3,067 research outputs found
A Branching Time Model of CSP
I present a branching time model of CSP that is finer than all other models
of CSP proposed thus far. It is obtained by taking a semantic equivalence from
the linear time - branching time spectrum, namely divergence-preserving coupled
similarity, and showing that it is a congruence for the operators of CSP. This
equivalence belongs to the bisimulation family of semantic equivalences, in the
sense that on transition systems without internal actions it coincides with
strong bisimilarity. Nevertheless, enough of the equational laws of CSP remain
to obtain a complete axiomatisation for closed, recursion-free terms.Comment: Dedicated to Bill Roscoe, on the occasion of his 60th birthda
Responses to supplementation by dairy cows given low pasture allowances in different seasons 2. Milk production
Two factorial experiments were designed to determine the effects of stage of lactation, and season of the year, on cow responses to supplementary feeding. These experiments were conducted over consecutive years with 128 high genetic merit multiparous Holstein-Friesian cows in early, mid and late lactation in spring, summer, autumn and winter. At each stage of lactation, and in each season of the year, cows were offered a restricted pasture allowance (25 to 35 kg dry matter (DM) per cow per day), either unsupplemented (control) or with supplement at 50 MJ metabolizable energy (ME) per cow per day in experiment 1 and 80 MJ ME per cow per day in experiment 2. The two supplements given in both years were rolled maize grain (MG) and a mixture of foods formulated to nutritionally balance the diet (BR). In experiment 2, another treatment, of a generous pasture allowance (60 to 75 kg DM per cow per day) (AP), was imposed on an additional group of early lactation cows during each season. Direct milk solids (MS) (milk fat plus milk protein) responses in experiment 1 to MG were 169, 279, 195 and 251 g MS per cow per day in spring, summer, autumn and winter, respectively, while those to BR were 107, 250, 192, 289 g MS per cow per day. In experiment 2, however, milk solids responses to both supplements during spring were slightly below the control treatment, with values similar to those in experiment 1 in summer and autumn for cows on the BR but not the MG supplement. Milk solids responses to supplementary foods were largest during seasons of the year when the quantity and quality of pasture on offer resulted in the lowest milk solids yield from unsupplemented cows. When carry-over effects of feeding MG and BR on milk solids production were detected, they were only about half the magnitude of the direct effects. Serum urea concentrations were higher in control cows than those offered MG with a similar effect for BR in all but summer in experiment 1, while serum glucose concentrations were highest in winter and lowest in summer. The most important factor influencing milk solids responses was the relative food deficit (RFD) represented by the decline in milk solids yield of the respective control groups after,changing from a generous pasture allowance to restricted allowance when the feeding treatments were imposed. Total milk solids responses (direct and carry-over) to supplements were greatest when severe food restrictions, relative to the cows' current food demand, resulted in large reductions in milk solids yield of the control groups. The RFD was the best predictor of milk solids response to supplementary foods. Therefore, it is likely that cows are most responsive to supplementary foods during or immediately after the imposition of a severe food restriction
Responses to supplementation by dairy cows given low pasture allowances in different seasons 1. Pasture intake and substitution
Two factorial experiments were designed to determine the effects of stage of lactation, and season of the year, on cow responses to supplementary feeding. These experiments were conducted over consecutive years with 128 high genetic merit multiparous Holstein-Friesian cows in early, mid and late lactation in spring, summer, autumn and winter. At each stage of lactation, and in each season of the year, cows were offered a restricted pasture allowance (25 to 35 kg dry matter (DM) per cow per day), either unsupplemented (control) or supplemented with 50 MJ metabolizable energy (ME) per cow per day in experiment 1 and 80 MJ ME per cow per day in experiment 2. Two different supplements were offered, namely, rolled maize grain (MG) and a mixture of foods (BR) formulated to nutritionally balance the diet. In experiment 2, a fourth treatment consisting solely of a generous pasture allowance (60 to 75 kg DM per cow per day, AP) was introduced. Offering MG and BR increased DM intake (DMI). At the restricted pasture allowance, increasing total ME allowance (MEA) by offering supplementary foods increased ME intake (MEI) by 0.68 (s.e. 0.047) MJ per extra MJ ME offered. This highly significant (P < 0.001) linear relationship was consistent across seasons, and did not diminish at higher MEA. In experiment 2, cows in early lactation had lower substitution rates than mid and late lactation cows irrespective of season. Substitution rate was higher when higher pasture allowance or quality of pasture on offer enabled the unsupplemented cows to achieve higher DMI from pasture than at other times of the year. These results suggest that one of the key factors determining the intake response to supplementary foods is pasture allowance. Within spring calving dairying systems, the largest increases in total DMI per kg of supplement offered is likely when offering supplements to early lactation cows grazing restricted allowances of high quality pasture
The TLR4 D299G and T399I SNPs Are Constitutively Active to Up-Regulate Expression of Trif-Dependent Genes
Peer reviewedPublisher PD
Observation and theoretical description of the pure Fano-effect in the valence-band photo-emission of ferromagnets
The pure Fano-effect in angle-integrated valence-band photo-emission of
ferromagnets has been observed for the first time. A contribution of the
intrinsic spin polarization to the spin polarization of the photo-electrons has
been avoided by an appropriate choice of the experimental parameters. The
theoretical description of the resulting spectra reveals a complete analogy to
the Fano-effect observed before for paramagnetic transition metals. While the
theoretical photo-current and spin difference spectra are found in good
quantitative agreement with experiment in the case of Fe and Co only a
qualitative agreement could be achieved in the case of Ni by calculations on
the basis of plain local spin density approximation (LSDA). Agreement with
experimental data could be improved in this case in a very substantial way by a
treatment of correlation effects on the basis of dynamical mean field theory
(DMFT).Comment: 11 pages, 3 figures accepted by PR
Enhancer SINEs Link Pol III to Pol II Transcription in Neurons
Spatiotemporal regulation of gene expression depends on the cooperation of multiple mechanisms, including the functional interaction of promoters with distally located enhancers. Here, we show that, in cortical neurons, a subset of short interspersed nuclear elements (SINEs) located in the proximity of activity-regulated genes bears features of enhancers. Enhancer SINEs (eSINEs) recruit the Pol III cofactor complex TFIIIC in a stimulus-dependent manner and are transcribed by Pol III in response to neuronal depolarization. Characterization of an eSINE located in proximity to the Fos gene (FosRSINE1) indicated that the FosRSINE1-encoded transcript interacts with Pol II at the Fos promoter and mediates Fos relocation to Pol II factories, providing an unprecedented molecular link between Pol III and Pol II transcription. Strikingly, knockdown of the FosRSINE1 transcript induces defects of both cortical radial migration in vivo and activity-dependent dendritogenesis in vitro, demonstrating that FosRSINE1 acts as a strong enhancer of Fos expression in diverse physiological contexts
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