Intraspecific Variation in Armillaria Species from Shrubs and Trees in Northwestern Spain

Until recently, the identification of Armillaria species relied upon morphological characteristics and mating tests, but now molecular techniques based on polymorphisms in the IGS region of the fungal rDNA are more commonly used, since these are more rapid and reliable. Differences found in RFLP patterns identifying Armillaria species have suggested the existence of intraspecific variation. In this work, 185 Armillaria isolates from different plant species (including fruit trees, broadleaf and coniferous trees, ornamental shrubs, kiwifruit and grapevine) affected by white root rot were analyzed by RFLP-PCR, in order to study intraspecific variation in Armillaria and the relationship with the plant host. Armillaria mellea was found in the majority of samples (71%), and was the most frequent Armillaria species in symptomatic ornamental shrubs, kiwifruit, grapevine, fruit trees and broadleaf trees. In conifers however white root rot was generally caused by Armillaria ostoyae. Armillaria gallica was identified, although with low incidence, in ornamental, coniferous, broadleaf and fruit hosts. Intraspecies variation was recorded only in A. mellea, for which RFLP patterns mel 1 and mel 2 were found. Most plants infected with A. mellea showed the mel 2 pattern. Further research is needed to study whether Armillaria RFLP patterns are specific to certain plant hosts, and whether intraspecific variation is related to differences in pathogenicity

Scattering polarization of hydrogen lines in the presence of turbulent electric fields

We study the broadband polarization of hydrogen lines produced by scattering of radiation, in the presence of isotropic electric fields. In this paper, we focus on two distinct problems: a) the possibility of detecting the presence of turbulent electric fields by polarimetric methods, and b) the influence of such fields on the polarization due to a macroscopic, deterministic magnetic field. We found that isotropic electric fields decrease the degree of linear polarization in the scattered radiation, with respect to the zero-field case. On the other hand, a distribution of isotropic electric fields superimposed onto a deterministic magnetic field can generate a significant increase of the degree of magnetic-induced, net circular polarization. This phenomenon has important implications for the diagnostics of magnetic fields in plasmas using hydrogen lines, because of the ubiquitous presence of the Holtsmark, microscopic electric field from neighbouring ions. In particular, previous solar magnetographic studies of the Balmer lines of hydrogen may need to be revised because they neglected the effect of turbulent electric fields on the polarization signals. In this work, we give explicit results for the Lyman-alpha and Balmer-alpha lines.Comment: 15 pages, 6 figure

Scattering polarization of hydrogen lines from electric-induced atomic alignment

We consider a gas of hydrogen atoms illuminated by a broadband, unpolarized radiation with zero anisotropy. In the absence of external fields, the atomic J-levels are thus isotropically populated. While this condition persists in the presence of a magnetic field, we show instead that electric fields can induce the alignment of those levels. We also show that this electric alignment cannot occur in a two-term model of hydrogen (e.g., if only the Ly-alpha transition is excited), or if the level populations are distributed according to Boltzmann's law.Comment: 10 pages, 4 figures. Accepted by J.Phys.B: At.Mol.Opt.Phy

Spectral Inversion of Multi-Line Full-Disk Observations of Quiet Sun Magnetic Fields

Spectral inversion codes are powerful tools to analyze spectropolarimetric observations, and they provide important diagnostics of solar magnetic fields. Inversion codes differ by numerical procedures, approximations of the atmospheric model, and description of radiative transfer. Stokes Inversion based on Response functions (SIR) is an implementation widely used by the solar physics community. It allows to work with different atmospheric components, where gradients of different physical parameters are possible, e.g., magnetic field strength and velocities. The spectropolarimetric full-disk observations were carried out with the Stokesmeter of the Solar Telescope for Operative Predictions (STOP) at the Sayan Observatory on 3 February 2009, when neither an active region nor any other extended flux concentration was present on the Sun. In this study of quiet Sun magnetic fields, we apply the SIR code simultaneously to 15 spectral lines. A tendency is found that weaker magnetic field strengths occur closer to the limb. We explain this finding by the fact that close to the limb, we are more sensitive to higher altitudes in an expanding flux tube, where the field strength should be smaller since the magnetic flux is conserved with height. Typically, the inversions deliver two populations of magnetic elements: (1) high magnetic field strengths (1500-2000 G) and high temperatures (5500-6500 K) and (2) weak magnetic fields (50-150 G) and low temperatures (5000-5300 K).Comment: 10 pages, 6 figures, accepted for Solar Physic

Origin of spatial variations of scattering polarization in the wings of the Ca {\sc i} 4227 \AA line

Polarization that is produced by coherent scattering can be modified by magnetic fields via the Hanle effect. According to standard theory the Hanle effect should only be operating in the Doppler core of spectral lines but not in the wings. In contrast, our observations of the scattering polarization in the Ca {\sc i} 4227 \AA line reveals the existence of spatial variations of the scattering polarization throughout the far line wings. This raises the question whether the observed spatial variations in wing polarization have a magnetic or non-magnetic origin. A magnetic origin may be possible if elastic collisions are able to cause sufficient frequency redistribution to make the Hanle effect effective in the wings without causing excessive collisional depolarization, as suggested by recent theories for partial frequency redistribution with coherent scattering in magnetic fields. To model the wing polarization we apply an extended version of the technique based on the "last scattering approximation". This model is highly successful in reproducing the observed Stokes $Q/I$ polarization (linear polarization parallel to the nearest solar limb), including the location of the wing polarization maxima and the minima around the Doppler core, but it fails to reproduce the observed spatial variations of the wing polarization in terms of magnetic field effects with frequency redistribution. This null result points in the direction of a non-magnetic origin in terms of local inhomogeneities (varying collisional depolarization, radiation-field anisotropies, and deviations from a plane-parallel atmospheric stratification).Comment: Accepted in May 2009 for publication in The Astrophysical Journa

