1,895 research outputs found

    Chromosomal Integration of the Klebsiella pneumoniae carbapenemase gene (blaKPC) in Klebsiella Species: Elusive but not Rare

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    Carbapenemase genes in Enterobacteriaceae are mostly described as being plasmid-associated. However, the genetic context of carbapenemase genes is not always confirmed in epidemiological surveys, and the frequency of their chromosomal integration is therefore unknown. A previously sequenced collection of blaKPC-positive Enterobacteriaceae from a single US institution (2007 2012; n=281 isolates, 182 patients) was analyzed to identify chromosomal insertions of Tn4401, the transposon most frequently harboring blaKPC. Using a combination of short- and long-read sequencing, we confirmed five independent chromosomal integration events from 6/182 (3%) patients, corresponding to 15/281 (5%) isolates. Three patients had isolates identified by peri-rectal screening and three had infections which were all successfully treated. When a single copy of blaKPC was in the chromosome one or both of the phenotypic carbapenemase tests were negative. All chromosomally integrated blaKPC were from Klebsiella spp., predominantly K. pneumoniae clonal group (CG)258, even though these represented only a small proportion of the isolates. Integration occurred via IS15-ΔI mediated transposition of a larger, composite region encompassing Tn4401 at one locus of chromosomal integration, seen in the same strain (K. pneumoniae ST340) in two patients. In summary, we identified five independent chromosomal integrations of blaKPC in a large outbreak, demonstrating that this is not a rare event. blaKPC was more frequently integrated into the chromosome of epidemic CG258 K. pneumoniae lineages (ST11, ST258, ST340), and was more difficult to detect by routine phenotypic methods in this context. The presence of chromosomally integrated blaKPC within successful, globally disseminated K. pneumoniae strains is therefore likely underestimated

    Unconventional motional narrowing in the optical spectrum of a semiconductor quantum dot

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    Motional narrowing refers to the striking phenomenon where the resonance line of a system coupled to a reservoir becomes narrower when increasing the reservoir fluctuation. A textbook example is found in nuclear magnetic resonance, where the fluctuating local magnetic fields created by randomly oriented nuclear spins are averaged when the motion of the nuclei is thermally activated. The existence of a motional narrowing effect in the optical response of semiconductor quantum dots remains so far unexplored. This effect may be important in this instance since the decoherence dynamics is a central issue for the implementation of quantum information processing based on quantum dots. Here we report on the experimental evidence of motional narrowing in the optical spectrum of a semiconductor quantum dot broadened by the spectral diffusion phenomenon. Surprisingly, motional narrowing is achieved when decreasing incident power or temperature, in contrast with the standard phenomenology observed for nuclear magnetic resonance

    Tactile Interactions with a Humanoid Robot : Novel Play Scenario Implementations with Children with Autism

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    Acknowledgments: This work has been partially supported by the European Commission under contract number FP7-231500-ROBOSKIN. Open Access: This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.The work presented in this paper was part of our investigation in the ROBOSKIN project. The project has developed new robot capabilities based on the tactile feedback provided by novel robotic skin, with the aim to provide cognitive mechanisms to improve human-robot interaction capabilities. This article presents two novel tactile play scenarios developed for robot-assisted play for children with autism. The play scenarios were developed against specific educational and therapeutic objectives that were discussed with teachers and therapists. These objectives were classified with reference to the ICF-CY, the International Classification of Functioning – version for Children and Youth. The article presents a detailed description of the play scenarios, and case study examples of their implementation in HRI studies with children with autism and the humanoid robot KASPAR.Peer reviewedFinal Published versio

    Pulling together: keeping track of pedagogy, design and evaluation through the development of scenarios: a case study

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    This case study describes the multipurpose use of scenarios in a large multinational research project (MOBIlearn) whose aims are to design and develop a pedagogically sound mobile learning environment. Maintaining effective communication and design focus in large consortia is a wellknown problem (see Carroll, 2000), and we describe the role of scenarios in addressing this. Scenarios were initially used to simply envision the future system in order to inform design, but as the project progressed, the role of the scenarios grew to encompass (i) relating system design and implementation to pedagogy by providing a common frame of reference for developers and pedagogic experts; (ii) through a process of refinement, defining the evaluation strategy for the user trials; and (iii) allowing us to keep the user at the heart of the development project. Thus, scenarios helped to resolve the difficulty identified by Taylor (2004) of how to bring together the relatively high level issues of pedagogic evaluation and the more technical user-centred system evaluation. The development of a first-aid training scenario is used as an illustrative example

    Outcomes of patients hospitalized for acute decompensated heart failure: does nesiritide make a difference?

