It is well-known that in a dense, gravity-driven flow, large particles typically rise to the top relative to smaller equal-density particles. In dense flows, this has historically been attributed to gravity alone. However, recently kinetic stress gradients have been shown to segregate large particles to regions with higher granular temperature, in contrast to sparse energetic granular mixtures where the large particles segregate to regions with lower granular temperature. We present a segregation theory for dense gravity-driven granular flows that explicitly accounts for the effects of both gravity and kinetic stress gradients involving a separate partitioning of contact and kinetic stresses among the mixture constituents. We use discrete-element-method (DEM) simulations of different-sized particles in a rotated drum to validate the model and determine diffusion, drag, and stress partition coefficients. The model and simulations together indicate, surprisingly, that gravity-driven kinetic sieving is not active in these flows. Rather, a gradient in kinetic stress is the key segregation driving mechanism, while gravity plays primarily an implicit role through the kinetic stress gradients. Finally, we demonstrate that this framework captures the experimentally observed segregation reversal of larger particles downward in particle mixtures where the larger particles are sufficiently denser than their smaller counterparts.

Our understanding of how fast mating behaviour evolves in insects is rather poor due to a lack of comparative studies among insect groups for which phylogenetic relationships are known. Here, we present a detailed study of the mating behaviour of 27 species of Sepsidae (Diptera) for which a well‐resolved and supported phylogeny is available. We demonstrate that mating behaviour is extremely diverse in sepsids with each species having its own mating profile. We define 32 behavioural characters and document them with video clips. Based on sister species comparisons, we provide several examples where mating behaviour evolves faster than all sexually dimorphic morphological traits. Mapping the behaviours onto the molecular tree reveals much homoplasy, comparable to that observed for third positions of mitochondrial protein‐encoding genes. A partitioned Bremer support (PBS) analysis reveals conflict between the molecular and behavioural data, but behavioural characters have higher PBS values per parsimony‐informative character than DNA sequence characters.

Background: Because cells progressing to cancer must proliferate, marker proteins specific to proliferating cells may permit detection of premalignant lesions. Here we compared the sensitivities of a classic proliferation marker, Ki-67, with a new proliferation marker, MCM2, in 41 bronchial biopsy specimens representing normal mucosa, metaplasia, dysplasia, and carcinoma in situ.

R. (2010). From 'cryptic species' to integrative taxonomy: an iterative process involving DNA sequences, morphology, and behaviour leads to the resurrection of Sepsis pyrrhosoma (Sepsidae: Diptera). -Zoologica Scripta, 39, 51-61. The increased availability of DNA sequences has led to a surge of 'cryptic species' in the literature. These units are usually proposed based on finding genetically distinct lineages within species that were initially defined based on morphological characters. However, few authors attempt to confirm whether these 'cryptic' units are species and even fewer authors are explicit about which species concept is applied. Here, we use an example from Sepsidae (Diptera) to demonstrate how cryptic species can be validated by an iterative process involving several data sources and an evaluation of the data under different species concepts. A phylogeographic analysis based on 50 specimens for five species of the flavimana group revealed deep mitochondrial splits within Sepsis flavimana which was suggestive of a cryptic species. We resolve the initial conflict between DNA sequences and morphology by adding new morphological data as well as behavioural evidence and tests for reproductive isolation. One cryptic species is confirmed and Sepsis pyrrhosoma, a former synonym of S. flavimana, is here shown to be a valid species under most species concepts. We can thus document that the same data can lead to similar conclusions under conflicting concepts once different kinds of data are integrated.