We show that the variety generated by the three-element Heyting algebra admits a meet dense, regular completion even though it is not closed under MacNeille completions.

Let X be a 2-dimensional right-angled hyperbolic building. We characterise the set of covolumes of uniform lattices in Aut(X). We also show that the group Aut(X) admits an infinite ascending tower of uniform lattices.

A stochastic epidemic model allowing for both mildly and severely infectious individuals is defined, where an individual can become severely infectious directly upon infection or if additionally exposed to infection. It is shown that, assuming a large community, the initial phase of the epidemic may be approximated by a suitable branching process and that the main part of an epidemic that becom...

Community-dwelling individuals (n = 143, 73-98 years old) were assessed to consider if their use of task-specific control strategies predicted hospital outcomes in the subsequent 2 years. The authors were interested in whether men and women facing health-induced task restrictions benefited equally from the use of primary- and secondary-control strategies. Gender interacted with primary-control ...

Within the last decade, many Chinese provinces have transitioned from a ‘sequential’ to a ‘parallel’ college admissions mechanisms. Inspired by this natural experiment, we evaluate the sequential (immediate acceptance), parallel, and deferred acceptance mechanisms in the laboratory, treating each mechanism as a special case in a nested parametric family of mechanisms. We find that participants ...

We prove that for every homogeneous and strongly locally homogeneous Polish space X there is a Polish group admitting a transitive action on X. We also construct an example of a homogeneous Polish space which is not a coset space and on which no separable metrizable topological group acts transitively.

We investigate finite elation Laguerre planes admitting a group of automorphisms that is two-transitive on the set of generators. We exclude the sporadic cases of socles in two-transitive groups, as well as the cases with abelian socle (except for the smallest ones, where the Laguerre planes are Miquelian of order at most four). The remaining cases are dealt with in a separate paper. As a conse...

We say that a group G is acylindrically hyperbolic if it admits a non-elementary acylindrical action on a hyperbolic space. We prove that the class of acylindrically hyperbolic groups coincides with many other classes studied in the literature, e.g., the class Cgeom introduced by Hamenstädt, the class of groups admitting a non-elementary weakly properly discontinuous action on a hyperbolic spac...

Gaining entrance to a four-year college or university, particularly a selective institution, has become increasingly competitive over the last several decades. We document this phenomenon and show how it has varied across different parts of the student ability distribution and across region, with the most pronounced increases in competition being found among higher-ability students and in the N...

We prove that for each closed smooth spin 4-manifold M there exists a closed smooth 4-manifold N such that M#N admits a conformally at Riemannian metric.