Integrated Flush Air Data Sensing System Modeling for Planetary Entry Guidance with Direct Force Control

Flush air data sensing (FADS) systems have been previously used at both Earth and Mars to provide onboard estimates of angle of attack, sideslip angle, and dynamic pressure. However, these FADS data were often not used in an in-the-loop sense to inform the onboard guidance and control systems. A method to integrate FADS-derived density and wind estimates with a numerical predictor-corrector guidance algorithm is presented. The method is demonstrated in a high-fidelity simulation of a human-scale Mars entry vehicle that utilizes a hypersonic inflatable aerodynamic decelerator (HIAD) with direct force control. Effects on guidance commands and state uncertainties both with and without FADS system modeling are presented and discussed

Pathguide: a Pathway Resource List

Pathguide: the Pathway Resource List () is a meta-database that provides an overview of more than 190 web-accessible biological pathway and network databases. These include databases on metabolic pathways, signaling pathways, transcription factor targets, gene regulatory networks, genetic interactions, protein–compound interactions, and protein–protein interactions. The listed databases are maintained by diverse groups in different locations and the information in them is derived either from the scientific literature or from systematic experiments. Pathguide is useful as a starting point for biological pathway analysis and for content aggregation in integrated biological information systems

DNA structural deformations in the interaction of the controller protein C.AhdI with its operator sequence

Controller proteins such as C.AhdI regulate the expression of bacterial restriction–modification genes, and ensure that methylation of the host DNA precedes restriction by delaying transcription of the endonuclease. The operator DNA sequence to which C.AhdI binds consists of two adjacent binding sites, OL and OR. Binding of C.AhdI to OL and to OL + OR has been investigated by circular permutation DNA-bending assays and by circular dichroism (CD) spectroscopy. CD indicates considerable distortion to the DNA when bound by C.AhdI. Binding to one or two sites to form dimeric and tetrameric complexes increases the CD signal at 278 nm by 40 and 80% respectively, showing identical local distortion at both sites. In contrast, DNA-bending assays gave similar bend angles for both dimeric and tetrameric complexes (47 and 38°, respectively). The relative orientation of C.AhdI dimers in the tetrameric complex and the structural role of the conserved Py-A-T sequences found at the centre of C-protein-binding sites are discussed

DNA structural deformations in the interaction of the controller protein C.AhdI with its operator sequence

Controller proteins such as C.AhdI regulate the expression of bacterial restriction–modification genes, and ensure that methylation of the host DNA precedes restriction by delaying transcription of the endonuclease. The operator DNA sequence to which C.AhdI binds consists of two adjacent binding sites, OL and OR. Binding of C.AhdI to OL and to OL + OR has been investigated by circular permutation DNA-bending assays and by circular dichroism (CD) spectroscopy. CD indicates considerable distortion to the DNA when bound by C.AhdI. Binding to one or two sites to form dimeric and tetrameric complexes increases the CD signal at 278 nm by 40 and 80% respectively, showing identical local distortion at both sites. In contrast, DNA-bending assays gave similar bend angles for both dimeric and tetrameric complexes (47 and 38°, respectively). The relative orientation of C.AhdI dimers in the tetrameric complex and the structural role of the conserved Py-A-T sequences found at the centre of C-protein-binding sites are discussed

Decay Rate of Triaxially-Deformed Proton Emitters

The decay rate of a triaxially-deformed proton emitter is calculated in a particle-rotor model, which is based on a deformed Woods-Saxon potential and includes a deformed spin-orbit interaction. The wave function of the $I=7/2^{-}$ ground state of the deformed proton emitter $^{141}$Ho is obtained in the adiabatic limit, and a Green's function technique is used to calculate the decay rate and branching ratio to the first excited 2$^{+}$ state of the daughter nucleus. Only for values of the triaxial angle $\gamma$ $<5^{\circ}$ is good agreement obtained for both the total decay rate and the 2$^{+}$ branching ratio.Comment: 19 pages, 4 figure

The Theory of the Interleaving Distance on Multidimensional Persistence Modules

In 2009, Chazal et al. introduced $\epsilon$-interleavings of persistence modules. $\epsilon$-interleavings induce a pseudometric $d_I$ on (isomorphism classes of) persistence modules, the interleaving distance. The definitions of $\epsilon$-interleavings and $d_I$ generalize readily to multidimensional persistence modules. In this paper, we develop the theory of multidimensional interleavings, with a view towards applications to topological data analysis. We present four main results. First, we show that on 1-D persistence modules, $d_I$ is equal to the bottleneck distance $d_B$. This result, which first appeared in an earlier preprint of this paper, has since appeared in several other places, and is now known as the isometry theorem. Second, we present a characterization of the $\epsilon$-interleaving relation on multidimensional persistence modules. This expresses transparently the sense in which two $\epsilon$-interleaved modules are algebraically similar. Third, using this characterization, we show that when we define our persistence modules over a prime field, $d_I$ satisfies a universality property. This universality result is the central result of the paper. It says that $d_I$ satisfies a stability property generalizing one which $d_B$ is known to satisfy, and that in addition, if $d$ is any other pseudometric on multidimensional persistence modules satisfying the same stability property, then $d\leq d_I$. We also show that a variant of this universality result holds for $d_B$, over arbitrary fields. Finally, we show that $d_I$ restricts to a metric on isomorphism classes of finitely presented multidimensional persistence modules.Comment: Major revision; exposition improved throughout. To appear in Foundations of Computational Mathematics. 36 page

Long-time discrete particle effects versus kinetic theory in the self-consistent single-wave model

The influence of the finite number N of particles coupled to a monochromatic wave in a collisionless plasma is investigated. For growth as well as damping of the wave, discrete particle numerical simulations show an N-dependent long time behavior resulting from the dynamics of individual particles. This behavior differs from the one due to the numerical errors incurred by Vlasov approaches. Trapping oscillations are crucial to long time dynamics, as the wave oscillations are controlled by the particle distribution inhomogeneities and the pulsating separatrix crossings drive the relaxation towards thermal equilibrium.Comment: 11 pages incl. 13 figs. Phys. Rev. E, in pres

Phase transition in the collisionless regime for wave-particle interaction

Gibbs statistical mechanics is derived for the Hamiltonian system coupling self-consistently a wave to N particles. This identifies Landau damping with a regime where a second order phase transition occurs. For nonequilibrium initial data with warm particles, a critical initial wave intensity is found: above it, thermodynamics predicts a finite wave amplitude in the limit of infinite N; below it, the equilibrium amplitude vanishes. Simulations support these predictions providing new insight on the long-time nonlinear fate of the wave due to Landau damping in plasmas.Comment: 12 pages (RevTeX), 2 figures (PostScript