Control of Arabidopsis apical-basal embryo polarity by antagonistic transcription factors.

Plants, similarly to animals, form polarized axes during embryogenesis on which cell differentiation and organ patterning programs are orchestrated. During Arabidopsis embryogenesis, establishment of the shoot and root stem cell populations occurs at opposite ends of an apical-basal axis. Recent work has identified the PLETHORA (PLT) genes as master regulators of basal/root fate, whereas the master regulators of apical/shoot fate have remained elusive. Here we show that the PLT1 and PLT2 genes are direct targets of the transcriptional co-repressor TOPLESS (TPL) and that PLT1/2 are necessary for the homeotic conversion of shoots to roots in tpl-1 mutants. Using tpl-1 as a genetic tool, we identify the CLASS III HOMEODOMAIN-LEUCINE ZIPPER (HD-ZIP III) transcription factors as master regulators of embryonic apical fate, and show they are sufficient to drive the conversion of the embryonic root pole into a second shoot pole. Furthermore, genetic and misexpression studies show an antagonistic relationship between the PLT and HD-ZIP III genes in specifying the root and shoot poles

The Anchorage, Alaska Municipal Pretrial Diversion Program: An Initial Assessment

Pretrial diversion programs have the potential to prevent future criminal behavior through intervention and community based services. This may be particularly true for specific populations of offenders such as those with mental illness, substance abuse disorder, and those with co-occuring disorders. Pretrial diversion programs take low-level offenders out of the jail population, both reducing system overpopulation and costs of incarceration. The programs also provide speedy case processing for minor crimes resulting in savings to the court system and personnel. Pretrial diversion can help an offender avoid a criminal conviction and potentially avoid future criminal violations. Results indicate that most Anchorage pretrial defendants comply with and complete the pretrial conditions in a very short time period, an additional savings in case processing time. This research details the initial assessment of the Anchorage Municipal Prosecutor Pretrial Diversion program. This assessment examines system savings in time and money, as well as policy implications for the justice system that may assist other jurisdictions as they consider implementing a pretrial diversion program

The Anchorage, Alaska Municipal Pretrial Diversion Program: Initial Outcome Assessment

This report provides an initial outcome assessment of the Anchorage Municipal Pretrial Diversion Program, a voluntary program aimed at diverting first-time offenders in certain criminal and traffic cases from traditional case processing, with successful complion of the terms of the program resulting in dismissal of charges. Pretrial diversion agreements under AMC 08.05.060 typically require the defendant to pay a fine or do community work service, usually within a month. The initial assessment examines offender completion under the program, adherence to conditions of probation, and time and cost savings for the Anchorage Municipal Prosecutor's Office.Office of the Anchorage Municipal Prosecutor, Municipality of Anchorage, AKAcknowledgments / Section I: Executive Summary / Counts and Charges of Defendants Offered Pretrial Diversion / Demographic Variations Among Defendants Offered Pretrial Diversion / Conditions of Pretrial Diversion / Length of Time for Pretrial Diversion Processes / Number of Court Hearings and Estimated Time Spent / Section II: Introduction / Section III: Literature Review / Descriptions of Pretrial Diversion / Pretrial Diversion in the United States / Description of Pretrial Diversion in Anchorage / Section IV: Methods / Data Collection / Section VI: Findings / Counts and Charges of Defendants Offered Pretrial Diversion / Demographic Variations Among Defendants Offered Pretrial Diversion / Conditions of Pretrial Diversion / Length of Time for Pretrial Diversion Processes / Number of Court Hearings and Estimated Time Spent / Section VII: Conclusion / References / Appendix: Anchorage Municipal Pretrial Diversion Data Collection For

Kaluza-Klein Towers in the Early Universe: Phase Transitions, Relic Abundances, and Applications to Axion Cosmology

We study the early-universe cosmology of a Kaluza-Klein (KK) tower of scalar fields in the presence of a mass-generating phase transition, focusing on the time-development of the total tower energy density (or relic abundance) as well as its distribution across the different KK modes. We find that both of these features are extremely sensitive to the details of the phase transition and can behave in a variety of ways significant for late-time cosmology. In particular, we find that the interplay between the temporal properties of the phase transition and the mixing it generates are responsible for both enhancements and suppressions in the late-time abundances, sometimes by many orders of magnitude. We map out the complete model parameter space and determine where traditional analytical approximations are valid and where they fail. In the latter cases we also provide new analytical approximations which successfully model our results. Finally, we apply this machinery to the example of an axion-like field in the bulk, mapping these phenomena over an enlarged axion parameter space that extends beyond those accessible to standard treatments. An important by-product of our analysis is the development of an alternate "UV-based" effective truncation of KK theories which has a number of interesting theoretical properties that distinguish it from the more traditional "IR-based" truncation typically used in the extra-dimension literature.Comment: 30 pages, LaTeX, 18 figures. Replaced to match published versio

A Tale of Two Timescales: Mixing, Mass Generation, and Phase Transitions in the Early Universe

