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Sample records for based cellular phosphoinositides

  1. The phosphoinositide 3-kinase signalling pathway in normal and malignant B cells: activation mechanisms, regulation and impact on cellular functions

    Directory of Open Access Journals (Sweden)

    Samantha D Pauls

    2012-08-01

    Full Text Available The phosphoinositide 3-kinase (PI3K pathway is a central signal transduction axis controlling normal B cell homeostasis and activation in humoral immunity. The p110δ PI3K catalytic subunit has emerged as a critical mediator of multiple B cell functions. The activity of this pathway is regulated at multiple levels, with inositol phosphatases PTEN and SHIP both playing critical roles. When deregulated, the PI3K pathway can contribute to B cell malignancies and autoantibody production. This review summarizes current knowledge on key mechanisms that activate and regulate the PI3K pathway and influence normal B cell functional responses including the development of B cell subsets, antigen presentation, immunogloblulin isotype switch, germinal center responses and maintenance of B cell anergy. We also discuss PI3K pathway alterations reported in select B cell malignancies and highlight studies indicating the functional significance of this pathway in malignant B cell survival and growth within tissue microenvironments. Finally, we comment on early clinical trial results, which support PI3K inhibition as a promising treatment of chronic lymphocytic leukemia.

  2. The phosphoinositide 3-kinase signaling pathway in normal and malignant B cells: activation mechanisms, regulation and impact on cellular functions.

    Science.gov (United States)

    Pauls, Samantha D; Lafarge, Sandrine T; Landego, Ivan; Zhang, Tingting; Marshall, Aaron J

    2012-01-01

    The phosphoinositide 3-kinase (PI3K) pathway is a central signal transduction axis controlling normal B cell homeostasis and activation in humoral immunity. The p110δ PI3K catalytic subunit has emerged as a critical mediator of multiple B cell functions. The activity of this pathway is regulated at multiple levels, with inositol phosphatases PTEN and SHIP both playing critical roles. When deregulated, the PI3K pathway can contribute to B cell malignancies and autoantibody production. This review summarizes current knowledge on key mechanisms that activate and regulate the PI3K pathway and influence normal B cell functional responses including the development of B cell subsets, antigen presentation, immunoglobulin isotype switch, germinal center responses, and maintenance of B cell anergy. We also discuss PI3K pathway alterations reported in select B cell malignancies and highlight studies indicating the functional significance of this pathway in malignant B cell survival and growth within tissue microenvironments. Finally, we comment on early clinical trial results, which support PI3K inhibition as a promising treatment of chronic lymphocytic leukemia.

  3. Phosphoinositides and lipid kinases in oxidative stress signalling and cancer

    NARCIS (Netherlands)

    Keune, W.J.H.

    2013-01-01

    Phosphoinositides are implicated in virtually all aspects of cellular welfare. They help to maintain the structure of biomembranes, but are also essential signal transduction molecules. This is illustrated by PtdIns(4,5)P2, a versatile and important phosphoinositide that regulates many cellular proc

  4. Cell Permeable Ratiometric Fluorescent Sensors for Imaging Phosphoinositides.

    Science.gov (United States)

    Mondal, Samsuzzoha; Rakshit, Ananya; Pal, Suranjana; Datta, Ankona

    2016-07-15

    Phosphoinositides are critical cell-signal mediators present on the plasma membrane. The dynamic change of phosphoinositide concentrations on the membrane including clustering and declustering mediates signal transduction. The importance of phosphoinositides is scored by the fact that they participate in almost all cell-signaling events, and a defect in phosphoinositide metabolism is linked to multiple diseases including cancer, bipolar disorder, and type-2 diabetes. Optical sensors for visualizing phosphoinositide distribution can provide information on phosphoinositide dynamics. This exercise will ultimately afford a handle into understanding and manipulating cell-signaling processes. The major requirement in phosphoinositide sensor development is a selective, cell permeable probe that can quantify phosphoinositides. To address this requirement, we have developed short peptide-based ratiometric fluorescent sensors for imaging phosphoinositides. The sensors afford a selective response toward two crucial signaling phosphoinositides, phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2) and phosphatidylinositol-4-phosphate (PI4P), over other anionic membrane phospholipids and soluble inositol phosphates. Dissociation constant values indicate up to 4 times higher probe affinity toward PI(4,5)P2 when compared to PI4P. Significantly, the sensors are readily cell-permeable and enter cells within 15 min of incubation as indicated by multiphoton excitation confocal microscopy. Furthermore, the sensors light up signaling phosphoinositides present both on the cell membrane and on organelle membranes near the perinuclear space, opening avenues for quantifying and monitoring phosphoinositide signaling.

  5. Phosphoinositide 5-Phosphate and Phosphoinositide 4-Phosphate Trigger Distinct Specific Responses of Arabidopsis Genes: Genome-Wide Expression Analyses

    OpenAIRE

    2006-01-01

    Phosphoinositide phosphates, PtdInsP, are important components of the cell lipid pool that can function as messengers in diverse cellular processes. Lack of information on downstream targets, however, has impeded our understanding of the potential of lipid-signaling to influence gene activity. Our goals here were to identify genes that altered expression in the presence of two isomeric monophosphate lipid messengers (Phosphoinositide 5-Phosphate, PtdIns(5)P, and Phosphoinositide 4-Phosphate, ...

  6. Inositol Pentakisphosphate Isomers Bind PH Domains with Varying Specificity and Inhibit Phosphoinositide Interactions

    Energy Technology Data Exchange (ETDEWEB)

    S Jackson; S Al-Saigh; C Schultz; M Junop

    2011-12-31

    PH domains represent one of the most common domains in the human proteome. These domains are recognized as important mediators of protein-phosphoinositide and protein-protein interactions. Phosphoinositides are lipid components of the membrane that function as signaling molecules by targeting proteins to their sites of action. Phosphoinositide based signaling pathways govern a diverse range of important cellular processes including membrane remodeling, differentiation, proliferation and survival. Myo-Inositol phosphates are soluble signaling molecules that are structurally similar to the head groups of phosphoinositides. These molecules have been proposed to function, at least in part, by regulating PH domain-phosphoinositide interactions. Given the structural similarity of inositol phosphates we were interested in examining the specificity of PH domains towards the family of myo-inositol pentakisphosphate isomers. In work reported here we demonstrate that the C-terminal PH domain of pleckstrin possesses the specificity required to discriminate between different myo-inositol pentakisphosphate isomers. The structural basis for this specificity was determined using high-resolution crystal structures. Moreover, we show that while the PH domain of Grp1 does not possess this high degree of specificity, the PH domain of protein kinase B does. These results demonstrate that some PH domains possess enough specificity to discriminate between myo-inositol pentakisphosphate isomers allowing for these molecules to differentially regulate interactions with phosphoinositides. Furthermore, this work contributes to the growing body of evidence supporting myo-inositol phosphates as regulators of important PH domain-phosphoinositide interactions. Finally, in addition to expanding our knowledge of cellular signaling, these results provide a basis for developing tools to probe biological pathway.

  7. Inositol pentakisphosphate isomers bind PH domains with varying specificity and inhibit phosphoinositide interactions

    Directory of Open Access Journals (Sweden)

    Schultz Carsten

    2011-02-01

    Full Text Available Abstract Background PH domains represent one of the most common domains in the human proteome. These domains are recognized as important mediators of protein-phosphoinositide and protein-protein interactions. Phosphoinositides are lipid components of the membrane that function as signaling molecules by targeting proteins to their sites of action. Phosphoinositide based signaling pathways govern a diverse range of important cellular processes including membrane remodeling, differentiation, proliferation and survival. Myo-Inositol phosphates are soluble signaling molecules that are structurally similar to the head groups of phosphoinositides. These molecules have been proposed to function, at least in part, by regulating PH domain-phosphoinositide interactions. Given the structural similarity of inositol phosphates we were interested in examining the specificity of PH domains towards the family of myo-inositol pentakisphosphate isomers. Results In work reported here we demonstrate that the C-terminal PH domain of pleckstrin possesses the specificity required to discriminate between different myo-inositol pentakisphosphate isomers. The structural basis for this specificity was determined using high-resolution crystal structures. Moreover, we show that while the PH domain of Grp1 does not possess this high degree of specificity, the PH domain of protein kinase B does. Conclusions These results demonstrate that some PH domains possess enough specificity to discriminate between myo-inositol pentakisphosphate isomers allowing for these molecules to differentially regulate interactions with phosphoinositides. Furthermore, this work contributes to the growing body of evidence supporting myo-inositol phosphates as regulators of important PH domain-phosphoinositide interactions. Finally, in addition to expanding our knowledge of cellular signaling, these results provide a basis for developing tools to probe biological pathways.

  8. Cellular based cancer vaccines

    DEFF Research Database (Denmark)

    Hansen, Morten; Met, O; Svane, I M;

    2012-01-01

    Cancer vaccines designed to re-calibrate the existing host-tumour interaction, tipping the balance from tumor acceptance towards tumor control holds huge potential to complement traditional cancer therapies. In general, limited success has been achieved with vaccines composed of tumor...... in vitro migration via autocrine receptor-mediated endocytosis of CCR7. In the current review, we discuss optimal design of DC maturation focused on pre-clinical as well as clinical results from standard and polarized dendritic cell based cancer vaccines....

  9. Structure-Based Design of Potent and Selective 3-Phosphoinositide-Dependent Kinase-1 (PDK1) Inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Medina, Jesus R.; Becker, Christopher J.; Blackledge, Charles W.; Duquenne, Celine; Feng, Yanhong; Grant, Seth W.; Heerding, Dirk; Li, William H.; Miller, William H.; Romeril, Stuart P.; Scherzer, Daryl; Shu, Arthur; Bobko, Mark A.; Chadderton, Antony R.; Dumble, Melissa; Gardiner, Christine M.; Gilbert, Seth; Liu, Qi; Rabindran, Sridhar K.; Sudakin, Valery; Xiang, Hong; Brady, Pat G.; Campobasso, Nino; Ward, Paris; Axten, Jeffrey M. (GSKPA)

    2014-10-02

    Phosphoinositide-dependent protein kinase-1(PDK1) is a master regulator of the AGC family of kinases and an integral component of the PI3K/AKT/mTOR pathway. As this pathway is among the most commonly deregulated across all cancers, a selective inhibitor of PDK1 might have utility as an anticancer agent. Herein we describe our lead optimization of compound 1 toward highly potent and selective PDK1 inhibitors via a structure-based design strategy. The most potent and selective inhibitors demonstrated submicromolar activity as measured by inhibition of phosphorylation of PDK1 substrates as well as antiproliferative activity against a subset of AML cell lines. In addition, reduction of phosphorylation of PDK1 substrates was demonstrated in vivo in mice bearing OCl-AML2 xenografts. These observations demonstrate the utility of these molecules as tools to further delineate the biology of PDK1 and the potential pharmacological uses of a PDK1 inhibitor.

  10. Ligand-based pharmacophore modeling; atom-based 3D-QSAR analysis and molecular docking studies of phosphoinositide-dependent kinase-1 inhibitors

    Directory of Open Access Journals (Sweden)

    P Kirubakaran

    2012-01-01

    Full Text Available Phosphoinositide-dependent kinase-1 plays a vital role in the PI3-kinase signaling pathway that regulates gene expression, cell cycle growth and proliferation. The common human cancers include lung, breast, blood and prostate possess over stimulation of the phosphoinositide-dependent kinase-1 signaling and making phosphoinositide-dependent kinase-1 an interesting therapeutic target in oncology. A ligand-based pharmacophore and atom-based 3D-QSAR studies were carried out on a set of 82 inhibitors of PDK1. A six point pharmacophore with two hydrogen bond acceptors (A, three hydrogen bond donors (D and one hydrophobic group (H was obtained. The pharmacophore hypothesis yielded a 3D-QSAR model with good partial least square statistics results. The training set correlation is characterized by partial least square factors (R2 = 0.9557, SD = 0.2334, F = 215.5, P = 1.407e-32. The test set correlation is characterized by partial least square factors (Q2 ext = 0.7510, RMSE = 0.5225, Pearson-R =0.8676. The external validation indicated that our QSAR model possess high predictive power with good value of 0.99 and value of 0.88. The docking results show the binding orientations of these inhibitors at active site amino acid residues (Ala162, Thr222, Glu209 and Glu166 of phosphoinositide-dependent kinase-1 protein. The binding free energy interactions of protein-ligand complex have been calculated, which plays an important role in molecular recognition and drug design approach.

  11. The emerging role of phosphoinositide clustering in intracellular trafficking and signal transduction

    Science.gov (United States)

    Picas, Laura; Gaits-Iacovoni, Frederique; Goud, Bruno

    2016-01-01

    Phosphoinositides are master regulators of multiple cellular processes: from vesicular trafficking to signaling, cytoskeleton dynamics, and cell growth. They are synthesized by the spatiotemporal regulated activity of phosphoinositide-metabolizing enzymes. The recent observation that some protein modules are able to cluster phosphoinositides suggests that alternative or complementary mechanisms might operate to stabilize the different phosphoinositide pools within cellular compartments. Herein, we discuss the different known and potential molecular players that are prone to engage phosphoinositide clustering and elaborate on how such a mechanism might take part in the regulation of intracellular trafficking and signal transduction. PMID:27092250

  12. ERK and phosphoinositide 3-kinase temporally coordinate different modes of actin-based motility during embryonic wound healing.

    Science.gov (United States)

    Li, Jingjing; Zhang, Siwei; Soto, Ximena; Woolner, Sarah; Amaya, Enrique

    2013-11-01

    Embryonic wound healing provides a perfect example of efficient recovery of tissue integrity and homeostasis, which is vital for survival. Tissue movement in embryonic wound healing requires two functionally distinct actin structures: a contractile actomyosin cable and actin protrusions at the leading edge. Here, we report that the discrete formation and function of these two structures is achieved by the temporal segregation of two intracellular upstream signals and distinct downstream targets. The sequential activation of ERK and phosphoinositide 3-kinase (PI3K) signalling divides Xenopus embryonic wound healing into two phases. In the first phase, activated ERK suppresses PI3K activity, and is responsible for the activation of Rho and myosin-2, which drives actomyosin cable formation and constriction. The second phase is dominated by restored PI3K signalling, which enhances Rac and Cdc42 activity, leading to the formation of actin protrusions that drive migration and zippering. These findings reveal a new mechanism for coordinating different modes of actin-based motility in a complex tissue setting, namely embryonic wound healing.

  13. Aggregation of Phosphoinositides at Phisiological Calcium Concentrations

    Science.gov (United States)

    Kazadi Badiambile, Adolphe; Forstner, Martin B.

    2012-02-01

    Phosphoinositides play a crucial role in many cellular functions such as calcium signaling, endocytosis, exocytosis and the targeting of proteins to specific membrane sites. To maintain functional specificity, it has been suggested that phosphoinositides are spatially organized in ``pools'' in the cellular plasma membrane. A possible mechanism that could induce and regulate such organization of phosphoinositides is their interaction with Ca2+ ions. Understanding the physicochemical mechanism that can regulate membrane structure is a crucial step in the development of adaptive biomimetic membrane systems. Using Langmuir monolayers, we investigated the effect of bivalent calcium and magnesium cations on the surface pressure-area/lipid isotherm of monolayers of phosphatidylinositol (PI), phosphatidylinositol bisphosphate (PIP2) and dioleoylphosphatidylglycerol (DOPG) and dipalmitoylphosphatidylcholine (DPPC). It is found that the decrease of area per lipid, i.e. the increase in aggregation, is dependent on both the lipid's head group charge, the bivalent cation and temperature. However, electrostatics are not sufficient to account for all experimental observations. Thus additional interactions between ions and phosphoinositides need to be considered.

  14. WNT16B is a new marker of cellular senescence that regulates p53 activity and the phosphoinositide 3-kinase/AKT pathway.

    Science.gov (United States)

    Binet, Romuald; Ythier, Damien; Robles, Ana I; Collado, Manuel; Larrieu, Delphine; Fonti, Claire; Brambilla, Elisabeth; Brambilla, Christian; Serrano, Manuel; Harris, Curtis C; Pedeux, Rémy

    2009-12-15

    Senescence is a tumor suppression mechanism that is induced by several stimuli, including oncogenic signaling and telomere shortening, and controlled by the p53/p21(WAF1) signaling pathway. Recently, a critical role for secreted factors has emerged, suggesting that extracellular signals are necessary for the onset and maintenance of senescence. Conversely, factors secreted by senescent cells may promote tumor growth. By using expression profiling techniques, we searched for secreted factors that were overexpressed in fibroblasts undergoing replicative senescence. We identified WNT16B, a member of the WNT family of secreted proteins. We found that WNT16B is overexpressed in cells undergoing stress-induced premature senescence and oncogene-induced senescence in both MRC5 cell line and the in vivo murine model of K-Ras(V12)-induced senescence. By small interfering RNA experiments, we observed that both p53 and WNT16B are necessary for the onset of replicative senescence. WNT16B expression is required for the full transcriptional activation of p21(WAF1). Moreover, WNT16B regulates activation of the phosphoinositide 3-kinase (PI3K)/AKT pathway. Overall, we identified WNT16B as a new marker of senescence that regulates p53 activity and the PI3K/AKT pathway and is necessary for the onset of replicative senescence.

  15. The emerging role of phosphoinositide clustering in intracellular trafficking and signal transduction [version 1; referees: 4 approved

    Directory of Open Access Journals (Sweden)

    Laura Picas

    2016-03-01

    Full Text Available Phosphoinositides are master regulators of multiple cellular processes: from vesicular trafficking to signaling, cytoskeleton dynamics, and cell growth. They are synthesized by the spatiotemporal regulated activity of phosphoinositide-metabolizing enzymes. The recent observation that some protein modules are able to cluster phosphoinositides suggests that alternative or complementary mechanisms might operate to stabilize the different phosphoinositide pools within cellular compartments. Herein, we discuss the different known and potential molecular players that are prone to engage phosphoinositide clustering and elaborate on how such a mechanism might take part in the regulation of intracellular trafficking and signal transduction.

  16. Indolinone based phosphoinositide-dependent kinase-1 (PDK1) inhibitors. Part 2: optimization of BX-517.

    Science.gov (United States)

    Islam, Imadul; Brown, Greg; Bryant, Judi; Hrvatin, Paul; Kochanny, Monica J; Phillips, Gary B; Yuan, Shendong; Adler, Marc; Whitlow, Marc; Lentz, Dao; Polokoff, Mark A; Wu, James; Shen, Jun; Walters, Janette; Ho, Elena; Subramanyam, Babu; Zhu, Daguang; Feldman, Richard I; Arnaiz, Damian O

    2007-07-15

    Based on the lead compound BX-517, a series of C-4' substituted indolinones have been synthesized and evaluated for PDK1 inhibition. Modification at C-4' of the pyrrole afforded potent compounds (7b and 7d) with improved solubility and ADME properties. In this letter, we describe the synthesis, selectivity profile, and pharmacokinetic data of selected compounds.

  17. SNX-BAR proteins in phosphoinositide-mediated, tubular-based endosomal sorting.

    Science.gov (United States)

    van Weering, Jan R T; Verkade, Paul; Cullen, Peter J

    2010-06-01

    The endocytic network is morphologically characterized by a wide variety of membrane bound compartments that are able to undergo dynamic re-modeling through tubular and vesicular structures. The precise molecular mechanisms governing such re-modeling, and the events that co-ordinated this with the major role of endosomes, cargo sorting, remain unclear. That said, recent work on a protein family of sorting nexins (SNX) - especially a subfamily of SNX that contain a BAR domain (SNX-BARs) - has begun to shed some much needed light on these issues and in particular the process of tubular-based endosomal sorting. SNX-BARs are evolutionary conserved in endosomal protein complexes such as retromer, where they co-ordinate membrane deformation with cargo selection. Furthermore a central theme emerges of SNX-BARs linking the forming membrane carrier to cytoskeletal elements for transport through motor proteins such as dynein. By studying these SNX-BARs, we are gaining an increasingly detailed appreciation of the mechanistic basis of endosomal sorting and how this highly dynamic process functions in health and disease.

  18. Cryptographic primitives based on cellular transformations

    Directory of Open Access Journals (Sweden)

    B.V. Izotov

    2003-11-01

    Full Text Available Design of cryptographic primitives based on the concept of cellular automata (CA is likely to be a promising trend in cryptography. In this paper, the improved method performing data transformations by using invertible cyclic CAs (CCA is considered. Besides, the cellular operations (CO as a novel CAs application in the block ciphers are introduced. Proposed CCAs and COs, integrated under the name of cellular transformations (CT, suit well to be used in cryptographic algorithms oriented to fast software and cheap hardware implementation.

  19. Cellular-based sea level gauge

    Digital Repository Service at National Institute of Oceanography (India)

    Desai, R.G.P.; Joseph, A.

    , and cellular modem are mounted on the top portion of this structure. The pressure sensor and the logger are continuously powered on, and their electrical current consumption is 30 and 15 mA respectively. The cellular modem consumes 15 mA and 250 mA during... standby and data transmission modes, respectively. The pressure sensor located below the low-tide level measures the hydrostatic pressure of the overlying water layer. An indigenously designed and developed microprocessor-based data logger interrogates...

  20. Light weight cellular structures based on aluminium

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, O. [Indian Inst. of Tech., Kanpur (India); Embury, J.D.; Sinclair, C. [McMaster Univ., Hamilton, ON (Canada); Sang, H. [Queen`s Univ., Kingston, ON (Canada); Silvetti, P. [Cordoba Univ. Nacional (Argentina). Facultad de Ciencias Exactas, Fisicas y Naturales

    1997-02-01

    An interesting form of lightweight material which has emerged in the past 2 decades is metallic foam. This paper deals with the basic concepts of making metallic foams and a detailed study of foams produced from Al-SiC. In addition, some aspects of cellular solids based on honeycomb structures are outlined including the concept of producing both two-phase foams and foams with composite walls.

  1. Agent-Based Modeling of Mitochondria Links Sub-Cellular Dynamics to Cellular Homeostasis and Heterogeneity

    Science.gov (United States)

    Dalmasso, Giovanni; Marin Zapata, Paula Andrea; Brady, Nathan Ryan; Hamacher-Brady, Anne

    2017-01-01

    Mitochondria are semi-autonomous organelles that supply energy for cellular biochemistry through oxidative phosphorylation. Within a cell, hundreds of mobile mitochondria undergo fusion and fission events to form a dynamic network. These morphological and mobility dynamics are essential for maintaining mitochondrial functional homeostasis, and alterations both impact and reflect cellular stress states. Mitochondrial homeostasis is further dependent on production (biogenesis) and the removal of damaged mitochondria by selective autophagy (mitophagy). While mitochondrial function, dynamics, biogenesis and mitophagy are highly-integrated processes, it is not fully understood how systemic control in the cell is established to maintain homeostasis, or respond to bioenergetic demands. Here we used agent-based modeling (ABM) to integrate molecular and imaging knowledge sets, and simulate population dynamics of mitochondria and their response to environmental energy demand. Using high-dimensional parameter searches we integrated experimentally-measured rates of mitochondrial biogenesis and mitophagy, and using sensitivity analysis we identified parameter influences on population homeostasis. By studying the dynamics of cellular subpopulations with distinct mitochondrial masses, our approach uncovered system properties of mitochondrial populations: (1) mitochondrial fusion and fission activities rapidly establish mitochondrial sub-population homeostasis, and total cellular levels of mitochondria alter fusion and fission activities and subpopulation distributions; (2) restricting the directionality of mitochondrial mobility does not alter morphology subpopulation distributions, but increases network transmission dynamics; and (3) maintaining mitochondrial mass homeostasis and responding to bioenergetic stress requires the integration of mitochondrial dynamics with the cellular bioenergetic state. Finally, (4) our model suggests sources of, and stress conditions amplifying

  2. Cellular automaton-based position sensitive detector equalization

    Energy Technology Data Exchange (ETDEWEB)

    Ferrando, Nestor [Grupo de Diseno de Sistemas Digitales, Instituto de Aplicaciones de las Tecnologias de la Informacion y de las Comunicaciones Avanzadas, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain)], E-mail: nesferjo@upvnet.upv.es; Herrero, V.; Cerda, J.; Lerche, C.W.; Colom, R.J.; Gadea, R.; Martinez, J.D.; Monzo, J.M.; Mateo, F.; Sebastia, A.; Benlloch, J.M. [Grupo de Diseno de Sistemas Digitales, Instituto de Aplicaciones de las Tecnologias de la Informacion y de las Comunicaciones Avanzadas, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain)

    2009-06-01

    Indirect position detectors based on scintillator crystals lack of spacial uniformity in their response. This happens due to crystal inhomogeneities and gain differences among the photomultiplier anodes. In order to solve this, PESIC, an integrated front-end for multianode photomultiplier based nuclear imaging devices was created. One of its main features is the digitally programmable gain adjustment for every photomultiplier output. On another front, cellular automata have been proved to be a useful method for dynamic system modeling. In this paper, a cellular automaton which emulates the behavior of the scintillator crystal, the photomultiplier and the front-end is introduced. Thanks to this model, an automatic energy-based calibration of the detector can be done by configuring the cellular automaton with experimental data and making it evolve up to an stable state. This can be useful as a precalibration method of the detector.

  3. Ion Induced Changes in Phosphoinositide Monolayers at Phisiological Concentrations

    Science.gov (United States)

    Kazadi Badiambile, Adolphe; Forstner, Martin

    2013-03-01

    Phosphoinositides (PIPs) play a crucial role in many cellular process that occur at the plasma membrane such as calcium release, exocytosis or endocytosis. In order to specifically regulate these functions PIPs must segregate in pools at the plasma membrane. A possible mechanism that could induce and regulate such organization of phosphoinositides is their interaction with bivalent cations. Understanding the physicochemical mechanism that can regulate membrane structure is a crucial step in the development of adaptive biomimetic membrane systems. Using Langmuir monolayers, we investigated the effect of calcium and magnesium on the surface pressure-area/lipid isotherm of monolayer of phosphatidylinositol (PI), phosphatidylinositol bisphosphate (PIP2), dioleoylphosphatidylglycerol (DOPG) and palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). It is found that the decrease of area per lipid, i.e. the increase in aggregation, is mostly dependent on the lipid's head group charge but ion specific. In addition, we discuss changes in free energy and compressibility of these monolayer-ion systems. NSF

  4. Bases of Schur algebras associated to cellularly stratified diagram algebras

    CERN Document Server

    Bowman, C

    2011-01-01

    We examine homomorphisms between induced modules for a certain class of cellularly stratified diagram algebras, including the BMW algebra, Temperley-Lieb algebra, Brauer algebra, and (quantum) walled Brauer algebra. We define the `permutation' modules for these algebras, these are one-sided ideals which allow us to study the diagrammatic Schur algebras of Hartmann, Henke, Koenig and Paget. We construct bases of these Schur algebras in terms of modified tableaux. On the way we prove that the (quantum) walled Brauer algebra and the Temperley-Lieb algebra are both cellularly stratified and therefore have well-defined Specht filtrations.

  5. WWW Business Applications Based on the Cellular Model

    Institute of Scientific and Technical Information of China (English)

    Toshio Kodama; Tosiyasu L. Kunii; Yoichi Seki

    2008-01-01

    A cellular model based on the Incrementally Modular Abstraction Hierarchy (IMAH) is a novel model that can represent the architecture of and changes in cyberworlds, preserving invariants from a general level to a specific one. We have developed a data processing system called the Cellular Data System (CDS). In the development of business applications, you can prevent combinatorial explosion in the process of business design and testing by using CDS. In this paper, we have first designed and implemented wide-use algebra on the presentation level. Next, we have developed and verified the effectiveness of two general business applications using CDS: 1) a customer information management system, and 2) an estimate system.

  6. A cellular automaton evacuation model based on mobile robot's behaviors

    Institute of Scientific and Technical Information of China (English)

    WENG WenGuo; YUAN HongYong; FAN WeiCheng

    2007-01-01

    The research of evacuation in some emergencies, e.g. fire, is of great benefit to reducing the injuries of persons. In this paper, a cellular automaton evacuation model based on mobile robot's behaviors is presented. Each person is treated as an intelligent mobile robot, and motor schemas, including move-to-goal, avoid-obstacle, swirl-obstacle and nervous-motion, drive persons to interact with their environment. The motor schemas are combined with cellular automaton theory, and an evacuation model is built. Evacuation simulation of persons with different move velocities shows that the presented model can predict accurately the evacuation phenomena in some emergencies.

  7. Finite Field Arithmetic Architecture Based on Cellular Array

    Directory of Open Access Journals (Sweden)

    Kee-Won Kim

    2015-05-01

    Full Text Available Recently, various finite field arithmetic structures are introduced for VLSI circuit implementation on cryptosystems and error correcting codes. In this study, we present an efficient finite field arithmetic architecture based on cellular semi-systolic array for Montgomery multiplication by choosing a proper Montgomery factor which is highly suitable for the design on parallel structures. Therefore, our architecture has reduced a time complexity by 50% compared to typical architecture.

  8. Phosphoinositide isoforms determine compartment-specific ion channel activity.

    Science.gov (United States)

    Zhang, Xiaoli; Li, Xinran; Xu, Haoxing

    2012-07-10

    Phosphoinositides serve as address labels for recruiting peripheral cytoplasmic proteins to specific subcellular compartments, and as endogenous factors for modulating the activity of integral membrane proteins. Phosphatidylinositol 4,5-bisphosphate (PI(4,5)P(2)) is a plasma-membrane (PM)-specific phosphoinositide and a positive cofactor required for the activity of most PM channels and transporters. This requirement for phosphoinositide cofactors has been proposed to prevent PM channel/transporter activity during passage through the biosynthetic/secretory and endocytic pathways. To determine whether intracellularly localized channels are similarly "inactivated" at the PM, we studied PIP(2) modulation of intracellular TRPML1 channels. TRPML1 channels are primarily localized in lysosomes, but can also be detected temporarily in the PM upon lysosomal exocytosis. By directly patch-clamping isolated lysosomes, we previously found that lysosomal, but not PM-localized, TRPML1 is active with PI(3,5)P(2), a lysosome-specific PIP(2), as the underlying positive cofactor. Here we found that "silent" PM-localized TRPML1 could be activated by depleting PI(4,5)P(2) levels and/or by adding PI(3,5)P(2) to inside-out membrane patches. Unlike PM channels, surface-expressed TRPML1 underwent a unique and characteristic run-up upon patch excision, and was potently inhibited by a low micromolar concentration of PI(4,5)P(2). Conversely, depletion of PI(4,5)P(2) by either depolarization-induced activation or chemically induced translocation of 5'-phosphatase potentiated whole-cell TRPML1 currents. PI(3,5)P(2) activation and PI(4,5)P(2) inhibition of TRPML1 were mediated by distinct basic amino acid residues in a common PIP(2)-interacting domain. Thus, PI(4,5)P(2) may serve as a negative cofactor for intracellular channels such as TRPML1. Based on these results, we propose that phosphoinositide regulation sets compartment-specific activity codes for membrane channels and transporters.

  9. Chaotic Encryption Method Based on Life-Like Cellular Automata

    CERN Document Server

    Machicao, Marina Jeaneth; Bruno, Odemir M

    2011-01-01

    We propose a chaotic encryption method based on Cellular Automata(CA), specifically on the family called the "Life-Like" type. Thus, the encryption process lying on the pseudo-random numbers generated (PRNG) by each CA's evolution, which transforms the password as the initial conditions to encrypt messages. Moreover, is explored the dynamical behavior of CA to reach a "good" quality as PRNG based on measures to quantify "how chaotic a dynamical system is", through the combination of the entropy, Lyapunov exponent, and Hamming distance. Finally, we present the detailed security analysis based on experimental tests: DIEHARD and ENT suites, as well as Fouriers Power Spectrum, used as a security criteria.

  10. Shape Memory Alloy-Based Periodic Cellular Structures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I effort will develop and demonstrate an innovative shape memory alloy (SMA) periodic cellular structural technology. Periodic cellular structures...

  11. Basalt fiber reinforced porous aggregates-geopolymer based cellular material

    Science.gov (United States)

    Luo, Xin; Xu, Jin-Yu; Li, Weimin

    2015-09-01

    Basalt fiber reinforced porous aggregates-geopolymer based cellular material (BFRPGCM) was prepared. The stress-strain curve has been worked out. The ideal energy-absorbing efficiency has been analyzed and the application prospect has been explored. The results show the following: fiber reinforced cellular material has successively sized pore structures; the stress-strain curve has two stages: elastic stage and yielding plateau stage; the greatest value of the ideal energy-absorbing efficiency of BFRPGCM is 89.11%, which suggests BFRPGCM has excellent energy-absorbing property. Thus, it can be seen that BFRPGCM is easy and simple to make, has high plasticity, low density and excellent energy-absorbing features. So, BFRPGCM is a promising energy-absorbing material used especially in civil defense engineering.

  12. Fire Spread Model for Old Towns Based on Cellular Automaton

    Institute of Scientific and Technical Information of China (English)

    GAO Nan; WENG Wenguo; MA Wei; NI Shunjiang; HUANG Quanyi; YUAN Hongyong

    2008-01-01

    Old towns like Lijiang have enormous historic,artistic,and architectural value.The buildings in such old towns are usually made of highly combustible materials,such as wood and grass.If a fire breaks out,it will spread to multiple buildings,so fire spreading and controlling in old towns need to be studied.This paper presents a fire spread model for old towns based on cellular automaton.The cellular automaton rules were set according to historical fire data in empirical formulas.The model also considered the effects of climate.The simulation results were visualized in a geography information system.An example of a fire spread in Lijiang was investigated with the results showing that this model provides a realistic tool for predicting fire spread in old towns.Fire brigades can use this tool to predict when and how a fire spreads to minimize the losses.

  13. Microbial Growth Modeling and Simulation Based on Cellular Automata

    Directory of Open Access Journals (Sweden)

    Hong Men

    2013-07-01

    Full Text Available In order to simulate the micro-evolutionary process of the microbial growth, [Methods] in this study, we adopt two-dimensional cellular automata as its growth space. Based on evolutionary mechanism of microbial and cell-cell interactions, we adopt Moore neighborhood and make the transition rules. Finally, we construct the microbial growth model. [Results] It can describe the relationships among the cell growth, division and death. And also can effectively reflect spatial inhibition effect and substrate limitation effect. [Conclusions] The simulation results show that CA model is not only consistent with the classic microbial kinetic model, but also be able to simulate the microbial growth and evolution.

  14. Public Evacuation Process Modeling and Simulatiaon Based on Cellular Automata

    Directory of Open Access Journals (Sweden)

    Zhikun Wang

    2013-11-01

    Full Text Available Considering attraction of the nearest exit, repulsive force of the fire, barrier and its display style, effect of fire exit location on escape time in fire hazard, a mathematical model of evacuation process model was build based on cellular automatic theory. The program was developed by JavaScript. The influencing factors of evacuation were obtained through the simulation model by inputting crew size, creating initial positions of crew and fire seat stochastically. The experimental results show that the evacuation simulation model with authenticity and validity, which has guiding significance for people evacuation and public escape system design.  

  15. Bilayer Beams and Relay Sharing based OFDMA Cellular Architecture

    Directory of Open Access Journals (Sweden)

    Yanxiong Pan

    2011-08-01

    Full Text Available Over the past decade, researchers have been putting a lot of energy on co-channel interference suppression in the forthcoming fourth generation (4G wireless networks. Existing approaches to interference suppression are mainly based on signal processing, cooperative communication or coordination techniques. Though good performance has been attained already, a more complex receiver is needed, and there is still room for improvement through other ways.Considering spatial frequency reuse, which provides an easier way to cope with the co-channel interference, this paper proposed a bilayer beams and relay sharing based (BBRS OFDMA cellular architecture and corresponding frequency planning scheme. The main features of the novel architecture are as follows. Firstly, the base station (BS uses two beams, one composed of six wide beams providing coverage to mobile stations (MSs that access to the BS, and the other composed of six narrow beams communicating with fixed relay stations (FRSs. Secondly, in the corresponding frequency planning scheme, soft frequency reuse is considered on all FRSs further. System-level simulation results demonstrate that better coverage performance is obtained and the mean data rate of MSs near the cell edge is improved significantly. The BBRS cellular architecture provides a practical method to interference suppression in 4G networks since a better tradeoff between performance and complexity is achieved.

