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We synthesized Poly(p-phenylene sulfonic acid-ran-2,5-benzophenone) (PPPS-BP) with high ion exchange capacity (IEC). This polymer formed a highly packed acid structure in the pores of porous thin substrates. In addition, the filled electrolyte polymer was cross-linked to obtain a practical membrane. In particular, the pores of the polyethylene microporous membrane were filled with cross-linked electrolytes with high IEC (5.1 meq g−1), derived from PPPS-BP, vinyl sulfonic acid, and triallyl isocyanurate. The membrane exhibited high proton conductivity and good single cell performance (H2/O2), equal to or higher than a commercial membrane (Nafion® HP) under a wide range of humidity conditions. The high proton conductivity appeared to be conferred by the highly packed acid structure in the membrane. The membrane also showed high mechanical durability in dry–wet cycle test. Therefore, the fabricated membrane presents as a good candidate for fuel cell applications under low relative humidity conditions.

SpaceWire is valuable because it facilitates the development of spacecraft subsystems such as payload instruments, mass memory, and onboard computers. On the other hand, it takes much time and effort for developers to configure an initiator of the SpaceWire network because they have to take account of the entire SpaceWire network in a spacecraft. As the target network becomes larger, the path addressing and the packet collision-free timeslot allocation are harder for the developers to configure. Furthermore, the configuration tables of the initiator should satisfy various constraints, such as the bandwidth limitation and priority of specific packets. These constraints are different in each spacecraft. In order that the developers can design the large-scale SpaceWire network efficiently, automatic configuration table generation under the constraints is indispensable. This paper presents a constraint-based configuration table generator (CTG) that automatically provides reliable redundant path routing and collision-free timeslot allocation for required transactions in the target topology. We apply a constraint solver to the CTG to set many kinds of user-defined constraints in the network. For example, the bandwidth limitation, priority of the packets, and other various constraints can be easily inputted into the CTG. The CTG automatically generates configuration tables satisfying these constraints. Additionally, the CTG reports network topology views with bandwidth utilization ratios. This helps developers to verify whether a generated configuration is just as designed. The CTG can also notify developers that their requirements cannot be solved. In this paper, we show the feasibility and effectiveness of this tool through evaluation using a large-scale SpaceWire network case.

Viral vectors that can infect neurons transsynaptically and can strongly express foreign genes are useful for investigating the organization of neural circuits. We previously developed a propagation-competent rabies virus (RV) vector based on a highly attenuated HEP-Flury strain (rHEP5.0-CVSG), which selectively infects neurons and propagates between synaptically connected neurons in a retrograde direction. Its relatively low level of transgene expression, however, makes immunostaining necessary to visualize the morphological features of infected neurons. To increase the transgene expression level of this RV vector, in this study we focused on two viral proteins: the large protein (L) and matrix protein (M). We first attempted to enhance the expression of L, which is a viral RNA polymerase, by deleting the extra transcription unit and shortening the intergenic region between the G and L genes. This viral vector (rHEP5.0-GctL) showed increased transgene expression level with efficient transsynaptic transport. We next constructed an RV vector with a rearranged gene order (rHEP5.0-GML) with the aim to suppress the expression of M, which plays a regulatory role in virus RNA synthesis. Although this vector showed high transgene expression level, the efficiency of transsynaptic transport was low. To further evaluate the usability of rHEP5.0-GctL as a transsynaptic tracer, we inserted a fluorescent timer as a transgene, which changes the color of its fluorescence from blue to red over time. This viral vector enabled us the differentiation of primary infected neurons from secondary infected neurons in terms of the fluorescence wavelength. We expect this propagation-competent RV vector to be useful for elucidating the complex organization of the central nervous system.