Photo-strobo-acoustic Imaging at the Microscale by Laser-Induced Ultrasound

The combination of microfluidic technology and optical fluids characterization techniques has been recently applied to produce lab-on-a-chip systems. In the present work, bringing together the imaging technique called photoacoustic imaging (PAI) and microfluidic technology were implemented to obtain micro-scale imaging. Laser-induced ultrasound signals were measured from microdroplets produced in a simple T-junction microfluidic system. Single pulse laser images were produced as a result of the combination of the aforementioned techniques, allowing to obtain of geometrical information of the microdroplets and its spatial position.Comment: Manuscript in proces

Acidithiobacillus ferrianus sp. nov.:an ancestral extremely acidophilic and facultatively anaerobic chemolithoautotroph

Strain MG, isolated from an acidic pond sediment on the island of Milos (Greece), is proposed as a novel species of ferrous iron- and sulfur-oxidizing Acidithiobacillus. Currently, four of the eight validated species of this genus oxidize ferrous iron, and strain MG shares many key characteristics with these four, including the capacities for catalyzing the oxidative dissolution of pyrite and for anaerobic growth via ferric iron respiration. Strain MG also grows aerobically on hydrogen and anaerobically on hydrogen coupled to ferric iron reduction. While the 16S rRNA genes of the iron-oxidizing Acidithiobacillus species (and strain MG) are located in a distinct phylogenetic clade and are closely related (98–99% 16S rRNA gene identity), genomic relatedness indexes (ANI/dDDH) revealed strong genomic divergence between strain MG and all sequenced type strains of the taxon, and placed MG as the first cultured representative of an ancestral phylotype of iron oxidizing acidithiobacilli. Strain MG is proposed as a novel species, Acidithiobacillus ferrianus sp. nov. The type strain is MGT(= DSM 107098T= JCM 33084T).Similar strains have been found as isolates or indicated by cloned 16S rRNA genes from several mineral sulfide mine sites.Indexación: Scopu

Dissecting an intermediate-mass (IM) protostar: Chemical differentiation in IC1396N

We have carried out high-angular resolution (1.4") observations in the continuum at 3.1mm and in the N2H+ 1-0, CH3CN 5_k-4_k and 13CS 2-1 lines using the Plateau de Bure Interferometer (PdBI) towards the intermediate mass (IM) protostar IRAS21391+5802 (IC1396N). In addition, we have merged the PdBI images with previous BIMA (continuum data at 1.2mm and 3.1mm) and single-dish (N2H+ 1-0) data to have a comprehensive description of the region. The combination of our data with BIMA and 30m data show that the bipolar outflow associated has completely eroded the initial molecular globule. The 1.2mm and 3.1mm continuum emissions are extended along the outflow axis tracing the warm walls of the biconical cavity. Most of the molecular gas, however, is located in an elongated feature in the direction perpendicular to the outflow. A strong chemical differentiation is detected across the molecular toroid, with the N2H+ 1-0 emission absent in the inner region.This chemical differentiation can be understood in terms of the different gas kinetic temperature. The [CH3CN]/[N2H+] ratio increases by 5 orders of magnitude with gas temperature, for temperatures between 20K and 100K. The CH3CN abundance towards IRAM 2A, the most massive protostellar core, is similar to that found in hot corinos and lower than that expected towards IM and high mass hot cores. This could indicate that IRAM 2A is a low mass or at most Herbig Ae star (IRAM 2A) instead of the precursor of a massive Be star. Alternatively, the low CH3CN abundance could also be the consequence of IRAM 2A being a Class 0/I transition object which has already formed a small photodissociation region (PDR).Comment: accepted A&

Association of Motivational Climate With Addictive Behaviors Depending on Type of Sport in University Students: Structural Equation Analysis

