Ultraviolet cutoffs for quantum fields in cosmological spacetimes

We analyze critically the renormalization of quantum fields in cosmological spacetimes, using non covariant ultraviolet cutoffs. We compute explicitly the counterterms necessary to renormalize the semiclassical Einstein equations, using comoving and physical ultraviolet cutoffs. In the first case, the divergences renormalize bare conserved fluids, while in the second case it is necessary to break the covariance of the bare theory. We point out that, in general, the renormalized equations differ from those obtained with covariant methods, even after absorbing the infinities and choosing the renormalized parameters to force the consistency of the renormalized theory. We repeat the analysis for the evolution equation for the mean value of an interacting scalar fieldComment: 19 pages. Minor changes. References adde

¿Quiénes hacen las políticas públicas en las provincias argentinas? Efectos de los mecanismos de selección de candidatos y de conformación de Gabinetes en Entre Ríos y Santa Fe (2003-2015) en perspectiva comparada

La investigación parte de la premisa de que tanto el sistema de partidos como la estructura estatal afectan el proceso de políticas. La Ciencia Política ha tratado de determinar y sopesar, alternativamente, la influencia que han tenido tanto uno y otro factor en el proceso de políticas, pero por separado. Aunque alguna atención ha capturado simultáneamente en estudios multidimensionales sobre el particular, escasa han sido estas indagaciones en el ámbito subnacional. Las dinámicas que se producen entre estos dos factores, y cómo estos afectan el proceso de políticas y sus resultados, son el centro de interés de este proyecto. Importan especialmente los efectos sobre elementos o componentes claves del proceso de políticas; en particular, quiénes son los que deciden y cómo han llegado a esas posiciones

Efficient location strategy for airport surveillance using mode-s multilateration systems

© Cambridge University Press and the European Microwave Association, 2012[EN] In this paper, the use of regularization methods to solve the location problem in multilateration systems, using Mode-S signals, is studied, evaluated, and developed. The Tikhonov method has been implemented as a first application to solve the classical system of hyperbolic equations in multilateration systems. Some simulations are obtained and the results are compared with those obtained by the well-established Taylor linearization and with the Cramér-Rao lower bound analysis. Significant improvements, for the accuracy, convergence, and the probability of location, are found for the application of the Tikhonov method. © Cambridge University Press and the European Microwave Association, 2012.Mr. Ivan A. Mantilla-Gaviria has been supported by a FPU scholarship (AP2008-03300) from the Spanish Ministry of Education. Moreover, the authors are grateful to Thales Italia S. p. A. (Dr. Ing. R. Scaroni) who supplied the geometry of the Multilateration system in Linate (Milan, Italy) airport.Mantilla Gaviria, IA.; Leonardi, M.; Galati, G.; Balbastre Tejedor, JV.; Reyes Davó, EDL. (2012). Efficient location strategy for airport surveillance using mode-s multilateration systems. International Journal of Microwave and Wireless Technologies. 1-8. https://doi.org/10.1017/S1759078712000104S18Bertero, M., Boccacci, P., Brakenhoff, G. J., Malfanti, F., & Voort, H. T. M. (1990). Three-dimensional image restoration and super-resolution in fluorescence confocal microscopy. Journal of Microscopy, 157(1), 3-20. doi:10.1111/j.1365-2818.1990.tb02942.xSchau, H., & Robinson, A. (1987). Passive source localization employing intersecting spherical surfaces from time-of-arrival differences. IEEE Transactions on Acoustics, Speech, and Signal Processing, 35(8), 1223-1225. doi:10.1109/tassp.1987.1165266Gfrerer, H. (1987). An a posteriori parameter choice for ordinary and iterated Tikhonov regularization of ill-posed problems leading to optimal convergence rates. Mathematics of Computation, 49(180), 507. doi:10.1090/s0025-5718-1987-0906185-4[6] Galati G. ; Leonardi M. ; Tosti M. : Multilateration (local and wide area) as a distributed sensor system: lower bounds of accuracy, in European Radar Conf., EuRAD, Amsterdam, 30–31 October 2008.[1]The European Organisation for the Safety of Air Navigation. The ATM surveillance strategy for ECAC, in European Air Traffic Management Programme, Eurocontrol, 2008.Torrieri, D. (1984). Statistical Theory of Passive Location Systems. IEEE Transactions on Aerospace and Electronic Systems, AES-20(2), 183-198. doi:10.1109/taes.1984.310439[12] Perl E. ; Gerry M.J. : Target localization using TDOA distributed antenna, US 2005/0035897 A1, USA, 17 February 2005.[2]The European Organisation for Civil Aviation Equipment. Ed-117, mops for mode s multilateration systems for use in advanced surface movement guidance and control systems (a-smgcs), in EUROCAE (Ed.), EUROCAE, November 2003.Leonardi, M., Mathias, A., & Galati, G. (2009). Two efficient localization algorithms for multilateration. International Journal of Microwave and Wireless Technologies, 1(3), 223-229. doi:10.1017/s1759078709000245Ho, K. C., & Chan, Y. T. (1993). Solution and performance analysis of geolocation by TDOA. IEEE Transactions on Aerospace and Electronic Systems, 29(4), 1311-1322. doi:10.1109/7.259534FOY, W. (1976). Position-Location Solutions by Taylor-Series Estimation. IEEE Transactions on Aerospace and Electronic Systems, AES-12(2), 187-194. doi:10.1109/taes.1976.308294Phillips, D. L. (1962). A Technique for the Numerical Solution of Certain Integral Equations of the First Kind. Journal of the ACM, 9(1), 84-97. doi:10.1145/321105.321114Hanke, M., & Raus, T. (1996). A General Heuristic for Choosing the Regularization Parameter in Ill-Posed Problems. SIAM Journal on Scientific Computing, 17(4), 956-972. doi:10.1137/0917062Golub, G. H., Heath, M., & Wahba, G. (1979). Generalized Cross-Validation as a Method for Choosing a Good Ridge Parameter. Technometrics, 21(2), 215-223. doi:10.1080/00401706.1979.10489751Harrington, R. F. (1993). Field Computation by Moment Methods. doi:10.1109/978047054463

