Sexual dimorphism of the cuticle and body-wall muscle in free-living mycophagous nematodes

Sexual dimorphism in motility-related traits is widespread among animals, including several species of Nematoda. However, no study has examined motility-related structural components and compared them between sexes. We examined the motility-related components in four species: Bursaphelenchus conicaudatus Kanzaki, Tsuda and Futai, 2000; Bursaphelenchus rainulfi Braasch and Burgermeister, 2002; Bursaphelenchus doui Braasch, Gu, Burgermeister and Zhang, 2005; Parasitaphelenchus costati Kanzaki, Ekino, Ide, Masuya and Degawa, 2018. We measured the structure and amount of cuticle and body-wall muscles and estimated their relationship to body diameter or total cross-sectional area. Although no structural differences were observed in muscle, the relevant muscle area of B. doui and P. costati was significantly smaller in females than in males. This difference was greatest in P. costati. In all but B. doui, the relative cuticle thickness was significantly smaller in females than in males. Furthermore, only P. costati females had no striated basal zones in their cuticles; these are thought to be cross-linked proteins that provide strength to nematode cuticle during body movement. These results indicate that sexual dimorphism in motility-related structural components is present in P. costati and that females invest less energy in the components than do males.

Quasiparticle conductance-voltage characteristics for break junctions involving d-wave superconductors: charge-density-wave effects

Quasiparticle tunnel conductance-voltage characteristics (CVCs), [Formula: see text], were calculated for break junctions (BJs) made up of layered d-wave superconductors partially gapped by charge-density waves (CDWs). The current is assumed to flow in the ab-plane of electrodes. The influence of CDWs is analyzed by comparing the resulting CVCs with CVCs calculated for BJs made up of pure d-wave superconductors with relevant parameters. The main CDW-effects were found to be the appearance of new CVC peculiarities and the loss of CVC symmetry with respect to the V-sign. Tunnel directionality was shown to be one of the key factors in the formation of [Formula: see text] dependences. In particular, the orientation of electrodes with respect to the current channel becomes very important. As a result, [Formula: see text] can acquire a large variety of forms similar to those for tunnel junctions between superconductors with s-wave, d-wave, and mixed symmetry of their order parameters. The diversity of peculiarities is especially striking at finite temperatures. In the case of BJs made up of pure d-wave superconductors, the resulting CVC can include a two-peak gap-driven structure. The results were compared with the experimental BJ data for a number of high-T _c oxides. It was shown that the large variety of the observed current-voltage characteristics can be interpreted in the framework of our approach. Thus, quasiparticle tunnel currents in the ab-plane can be used as an additional mean to detect CDWs competing with superconductivity in cuprates or other layered superconductors.

Influence of the spatially inhomogeneous gap distribution on the quasiparticle current in c-axis junctions involving d-wave superconductors with charge density waves

The quasiparticle tunnel current J(V) between the superconducting ab-planes along the c-axis and the corresponding conductance [Formula: see text] were calculated for symmetric junctions composed of disordered d-wave layered superconductors partially gapped by charge density waves (CDWs). Here, V is the voltage. Both the checkerboard and unidirectional CDWs were considered. It was shown that the spatial spread of the CDW-pairing strength substantially smears the peculiarities of G(V) appropriate to uniform superconductors. The resulting curves G(V) become very similar to those observed for a number of cuprates in intrinsic junctions, e.g. mesas. In particular, the influence of CDWs may explain the peak-dip-hump structures frequently found for high-T c oxides.