An electric field partly lifts the degeneracies of atomic energy levels. This splitting was observed by Stark [1] and explained by Schrödinger [2]. We compute the Stark effect on atomic hydrogen using perturbation theory by diagonalizing the perturbation term in the N-fold degenerate multiplet of states with principal quantum number N . We exploit the symmetries of this problem to simplify the ...

PREMISE OF THE STUDY Microsatellite primers were developed for a widespread limestone endemic sedge, Carex eburnea, to facilitate investigation of the genetic diversity and phylogeography of this taxon and its closest relative, C. mckittrickensis. METHODS AND RESULTS Forty-eight primer pairs were designed from Illumina sequence data and screened for suitability. Fourteen of these primer pairs...

In this paper, we introduce a sectorial episode of the form C → r, where C is a set of events and r is an event. The sectorial episode C → r means that every event of C is followed by an event r. Then, by formulating the support and the confidence of sectorial episodes, in this paper, we design the algorithm Sect to extract all of the sectorial episodes that are frequent and confidential from a...

Allium therinanthum, a new species of A. sect. Codonoprasum, is described and illustrated from southern Mt. Hermon (Israel). It is a late-flowering diploid species (2n = 16), growing on calcareous substrates of the mountain belt. It is a narrowly distributed geophyte, showing morphological relationships mainly with A. tardiflorum, a typical autumnal species also occurring in Israel within the p...