Dual Chains Research Articles

A Symmetry Property for a Class of Random Walks in Stationary Random Environments on Z

A correspondence formula between the laws of dual Markov chains on Z with two transition jumps is established. This formula contributes to the study of random walks in stationary random environments. Counterexamples with more than two jumps are exhibited.

A Symmetry Property for a Class of Random Walks in Stationary Random Environments on Z

A correspondence formula between the laws of dual Markov chains on Z with two transition jumps is established. This formula contributes to the study of random walks in stationary random environments. Counterexamples with more than two jumps are exhibited.

Dual pairing of symmetry and dynamical groups in physics

This article reviews many manifestations and applications of dual representations of pairs of groups, primarily in atomic and nuclear physics. Examples are given to show how such paired representations are powerful aids in understanding the dynamics associated with shell-model coupling schemes and in identifying the physical situations for which a given scheme is most appropriate. In particular, they suggest model Hamiltonians that are diagonal in the various coupling schemes. The dual pairing of group representations has been applied profitably in mathematics to the study of invariant theory. We show that parallel applications to the theory of symmetry and dynamical groups in physics are equally valuable. In particular, the pairing of the representations of a discrete group with those of a continuous Lie group or those of a compact Lie with those of a non-compact Lie group makes it possible to infer many properties of difficult groups from those of simpler groups. This review starts with the representations of the symmetric and unitary groups, which are used extensively in the many-particle quantum mechanics of bosonic and fermionic systems. It gives a summary of the many solutions and computational techniques for solving problems that arise in applications of symmetry methods in physics and which result from the famous Schur-Weyl duality theorem for the pairing of these representations. It continues to examine many chains of symmetry groups and dual chains of dynamical groups associated with the several coupling schemes in atomic and nuclear shell models and the valuable insights and applications that result from this examination.

Strong stationary duality for Möbius monotone Markov chains

For Markov chains with a finite, partially ordered state space, we show strong stationary duality under the condition of Möbius monotonicity of the chain. We give examples of dual chains in this context which have no downwards transitions. We illustrate general theory by an analysis of nonsymmetric random walks on the cube with an interpretation for unreliable networks of queues.

Amphiphilic ethyl cellulose brush polymers with mono and dual side chains: Facile synthesis, self-assembly, and tunable temperature-pH responsivities

Novel amphiphilic ethyl cellulose (EC) brush polymers with mono and dual side chains of poly(2-(2-methoxyethoxy)ethyl methacrylate)-co-oligo(ethylene glycol) methacrylate) (P(MEO2MA-co-OEGMA)) and poly(2-(N,N-dimethylamino)ethyl methacrylate) (PDMAEMA) were synthesized by the combination of atom transfer radical polymerization (ATRP) and click chemistry. The molar ratio of P(MEO2MA-co-OEGMA) and PDMAEMA was varied through changing the feed ratio of these polymers and the coupling efficiency of click chemistry is relatively high. The brush polymers can self-assemble into spherical micelles/aggregates. The micelles/aggregates show the tunable temperature-pH responsive properties. The cloud points and the pH-triggered phase transition were influenced by EC chains and the ratio of P(MEO2MA-co-OEGMA) and PDMAEMA side chains. The brush polymers have the great potential applications as biomedical or intelligent materials.

A Mouse Model of Clonal CD8+ T Lymphocyte-Mediated Alopecia Areata Progressing to Alopecia Universalis

Alopecia areata is among the most prevalent autoimmune diseases, yet compared with other autoimmune conditions, it is not well studied. This in part results from limitations in the C3H/HeJ mouse and DEBR rat model systems most commonly used to study the disease, which display a low frequency and late onset. We describe a novel high-incidence model for spontaneous alopecia areata. The 1MOG244 T cell expresses dual TCRA chains, one of which, when combined with the single TCRB present, promotes the development of CD8(+) T cells with specificity for hair follicles. Retroviral transgenic mice expressing this TCR develop spontaneous alopecia areata at nearly 100% incidence. Disease initially follows a reticular pattern, with regionally cyclic episodes of hair loss and regrowth, and ultimately progresses to alopecia universalis. Alopecia development is associated with CD8(+) T cell activation, migration into the intrafollicular region, and hair follicle destruction. The disease may be adoptively transferred with T lymphocytes and is class I and not class II MHC-dependent. Pathologic T cells primarily express IFNG and IL-17 early in disease, with dramatic increases in cytokine production and recruitment of IL-4 and IL-10 production with disease progression. Inhibition of individual cytokines did not significantly alter disease incidence, potentially indicating redundancy in cytokine responses. These results therefore characterize a new high-incidence model for alopecia areata in C57BL/6J mice, the first to our knowledge to apply a monoclonal TCR, and indicate that class I MHC-restricted CD8(+) T lymphocytes can independently mediate the pathologic response.

