1,006 research outputs found
Numerical calculations of viscous compressible fluid flow over a flat plate and step geometry
Computer programs for numerical calculation of viscous compressible fluid flow over flat plat
Calculation of two-dimensional turbulent flow fields
Navier-Stokes equation solutions for two- dimensional turbulent flow fields of compressible viscous flui
Inducible Control of Subcellular RNA Localization Using a Synthetic Protein-RNA Aptamer Interaction
Evidence is accumulating in support of the functional importance of subcellular RNA localization in diverse biological contexts. In different cell types, distinct RNA localization patterns are frequently observed, and the available data indicate that this is achieved through a series of highly coordinated events. Classically, cis–elements within the RNA to be localized are recognized by RNA-binding proteins (RBPs), which then direct specific localization of a target RNA. Until now, the precise control of the spatiotemporal parameters inherent to regulating RNA localization has not been experimentally possible. Here, we demonstrate the development and use of a chemically–inducible RNA–protein interaction to regulate subcellular RNA localization. Our system is composed primarily of two parts: (i) the Tet Repressor protein (TetR) genetically fused to proteins natively involved in localizing endogenous transcripts; and (ii) a target transcript containing genetically encoded TetR–binding RNA aptamers. TetR–fusion protein binding to the target RNA and subsequent localization of the latter are directly regulated by doxycycline. Using this platform, we demonstrate that enhanced and controlled subcellular localization of engineered transcripts are achievable. We also analyze rules for forward engineering this RNA localization system in an effort to facilitate its straightforward application to studying RNA localization more generally.National Institutes of Health (U.S.) (Director’s New Innovator Award Program (grant number 1DP2OD007124 )
Second cohomology for finite groups of Lie type
Let be a simple, simply-connected algebraic group defined over
. Given a power of , let
be the subgroup of -rational points. Let be the
simple rational -module of highest weight . In this paper we
establish sufficient criteria for the restriction map in second cohomology
to be an
isomorphism. In particular, the restriction map is an isomorphism under very
mild conditions on and provided is less than or equal to a
fundamental dominant weight. Even when the restriction map is not an
isomorphism, we are often able to describe in
terms of rational cohomology for . We apply our techniques to compute
in a wide range of cases, and obtain new
examples of nonzero second cohomology for finite groups of Lie type.Comment: 29 pages, GAP code included as an ancillary file. Rewritten to
include the adjoint representation in types An, B2, and Cn. Corrections made
to Theorem 3.1.3 and subsequent dependent results in Sections 3-4. Additional
minor corrections and improvements also implemente
First cohomology for finite groups of Lie type: simple modules with small dominant weights
Let be an algebraically closed field of characteristic , and let
be a simple, simply connected algebraic group defined over .
Given , set , and let be the corresponding
finite Chevalley group. In this paper we investigate the structure of the first
cohomology group where is the
simple -module of highest weight . Under certain very mild
conditions on and , we are able to completely describe the first
cohomology group when is less than or equal to a fundamental dominant
weight. In particular, in the cases we consider, we show that the first
cohomology group has dimension at most one. Our calculations significantly
extend, and provide new proofs for, earlier results of Cline, Parshall, Scott,
and Jones, who considered the special case when is a minimal nonzero
dominant weight.Comment: 24 pages, 5 figures, 6 tables. Typos corrected and some proofs
streamlined over previous versio
On the Origin of the -4.4 eV Band in CdTe(100)"
We calculate the bulk- (infinite system), (100)-bulk-projected- and
(100)-Surface-projected Green's functions using the Surface Green's Function
Matching method (SGFM) and an empirical tight-binding hamiltonian with
tight-binding parameters (TBP) that describe well the bulk band structure of
CdTe. In particular, we analyze the band (B--4) arising at --4.4 eV from the
top of the valence band at according to the results of Niles and
H\"ochst and at -4.6 eV according to Gawlik {\it et al.} both obtained by
Angle-resolved photoelectron spectroscopy (ARPES). We give the first
theoretical description of this band.Comment: 17 pages, Rev-TEX, CIEA-Phys. 02/9
Study of UV Degradation on Plastic (PET) Aerosols
The present study was aimed to explore the impact of UV radiation, from ‘real world’ environmental exposure, on the degradation of plastic PET aerosol containers. Additionally, the intent was to correlate the ‘real world’ environmental exposure to artificial sunlight, using a Xenon-Arc lamp, to develop a simulated test. The standardized methodology could then be used to evaluate the integrity of the plastic aerosol container and product, without the complexity of using ‘real world’ exposure. Through this study, a lab method was developed and validated that would simulate the effect of UV radiation using the Xenon-Arc. Moreover, a correlation was made for conditions inside the Xenon-Arc chamber that were conducive to testing a plastic pressurized container
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