Transactional Distance Theory and Scaffolding Removal Design for Nurturing Students’ Autonomy

This paper prorposes eight design principles to nurture autonomy of college students, based on re-conceptualization of Michael Moore\u27s Transactional Distance Theory (TDT). After proposed in 1970’s, TDT has been helping to concepturalize distance education in terms of psychological, not physical, distance among people involved. TDT, on the other hand, has been creating confusions and misinterpretations when utilized in the research and practices of distance education. COVID-19 has forced all educational practices to be offered as distance education, which made us realized the importance of student autonomy, when limited guidance could be offered. Utilizing the framework of TDT, this paper proposes eight ways to create and then withdraw scaffoldings to help learners more self-independent and autonomous

Electronic structure and magnetism of intermetallic mixed compound Mn₄N₁₋xCx

By applying the recursion method to the intermetallic mixed compound Mn₄N₁₋xCx with cubic perovskite-type structure we investigate the effects of substitution of C atoms for N atoms on the electronic structure and the magnetic properties of Mn₄N. By calculating the DOS's for the ferrimagnetic states of both Mn₄N and Mn₄N₀.₇₅C₀.₂₅ we have determined the magnetic moments at two types of Mn site, Mn(I)(corner site) and Mn(II) (face center site), which are antiparallel to each other. The obtained magnetic moment of Mn(I) in Mn₄N₀.₇₅C₀.₂₅ is found to be the same with that in Mn₄N while the absolute value of Mn(II) moment increases by the substitution of C atoms. As the result the total ferromagnetic moment decreases by the substitution of C atoms. These results are in good agreement with the observations.Article信州大学理学部紀要 30(1): 25-36(1995)departmental bulletin pape

A self-consistent first-principles calculation scheme for correlated electron systems

A self-consistent calculation scheme for correlated electron systems is created based on the density-functional theory (DFT). Our scheme is a multi-reference DFT (MR-DFT) calculation in which the electron charge density is reproduced by an auxiliary interacting Fermion system. A short-range Hubbard-type interaction is introduced by a rigorous manner with a residual term for the exchange-correlation energy. The Hubbard term is determined uniquely by referencing the density fluctuation at a selected localized orbital. This strategy to obtain an extension of the Kohn-Sham scheme provides a self-consistent electronic structure calculation for the materials design. Introducing an approximation for the residual exchange-correlation energy functional, we have the LDA+U energy functional. Practical self-consistent calculations are exemplified by simulations of Hydrogen systems, i.e. a molecule and a periodic one-dimensional array, which is a proof of existence of the interaction strength U as a continuous function of the local fluctuation and structural parameters of the system.Comment: 23 pages, 8 figures, to appear in J. Phys. Condens. Matte

A Nondestructive Eggshell Thickness Measurement Technique Using Terahertz Waves

Eggshells play a number of important roles in the avian and reptile kingdom: protection of internal contents and as a major source of minerals for developing embryos. However, when researching these respective roles, eggshell thickness measurement remains a bottleneck due to the lack of a non-destructive measurement techniques. As a result, many avian and reptile research protocols omit consideration of eggshell thickness bias on egg or embryo growth and development. Here, we validate a non-destructive method to estimate eggshell thickness based on terahertz (THz) reflectance spectroscopy using chicken white coloured eggs. Since terahertz waves are reflected from outer air-eggshell interface, as well as the inner eggshell-membrane boundary, the resulting interference signals depend on eggshell thickness. Thus, it is possible to estimate shell thickness from the oscillation distance in frequency-domain. A linear regression-based prediction model for non-destructive eggshell thickness measurement was developed, which had a coefficient of determination (R2) of 0.93, RMSEP of 0.009, RPD of 3.45 and RER 13.67. This model can estimate eggshell thickness to a resolution of less than 10 μm. This method has the potential to expand the protocols in the field of avian and reptile research, as well as be applied to industrial grading of eggs

Finding the structure of phosphorus in the phase IV

We have explored the unknown structure of the phosphorus in the phase IV (P-IV phase) based on the first-principles calculations using the metadynamics simulation method. Starting from the simple cubic structure, we found a new modulated structure of a monoclinic lattice. The modulation is crucial to the stability of the structure. Refining further the structure by changing the modulation period, we have found the structure which shows the X-ray powder pattern in the best agreement with the experimental one.We can not exclude the possibility that the unknown structure of the phase IV of phosphorus is an incommensurately modulated one.Comment: 4 pages, 4 figure

Inner membrane YfgM–PpiD heterodimer acts as a functional unit that associates with the SecY/E/G translocon and promotes protein translocation

PpiD and YfgM are inner membrane proteins that are both composed of an N-terminal transmembrane segment and a C-terminal periplasmic domain. Escherichia coli YfgM and PpiD form a stable complex that interacts with the SecY/E/G (Sec) translocon, a channel that allows protein translocation across the cytoplasmic membrane. Although PpiD is known to function in protein translocation, the functional significance of PpiD-YfgM complex formation as well as the molecular mechanisms of PpiD-YfgM and PpiD/YfgM- Sec translocon interactions remain unclear. Here, we conducted genetic and biochemical studies using yfgM and ppiD mutants and demonstrated that a lack of YfgM caused partial PpiD degradation at its C-terminal region and hindered the membrane translocation of VemP, a Vibrio secretory protein in both Escherichia coli and Vibrio alginolyticus. While ppiD disruption also impaired VemP translocation, we found that the yfgM and ppiD double deletion exhibited no additive or synergistic effects. Together, these results strongly suggest that both PpiD and YfgM are required for efficient VemP translocation. Furthermore, our site-directed in vivo photo-crosslinking analysis revealed that the tetratricopeptide repeat domain of YfgM and a conserved structural domain (NC domain) in PpiD interact with each other and that YfgM, like PpiD, directly interacts with the SecG translocon subunit. Crosslinking analysis also suggested that PpiD/YfgM complex formation is required for these proteins to interact with SecG. In summary, we propose that PpiD and YfgM form a functional unit that stimulates protein translocation by facilitating proper interactions with the Sec translocon