Hexagonal Tilings: Tutte Uniqueness

We develop the necessary machinery in order to prove that hexagonal tilings are uniquely determined by their Tutte polynomial, showing as an example how to apply this technique to the toroidal hexagonal tiling.Comment: 12 figure

Hexagonal Tilings and Locally C6 Graphs

We give a complete classification of hexagonal tilings and locally C6 graphs, by showing that each of them has a natural embedding in the torus or in the Klein bottle. We also show that locally grid graphs are minors of hexagonal tilings (and by duality of locally C6 graphs) by contraction of a perfect matching and deletion of the resulting parallel edges, in a form suitable for the study of their Tutte uniqueness.Comment: 14 figure

Extended reagions of radio emission not associated with the AGN phenomenon as sources of acceleration of cosmic rays: The case of cD galaxies

Diffuse, non-thermal extended emission not associated with the AGN phenomenon, found in many clusters of galaxies hosted by an AGN, are related to the acceleration of cosmic rays. In the current work we present preliminary evidence of absence of such formations in clusters of galaxies hosted by optically identified cD galaxies. Our subsample consists of three powerful low redshift radiogalaxies, centered in poor clusters of galaxies. We have searched for radio relics and (mini)halos which could be forming as a result of the confinement of cosmic rays by bubbles creayed by the AGN. We report on the work in progress.Comment: 4 pages, Conference HEPRO II

Singular perturbations of zⁿ with a pole on the unit circle

We consider the family of complex maps given by fλ,a (z) = z n + λ/(z − a)d where n, d ≥ 1 are integers, and a and λ are complex parameters such that a = 1 and is sufficiently small. We focus on the topological characteristics of the Julia and Fatou sets of fλ,a

Generalized rings around the McMullen domain

We consider the family of rational maps given by F (z) = z + λ/ z where n, d∈ N with 1 / n+ 1 / d 1 is given by τkn,d=dnk-2(n-1)-nk-1+1

La economía colaborativa en el ámbito de la vivienda: cuestiones fiscales pendientes

La economía colaborativa constituye un modelo de consumo que permite, gracias a las tecnologías, acceder a bienes y servicios de forma eficiente y participativa. Es un fenómeno creciente en los últimos años, en especial en el sector del transporte y del alojamiento. Los retos son, sin embargo, muchos. Su complejidad y su trascendencia exigen que los Estados aborden la regulación y la ordenación de todas las prácticas que se desarrollan para que puedan conciliarse los derechos y obligaciones de todos los operadores.En esta comunicación analizaremos los retos fiscales de la economía colaborativa en la vivienda. Para que sea una salida eficaz de la crisis y proporcione ingresos a los Estados (también ingresos fiscales), es necesario el cumplimiento de las obligaciones fiscales por parte de los operadores, de forma socialmente responsable. Igualmente, habrá que plantearse la necesidad de realizar reformas fiscales para facilitar el cumplimiento de dichas obligaciones.------------------------------------------------------------------Sharing economy is a consumption model that allows, thanks to the technologies, to access goods and services in an efficient and participatory way. It is a growing phenomenon in recent years, especially in the transport and accommodation sector. The challenges are, however, many. Their complexity and their importance require that States address the regulation and management of all practices that are developed in order to reconcile the rights and obligations of all operators.In this communication we will analyze the fiscal challenges of the sharing economy in housing. In order to be an effective way out of the crisis and to provide revenue to States (also tax revenues), it is necessary to fulfill the tax obligations on the part of the operators in a socially responsible way. Likewise, it will be necessary to consider the need to carry out fiscal reforms to facilitate the fulfillment of these obligations

Random-walk simulation of cell migration and proliferation

Cell migration and proliferation has been modelled in several works of the literature as a process similar to diffusion. However, diffusion models to simulate the proliferation and migration of cells tend to create a homogeneous distribution in the cell density, but this result is not real. Diffusion is not the mechanism of cell dispersal: cells disperse by crawling or proliferation, or are transported in a moving fluid. The use of stochastic models or other (cellular automata, models particles, etc...) can modify this limitation. Therefore, this paper presents a stochastic model (random-walk) to simulate the proliferation and migration of cells. Both processes are considered as completely stochastic as discrete. The model developed aims to predict the behavior of in vitro cell cultures performed with adult muscle satellite cells. Non homogeneous distribution of cells has been observed inside the culture well. Using previous stochastic model we have been able to predict the non homogeneous cell distribution and accurate quantitative results have been computed. In a future, the model will allow us to incorporate other aspects such as cell differentiation, incorporate several cell populations simultaneously, etc

TEMPORAL AND SPATIAL DISTRIBUTION OF POACEAE POLLEN IN AREAS OF SOUTHERN UNITED KINGDOM, SPAIN AND PORTUGAL

Overall, longer Poaceae pollen seasons coincided with earlier pollen season start dates. Winter rainfall noticeably affects the intensity of Poaceae pollen seasons in Mediterranean areas, but this was not as important in Worcester. Weekly data from Worcester followed a similar pattern to that of Badajoz and Évora but at a distance of more than 1500 km and 4-5 weeks later

Globular Clusters in Dense Clusters of Galaxies

Deep imaging data from the Keck II telescope are employed to study the globular cluster (GC) populations in the cores of six rich Abell clusters. The sample includes A754, A1644, A2124, A2147, A2151, and A2152, and spans the redshift range z = 0.035-0.066. The clusters also range in morphology from spiral-rich, irregular systems to centrally concentrated cD clusters rich in early-type galaxies. Globular cluster specific frequencies S_N and luminosity function dispersions are measured for a total of 9 galaxies in six central fields. The measured values of S_N for the six brightest cluster galaxies (BCGs) are all higher than typical values for giant ellipticals, in accord with the known S_N-density correlations. The three non-BCGs analyzed also have elevated values of S_N, confirming that central location is a primary factor. The number of GCs per unit mass for these fields are consistent with those found in an earlier sample, giving further evidence that GC number scales with mass and that the S_N variations are due to a deficit of halo light, i.e., S_N reflects mass-to-light ratio. The discussion builds on an earlier suggestion that the GCs (both metal rich and metal poor) around the central cluster galaxies were assembled at early times, and that star formation halted prematurely in the central galaxies at the epoch of cluster collapse. This is consistent with recent simulations of BCG/cluster formation. The subsequent addition of luminous material through cluster dynamical evolution can cause S_N to decrease, and we may be seeing the first evidence of this. Finally, the GC luminosity function measurements are used to constrain the relative distances of the three clusters that make up the Hercules supercluster.Comment: Uses emulateapj.sty (included); 17 pages with 9 included PostScript figures. Figures 1-6 are separate GIF images (so 15 figures total) available from http://astro.caltech.edu/~jpb/clusters -- the full PostScript version of the paper (20 pages; 2.2 Mb compressed) incorporating Figures 1-6 can also be grabbed from this URL. Accepted for publication in A

Differential protein expression analysis to study the pathogenicity of the protozoa parasite Trichomonas Gallinae

Comunicaciones a congreso