The well known cloud computing is being extended by the idea of fog with the computing nodes placed closer to end users to allow for task processing with tighter latency requirements. However, offloading of tasks (from end devices to either the cloud or to the fog nodes) should be designed taking energy consumption for both transmission and computation into account. The task allocation procedure can be challenging considering the high number of arriving tasks with various computational, communication and delay requirements, and the high number of computing nodes with various communication and computing capabilities.
View Article and Find Full Text PDFThe development of wireless networks can be characterized by both the increased number of deployed network nodes as well as their greater heterogeneity. As a consequence, the distance between the neighboring nodes decreases significantly, the density of such a wireless network is very high, and it brings to the mind the analogy to the human brain and nervous system, where a highly simplified scheme of information delivery is applied. Motivated by this similarity, in this paper, we study the possibility of the application of various transmission profiles in order to optimize the overall energy consumption in such dense wireless networks.
View Article and Find Full Text PDFEnergy efficiency is a key aspect when designing and optimizing contemporary wireless networks and transceivers. Assessment of energy efficiency requires proper energy consumption models. The most common solutions are to measure a single device and propose a device-specific model or to propose a simplified model for many transceivers but not reflecting all phenomena visible in a given transceiver energy consumption.
View Article and Find Full Text PDFIn this paper, a new perspective of using flexible, brain-inspired, analog and digital wireless transmission in massive future networks, is presented. Inspired by the nervous impulses transmission mechanisms in the human brain which is highly energy efficient, we consider flexible, wireless analog and digital transmission on very short distances approached from the energy efficiency point of view. The energy efficiency metric is compared for the available transmission modes, taking the circuit power consumption model into account.
View Article and Find Full Text PDFMitochondria are dynamic organelles that continually adapt their morphology by fusion and fission events. An imbalance between fusion and fission has been linked to major neurodegenerative diseases, including Huntington's, Alzheimer's, and Parkinson's diseases. A member of the Dynamin superfamily, dynamin-related protein 1 (DRP1), a dynamin-related GTPase, is required for mitochondrial membrane fission.
View Article and Find Full Text PDFSuperoxide dismutase 1 (SOD1) knockout () mice exhibit an accelerated aging phenotype. In humans, mutations are linked to familial amyotrophic lateral sclerosis (ALS), and post-translational modification (PTM) of wild-type SOD1 has been associated with sporadic ALS. Reversible acetylation regulates many enzymes and proteomic studies have identified SOD1 acetylation at lysine 123 (K123).
View Article and Find Full Text PDFEvidence indicates that nitrosative stress and mitochondrial dysfunction participate in the pathogenesis of Alzheimer's disease (AD). Amyloid beta (Aβ) and peroxynitrite induce mitochondrial fragmentation and neuronal cell death by abnormal activation of dynamin-related protein 1 (DRP1), a large GTPase that regulates mitochondrial fission. The exact mechanisms of mitochondrial fragmentation and DRP1 overactivation in AD remain unknown; however, DRP1 serine 616 (S616) phosphorylation is likely involved.
View Article and Find Full Text PDFCell Death Differ
February 2013
Optic atrophy 1 (OPA1) mutations cause dominant optic atrophy (DOA) with retinal ganglion cell (RGC) and optic nerve degeneration. The mechanism for the selective degeneration of RGCs in DOA remains elusive. To address the mechanism, we reduced OPA1 protein expression in cell lines and RGCs by RNA interference.
View Article and Find Full Text PDFMutations in the Cu/Zn Superoxide Dismutase (SOD1) gene cause an inherited form of ALS with upper and lower motor neuron loss. The mechanism underlying mutant SOD1-mediated motor neuron degeneration remains unclear. While defects in mitochondrial dynamics contribute to neurodegeneration, including ALS, previous reports remain conflicted.
View Article and Find Full Text PDFHuntington's disease is an inherited and incurable neurodegenerative disorder caused by an abnormal polyglutamine (polyQ) expansion in huntingtin (encoded by HTT). PolyQ length determines disease onset and severity, with a longer expansion causing earlier onset. The mechanisms of mutant huntingtin-mediated neurotoxicity remain unclear; however, mitochondrial dysfunction is a key event in Huntington's disease pathogenesis.
View Article and Find Full Text PDFMitochondrial dysfunction and synaptic loss are among the earliest events linked to Alzheimer's disease (AD) and might play a causative role in disease onset and progression. The underlying mechanisms of mitochondrial and synaptic dysfunction in AD remain unclear. We previously reported that nitric oxide (NO) triggers persistent mitochondrial fission and causes neuronal cell death.
View Article and Find Full Text PDFCurr Neuropharmacol
June 2008
Protein aggregates or inclusion bodies are common hallmarks of age-related neurodegenerative disorders. Why these aggregates form remains unclear. Equally debated is whether they are toxic, protective, or simple by-products.
