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In the first study, we tested the ability of a commercial feed additive (OmniGen-AF) to affect markers of innate immunity in immunosuppressed sheep and the ability of a pathogen challenge (mould) to affect the immune response to the additive. Treatments consisted of (1) control, (2) immunosuppressed with dexamethasone (DEX), (3) immunosuppressed plus the feed additive, (4) immunosuppressed plus Aspergillus fumigatus and (5) immunosuppressed, A. fumigatus and the additive. Animal health was monitored and indexes of innate immunity (neutrophil L-selectin and interleukin-1b (IL-1b)) were collected. DEX caused immunosuppression (i.e. reduced abundance of neutrophil L-selectin and IL-1b). This immunosuppressive effect was countered by the provision of the additive in the ration. Provision of mould in the ration increased the ability of the additive to regulate markers of innate immune function. A second study was completed to re-assess the properties of the additive and other feed products. The study consisted of seven treatments: (1) immunosuppressed, (2) immunosuppressed with additive, (3) immunosuppressed with additive in pelleted form (low-temperature pellet) and (4) immunosuppressed with additive in a high-temperature pellet. The remaining three treatments assessed abilities of three other additives to regulate markers of innate immune function. In this study, OmniGen-AF increased expression of neutrophil L-selectin abundance in immunosuppressed animals and this was unaffected by the pelleting temperature. None of the other additives affected markers of innate immunity. In these studies we discovered mechanisms by which a feed product may affect the immune function of ruminant livestock. The product countered DEX-dependent down-regulation of markers of innate immune function and its actions were enhanced by the presence of pathogen (mould) in the ration.

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The noise-coupling technique successfully used in discrete-time deltasigma analogue-to-digital converters (ADCs) is extended to the realisation of continuous-time delta-sigma ADCs, resulting in improved quantisation noise shaping. To verify the proposed design methodology, a second-order continuous-time delta-sigma modulator with noise coupling is designed and simulated.Introduction: Noise coupling was introduced by Lee et al.[1] to enhance quantisation noise shaping in discrete-time (DT) delta-sigma (DS) modulators. The resulting analogue-to-digital converters (ADCs) demonstrated excellent linearity and power efficiency [2,3]. Recently continuous-time (CT) DS modulators have become popular owing to their inherent anti-aliasing performance and lower bandwidth requirements. These properties are particularly important in low-power and wideband applications. Further improvements in power efficiency and performance can be expected if the noise-coupling technique can also be used for continuous-time DS ADCs. This Letter proposes a method for the practical implementation of such structures.

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