  16. Measurements of Electromagnetic Fields Emitted from Cellular Base Stations in

    Directory of Open Access Journals (Sweden)

    K. J. Ali

    2013-05-01

    Full Text Available With increasing the usage of mobile communication devices and internet network information, the entry of private telecommunications companies in Iraq has been started since 2003. These companies began to build up cellular towers to accomplish the telecommunication works but they ignore the safety conditions imposed for the health and environment that are considered in random way. These negative health effects which may cause a health risk for life beings and environment pollution. The aim of this work is to determine the safe and unsafe ranges and discuss damage caused by radiation emitted from Asia cell base stations in Shirqat city and discuses the best ways in which can be minimize its exposure level to avoid its negative health effects. Practical measurements of power density around base stations has been accomplished by using a radiation survey meter type (Radio frequency EMF Strength Meter 480846 in two ways. The first way of measurements has been accomplished at a height of 2 meters above ground for different distances from (0-300 meters .The second way is at a distance of 150 meters for different levels from (2-15 meters above ground level. The maximum measured power density is about (3 mW/m2. Results indicate that the levels of power density are far below the RF radiation exposure of USSR safety standards levels. And that means these cellular base station don't cause negative the health effect for life being if the exposure is within the acceptable international standard levels.

  17. Mosquito population dynamics from cellular automata-based simulation

    Science.gov (United States)

    Syafarina, Inna; Sadikin, Rifki; Nuraini, Nuning

    2016-02-01

    In this paper we present an innovative model for simulating mosquito-vector population dynamics. The simulation consist of two stages: demography and dispersal dynamics. For demography simulation, we follow the existing model for modeling a mosquito life cycles. Moreover, we use cellular automata-based model for simulating dispersal of the vector. In simulation, each individual vector is able to move to other grid based on a random walk. Our model is also capable to represent immunity factor for each grid. We simulate the model to evaluate its correctness. Based on the simulations, we can conclude that our model is correct. However, our model need to be improved to find a realistic parameters to match real data.

  18. Exploring Quantum Dot Cellular Automata Based Reversible Circuit

    Directory of Open Access Journals (Sweden)

    Saroj Kumar Chandra

    2012-03-01

    Full Text Available Quantum-dot Cellular Automata (QCA is a new technology for development of logic circuits based on nanotechnology, and it is an one of the alternative for designing high performance computing over existing CMOS technology. The basic logic in QCA does not use voltage level for logic representation rather it represent binary state by polarization of electrons on the Quantum Cell which is basic building block of QCA. Extensive work is going on QCA for circuit design due to low power consumption and regularity in the circuit.. Clocking is used in QCA circuit to synchronize and control the information flow and to provide the power to run the circuit. Reversible logic design is a well-known paradigm in digital computation, and if circuit developed is reversible then it consumes very low power. Here, in this paper we are presenting a Reversible Universal Gate (RUG based on Quantum-dot Cellular Automata (QCA. The RUG implemented by QCA Designer tool and also its behavior is simulated by it.

  19. Exploring Quantum Dot Cellular Automata Based Reversible Circuit

    Directory of Open Access Journals (Sweden)

    Saroj Kumar Chandra

    2012-03-01

    Full Text Available Quantum-dot Cellular Automata (QCA is a new technology for development of logic circuits based on nanotechnology, and it is an one of the alternative for designing high performance computing over existing CMOS technology. The basic logic in QCA does not use voltage level for logic representation rather it represent binary state by polarization of electrons on the Quantum Cell which is basic building block of QCA. Extensive work is going on QCA for circuit design due to low power consumption and regularity in the circuit.. Clocking is used in QCA circuit to synchronize and control the information flow and to provide the power to run the circuit. Reversible logic design is a well-known paradigm in digital computation, and if circuit developed is reversible then it consumes very low power . Here, in this paper we are presenting a Reversible Universal Gate (RUG based on Quantum-dot Cellular Automata (QCA. The RUG implemented by QCA Designer tool and also its behavior is simulated by it.

  20. Shape Memory Alloy-Based Periodic Cellular Structures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase II effort will continue to develop and demonstrate an innovative shape memory alloy (SMA) periodic cellular structural technology. Periodic cellular...

  1. A Self-organized MIMO-OFDM-based Cellular Network

    Science.gov (United States)

    Grünheid, Rainer; Fellenberg, Christian

    2012-05-01

    This paper presents a system proposal for a self-organized cellular network, which is based on the MIMO-OFDM transmission technique. Multicarrier transmission, combined with appropriate beamforming concepts, yields high bandwidth-efficiency and shows a robust behavior in multipath radio channels. Moreover, it provides a fine and tuneable granularity of space-time-frequency resources. Using a TDD approach and interference measurements in each cell, the Base Stations (BSs) decide autonomously which of the space-time-frequency resource blocks are allocated to the Mobile Terminals (MTs) in the cell, in order to fulfil certain Quality of Service (QoS) parameters. Since a synchronized Single Frequency Network (SFN), i.e., a re-use factor of one is applied, the resource blocks can be shared adaptively and flexibly among the cells, which is very advantageous in the case of a non-uniform MT distribution.

  2. The Cellular Differential Evolution Based on Chaotic Local Search

    Directory of Open Access Journals (Sweden)

    Qingfeng Ding

    2015-01-01

    Full Text Available To avoid immature convergence and tune the selection pressure in the differential evolution (DE algorithm, a new differential evolution algorithm based on cellular automata and chaotic local search (CLS or ccDE is proposed. To balance the exploration and exploitation tradeoff of differential evolution, the interaction among individuals is limited in cellular neighbors instead of controlling parameters in the canonical DE. To improve the optimizing performance of DE, the CLS helps by exploring a large region to avoid immature convergence in the early evolutionary stage and exploiting a small region to refine the final solutions in the later evolutionary stage. What is more, to improve the convergence characteristics and maintain the population diversity, the binomial crossover operator in the canonical DE may be instead by the orthogonal crossover operator without crossover rate. The performance of ccDE is widely evaluated on a set of 14 bound constrained numerical optimization problems compared with the canonical DE and several DE variants. The simulation results show that ccDE has better performances in terms of convergence rate and solution accuracy than other optimizers.

  3. Motor Schema-Based Cellular Automaton Model for Pedestrian Dynamics

    Science.gov (United States)

    Weng, Wenguo; Hasemi, Yuji; Fan, Weicheng

    A new cellular automaton model for pedestrian dynamics based on motor schema is presented. Each pedestrian is treated as an intelligent mobile robot, and motor schemas including move-to-goal, avoid-away and avoid-around drive pedestrians to interact with their environment. We investigate the phenomenon of many pedestrians with different move velocities escaping from a room. The results show that the pedestrian with high velocity have predominance in competitive evacuation, if we only consider repulsion from or avoiding around other pedestrians, and interaction with each other leads to disordered evacuation, i.e., decreased evacuation efficiency. Extensions of the model using learning algorithms for controlling pedestrians, i.e., reinforcement learning, neural network and genetic algorithms, etc. are noted.

  4. Doped semiconductor nanocrystal based fluorescent cellular imaging probes.

    Science.gov (United States)

    Maity, Amit Ranjan; Palmal, Sharbari; Basiruddin, S K; Karan, Niladri Sekhar; Sarkar, Suresh; Pradhan, Narayan; Jana, Nikhil R

    2013-06-21

    Doped semiconductor nanocrystals such as Mn doped ZnS, Mn doped ZnSe and Cu doped InZnS, are considered as new classes of fluorescent biological probes with low toxicity. Although the synthesis in high quality of such nanomaterials is now well established, transforming them into functional fluorescent probes remains a challenge. Here we report a fluorescent cellular imaging probe made of high quality doped semiconductor nanocrystals. We have identified two different coating approaches suitable for transforming the as synthesized hydrophobic doped semiconductor nanocrystals into water-soluble functional nanoparticles. Following these approaches we have synthesized TAT-peptide- and folate-functionalized nanoparticles of 10-80 nm hydrodynamic diameter and used them as a fluorescent cell label. The results shows that doped semiconductor nanocrystals can be an attractive alternative for conventional cadmium based quantum dots with low toxicity.

  5. Measurement of oxidatively generated base damage in cellular DNA.

    Science.gov (United States)

    Cadet, Jean; Douki, Thierry; Ravanat, Jean-Luc

    2011-06-03

    This survey focuses on the critical evaluation of the main methods that are currently available for monitoring single and complex oxidatively generated damage to cellular DNA. Among chromatographic methods, HPLC-ESI-MS/MS and to a lesser extent HPLC-ECD which is restricted to a few electroactive nucleobases and nucleosides are appropriate for measuring the formation of single and clustered DNA lesions. Such methods that require optimized protocols for DNA extraction and digestion are sensitive enough for measuring base lesions formed under conditions of severe oxidative stress including exposure to ionizing radiation, UVA light and high intensity UVC laser pulses. In contrast application of GC-MS and HPLC-MS methods that are subject to major drawbacks have been shown to lead to overestimated values of DNA damage. Enzymatic methods that are based on the use of DNA repair glycosylases in order to convert oxidized bases into strand breaks are suitable, even if they are far less specific than HPLC methods, to deal with low levels of single modifications. Several other methods including immunoassays and (32)P-postlabeling methods that are still used suffer from drawbacks and therefore are not recommended. Another difficult topic is the measurement of oxidatively generated clustered DNA lesions that is currently achieved using enzymatic approaches and that would necessitate further investigations.

  6. Measurement of oxidatively generated base damage in cellular DNA

    Energy Technology Data Exchange (ETDEWEB)

    Cadet, Jean, E-mail: jean.cadet@cea.fr [Laboratoire ' Lesions des Acides Nucleiques' , SCIB-UMR-E no3 (CEA/UJF), FRE CNRS 3200, Departement de Recherche Fondamentale sur la Matiere Condensee, CEA/Grenoble, F-38054 Grenoble Cedex 9 (France); Douki, Thierry; Ravanat, Jean-Luc [Laboratoire ' Lesions des Acides Nucleiques' , SCIB-UMR-E no3 (CEA/UJF), FRE CNRS 3200, Departement de Recherche Fondamentale sur la Matiere Condensee, CEA/Grenoble, F-38054 Grenoble Cedex 9 (France)

    2011-06-03

    This survey focuses on the critical evaluation of the main methods that are currently available for monitoring single and complex oxidatively generated damage to cellular DNA. Among chromatographic methods, HPLC-ESI-MS/MS and to a lesser extent HPLC-ECD which is restricted to a few electroactive nucleobases and nucleosides are appropriate for measuring the formation of single and clustered DNA lesions. Such methods that require optimized protocols for DNA extraction and digestion are sensitive enough for measuring base lesions formed under conditions of severe oxidative stress including exposure to ionizing radiation, UVA light and high intensity UVC laser pulses. In contrast application of GC-MS and HPLC-MS methods that are subject to major drawbacks have been shown to lead to overestimated values of DNA damage. Enzymatic methods that are based on the use of DNA repair glycosylases in order to convert oxidized bases into strand breaks are suitable, even if they are far less specific than HPLC methods, to deal with low levels of single modifications. Several other methods including immunoassays and {sup 32}P-postlabeling methods that are still used suffer from drawbacks and therefore are not recommended. Another difficult topic is the measurement of oxidatively generated clustered DNA lesions that is currently achieved using enzymatic approaches and that would necessitate further investigations.

  7. Targeted cellular ablation based on the morphology of malignant cells

    Science.gov (United States)

    Ivey, Jill W.; Latouche, Eduardo L.; Sano, Michael B.; Rossmeisl, John H.; Davalos, Rafael V.; Verbridge, Scott S.

    2015-11-01

    Treatment of glioblastoma multiforme (GBM) is especially challenging due to a shortage of methods to preferentially target diffuse infiltrative cells, and therapy-resistant glioma stem cell populations. Here we report a physical treatment method based on electrical disruption of cells, whose action depends strongly on cellular morphology. Interestingly, numerical modeling suggests that while outer lipid bilayer disruption induced by long pulses (~100 μs) is enhanced for larger cells, short pulses (~1 μs) preferentially result in high fields within the cell interior, which scale in magnitude with nucleus size. Because enlarged nuclei represent a reliable indicator of malignancy, this suggested a means of preferentially targeting malignant cells. While we demonstrate killing of both normal and malignant cells using pulsed electric fields (PEFs) to treat spontaneous canine GBM, we proposed that properly tuned PEFs might provide targeted ablation based on nuclear size. Using 3D hydrogel models of normal and malignant brain tissues, which permit high-resolution interrogation during treatment testing, we confirmed that PEFs could be tuned to preferentially kill cancerous cells. Finally, we estimated the nuclear envelope electric potential disruption needed for cell death from PEFs. Our results may be useful in safely targeting the therapy-resistant cell niches that cause recurrence of GBM tumors.

  8. Effects of ibogaine and noribogaine on phosphoinositide hydrolysis.

    Science.gov (United States)

    Rabin, R A; Winter, J C

    1996-08-26

    The effects of the antiaddictive compound, ibogaine, and its primary metabolite, noribogaine (12-hydroxyibogamine), on phosphoinositide hydrolysis were investigated. Although ibogaine did not alter phosphoinositide turnover in either striatal or hippocampal slices, noribogaine elicited a concentration-dependent increase in the generation of [3H]inositol phosphates. This stimulation was not altered by inclusion of tetrodotoxin, cadmium or omega-conotoxin indicating that the increased production of [3H]inositol phosphates was not secondary to a release of one or more neurotransmitters. The present study indicates a stimulation of phosphoinositide hydrolysis by noribogaine may be involved in the behavioral effects of ibogaine.

  9. Pickering Emulsion-Based Marbles for Cellular Capsules

    Directory of Open Access Journals (Sweden)

    Guangzhao Zhang

    2016-07-01

    Full Text Available The biodegradable cellular capsule, being prepared from simple vaporization of liquid marbles, is an ideal vehicle for the potential application of drug encapsulation and release. This paper reports the fabrication of cellular capsules via facile vaporization of Pickering emulsion marbles in an ambient atmosphere. Stable Pickering emulsion (water in oil was prepared while utilizing dichloromethane (containing poly(l-lactic acid and partially hydrophobic silica particles as oil phase and stabilizing agents respectively. Then, the Pickering emulsion marbles were formed by dropping emulsion into a petri dish containing silica particles with a syringe followed by rolling. The cellular capsules were finally obtained after the complete vaporization of both oil and water phases. The technique of scanning electron microscope (SEM was employed to research the microstructure and surface morphology of the prepared capsules and the results showed the cellular structure as expected. An in vitro drug release test was implemented which showed a sustained release property of the prepared cellular capsules. In addition, the use of biodegradable poly(l-lactic acid and the biocompatible silica particles also made the fabricated cellular capsules of great potential in the application of sustained drug release.

  10. [Phosphoinositides: lipidic essential actors in the intracellular traffic].

    Science.gov (United States)

    Bertazzi, Dimitri L; De Craene, Johan-Owen; Bär, Séverine; Sanjuan-Vazquez, Myriam; Raess, Matthieu A; Friant, Sylvie

    2015-01-01

    Phosphoinositides (PPIn) are lipids involved in the vesicular transport of proteins between the different intracellular compartments. They act by recruiting and/or activating effector proteins and are thus involved in crucial cellular functions including vesicle budding, fusion and dynamics of membranes and regulation of the cytoskeleton. Although they are present in low concentrations in membranes, their activity is essential for cell survival and needs to be tightly controlled. Therefore, phosphatases and kinases specific of the various cellular membranes can phosphorylate/dephosphorylate their inositol ring on the positions D3, D4 and/or D5. The differential phosphorylation determines the intracellular localisation and the activity of the PPIn. Indeed, non-phosphorylated phosphatidylinositol (PtdIns) is the basic component of the PPIn and can be found in all eukaryotic cells at the cytoplasmic face of the ER, the Golgi, mitochondria and microsomes. It can get phosphorylated on position D4 to obtain PtdIns4P, a PPIn enriched in the Golgi compartment and involved in the maintenance of this organelle as well as anterograde and retrograde transport to and from the Golgi. PtdIns phosphorylation on position D3 results in PtdIns3P that is required for endosomal transport and multivesicular body (MVB) formation and sorting. These monophosphorylated PtdIns can be further phosphorylated to produce bisphophorylated PtdIns. Thus, PtdIns(4,5)P2, mainly produced by PtdIns4P phosphorylation, is enriched in the plasma membrane and involved in the regulation of actin cytoskeleton and endocytosis. PtdIns(3,5)P2, mainly produced by PtdIns3P phosphorylation, is enriched in late endosomes, MVBs and the lysosome/vacuole and plays a role in endosome to vacuole transport. PtdIns(3,4)P2 is absent in yeast, cells and mainly produced by PtdIns4P phosphorylation in human cells; PtdIns(3,4)P2 is localised in the plasma membrane and plays an important role as a second messenger by recruiting

  11. Phosphoinositide metabolism and adrenergic receptors in astrocytes

    Energy Technology Data Exchange (ETDEWEB)

    Noble, E.P.; Ritchie, T.; de Vellis, J.

    1986-03-01

    Agonist-induced phosphoinositide (PI) breakdown functions as a signal generating system. Diacylglycerol, one breakdown product of phosphotidylinositol-4,5-diphosphate hydrolysis, can stimulate protein kinase C, whereas inositol triphosphate, the other product, has been proposed to be a second messenger for Ca/sup + +/ mobilization. Using purified astrocyte cultures from neonatal rat brain, the effects of adrenergic agonists and antagonists at 10/sup -5/ M were measured on PI breakdown. Astrocytes grown in culture were prelabeled with (/sup 3/H)inositol, and basal (/sup 3/H) inositol phosphate (IP/sub 1/) accumulation was measured in the presence of Li/sup +/. Epinephrine > norepinephrine (NE) were the most active stimulants of IP/sub 1/ production. The ..cap alpha../sub 1/ adrenoreceptor blockers, phentolamine and phenoxybenzamine, added alone had no effect on IP/sub 1/ production was reduced below basal levels. Propranolol partially blocked the effects of NE. Clonidine and isoproterenol, separately added, reduced IP/sub 1/ below basal levels and when added together diminished IP/sub 1/ accumulation even further. The role of adrenergic stimulation in the production of c-AMP.

  12. Accurate assessment of cell density in low cellular liquid-based cervical cytology

    NARCIS (Netherlands)

    Siebers, A.G.; Laak, J.A.W.M. van der; Huberts-Manders, R.; Vedder, J.E.M.; Bulten, J.

    2013-01-01

    A. G. Siebers, J. A. W. M. van der Laak, R. Huberts-Manders, J. E. M. Vedder and J. Bulten Accurate assessment of cell density in low cellular liquid-based cervical cytology Objective: Scant cellularity is the most important source of unsatisfactory liquid-based cytology. Although still being debate

  13. Modulation of phosphoinositide metabolism in aortic smooth muscle cells by allylamine

    Energy Technology Data Exchange (ETDEWEB)

    Cox, L.R.; Murphy, S.K.; Ramos, K. (Philadelphia College of Pharmacy and Science, PA (USA))

    1990-08-01

    Aortic smooth muscle cells (SMC) modulate from a contractile to a proliferative phenotype upon subchronic exposure to allylamine. The present studies were designed to determine if this phenotypic modulation is associated with alterations in the metabolism of membrane phosphoinositides. 32P incorporation into phosphatidylinositol 4-phosphate (PIP), phosphatidylinositol 4,5-bisphosphate (PIP2), and phosphatidic acid (PA) was lower by 31, 35, and 22%, respectively, in SMC from allylamine-treated animals relative to controls. In contrast, incorporation of (3H)myoinositol into inositol phosphates did not differ in allylamine cells relative to control cells. Exposure to dibutyryl (db) cAMP (0.2 mM) and theophylline (0.1 mM) reduced 32P incorporation into PIP and PIP2 in SMC from both experimental groups. Under these conditions, a decrease in (3H)myoinositol incorporation into inositol 1-phosphate was only observed in allylamine cells. The effects of db cAMP and theophylline in allylamine and control SMC correlated with a marked decrease in cellular proliferation. These results suggest that alterations in phosphoinositide synthesis and/or degradation contribute to the enhanced proliferation of SMC induced by allylamine. To further examine this concept, the effects of agents which modulate protein kinase C (PKC) activity were evaluated. Sphingosine (125-500 ng/ml), a PKC inhibitor, decreased SMC proliferation in allylamine, but not control cells. 12-O-Tetradecanoylphorbol-13-acetate (1-100 ng/ml), a PKC agonist, stimulated proliferation in control cells, but inhibited proliferation in cells from allylamine-treated animals. We conclude that allylamine-induced phenotypic modulation of SMC is associated with alterations in phosphoinositide metabolism.

  14. Predicting the structures of complexes between phosphoinositide 3-kinase (PI3K) and romidepsin-related compounds for the drug design of PI3K/histone deacetylase dual inhibitors using computational docking and the ligand-based drug design approach.

    Science.gov (United States)

    Oda, Akifumi; Saijo, Ken; Ishioka, Chikashi; Narita, Koichi; Katoh, Tadashi; Watanabe, Yurie; Fukuyoshi, Shuichi; Takahashi, Ohgi

    2014-11-01

    Predictions of the three-dimensional (3D) structures of the complexes between phosphoinositide 3-kinase (PI3K) and two inhibitors were conducted using computational docking and the ligand-based drug design approach. The obtained structures were refined by structural optimizations and molecular dynamics (MD) simulations. The ligands were located deep inside the ligand binding pocket of the p110α subunit of PI3K, and the hydrogen bond formations and hydrophobic effects of the surrounding amino acids were predicted. Although rough structures were obtained for the PI3K-inhibitor complexes before the MD simulations, the refinement of the structures by these simulations clarified the hydrogen bonding patterns of the complexes.

  15. Evaluation of Cellular Toxicity of Three Denture Base Acrylic Resins

    OpenAIRE

    Ebrahimi Saravi, M.; M. Vojdani; Bahrani, F

    2012-01-01

    Objective This study aimed to evaluate the cellular toxicity of two newly-released acrylic resins (Futura Gen and GC Reline Hard) in comparison with the conventional heat-cure resin (Meliodent). Materials and Methods: Sample discs from each acrylic resin were placed in 24-well culture plates along with L929 mouse fibroblast cell line. A mixture of the RPMI 1640 medium, antibiotics and 10% FBS was added to the plates and the specimens were incubated in a CO2 incubator. The amount of light abso...

  16. The Algorithm of Continuous Optimization Based on the Modified Cellular Automaton

    Directory of Open Access Journals (Sweden)

    Oleg Evsutin

    2016-08-01

    Full Text Available This article is devoted to the application of the cellular automata mathematical apparatus to the problem of continuous optimization. The cellular automaton with an objective function is introduced as a new modification of the classic cellular automaton. The algorithm of continuous optimization, which is based on dynamics of the cellular automaton having the property of geometric symmetry, is obtained. The results of the simulation experiments with the obtained algorithm on standard test functions are provided, and a comparison between the analogs is shown.

  17. Membrane-Based Functions in the Origin of Cellular Life

    Science.gov (United States)

    Chipot, Christophe; New, Michael H.; Schweighofer, Karl; Pohorille, Andrew; Wilson, Michael A.

    1999-01-01

    Our objective is to help explain how the earliest ancestors of contemporary cells (protocells) performed their essential functions employing only the molecules available in the protobiological milieu. Our hypothesis is that vesicles, built of amphiphilic, membrane-forming materials, emerged early in protobiological evolution and served as precursors to protocells. We further assume that the cellular functions associated with contemporary membranes, such as capturing and, transducing of energy, signaling, or sequestering organic molecules and ions, evolved in these membrane environments. An alternative hypothesis is that these functions evolved in different environments and were incorporated into membrane-bound structures at some later stage of evolution. We focus on the application of the fundamental principles of physics and chemistry to determine how they apply to the formation of a primitive, functional cell. Rather than attempting to develop specific models for cellular functions and to identify the origin of the molecules which perform these functions, our goal is to define the structural and energetic conditions that any successful model must fulfill, therefore providing physico-chemical boundaries for these models. We do this by carrying out large-scale, molecular level computer simulations on systems of interest.

  18. Targeting phosphoinositide 3-kinase δ for allergic asthma.

    Science.gov (United States)

    Rowan, Wendy C; Smith, Janet L; Affleck, Karen; Amour, Augustin

    2012-02-01

    Chronic inflammation in the lung has long been linked to the pathogenesis of asthma. Central to this airway inflammation is a T-cell response to allergens, with Th2 cytokines driving the differentiation, survival and function of the major inflammatory cells involved in the allergic cascade. PI3Kδ (phosphoinositide 3-kinase δ) is a lipid kinase, expressed predominantly in leucocytes, where it plays a critical role in immune receptor signalling. A selective PI3Kδ inhibitor is predicted to block T-cell activation in the lung, reducing the production of pro-inflammatory Th2 cytokines. PI3Kδ is also involved in B-cell and mast cell activation. Therefore the inhibition of PI3Kδ should dampen down the inflammatory cascade involved in the asthmatic response through a wide breadth of pharmacology. Current anti-inflammatory therapies, which are based on corticosteroids, are effective in controlling inflammation in mild asthmatics, but moderate/severe asthmatic patients remain poorly controlled, experiencing recurrent exacerbations. Corticosteroids have no effect on mast cell degranulation and do not act directly on B-cells, so, overall, a PI3Kδ inhibitor has the potential to deliver improvements in onset of action, efficacy and reduced exacerbations in moderate/severe asthmatics. Additionally, PI3Kδ inhibition is expected to block effects of Th17 cells, which are increasingly implicated in steroid-insensitive asthma.

  19. Phosphoinositide 3-kinase inhibitors induce DNA damage through nucleoside depletion.

    Science.gov (United States)

    Juvekar, Ashish; Hu, Hai; Yadegarynia, Sina; Lyssiotis, Costas A; Ullas, Soumya; Lien, Evan C; Bellinger, Gary; Son, Jaekyoung; Hok, Rosanna C; Seth, Pankaj; Daly, Michele B; Kim, Baek; Scully, Ralph; Asara, John M; Cantley, Lewis C; Wulf, Gerburg M

    2016-07-26

    We previously reported that combining a phosphoinositide 3-kinase (PI3K) inhibitor with a poly-ADP Rib polymerase (PARP)-inhibitor enhanced DNA damage and cell death in breast cancers that have genetic aberrations in BRCA1 and TP53. Here, we show that enhanced DNA damage induced by PI3K inhibitors in this mutational background is a consequence of impaired production of nucleotides needed for DNA synthesis and DNA repair. Inhibition of PI3K causes a reduction in all four nucleotide triphosphates, whereas inhibition of the protein kinase AKT is less effective than inhibition of PI3K in suppressing nucleotide synthesis and inducing DNA damage. Carbon flux studies reveal that PI3K inhibition disproportionately affects the nonoxidative pentose phosphate pathway that delivers Rib-5-phosphate required for base ribosylation. In vivo in a mouse model of BRCA1-linked triple-negative breast cancer (K14-Cre BRCA1(f/f)p53(f/f)), the PI3K inhibitor BKM120 led to a precipitous drop in DNA synthesis within 8 h of drug treatment, whereas DNA synthesis in normal tissues was less affected. In this mouse model, combined PI3K and PARP inhibition was superior to either agent alone to induce durable remissions of established tumors.

  20. Occupant evacuation model based on cellular automata in fire

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    By applying the rules set in traffic flow and pedestrian flow models, a basic cellular automata model is presented to simulate occupant evacuation in fire. Some extended models are introduced to study the special phenomena of evacuation from the fire room. The key of the models is the introduction of the danger grade which makes the route choice convenient and reasonable. Fire not only influences the emotional and behavioral characteristics of an individual but also affects his physical constitution, which reduces his maximal possible velocity. The models consider these influence factors by applying a set of simple but effective rules. It is needed to emphasize that all rules are established according to the essential phenomenon in fire evacuation, that is, all the occupants would try to move to the safest place as fast as possible. Some simulation examples are also presented to validate the applicability of the models.

  1. Medical image segmentation based on cellular neural network

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The application of cellular neural network (CNN) has made great progress in image processing. When the selected objects extraction (SOE) CNN is applied to gray scale images, its effects depend on the choice of initial points. In this paper, we take medical images as an example to analyze this limitation. Then an improved algorithm is proposed in which we can segment any gray level objects regardless of the limitation stated above. We also use the gradient information and contour detection CNN to determine the contour and ensure the veracity of segmentation effectively. Finally, we apply the improved algorithm to tumor segmentation of the human brain MR image. The experimental results show that the algorithm is practical and effective.

  2. Network modeling of membrane-based artificial cellular systems

    Science.gov (United States)

    Freeman, Eric C.; Philen, Michael K.; Leo, Donald J.

    2013-04-01

    Computational models are derived for predicting the behavior of artificial cellular networks for engineering applications. The systems simulated involve the use of a biomolecular unit cell, a multiphase material that incorporates a lipid bilayer between two hydrophilic compartments. These unit cells may be considered building blocks that enable the fabrication of complex electrochemical networks. These networks can incorporate a variety of stimuli-responsive biomolecules to enable a diverse range of multifunctional behavior. Through the collective properties of these biomolecules, the system demonstrates abilities that recreate natural cellular phenomena such as mechanotransduction, optoelectronic response, and response to chemical gradients. A crucial step to increase the utility of these biomolecular networks is to develop mathematical models of their stimuli-responsive behavior. While models have been constructed deriving from the classical Hodgkin-Huxley model focusing on describing the system as a combination of traditional electrical components (capacitors and resistors), these electrical elements do not sufficiently describe the phenomena seen in experiment as they are not linked to the molecular scale processes. From this realization an advanced model is proposed that links the traditional unit cell parameters such as conductance and capacitance to the molecular structure of the system. Rather than approaching the membrane as an isolated parallel plate capacitor, the model seeks to link the electrical properties to the underlying chemical characteristics. This model is then applied towards experimental cases in order that a more complete picture of the underlying phenomena responsible for the desired sensing mechanisms may be constructed. In this way the stimuli-responsive characteristics may be understood and optimized.

  3. Multiple implications of 3-phosphoinositide-dependent protein kinase 1 in human cancer

    Institute of Scientific and Technical Information of China (English)

    Keum-Jin; Yang; Jongsun; Park

    2010-01-01

    3-phosphoinositide-dependent protein kinase-1(PDK1) is a central mediator of cellular signaling between phosphoinositide-3 kinase and various intracellular serine/threonine kinases,including protein kinase B,p70 ribosomal S6 kinase,serum and glucocorticoid-inducible kinase,and protein kinase C.PDK1 activates members of the AGC family of protein kinases by phosphorylating serine/threonine residues in the activation loop.Here,we review the regulatory mechanisms of PDK1 and its roles in cancer.PDK1 is activated by autophosphorylation in the activation loop and other serine residues,as well as by phosphorylation of Tyr-9 and Tyr-373/376.Src appears to recognize PDK1 following tyrosine phosphorylation.The role of heat shock protein 90 in regulating PDK1 stability and PDK1-Src complex formation are also discussed.Furthermore,we summarize the subcellular distribution of PDK1.Finally,an important role for PDK1 in cancer chemotherapy is proposed.In conclusion,a better understanding of its molecular regulatory mechanisms in various signaling pathways will help to explain how PDK1 acts as an oncogenic kinase in various cancers,and will contribute to the development of novel cancer chemotherapies.

  4. An Analysis of Base Station Location Accuracy within Mobile-Cellular Networks

    Directory of Open Access Journals (Sweden)

    Liam Smit

    2015-05-01

    Full Text Available An important feature within a mobile-cellular net- work is that the location of a cellphone can be determined. As long as the cellphone is powered on, the location of the cellphone can always be traced to at least the cell from which it is receiving, or last received, signal from the cellular network. Such network-based methods of estimating the location of a cellphone is useful in cases where the cellphone user is unable or unwilling to reveal his or her location, and have practical value in digital forensic investigations. This study investigates the accuracy of using mobile-cellular network base station information for estimating the location of cellphones. Through quantitative analysis of mobile-cellular network base station data, large variations between the best and worst accuracy of recorded location information is exposed. Thus, depending on the requirements, base station locations may or may not be accurate enough for a particular application.

  5. Cellular and molecular bases of memory: synaptic and neuronal plasticity.

    Science.gov (United States)

    Wang, J H; Ko, G Y; Kelly, P T

    1997-07-01

    Discoveries made during the past decade have greatly improved our understanding of how the nervous system functions. This review article examines the relation between memory and the cellular mechanisms of neuronal and synaptic plasticity in the central nervous system. Evidence indicating that activity-dependent short- and long-term changes in strength of synaptic transmission are important for memory processes is examined. Focus is placed on one model of synaptic plasticity called long-term potentiation, and its similarities with memory processes are illustrated. Recent studies show that the regulation of synaptic strength is bidirectional (e.g., synaptic potentiation or depression). Mechanisms involving intracellular signaling pathways that regulate synaptic strength are described, and the specific roles of calcium, protein kinases, protein phosphatases, and retrograde messengers are emphasized. Evidence suggests that changes in synaptic ultrastructure, dendritic ultrastructure, and neuronal gene expression may also contribute to mechanisms of synaptic plasticity. Also discussed are recent findings about postsynaptic mechanisms that regulate short-term synaptic facilitation and neuronal burst-pattern activity, as well as evidence about the subcellular location (presynaptic or postsynaptic) of mechanisms involved in long-term synaptic plasticity.

  6. Membrane-Based Functions in the Origin of Cellular Life

    Science.gov (United States)

    Wilson, Michael A.

    2003-01-01

    How simple membrane peptides performed such essential proto-cellular functions as transport of ions and organic matter across membranes separating the interior of the cell from the environment, capture and utilization of energy, and transduction of environmental signals, is a key question in protobiological evolution. On the basis of detailed, molecular-level computer simulations we investigate how these peptides insert into membranes, self-assemble into higher-order structures and acquire functions. We have studied the insertion of an a-helical peptide containing leucine (L) and serine (S) of the form (LSLLLSL)S into a model membrane. The transmembrane state is metastable, and approximately 15 kcal/mol is required to insert the peptide into the membrane. Investigations of dimers formed by (LSLLLSL)S and glycophorin A demonstrate how the favorable free energy of helix association can offset the unfavorable free energy of insertion, leading to self- assembly of peptide helices in the membrane. An example of a self-assembled structure is the tetrameric transmembrane pore of the influenza virus M2 protein, which is an efficient and selective voltage-gated proton channel. Our simulations explain the gating mechanism and provide guidelines how to reengineering the channel to act as a simple proton pump. In general, emergence of integral membrane proteins appears to be quite feasible and may be easier to envision than the emergence of water-soluble proteins.

  7. The cellular bases of antibody responses during dengue virus infection

    Directory of Open Access Journals (Sweden)

    Juan Carlos Yam-Puc

    2016-06-01

    Full Text Available Dengue virus (DENV is one of the most significant human viral pathogens transmitted by mosquitoes and can cause from an asymptomatic disease to mild undifferentiated fever, classical dengue, and severe dengue. Neutralizing memory antibody (Ab responses are one of the most important mechanisms that counteract reinfections and are therefore the main aim of vaccination. However, it has also been proposed that in dengue, some of these class-switched (IgG memory Abs might worsen the disease. Although these memory Abs derive from B cells by T-cell dependent processes, we know rather little about the (acute, chronic or memory B cell responses and the complex cellular mechanisms generating these Abs during DENV infections.This review aims to provide an updated and comprehensive perspective of the B cell responses during DENV infection, starting since the very early events like the cutaneous DENV entrance and the arrival into draining lymph nodes, to the putative B cell activation, proliferation and germinal centers (GCs formation (the source of affinity-matured class-switched memory Abs, till the outcome of GC reactions such as the generation of plasmablasts, Ab-secreting plasma cells and memory B cells. We discuss topics very poorly explored such as the possibility of B cell infection by DENV or even activation-induced B cell death. The current information about the nature of the Ab responses to DENV is also illustrated.

