377 research outputs found
Combinatorial Solutions to Normal Ordering of Bosons
We present a combinatorial method of constructing solutions to the normal
ordering of boson operators. Generalizations of standard combinatorial notions
- the Stirling and Bell numbers, Bell polynomials and Dobinski relations - lead
to calculational tools which allow to find explicitly normally ordered forms
for a large class of operator functions.Comment: Presented at 14th Int. Colloquium on Integrable Systems, Prague,
Czech Republic, 16-18 June 2005. 6 pages, 11 reference
DobiΕski relations and ordering of boson operators
We introduce a generalization of the DobiΕski relation, through which we define a family of Bell-type numbers and polynomials. Such generalized DobiΕski relations are coherent state matrix elements of expressions involving boson ladder operators. This may be used in order to obtain normally ordered forms of polynomials in creation and annihilation operators, both if the latter satisfy canonical and deformed commutation relations
Heisenberg-Weyl algebra revisited: Combinatorics of words and paths
The Heisenberg-Weyl algebra, which underlies virtually all physical
representations of Quantum Theory, is considered from the combinatorial point
of view. We provide a concrete model of the algebra in terms of paths on a
lattice with some decomposition rules. We also discuss the rook problem on the
associated Ferrers board; this is related to the calculus in the normally
ordered basis. From this starting point we explore a combinatorial underpinning
of the Heisenberg-Weyl algebra, which offers novel perspectives, methods and
applications.Comment: 5 pages, 3 figure
Exponential Operators, Dobinski Relations and Summability
We investigate properties of exponential operators preserving the particle
number using combinatorial methods developed in order to solve the boson normal
ordering problem. In particular, we apply generalized Dobinski relations and
methods of multivariate Bell polynomials which enable us to understand the
meaning of perturbation-like expansions of exponential operators. Such
expansions, obtained as formal power series, are everywhere divergent but the
Pade summation method is shown to give results which very well agree with exact
solutions got for simplified quantum models of the one mode bosonic systems.Comment: Presented at XIIth Central European Workshop on Quantum Optics,
Bilkent University, Ankara, Turkey, 6-10 June 2005. 4 figures, 6 pages, 10
reference
