Fast SPT-Term Allocation and Efficient FPGA Implementation of FIR Filters for Software Defined Radio Applications

This paper presents a fast SPT-term allocation scheme and an efficient FPGA implementation of FIR filters for Software Defined Radio (SDR) applications. Direct conversion method based on RF direct sampling is nowadays widely used in SDR applications. Fast and accurate digital filters are required for RF direct sampling and processing in direct conversion, however such filters often require large digital circuit area. Signed-Power-of-Two (SPT) terms will be suitable for fast processing and efficient implementation of FIR filters. This paper first aims at developing a fast SPT-term allocation scheme for designing FIR filters, and then tries to efficiently implement FIR filters on FPGA. Performance of SPT-term allocation and FPGA implementation is evaluated through computer simulation and hardware implementation.APSIPA ASC 2009: Asia-Pacific Signal and Information Processing Association, 2009 Annual Summit and Conference. 4-7 October 2009. Sapporo, Japan. Poster session: Signal Processing and Implementations in Communications (6 October 2009)

Brain p3-Alcβ peptide restores neuronal viability impaired by Alzheimer's amyloid β-peptide

We propose a new therapeutic strategy for Alzheimer's disease (AD). Brain peptide p3-Alc beta 37 is generated from the neuronal protein alcadein beta through cleavage of gamma-secretase, similar to the generation of amyloid beta (A beta) derived from A beta-protein precursor/APP. Neurotoxicity by A beta oligomers (A beta o) is the prime cause prior to the loss of brain function in AD. We found that p3-Alc beta 37 and its shorter peptide p3-Alc beta 9-19 enhanced the mitochondrial activity of neurons and protected neurons against A beta o-induced toxicity. This is due to the suppression of the A beta o-mediated excessive Ca2+ influx into neurons by p3-Alc beta. Successful transfer of p3-Alc beta 9-19 into the brain following peripheral administration improved the mitochondrial viability in the brain of AD mice model, in which the mitochondrial activity is attenuated by increasing the neurotoxic human A beta 42 burden, as revealed through brain PET imaging to monitor mitochondrial function. Because mitochondrial dysfunction is common in the brain of AD patients alongside increased A beta and reduced p3-Alc beta 37 levels, the administration of p3-Alc beta 9-19 may be a promising treatment for restoring, protecting, and promoting brain functions in patients with AD

Successful treatment of murine autoimmune cholangitis by parabiosis: Implications for hematopoietic therapy

There is a significant unmet need in the treatment of primary biliary cirrhosis (PBC) despite significant data on the effector pathways that lead to biliary duct damage. We focused attention on a murine model of PBC, the dominant negative transforming growth factor β receptor II (Tg) mice. To further define the pathways that lead to biliary pathology in these mice, we developed Tg mice deleted of CD4 cells (CD4(−/−)Tg). Interestingly, these mice developed more severe cholangitis than control Tg mice. These mice, which lack CD4 cells, manifested increased levels of IFN-γ produced by effector CD8 cells. It appears that increased cholangitis is due to the absence of CD4 Treg cells. Based on these data, we parabiosed CD4(−/−)Tg mice with established disease at 8–9 weeks of age with C57BL/6 control mice. Such parabiotic “twins” had a significant reduction in autoimmune cholangitis, even though they had established pathology at the time of surgery. We prepared mixed bone marrow chimera mice constructed from CD4(−/−)Tg and CD8(−/−) mice and not only was cholangitis improved, but a decrease in terminally differentiated CD8(+) T effector cells in the presence of wild type CD4 cells was noted. In conclusion, “correcting” the CD4 T cell subset, even in the presence of pathogenic CD8 T cells, is effective in treating autoimmune cholangitis