  8. An Inquiry-Based Approach to Teaching Photosynthesis & Cellular Respiration

    Science.gov (United States)

    O'Connell, Dan

    2008-01-01

    Recent studies of American science education have highlighted the need for more inquiry-based lessons. For example, when the National Research Counsel evaluated the Advanced Placement (AP) Biology program, it pointed out, "AP laboratory exercises tend to be "cookbook" rather than inquiry based. This criticism is particularly apt for the lab…

  9. TOA-BASED ROBUST LOCATION ALGORITHMS FOR WIRELESS CELLULAR NETWORKS

    Institute of Scientific and Technical Information of China (English)

    Sun Guolin; Guo Wei

    2005-01-01

    Caused by Non-Line-Of-Sight (NLOS) propagation effect, the non-symmetric contamination of measured Time Of Arrival (TOA) data leads to high inaccuracies of the conventional TOA based mobile location techniques. Robust position estimation method based on bootstrapping M-estimation and Huber estimator are proposed to mitigate the effects of NLOS propagation on the location error. Simulation results show the improvement over traditional Least-Square (LS)algorithm on location accuracy under different channel environments.

  10. The Essential Role of Phosphoinositide 3-Kinases (PI3Ks) in Regulating Pro-Inflammatory Responses and the Progression of Cancer

    Institute of Scientific and Technical Information of China (English)

    Keqiang Chen; Pablo Iribarren; Wanghua Gong; Ji-Ming Wang

    2005-01-01

    Phosphoinositide 3-Kinases (PI3Ks) are proteins coupled to a variety of cell surface receptors and play a key role in signal transduction cascade regulating fundamental cellular functions such as transcription, proliferation, and survival. PI3Ks also are important in disease processes such as inflammation and cancer. The aim of this review is to outline current understandings of the PI3K family, mechanism of their activation, their role in inflammatory responses and the development of malignant tumors.

  11. The metastasis-promoting phosphatase PRL-3 shows activity toward phosphoinositides.

    Science.gov (United States)

    McParland, Victoria; Varsano, Giulia; Li, Xun; Thornton, Janet; Baby, Jancy; Aravind, Ajay; Meyer, Christoph; Pavic, Karolina; Rios, Pablo; Köhn, Maja

    2011-09-06

    Phosphatase of regenerating liver 3 (PRL-3) is suggested as a biomarker and therapeutic target in several cancers. It has a well-established causative role in cancer metastasis. However, little is known about its natural substrates, pathways, and biological functions, and only a few protein substrates have been suggested so far. To improve our understanding of the substrate specificity and molecular determinants of PRL-3 activity, the wild-type (WT) protein, two supposedly catalytically inactive mutants D72A and C104S, and the reported hyperactive mutant A111S were tested in vitro for substrate specificity and activity toward phosphopeptides and phosphoinositides (PIPs), their structural stability, and their ability to promote cell migration using stable HEK293 cell lines. We discovered that WT PRL-3 does not dephosphorylate the tested phosphopeptides in vitro. However, as shown by two complementary biochemical assays, PRL-3 is active toward the phosphoinositide PI(4,5)P(2). Our experimental results substantiated by molecular docking studies suggest that PRL-3 is a phosphatidylinositol 5-phosphatase. The C104S variant was shown to be not only catalytically inactive but also structurally destabilized and unable to promote cell migration, whereas WT PRL-3 promotes cell migration. The D72A mutant is structurally stable and does not dephosphorylate the unnatural substrate 3-O-methylfluorescein phosphate (OMFP). However, we observed residual in vitro activity of D72A against PI(4,5)P(2), and in accordance with this, it exhibits the same cellular phenotype as WT PRL-3. Our analysis of the A111S variant shows that the hyperactivity toward the unnatural OMFP substrate is not apparent in dephosphorylation assays with phosphoinositides: the mutant is completely inactive against PIPs. We observed significant structural destabilization of this variant. The cellular phenotype of this mutant equals that of the catalytically inactive C104S mutant. These results provide a possible

  12. Cell-based biosensors: Towards the development of cellular monitoring

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Cell-based biosensors (CBBs), a research hotspot of biosensors, which treat living cells as sensing elements, can detect the functional information of biologically active analytes. They characterize with high sensitivity, excellent selectivity and rapid response, and have been applied in many fields, such as biomedicine, environmental monitoring and pharmaceutical screening. Recently cell-cultured technology, silicon microfabrication technology and genetic technology have promoted exploration of CBBs dramatically. To elucidate the novel research findings and applications of cell- based biosensors, this paper summarizes various research approaches, presents some challenges and proposes the research trends.

  13. Model of Handover and Traffic Based on Cellular Geometry with Smart Antenna

    Directory of Open Access Journals (Sweden)

    Zufan Zhang

    2014-01-01

    Full Text Available Based on the application of smart antennas in cellular mobile communications, this paper introduces the impact of the width of the antenna beams playing on the dwell time probability density function in cellular geometry with smart antenna. The research results indicate that the smart cell structure can improve the dwell time of users within the cell and improve the traffic system performance.

  14. Individual Subjective Initiative Merge Model Based on Cellular Automaton

    Directory of Open Access Journals (Sweden)

    Yin-Jie Xu

    2013-01-01

    Full Text Available The merge control models proposed for work zones are classified into two types (Hard Control Merge (HCM model and Soft Control Merge (SCM model according to their own control intensity and are compared with a new model, called Individual Subjective Initiative Merge (ISIM model, which is based on the linear lane-changing probability strategy in the merging area. The attention of this paper is paid to the positive impact of the individual subjective initiative for the whole traffic system. Three models (ISIM, HCM, and SCM are established and compared with each other by two order parameters, that is, system output and average vehicle travel time. Finally, numerical results show that both ISIM and SCM perform better than HCM. Compared with SCM, the output of ISIM is 20 vehicles per hour higher under the symmetric input condition and is more stable under the asymmetric input condition. Meanwhile, the average travel time of ISIM is 2000 time steps less under the oversaturated input condition.

  15. Biomedical Platforms Based on Composite Nanomaterials and Cellular Toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Bellucci, Stefano [INFN-Laboratori Nazionali di Frascati, Via E. Fermi 40, 00044 Frascati (Italy); Bergamaschi, A [Department of Environmental, Occupational and Social Medicine, University of Rome Tor Vergata, Via Montpellier 1, I-00133 Rome (Italy); Bottini, M [INFN-Laboratori Nazionali di Frascati, Via E. Fermi 40, 00044 Frascati (Italy); Magrini, A [Department of Environmental, Occupational and Social Medicine, University of Rome Tor Vergata, Via Montpellier 1, I-00133 Rome (Italy); Mustelin, T [Burnham Institute for Medical Research, 10901 North Torrey Pines Road, La Jolla, CA 92037 (United States)

    2007-03-15

    Carbon nanotubes possess unique chemical, physical, optical, and magnetic properties, which make them suitable for many uses in industrial products and in the field of nanotechnology, including nanomedicine. We describe fluorescent nanocomposites for use in biosensors or nanoelectronics. Then we describe recent results on the issue of cytotoxicity of carbon nanotubes obtained in our labs. Silica nanoparticles have been widely used for biosensing and catalytic applications due to their large surface area-to-volume ratio, straightforward manufacture, and the compatibility of silica chemistry with covalent coupling of biomolecules. Carbon nanotubes-composite materials, such as those based on Carbon nanotubes bound to nanoparticles, are suitable, in order to tailor Carbon nanotubes properties for specific applications. We present a tunable synthesis of Multi Wall Carbon nanotubes-Silica nanoparticles. The control of the nanotube morphology and the bead size, coupled with the versatility of silica chemistry, makes these structures an excellent platform for the development of biosensors (optical, magnetic and catalytic applications). We describe the construction and characterization of supramolecular nanostructures consisting of ruthenium-complex luminophores, directly grafted onto short oxidized single-walled carbon nanotubes or physically entrapped in silica nanobeads, which had been covalently linked to short oxidized single-walled carbon nanotubes or hydrophobically adsorbed onto full-length multi-walled carbon nanotubes. These structures have been evaluated as potential electron-acceptor complexes for use in the fabrication of photovoltaic devices, and for their properties as fluorescent nanocomposites for use in biosensors or nanoelectronics. Finally, we compare the toxicity of pristine and oxidized Multi Walled Carbon nanotubes on human T cells - which would be among the first exposed cell types upon intravenous administration of Carbon nanotubes in therapeutic

  16. Numerical and Experimental Studies of a Light-Weight Auxetic Cellular Vibration Isolation Base

    Directory of Open Access Journals (Sweden)

    Xiang-Wen Zhang

    2016-01-01

    Full Text Available This paper presents a preliminary study of the dynamic performance of a novel light-weight auxetic (negative Poisson’s ratio cellular vibration isolation base constituted by reentrant hexagonal honeycombs. Numerical and experimental analyses were conducted to reveal the effects of Poisson’s ratio (cell angle and relative density (cell thickness of these reentrant honeycombs on the dynamic performance of this novel base and to propose design guidelines for the best use of the auxetic cellular vibration isolation system. By doing numerical analysis, we found that, by decreasing the relative density of reentrant honeycombs and increasing Poisson’s ratio of them, excellent vibration isolation performance of the auxetic cellular base will be achieved. This analysis was followed by static, modal, and frequency response tests, which verified the results of the numerical analysis.

  17. Role of the phosphoinositide signal transduction pathway in the endometrium

    Institute of Scientific and Technical Information of China (English)

    Vincenza Rita Lo Vasco

    2012-01-01

    The regulation of calcium concentration triggers physiological events in all cell types. Unregulated elevation in calcium concentrations is often cytotoxic.In fact, uncontrolled calcium levels alter proteins’ function, apoptosis regulation, as well as proliferation, secretion and contraction.Calcium levels are tightly regulated.A great interest was paid to signal transduction pathways for their role in mammalian reproduction.The role of phosphoinositide(PI) signal transduction pathway and related phosphoinositide-specific phospholipaseC(PI-PLC) enzymes in the regulation of calcium levels was actively studied and characterized.However, the role of PI signaling andPI-PLC enzymes in the endometrium is far to be completely highlighted.In the present review the role ofPI, the expression of selectedPI-PLC enzymes and the crosstalk with further signaling systems in the endometrium will be discussed.

  18. Cell Based GIS as Cellular Automata for Disaster Spreading Predictions and Required Data Systems

    Directory of Open Access Journals (Sweden)

    Kohei Arai

    2013-03-01

    Full Text Available A method for prediction and simulation based on the Cell Based Geographic Information System(GIS as Cellular Automata (CA is proposed together with required data systems, in particular metasearch engine usage in an unified way. It is confirmed that the proposed cell based GIS as CA has flexible usage of the attribute information that is attached to the cell in concert with location information and does work for disaster spreading simulation and prediction.

  19. Stochastic Ordering based Carrier-to-Interference Ratio Analysis for the Shotgun Cellular Systems

    CERN Document Server

    Madhusudhanan, Prasanna; Youjian,; Liu,; Brown, Timothy X; Baker, Kenneth R

    2011-01-01

    A simple analytical tool based on stochastic ordering is developed to compare the distributions of carrier-to-interference ratio at the mobile station of two cellular systems where the base stations are distributed randomly according to certain non-homogeneous Poisson point processes. The comparison is conveniently done by studying only the base station densities without having to solve for the distributions of the carrier-to-interference ratio, that are often hard to obtain.

  20. Parallel Cellular Automata-based simulation of laser dynamics using dynamic load balancing

    NARCIS (Netherlands)

    Guisado, J.L.; Fernández de Vega, F.; Jiménez Morales, F.; Iskra, K.A.; Sloot, P.M.A.; Garnica, Ó.

    2008-01-01

    In order to analyze the feasibility of executing a parallel bioinspired model of laser dynamics on a heterogeneous non-dedicated cluster, we evaluate its performance including artificial load to simulate other tasks or jobs submitted by other users. As the model is based on a synchronous cellular au

  1. Management of Location Based Advertisement Services using Spatial Triggers in Cellular Networks

    CERN Document Server

    Irfan, M; Khan, Furqan H; Hashmi, Raheel M; Shehzad, Khurram; Ali, Assad

    2009-01-01

    This paper discusses the advent of new technologies which have emerged under the area of Location Based Services (LBS). An innovative implementation and approach has been presented for design of applications which are inventive and attractive towards the user. Spatial Trigger is one of the most promising additions to the LBS technologies. This paper describes ways in which mobile advertisement services can be introduced effectively in the cellular market by bringing innovation in them through effective usage of Spatial Triggers. Hence, opening new horizons to make the consumer cellular networks, commercially, more effective and informative.

  2. Management of Location Based Advertisement Services using Spatial Triggers in Cellular Networks

    Directory of Open Access Journals (Sweden)

    Assad Ali

    2009-10-01

    Full Text Available This paper discusses the advent of new technologies which have emerged under the area of Location Based Services (LBS. An innovative implementation and approach has been presented for design of applications which are inventive and attractive towards the user. Spatial Trigger is one of the most promising additions to the LBS technologies. This paper describes ways in which mobile advertisement services can be introduced effectively in the cellular market by bringing innovation in them through effective usage of Spatial Triggers. Hence, opening new horizons to make the consumer cellular networks, commercially, more effective and informative.

  3. CCABC: Cyclic Cellular Automata Based Clustering For Energy Conservation in Sensor Networks

    CERN Document Server

    Banerjee, Indrajit; Rahaman, Hafizur

    2011-01-01

    Sensor network has been recognized as the most significant technology for next century. Despites of its potential application, wireless sensor network encounters resource restriction such as low power, reduced bandwidth and specially limited power sources. This work proposes an efficient technique for the conservation of energy in a wireless sensor network (WSN) by forming an effective cluster of the network nodes distributed over a wide range of geographical area. The clustering scheme is developed around a specified class of cellular automata (CA) referred to as the modified cyclic cellular automata (mCCA). It sets a number of nodes in stand-by mode at an instance of time without compromising the area of network coverage and thereby conserves the battery power. The proposed scheme also determines an effective cluster size where the inter-cluster and intra-cluster communication cost is minimum. The simulation results establish that the cyclic cellular automata based clustering for energy conservation in sens...

  4. Laboratory testing of a building envelope segment based on cellular concrete

    Science.gov (United States)

    Fořt, Jan; Pavlík, Zbyšek; Černý, Robert

    2016-07-01

    Hygrothermal performance of a building envelope based on cellular concrete blocks is studied in the paper. Simultaneously, the strain fields induced by the heat and moisture changes are monitored. The studied wall is exposed to the climatic load corresponding to the winter climatic conditions of the moderate year for Prague. The winter climatic exposure is chosen in order to simulate the critical conditions of the building structure from the point of view of material performance and temperature and humidity loading. The evaluation of hygrothermal performance of a researched wall is done on the basis of relative humidity and temperature profiles measured along the cross section of the cellular concrete blocks. Strain gauges are fixed on the wall surface in expected orientation of the blocks expansion. The obtained results show a good hygrothermal function of the analyzed cellular concrete wall and its insignificant strain.

  5. Sensitivity analysis of FBMC-based multi-cellular networks to synchronization errors and HPA nonlinearities

    Science.gov (United States)

    Elmaroud, Brahim; Faqihi, Ahmed; Aboutajdine, Driss

    2017-01-01

    In this paper, we study the performance of asynchronous and nonlinear FBMC-based multi-cellular networks. The considered system includes a reference mobile perfectly synchronized with its reference base station (BS) and K interfering BSs. Both synchronization errors and high-power amplifier (HPA) distortions will be considered and a theoretical analysis of the interference signal will be conducted. On the basis of this analysis, we will derive an accurate expression of signal-to-noise-plus-interference ratio (SINR) and bit error rate (BER) in the presence of a frequency-selective channel. In order to reduce the computational complexity of the BER expression, we applied an interesting lemma based on the moment generating function of the interference power. Finally, the proposed model is evaluated through computer simulations which show a high sensitivity of the asynchronous FBMC-based multi-cellular network to HPA nonlinear distortions.

  6. Integration of Multiple Components in Polystyrene-based Microfluidic Devices Part 2: Cellular Analysis

    Science.gov (United States)

    Anderson, Kari B.; Halpin, Stephen T.; Johnson, Alicia S.; Martin, R. Scott; Spence, Dana M.

    2012-01-01

    In Part II of this series describing the use of polystyrene (PS) devices for microfluidic-based cellular assays, various cellular types and detection strategies are employed to determine three fundamental assays often associated with cells. Specifically, using either integrated electrochemical sensing or optical measurements with a standard multi-well plate reader, cellular uptake, production, or release of important cellular analytes are determined on a PS-based device. One experiment involved the fluorescence measurement of nitric oxide (NO) produced within an endothelial cell line following stimulation with ATP. The result was a four-fold increase in NO production (as compared to a control), with this receptor-based mechanism of NO production verifying the maintenance of cell receptors following immobilization onto the PS substrate. The ability to monitor cellular uptake was also demonstrated by optical determination of Ca2+ into endothelial cells following stimulation with the Ca2+ ionophore A20317. The result was a significant increase (42%) in the calcium uptake in the presence of the ionophore, as compared to a control (17%) (p < 0.05). Finally, the release of catecholamines from a dopaminergic cell line (PC 12 cells) was electrochemically monitored, with the electrodes being embedded into the PS-based device. The PC 12 cells had better adherence on the PS devices, as compared to use of PDMS. Potassium-stimulation resulted in the release of 114 ± 11 µM catecholamines, a significant increase (p < 0.05) over the release from cells that had been exposed to an inhibitor (reserpine, 20 ± 2 µM of catecholamines). The ability to successfully measure multiple analytes, generated in different means from various cells under investigation, suggests that PS may be a useful material for microfluidic device fabrication, especially considering the enhanced cell adhesion to PS, its enhanced rigidity/amenability to automation, and its ability to enable a wider range of

  7. Modeling and Experimental Study of Soft Error Propagation Based on Cellular Automaton

    OpenAIRE

    2016-01-01

    Aiming to estimate SEE soft error performance of complex electronic systems, a soft error propagation model based on cellular automaton is proposed and an estimation methodology based on circuit partitioning and error propagation is presented. Simulations indicate that different fault grade jamming and different coupling factors between cells are the main parameters influencing the vulnerability of the system. Accelerated radiation experiments have been developed to determine the main paramet...

  8. IQGAP Proteins Reveal an Atypical Phosphoinositide (aPI) Binding Domain with a Pseudo C2 Domain Fold

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, Miles J.; Gray, Alexander; Schenning, Martijn; Agacan, Mark; Tempel, Wolfram; Tong, Yufeng; Nedyalkova, Lyudmila; Park, Hee-Won; Leslie, Nicholas R.; van Aalten, Daan M.F.; Downes, C. Peter; Batty, Ian H. (Toronto); (Dundee)

    2012-10-16

    Class I phosphoinositide (PI) 3-kinases act through effector proteins whose 3-PI selectivity is mediated by a limited repertoire of structurally defined, lipid recognition domains. We describe here the lipid preferences and crystal structure of a new class of PI binding modules exemplified by select IQGAPs (IQ motif containing GTPase-activating proteins) known to coordinate cellular signaling events and cytoskeletal dynamics. This module is defined by a C-terminal 105-107 amino acid region of which IQGAP1 and -2, but not IQGAP3, binds preferentially to phosphatidylinositol 3,4,5-trisphosphate (PtdInsP3). The binding affinity for PtdInsP3, together with other, secondary target-recognition characteristics, are comparable with those of the pleckstrin homology domain of cytohesin-3 (general receptor for phosphoinositides 1), an established PtdInsP3 effector protein. Importantly, the IQGAP1 C-terminal domain and the cytohesin-3 pleckstrin homology domain, each tagged with enhanced green fluorescent protein, were both re-localized from the cytosol to the cell periphery following the activation of PI 3-kinase in Swiss 3T3 fibroblasts, consistent with their common, selective recognition of endogenous 3-PI(s). The crystal structure of the C-terminal IQGAP2 PI binding module reveals unexpected topological similarity to an integral fold of C2 domains, including a putative basic binding pocket. We propose that this module integrates select IQGAP proteins with PI 3-kinase signaling and constitutes a novel, atypical phosphoinositide binding domain that may represent the first of a larger group, each perhaps structurally unique but collectively dissimilar from the known PI recognition modules.

  9. Excellent approach to modeling urban expansion by fuzzy cellular automata: agent base model

    Science.gov (United States)

    Khajavigodellou, Yousef; Alesheikh, Ali A.; Mohammed, Abdulrazak A. S.; Chapi, Kamran

    2014-09-01

    Recently, the interaction between humans and their environment is the one of important challenges in the world. Landuse/ cover change (LUCC) is a complex process that includes actors and factors at different social and spatial levels. The complexity and dynamics of urban systems make the applicable practice of urban modeling very difficult. With the increased computational power and the greater availability of spatial data, micro-simulation such as the agent based and cellular automata simulation methods, has been developed by geographers, planners, and scholars, and it has shown great potential for representing and simulating the complexity of the dynamic processes involved in urban growth and land use change. This paper presents Fuzzy Cellular Automata in Geospatial Information System and remote Sensing to simulated and predicted urban expansion pattern. These FCA-based dynamic spatial urban models provide an improved ability to forecast and assess future urban growth and to create planning scenarios, allowing us to explore the potential impacts of simulations that correspond to urban planning and management policies. A fuzzy inference guided cellular automata approach. Semantic or linguistic knowledge on Land use change is expressed as fuzzy rules, based on which fuzzy inference is applied to determine the urban development potential for each pixel. The model integrates an ABM (agent-based model) and FCA (Fuzzy Cellular Automata) to investigate a complex decision-making process and future urban dynamic processes. Based on this model rapid development and green land protection under the influences of the behaviors and decision modes of regional authority agents, real estate developer agents, resident agents and non- resident agents and their interactions have been applied to predict the future development patterns of the Erbil metropolitan region.

  10. GAME THEORY BASED INTERFERENCE CONTROL AND POWER CONTROL FOR D2D COMMUNICATION IN CELLULAR NETWORKS

    Directory of Open Access Journals (Sweden)

    Fa-Bin Li

    2016-09-01

    Full Text Available With the current development of mobile communication services, people need personal communication of high speed, excellent service, high quality and low latency,however, limited spectrum resources become the most important factor to hamper improvement of cellular systems. As big amount of data traffic will cause greater local consumption of spectrum resources, future networks are required to have appropriate techniques to better support such forms of communication. D2D (Device-to-device communication technology in a cellular network makes full use of spectrum resources underlaying, reduces the load of the base station, minimizes transmit power of the terminals and the base stations, thereby enhances the overall throughput of the networks. Due to the use of multiplexing D2D UE (User equipment resources and spectrum, and the interference caused by the sharing of resources between adjacent cells, it has become a major factor affecting coexisting of cellular subscribers and D2D users. When D2D communication multiplexes the uplink resources, the base-stations are easily to be disturbed; when the downlink resources are multiplexed, the users of downlink are susceptible to interference. In order to build a high-efficient mobile network, we can meet the QoS requirements by controlling the power to suppress the interference between the base station and a terminal user.

  11. Color image encryption based on hybrid hyper-chaotic system and cellular automata

    Science.gov (United States)

    Yaghouti Niyat, Abolfazl; Moattar, Mohammad Hossein; Niazi Torshiz, Masood

    2017-03-01

    This paper proposes an image encryption scheme based on Cellular Automata (CA). CA is a self-organizing structure with a set of cells in which each cell is updated by certain rules that are dependent on a limited number of neighboring cells. The major disadvantages of cellular automata in cryptography include limited number of reversal rules and inability to produce long sequences of states by these rules. In this paper, a non-uniform cellular automata framework is proposed to solve this problem. This proposed scheme consists of confusion and diffusion steps. In confusion step, the positions of the original image pixels are replaced by chaos mapping. Key image is created using non-uniform cellular automata and then the hyper-chaotic mapping is used to select random numbers from the image key for encryption. The main contribution of the paper is the application of hyper chaotic functions and non-uniform CA for robust key image generation. Security analysis and experimental results show that the proposed method has a very large key space and is resistive against noise and attacks. The correlation between adjacent pixels in the encrypted image is reduced and the amount of entropy is equal to 7.9991 which is very close to 8 which is ideal.

  12. An agent-based model of cellular dynamics and circadian variability in human endotoxemia.

    Directory of Open Access Journals (Sweden)

    Tung T Nguyen

    Full Text Available As cellular variability and circadian rhythmicity play critical roles in immune and inflammatory responses, we present in this study an agent-based model of human endotoxemia to examine the interplay between circadian controls, cellular variability and stochastic dynamics of inflammatory cytokines. The model is qualitatively validated by its ability to reproduce circadian dynamics of inflammatory mediators and critical inflammatory responses after endotoxin administration in vivo. Novel computational concepts are proposed to characterize the cellular variability and synchronization of inflammatory cytokines in a population of heterogeneous leukocytes. Our results suggest that there is a decrease in cell-to-cell variability of inflammatory cytokines while their synchronization is increased after endotoxin challenge. Model parameters that are responsible for IκB production stimulated by NFκB activation and for the production of anti-inflammatory cytokines have large impacts on system behaviors. Additionally, examining time-dependent systemic responses revealed that the system is least vulnerable to endotoxin in the early morning and most vulnerable around midnight. Although much remains to be explored, proposed computational concepts and the model we have pioneered will provide important insights for future investigations and extensions, especially for single-cell studies to discover how cellular variability contributes to clinical implications.

  13. Integrated Circuit-Based Biofabrication with Common Biomaterials for Probing Cellular Biomechanics.

    Science.gov (United States)

    Sung, Chun-Yen; Yang, Chung-Yao; Yeh, J Andrew; Cheng, Chao-Min

    2016-02-01

    Recent advances in bioengineering have enabled the development of biomedical tools with modifiable surface features (small-scale architecture) to mimic extracellular matrices and aid in the development of well-controlled platforms that allow for the application of mechanical stimulation for studying cellular biomechanics. An overview of recent developments in common biomaterials that can be manufactured using integrated circuit-based biofabrication is presented. Integrated circuit-based biofabrication possesses advantages including mass and diverse production capacities for fabricating in vitro biomedical devices. This review highlights the use of common biomaterials that have been most frequently used to study cellular biomechanics. In addition, the influence of various small-scale characteristics on common biomaterial surfaces for a range of different cell types is discussed.

  14. Mimo radar waveform design for spectrum sharing with cellular systems a Matlab based approach

    CERN Document Server

    Khawar, Awais; Clancy, T Charles

    2016-01-01

    This book discusses spectrum sharing between cellular systems and radars. The book addresses a novel way to design radar waveforms that can enable spectrum sharing between radars and communication systems, without causing interference to communication systems, and at the same time achieving radar objectives of target detection, estimation, and tracking. The book includes a MATLAB-based approach, which provides reader with a way to learn, experiment, compare, and build on top of existing algorithms.

  15. HIV-1 Reverse Transcriptase based assay to determine cellular dNTP concentrations

    Science.gov (United States)

    Hollenbaugh, Joseph A.; Kim, Baek

    2016-01-01

    Summary Deoxynucleoside triphosphates (dNTPs) are the building blocks of DNA and their biosynthesis are tightly regulated in the cell. HPLC-MS and enzyme-based methods are currently employed to determine dNTP concentrations from cellular extracts. Here, we describe a highly efficient, HIV-1 reverse transcriptase (RT)-based assay to quantitate dNTP concentrations. The assay is based on the ability of HIV-1 RT to function at very low dNTP concentrations, thus providing for the high sensitivity of detection. PMID:26714705

  16. A Geometrical-Based Model for Cochannel Interference Analysis and Capacity Estimation of CDMA Cellular Systems

    Directory of Open Access Journals (Sweden)

    Konstantinos B. Baltzis

    2008-10-01

    Full Text Available A common assumption in cellular communications is the circular-cell approximation. In this paper, an alternative analysis based on the hexagonal shape of the cells is presented. A geometrical-based stochastic model is proposed to describe the angle of arrival of the interfering signals in the reverse link of a cellular system. Explicit closed form expressions are derived, and simulations performed exhibit the characteristics and validate the accuracy of the proposed model. Applications in the capacity estimation of WCDMA cellular networks are presented. Dependence of system capacity of the sectorization of the cells and the base station antenna radiation pattern is explored. Comparisons with data in literature validate the accuracy of the proposed model. The degree of error of the hexagonal and the circular-cell approaches has been investigated indicating the validity of the proposed model. Results have also shown that, in many cases, the two approaches give similar results when the radius of the circle equals to the hexagon inradius. A brief discussion on how the proposed technique may be applied to broadband access networks is finally made.

  17. A Geometrical-Based Model for Cochannel Interference Analysis and Capacity Estimation of CDMA Cellular Systems

    Directory of Open Access Journals (Sweden)

    Baltzis KonstantinosB

    2008-01-01

    Full Text Available Abstract A common assumption in cellular communications is the circular-cell approximation. In this paper, an alternative analysis based on the hexagonal shape of the cells is presented. A geometrical-based stochastic model is proposed to describe the angle of arrival of the interfering signals in the reverse link of a cellular system. Explicit closed form expressions are derived, and simulations performed exhibit the characteristics and validate the accuracy of the proposed model. Applications in the capacity estimation of WCDMA cellular networks are presented. Dependence of system capacity of the sectorization of the cells and the base station antenna radiation pattern is explored. Comparisons with data in literature validate the accuracy of the proposed model. The degree of error of the hexagonal and the circular-cell approaches has been investigated indicating the validity of the proposed model. Results have also shown that, in many cases, the two approaches give similar results when the radius of the circle equals to the hexagon inradius. A brief discussion on how the proposed technique may be applied to broadband access networks is finally made.

  18. Phosphoinositides in the hepatitis C virus life cycle.

    Science.gov (United States)

    Bishé, Bryan; Syed, Gulam; Siddiqui, Aleem

    2012-10-19

    Eukaryotes possess seven different phosphoinositides (PIPs) that help form the unique signatures of various intracellular membranes. PIPs serve as docking sites for the recruitment of specific proteins to mediate membrane alterations and integrate various signaling cascades. The spatio-temporal regulation of PI kinases and phosphatases generates distinct intracellular hubs of PIP signaling. Hepatitis C virus (HCV), like other plus-strand RNA viruses, promotes the rearrangement of intracellular membranes to assemble viral replication complexes. HCV stimulates enrichment of phosphatidylinositol 4-phosphate (PI4P) pools near endoplasmic reticulum (ER) sites by activating PI4KIIIα, the kinase responsible for generation of ER-specific PI4P pools. Inhibition of PI4KIIIα abrogates HCV replication. PI4P, the most abundant phosphoinositide, predominantly localizes to the Golgi and plays central roles in Golgi secretory functions by recruiting effector proteins involved in transport vesicle generation. The PI4P effector proteins also include the lipid-transfer and structural proteins such as ceramide transfer protein (CERT), oxysterol binding protein (OSBP) and Golgi phosphoprotein 3 (GOLPH3) that help maintain Golgi-membrane composition and structure. Depletion of Golgi-specific PI4P pools by silencing PI4KIIIβ, expression of dominant negative CERT and OSBP mutants, or silencing GOLPH3 perturb HCV secretion. In this review we highlight the role of PIPs and specifically PI4P in the HCV life cycle.

  19. Odorant-stimulated phosphoinositide signaling in mammalian olfactory receptor neurons

    Science.gov (United States)

    Klasen, K.; Corey, E.A.; Kuck, F.; Wetzel, C.H.; Hatt, H.; Ache, B.W.

    2009-01-01

    Recent evidence has revived interest in the idea that phosphoinositides (PIs) may play a role in signal transduction in mammalian olfactory receptor neurons (ORNs). To provide direct evidence that odorants indeed activate PI signaling in ORNs, we used adenoviral vectors carrying two different fluorescently tagged probes, the pleckstrin homology (PH) domains of phospholipase Cδ1 (PLCδ1) and the general receptor of phosphoinositides (GRP1), to monitor PI activity in the dendritic knobs of ORNs in vivo. Odorants mobilized PI(4,5)P2/IP3 and PI(3,4,5)P3, the substrates and products of PLC and PI3K. We then measured odorant activation of PLC and PI3K in olfactory ciliary-enriched membranes in vitro using a phospholipid overlay assay and ELISAs. Odorants activated both PLC and PI3K in the olfactory cilia within 2 sec of odorant stimulation. Odorant-dependent activation of PLC and PI3K in the olfactory epithelium could be blocked by enzyme-specific inhibitors. Odorants activated PLC and PI3K with partially overlapping specificity. These results provide direct evidence that odorants indeed activate PI signaling in mammalian ORNs in a manner that is consistent with the idea that PI signaling plays a role in olfactory transduction. PMID:19781634

  20. Cooperative Game-Based Energy Efficiency Management over Ultra-Dense Wireless Cellular Networks.

    Science.gov (United States)

    Li, Ming; Chen, Pengpeng; Gao, Shouwan

    2016-09-13

    Ultra-dense wireless cellular networks have been envisioned as a promising technique for handling the explosive increase of wireless traffic volume. With the extensive deployment of small cells in wireless cellular networks, the network spectral efficiency (SE) is improved with the use of limited frequency. However, the mutual inter-tier and intra-tier interference between or among small cells and macro cells becomes serious. On the other hand, more chances for potential cooperation among different cells are introduced. Energy efficiency (EE) has become one of the most important problems for future wireless networks. This paper proposes a cooperative bargaining game-based method for comprehensive EE management in an ultra-dense wireless cellular network, which highlights the complicated interference influence on energy-saving challenges and the power-coordination process among small cells and macro cells. Especially, a unified EE utility with the consideration of the interference mitigation is proposed to jointly address the SE, the deployment efficiency (DE), and the EE. In particular, closed-form power-coordination solutions for the optimal EE are derived to show the convergence property of the algorithm. Moreover, a simplified algorithm is presented to reduce the complexity of the signaling overhead, which is significant for ultra-dense small cells. Finally, numerical simulations are provided to illustrate the efficiency of the proposed cooperative bargaining game-based and simplified schemes.

  1. Cooperative Game-Based Energy Efficiency Management over Ultra-Dense Wireless Cellular Networks

    Directory of Open Access Journals (Sweden)

    Ming Li

    2016-09-01

    Full Text Available Ultra-dense wireless cellular networks have been envisioned as a promising technique for handling the explosive increase of wireless traffic volume. With the extensive deployment of small cells in wireless cellular networks, the network spectral efficiency (SE is improved with the use of limited frequency. However, the mutual inter-tier and intra-tier interference between or among small cells and macro cells becomes serious. On the other hand, more chances for potential cooperation among different cells are introduced. Energy efficiency (EE has become one of the most important problems for future wireless networks. This paper proposes a cooperative bargaining game-based method for comprehensive EE management in an ultra-dense wireless cellular network, which highlights the complicated interference influence on energy-saving challenges and the power-coordination process among small cells and macro cells. Especially, a unified EE utility with the consideration of the interference mitigation is proposed to jointly address the SE, the deployment efficiency (DE, and the EE. In particular, closed-form power-coordination solutions for the optimal EE are derived to show the convergence property of the algorithm. Moreover, a simplified algorithm is presented to reduce the complexity of the signaling overhead, which is significant for ultra-dense small cells. Finally, numerical simulations are provided to illustrate the efficiency of the proposed cooperative bargaining game-based and simplified schemes.

