Fungi are cosmopolitan organisms that grow in and adapt to a vast number of substrates and environments, and that can cause diseases in humans and animals, as well as in crops. The vast area and ...diverse geographical characteristics of Argentina, with the consequent climatic diversity make the country an important source of biological resources suitable for the search of new compounds. The aim of the present study was to describe the antifungal activity of extracts of Parastrephia quadrangularis, a species from northern Argentina, against Fusarium verticillioides M7075. Bio‐guided fractionation and MS/MS studies were conducted to elucidate the chemical structure of active compounds. The extracts exhibited a minimum inhibitory concentration among 118·74 and 250 μg ml−1 and the differences between the treatments and the inoculum control was 12·5–16·5 mm, respectively, in colony growth. Moreover, hyphae treated with the extracts stained blue with Evans blue, showed alterations in permeability of plasma membranes. HLPC‐MS analysis of active fractions revealed the presence of p‐coumaroyloxitremetone, and a derivate structure for another compound is proposed.
Significance and Impact of the Study
In Argentina, Fusarium verticillioides causes ‘ear rot’, a disease that produces important yield and nutritional quality losses in the maize producing region. This study suggests that Parastrephia quadrangularis extracts have potential for the growth inhibition against F. verticillioides M7075, and the bioactivity is reported for the first time. The results obtained will provide a starting point for discover new antimicotic candidate in natural products.
Significance and Impact of the Study: In Argentina, Fusarium verticillioides causes ‘ear rot’, a disease that produces important yield and nutritional quality losses in the maize producing region. This study suggests that Parastrephia quadrangularis extracts have potential for the growth inhibition against F. verticillioides M7075, and the bioactivity is reported for the first time. The results obtained will provide a starting point for discover new antimicotic candidate in natural products.
La découverte du boson de Higgs, annoncée le 4 juillet 2012 au CERN par les collaborations internationales ATLAS et CMS, représente l’accomplissement d’une quête dont l’origine remonte aux années ...1960.Depuis cet événement, les physiciens d’ATLAS et CMS poursuivent l’étude des propriétés de cette nouvelle particule fondamentale avec l’analyse des données de collisions de protons produites au Large Hadron Collider (LHC) du CERN en 2011 et 2012.Quelques mois après le redémarrage du LHC à l’issue de 18 mois de travaux de consolidation, cet article dresse le bilan des connaissances expérimentales sur le boson de Higgs.
•Polyploidization enables plants to occupy, conquer different habitats and, from an evolutionary standpoint, achieve success.•In recent years, polyploidization has become a powerful tool for the ...improvement of medicinal and aromatic species.•There is a lack of linearity between the increase in genetic material and secondary metabolite production.•A good experimental design is relevant to differentiate the “polyploid effect” from the ones derived from tissue culture conditions.•The constitution of a consortium or a network of laboratories to amplify our knowledge about the “polyploid effect” is essential.
The secondary metabolism of plants delivers a wide range of chemical structures with application for a vast array of activities, thus offering opportunities for social and economic development. Polyploidy is the possession of three or more complete sets of chromosomes. The duplication of the genome, and its possible adaptive advantages, has been an important factor in the speciation and evolution of eukaryotes. The generation of synthetic polyploids as a plant breeding strategy has enabled the development of new and improved cultivars. The aim of this paper is to examine the state-of-the-art concerning the application of polyploidization techniques as a breeding tool and its effects on the phenotypical, biochemical and genetic characteristics in some medicinal aromatic plant (MAP) species to explore our current knowledge of the possible mechanisms involved. Over the last years, new studies have demonstrated that autopolyploidization can remodel the transcriptome and the metabolome generating genomic stress. Consequently, polyploidism can also result in a wide spectrum of modifications, both molecular and physiological, with non-linear results and consequences that also depend on the experimental conditions. Likewise, concepts such as genomic shock and genome fluidity are also involved in this phenomenon, which further increase the complexity of the process.
