4,790 research outputs found
Non linear evolution: revisiting the solution in the saturation region
In this paper we revisit the problem of the solution to Balitsky-Kovchegov
equation deeply in the saturation domain. We find that solution has the form of
Levin-Tuchin solution but it depends on variable \bar{z} = \ln(r^2 Q^2_s) +
\mbox{Const} and the value of \mbox{Const} is calculated in this paper. We
propose the solution for full BFKL kernel at large in the entire kinematic
region that satisfies the McLerram-Venugopalan initial conditionComment: 15 pp, 8 figures in eps file
Dopamine receptor D5 signaling plays a dual role in experimental autoimmune encephalomyelitis potentiating Th17-mediated immunity and favoring suppressive activity of regulatory T-cells
Indexación: Scopus.This work was supported by grants FONDECYT-1170093 (to RP) and FONDECYT-3160383 (to CP) from ‘‘Fondo Nacional de Desarrollo Científico y Tecnológico de Chile’’, AFB170004 (to RP) from ‘‘Comisión Nacional de Investigación Científica y Tecnológica de Chile (CONICYT)’’ and DI-1224-16/R (to RP) from Universidad Andres Bello.A number of studies have shown pharmacologic evidence indicating that stimulation of type I dopamine receptor (DR), favors T-helper-17 (Th17)-mediated immunity involved in experimental autoimmune encephalomyelitis (EAE) and in some other inflammatory disorders. Nevertheless, the lack of drugs that might discriminate between DRD1 and DRD5 has made the pharmacological distinction between the two receptors difficult. We have previously shown genetic evidence demonstrating a relevant role of DRD5-signaling in dendritic cells (DCs) favoring the CD4+ T-cell-driven inflammation in EAE. However, the role of DRD5-signaling confined to CD4+ T-cells in the development of EAE is still unknown. Here, we analyzed the functional role of DRD5-signaling in CD4+ T-cell-mediated responses and its relevance in EAE by using a genetic approach. Our results show that DRD5-signaling confined to naive CD4+ T-cells exerts a pro-inflammatory effect promoting the development of EAE with a stronger disease severity. This pro-inflammatory effect observed for DRD5-signaling in naive CD4+ T-cells was related with an exacerbated proliferation in response to T-cell activation and to an increased ability to differentiate toward the Th17 inflammatory phenotype. On the other hand, quite unexpected, our results show that DRD5-signaling confined to Tregs strengthens their suppressive activity, thereby dampening the development of EAE manifestation. This anti-inflammatory effect of DRD5-signaling in Tregs was associated with a selective increase in the expression of glucocorticoid-induced tumor necrosis factor receptor-related protein (GITR), which has been described to play a critical role in the expansion of Tregs. Our findings here indicate a complex role for DRD5-signaling in CD4+ T-cells-driven responses potentiating early inflammation mediated by effector T-cells in EAE, but exacerbating suppressive activity in Tregs and thereby dampening disease manifestation in late EAE stages. © 2018 Osorio-Barrios, Prado, Contreras and Pacheco.https://www.frontiersin.org/articles/10.3389/fncel.2018.00192/ful
Anti-Crime Programs: An Evaluation of the Comuna Segura Program
The aim of this paper is to evaluate the impact that the anti-crime program Comuna Segura: Compromiso 100 had on the reporting rate of different types of crimes. This program, implemented in Chile starting in 2001, was very highly criticized and, therefore, was eliminated in 2006. This paper provides statistical evidence, using the impact assessment methodology, which shows that the program was successful in increasing the reporting rate in targeted municipalities and also in decreasing levels of crimes associated with other crimes, such as rape. All this underlies the importance of carrying out formal impact assessments in order to determine benefits that are associated with a particular program. However, financial issues are also very important too and it is necessary to take them in account when making a fair statement about the cost-effectiveness of the program. This point is, however, not addressed in this paper but should be kept in mind in order to have a complete picture of the program.Crime, Program evaluation, Matching.
