Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model

We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47×10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society

A summary of DO-178A

Paper at Conf. on software control of gas turbines IEE London (GB) 7 Feb 1985Available from British Library Document Supply Centre- DSC:8019.3153(PNR--90294) / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Source and nature of disturbance-chemical system in crayfish

The responses of crayfish to water from aquaria containing either undisturbed or disturbed animals were observed. The crayfish Orconectes propinquus and O. rusticus showed no response to disturbed-conspecific water. Individuals of O. virilis respond not only to disturbed crayfish but to other taxa (the leech Macrobdella decora , the darter Etheostoma exile , and rock bass Ambloplites rupestris ), but not to the painted turtle Chrsymes picta . Additional tests indicated partial responses by O. virilis to ammonium and to a chemical or chemicals released from the green gland of crayfish. Ablation experiments indicated the antennules as the site of reception of the chemicals. Additional behavioral tests indicated that detection of the disturbance chemical(s) results in the crayfish showing low-level alert for more than 15 min, once an initial priming period has passed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44879/1/10886_2005_Article_BF01026936.pd