Exchange Interaction between the Co^<2+> Ions with Degenerate Orbital States in CoO(Physics)

The kinetic exchange mechanism in Anderson\u27s theory of superexchange is formulated for the case of Co^ ion-pairs in CoO. The exchange interaction depends on the orbital angular-momentum operators as well as on the spin operators. The nearest neighbor interaction is shown to be largely anisotropic. The coefficients of the exchange interaction are estimated with the use of the following parameters : Mattheiss\u27 APW result and its modification for the transfer integrals, Anderson\u27s value for the effective Coulomb integral, and the experimental values for the intra-ionic exchange integral and the crystalline field splitting. The estimated values should be correct at least in order of magnitude on account of the fact that the same procedure in the cases of NiO and MnO give result in fairly good agreement with the experimental result. The potential exchange in CoO is also discussed

Periodicities of T and Y-systems, dilogarithm identities, and cluster algebras II: Types C_r, F_4, and G_2

We prove the periodicities of the restricted T and Y-systems associated with the quantum affine algebra of type C_r, F_4, and G_2 at any level. We also prove the dilogarithm identities for these Y-systems at any level. Our proof is based on the tropical Y-systems and the categorification of the cluster algebra associated with any skew-symmetric matrix by Plamondon.Comment: 36 pages; minor changes, references update

The Ca2+-dependent Binding of Calmodulin to an N-terminal Motif of the Heterotrimeric G Protein beta Subunit

Ca2+ ion concentration changes are critical events in signal transduction. The Ca2+-dependent interactions of calmodulin (CaM) with its target proteins play an essential role in a variety of cellular functions. In this study, we investigated the interactions of G protein beta gamma subunits with CaM. We found that CaM binds to known beta gamma subunits and these interactions are Ca2+-dependent. The CaM-binding domain in Gbeta gamma subunits is identified as Gbeta residues 40-63. Peptides derived from the Gbeta protein not only produce a Ca2+-dependent gel mobility shifting of CaM but also inhibit the CaM-mediated activation of CaM kinase II. Specific amino acid residues critical for the binding of Gbeta gamma to CaM were also identified. We then investigated the potential function of these interactions and showed that binding of CaM to Gbeta gamma inhibits the pertussis toxin-catalyzed ADP-ribosylation of Galpha o subunits, presumably by inhibiting heterotrimer formation. Furthermore, we demonstrated that interaction with CaM has little effect on the activation of phospholipase C-beta 2 by Gbeta gamma subunits, supporting the notion that different domains of Gbeta gamma are responsible for the interactions of different effectors. These findings shed light on the molecular basis for the interactions of Gbeta gamma with Ca2+-CaM and point to the potential physiological significance of these interactions in cellular functions

Periodicities of T and Y-systems, dilogarithm identities, and cluster algebras I: Type B_r

We prove the periodicities of the restricted T and Y-systems associated with the quantum affine algebra of type B_r at any level. We also prove the dilogarithm identities for the Y-systems of type B_r at any level. Our proof is based on the tropical Y-systems and the categorification of the cluster algebra associated with any skew-symmetric matrix by Plamondon. Using this new method, we also give an alternative and simplified proof of the periodicities of the T and Y-systems associated with pairs of simply laced Dynkin diagrams.Comment: 35 pages; minor changes, references update

Structural analysis of zirconium oxynitride/water interface using neural network potential

Zr oxides with oxygen-nitrogen substitutions and oxygen vacancies are promising candidates to replace Pt as electrocatalyst for the oxygen reduction reaction. To understand the microscopic structure of the catalyst/water interface, many nanosecond-long molecular dynamics simulations were performed using the interatomic force field constructed by machine learning the ab initio calculations. A defective Zr$_7$O$_8$N$_4$/H$_2$O interface model was simulated and compared with a pristine ZrO$_2$/H$_2$O interface model. Water was found to be adsorbed on the surface partly as a H$_2$O molecule or as dissociated components, OH and H, on both surfaces. On the pristine ZrO$_2$ surface, H$_2$O molecules show a monolayer adsorption structure and adsorb on all Zr atoms with equal probability. On defective Zr$_7$O$_8$N$_4$ surface, however, H$_2$O molecules show a bilayer adsorption structure and do not adsorb on the oxygen vacancies but only on some of the surrounding Zr atoms. The total number of the molecular and dissociative adsorptions are almost the same on both surfaces, but a larger number are dissociatively adsorbed on the pristine surface. Possible implications for the catalytic behaviour are discussed.Comment: 27 pages, 6 figure