Análisis de la diversidad genética del capulí (Prunus Serotina), en la región andina del Ecuador, utilizando marcadores moleculares AFLP
The Capulí (Prunus serotina) is a tetraploid species of the family Rosaceae, native from North America, but also present in Central America and throughout the Andean alley of South American. The species is widely distributed in the Ecuadorian highlands. Capulí has great ethnobotanic importance in the region, mainly for its fruit, much appreciated by very fond of the inhabitants of the ecuadorian highlands, but also for its timber.
A first analysis of genetic diversity and population structure in capulí was carried out by Guadalupe et al. (2015). The main results were the finding of a moderate level of genetic diversity (He = 0.71), and a slight genetic differentiation between subpopulations from the southern provinces (Cañar and Azuay) and those of the center and north of the country.
The present research contributed with additional information regarding the level of genetic diversity of the ecuadorian capulí (Prunus serotina) and its population structure. Through the use of AFLP molecular markers, 80 capuli accessions from 8 provinces of the Ecuadorian highlands were characterized molecularly: Carchi, Tulcán, Imbabura, Tungurahua, Cotopaxi, Chimborazo, Cañar and Azuay. Five combinations of AFLP primers were tested, of which three were polymorphic and showed clear and reproducible signals on acrylamide gels. The results of this study reveal a low level of genetic diversity (uHe = 0.284) for capuli, a characteristic finding of non-endemic related species subject to partial domestication events (Xu et al, 2006). Furthermore, population structure analyzes do not show a genetic differentiation by provinces (Nei values: 0.018 to 0.069), so there is no clear evidence of population structure. However, it was shown that the province of Cañar (located furthest south) exhibits a greater genetic differentiation with respect to other provinces analyzed.
The use of SSR and AFLP molecular markers, give a first overview of the current state of genetic diversity of P. serotina in Ecuador. Further anthropological, economic and evolutionary information of the species is required, to support the hypotheses develop in both studies.El capulí (Prunus serotina) es una especie tetraploide de la familia Rosaceae, originaria de Norteamérica, presente también en Centroamérica y el callejón interandino suramericano. La especie está distribuida ampliamente en la sierra ecuatoriana. El capulí tiene una gran importancia etnobotánica en la región, ya que su fruto es muy apetecido por los habitantes de la sierra, así también por su madera.
Un primer análisis de diversidad genética y estructura poblacional en capulí fue realizado por Guadalupe y colaboradores (2015). Los principales resultados fueron el hallazgo de un moderado nivel de diversidad genética (He= 0.71), y una sutil diferenciación genética entre las provincias sureñas (Cañar y Azuay) y aquellas del centro-norte.
La presente investigación contribuyó con información adicional respecto al nivel de diversidad genética del capulí (Prunus Serotina) y su estructura poblacional. Mediante el uso de marcadores moleculares tipo AFLP, se caracterizó molecularmente 80 accesiones de capulí de 8 provincias de la Sierra ecuatoriana: Carchi, Tulcán, Imbabura, Tungurahua, Cotopaxi, Chimborazo, Cañar y Azuay. Se probó 5 combinaciones de primers AFLP, de los cuales 3 fueron polimórficos y presentaron señales claras y reproducibles en geles de acrilamida. Los resultados de este estudio develan un bajo nivel de diversidad genética (uHe=0.284) para el capulí, hallazgo característico de especies emparentadas no endémicas sujetas a eventos parciales de domesticación (Xu et al, 2006). Los análisis de estructura poblacional no muestran una diferenciación por provincias (valores de Nei: 0.018 a 0.069), por lo que no hay evidencia clara de estructura en la población. Sin embargo, se evidenció que la provincia de Cañar muestra una mayor diferenciación genética con respecto al resto de provincias analizadas.
