Abstract Relativistic outflows are believed to be a common feature of black hole X-ray binaries (BHXBs) at the lowest accretion rates, when they are in their “quiescent” spectral state. However, we still lack a detailed understanding of how quiescent jet emission varies with time. Here we present 24 yr of archival radio observations (from the Very Large Array and the Very Long Baseline Array) of the BHXB V404 Cygni in quiescence (totaling 150 observations from 1.4 to 22 GHz). The observed flux densities follow lognormal distributions with means and standard deviations of and at 4.9 and 8.4 GHz, respectively (where f ν is the flux density in units of mJy). As expected, the average radio spectrum is flat with a mean and standard deviation of , where . We find that radio flares that increase the flux density by factors of 2–4 over timescales as short as <10 minutes are commonplace, and that long-term variations (over 10–4000 day timescales) are consistent with shot-noise impulses that decay to stochastic variations on timescales ≲10 days (and perhaps as short as tens of minutes to several hr). We briefly compare the variability characteristics of V404 Cygni to jetted active galactic nuclei, and we conclude with recommendations on how to account for variability when placing quiescent BHXB candidates with radio luminosities comparable to V404 Cygni (L R ≈ 1028 erg s−1) onto the radio/X-ray luminosity plane.

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Sir: Breast augmentation is the most common procedure in cosmetic surgery. For many years, the presence of infection in the setting of breast prostheses has necessitated implant removal and delayed reinsertion.1–5 Although successful salvage of prostheses in the presence of periprosthetic infections has been reported before, it is not a generally accepted practice. We review our experience with implant salvage in patients with periprosthetic infections following cosmetic breast surgery with implants for a 1-year period. The protocol included a “sequential cleaning,” an implant replacement, and prolonged postoperative antibiotics. Six patients, all with silicone cohesive gel prostheses, underwent implant salvage. Patients with periprosthetic infections were submitted to this protocol if they manifested the following criteria: clinical infection symptoms, no sign of sepsis (clinical and/or laboratorial), and implant exposure less than 48 hours. The risks involved in saving the implant were systematically clarified to the patients, as the procedure could be successful or not. Wound swabs from the pocket were sent for culture and sensitivity testing. The implant was removed. The sequential cleaning steps were as follows: The cavity of the capsule was scrubbed with chlorhexidine gluconate 2% scrub, and an abdominal swab wet with chlorhexidine alcohol 0.5% solution was left in the pocket for 5 minutes. The cavity of the capsule was scrubbed with abdominal swabs full of half-strength hydrogen peroxide, and an abdominal swab wet with half-strength hydrogen peroxide was left in the pocket for 5 minutes. The cavity was then irrigated with copious amounts of normal saline, approximately 2 liters. The cavity of the capsule was scrubbed with povidone-iodine surgical scrubs, an abdominal swab wet with povidone-iodine was left in the pocket for 5 minutes, and then a drain was positioned. Subsequently, a new implant was placed in the pocket and the scar was closed in four layers with nonabsorbable sutures. A solution consisting of 1.5 g of cefuroxime diluted with 18 ml of saline plus 80 mg of gentamicin (2-ml ampule) plus 40 ml of povidone-iodine was given through the drain. The drain was kept closed for 4 hours. Postoperatively, patients received intravenous antibiotics, 1.5 g cefuroxime (three times per day) plus gentamicin 120 mg (one dose) for 24 hours. Patients were discharged from the hospital without drains and with oral ciprofloxacin 500 mg (three times per day) for up to 10 days. The antibiotics should be adjusted according to the antibiogram result. The patients were followed closely for 8 months. Five of the patients had periprosthetic infections following simple primary breast enlargement, and one was associated with a mastopexy procedure. Of these six patients, Pseudomonas aeruginosa was isolated in one, Staphylococcus aureus was isolated in three, and mixed flora was isolated in two. All patients managed to keep their implants and, at more than 1-year follow-up, there were no signs of rejection or capsular contracture in any of the patients. DISCLOSURE The authors have no financial interest to declare in relation to the content of this article. Marcos Sforza, M.D. Dolan Park Hospital Bromsgrove, United Kingdom Katarina Andjelkov, M.D., Ph.D. University of Belgrade Belgrade, Serbia Renato Zaccheddu, M.D. Dolan Park Hospital Bromsgrove, United Kingdom

L'A. presente les stages pratiques de recherche organises par divers organismes officiels ayant adopte la politique STS d'incitation des jeunes a l'etude des sciences et de la technologie