Conformation, protein-carbohydrate interactions and a novel subunit association in the refined structure of peanut lectin-lactose complex

The structure of the complex of the tetrameric peanut lectin with lactose has been refined to an R-value of 16.4% using 2.25 angstroms resolution X-ray diffraction data. The subunit conformation in the structure is similar to that in other legume lectins except in the loops. It has been shown that in the tertiary structure of legume lectins, the short five-stranded sheet plays a major role in connecting the larger flat six-stranded and curved seven-stranded sheets. Furthermore, the loops that connect the strands at the two ends of the seven-stranded sheet curve toward and interact with each other to produce a second hydrophobic core in addition to the one between the two large sheets. The protein-lactose interactions involve the invariant features observed in other legume lectins in addition to those characteristic of peanut lectin. The "open" quaternary association in peanut lectin is stabilised by hydrophobic, hydrogen-bonded and water-mediated interactions. Contrary to the earlier belief, the structure of peanut lectin demonstrates that the variability in quaternary association in legume lectins, despite all of them having nearly the same tertiary structure, is not necessarily caused by covalently bound carbohydrate. An attempt has been made to provide a structural rationale for this variability, on the basis of buried surface areas during dimerisation. A total of 45 water molecules remain invariant when the hydration shells of the four subunits are compared. A majority of them appear to be involved in stabilising loops.     

Learning as a nonlinear line of attraction in a recurrent neural network

A method to embed N dimensional, multi-valued patterns into an auto-associative memory represented as a nonlinear line of attraction in a fully connected recurrent neural network is presented in this paper. The curvature of the nonlinear attractor is defined by the Kth degree polynomial line which best fits the training data in N dimensional state space. The width of the nonlinear line is then characterized by the statistical characteristics of the training patterns. Stability of the recurrent network is verified by analyzing the trajectory of the points in the state space during convergence. The performance of the network is benchmarked through the reconstruction of original gray-scale images from their corrupted versions. It is observed that the proposed method can quickly and successfully reconstruct each image with an average convergence rate of 3.10 iterations.     

A Capability Assessment Model for Emergency Management Organizations

Natural and manmade disasters may cause a great deal of loss of life and threat to the human society. As a result, an effective emergency management organization becomes more and more significant for the purpose of minimizing loss. In this paper, a capability assessment model, namely, disaster management and control model, is proposed to provide a general guideline for different types of emergency management organization. Eight indicators are proposed for assessing the capability of the organization. The assessment process includes collecting, analyzing, reporting and planning. The result of capability assessment is divided into four levels and recommendations are presented for reporting the details of the indicators.     

Structural basis for ligand recognition at the benzodiazepine binding site of GABAA alpha 3 receptor, and pharmacophore-based virtual screening approach

Given the heterogeneity of GABA(A) receptor, the pharmacological significance of identifying subtype selective modulators is increasingly being recognized. Thus, drugs selective for GABA(A) alpha(3) receptors are expected to display fewer side effects than the drugs presently in clinical use. Hence we carried out 3D QSAR (three-dimensional quantitative structure-activity relationship) studies on a series of novel GABA(A) alpha(3) subtype selective modulators to gain more insight into subtype affinity. To identify the 3D functional attributes required for subtype selectivity, a chemical feature-based pharmacophore, primarily based on selective ligands representing diverse structural classes was generated. The obtained pseudo receptor model of the benzodiazepine binding site revealed a binding mode akin to "Message-Address" concept. Scaffold hopping was carried out across multi-conformational May Bridge database for the identification of novel chemotypes. Further a focused data reduction approach was employed to choose a subset of enriched compounds based on "Drug likeness" and "Similarity-based" methods. These results taken together could provide impetus for rational design and optimization of more selective and high affinity leads with a potential to have decreased adverse effects.     

Enhanced 3D Human Pose Estimation from Videos by Using Attention-Based Neural Network with Dilated Convolutions

International Journal of Computer Vision - The attention mechanism provides a sequential prediction framework for learning spatial models with enhanced implicit temporal consistency. In this work,...     