Le 13 décembre 2011, les expériences ATLAS et CMS du LHC ont présenté au CERN, à Genève, les résultats préliminaires de la chasse au boson de Higgs, la pièce manquante du " modèle standard ", une ...théorie qui rend compte de la totalité des résultats expérimentaux observés jusqu'à présent en physique des particules. Les deux expériences observent un excès d'événements compatible avec la production d'un boson de Higgs de masse située dans la région 124-126 GeV. Cet excès, cependant, est également compatible avec une fluctuation positive des bruits de fond.
The four LEP Collaborations, ALEPH, DELPHI, L3 and OPAL, have collected a total of 2461 pb−1 of e+e− collision data at centre-of-mass energies between 189 and 209 GeV. The data are used to search for ...the Standard Model Higgs boson. The search results of the four Collaborations are combined and examined in a likelihood test for their consistency with two hypotheses: the background hypothesis and the signal plus background hypothesis. The corresponding confidences have been computed as functions of the hypothetical Higgs boson mass. A lower bound of 114.4 GeV/c2 is established, at the 95% confidence level, on the mass of the Standard Model Higgs boson. The LEP data are also used to set upper bounds on the HZZ coupling for various assumptions concerning the decay of the Higgs boson.
A high-granularity timing detector for the ATLAS phase-II upgrade Casado, M.P.; Adam Bourdarios, C.; Belfkir, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
2022, Letnik:
1032
Journal Article
Recenzirano
Odprti dostop
The large increase of pileup interactions is one of the main experimental challenges for the HL-LHC physics programme. A powerful new way to mitigate the effects of pileup is to use high-precision ...timing information to distinguish between collisions occurring close in space but well-separated in time. A High-Granularity Timing Detector, based on low gain avalanche detector technology, is therefore proposed for the ATLAS Phase-II upgrade. Covering the pseudorapidity region between 2.4 and 4.0, this device will improve the detector physics performance in the forward region. The typical number of hits per track in the detector was optimized so that the target average time resolution per track for a minimum-ionising particle is 30 ps at the start of lifetime, increasing to 50 ps at the end of HL-LHC operation. The high-precision timing information improves the pileup reduction to improve the forward object reconstruction, complementing the capabilities of the upgraded Inner Tracker (ITk) in the forward regions of ATLAS and leading to an improved performance for both jet and lepton reconstruction. These improvements in object reconstruction performance translate into sensitivity gains and enhance the reach of the ATLAS physics programme at the HL-LHC. In addition, the HGTD offers unique capabilities for the online and offline luminosity determination, an important requirement for precision physics measurements.
El género Senna comprende alrededor de 360 especies presentándose el 80% en el continente americano. Varias son conocidas por las propiedades antimicrobianas y farmacológicas. Los antecedentes de ...actividad antifúngica en Argentina fueron reportados en un estudio de extractos metanólicos de hojas de S. spectabilis frente a Fusarium graminearum. El objetivo de este trabajo fue analizar la actividad antifúngica de 12 extractos metanólicos de distintos órganos de 10 especies del género Senna, recolectadas en el norte de Argentina frente a Fusarium verticillioides, responsable de la podredumbre de la espiga en maíz. Primeramente, todos los extractos fueron evaluados con un ensayo colorimétrico de susceptibilidad. Aquellos que mostraron actividad inhibitoria, luego fueron evaluados mediante bioautografía de contacto, tinción con azul de Evans y azul de anilina, test de crecimiento radial del micelio y por su capacidad para inhibir la producción de fumonisinas. El extracto de frutos de S. spectabilis mostró actividad antifúngica con una Concentración Mínima Inhibitoria de 99,9 μg ml-1. Asimismo, se observaron halos de inhibición significativos en la bioautografía de contacto, mientras que en la tinción con azul de Evans y azul de anilina se visualizaron algunas alteraciones en las hifas. En el test de crecimiento radial del micelio, se observó una reducción significativa, y en lo que respecta a la producción de fumonisinas, los extractos provenientes de frutos mostraron una inhibición en su producción de 48,3% mientras que los extractos de flores el porcentaje fue mayor (86,3%). Finalmente, se pudo determinar que S. spectabilis presenta actividad antifúngica frente F. verticillioides, confiriéndole un nuevo registro de bioactividad a esta especie vegetal.