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    <p>Abstract</p> <p>Background</p> <p>Nesiritide is indicated in the treatment of acute decompensated heart failure. However, a recent meta-analysis reported that nesiritide may be associated with an increased risk of death. Our goal was to evaluate the impact of nesiritide treatment on four outcomes among adults hospitalized for congestive heart failure (CHF) during a three-year period.</p> <p>Methods</p> <p>CHF patients discharged between 1/1/2002 and 12/31/2004 from the Adventist Health System, a national, not-for-profit hospital system, were identified. 25,330 records were included in this retrospective study. Nesiritide odds ratios (OR) were adjusted for various factors including nine medications and/or an APR-DRG severity score.</p> <p>Results</p> <p>Initially, treatment with nesiritide was found to be associated with a 59% higher odds of hospital mortality (Unadjusted OR = 1.59, 95% confidence interval [CI]: 1.31–1.93). Adjusting for race, low economic status, APR-DRG severity of illness score, and the receipt of nine medications yielded a nonsignificant nesiritide OR of 1.07 for hospital death (95% CI: 0.85–1.35). Nesiritide was positively associated with the odds of prolonged length of stay (all adjusted ORs = 1.66) and elevated pharmacy cost (all adjusted ORs > 5).</p> <p>Conclusion</p> <p>In this observational study, nesiritide therapy was associated with increased length of stay and pharmacy cost, but not hospital mortality. Randomized trials are urgently needed to better define the efficacy, if any, of nesiritide in the treatment of decompensated heart failure.</p

    Normal levels of p27Xic1 are necessary for somite segmentation and determining pronephric organ size

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    The Xenopus laevis cyclin dependent kinase inhibitor p27Xic1 has been shown to be involved in exit from the cell cycle and differentiation of cells into a quiescent state in the nervous system, muscle tissue, heart and retina. We show that p27Xic1 is expressed in the developing kidney in the nephrostomal regions. Using over-expression and morpholino oligonucleotide (MO) knock-down approaches we show normal levels of p27Xic1 regulate pronephros organ size by regulating cell cycle exit. Knock-down of p27Xic1 expression using a MO prevented myogenesis, as previously reported; an effect that subsequently inhibits pronephrogenesis. Furthermore, we show that normal levels of p27Xic1 are required for somite segmentation also through its cell cycle control function. Finally, we provide evidence to suggest correct paraxial mesoderm segmentation is not necessary for pronephric induction in the intermediate mesoderm. These results indicate novel developmental roles for p27Xic1, and reveal its differentiation function is not universally utilised in all developing tissues

    Dietary soy and meat proteins induce distinct physiological and gene expression changes in rats

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    This study reports on a comprehensive comparison of the effects of soy and meat proteins given at the recommended level on physiological markers of metabolic syndrome and the hepatic transcriptome. Male rats were fed semi-synthetic diets for 1 wk that differed only regarding protein source, with casein serving as reference. Body weight gain and adipose tissue mass were significantly reduced by soy but not meat proteins. The insulin resistance index was improved by soy, and to a lesser extent by meat proteins. Liver triacylglycerol contents were reduced by both protein sources, which coincided with increased plasma triacylglycerol concentrations. Both soy and meat proteins changed plasma amino acid patterns. The expression of 1571 and 1369 genes were altered by soy and meat proteins respectively. Functional classification revealed that lipid, energy and amino acid metabolic pathways, as well as insulin signaling pathways were regulated differently by soy and meat proteins. Several transcriptional regulators, including NFE2L2, ATF4, Srebf1 and Rictor were identified as potential key upstream regulators. These results suggest that soy and meat proteins induce distinct physiological and gene expression responses in rats and provide novel evidence and suggestions for the health effects of different protein sources in human diets

    The combined effect of two mutations that alter serially homologous color pattern elements on the fore and hindwings of a butterfly

