3,881 research outputs found

    Escherichia coli of sequence type 3835 carrying blaNDM-1, blaCTX-M-15, blaCMY-42 and blaSHV-12

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    New Delhi metallo-β-lactamase (NDM) represents a serious challenge for treatment and public health. A carbapenem-resistant Escherichia coli clinical strain WCHEC13-8 was subjected to antimicrobial susceptibility tests, whole genome sequencing and conjugation experiments. It was resistant to imipenem (MIC, >256 μg/ml) and meropenem (MIC, 128 μg/ml) and belonged to ST3835. blaNDM-1 was the only carbapenemase gene detected. Strain WCHEC13-8 also had a plasmid-borne AmpC gene (blaCMY-42) and two extended-spectrum β-lactamase genes (blaCTX-M-15 and blaSHV-12). blaNDM-1 and blaSHV-12 were carried by a 54-kb IncX3 self-transmissible plasmid, which is identical to plasmid pNDM-HF727 from Enterobacter cloacae. blaCMY-42 was carried by a 64-kb IncI1 plasmid and blaCTX-M-15 was located on a 141-kb plasmid with multiple F replicons (replicon type: F36:A4:B1). blaCMY-42 was in a complicated context and the mobilisation of blaCMY-42 was due to the transposition of IS Ecp1 by misidentifying its right-end boundary. Genetic context of blaNDM-1 in strain WCHEC13-8 was closely related to those on IncX3 plasmids in various Enterobacteriaceae species in China. In conclusion, a multidrug-resistant ST3835 E. coli clinical strain carrying blaNDM-1, blaCTX-M-15, blaCMY-42 and blaSHV-12 was identified. IncX3 plasmids may be making a significant contribution to the dissemination of blaNDM among Enterobacteriaceae in China

    Preparing Teacher Candidates to Address Academic Language for the edTPA: A Collaborative Teacher Educator’s Self Study

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    One of the more challenging skills that preservice teachers will need to master in order to pass the edTPA–the new performance-based assessment that measures teacher candidates’ readiness to teach–is academic language. Academic language consists of several components- vocabulary, functions, discourse, and syntax, and in order to successfully complete the edTPA tasks, teacher candidates will need to be able to demonstrate how they will plan the opportunities (functions) for students to use language (vocabulary, syntax, and discourse) in their learning activities. The presenters–teacher educators who have piloted edTPA in clinical settings–will help participants better understand the components of academic language and will demonstrate strategies (in language arts, science, math, and social studies) that will support the effective use of academic language in their candidates’ learning activities

    Complementary Constraints on Brane Cosmology

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    The acceleration of the expansion of the universe represents one of the major challenges to our current understanding of fundamental physics. In principle, to explain this phenomenon, at least two different routes may be followed: either adjusting the energy content of the Universe -- by introducing a negative-pressure dark energy -- or modifying gravity at very large scales -- by introducing new spatial dimensions, an idea also required by unification theories. In the cosmological context, the role of such extra dimensions as the source of the dark pressure responsable for the acceleration of our Universe is translated into the so-called brane world (BW) cosmologies. Here we study complementary constraints on a particular class of BW scenarios in which the modification of gravity arises due to a gravitational \emph{leakage} into extra dimensions. To this end, we use the most recent Chandra measurements of the X-ray gas mass fraction in galaxy clusters, the WMAP determinations of the baryon density parameter, measurements of the Hubble parameter from the \emph{HST}, and the current supernova data. In agreement with other recent results, it is shown that these models provide a good description for these complementary data, although a closed scenario is always favored in the joint analysis. We emphasize that observational tests of BW scenarios constitute a natural verification of the role of possible extra dimensions in both fundamental physics and cosmology.Comment: 6 Pages, 4 Figures, LaTe

    The Calculation of Vacuum Properties from the Global Color Symmetry Model

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    A modified method for calculating the non-perturbative quark vacuum condensates from the global color symmetry model is derived. Within this approach it is shown that the vacuum condensates are free of ultraviolet divergence which is different from previous studies. As a special, the two-quark condensate and the mixed quark-gluon condensate are calculated. A comparision with the results of the other nonperturbative QCD approaches is given.Comment: 17 page