Tissue remodelling and increased DNA damage in patients with incompetent valves in chronic venous insufficiency

Chronic venous insufficiency (CVI), in which blood return to the heart is impaired, is a prevalent condition worldwide. Valve incompetence is a complication of CVI that results in blood reflux, thereby aggravating venous hypertension. While CVI has a complex course and is known to produce alterations in the vein wall, the underlying pathological mechanisms remain unclear. This study examined the presence of DNA damage, pro-inflammatory cytokines and extracellular matrix remodelling in CVI-related valve incompetence. One hundred and ten patients with CVI were reviewed and divided into four groups according to age (<50 and ≥50 years) and a clinical diagnosis of venous reflux indicating venous system valve incompetence (R) (n = 81) or no reflux (NR) (n = 29). In vein specimens (greater saphenous vein) from each group, PARP, IL-17, COL-I, COL-III, MMP-2 and TIMP-2 expression levels were determined by RT-qPCR and immunohistochemistry. The younger patients with valve incompetence showed significantly higher PARP, IL-17, COL-I, COL-III, MMP-2 and reduced TIMP-2 expression levels and a higher COL-I/III ratio. Young CVI patients with venous reflux suffer chronic DNA damage, with consequences at both the local tissue and systemic levels, possibly associated with ageing.This study (FIS-PI18/00912) was supported by the Instituto de Salud Carlos III (Plan Estatal de I + D+i 2013-2016) and co-financed by the European Development Regional Fund “A way to achieve Europe” (ERDF) and B2017/BMD-3804 MITIC-CM

Propuesta metodológica para evaluar el grado de desarrollo de la innovación en pequeñas empresas aplicando la técnica del diagramador polar

For companies, the change is the process through which one becomes, in a different way, what it was at an earlier time. It is the age of accelerated changes for innovation, in almost, all areas of human activities. Toffler (2006) maintains that “The values to proclaim within the innovation process are curiosity, thought, creativity, individuality and entrepreneurial spirit.” Innovation does not only associates to the product or service but it involves the entire company; in their strategies, processes, marketing and distribution of products or services that are offered. This is initiated by the staff of the company, provided that the conditions and enabling environments are taken by the company at one time. For Hamel (2000) the company combines four components: the relationship with the client, the key strategy, strategic resources and the value connections, where the innovative enterprise redefines totally or partially some of these concepts. But success goes out indisputably from the current human talent and its development. Thus, the SMEs must identify the primary factors that allow a diagnosis of potentiality for innovation. Such factors are representative of the human characteristics and organization elements the company must have. In this paper the basic elements are presented, which are required for small businesses to identify and assess its potential in terms of innovation. Para las empresas, el cambio es el proceso a través del cual se llega a ser, de un modo diferente, a lo que se era en un momento anterior. Se vive la época de cambios acelerados por la innovación, en casi todos los ámbitos de la actividad humana. Toffler (2006) sustenta que ”Los valores a pregonar dentro de los procesos de innovación son la curiosidad, el pensamiento, la creatividad, la individualidad y la vocación empresarial”. La innovación, no sólo se asocia al producto o servicio, sino que mapea toda la empresa; en sus estrategias, procesos, comercialización y distribución de los productos o servicios que oferta. Lo anterior, se inicia por el personal de la empresa, siempre y cuando se tengan las condiciones y medios propicios por parte de empresa en un mismo tiempo. Para Hamel (2000) la empresa conjuga cuatro componentes: la relación con el cliente, la estrategia clave, los recursos estratégicos y las conexiones de valor, donde la empresa innovadora redefine total o parcialmente alguno de estos conceptos. Pero el éxito parte indiscutiblemente del talento humano actual y de su desarrollo. De esta manera, la pequeña y mediana empresa deben identificar los factores primarios que permitan realizar un diagnóstico su potencialidad de la innovación. El análisis de mercado, la gestión de proyectos, el alineamiento estratégico, la creatividad, conducta creativa, el proceso de innovación y el pensamiento creativo son los principales factores representativos de las caracterí­sticas humanas y los elementos de organización que conforman en conjunción el avance que la empresa tiene en materia de innovación. En sensu stricto los factores corresponden a Sistemas Suaves que en principio son difí­ciles de definir, tienen un componente social y una estructura de regularización. En estos casos, no se piensa en problemas sino en situaciones problema. El objetivo de este trabajo, sustentado en los factores antes citados y con la aplicación la Técnica del Diagrama Polar, pretende identificar la prioridad en acciones para potenciar la innovación y observar su evolución en conjunto

Zero-Field Dichroism in the Solar Chromosphere

We explain the linear polarization of the Ca II infrared triplet observed close to the edge of the solar disk. In particular, we demonstrate that the physical origin of the enigmatic polarizations of the 866.2 nm and 854.2 nm lines lies in the existence of atomic polarization in their metastable lower levels, which produces differential absorption of polarization components (dichroism). To this end, we have solved the problem of the generation and transfer of polarized radiation by taking fully into account all the relevant optical pumping mechanisms in multilevel atomic models. We argue that `zero-field' dichroism may be of great diagnostic value in astrophysics.Comment: 10 pages, 3 figure