Biopesticide activity from drimanic compounds to control tomato pathogens

Indexación: Scopus.Tomato crops can be affected by several infectious diseases produced by bacteria, fungi, and oomycetes. Four phytopathogens are of special concern because of the major economic losses they generate worldwide in tomato production; Clavibacter michiganensis subsp. michiganensis and Pseudomonas syringae pv. tomato, causative agents behind two highly destructive diseases, bacterial canker and bacterial speck, respectively; fungus Fusarium oxysporum f. sp. lycopersici that causes Fusarium Wilt, which strongly affects tomato crops; and finally, Phytophthora spp., which affect both potato and tomato crops. Polygodial (1), drimenol (2), isonordrimenone (3), and nordrimenone (4) were studied against these four phytopathogenic microorganisms. Among them, compound 1, obtained from Drimys winteri Forst, and synthetic compound 4 are shown here to have potent activity. Most promisingly, the results showed that compounds 1 and 4 affect Clavibacter michiganensis growth at minimal inhibitory concentrations (MIC) values of 16 and 32 μg/mL, respectively, and high antimycotic activity against Fusarium oxysporum and Phytophthora spp. with MIC of 64 μg/mL. The results of the present study suggest novel treatment alternatives with drimane compounds against bacterial and fungal plant pathogens. © 2018 by the authors.https://www.mdpi.com/1420-3049/23/8/205

Ethane internal rotation-Vibrational Hamiltonian

One of the main purposes of a theoretical spectroscopist is to propose a model to reproduce the xperimental spectra available in the literature as accurate and with as much physical information as possible. In this case it has been studied the Far infrared an Infrared spectra of non-rigid molecules, introducing in the Vibrational Potential their dependence on the large amplitude variables. The molecule that has been selected to test our proposed Hamiltonian is ethane which is a very well studied molecule. The molecule is a non-rigid molecule and their experimental spectra have been reported in the literature. © 2008, Sociedad Química de MéxicoPeer Reviewe

Detection of a multi-shell planetary nebula around the hot subdwarf O-type star 2MASS J19310888+4324577

(Abridged) The origin of hot subdwarf O-type stars (sdOs) remains unclear since their discovery in 1947. Among others, a post-Asymptotic Giant Branch (post-AGB) origin is possible for a fraction of sdOs. We are involved in a comprehensive ongoing study to search for and to analyze planetary nebulae (PNe) around sdOs with the aim of establishing the fraction and properties of sdOs with a post-AGB origin. We use deep Halpha and [OIII] images of sdOs to detect nebular emission and intermediate resolution, long-slit optical spectroscopy of the detected nebulae and their sdO central stars. These data are complemented with other observations for further analysis of the detected nebulae. We report the detection of an extremely faint, complex PN around 2MASS J19310888+4324577 (2M1931+4324), a star classified as sdO in a binary system. The PN shows a bipolar and an elliptical shell, whose major axes are oriented perpendicular to each other, and high-excitation structures outside the two shells. WISE archive images show faint, extended emission at 12 and 22 microns in the inner nebular regions. The internal nebular kinematics is consistent with a bipolar and a cylindrical/ellipsoidal shell, in both cases with the main axis mainly perpendicular to the line of sight. The nebular spectrum only exhibits Halpha, Hbeta and [OIII]4959,5007 emission lines, but suggests a very low-excitation ([OIII]/Hbeta = 1.5), in strong contrast with the absence of low-excitation emission lines. The spectrum of 2M1931+4324 presents narrow, ionized helium absorptions that confirm the previous sdO classification and suggest an effective temperature >= 60000 K. The binary nature of 2M1931+4324, its association with a complex PN, and several properties of the system provide strong support for the idea that binary central stars are a crucial ingredient in the formation of complex PNe.Comment: 8 pages, 7 figures, accepted in Astronomy and Astrophysic

Generación de Tareas Periódicas y Aperiódicas para Simulación de Sistemas de Tiempo Real