View Article and Find Full Text PDFMitochondrial respiratory complex II inhibition plays a central role in Huntington's disease (HD). Remarkably, 3-NP, a complex II inhibitor, recapitulates HD-like symptoms. Furthermore, decreases in mitochondrial fusion or increases in mitochondrial fission have been implicated in neurodegenerative diseases.
View Article and Find Full Text PDFMitochondrial morphology and length change during fission and fusion and mitochondrial movement varies dependent upon the cell type and the physiological conditions. Here, we describe fundamental wide-field fluorescence microscopy and 3D imaging techniques to assess mitochondrial shape, number and length in various cell types including cancer cell lines, motor neurons and astrocytes. Furthermore, we illustrate how to assess mitochondrial fission and fusion events by 3D time-lapse imaging and to calculate mitochondrial length and numbers as a function of time.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2008
Maturation of neuronal synapses is thought to involve mitochondria. Bcl-xL protein inhibits mitochondria-mediated apoptosis but may have other functions in healthy adult neurons in which Bcl-xL is abundant. Here, we report that overexpression of Bcl-xL postsynaptically increases frequency and amplitude of spontaneous miniature synaptic currents in rat hippocampal neurons in culture.
View Article and Find Full Text PDFMitochondria are present as tubular organelles in neuronal projections. Here, we report that mitochondria undergo profound fission in response to nitric oxide (NO) in cortical neurons of primary cultures. Mitochondrial fission by NO occurs long before neurite injury and neuronal cell death.
View Article and Find Full Text PDFPurpose: To examine the feasibility for identifying and enumerating cytokeratin positive (CK+) cells in the peripheral blood of breast cancer patients.
Experimental Design: Blood specimens from 34 normal donors (negative controls), 15 samples to which carcinoma cells were added (positive controls), and 84 breast cancer patients [27 node-negative (N-), 29 node-positive (N+), and 28 metastatic] were studied. RBCs were lysed with ammonium chloride and the resulting cell suspension incubated with anti-EpCAM-conjugated immunomagnetic beads for carcinoma cell enrichment.
The presence of occult bone marrow metastases (OM) has been reported to represent an important prognostic indicator for patients with operable breast cancer and other malignancies. Assaying for OM most commonly involves labor-intensive manual microscopic analysis. The present report examines the performance of a recently developed automated cellular image analysis system (ACIS; ChromaVision Medical Systems, Inc.
View Article and Find Full Text PDFThe integrin alpha 8 subunit, isolated by low stringency hybridization, is a novel integrin subunit that associates with beta 1. To identify ligands, we have prepared a function-blocking antiserum to the extracellular domain of alpha 8, and we have established by transfection K562 cell lines that stably express alpha 8 beta 1 heterodimers on the cell surface. We demonstrate here by cell adhesion and neurite outgrowth assays that alpha 8 beta 1 is a fibronectin receptor.
View Article and Find Full Text PDFTo identify potentially important extracellular matrix adhesive molecules in neural crest cell migration, the possible role of vitronectin and its corresponding integrin receptors was examined in the adhesion and migration of avian neural crest cells in vitro. Adhesion and migration on vitronectin were comparable to those found on fibronectin and could be almost entirely abolished by antibodies against vitronectin and by RGD peptides. Immunoprecipitation and immunocytochemistry analyses revealed that neural crest cells expressed primarily the alpha V beta 1, alpha V beta 3 and alpha V beta 5 integrins as possible vitronectin receptors.
View Article and Find Full Text PDFCold Spring Harb Symp Quant Biol
November 1993
In this article, we describe the primary structure, the biochemical characterization and the tissue distribution of a novel integrin alpha subunit, named alpha 8. This subunit associates with the integrin beta 1 subunit to form alpha 8 beta 1 heterodimers. By sequence analysis, alpha 8 is more closely related to the alpha 5 and alpha v subunits than to other characterized integrin alpha subunits, but is clearly distinct from each of these.
View Article and Find Full Text PDFWe have cloned and characterized a chick homologue of the human vitronectin receptor alpha subunit (alpha v) whose primary sequence is 83% identical with its human counterpart but less than 40% identical with any other known integrin alpha subunit. Comparison of the chick and human sequences reveals several highly conserved regions, including the cytoplasmic domain. The putative ligand binding domain contains alpha v-specific residues that may contribute to ligand binding specificity.
View Article and Find Full Text PDFNicotinic acetylcholine receptors (nAChR) are found both in vertebrate and insect central nervous systems. We have isolated a Drosophila gene by crosshybridization with a vertebrate probe. Structural conservation of domains of the deduced protein and of intron/exon boundaries indicate that the Drosophila gene encodes an nAChR alpha-like subunit (ALS).
View Article and Find Full Text PDF