This paper presents DFT-generator, a small tool to generate DeadlockFreeness Theorems (DFT) in Event-B specifications. Event-B, a companion to the B-method, allows specifiers to model systems and environments with the help states, invariants, and events. Events are guarded generalized substitutions which are fired non-deterministically. Assessing temporal properties such as termination or as no...

A potential strategy for controlling pests is through the use of "companion plants" within a crop system. This strategy has been used in several trials to fight against a major crop insect pest: the aphid. We reviewed the literature to highlight the major mechanisms by which a companion plant may act. Trials carried out under laboratory or field conditions revealed that companion plants operate...

The ultrastructural features of the sieve element/companion cell complexes were screened in the stem phloem of two symplasmically loading (squash, [Cucurbita maxima L.] and Lythrum salicaria L.) and two apoplasmically loading (broad bean [Vicia faba L.] and Zinnia elegans L.) species. The distinct ultrastructural differences between the companion cells in the collection phloem of symplasmically...

The paper summarises activities within a broad-based research program for the reconstruction of the evolution of Italian climate in the twentieth century. The main result of the program is that Italian climate is becoming warmer and drier with an increase of both heavy precipitation events and long dry spells. Most of the observed signals appear to be due to changes in atmospheric circulation c...

Sieve tubes are comprised of sieve elements, enucleated cells that are incapable of RNA and protein synthesis. The proteins in sieve elements are supplied from the neighboring companion cells through plasmodesmata. In rice plants, it was unclear whether or not all proteins produced in companion cells had the same distribution pattern in the sieve element-companion cell complex. In this study, t...

Based on our intensive spectroscopic campaign with the GoldCam spectrograph on the Kitt Peak National Observatory (KPNO) 2.1-m telescope, we have constructed the first catalogue of E+A galaxies with spectroscopic companion galaxies, and investigated a probability that an E+A galaxy have close companion galaxies. We selected 660 E+A galaxies with 4.0Å < Hδ EW at a redshift of < 0.167 from the Da...

We consider the classical problem of aggregating di¤erent individuals’probability assignments (opinions) over a -algebra of events. In practice, some events represent basic propositions, such as ‘it rains’or ‘CO2 emissions cause global warming’, while others represent combinations thereof, for instance disjunctions (unions) of basic events. It is plausible to treat the basic events as premises ...

This paper is concerned with online caching algorithms for the (n, k)-companion cache, defined by Brehob et. al. [3]. In this model the cache is composed of two components: a k-way set-associative cache and a companion fully-associative cache of size n. We show that the deterministic competitive ratio for this problem is (n+1)(k+1)−1, and the randomized competitive ratio is O(log n log k) and Ω...