60 research outputs found
Agrikulturkemisk Konsulentvirksomhed i 1908.
Agrikulturkemisk Konsulentvirksomhed i 1908
Planters Evne til direkte at binde Luftens Kvælstof i Følge de af Th. Jamieson i 1905 udførte Undersøgelser med nogle supplerende Bemærkninger.
Planters Evne til direkte at binde Luftens Kvælstof i Følge de af Th. Jamieson i 1905 udførte Undersøgelser med nogle supplerende Bemærkninger
Vore Kunstgødninger. 1. Kvælstofgødninger i 1905.
Vore Kunstgødninger. 1. Kvælstofgødninger i 1905
Relative commutants of strongly self-absorbing C*-algebras
The relative commutant of a strongly self-absorbing
algebra is indistinguishable from its ultrapower . This
applies both to the case when is the hyperfinite II factor and to the
case when it is a strongly self-absorbing C*-algebra. In the latter case we
prove analogous results for and reduced powers
corresponding to other filters on . Examples of algebras with
approximately inner flip and approximately inner half-flip are provided,
showing the optimality of our results. We also prove that strongly
self-absorbing algebras are smoothly classifiable, unlike the algebras with
approximately inner half-flip.Comment: Some minor correction
The topological dimension of type I C*-algebras
While there is only one natural dimension concept for separable, metric
spaces, the theory of dimension in noncommutative topology ramifies into
different important concepts. To accommodate this, we introduce the abstract
notion of a noncommutative dimension theory by proposing a natural set of
axioms. These axioms are inspired by properties of commutative dimension
theory, and they are for instance satisfied by the real and stable rank, the
decomposition rank and the nuclear dimension.
We add another theory to this list by showing that the topological dimension,
as introduced by Brown and Pedersen, is a noncommutative dimension theory of
type I C*-algebras. We also give estimates of the real and stable rank of a
type I C*-algebra in terms of its topological dimension.Comment: 20 pages; minor correction
A Simple Separable Exact C*-Algebra not Anti-isomorphic to Itself
We give an example of an exact, stably finite, simple. separable C*-algebra D
which is not isomorphic to its opposite algebra. Moreover, D has the following
additional properties. It is stably finite, approximately divisible, has real
rank zero and stable rank one, has a unique tracial state, and the order on
projections over D is determined by traces. It also absorbs the Jiang-Su
algebra Z, and in fact absorbs the 3^{\infty} UHF algebra. We can also
explicitly compute the K-theory of D, namely K_0 (D) = Z[1/3] with the standard
order, and K_1 (D) = 0, as well as the Cuntz semigroup of D.Comment: 16 pages; AMSLaTeX. The material on other possible K-groups for such
an algebra has been moved to a separate paper (1309.4142 [math.OA]
Monoids of intervals of simple refinement monoids and non-stable K-Theory of multiplier algebras
We show that the representation of the monoid of intervals of a simple refinement monoid in terms of affine semicontinuous functions, given by Perera in 2001, fails to be faithful in the case of strictly perforated monoids. We give some potential applications of this result in the context of monoids of intervals and K-Theory of multiplier rings
Centralized Modularity of N-Linked Glycosylation Pathways in Mammalian Cells
Glycosylation is a highly complex process to produce a diverse repertoire of
cellular glycans that are attached to proteins and lipids. Glycans are involved
in fundamental biological processes, including protein folding and clearance,
cell proliferation and apoptosis, development, immune responses, and
pathogenesis. One of the major types of glycans, N-linked glycans, is formed by
sequential attachments of monosaccharides to proteins by a limited number of
enzymes. Many of these enzymes can accept multiple N-linked glycans as
substrates, thereby generating a large number of glycan intermediates and their
intermingled pathways. Motivated by the quantitative methods developed in
complex network research, we investigated the large-scale organization of such
N-linked glycosylation pathways in mammalian cells. The N-linked glycosylation
pathways are extremely modular, and are composed of cohesive topological
modules that directly branch from a common upstream pathway of glycan
synthesis. This unique structural property allows the glycan production between
modules to be controlled by the upstream region. Although the enzymes act on
multiple glycan substrates, indicating cross-talk between modules, the impact
of the cross-talk on the module-specific enhancement of glycan synthesis may be
confined within a moderate range by transcription-level control. The findings
of the present study provide experimentally-testable predictions for
glycosylation processes, and may be applicable to therapeutic glycoprotein
engineering
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