Search

Three hymenopteran species - the ichneumonids Amblyteles armatorius and Diphyus quadripunctorius, and the proctotrupid Exallonyx longicornis - are most frequently cited from all over Europe as executing their inactive hypogean ecophase in caves. Yet, little is known about their environmental requirements during their summer quiescence and/or winter diapause; only limited data are known from Western and Eastern Europe. In this investigation, the sojourn of hymenopterans in hypogean environments is ecologically evaluated on the basis of data obtained from 63 systematically investigated caves and artificial tunnels in central and northern Slovenia, as being representative of the Central European countries. Nine environmental parameters measured at the resting sites of individuals were subjected to Principal Component Analysis (PCA). The species differ significantly from each other on ecological parameters: the euryecious A. armatorius occupies a narrow central position with respect to environmental requirements in caves; the montane D. quadripunctorius exhibits the best, and the lowland E. longicornis the feeblest adaptation to hypogean environments. In contrast to Western and Eastern Europe, in the central countries, the three hymenopteran species prefer dormancy habitats other than caves. These regional differences deserve more attention in future investigations of European hypogean fauna. [ABSTRACT FROM AUTHOR]

Domain wall propagation in modulated-diameter cylindrical nanowires is a key phenomenon to be studied with a view to designing three-dimensional magnetic memory devices. This paper presents a theoretical study of transverse domain wall behavior under the influence of a magnetic field within a cylindrical nanowire with diameter modulations. In particular, domain wall pinning close to the diameter modulation was quantified, both numerically, using finite element micromagnetic simulations, and analytically. Qualitative analytical model for gently sloping modulations resulted in a simple scaling law which may be useful to guide nanowire design when analyzing experiments. It shows that the domain wall depinning field value is proportional to the modulation slope. [ABSTRACT FROM AUTHOR]