12,833 research outputs found
Method of measuring sea surface water temperature with a satellite including wideband passive synthetic-aperture multichannel receiver
A wideband passive synthetic-aperture multichannel receiver with an antenna is mounted on a satellite which travels in an orbit above the Earth passing over large bodies of water, e.g., the Atlantic Ocean. The antenna is scanned to receive signals over a wide frequency band from each incremental surface area (pixel) of the water which are related to the pixel's sea temperature. The received signals are fed to several channels which are tuned to separate selected frequencies. Their outputs are fed to a processor with a memory for storage. As the antenna points to pixels within a calibration area around a buoy of known coordinates, signals are likewise received and stored. Exactly measured sea temperature is received from the buoy. After passing over several calibration areas, a forward stepwise regression analysis is performed to produce an expression which selects the significant from the insignificant channels and assigns weights (coefficients) to them. The expression is used to determine the sea temperature at each pixel based on the signals received therefrom. Wind temperature, pressure, and wind speed at each pixel can also be calculated
Microwave properties of a quiet sea
The microwave flux responses of a quiet sea are observed at five microwave frequencies and with both horizontal and vertical polarizations at each frequency--a simultaneous 10 channel receiving system. The measurements are taken from Earth orbit with an articulating antenna. The 10 channel responses are taken simultaneously since they share a common articulating collector with a multifrequency feed. The plotted flux responses show: (1) the effects of the relative, on-axis-gain of the collecting aperture for each frequency; (2) the effects of polarization rotation in the output responses of the receive when the collecting aperture mechanically rotates about a feed that is fixed; (3) the difference between the flux magnitudes for the horizontal and vertical channels, at each of the five frequencies, and for each pointing position, over a 44 degree scan angle; and (4) the RMS value of the clutter--as reckoned over the interval of a full swath for each of the 10 channels. The clutter is derived from the standard error of estimate of the plotted swath response for each channel. The expected value of the background temperature is computed for each of the three quiet seas. The background temperature includes contributions from the cosmic background, the downwelling path, the sea surface, and the upwelling path
Power transfer from natural emitters to collection apertures at microwave wavelengths
The power transfer criteria necessary and sufficient to produce a detection of the emitting object by the collecting aperture and its receiver are shown. Range equations show the transfer of microwave energy from a passive, diffuse, emitting object that is located on a planetary surface, to a collecting aperture that is carried on an aerial platform or spacecraft. The mathematical relationships show in closed form the expressions for signal to noise ratio as a function of certain key parameters. The practical case of an emitting object on the Earth and a collecting aperture in orbit is presented
What Would Health Care Reform Mean for Small Employers and Their Workers?
Analyzes the implications of the House and Senate reform bills for improving access to and affordability of insurance for small employers. Examines the proposed insurance exchanges, market reforms, subsidies for low-income individuals, and tax provisions
A flux-ratio anomaly in the CO spectral line emission from gravitationally-lensed quasar MG J0414+0534
We present an analysis of archival observations with the Atacama Large
(sub-)Millimetre Array (ALMA) of the gravitationally lensed quasar MG
J0414+0534, which show four compact images of the quasar and an Einstein ring
from the dust associated with the quasar host galaxy. We confirm that the
flux-ratio anomalies observed in the mid-infrared and radio persists into the
sub-mm for the continuum images of the quasar. We report the detection of CO
(11-10) spectral line emission, which traces a region of compact gas around the
quasar nucleus. This line emission also shows evidence of a flux-ratio anomaly
between the merging lensed images that is consistent with those observed at
other wavelengths, suggesting high-excitation CO can also provide a useful
probe of substructures that is unaffected by microlensing or dust extinction.
However, we do not detect the candidate dusty dwarf galaxy that was previously
reported with this dataset, which we conclude is due to a noise artefact. Thus,
the cause of the flux-ratio anomaly between the merging lensed images is still
unknown. The composite compact and diffuse emission in this system suggest
lensed quasar-starbursts will make excellent targets for detecting dark
sub-haloes and testing models for dark matter.Comment: Accepted as MNRAS Lette
A Toll for lupus
Toll-like receptor (TLR)-9 recognizes CpG motifs in microbial DNA. TLR9 signalling stimulates innate antimicrobial immunity and modulates adaptive immune responses including autoimmunity against chromatin, e.g., in systemic lupus erythematosus (SLE). This review summarizes the available data for a role of TLR9 signalling in lupus and discusses the following questions that arise from these observations: 1) Is CpG-DNA/TLR9 interaction involved in infection-induced disease activity of lupus? 2) What are the risks of CpG motifs in vaccine adjuvants for lupus patients? 3) Is TLR9 signalling involved in the pathogenesis of lupus by recognizing self DNA
The Effects of Health Reform on Small Businesses and Their Workers
Synthesizes research findings about how the 2010 healthcare reform will affect small business owners and employees, including savings in healthcare costs and premium contributions, coverage for workers and dependents, offer rates, and number of uninsured
Microwave responses of the western North Atlantic
Features and objects in the Western North Atlantic Ocean - the Eastern Seaboard of the United States - are observed from Earth orbit by passive microwaves. The intensities of their radiated flux signatures are measured and displayed in color as a microwave flux image. The features of flux emitting objects such as the course of the Gulf Stream and the occurrence of cold eddies near the Gulf Stream are identified by contoured patterns of relative flux intensities. The flux signatures of ships and their wakes are displayed and discussed. Metal data buoys and aircraft are detected. Signal to clutter ratios and probabilities of detection are computed from their measured irradiances. Theoretical models and the range equations that explain passive microwave detection using the irradiances of natural sources are summarized
The volume and source of cyberabuse influences victim blame and perceptions of attractiveness
Cyberabuse is an escalating problem in society, as opportunities for abuse to occur in online public domains increase. Such acts are often defined by the frequency of abuse, and in many cases multiple individuals play a part in the abuse. Although consequences of such acts are often severe, there is typically little public sympathy/support for victims. To better understand perceptions of victims of abusive online acts, we manipulated the Volume (low, high) and Source (same-source, multi-source) of abusive posts in artificially-manipulated Facebook timelines of four fictitious ‘victims’. One hundred and sixty-four participants [United Kingdom-based; aged 18–59] rated ‘victims’ on measures of direct victim blame (DVB) and perceived social-, physical- and task-attractiveness. Results revealed significant Volume × Source interactions on DVB and social-attractiveness ratings. Few abusive posts authored by a single source yielded higher DVB and lower social-attractiveness ratings. Strong correlations between attractiveness and DVB were observed. We propose that our results could be due to an observer desensitization effect, or that participants interpreted the posts as indicative of friendly ‘teasing’ or ‘banter’ within an established social relationship, helping to explain why victims of online abuse often receive little sympathy or support
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The spiral of applied research: A methodological view on integrated design research
Abstract not available
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