651 research outputs found
Derivations in the Banach ideals of -compact operators
Let be a von Neumann algebra equipped with a faithful normal
semi-finite trace and let be the algebra of all
-compact operators affiliated with . Let be a symmetric operator space (on ) and let
be a symmetrically-normed Banach ideal of -compact
operators in . We study (i) derivations on
with the range in and (ii) derivations on the Banach algebra
. In the first case our main results assert that such derivations
are continuous (with respect to the norm topologies) and also inner (under some
mild assumptions on ). In the second case we show that any such
derivation is necessarily inner when is a type factor. As an
interesting application of our results for the case (i) we deduce that any
derivation from into an -space, ,
() associated with is inner
Commutator estimates in -factors
Let be a -factor and let be
the space of all measurable operators affiliated with . It is
shown that for any self-adjoint element there exists a
scalar , such that for all , there
exists a unitary element from , satisfying
. A corollary
of this result is that for any derivation on with the
range in an ideal , the derivation is inner,
that is , and . Similar
results are also obtained for inner derivations on .Comment: 21 page
Derivations on symmetric quasi-Banach ideals of compact operators
Let be symmetric quasi-Banach ideals of compact operators on
an infinite-dimensional complex Hilbert space , let be a
space of multipliers from to . Obviously, ideals
and are quasi-Banach algebras and it is clear that
ideal is a bimodule for . We study the set of all
derivations from into . We show that any such
derivation is automatically continuous and there exists an operator
such that , moreover
, where is the modulus of concavity of the quasi-norm
. In the special case, when is a
symmetric Banach ideal of compact operators on our result yields the
classical fact that any derivation on may be written
as , where is some bounded operator on and
.Comment: 21 page
Effect of Feed Restriction on the Behaviour and Welfare of Broiler Chickens
Under intensive rearing conditions, the welfare of broiler chickens may be at risk
depending on genotype and sex, due to their different growth rates. The practice of quantitative
feed restriction may also impact on welfare. This study aimed to evaluate behaviour and
corticosterone content in plasma and faeces at different ages using 896 one-day-old chicks housed
in 32 pens, allocated to 8 groups, i.e., 2 genotypes (standard vs. high breast yield)
7 2 sex
7 2 feeding
plans (ad libitum vs. restricted, AL vs. FR). The feeding system affected the percentage of standing
(9.84% vs. 11.7% in AL vs. FR; p 64 0.001), feeding (7.51% vs. 8.17%; p 64 0.01) and sitting/lying (67.0%
vs. 64.1%; p 64 0.001), and the faeces corticosterone content (12.2 vs. 13.6 ng/g in AL vs. FR; p 64 0.10).
Sex affected the percentage of pecking other chickens, standing and comfort behaviours. Changes
in behaviour were recorded between high and standard breast yield genotypes with faeces
corticosterone which tended to be higher in the former (p 64 0.10). Significant interactions between the main factors and age were observed. Major changes in behaviour were due to feed restriction,
which stimulated activity during restriction
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