In this letter note we present two new parameter identifiers whose estimates converge in finite time under weak interval excitation assumptions. The main novelty is that, contrast with other finite-convergence (FCT) estimators, our schemes preserve the FCT property when parameters change. previous versions of estimators can track variations only asymptotically. Continuous-time and discrete-time...

A class of structures satisfies the extension preservation theorem if, on this class, every first order sentence is preserved under extension iff it is equivalent to an existential sentence. We consider different acyclicity notions for hypergraphs (γ, β and α-acyclicity and also acyclicity on hypergraph quotients) and estimate their influence on the validity of the extension preservation theore...

Long-term preservation is crucial as an enabling technology for tissue banking for transplantation, regenerative medicine products that contain living cells and biopsy samples. Regenerative medicine reviews in particular have consistently highlighted the need for preservation methods for product development and commercialization. Strategic assessments of regenerative medicine have provided thre...

71 samples of milk and dairy products were collected from 18 cities throughout Iran. 93 strains of lactic acid bacteria (LAB) were isolated and assayed against four opportunistic patho gens including E. coli, proteus and klebsiella as gram-negative and S. aureus as a gram-positive organism. All indicators (organisms) were hospital strains. Among isolated bacteria, lactobacilli (37 isolates)...

We present new parameterized preservation properties that provide for each natural number k, semantic characterizations of the ∃∀ and ∀∃ prefix classes of first order logic sentences, over the class of all structures and for arbitrary finite vocabularies. These properties, that we call preservation under substructures modulo k-cruxes and preservation under k-ary covered extensions respectively,...

Various problems on integers lead to the class of functions defined on a ring of numbers (or a subset of such a rings) METTRE RING AU SINGULIER and verifying a − b divides f(a) − f(b) for all a, b. We say that such functions are “congruence preserving”. In previous works, we characterized these classes of functions for the cases N → Z, Z→ Z and Z/nZ→ Z/mZ in terms of sums series of rational pol...