Fungi (Ascomycota, Basidiomycota) form crystals of various inorganic and organic compounds on their mycelium and fruitbodies. Crystals are formed either when fungal metabolites released into the surrounding environment react with compounds already present and then crystallise, or when the metabolites produced in sufficient quantities crystallise directly at optimal conditions. Both examples were observed in nature and also under labora - tory conditions and show a wide spectra of metabolites produced by fungi. and Ondřej Koukol.
Cosmic reionization, which took place in the first billion years after the Big Bang, was a major event in the cosmic history. This transformation of all neutral hydrogen to ionize was probably caused by the first stars, galaxies and quasars. However, a direct proof of which sources were dominant is still missing. Dr. Ivana Orlitová from the Institute of Astronomy of the CAS reviews results of the serach for ionizing sources in both distant and nearby Universe, and presents a recent discovery of starforming galaxies that show signs of strong ionizing activity. and Ivana Orlitová.
Cuckoos parasitize many rare and inconspicuous host species but avoid other common and conspicuous ones. In this article, results of a study that solved this long-standing ecological conundrum are described. I use this work to illustrate va - rious weaknesses of typical ecological studies (sample size, data representativeness, reification) and give suggestions for a better research practice in the future. and Tomáš Grim.