920 research outputs found
Discovery of a wandering radio jet base after a large X-ray flare in the blazar Markarian 421
We investigate the location of the radio jet bases ("radio cores") of blazars
in radio images, and their stationarity by means of dense very long baseline
interferometry (VLBI) observations. In order to measure the position of a radio
core, we conducted 12 epoch astrometric observation of the blazar Markarian 421
with the VLBI Exploration of Radio Astrometry at 22 GHz immediately after a
large X-ray flare, which occurred in the middle of 2011 September. For the
first time, we find that the radio core is not stationary but rather changes
its location toward 0.5 mas downstream. This angular scale corresponds to the
de-projected length of a scale of Schwarzschild radii (Rs) at the
distance of Markarian~421. This radio-core wandering may be a new type of
manifestation associated with the phenomena of large X-ray flares.Comment: 6 pages, 4 figures, 1 table, has been published in ApJ Letter
ALMA Science Verification Data: Millimeter Continuum Polarimetry of the Bright Radio Quasar 3C 286
We present full-polarization observations of the compact, steep-spectrum
radio quasar 3C~286 made with the ALMA at 1.3~mm. These are the first
full-polarization ALMA observations, which were obtained in the framework of
Science Verification. A bright core and a south-west component are detected in
the total intensity image, similar to previous centimeter images. Polarized
emission is also detected toward both components. The fractional polarization
of the core is about 17\%, this is higher than the fractional polarization at
centimeter wavelengths, suggesting that the magnetic field is even more ordered
in the millimeter radio core than it is further downstream in the jet. The
observed polarization position angle (or EVPA) in the core is
\,, which confirms the trend that the EVPA slowly increases
from centimeter to millimeter wavelengths. With the aid of multi-frequency VLBI
observations, we argue that this EVPA change is associated with the
frequency-dependent core position. We also report a serendipitous detection of
a sub-mJy source in the field of view, which is likely to be a submillimeter
galaxy.Comment: 10 pages, 9 figures, Accepted for publication in the Ap
Drivers' visual attention to in-vehicle displays: effects of display location and road types
Mitsubishi Motors Corporation, Okazaki (Japan)http://deepblue.lib.umich.edu/bitstream/2027.42/1061/2/90851.0001.001.pd
Development of a posture detector using a flex sensor
In this digital age, many people spend hours every day looking at their cell phones and computers. Overuse of these devices can result in users\u27 posture deterioration. Poor postures not only detract from a person\u27s appearance but can also lead to chronic back discomfort and inflammation. Even though everyone knows the detrimental effects of poor postures, it is difficult for them to correct their bad habits. This is because poor postures are gradually developed, and they are usually related to a person\u27s lifestyle. The purpose of this project was to embed a poor posture detector (a posture coach) into clothing so that users could wear it unobtrusively and comfortably. Its functions were to detect and alert users of poor postures, to help the users maintain proper postures continuously, and to help users correct their habits related to bad postures
Limb-Brightened Jet of 3C 84 Revealed by the 43-GHz Very-Long-Baseline-Array Observation
We present a study of sub-pc scale radio structure of the radio galaxy 3C
84/NGC 1275 based on the Very Long Baseline Array (VLBA) data at 43 GHz. We
discover a limb-brightening in the "restarted" jet associated with the 2005
radio outburst. In the 1990s, the jet structure was ridge-brightening rather
than limb-brightening, despite the observations being done with similar angular
resolution. This indicates that the transverse jet structure has changed
recently. This change in the morphology shows an interesting agreement with the
-ray flux increase, i.e., the -ray flux in 1990s was at least
seven times lower than the current one. One plausible explanation for the
limb-brightening is the velocity structure of the jet in the context of the
stratified jet, which is a successful scenario to explain the -ray
emission in some active galactic nuclei (AGNs). If this is the case, the change
in apparent transverse structure might be caused by the change in the
transverse velocity structure. We argue the possibility that the transition
from ridge-brightening to limb-brightening is related to the -ray time
variability on the timescale of decades. We also discuss the collimation
profile of the jet.Comment: 22 pages, 4 figures, Accepted for Publication in Ap
Phenotypic and Genotyping Study of Aspergillus Niger: Molecular Detection of Calmodulin, 18srRNA and Pepsin like Protease Genes Based on Multiplex PCR
Aims: Aspergillosis can be diagnosed using PCR. For this purpose, the genes encoding the 18S rRNA, Calmodulin and Pepsin-like protease genes of Aspergillus niger, were elucidated. Genus specific sequences could be identified in region of 18S rRNA. Methodology: 24 fungal strains were isolated from different localities of Al-Hillah city. Isolates were screened for glucose oxidase production using submerged fermentation and molecular techniques like 18S rRNA. DNA was isolated and amplified using PCR. Gene sequencing was done and homology analysis was studied. Rate of glucose oxidase production was also analyzed. Results: The method described in this study represents a rapid and reliable procedure to assess the presence in food products of two ochratoxigenic species of section Nigri. Glucose oxidase hyper producing isolate was identified as A. niger strain. The F17 strain gave best reproducible results (87. 5±0.05U/g of cell mass) after 72 h. of fermentation at 30ºC and at a medium pH of 7.2.The 18srDNA was used to detect A. niger was very affective. The identification and isolation of tannase gene from A. niger which is considered as an important bioreactor and industrial fungus were reported Conclusion: Our results revealed that Glucose oxidase was produced naturally by A. niger in large quantity instead of using other manipulation techniques of genetic. The PCR technique we have used appears to be adequate to study a large group of microorganisms (fungi) and it help to identify risk of pathogenicity of aspergillosis. Keywords:Aspergillus niger, Calmodulin, Pepsin-like protease, 18S rRNA, aspergillosis, Tannase
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