhoea. The antibacterial activity of this fruit is reported here for the first time. The fruit pulp was extracted with methanol (ME) and the extract was fractionated with solvents. ME and their fractions [hexanic (HF), chloroformic (CF), ethyl acetate (EAF) and aqueous (AqF)] were assayed against human pathogenic bacteria (microdilution test) and their phytochemicals determined (qualitative chemical determinations). The samples (i.e., ME, HE, CF, EAF and AqF) showed antibacterial activity; EAF was the most active, showing such activity against Shigella dysenteriae [minimal inhibitory concentration (MIC)=2 mg/ml]. Phenolics were mainly found in ME and EAF; compounds of this chemical family are well known for their antidiarrhoeal and antimicrobial activities. The reported antibacterial activity and phenolics content of V. mollis fruit could be associated with its use in the treatment of diarrhoea.
Jo o José de Cunto
Tincani Fernando Félix
Revista Brasileira de Anestesiologia , 2004,
Abstract:
The humpback whale off The Coast of Ecuador, population parameters and behavior
Félix,Fernando; Haase,Ben;
Revista de biología marina y oceanografía , 2001, DOI: 10.4067/S0718-19572001000100006
Abstract: between 1991 and 1997 the southeastern pacific humpback whale (megaptera novaeangliae) stock was studied off the central part of ecuador (01°24's, 80°55'w) during the breeding season (june-september). for this purpose, surveys were carried out onboard whale-watching boats at two different sites: puerto lópez and puerto cayo. some population parameters such as distribution, group structure, population size, calving rate and behavior were evaluated. the first whales arrived by the end of may, they peaked in july and most of them had left the area by the end of september. along the puerto lópez route, groups were significantly larger (p<0.01) but whales were significantly less abundant (p<0.01) than puerto cayo's. gps-positioned sightings showed that whales presented a clumped distribution with concentrations at specific sites along both surveyed routes. analyses of group composition suggest a type of age/sex-class segregation inside the study area. around sites such as la plata island and the bajo de cantagallo groups were composed mainly of adult and subadult animals. in contrast, nearby puerto cayo groups were composed mainly of mothers with calves and solitary individuals. groups changed at least one member every 257 minutes on the average, but no change in membership was noticed when a mother-calf pair was present. most calves were recorded from the second half of august onward and showed a preference for shallow waters with 20m or less in depth. the crude birth rate average obtained (0.039) is considered underestimated. a low resighting rate of photo-identified individuals indicates both a low residence level and a poor degree of fidelity to the study site. the size of the stock was estimated in 1996 to be 1,922 whales (95% c.i. 77-3,367).
On Entrepreneurship, Intentionality and Economic Policymaking  [PDF]
Félix-Fernando MU?OZ, María-Isabel ENCINAR, Carolina CA?IBANO
iBusiness (IB) , 2009, DOI: 10.4236/ib.2009.12009
Abstract: Within evolutionary economics, entrepreneurship is seen as the main force of economic change, as the agency of self-transformation within restless capitalist economic systems. Therefore, a truly evolutionary perspective on economic policy-making must consider the significance and scope of entrepreneurship. On the basis of such a perspective, it might be possible to assess future outcomes of economic evolution under different policy measures related with, for instance, stimulating entrepreneurship as a policy that would provide the seeds for recovery from a slump in an economy. In this short note, our main claim is that the very nature of entrepreneurship implies the recognition of the role played by entrepreneurs’ intentions, their tendency towards transforming goals and agents’ spaces of action. Recognition is possible due to a more systematic analytical integration of these elements into a theory of entrepreneurship based on a ‘production of action’ conception (vs. the standard framework based on a ‘technology of choice’). This analytical vision sheds light on how economic policymaking should be implemented to stimulate entrepreneurship.
On Economics, Ethics, and Corporate Social Responsibility  [PDF]
Félix-Fernando Mu?oz, María-Isabel Encinar, Carolina Ca?ibano
Modern Economy (ME) , 2012, DOI: 10.4236/me.2012.34046
Abstract: This paper suggests that understanding questions such as those related to Corporate Social Responsibility (CSR) requires economic theorizing to include in its explanatory models the very fact that (economic) agents have their own distinctive conception of how reality ought to be (which implies making judgments of value). Under standard economic theorizing, the relationship between social or ethical values and economics is one of mere juxtaposition. Ethical and economic issues are being put together side by side in such a way that the anomalies pointed out by economics, which refer to the presence of goal paradoxes and the problem of altruism, etc., denote the presence of ethical issues within the processes of valuation and choice by agents. To surpass this relationship a change of perspective by means of the agents’ action plans approach is proposed. The action plan approach allows to pass from a conception of economics understood as a technology-of-choice to economics understood as a theory of production-of-action. In particular, it is shown that the ethical dynamics of agents are capable of generating “ethical novelties’, which consequently alter the agents’ space of goals. Insofar as this is heavily influenced by CSR, the consequence is that CSR is neither strange to Economics nor a concept juxtaposed with the analysis of autonomous economic processes.
