Exchange interaction of hole-spin qubits in double quantum dots in highly anisotropic semiconductors

We study the exchange interaction between two hole-spin qubits in a double quantum dot setup in a silicon nanowire in the presence of magnetic and electric fields. Based on symmetry arguments we show that there exists an effective spin that is conserved even in highly anisotropic semiconductors, provided that the system has a twofold symmetry with respect to the direction of the applied magnetic field. This finding facilitates the definition of qubit basis states and simplifies the form of exchange interaction for two-qubit gates in coupled quantum dots. If the magnetic field is applied along a generic direction, cubic anisotropy terms act as an effective spin-orbit interaction introducing novel exchange couplings even for an inversion symmetric setup. Considering the example of a silicon nanowire double dot, we present the relative strength of these anisotropic exchange interaction terms and calculate the fidelity of the $\sqrt{\text{SWAP}}$ gate. Furthermore, we show that the anisotropy-induced spin-orbit effects can be comparable to that of the direct Rashba spin-orbit interaction for experimentally feasible electric field strengths.Comment: 18 pages, 7 figure

Modeliranje čimbenika koji utječu na suradnju između prodaje i marketinga u farmaceutskim i nefarmaceutskim proizvodnim poduzećima primjenom PLS metode parcijalnih najmanjih kvadrata

Purpose – This paper aims to explore the manner in which cooperation between sales and marketing in pharmaceutical manufacturing companies (PMC) (n=16) and non-pharmaceutical manufacturing companies (NPMC) (n=31) is affected by selected indicators. It also attempts to demonstrate how the Partial Least Square (PLS) path modelling technique can reveal latent mechanisms in the interplay of the examined factors affecting SM cooperation. Design/methodology/approach – Data collection was carried out in the form of an online questionnaire. The rating scale data gathered was analyzed using PLS path modelling. Findings – Management culture (information exchange, coordination, vision, and communication) as the superblock of the model accounts for a high variance in SM cooperation in both PMCs (R 2=0.619) and NPMCs (R2=0.741). Out of the three variables determining management culture, in PMCs it is coordination (R2%=44), while in NPMCs it is information exchange (R2%=57) that accounts for most of the variance. The results clearly demonstrate that there are factors affecting SM cooperation that work differently in PMCs and NPMCs. Limitations – As the analysis in this research study was based on a convenience sample, its result should be interpreted with caution and cannot be generalized. Originality/value – This is the first time that the SM interface mechanisms were compared in PMCs and NPMCs using PLS path modelling. PLS revealed latent relationships and mechanisms that play an important role in optimising SM cooperation.Svrha – Cilj je rada istražiti kako odabrani indikatori utječu na suradnju između prodaje i marketinga u farmaceutskim (n=16) i nefarmaceutskim proizvodnim poduzećima (n=31). Isto tako, rad pokušava pokazati kako PLS metoda parcijalnih najmanjih kvadrata, kao tehnika modeliranja staza, može otkriti latentne mehanizme u međusobnom djelovanju istraživanih faktora koji utječu na suradnju između prodaje i marketinga. Metodološki pristup – Podaci su prikupljeni korištenjem online anketnog upitnika s mjernim ljestvicama. Analizirani su primjenom PLS metode parcijalnih najmanjih kvadrata. Rezultati i implikacije – Menadžerska kultura (razmjena informacija, koordinacija, vizija i komunikacija) kao superblok u modelu objašnjava veliki udio varijance u suradnji između prodaje i marketinga i u farmaceutskim (R2=0,619) i u nefarmaceutskim proizvodnim poduzećima (R2=0,741). Od tri varijable koje određuju menadžersku kulturu, najveću varijancu imaju koordinacija (R2%= 44) u farmaceutskim, a razmjena informacija (R2%= 57) u nefarmaceutskim prozvodnim poduzećima. Rezultati jasno pokazuju da postoje čimbenici koji utječu na suradnju između prodaje i marketinga, a djeluju različito u farmaceutskim i nefarmaceutskim proizvodnim poduzećima. Ograničenja – Analiza se temelji na prigodnom uzorku, stoga se rezultati trebaju interpretirati s oprezom i ne mogu se generalizirati. Doprinos – Ovo je prvi put da se uspoređuje međusobno djelovanje prodaje i marketinga u farmaceutskim i nefarmaceutskim proizvodnim poduzećima korištenjem metode PLS modeliranja staza. PLS je otkrio latentne odnose i mehanizme koji imaju važnu ulogu u optimiziranju suradnje između prodaje i marketinga

BSP‐SLIM: A blind low‐resolution ligand‐protein docking approach using predicted protein structures

