The guardians of cell fate: protective mechanisms that ensure proper cell fate and patterning during imaginal disc regeneration in drosophila

Regenerating tissue must replace lost structures with cells of the proper identity and pattern in order to restore function. This thesis will describe two major insights into how patterning and cell fate is maintained and restored during the late phases of regeneration in the wing imaginal disc of Drosophila. First, the identification of taranis as a regeneration-specific patterning gene and its subsequent characterization as a factor that is required to protect the regenerating cells in the wing imaginal disc from inappropriate posterior to anterior cell fate changes that are induced by the powerful JNK signaling cascade at the wound misregulating the expression of engrailed. The other chapter will detail the identification of the pioneer transcription factor Zelda as being upstream of taranis expression during regeneration. Zelda is found to be expressed at the same place and time as Taranis, and reduction of Zelda levels results in profound anterior and posterior patterning defects. Speculation is provided suggesting that Zelda may also be essential for the large developmental transition from a program devoted to regenerative growth to the repatterning phase that allows for the restoration of cell fate and patterning genes that was lost earlier in regeneration. This work describes identification of a novel gene regulatory network essential for patterning and cell fate during regeneration

Identifying Very Metal-Rich Stars with Low-Resolution Spectra: Finding Planet-Search Targets

We present empirical calibrations that estimate stellar metallicity, effective temperature and surface gravity as a function of Lick/IDS indices. These calibrations have been derived from a training set of 261 stars for which (1) high-precision measurements of [Fe/H], T_eff and log g have been made using spectral-synthesis analysis of HIRES spectra, and (2) Lick indices have also been measured. Our [Fe/H] calibration, which has precision 0.07 dex, has identified a number of bright (V < 9) metal-rich stars which are now being screened for hot Jupiter-type planets. Using the Yonsei-Yale stellar models, we show that the calibrations provide distance estimates accurate to 20% for nearby stars. This paper outlines the second tier of the screening of planet-search targets by the N2K Consortium, a project designed to identify the stars most likely to harbor extrasolar planets. Discoveries by the N2K Consortium include the transiting hot Saturn HD 149026 b (Sato et al. 2005, astro-ph/0507009) and HD 88133 b (Fischer et al. 2005). See Ammons et al. (2005, In Press) for a description of the first tier of N2K metallicity screening, calibrations using broadband photometry.Comment: Accepted for publication in the Astrophysical Journa

EXOPEPTIDASE CATALYZED SITE-SPECIFIC BONDING OF SUPPORTS, LABELS AND BIOACTIVE AGENTS TO PROTEINS

The invention provides a means for attaching a label, support or bioactive agent to a protein with an exopeptidase at a site that is remote from the active site of the protein. More specifically the invention is directed to a method for the attachment of an amino acid, amine and alcohol nucleophile to the carboxyl terminus of a protein. In one embodiment, a labeled nucleophile is attached to a protein such as an antibody. In other embodiments, the invention is directed to a method for the attachment of a protein to an immobilization support and to a method for the attachment of a bioactive agent to a protein

EXOPEPTIDASE CATALYZED SITE-SPECIFIC BONDING OF SUPPORTS, LABELS AND BIOACTIVE AGENTS TO PROTEINS

An auxiliary substance such as a label, support, or bioactive agent is attached to a protein at a site that is remote from the active site of the protein by the use of exopeptidase and a nucleophile which is an amino acid, amino acid derivative, amine or alcohol. In one embodiment, the nucleophile is attached to the carboxy terminus of a protein by catalysis with exopeptidase to form an adduct and then the adduct or its combination with a linker arm is bound to the auxiliary substance. In another embodiment, the auxiliary substance or its combination with a linker arm is bound to the nucleophile to form an intermediate substance which is then coupled by catalysis with exopeptidase to the carboxy terminus of a protein

Exile Vol. XXX

Black and White by Seymour Buffalo 1 Demosthenes by A. T. McMullen 2 Losing Face by K. Kiefer 3 untitled by Christ Paul 4 Graduations by Jay Krieger 5-6 Anonymous #1 7 Sorry We Are Close by Scott Schuster 8-25 The Roommates by Gregor Macdonald 26 Perfectly Good Words by Gregor Macdonald 27 Trees Fall Without Me, Would You? by Kate Reynolds 28-29 Anonymous #2 30 Here at the House by Joan Dewitt 31-34 An 11 year old Mother in Stanton, Tennessee by Kate Reynolds 35 In the Livingroom by Don Wenzel 36-40 Minimata by Seymour Buffalo 41 Innocent Intentions by Funkmahn 42 Bird to Brittany by A. T. McMullen 43 Fall Parent\u27s Weekend by Jacqueline Ondy 44 Cover Drawing by Jim Kenne

Quantum trajectory approach to circuit QED: Quantum jumps and the Zeno effect

We present a theoretical study of a superconducting charge qubit dispersively coupled to a transmission line resonator. Starting from a master equation description of this coupled system and using a polaron transformation, we obtain an exact effective master equation for the qubit. We then use quantum trajectory theory to investigate the measurement of the qubit by continuous homodyne measurement of the resonator out-field. Using the same porlaron transformation, a stochastic master equation for the conditional state of the qubit is obtained. From this result, various definitions of the measurement time are studied. Furthermore, we find that in the limit of strong homodyne measurement, typical quantum trajectories for the qubit exhibit a crossover from diffusive to jump-like behavior. Finally, in the presence of Rabi drive on the qubit, the qubit dynamics is shown to exhibit quantum Zeno behavior.Comment: 20 pages, 12 figure

Qubit-photon interactions in a cavity: Measurement induced dephasing and number splitting

We theoretically study measurement induced-dephasing of a superconducting qubit in the circuit QED architecture and compare the results to those obtained experimentally by Schuster {\it et al.}, [Phys. Rev. Lett. 94, 123602 (2005)]. Strong coupling of the qubit to the resonator leads to a significant ac-Stark shift of the qubit transition frequency. As a result, quantum fluctuations in the photon number populating the resonator cause dephasing of the qubit. We find good agreement between the predicted line shape of the qubit spectrum and the experimental results. Furthermore, in the strong dispersive limit, where the Stark shift per photon is large compared to the cavity decay rate and the qubit linewidth, we predict that the qubit spectrum will be split into multiple peaks, with each peak corresponding to a different number of photons in the cavity.Comment: 15 pages and 10 figures. Section IV revised. Author and references added. Version with high resolution figures available at available at http://www.physique.usherbrooke.ca/~ablais/publications.ht

Composite Inelastic Dark Matter

Peaking consistently in June for nearly eleven years, the annual modulation signal reported by DAMA/NaI and DAMA/LIBRA offers strong evidence for the identity of dark matter. DAMA's signal strongly suggest that dark matter inelastically scatters into an excited state split by O(100 keV). We propose that DAMA is observing hyperfine transitions of a composite dark matter particle. As an example, we consider a meson of a QCD-like sector, built out of constituent fermions whose spin-spin interactions break the degeneracy of the ground state. An axially coupled U(1) gauge boson that mixes kinetically with hypercharge induces inelastic hyperfine transitions of the meson dark matter that can explain the DAMA signal.Comment: 5 pages (two-column), 1 figure, revised version, references adde