393 research outputs found
Methicillin-resistant Staphylococcus aureus isolated from various types of hospital infections in pediatrics: Panton-valentine leukocidin, staphylococcal chromosomal cassette mec SCCmec phenotypes and antibiotic resistance properties
Background: Staphylococcus aureus has long been considered as a major pathogen of hospital infections. Objectives: The present investigation was carried out to study the distribution of Staphylococcal Chromosomal Cassette mec (SCCmec) types, Panton-Valentine Leukocidin (PVL) gene and antibiotic resistance properties of Methicillin Resistant Staphylococcus aureus (MRSA) strains isolated from various types of infections found in Iranian pediatric patients. Patients and Methods: Two-hundred and fifty-five clinical specimens were collected from four major provinces of Iran. Samples were cultured and the MRSA strains were subjected to Polymerase Chain Reaction (PCR). The patterns of antibiotic resistance were determined using the disk diffusion method. Results: Seventy-four out of 255 (29.01) clinical samples were positive for MRSA. Of the 74 MRSA strains, 47 (63.51) were PVL positive. The clinical samples of respiratory tract infections (36.36), those from the Shiraz province (37.87) and samples collected during the summer season (56.48) were the most commonly infected samples. The most commonly detected antibiotic resistance genes were tetK (89.18), mecA (71.62), msrA (56.75) and tetM (54.05). Methicillin Resistant Staphylococcus aureus had the highest levels of resistance against penicillin (100), tetracycline (98.64), ampicillin (93.24) and oxacillin (93.24). The most commonly detected SCCmec types in the MRSA strains were type V (18.91) and III (17.56). Conclusions: Regular surveillance of hospital-associated infections and monitoring of the antibiotic sensitivity patterns are required to reduce the prevalence of MRSA. We recommend initial management of children affected by MRSA with imipenem, lincomycin and cephalothin prescriptions. © 2015, Ahvaz Jundishapur University of Medical Sciences
Re-vision: the last chance to make it glow
У статті розглянуто прийоми редагування текстів, писаних англійською, задля покращання професійної комунікації у глобальному контексті за допомогою цієї мови. Увагу зосереджено на універсальних аспектах англомовного редагування, релевантних як для носіїв англійської, так і для тих, для кого вона не є рідною мовою, а саме: перефразування, скорочення, переміщення, а також ланцюжки еквівалентів, колокації, структурація за допомогою заголовків. Розглянутий матеріал рясно ілюстрований відповідними прикладами.В статье рассмотрены приемы редактирования англоязычных текстов с целью повышения эффективности профессиональной коммуникации на английском языке в глобальном контексте. Особое внимание уделяется универсальным аспектам англоязычного редактирования, релевантных как для носителей английского языка, так и для тех, для кого этот язык не является родным. Рассмотрены приемы перефразирования, сокращения, перемещения, а также цепочки эквивалентов, коллокации, структурирование при помощи заголовков. Материал статьи хорошо иллюстрирован соответствующими примерами.This paper presents the editing techniques that make professional writing more effective to help people develop their ability to communicate clearly and persuasively in English in its global context. It focuses specifically on those universal writing techniques that help the writers connect with other people whose first language may or may not be English. These include: paraphrasing, reduction and deletion, relocation, equivalency chains, collocations,and headings. The material is amply illustrated with relevant examples
Anisotropic Inflation with Non-Abelian Gauge Kinetic Function
We study an anisotropic inflation model with a gauge kinetic function for a
non-abelian gauge field. We find that, in contrast to abelian models, the
anisotropy can be either a prolate or an oblate type, which could lead to a
different prediction from abelian models for the statistical anisotropy in the
power spectrum of cosmological fluctuations. During a reheating phase, we find
chaotic behaviour of the non-abelian gauge field which is caused by the
nonlinear self-coupling of the gauge field. We compute a Lyapunov exponent of
the chaos which turns out to be uncorrelated with the anisotropy.Comment: 16 pages, 4 figure
Hamilton-Jacobi Solutions for Strongly-Coupled Gravity and Matter
A Green's function method is developed for solving strongly-coupled gravity
and matter in the semiclassical limit. In the strong-coupling limit, one
assumes that Newton's constant approaches infinity. As a result, one may
neglect second order spatial gradients, and each spatial point evolves like an
homogeneous universe. After constructing the Green's function solution to the
Hamiltonian constraint, the momentum constraint is solved using functional
methods in conjunction with the superposition principle for Hamilton-Jacobi
theory. Exact and approximate solutions are given for a dust field or a scalar
field interacting with gravity.Comment: 26 pages Latex (IOP) file with 2 IOP style files, to be published in
Classical and Quantum Gravity (1998
Stabilization of the Yang-Mills chaos in non-Abelian Born-Infeld theory
We investigate dynamics of the homogeneous time-dependent SU(2) Yang-Mills
fields governed by the non-Abelian Born-Infeld lagrangian which arises in
superstring theory as a result of summation of all orders in the string slope
parameter . It is shown that generically the Born-Infeld dynamics is
less chaotic than that in the ordinary Yang-Mills theory, and at high enough
field strength the Yang-Mills chaos is stabilized. More generally, a smothering
effect of the string non-locality on behavior of classical fields is
conjectured.Comment: 7 pages, 5 figure
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Artificial Light Increases Local Predator Abundance, Predation Rates, and Herbivory.
