(Sub)stellar companions shape the winds of evolved stars.

Binary interactions dominate the evolution of massive stars, but their role is less clear for low- and intermediate-mass stars. The evolution of a spherical wind from an asymptotic giant branch (AGB) star into a nonspherical planetary nebula (PN) could be due to binary interactions. We observed a sample of AGB stars with the Atacama Large Millimeter/submillimeter Array (ALMA) and found that their winds exhibit distinct nonspherical geometries with morphological similarities to planetary nebulae (PNe). We infer that the same physics shapes both AGB winds and PNe; additionally, the morphology and AGB mass-loss rate are correlated. These characteristics can be explained by binary interaction. We propose an evolutionary scenario for AGB morphologies that is consistent with observed phenomena in AGB stars and PNe.

Electron-Hole Tunneling Revealed by Quantum Oscillations in the Nodal-Line Semimetal HfSiS.

We report a study of quantum oscillations in the high-field magnetoresistance of the nodal-line semimetal HfSiS. In the presence of a magnetic field up to 31 T parallel to the c axis, we observe quantum oscillations originating both from orbits of individual electron and hole pockets, and from magnetic breakdown between these pockets. In particular, we reveal a breakdown orbit enclosing one electron and one hole pocket in the form of a "figure of eight," which is a manifestation of Klein tunneling in momentum space, although in a regime of partial transmission due to the finite separation between the pockets. The observed very strong dependence of the oscillation amplitude on the field angle and the cyclotron masses of the orbits are in agreement with the theoretical predictions for this novel tunneling phenomenon.

Linear Magnetoresistance in a Quasifree Two-Dimensional Electron Gas in an Ultrahigh Mobility GaAs Quantum Well.

We report a high-field magnetotransport study of an ultrahigh mobility (µ[over ¯]≈25×10^{6} cm^{2} V^{-1} s^{-1}) n-type GaAs quantum well. We observe a strikingly large linear magnetoresistance (LMR) up to 33 T with a magnitude of order 10^{5}% onto which quantum oscillations become superimposed in the quantum Hall regime at low temperature. LMR is very often invoked as evidence for exotic quasiparticles in new materials such as the topological semimetals, though its origin remains controversial. The observation of such a LMR in the "simplest system"-with a free electronlike band structure and a nearly defect-free environment-excludes most of the possible exotic explanations for the appearance of a LMR and rather points to density fluctuations as the primary origin of the phenomenon. Both, the featureless LMR at high T and the quantum oscillations at low T follow the empirical resistance rule which states that the longitudinal conductance is directly related to the derivative of the transversal (Hall) conductance multiplied by the magnetic field and a constant factor α that remains unchanged over the entire temperature range. Only at low temperatures, small deviations from this resistance rule are observed beyond ν=1 that likely originate from a different transport mechanism for the composite fermions.

[Accidental out-of-hospital deliveries]. / Accouchements inopinés extrahospitaliers.

Unexpected out-of-hospital delivery accounts for 0.5% of the total number of delivery in France. The parturient is placed under constant multiparametric monitoring. Fetus heart rate is monitored thanks to fetal doppler. A high concentration mask containing a 50-to-50 percent mix of O(2) and NO performs analgesia. Assistance of mobile pediatric service can be required under certain circumstances such as premature birth, gemellary pregnancy, maternal illness or fetal heart rate impairment. Maternal efforts should start only when head reaches the pelvic floor, only if the rupture of the membranes is done and the dilation is completed. The expulsion should not exceed 30 min. Episiotomy should not be systematically performed. A systematic active management of third stage of labour is recommended. Routine care such as warming and soft drying can be performed when the following conditions are fulfilled: clear amniotic liquid, normal breathing, crying and a good tonus. Every 30 seconds assessment of heart rate, breathing quality and muscular tonus then guide the care. The redaction of birth certificate is a legal obligation and rests with the attending doctor.