    [Report of] Specialist Committee V.4: ocean, wind and wave energy utilization

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    The committee's mandate was :Concern for structural design of ocean energy utilization devices, such as offshore wind turbines, support structures and fixed or floating wave and tidal energy converters. Attention shall be given to the interaction between the load and the structural response and shall include due consideration of the stochastic nature of the waves, current and wind

    The contribution of ultracompact dark matter minihalos to the isotropic radio background

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    The ultracompact minihalos could be formed during the earlier epoch of the universe. The dark matter annihilation within them is very strong due to the steep density profile, ρr2.25\rho \sim r^{-2.25}. The high energy electrons and positrons from the dark matter annihilation can inverse Compton scatter (ICS) with the background photons, such as CMB photons, to acquire higher energy. On the other hand, the synchrotron radiation can also be produced when they meet the magnetic field. In this paper, we study the signals from the UCMHs due to the dark matter annihilation for the radio, X-ray and γ\gamma-ray band. We found that for the radio emission the UCMHs can provide one kind of source for the radio excess observed by ARCADE 2. But the X-ray signals due to the ICS effect or the γ\gamma-ray signals mainly due to the prompt emission from dark matter would exceed the present observations, such as Fermi, COMPTEL and CHANDRA. We found that the strongest limits on the fraction of UCMHs come from the X-ray observations and the constraints from the radio data are the weakest.Comment: 6 pages, 8 figures, Comments Welcome! Some Refs. are added, some presentation have been corrected. The conclusions remain unchanged. One important reference has been corrected. Some presentations are changed and added according to the referee's comments. Accepted for publication in PR

    Ecology and hydrology of early rice farming: geoarchaeological and palaeo-ecological evidence from the Late Holocene paddy field site at Maoshan, the Lower Yangtze

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    The well-preserved Maoshan paddy fields (4700–4300 bp) were built on an intermediate landscape between the foothills and alluvial plain of the Lower Yangtze River. Despite several interdisciplinary research, there has been a lack of detailed environmental and ecological data to contextualise the reconstructed rice farming practices within a wider paleo-environmental background. Our research provides key information on the chronology, vegetation, and long-term hydrological fluctuations at and surrounding the paddy fields. Our 14C and OSL dates show that the initial occupation began at around 5740 ± 140 cal. bp, and the paddy fields were built at around 4675 ± 145 cal. bp and were in use continuously until around 4000 cal. bp. Our pollen, diatom and phytolith data shows that whilst the vegetation in the field was sensitive to changes caused by water management and rice farming, the ecological system surrounding the fields was relatively stable. We suggest that this high frequency of in-field vegetation changes was closely related to intensifying water management for rice farming. This thesis is supported by our geophysical and geochemical analyses of bulk sediments, which shows that the steady build-up of the alluvial sequence was punctuated by several short-term episodes of high-energy surface runoff, including strong flushing in of sandy sediments into the fields perhaps through irrigation activities. Our paleo-ecological and geoarchaeological investigation at Maoshan permits an overview of the development of rice farming and intensifying water management practices in a wider environmental context and offers significant insights to the ongoing debate on the wet-dry dichotomy of early rice farming

    A Tracker Solution for a Holographic Dark Energy Model

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    We investigate a kind of holographic dark energy model with the future event horizon the IR cutoff and the equation of state -1. In this model, the constraint on the equation of state automatically specifies an interaction between matter and dark energy. With this interaction included, an accelerating expansion is obtained as well as the transition from deceleration to acceleration. It is found that there exists a stable tracker solution for the numerical parameter d>1d>1, and dd smaller than one will not lead to a physical solution. This model provides another possible phenomenological framework to alleviate the cosmological coincidence problem in the context of holographic dark energy. Some properties of the evolution which are relevant to cosmological parameters are also discussed.Comment: 10 pages, 3 figures; accepted for publication in Int.J.Mod.Phys.
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