5-Chloro-3-cyclopentylsulfonyl-2-methyl-1-benzofuran

In the title compound, C14H15ClO3S, the cyclo­penyl ring adopts an envelope conformation. In the crystal, mol­ecules are linked by weak inter­molecular C—H⋯O hydrogen bonds into dual chains propagating in [100]. The dual chains arise from pairs of the same or different hydrogen bonds between adjacent molecules.

Platelet satellitism and dual surface immunoglobulin light-chain expression in circulating splenic marginal zone lymphoma cells

Platelet satellitism is believed to be an in vitro phenomenon induced at room temperature in ethylenediamine tetraacetic acid-anticoagulated blood. Most reports involve neutrophils; involvement with circulating lymphoma cells are exceedingly rare. Normally, mature B cells exhibit allelic exclusion in which a single class of surface immunoglobulin light chains (either κ or λ) is expressed. The simultaneous expression of both κ and λ immunoglobulin light chains is rare. Herein, we report the unusual case of a patient with splenic marginal zone lymphoma in which circulating lymphoma cells express dual surface immunoglobulin light chains and exhibit platelet satellitism. In addition to clinical findings, a comprehensive analysis of the peripheral blood including correlated light and electron microscopy as well as flow cytometry are described.

Mass measurement in boosted decay chains with missing energy

We explore a novel method of mass reconstruction in events with missing transverse momentum at hadron colliders. In events with sizeable boost factors in the final steps of dual multi-stage decay chains, the missing energy particles may each be approximately collinear with a visible standard model particle, spanning a narrow "MET-cone." We exploit this collinear approximation, when applicable, to reconstruct the masses of exotica.

Simultaneous spectrum and coherent combining by active phasing dual two-tone all-fiber MOPA chains

We present a new approach for simultaneous spectral and coherent combining in a master oscillator power amplifier (MOPA) configuration with active phasing. Spectrally combined single-frequency seed lasers are employed as a master oscillator for the all-fiber power amplifier chain, which provides robust performance suppressing of the stimulated Brillouin scattering effect, while coherent combining of spectrally combined amplifiers with active phase control provides stable in-phase combining, despite the strong phase fluctuation. In experiments, two spectrally combined seed MOPA chains are coherently combined with a total output power of 390 W. The power of the main lobe in the closed loop is two times of that value in the open loop, and visibility of more than 75% of the long-exposure interference pattern at the receiving plane is obtained.

Mechanistic analysis of massive endocytosis in relation to functionally defined surface membrane domains

A large fraction of endocytosis in eukaryotic cells occurs without adaptors or dynamins. Here, we present evidence for the involvement of lipid domains in massive endocytosis (MEND) activated by both large Ca transients and amphipathic compounds in baby hamster kidney and HEK293 cells. First, we demonstrate functional coupling of the two MEND types. Ca transients can strongly facilitate detergent-activated MEND. Conversely, an amphipath with dual alkyl chains, ditridecylphthalate, is without effect in the absence of Ca transients but induces MEND to occur within seconds during Ca transients. Ca transients, like amphipaths, enhance the extraction of lipids from cells by β-cyclodextrins. Second, we demonstrate that electrical and/or optical signals generated by selected membrane probes are nearly insensitive to MEND, suggesting that those probes segregate into membrane domains that are not taken up by MEND. Triphenylphosphoniums are increasingly excluded from domains that internalize as the carbon chain length increases from 4 to 12. The small cationic membrane dye, FM 4–64, binds well to domains that internalize, whereas a closely related dye with a larger hydrophobic moiety, di-4-ANEPPDHQ (ANEPPDHQ) is excluded. Multiple carrier-type ionophores and a small amphipathic anion, niflumic acid, are also excluded. Probes with modest MEND sensitivity include the hydrophobic anion, dipicrylamine, carbonyl cyanide m-chlorophenylhydrazone, and NBD-phosphatidylethanolamine. Third, we demonstrate that large Ca transients can strongly enhance the extracellular binding of several membrane probes, monitored electrically or optically, consistent with a more disordered membrane with more amphipath-binding sites. Fluorescence shifts of ANEPPDHQ report increased disorder of the extracellular monolayer after large Ca transients, consistent with an increased propensity of the membrane to phase separate and vesiculate. Collectively, the results indicate that >50% of the outer monolayer is ordered and can be selectively internalized during MEND responses initiated by two very different cell perturbations.

