41 research outputs found

    Dynamic evolving neural fuzzy inference system equalization scheme in mode division multiplexer for optical fiber transmission

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    The performance of optical mode division multiplexer (MDM) is affected by inter-symbol interference (ISI), which arises from higher-order mode coupling and modal dispersion in multimode fiber (MMF). Existing equalization algorithms in MDM can mitigate linear channel impairments, but cannot tackle nonlinear channel impairments accurately. Therefore, mitigating the noise in the received signal of MDM in the presence of ISI to recover the transmitted signal is important issue. This paper aims at controlling the broadening of the signal from MDM and minimizing the undesirable noise among channels. A dynamic evolving neural fuzzy inference system (DENFIS) equalization scheme has been used to achieve this objective. Results illustrate that nonlinear DENFIS equalization scheme can improve the received distorted signal from an MDM with better accuracy than previous linear equalization schemes such as recursive‐least‐square (RLS) algorithm. Desirably, this effect allows faster data transmission rate in MDM. Additionally, the successful offline implementation of DENFIS equalization in MDM encourages future online implementation of DENFIS equalization in embedded optical systems

    Generating and Characterising Knockout and Transgenic Mouse Models of Frontotemporal Dementia Caused by CHMP2B Mutation

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    A mutation in the charged multivesicular body protein 2B (CHMP2B) gene, identified in a kindred from the Jutland region of Denmark, segregates with affected family members with clinical presentations of frontotemporal dementia (FTD) and is absent in control populations (Gydesen et al., 1987; Gydesen et al., 2002; Skibinski et al., 2005). The mutation is a G>C transition in the splice acceptor site of exon 6 resulting in two novel splice variants CHMP2BInt5 and CHMP2BA10 leading to C-terminal truncation of the CHMP2B protein (Skibinski et al., 2005). Chmp2b knockout (Chmp2b-/-) mice and transgenic mice expressing either wild-type or C-terminally truncated mutant CHMP2B splice variants CHMP2BInt5 and CHMP2BA10 were generated with the aims of examining the normal function of Chmp2b and the effect of mutant CHMP2B species in vivo, as well as providing insight into a potential common FTD mechanism of disease. Quantification of Chmp2b protein in Chmp2b-/- mice demonstrates a significant (85%) depletion of endogenous Chmp2b in the mouse brain. No pathology is identified in the CNS or muscle tissue of these mice however, they do demonstrate significant motor and behavioural abnormalities. CHMP2BInt5 transgenic mice demonstrate neurodegenerative changes including progressive gliosis, accumulation of CHMP2B, p62 and ubiquitin inclusions which are negative for TDP-43 and FUS proteins, consistent with the inclusion pathology observed in patients with CHMP2B mutation. Furthermore, these mice have reduced survival and develop progressive axonopathy characterized by axonal swellings and accumulation of mitochondria and vesicles likely from the endosome¬lysosome and autophagy pathway, implicating altered axonal function in disease pathogenesis. This thesis describes the first mouse models of FTD-3 caused by CHMP2B mutation and presents evidence consistent with a gain-of-function effect unique to the CHMP2BInt5 isoform and provides new insights into the mechanisms of CHMP2B-induced neurodegeneration

    Design & investigation of 10x10 gbit/s MDM over hybrid FSO link under different weather conditions and fiber to the home

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    In this paper, we design and investigate 10-channels of mode division multiplexer (MDM) over hybrid free-space optics (FSO) link in several weather conditions to achieve the maximum possible medium range and fiber to the home (FTTH) for high bandwidth access networks. System capacity can be effectively increased with the use of MDM over hybrid FSO-FTTH. In this study, a 10-channel MDM over FSO-FTTH system has been analyzed in different weather conditions that operate at 1550 nm wavelength. The simulated system has transmitted 100 Gbit/s up for a distance of 3200 meters FSO in superbly clear weather condition. It also transmitted 100 Gbit/s up for a distance of 650 meters FSO during heavy rain. The validation of this study is measures based on eye diagrams bit-error rates (BER) that have been analyzed

    Minocycline and doxycycline are not beneficial in a model of Huntington's disease

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    Huntington's Disease (HD) is an inherited neurological disorder causing movement impairment, personality changes, dementia, and premature death, for which there is currently no effective therapy. The modified tetracycline antibiotic, minocycline, has been reported to ameliorate the disease phenotype in the R6/2 mouse model of HD. Because the tetracyclines have also been reported to inhibit aggregation in other amyloid disorders, we have investigated their ability to inhibit huntingtin aggregation and further explored their efficacy in preclinical mouse trials. We show that tetracyclines are potent inhibitors of huntingtin aggregation in a hippocampal slice culture model of HD at an effective concentration of 30μM. However, despite achieving tissue levels approaching this concentration by oral treatment of R6/2 mice with minocycline, we observed no clear difference in their behavioral abnormalities, or in aggregate load postmortem. In the light of these new data, we would advise that caution be exercised in proceeding into human clinical trials of minocycline. Ann Neurol 200
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