Local units versus local projectivity. Dualisations: Corings with local structure maps

We unify and generalize different notions of local units and local projectivity. We investigate the connection between these properties by constructing elementary algebras from locally projective modules. Dual versions of these constructions are discussed, leading to corings with local comultiplications, corings with local counits and rings with local multiplications.Comment: 22 pages, including a correction to Proposition 1.

Over talen en tekens: bijdragen van jonge Gentse linguïsten

This volume in the annual series of the BGG presents contributions of four young linguists: Jesse Berwouts (on the construction "eat yourself thin"); Sara Delva (on "sollte", "moest" and "mocht" in conditional clauses); Dario Rens (on the transition from a dative construction to a prepositional construction in Dutch); and Doesjka Tilkin (on spelling issues in Scandinavian runic inscriptions)

Determinancy → (observation EQUIVALENCE = trace equivalence)

AbstractIf an experiment s is conducted on a parallel process p, then, in general, different processes may result from the experiment, due to the nondeterministic behaviour of p (in the notation of Milner (1980): pp′ for different p′. Process p is called determinate if the resulting processes are all equivalent (i.e., if pp′ and pp″, then p′ and p″ are equivalent). This means that, although p behaves nondeterministically, this cannot be detected by an observer of p. Let ⋍ denote observation equivalence, used in CCS (Milner, 1980), let ⋍f denote (the much weaker) failure equivalence, used for CSP (Hoare et al., 1981; Brookes, 1983), and let ⋍t denote (the still weaker) trace equivalence. We show that the three corresponding notions of determinancy are the same, and that for determinate processes ⋍, ⋍f, and ⋍t are the same. Determinacy is preserved under ⋍ and ⋍f, but not under ⋍t

The role of the deep roots of perennial cereal kernza in a drying climate

Agricultural lands under annual crop production are prone to degradation and as the climate becomes increasingly variable researchers and farmers alike are looking at resilient crops such as perennial grains to produce food regeneratively. Perennial grain crops support a myriad of ecosystem services, such as reducing nitrate leaching, erosion control and increasing carbon storage. With their deep roots, perennial grain crops like Kernza (Intermediate wheatgrass) could furthermore avoid surface stresses such as droughts. This has however not been investigated before. Therefore we set out to determine the depth of root water uptake (RWU) of this crop and compared the contribution of deep roots before and after anthesis and between a year of adequate water supply (2019) and a year of drought (2018). Natural abundances of 2H and 18O were determined, but were unable to be used properly due to mistakes during sampling. A tracer application showed limited uptake from 2m depth. Furthermore, soil water content measurements were used to inverse model the soil hydraulic parameters under the Kernza crop in Hydrus 1D. Modelling RWU showed that the deep roots (>1m) were responsible for almost 50% of the RWU between anthesis and harvest in 2018, whereas they only contributed between 10% and 15% throughout 2019 and most of 2018 outside of the indicated period. Kernza may thus be an important addition to a farmers toolbox in areas with periodic droughts, but only if grain yields are increased to be competitive with annual cereals or when used as a multifunctional crop for grain, forage and other ecosystem services

Yeats and Auden: Some Verbal Parallels

As has been previously observed, Auden verbally resembles Yeats on more than one occasion, and Yeats sometimes resembles Auden. But, as far as Daalder is aware, several genuine or possible parallels are yet to be discussed. Daalder's examples are meant to suggest that Auden imitates Yeats, alludes to him, or shows kinship with him; in this article, Daalder is not, however, concerned with Auden's impact on Yeats