950 research outputs found
Noninvasive Two-Dimensional Strain Imaging of Atherosclerosis: A Preliminary Study in Carotid Arteries In Vivo
AbstractAtherosclerosis remains a major cause of mortality all over the world and the sudden rupture of atherosclerotic plaque is the most important assassin. Vascular ultrasound elastography has shown promise in estimating the elastic properties to evaluate the plaque vulnerability. Contrary to intravascular elastography, noninvasive applications use a transcutaneous ultrasound transducer that is inexpensive, re-useable and convenient. To estimate the strain map, we employ a cross-correlation method in complex field to extract both the magnitude and phase messages of the ultrasound RF-echo signal. Two-dimension noninvasive carotid elastography was studied in atherosclerotic rats and New Zealand Rabbits and also in healthy volunteer, and the results indicate huge potential for diagnosis of the vulnerability of atheromatous plaques
Fungicide application effects on diversity components of chickpea rhizospheric bacterial community
Non-Peer ReviewedMolecular (polymerase chain reaction – denaturing gradient gel electrophoresis) methods and
correspondent analysis have been used in order to test changes of the diversity of bacterial
communities in chickpea rhizospheric soil under different cultivars and fungicide treatments.
Results showed that chickpea genotypes influence their microbial environment differently.
Besides, fungicide applications could negatively affect the diversity of dominant bacterial
DNA sequences, and this effect increased with the number of fungicide application on
chickpea aerial parts
Coordinated regulatory efforts needed to strengthen travel related immunization requirements against importation of infectious diseases
Along with increases in international travel come increased opportunities for importation of infectious disease to the United States (U.S.). Many infectious diseases can lead to severe negative health outcomes for those infected, including disability and death, as seen recently through the importation of Ebola from West Africa and Zika from South America. Additionally, disease importation is a key contributing factor to the potential threat of emerging pathogens, such as novel strains of influenza, and the reemergence of vaccine-preventable diseases, such as measles. In the U.S., most of the recent measles outbreaks originated from international travel, where the disease was brought into the U.S. by unvaccinated persons who were infected in other countries
Calibration of RGB-D sensors for Robot SLAM
[[abstract]]This paper presents a calibration procedure for a Kinect RGB-D sensor and its application
to robot simultaneous localization and mapping (SLAM). The calibration procedure consists of two stages: in the first stage, the RGB image is aligned with the depth image by using the bilinear interpolation. The distorted RGB image is further corrected in the second stage. The calibrated RGB-D sensor is used as the sensing device for robot navigation in unknown environment. In SLAM
tasks, the speeded-up robust features (SURF) are detected from the RGB image and used as
landmarks for the environment map. The depth image could provide the stereo information of each landmark. Meanwhile, the robot estimates its own state and landmark locations by mean of the extended Kalman filter (EKF). The EKF SLAM has been carried out in the paper and the
experimental results showed that the Kinect sensors could provide reliable measurement information for mobile robots when navigating in unknown environment.[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]EI[[ispeerreviewed]]Y[[booktype]]電子版[[countrycodes]]CH
Establishment of an arabinose-inducible system in Stenotrophomonas maltophilia
A pBBad22T-derived conditioned arabinose (Ara)-inducible expression system was evaluated in Stenotrophomonas maltophilia (an opportunistic pathogen and has gained increasing attention as a cause of healthcare-associated infection). S. maltophilia cannot grow well when Ara is the sole available carbon source. The induction kinetic study, optimal inducer concentration determination, and depletion experiment were performed by using a xylE gene fusion construct, pBxylE, to monitor the expression of pBBad22T in S. maltophilia. For induction survey, the expression of catechol 2,3-dioxygenase (C23O), encoded by xylE gene, continuously increases during an 8-h induced course and can be modulated by different inducer concentrations. The applied induction condition of pBBad22T in S. maltophilia is the inducer concentration ranging from 0.1% to 0.5% for an induction time of 4 h. For repression evaluation, the C23O expression is rapidly turned off within 30 min after the removal of Ara. Accordingly, the established Ara-inducible system can provide a convenient tool for the study of S. maltophilia
Time series irreversibility: a visibility graph approach
We propose a method to measure real-valued time series irreversibility which
combines two differ- ent tools: the horizontal visibility algorithm and the
Kullback-Leibler divergence. This method maps a time series to a directed
network according to a geometric criterion. The degree of irreversibility of
the series is then estimated by the Kullback-Leibler divergence (i.e. the
distinguishability) between the in and out degree distributions of the
associated graph. The method is computationally effi- cient, does not require
any ad hoc symbolization process, and naturally takes into account multiple
scales. We find that the method correctly distinguishes between reversible and
irreversible station- ary time series, including analytical and numerical
studies of its performance for: (i) reversible stochastic processes
(uncorrelated and Gaussian linearly correlated), (ii) irreversible stochastic
pro- cesses (a discrete flashing ratchet in an asymmetric potential), (iii)
reversible (conservative) and irreversible (dissipative) chaotic maps, and (iv)
dissipative chaotic maps in the presence of noise. Two alternative graph
functionals, the degree and the degree-degree distributions, can be used as the
Kullback-Leibler divergence argument. The former is simpler and more intuitive
and can be used as a benchmark, but in the case of an irreversible process with
null net current, the degree-degree distribution has to be considered to
identifiy the irreversible nature of the series.Comment: submitted for publicatio
Superconducting transition in Pb/Co nanocomposites: effect of Co volume fraction and external magnetic field
Pb films embedded with homogeneously distributed cobalt (Co) nanoparticles
(mean size 4.5 nm) have been prepared. Previous transport investigations have
shown that Co particles induce spontaneous vortices below the superconducting
transition temperature (T) in zero external magnetic field. In this paper
we study in detail the influence of the Co volume franction and an external
magnetic field on the superconducting transition in such composites. The large
difference in T-reduction between the as-prepared and annealed samples can
be attributed to the different superconducting coherence lengths and the
resulting different diameters of the spontaneous vortices in these samples.Comment: 4 pages, 5 figure
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