  2. Cooperative Game-Based Energy Efficiency Management over Ultra-Dense Wireless Cellular Networks

    Science.gov (United States)

    Li, Ming; Chen, Pengpeng; Gao, Shouwan

    2016-01-01

    Ultra-dense wireless cellular networks have been envisioned as a promising technique for handling the explosive increase of wireless traffic volume. With the extensive deployment of small cells in wireless cellular networks, the network spectral efficiency (SE) is improved with the use of limited frequency. However, the mutual inter-tier and intra-tier interference between or among small cells and macro cells becomes serious. On the other hand, more chances for potential cooperation among different cells are introduced. Energy efficiency (EE) has become one of the most important problems for future wireless networks. This paper proposes a cooperative bargaining game-based method for comprehensive EE management in an ultra-dense wireless cellular network, which highlights the complicated interference influence on energy-saving challenges and the power-coordination process among small cells and macro cells. Especially, a unified EE utility with the consideration of the interference mitigation is proposed to jointly address the SE, the deployment efficiency (DE), and the EE. In particular, closed-form power-coordination solutions for the optimal EE are derived to show the convergence property of the algorithm. Moreover, a simplified algorithm is presented to reduce the complexity of the signaling overhead, which is significant for ultra-dense small cells. Finally, numerical simulations are provided to illustrate the efficiency of the proposed cooperative bargaining game-based and simplified schemes. PMID:27649170

  3. Computational energetic model of morphogenesis based on multi-agent Cellular Potts Model.

    Science.gov (United States)

    Tripodi, Sébastien; Ballet, Pascal; Rodin, Vincent

    2010-01-01

    The Cellular Potts Model (CPM) is a cellular automaton (CA), developed by Glazier and Graner in 1992, to model the morphogenesis. In this model, the entities are the cells. It has already been improved in many ways; however, a key point in biological systems, not defined in CPM, is energetic exchange between entities. We integrate this energetic concept inside the CPM. We simulate a cell differentiation inside a growing cell tissue. The results are the emergence of dynamic patterns coming from the consumption and production of energy. A model described by CA is less scalable than one described by a multi-agent system (MAS). We have developed a MAS based on the CPM, where a cell agent is implemented from the cell of CPM together with several behaviours, in particular the consumption and production of energy from the consumption of molecules.

  4. An authenticated image encryption scheme based on chaotic maps and memory cellular automata

    Science.gov (United States)

    Bakhshandeh, Atieh; Eslami, Ziba

    2013-06-01

    This paper introduces a new image encryption scheme based on chaotic maps, cellular automata and permutation-diffusion architecture. In the permutation phase, a piecewise linear chaotic map is utilized to confuse the plain-image and in the diffusion phase, we employ the Logistic map as well as a reversible memory cellular automata to obtain an efficient and secure cryptosystem. The proposed method admits advantages such as highly secure diffusion mechanism, computational efficiency and ease of implementation. A novel property of the proposed scheme is its authentication ability which can detect whether the image is tampered during the transmission or not. This is particularly important in applications where image data or part of it contains highly sensitive information. Results of various analyses manifest high security of this new method and its capability for practical image encryption.

  5. Asynchronous cellular automaton-based neuron: theoretical analysis and on-FPGA learning.

    Science.gov (United States)

    Matsubara, Takashi; Torikai, Hiroyuki

    2013-05-01

    A generalized asynchronous cellular automaton-based neuron model is a special kind of cellular automaton that is designed to mimic the nonlinear dynamics of neurons. The model can be implemented as an asynchronous sequential logic circuit and its control parameter is the pattern of wires among the circuit elements that is adjustable after implementation in a field-programmable gate array (FPGA) device. In this paper, a novel theoretical analysis method for the model is presented. Using this method, stabilities of neuron-like orbits and occurrence mechanisms of neuron-like bifurcations of the model are clarified theoretically. Also, a novel learning algorithm for the model is presented. An equivalent experiment shows that an FPGA-implemented learning algorithm enables an FPGA-implemented model to automatically reproduce typical nonlinear responses and occurrence mechanisms observed in biological and model neurons.

  6. Direct translocation as major cellular uptake for CADY self-assembling peptide-based nanoparticles.

    Directory of Open Access Journals (Sweden)

    Anna Rydström

    Full Text Available Cell penetrating peptides constitute a potent approach to overcome the limitations of in vivo siRNA delivery. We recently proposed a peptide-based nanoparticle system, CADY, for efficient delivery of siRNA into numerous cell lines. CADY is a secondary amphipathic peptide that forms stable complexes with siRNA thereby improving both their cellular uptake and biological response. With the aim of understanding the cellular uptake mechanism of CADY:siRNA complexes, we have combined biochemical, confocal and electron microscopy approaches. In the present work, we provide evidence that the major route for CADY:siRNA cellular uptake involves direct translocation through the membrane but not the endosomal pathway. We have demonstrated that CADY:siRNA complexes do not colocalize with most endosomal markers and remain fully active in the presence of inhibitors of the endosomal pathway. Moreover, neither electrostatic interactions with cell surface heparan sulphates nor membrane potential are essential for CADY:siRNA cell entry. In contrast, we have shown that CADY:siRNA complexes clearly induce a transient cell membrane permeabilization, which is rapidly restored by cell membrane fluidity. Therefore, we propose that direct translocation is the major gate for cell entry of CADY:siRNA complexes. Membrane perturbation and uptake are driven mainly by the ability of CADY to interact with phospholipids within the cell membrane, followed by rapid localization of the complex in the cytoplasm, without affecting cell integrity or viability.

  7. Differential regulatory functions of three classes of phosphatidylinositol and phosphoinositide 3-kinases in autophagy.

    Science.gov (United States)

    Yu, Xinlei; Long, Yun Chau; Shen, Han-Ming

    2015-01-01

    Autophagy is an evolutionarily conserved and exquisitely regulated self-eating cellular process with important biological functions. Phosphatidylinositol 3-kinases (PtdIns3Ks) and phosphoinositide 3-kinases (PI3Ks) are involved in the autophagic process. Here we aim to recapitulate how 3 classes of these lipid kinases differentially regulate autophagy. Generally, activation of the class I PI3K suppresses autophagy, via the well-established PI3K-AKT-MTOR (mechanistic target of rapamycin) complex 1 (MTORC1) pathway. In contrast, the class III PtdIns3K catalytic subunit PIK3C3/Vps34 forms a protein complex with BECN1 and PIK3R4 and produces phosphatidylinositol 3-phosphate (PtdIns3P), which is required for the initiation and progression of autophagy. The class II enzyme emerged only recently as an alternative source of PtdIns3P and autophagic initiator. However, the orthodox paradigm is challenged by findings that the PIK3CB catalytic subunit of class I PI3K acts as a positive regulator of autophagy, and PIK3C3 was thought to be an amino acid sensor for MTOR, which curbs autophagy. At present, a number of PtdIns3K and PI3K inhibitors, including specific PIK3C3 inhibitors, have been developed for suppression of autophagy and for clinical applications in autophagy-related human diseases.

  8. Paper-based microreactor integrating cell culture and subsequent immunoassay for the investigation of cellular phosphorylation.

    Science.gov (United States)

    Lei, Kin Fong; Huang, Chia-Hao

    2014-12-24

    Investigation of cellular phosphorylation and signaling pathway has recently gained much attention for the study of pathogenesis of cancer. Related conventional bioanalytical operations for this study including cell culture and Western blotting are time-consuming and labor-intensive. In this work, a paper-based microreactor has been developed to integrate cell culture and subsequent immunoassay on a single paper. The paper-based microreactor was a filter paper with an array of circular zones for running multiple cell cultures and subsequent immunoassays. Cancer cells were directly seeded in the circular zones without hydrogel encapsulation and cultured for 1 day. Subsequently, protein expressions including structural, functional, and phosphorylated proteins of the cells could be detected by their specific antibodies, respectively. Study of the activation level of phosphorylated Stat3 of liver cancer cells stimulated by IL-6 cytokine was demonstrated by the paper-based microreactor. This technique can highly reduce tedious bioanalytical operation and sample and reagent consumption. Also, the time required by the entire process can be shortened. This work provides a simple and rapid screening tool for the investigation of cellular phosphorylation and signaling pathway for understanding the pathogenesis of cancer. In addition, the operation of the paper-based microreactor is compatible to the molecular biological training, and therefore, it has the potential to be developed for routine protocol for various research areas in conventional bioanalytical laboratories.

  9. Analysis of hormone-induced changes of phosphoinositide metabolism in rat liver

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, M.A.; Fain, J.N.

    1985-01-01

    The relationship between hormone-stimulated phosphoinositide turnover and Ca/sup 2 +/ flux can be investigated using radiolabelled hepatocytes and the subcellular fractions derived from them or from whole liver. Comparison of the results obtained using intact cells to those from subcellular fractions should ultimately lead to a reconstruction of the transmembrane signaling events through which hormone such as vasopressin, angiotensin, and catecholamines acutely activate liver glycogenolysis. The paper reviews hormone-stimulated phosphoinositide metabolism in intact hepatocytes as well as hepatic enzymes involved in phosphoinositide metabolism. Also discussed is the current status of studies on hormone action in broken cell preparations in liver.

  10. New color image encryption algorithm based on compound chaos mapping and hyperchaotic cellular neural network

    Science.gov (United States)

    Li, Jinqing; Bai, Fengming; Di, Xiaoqiang

    2013-01-01

    We propose an image encryption/decryption algorithm based on chaotic control parameter and hyperchaotic system with the composite permutation-diffusion structure. Compound chaos mapping is used to generate control parameters in the permutation stage. The high correlation between pixels is shuffled. In the diffusion stage, compound chaos mapping of different initial condition and control parameter generates the diffusion parameters, which are applied to hyperchaotic cellular neural networks. The diffusion key stream is obtained by this process and implements the pixels' diffusion. Compared with the existing methods, both simulation and statistical analysis of our proposed algorithm show that the algorithm has a good performance against attacks and meets the corresponding security level.

  11. Hologram authentication based on a secure watermarking algorithm using cellular automata.

    Science.gov (United States)

    Hwang, Wen-Jyi; Chan, Hao-Tang; Cheng, Chau-Jern

    2014-09-20

    A secure watermarking algorithm for hologram authentication is presented in this paper. The algorithm exploits the noise-like feature of holograms to randomly embed a watermark in the domain of the discrete cosine transform with marginal degradation in transparency. The pseudo random number (PRN) generators based on a cellular automata algorithm with asymmetrical and nonlocal connections are used for the random hiding. Each client has its own unique PRN generators for enhancing the watermark security. In the proposed algorithm, watermarks are also randomly generated to eliminate the requirements of prestoring watermarks in the clients and servers. An authentication scheme is then proposed for the algorithm with random watermark generation and hiding.

  12. The FPGA realization of the general cellular automata based cryptographic hash functions: Performance and effectiveness

    Directory of Open Access Journals (Sweden)

    P. G. Klyucharev

    2014-01-01

    Full Text Available In the paper the author considers hardware implementation of the GRACE-H family general cellular automata based cryptographic hash functions. VHDL is used as a language and Altera FPGA as a platform for hardware implementation. Performance and effectiveness of the FPGA implementations of GRACE-H hash functions were compared with Keccak (SHA-3, SHA-256, BLAKE, Groestl, JH, Skein hash functions. According to the performed tests, performance of the hardware implementation of GRACE-H family hash functions significantly (up to 12 times exceeded performance of the hardware implementation of previously known hash functions, and effectiveness of that hardware implementation was also better (up to 4 times.

  13. In vivo and in vitro cellular response to PEG-based hydrogels for wound repair

    Science.gov (United States)

    Waldeck, Heather

    Biomaterials are continuously being explored as a means to support, improve, or influence wound healing processes. Understanding the determining factors controlling the host response to biomaterials is crucial in developing strategies to employ materials for biomedical uses. In order to evaluate the host response to poly(ethylene glycol) (PEG)-based hydrogels, both in vivo and in vitro studies were performed to determine its efficacy as a dermal wound treatment and to investigate the mechanisms controlling cell-material interaction, respectively. The results of an in vivo study using a full thickness wound in a rat model demonstrated that both soluble and immobilized bioactive factors could be incorporated into a PEG-based semi-interpenetrating network (sIPN) to enhance the rate and the quality of dermal wound healing. To gain a better understanding of the results observed in vivo, in vitro studies were then conducted to examine the dynamics and mechanisms of the cell-material interaction. Degradation of the sIPN was explored as an influential factor in both mediating cellular response and controlling solute transport from the material. As degradation through gelatin dissolution could be influenced by simple alterations to the material formulation, these results provide facile guidelines to control the delivery of high molecular weight compounds. Further investigation of the cellular response to PEG-based biomaterials focused on key factors influencing cell-material interaction. Specifically, the role of the beta1 integrin subunit and several serum proteins (TGF-aalpha, IL-1beta and PDGF-BB) in mediating cellular response was explored. As cell-material interactions are based on commonly occurring interfaces between cells and molecules of the native extracellular environment, these studies provided insight into the mechanisms controlling the observed cellular response. Finally, the inflammatory response of primary monocytes to biomaterials was examined. Monocytes

  14. Electric Energy Demand Forecast of Nanchang based on Cellular Genetic Algorithm and BP Neural Network

    Directory of Open Access Journals (Sweden)

    Cheng Yugui

    2013-07-01

    Full Text Available A kind of power forecast model combined cellular genetic algorithm with BP neural network was established in this article. Mid-long term power demand in urban areas was done load forecasting and analysis based on material object of the actual power consumption in urban areas of Nanchang. The results show that this method has the characteristic of the minimum training times, the shortest consumption time, the minimum error and the shortest operation time to obtain the best fitting effect.  

  15. Admission Control Scheme for Multi-class Services in QoS-based Mobile Cellular Networks

    Institute of Scientific and Technical Information of China (English)

    YINZhiming; XIEJianying

    2004-01-01

    Call admission control (CAC) is one of the key schemes to guarantee Quality of service (QoS) in mobile cellular networks. In this paper, we propose an optimal CAC scheme based on Semi-Markov decision processes (SMDP) theory to support multi-class services for QoS wireless networks. Linear programming formulation is used to find the optimal solution, which maximizes the channel utilization while meeting the requirements of QoS constraints. The numerical results show that the performance of our scheme outperforms DCAC scheme.

  16. One-way hash function based on hyper-chaotic cellular neural network

    Institute of Scientific and Technical Information of China (English)

    Yang Qun-Ting; Gao Tie-Gang

    2008-01-01

    The design of an efficient one-way hash function with good performance is a hot spot in modern cryptography researches. In this paper, a hash function construction method based on cell neural network with hyper-chaos characteristics is proposed. First, the chaos sequence is gotten by iterating cellular neural network with Runge-Kutta algorithm, and then the chaos sequence is iterated with the message. The hash code is obtained through the corresponding transform of the latter chaos sequence. Simulation and analysis demonstrate that the new method has the merit of convenience, high sensitivity to initial values, good hash performance, especially the strong stability.

  17. A novel chaotic based image encryption using a hybrid model of deoxyribonucleic acid and cellular automata

    Science.gov (United States)

    Enayatifar, Rasul; Sadaei, Hossein Javedani; Abdullah, Abdul Hanan; Lee, Malrey; Isnin, Ismail Fauzi

    2015-08-01

    Currently, there are many studies have conducted on developing security of the digital image in order to protect such data while they are sending on the internet. This work aims to propose a new approach based on a hybrid model of the Tinkerbell chaotic map, deoxyribonucleic acid (DNA) and cellular automata (CA). DNA rules, DNA sequence XOR operator and CA rules are used simultaneously to encrypt the plain-image pixels. To determine rule number in DNA sequence and also CA, a 2-dimension Tinkerbell chaotic map is employed. Experimental results and computer simulations, both confirm that the proposed scheme not only demonstrates outstanding encryption, but also resists various typical attacks.

  18. A synthesis procedure for associative memories based on space-varying cellular neural networks.

    Science.gov (United States)

    Park, J; Kim, H Y; Park, Y; Lee, S W

    2001-01-01

    In this paper, we consider the problem of realizing associative memories via space-varying CNNs (cellular neural networks). Based on some known results and a newly derived theorem for the CNN model, we propose a synthesis procedure for obtaining a space-varying CNN that can store given bipolar vectors with certain desirable properties. The major part of our synthesis procedure consists of solving generalized eigenvalue problems and/or linear matrix inequality problems, which can be efficiently solved by recently developed interior point methods. The validity of the proposed approach is illustrated by a design example.

  19. Identification of key residues in the A-Raf kinase important for phosphoinositide lipid binding specificity.

    Science.gov (United States)

    Johnson, Lindsey M; James, Kristy M; Chamberlain, M Dean; Anderson, Deborah H

    2005-03-01

    Raf kinases are involved in regulating cellular signal transduction pathways in response to a wide variety of external stimuli. Upstream signals generate activated Ras-GTP, important for the relocalization of Raf kinases to the membrane. Upon full activation, Raf kinases phosphorylate and activate downstream kinase in the mitogen-activated protein kinase (MAPK) signaling pathway. The Raf family of kinases has three members, Raf-1, B-Raf, and A-Raf. The ability of Raf-1 and B-Raf to bind phosphatidylserine (PS) and phosphatidic acid (PA) has been show to facilitate Raf membrane associations and regulate Raf kinase activity. We have characterized the lipid binding properties of A-Raf, as well as further characterized those of Raf-1. Both A-Raf and Raf-1 were found to bind to 3-, 4-, and 5-monophosphorylated phosphoinositides [PI(3)P, PI(4)P, and PI(5)P] as well as phosphatidylinositol 3,5-bisphosphate [PI(3,5)P(2)]. In addition, A-Raf also bound specifically to phosphatidylinositol 4,5- and 3,4-bisphosphates [PI(4,5)P(2) and PI(3,4)P(2)] and to PA. A mutational analysis of A-Raf localized the PI(4,5)P(2) binding site to two basic residues (K50 and R52) within the Ras binding domain. Additionally, an A-Raf mutant lacking the first 199 residues [i.e., the entire conserved region 1 (CR1) domain] bound the same phospholipids as full-length Raf-1. This suggests that a second region of A-Raf between amino acids 200 and 606 was responsible for interactions with the monophosphorylated PIs and PI(3,5)P(2). These results raise the possibility that Raf-1 and A-Raf bind to specific phosphoinositides as a mechanism to localize them to particular membrane microdomains rich in these phospholipids. Moreover, the differences in their lipid binding profiles could contribute to their proposed isoform-specific Raf functions.

  20. Phosphoinositide pathway and the signal transduction network in neural development

    Institute of Scientific and Technical Information of China (English)

    Vincenza Rita Lo Vasco

    2012-01-01

    The development of the nervous system is under the strict control of a number of signal transduction pathways,often interconnected.Among them,the phosphoinositide (PI) pathway and the related phospholipase C (PI-PLC) family of enzymes have been attracting much attention.Besides their well-known role in the regulation of intracellular calcium levels,PI-PLC enzymes interact with a number of molecules belonging to further signal transduction pathways,contributing to a specific and complex network in the developing nervous system.In this review,the connections of PI signalling with further transduction pathways acting during neural development are discussed,with special regard to the role of the PI-PLC family of enzymes.

  1. A Vector-based Cellular Automata Model for Simulating Urban Land Use Change

    Institute of Scientific and Technical Information of China (English)

    LU Yi; CAO Min; ZHANG Lei

    2015-01-01

    Cellular Automata (CA) is widely used for the simulation of land use changes.This study applied a vector-based CA model to simulate land use change in order to minimize or eliminate the scale sensitivity in traditional raster-based CA model.The cells of vector-based CA model are presented according to the shapes and attributes of geographic entities,and the transition rules of vector-based CA model are improved by taking spatial variables of the study area into consideration.The vector-based CA model is applied to simulate land use changes in downtown of Qidong City,Jiangsu Province,China and its validation is confirmed by the methods of visual assessment and spatial accuracy.The simulation result of vector-based CA model reveals that nearly 75% of newly increased urban cells are located in the northwest and southwest parts of the study area from 2002 to 2007,which is in consistent with real land use map.In addition,the simulation results of the vector-based and raster-based CA models are compared to real land use data and their spatial accuracies are found to be 84.0% and 81.9%,respectively.In conclusion,results from this study indicate that the vector-based CA model is a practical and applicable method for the simulation of urbanization processes.

  2. MICROMECHANICS OF THE DAMAGE-INDUCED CELLULAR MICROSTRUCTURE IN SINGLE CRYSTAL Ni-BASED SUPERALLOYS

    Institute of Scientific and Technical Information of China (English)

    M.Sakaguchi; M.Okazaki

    2004-01-01

    An analytical method to investigate the morphological evolution of the cellular microstructure is explored and proposed. The method is essentially based on the Eshelby's micromechanics theory, and it is extended so as to be applied for a material system containing inclusions with high volume fraction, by employing the average stress field approximation by Mori and Tanaka. The proposed method enables us to discuss a stable shape of precipitate in the material system, which must be influenced by many factors: e.g., volume fraction of precipitate; Young's modulus ratio and lattice misfit between matrix and precipitate; external stress field in multiaxial state; and heterogeneity of plastic strain between matrix and precipitate. A series of numerical calculations were summarized on stable shape maps. The application of the method to predict the γ' rafting in superalloys during creep showed that the heterogeneity of plastic strain between matrix and precipitates may play a significant role in the shape stability of the precipitate. Furthermore, it was shown that the method was successfully applied to estimate the morphology of the cellular microstructure formed in CMSX-4single crystal Ni-based superalloy.

  3. Vehicle Speed Estimation and Forecasting Methods Based on Cellular Floating Vehicle Data

    Directory of Open Access Journals (Sweden)

    Wei-Kuang Lai

    2016-02-01

    Full Text Available Traffic information estimation and forecasting methods based on cellular floating vehicle data (CFVD are proposed to analyze the signals (e.g., handovers (HOs, call arrivals (CAs, normal location updates (NLUs and periodic location updates (PLUs from cellular networks. For traffic information estimation, analytic models are proposed to estimate the traffic flow in accordance with the amounts of HOs and NLUs and to estimate the traffic density in accordance with the amounts of CAs and PLUs. Then, the vehicle speeds can be estimated in accordance with the estimated traffic flows and estimated traffic densities. For vehicle speed forecasting, a back-propagation neural network algorithm is considered to predict the future vehicle speed in accordance with the current traffic information (i.e., the estimated vehicle speeds from CFVD. In the experimental environment, this study adopted the practical traffic information (i.e., traffic flow and vehicle speed from Taiwan Area National Freeway Bureau as the input characteristics of the traffic simulation program and referred to the mobile station (MS communication behaviors from Chunghwa Telecom to simulate the traffic information and communication records. The experimental results illustrated that the average accuracy of the vehicle speed forecasting method is 95.72%. Therefore, the proposed methods based on CFVD are suitable for an intelligent transportation system.

  4. [{sup 18}F] labeled diacylglycerol analogue as a potential agent to trace myocardial phosphoinositide metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Chida, Masanobu; Kagaya, Yutaka; Nagata, Shinji; Mukoyoshi, Masanori; Namiuchi, Shigeto; Yamane, Yuriko; Ishide, Nobumasa; Watanabe, Jun; Takahashi, Toshihiro; Ido, Tatsuo; Shirato, Kunio E-mail: shirato@int1.med.tohoku.ac.jp

    2001-10-01

    Phosphoinositide metabolism plays an important role in cardiac pathophysiology. To investigate whether [{sup 18}F]diacylglycerol could be used to trace myocardial phosphoinositide metabolism, lipids were extracted from rat myocardium after the injection. 1-[8-[{sup 18}F]fluorooctanoyl]-2-palmitoylglycerol and 1-[8-[{sup 18}F]fluoropalmitoyl]-2-palmitoylglycerol were predominantly metabolized to phosphatidylethanolamine and triacylglycerol, respectively. The radioactivity incorporated into phosphoinositide metabolism was 51, 44, 32, and 30% 3, 5, 10, and 30 minutes after the injection of 1-[4-[{sup 18}F]fluorobutyryl]-2-palmitoylglycerol, respectively. 1-[4-[{sup 18}F]fluorobutyryl]-2-palmitoylglycerol might be a potential tracer to evaluate myocardial phosphoinositide metabolism early after the injection.

  5. Ion channel regulation by phosphoinositides analyzed with VSPs-PI(4,5)P2 affinity, phosphoinositide selectivity, and PI(4,5)P2 pool accessibility.

    Science.gov (United States)

    Rjasanow, Alexandra; Leitner, Michael G; Thallmair, Veronika; Halaszovich, Christian R; Oliver, Dominik

    2015-01-01

    The activity of many proteins depends on the phosphoinositide (PI) content of the membrane. E.g., dynamic changes of the concentration of PI(4,5)P2 are cellular signals that regulate ion channels. The susceptibility of a channel to such dynamics depends on its affinity for PI(4,5)P2. Yet, measuring affinities for endogenous PIs has not been possible directly, but has relied largely on the response to soluble analogs, which may not quantitatively reflect binding to native lipids. Voltage-sensitive phosphatases (VSPs) turn over PI(4,5)P2 to PI(4)P when activated by depolarization. In combination with voltage-clamp electrophysiology VSPs are useful tools for rapid and reversible depletion of PI(4,5)P2. Because cellular PI(4,5)P2 is resynthesized rapidly, steady state PI(4,5)P2 changes with the degree of VSP activation and thus depends on membrane potential. Here we show that titration of endogenous PI(4,5)P2 with Ci-VSP allows for the quantification of relative PI(4,5)P2 affinities of ion channels. The sensitivity of inward rectifier and voltage-gated K(+) channels to Ci-VSP allowed for comparison of PI(4,5)P2 affinities within and across channel subfamilies and detected changes of affinity in mutant channels. The results also reveal that VSPs are useful only for PI effectors with high binding specificity among PI isoforms, because PI(4,5)P2 depletion occurs at constant overall PI level. Thus, Kir6.2, a channel activated by PI(4,5)P2 and PI(4)P was insensitive to VSP. Surprisingly, despite comparable PI(4,5)P2 affinity as determined by Ci-VSP, the Kv7 and Kir channel families strongly differed in their sensitivity to receptor-mediated depletion of PI(4,5)P2. While Kv7 members were highly sensitive to activation of PLC by Gq-coupled receptors, Kir channels were insensitive even when PI(4,5)P2 affinity was lowered by mutation. We hypothesize that different channels may be associated with distinct pools of PI(4,5)P2 that differ in their accessibility to PLC and VSPs.

  6. Ion channel regulation by phosphoinositides analyzed with VSPs – PI(4,5P2 affinity, phosphoinositide selectivity, and PI(4,5P2 pool accessibility

    Directory of Open Access Journals (Sweden)

    Alexandra eRjasanow

    2015-06-01

    Full Text Available The activity of many proteins depends on the phosphoinositide (PI content of the membrane. E.g., dynamic changes of the concentration of PI(4,5P2 are cellular signals that regulate ion channels. The susceptibility of a channel to such dynamics depends on its affinity for PI(4,5P2. Yet, measuring affinities for endogenous PIs has not been possible directly, but has relied largely on the response to soluble analogs, which may not quantitatively reflect binding to native lipids.Voltage-sensitive phosphatases (VSPs turn over PI(4,5P2 to PI(4P when activated by depolarization. In combination with voltage-clamp electrophysiology VSPs are useful tools for rapid and reversible depletion of PI(4,5P2. Because cellular PI(4,5P2 is resynthesized rapidly, steady state PI(4,5P2 changes with the degree of VSP activation and thus depends on membrane potential.Here we show that titration of endogenous PI(4,5P2 with Ci-VSP allows for the quantification of relative PI(4,5P2 affinities of ion channels. The sensitivity of inward rectifier and voltage-gated K+ channels to Ci-VSP allowed for comparison of PI(4,5P2 affinities within and across channel subfamilies and detected changes of affinity in mutant channels. The results also reveal that VSPs are useful only for PI effectors with high binding specificity among PI isoforms, because PI(4,5P2 depletion occurs at constant overall PI level. Thus, Kir6.2, a channel activated by PI(4,5P2 and PI(4P was insensitive to VSP.Surprisingly, despite comparable PI(4,5P2 affinity as determined by Ci-VSP, the Kv7 and Kir channel families strongly differed in their sensitivity to receptor-mediated depletion of PI(4,5P2. While Kv7 members were highly sensitive to activation of PLC by Gq-coupled receptors, Kir channels were insensitive even when PI(4,5P2 affinity was lowered by mutation. We hypothesize that different channels may be associated with distinct pools of PI(4,5P2 that differ in their accessibility to PLC and VSPs.

  7. Combined Base Station Association and Power Control in Multi-channel Cellular Networks

    CERN Document Server

    Singh, Chandramani; Sundaresan, Rajesh

    2011-01-01

    A combined base station association and power control problem is studied for the uplink of multichannel multicell cellular networks, in which each channel is used by exactly one cell (i.e., base station). A distributed association and power update algorithm is proposed and shown to converge to a Nash equilibrium of a noncooperative game. We consider network models with discrete mobiles (yielding an atomic congestion game), as well as a continuum of mobiles (yielding a population game). We find that the equilibria need not be Pareto efficient, nor need they be system optimal. To address the lack of system optimality, we propose pricing mechanisms. It is shown that these mechanisms can be implemented in a distributed fashion.

  8. Modeling and Simulation for Urban Rail Traffic Problem Based on Cellular Automata

    Institute of Scientific and Technical Information of China (English)

    许琰; 曹成铉; 李明华; 罗金龙

    2012-01-01

    Based on the Nagel-Schreckenberg model, we propose a new cellular automata model to simulate the urban rail traffic flow under moving block system and present a new minimum instantaneous distance formula under pure moving block. We also analyze the characteristics of the urban rail traffic flow under the influence of train density, station dwell times, the length of train, and the train velocity. Train delays can be decreased effectively through flexible departure intervals according to the preceding train type before its departure. The results demonstrate that a suitable adjustment of the current train velocity based on the following train velocity can greatly shorten the minimum departure intervals and then increase the capacity of rail transit.

  9. A parallel block-based encryption schema for digital images using reversible cellular automata

    Directory of Open Access Journals (Sweden)

    Faraoun Kamel Mohamed

    2014-06-01

    Full Text Available We propose a novel images encryption schema based on reversible one-dimensional cellular automata. Contrasting to the sequential operating mode of several existing approaches, the proposed one is fully parallelizable since the encryption/decryption tasks can be executed using multiple processes running independently for the same single image. The parallelization is made possible by defining a new RCA-based construction of an extended pseudorandom permutation that takes a nonce as a supplementary parameter. The defined PRP exploit the chaotic behavior and the high initial condition's sensitivity of the RCAs to ensure perfect cryptographic security properties. Results of various experiments and analysis show that high security and execution performances can be achieved using the approach, and furthermore, it provides the ability to perform a selective area decryption since any part of the ciphered-image can be deciphered independently from others, which is very useful for real time applications.

  10. Global Detection of Live Virtual Machine Migration Based on Cellular Neural Networks

    Directory of Open Access Journals (Sweden)

    Kang Xie

    2014-01-01

    Full Text Available In order to meet the demands of operation monitoring of large scale, autoscaling, and heterogeneous virtual resources in the existing cloud computing, a new method of live virtual machine (VM migration detection algorithm based on the cellular neural networks (CNNs, is presented. Through analyzing the detection process, the parameter relationship of CNN is mapped as an optimization problem, in which improved particle swarm optimization algorithm based on bubble sort is used to solve the problem. Experimental results demonstrate that the proposed method can display the VM migration processing intuitively. Compared with the best fit heuristic algorithm, this approach reduces the processing time, and emerging evidence has indicated that this new approach is affordable to parallelism and analog very large scale integration (VLSI implementation allowing the VM migration detection to be performed better.

  11. Global detection of live virtual machine migration based on cellular neural networks.

    Science.gov (United States)

    Xie, Kang; Yang, Yixian; Zhang, Ling; Jing, Maohua; Xin, Yang; Li, Zhongxian

    2014-01-01

    In order to meet the demands of operation monitoring of large scale, autoscaling, and heterogeneous virtual resources in the existing cloud computing, a new method of live virtual machine (VM) migration detection algorithm based on the cellular neural networks (CNNs), is presented. Through analyzing the detection process, the parameter relationship of CNN is mapped as an optimization problem, in which improved particle swarm optimization algorithm based on bubble sort is used to solve the problem. Experimental results demonstrate that the proposed method can display the VM migration processing intuitively. Compared with the best fit heuristic algorithm, this approach reduces the processing time, and emerging evidence has indicated that this new approach is affordable to parallelism and analog very large scale integration (VLSI) implementation allowing the VM migration detection to be performed better.

  12. Crucial role of phosphatidylinositol 4-kinase IIIα in development of zebrafish pectoral fin is linked to phosphoinositide 3-kinase and FGF signaling

    OpenAIRE

    MA, HUI; Blake, Trevor; Chitnis, Ajay; Liu, Paul; Balla, Tamas

    2009-01-01

    Phosphatidylinositol 4-kinases (PI4Ks) catalyze the first committed step in the synthesis of phosphoinositides, important lipid regulators of signaling and trafficking pathways. Here we cloned Pik4a, one of the zebrafish PI4K enzymes, and studied its role(s) in vertebrate development using morpholino oligonucleotide-based gene silencing in zebrafish. Downregulation of Pik4a led to multiple developmental abnormalities, affecting the brain, heart, trunk and most prominen...

  13. Design and Analysis of Adders using Nanotechnology Based Quantum dot Cellular Automata

    Directory of Open Access Journals (Sweden)

    S. K. Lakshmi

    2011-01-01

    Full Text Available Problem statement: The area and complexity are the major issues in circuit design. Here, we propose different types of adder designs based on Quantum dot Cellular Automata (QCA that reduces number of QCA cells and area compare to previous designs. The quantum dot cellular automata is a novel computing paradigm in nanotechnology that can implement digital circuits with faster speed, smaller size and low power consumption. By taking the advantages of QCA we are able to design interesting computational architectures. The QCA cell is a basic building block of nanotechnology that can be used to make gates, wires and memories. The basic logic circuits used in this technology are the inverter and the Majority Gate (MG, using this other logical circuits can be designed. Approach: In this paper, the adders such as half, full and serial bit were designed and analyzed. These structures were designed with minimum number of cells by using cell minimization techniques. The techniques are (1 using two cells inverter and (2 suitable arrangement of cells without overlapping of neighboring cells. The proposed method can be used to minimize area and complexity. Results: These circuits were designed by majority gate and implemented by QCA cells. Then, they simulated using QCA Designer. The simulated results were verified according to the truth table. Conclusion: The performance analyses of those circuits are compared according to complexity, area and number of clock cycles and are also compared with previous designs.

  14. Optimization Framework and Graph-Based Approach for Relay-Assisted Bidirectional OFDMA Cellular Networks

    CERN Document Server

    Liu, Yuan; Li, Bin; Shen, Hui

    2010-01-01

    This paper considers a relay-assisted bidirectional cellular network where the base station (BS) communicates with each mobile station (MS) using OFDMA for both uplink and downlink. The goal is to improve the overall system performance by exploring the full potential of the network in various dimensions including user, subcarrier, relay, and bidirectional traffic. In this work, we first introduce a novel three-time-slot time-division duplexing (TDD) transmission protocol. This protocol unifies direct transmission, one-way relaying and network-coded two-way relaying between the BS and each MS. Using the proposed three-time-slot TDD protocol, we then propose an optimization framework for resource allocation to achieve the following gains: cooperative diversity (via relay selection), network coding gain (via bidirectional transmission mode selection), and multiuser diversity (via subcarrier assignment). We formulate the problem as a combinatorial optimization problem, which is NP-complete. To make it more tracta...

  15. Cellular Automation Model of Traffic Flow Based on the Car-Following Model

    Institute of Scientific and Technical Information of China (English)

    LI Ke-Ping; GAO Zi-You

    2004-01-01

    @@ We propose a new cellular automation (CA) traffic model that is based on the car-following model. A class of driving strategies is used in the car-following model instead of the acceleration in the NaSch traffic model. In our model, some realistic driver behaviour and detailed vehicle characteristics have been taken into account, such as distance-headway and safe distance, etc. The simulation results show that our model can exhibit some traffic flow states that have been observed in the real traffic, and both of the maximum flux and the critical density are very close to the real measurement. Moreover, it is easy to extend our method to multi-lane traffic.

  16. Pattern-oriented Agent-based Monte Carlo simulation of Cellular Redox Environment

    DEFF Research Database (Denmark)

    Tang, Jiaowei; Holcombe, Mike; Boonen, Harrie C.M.

    Research suggests that cellular redox environment could affect the phenotype and function of cells through a complex reaction network[1]. In cells, redox status is mainly regulated by several redox couples, such as Glutathione/glutathione disulfide (GSH/GSSG), Cysteine/ Cystine (CYS......, that there is a connection between extracellular and intracellular redox [2], whereas others oppose this view [3]. In general however, these experiments lack insight into the dynamics, complex network of reactions and transportation through cell membrane of redox. Therefore, current experimental results reveal......] could be very important factors. In our project, an agent-based Monte Carlo modeling [6] is offered to study the dynamic relationship between extracellular and intracellular redox and complex networks of redox reactions. In the model, pivotal redox-related reactions will be included, and the reactants...

