Search for gravitational-wave transients associated with magnetar bursts in advanced LIGO and advanced Virgo data from the third observing run

Gravitational waves are expected to be produced from neutron star oscillations associated with magnetar giant f lares and short bursts. We present the results of a search for short-duration (milliseconds to seconds) and longduration (∼100 s) transient gravitational waves from 13 magnetar short bursts observed during Advanced LIGO, Advanced Virgo, and KAGRA’s third observation run. These 13 bursts come from two magnetars, SGR1935 +2154 and SwiftJ1818.0−1607. We also include three other electromagnetic burst events detected by FermiGBM which were identified as likely coming from one or more magnetars, but they have no association with a known magnetar. No magnetar giant flares were detected during the analysis period. We find no evidence of gravitational waves associated with any of these 16 bursts. We place upper limits on the rms of the integrated incident gravitational-wave strain that reach 3.6 × 10−²³ Hz at 100 Hz for the short-duration search and 1.1 ×10−²² Hz at 450 Hz for the long-duration search. For a ringdown signal at 1590 Hz targeted by the short-duration search the limit is set to 2.3 × 10−²² Hz. Using the estimated distance to each magnetar, we derive upper limits upper limits on the emitted gravitational-wave energy of 1.5 × 1044 erg (1.0 × 1044 erg) for SGR 1935+2154 and 9.4 × 10^43 erg (1.3 × 1044 erg) for Swift J1818.0−1607, for the short-duration (long-duration) search. Assuming isotropic emission of electromagnetic radiation of the burst fluences, we constrain the ratio of gravitational-wave energy to electromagnetic energy for bursts from SGR 1935+2154 with the available fluence information. The lowest of these ratios is 4.5 × 103

Glicentin-related pancreatic polypeptide inhibits glucose-stimulated insulin secretion from the isolated pancreas of adult male rats.

Several peptides derived from the glucagon gene Gcg, for example glucagon and glucagon-like peptide 1 (GLP-1), act as major regulators of fuel metabolism. GLP-1 is an incretin which has given rise to two new classes of anti-diabetic agents, the GLP-1 agonists and the DPP4 inhibitors. Glucagon is another potent Gcg-derived glucoregulatory hormone whose main regulatory role is to increase glucose output from the liver. Peptides derived from Gcg are thus of major interest in the regulation of intermediary metabolism, the pathogenesis of diseases such as type-2 diabetes and obesity, and their therapeutic management. Glicentin-related pancreatic polypeptide (GRPP) is a further, 30 amino-acid Gcg-derived peptide identified in human, mouse, rat and pig. A closely-related peptide, GRPP-like peptide (GRPP-LP) has also been identified in rat islets. The potential glucoregulatory functions of these peptides are largely unknown. We synthesized rat GRPP (rGRPP) and rat GRPP-LP (rGRPP-LP) and determined their actions in the liver and pancreas of adult male rats by employing isolated-perfused organ preparations. Rat GRPP and rGRPP-LP did not affect glucose output from the liver but both elicited potent inhibition of glucose-stimulated insulin secretion from the rat pancreas. This action is unlikely to be mediated by glucagon or GLP-1 receptors as rGRPP and rGRPP-LP did not stimulate cyclic adenosine monophosphate (cAMP) production from the glucagon or GLP-1 receptors, nor did they antagonize glucagon- or GLP-1-stimulated cAMP-production at either receptor. GRPP and GRPP-LP may be novel regulators of insulin secretion, acting through an as-yet undefined receptor