Evidence for a radiation belt around a brown dwarf.

Ultracool dwarfs (UCDs) are a category of astronomical objects that includes brown dwarfs and very-low-mass stars. Radio observations of UCDs have measured their brightness as a function of time (light curves) and spectral energy distributions, providing insight into their magnetic fields. We present spatially resolved radio observations of the brown dwarf LSR J1835+3259 using very-long-baseline interferometry showing extended radio emission. The detected morphology is consistent with the presence of a radiation belt. Comparison with models indicates that the radiation belt contains energetic particles confined by magnetic mirroring. We contend that radio-emitting UCDs have dipole-ordered magnetic fields with radiation belt-like morphologies and aurorae that are similar to those of Jupiter.

Compact radio emission indicates a structured jet was produced by a binary neutron star merger.

The binary neutron star merger event GW170817 was detected through both electromagnetic radiation and gravitational waves. Its afterglow emission may have been produced by either a narrow relativistic jet or an isotropic outflow. High-spatial-resolution measurements of the source size and displacement can discriminate between these scenarios. We present very-long-baseline interferometry observations, performed 207.4 days after the merger by using a global network of 32 radio telescopes. The apparent source size is constrained to be smaller than 2.5 milli-arc seconds at the 90% confidence level. This excludes the isotropic outflow scenario, which would have produced a larger apparent size, indicating that GW170817 produced a structured relativistic jet. Our rate calculations show that at least 10% of neutron star mergers produce such a jet.

A dust-enshrouded tidal disruption event with a resolved radio jet in a galaxy merger.

Tidal disruption events (TDEs) are transient flares produced when a star is ripped apart by the gravitational field of a supermassive black hole (SMBH). We have observed a transient source in the western nucleus of the merging galaxy pair Arp 299 that radiated >1.5 × 1052 erg at infrared and radio wavelengths but was not luminous at optical or x-ray wavelengths. We interpret this as a TDE with much of its emission reradiated at infrared wavelengths by dust. Efficient reprocessing by dense gas and dust may explain the difference between theoretical predictions and observed luminosities of TDEs. The radio observations resolve an expanding and decelerating jet, probing the jet formation and evolution around a SMBH.

[Is obesity a risk factor for complications, hospital admissions, and surgical cancellations in ambulatory surgery?]. / ¿Es la obesidad un factor de riesgo de complicaciones, ingresos y suspensiones quirúrgicas en cirugía mayor ambulatoria?

OBJECTIVES: To determine the incidence of outcomes, unanticipated admissions and cancellations in patients operated in an Ambulatory surgery unit, and to establish the relationships with their body mass index (BMI). SUBJECTS AND METHODS: An observational descriptive prospective study was conducted in the Ambulatory surgery unit of the University Hospital Virgen del Rocío of Seville, on ASA I or II adult patients proposed for day case surgery with loco-regional or general anesthesia. A cohort of 1,088 patients was classified according to their body mass index into four groups: no obesity (BMI<30), obesity i (BMI 30-34.9), obesity ii (BMI 35-39.9), and morbid obesity iii (BMI 40-49.9). Postoperative outcomes (48h), inpatient admissions, and cancellations where calculated. RESULTS: The obesity ii (BMI 35-39.9) group showed a higher incidence of postoperative complications (7.69%), unplanned admissions (7.69%), and surgical cancellations (4.87%), doubling, at least, the incidence of adverse events of the other study groups, even when no significant difference was found. Outcomes where similar in all study groups. CONCLUSIONS: The results of this study suggest that moderate and severe obesity should be a risk factor for postoperative complications, unplanned admissions, and cancellations in outpatient surgery. Adequate patient selection and preoperative evaluation, as well as strategies for the prevention and control of the most frequents complications in obese patients are the key factors for their integration in major ambulatory surgery programs.

Anaesthesia and the Beckwith-Wiedemann syndrome.

Infants with Beckwith-Wiedemann syndrome usually present different abnormalities which may require surgical correction. Anaesthetic management may be complicated by abnormal airway anatomy, congenital heart disease and severe hypoglycaemia. Careful preoperative evaluation, perioperative monitoring and suitable choice of anaesthetic technique are required for a successful outcome. We report the perioperative management of a patient with Beckwith-Wiedemann syndrome presenting for omphalocoele surgery on his first day of life and for bilateral inguinal hernia repair four months later.