Relaxor characteristics at the interfaces of [NdMnO3/SrMnO3/LaMnO3] superlattices

We have investigated the magnetic properties of transition metal oxide superlattices with broken inversion symmetry composed of three different antiferromagnetic insulators, [NdMnO3/SrMnO3/LaMnO3]. In the superlattices studied here, we identify the emergence of a relaxor, glassy-like behavior below spin glass temperature, T=36K. Our results offer the possibility to study and utilize magnetically metastable devices confined in nano-scale interfaces

Quasiparticle Scattering Interference in Superconducting Iron-pnictides

Using both two orbital and five orbital models, we investigate the quasiparticle interference (QPI) patterns in the superconducting (SC) state of iron-based superconductors. We compare the results for nonmagnetic and magnetic impurities in sign-changed s-wave $\cos(k_x)\cdot\cos(k_y)$ and sign-unchanged $|\cos(k_x)\cdot\cos(k_y)|$ SC states. While the patterns strongly depend on the chosen band structures, the sensitivity of peaks around $(\pm\pi,0)$ and $(0,\pm\pi)$ wavevectors on magnetic or non-magnetic impurity, and sign change or sign unchanged SC orders is common in two models. Our results strongly suggest that QPI may provide direct information of band structures and evidence of the pairing symmetry in the SC states.Comment: 12 pages, 16 figure

A performance comparison of the contiguous allocation strategies in 3D mesh connected multicomputers

The performance of contiguous allocation strategies can be significantly affected by the distribution of job execution times. In this paper, the performance of the existing contiguous allocation strategies for 3D mesh multicomputers is re-visited in the context of heavy-tailed distributions (e.g., a Bounded Pareto distribution). The strategies are evaluated and compared using simulation experiments for both First-Come-First-Served (FCFS) and Shortest-Service-Demand (SSD) scheduling strategies under a variety of system loads and system sizes. The results show that the performance of the allocation strategies degrades considerably when job execution times follow a heavy-tailed distribution. Moreover, SSD copes much better than FCFS scheduling strategy in the presence of heavy-tailed job execution times. The results also show that the strategies that depend on a list of allocated sub-meshes for both allocation and deallocation have lower allocation overhead and deliver good system performance in terms of average turnaround time and mean system utilization

Structural and functional conservation of key domains in InsP3 and ryanodine receptors.

Inositol-1,4,5-trisphosphate receptors (InsP(3)Rs) and ryanodine receptors (RyRs) are tetrameric intracellular Ca(2+) channels. In each of these receptor families, the pore, which is formed by carboxy-terminal transmembrane domains, is regulated by signals that are detected by large cytosolic structures. InsP(3)R gating is initiated by InsP(3) binding to the InsP(3)-binding core (IBC, residues 224-604 of InsP(3)R1) and it requires the suppressor domain (SD, residues 1-223 of InsP(3)R1). Here we present structures of the amino-terminal region (NT, residues 1-604) of rat InsP(3)R1 with (3.6 Å) and without (3.0 Å) InsP(3) bound. The arrangement of the three NT domains, SD, IBC-β and IBC-α, identifies two discrete interfaces (α and β) between the IBC and SD. Similar interfaces occur between equivalent domains (A, B and C) in RyR1 (ref. 9). The orientations of the three domains when docked into a tetrameric structure of InsP(3)R and of the ABC domains docked into RyR are remarkably similar. The importance of the α-interface for activation of InsP(3)R and RyR is confirmed by mutagenesis and, for RyR, by disease-causing mutations. Binding of InsP(3) causes partial closure of the clam-like IBC, disrupting the β-interface and pulling the SD towards the IBC. This reorients an exposed SD loop ('hotspot' (HS) loop) that is essential for InsP(3)R activation. The loop is conserved in RyR and includes mutations that are associated with malignant hyperthermia and central core disease. The HS loop interacts with an adjacent NT, suggesting that activation re-arranges inter-subunit interactions. The A domain of RyR functionally replaced the SD in full-length InsP(3)R, and an InsP(3)R in which its C-terminal transmembrane region was replaced by that from RyR1 was gated by InsP(3) and blocked by ryanodine. Activation mechanisms are conserved between InsP(3)R and RyR. Allosteric modulation of two similar domain interfaces within an N-terminal subunit reorients the first domain (SD or A domain), allowing it, through interactions of the second domain of an adjacent subunit (IBC-β or B domain), to gate the pore