This research study aims at contrasting a structural model of the associations between the alcohol consumption, tobacco dependence, and the problematic use of video games with motivational climate toward sport depending on the category of sports practiced in a sample of Physical Education university students. The sample consisted of 775 university students from the Autonomous Community of Andalusia (Spain), aged between 21 and 35 (22.22 ± 3.76) years. The instruments used were the Perceived Motivational Climate in Sport Questionnaire (PMCSQ-2), the Alcohol Use Disorders Identification Test (AUDIT), the Fagerström Test for Nicotine Dependence (FTND), and the Questionnaire of Experiences Related to Video Games (QERV) questionnaires. A path model that fitted properly in the multigroup analysis for both categories of sports was used, χ2 = 19.843; gl = 8; p = .011; comparative fit index (CFI) = 0.911; normed fit index (NFI) = 0.903; incremental fit index (IFI) = 0.912; root mean square error approximation (RMSEA) = 0.085. An inverse association was shown between task climate and tobacco consumption in individual sports, being weaker in collective sports. This association is not significant for collective sports, but it is for individual sports for ego climate. However, a positive association was found between ego climate and the use of video games in individual sports, not being significant in the case of collective sports. The importance of promoting motivational climates oriented toward tasks that are based on the practice of collective sports is established, because they could act as protective factors against the development of addictive behavior in university students.This research study has been supported by the Education Innovation Project PID 16-45, named “Implementation of digital resources in the classroom for the development of psychosocial and motivational factors in students of the degree in Primary Education with the speciality in Physical Education,” funded by the University of Granada. Education Innovation Project PIBD Advanced 470, named “Program of teaching intervention in students of the degree in primary education and early childhood education through the use of new technologies for the improvement of the psychosocial factors of the students,” funded by the University of Granada. Project I+D+I “DISPERSA,” with code number TIN2015-67149-C3-R, named “Design of Pervasive Games Based on Learning Experiences Sensitive to Context” funded by the Ministry of Economy and Competitiveness. Precompetitive Research Projects for Young Researchers (PPJI_B-05); Self-plan Research of the University of Granada

The First IRAM/PdBI Polarimetric Millimeter Survey of Active Galactic Nuclei. I. Global Properties of the Sample

We have studied the linear polarization of 86 active galactic nuclei (AGN) in the observed frequency range 80-267 GHz (3.7-1.1mm in wavelength), corresponding to rest-frame frequencies 82-738 GHz, with the IRAM Plateau de Bure Interferometer (PdBI). The large number of measurements, 441, makes our analysis the largest polarimetric AGN survey in this frequency range to date. We extracted polarization parameters via earth rotation polarimetry with unprecedented median precisions of ~0.1% in polarization fractions and ~1.2 degrees in polarization angles. For 73 of 86 sources we detect polarization at least once. The degrees of polarization are as high as ~19%, with the median over all sources being ~4%. Source fluxes and polarizations are typically highly variable, with fractional variabilities up to ~60%. We find that BLLac sources have on average the highest level of polarization. There appears to be no correlation between degree of polarization and redshift, indicating that there has been no substantial change of polarization properties since z~2.4. Our polarization and spectral index distributions are in good agreement with results found from various samples observed at cm/radio wavelengths; thus our frequency range is likely tracing the signature of synchrotron radiation without noticeable contributions from other emission mechanisms. The "millimeter-break" located at frequencies >1 THz appears to be not detectable in the frequency range covered by our survey.Comment: 19 pages, 9 figures, 2 long tables (p. 12-19). Accepted by A&A

Third-order nonlinear optical response and photoluminescence characterization of tellurite glasses with different alkali metal oxides as network modifiers

Studies of the third-order nonlinear optical properties in TeO(2)-MO-R(2)O glasses with three different alkali metal oxides R(2)O (R - Li, Na, K) as network modifiers and two network intermediates MO (M - Zn, Mg) are reported. The influence of such modifiers and intermediates on the nonlinear optical properties of these glasses was investigated using the standard Z-scan and the thermally managed Z-scan techniques under femtosecond pulse excitation at 800 nm. For different modifiers and intermediates, the nonlinear refraction indices n(2) of these glasses varied in the range 1.31-2.81 (x10(-15) cm(2)/W). It was found that n(2) increases as the ionic radius of both network modifiers and intermediates decreases. Furthermore, the measurements show that the contribution from thermo-optical effects to the nonlinear refraction index is negligible for all of the studied glass compositions. In addition, the effect of modifiers and intermediates in the formation of localized states in the vicinity of the optical bandgap was also studied through photoluminescence experiments. These experiments revealed the presence of two emission bands (red and blue) originating from these localized states that can be populated after optical excitation and subsequent relaxation