  17. Modeling of Solidification Microstructures Based on Fully Coupling of Macro-transport Phenomena with Cellular Automata

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper has attempted to simulate the microstructure formation based on fully coupling of temperature field, concentration field and velocity field with micro-kinetics. The authors presented a new way, wlich is the combination of FDM and cellular automata (CAFD) to visualize the microstructure formation of the thin complex superalloy turbine blades cast by the vacuum investment process. The distribution, orientation and mechanism of the heterogeneous nucleation, the growth kinetics of dendrites and the columnar to equiaxed transition (CET) are considered. Capitalizing on these simulating schemes, the comprehensive influence of key process variables on the scale and uniformity of grains has been investigated quantitatively. The simulated grain size and morphology agree well with the experimental results.

  18. A carbon nanotubes based ATP apta-sensing platform and its application in cellular assay.

    Science.gov (United States)

    Zhang, Libing; Wei, Hui; Li, Jing; Li, Tao; Li, Dan; Li, Yunhui; Wang, Erkang

    2010-04-15

    In this paper, a sensitive and selective fluorescent aptasensor for adenosine triphosphate (ATP) detection is constructed, based on the noncovalent assembly of dye-labeled ATP aptamer and single-walled carbon nanotubes (SWNTs). In the absence of ATP, the dye tethered to the ATP aptamer is close to SWNTs, which can effectively quench fluorescence of the dye. Upon adding ATP, the fluorophore keeps away from the quencher, since ATP specifically binds to the aptamer and competes with carbon nanotubes, resulting in an increase in the fluorescence intensity. This enables ATP to be detected down to 4.5nM. To the best of our knowledge, this is the most sensitive fluorescent ATP aptasensor. In addition, prominent fluorescence signals were obtained in cellular ATP assays, thus the aptasensor could be used to detect ATP in real samples.

  19. Throughput of Cellular Systems with Conferencing Mobiles and Cooperative Base Stations

    Directory of Open Access Journals (Sweden)

    Somekh O

    2008-01-01

    Full Text Available This paper considers an enhancement to multicell processing for the uplink of a cellular system, whereby the mobile stations are allowed to exchange messages on orthogonal channels of fixed capacity (conferencing. Both conferencing among mobile stations in different cells and in the same cell (inter- and intracell conferencing, resp. are studied. For both cases, it is shown that a rate-splitting transmission strategy, where part of the message is exchanged on the conferencing channels and then transmitted cooperatively to the base stations, is capacity achieving for sufficiently large conferencing capacity. In case of intercell conferencing, this strategy performs convolutional pre-equalization of the signal encoding the common messages in the spatial domain, where the number of taps of the finite-impulse response equalizer depends on the number of conferencing rounds. Analysis in the low signal-to-noise ratio regime and numerical results validate the advantages of conferencing as a complementary technology to multicell processing.

  20. Throughput of Cellular Systems with Conferencing Mobiles and Cooperative Base Stations

    Directory of Open Access Journals (Sweden)

    S. Shamai (Shitz

    2008-05-01

    Full Text Available This paper considers an enhancement to multicell processing for the uplink of a cellular system, whereby the mobile stations are allowed to exchange messages on orthogonal channels of fixed capacity (conferencing. Both conferencing among mobile stations in different cells and in the same cell (inter- and intracell conferencing, resp. are studied. For both cases, it is shown that a rate-splitting transmission strategy, where part of the message is exchanged on the conferencing channels and then transmitted cooperatively to the base stations, is capacity achieving for sufficiently large conferencing capacity. In case of intercell conferencing, this strategy performs convolutional pre-equalization of the signal encoding the common messages in the spatial domain, where the number of taps of the finite-impulse response equalizer depends on the number of conferencing rounds. Analysis in the low signal-to-noise ratio regime and numerical results validate the advantages of conferencing as a complementary technology to multicell processing.

  1. A federation of simulations based on cellular automata in cyber-physical systems

    Directory of Open Access Journals (Sweden)

    Hoang Van Tran

    2016-02-01

    Full Text Available In cyber-physical system (CPS, cooperation between a variety of computational and physical elements usually poses difficulties to current modelling and simulation tools. Although much research has proposed to address those challenges, most solutions do not completely cover uncertain interactions in CPS. In this paper, we present a new approach to federate simulations for CPS. A federation is a combination of, and coordination between simulations upon a standard of communication. In addition, a mixed simulation is defined as several parallel simulations federated in a common time progress. Such simulations run on the models of physical systems, which are built based on cellular automata theory. The experimental results are performed on a federation of three simulations of forest fire spread, river pollution diffusion and wireless sensor network. The obtained results can be utilized to observe and predict the behaviours of physical systems in their interactions.

  2. A novel root-index based prioritized random access scheme for 5G cellular networks

    Directory of Open Access Journals (Sweden)

    Taehoon Kim

    2015-12-01

    Full Text Available Cellular networks will play an important role in realizing the newly emerging Internet-of-Everything (IoE. One of the challenging issues is to support the quality of service (QoS during the access phase, while accommodating a massive number of machine nodes. In this paper, we show a new paradigm of multiple access priorities in random access (RA procedure and propose a novel root-index based prioritized random access (RIPRA scheme that implicitly embeds the access priority in the root index of the RA preambles. The performance evaluation shows that the proposed RIPRA scheme can successfully support differentiated performance for different access priority levels, even though there exist a massive number of machine nodes.

  3. Cellular automata-based artificial life system of horizontal gene transfer

    Directory of Open Access Journals (Sweden)

    Ji-xin Liu

    2016-02-01

    Full Text Available Mutation and natural selection is the core of Darwin's idea about evolution. Many algorithms and models are based on this idea. However, in the evolution of prokaryotes, more and more researches have indicated that horizontal gene transfer (HGT would be much more important and universal than the authors had imagined. Owing to this mechanism, the prokaryotes not only become adaptable in nearly any environment on Earth, but also form a global genetic bank and a super communication network with all the genes of the prokaryotic world. Under this background, they present a novel cellular automata model general gene transfer to simulate and study the vertical gene transfer and HGT in the prokaryotes. At the same time, they use Schrodinger's life theory to formulate some evaluation indices and to discuss the intelligence and cognition of prokaryotes which is derived from HGT.

  4. Three dimensional multi-cellular muscle-like tissue engineering in perfusion-based bioreactors.

    Science.gov (United States)

    Cerino, Giulia; Gaudiello, Emanuele; Grussenmeyer, Thomas; Melly, Ludovic; Massai, Diana; Banfi, Andrea; Martin, Ivan; Eckstein, Friedrich; Grapow, Martin; Marsano, Anna

    2016-01-01

    Conventional tissue engineering strategies often rely on the use of a single progenitor cell source to engineer in vitro biological models; however, multi-cellular environments can better resemble the complexity of native tissues. Previous described co-culture models used skeletal myoblasts, as parenchymal cell source, and mesenchymal or endothelial cells, as stromal component. Here, we propose instead the use of adipose tissue-derived stromal vascular fraction cells, which include both mesenchymal and endothelial cells, to better resemble the native stroma. Percentage of serum supplementation is one of the crucial parameters to steer skeletal myoblasts toward either proliferation (20%) or differentiation (5%) in two-dimensional culture conditions. On the contrary, three-dimensional (3D) skeletal myoblast culture often simply adopts the serum content used in monolayer, without taking into account the new cell environment. When considering 3D cultures of mm-thick engineered tissues, homogeneous and sufficient oxygen supply is paramount to avoid formation of necrotic cores. Perfusion-based bioreactor culture can significantly improve the oxygen access to the cells, enhancing the viability and the contractility of the engineered tissues. In this study, we first investigated the influence of different serum supplementations on the skeletal myoblast ability to proliferate and differentiate during 3D perfusion-based culture. We tested percentages of serum promoting monolayer skeletal myoblast-proliferation (20%) and differentiation (5%) and suitable for stromal cell culture (10%) with a view to identify the most suitable condition for the subsequent co-culture. The 10% serum medium composition resulted in the highest number of mature myotubes and construct functionality. Co-culture with stromal vascular fraction cells at 10% serum also supported the skeletal myoblast differentiation and maturation, hence providing a functional engineered 3D muscle model that resembles

  5. Studying the Effects of Matrix Stiffness on Cellular Function using Acrylamide-based Hydrogels

    Science.gov (United States)

    Cretu, Alexandra; Castagnino, Paola; Assoian, Richard

    2010-01-01

    Tissue stiffness is an important determinant of cellular function, and changes in tissue stiffness are commonly associated with fibrosis, cancer and cardiovascular disease1-11. Traditional cell biological approaches to studying cellular function involve culturing cells on a rigid substratum (plastic dishes or glass coverslips) which cannot account for the effect of an elastic ECM or the variations in ECM stiffness between tissues. To model in vivo tissue compliance conditions in vitro, we and others use ECM-coated hydrogels. In our laboratory, the hydrogels are based on polyacrylamide which can mimic the range of tissue compliances seen biologically12. "Reactive" cover slips are generated by incubation with NaOH followed by addition of 3-APTMS. Glutaraldehyde is used to cross-link the 3-APTMS and the polyacrylamide gel. A solution of acrylamide (AC), bis-acrylamide (Bis-AC) and ammonium persulfate is used for the polymerization of the hydrogel. N-hydroxysuccinimide (NHS) is incorporated into the AC solution to crosslink ECM protein to the hydrogel. Following polymerization of the hydrogel, the gel surface is coated with an ECM protein of choice such as fibronectin, vitronectin, collagen, etc. The stiffness of a hydrogel can be determined by rheology or atomic force microscopy (AFM) and adjusted by varying the percentage of AC and/or bis-AC in the solution12. In this manner, substratum stiffness can be matched to the stiffness of biological tissues which can also be quantified using rheology or AFM. Cells can then be seeded on these hydrogels and cultured based upon the experimental conditions required. Imaging of the cells and their recovery for molecular analysis is straightforward. For this article, we define soft substrata as those having elastic moduli (E) 20,000 Pascal. PMID:20736914

  6. Phosphoinositide metabolism links cGMP-dependent protein kinase G to essential Ca²⁺ signals at key decision points in the life cycle of malaria parasites.

    Directory of Open Access Journals (Sweden)

    Mathieu Brochet

    2014-03-01

    Full Text Available Many critical events in the Plasmodium life cycle rely on the controlled release of Ca²⁺ from intracellular stores to activate stage-specific Ca²⁺-dependent protein kinases. Using the motility of Plasmodium berghei ookinetes as a signalling paradigm, we show that the cyclic guanosine monophosphate (cGMP-dependent protein kinase, PKG, maintains the elevated level of cytosolic Ca²⁺ required for gliding motility. We find that the same PKG-dependent pathway operates upstream of the Ca²⁺ signals that mediate activation of P. berghei gametocytes in the mosquito and egress of Plasmodium falciparum merozoites from infected human erythrocytes. Perturbations of PKG signalling in gliding ookinetes have a marked impact on the phosphoproteome, with a significant enrichment of in vivo regulated sites in multiple pathways including vesicular trafficking and phosphoinositide metabolism. A global analysis of cellular phospholipids demonstrates that in gliding ookinetes PKG controls phosphoinositide biosynthesis, possibly through the subcellular localisation or activity of lipid kinases. Similarly, phosphoinositide metabolism links PKG to egress of P. falciparum merozoites, where inhibition of PKG blocks hydrolysis of phosphatidylinostitol (4,5-bisphosphate. In the face of an increasing complexity of signalling through multiple Ca²⁺ effectors, PKG emerges as a unifying factor to control multiple cellular Ca²⁺ signals essential for malaria parasite development and transmission.

  7. Evolutionary Computational Method of Facial Expression Analysis for Content-based Video Retrieval using 2-Dimensional Cellular Automata

    CERN Document Server

    Geetha, P

    2010-01-01

    In this paper, Deterministic Cellular Automata (DCA) based video shot classification and retrieval is proposed. The deterministic 2D Cellular automata model captures the human facial expressions, both spontaneous and posed. The determinism stems from the fact that the facial muscle actions are standardized by the encodings of Facial Action Coding System (FACS) and Action Units (AUs). Based on these encodings, we generate the set of evolutionary update rules of the DCA for each facial expression. We consider a Person-Independent Facial Expression Space (PIFES) to analyze the facial expressions based on Partitioned 2D-Cellular Automata which capture the dynamics of facial expressions and classify the shots based on it. Target video shot is retrieved by comparing the similar expression is obtained for the query frame's face with respect to the key faces expressions in the database video. Consecutive key face expressions in the database that are highly similar to the query frame's face, then the key faces are use...

  8. Simple Cellular Automata-Based Linear Models for the Shrinking Generator

    CERN Document Server

    Fúster-Sabater, Amparo

    2010-01-01

    Structural properties of two well-known families of keystream generators, Shrinking Generators and Cellular Automata, have been analyzed. Emphasis is on the equivalence of the binary sequences obtained from both kinds of generators. In fact, Shrinking Generators (SG) can be identified with a subset of linear Cellular Automata (mainly rule 90, rule 150 or a hybrid combination of both rules). The linearity of these cellular models can be advantageously used in the cryptanalysis of those keystream generators.

  9. Kappa opioid receptors stimulate phosphoinositide turnover in rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Periyasamy, S.; Hoss, W. (Univ. of Toledo, OH (USA))

    1990-01-01

    The effects of various subtype-selective opioid agonists and antagonists on the phosphoinositide (PI) turnover response were investigated in the rat brain. The {kappa}-agonists U-50,488H and ketocyclazocine produced a concentration-dependent increase in the accumulation of IP's in hippocampal slices. The other {kappa}-agonists Dynorphin-A (1-13) amide, and its protected analog D(Ala){sup 2}-dynorphin-A (1-13) amide also produced a significant increase in the formation of ({sup 3}H)-IP's, whereas the {mu}-selective agonists (D-Ala{sup 2}-N-Me-Phe{sup 4}-Gly{sup 5}-ol)-enkephalin and morphine and the {delta}-selective agonist (D-Pen{sup 2,5})-enkephalin were ineffective. The increase in IP's formation elicited by U-50,488H was partially antagonized by naloxone and more completely antagonized by the {kappa}-selective antagonists nor-binaltorphimine and MR 2266. The formation of IP's induced by U-50,488H varies with the regions of the brain used, being highest in hippocampus and amygdala, and lowest in striatum and pons-medullar. The results indicate that brain {kappa}- but neither {mu}- nor {delta}- receptors are coupled to the PI turnover response.

  10. At the poles across kingdoms: phosphoinositides and polar tip growth.

    Science.gov (United States)

    Ischebeck, Till; Seiler, Stephan; Heilmann, Ingo

    2010-04-01

    Phosphoinositides (PIs) are minor, but essential phospholipid constituents of eukaryotic membranes, and are involved in the regulation of various physiological processes. Recent genetic and cell biological advances indicate that PIs play important roles in the control of polar tip growth in plant cells. In root hairs and pollen tubes, PIs control directional membrane trafficking required for the delivery of cell wall material and membrane area to the growing tip. So far, the exact mechanisms by which PIs control polarity and tip growth are unresolved. However, data gained from the analysis of plant, fungal and animal systems implicate PIs in the control of cytoskeletal dynamics, ion channel activity as well as vesicle trafficking. The present review aims at giving an overview of PI roles in eukaryotic cells with a special focus on functions pertaining to the control of cell polarity. Comparative screening of plant and fungal genomes suggests diversification of the PI system with increasing organismic complexity. The evolutionary conservation of the PI system among eukaryotic cells suggests a role for PIs in tip growing cells in models where PIs so far have not been a focus of attention, such as fungal hyphae.

  11. Development of cross-protective influenza A vaccines based on cellular responses

    Directory of Open Access Journals (Sweden)

    Peter Christiaan Soema

    2015-05-01

    Full Text Available Seasonal influenza vaccines provide protection against matching influenza A virus (IAV strains mainly through the induction of neutralizing serum IgG antibodies. However, these antibodies fail to confer a protective effect against mismatched IAV. This lack of efficacy against heterologous influenza strains has spurred the vaccine development community to look for other influenza vaccine concepts, which have the ability to elicit cross-protective immune responses.One of the concepts that is currently been worked on are influenza vaccines inducing influenza-specific T cell responses. T cells are able to lyse infected host cells, thereby clearing the virus. More interestingly, these T cells can recognize highly conserved epitopes of internal influenza proteins, making cellular responses less vulnerable to antigenic variability. T cells are therefore cross-reactive against many influenza strains, and thus are a promising concept for future influenza vaccines. Despite their potential, there are currently no T cell based IAV vaccines on the market. Selection of the proper antigen, appropriate vaccine formulation and evaluation of the efficacy of T cell vaccines remains challenging, both in preclinical and clinical settings.In this review, we will discuss the current developments in influenza T cell vaccines, focusing on existing protein-based and novel peptide-based vaccine formulations. Furthermore, we will discuss the feasibility of influenza T cell vaccines and their possible use in the future.

  12. Researches on the behaviour of cellular antiballistic composites based on AlMg-SiC alloys

    Science.gov (United States)

    Bălţătescu, O.; Florea, R. M.; Rusu, I.; Carcea, I.

    2015-11-01

    The researches presented in this paper refers basically to the impact of a small/medium caliber bullet shot on a light armor built on the base of a AlMg-SiC metallic composite cellular/foam. Thus, we study the antiballistic behavior and protection properties of the armor, based on the effects that occur at the impact zone of the bullet with the composite surface. We performed an antiballistic behavior modeling by means of a finite element analysis, based on a "multi grid" Fast Finite Element (FFE) system. We used for this purpose the DYNA 2D software package. The obtained samples show after the impact the occurrence of concentration / deformation pores effect and intercellular cracks development to the interior of the composite. Those effects, depending on speed, mass and length of the projectile ballistic trajectory, reduce zonal tensions due to the effect of cell walls deformation. It was obtained a good correlation between modeling results and the electron microscope analyse of the impact area. It is worth mentioning that almost all values for impact energy absorbed by the composite armor are in the protection active zone provided by it.

  13. A Multitarget Land Use Change Simulation Model Based on Cellular Automata and Its Application

    Directory of Open Access Journals (Sweden)

    Jun Yang

    2014-01-01

    Full Text Available Based on the analysis of the existing land use change simulation model, combined with macroland use change driving factors and microlocal land use competition, and through the application of Python language integrated technical approaches such as CA, GIS, AHP, and Markov, a multitarget land use change simulation model based on cellular automata(CA is established. This model was applied to conduct scenario simulation of land use/cover change of the Jinzhou New District, based on 1:10000 map scale land use, planning, topography, statistics, and other data collected in the year of 1988, 2003, and 2012. The simulation results indicate the following: (1 this model can simulate the mutual transformation of multiple land use types in a relatively satisfactory way; it takes land use system as a whole and simultaneously takes the land use demand in the macrolevel and the land use suitability in the local scale into account; and (2 the simulation accuracy of the model reaches 72%, presenting higher creditability. The model is capable of providing auxiliary decision-making support for coastal regions with the analysis of the land use change driving mechanism, prediction of land use change tendencies, and establishment of land resource sustainable utilization policies.

  14. Extrasynaptic glutamate receptor activation as cellular bases for dynamic range compression in pyramidal neurons

    Directory of Open Access Journals (Sweden)

    Katerina D Oikonomou

    2012-08-01

    Full Text Available Repetitive synaptic stimulation overcomes the ability of astrocytic processes to clear glutamate from the extracellular space, allowing some dendritic segments to become submerged in a pool of glutamate. This dynamic arrangement activates extrasynaptic NMDA receptors located on dendritic shafts. We used voltage-sensitive and calcium-sensitive dyes to probe dendritic function in this glutamate-rich location. An excess of glutamate in the extrasynaptic space was achieved either by repetitive synaptic stimulation or by glutamate iontophoresis onto the dendrites of pyramidal neurons. Two successive activations of synaptic inputs produced a typical NMDA spike, whereas five successive synaptic inputs produced characteristic plateau potentials, reminiscent of cortical UP states. While NMDA spikes were coupled with brief calcium transients highly restricted to the glutamate input site, the dendritic plateau potentials were accompanied by calcium influx along the entire dendritic branch. Once initiated, the glutamate-mediated dendritic plateau potentials could not be interrupted by negative voltage pulses. Activation of extrasynaptic NMDA receptors in cellular compartments void of spines is sufficient to initiate and support plateau potentials. The only requirement for sustained depolarizing events is a surplus of free glutamate near a group of extrasynaptic receptors. Highly nonlinear dendritic spikes (plateau potentials are summed in a highly sublinear fashion at the soma, revealing the cellular bases of signal compression in cortical circuits. Extrasynaptic NMDA receptors provide pyramidal neurons with a function analogous to a dynamic range compression in audio engineering. They limit or reduce the volume of loud sounds (i.e. strong glut. inputs and amplify quiet sounds (i.e. glutamatergic inputs that barely cross the dendritic threshold for local spike initiation. Our data also explain why consecutive cortical UP states have uniform amplitudes in a

  15. Fuzzy Case-Based Reasoning in Product Style Acquisition Incorporating Valence-Arousal-Based Emotional Cellular Model

    Directory of Open Access Journals (Sweden)

    Fuqian Shi

    2012-01-01

    Full Text Available Emotional cellular (EC, proposed in our previous works, is a kind of semantic cell that contains kernel and shell and the kernel is formalized by a triple- L = , where P denotes a typical set of positive examples relative to word-L, d is a pseudodistance measure on emotional two-dimensional space: valence-arousal, and δ is a probability density function on positive real number field. The basic idea of EC model is to assume that the neighborhood radius of each semantic concept is uncertain, and this uncertainty will be measured by one-dimensional density function δ. In this paper, product form features were evaluated by using ECs and to establish the product style database, fuzzy case based reasoning (FCBR model under a defined similarity measurement based on fuzzy nearest neighbors (FNN incorporating EC was applied to extract product styles. A mathematical formalized inference system for product style was also proposed, and it also includes uncertainty measurement tool emotional cellular. A case study of style acquisition of mobile phones illustrated the effectiveness of the proposed methodology.

  16. The phosphoinositide-dependent protein kinase 1 inhibitor, UCN-01, induces fragmentation: possible role of metalloproteinases.

    Science.gov (United States)

    Alcántara-Hernández, Rocío; Hernández-Méndez, Aurelio; García-Sáinz, J Adolfo

    2014-10-05

    Phosphoinositide-dependent protein kinase 1 (PDK1) is a key enzyme, master regulator of cellular proliferation and metabolism; it is considered a key target for pharmacological intervention. Using membranes obtained from DDT1 MF-2 cells, phospho-PDK1 was identified by Western blotting, as two major protein bands of Mr 58-68 kDa. Cell incubation with the PDK1 inhibitor, UCN-01, induced a time- and concentration-dependent decrease in the amount of phospho-PDK1 with a concomitant appearance of a ≈42 kDa phosphorylated fragment. Knocking down PDK1 diminished the amount of phospho-PDK1 detected in membranes, accompanied by similarly decreased fragment generation. UCN-01-induced fragment generation was also observed in membranes from cells stably expressing a myc-tagged PDK1 construct. Other PDK1 inhibitors were also tested: OSU-03012 induced a clear decrease in phospho-PDK1 and increased the presence of the phosphorylated fragment in membrane preparations; in contrast, GSK2334470 and staurosporine induced only marginal increases in the amount of PDK1 fragment. Galardin and batimastat, two metalloproteinase inhibitors, markedly attenuated inhibitor-induced PDK1 fragment generation. Metalloproteinases 2, 3, and 9 co-immunoprecipitated with myc-PDK1 under baseline conditions and this interaction was stimulated by UCN-01; batimastat also markedly diminished this effect of the PDK1 inhibitor. Our results indicate that a series of protein kinase inhibitors, namely UCN-01 and OSU-03012 and to a lesser extent GSK2334470 and staurosporine induce PDK1 fragmentation and suggest that metalloproteinases could participate in this effect.

  17. The role of phosphoinositide-3 kinase and PTEN in cardiovascular physiology and disease.

    Science.gov (United States)

    Oudit, Gavin Y; Sun, Hui; Kerfant, Benoit-Gilles; Crackower, Michael A; Penninger, Josef M; Backx, Peter H

    2004-08-01

    Phosphoinositide-3 kinases (PI3Ks) are a family of evolutionary conserved lipid kinases that mediate many cellular responses in both physiologic and pathophysiologic states. Class I PI3K can be activated by either receptor tyrosine kinase (RTK)/cytokine receptor activation (class I(A)) or G-protein-coupled receptors (GPCR) (class I(B)). Once activated PI3Ks generate phosphatidylinositols (PtdIns) (3,4,5)P(3) leading to the recruitment and activation of Akt/protein kinase B (PKB), PDK1 and monomeric G-proteins (e.g. Rac-GTPases), which then activate a range of downstream targets including glycogen synthase kinase-3beta (GSK-3beta), mammalian target of rapamycin (mTOR), p70S6 kinase, endothelial nitric oxide synthase (eNOS) and several anti-apoptotic effectors. Class I(A) (PI3Kalpha, beta and delta) and class I(B) (PI3Kgamma) PI3Ks mediate distinct phenotypes in the heart and under negative control by the 3'-lipid phosphatase, phosphatase and tensin homolog on chromosome ten (PTEN) which dephosphorylate PtdIns(3,4,5)P(3) into PtdIns(4,5)P(2). PI3Kalpha, gamma and PTEN are expressed in cardiomyocytes, fibroblasts, endothelial cells and vascular smooth muscle cells where they modulate cell survival/apoptosis, hypertrophy, contractility, metabolism and mechanotransduction. Several transgenic and knockout models support a fundamental role of PI3K/PTEN signaling in the regulation of myocardial contractility and hypertrophy. Consequently the PI3K/PTEN signaling pathways are involved in a wide variety of diseases including cardiac hypertrophy, heart failure, preconditioning and hypertension. In this review, we discuss the biochemistry and molecular biology of PI3K (class I isoforms) and PTEN and their critical role in cardiovascular physiology and diseases.

  18. Implementation of a cellular neural network-based segmentation algorithm on the bio-inspired vision system

    Science.gov (United States)

    Karabiber, Fethullah; Grassi, Giuseppe; Vecchio, Pietro; Arik, Sabri; Yalcin, M. Erhan

    2011-01-01

    Based on the cellular neural network (CNN) paradigm, the bio-inspired (bi-i) cellular vision system is a computing platform consisting of state-of-the-art sensing, cellular sensing-processing and digital signal processing. This paper presents the implementation of a novel CNN-based segmentation algorithm onto the bi-i system. The experimental results, carried out for different benchmark video sequences, highlight the feasibility of the approach, which provides a frame rate of about 26 frame/sec. Comparisons with existing CNN-based methods show that, even though these methods are from two to six times faster than the proposed one, the conceived approach is more accurate and, consequently, represents a satisfying trade-off between real-time requirements and accuracy.

  19. Performance Analysis of 3D Massive MIMO Cellular Systems with Collaborative Base Station

    Directory of Open Access Journals (Sweden)

    Xingwang Li

    2014-01-01

    Full Text Available Massive MIMO have drawn considerable attention as they enable significant capacity and coverage improvement in wireless cellular network. However, pilot contamination is a great challenge in massive MIMO systems. Under this circumstance, cooperation and three-dimensional (3D MIMO are emerging technologies to eliminate the pilot contamination and to enhance the performance relative to the traditional interference-limited implementations. Motivated by this, we investigate the achievable sum rate performance of MIMO systems in the uplink employing cooperative base station (BS and 3D MIMO systems. In our model, we consider the effects of both large-scale and small-scale fading, as well as the spatial correlation and indoor-to-outdoor high-rise propagation environment. In particular, we investigate the cooperative communication model based on 3D MIMO and propose a closed-form lower bound on the sum rate. Utilizing this bound, we pursue a “large-system” analysis and provide the asymptotic expression when the number of antennas at the BS grows large, and when the numbers of antennas at transceiver grow large with a fixed ratio. We demonstrate that the lower bound is very tight and becomes exact in the massive MIMO system limits. Finally, under the sum rate maximization condition, we derive the optimal number of UTs to be served.

  20. Indoor localization based on cellular telephony RSSI fingerprints containing very large numbers of carriers

    Directory of Open Access Journals (Sweden)

    Oussar Yacine

    2011-01-01

    Full Text Available Abstract A new approach to indoor localization is presented, based upon the use of Received Signal Strength (RSS fingerprints containing data from very large numbers of cellular base stations--up to the entire GSM band of over 500 channels. Machine learning techniques are employed to extract good quality location information from these high-dimensionality input vectors. Experimental results in a domestic and an office setting are presented, in which data were accumulated over a 1-month period in order to assure time robustness. Room-level classification efficiencies approaching 100% were obtained, using Support Vector Machines in one-versus-one and one-versus-all configurations. Promising results using semi-supervised learning techniques, in which only a fraction of the training data is required to have a room label, are also presented. While indoor RSS localization using WiFi, as well as some rather mediocre results with low-carrier count GSM fingerprints, have been discussed elsewhere, this is to our knowledge the first study to demonstrate that good quality indoor localization information can be obtained, in diverse settings, by applying a machine learning strategy to RSS vectors that contain the entire GSM band.

  1. Fundamental insight into the effect of carbodiimide crosslinking on cellular recognition of collagen-based scaffolds.

    Science.gov (United States)

    Bax, Daniel V; Davidenko, Natalia; Gullberg, Donald; Hamaia, Samir W; Farndale, Richard W; Best, Serena M; Cameron, Ruth E

    2017-02-01

    Research on the development of collagen constructs is extremely important in the field of tissue engineering. Collagen scaffolds for numerous tissue engineering applications are frequently crosslinked with 1-ethyl-3-(3-dimethylaminopropyl-carbodiimide hydrochloride (EDC) in the presence of N-hydroxy-succinimide (NHS). Despite producing scaffolds with good biocompatibility and low cellular toxicity the influence of EDC/NHS crosslinking on the cell interactive properties of collagen has been overlooked. Here we have extensively studied the interaction of model cell lines with collagen I-based materials after crosslinking with different ratios of EDC in relation to the number of carboxylic acid residues on collagen. Divalent cation-dependent cell adhesion, via integrins α1β1, α2β1, α10β1 and α11β1, were sensitive to EDC crosslinking. With increasing EDC concentration, this was replaced with cation-independent adhesion. These results were replicated using purified recombinant I domains derived from integrin α1 and α2 subunits. Integrin α2β1-mediated cell spreading, apoptosis and proliferation were all heavily influenced by EDC crosslinking of collagen. Data from this rigorous study provides an exciting new insight that EDC/NHS crosslinking is utilising the same carboxylic side chain chemistry that is vital for native-like integrin-mediated cell interactions. Due to the ubiquitous usage of EDC/NHS crosslinked collagen for biomaterials fabrication this data is essential to have a full understanding in order to ensure optimized collagen-based material performance.

  2. Memristor-based cellular nonlinear/neural network: design, analysis, and applications.

    Science.gov (United States)

    Duan, Shukai; Hu, Xiaofang; Dong, Zhekang; Wang, Lidan; Mazumder, Pinaki

    2015-06-01

    Cellular nonlinear/neural network (CNN) has been recognized as a powerful massively parallel architecture capable of solving complex engineering problems by performing trillions of analog operations per second. The memristor was theoretically predicted in the late seventies, but it garnered nascent research interest due to the recent much-acclaimed discovery of nanocrossbar memories by engineers at the Hewlett-Packard Laboratory. The memristor is expected to be co-integrated with nanoscale CMOS technology to revolutionize conventional von Neumann as well as neuromorphic computing. In this paper, a compact CNN model based on memristors is presented along with its performance analysis and applications. In the new CNN design, the memristor bridge circuit acts as the synaptic circuit element and substitutes the complex multiplication circuit used in traditional CNN architectures. In addition, the negative differential resistance and nonlinear current-voltage characteristics of the memristor have been leveraged to replace the linear resistor in conventional CNNs. The proposed CNN design has several merits, for example, high density, nonvolatility, and programmability of synaptic weights. The proposed memristor-based CNN design operations for implementing several image processing functions are illustrated through simulation and contrasted with conventional CNNs. Monte-Carlo simulation has been used to demonstrate the behavior of the proposed CNN due to the variations in memristor synaptic weights.

  3. Cellular morphology of organic-inorganic hybrid foams based on alkali alumino-silicate matrix

    Energy Technology Data Exchange (ETDEWEB)

    Verdolotti, Letizia; Capasso, Ilaria; Lavorgna, Marino [Institute of Composite and Biomedical Materials, National Research Council, Naples (Italy); Liguori, Barbara; Caputo, Domenico [Department of Chemical, Materials and Industrial Engineering, University of Naples Federico II, Naples (Italy); Iannace, Salvatore [Institute of Composite and Biomedical Materials, National Research Council, Naples, Italy and IMAST SCRAL, Piazza Bovio 22 Napoli 80133 (Italy)

    2014-05-15

    Organic-inorganic hybrid foams based on an alkali alumino-silicate matrix were prepared by using different foaming methods. Initially, the synthesis of an inorganic matrix by using aluminosilicate particles, activated through a sodium silicate solution, was performed at room temperature. Subsequently the viscous paste was foamed by using three different methods. In the first method, gaseous hydrogen produced by the oxidization of Si powder in an alkaline media, was used as blowing agent to generate gas bubbles in the paste. In the second method, the porous structure was generated by mixing the paste with a “meringue” type of foam previously prepared by whipping, under vigorous stirring, a water solution containing vegetal proteins as surfactants. In the third method, a combination of these two methods was employed. The foamed systems were consolidated for 24 hours at 40°C and then characterized by FTIR, X-Ray diffraction, scanning electron microscopy (SEM) and compression tests. Low density foams (∼500 Kg/m{sup 3}) with good cellular structure and mechanical properties were obtained by combining the “meringue” approach with the use of the chemical blowing agent based on Si.

  4. Should big cities grow? Scenario-based cellular automata urban growth modeling and policy applications

    Directory of Open Access Journals (Sweden)

    ChengHe Guan

    2016-12-01

    Full Text Available The formation of ‘Urban Networks’ has become a wide-spread phenomenon around the world. In the study of metropolitan regions, there are competing or diverging views about management and control of environmental and land-use factors as well as about scales and arrangements of settlements. Especially in China, these matters alongside of regulatory aspects, infrastructure applications, and resource allocations, are important because of population concentrations and the overlapping of urban areas with other land resources. On the other hand, the increasing sophistication of models operating on iterative computational power and widely-available spatial information and analytical techniques make it possible to simulate and investigate the spatial distribution of urban territories at a regional scale. This research applies a scenario-based Cellular Automata model to a case study of the Changjiang Delta Region, which produces useful and predictive scenario-based projections within the region, using quantitative methods and baseline conditions that address issues of regional urban development. The contribution of the research includes the improvement of computer simulation of urban growth, the application of urban form and other indices to evaluate complex urban conditions, and a heightened understanding of the performance of an urban network in the Changjiang Delta Region composed of big, medium, and small-sized cities and towns.

  5. A Dual Microscopy-Based Assay To Assess Listeria monocytogenes Cellular Entry and Vacuolar Escape.

    Science.gov (United States)

    Quereda, Juan J; Pizarro-Cerdá, Javier; Balestrino, Damien; Bobard, Alexandre; Danckaert, Anne; Aulner, Nathalie; Shorte, Spencer; Enninga, Jost; Cossart, Pascale

    2015-10-23

    Listeria monocytogenes is a Gram-positive bacterium and a facultative intracellular pathogen that invades mammalian cells, disrupts its internalization vacuole, and proliferates in the host cell cytoplasm. Here, we describe a novel image-based microscopy assay that allows discrimination between cellular entry and vacuolar escape, enabling high-content screening to identify factors specifically involved in these two steps. We first generated L. monocytogenes and Listeria innocua strains expressing a β-lactamase covalently attached to the bacterial cell wall. These strains were then incubated with HeLa cells containing the Förster resonance energy transfer (FRET) probe CCF4 in their cytoplasm. The CCF4 probe was cleaved by the bacterial surface β-lactamase only in cells inoculated with L. monocytogenes but not those inoculated with L. innocua, thereby demonstrating bacterial access to the host cytoplasm. Subsequently, we performed differential immunofluorescence staining to distinguish extracellular versus total bacterial populations in samples that were also analyzed by the FRET-based assay. With this two-step analysis, bacterial entry can be distinguished from vacuolar rupture in a single experiment. Our novel approach represents a powerful tool for identifying factors that determine the intracellular niche of L. monocytogenes.

