2,845 research outputs found

    A Kalman filter approach to direct depth estimation incorporating surface structure

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    The problem of depth-from-motion using a monocular image sequence is considered. A pixel-based model is developed for direct depth estimation within a Kaiman filtering framework. A method is proposed for incorporating local surface structure into the Kaiman filter. Experimental results are provided to illustrate the effect of structural information on depth estimation. ©1999 IEEE.published_or_final_versio

    Modulation of mitochondrial calcium as a pharmacological target for Alzheimer's disease

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    Perturbed neuronal calcium homeostasis is a prominent feature in Alzheimer's disease (AD). Mitochondria accumulate calcium ions (Ca2+) for cellular bioenergetic metabolism and suppression of mitochondrial motility within the cell. Excessive Ca2+ uptake into mitochondria often leads to mitochondrial membrane permeabilization and induction of apoptosis. Ca2+ is an interesting second messenger which can initiate both cellular life and death pathways in mitochondria. This review critically discusses the potential of manipulating mitochondrial Ca2+ concentrations as a novel therapeutic opportunity for treating AD. This review also highlights the neuroprotective role of a number of currently available agents that modulate different mitochondrial Ca2+ transport pathways. It is reasoned that these mitochondrial Ca2+ modulators are most effective in combination with agents that increase the Ca2+ buffering capacity of mitochondria. Modulation of mitochondrial Ca2+ handling is a potential pharmacological target for future development of AD treatments. © 2010 Elsevier B.V.postprin

    From small to big molecules: how do we prevent and delay the progression of age-related neurodegeneration?

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    Age-related neurodegeneration in the brain and retina is complicated. It comprises a series of events encompassing different modes of degeneration in neurons, as well as inflammation mediated by glial cells. Systemic inflammation and risk factors can contribute to disease progression. Age-related conditions such as Alzheimer's disease (AD), Parkinson's disease (PD) and Age-related Macular Degeneration (AMD) affect patients for 5 to 20 years and are highly associated with risk factors such as hyperhomocysteinaemia, hypercholesterolaemia, hypertension, and symptoms of mood disorder. The long duration of the degeneration and the wide array of systemic factors provide the opportunity for nutraceutical intervention to prevent or delay disease progression. Small molecules such as phenolic compounds are candidates for neuroprotection because they have anti-oxidant activities and can modulate intracellular signaling pathways. Bigger entities such as oligosaccharides and polysaccharides have often been neglected because of their complex structure. However, certain big molecules can provide neuroprotective effects. They may also have a wide spectrum of action against risk factors. In this review we use an integrative approach to the potential uses of nutraceutical products to prevent age-related neurodegeneration. These include direct effects of phenolic compounds and polysaccharides on neurons to antagonize various neurodegenerative mechanisms in AD, PD and AMD, and indirect effects of these compounds on peripheral disease-related risk factors.postprin

    Oral feeding of minocycline attenuates glial activation and reductions of tau and drebrin in response to systemically injected cytokines

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    Application of ASK modulation for DC/DC converters control in DC distribution power system

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    Author name used in this publication: K. W. E. ChengAuthor name used in this publication: D. SutantoRefereed conference paper2004-2005 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

    Polysaccharides from wolfberry antagonizes glutamate excitotoxicity in rat cortical neurons

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    Glutamate excitotoxicity is involved in many neurodegenerative diseases including Alzheimer's disease (AD). Attenuation of glutamate toxicity is one of the therapeutic strategies for AD. Wolfberry (Lycium barbarum) is a common ingredient in oriental cuisines. A number of studies suggest that wolfberry has anti-aging properties. In recent years, there is a trend of using dried Wolfberry as food supplement and health product in UK and North America. Previously, we have demonstrated that a fraction of polysaccharide from Wolfberry (LBA) provided remarkable neuroprotective effects against beta-amyloid peptide-induced cytotoxicity in primary cultures of rat cortical neurons. To investigate whether LBA can protect neurons from other pathological factors such as glutamate found in Alzheimer brain, we examined whether it can prevent neurotoxicity elicited by glutamate in primary cultured neurons. The glutamate-induced cell death as detected by lactate dehydrogenase assay and caspase-3-like activity assay was significantly reduced by LBA at concentrations ranging from 10 to 500 μg/ml. Protective effects of LBA were comparable to memantine, a non-competitive NMDA receptor antagonist. LBA provided neuroprotection even 1 h after exposure to glutamate. In addition to glutamate, LBA attenuated N-methyl-d-aspartate (NMDA)-induced neuronal damage. To further explore whether LBA might function as antioxidant, we used hydrogen peroxide (H2O2) as oxidative stress inducer in this study. LBA could not attenuate the toxicity of H2O2. Furthermore, LBA did not attenuate glutamate-induced oxidation by using NBT assay. Western blot analysis indicated that glutamate-induced phosphorylation of c-jun N-terminal kinase (JNK) was reduced by treatment with LBA. Taken together, LBA exerted significant neuroprotective effects on cultured cortical neurons exposed to glutamate. © 2009 Springer Science+Business Media, LLC.postprin
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