1,655 research outputs found
Microentrepreneurship and the business cycle: is self-employment a desired outcome?
Should a central bank accommodate energy price shocks? Should the central bank use core inflation or headline inflation with the volatile energy component in its Taylor rule? To answer these questions, we build a dynamic stochastic general equilibrium model with energy use, durable goods, and nominal rigidities to study the effects of an energy price shock and its impact on the macroeconomy when the central bank follows a Taylor rule. We then study how the economy performs under alternative parameterizations of the rule with different weights on headline and core inflation after an increase in the energy price. Our simulation results indicate that a central bank using core inflation in its Taylor rule does better than one using headline inflation because the output drop is less severe. In general, we show that the lower the weight on energy price inflation in the Taylor rule, the impact of an energy price increase on gross domestic product and inflation is also lower.
Bloodstream form pre-adaptation to the tsetse fly in Trypanosoma brucei
African trypanosomes are sustained in the bloodstream of their mammalian hosts by their extreme capacity for antigenic variation. However, for life cycle progression, trypanosomes also must generate transmission stages called stumpy forms that are pre-adapted to survive when taken up during the bloodmeal of the disease vector, tsetse flies. These stumpy forms are rather different to the proliferative slender forms that maintain the bloodstream parasitaemia. Firstly, they are non proliferative and morphologically distinct, secondly, they show particular sensitivity to environmental cues that signal entry to the tsetse fly and, thirdly, they are relatively robust such that they survive the changes in temperature, pH and proteolytic environment encountered within the tsetse midgut. These characteristics require regulated changes in gene expression to pre-adapt the parasite and the use of environmental sensing mechanisms, both of which allow the rapid initiation of differentiation to tsetse midgut procyclic forms upon transmission. Interestingly, the generation of stumpy forms is also regulated and periodic in the mammalian blood, this being governed by a density-sensing mechanism whereby a parasite-derived signal drives cell cycle arrest and cellular development both to optimise transmission and to prevent uncontrolled parasite multiplication overwhelming the host.In this review we detail recent developments in our understanding of the molecular mechanisms that underpin the production of stumpy forms in the mammalian bloodstream and their signal perception pathways both in the mammalian bloodstream and upon entry into the tsetse fly. These discoveries are discussed in the context of conserved eukaryotic signalling and differentiation mechanisms. Further, their potential to act as targets for therapeutic strategies that disrupt parasite development either in the mammalian bloodstream or upon their transmission to tsetse flies is also discussed
The octahedral manipulator revisited
Trabajo presentado al ICRA celebrado en Minnesota del 14 al 18 de mayo de 2012.In most practical implementations of the Gough-Stewart platform, the octahedral form is either taken as it stands or is approximated. The kinematics of this particular instance of the Gough-Stewart platform, commonly known as the octahedral manipulator, has been thoughtfully studied. It is well-known, for example, that its forward kinematics can be solved by computing the roots of an octic polynomial and its singularities have a simple geometric interpretation in terms of the intersection of four planes in a single point. In this paper, using a distance-based formulation, it is shown how these properties can be derived without relying neither on variable eliminations nor trigonometric substitutions. Moreover, thanks to this formulation, a family of platforms kinematically equivalent to the octahedral manipulator is obtained. Herein, two Gough-Stewart parallel platforms are said to be kinematically equivalent if there is a one-to-one correspondence between their squared leg lengths for the same configuration of their moving platforms with respect to their bases. If this condition is satisfied, it can be shown that both platforms have the same assembly modes and their singularities, in the configuration space of the moving platform, are located in the same place.Peer Reviewe
Una pedagogía de la confianza el relato de un encuentro con lo literario
Lo que en estas páginas se cuenta, es el relato de una experiencia. La historia de cómo sus autores se plantearon ciertas preguntas respecto a los Estudios Literarios como disciplina, y de qué manera fueron resolviéndolas hasta llegar a formular las bases de una pedagogía. Da cuenta de todas aquellas personas con las que se encontraron en el trayecto, en agradecimiento por los aprendizajes compartidos, y los matices que le otorgaron a un objetivo multiforme y polifacético, relacionado con la literatura y sus posibilidades en un escenario de educación con adultos. Aquí se cocina el relato de una Pedagogía de la confianza y de su componente más importante: las prácticas literarias, una nueva perspectiva para pensar la ciencia literaria y su historia. Distintos conocimientos y perspectivas se mezclan aquí, dando origen al banquete teórico que sostiene este proyecto. Y finalmente, un sustancioso cierre con algunas conclusiones y recomendaciones, para aquellos maestros que deseen nutrirlas y continuar por este camino pedagógico.What is told in these pages, is the tale of an experience. The story of how its authors questioned themselves regarding Literature Studies as a discipline, and in which ways they resolved these inquiries along the road of formulating the foundation of a pedagogy. It accounts for all those people with whom they met on the way, in gratitude for shared learning, and the nuances they gave to a multiform and multifaceted objective, related to literature and its possibilities in a scenario of adult education. Here, the culinary story of a Pedagogy of trust is being cooked, as well as the one of its main component: the literary practices, a new perspective in order to think literary science and its history. Different knowledge and perspectives are mixed here, giving birth to the theoretical banquet holding this project. And finally, a substantial closure with some conclusions and recommendations, for those teachers who wish to nurture them and continue along this educational path.Profesional en Estudios LiterariosPregrad
