1,249 research outputs found

    Bridging reproductive and microbial ecology: a case study in arbuscular mycorrhizal fungi

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    Offspring size is a key trait for understanding the reproductive ecology of species, yet studies addressing the ecological meaning of offspring size have so far been limited to macro-organisms. We consider this a missed opportunity in microbial ecology and provide what we believe is the first formal study of offspring-size variation in microbes using reproductive models developed for macro-organisms. We mapped the entire distribution of fungal spore size in the arbuscular mycorrhizal (AM) fungi (subphylum Glomeromycotina) and tested allometric expectations of this trait to offspring (spore) output and body size. Our results reveal a potential paradox in the reproductive ecology of AM fungi: while large spore-size variation is maintained through evolutionary time (independent of body size), increases in spore size trade off with spore output. That is, parental mycelia of large-spored species produce fewer spores and thus may have a fitness disadvantage compared to small-spored species. The persistence of the large-spore strategy, despite this apparent fitness disadvantage, suggests the existence of advantages to large-spored species that could manifest later in fungal life history. Thus, we consider that solving this paradox opens the door to fruitful future research establishing the relationship between offspring size and other AM life history traits

    Aislamiento y desarrollo micelial de cepas silvestres de Agaricus bisporus (JE Lange) Imbach en la Región del Cusco

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    Se realizó el aislamiento de cepas a partir de especímenes silvestres de Agaricus bisporus colectadas en 5 localidades de la región del Cusco pertenecientes a las provincias de Anta yCusco, obteniendo 6 cepas silvestres codificadas como: Ag01, Ag02, Ag03, Ag04, Ag05 y Ag06, las cuales se encuentran almacenadas en el CIPHAM y banco de cepas de la Sociedad deMicología Aplicada del Cusco - IIFAA. Posteriormente se realizó la caracterización micelial, obteniendo como moda las siguientes características: micelio de color blanco en el anverso,crema rosácea en el reverso, de forma irregular, plana, de margen filiforme lobulada, textura aterciopelada, densidad media, con pocas hifas aéreas y con regular abundancia de rizomorfos. Además, una característica sobresaliente en algunas cepas fue la presencia de conglomerados miceliales con producción de exudados de color café. Por otro lado, se realizó la evaluación comparativa de la velocidad de crecimiento de las cepas en 6 medios de cultivo: papa dextrosa agar (PDA), PDA + extracto de levadura (PDAy), PDA + peptona (PDAp), extracto de malta agar (EMA), EMA + extracto de levadura (EMAy) y EMA + peptona (EMAp). Los mejores resultados se presentaron en el medio de cultivo EMA con la cepa Ag03 (3.07 mm/día) originaria del C.P. Compone de la provincia de Anta, Región del Cusco

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+μ+νW^+ \rightarrow \mu^+\nu and WμνW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

    Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

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    A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

    Influence of soil on the efficacy of entomopathogenic nematodes in reducing Diabrotica virgifera virgifera in maize

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    The use of entomopathogenic nematodes is one potential non-chemical approach to control the larvae of the invasive western corn rootworm (Diabrotica virgifera virgifera LeConte, Coleoptera: Chrysomelidae) in Europe. This study investigated the efficacy of Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae), Heterorhabditis megidis Poinar, Jackson and Klein (Rh., Heterorhabditidae) and Steinernema feltiae Filipjev (Rh., Steinernematidae) in reducing D. v. virgifera as a function of soil characteristics. A field experiment was repeated four times in southern Hungary using artificially infested maize plants potted into three different soils. Sleeve gauze cages were used to assess the number of emerging adult D. v. virgifera from the treatments and untreated controls. Results indicate that nematodes have the potential to reduce D. v. virgifera larvae in most soils; however, their efficacy can be higher in maize fields with heavy clay or silty clay soils than in sandy soils, which is in contrast to the common assumption that nematodes perform better in sandy soils than in heavy soils

    Hilando generaciones y moda

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    El proyecto Hilando Generaciones y Moda tiene como objetivo principal fomentar el intercambio y la convivencia intergeneracional entre jóvenes del ITESO y adultos mayores que acuden al Centro Tapatío de Atención al Adulto Mayor, ubicado en Guadalajara, Jalisco. La problemática que se busca resolver con este proyecto es la falta de interacción y comunicación entre estas dos generaciones, lo que puede llevar a la desconexión y aislamiento social de los adultos mayores, así como a una falta de perspectiva y comprensión por parte de los jóvenes sobre las experiencias y desafíos que enfrentan las personas mayores. El proyecto busca romper con estas barreras mediante la realización de actividades que promuevan la convivencia y el aprendizaje mutuo entre ambas generaciones, permitiendo la integración social y emocional de los adultos mayores, así como el desarrollo de habilidades sociales y empáticas en los jóvenes. A través de la interacción y el diálogo entre ambas generaciones, se espera generar un ambiente de respeto y valoración hacia la sabiduría y experiencia de los adultos mayores, así como una comprensión más profunda de las realidades sociales y culturales que enfrentan. A lo largo del semestre hicimos distintas actividades relacionadas con moda, que fueron propuestas por nosotros mismos. Estos talleres pensados en los adultos mayores nos dejarían productos que reflejaran la identidad de cada adulto y con los que después haremos una exposición final. Nuestras primeras actividades con los adultos fueron hacer un collage y un esqueleto exquisito, en el que hablarían sobre ellos y podríamos conocerlos mejor. Después tuvimos un taller de joyería en el CETAM, donde los adultos crearon dijes personalizados. La siguiente actividad fue un taller de creación y personalización de playeras. Para esta, los adultos nos visitaron en el ITESO, donde compartimos desayuno, baile y creatividad con las pinturas para personalizar cada playera. Este semestre colaboramos con Andrés Moreno, stylist y creador de Vintage Ceremony. Andrés nos asesoró en nuestro camino para nuestra siguiente actividad: una sesión de fotos que buscó resaltar la identidad de cada adulto mayor. En esta sesión de fotos contamos con patrocinio de peinado y maquillaje. Nuestra última actividad será la exposición final, donde mostraremos los resultados de todas las actividades, como prendas hechas por los alumnos de moda (con telas diseñadas por ellos, inspiradas en los adultos).ITESO, A.C