Light scalar fields such as axions and string moduli can play an important role in early-universe cosmology. However, many factors can significantly impact their late-time cosmological abundances. For example, in cases where the potentials for these fields are generated dynamically --- such as during cosmological mass-generating phase transitions --- the duration of the time interval required for these potentials to fully develop can have significant repercussions. Likewise, in scenarios with multiple scalars, mixing amongst the fields can also give rise to an effective timescale that modifies the resulting late-time abundances. Previous studies have focused on the effects of either the first or the second timescale in isolation. In this paper, by contrast, we examine the new features that arise from the interplay between these two timescales when both mixing and time-dependent phase transitions are introduced together. First, we find that the effects of these timescales can conspire to alter not only the total late-time abundance of the system --- often by many orders of magnitude --- but also its distribution across the different fields. Second, we find that these effects can produce large parametric resonances which render the energy densities of the fields highly sensitive to the degree of mixing as well as the duration of the time interval over which the phase transition unfolds. Finally, we find that these effects can even give rise to a "re-overdamping" phenomenon which causes the total energy density of the system to behave in novel ways that differ from those exhibited by pure dark matter or vacuum energy. All of these features therefore give rise to new possibilities for early-universe phenomenology and cosmological evolution. They also highlight the importance of taking into account the time dependence associated with phase transitions in cosmological settings.Comment: Comments: 35 pages, LaTeX, 31 figures, 1 tabl

Laterites and paleoclimates. Weathering processes and anthropogenic impact

The European Union of Geosciences held its 9th biannual meeting in Strasbourg, March 23–27, 1997. During this meeting, Symposium No. 63, Weathering Processes: Mineral deposits and soil formation in tropical enÍironments, was merged with Symposium No. 78, Anthropogenic Impact on Weathering processesco-sponsored by IGCP Project 405. The resulting symposium No. 63, Weathering processes and Anthropogenic Impact, was held under the sponsorship of EUROLAT1 and attracted 36 oral and poster presentations and about 100 participants, reflecting the interest of the Earth Sciences community in weathering processes and anthropogenic impact

Deep narrow band imagery of the diffuse ISM in M33

Very deep narrow band images were obtained for several fields in the local group spiral galaxy M33 using a wide field reimaging Charge Coupled Device (CCD) camera on the 1.5 m telescope at Palomar Observatory. The reimaging system uses a 306 mm collimator and a 58 mm camera lens to put a 16 minute by 16 minute field onto a Texas Instruments 800 x 800 pixel CCD at a resolution of 1.2 arcseconds pixel (-1). The overall system is f/1.65. Images were obtained in the light of H alpha (S II) lambda lambda 6717, 6731, (O III) lambda 5007, and line-free continuum bands 100A wide, centered at 6450A and 5100A. Assuming a distance of 600 kpc to M33 (Humphreys 1980, Ap. J., 241, 587), this corresponds to a linear scale of 3.5 pc pixel (-1), and a field size of 2.8 kpc x 2.8 kpc. Researchers discuss the H alpha imagery of a field centered approx. equal to 8 minutes NE of the nucleus, including the supergiant HII region complex NGC 604. Two 2000 second H alpha images and two 300 second red continuum images were obtained of two slightly offset fields. The fields were offset to allow for discrimination between real emission and possible artifacts in the images. All images were resampled to align them with one of the H alpha frames. The continuum images were normalized to the line images using the results of aperture photometry on a grid of stars in the field, then the rescaled continuum data were directly subtracted from the line data

Carbon and titanium diboride (TiB2) multilayer coatings.

Titanium Diboride, (TiB2) is a metal-based refractory ceramic material that has been investigated in industrial applications ranging from, cutting tools to wear parts and for use in the aerospace industry. The unique properties which make this material so fascinating are, its high hardness, high melting point and its corrosion resistance. TiB2 is prevented from wider mainstream use because of its inherent brittle nature. With a view to overcome this in coating form and with the aim of providing in addition inherent lubricity, in this study 50 layer TiB2/C multilayer stacks have been fabricated, with varying volume fractions of ceramic, whereby the interfaces of the layers limit crack propagation in the TiB2 ceramic. TiB2 has been multilayered with carbon, to make use of the unique and hybrid nature of the bonding in carbon coatings. DC magnetron sputtering with substrate bias was the preferred route for the fabrication of these coatings. AISI tool steel has been used as the substrate material. By varying the amount of TiB2 ceramic from 50% to 95%, the Hardness of the coating is seen to increase from 5 GPa to 17GPa. The Hardness is observed to decrease as a function of increasing carbon content, agreeing with other studies that the carbon layers are not load-bearing. The graphitic nature of the sp2 bond, however, acts as a lubricant layer

Cooperative Control and Potential Games

We present a view of cooperative control using the language of learning in games. We review the game-theoretic concepts of potential and weakly acyclic games, and demonstrate how several cooperative control problems, such as consensus and dynamic sensor coverage, can be formulated in these settings. Motivated by this connection, we build upon game-theoretic concepts to better accommodate a broader class of cooperative control problems. In particular, we extend existing learning algorithms to accommodate restricted action sets caused by the limitations of agent capabilities and group based decision making. Furthermore, we also introduce a new class of games called sometimes weakly acyclic games for time-varying objective functions and action sets, and provide distributed algorithms for convergence to an equilibrium