Zinc differentially modulates DNA damage induced by anthracyclines in normal and cancer cells
Zinc is one of the most essential trace elements in human organism. Low blood level of zinc is often noted in acute lymphocytic leukemia (ALL). Treatment with zinc adjuvant is hypothesized to accelerate recovery from ALL, and in conjunction with chemotherapy, cure ALL. Aim: We determined the effect of zinc on DNA damage induced by doxorubicin and idarubicin, two anthracyclines used in ALL treatment. Methods: The experiment was performed on acute lymphoblastic leukemia cell line (CCRF-CEM) and lymphocytes from peripheral blood of healthy, adult subjects. To evaluate the level of DNA damage the comet assay in the alkaline version was used. Results: We observed a significant difference in DNA damage level between normal and cancer cells in the presence of zinc. Cancer cells exhibited a significant increase of DNA damage in the presence of zinc, while in lymphocytes no such effect was observed. Conclusion: Our results suggest that zinc may protect normal cells against DNA-damaging action of anthracyclins and increase this action in cancer cells
Combinatorics and Boson normal ordering: A gentle introduction
We discuss a general combinatorial framework for operator ordering problems
by applying it to the normal ordering of the powers and exponential of the
boson number operator. The solution of the problem is given in terms of Bell
and Stirling numbers enumerating partitions of a set. This framework reveals
several inherent relations between ordering problems and combinatorial objects,
and displays the analytical background to Wick's theorem. The methodology can
be straightforwardly generalized from the simple example given herein to a wide
class of operators.Comment: 8 pages, 1 figur
Amifostine can differentially modulate DNA double-strand breaks and apoptosis induced by idarubicin in normal and cancer cells
We have previously shown that amifostine differentially modulated the DNA-damaging action of idarubicin in normal and cancer cells and that the presence of p53 protein and oncogenic tyrosine kinases might play a role in this diversity. Aim: To investigate further this effect we have studied the influence of amifostine on idarubicin-induced DNA double-strand breaks (DSBs) and apoptosis. Methods: We employed pulse-field gel electrophoresis () for the detection of DSBs and assessment of their repair in human normal lymphocytes and chronic myelogenous leukaemia K562 cells lacking p53 activity