Analysis of Three-Phase Thyristor Phase Control Circuit with Series RLC Elements

An ac phase control circuit by thyristor is widely used in industry, The characteristics of the singlephase circuit with series RLC elements are numerically analyzed, and is reported the interesting phenomenon of step-up voltage without transformer. However, the performance of three phase phase control circuit with series RLC elements is not made clear. In this paper, the performance of three-phase control circuit of a balanced and an unbalanced load with series RLC elements is described. The analytical programs with each load are developed, and it is clarified that the calculated by this analytical program agree well with the measured. The calculated results, e.g. waveforms, RMS values of voltage and current, power, and power factor are illustrated and discussed the step-up phenomenon in three phase

V3 Tip-Dependent Species Specificity of HIV-1 Env

Molecular interactions of the variable envelope gp120 subunit of HIV-1 with two cellular receptors are the first step of viral infection, thereby playing pivotal roles in determining viral infectivity and cell tropism. However, the underlying regulatory mechanisms for interactions under gp120 spontaneous variations largely remain unknown. Here, we show an allosteric mechanism in which a single gp120 mutation remotely controls the ternary interactions between gp120 and its receptors for the switch of viral cell tropism. Virological analyses showed that a G310R substitution at the tip of the gp120 V3 loop selectively abolished the viral replication ability in human cells, despite evoking enhancement of viral replication in macaque cells. Molecular dynamics (MD) simulations predicted that the G310R substitution at a site away from the CD4 interaction site selectively impeded the binding ability of gp120 to human CD4. Consistently, virions with the G310R substitution exhibited a reduced binding ability to human lymphocyte cells. Furthermore, the G310R substitution influenced the gp120-CCR5 interaction in a CCR5-type dependent manner as assessed by MD simulations and an infectivity assay using exogenously expressed CCR5s. Interestingly, an I198M mutation in human CCR5 restored the infectivity of the G310R virus in human cells. Finally, MD simulation predicted amino acid interplays that physically connect the V3 loop and gp120 elements for the CD4 and CCR5 interactions. Collectively, these results suggest that the V3 loop tip is a cis-allosteric regulator that remotely controls intra- and intermolecular interactions of HIV-1 gp120 for balancing ternary interactions with CD4 and CCR5

The Atomic and Electronic structure of 0{\deg} and 60{\deg} grain boundaries in MoS2

We have investigated atomic and electronic structure of grain boundaries in monolayer MoS2, where relative angles between two different grains are 0 and 60 degree. The grain boundaries with specific relative angle have been formed with chemical vapor deposition growth on graphite and hexagonal boron nitride flakes; van der Waals interlayer interaction between MoS2 and the flakes restricts the relative angle. Through scanning tunneling microscopy and spectroscopy measurements, we have found that the perfectly stitched structure between two different grains of MoS2 was realized in the case of the 0 degree grain boundary. We also found that even with the perfectly stitched structure, valence band maximum and conduction band minimum shows significant blue shift, which probably arise from lattice strain at the boundary

Integrating Preprocessing Operations into Deep Learning Model: Case Study of Posttreatment Visual Acuity Prediction

Designing a deep neural network model that integrates clinical images with other electronic medical records entails various preprocessing operations. Preprocessing of clinical images often requires trimming of parts of the lesions shown in the images, whereas preprocessing of other electronic medical records requires vectorization of these records; for example, patient age is often converted into a categorical vector of 10-year intervals. Although these preprocessing operations are critical to the performance of the classification model, there is no guarantee that the preprocessing step chosen is appropriate for model training. The ability to integrate these preprocessing operations into a deep neural network model and to train the model, including the preprocessing operations, can help design a multi-modal medical classification model. This study proposes integration layers of preprocessing, both for clinical images and electronic medical records, in deep neural network models. Preprocessing of clinical images is realized by a vision transformer layer that selectively adopts the parts of the images requiring attention. The preprocessing of other medical electrical records is performed by adopting full-connection layers and normalizing these layers. These proposed preprocessing-integrated layers were verified using a posttreatment visual acuity prediction task in ophthalmology as a case study. This prediction task requires clinical images as well as patient profile data corresponding to each patient's posttreatment logMAR visual acuity. The performance of a heuristically designed prediction model was compared with the performance of the prediction model that includes the proposed preprocessing integration layers. The mean square errors between predicted and correct results were 0.051 for the heuristic model and 0.054 for the proposed model. Experimental results showed that the proposed model utilizing preprocessing integration layers achieved nearly the same performance as the heuristically designed model