Search results for "rings"
showing 10 items of 434 documents
The translocation of signaling molecules in dark adapting mammalian rod photoreceptor cells is dependent on the cytoskeleton.
2008
In vertebrate rod photoreceptor cells, arrestin and the visual G-protein transducin move between the inner segment and outer segment in response to changes in light. This stimulus dependent translocation of signalling molecules is assumed to participate in long term light adaptation of photoreceptors. So far the cellular basis for the transport mechanisms underlying these intracellular movements remains largely elusive. Here we investigated the dependency of these movements on actin filaments and the microtubule cytoskeleton of photoreceptor cells. Co-cultures of mouse retina and retinal pigment epithelium were incubated with drugs stabilizing and destabilizing the cytoskeleton. The actin a…
Endringskapasitet – en nøkkel for å lykkes med gevinstrealisering i spesialisthelsetjenesten? : En studie av hvordan mellomledere opplever at endring…
2018
Masteroppgave i helse- og sosialinformatikk HSI500 - Universitetet i Agder 2018 Background: If an organisation is to reap the potential benefits of new technology, it must modify its work processes. However, the specialist health service appears to be experiencing significant challenges because it is constantly under pressure to change and improve its efficiency. This can weaken its capacity for change and, at worst, lead to long-term reductions in productivity and efficiency. Purpose: The purpose of this study is to examine how middle managers in the specialist health service feel they can influence developments in change capacity. The aim is to contribute to an awareness of the importance…
Correspondence between some metabelian varieties and left nilpotent varieties
2021
Abstract In the class of left nilpotent algebras of index two it was proved that there are no varieties of fractional polynomial growth ≈ n α with 1 α 2 and 2 α 3 instead it was established the existence of a variety of fractional polynomial growth with α = 7 2 . In this paper we investigate similar problems for varieties of commutative or anticommutative metabelian algebras. We construct a correspondence between left nilpotent algebras of index two and commutative metabelian algebras or anticommutative metabelian algebras and we prove that the codimensions sequences of the corresponding algebras coincide up to a constant. This allows us to transfer the above results concerning varieties of…
Computing with Rational Symmetric Functions and Applications to Invariant Theory and PI-algebras
2012
The research of the first named author was partially supported by INdAM. The research of the second, third, and fourth named authors was partially supported by Grant for Bilateral Scientific Cooperation between Bulgaria and Ukraine. The research of the fifth named author was partially supported by NSF Grant DMS-1016086.
Multiplicative loops of 2-dimensional topological quasifields
2015
We determine the algebraic structure of the multiplicative loops for locally compact $2$-dimensional topological connected quasifields. In particular, our attention turns to multiplicative loops which have either a normal subloop of positive dimension or which contain a $1$-dimensional compact subgroup. In the last section we determine explicitly the quasifields which coordinatize locally compact translation planes of dimension $4$ admitting an at least $7$-dimensional Lie group as collineation group.
Extending the star order to Rickart rings
2015
Star partial order was initially introduced for semigroups and rings with (proper) involution. In particular, this order has recently been studied on Rickart *-rings. It is known that the star order in such rings can be characterized by conditions not involving involution explicitly. Owing to these characterizations, the order can be extended to certain special Rickart rings named strong in the paper; this extension is the objective of the paper. The corresponding order structure of strong Rickart rings is studied more thoroughly. In particular, the most significant lattice properties of star-ordered Rickart *-rings are successfully transferred to strong Rickart rings; also several new resu…
Subdirectly irreducible generalized sums of upper semilattice ordered systems of algebras
2002
In [15] the generalized sum of an upper (F 1 , F 2 )-semilattice ordered system of algebras was defined. In this paper we find necessary and sufficient conditions under which this construction yields subdirectly irreducible algebras.
Hurwitz spaces of coverings with two special fibers and monodromy group a Weyl group of typeBd
2012
f! Y; where is a degree-two coverings with n1 branch points and branch locus D and f is a degree-d coverings with n2 points of simple branching and two special points whose local monodromy is given by e and q, respectively. Furthermore the covering f has monodromy group Sd and f. D /\ D fD? where D f denotes the branch locus of f . We prove that the corresponding Hurwitz spaces are irreducible under the hypothesis n2 s r dC 1.
Product of nilpotent subgroups
2000
We will say that a subgroup X of G satisfies property C in G if \({\rm C}_{G}(X\cap X^{{g}})\leqq X\cap X^{{g}}\) for all \({g}\in G\). We obtain that if X is a nilpotent subgroup satisfying property C in G, then XF(G) is nilpotent. As consequence it follows that if \(N\triangleleft G\) is nilpotent and X is a nilpotent subgroup of G then \(C_G(N\cap X)\leqq X\) implies that NX is nilpotent.¶We investigate the relationship between the maximal nilpotent subgroups satisfying property C and the nilpotent injectors in a finite group.
The solution to a conjecture of Tits on the subgroup generated by the squares of the generators of an Artin group
2000
It was conjectured by Tits that the only relations amongst the squares of the standard generators of an Artin group are the obvious ones, namely that a^2 and b^2 commute if ab=ba appears as one of the Artin relations. In this paper we prove Tits' conjecture for all Artin groups. More generally, we show that, given a number m(s)>1 for each Artin generator s, the only relations amongst the powers s^m(s) of the generators are that a^m(a) and b^m(b) commute if ab=ba appears amongst the Artin relations.