Finding the nucleolus of any n-person cooperative game by a single linear program
In this paper we show a new method for calculating the nucleolus by solving a unique minimization
linear program with Oð4n
Þ constraints whose coefficients belong to f−1; 0; 1g. We discuss the need of having
all these constraints and empirically prove that they can be reduced to Oðkmax2n
Þ, where kmax is a positive
integer comparable with the number of players. A computational experience shows the applicability of our
method over (pseudo)random transferable utility cooperative games with up to 18 playersThe authors want to thank Javier Arin, Safae El Haj Ben Ali, Guillermo Owen and Johannes H. Reijnierse for their useful and valuable help. The research of the authors has been partially supported by the projects FQM-5849 (Junta de Andalucia \ FEDER), and by the project MTM2010-19576-C02-01 (MICINN, Spain). This paper was written while the second author was enjoying a grant for a short postdoctoral research visit at the Instituto Universitario de Investigacion de Matematicas de la Universidad de Sevilla (IMUS). Special thanks are due to one anonymous referee for his/her valuable comments.Puerto Albandoz, J.; Perea Rojas Marcos, F. (2013). Finding the nucleolus of any n-person cooperative game by a single linear program. Computers and Operations Research. 40(10):2308-2313. https://doi.org/10.1016/j.cor.2013.03.01123082313401
On minimax and Pareto optimal security payoffs in multicriteria games
[EN] In this paper, we characterize minimax and Pareto-optimal security payoff vectors for general multicriteria zero-sum matrix games, using properties similar to the ones that have been used in the single criterion case. Our results show that these two solution concepts are rather similar, since they can be characterized with nearly the same sets of properties. Their main difference is the form of consistency that each solution concept satisfies. We also prove that both solution concepts can transform into each other, in their corresponding domains. (C) 2017 Elsevier Inc. All rights reserved.We would like to thank Dr. Francisco R. Fernandez for his useful comments on earlier versions of this paper. The authors also want to acknowledge the financial support from grants FQM-5849 (Junta de Andalucia\FEDER) and MTM2016-74983-C02-01, MTM2013-46962-C02-01 (MICINN, Spain).Puerto Albandoz, J.; Perea Rojas Marcos, F. (2018). On minimax and Pareto optimal security payoffs in multicriteria games. Journal of Mathematical Analysis and Applications. 457(2):1634-1648. https://doi.org/10.1016/j.jmaa.2017.01.002S16341648457
Estudio de viabilidad para la creación de una empresa exportadora de artesanías elaboradas en el Municipio de Nobsa - Boyacá
NO APLICAEsta investigación pretende establecer la viabilidad para la creación de una empresa exportadora de artesanías teniendo en cuenta que este municipio goza de popularidad por productos como forja, muebles rústicos y campanas, sumado al imponente viñedo en el sector de Puntalarga y, especialmente, a los tejidos en lana de oveja principalmente las ruanas boyacenses.
Se pretende realizar un estudio de viabilidad para la creación de una empresa exportadora de artesanías de tejido en lana teniendo en cuenta el potencial y calidad que se encuentra en cada uno de los almacenes ubicados cerca de la plaza principal del municipio.
El proyecto se basa en un estudio cualitativo de tipo descriptivo, el cual parte de una revisión bibliográfica y una encuesta, de cara a determinar su viabilidad en las clásicas evaluaciones del Business Plan (mercado, técnico, legal y financiero) y sus impactos de sostenibilidad.This research aims to establish the viability for the creation of a company exporting crafts taking into account that this municipality enjoys popularity for products such as forging, rustic furniture and bells, added to the imposing vineyard in the sector of Puntalarga and, In particular, to the fabrics in wool of sheep mainly the ruanas boyacenses.
It is intended to conduct a feasibility study for the creation of an exporting company of wool weaving crafts taking into account the potential and quality found in each of the warehouses located near the main square of the municipality.
The project is based on a qualitative descriptive study, which starts from a bibliographic review and a survey, in order to determine its feasibility in the classic assessments of the Business Plan (market, technical, legal and financial) and its sustainability impacts
Greedy and K-Greedy algoritmhs for multidimensional data association
[EN] The multidimensional assignment (MDA) problem is a combinatorial optimization problem arising in many applications, for instance multitarget tracking (MTT). The objective of an MDA problem of dimension is to match groups of objects in such a way that each measurement is associated with at most one track and each track is associated with at most one measurement from each list, optimizing a certain objective function. It is well known that the MDA problem is NP-hard for . In this paper five new polynomial time heuristics to solve the MDA problem arising in MTT are presented. They are all based on the semi-greedy approach introduced in earlier research. Experimental results on the accuracy and speed of the proposed algorithms in MTT problems are provided. © 2006 IEEE.This research was supported by a Marie Curie fellowship of the European Community program "Improving Human Research Potential and the Socio-economic Knowledge Base" under Contract HPMI-CT-2002-00221.Perea Rojas Marcos, F.; De Waard, HW. (2011). Greedy and K-Greedy algoritmhs for multidimensional data association. IEEE Transactions on Aerospace and Electronic Systems. 47(3):1915-1925. doi:10.1109/TAES.2011.59372731915192547
- …