  6. Simulation of Microstructure during Laser Rapid Forming Solidification Based on Cellular Automaton

    Directory of Open Access Journals (Sweden)

    Zhi-jian Wang

    2014-01-01

    Full Text Available The grain microstructure of molten pool during the solidification of TC4 titanium alloy in the single point laser cladding was investigated based on the CAFE model which is the cellular automaton (CA coupled with the finite element (FE method. The correct temperature field is the prerequisite for simulating the grain microstructure during the solidification of the molten pool. The model solves the energy equation by the FE method to simulate the temperature distribution in the molten pool of the single point laser cladding. Based on the temperature field, the solidification microstructure of the molten pool is also simulated with the CAFE method. The results show that the maximum temperature in the molten pool increases with the laser power and the scanning rate. The laser power has a larger influence on the temperature distribution of the molten pool than the scanning rate. During the solidification of the molten pool, the heat at the bottom of the molten pool transfers faster than that at the top of the molten pool. The grains rapidly grow into the molten pool, and then the columnar crystals are formed. This study has a very important significance for improving the quality of the structure parts manufactured through the laser cladding forming.

  7. Presentation of a research project addressed to the realisation of a diamond-based cellular biosensing device

    Science.gov (United States)

    Boarino, Luca; Carabelli, Valentina; Carbone, Emilio; Genovese, Marco; Gosso, Sara; Olivero, Paolo; Pasquarelli, Alberto; Picollo, Federico; Traina, Paolo

    2012-02-01

    In this proceedings we will present a research project financed by Piedmont regional government (Italy; finalized to the realization and commercialization of functional devices for cellular bio-sensing based on diamond. Partners of the project are: Crisel Instruments, Torino University, Torino Polytechnic, INRIM, Politronica, Bionica Tech, Ulm University Here the main features of the final devices will be briefly summarized. We envisage an active diamond-based cellular substrate that can simultaneously stimulate and detect a variety of signals (chemical, optical, electrical) to and from neuroendocrine cells, in a fully biocompatible environment for the cellular system under test. Such a device can be realized by fully exploiting the peculiar properties of diamond: optical transparency, biocompatibility, chemical inertness, accessibility to a conductive graphite-like phase; properties that will be further explored and tested during the project.

  8. Dynamic modeling of cellular response to DNA damage based on p53 stress response networks

    Institute of Scientific and Technical Information of China (English)

    Jinpeng Qi; Yongsheng Ding; Shihuang Shao

    2009-01-01

    Under acute perturbations from the outside, cells can trigger self-defensive mechanisms to fight against genome stress. To investigate the cellular response to continuous ion radiation (IR), a dynamic model for p53 stress response networks at the cellular level is proposed. The model can successfully be used to simulate the dynamic processes of double-strand breaks (DSBs) generation and their repair, switch-like ataxia telangiectasia mutated (ATM) activation, oscillations occurring in the p53-MDM2 feedback loop, as well as toxins elimination triggered by p53 stress response networks. Especially, the model can predict the plausible outcomes of cellular response under different IR dose regimes.

  9. Behind the NAT??? A measurement based evaluation of cellular service quality

    DEFF Research Database (Denmark)

    Kaup, F.; Michelinakis, F.; Bui, N.

    2015-01-01

    quality is affected by a number of factors, including network operator and available technologies. However, most studies focusing on measuring the cellular network do not consider the performance implications of network configuration and management. To this end, this paper reports about an extensive data...... set of cellular network measurements, focused on analyzing root causes of mobile network performance variability. Measurements conducted over four weeks in a 4G cellular network in Germany show that management and configuration decisions have a substantial impact on the performance. Specifically...... is developed. RTT increases of 58% to 73% compared to the optimum performance are observed in more than 57% of the measurements....

  10. Anchors for effectors: subversion of phosphoinositide lipids by Legionella

    Directory of Open Access Journals (Sweden)

    Hubert eHilbi

    2011-04-01

    Full Text Available The facultative intracellular pathogen Legionella pneumophila replicates in free-living amoebae and macrophages within a distinct compartment, the Legionella-containing vacuole (LCV. LCV formation involves phosphoinositide (PI glycerolipids, which are key factors controlling vesicle trafficking pathways and membrane dynamics of eukaryotic cells. To govern the interactions with host cells, L. pneumophila employs the Icm/Dot type IV secretion system and more than 250 translocated effector proteins that presumably subvert host signaling and vesicle trafficking pathways. Some of the effector proteins anchor through distinct PIs to the cytosolic face of LCVs and promote the interaction with host vesicles and organelles, catalyze guanine nucleotide exchange of small GTPases, or bind to PI-metabolizing enzymes, such as OCRL1. The PI 5-phosphatase OCRL1 and its Dictyostelium homologue Dd5P4 restrict intracellular growth of L. pneumophila. Moreover, OCRL1/Dd5P4, PI 3-kinases (PI3Ks and PI4KIIIβ regulate LCV formation and localization of the effector protein SidC, which selectively decorates the LCV membrane. SidC or its 20 kDa P4C fragment are robust and specific probes for phosphatidylinositol-4-phosphate, and SidC can be targeted to purify intact LCVs by immuno-magnetic separation. Taken together, bacterial PI-binding effectors as well as host PIs and PI-modulating enzymes play a pivotal role for intracellular replication of L. pneumophila, and the PI-binding effectors are valuable tools for the analysis of eukaryotic PI lipids.

  11. Applying Cellular Automata for Simulating and Assessing Urban Growth Scenario Based in Nairobi, Kenya

    Directory of Open Access Journals (Sweden)

    Kenneth Mubea

    2014-01-01

    Full Text Available This research explores urban growth based scenarios for the city of Nairobi using a cellular automata urban growth model (UGM. African cities have experienced rapid urbanization over the last decade due to increased population growth and high economic activities. We used multi-temporal Landsat imageries for 1976, 1986, 2000 and 2010 to investigate urban land-use changes in Nairobi. Our UGM used data from urban land-use of 1986 and 2010, road data, slope data and exclusion layer. Monte-Carlo technique was used for model calibration and Multi Resolution Validation (MRV technique for validation. Simulation of urban land-use was done up to the year 2030 when Kenya plans to attain Vision 2030. Three scenarios were explored in the urban modelling process; unmanaged growth with no restriction on environmental areas, managed growth with moderate protection, and a managed growth with maximum protection on forest, agricultural areas, and urban green. Thus alternative scenario development using UGM is useful for planning purposes so as to ensure sustainable development is achieved. UGM provides quantitative, visual, spatial and temporal information which aid policy and decision makers can make informed decisions.

  12. Identifying disease feature genes based on cellular localized gene functional modules and regulation networks

    Institute of Scientific and Technical Information of China (English)

    ZHANG Min; ZHU Jing; GUO Zheng; LI Xia; YANG Da; WANG Lei; RAO Shaoqi

    2006-01-01

    Identifying disease-relevant genes and functional modules, based on gene expression profiles and gene functional knowledge, is of high importance for studying disease mechanisms and subtyping disease phenotypes. Using gene categories of biological process and cellular component in Gene Ontology, we propose an approach to selecting functional modules enriched with differentially expressed genes, and identifying the feature functional modules of high disease discriminating abilities. Using the differentially expressed genes in each feature module as the feature genes, we reveal the relevance of the modules to the studied diseases. Using three datasets for prostate cancer, gastric cancer, and leukemia, we have demonstrated that the proposed modular approach is of high power in identifying functionally integrated feature gene subsets that are highly relevant to the disease mechanisms. Our analysis has also shown that the critical disease-relevant genes might be better recognized from the gene regulation network, which is constructed using the characterized functional modules, giving important clues to the concerted mechanisms of the modules responding to complex disease states. In addition, the proposed approach to selecting the disease-relevant genes by jointly considering the gene functional knowledge suggests a new way for precisely classifying disease samples with clear biological interpretations, which is critical for the clinical diagnosis and the elucidation of the pathogenic basis of complex diseases.

  13. Scalar Parameters Optimization in PDE Based Medical Image Denoising by using Cellular Wave Computing

    Directory of Open Access Journals (Sweden)

    GACSÁDI Alexandru

    2016-10-01

    Full Text Available In order to help with biomedical images, a set of complex and effective mathematical models are available, based on the PDE (PDE - partial differential equation. On one hand, effective implementation of these methods is difficult, due to the difficulty of determining the scalar parameter values, on which the image processing efficiency depends, while on the other hand, due to the considerable computing power needed in order to perform in real time. Currently there are no analytical and / or experimental methods in the literature for the exact values determination of the scaled parameters to provide the best results for a specific image processing. This paper proposes a method for optimizing the values of a scaling parameter set, which ensure effective noise reduction of medical images by using cellular wave computing. To assess the overall performance of noise extraction, the error function (quantitative component and direct visualization (qualitative component are used at the same time. Moreover, by using this analysis, the degree to which the CNN templates are robust against the range of values of the scalar parameter, is obtainable.

  14. Switched-based interference reduction scheme for open-access overlaid cellular networks

    KAUST Repository

    Radaydeh, Redha Mahmoud Mesleh

    2012-06-01

    Femtocells have been proposed to enhance the spatial coverage and system capacity of existing cellular networks. However, this technology may result in significant performance loss due to the increase in co-channel interference, particularly when coordination between access points is infeasible. This paper targets interference management in such overlaid networks. It is assumed that the femtocells employ the open-access strategy to reduce cross-tier interference, and can share resources concurrently. It is also assumed that each end user (EU) can access one channel at a time, and transfer limited feedback. To reduce the effect of co-tier interference in the absence of the desired EU channel state information (CSI) at the serving access point as well as coordination between active access points, a switched scheme based on the interference levels associated with available channels is proposed. Through the analysis, the scheme modes of operation in under-loaded and over-loaded channels are studied, from which the statistics of the resulting interference power are quantified. The impact of the proposed scheme on the received desired power is thoroughly discussed. In addition, the effect of the switching threshold on the achieved performance of the desired EU is investigated. The results clarify that the proposed scheme can improve the performance while reducing the number of examined channels and feedback load. © 2012 IEEE.

  15. Modeling and Simulation of Polarization in Internet Group Opinions Based on Cellular Automata

    Directory of Open Access Journals (Sweden)

    Yaofeng Zhang

    2015-01-01

    Full Text Available Hot events on Internet always attract many people who usually form one or several opinion camps through discussion. For the problem of polarization in Internet group opinions, we propose a new model based on Cellular Automata by considering neighbors, opinion leaders, and external influences. Simulation results show the following: (1 It is easy to form the polarization for both continuous opinions and discrete opinions when we only consider neighbors influence, and continuous opinions are more effective in speeding the polarization of group. (2 Coevolution mechanism takes more time to make the system stable, and the global coupling mechanism leads the system to consensus. (3 Opinion leaders play an important role in the development of consensus in Internet group opinions. However, both taking the opinion leaders as zealots and taking some randomly selected individuals as zealots are not conductive to the consensus. (4 Double opinion leaders with consistent opinions will accelerate the formation of group consensus, but the opposite opinions will lead to group polarization. (5 Only small external influences can change the evolutionary direction of Internet group opinions.

  16. A cellular automata-based model of Earth's magnetosphere in relation with Dst index

    Science.gov (United States)

    Banerjee, Adrija; Bej, Amaresh; Chatterjee, T. N.

    2015-05-01

    The disturbance storm time (Dst) index, a measure of the strength of a geomagnetic storm, is difficult to predict by some conventional methods due to its abstract structural complexity and stochastic nature though a timely geomagnetic storm warning could save society from huge economic losses and hours of related hazards. Self-organized criticality and the concept of many-body interactive nonlinear system can be considered an explanation for the fundamental mechanism of the nonstationary geomagnetic disturbances controlled by the perturbed interplanetary conditions. The present paper approaches this natural phenomena by a sandpile-like cellular automata-based model of magnetosphere, taking the real-time solar wind and both the direction and magnitude of the BZ component of the real-time interplanetary magnetic field as the system-controlling input parameters. Moreover, three new parameters had been introduced in the model which modify the functional relationships between the variables and regulate the dynamical behavior of the model to closely approximate the actual geomagnetic fluctuations. The statistical similarities between the dynamics of the model and that of the actual Dst index series during the entire 22nd solar cycle signifies the acceptability of the model.

  17. A universal concept based on cellular neural networks for ultrafast and flexible solving of differential equations.

    Science.gov (United States)

    Chedjou, Jean Chamberlain; Kyamakya, Kyandoghere

    2015-04-01

    This paper develops and validates a comprehensive and universally applicable computational concept for solving nonlinear differential equations (NDEs) through a neurocomputing concept based on cellular neural networks (CNNs). High-precision, stability, convergence, and lowest-possible memory requirements are ensured by the CNN processor architecture. A significant challenge solved in this paper is that all these cited computing features are ensured in all system-states (regular or chaotic ones) and in all bifurcation conditions that may be experienced by NDEs.One particular quintessence of this paper is to develop and demonstrate a solver concept that shows and ensures that CNN processors (realized either in hardware or in software) are universal solvers of NDE models. The solving logic or algorithm of given NDEs (possible examples are: Duffing, Mathieu, Van der Pol, Jerk, Chua, Rössler, Lorenz, Burgers, and the transport equations) through a CNN processor system is provided by a set of templates that are computed by our comprehensive templates calculation technique that we call nonlinear adaptive optimization. This paper is therefore a significant contribution and represents a cutting-edge real-time computational engineering approach, especially while considering the various scientific and engineering applications of this ultrafast, energy-and-memory-efficient, and high-precise NDE solver concept. For illustration purposes, three NDE models are demonstratively solved, and related CNN templates are derived and used: the periodically excited Duffing equation, the Mathieu equation, and the transport equation.

  18. Image encryption and compression based on kronecker compressed sensing and elementary cellular automata scrambling

    Science.gov (United States)

    Chen, Tinghuan; Zhang, Meng; Wu, Jianhui; Yuen, Chau; Tong, You

    2016-10-01

    Because of simple encryption and compression procedure in single step, compressed sensing (CS) is utilized to encrypt and compress an image. Difference of sparsity levels among blocks of the sparsely transformed image degrades compression performance. In this paper, motivated by this difference of sparsity levels, we propose an encryption and compression approach combining Kronecker CS (KCS) with elementary cellular automata (ECA). In the first stage of encryption, ECA is adopted to scramble the sparsely transformed image in order to uniformize sparsity levels. A simple approximate evaluation method is introduced to test the sparsity uniformity. Due to low computational complexity and storage, in the second stage of encryption, KCS is adopted to encrypt and compress the scrambled and sparsely transformed image, where the measurement matrix with a small size is constructed from the piece-wise linear chaotic map. Theoretical analysis and experimental results show that our proposed scrambling method based on ECA has great performance in terms of scrambling and uniformity of sparsity levels. And the proposed encryption and compression method can achieve better secrecy, compression performance and flexibility.

  19. Molecular and cellular bases of adaptation to a changing environment in microorganisms.

    Science.gov (United States)

    Bleuven, Clara; Landry, Christian R

    2016-10-26

    Environmental heterogeneity constitutes an evolutionary challenge for organisms. While evolutionary dynamics under variable conditions has been explored for decades, we still know relatively little about the cellular and molecular mechanisms involved. It is of paramount importance to examine these molecular bases because they may play an important role in shaping the course of evolution. In this review, we examine the diversity of adaptive mechanisms in the face of environmental changes. We exploit the recent literature on microbial systems because those have benefited the most from the recent emergence of genetic engineering and experimental evolution followed by genome sequencing. We identify four emerging trends: (i) an adaptive molecular change in a pathway often results in fitness trade-off in alternative environments but the effects are dependent on a mutation's genetic background; (ii) adaptive changes often modify transcriptional and signalling pathways; (iii) several adaptive changes may occur within the same molecular pathway but be associated with pleiotropy of different signs across environments; (iv) because of their large associated costs, macromolecular changes such as gene amplification and aneuploidy may be a rapid mechanism of adaptation in the short-term only. The course of adaptation in a variable environment, therefore, depends on the complexity of the environment but also on the molecular relationships among the genes involved and between the genes and the phenotypes under selection.

  20. Cellular Systems with Full-Duplex Compress-and-Forward Relaying and Cooperative Base Stations

    CERN Document Server

    Somekh, Oren; Poor, H Vincent; Shamai, Shlomo

    2008-01-01

    In this paper the advantages provided by multicell processing of signals transmitted by mobile terminals (MTs) which are received via dedicated relay terminals (RTs) are studied. It is assumed that each RT is capable of full-duplex operation and receives the transmission of adjacent relay terminals. Focusing on intra-cell TDMA and non-fading channels, a simplified relay-aided uplink cellular model based on a model introduced by Wyner is considered. Assuming a nomadic application in which the RTs are oblivious to the MTs' codebooks, a form of distributed compress-and-forward (CF) scheme with decoder side information is employed. The per-cell sum-rate of the CF scheme is derived and is given as a solution of a simple fixed point equation. This achievable rate reveals that the CF scheme is able to completely eliminate the inter-relay interference, and it approaches a ``cut-set-like'' upper bound for strong RTs transmission power. The CF rate is also shown to surpass the rate of an amplify-and-forward scheme via ...

  1. ONE-DIMENSIONAL CELLULAR AUTOMATON MODEL OF TRAFFIC FLOW BASED ON CAR-FOLLOWING IDEA

    Institute of Scientific and Technical Information of China (English)

    董力耘; 薛郁; 戴世强

    2002-01-01

    An improved one-dimensional CA (Cellular Automaton) traffic model was proposed to describe the highway traffic under the periodic boundary conditions. This model was based on the idea of the car-following model, which claims that the motion of a vehicle at one time step depends on both its headway and the synchronous motion of the front vehicle,thus including indirectly the influence of its sub-neighboring vehicle. In addition, the socalled safety distance was introduced to consider the deceleration behavior of vehicles and the stochastic factor was taken into account by introducing the deceleration probability.Meanwhile, the conditional deceleration in the model gives a better description of the phenomena observed on highways. It is found that there exists the metastability and hysteresis effect of traffic flow in the neighborhood of critical density under different initial conditions.Since this model gives a reasonable depiction of the motion of a single vehicle, it is easy to be extended to the case of traffic flow under the control of traffic lights in cities.

  2. Molecular cloning and biochemical characterization of a Drosophila phosphatidylinositol-specific phosphoinositide 3-kinase.

    Science.gov (United States)

    Linassier, C; MacDougall, L K; Domin, J; Waterfield, M D

    1997-02-01

    Molecular, biochemical and genetic characterization of phosphoinositide 3-kinases (PI3Ks) have identified distinct classes of enzymes involved in processes mediated by activation of cell-surface receptors and in constitutive intracellular protein trafficking events. The latter process appears to involve a PtdIns-specific PI3K first described in yeast as a mutant, vps34, defective in the sorting of newly synthesized proteins from the Golgi to the vacuole. We have identified a representative member of each class of PI3Ks in Drosophila using a PCR-based approach. In the present paper we describe the molecular cloning of a PI3K from Drosophila, P13K_59F, that shows sequence similarity to Vps34. PI3K_59F encodes a protein of 108 kDa co-linear with Vps34 homologues, and with three regions of sequence similarity to other PI3Ks. Biochemical characterization of the enzyme, by expression of the complete coding sequence as a glutathione S-transferase fusion protein in Sf9 cells, demonstrates that PI3K_59F is a PtdIns-specific PI3K that can utilize either Mg2+ or Mn2+. This activity is sensitive to inhibition both by non-ionic detergent (Nonidet P40) and by wortmannin (IC50 10 nM). PI3K_59F, therefore, conserves both the structural and biochemical properties of the Vps34 class of enzymes.

  3. Decrease in platelet activating factor stimulated phosphoinositide turnover during storage of human platelets in plasma

    Energy Technology Data Exchange (ETDEWEB)

    Carter, M.G.; Shukla, S.D. (Univ. of Missouri School of Medicine, Columbia (USA))

    1987-05-01

    Human platelet concentrate from the American Red Cross Blood Center was stored at 24{degree}C in a shaker and aliquots were taken out at time intervals aseptically. Platelet activating factor (PAF) stimulated turnover of phosphoinositide (PPI) was monitored by assaying {sup 32}P incorporation into phosphoinositides using platelet rich plasma (PRP). Platelets in PRP were incubated with 1 {times} 10{sup {minus}7} M PAF at 37{degree}C with gentle shaking and after 5 min their lipids were extracted and analysed by TLC for {sup 32}P-phosphoinositides. The percent stimulation of {sup 32}P incorporation by PAF (over control) into PPI was approximately 250, 100, 60, 25 and 20 on days 1, 2, 3, 5 and 6, respectively. This indicated a dramatic decrease in PAF responsive turnover of platelet PPI during storage. These findings have important implications in relation to PAF receptor activity and viability of platelets at different periods of storage.

  4. rSac3,a new member of Sac domain phosphoinositide phosphatases family

    Institute of Scientific and Technical Information of China (English)

    Lijun Li; Qi Wan

    2007-01-01

    @@ Inositol phospholipids are concentrated in the cytosolic surface of membranes.Phosphatidylinositol(Ptdlns),the precursor of phosphoinositides,iS synthesized primarily in the endoplasmic reticulum.Reversible phosphorylation in the inositol ring of PtdIns at positions 3.4 and 5results in the generation of seven phOsphOinOsitide species:Ptdlns(3)P,PtdIns(4)P,PtdIns(5)P,PtdIns(3,4)P2,PtdIns(3,5)P2,PtdIns(4,5)P2,PtdIns(3,4,5)P3.Phosphoinositides can be rapidly interconverted from one species to another by strategically localized kinases and phosphatases[1].

  5. Decoding the role of phosphoinositides in phototropin signaling involved in chloroplast movements.

    Science.gov (United States)

    Aggarwal, Chhavi; Labuz, Justyna; Gabryś, Halina

    2013-08-01

    In angiosperms, light-dependent chloroplast movements are exclusively mediated by UVA/blue light receptors - phototropins. The two photoreceptors of Arabidopsis thaliana, phot1 and phot2, have overlapping roles in the control of these movements. Experiments performed in different plant species point to the participation of phosphoinositides in blue light-controlled chloroplast relocations. Here, we report a summary of recent findings presenting the involvement of phosphatidylinositol 4,5-bisphosphate as well as phosphatidylinositol 3- and 4-phosphates in weak blue light-mediated (accumulation) and strong blue light-mediated (avoidance) responses of chloroplasts. The blue light-activated alterations in phosphoinositide concentration are partly responsible for cytosolic Ca (2+) changes. Ca (2+) influx from apoplast does not seem to be involved in the mechanism of movement responses. In summary, interplay between phosphoinositides and intracellular Ca (2+) regulates chloroplast redistribution in response to blue light in higher plants.

  6. DMPD: The p110delta subunit of phosphoinositide 3-kinase is required for thelipopolysaccharide response of mouse B cells. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15494016 The p110delta subunit of phosphoinositide 3-kinase is required for thelipo... 5):789-91. (.png) (.svg) (.html) (.csml) Show The p110delta subunit of phosphoinositide 3-kinase is required...e p110delta subunit of phosphoinositide 3-kinase is required for thelipopolysaccharide response of mouse B c

  7. Stackelberg Game Based Power Allocation for Physical Layer Security of Device-to-device Communication Underlaying Cellular Networks

    Science.gov (United States)

    Qu, Junyue; Cai, Yueming; Wu, Dan; Chen, Hualiang

    2014-05-01

    The problem of power allocation for device-to-device (D2D) underlay communication to improve physical layer security is addressed. Specifically, to improve the secure communication of the cellular users, we introduce a Stackelberg game for allocating the power of the D2D link under a total power constraint and a rate constraint at the D2D pair. In the introduced Stackelberg game the D2D pair works as a seller and the cellular UEs work as buyers. Firstly, because the interference signals from D2D pair are unknown to both the legitimate receiver and the illegitimate eavesdropper, it is possible that a cellular UE decline to participate in the introduced Stackelberg game. So the condition under which a legitimate user will participate in the introduced Stackelberg game is discussed. Then, based on the Stackelberg game, we propose a semi-distributed power allocation algorithm, which is proved to conclude after finite-time iterations. In the end, some simulations are presented to verify the performance improvement in the physical layer security of cellular UEs using the proposed power allocation algorithm. We can determine that with the proposed algorithm, while the D2D pair's communication demand is met, the physical layer security of cellular UEs can be improved.

  8. A phosphatidylinositol transfer protein integrates phosphoinositide signaling with lipid droplet metabolism to regulate a developmental program of nutrient stress-induced membrane biogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Jihui; Lin, Coney Pei-Chen; Pathak, Manish C.; Temple, Brenda R.S.; Nile, Aaron H.; Mousley, Carl J.; Duncan, Mara C.; Eckert, Debra M.; Leiker, Thomas J.; Ivanova, Pavlina T.; Myers, David S.; Murphy, Robert C.; Brown, H. Alex; Verdaasdonk, Jolien; Bloom, Kerry S.; Ortlund, Eric A.; Neiman, Aaron M.; Bankaitis, Vytas A. (Emory-MED); (UNCSM); (UNC); (UCHSC); (TAM); (Vanderbilt-MED); (SBU); (Utah)

    2016-07-06

    Lipid droplet (LD) utilization is an important cellular activity that regulates energy balance and release of lipid second messengers. Because fatty acids exhibit both beneficial and toxic properties, their release from LDs must be controlled. Here we demonstrate that yeast Sfh3, an unusual Sec14-like phosphatidylinositol transfer protein, is an LD-associated protein that inhibits lipid mobilization from these particles. We further document a complex biochemical diversification of LDs during sporulation in which Sfh3 and select other LD proteins redistribute into discrete LD subpopulations. The data show that Sfh3 modulates the efficiency with which a neutral lipid hydrolase-rich LD subclass is consumed during biogenesis of specialized membrane envelopes that package replicated haploid meiotic genomes. These results present novel insights into the interface between phosphoinositide signaling and developmental regulation of LD metabolism and unveil meiosis-specific aspects of Sfh3 (and phosphoinositide) biology that are invisible to contemporary haploid-centric cell biological, proteomic, and functional genomics approaches.

  9. A phosphatidylinositol transfer protein integrates phosphoinositide signaling with lipid droplet metabolism to regulate a developmental program of nutrient stress-induced membrane biogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Jihui; Lin, Coney Pei-Chen; Pathak, Manish C.; Temple, Brenda R.S.; Nile, Aaron H.; Mousley, Carl J.; Duncan, Mara C.; Eckert, Debra M.; Leiker, Thomas J.; Ivanova, Pavlina T.; Myers, David S.; Murphy, Robert C.; Brown, H. Alex; Verdaasdonk, Jolien; Bloom, Kerry S.; Ortlund, Eric A.; Neiman, Aaron M.; Bankaitis, Vytas A. [Emory-MED; (SBU); (TAM); (UNC); (Vanderbilt-MED); (Utah); (UCHSC)

    2014-07-11

    Lipid droplet (LD) utilization is an important cellular activity that regulates energy balance and release of lipid second messengers. Because fatty acids exhibit both beneficial and toxic properties, their release from LDs must be controlled. Here we demonstrate that yeast Sfh3, an unusual Sec14-like phosphatidylinositol transfer protein, is an LD-associated protein that inhibits lipid mobilization from these particles. We further document a complex biochemical diversification of LDs during sporulation in which Sfh3 and select other LD proteins redistribute into discrete LD subpopulations. The data show that Sfh3 modulates the efficiency with which a neutral lipid hydrolase-rich LD subclass is consumed during biogenesis of specialized membrane envelopes that package replicated haploid meiotic genomes. These results present novel insights into the interface between phosphoinositide signaling and developmental regulation of LD metabolism and unveil meiosis-specific aspects of Sfh3 (and phosphoinositide) biology that are invisible to contemporary haploid-centric cell biological, proteomic, and functional genomics approaches.

  10. Phosphoinositide hydrolysis mediated by H1 receptors in autoimmune myocarditis mice

    Directory of Open Access Journals (Sweden)

    Nora Goren

    1993-01-01

    Full Text Available Stimulation of phosphoinositide hydrolysis in myocardium from autoimmune myocarditis mice by ThEA and histamine was assayed. Myocardium from autoimmune heart, but not the normal forms, specifically increased phosphoinositide turnover in the presence of histaminergic agonists. This increment was blocked by a specific H1 antagonist mepyramine and to the same extent by the phospholipase C inhibitor NCDC. By using a binding assay H1 histaminergic receptors were detected in autoimmune heart membrane preparations, but this was not observed in normal heart. These data suggest that autoimmune myocardium expressed a functional H1 receptor that could involve a distinctive mechanism operating in the disease.

  11. Different phosphoinositide 3-kinase isoforms mediate carrageenan nociception and inflammation.

    Science.gov (United States)

    Pritchard, Rory A; Falk, Lovissa; Larsson, Mathilda; Leinders, Mathias; Sorkin, Linda S

    2016-01-01

    Phosphoinositide 3-kinases (PI3Ks) participate in signal transduction cascades that can directly activate and sensitize nociceptors and enhance pain transmission. They also play essential roles in chemotaxis and immune cell infiltration leading to inflammation. We wished to determine which PI3K isoforms were involved in each of these processes. Lightly anesthetized rats (isoflurane) were injected subcutaneously with carrageenan in their hind paws. This was preceded by a local injection of 1% DMSO vehicle or an isoform-specific antagonist to PI3K-α (compound 15-e), -β (TGX221), -δ (Cal-101), or -γ (AS252424). We measured changes in the mechanical pain threshold and spinal c-Fos expression (4 hours after injection) as indices of nociception. Paw volume, plasma extravasation (Evans blue, 0.3 hours after injection), and neutrophil (myeloperoxidase; 1 hour after injection) and macrophage (CD11b+; 4 hour after injection) infiltration into paw tissue were the measured inflammation endpoints. Only PI3K-γ antagonist before treatment reduced the carrageenan-induced pain behavior and spinal expression of c-Fos (P ≤ 0.01). In contrast, pretreatment with PI3K-α, -δ, and-γ antagonists reduced early indices of inflammation. Plasma extravasation PI3K-α (P ≤ 0.05), -δ (P ≤ 0.05), and -γ (P ≤ 0.01), early (0-2 hour) edema -α (P ≤ 0.05), -δ (P ≤ 0.001), and -γ (P ≤ 0.05), and neutrophil infiltration (all P ≤ 0.001) were all reduced compared to vehicle pretreatment. Later (2-4 hour), edema and macrophage infiltration (P ≤ 0.05) were reduced by only the PI3K-δ and -γ isoform antagonists, with the PI3K-δ antagonist having a greater effect on edema. PI3K-β antagonism was ineffective in all paradigms. These data indicate that pain and clinical inflammation are pharmacologically separable and may help to explain clinical conditions in which inflammation naturally wanes or goes into remission, but pain continues unabated.

  12. Genome-wide analysis of the phosphoinositide kinome from two ciliates reveals novel evolutionary links for phosphoinositide kinases in eukaryotic cells.

    Directory of Open Access Journals (Sweden)

    George Leondaritis

    Full Text Available BACKGROUND: The complexity of phosphoinositide signaling in higher eukaryotes is partly due to expansion of specific families and types of phosphoinositide kinases (PIKs that can generate all phosphoinositides via multiple routes. This is particularly evident in the PI3Ks and PIPKs, and it is considered an evolutionary trait associated with metazoan diversification. Yet, there are limited comprehensive studies on the PIK repertoire of free living unicellular organisms. METHODOLOGY/PRINCIPAL FINDINGS: We undertook a genome-wide analysis of putative PIK genes in two free living ciliated cells, Tetrahymena and Paramecium. The Tetrahymena thermophila and Paramecium tetraurelia genomes were probed with representative kinases from all families and types. Putative homologs were verified by EST, microarray and deep RNA sequencing database searches and further characterized for domain structure, catalytic efficiency, expression patterns and phylogenetic relationships. In total, we identified and characterized 22 genes in the Tetrahymena thermophila genome and 62 highly homologues genes in Paramecium tetraurelia suggesting a tight evolutionary conservation in the ciliate lineage. Comparison to the kinome of fungi reveals a significant expansion of PIK genes in ciliates. CONCLUSIONS/SIGNIFICANCE: Our study highlights four important aspects concerning ciliate and other unicellular PIKs. First, ciliate-specific expansion of PI4KIII-like genes. Second, presence of class I PI3Ks which, at least in Tetrahymena, are associated with a metazoan-type machinery for PIP3 signaling. Third, expansion of divergent PIPK enzymes such as the recently described type IV transmembrane PIPKs. Fourth, presence of possible type II PIPKs and presumably inactive PIKs (hence, pseudo-PIKs not previously described. Taken together, our results provide a solid framework for future investigation of the roles of PIKs in ciliates and indicate that novel functions and novel regulatory

  13. Knowledge-based matrix factorization temporally resolves the cellular responses to IL-6 stimulation

    Directory of Open Access Journals (Sweden)

    Gretz Norbert

    2010-11-01

    Full Text Available Abstract Background External stimulations of cells by hormones, cytokines or growth factors activate signal transduction pathways that subsequently induce a re-arrangement of cellular gene expression. The analysis of such changes is complicated, as they consist of multi-layered temporal responses. While classical analyses based on clustering or gene set enrichment only partly reveal this information, matrix factorization techniques are well suited for a detailed temporal analysis. In signal processing, factorization techniques incorporating data properties like spatial and temporal correlation structure have shown to be robust and computationally efficient. However, such correlation-based methods have so far not be applied in bioinformatics, because large scale biological data rarely imply a natural order that allows the definition of a delayed correlation function. Results We therefore develop the concept of graph-decorrelation. We encode prior knowledge like transcriptional regulation, protein interactions or metabolic pathways in a weighted directed graph. By linking features along this underlying graph, we introduce a partial ordering of the features (e.g. genes and are thus able to define a graph-delayed correlation function. Using this framework as constraint to the matrix factorization task allows us to set up the fast and robust graph-decorrelation algorithm (GraDe. To analyze alterations in the gene response in IL-6 stimulated primary mouse hepatocytes, we performed a time-course microarray experiment and applied GraDe. In contrast to standard techniques, the extracted time-resolved gene expression profiles showed that IL-6 activates genes involved in cell cycle progression and cell division. Genes linked to metabolic and apoptotic processes are down-regulated indicating that IL-6 mediated priming renders hepatocytes more responsive towards cell proliferation and reduces expenditures for the energy metabolism. Conclusions GraDe provides

  14. A simple yeast-based strategy to identify host cellular processes targeted by bacterial effector proteins.

    Directory of Open Access Journals (Sweden)

    Eran Bosis

    Full Text Available Bacterial effector proteins, which are delivered into the host cell via the type III secretion system, play a key role in the pathogenicity of gram-negative bacteria by modulating various host cellular processes to the benefit of the pathogen. To identify cellular processes targeted by bacterial effectors, we developed a simple strategy that uses an array of yeast deletion strains fitted into a single 96-well plate. The array is unique in that it was optimized computationally such that despite the small number of deletion strains, it covers the majority of genes in the yeast synthetic lethal interaction network. The deletion strains in the array are screened for hypersensitivity to the expression of a bacterial effector of interest. The hypersensitive deletion strains are then analyzed for their synthetic lethal interactions to identify potential targets of the bacterial effector. We describe the identification, using this approach, of a cellular process targeted by the Xanthomonas campestris type III effector XopE2. Interestingly, we discover that XopE2 affects the yeast cell wall and the endoplasmic reticulum stress response. More generally, the use of a single 96-well plate makes the screening process accessible to any laboratory and facilitates the analysis of a large number of bacterial effectors in a short period of time. It therefore provides a promising platform for studying the functions and cellular targets of bacterial effectors and other virulence proteins.