La utilización de los marcadores moleculares SSR y AFLP, dan un primer panorama del estado actual de la diversidad genética de Prunus serotina en el Ecuador. Se requiere información antropológica, económica y evolutiva de la especie, para sustentar las hipótesis planteadas en ambos estudios
Primer registro de Scelidotheriinae Ameghino (Xenartha, Mylodontidae) del Piso/Edad Chasiquense (Mioceno tardío) de la Argentina
The subfamily Scelidotheriinae constitutes a group of mylodontids widely represented in the Quaternary of South America; however, the fossil record of the Neogene taxa is still scarce. In the present paper, a new specimen of this subfamily, corresponding to a right partial hemimandible with complete dental series, is reported. The material was recovered from the lower levels of the Arenisca Albardón Member of the Loma de Las Tapias Formation (San Juan Province, Argentina), assigned to the late Miocene. This finding represents the first record of a member of the Scelidotheriinae from the Chasicoan Stage/Age and provides new information about the anatomical characteristics and the geographic distribution of the Neogene representatives of this subfamily.Fil: Miño Boilini, Ángel Ramón. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Tomassini, Rodrigo Leandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Geológico del Sur. Universidad Nacional del Sur. Departamento de Geología. Instituto Geológico del Sur; ArgentinaFil: Contreras, Victor Hugo. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Fisicas y Naturales. Instituto de Geologia "Dr. Emiliano Aparicio"; Argentin
Complex source geometries in volcano seismology
The seismic source for small to moderate earthquakes is usually described by a point source on a planar geometry, where the amplitudes
observed are linearly dependent on the seismic moment and the waveforms are predicted by the seismic theory. Particularly in volcanic settings, there is increasing evidence of non-planar ruptures which follow complex geometries instead, such as ring faults (conduits and calderas) and dyke faults. I propose and describe the action of complex sources as a superposition of point sources aligned along with ring structures and dykes. Synthetic seismograms are calculated and their magnitudes and waveforms analysed, finding that moment tensor inversions systematically underestimate the seismic moment or magnitude, the displacement at the fault is misinterpreted and the source dynamics follow mainly isotropic behaviour. For long wavelengths, I can treat the waves as coherent and a moment tensor inversion under a point source approach is applicable. However, this source parameters need to be carefully analysed and eventually corrected for a complex source. The correction factor for each different source studied can be calculated, thus, a corrected value for the seismic moment is available under these conditions. To test the results obtained, low-frequency events at Soufrière Hills are considered, in which the rupture is produced by brittle behaviour of magma within a conduit, the seismic moment correction is applied to the slip maintaining the area as constant, enhancing those values to match geological observations in rhyolitic volcanoes. Furthermore, partial-ring ruptures are modelled to emulate the collapse of Bárðarbunga caldera in Iceland. In this case, the correction over the seismic moment is attributable to the rupture area, maintaining the cumulative slip as constant. This applied correction improves the reconciliation of the seismic and geodetic moment for Bárðarbunga. For both cases, the inclusion of a curved source explains more accurately the observations and the conclusions are more realistic. Collaterally, I found evidence of network-dependent results, alongside intrinsic uncertainties in the location of these sources which needs to be taken into account for an improved source description
Microlensing events in the Galactic bulge
For the first time we detected microlensing events at zero latitude in the
Galactic bulge using the VISTA Variables in the Via Lactea Survey (VVV) data.
We have discovered a total sample of N = 630 events within an area covering
20.7 sq. deg. Using the near-IR color magnitude diagram we selected N = 291 red
clump sources, allowing us to analyse the longitude dependence of microlensing
across the central region of the Galactic plane. We thoroughly accounted for
the photometric and sampling efficiency. The spatial distribution is
homogeneous, with the number of events smoothly increasing toward the Galactic
center. We find a slight asymmetry, with a larger number of events toward
negative longitudes than positive longitudes, that is possibly related with the
inclination of the bar along the line of sight. We also examined the timescale
distribution which shows a mean on 17.4 +- 1.0 days for the whole sample, and
20.7 +- 1.0 for the Red Clump subsample.Comment: Proceedings of the Fifteenth Marcel Grossman Meeting on General
Relativity Edited by Elia Battistelli, Robert T. Jantzen, and Remo Ruffini. 6
pages, 3 figures, to be published in Open access e-book proceedings World
Scientific, Singapore, 201
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