An Efficient and Secure Self-Healing Scheme for LKH

With the growing interest in converging fixed and mobile networks (FMC), mobile applications will require more and more resources from both the network and the mobile device. In such context, multicasting is essential because it lowers bandwidth consumption by simultaneously reaching a group of multiple recipients. Securing multicast flows has been extensively studied in the past, but none of the existing solutions were meant to handle the constraints imposed by mobile scenarios, in particular the high packet-loss rate. The need for a low overhead self-healing rekeying mechanism that is scalable, reliable and suitable for mobile environments has never been more urgent than with the arrival of FMC in 4G networks. This paper presents two self-healing recovery schemes based on the dual directional hash chains (DDHC) for the logical key hierarchy (LKH) rekeying protocol. This enables a member that has missed up to m consecutive key updates to recover the missing decryption keys without asking the group controller key server (GCKS) for retransmission. Conducted simulations show considerable improvements in the ratio of decrypted messages and in the rekey message overhead in high packet loss environments.

Duality for digital sequences

A duality theory for digital nets, i.e., for finite point sets with strong uniformity properties, was introduced by Niederreiter and Pirsic. This duality theory is based on the concept of the dual space M of a digital net. In this paper we extend the duality theory from (finite) digital nets to (infinite) digital sequences. The analogue of the dual space is now a chain of dual spaces ( M m ) m ≥ 1 for which a certain projection of M m + 1 is a subspace of M m . As an example of the use of dual space chains, we show how a well-known construction of digital sequences by Niederreiter and Xing can be achieved in a simpler manner by using our duality theory for digital sequences.

Synthesis and crystal structure of aqua(dibenzo-18-crown-6)potassium (dibenzo-18-crown-6)-(tetrachlorocuprato(II)-Cl)potassium

New mixed complex compound aqua(dibenzo-18-crown-6)potassium (dibenzo-18-crown-6)(tetrachlorocuprato(II)-Cl)potassium, [K(CuCl4)(Db18C6)]− · [K(Db18C6)(H2O)]+, is synthesized and its crystal structure is studied by the method of x-ray structural analysis. The structure includes two independent complex ions, both of guest-host type: two cations K+ are located in the respective cavities of the Db18C6 crown-ligand (one in each) and each is coordinated by all its six O atoms and one Cl atom of the anion-ligand [CuCl4]2− or O atom of the ligand water molecule. Coordination of these two K+ cations is completed to hexagonal pyramidal one by formation by each of unusually weak coordination bond K+ → π(\( C\dddot - C \)) with two C atoms of respective benzene ring in the neighboring Db18C6 ligand. In this crystal structure the complex anions and cations form dual infinite chains via these coordination bonds and interionic O-H⋯Cl hydrogen bonds.

Graft-type poly(N-isopropylacrylamide-co-acrylic acid) microgels exhibiting rapid thermo- and pH-responsive properties

A novel graft-type poly(N-isopropylacrylamide-co-acrylic acid) (poly(NIPAM-co-AAc)) microgel with linear grafted poly(NIPAM-co-AAc) side chains was prepared by incorporating the dual stimuli-responsive chains into conventional copolymerized poly(NIPAM-co-AAc) backbones as side chains through a grafted modification of molecular structure. The grafted chains with unfettered ends can unfold and shrink freely in response to environmental stimuli. Due to the mobile nature and the tractive force of the grafted poly(NIPAM-co-AAc) side chains, the prepared microgels were verified to have a synchronously rapid thermo- and pH-response property. When the environmental temperature was increased suddenly from 25°C to about 63°C, the graft-type microgels in ultrapure water deswelled 95% by volume at best within 40s but the normal-type microgels deswelled only 17% by volume within the same period. The analogous trends were observed in either alkaline or acid buffered solution. The graft-type microgels may thus be very promising for use in many applications in which rapid responses to dual environmental stimuli are required.

