Piptatherum ferganense is recorded as a new grass species for the flora of Iran collected from Ghorkhod Protected Area and Aladagh Mountains in North Khorassan province. The core distribution range of the species is Eastern Irano-Turanian with a disjunction in northeastern Iran. The morphological characters of P. ferganense are illustrated and compared with the closely related P. latifolium. I...

 According to a class of constrained‎ ‎minimization problems‎, ‎the Schwartz symmetrization process and the‎ ‎compactness lemma of Strauss‎, ‎we prove that there is a‎ ‎nontrivial ground state solution for a class of $p$-Laplace‎ ‎equations without the Ambrosetti-Rabinowitz condition‎.

In the past few years secure messaging has become mainstream, with over a billion active users of end-to-end encryption protocols through apps such as WhatsApp, Signal, Facebook Messenger, Google Allo, Wire and many more. While these users’ two-party communications now enjoy very strong security guarantees, it turns out that many of these apps provide, without notifying the users, a weaker prop...

Koenig’s infinity lemma states that an infinite rooted tree in which every node has finite degree has an infinite path. A variation of this lemma about mappings from one tree to another is presented in this note. Its proof utilizes Koenig’s lemma, and Koenig’s lemma follows from this variation.