The first IRAM/PdBI polarimetric millimeter survey of active galactic nuclei. II. Activity and properties of individual sources

We present an analysis of the linear polarization of six active galactic nuclei - 0415+379 (3C~111), 0507+179, 0528+134 (OG+134), 0954+658, 1418+546 (OQ+530), and 1637+574 (OS+562). Our targets were monitored from 2007 to 2011 in the observatory-frame frequency range 80-253 GHz, corresponding to a rest-frame frequency range 88-705 GHz. We find average degrees of polarization m_L ~ 2-7%; this indicates that the polarization signals are effectively averaged out by the emitter geometries. We see indication for fairly strong shocks and/or complex, variable emission region geometries in our sources, with compression factors 10 deg. An analysis of correlations between source fluxes and polarization parameter points out special cases: the presence of (at least) two distinct emission regions with different levels of polarization (for 0415+379) as well as emission from a single, predominant component (for 0507+179 and 1418+546). Regarding the evolution of flux and polarization, we find good agreement between observations and the signal predicted by "oblique shock in jet" scenarios in one source (1418+546). We attempt to derive rotation measures for all sources, leading to actual measurements for two AGN and upper limits for three sources. We derive values of RM = -39,000 +/- 1,000 (stat) +/- 13,000 (sys) rad/m^2 and RM = 420,000 +/- 10,000 (stat) +/- 110,000 (sys) rad/m^2 for 1418+546 and 1637+574, respectively; these are the highest values reported to date for AGN. These values indicate magnetic field strengths of the order ~0.0001 G. For 0415+379, 0507+179, and 0954+658 we derive upper limits |RM| < 17,000 rad/m^2. From the relation |RM| ~ nu^a we find a = 1.9 +/- 0.3 for 1418+546, in good agreement with a = 2 as expected for a spherical or conical outflow.Comment: 23 pages, 8 figures, 4 tables. Accepted by Astronomy and Astrophysics. Minor language editing, one missing reference (Macquart et al. 2006) adde

Ceratocystis fimbriata agente causal de la enfermedad de marchitez vascular de Tectona grandis L.f. (teca) en Ecuador

Tectona grandis L.f. es una especie forestal de madera dura que, a pesar de no ser nativa de América, su plasticidad de adaptación ha permitido que en Ecuador se establezcan plantaciones intensivas con fines de exportación. Una compleja enfermedad con características de marchitez vascular está matando miles de árboles de diferentes edades en el país. Se planteó conocer el agente fitopatógeno causante de la patogénesis y muerte de los árboles. Se aislaron los hongos Fusarium sp. y Ceratocystis fimbriata Ellis &amp; Halst. desde árboles enfermos. A nivel de invernadero se plantearon los postulados de Koch, para el efecto 30 plantas de T. grandis de cuatro meses de edad por cada tratamiento, se inocularon con los microrganismos como se describe a continuación: T1= C. fimbriata, T2 = Fusarium sp., T3 = C. fimbriata + Fusarium sp., T4 = agar-agar (control). Se empleó un diseño completo al azar (DCA) y las plantas se evaluaron a los 45 días después de inoculadas. Los tratamientos C. fimbriata, y C. fimbriata + Fusarium sp., mostraron mayores volúmenes aparentes de necrosis, con 1.52 cm3 y 1.93 cm3, y plantas muertas por la infección durante el tiempo de evaluación, mientras que Fusarium sp. mostró baja o nula patogenicidad y comportamiento similar al control, con 0.27 cm3 y 0.16 cm3 respectivamente. Estos resultados sugieren que el agente causal de la enfermedad de marchitez vascular en T. grandis es C. fimbriata y sería el primer reporte del fitopatógeno atacando teca en Ecuador