Regioselective Acylation of Octyl β-d-Glucopyranoside by Chiral 4-Pyrrolidinopyridine Analogues

Chiral 4-pyrrolidinopyridine (PPY) analogues with dual functional side chains consisting of indole units have been prepared from TRANS-4-hydroxy- L-proline. Treatment of octyl β- D-glucopyranoside with isobutyric anhydride in the presence of the catalysts gave the 6- O-acylate as the major product via acylation of a primary hydroxyl group. On the other hand, the 4- O-acylate was obtained as the major product in 66% regioselectivity via acylation of the secondary hydroxyl group at C-4 on treatment of octyl β- D-glucopyranoside with isobutyric anhydride in the presence of a PPY catalyst. Use of isobutyryl chloride instead of isobutyric anhydride in the presence of the catalyst gave the 6- O-acylate in 87% regioselectivity.

A New Series of Chalcohalide Semiconductors with Composite CdBr2/Sb2Se3 Lattices: Synthesis and Characterization of CdSb2Se3Br2 and Indium Derivatives InSb2S4X (X = Cl and Br) and InM2Se4Br (M = Sb and Bi)

A new series of mixed-framework compounds in the chalcohalide family has been synthesized using the conventional solid-state reactions. These include CdSb2Se3Br2 1 and its isoelectronic indium derivatives InSb2S4X (X = Cl 2 and Br 3) and InM2Se4Br (M = Sb 4 and Bi 5). Single crystals were grown from direct interaction of stoichiometric mixtures of respective elemental and binary compounds. The parent compound cadmium antimony selenobromide, CdSb2Se3Br2, was synthesized by heating the stoichiometric mixture of CdBr2 and Sb and Se at 450 °C followed by slow cooling. Single-crystal structure analysis was carried out by employing X-ray diffraction methods, showing that this compound crystallizes in the monoclinic crystal system (C2/m, No. 12) with a = 20.998(4) A, b = 4.0260(8) A, c = 12.149(2) A, β = 119.00(3)°, and V = 898.3(3) A3. The framework exhibits mixed CdBr2 and Sb2Se3 sublattices, respectively, adopting the (110) and (100) NaCl-type structures. The former consists of dual octahedral chains of Cd-ce...

Classical open string integrability

We present a simple procedure to construct non-local conserved charges for classical open strings on coset spaces. This is done by including suitable reflection matrices on the classical transfer matrix. The reflection matrices must obey certain conditions for the charges to be conserved and in involution. We then study bosonic open strings on $AdS_5\times S^5$. We consider boundary conditions corresponding to Giant Gravitons on $S^5$, $AdS_4\times S^2$ D5-branes and $AdS_5 \times S^3$ D7-branes. We find that we can construct the conserved charges for the full bosonic string on a Maximal Giant Graviton or a D7-brane. For the D5-brane, we find that this is possible only in a SU(2) sub-sector of the open string. Moreover, the charges can not be constructed at all for non-maximal Giant Gravitons. We discuss the interpretation of these results in terms of the dual gauge theory spin chains.

One-dimensional aligned InAs/InP quantum dots chain growth by metalorganic vapor phase epitaxy for 1.55 μm application

We report one-dimensional aligned growth of InAs quantum dots (QDs) in a dielectric grating on InP (0 0 1) by metalorganic vapor phase epitaxy (MOVPE). InAs QDs were grown selectively along the edge of the SiO 2 stripes to form dual chains in each period of the grating formed by laser holography method with a period of 244 nm. The linear alignment property of InAs dots was maintained in wet chemical etched SiO 2 array template with 1.7 μm openings. The InAs QDs grown in SiO 2 grating template showed room temperature photoluminescence (PL) emission around 1.5 μm, red shifted from QDs grown on plain InP substrate. The results can be applied to naturally gain coupled distributed feedback lasers and coupled QDs growth.

Synthesis and crystal structure of metal-organic frameworks [Ln 2(pydc-3,5) 3(H 2O) 9] n3 nH 2O (Ln = Sm, Eu, Gd, Dy; pydc-3,5 = pyridine-3,5-dicarboxylate) along with the photoluminescent property of its europium one

Rare-earth metal-organic frameworks, [Ln 2( pydc) 3(H 2O) 9] n 3 nH 2O (Ln = Sm, Eu, Gd, Dy; pydc = pyridine-3,5-dicarboxylate), were synthesized and characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction. The solid-state photoluminescence measurements exhibited red light-emitting characteristic of europium (III) coordination polymer. The title compounds consist of one-dimensional dual chains, in which each metal atom is nine-coordinated with oxygen atoms.