The Prime Focus Spectrograph (PFS) is a new optical/near-infrared multi-fiber spectrograph design for the prime focus of the 8.2m Subaru telescope. PFS will cover 1.3 degree diameter field with 2394 ...fibers to complement the imaging capability of Hyper SuprimeCam (HSC). The prime focus unit of PFS called Prime Focus Instrument (PFI) provides the interface with the top structure of Subaru telescope and also accommodates the optical bench in which Cobra fiber positioners are located. In addition, the acquisition and guiding (A&G) cameras, the optical fiber positioner system, the cable wrapper, the fiducial fibers, illuminator, and viewer, the field element, and the telemetry system are located inside the PFI. The mechanical structure of the PFI was designed with special care such that its deflections sufficiently match those of the HSC Wide Field Corrector (WFC) so the fibers will stay on targets over the course of the observations within the required accuracy.
The urothelium is a multilayered epithelium that serves as a barrier between the urinary tract and blood, preventing the exchange of water and toxic substances. It consists of superficial cells ...specialized for synthesis and transport of uroplakins that assemble into a tough apical plaque, one or more layers of intermediate cells, and keratin 5-expressing basal cells (K5-BCs), which are considered to be progenitors in the urothelium and other specialized epithelia. Fate mapping, however, reveals that intermediate cells rather than K5-BCs are progenitors in the adult regenerating urothelium, that P cells, a transient population, are progenitors in the embryo, and that retinoids are critical in P cells and intermediate cells, respectively, for their specification during development and regeneration. These observations have important implications for tissue engineering and repair and, ultimately, may lead to treatments that prevent loss of the urothelial barrier, a major cause of voiding dysfunction and bladder pain syndrome.
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•The authors identify progenitors critical for urothelial formation and regeneration•Development and repair utilize two separate populations of progenitors•RA is critical in urothelial progenitors for specification and regeneration
The urothelial barrier prevents the exchange of water and toxins between the urinary tract and blood; chronic urinary tract infections can damage this barrier. Gandhi et al. identify distinct progenitors important for urothelial formation versus repair, both controlled by retinoids. These findings could have implications for therapeutic approaches to urothelial repair.
In a sealed bid second-price auction (or English auction) with independent private values, bidders with a single unit demand truthfully bid their value (stay in the auction until the price reaches ...their value and then drop out). The discovery that such bidding is a dominant strategy is a celebrated result due to William Vickery. Vickery also determined the type of simultaneous bidding auction that is needed to induce truthful bidding as a dominant strategy when m (m>2) units are auctioned and bidders have multi-unit demand. This procedure is more complicated than second price (or English) auctions and, to the author's knowledge has never been used except in experimental laboratories. Lawrence M. Ausubel introduced a dynamic implementation for Vickery's multi-unit demand auction where sincere bidding is the unique equilibrium surviving iterated elimination of weakly dominated strategies.
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