The top quark mass is measured in the $t\bar{t}\to$ dilepton channel (lepton $= e, \mu$) using ATLAS data recorded in the year 2012 at the LHC. The data were taken at a proton--proton centre-of-mass ...energy of $\sqrt{s}=$ 8 TeV and correspond to an integrated luminosity of about 20.2 fb$^{-1}$. Exploiting the template method, and using the distribution of invariant masses of lepton--b-jet pairs, the top quark mass is measured to be $m_{top} =$ 172.99 $\pm$ 0.41 (stat) $\pm$ 0.74 (syst) GeV, with a total uncertainty of 0.84 GeV. Finally, a combination with previous ATLAS $m_{top}$ measurements from $\sqrt{s}=$7 TeV data in the $t\bar{t}\to$ dilepton and $t\bar{t}\to$ lepton+jets channels results in $m_{top} =$ 172.84 $\pm$ 0.34 (stat) $\pm$ 0.61 (syst) GeV, with a total uncertainty of 0.70 GeV.
This paper describes a measurement of the inclusive top quark pair production cross-section ($\sigma_{t\bar{t}}$) with a data sample of 3.2 fb$^{-1}$ of proton--proton collisions at a centre-of-mass ...energy of $\sqrt{s}$=13 TeV, collected in 2015 by the ATLAS detector at the LHC. This measurement uses events with an opposite-charge electron--muon pair in the final state. Jets containing $b$-quarks are tagged using an algorithm based on track impact parameters and reconstructed secondary vertices. The numbers of events with exactly one and exactly two $b$-tagged jets are counted and used to determine simultaneously $\sigma_{t\bar{t}}$ and the efficiency to reconstruct and $b$-tag a jet from a top quark decay, thereby minimising the associated systematic uncertainties. The cross-section is measured to be: $\sigma_{t\bar{t}}$= 818 $\pm$ 8 (stat) $\pm$ 27 (syst) $\pm$ 19 (lumi) $\pm$ 12 (beam) pb, where the four uncertainties arise from data statistics, experimental and theoretical systematic effects, the integrated luminosity and the LHC beam energy, giving a total relative uncertainty of 4.4%. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. A fiducial measurement corresponding to the experimental acceptance of the leptons is also presented.
A measurement of the $ZZ$ production in the $\ell^{-}\ell^{+}\ell^{\prime -}\ell^{\prime +}$ and $\ell^{-}\ell^{+}\nu\bar{\nu}$ channels $(\ell = e, \mu)$ in proton--proton collisions at $\sqrt{s} = ...8$ TeV at the Large Hadron Collider at CERN, using data corresponding to an integrated luminosity of 20.3 fb$^{-1}$ collected by the ATLAS experiment in 2012 is presented. The fiducial cross sections for $ZZ\to\ell^{-}\ell^{+}\ell^{\prime -}\ell^{\prime +}$ and $ZZ\to \ell^{-}\ell^{+}\nu\bar{\nu}$ are measured in selected phase-space regions. The total cross section for $ZZ$ events produced with both $Z$ bosons in the mass range 66 to 116 GeV is measured from the combination of the two channels to be $7.3\pm0.4\textrm{(stat)}\pm0.3\textrm{(syst)}\pm0.2\textrm{(lumi)}$ pb, which is consistent with the Standard Model prediction of $6.6^{+0.7}_{-0.6}$ pb. The differential cross sections in bins of various kinematic variables are presented. The differential event yield as a function of the transverse momentum of the leading $Z$ boson is used to set limits on anomalous neutral triple gauge boson couplings in $ZZ$ production.
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