Robust Output Regulation of Linear Passive Systems with Multivalued Upper Semicontinuous Controls
Félix A. Miranda,Fernando Casta?os
Mathematics , 2014,
Abstract: The use of multivalued controls derived from a special maximal monotone operator are studied in this note. Starting with a strictly passive linear system (with possible parametric uncertainty and external disturbances) a multivalued control law is derived, ensuring regulation of the output to a desired value. The methodology used falls in a passivity-based control context, where we study how the multivalued control affects the dissipation equation of the closed-loop system, from which we derive its robustness properties. Finally, some numerical examples together with implementation issues are presented to support the main result.
Modelos de pérdida de masa de acero por corrosión atmosférica en Colombia usando inteligencia computacional
Velilla,Esteban; Villada,Fernando; Echeverría,Félix;
Revista Facultad de Ingeniería Universidad de Antioquia , 2009,
Abstract: in order to classify the corrosivity of the different colombian atmospheres, as part of an extensive research project [1], plates of carbon steel were placed in 21 stations spread along the country electrical infrastructure (transmission lines and substations). there were measured among others at these stations, the time of wetness and deposition of sulfates and chlorides for 12 months, in addition steel plates were taken bimonthly to the laboratory in order to measure the mass loss suffered by these during the time of exposure. the classification of the 21 stations was done in 4 groups, considering the time of moisture, content of chlorides and sulfates, height above sea level and the plates exposure time; these are considered linearly independent variables according to the implemented technique of decomposition unique values (dps). the criterion used for classification was the similarity of the variables using the euclidean rule considered in the kohonen unsupervised neural network. additionally, models were implemented for the steel mass loss for each one of the groups using feed forward neural networks (rn), defining the above variables as inputs and the mass loss as the output. besides, the comparison between the rn model for the group 1, with other models using genetic algorithms (ga) and the simplex method is presented.
Reflexiones sobre la evidencia en medicina
Mu?oz C,Félix; Cabrera R,Fernando;
Revista médica de Chile , 2005, DOI: 10.4067/S0034-98872005001000016
Abstract: this is a review of the basic concepts of evidence, medicine, evidence-based medicine and its effects. evidence-based medicine is a contribution for statistical design and management, that allows the gathering of scientific information, but does not completely exclude bias. its methodology proceeds with order and caution, generating a highly probable mass of knowledge. the quality of the information obtained from diverse sources such as meta-analysis to expert opinions is classified in different levels according to the ?strength? of the evidence in which it is based. the best contribution of evidence-based medicine is probably for diseases of incidence and does not replace clinical experience and patients-physician relationship. basically we treat ill people and not illnesses. without clinical experience, medical practice can be tyrannized by evidence-based medicine that can become inapplicable or inappropriate. without evidence-based medicine, medical practice will not be updated, limiting our professional skills (rev méd chile 2005; 133: 1252-8)
Inventario de la fauna de hormigas de San Andrés Isla (Colombia)
Castellanos Suárez Félix Andrés,Fernández Fernando
Acta Biológica Colombiana , 2006,
Abstract: En este documento se registra por primera vez información parcial del inventario de las hormigas de San Andrés Isla. Se presenta a continuación un listado de los géneros y se proponen claves ilustradas para subfamilias, tribus y géneros. En total se encontraron 24 géneros: Azteca, Linepithema y Tapinoma de la subfamilia Dolichoderinae; Camponotus, Brachymyrmex y Paratrechina de Formicinae; Pseudomyrmex de Pseudomyrmecinae; Hypoponera, Leptogenys, Odontomachus, Pachycondyla y Platythyrea de Ponerinae; Ectatomma de Ectatomminae y de Myrmicinae: Cyphomyrmex, Wasmannia, Crematogaster, Pyramica, Strumigenys, Cardiocondyla, Pheidole, Monomorium, Solenopsis, Rogeria y Tetramorium.
Algoritmos y cajas negras: el `programa Matlab en la formación básica en Economía y Finanzas
Fernando Fernández Rodríguez,Julián Andrada Félix
[email protected] , 2000,
Abstract: Los cursos de métodos cuantitativos que se imparten en las distintas facultades de Ciencias Económicas y Empresariales en general, permiten al alumno disponer de una serie de programas informáticos -cajas negras- que le otorgan la capacidad de realizar ciertos estudios interesantes. El alumno sabe qué necesita para resolver un problema cuantitativo y utiliza el programa informático adecuado para tal fin, pero no sabe de qué manera el ordenador resuelve el problema. En este trabajo pretendemos dar un giro respecto a esta metodología, enfatizando en un concepto fundamental en todo el desarrollo cuantitativo: el algoritmo. El enfoque del aprendizaje será la construcción de algoritmos netamente prácticos, de forma que se asimile su concepto a la misma vez que se implemente. Haremos un sencillo recorrido por ciertos problemas fácilmente resolubles a través de algoritmos implementados bajo el entorno de trabajo MATLAB.
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