  15. Floating point based Cellular Automata simulations using a dual FPGA-enabled system

    NARCIS (Netherlands)

    Murtaza, S.; Hoekstra, A.G.; Sloot, P.M.A.; Kindratenko, V.

    2008-01-01

    With the recent emergence of multicore architectures, the age of multicore computing might have already dawned upon us. This shift might have triggered the evolution of von Neumann architecture towards a parallel processing paradigm. Cellular Automata- inherently decentralized spatially extended sys

  16. Impairment of membrane phosphoinositide metabolism by aminoglycoside antibiotics: streptomycin, amikacin, kanamycin, dibekacin, gentamicin and neomycin.

    Science.gov (United States)

    Marche, P; Koutouzov, S; Girard, A

    1983-11-01

    Like many amphiphilic cationic drugs, aminoglycosides are able to produce phospholipidosis, mainly by inhibiting enzymes involved in phospholipid metabolism. Phosphoinositides have been suggested to function as receptors for aminoglycosides. Therefore, we investigated the influence of these drugs upon phosphoinositide metabolism by measuring the 32P-incorporation into the polyphosphoinositides, using the rat erythrocyte membrane as a model. Depending upon the experimental conditions, neomycin induced a decrease and/or an increase in the 32P-labeling of triphosphoinositides (TPI) and of diphosphoinositides (DPI), respectively. These variations were rapid and depended upon the drug concentration. At 0.3 mM, neomycin reversed the distribution of radioactivities associated with DPI and TPI without modifying the total radioactivity incorporated. This drug concentration altered neither the Mg++-activated TPI-specific phosphomonoesterase activity nor the Ca++-activated polyphosphoinositide phosphodiesterase activity. It appears likely that the drug inhibits the DPI-kinase activity, by interacting with DPI and thereby lowering the substrate availability. Over the range of concentrations studied (up to 1-2 mM), gentamicin, kanamycin and dibekacin behave as neomycin. However, their effects could be observed only at drug concentrations higher than those of neomycin. By contrast, streptomycin and amikacin did not alter the 32P-labeling of TPI and of DPI. The order of potency of aminoglycosides for the impairment of the phosphoinositide interconversion was neomycin, gentamicin, dibekacin, kanamycin. A possible relationship between the toxicity of aminoglycosides and their capacity to impair the phosphoinositide metabolism is discussed.

  17. Specificity and commonality of the phosphoinositide-binding proteome analyzed by quantitative mass spectrometry

    DEFF Research Database (Denmark)

    Jungmichel, Stephanie; Sylvestersen, Kathrine B; Choudhary, Chuna Ram;

    2014-01-01

    Phosphoinositides (PIPs) play key roles in signaling and disease. Using high-resolution quantitative mass spectrometry, we identified PIP-interacting proteins and profiled their binding specificities toward all seven PIP variants. This analysis revealed 405 PIP-binding proteins, which is greater...

  18. Coordinated Expression of Phosphoinositide Metabolic Genes during Development and Aging of Human Dorsolateral Prefrontal Cortex.

    Directory of Open Access Journals (Sweden)

    Stanley I Rapoport

    Full Text Available Phosphoinositides, lipid-signaling molecules, participate in diverse brain processes within a wide metabolic cascade.Gene transcriptional networks coordinately regulate the phosphoinositide cascade during human brain Development and Aging.We used the public BrainCloud database for human dorsolateral prefrontal cortex to examine age-related expression levels of 49 phosphoinositide metabolic genes during Development (0 to 20+ years and Aging (21+ years.We identified three groups of partially overlapping genes in each of the two intervals, with similar intergroup correlations despite marked phenotypic differences between Aging and Development. In each interval, ITPKB, PLCD1, PIK3R3, ISYNA1, IMPA2, INPPL1, PI4KB, and AKT1 are in Group 1, PIK3CB, PTEN, PIK3CA, and IMPA1 in Group 2, and SACM1L, PI3KR4, INPP5A, SYNJ1, and PLCB1 in Group 3. Ten of the genes change expression nonlinearly during Development, suggesting involvement in rapidly changing neuronal, glial and myelination events. Correlated transcription for some gene pairs likely is facilitated by colocalization on the same chromosome band.Stable coordinated gene transcriptional networks regulate brain phosphoinositide metabolic pathways during human Development and Aging.

  19. Enhanced phosphodiesteratic breakdown and turnover of phosphoinositides during reperfusion of ischemic rat heart.

    Science.gov (United States)

    Otani, H; Prasad, M R; Engelman, R M; Otani, H; Cordis, G A; Das, D K

    1988-11-01

    In this study, we examined phosphoinositide metabolism during ischemia and reperfusion using an isolated and perfused rat heart. When myocardial phosphoinositides were prelabeled with [3H]inositol, reperfusion after 30 minutes of normothermic global ischemia resulted in significant accumulations of radiolabeled inositol phosphate, inositol bisphosphate, and inositol trisphosphate. Isotopic incorporation of [3H]inositol into phosphatidylinositol, phosphatidylinositol-4-phosphate, and phosphatidylinositol-4,5-bisphosphate was increased significantly in the heart reperfused with [3H]inositol after 30 minutes of ischemia compared with that perfused with [3H]inositol after 30 minutes of nonischemic perfusion. However, isotopic incorporation of [3H]glycerol into diacylglycerol, phosphatidic acid, and all of the three phosphoinositides was diminished in the reperfused hearts. Reperfusion of the ischemic heart prelabeled with [14C]arachidonic acid resulted in significant increases in [14C]diacylglycerol and [14C]phosphatidic acid. The enhanced accumulations of [3H]inositol phosphates during reperfusion were not affected by treatment with prazosin plus atropine or indomethacin, but were inhibited by hypoxic reperfusion, reperfusion with Ca2+-free buffer, or by mepacrine. These results suggest that myocardial reperfusion stimulates phosphodiesteratic breakdown and turnover of phosphoinositides, and increased Ca2+ influx caused by reperfusion may be involved in the mechanism of stimulation of phosphatidylinositol-specific phospholipase C activity in the rat heart.

  20. Treatment Analysis in a Cancer Stem Cell Context Using a Tumor Growth Model Based on Cellular Automata.

    Directory of Open Access Journals (Sweden)

    Ángel Monteagudo

    Full Text Available Cancer can be viewed as an emergent behavior in terms of complex system theory and artificial life, Cellular Automata (CA being the tool most used for studying and characterizing the emergent behavior. Different approaches with CA models were used to model cancer growth. The use of the abstract model of acquired cancer hallmarks permits the direct modeling at cellular level, where a cellular automaton defines the mitotic and apoptotic behavior of cells, and allows for an analysis of different dynamics of the cellular system depending on the presence of the different hallmarks. A CA model based on the presence of hallmarks in the cells, which includes a simulation of the behavior of Cancer Stem Cells (CSC and their implications for the resultant growth behavior of the multicellular system, was employed. This modeling of cancer growth, in the avascular phase, was employed to analyze the effect of cancer treatments in a cancer stem cell context. The model clearly explains why, after treatment against non-stem cancer cells, the regrowth capability of CSCs generates a faster regrowth of tumor behavior, and also shows that a continuous low-intensity treatment does not favor CSC proliferation and differentiation, thereby allowing an unproblematic control of future tumor regrowth. The analysis performed indicates that, contrary to the current attempts at CSC control, trying to make CSC proliferation more difficult is an important point to consider, especially in the immediate period after a standard treatment for controlling non-stem cancer cell proliferation.

  1. Revisions to Exceptions Applicable to Certain Human Cells, Tissues, and Cellular and Tissue-Based Products. Final rule.

    Science.gov (United States)

    2016-06-22

    : The Food and Drug Administration (FDA or Agency or we) is issuing this final rule to amend certain regulations regarding donor eligibility, including the screening and testing of donors of particular human cells, tissues, and cellular and tissue-based products (HCT/Ps), and related labeling. This final rule is in response to our enhanced understanding in this area and in response to comments from stakeholders regarding the importance of embryos to individuals and couples seeking access to donated embryos.

  2. A new model for anaerobic processes of up-flow anaerobic sludge blanket reactors based on cellular automata

    DEFF Research Database (Denmark)

    Skiadas, Ioannis V.; Ahring, Birgitte Kiær

    2002-01-01

    characteristics and lead to different reactor behaviour. A dynamic mathematical model has been developed for the anaerobic digestion of a glucose based synthetic wastewater in UASB reactors. Cellular automata (CA) theory has been applied to simulate the granule development process. The model takes...... into consideration that granule diameter and granule microbial composition are functions of the reactor operational parameters and is capable of predicting the UASB performance and the layer structure of the granules....

  3. Activity-based Calculation Models for the Brazilian Air Force Cellular Unit of Intendancy

    Science.gov (United States)

    2013-03-01

    readiness (Operations “Aghata” and “Cruzex”), humanitarian missions (support to combat dengue in the city of Rio de Janeiro ; support of the military...disinfection, sanitary and barber shop; u) water supply ; v) water treatment; x) providing electrical power. 1.8 Organization This research will be...recreation, and water and electricity supply . 2.1.1 Cellular Unit of Intendancy. The CUI provides the Air Force with the necessary mobility to

  4. A Proposal for Energy-Efficient Cellular Neural Network based on Spintronic Devices

    OpenAIRE

    2016-01-01

    Due to the massive parallel computing capability and outstanding image and signal processing performance, cellular neural network (CNN) is one promising type of non-Boolean computing system that can outperform the traditional digital logic computation and mitigate the physical scaling limit of the conventional CMOS technology. The CNN was originally implemented by VLSI analog technologies with operational amplifiers and operational transconductance amplifiers as neurons and synapses, respecti...

  5. Throughput of Cellular Systems with Conferencing Mobiles and Cooperative Base Stations

    OpenAIRE

    Somekh O; Poor HV; Shamai (Shitz) S; Kramer G.; Simeone O.

    2008-01-01

    This paper considers an enhancement to multicell processing for the uplink of a cellular system, whereby the mobile stations are allowed to exchange messages on orthogonal channels of fixed capacity (conferencing). Both conferencing among mobile stations in different cells and in the same cell (inter- and intracell conferencing, resp.) are studied. For both cases, it is shown that a rate-splitting transmission strategy, where part of the message is exchanged on the conferencing channels and ...

  6. Visualization of Gene Mutation Complicated Pattern of Hepatitis B Virus Based on Cellular Automata

    Institute of Scientific and Technical Information of China (English)

    SHAO Shi-huang; XIAO Xuan; DING Yong-sheng; HUANG Zhen-de

    2005-01-01

    Hepatitis B virus shows instantaneous and high rate mutations in biological experiments, some sorts of which affect the efficiency of virus replication greatly through enhancing or depressing the viral replication, while others have no influence at all. Taking advantage of prominent features of cellular automata, we simulate the effect of hepatitis B virus gene mutation on its replication efficiency. The computer simulation results demonstrate the feasibility of our novel model by comparing with the results of biological experiments.

  7. Simulation Based Optimization of Complex Monolithic Composite Structures Using Cellular Core Technology

    Science.gov (United States)

    Hickmott, Curtis W.

    Cellular core tooling is a new technology which has the capability to manufacture complex integrated monolithic composite structures. This novel tooling method utilizes thermoplastic cellular cores as inner tooling. The semi-rigid nature of the cellular cores makes them convenient for lay-up, and under autoclave temperature and pressure they soften and expand providing uniform compaction on all surfaces including internal features such as ribs and spar tubes. This process has the capability of developing fully optimized aerospace structures by reducing or eliminating assembly using fasteners or bonded joints. The technology is studied in the context of evaluating its capabilities, advantages, and limitations in developing high quality structures. The complex nature of these parts has led to development of a model using the Finite Element Analysis (FEA) software Abaqus and the plug-in COMPRO Common Component Architecture (CCA) provided by Convergent Manufacturing Technologies. This model utilizes a "virtual autoclave" technique to simulate temperature profiles, resin flow paths, and ultimately deformation from residual stress. A model has been developed simulating the temperature profile during curing of composite parts made with the cellular core technology. While modeling of composites has been performed in the past, this project will look to take this existing knowledge and apply it to this new manufacturing method capable of building more complex parts and develop a model designed specifically for building large, complex components with a high degree of accuracy. The model development has been carried out in conjunction with experimental validation. A double box beam structure was chosen for analysis to determine the effects of the technology on internal ribs and joints. Double box beams were manufactured and sectioned into T-joints for characterization. Mechanical behavior of T-joints was performed using the T-joint pull-off test and compared to traditional

  8. Supramolecular nanoparticles that target phosphoinositide-3-kinase overcome insulin resistance and exert pronounced antitumor efficacy.

    Science.gov (United States)

    Kulkarni, Ashish A; Roy, Bhaskar; Rao, Poornima S; Wyant, Gregory A; Mahmoud, Ayaat; Ramachandran, Madhumitha; Sengupta, Poulomi; Goldman, Aaron; Kotamraju, Venkata Ramana; Basu, Sudipta; Mashelkar, Raghunath A; Ruoslahti, Erkki; Dinulescu, Daniela M; Sengupta, Shiladitya

    2013-12-01

    The centrality of phosphoinositide-3-kinase (PI3K) in cancer etiology is well established, but clinical translation of PI3K inhibitors has been limited by feedback signaling, suboptimal intratumoral concentration, and an insulin resistance "class effect." This study was designed to explore the use of supramolecular nanochemistry for targeting PI3K to enhance antitumor efficacy and potentially overcome these limitations. PI3K inhibitor structures were rationally modified using a cholesterol-based derivative, facilitating supramolecular nanoassembly with L-α-phosphatidylcholine and DSPE-PEG [1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polythylene glycol)]. The supramolecular nanoparticles (SNP) that were assembled were physicochemically characterized and functionally evaluated in vitro. Antitumor efficacy was quantified in vivo using 4T1 breast cancer and K-Ras(LSL/+)/Pten(fl/fl) ovarian cancer models, with effects on glucose homeostasis evaluated using an insulin sensitivity test. The use of PI103 and PI828 as surrogate molecules to engineer the SNPs highlighted the need to keep design principles in perspective; specifically, potency of the active molecule and the linker chemistry were critical principles for efficacy, similar to antibody-drug conjugates. We found that the SNPs exerted a temporally sustained inhibition of phosphorylation of Akt, mTOR, S6K, and 4EBP in vivo. These effects were associated with increased antitumor efficacy and survival as compared with PI103 and PI828. Efficacy was further increased by decorating the nanoparticle surface with tumor-homing peptides. Notably, the use of SNPs abrogated the insulin resistance that has been associated widely with other PI3K inhibitors. This study provides a preclinical foundation for the use of supramolecular nanochemistry to overcome current challenges associated with PI3K inhibitors, offering a paradigm for extension to other molecularly targeted therapeutics being explored for cancer

  9. Cellular automata

    CERN Document Server

    Codd, E F

    1968-01-01

    Cellular Automata presents the fundamental principles of homogeneous cellular systems. This book discusses the possibility of biochemical computers with self-reproducing capability.Organized into eight chapters, this book begins with an overview of some theorems dealing with conditions under which universal computation and construction can be exhibited in cellular spaces. This text then presents a design for a machine embedded in a cellular space or a machine that can compute all computable functions and construct a replica of itself in any accessible and sufficiently large region of t

  10. Modeling and Analysis of Hybrid Cellular/WLAN Systems with Integrated Service-Based Vertical Handoff Schemes

    Science.gov (United States)

    Xia, Weiwei; Shen, Lianfeng

    We propose two vertical handoff schemes for cellular network and wireless local area network (WLAN) integration: integrated service-based handoff (ISH) and integrated service-based handoff with queue capabilities (ISHQ). Compared with existing handoff schemes in integrated cellular/WLAN networks, the proposed schemes consider a more comprehensive set of system characteristics such as different features of voice and data services, dynamic information about the admitted calls, user mobility and vertical handoffs in two directions. The code division multiple access (CDMA) cellular network and IEEE 802.11e WLAN are taken into account in the proposed schemes. We model the integrated networks by using multi-dimensional Markov chains and the major performance measures are derived for voice and data services. The important system parameters such as thresholds to prioritize handoff voice calls and queue sizes are optimized. Numerical results demonstrate that the proposed ISHQ scheme can maximize the utilization of overall bandwidth resources with the best quality of service (QoS) provisioning for voice and data services.

  11. Associative memories based on continuous-time cellular neural networks designed using space-invariant cloning templates.

    Science.gov (United States)

    Zeng, Zhigang; Wang, Jun

    2009-01-01

    Associative memories are brain-style devices designed to store a set of patterns as stable equilibria such that the stored patterns can be reliably retrieved with the initial probes containing sufficient information about the patterns. This paper presents a new design procedure for synthesizing associative memories based on continuous-time cellular neural networks with time delays characterized by input and output matrices obtained using two-dimensional space-invariant cloning templates. The design procedure enables hetero-associative or auto-associative memories to be synthesized by solving a set of linear inequalities with few design parameters and retrieval probes feeding from external inputs instead of initial states. The designed associative memories are robust in terms of design parameter selection. In addition, the hosting cellular neural networks are guaranteed to be globally exponentially stable. Simulation and experimental results of illustrative examples and Monte Carlo tests demonstrate the applicability and superiority of the methodology.

  12. Tetrazolium-based assays for cellular viability: a critical examination of selected parameters affecting formazan production.

    Science.gov (United States)

    Vistica, D T; Skehan, P; Scudiero, D; Monks, A; Pittman, A; Boyd, M R

    1991-05-15

    The hydrogen acceptor 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) is commonly utilized to estimate cellular viability in drug screening protocols. The present investigation was prompted, in part, by observations that reduction of MTT to its colored reaction product, MTT formazan, varied between cell lines and with culture age. A correlation was established between the D-glucose concentration of the culture medium at the time of assay and the production of MTT formazan for cell lines representing seven tumor histologies. A decrease in the concentration of D-glucose from culture medium was accompanied by a decrease in MTT specific activity (MTT formazan/microgram cell protein) for a number of cell lines. Cells which extensively metabolized D-glucose exhibited the greatest reduction in MTT specific activity. Further evidence that the D-glucose concentration of the culture medium played an important role in MTT reduction was provided by experiments which demonstrated that transfer of cells to a glucose-free medium (L-15) was accompanied by an immediate decrease in MTT reduction which was pH independent. These studies suggested that cellular transport and constant metabolism of glucose were required for maximum MTT reduction. Decreases in the cellular concentration of the reduced pyridine nucleotides NADH and NADPH were accompanied by concomitant decreases in MTT formazan production. MTT formazan varied significantly among cell lines in both the kinetics of its formation and the degree of saturability exhibited. Apparent IC50 values for Adriamycin varied, in a cell line-specific manner, with MTT exposure time. These results indicate that MTT specific activity is significantly influenced by a number of parameters and suggest that assay conditions should be established which minimize their effects.

  13. Improving cellularity and quality of liquid-based cytology slides processed from pancreatobiliary tract brushings.

    Science.gov (United States)

    Campion, Michael B; Kipp, Benjamin R; Humphrey, Sandra K; Zhang, Jun; Clayton, Amy C; Henry, Michael R

    2010-09-01

    Cytology has been reported to have suboptimal sensitivity for detecting pancreatobiliary tract cancer in biliary tract specimens partly as a result of low specimen cellularity and obscuring noncellular components. The goal of this study was to determine if the use of a glacial acetic acid wash prior to processing would increase the cellularity and improve the quality of ThinPrep slides when compared to standard non-gyn ThinPrep processing. Fifty consecutive pancreatobiliary tract specimens containing 20 ml of sample/PreservCyt were divided equally for standard non-gyn ThinPrep (STP) and glacial acetic acid ThinPrep processing (GATP). A manual drop preparation was also performed on residual STP specimen to determine the number of cells left in the vial during STP processing. Twenty-six (52%) specimens had more epithelial cell groupings with the GATP methodology while 19 (38%) had equivalent cellularity with both methods. The STP method produced more epithelial cell groupings in 5 (10%) of the specimens. Of the 26 specimens that had less cells with the STP method, 14 (54%) had > or = 50 cell groupings on the manual drop slide processed from the residual STP specimen suggesting that many cells remain in the vial after STP processing. The GATP method was preferred in 25 (50%) of the specimens, the STP method in 5 (10%), while both methodologies provided similar findings in the remaining 20 (40%) of specimens. The data from this study suggests that the GATP method results in more cells being placed on the slide and was preferred over the STP method in a majority of specimens.

  14. The analysis of speed-reporting rates from a cellular network based on a fingerprint-positioning algorithm

    Directory of Open Access Journals (Sweden)

    Chi-Hua Chen

    2013-05-01

    Full Text Available The collection of real-time traffic information is an important part of intelligent transportation systems. In particular, cellular floating vehicle data (CFVD technology has become increasingly widespread, and more and more popular for measuring and forecasting real-time traffic information, based on anonymous sampling of the positions of mobile phones. This study proposes an analytical model to analyse the speed-reporting rates based on communication behaviour, traffic conditions, and the two consecutive fingerprint-positioning locations from the call arrival and call completion signals of the same call for a feasibility evaluation of CFVD.

  15. Real-time reporting and internet-accessible cellular based coastal sea level gauge

    Digital Repository Service at National Institute of Oceanography (India)

    Desai, R.G.P.; Joseph, A.; Agarvadekar, Y.; Mehra, P.; Dabholkar, N.; Parab, A.; Gouveia, A.D.; Tengali, S.

    -level data communication systems for the benefit the coastal communities and the local administrators (Joseph and Prabhudesai, 2005). Further, real-time sea-level data would form an important input to storm-surge predictive models and warning systems. Given... as on the receiving- side. This adds to the hardware cost as well as software overheads on the receiving- side to check the data integrity for transmission errors. The main benefit of cellular connectivity with GPRS technology is that it utilizes radio resources only...

  16. Pattern-oriented Agent-based Monte Carlo simulation of Cellular Redox Environment

    DEFF Research Database (Denmark)

    Tang, Jiaowei; Holcombe, Mike; Boonen, Harrie C.M.

    , that there is a connection between extracellular and intracellular redox [2], whereas others oppose this view [3]. In general however, these experiments lack insight into the dynamics, complex network of reactions and transportation through cell membrane of redox. Therefore, current experimental results reveal......, 2012. 287(7): p. 4397-402. 3. Anderson, C.L., et al., Control of extracellular cysteine/cystine redox state by HT-29 cells is independent of cellular glutathione. Am J Physiol Regul Integr Comp Physiol, 2007. 293(3): p. R1069-75. 4. Go, Y.M. and D.P. Jones, Redox compartmentalization in eukaryotic...

  17. A new TDOA algorithm based on Taylor series expansion in cellular networks

    Institute of Scientific and Technical Information of China (English)

    Lingwen ZHANG; Zhenhui TAN

    2008-01-01

    Time difference of arrival (TDOA) is the positioning technique with the most potential in cellular mobile telecommunication systems. The Taylor series expansion method has been widely used in solving nonlinear equations for its high accuracy and good robustness. However, the performance of the Taylor's method depends highly on the initial estimation. Therefore, one new algorithm, hybrid optimizing algo-rithm (HOA) was proposed, which combines the Taylor series expansion method with the steepest decent method. The steepest decent method features fast convergence at the initial iteration and small computation complexity. HOA takes great advantage of both methods. Simulation results show that HOA achieves better performance on positioning accuracy and efficiency.

  18. Effects of thyroxine and 1-methyl, 2-mercaptoimidazol on phosphoinositides synthesis in rat liver

    Directory of Open Access Journals (Sweden)

    Krasilnikova Oksana A

    2004-12-01

    Full Text Available Abstract Background Phosphoinositides mediate one of the intracellular signal transduction pathways and produce a class of second messengers that are involved in the action of hormones and neurotransmitters on target cells. Thyroid hormones are well known regulators of lipid metabolism and modulators of signal transduction in cells. However, little is known about phosphoinositides cycle regulation by thyroid hormones. The present paper deals with phosphoinositides synthesis de novo and acylation in liver at different thyroid status of rats. Results The experiments were performed in either the rat liver or hepatocytes of 90- and 720-day-old rats. Myo-[3H]inositol, [14C]CH3COONa, [14C]oleic and [3H]arachidonic acids were used to investigate the phosphatidylinositol (PtdIns, phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate (PtdInsP2 synthesis. 1-methyl, 2-mercaptoimidazol-induced hypothyroidism was associated with the decrease of myo-[3H]inositol and [3H]arachidonic acids incorporation into liver phosphoinositides and total phospholipids, respectively. The thyroxine (L-T4 injection to hypothyroid animals increased the hormones contents in blood serum and PtdInsP2 synthesis de novo as well as [3H]arachidonic acids incorporation into the PtdIns and PtdInsP2. Under the hormone action, the [14C]oleic acid incorporation into PtdIns reduced in the liver of hypothyroid animals. A single injection of L-T4 to the euthyroid [14C]CH3COONa-pre-treated animals or addition of the hormone to a culture medium of hepatocytes was accompanied by the rapid prominent increase in the levels of the newly synthesized PtdIns and PtdInsP2 and in the mass of phosphatidic acid in the liver or the cells. Conclusions The data obtained have demonstrated that thyroid hormones are of vital importance in the regulation of arachidonate-containing phosphoinositides metabolism in the liver. The drug-induced malfunction of thyroid gland noticeably changed the

  19. Cellular Mechanisms of Liver Regeneration and Cell-Based Therapies of Liver Diseases

    Science.gov (United States)

    Yarygin, Konstantin N.

    2017-01-01

    The emerging field of regenerative medicine offers innovative methods of cell therapy and tissue/organ engineering as a novel approach to liver disease treatment. The ultimate scientific foundation of both cell therapy of liver diseases and liver tissue and organ engineering is delivered by the in-depth studies of the cellular and molecular mechanisms of liver regeneration. The cellular mechanisms of the homeostatic and injury-induced liver regeneration are unique. Restoration of the mass of liver parenchyma is achieved by compensatory hypertrophy and hyperplasia of the differentiated parenchymal cells, hepatocytes, while expansion and differentiation of the resident stem/progenitor cells play a minor or negligible role. Participation of blood-borne cells of the bone marrow origin in liver parenchyma regeneration has been proven but does not exceed 1-2% of newly formed hepatocytes. Liver regeneration is activated spontaneously after injury and can be further stimulated by cell therapy with hepatocytes, hematopoietic stem cells, or mesenchymal stem cells. Further studies aimed at improving the outcomes of cell therapy of liver diseases are underway. In case of liver failure, transplantation of engineered liver can become the best option in the foreseeable future. Engineering of a transplantable liver or its major part is an enormous challenge, but rapid progress in induced pluripotency, tissue engineering, and bioprinting research shows that it may be doable. PMID:28210629

  20. Reuse Partitioning-Based Frequency Assignment in Fixed Two-Hop Relay Cellular Network

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In relay cellular network, relay links will consume extra frequency resources, which makes radio resource allocation become more complex and important. A new frequency allocation scheme is proposed to increase cell capacity and improve signal-to-interference ratio (SIR) of users located at cell edges. By dividing cell into different parts and configuring each of these parts with a unique reuse factor, this scheme improves spectral utilization efficiency and avoids inter-cell interference effectively. Optimal combinations of reuse factors and locations of relay nodes are also addressed and investigated. Computer simulation results show that, by employing the proposed scheme, maximum cell capacity gains of about 50%, 35% and 30% can be achieved in comparison with conventional cellular network scheme, traditional reuse partitioning scheme and reuse-adjacent-cell-frequencies scheme, respectively. Moreover, since in the proposed scheme resources are dynamically allocated among relay nodes, more benefits can be obtained in comparison with fixed resource allocation schemes under non-uniform traffic distribution.

  1. Study on Parameter Optimization Design of Drum Brake Based on Hybrid Cellular Multiobjective Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Yi Zhang

    2012-01-01

    Full Text Available In consideration of the significant role the brake plays in ensuring the fast and safe running of vehicles, and since the present parameter optimization design models of brake are far from the practical application, this paper proposes a multiobjective optimization model of drum brake, aiming at maximizing the braking efficiency and minimizing the volume and temperature rise of drum brake. As the commonly used optimization algorithms are of some deficiency, we present a differential evolution cellular multiobjective genetic algorithm (DECell by introducing differential evolution strategy into the canonical cellular genetic algorithm for tackling this problem. For DECell, the gained Pareto front could be as close as possible to the exact Pareto front, and also the diversity of nondominated individuals could be better maintained. The experiments on the test functions reveal that DECell is of good performance in solving high-dimension nonlinear multiobjective problems. And the results of optimizing the new brake model indicate that DECell obviously outperforms the compared popular algorithm NSGA-II concerning the number of obtained brake design parameter sets, the speed, and stability for finding them.

  2. Rapid enrichment of rare-earth metals by carboxymethyl cellulose-based open-cellular hydrogel adsorbent from HIPEs template.

    Science.gov (United States)

    Zhu, Yongfeng; Wang, Wenbo; Zheng, Yian; Wang, Feng; Wang, Aiqin

    2016-04-20

    A series of monolithic open-cellular hydrogel adsorbents based on carboxymethylcellulose (CMC) were prepared through high internal phase emulsions (HIPEs) and used to enrich the rare-earth metals La(3+) and Ce(3+). The changes of pore structure, and the effects of pH, contact time, initial concentration on the adsorption performance were systematically studied. The results show that the as-prepared monolithic hydrogel adsorbents possess good open-cellular framework structure and have fast adsorption kinetics and high adsorption capacity for La(3+) and Ce(3+). The involved adsorption system can reach equilibrium within 30min and the maximal adsorption capacity is determined to be 384.62mg/g for La(3+) and 333.33mg/g for Ce(3+). Moreover, these porous hydrogel adsorbents show an excellent adsorptive reusability for La(3+) and Ce(3+) through five adsorption-desorption cycles. Such a pore hierarchy structure makes this monolithic open-cellular hydrogel adsorbent be an effective adsorbent for effective enrichment of La(3+) and Ce(3+) from aqueous solution.

  3. Low Density Nanocellular Polymers Based on PMMA Produced by Gas Dissolution Foaming: Fabrication and Cellular Structure Characterization

    Directory of Open Access Journals (Sweden)

    Judith Martín-de León

    2016-07-01

    Full Text Available This paper describes the processing conditions needed to produce low density nanocellular polymers based on polymethylmethacrylate (PMMA with relative densities between 0.45 and 0.25, cell sizes between 200 and 250 nm and cell densities higher than 1014 cells/cm3. To produce these nanocellular polymers, the foaming parameters of the gas dissolution foaming technique using CO2 as blowing agent have been optimized. Taking into account previous works, the amount of CO2 uptake was maintained constant (31% by weight for all the materials. Foaming parameters were modified between 40 °C and 110 °C for the foaming temperature and from 1 to 5 min for the foaming time. Foaming temperatures in the range of 80 to 100 °C and foaming times of 2 min allow for production of nanocellular polymers with relative densities as low as 0.25. Cellular structure has been studied in-depth to obtain the processing-cellular structure relationship. In addition, it has been proved that the glass transition temperature depends on the cellular structure. This effect is associated with a confinement of the polymer in the cell walls, and is one of the key reasons for the improved properties of nanocellular polymers.

  4. Confocal microscopy-based three-dimensional cell-specific modeling for large deformation analyses in cellular mechanics.

    Science.gov (United States)

    Slomka, Noa; Gefen, Amit

    2010-06-18

    This study introduces a new confocal microscopy-based three-dimensional cell-specific finite element (FE) modeling methodology for simulating cellular mechanics experiments involving large cell deformations. Three-dimensional FE models of undifferentiated skeletal muscle cells were developed by scanning C2C12 myoblasts using a confocal microscope, and then building FE model geometries from the z-stack images. Strain magnitudes and distributions in two cells were studied when the cells were subjected to compression and stretching, which are used in pressure ulcer and deep tissue injury research to induce large cell deformations. Localized plasma membrane and nuclear surface area (NSA) stretches were observed for both the cell compression and stretching simulation configurations. It was found that in order to induce large tensile strains (>5%) in the plasma membrane and NSA, one needs to apply more than approximately 15% of global cell deformation in cell compression tests, or more than approximately 3% of tensile strains in the elastic plate substrate in cell stretching experiments. Utilization of our modeling can substantially enrich experimental cellular mechanics studies in classic cell loading designs that typically involve large cell deformations, such as static and cyclic stretching, cell compression, micropipette aspiration, shear flow and hydrostatic pressure, by providing magnitudes and distributions of the localized cellular strains specific to each setup and cell type, which could then be associated with the applied stimuli.

  5. Examining the limits of cellular adaptation bursting mechanisms in biologically-based excitatory networks of the hippocampus.

    Science.gov (United States)

    Ferguson, K A; Njap, F; Nicola, W; Skinner, F K; Campbell, S A

    2015-12-01

    Determining the biological details and mechanisms that are essential for the generation of population rhythms in the mammalian brain is a challenging problem. This problem cannot be addressed either by experimental or computational studies in isolation. Here we show that computational models that are carefully linked with experiment provide insight into this problem. Using the experimental context of a whole hippocampus preparation in vitro that spontaneously expresses theta frequency (3-12 Hz) population bursts in the CA1 region, we create excitatory network models to examine whether cellular adaptation bursting mechanisms could critically contribute to the generation of this rhythm. We use biologically-based cellular models of CA1 pyramidal cells and network sizes and connectivities that correspond to the experimental context. By expanding our mean field analyses to networks with heterogeneity and non all-to-all coupling, we allow closer correspondence with experiment, and use these analyses to greatly extend the range of parameter values that are explored. We find that our model excitatory networks can produce theta frequency population bursts in a robust fashion.Thus, even though our networks are limited by not including inhibition at present, our results indicate that cellular adaptation in pyramidal cells could be an important aspect for the occurrence of theta frequency population bursting in the hippocampus. These models serve as a starting framework for the inclusion of inhibitory cells and for the consideration of additional experimental features not captured in our present network models.

  6. Characterization of the binding between a 70-kDa heat shock protein, HspA1A, and phosphoinositides.

    Science.gov (United States)

    McCallister, Chelsea; Kdeiss, Brianna; Oliverio, Ryan; Nikolaidis, Nikolas

    2016-03-25

    HspA1A, a seventy-kilodalton heat shock protein, binds to specific anionic lipids and this interaction regulates important physiological phenomena like apoptosis, tumor growth, and lysosomal rescue. However, whether HspA1A binds to phosphoinositides has yet to be established and quantified. Therefore, in this study, we determined the binding affinity of HspA1A to several phosphoinositides and characterized five aspects of their molecular interaction. First, we established that HspA1A binds phosphatidylinositol monophosphates with higher affinity than di- and triphosphorylated inositides. Second, using high concentrations of potassium we found that HSPA1A embeds within the lipid bilayer of all phosphoinositides tested. However, the effects of the high salt concentrations were significantly different between the different phosphoinositides. Third, using calcium and reaction buffers equilibrated at different pH values we found that these differentially affected HspA1A-phosphoinositide binding, revealing a lipid-specific pattern of binding. Fourth, by assessing the binding properties of the two HspA1A domains, the nucleotide-binding domain and the substrate-binding domain, we determined that in most cases the full-length protein is necessary for binding to phosphoinositides. Fifth, by including in the reactions nucleotides and protein substrates we determined that they minimally and differentially affected phosphoinositide-binding. Collectively, these findings strongly suggest that the HspA1A-phosphoinositide binding is complex yet specific, is mediated by both electrostatic and hydrophobic interactions, is not related to the lipid-head charge, and depends on the physicochemical properties of the lipid.

  7. Novel optical-based methods and analyses for elucidating cellular mechanics and dynamics

    Science.gov (United States)

    Koo, Peter K.