and expressing the BCR/ABL tyrosine kinase. Apoptosis was evaluated by caspase-3 activity assay assisted by the alkaline comet assay and DAPI staining. Results: Idarubicin induced DSBs in a dose-independent manner in normal and cancer cells. Both types of the cells did not repair these lesions in 120 min and amifostine differentially modulated their level β decreased it in the lymphocytes and increased in K562 cells. In contrast to control cells, amifostine potentated apoptotic DNA fragmentation, chromatin condensation and the activity of caspase-3 in leukaemia cells. Conclusion: Amifostine can differentially modulate DSBs and apoptosis induced by idarubicin in normal and cancer cells. It can protect normal cells against drug-induced DNA damage and it can potentate the action of the drug in leukaemic cells. Further studies on link between amifostine-induced modulation of DSBs and apoptosis of cancer cells will bring a deeper insight into molecular mechanism of amifostine action.Π Π°Π½Π΅Π΅ Π½Π°ΠΌΠΈ Π±ΡΠ»ΠΎ ΠΏΠΎΠΊΠ°Π·Π°Π½ΠΎ, ΡΡΠΎ Π°ΠΌΠΈΡΠΎΡΡΠΈΠ½ Π΄ΠΈΡΡΠ΅ΡΠ΅Π½ΡΠΈΠ°Π»ΡΠ½ΠΎ ΠΌΠΎΠ΄ΡΠ»ΠΈΡΡΠ΅Ρ ΠΠΠ-ΠΏΠΎΠ²ΡΠ΅ΠΆΠ΄Π°ΡΡΠ΅Π΅ Π΄Π΅ΠΉΡΡΠ²ΠΈΠ΅ ΠΈΠ΄Π°ΡΡΠ±ΠΈΡΠΈΠ½Π° Π²
Π½ΠΎΡΠΌΠ°Π»ΡΠ½ΡΡ
ΠΈ Π·Π»ΠΎΠΊΠ°ΡΠ΅ΡΡΠ²Π΅Π½Π½ΡΡ
ΠΊΠ»Π΅ΡΠΊΠ°Ρ
, ΠΈ ΡΡΠΎ Π½Π°Π»ΠΈΡΠΈΠ΅ Π±Π΅Π»ΠΊΠ° Ρ53 ΠΈ ΠΎΠ½ΠΊΠΎΠ³Π΅Π½Π½ΡΡ
ΡΠΈΡΠΎΠ·ΠΈΠ½ ΠΊΠΈΠ½Π°Π· ΠΌΠΎΠΆΠ΅Ρ ΠΈΠΌΠ΅ΡΡ Π·Π½Π°ΡΠ΅Π½ΠΈΠ΅ Π΄Π»Ρ
ΡΡΠΈΡ
ΡΠ°Π·Π»ΠΈΡΠΈΠΉ. Π¦Π΅Π»Ρ: ΠΈΠ·ΡΡΠΈΡΡ Π²Π»ΠΈΡΠ½ΠΈΠ΅ Π°ΠΌΠΈΡΠΎΡΡΠΈΠ½Π° Π½Π° ΠΈΠ΄Π°ΡΡΠ±ΠΈΡΠΈΠ½-ΠΎΠΏΠΎΡΡΠ΅Π΄ΠΎΠ²Π°Π½Π½ΡΠ΅ Π΄Π²ΡΡ
Π½ΠΈΡΠ΅Π²ΡΠ΅ ΡΠ°Π·ΡΡΠ²Ρ ΠΠΠ (DSBs)
ΠΈ Π°ΠΏΠΎΠΏΡΠΎΠ·. ΠΠ΅ΡΠΎΠ΄Ρ: ΠΌΡ ΠΏΡΠΈΠΌΠ΅Π½ΠΈΠ»ΠΈ Π³Π΅Π»Ρ-ΡΠ»Π΅ΠΊΡΡΠΎΡΠΎΡΠ΅Π· Π² ΠΏΡΠ»ΡΡΠΈΡΡΡΡΠ΅ΠΌ ΠΏΠΎΠ»Π΅ (PFGE) Π΄Π»Ρ Π²ΡΡΠ²Π»Π΅Π½ΠΈΡ DSBs ΠΈ ΠΈΠ·ΡΡΠ΅Π½ΠΈΡ
ΠΈΡ
ΡΠ΅ΠΏΠ°ΡΠ°ΡΠΈΠΈ Π² Π½ΠΎΡΠΌΠ°Π»ΡΠ½ΡΡ
Π»ΠΈΠΌΡΠΎΡΠΈΡΠ°Ρ
ΡΠ΅Π»ΠΎΠ²Π΅ΠΊΠ° ΠΈ ΠΊΠ»Π΅ΡΠΊΠ°Ρ
K562 Ρ
ΡΠΎΠ½ΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΌΠΈΠ΅Π»ΠΎΠΈΠ΄Π½ΠΎΠΉ Π»Π΅ΠΉΠΊΠ΅ΠΌΠΈΠΈ, Ρ ΠΊΠΎΡΠΎΡΡΡ
Ρ53
Π½Π΅Π°ΠΊΡΠΈΠ²Π΅Π½ ΠΈ ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΡΠΎΠ²Π°Π½Π° BCR/ABL-ΡΠΈΡΠΎΠ·ΠΈΠ½ ΠΊΠΈΠ½Π°Π·Π°. ΠΠΏΠΎΠΏΡΠΎΠ· ΠΎΡΠ΅Π½ΠΈΠ²Π°Π»ΠΈ Ρ ΠΏΠΎΠΌΠΎΡΡΡ ΡΠ΅Π°ΠΊΡΠΈΠ²ΠΎΠ² Π΄Π»Ρ Π²ΡΡΠ²Π»Π΅Π½ΠΈΡ
Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ ΠΊΠ°ΡΠΏΠ°Π·Ρ-3, ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½ΠΈΡ ΡΠ΅Π»ΠΎΡΠ½ΠΎΠ³ΠΎ Π³Π΅Π»Ρ-ΡΠ»Π΅ΠΊΡΡΠΎΡΠΎΡΠ΅Π·Π° ΠΎΠ΄ΠΈΠ½ΠΎΡΠ½ΡΡ
ΠΊΠ»Π΅ΡΠΎΠΊ ΠΈ DAPI-ΠΎΠΊΡΠ°ΡΠΈΠ²Π°Π½ΠΈΡ. Π Π΅Π·ΡΠ»ΡΡΠ°ΡΡ:
ΠΈΠ΄Π°ΡΡΠ±ΠΈΡΠΈΠ½ Π²ΡΠ·ΡΠ²Π°Π΅Ρ ΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°Π½ΠΈΠ΅ DSBs Π² Π½ΠΎΡΠΌΠ°Π»ΡΠ½ΡΡ
ΠΈ Π·Π»ΠΎΠΊΠ°ΡΠ΅ΡΡΠ²Π΅Π½Π½ΡΡ
ΠΊΠ»Π΅ΡΠΊΠ°Ρ
