Arch Gynecol Obstet
September 2024
Objectives: The timing of planned repeat cesarean delivery (CD) is debateful in clinical practice. Planned repeat CD is typically scheduled before the spontaneous onset of labor to minimize the risk of uterine rupture during labor and the associated risk for fetal compromise. This timing should be balanced with the potential risk of delivering an infant who could benefit from additional maturation in utero.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
September 2023
I propose that there exists in natural and artificial environments a class of resonant oscillations that can be excited directly by a steady, zero-frequency force such as that of wind, water, electric field. A member of this class comprises two normally independent oscillating modes of a system, for example, a building or bridge, which, separately, cannot be driven by a zero-frequency force. Agreeing on terms of collaboration, the two modes engage in a joint oscillation powered by the steady zero-frequency force in which they drive each other, one directly and the other parametrically.
View Article and Find Full Text PDFVaricella vaccination in children has been performed worldwide in recent years. Despite established effectiveness, many countries still do not routinely vaccinate children against varicella, probably due to concerns about complications, such as herpes zoster infection. We aimed to compare the herpes zoster incidence in children before and after implementing the mandatory varicella vaccine in Israel in 2008.
View Article and Find Full Text PDFWe have recently introduced a new semiconductor laser design which is based on an extreme, 99%, reduction of the laser mode absorption losses. In previous reports, we showed that this was achieved by a laser mode design which confines the great majority of the modal energy (> 99%) in a low-loss Silicon guiding layer rather than in highly-doped, thus lossy, III-V p[Formula: see text] and n[Formula: see text] layers, which is the case with traditional III-V lasers. The resulting reduced electron-field interaction was shown to lead to a commensurate reduction of the spontaneous emission rate by the excited conduction band electrons into the laser mode and thus to a reduction of the frequency noise spectral density of the laser field often characterized by the Schawlow-Townes linewidth.
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