Human activity is rapidly increasing the radiance and geographic extent of artificial light at night (ALAN) leading to alterations in the development, behavior, and physiological state of many organisms. A limited number of community-scale studies investigating the effects of ALAN have allowed for spatial aggregation through positive phototaxis, the commonly observed phenomenon of arthropod movement toward light. We performed an open field study (without restricted arthropod access) to determine the effects of ALAN on local arthropod community composition, plant traits, and local herbivory and predation rates. We found strong positive phototaxis in 10 orders of arthropods, with increased (159% higher) overall arthropod abundance under ALAN compared to unlit controls. The arthropod community under ALAN was more diverse and contained a higher proportion of predaceous arthropods (15% vs 8%). Predation of immobilized flies occurred 3.6 times faster under ALAN; this effect was not observed during the day. Contrary to expectations, we also observed a 6% increase in herbivory under ALAN. Our results highlight the importance of open experimental field studies in determining community-level effects of ALAN
Axially Symmetric Bianchi I Yang-Mills Cosmology as a Dynamical System
We construct the most general form of axially symmetric SU(2)-Yang-Mills
fields in Bianchi cosmologies. The dynamical evolution of axially symmetric YM
fields in Bianchi I model is compared with the dynamical evolution of the
electromagnetic field in Bianchi I and the fully isotropic YM field in
Friedmann-Robertson-Walker cosmologies. The stochastic properties of axially
symmetric Bianchi I-Einstein-Yang-Mills systems are compared with those of
axially symmetric YM fields in flat space. After numerical computation of
Liapunov exponents in synchronous (cosmological) time, it is shown that the
Bianchi I-EYM system has milder stochastic properties than the corresponding
flat YM system. The Liapunov exponent is non-vanishing in conformal time.Comment: 18 pages, 6 Postscript figures, uses amsmath,amssymb,epsfig,verbatim,
to appear in CQ
Validation of low-dose lung cancer PET-CT protocol and PET image improvement using machine learning
PURPOSE: To conduct a simplified lesion-detection task of a low-dose (LD) PET-CT protocol for frequent lung screening using 30% of the effective PETCT dose and to investigate the feasibility of increasing clinical value of low-statistics scans using machine learning. METHODS: We acquired 33 SD PET images, of which 13 had actual LD (ALD) PET, and simulated LD (SLD) PET images at seven different count levels from the SD PET scans. We employed image quality transfer (IQT), a machine learning algorithm that performs patch-regression to map parameters from low-quality to high-quality images. At each count level, patches extracted from 23 pairs of SD/SLD PET images were used to train three IQT models - global linear, single tree, and random forest regressions with cubic patch sizes of 3 and 5 voxels. The models were then used to estimate SD images from LD images at each count level for 10 unseen subjects. Lesion-detection task was carried out on matched lesion-present and lesion-absent images. RESULTS: LD PET-CT protocol yielded lesion detectability with sensitivity of 0.98 and specificity of 1. Random forest algorithm with cubic patch size of 5 allowed further 11.7% reduction in the effective PETCT dose without compromising lesion detectability, but underestimated SUV by 30%. CONCLUSION: LD PET-CT protocol was validated for lesion detection using ALD PET scans. Substantial image quality improvement or additional dose reduction while preserving clinical values can be achieved using machine learning methods though SUV quantification may be biased and adjustment of our research protocol is required for clinical use
The Politics of Commerce : The Congress of Chambers of Commerce of the Empire, 1886-1914
Peer reviewedPublisher PD
Chaos in the Einstein-Yang-Mills Equations
Yang-Mills color fields evolve chaotically in an anisotropically expanding
universe. The chaotic behaviour differs from that found in anisotropic
Mixmaster universes. The universe isotropizes at late times, approaching the
mean expansion rate of a radiation-dominated universe. However, small chaotic
oscillations of the shear and color stresses continue indefinitely. An
invariant, coordinate-independent characterisation of the chaos is provided by
means of fractal basin boundaries.Comment: 3 pages LaTeX + 3 pages of figure
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