5,219 research outputs found

    Enhanced nasopharyngeal infection and shedding associated with an epidemic lineage of emm3 group A Streptococcus

    Get PDF
    Background: A group A Streptococcus (GAS) lineage of genotype emm3, sequence type 15 (ST15) was associated with a six month upsurge in invasive GAS disease in the UK. The epidemic lineage (Lineage C) had lost two typical emm3 prophages, Φ315.1 and Φ315.2 associated with the superantigen ssa, but gained a different prophage (ΦUK-M3.1) associated with a different superantigen, speC and a DNAse spd1. Methods and Results: The presence of speC and spd1 in Lineage C ST15 strains enhanced both in vitro mitogenic and DNAse activities over non-Lineage C ST15 strains. Invasive disease models in Galleria mellonella and SPEC-sensitive transgenic mice, revealed no difference in overall invasiveness of Lineage C ST15 strains compared to non-Lineage C ST15 strains, consistent with clinical and epidemiological analysis. Lineage C strains did however markedly prolong murine nasal infection with enhanced nasal and airborne shedding compared to non-Lineage C strains. Deletion of speC or spd1 in two Lineage C strains identified a possible role for spd1 in airborne shedding from the murine nasopharynx. Conclusions: Nasopharyngeal infection and shedding of Lineage C strains was enhanced compared to nonLineage C strains and this was, in part, mediated by the gain of the DNase spd1 through prophage acquisition

    Building professional discourse in emerging markets: Language, context and the challenge of sensemaking

    Get PDF
    Using ethnographic evidence from the former Soviet republics, this article examines a relatively new and mainly unobserved in the International Business (IB) literature phenomenon of communication disengagement that manifests itself in many emerging markets. We link it to the deficiencies of the local professional business discourse rooted in language limitations reflecting lack of experience with the market economy. This hampers cognitive coherence between foreign and local business entities, adding to the liability of foreignness as certain instances of professional experience fail to find adequate linguistic expression, and complicates cross-cultural adjustments causing multi-national companies (MNCs) financial losses. We contribute to the IB literature by examining cross-border semantic sensemaking through a retrospectively constructed observational study. We argue that a relative inadequacy of the national professional idiom is likely to remain a feature of business environment in post-communist economies for some time and therefore should be factored into business strategies of MNCs. Consequently, we recommend including discursive hazards in the risk evaluation of international projects

    Providers' assessment of a novel interactive health information technology in a pediatric intensive care unit

    Get PDF
    Objective: To explore perceptions of critical care providers about a novel collaborative inpatient health information technology (HIT) in a pediatric intensive care unit (PICU) setting. Methods: This cross-sectional, concurrent mixed methods study was conducted in the PICU of a large midwestern children's hospital. The technology, the Large Customizable Interactive Monitor (LCIM), is a flat panel touch screen monitor that displays validated patient information from the electronic health record. It does not require a password to login and is available in each patient's room for viewing and interactive use by physicians, nurses, and families. Quantitative data were collected via self-administered, standardized surveys, and qualitative data via in-person, semistructured interviews between January and April 2015. Data were analyzed using descriptive statistics and inductive thematic analysis. Results: The qualitative analysis showed positive impacts of the LCIM on providers' workflow, team interactions, and interactions with families. Providers reported concerns regarding perceived patient information overload and associated anxiety and burden for families. Sixty percent of providers thought that LCIM was useful for their jobs at different levels, and almost 70% of providers reported that LCIM improved information sharing and communication with families. The average overall satisfaction score was 3.4 on a 0 to 6 scale, between "a moderate amount" and "pretty much." Discussion and Conclusion: This study provides new insight into collaborative HIT in the inpatient pediatric setting and demonstrates that using such technology has the potential to improve providers' experiences with families and just-in-time access to EHR information in a format more easily shared with families

    Donor characteristics and the allocation of aid to climate mitigation finance

    Get PDF
    We make use of a panel dataset of 22 donor countries from 1998 to 2009 to examine the links between donor characteristics and the share of overseas development assistance allocated to climate mitigation finance. We find that donors with a larger green domestic budget tend to allocate a smaller portion of overseas aid to mitigation finance (possibly as a result of a competing interest between spending on domestic environmental projects and international climate projects). The opposite holds for donor countries with better institutions (governance) that have ratified the Kyoto Protocol. We also find important discrepancies when comparing the effects of donor characteristics on committed versus disbursed mitigation finance (as a share of aid). For the latter, only commitment to the Kyoto Protocol appears to be of high statistical significance