A Nanoindentation Study of the Plastic Deformation and Fracture Mechanisms in Single-Crystalline CaFe<Subscript>2</Subscript>As<Subscript>2</Subscript>

The plastic deformation and fracture mechanisms in single-crystalline CaFe₂As₂ has been studied using nanoindentation and density functional theory simulations. CaFe₂As₂ single crystals were grown in a Sn-flux, resulting in homogeneous and nearly defect-free crystals. Nanoindentation along the [001] direction produces strain bursts, radial cracking, and lateral cracking. Ideal cleavage simulations along the [001] and [100] directions using density functional theory calculations revealed that cleavage along the [001] direction requires a much lower stress than cleavage along the [100] direction. This strong anisotropy of cleavage strength implies that CaFe₂As₂ has an atomic-scale layered structure, which typically exhibits lateral cracking during nanoindentation. This special layered structure results from weak atomic bonding between the (001) Ca and Fe₂As₂ layers.     

The effect of Sr modification on thermal diffusivity of Al–8Si alloy

Newtonian and Fourier analysis techniques were used to calculate the solid fraction and latent heat during the solidification of Al–8Si alloy and the subsequent results were used to study the effect of Sr modification on thermal diffusivity of the solidifying melt. The results indicate that the thermal diffusivity increased significantly with increase in Sr content. The increase in the thermal diffusivity was attributed to the increase in the electronic conduction of the modified alloy due to the decreased activity of the bifilm. The results also indicate that the latent heat evolved during solidification increased with increase in Sr concentration and was associated with the increase in the solidification range that occurred during the modification process.     

Multiple Performance Optimization in Wear Characteristics of Mg-SiC Nanocomposites Using Grey-Fuzzy Algorithm

Silicon - The present investigation attempts to evaluate the effect of the SiC nano particles on the wear characteristics of Mg matrix nano composites. The wear tests on Mg matrix composites...     

Web assurance seal services,trust and consumers’ concerns: an investigation of e-commerce transaction intentions across two nations

Trust is considered as a critical enabler in reducing consumer concerns regarding e-commerce transactions. Another enabler that helps reduce consumers’ concerns is Web Assurance Seal Services (WASS). We suggest that both factors help in the reduction of a critical hindrance to e-commerce, namely consumer concerns, and foster e-commerce transactions. Prior research has focused on trust in e-commerce, and separately, on the effectiveness of WASS within certain nations or cultures. However, given that e-commerce is now a global phenomenon we contend that the national or cultural characteristics of consumers are important to understand. This comparative national research attempts to fill this gap. This study makes the following contributions: It identifies a hindrance (i.e., consumers’ concerns), and two enablers (i.e., effectiveness of WASS and trust) in e-commerce technologies as a shopping channel (i.e., trust in e-Channel). It proposes consumers’ concerns for e-commerce as a second-order three-dimensional construct (i.e., security, privacy, and business integrity concern) and compares the effects of trust in e-Channel and WASS on consumers’ e-commerce transaction intention in two different national/cultural contexts (i.e., the U.S.A. and South Korea). The results of the study indicate that the perceived effectiveness of WASS of the U.S. consumers has a strong positive impact on their transaction intention and has a strong negative influence on their concerns for e-commerce. In contrast, Korean consumers’ perceived effectiveness of WASS does not significantly influence their transaction intention and their concerns for e-commerce. The results of group comparison analysis confirm that the strength of perceived effectiveness of WASS of the U.S. consumers is significantly stronger than that of Korean consumers. Interpretations from a cross-national perspective, theoretical and practical implications as well as limitations are discussed.     

Polyaniline–polyelectrolyte–gold(0) ternary nanocomposites: Synthesis and electrochemical properties

Ternary composites based on polyaniline (PAni), a polyelectrolyte-namely poly(diallyldimethylammoniumchloride) (PDDMAC) and gold (Au(0)) nanoparticles have been formulated and synthesized where the high concentration of PDDMAC acted as medium of reaction. The nanocomposites are characterized by FT-IR, UV–vis, XRD, XPS, SEM, AFM and TEM techniques. XRD showed the presence of all three viz., polyaniline, PDDMAC and Au(0) components in the ternary system. The composites exhibited higher conductivities in the range 26 × 10⁻⁶ to 217 × 10⁻⁶ S/cm compared with the binary composite of PAni–PDDMAC. The ternary composites were adsorbed on a GC electrode and used for sensing dopamine. The composites are useful in sensing as low as 0.05 mM concentration of dopamine at lower potential values compared to some binary PAni–Au nanocomposites.