Keratinocytes from human skin respond as typical immune cells after the stimulation with _Trichophyton rubrum_

_Trichophyton rubrum_ is the main agent causing dermatophytosis (1). Keratinocytes are
considered to be the first physical barrier of defense against pathogens (2). But not
only a physical barrier. They recognize antigens through Toll like receptors (TLR) (3).
The activation of this TLR, present on the surface of the keratinocytes, induce the
expression of different pro-inflammatory cytokines, co-stimulatory molecules and
antimicrobial peptides such as [beta]-defensins (4).
The main objective of this work is to determine if lipopolysaccharides of G – bacteria
(LPS), lipotheichoic acid from G+ bacteria (LTA), and conidias, isolated from _T. rubrum_
were able to activate the expression of TLR2 and TLR6 on the cell surface of a primary
culture of human keratinocytes through Flow cytometry. Furthermore we are looking for
the presence of [beta]-defensins 1 and 2, IL-1b and IL-8 in the supernatant, of the above
mentioned culture of cells, by Western blot.
From the flow cytometry data, the preliminary results showed an important dispersion
in terms of proliferation, increase in size and granularity of keratinocytes, from primary
cultures of skin from healthy donors, stimulated 6 hours with conidias of _T. rubrum_, and
LTA, but not when non stimulated, or stimulated with LPS (Fig 1).
When keratinocytes from primary cultures of skin from healthy donors were cultivated
48 hours, it was found dispersion in terms of proliferation, increase in size and
granularity when stimulated with conidias of _T. rubrum_, and LPS but not when non
stimulated, or stimulated with LTA (Fig 2).
The keratinocytes expressed increased levels of TLR2 and TLR6 when were
stimulated with LTA and less to _T. rubrum_, in the 6 hours cultures, but this last cells still
showed increased size (Fig 3).
The Keratinocytes expressed increased levels of TLR2 in the 48 hours cultures when
were stimulated with LPS and _T. rubrum_.(Fig 4)
Besides, [beta]-defensin-2 was detected in the supernatant of cultures of keratinocytes
stimulated with LPS (Fig 5).
It can preliminary be concluded that keratinocytes from primary cultures of human skin from healthy donors, are cells that respond as typical immune cells, after stimulation
with _T. rubrum_, LTA and LPS in different conditions, and that this mechanism may be
very important, for the protection of local environment. 

References
1.- Arenas R., Dermatofitosis en México. Rev Iberoam Micol 2002; 19: 63-67.
2.- Kupper T. and Fuhlbrigge R. Immune surveillance in the skin: mechanims and clinical consecuences.
Nat Rev Immunol 2004; 4: 211-222
3.- Kôllish G., Naderi B., Voelcker V., Wallich R., Behrendt H., Ring J., Bauer S., Jacob T., Mempel M. and
Olelrt M. Various members of the Toll-Like receptor family contribute to the innate immune response of
human epidermal keratinocytes. Immunology 2005; 114: 531-541.
4.- Akira, S. and Takeda K. 2004. Toll-like Receptor Signalling. Nature Reviews Immunology 4:499-511

A Visualization of Null Geodesics for the Bonnor Massive Dipole

In this work we simulate null geodesics for the Bonnor massive dipole metric by implementing a symbolic-numerical algorithm in Sage and Python. This program is also capable of visualizing in 3D, in principle, the geodesics for any given metric. Geodesics are launched from a common point, collectively forming a cone of light beams, simulating a solid-angle section of a point source in front of a massive object with a magnetic field. Parallel light beams also were considered, and their bending due to the curvature of the space-time was simulated.Comment: 9 pages, 5 figures, Presented at XIX Simposio Internacional de M\'etodos Matem\'aticos Aplicados a las Ciencias (19th International Symposium of Mathematical Methods Applied to Sciences, XIX-SIMMAC

Sistematizaci?n de experiencias y su aporte a la pr?ctica pedag?gica

56 p. Recurso Electr?nicoNuestro prop?sito en el presente trabajo es recalcar la importancia de la sistematizaci?n de experiencia en el ?mbito pedag?gico, para lo cual nos enfocaremos en analizar diferentes teor?as referentes al tema, esto con el fin de explicar cuan profundo y complejo es este proceso y c?mo su realizaci?n nos genera grandes aportes en un campo como la ense?anza. Para nuestro trabajo utilizaremos los aportes realizados por autores como: Marco Ra?l Mej?a, Oscar Jara Holliday, Ana Bickel, Antoni Verger Planells, Herman Van de Velde, Claudia Patricia Roa Mendoza, Alexander Arbey S?nchez Upegui, Mar?a Mercedes Barnechea Garc?a, Luz Dary Ruiz Botero. Analizaremos la convergencia que tienen estos autores respecto a 3 categor?as (Concepto, Estrategias de sistematizaci?n y Herramientas de sistematizaci?n) pudiendo as? establecer un conceso entre dichos te?ricos lo que nos permitir? plantear una nueva mirada a ?ste tipo de procesos.Our purpose in the present work is to emphasize the importance of the systematization of experience in the pedagogical field, for which we will focus on analyzing different theories referring to the theme, in order to explain how deep and complex this process is and how its realization generates great contributions in a field such as teaching. For our work we will use the contributions made by authors such as Marco Ra?l Mej?a, Oscar Jara Holliday, Ana Bickel, Antoni Verger Planells, Herman Van de Velde, Claudia Patricia Roa Mendoza, Alexander Arbey S?nchez Upegui, Mar?a Mercedes Barnechea Garc?a, Luz Dary Ruiz Botero . We will analyze the convergence that these authors have with respect to 3 categories (Concept, Strategies of systematization and Tools of systematization), thus establishing a concession between these theorists which will allow us to propose a new look at this type of processes. Keywords: Systematization of experiences, pedagogy, process analysis, teaching, systematization, strategies, systematization tools