    Magnetic phase diagram and transport properties of FeGe_2

    Full text link
    We have used resistivity measurements to study the magnetic phase diagram of the itinerant antiferromagnet FeGe_2 in the temperature range from 0.3->300 K in magnetic fields up to 16 T. In contrast to theoretical predictions, the incommensurate spin density wave phase is found to be stable at least up to 16 T, with an estimated critical field \mu _0H_c of ~ 30 T. We have also studied the low temperature magnetoresistance in the [100], [110], and [001] directions. The transverse magnetoresistance is well described by a power law for magnetic fields above 1 T with no saturation observed at high fields. We discuss our results in terms of the magnetic structure and the calculated electronic bandstructure of FeGe_2. We have also observed, for the first time in this compound, Shubnikov-de Haas oscillations in the transverse magnetoresistance with a frequency of 190 +- 10 T for a magnetic field along [001].Comment: 13 pages, RevTeX, 7 postscript figures, to appear in Journal of Physics: Condensed Matte

    A General Organocatalytic System for Enantioselective Radical Conjugate Additions to Enals

    Get PDF
    Herein, we report a general iminium ion-based catalytic method for the enantioselective conjugate addition of carbon-centered radicals to aliphatic and aromatic enals. The process uses an organic photoredox catalyst, which absorbs blue light to generate radicals from stable precursors, in combination with a chiral amine catalyst, which secures a consistently high level of stereoselectivity. The generality of this catalytic platform is demonstrated by the stereoselective interception of a wide variety of radicals, including non-stabilized primary ones which are generally difficult to engage in asymmetric processes. The system also served to develop organocatalytic cascade reactions that combine an iminium-ion-based radical trap with an enamine-mediated step, affording stereochemically dense chiral products in one-step

    A comparative study of different integrate-and-fire neurons: spontaneous activity, dynamical response, and stimulus-induced correlation

    Full text link
    Stochastic integrate-and-fire (IF) neuron models have found widespread applications in computational neuroscience. Here we present results on the white-noise-driven perfect, leaky, and quadratic IF models, focusing on the spectral statistics (power spectra, cross spectra, and coherence functions) in different dynamical regimes (noise-induced and tonic firing regimes with low or moderate noise). We make the models comparable by tuning parameters such that the mean value and the coefficient of variation of the interspike interval match for all of them. We find that, under these conditions, the power spectrum under white-noise stimulation is often very similar while the response characteristics, described by the cross spectrum between a fraction of the input noise and the output spike train, can differ drastically. We also investigate how the spike trains of two neurons of the same kind (e.g. two leaky IF neurons) correlate if they share a common noise input. We show that, depending on the dynamical regime, either two quadratic IF models or two leaky IFs are more strongly correlated. Our results suggest that, when choosing among simple IF models for network simulations, the details of the model have a strong effect on correlation and regularity of the output.Comment: 12 page

    Sampling Effects on Gene Expression Data from a Human Tumour Xenograft

    Get PDF
    Human tumour tissue transplanted to and passed through immunodeficient mice as xenografts make powerful  model systems to study tumour biology, in particular to investigate the dynamics of treatment responses,  e.g. to chemotherapeutic agents. Before embarking on large-scale gene expression analysis of chemotherapy  response in human sarcoma xenografts, we investigated the reproducibility of expression  patterns derived from such samples. We compared expression profiles from tumours from the same or different  mice and of various sizes, as well as central and peripheral parts of the same tumours. Twenty-three  microarray hybridisations were performed on cDNA arrays representing 13000 genes, using direct labelling  of target cDNAs. An ANOVA-based linear mixed-effects model was constructed, and variances of  experimental and biological factors contributing to variability were estimated. With our labelling procedure  used, the effect of switching the dyes was pronounced compared to all other factors. We detected a small  variation in gene expression between two tumours in the same mouse as well as between tumours from different  mice. Furthermore, central or peripheral position in the tumour had only moderate influence on the  variability of the expression profiles. The biological variability was comparable to experimental variability  caused by labelling, confirming the importance of both biological and technical replicates. We further  analysed the data by pair-wise Fisher’s linear discriminant method and identified genes that were significantly  differentially expressed between samples taken from peripheral or central parts of the tumours.  Finally, we evaluated the result of pooling biological samples to estimate the recommended number of  arrays and hybridisations for microarray experiments in this model.
    • …
    corecore