En la disciplina Sistemas de Tiempo Real, una forma de comprobar las nuevas teorías o modelos heterogéneos de planificación, es realizar simulaciones masivas con los nuevos algoritmos desarrollados. Estas simulaciones permiten validar los resultados antes de ser implementados. No obstante, es necesario generar millones de sistemas heterogéneos sintéticos. Estos sistemas deben ser generados bajo ciertas premisas y formatos. En este trabajo, se presenta un software para generar conjuntos de sistemas de tiempo real heterogéneos. El software se encuentra desarrollado en el lenguaje Ada 2005, es de código abierto, genera conjuntos de tareas periódicas, conjuntos de tareas aperiódicas y verifica que los sistemas periódicos sean planificables por Rate Monotonic, Deadline Monotonic o Earliest Deadline First. Se adapta fácilmente a diferentes requerimientos de los simuladores y dispone de una interfaz gráfica.Sociedad Argentina de Informática e Investigación Operativ

Generador de conjuntos de tareas para simulación en sistemas de tiempo real

En la disciplina Sistemas de Tiempo Real, una forma de comprobar las nuevas teorías o modelos es realizar simulaciones. El objetivo de estas simulaciones es validar los resultados que se obtendrían de estos modelos o teorías en la práctica. Para esto, es necesario generar miles o millones de sistemas de tiempo real sintéticos automáticamente. Estos sistemas deben ser generados bajo ciertas premisas y formatos para que el simulador pueda utilizarlos y al mismo tiempo validar los resultados. En este trabajo, se presenta un software para generar conjuntos de sistemas de tiempo real sintéticos. El software se encuentra escrito en el lenguaje Ada 2005 y es de código abierto.Sociedad Argentina de Informática e Investigación Operativ

First release of the IPHAS catalogue of new extended planetary nebulae

Date of Acceptance: 30/06/2014We present the first results of our search for new, extended planetary nebulae (PNe) based on careful, systematic, visual scrutiny of the imaging data from the Isaac Newton Telescope Photometric Ha Survey of the Northern Galactic plane (IPHAS). The newly uncovered PNe will help to improve the census of this important population of Galactic objects that serve as key windows into the late-stage evolution of low- to intermediate-mass stars. They will also facilitate study of the faint end of the ensemble Galactic PN luminosity function. The sensitivity and coverage of IPHAS allows PNe to be found in regions of greater extinction in the Galactic plane and/or those PNe in a more advanced evolutionary state and at larger distances compared to the general Galactic PN population. Using a set of newly revised optical diagnostic diagrams in combination with access to a powerful, new, multiwavelength imaging data base, we have identified 159 true, likely and possible PNe for this first catalogue release. The ability of IPHAS to unveil PNe at low Galactic latitudes and towards the Galactic Anticentre, compared to previous surveys, makes this survey an ideal tool to contribute to the improvement of our knowledge of the whole Galactic PN population.Peer reviewe

The origin of the planetary nebula M 1-16. A morphokinematic and chemical analysis

We investigated the origin of the Planetary Nebula (PN) M 1-16 using narrow-band optical imaging, and high- and low-resolution optical spectra to perform a detailed morpho-kinematic and chemical studies. M 1-16 is revealed to be a multipolar PN that predominantly emits in [O III] in the inner part of the nebula and [N II] in the lobes. A novel spectral unsharp masking technique was applied to the position-velocity (PV) maps to reveal a set of multiple structures at the centre of M 1-16 spanning radial velocities from $-$40km$\,$s$^{-1}$ to 20km$\,$s$^{-1}$, with respect to the systemic velocity. The morpho-kinematic model indicates that the deprojected velocity of the lobe outflows are $\geq$100km$\,$s$^{-1}$, and particularly the larger lobes and knots have a deprojected velocity of $\simeq$350km$\,$s$^{-1}$; the inner ellipsoidal component has a deprojected velocity of $\simeq$29km$\,$s$^{-1}$. A kinematical age of $\sim$8700yr has been obtained from the model assuming a homologous velocity expansion law and a distance of 6.2$\pm$1.9kpc. The chemical analysis indicates that M 1-16 is a Type I PN with a central star of PN (CSPN) mass in the range of $\simeq$0.618-0.713M$_\odot$ and an initial mass for the progenitor star between 2.0 and 3.0M$_\odot$ (depending on metallicity). An $T_\mathrm{eff}\simeq$140$\,$000K and log$(L/L_{\odot})$=2.3 was estimated using the 3MdB photoionisation models to reproduce the ionisation stage of the PN. All of these results have led us to suggest that M 1-16 is an evolved PN, contrary to the scenario of proto-PN suggested in previous studies. We propose that the mechanism responsible for the morphology of M 1-16 is related to the binary (or multiple star) evolution scenario.Comment: A&A in press. 11 pages, 9 figure