DNA sequence-specific recognition by a transcriptional regulator requires indirect readout of A-tracts

The bacteriophage Ø29 transcriptional regulator p4 binds to promoters of different intrinsic activities. The p4–DNA complex contains two identical protomers that make similar interactions with the target sequence 5′-AACTTTTT-15 bp-AAAATGTT-3′. To define how the various elements in the target sequence contribute to p4's affinity, we studied p4 binding to a series of mutated binding sites. The binding specificity depends critically on base pairs of the target sequence through both direct as well as indirect readout. There is only one specific contact between a base and an amino acid residue; other contacts take place with the phosphate backbone. Alteration of direct amino acid–base contacts, or mutation of non-contacted A·T base pairs at A-tracts abolished binding. We generated three 5 ns molecular dynamics (MD) simulations to investigate the basis for the p4–DNA complex specificity. Recognition is controlled by the protein and depends on DNA dynamic properties. MD results on protein–DNA contacts and the divergence of p4 affinity to modified binding sites reveal an inherent asymmetry, which is required for p4-specific binding and may be crucial for transcription regulation

Saberes, Culturas y Derechos Sexuales en Colombia

Este libro reúne artículos de gran pertinencia académica en el tema, ponencias y discusiones que realizaron distintos grupos de trabajo en el marco del seminario Hacia una Agenda sobre Sexualidad y Derechos Humanos en Colombia, realizado en Bogotá durante los días 18, 19 y 20 de marzo de 2004. Este texto acerca a un público más amplio el debate que vienen desarrollando en Colombia investigadores, militantes, responsables y ejecutores de políticas públicas en materia de sexualidad y de derechos sexuales y reproductivos. La divulgación de los trabajos presentados en este libro permitirá a los lectores identificar las líneas de debate que orientan la investigación, las políticas públicas, los programas de intervención social y el derecho en este ámbito. El texto presenta hallazgos en torno a estos temas, con el objetivo de construir un referente común sobre la sexualidad como una construcción sociocultural e histórica objeto de una regulación pública. Igualmente, pretende inscribir la sexualidad en el ámbito de la construcción de ciudadanía y de la reivindicación de los derechos humanos

Capitulo 5. Ciencias Agrícolas, Pecuarias y del Medio Ambiente

El aumento de las concentraciones de GEI es considerado como el responsable del actual calentamiento global, siendo el CO2 el principal GEI debido a las emisiones antropogénicas y registrando un aumento de 2.2 ppm más que en 2016, llegando a alcanzar las 405 ppm de la concentración global en los últimos 58 años (Blunden, 2018). Por lo cual el objetivo de esta investigación fue estimar la capacidad de captura de CO2 de las especies de microalgas Chlorella Vulgaris. y Scenedesmus Obliquus. mediante el uso de fotobiorreactores como herramienta biotecnológica para el control de la contaminación atmosférica. Con los resultados de esta investigación, se pretende contribuir al desarrollo de biotecnologías para el control de la contaminación atmosférica enfocadas en las emisiones de CO2

Evaluation of the conservation program of the paramo ecosystem and its socio-environmental effects in a rural commune

The paramo Casaiches Arenal, shares its resources with the community of the same name. Although conservation has been carried out in Ecuador on a voluntary basis, this has not been enough for the productive and population requirements, which has caused the loss of characteristics typical of the páramo. In this situation, the world community has joined efforts to mitigate the anthropogenic effects on this ecosystem. In 2008, the Association of Agricultural Workers Casaiches Arenal entered the forest conservation program and put 80 ha of páramo under this system. The knowledge of the socio-environmental effects of the program will allow us to answer your questioning. To know aspects of socio-economic development in the community under study, the empirical method of the survey was used, which investigated socioeconomic aspects in the area. As an independent variable, the paramos conservation incentive program was conceived and as dependent variables, social development; economic development and the conservation of the páramo ecosystem. To assess the environmental impact from the adhesion as beneficiaries, a cause-effect matrix was applied, as a method of identification and assessment with qualitative and quantitative results. It is concluded that the national policies on which the conservation program is based decrease the pressures on the paramo ecosystem, as long as it is complemented with on-site actions that allow for an efficient and systematic intervention in the region