A WC/WO star exploding within an expanding carbon-oxygen-neon nebula.

The final fate of massive stars, and the nature of the compact remnants they leave behind (black holes and neutron stars), are open questions in astrophysics. Many massive stars are stripped of their outer hydrogen envelopes as they evolve. Such Wolf-Rayet stars1 emit strong and rapidly expanding winds with speeds greater than 1,000 kilometres per second. A fraction of this population is also helium-depleted, with spectra dominated by highly ionized emission lines of carbon and oxygen (types WC/WO). Evidence indicates that the most commonly observed supernova explosions that lack hydrogen and helium (types Ib/Ic) cannot result from massive WC/WO stars2,3, leading some to suggest that most such stars collapse directly into black holes without a visible supernova explosion4. Here we report observations of SN 2019hgp, beginning about a day after the explosion. Its short rise time and rapid decline place it among an emerging population of rapidly evolving transients5-8. Spectroscopy reveals a rich set of emission lines indicating that the explosion occurred within a nebula composed of carbon, oxygen and neon. Narrow absorption features show that this material is expanding at high velocities (greater than 1,500 kilometres per second), requiring a compact progenitor. Our observations are consistent with an explosion of a massive WC/WO star, and suggest that massive Wolf-Rayet stars may be the progenitors of some rapidly evolving transients.

The Detection of Multimodal Oscillations on alpha Ursae Majoris.

We have used the star camera on the Wide-Field Infrared Explorer satellite to observe the K0 III star alpha UMa, and we report the apparent detection of 10 oscillation modes. The lowest frequency mode is at 1.82 µHz, and it appears to be the fundamental mode. The mean spacing between the mode frequencies is 2.94 µHz, which implies that all detected modes are radial. The mode frequencies are consistent with the physical parameters of a K0 III star, if we assume that only radial modes are excited. Mode amplitudes are 100-400 µmag, which is consistent with the scaling relation of Kjeldsen & Bedding.

Does home care lessen hospital readmissions for the elderly?

To remain competitive in the healthcare arena, home healthcare services must show cost effectiveness. One approach is to demonstrate that home healthcare results in fewer hospital readmissions.

Ulnar neuropathy in the distal ulnar tunnel.

A brief anatomical review of the ulnar nerve and areas of ulnar nerve entrapment is discussed. The importance of the dorsal cutaneous nerve is presented with regard to localizing a lesion to the ulnar nerve in the forearm. A classification system is described for ulnar entrapment that occurs distal to the wrist. The case of a nine-year-old girl with a fibrous entrapment of the ulnar nerve in the distal ulnar tunnel is presented. The clinical and diagnostic procedures required for localizing the level of the ulnar nerve entrapment are described, along with the operative findings of this case report. J Orthop Sports Phys Ther 1991;13(1):6-10.

Fiber resonator gyroscope: sensitivity and thermal nonreciprocity.

The rotational sensitivity of the fiber resonator gyro is derived and shown to be approximately equal to that of the fiber interferometer gyro for typical fiber and source parameters. The fiber resonator, like the fiber interferometer, is susceptible to errors due to thermally induced nonreciprocity; however, by reducing splice and coupler losses, it should be possible to reduce these errors well below those in the fiber interferometer.

Moiré inspection of multicomponent assemblies.

This paper discusses the use of moiré techniques to enhance optically the generation of binary images in automatic visual inspection systems. Techniques for enhancing the illumination of out-of-plane features or highlighting areas of missing or misaligned parts on an assembly were investigated. The applications of these techniques to a practical inspection problem were demonstrated.