The peculiar nova V1309 Sco/Nova Sco 2008: A candidate twin of V838 Mon

Nova Scorpii 2008 was the target of our Directory Discretionary Time proposal at VLT+UVES in order to study the evolution, origin and abundances of the heavy-element absorption system recently discovered in 80% of classical novae in outburst. The early decline of Nova Scorpii 2008 was monitored with high resolution echelle spectroscopy at 5 different epochs. The analysis of the absorption and the emission lines show many unusual characteristics. Nova Scorpii 2008 is confirmed to differ from a common Classical Nova as well as a Symbiotic Recurrent Nova, and it shows characteristics which are common to the so called, yet debated, red-novae. The origin of this new nova remains uncertain.Comment: 10 pages, 8 figures. Accepted by A&

Assessment of transrectal ultrasonography for detection of ovarian follicles in hair sheep

This study evaluated the accuracy of transrectal ultrasonography (US) for the determination of ovarian follicles in hair sheep. Number and size of follicles in 24 ovaries (n= 12 ewes) were determined using an ultrasound machine (Aloka SSD 500), fitted with a 7.5 MHz transrectal probe. The ovaries were collected just after US, for measurement of the number and size of follicles (postmortem findings; PM). There were no differences in the number of small (2 to 2.9 mm), medium (3 to 3.9 mm), large (≥ 4 mm) and total follicles/ovary as detected by US and PM (1.3 ± 0.3 vs 1.6 ± 0.3; 0.5 ± 0.2 vs 0.8 ± 0.2; 0.5 ± 0.2 vs 0.5 ± 0.2; and 2.3 ± 0.3 vs 2.9 ± 0.4; respectively). The sensitivity and predictive value of US for detection of follicles in each category were 71.1, and 87%; 68.4, and 100%; 91.7, and 100%; 73.9, and 92.7%, respectively; the correlation coefficiennts (r) for number of small, medium, large and total follicles being 0.75, 0.83, 0.96 and 0,75 (P<0.001), respectively. It was concluded that US is an efficient tool for detection and measurement of ovarian follicles in studies of the reproductive physiology in hair ewes

Infrared photometry and CaT spectroscopy of globular cluster M 28 (NGC 6626)

Recent studies show that the inner Galactic regions host genuine bulge globular clusters, but also halo intruders, complex remnants of primordial building blocks, and objects likely accreted during major merging events. In this study we focus on the properties of M 28, a very old and massive cluster currently located in the Galactic bulge. We analysed wide-field infrared photometry collected by the VVV survey, VVV proper motions, and intermediate-resolution spectra in the calcium triplet range for 113 targets in the cluster area. Our results in general confirm previous estimates of the cluster properties available in the literature. We find no evidence of differences in metallicity between cluster stars, setting an upper limit of Delta[Fe/H]<0.08 dex to any internal inhomogeneity. We confirm that M 28 is one of the oldest objects in the Galactic bulge (13-14 Gyr). From this result and the literature data, we find evidence of a weak age-metallicity relation among bulge globular clusters that suggests formation and chemical enrichment. In addition, wide-field density maps show that M 28 is tidally stressed and that it is losing mass into the general bulge field. Our study indicates that M 28 is a genuine bulge globular cluster, but its very old age and its mass loss suggest that this cluster could be the remnant of a larger structure, possibly a primeval bulge building block.Comment: Accepted for publication in Astronomy & Astrophysic

Classification of strengthening exercises of the lower member posterior chain, based on the amplitude of muscular activation in amateur soccer players between 18-25 years