    Global Perspectives on Task Shifting and Task Sharing in Neurosurgery.

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    BACKGROUND: Neurosurgical task shifting and task sharing (TS/S), delegating clinical care to non-neurosurgeons, is ongoing in many hospital systems in which neurosurgeons are scarce. Although TS/S can increase access to treatment, it remains highly controversial. This survey investigated perceptions of neurosurgical TS/S to elucidate whether it is a permissible temporary solution to the global workforce deficit. METHODS: The survey was distributed to a convenience sample of individuals providing neurosurgical care. A digital survey link was distributed through electronic mailing lists of continental neurosurgical societies and various collectives, conference announcements, and social media platforms (July 2018-January 2019). Data were analyzed by descriptive statistics and univariate regression of Likert Scale scores. RESULTS: Survey respondents represented 105 of 194 World Health Organization member countries (54.1%; 391 respondents, 162 from high-income countries and 229 from low- and middle-income countries [LMICs]). The most agreed on statement was that task sharing is preferred to task shifting. There was broad consensus that both task shifting and task sharing should require competency-based evaluation, standardized training endorsed by governing organizations, and maintenance of certification. When perspectives were stratified by income class, LMICs were significantly more likely to agree that task shifting is professionally disruptive to traditional training, task sharing should be a priority where human resources are scarce, and to call for additional TS/S regulation, such as certification and formal consultation with a neurosurgeon (in person or electronic/telemedicine). CONCLUSIONS: Both LMIC and high-income countries agreed that task sharing should be prioritized over task shifting and that additional recommendations and regulations could enhance care. These data invite future discussions on policy and training programs

    Search for pair production of heavy vector-like quarks decaying into high-pT W bosons and top quarks in the lepton-plus-jets final state in pp collisions at √s = 13 TeV with the ATLAS detector

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    A search is presented for the pair production of heavy vector-like B quarks, primarily targeting B quark decays into a W boson and a top quark. The search is based on 36.1 fb −1 of pp collisions at √s = 13 TeV recorded in 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. Data are analysed in the lepton-plus-jets final state, characterised by a high-transverse-momentum isolated electron or muon, large missing transverse momentum, and multiple jets, of which at least one is b -tagged. No significant deviation from the Standard Model expectation is observed. The 95% confidence level lower limit on the B mass is 1350 GeV assuming a 100% branching ratio to Wt. In the SU(2) singlet scenario, the lower mass limit is 1170 GeV. This search is also sensitive to a heavy vector-like B quark decaying into other final states (Zb and Hb ) and thus mass limits on B production are set as a function of the decay branching ratios. The 100% branching ratio limits are found to be also applicable to heavy vector-like X production, with charge +5/3, that decay into Wt

    Measurement of jet fragmentation in Pb+Pb and pp collisions at √s NN =5.02 TeV with the ATLAS detector

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    This paper presents a measurement of jet fragmentation functions in 0.49 nb −1 of Pb+Pb collisions and 25 pb −1 of pp collisions at √ sNN =5.02 TeV collected in 2015 with the ATLAS detector at the LHC. These measurements provide insight into the jet quenching process in the quark-gluon plasma created in the aftermath of ultra-relativistic collisions between two nuclei. The modifications to the jet fragmentation functions are quantified by dividing the measurements in Pb+Pb collisions by baseline measurements in pp collisions. This ratio is studied as a function of the transverse momentum of the jet, the jet rapidity, and the centrality of the collision. In both collision systems, the jet fragmentation functions are measured for jets with transverse momentum between 126 GeV and 398 GeV and with an absolute value of jet rapidity less than 2.1. An enhancement of particles carrying a small fraction of the jet momentum is observed, which increases with centrality and with increasing jet transverse momentum. Yields of particles carrying a very large fraction of the jet momentum are also observed to be enhanced. Between these two enhancements of the fragmentation functions a suppression of particles carrying an intermediate fraction of the jet momentum is observed in Pb+Pb collisions. A small dependence of the modifications on jet rapidity is observed

    Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

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