27 research outputs found
Implication of Barrier Fluctuations on the Rate of Weakly Adiabatic Electron Transfer
The problem of escape of a Brownian particle in a cusp-shaped metastable
potential is of special importance in nonadiabatic and weakly-adiabatic rate
theory for electron transfer (ET) reactions. Especially, for the
weakly-adiabatic reactions, the reaction follows an adiabaticity criterion in
the presence of a sharp barrier. In contrast to the non-adiabatic case, the ET
kinetics can be, however considerably influenced by the medium dynamics.
In this paper, the problem of the escape time over a dichotomously
fluctuating cusp barrier is discussed with its relevance to the high
temperature ET reactions in condensed media.Comment: RevTeX 4, 14 pages, 3 figures. To be printed in IJMP C. References
corrected and update
Position-dependent random maps in one and higher dimensions
A random map is a discrete-time dynamical system in which one of a number of transformations is randomly selected and applied on each iteration of the process. We study random maps with position dependent probabilities on the interval and on a bounded domain of Rn. Sufficient conditions for the existence of an absolutely continuous invariant measure for a random map with position dependent probabilities on the interval and on a bounded domain of Rn are the main results
SRB measures for certain Markov processes
We study Markov processes generated by iterated function systems (IFS). The constituent maps of the IFS are monotonic transformations of the interval. We first obtain an upper bound on the number of SRB (Sinai-Ruelle-Bowen) measures for the IFS. Then, when all the constituent maps have common fixed points at 0 and 1, theorems are given to analyze properties of the ergodic invariant measures \delta_0 and \delta_1. In particular, sufficient conditions for \delta_0 and/or \delta_1 to be, or not to be, SRB measures are given. We apply some of our results to asset market games
Absolutely Continuous Invariant measures for non-autonomous dynamical systems
We consider the non autonomous dynamical system where
is a continuous map and is a compact metric
space. We assume that converges uniformly to The
inheritance of chaotic properties as well as topological entropy by
from the sequence has been studied in \cite{Can1, Can2,
Li,Ste,Zhu}. In \cite{You} the generalization of SRB\ measures to
non-autonomous systems has been considered. In this paper we study absolutely
continuous invariant measures (acim) for non autonomous systems. After
generalizing the Krylov-Bogoliubov Theorem \cite{KB} and Straube's Theorem
\cite{Str} to the non autonomous setting, we prove that under certain
conditions the limit map of a non autonomous sequence of maps
with acims has an acim
Statistical and Deterministic Dynamics of Maps with Memory
We consider a dynamical system to have memory if it remembers the current state as well as the state before that. The dynamics is defined as follows: where is a one-dimensional map on and determines how much memory is being used. does not define a dynamical system since it maps into . In this note we let to be the symmetric tent map. We shall prove that
for the orbits of are described statistically by an absolutely continuous invariant measure (acim) in two dimensions. As approaches from below, that is, as we approach a balance between the memory state and the present state, the support of the acims become thinner until at , all points have period 3 or eventually possess period 3. For , we have a global attractor: for all starting points in except , the orbits are attracted to the fixed point At we have slightly more complicated periodic behavior
Two novel C-terminal frameshift mutations in the β-globin gene lead to rapid mRNA decay
BACKGROUND:
The thalassemia syndromes are classified according to the globin chain or chains whose production is affected. β-thalassemias are caused by point mutations or, more rarely, deletions or insertions of a few nucleotides in the β-globin gene or its immediate flanking sequences. These mutations interfere with the gene function either at the transcriptional, translational or posttranslational level.
METHODS:
Two cases of Polish patients with hereditary hemolytic anemia suspected of thalassemia were studied. DNA sequencing and mRNA quantification were performed. Stable human cell lines which express wild-type HBB and mutated versions were used to verify that detected mutation are responsible for mRNA degradation.
RESULTS:
We identified two different frameshift mutations positioned in the third exon of HBB. Both patients harboring these mutations present the clinical phenotype of thalassemia intermedia and showed dominant pattern of inheritance. In both cases the mutations do not generate premature stop codon. Instead, slightly longer protein with unnatural C-terminus could be produced. Interestingly, although detected mutations are not expected to induce NMD, the mutant version of mRNA is not detectable. Restoring of the open reading frame brought back the RNA to that of the wild-type level.
CONCLUSION:
Our results show that a lack of natural stop codon due to the frameshift in exon 3 of β-globin gene causes rapid degradation of its mRNA and indicate existence of novel surveillance pathway
Quantum games and interactive tools for quantum technologies outreach and education
We provide an extensive overview of a wide range of quantum games and interactive tools that have been employed by the quantum community in recent years. We present selected tools as described by their developers, including "Hello Quantum, Hello Qiskit, Particle in a Box, Psi and Delta, QPlayLearn, Virtual Lab by Quantum Flytrap, Quantum Odyssey, ScienceAtHome, and the Virtual Quantum Optics Laboratory." In addition, we present events for quantum game development: hackathons, game jams, and semester projects. Furthermore, we discuss the Quantum Technologies Education for Everyone (QUTE4E) pilot project, which illustrates an effective integration of these interactive tools with quantum outreach and education activities. Finally, we aim at providing guidelines for incorporating quantum games and interactive tools in pedagogic materials to make quantum technologies more accessible for a wider population. (C) The Authors. Published by SPIE under a Creative Commons Attribution 4.0 International License.Peer reviewe