Surface diffusion of K on Pd{111}: Coverage dependence of the diffusion coefficient determined with the Boltzmann–Matano method

The surface diffusion of potassium on Pd{111} has been studied with photoelectron emission microscopy (PEEM) for coverages up to one monolayer. The coverage dependence of the chemical diffusion coefficient is determined by analysis of the concentration profiles obtained from the PEEM images with the Boltzmann–Matano method. The diffusion coefficient, D, decreases with increasing coverage but a local maximum is found at a coverage of Θ≈0.5 ML. The values of D at low coverages (Θ<0.3 ML) agree well with those obtained in a previous investigation for Θ≈0.12 ML. The maximum in D is interpreted in terms of an order–disorder phase transition in the adsorbed layer

Temperature dependence of the surface diffusion coefficient of K atoms on Pd{111} measured with PEEM

The surface diffusion of potassium on Pd{111} has been studied in real time as a function of temperature between 100 and 190 K in the limit of zero concentration (Θ < 0.05 ML) using photoelectron emission microscopy (PEEM). Very fast migration of K atoms was observed on flat, quasi-one-dimensional regions of the surface between the step bunches. The temperature dependence of the diffusion coefficient indicates an activated process with an energy barrier of 66 ± 11 meV

Has taxonomic vandalism gone too far? A case study, the rise of the pay-to-publish model and the pitfalls of Morchella systematics

The genus Morchella has gone through turbulent taxonomic treatments. Although significant progress in Morchella systematics has been achieved in the past decade, several problems remain unresolved and taxonomy in the genus is still in flux. In late 2019, a paper published in the open-access journal Scientific Reports raised serious concerns about the taxonomic stability of the genus, but also about the future of academic publishing. The paper, entitled “High diversity of Morchella and a novel lineage of the esculenta clade from the north Qinling Mountains revealed by GCPSR-based study” by Phanpadith and colleagues, suffered from gross methodological errors, included false results and artifactual phylogenies, had misapplied citations throughout, and proposed a new species name invalidly. Although the paper was eventually retracted by Scientific Reports in 2021, the fact that such an overtly flawed and scientifically unsound paper was published in a high-ranked Q1 journal raises alarming questions about quality controls and safekeeping procedures in scholarly publishing. Using this paper as a case study, we provide a critical review on the pitfalls of Morchella systematics followed by a series of recommendations for the delimitation of species, description of taxa, and ultimately for a sustainable taxonomy in Morchella. Problems and loopholes in the academic publishing system are also identified and discussed, and additional quality controls in the pre- and post-publication stages are proposed. © 2022, German Mycological Society and Springer-Verlag GmbH Germany, part of Springer Nature

Truffles and Morels: Two Different Evolutionary Strategies of Fungal-Plant Interactions in the Pezizales

Pezizales are a widespread group of fungi, basal to the other filamentous ascomycetes. Most species live in soil as saprobes, in a mycorrhizal relationship with a wide range of plants, or as plant parasites. The lineage Morchellaceae–Discinaceae–Helvellaceae–Tuberaceae includes most of the commercially valuable species in the order. The truffles in the genus Tuber and morels in the genus Morchella arguably command more interest in culinary circles than any other groups of mushrooms. In recent years, the interactions of these fungi with plants have been thoroughly researched although many aspects still need to be clarified. In this chapter, we describe and compare these two groups of mushrooms and take a look at the evidence as to whether there are real trophic differences from those traditionally held and if things are not quite as simple as our forebears would have had us believe. We explore the range of host plants involved in the interactions, the morpho-anatomy of symbiotic structures, the molecular mechanisms of symbiosis, and the influence of other microbial species