Thermal properties and phase transition behaviors of possible caloric materials Bi₀.₉₅Ln₀.₀₅NiO₃

Thermal properties and phase transition behaviors of possible caloric materials Bi₀.₉₅Ln₀.₀₅NiO₃ (Ln = La, Nd, Sm, Eu, Gd, Dy), which show intersite charge transfer between Bi and Ni ions, were investigated. Although a few of the compounds showed large latent heats at the intersite-charge-transfer transition temperatures, the values are not comparable to that observed in the giant caloric effect compound NdCu₃Fe₄O₁₂. In the present Bi₀.₉₅Ln₀.₀₅NiO₃, contrary to our expectation, the magnetic transitions of Ni²⁺ spins are not induced by the intersite-charge-transfer transitions and the magnetic entropy changes do not contribute to the latent heat produced by the intersite-charge-transfer transitions. To obtain giant caloric effects, materials for which the “intrinsic” magnetic transition temperatures are much higher than the charge-transfer-transition temperatures may be needed

Dynamic optimization of multicast active probing path to locate lossy links for OpenFlow networks

To maintain a high quality of service in managed networks, detecting and locating high loss-rate links (i.e., lossy links that are likely congested or physically unstable) in a fast and efficient manner is required. In our previous work, we proposed a centrally-managed network-assisted framework of locating lossy links on OpenFlow networks. In the framework, the OpenFlow controller builds a multicast measurement route; a measurement host launches a series of multicast probe packets traversing all full-duplex links along the measurement route; and then the controller collects statistical information (flow-stats) on the arrival of those probe packets at different input ports on selected switches and compares them to narrow down and identify the locations of high loss-rate links. The number of accesses to switches in collecting the flow-stats until locating all lossy links should be as small as possible for fast and efficient measurement. However, it strongly depends on not only the collection order of the flow-stats but also the topological locations of lossy links in the multicast measurement route; the former one was investigated in the previous work but the latter has not been well explored. Therefore, in this paper, we develop a new dynamic scheme of building the multicast measurement route and controlling the collection order of flow-stats from switches, which leverages lossy link locations obtained in the recent past measurements in a repeated-measurement setting. The results of numerical simulation on real-world large-scale network topologies suggest the effectiveness and also the issues of the proposed lossy link location scheme.The 34th International Conference on Information Networking (ICOIN 2020), January 7-10, 2020, Barcelona, Spai

Modes of Retrotransposition of Long Interspersed Element-1 by Environmental Factors

Approximately 42% of the human genome is composed of endogenous retroelements, and the major retroelement component, long interspersed element-1 (L1), comprises ∼17% of the total genome. A single human cell has more than 5 × 105 copies of L1, 80∼100 copies of which are competent for retrotransposition (RTP). Notably, L1 can induce RTP of other retroelements, such as Alu and SVA, and is believed to function as a driving force of evolution. Although L1-RTP during early embryogenesis has been highlighted in the literature, recent observations revealed that L1-RTP also occurs in somatic cells. However, little is known about how environmental factors induce L1-RTP. Here, we summarize our current understanding of the mechanism of L1-RTP in somatic cells. We have focused on the mode of L1-RTP that is dependent on the basic helix–loop–helix/per–arnt–sim (bHLH/PAS) family of transcription factors. Along with the proposed function of bHLH/PAS proteins in environmental adaptation, we discuss the functional linking of L1-RTP and bHLH/PAS proteins for environmental adaptation and evolution

Giant multiple caloric effects in charge transition ferrimagnet

磁場と圧力でマルチに冷却可能な酸化物新材料 --フェリ磁性電荷転移酸化物におけるマルチ熱量効果の実証--. 京都大学プレスリリース. 2021-06-22.Caloric effects of solids can provide us with innovative refrigeration systems more efficient and environment-friendly than the widely-used conventional vapor-compression cooling systems. Exploring novel caloric materials is challenging but critically important in developing future technologies. Here we discovered that the quadruple perovskite structure ferrimagnet BiCu₃Cr₄O₁₂ shows large multiple caloric effects at the first-order charge transition occurring around 190 K. Large latent heat and the corresponding isothermal entropy change, 28.2 J K⁻¹ kg⁻¹, can be utilized by applying both magnetic fields (a magnetocaloric effect) and pressure (a barocaloric effect). Adiabatic temperature changes reach 3.9 K for the 50 kOe magnetic field and 4.8 K for the 4.9 kbar pressure, and thus highly efficient thermal controls are achieved in multiple ways