Π½Π΅Π·Π°Π²ΠΈΡΠΈΠΌΠΎ ΠΎΡ Π΄ΠΎΠ·Ρ. ΠΠ±Π° ΡΠΈΠΏΠ° ΠΊΠ»Π΅ΡΠΎΠΊ Π½Π΅
ΡΠ΅ΠΏΠ°ΡΠΈΡΠΎΠ²Π°Π»ΠΈ ΡΡΠΈ ΠΏΠΎΠ²ΡΠ΅ΠΆΠ΄Π΅Π½ΠΈΡ Π·Π° 120 ΠΌΠΈΠ½, ΠΏΡΠΈ ΡΡΠΎΠΌ Π°ΠΌΠΈΡΠΎΡΡΠΈΠ½ Π΄ΠΈΡΡΠ΅ΡΠ΅Π½ΡΠΈΠ°Π»ΡΠ½ΠΎ ΠΌΠΎΠ»ΡΠ»ΠΈΡΠΎΠ²Π°Π» ΡΡΠΎΠ²Π΅Π½Ρ DSBs β ΡΠΌΠ΅Π½ΡΡΠ°Π»
Π² Π»ΠΈΠΌΡΠΎΡΠΈΡΠ°Ρ
ΠΈ ΡΠ²Π΅Π»ΠΈΡΠΈΠ²Π°Π» Π² K562-ΠΊΠ»Π΅ΡΠΊΠ°Ρ
. Π ΠΎΡΠ»ΠΈΡΠΈΠ΅ ΠΎΡ ΠΊΠΎΠ½ΡΡΠΎΠ»ΡΠ½ΡΡ
ΠΊΠ»Π΅ΡΠΎΠΊ Π°ΠΌΠΈΡΠΎΡΡΠΈΠ½ ΠΏΠΎΡΠ΅Π½ΡΠΈΠΈΡΠΎΠ²Π°Π» Π°ΠΏΠΎΠΏΡΠΈΡΠ΅ΡΠΊΡΡ
ΡΡΠ°Π³ΠΌΠ΅Π½ΡΠ°ΡΠΈΡ ΠΠΠ, ΠΊΠΎΠ½Π΄Π΅Π½ΡΠ°ΡΠΈΡ Ρ
ΡΠΎΠΌΠ°ΡΠΈΠ½Π° ΠΈ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΡ ΠΊΠ°ΡΠΏΠ°Π·Ρ-3 Π² Π»Π΅ΠΉΠΊΠ΅ΠΌΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΊΠ»Π΅ΡΠΊΠ°Ρ
. ΠΡΠ²ΠΎΠ΄Ρ: Π°ΠΌΠΈΡΠΎΡΡΠΈΠ½ ΠΌΠΎΠΆΠ΅Ρ
Π΄ΠΈΡΡΠ΅ΡΠ΅Π½ΡΠΈΠ°Π»ΡΠ½ΠΎ ΠΌΠΎΠ΄ΡΠ»ΠΈΡΠΎΠ²Π°ΡΡ DSBs ΠΈ Π°ΠΏΠΎΠΏΡΠΎΠ·, Π²ΡΠ·Π²Π°Π½Π½ΡΠ΅ ΠΈΠ΄Π°ΡΡΠ±ΠΈΡΠΈΠ½ΠΎΠΌ Π² Π½ΠΎΡΠΌΠ°Π»ΡΠ½ΡΡ
ΠΈ Π·Π»ΠΎΠΊΠ°ΡΠ΅ΡΡΠ²Π΅Π½Π½ΡΡ
ΠΊΠ»Π΅ΡΠΊΠ°Ρ
. ΠΠ½
ΠΌΠΎΠΆΠ΅Ρ Π·Π°ΡΠΈΡΠΈΡΡ Π½ΠΎΡΠΌΠ°Π»ΡΠ½ΡΠ΅ ΠΊΠ»Π΅ΡΠΊΠΈ ΠΎΡ ΠΏΠΎΠ²ΡΠ΅ΠΆΠ΄Π΅Π½ΠΈΡ ΠΠΠ, Π²ΡΠ·Π²Π°Π½Π½ΠΎΠ³ΠΎ Ρ
ΠΈΠΌΠΈΠΎΠΏΡΠ΅ΠΏΠ°ΡΠ°ΡΠΎΠΌ, ΠΈ Π² ΡΠΎ ΠΆΠ΅ Π²ΡΠ΅ΠΌΡ ΠΏΠΎΡΠ΅Π½ΡΠΈΠΈΡΠΎΠ²Π°ΡΡ
Π΄Π΅ΠΉΡΡΠ²ΠΈΠ΅ ΠΏΡΠ΅ΠΏΠ°ΡΠ°ΡΠ° Π½Π° Π»Π΅ΠΉΠΊΠ΅ΠΌΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΠΊΠ»Π΅ΡΠΊΠΈ. ΠΠ°Π»ΡΠ½Π΅ΠΉΡΠΈΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΡΠ²ΡΠ·ΠΈ ΠΌΠ΅ΠΆΠ΄Ρ Π²ΡΠ·Π²Π°Π½Π½ΠΎΠΉ Π°ΠΌΠΈΡΠΎΡΡΠΈΠ½ΠΎΠΌ ΠΌΠΎΠ΄ΡΠ»ΡΡΠΈΠ΅ΠΉ
DSBs ΠΈ Π°ΠΏΠΎΠΏΡΠΎΠ·Π° ΠΎΠΏΡΡ
ΠΎΠ»Π΅Π²ΡΡ
ΠΊΠ»Π΅ΡΠΎΠΊ ΠΏΠΎΠ·Π²ΠΎΠ»ΠΈΡ Π»ΡΡΡΠ΅ ΠΏΠΎΠ½ΡΡΡ ΠΌΠΎΠ»Π΅ΠΊΡΠ»ΡΡΠ½ΡΠ΅ ΠΌΠ΅Ρ
Π°Π½ΠΈΠ·ΠΌΡ Π΄Π΅ΠΉΡΡΠ²ΠΈΡ Π°ΠΌΠΈΡΠΎΡΡΠΈΠ½Π°
Hierarchical Dobinski-type relations via substitution and the moment problem
We consider the transformation properties of integer sequences arising from
the normal ordering of exponentiated boson ([a,a*]=1) monomials of the form
exp(x (a*)^r a), r=1,2,..., under the composition of their exponential
generating functions (egf). They turn out to be of Sheffer-type. We demonstrate
that two key properties of these sequences remain preserved under
substitutional composition: (a)the property of being the solution of the
Stieltjes moment problem; and (b) the representation of these sequences through
infinite series (Dobinski-type relations). We present a number of examples of
such composition satisfying properties (a) and (b). We obtain new Dobinski-type
formulas and solve the associated moment problem for several hierarchically
defined combinatorial families of sequences.Comment: 14 pages, 31 reference
Monomiality principle, Sheffer-type polynomials and the normal ordering problem
We solve the boson normal ordering problem for
with arbitrary functions and and integer , where and
