29 research outputs found
The cost of hemiarthroplasty compared to that of internal fixation for femoral neck fractures: 2-year results involving 222 patients based on a randomized controlled trial
City of Hitchcock Comprehensive Plan 2020-2040
Hitchcock is a small town located in Galveston
County (Figure 1.1), nestled up on the Texas Gulf
Coast. It lies about 40 miles south-east of Houston.
The boundaries of the city encloses an area of
land of 60.46 sq. miles, an area of water of 31.64
sq. miles at an elevation just 16 feet above sea level.
Hitchcock has more undeveloped land (~90% of
total area) than the county combined. Its strategic
location gives it a driving force of opportunities in
the Houston-Galveston Region.The guiding principles for this planning process were Hitchcock’s vision statement and its corresponding goals, which were crafted by the
task force. The goals focus on factors of growth and development including public participation, development considerations,
transportation, community facilities, economic development, parks, and housing and social vulnerabilityTexas Target Communitie
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
All-sky search for gravitational-wave bursts in the second joint LIGO-Virgo run
We present results from a search for gravitational-wave bursts in the data
collected by the LIGO and Virgo detectors between July 7, 2009 and October 20,
2010: data are analyzed when at least two of the three LIGO-Virgo detectors are
in coincident operation, with a total observation time of 207 days. The
analysis searches for transients of duration < 1 s over the frequency band
64-5000 Hz, without other assumptions on the signal waveform, polarization,
direction or occurrence time. All identified events are consistent with the
expected accidental background. We set frequentist upper limits on the rate of
gravitational-wave bursts by combining this search with the previous LIGO-Virgo
search on the data collected between November 2005 and October 2007. The upper
limit on the rate of strong gravitational-wave bursts at the Earth is 1.3
events per year at 90% confidence. We also present upper limits on source rate
density per year and Mpc^3 for sample populations of standard-candle sources.
As in the previous joint run, typical sensitivities of the search in terms of
the root-sum-squared strain amplitude for these waveforms lie in the range 5
10^-22 Hz^-1/2 to 1 10^-20 Hz^-1/2. The combination of the two joint runs
entails the most sensitive all-sky search for generic gravitational-wave bursts
and synthesizes the results achieved by the initial generation of
interferometric detectors.Comment: 15 pages, 7 figures: data for plots and archived public version at
https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=70814&version=19, see
also the public announcement at
http://www.ligo.org/science/Publication-S6BurstAllSky
Herophilus and Erasistratus on the hēgemonikon
This is the author accepted manuscript. The final version is available from Cambridge University Press via the DOI in this record.In Alexandria at some point in the early third century bc, Herophilus of Chalcedon identified the nerves as a distinct system within the body, traced their origins to the brain, and recognised their role in transmitting sensation and voluntary motion. His discovery was based on dissection and vivisection, not only of animals, but also of human beings. Herophilus’ younger contemporary Erasistratus also integrated these findings into his rather bolder physiology. The implications of this discovery were of course wide-ranging. From a modern perspective, it is now widely celebrated as having established, for the first time on something like a scientific basis, that the brain has more or less the functions that we now ascribe to it. Likewise, in antiquity, Galen relied heavily on Herophilus’ discovery in his proof that the rational soul is located in the brain. As we shall see, it also had an impact on Stoic psychology. What exactly Herophilus and Erasistratus saw as its implications, however, is a different question, and the difficulties in answering it are considerable given the state of the evidence
Observation of Gravitational Waves from a Binary Black Hole Merger
On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave
Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in
frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0 × 10−21. It matches the waveform
predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the
resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a
false alarm rate estimated to be less than 1 event per 203 000 years, equivalent to a significance greater
than 5.1σ. The source lies at a luminosity distance of 410þ160
−180 Mpc corresponding to a redshift z ¼ 0.09þ0.03 −0.04 .
In the source frame, the initial black hole masses are 36þ5
−4M⊙ and 29þ4
−4M⊙, and the final black hole mass is
62þ4
−4M⊙, with 3.0þ0.5 −0.5M⊙c2 radiated in gravitational waves. All uncertainties define 90% credible intervals.
These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct
detection of gravitational waves and the first observation of a binary black hole merger