We developed BSP‐SLIM, a new method for ligand–protein blind docking using low‐resolution protein structures. For a given sequence, protein structures are first predicted by I‐TASSER; putative ligand binding sites are transferred from holo‐template structures which are analogous to the I‐TASSER models; ligand–protein docking conformations are then constructed by shape and chemical match of ligand with the negative image of binding pockets. BSP‐SLIM was tested on 71 ligand–protein complexes from the Astex diverse set where the protein structures were predicted by I‐TASSER with an average RMSD 2.92 Å on the binding residues. Using I‐TASSER models, the median ligand RMSD of BSP‐SLIM docking is 3.99 Å which is 5.94 Å lower than that by AutoDock; the median binding‐site error by BSP‐SLIM is 1.77 Å which is 6.23 Å lower than that by AutoDock and 3.43 Å lower than that by LIGSITE CSC . Compared to the models using crystal protein structures, the median ligand RMSD by BSP‐SLIM using I‐TASSER models increases by 0.87 Å, while that by AutoDock increases by 8.41 Å; the median binding‐site error by BSP‐SLIM increase by 0.69Å while that by AutoDock and LIGSITE CSC increases by 7.31 Å and 1.41 Å, respectively. As case studies, BSP‐SLIM was used in virtual screening for six target proteins, which prioritized actives of 25% and 50% in the top 9.2% and 17% of the library on average, respectively. These results demonstrate the usefulness of the template‐based coarse‐grained algorithms in the low‐resolution ligand–protein docking and drug‐screening. An on‐line BSP‐SLIM server is freely available at http://zhanglab.ccmb.med.umich.edu/BSP‐SLIM . Proteins 2012. © 2011 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/89455/1/23165_ftp.pd

Routing Nanomolar Protein Cargoes to Lipid Raft-Mediated/Caveolar Endocytosis through a Ganglioside GM1-Specific Recognition Tag

There is a pressing need to develop ways to deliver therapeutic macromolecules to their intracellular targets. Certain viral and bacterial proteins are readily internalized in functional form through lipid raft-mediated/caveolar endocytosis, but mimicking this process with protein cargoes at therapeutically relevant concentrations is a great challenge. Targeting ganglioside GM1 in the caveolar pits triggers endocytosis. A pentapeptide sequence WYKYW is presented, which specifically captures the glycan moiety of GM1 (K-D = 24 nm). The WYKYW-tag facilitates the GM1-dependent endocytosis of proteins in which the cargo-loaded caveosomes do not fuse with lysosomes. A structurally intact immunoglobulin G complex (580 kDa) is successfully delivered into live HeLa cells at extracellular concentrations ranging from 20 to 160 nm, and escape of the cargo proteins to the cytosol is observed. The short peptidic WYKYW-tag is an advantageous endocytosis routing sequence for lipid raft-mediated/caveolar cell delivery of therapeutic macromolecules, especially for cancer cells that overexpress GM1.Peer reviewe

Sedimentation record in the Konkan-Kerala Basin: implications for the evolution of the Western Ghats and the Western Indian passive margin

The Konkan and Kerala Basins constitute a major depocentre for sediment from the onshore hinterland of Western India and as such provide a valuable record of the timing and magnitude of Cenozoic denudation along the continental margin. This paper presents an analysis of sedimentation in the Konkan-Kerala Basin, coupledwith a mass balance study, and numerical modelling of flexural responses to onshore denudational unloading and o¡shore sediment loading in order to test competing conceptual models for the development of high-elevation passive margins. The Konkan-Kerala Basin contains an estimated 109,000 km<sup>3</sup>; of Cenozoic clastic sediment, a volume difficult to reconcile with the denudation of a downwarped rift flank onshore, and more consistent with denudation of an elevated rift flank. We infer from modelling of the isostatic response of the lithosphere to sediment loading offshore and denudation onshore that flexure is an important component in the development of the Western Indian Margin.There is evidence for two major pulses in sedimentation: an early phase in the Palaeocene, and a second beginning in the Pliocene. The Palaeocene increase in sedimentation can be interpreted in terms of a denudational response to the rifting between India and the Seychelles, whereas the mechanism responsible for the Pliocene pulse is more enigmatic

Axial kinematic response of end-bearing piles to P waves

Kinematic pile-soil interaction under vertically impinging seismic P waves is revisited through a novel continuum elastodynamic solution of the Tajimi type. The proposed model simulates the steady-state kinematic response of a cylindrical end-bearing pile embedded in a homogeneous viscoelastic soil stratum over a rigid base, subjected to vertically propagating harmonic compressional waves. Closed-form solutions are obtained for the following: (i) the displacement field in the soil and along the pile; (ii) the kinematic Winkler moduli (i.e., distributed springs and dashpots) along the pile; (iii) equivalent, depth-independent, Winkler moduli to match the motion at the pile head. The solution for displacements is expressed in terms of dimensionless transfer functions relating the motion of the pile head to the free-field surface motion and the rock motion. It is shown that (i) a pile foundation may significantly alter (possibly amplify) the vertical seismic excitation transmitted to the base of a structure and (ii) Winkler moduli pertaining to kinematic loading differ from those for inertial loading. Simple approximate expressions for kinematic Winkler moduli are derived for use in applications. © 2013 John Wiley & Sons, Ltd