43 research outputs found

    A genomic portrait of the emergence, evolution, and global spread of a methicillin-resistant staphylococcus aureus pandemic

    Get PDF
    The widespread use of antibiotics in association with high-density clinical care has driven the emergence of drug-resistant bacteria that are adapted to thrive in hospitalized patients. Of particular concern are globally disseminated methicillin-resistant Staphylococcus aureus (MRSA) clones that cause outbreaks and epidemics associated with health care. The most rapidly spreading and tenacious health-care-associated clone in Europe currently is EMRSA-15, which was first detected in the UK in the early 1990s and subsequently spread throughout Europe and beyond. Using phylogenomic methods to analyze the genome sequences for 193 S. aureus isolates, we were able to show that the current pandemic population of EMRSA-15 descends from a health-care-associated MRSA epidemic that spread throughout England in the 1980s, which had itself previously emerged from a primarily community-associated methicillin-sensitive population. The emergence of fluoroquinolone resistance in this EMRSA-15 subclone in the English Midlands during the mid-1980s appears to have played a key role in triggering pandemic spread, and occurred shortly after the first clinical trials of this drug. Genome-based coalescence analysis estimated that the population of this subclone over the last 20 yr has grown four times faster than its progenitor. Using comparative genomic analysis we identified the molecular genetic basis of 99.8% of the antimicrobial resistance phenotypes of the isolates, highlighting the potential of pathogen genome sequencing as a diagnostic tool. We document the genetic changes associated with adaptation to the hospital environment and with increasing drug resistance over time, and how MRSA evolution likely has been influenced by country-specific drug use regimens

    Neutrino oscillation physics at an upgraded CNGS with large next generation liquid Argon TPC detectors

    Get PDF
    The determination of the missing Ue3U_{e3} element (magnitude and phase) of the PMNS neutrino mixing matrix is possible via the detection of \numu\to\nue oscillations at a baseline LL and energy EE given by the atmospheric observations, corresponding to a mass squared difference E/LΔm22.5×103eV2E/L \sim \Delta m^2\simeq 2.5\times 10^{-3} eV^2. While the current optimization of the CNGS beam provides limited sensitivity to this reaction, we discuss in this document the physics potential of an intensity upgraded and energy re-optimized CNGS neutrino beam coupled to an off-axis detector. We show that improvements in sensitivity to θ13\theta_{13} compared to that of T2K and NoVA are possible with a next generation large liquid Argon TPC detector located at an off-axis position (position rather distant from LNGS, possibly at shallow depth). We also address the possibility to discover CP-violation and disentangle the mass hierarchy via matter effects. The considered intensity enhancement of the CERN SPS has strong synergies with the upgrade/replacement of the elements of its injector chain (Linac, PSB, PS) and the refurbishing of its own elements, envisioned for an optimal and/or upgraded LHC luminosity programme.Comment: 37 pages, 20 figure

    Reproductive biology of Cattleya eldorado, a species of Orchidaceae from the Amazonian white sand campinas

    Get PDF
    The orchid plants are highly prized for their lush exotic flowers. It is the largest plant family with more than 24000 species, which indicates a high diversity of forms and adaptations to different environments, including the capacity to attract, deceive and manipulate visitors involved in cross-pollination. Cattleya eldorado occurs in areas of white sand campinas, a typical vegetation type of the Amazon region, which is under strong anthropogenic pressure. This work's main objectives to know the biological processes of C. eldorado providing subsidies to maintain and manage it in its natural habitat. This study was conducted from 2000 to 2006 in the Campina Biological Reserve, during its flowering period. C. eldorado is an epiphytic orchid species that has the melittophyly syndrome and is adapted to its pollinator, the bee Eulaema mocsaryi recognizing their flowers by smell and by visual stimuli, through their color and reflection of ultraviolet light. C. eldorado is self-compatible, even if it requires a pollinating agent for the transfer of the pollinarium until its deposition in the stigmatic cavity of the flower.", 'enAs Orchidaceae são muito apreciadas por suas flores exóticas e exuberantes. É a maior família de plantas apresentando mais de 24000 espécies, o que denota uma alta diversidade de formas e adaptações a diferentes ambientes, como também para atração, engano e manipulação de visitantes na realização da polinização cruzada. Cattleya eldorado ocorre em áreas de campinas, que são formações vegetais típicas da região amazônica, que se encontram sob forte ação antrópica. Este trabalho tem como um de seus principais objetivos conhecer parte dos processos biológicos de C. eldorado fornecendo subsídios para conservá-la e manejá-la em seu habitat natural. Este estudo foi desenvolvido na Reserva Biológica de Campina, de 2000 a 2006, durante a sua floração. C. eldorado é uma espécie epifítica que apresenta a síndrome de melitofilia, estando adaptada ao seu polinizador, a abelha Eulaema mocsaryi, que reconhece suas flores pelo odor e pelo estímulo visual através de sua coloração e reflexão de luz ultravioleta. C. eldorado é uma espécie autocompatível, embora necessite de um agente polinizador para a transferência do polinário até sua deposição na cavidade estigmática da flor

    Pollination of Pagamea duckei Standl. (Rubiaceae): a functionally dioecious species

    Get PDF
    The floral biology, pollination and breeding system of Pagamea duckei Standl. (Rubiaceae) were studied at the Reserva Biológica da Campina, Manaus, Amazonas, Brazil. Floral morphology suggested that P. duckei is a distylous species. However, crossing experiments revealed that it is functionally dioecious. The flowers are actinomorphic, yellowish, produce nectar and a sweet odor, which is more intense in the morning. Anthesis started in the morning between 5.00 and 6.00 AM and extended until dusk, when the corolla tube abscissed. The flowers were visited mostly by bees of the genus Melipona. Pagamea duckei is not agamospermic and thus needs pollen vectors for effective pollination. The results of this study strengthen the idea that, in Pagamea, species with distylous flower morphology are actually functionally dioecious

    Towards a general explanation for the survival of the private asylum

    No full text
    Taken together, the ascendancy of community care and the dominant role of the state as a funder of services have meant that private sector residential care for people with mental health problems is now a rarity in most countries. Yet private asylums have persisted in some places. The authors propose an analytical framework for understanding such 'institutional survivals'. This frame-work problematises the public-private and community-asylum boundaries that have hitherto been taken for granted. The framework is applied to case studies in Canada and New Zealand. Survival of these institutions is found to be centrally associated with accommodations with legislative environments, proactive innovation, and the availability of markets

    Hybrid Inflatable/Rigidizable Wings for High Altitude Applications

    No full text
    corecore