Star-Forming AGN Host Galaxies

The symbiosis of nuclear activity and star-formation in galaxies, as manifested in their spectral energy distributions (SEDs) is reviewed. Attention is drawn to an Hertzsprung-Russell diagram-equivalent for such objects, as well as to the importance of the SEDs in cosmological context.Comment: Invited review for FIRSED2000 Workshop (Groningen, April 2000

Spin-orbit induced mixed-spin ground state in RRNiO3_3 perovskites probed by XAS: new insight into the metal to insulator transition

We report on a Ni L$_{2,3}$ edges x-ray absorption spectroscopy (XAS) study in $R$NiO$_3$ perovskites. These compounds exhibit a metal to insulator ($MI$) transition as temperature decreases. The L$_{3}$ edge presents a clear splitting in the insulating state, associated to a less hybridized ground state. Using charge transfer multiplet calculations, we establish the importance of the crystal field and 3d spin-orbit coupling to create a mixed-spin ground state. We explain the $MI$ transition in $R$NiO$_3$ perovskites in terms of modifications in the Ni$^{3+}$ crystal field splitting that induces a spin transition from an essentially low-spin (LS) to a mixed-spin state.Comment: 4 pages, 4 figures, accepted as PRB - Rapid Comm. Dez. 200

Short-range charge-order in RRNiO3_{3} perovskites (RR=Pr,Nd,Eu) probed by X-ray absorption spectroscopy

The short-range organization around Ni atoms in orthorhombic $R$NiO$_{3}$ ($R$=Pr,Nd,Eu) perovskites has been studied over a wide temperature range by Ni K-edge x-ray absorption spectroscopy. Our results demonstrate that two different Ni sites, with different average Ni-O bond lengths, coexist in those orthorhombic compounds and that important modifications in the Ni nearest neighbors environment take place across the metal-insulator transition. We report evidences for the existence of short-range charge-order in the insulating state, as found in the monoclinic compounds. Moreover, our results suggest that the two different Ni sites coexists even in the metallic state. The coexistence of two different Ni sites, independently on the $R$ ion, provides a common ground to describe these compounds and shed new light in the understanding of the phonon-assisted conduction mechanism and unusual antiferromagnetism present in all $R$NiO$_{3}$ compounds.Comment: 4 pages, 3 figures, accepted PRB - Brief Report Dec.200

CAST constraints on the axion-electron coupling

In non-hadronic axion models, which have a tree-level axion-electron interaction, the Sun produces a strong axion flux by bremsstrahlung, Compton scattering, and axiorecombination, the "BCA processes." Based on a new calculation of this flux, including for the first time axio-recombination, we derive limits on the axion-electron Yukawa coupling gae and axion-photon interaction strength ga using the CAST phase-I data (vacuum phase). For ma <~ 10 meV/c2 we find ga gae < 8.1 × 10−23 GeV−1 at 95% CL. We stress that a next-generation axion helioscope such as the proposed IAXO could push this sensitivity into a range beyond stellar energy-loss limits and test the hypothesis that white-dwarf cooling is dominated by axion emission

Spatial clustering of interacting bugs: Levy flights versus Gaussian jumps

A biological competition model where the individuals of the same species perform a two-dimensional Markovian continuous-time random walk and undergo reproduction and death is studied. The competition is introduced through the assumption that the reproduction rate depends on the crowding in the neighborhood. The spatial dynamics corresponds either to normal diffusion characterized by Gaussian jumps or to superdiffusion characterized by L\'evy flights. It is observed that in both cases periodic patterns occur for appropriate parameters of the model, indicating that the general macroscopic collective behavior of the system is more strongly influenced by the competition for the resources than by the type of spatial dynamics. However, some differences arise that are discussed.Comment: This version incorporates in the text the correction published as an Erratum in Europhysics Letters (EPL) 95, 69902 (2011) [doi: 10.1209/0295-5075/95/69902

On the Formation of Copper Linear Atomic Suspended Chains

We report high resolution transmission electron microscopy and classical molecular dynamics simulation results of mechanically stretching copper nanowires conducting to linear atomic suspended chains (LACs) formation. In contrast with some previous experimental and theoretical work in literature that stated that the formation of LACs for copper should not exist our results showed the existence of LAC for the [111], [110], and [100] crystallographic directions, being thus the sequence of most probable occurence.Comment: 4 pages, 3 figure