are boson annihilation and creation operators, satisfying
. This consequently provides the solution for the exponential
generalizing the shift operator. In the
course of these considerations we define and explore the monomiality principle
and find its representations. We exploit the properties of Sheffer-type
polynomials which constitute the inherent structure of this problem. In the end
we give some examples illustrating the utility of the method and point out the
relation to combinatorial structures.Comment: Presented at the 8'th International School of Theoretical Physics
"Symmetry and Structural Properties of Condensed Matter " (SSPCM 2005),
Myczkowce, Poland. 13 pages, 31 reference
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Quantum-like dynamics applied to cognition: a consideration of available options
Quantum probability theory (QPT) has provided a novel, rich mathematical framework for cognitive modelling, especially for situations which appear paradoxical from classical perspectives. This work concerns the dynamical aspects of QPT, as relevant to cognitive modelling. We aspire to shed light on how the mind's driving potentials (encoded in Hamiltonian and Lindbladian operators) impact the evolution of a mental state. Some existing QPT cognitive models do employ dynamical aspects when considering how a mental state changes with time, but it is often the case that several simplifying assumptions are introduced. What kind of modelling flexibility does QPT dynamics offer without any simplifying assumptions and is it likely that such flexibility will be relevant in cognitive modelling? We consider a series of nested QPT dynamical models, constructed with a view to accommodate results from a simple, hypothetical experimental paradigm on decision-making. We consider Hamiltonians more complex than the ones which have traditionally been employed with a view to explore the putative explanatory value of this additional complexity. We then proceed to compare simple models with extensions regarding both the initial state (e.g. a mixed state with a specific orthogonal decomposition; a general mixed state) and the dynamics (by introducing Hamiltonians which destroy the separability of the initial structure and by considering an open-system extension). We illustrate the relations between these models mathematically and numerically.
This article is part of the themed issue 'Second quantum revolution: foundational questions'
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