The hamstring injuries are recurrent in the sports disciplines of teams such as football, with rehabilitation being a key point to prevent future alterations. Within this process, the strengthening paradigms are rather empirical, therefore, criteria based on the exercises used are required. In this context, the objective of the present investigation is to classify the strengthening exercises of the posterior lower limb chain, based on the amplitude of muscular activation, in amateur soccer players of the Andrés Bello University (UNAB), for which a non-experimental, descriptive, cross-sectional design. The study population was 30 university students, who were studying from first to fifth year, during the academic period 2017. The participants were summoned to the Laboratory of Rehabilitation Sciences, where after signing the informed consent they had to perform a phase of heating on a cycle ergometer, then the MCIV (maximum voluntary isometric contraction) of the semimembranous, semitendinous, biceps femoral and gluteus maximus muscles was calculated, finally applying a battery of strengthening exercises, which were classified according to the intensity of muscle activation. In relation to this, it was obtained that 8 of the 13 exercises implemented were classified as low intensity (p <0.05), 3 of medium intensity (p <0.05) and 2 of high intensity (p <0.05), while the peak of amplitude of the semimembranous, semitendinous and biceps femoral muscles moved to the right in temporal terms, to the extent that the exercises classified as low, medium and high intensity are compared.Las lesiones de isquiotibiales son recurrentes en disciplinas deportivas de equipos como el fútbol, siendo la rehabilitación un punto clave para prevenir alteraciones futuras. Dentro de este proceso, los paradigmas de fortalecimiento son más bien empíricos, por lo tanto, criterios fundamentados en torno a los ejercicios utilizados son requeridos. Bajo este contexto, el objetivo de la presente investigación fue clasificar los ejercicios de fortalecimiento de la cadena posterior de miembro inferior, en base a la amplitud de activación muscular, en futbolistas amateur de la Universidad Andrés Bello (UNAB), para lo cual se utilizó un diseño no experimental de tipo descriptivo y de corte transversal. La población de estudio, fueron 30 estudiantes universitarios, que estaban cursando de primero a quinto año, durante el periodo académico 2017. Los participantes fueron citados al Laboratorio de Ciencias de Rehabilitación de la UNAB, en donde luego de firmar el consentimiento informado debieron realizar una fase de calentamiento en cicloergómetro, posteriormente se calculó la MCIV (Máxima contracción isométrica voluntaria) de los músculos semimembranoso, semitendinoso, bíceps femoral y glúteo mayor, para finalmente aplicar una batería de ejercicios de fortalecimientos, los cuales fueron clasificados según la intensidad de activación muscular. En relación con esto, se obtuvo que 8 de los 13 ejercicios implementados fueron clasificados de baja intensidad (p<0.05), 3 de mediana intensidad (p<0.05) y 2 de alta intensidad (p<0.05), mientras que el peak de amplitud de los músculos semimembranoso, semitendinoso y bíceps femoral se desplazó a la derecha en términos temporales, en la medida que se comparan los ejercicios clasificados como de baja, media y alta intensidad

Discovery of catalases in members of the Chlamydiales order.

Catalase is an important virulence factor for survival in macrophages and other phagocytic cells. In Chlamydiaceae, no catalase had been described so far. With the sequencing and annotation of the full genomes of Chlamydia-related bacteria, the presence of different catalase-encoding genes has been documented. However, their distribution in the Chlamydiales order and the functionality of these catalases remain unknown. Phylogeny of chlamydial catalases was inferred using MrBayes, maximum likelihood, and maximum parsimony algorithms, allowing the description of three clade 3 and two clade 2 catalases. Only monofunctional catalases were found (no catalase-peroxidase or Mn-catalase). All presented a conserved catalytic domain and tertiary structure. Enzymatic activity of cloned chlamydial catalases was assessed by measuring hydrogen peroxide degradation. The catalases are enzymatically active with different efficiencies. The catalase of Parachlamydia acanthamoebae is the least efficient of all (its catalytic activity was 2 logs lower than that of Pseudomonas aeruginosa). Based on the phylogenetic analysis, we hypothesize that an ancestral class 2 catalase probably was present in the common ancestor of all current Chlamydiales but was retained only in Criblamydia sequanensis and Neochlamydia hartmannellae. The catalases of class 3, present in Estrella lausannensis and Parachlamydia acanthamoebae, probably were acquired by lateral gene transfer from Rhizobiales, whereas for Waddlia chondrophila they likely originated from Legionellales or Actinomycetales. The acquisition of catalases on several occasions in the Chlamydiales suggests the importance of this enzyme for the bacteria in their host environment

Benznidazole biotransformation and multiple targets in <i>Trypanosoma</i> cruzi revealed by metabolomics

