Second Data Release from the European Pulsar Timing Array: Challenging the Ultralight Dark Matter Paradigm

Pulsar Timing Array experiments probe the presence of possible scalar or pseudoscalar ultralight dark matter particles through decade-long timing of an ensemble of galactic millisecond radio pulsars. With the second data release of the European Pulsar Timing Array, we focus on the most robust scenario, in which dark matter interacts only gravitationally with ordinary baryonic matter. Our results show that ultralight particles with masses 10^{-24.0}  eV≲m≲10^{-23.3}  eV cannot constitute 100% of the measured local dark matter density, but can have at most local density ρ≲0.3  GeV/cm^{3}.

The magnetic field and turbulence of the cosmic web measured using a brilliant fast radio burst

Fast radio bursts (FRBs) are millisecond-duration events thought to originate beyond the Milky Way galaxy. Uncertainty surrounding the burst sources, and their propagation through intervening plasma, has limited their use as cosmological probes. We report on a mildly dispersed (dispersion measure 266.5 ± 0.1 parsecs per cubic centimeter), exceptionally intense (120 ± 30 janskys), linearly polarized, scintillating burst (FRB 150807) that we directly localize to 9 square arc minutes. On the basis of a low Faraday rotation (12.0 ± 0.7 radians per square meter), we infer negligible magnetization in the circum-burst plasma and constrain the net magnetization of the cosmic web along this sightline to <21 nanogauss, parallel to the line-of-sight. The burst scintillation suggests weak turbulence in the ionized intergalactic medium.

Limits on Anisotropy in the Nanohertz Stochastic Gravitational Wave Background

The paucity of observed supermassive black hole binaries (SMBHBs) may imply that the gravitational wave background (GWB) from this population is anisotropic, rendering existing analyses suboptimal. We present the first constraints on the angular distribution of a nanohertz stochastic GWB from circular, inspiral-driven SMBHBs using the 2015 European Pulsar Timing Array data. Our analysis of the GWB in the ~2-90 nHz band shows consistency with isotropy, with the strain amplitude in l>0 spherical harmonic multipoles ≲40% of the monopole value. We expect that these more general techniques will become standard tools to probe the angular distribution of source populations.

[Perineal hernia]

The authors base this study on a case of perineal hernia referred to their attention. In the light of the scant international literature on this subject, they focus on the topographical anatomy of the pelvic floor in order to gain a clearer understanding of this pathology, as well as their classification into median, lateral, anterior and posterior forms. Above all, the authors draw attention to the importance of the differential diagnosis of perineal hernia from Bartholin cysts or vulvar tumours in relation to anterior perineal hernia, and perianal abscesses in relation to posterior hernia. They underline the value of ultrasonography or TAC during the diagnostic procedure. Lastly, they examine the channels of aggression for this type of hernia which may be abdominal, perianal or combined (abdominal and peri-anal), as well as the repair techniques used, varying from direct suture with non-absorbable material to the use of prolene mesh or flaps if the hernia breech is very large.

[Usefulness of supplemental treatment with glypressin during the eradication phase of esophageal varices using endoscopic sclerotherapy]

The response of 20 patients with oesophageal varices randomly assigned to treatment by endoscopic sclerotherapy with or without adjuvant Glipressina was assessed on the basis of the following parameters: mean eradication time for oesophageal varices and frequency of bleeding during that period. The preliminary results suggest that the drug may have a favourable influence on both eradication time and bleeding in sclerotherapy.