10 research outputs found
All-sky search for long-duration gravitational wave transients with initial LIGO
We present the results of a search for long-duration gravitational wave transients in two sets of data collected by the LIGO Hanford and LIGO Livingston detectors between November 5, 2005 and September 30, 2007, and July 7, 2009 and October 20, 2010, with a total observational time of 283.0 days and 132.9 days, respectively. The search targets gravitational wave transients of duration 10-500 s in a frequency band of 40-1000 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. All candidate triggers were consistent with the expected background; as a result we set 90% confidence upper limits on the rate of long-duration gravitational wave transients for different types of gravitational wave signals. For signals from black hole accretion disk instabilities, we set upper limits on the source rate density between 3.4×10-5 and 9.4×10-4 Mpc-3 yr-1 at 90% confidence. These are the first results from an all-sky search for unmodeled long-duration transient gravitational waves. © 2016 American Physical Society
All-sky search for long-duration gravitational wave transients with initial LIGO
We present the results of a search for long-duration gravitational wave transients in two sets of data collected by the LIGO Hanford and LIGO Livingston detectors between November 5, 2005 and September 30, 2007, and July 7, 2009 and October 20, 2010, with a total observational time of 283.0 days and 132.9 days, respectively. The search targets gravitational wave transients of duration 10-500 s in a frequency band of 40-1000 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. All candidate triggers were consistent with the expected background; as a result we set 90% confidence upper limits on the rate of long-duration gravitational wave transients for different types of gravitational wave signals. For signals from black hole accretion disk instabilities, we set upper limits on the source rate density between 3.4×10-5 and 9.4×10-4 Mpc-3 yr-1 at 90% confidence. These are the first results from an all-sky search for unmodeled long-duration transient gravitational waves. © 2016 American Physical Society
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Residential Cooking Behavior in the United States: Data Collected from a Web-Based Survey:
Cooking has a significant impact on indoor air quality. When cooking occurs, how foods are cooked, and
the types of food that are cooked have all been shown to impact the rate at which occupants are
exposed to pollutants. Home occupancy characteristics impact how concentrations in the home
translate into exposures for the occupants. With the intent of expanding our understanding of cooking
behavior in the U.S., we developed and advertised an online survey to collect household cooking
behavior for the 24 hrs prior to taking the survey. The survey questions were designed to address gaps
in knowledge needed to predict the impact of cooking on indoor concentrations of PM2.5 and other
pollutants. The survey included the following questions: 1) which meals households ate at home; 2)
number of household members at home during cooking; 3) the type of oil used for cooking; 4) the type
of foods cooked at each meal; 5) the type of cooking devices used; and 6) the methods selected for food
preparation. We also collected information on household characteristics such as their location (zip
code), ethnicity, and ages of family members. We analyzed the variability in home cooking
characteristics for households in different climate zones and with four different types of family
compositions: 1 senior living alone, 1 adult living alone, 2 or more adults/seniors, and families with
children. We used simple statistical tests to determine if the probability of certain cooking behaviors
differed between these subgroups
The biology of coral metamorphosis: Molecular responses of larvae to inducers of settlement and metamorphosis
Like many other cnidarians, corals undergo metamorphosis from a motile planula larva to a sedentary polyp. In some sea anemones such as Nematostella this process is a smooth transition requiring no extrinsic stimuli, but in many corals it is more complex and is cue-driven. To better understand the molecular events underlying coral metamorphosis, competent larvae were treated with either a natural inducer of settlement (crustose coralline algae chips/extract) or LWamide, which bypasses the settlement phase and drives larvae directly into metamorphosis. Microarrays featuring >8000 Acropora unigenes were used to follow gene expression changes during the 12h period after these treatments, and the expression patterns of specific genes, selected on the basis of the array experiments, were investigated by in situ hybridization. Three patterns of expression were common-an aboral pattern restricted to the searching/settlement phase, a second phase of aboral expression corresponding to the beginning of the development of the calicoblastic ectoderm and continuing after metamorphosis, and a later orally-restricted pattern.L.C. Grasso, A.P. Negri, S. FĂ´ret, R. Saint, D.C. Hayward, D.J. Miller, E.E. Bal
Characterization of the LIGO detectors during their sixth science run
In 2009-2010, the Laser Interferometer Gravitational-Wave Observatory (LIGO) operated together with international partners Virgo and GEO600 as a network to search for gravitational waves (GWs) of astrophysical origin. The sensitivity of these detectors was limited by a combination of noise sources inherent to the instrumental design and its environment, often localized in time or frequency, that couple into the GW readout. Here we review the performance of the LIGO instruments during this epoch, the work done to characterize the detectors and their data, and the effect that transient and continuous noise artefacts have on the sensitivity of LIGO to a variety of astrophysical sources