&lt;b&gt;Background&lt;/b&gt;&lt;p&gt;&lt;/p&gt; The first line treatment for Chagas disease, a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi, involves administration of benznidazole (Bzn). Bzn is a 2-nitroimidazole pro-drug which requires nitroreduction to become active, although its mode of action is not fully understood. In the present work we used a non-targeted MS-based metabolomics approach to study the metabolic response of T. cruzi to Bzn.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Methodology/Principal findings&lt;/b&gt;&lt;p&gt;&lt;/p&gt; Parasites treated with Bzn were minimally altered compared to untreated trypanosomes, although the redox active thiols trypanothione, homotrypanothione and cysteine were significantly diminished in abundance post-treatment. In addition, multiple Bzn-derived metabolites were detected after treatment. These metabolites included reduction products, fragments and covalent adducts of reduced Bzn linked to each of the major low molecular weight thiols: trypanothione, glutathione, γ-glutamylcysteine, glutathionylspermidine, cysteine and ovothiol A. Bzn products known to be generated in vitro by the unusual trypanosomal nitroreductase, TcNTRI, were found within the parasites, but low molecular weight adducts of glyoxal, a proposed toxic end-product of NTRI Bzn metabolism, were not detected.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Conclusions/significance&lt;/b&gt;&lt;p&gt;&lt;/p&gt; Our data is indicative of a major role of the thiol binding capacity of Bzn reduction products in the mechanism of Bzn toxicity against T. cruzi

Highlights from the Pierre Auger Observatory

The Pierre Auger Observatory is the world's largest cosmic ray observatory. Our current exposure reaches nearly 40,000 km$^2$ str and provides us with an unprecedented quality data set. The performance and stability of the detectors and their enhancements are described. Data analyses have led to a number of major breakthroughs. Among these we discuss the energy spectrum and the searches for large-scale anisotropies. We present analyses of our X$_{max}$ data and show how it can be interpreted in terms of mass composition. We also describe some new analyses that extract mass sensitive parameters from the 100% duty cycle SD data. A coherent interpretation of all these recent results opens new directions. The consequences regarding the cosmic ray composition and the properties of UHECR sources are briefly discussed.Comment: 9 pages, 12 figures, talk given at the 33rd International Cosmic Ray Conference, Rio de Janeiro 201

A search for point sources of EeV photons

Measurements of air showers made using the hybrid technique developed with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for point sources of EeV photons anywhere in the exposed sky. A multivariate analysis reduces the background of hadronic cosmic rays. The search is sensitive to a declination band from -85{\deg} to +20{\deg}, in an energy range from 10^17.3 eV to 10^18.5 eV. No photon point source has been detected. An upper limit on the photon flux has been derived for every direction. The mean value of the energy flux limit that results from this, assuming a photon spectral index of -2, is 0.06 eV cm^-2 s^-1, and no celestial direction exceeds 0.25 eV cm^-2 s^-1. These upper limits constrain scenarios in which EeV cosmic ray protons are emitted by non-transient sources in the Galaxy.Comment: 28 pages, 10 figures, accepted for publication in The Astrophysical Journa

Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory

The Pierre Auger Collaboration has reported evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies $E>E_{th}=5.5\times 10^{19}$ eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at $E>E_{th}$ are heavy nuclei with charge $Z$, the proton component of the sources should lead to excesses in the same regions at energies $E/Z$. We here report the lack of anisotropies in these directions at energies above $E_{th}/Z$ (for illustrative values of $Z=6,\ 13,\ 26$). If the anisotropies above $E_{th}$ are due to nuclei with charge $Z$, and under reasonable assumptions about the acceleration process, these observations imply stringent constraints on the allowed proton fraction at the lower energies

Reconstruction of inclined air showers detected with the Pierre Auger Observatory

We describe the method devised to reconstruct inclined cosmic-ray air showers with zenith angles greater than $60^\circ$ detected with the surface array of the Pierre Auger Observatory. The measured signals at the ground level are fitted to muon density distributions predicted with atmospheric cascade models to obtain the relative shower size as an overall normalization parameter. The method is evaluated using simulated showers to test its performance. The energy of the cosmic rays is calibrated using a sub-sample of events reconstructed with both the fluorescence and surface array techniques. The reconstruction method described here provides the basis of complementary analyses including an independent measurement of the energy spectrum of ultra-high energy cosmic rays using very inclined events collected by the Pierre Auger Observatory.Comment: 27 pages, 19 figures, accepted for publication in Journal of Cosmology and Astroparticle Physics (JCAP