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    <p>Abstract</p> <p>Background</p> <p>The ability for serially homologous structures to acquire a separate identity has been primarily investigated for structures dependent on Hox gene input but is still incompletely understood in other systems. The fore and hindwings of butterflies are serially homologous structures as are the serially homologous eyespots that can decorate each of these wings. Eyespots can vary in number between fore and hindwings of the same individual and mutations of large effect can control the total number of eyespots that each of the wings displays. Here we investigate the genetics of a new spontaneous color pattern mutation, <it>Missing</it>, that alters eyespot number in the nymphalid butterfly, <it>Bicyclus anynana</it>. We further test the interaction of <it>Missing </it>with a previously described mutation, <it>Spotty</it>, describe the developmental stage affected by <it>Missing</it>, and test whether <it>Missing </it>is a mutant variant of the gene <it>Distal-less </it>via a linkage association study.</p> <p>Results</p> <p><it>Missing </it>removes or greatly reduces the size of two of the hindwing eyespots from the row of seven eyespots, with no detectable effect on the rest of the wing pattern. Offspring carrying a single <it>Missing </it>allele display intermediate sized eyespots at these positions. <it>Spotty </it>has the opposite effect of <it>Missing</it>, i.e., it introduces two extra eyespots in homologous wing positions to those affected by <it>Missing</it>, but on the forewing. When <it>Missing </it>is combined with <it>Spotty </it>the size of the two forewing eyespots decreases but the size of the hindwing spots stays the same, suggesting that these two mutations have a combined effect on the forewing such that <it>Missing </it>reduces eyespot size when in the presence of a <it>Spotty </it>mutant allele, but that <it>Spotty </it>has no effect on the hindwing. <it>Missing </it>prevents the complete differentiation of two of the eyespot foci on the hindwing. We found no evidence for any linkage between the <it>Distal-less </it>and <it>Missing </it>genes.</p> <p>Conclusion</p> <p>The spontaneous mutation <it>Missing </it>controls the differentiation of the signaling centers of a subset of the serial homologous eyespots present on both the fore and the hindwing in a dose-dependent fashion. The effect of <it>Missing </it>on the forewing, however, is only observed when the mutation <it>Spotty </it>introduces additional eyespots on this wing. <it>Spotty</it>, on the other hand, controls the differentiation of eyespot centers only on the forewing. <it>Spotty</it>, unlike <it>Missing</it>, may be under Ubx gene regulation, since it affects a subset of eyespots on only one of the serially homologous wings.</p

    Critical research gaps and translational priorities for the successful prevention and treatment of breast cancer

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    INTRODUCTION Breast cancer remains a significant scientific, clinical and societal challenge. This gap analysis has reviewed and critically assessed enduring issues and new challenges emerging from recent research, and proposes strategies for translating solutions into practice. METHODS More than 100 internationally recognised specialist breast cancer scientists, clinicians and healthcare professionals collaborated to address nine thematic areas: genetics, epigenetics and epidemiology; molecular pathology and cell biology; hormonal influences and endocrine therapy; imaging, detection and screening; current/novel therapies and biomarkers; drug resistance; metastasis, angiogenesis, circulating tumour cells, cancer 'stem' cells; risk and prevention; living with and managing breast cancer and its treatment. The groups developed summary papers through an iterative process which, following further appraisal from experts and patients, were melded into this summary account. RESULTS The 10 major gaps identified were: (1) understanding the functions and contextual interactions of genetic and epigenetic changes in normal breast development and during malignant transformation; (2) how to implement sustainable lifestyle changes (diet, exercise and weight) and chemopreventive strategies; (3) the need for tailored screening approaches including clinically actionable tests; (4) enhancing knowledge of molecular drivers behind breast cancer subtypes, progression and metastasis; (5) understanding the molecular mechanisms of tumour heterogeneity, dormancy, de novo or acquired resistance and how to target key nodes in these dynamic processes; (6) developing validated markers for chemosensitivity and radiosensitivity; (7) understanding the optimal duration, sequencing and rational combinations of treatment for improved personalised therapy; (8) validating multimodality imaging biomarkers for minimally invasive diagnosis and monitoring of responses in primary and metastatic disease; (9) developing interventions and support to improve the survivorship experience; (10) a continuing need for clinical material for translational research derived from normal breast, blood, primary, relapsed, metastatic and drug-resistant cancers with expert bioinformatics support to maximise its utility. The proposed infrastructural enablers include enhanced resources to support clinically relevant in vitro and in vivo tumour models; improved access to appropriate, fully annotated clinical samples; extended biomarker discovery, validation and standardisation; and facilitated cross-discipline working. CONCLUSIONS With resources to conduct further high-quality targeted research focusing on the gaps identified, increased knowledge translating into improved clinical care should be achievable within five years
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