Should the poultry red mite Dermanyssus gallinae be of wider concern for veterinary and medical science?

The poultry red mite Dermanyssus gallinae is best known as a threat to the laying-hen industry; adversely affecting production and hen health and welfare throughout the globe, both directly and through its role as a disease vector. Nevertheless, D. gallinae is being increasingly implemented in dermatological complaints in non-avian hosts, suggesting that its significance may extend beyond poultry. The main objective of the current work was to review the potential of D. gallinae as a wider veterinary and medical threat. Results demonstrated that, as an avian mite, D. gallinae is unsurprisingly an occasional pest of pet birds. However, research also supports that these mites will feed from a range of other animals including: cats, dogs, rodents, rabbits, horses and man. We conclude that although reported cases of D. gallinae infesting mammals are relatively rare, when coupled with the reported genetic plasticity of this species and evidence of permanent infestations on non-avian hosts, potential for host-expansion may exist. The impact of, and mechanisms and risk factors for such expansion are discussed, and suggestions for further work made. Given the potential severity of any level of host-expansion in D. gallinae, we conclude that further research should be urgently conducted to confirm the full extent of the threat posed by D. gallinae to (non-avian) veterinary and medical sectors

The role of the dentate gyrus and adult neurogenesis in hippocampal-basal ganglia associated behaviour

The ability of the brain to continually generate new neurons throughout life is one of the most intensely researched areas of modern neuroscience. While great advancements in understanding the biochemical mechanisms of adult neurogenesis have been made, there remain significant obstacles and gaps in connecting neurogenesis with behavioural and cognitive processes such as learning and memory. The purpose of the thesis was to examine by review and laboratory experimentation the role of the dentate gyrus and of adult neurogenesis within the hippocampus in the performance of cognitive tasks dependent on the hippocampal formation and hippocampal-basal ganglia interactions. Advancement in understanding the role of neurogenesis in these processes may assist in improving treatments for common brain injury and cognitive diseases that affect this region of the brain. Mild chronic stress reduced the acquisition rate of a stimulus-response task (p=0.043), but facilitated the acquisition of a discrimination between a small and a large reward (p=0.027). In locomotor activity assays, chronic stress did not shift the dose-response to methamphetamine. Analysis of 2,5-bromodeoxyuridine incorporation showed that, overall, chronic mild stress did not effect survival of neuronal progenitors . However, learning of the tasks had a positive influence on cell survival in stressed animals (p=0.038). Microinjections of colchicine produced significant lesions of the dentate gyrus and surrounding CA1-CA3 and neocortex. Damage to these regions impaired hippocampal-dependent reference memory (p=0.054) while preserving hippocampal independent simple discrimination learning. In a delay discounting procedure, the lesions did not induce impulsive-like behaviour when delay associated with a large reward was introduced. The experiments uphold a current theory that learning acts as a buffer to mitigate the negative effects of stress on neurogenesis

A fast least-squares algorithm for linearly constrained adaptive filtering

An extension of the field of fast least-squares techniques is presented. It is shown that the adaptation gain, which is updated with a number of operations proportional to the number of transversal filter coefficients, can be used to update the coefficients of a linearly constrained adaptive filter. An algorithm that is robust to round-off errors is derived. It is general and flexible. It can handle multiple constraints and multichannel signals. Its performance is illustrated by simulations and compared with the classical LMS-based Frost algorithm.4451168117

Adaptive filtering in cascade form using a fast multichannel RLS algorithm

This brief proposes an approach to apply least-squares techniques to adaptive FIR filtering in cascade form. A triangular structure is combined with an adaptive multichannel filter, which can exploit a fast recursive least squares (RLS) algorithm. The resulting approximation and the behavior of the system in the learning case is discussed. Simulations results are given for the linear prediction case, for which an additional adaptive procedure is derived. Sinusoidal signals are used at the input. since the inherent cascade structure directly yields the frequencies of the sinusoids from the section coefficients. The proposed method brings the efficiency of least-squares techniques, in terms of accuracy and convergence rate, to adaptive filter in cascade form.44975776

A Nonlinear Prediction Approach to the Blind Separation of Convolutive Mixtures

We propose a method for source separation of convolutive mixture based on nonlinear prediction-error filters. This approach converts the original problem into an instantaneous mixture problem, which can be solved by any of the several existing methods in the literature. We employ fuzzy filters to implement the prediction-error filter, and the efficacy of the proposed method is illustrated by some examples

Spectral Efficiency Comparison of OFDM/FBMC for Uplink Cognitive Radio Networks

Cognitive radio (CR) is proposed to automatically detect and exploit unused spectrum while avoiding harmful interference to the incumbent system. In this paper, we emphasize the channel capacity comparison of a CR network using two types of multicarrier communications: conventional Orthogonal Frequency Division Multiplexing (OFDM) with Cyclic Prefix (CP) and Filter Bank based MultiCarrier (FBMC) modulations. We use a resource allocation algorithm in which subcarrier assignment and power allocation are carried out sequentially. By taking the impact of Inter-Cell Interference (ICI) resulting from timing offset into account, the maximization of total information rates is formulated under an uplink scenario with pathloss and Rayleigh fading, subject to maximum power constraint as well as mutual interference constraint between primary user (PU) and secondary user (SU). Final simulation results show that FBMC can achieve higher channel capacity than OFDM because of the low spectral leakage of its prototype filter