    Resolving distinct biochemical interaction states by analyzing the diffusive behaviors of individual protein trajectories is challenging due to the limited statistics provided by short trajectories and experimental noise sources, which are intimately coupled into each proteins localization. In the first part of this thesis, we introduce a novel, a machine-learning based classification methodology, called perturbation expectation-maximization (pEM), which simultaneously analyzes a population of protein trajectories to uncover the system of short-time diffusive behaviors which collectively result from distinct biochemical interactions. We then discuss an experimental application of pEM to Rho GTPase, an integral regulator of cytoskeletal dynamics and cellular homeostasis, inside live cells. We also derive the maximum likelihood estimator (MLE) for driven diffusion, confined diffusion, and fractional Brownian motion. We demonstrate that MLE yields improved estimates in comparison with traditional diffusion analysis, namely mean squared displacement analysis. In addition, we also introduce mleBayes, which is an empirical Bayesian model selection scheme to classify an individual protein trajectory to a given diffusion mode. By employing mleBayes on simulated data, we demonstrate that accurate determination of the underlying diffusive properties, beyond normal diffusion, remains challenging when analyzing particle trajectories on an individual basis. To improve upon the statistical limitations of classification from analyzing trajectories on an individual basis, we extend pEM with a new version (pEMv2) to simultaneously analyzing a collection of particle trajectories to uncover the system of interactions which give rise to unique normal or non-normal diffusive states. We test the performance of pEMv2 on various sets of simulated particle trajectories which transition between various modes of normal and non-normal diffusive states to highlight considerations when

  8. A Compact Self-organizing Cellular Automata-based Genetic Algorithm

    CERN Document Server

    Barmpoutis, Vasileios

    2007-01-01

    A Genetic Algorithm (GA) is proposed in which each member of the population can change schemata only with its neighbors according to a rule. The rule methodology and the neighborhood structure employ elements from the Cellular Automata (CA) strategies. Each member of the GA population is assigned to a cell and crossover takes place only between adjacent cells, according to the predefined rule. Although combinations of CA and GA approaches have appeared previously, here we rely on the inherent self-organizing features of CA, rather than on parallelism. This conceptual shift directs us toward the evolution of compact populations containing only a handful of members. We find that the resulting algorithm can search the design space more efficiently than traditional GA strategies due to its ability to exploit mutations within this compact self-organizing population. Consequently, premature convergence is avoided and the final results often are more accurate. In order to reinforce the superior mutation capability, ...

  9. Fatigue design of a cellular phone folder using regression model-based multi-objective optimization

    Science.gov (United States)

    Kim, Young Gyun; Lee, Jongsoo

    2016-08-01

    In a folding cellular phone, the folding device is repeatedly opened and closed by the user, which eventually results in fatigue damage, particularly to the front of the folder. Hence, it is important to improve the safety and endurance of the folder while also reducing its weight. This article presents an optimal design for the folder front that maximizes its fatigue endurance while minimizing its thickness. Design data for analysis and optimization were obtained experimentally using a test jig. Multi-objective optimization was carried out using a nonlinear regression model. Three regression methods were employed: back-propagation neural networks, logistic regression and support vector machines. The AdaBoost ensemble technique was also used to improve the approximation. Two-objective Pareto-optimal solutions were identified using the non-dominated sorting genetic algorithm (NSGA-II). Finally, a numerically optimized solution was validated against experimental product data, in terms of both fatigue endurance and thickness index.

  10. MEMS-based thermally-actuated image stabilizer for cellular phone camera

    Science.gov (United States)

    Lin, Chun-Ying; Chiou, Jin-Chern

    2012-11-01

    This work develops an image stabilizer (IS) that is fabricated using micro-electro-mechanical system (MEMS) technology and is designed to counteract the vibrations when human using cellular phone cameras. The proposed IS has dimensions of 8.8 × 8.8 × 0.3 mm3 and is strong enough to suspend an image sensor. The processes that is utilized to fabricate the IS includes inductive coupled plasma (ICP) processes, reactive ion etching (RIE) processes and the flip-chip bonding method. The IS is designed to enable the electrical signals from the suspended image sensor to be successfully emitted out using signal output beams, and the maximum actuating distance of the stage exceeds 24.835 µm when the driving current is 155 mA. Depending on integration of MEMS device and designed controller, the proposed IS can decrease the hand tremor by 72.5%.

  11. Numerical study on photoresist etching processes based on a cellular automata model

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    For the three-dimensional (3-D) numerical study of photoresist etching processes, the 2-D dynamic cellular automata (CA) model has been successfully extended to a 3-D dynamic CA model. Only the boundary cells will be processed in the 3-D dy-namic CA model and the structure of “if-else” description in the simulation pro-gram is avoided to speed up the simulation. The 3-D dynamic CA model has found to be stable, fast and accurate for the numerical study of photoresist etching processes. The exposure simulation, post-exposure bake (PEB) simulation and etching simulation are integrated together to further investigate the performances of the CA model. Simulation results have been compared with the available ex-perimental results and the simulations show good agreement with the available experiments.

  12. Numerical study on photoresist etching processes based on a cellular automata model

    Institute of Scientific and Technical Information of China (English)

    ZHOU ZaiFa; HUANG QingAn; LI WeiHua; LU Wei

    2007-01-01

    For the three-dimensional (3-D) numerical study of photoresist etching processes, the 2-D dynamic cellular automata (CA) model has been successfully extended to a 3-D dynamic CA model. Only the boundary cells will be processed in the 3-D dynamic CA model and the structure of "if-else" description in the simulation program is avoided to speed up the simulation. The 3-D dynamic CA model has found to be stable, fast and accurate for the numerical study of photoresist etching processes. The exposure simulation, post-exposure bake (PEB) simulation and etching simulation are integrated together to further investigate the performances of the CA model. Simulation results have been compared with the available experimental results and the simulations show good agreement with the available experiments.

  13. Quantitative MS-based enzymology of caspases reveals distinct protein substrate specificities, hierarchies, and cellular roles.

    Science.gov (United States)

    Julien, Olivier; Zhuang, Min; Wiita, Arun P; O'Donoghue, Anthony J; Knudsen, Giselle M; Craik, Charles S; Wells, James A

    2016-04-05

    Proteases constitute the largest enzyme family, yet their biological roles are obscured by our rudimentary understanding of their cellular substrates. There are 12 human caspases that play crucial roles in inflammation and cell differentiation and drive the terminal stages of cell death. Recent N-terminomics technologies have begun to enumerate the diverse substrates individual caspases can cleave in complex cell lysates. It is clear that many caspases have shared substrates; however, few data exist about the catalytic efficiencies (kcat/KM) of these substrates, which is critical to understanding their true substrate preferences. In this study, we use quantitative MS to determine the catalytic efficiencies for hundreds of natural protease substrates in cellular lysate for two understudied members: caspase-2 and caspase-6. Most substrates are new, and the cleavage rates vary up to 500-fold. We compare the cleavage rates for common substrates with those found for caspase-3, caspase-7, and caspase-8, involved in apoptosis. There is little correlation in catalytic efficiencies among the five caspases, suggesting each has a unique set of preferred substrates, and thus more specialized roles than previously understood. We synthesized peptide substrates on the basis of protein cleavage sites and found similar catalytic efficiencies between the protein and peptide substrates. These data suggest the rates of proteolysis are dominated more by local primary sequence, and less by the tertiary protein fold. Our studies highlight that global quantitative rate analysis for posttranslational modification enzymes in complex milieus for native substrates is critical to better define their functions and relative sequence of events.

  14. Application of neural networks to channel assignment for cellular CDMA networks with multiple services and mobile base stations

    Science.gov (United States)

    Hortos, William S.

    1996-03-01

    The use of artificial neural networks to the channel assignment problem for cellular code- division multiple access (CDMA) telecommunications systems is considered. CDMA takes advantage of voice activity and spatial isolation because its capacity is only interference limited, unlike time-division multiple access (TDMA) and frequency-division multiple access (FDMA) where capacities are bandwidth limited. Any reduction in interference in CDMA translates linearly into increased capacity. FDMA and TDMA use a frequency reuse pattern as a method to increase capacity, while CDMA reuses the same frequency for all cells and gains a reuse efficiency by means of orthogonal codes. The latter method can improve system capacity by factors of four to six over digital TDMA or FDMA. Cellular carriers are planning to provide multiple communication services using CDMA in the next generation cellular system infrastructure. The approach of this study is the use of neural network methods for automatic and local network control, based on traffic behavior in specific cell cites and demand history. The goal is to address certain problems associated with the management of mobile and personal communication services in a cellular radio communications environment. In planning a cellular radio network, the operator assigns channels to the radio cells so that the probability of the processed carrier-to-interference ratio, CII, exceeding a predefined value is sufficiently low. The RF propagation, determined from the topography and infrastructure in the operating area, is used in conjunction with the densities of expected communications traffic to formulate interference constraints. These constraints state which radio cells may use the same code (channel) or adjacent channels at a time. The traffic loading and the number of service grades can also be used to calculate the number of required channels (codes) for each cell. The general assignment problem is the task of assigning the required number

  15. Phosphoinositide-specific Phospholipase C β1 gene deletion in bipolar disorder affected patient.

    Science.gov (United States)

    Lo Vasco, Vincenza Rita; Longo, Lucia; Polonia, Patrizia

    2013-03-01

    The involvement of phosphoinositides (PI) signal transduction pathway and related molecules, such as the Phosphoinositide-specific Phospholipase C (PI-PLC) enzymes, in the pathophysiology of mood disorders is corroborated by a number of recent evidences. Our previous works identified the deletion of PLCB1 gene, which codifies for the PI-PLC β1 enzyme, in 4 out 15 patients affected with schizophrenia, and no deletion both in major depression affected patients and in normal controls. By using interphase fluorescent in situ hybridization methodology, we analyzed PLCB1 in paraffin embedded samples of orbito-frontal cortex of 15 patients affected with bipolar disorder. Deletion of PLCB1 was identified in one female patient.

  16. Parameter estimation with a novel gradient-based optimization method for biological lattice-gas cellular automaton models.

    Science.gov (United States)

    Mente, Carsten; Prade, Ina; Brusch, Lutz; Breier, Georg; Deutsch, Andreas

    2011-07-01

    Lattice-gas cellular automata (LGCAs) can serve as stochastic mathematical models for collective behavior (e.g. pattern formation) emerging in populations of interacting cells. In this paper, a two-phase optimization algorithm for global parameter estimation in LGCA models is presented. In the first phase, local minima are identified through gradient-based optimization. Algorithmic differentiation is adopted to calculate the necessary gradient information. In the second phase, for global optimization of the parameter set, a multi-level single-linkage method is used. As an example, the parameter estimation algorithm is applied to a LGCA model for early in vitro angiogenic pattern formation.

  17. The Receptor Binding Domain of Botulinum Neurotoxin Stereotype C Binds Phosphoinositides

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yanfeng; Varnum, Susan M.

    2012-03-01

    Botulinum neurotoxins (BoNTs) are the most toxic proteins known for humans and animals with an extremely low LD50 of {approx} 1 ng/kg. BoNTs generally require a protein and a ganglioside on the cell membrane surface for binding, which is known as a 'dual receptor' mechanism for host intoxication. Recent studies have suggested that in addition to gangliosides, other membrane lipids such as phosphoinositides may be involved in the interactions with the receptor binding domain (HCR) of BoNTs for better membrane penetration. Here, using two independent lipid-binding assays, we tested the interactions of BoNT/C-HCR with lipids in vitro. BoNT/C-HCR was found to bind negatively charged phospholipids, preferentially phosphoinositides. Additional interactions to phosphoinositides may help BoNT/C bind membrane more tightly and transduct signals for subsequent steps of intoxication. Our results provide new insights into the mechanisms of host cell membrane recognition by BoNTs.

  18. Involvement of Sac1 phosphoinositide phosphatase in the metabolism of phosphatidylserine in the yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Tani, Motohiro; Kuge, Osamu

    2014-04-01

    Sac1 is a phosphoinositide phosphatase that preferentially dephosphorylates phosphatidylinositol 4-phosphate. Mutation of SAC1 causes not only the accumulation of phosphoinositides but also reduction of the phosphatidylserine (PS) level in the yeast Saccharomyces cerevisiae. In this study, we characterized the mechanism underlying the PS reduction in SAC1-deleted cells. Incorporation of (32) P into PS was significantly delayed in sac1∆ cells. Such a delay was also observed in SAC1- and PS decarboxylase gene-deleted cells, suggesting that the reduction in the PS level is caused by a reduction in the rate of biosynthesis of PS. A reduction in the PS level was also observed with repression of STT4 encoding phosphatidylinositol 4-kinase or deletion of VPS34 encoding phophatidylinositol 3-kinase. However, the combination of mutations of SAC1 and STT4 or VPS34 did not restore the reduced PS level, suggesting that both the synthesis and degradation of phosphoinositides are important for maintenance of the PS level. Finally, we observed an abnormal PS distribution in sac1∆ cells when a specific probe for PS was expressed. Collectively, these results suggested that Sac1 is involved in the maintenance of a normal rate of biosynthesis and distribution of PS.

  19. Traffic Accident Propagation Properties and Control Measures for Urban Links Based on Cellular Automata

    Directory of Open Access Journals (Sweden)

    Xian-sheng Li

    2013-01-01

    Full Text Available With the rapid development of urban transport and the sharp increase in vehicle population, traffic accidents form one of the most important causes of urban traffic congestion other than the imbalance between traffic supply and demand. Traffic congestion causes severe problems, such as environment contamination and energy dissipation. Therefore, it would be useful to analyze the congestion propagation characteristics after traffic accidents. Numerical analysis and computer simulation were two of the typical methods used at present to study the traffic congestion propagation properties. The latter was more widespread as it is more consistent with the actual traffic flow and more visual than the former. In this paper, an improved cellular automata (CA model was presented to analyze traffic congestion propagation properties and to evaluate control strategies. In order to apply them to urban traffic flow simulation, the CA models have been improved and expanded on. Computer simulations were built for congestion not only extending to the upstream intersection, but also the upstream intersection and the entire road network, respectively. Congestion propagation characteristics after road traffic accidents were obtained, and controls of different severities and durations were analyzed. The results provide the theoretical foundation and practical means for the control of congestion.

  20. A cellular automata based FPGA realization of a new metaheuristic bat-inspired algorithm

    Science.gov (United States)

    Progias, Pavlos; Amanatiadis, Angelos A.; Spataro, William; Trunfio, Giuseppe A.; Sirakoulis, Georgios Ch.

    2016-10-01

    Optimization algorithms are often inspired by processes occuring in nature, such as animal behavioral patterns. The main concern with implementing such algorithms in software is the large amounts of processing power they require. In contrast to software code, that can only perform calculations in a serial manner, an implementation in hardware, exploiting the inherent parallelism of single-purpose processors, can prove to be much more efficient both in speed and energy consumption. Furthermore, the use of Cellular Automata (CA) in such an implementation would be efficient both as a model for natural processes, as well as a computational paradigm implemented well on hardware. In this paper, we propose a VHDL implementation of a metaheuristic algorithm inspired by the echolocation behavior of bats. More specifically, the CA model is inspired by the metaheuristic algorithm proposed earlier in the literature, which could be considered at least as efficient than other existing optimization algorithms. The function of the FPGA implementation of our algorithm is explained in full detail and results of our simulations are also demonstrated.

  1. Virtual cellular manufacturing system based on resource element approach and analyzing its performance over different basic layouts

    Directory of Open Access Journals (Sweden)

    G. R. Esmaeilian

    2012-01-01

    Full Text Available This research aims to present how choosing a suitable layout can improve the performance of virtual cellular manufacturing systems (VCMSs, especially minimizing the material flow between machines required by each family group. To present the efficacy of basic layouts on performances of VCMSs, a multi-objective mathematical model with a goal programming (GP approach is developed to generate VCMSs based on resource-elements (REs. The formulated model is coded in Lingo software and is run over functional and distributed arrangements of the same machines. The performance and the validity of the developed model are checked by a numerical example taken from the literature. The objective function of the mathematical model is measured for that example over two mentioned layout to compare the performance of the generated systems. Moreover, because of the material handling costs importance, material flows are measured to find the best option as a basic layout for VCMSs. To compare the performance of the generated system with the classical cellular manufacturing system (CMS, cell capacity utilization (CCU is employed as an independent criterion to evaluate each system. The result illustrates the priority of distributed layouts for generating RE-based VCMSs because of its flexibility, minimizing the objective function for the mathematical model, and smaller material flow by the components. In addition, the generated VCMSs outperforms the classical CMS from the CCU point of view.

  2. Radio Capacity Estimation for Millimeter Wave 5G Cellular Networks Using Narrow Beamwidth Antennas at the Base Stations

    Directory of Open Access Journals (Sweden)

    AlMuthanna Turki Nassar

    2015-01-01

    Full Text Available This paper presents radio frequency (RF capacity estimation for millimeter wave (mm-wave based fifth-generation (5G cellular networks using field-level simulations. It is shown that, by reducing antenna beamwidth from 65° to 30°, we can enhance the capacity of mm-wave cellular networks roughly by 3.0 times at a distance of 220 m from the base station (BS. This enhancement is far much higher than the corresponding enhancement of 1.2 times observed for 900 MHz and 2.6 GHz microwave networks at the same distance from the BS. Thus the use of narrow beamwidth transmitting antennas has more pronounced benefits in mm-wave networks. Deployment trials performed on an LTE TDD site operating on 2.6 GHz show that 6-sector site with 27° antenna beamwidth enhances the quality of service (QoS roughly by 40% and more than doubles the overall BS throughput (while enhancing the per sector throughput 1.1 times on average compared to a 3-sector site using 65° antenna beamwidth. This agrees well with our capacity simulations. Since mm-wave 5G networks will use arbitrary number of beams, with beamwidth much less than 30°, the capacity enhancement expected in 5G system when using narrow beamwidth antennas would be much more than three times observed in our simulations.

  3. Reversible quantum cellular automata

    CERN Document Server

    Schumacher, B

    2004-01-01

    We define quantum cellular automata as infinite quantum lattice systems with discrete time dynamics, such that the time step commutes with lattice translations and has strictly finite propagation speed. In contrast to earlier definitions this allows us to give an explicit characterization of all local rules generating such automata. The same local rules also generate the global time step for automata with periodic boundary conditions. Our main structure theorem asserts that any quantum cellular automaton is structurally reversible, i.e., that it can be obtained by applying two blockwise unitary operations in a generalized Margolus partitioning scheme. This implies that, in contrast to the classical case, the inverse of a nearest neighbor quantum cellular automaton is again a nearest neighbor automaton. We present several construction methods for quantum cellular automata, based on unitaries commuting with their translates, on the quantization of (arbitrary) reversible classical cellular automata, on quantum c...

  4. Computational Cellular Dynamics Based on the Chemical Master Equation: A Challenge for Understanding Complexity.

    Science.gov (United States)

    Liang, Jie; Qian, Hong

    2010-01-01

    Modern molecular biology has always been a great source of inspiration for computational science. Half a century ago, the challenge from understanding macromolecular dynamics has led the way for computations to be part of the tool set to study molecular biology. Twenty-five years ago, the demand from genome science has inspired an entire generation of computer scientists with an interest in discrete mathematics to join the field that is now called bioinformatics. In this paper, we shall lay out a new mathematical theory for dynamics of biochemical reaction systems in a small volume (i.e., mesoscopic) in terms of a stochastic, discrete-state continuous-time formulation, called the chemical master equation (CME). Similar to the wavefunction in quantum mechanics, the dynamically changing probability landscape associated with the state space provides a fundamental characterization of the biochemical reaction system. The stochastic trajectories of the dynamics are best known through the simulations using the Gillespie algorithm. In contrast to the Metropolis algorithm, this Monte Carlo sampling technique does not follow a process with detailed balance. We shall show several examples how CMEs are used to model cellular biochemical systems. We shall also illustrate the computational challenges involved: multiscale phenomena, the interplay between stochasticity and nonlinearity, and how macroscopic determinism arises from mesoscopic dynamics. We point out recent advances in computing solutions to the CME, including exact solution of the steady state landscape and stochastic differential equations that offer alternatives to the Gilespie algorithm. We argue that the CME is an ideal system from which one can learn to understand "complex behavior" and complexity theory, and from which important biological insight can be gained.

  5. PROFILIN ACTIVATES BACILLUS THURINGIENSIS PHOSPHOINOSITIDE SPECIFIC PHOSPHOLIPASE C

    Directory of Open Access Journals (Sweden)

    Sandeepta Burgula

    2012-08-01

    Full Text Available Many extracellular signaling molecules including hormones, growth factors, neurotransmitters andimmunoglobulins elicit intracellular responses by activating phosphatidylinositol-specific phospholipase C (PI-PLCupon binding to their cell surface receptors. Activated PLC catalyses the hydrolysis of Phosphotidylinositol 4,5-bisphosphate (PIP2 to generate DAG and IP3 , which act as signaling molecules that control various cellular processes.Exploring the mechanism of regulation of PLC activity may lead to understanding various signaling events thatregulate cell growth and differentiation. One of the dramatic effects of profilin is inhibition of PIP2 hydrolysis by PLC-γ in eukaryotic cells. In the present study, the effect of profilin on Phosphotidylinositol specific phospholipase C (PI-PLC purified from Bacillus thuringiensis (Bt was examined. Assay of PI-PLC activity indicated that Bovine profilinactivated the hydrolysis of phosphotidylinositol (PI by BtPI-PLC in a concentration dependent manner under in vitroconditions. A 250 % increase in activity was noted in the presence of profilin but not in presence of phosphoprofilin. Inthe presence of profilin more proteins are observed in the soluble fraction. In conclusion it can be stated that thatprofilin activates bacterial PLC activity towards PI hydrolysis

  6. BioJazz: in silico evolution of cellular networks with unbounded complexity using rule-based modeling.

    Science.gov (United States)

    Feng, Song; Ollivier, Julien F; Swain, Peter S; Soyer, Orkun S

    2015-10-30

    Systems biologists aim to decipher the structure and dynamics of signaling and regulatory networks underpinning cellular responses; synthetic biologists can use this insight to alter existing networks or engineer de novo ones. Both tasks will benefit from an understanding of which structural and dynamic features of networks can emerge from evolutionary processes, through which intermediary steps these arise, and whether they embody general design principles. As natural evolution at the level of network dynamics is difficult to study, in silico evolution of network models can provide important insights. However, current tools used for in silico evolution of network dynamics are limited to ad hoc computer simulations and models. Here we introduce BioJazz, an extendable, user-friendly tool for simulating the evolution of dynamic biochemical networks. Unlike previous tools for in silico evolution, BioJazz allows for the evolution of cellular networks with unbounded complexity by combining rule-based modeling with an encoding of networks that is akin to a genome. We show that BioJazz can be used to implement biologically realistic selective pressures and allows exploration of the space of network architectures and dynamics that implement prescribed physiological functions. BioJazz is provided as an open-source tool to facilitate its further development and use. Source code and user manuals are available at: http://oss-lab.github.io/biojazz and http://osslab.lifesci.warwick.ac.uk/BioJazz.aspx.

  7. An Asynchronous Recurrent Network of Cellular Automaton-Based Neurons and Its Reproduction of Spiking Neural Network Activities.

    Science.gov (United States)

    Matsubara, Takashi; Torikai, Hiroyuki

    2016-04-01

    Modeling and implementation approaches for the reproduction of input-output relationships in biological nervous tissues contribute to the development of engineering and clinical applications. However, because of high nonlinearity, the traditional modeling and implementation approaches encounter difficulties in terms of generalization ability (i.e., performance when reproducing an unknown data set) and computational resources (i.e., computation time and circuit elements). To overcome these difficulties, asynchronous cellular automaton-based neuron (ACAN) models, which are described as special kinds of cellular automata that can be implemented as small asynchronous sequential logic circuits have been proposed. This paper presents a novel type of such ACAN and a theoretical analysis of its excitability. This paper also presents a novel network of such neurons, which can mimic input-output relationships of biological and nonlinear ordinary differential equation model neural networks. Numerical analyses confirm that the presented network has a higher generalization ability than other major modeling and implementation approaches. In addition, Field-Programmable Gate Array-implementations confirm that the presented network requires lower computational resources.

  8. Cellular responses to chlorin-based photosensitizer DH-II-24 under darkness in human gastric adenocarcinoma AGS cells.

    Science.gov (United States)

    Lim, Young-Cheol; Yoo, Je-Ok; Kang, Seong-Sik; Kim, Young-Myeong; Ha, Kwon-Soo

    2011-03-01

    We investigated cellular responses to chlorin-based photosensitizer DH-II-24 under darkness in human gastric adenocarcinoma AGS cells. Cells were loaded with 0.5-10 μg/mL DH-II-24 for 12 h, and intracellular reactive oxygen species (ROS) and intracellular Ca(2+) levels, in situ tissue transglutaminase (tTGase) activity, cell viability, cell morphology and cell cycle were examined. DH-II-24 treatment had no effect on intracellular ROS production or cell morphology, and did not induce cell detachment at any concentrations tested. In addition, cell viability and cell cycle progression were not altered by the photosensitizer. However, DH-II-24 treatment elevated the basal level of intracellular Ca(2+) in a dose-dependent manner and inhibited tTGase activity without affecting tTGase expression levels. Furthermore, DH-II-24 inhibited lysophosphatidic acid-induced activation of tTGase in a dose-dependent manner. In contrast, photodynamic therapy (PDT) with 1 μg/mL DH-II-24 significantly elevated intracellular ROS and in situ tTGase activity in parallel with a rapid and large increase in intracellular Ca(2+) levels. DH-II-24-mediated PDT decreased cell viability and induced cell detachment. These results demonstrate that DH-II-24 treatment alone under darkness induced different cellular responses to DH-II-24-mediated PDT.

  9. Recent progress in design of protein-based fluorescent biosensors and their cellular applications.

    Science.gov (United States)

    Tamura, Tomonori; Hamachi, Itaru

    2014-12-19

    Protein-based fluorescent biosensors have emerged as key bioanalytical tools to visualize and quantify a wide range of biological substances and events in vitro, in cells, and even in vivo. On the basis of the construction method, the protein-based fluorescent biosensors can be principally classified into two classes: (1) genetically encoded fluorescent biosensors harnessing fluorescent proteins (FPs) and (2) semisynthetic biosensors comprised of protein scaffolds and synthetic fluorophores. Recent advances in protein engineering and chemical biology not only allowed the further optimization of conventional biosensors but also facilitated the creation of novel biosensors based on unique strategies. In this review, we survey the recent studies in the development and improvement of protein-based fluorescent biosensors and highlight the successful applications to live cell and in vivo imaging. Furthermore, we provide perspectives on possible future directions of the technique.

  10. An ANN Based Call Handoff Management Scheme for Mobile Cellular Network

    Directory of Open Access Journals (Sweden)

    P. P. Bhattacharya

    2013-12-01

    Full Text Available Handoff decisions are usually signal strength based because of simplicity and effectiveness. Apart fro m the conventional techniques, such as threshold and hyst eresis based schemes, recently many artificial intelligent techniques such as Fuzzy Logic, Artific ial Neural Network (ANN etc. are also used for tak ing handoff decision. In this paper, an Artificial Neur al Network based handoff algorithm is proposed and it’s performance is studied. We have used ANNhere for ta king fast and accurate handoff decision. In our proposed handoff algorithm, Backpropagation Neural Network model is used.The advantages of Backpropagation method are its simplicity and reaso nable speed. The algorithm is designed, tested and found to give optimum results.

  11. A literature mining-based approach for identification of cellular pathways associated with chemoresistance in cancer.

    Science.gov (United States)

    Oh, Jung Hun; Deasy, Joseph O

    2016-05-01

    Chemoresistance is a major obstacle to the successful treatment of many human cancer types. Increasing evidence has revealed that chemoresistance involves many genes and multiple complex biological mechanisms including cancer stem cells, drug efflux mechanism, autophagy and epithelial-mesenchymal transition. Many studies have been conducted to investigate the possible molecular mechanisms of chemoresistance. However, understanding of the biological mechanisms in chemoresistance still remains limited. We surveyed the literature on chemoresistance-related genes and pathways of multiple cancer types. We then used a curated pathway database to investigate significant chemoresistance-related biological pathways. In addition, to investigate the importance of chemoresistance-related markers in protein-protein interaction networks identified using the curated database, we used a gene-ranking algorithm designed based on a graph-based scoring function in our previous study. Our comprehensive survey and analysis provide a systems biology-based overview of the underlying mechanisms of chemoresistance.

  12. Cellular Telephone

    Institute of Scientific and Technical Information of China (English)

    杨周

    1996-01-01

    Cellular phones, used in automobiles, airliners, and passenger trains, are basically low-power radiotelephones. Calls go through radio transmitters that are located within small geographical units called cells. Because each cell’s signals are too weak to interfere with those of other cells operating on the same fre-

  13. Iris segmentation using an edge detector based on fuzzy sets theory and cellular learning automata.

    Science.gov (United States)

    Ghanizadeh, Afshin; Abarghouei, Amir Atapour; Sinaie, Saman; Saad, Puteh; Shamsuddin, Siti Mariyam

    2011-07-01

    Iris-based biometric systems identify individuals based on the characteristics of their iris, since they are proven to remain unique for a long time. An iris recognition system includes four phases, the most important of which is preprocessing in which the iris segmentation is performed. The accuracy of an iris biometric system critically depends on the segmentation system. In this paper, an iris segmentation system using edge detection techniques and Hough transforms is presented. The newly proposed edge detection system enhances the performance of the segmentation in a way that it performs much more efficiently than the other conventional iris segmentation methods.

  14. Study on cellular internalization of poly(vinyldiaminotriazine)-based hydrosen bonding type non-viral trans-gene vector

    Institute of Scientific and Technical Information of China (English)

    YE GuiXiang; CAO ZhiQiang; LIN Lin; CHEN DaYong; LIU WenGuang

    2008-01-01

    Previously we successfully prepared poly(vinyldiaminotriazine)(PVDT)-based non-viral vectors which complexed plasmid DNA via hydrogen bonding with adenine-thymine base pairs. In this report, surface charges and complex sizes of this system were further examined. The results showed that PVDT-based polymer could cover surface charges of DNA resulting in slightly negative or neutral complexes. It was also found that the complex sizes were governed by two events: the aggregation induced by the instability of neutral particles, and more compact complexes produced by PVDT-based polymers. In the study of cellular uptake, chlorpromazine and filipin III were used to inhibit clathrin- and caveolae-mediated endocytosis, respectively. We found that PVDT-based systems were transported into cells via a non-clathrin, non-caveolae mediated endocytosis. This special process was studied by temperature inhibition and kinetics assays. It was revealed that such a pathway was characterized by (i) a more energy dependent process and (ii) a much slow transfection-effective internalization.

  15. Key Instructional Design Issues in a Cellular Phone-Based Mobile Learning Project

    Science.gov (United States)

    Gedik, Nuray; Hanci-Karademirci, Arzu; Kursun, Engin; Cagiltay, Kursat

    2012-01-01

    Adding flexibility to the learning process, mobile learning offers great opportunities for education, especially for teenagers, who show great attentiveness to mobile technologies. Thus, the need to focus on design aspects of such learning is growing. This study aims to reveal critical issues in designing mobile learning based on a program for…

  16. Single Cell Microgel Based Modular Bioinks for Uncoupled Cellular Micro- and Macroenvironments.

    Science.gov (United States)

    Kamperman, Tom; Henke, Sieger; van den Berg, Albert; Shin, Su Ryon; Tamayol, Ali; Khademhosseini, Ali; Karperien, Marcel; Leijten, Jeroen

    2017-02-01

    Modular bioinks based on single cell microgels within distinct injectable prepolymers enable uncoupling of biomaterials' micro- and macroenvironments. These inks allow biofabrication of 3D constructs that recapitulate the multiscale modular design of native tissues with a single cell resolution. This approach represents a major step forward in endowing engineered constructs with the multifunctionality that underlies the behavior of native tissues.

  17. Single Cell Microgel Based Modular Bioinks for Uncoupled Cellular Micro- and Macrenvironments

    NARCIS (Netherlands)

    Kamperman, T.; Henke, S.J.; Berg, van den A.; Shin, S.R.; Tamayol, A.; Khademhosseini, A.; Karperien, H.B.J.; Leijten, J.C.H.

    2016-01-01

    Modular bioinks based on single cell microgels within distinct injectable prepolymers enable uncoupling of biomaterials' micro- and macroenvironments. These inks allow biofabrication of 3D constructs that recapitulate the multiscale modular design of native tissues with a single cell resolution. Thi

  18. Cell Identification based on Received Signal Strength Fingerprints: Concept and Application towards Energy Saving in Cellular Networks

    Directory of Open Access Journals (Sweden)

    Elke Roth-Mandutz

    2014-09-01

    Full Text Available The increasing deployment of small cells aimed at off-loading data traffic from macrocells in heterogeneous networks has resulted in a drastic increase in energy consumption in cellular networks. Energy consumption can be optimized in a selforganized way by adapting the number of active cells in response to the current traffic demand. In this paper we concentrate on the complex problem of how to identify small cells to be reactivated in situations where multiple cells are concurrently inactive. Solely based on the received signal strength, we present cell-specific patterns for the generation of unique cell fingerprints. The cell fingerprints of the deactivated cells are matched with measurements from a high data rate demanding mobile device to identify the most appropriate candidate. Our scheme results in a matching success rate of up to 100% to identify the best cell depending on the number of cells to be activated.

  19. High resolution light-sheet based high-throughput imaging cytometry system enables visualization of intra-cellular organelles

    Directory of Open Access Journals (Sweden)

    Raju Regmi

    2014-09-01

    Full Text Available Visualization of intracellular organelles is achieved using a newly developed high throughput imaging cytometry system. This system interrogates the microfluidic channel using a sheet of light rather than the existing point-based scanning techniques. The advantages of the developed system are many, including, single-shot scanning of specimens flowing through the microfluidic channel at flow rate ranging from micro- to nano- lit./min. Moreover, this opens-up in-vivo imaging of sub-cellular structures and simultaneous cell counting in an imaging cytometry system. We recorded a maximum count of 2400 cells/min at a flow-rate of 700 nl/min, and simultaneous visualization of fluorescently-labeled mitochondrial network in HeLa cells during flow. The developed imaging cytometry system may find immediate application in biotechnology, fluorescence microscopy and nano-medicine.

  20. Nanostructured cellular networks.

    Science.gov (United States)

    Moriarty, P; Taylor, M D R; Brust, M

    2002-12-01

    Au nanocrystals spin-coated onto silicon from toluene form cellular networks. A quantitative statistical crystallography analysis shows that intercellular correlations drive the networks far from statistical equilibrium. Spin-coating from hexane does not produce cellular structure, yet a strong correlation is retained in the positions of nanocrystal aggregates. Mechanisms based on Marangoni convection alone cannot account for the variety of patterns observed, and we argue that spinodal decomposition plays an important role in foam formation.

  1. Investigating the Effects of Stress Interaction Using a Cellular-automaton Based Model in Fault Networks of Varying Complexity.

    Science.gov (United States)

    Hetherington, A. P.; Steacy, S.; McCloskey, J.

    2007-12-01

    Seismicity spatial and temporal patterns are strongly influenced by stress interaction between faults. However the effects of such interaction on earthquake statistics is not yet well understood. Computer models provide accurate, large and complete datasets to investigate this issue and also have the benefit of allowing direct comparison of seismicity behavior in time and space in networks, with and without fault interaction. We investigate the effect of such interaction on modeled real-world fault networks of varying complexity using a cellular-automata based model. Each 3-D fault within the fault network is modeled by a discrete cellular automaton. The cell size is 1 km square which allows for a minimum earthquake size of approximately Mw=4. The cell strength is distributed fractally across each fault and all cells are loaded by a remote tectonic stressing rate. When the stress on a cell exceeds its strength, the cell fails and stress is transferred to its nearest neighbors which may in turn cause them to break allowing the earthquake to grow. These stress transfer rules allow realistic stress concentrations to develop at the boundary of the rupture. If the extent of the rupture exceeds a user defined minimum length, and if interaction between faults is allowed, a boundary element method is used to calculate stress transfer to neighboring faults. Here we present results from four simulated fault networks based on active faults in the San Francisco Bay Area, California, the Northern Anatolian Fault, Turkey, Southern California, and the Marlborough Fault System, South Island, New Zealand. These are chosen for their varying level of fault complexity and we examine both interacting and non-interacting models in terms of their b-value and recurrence intervals for each region. Results will be compared and discussed.

  2. Cellular Automata-Based Application for Driver Assistance in Indoor Parking Areas

    Directory of Open Access Journals (Sweden)

    Cándido Caballero-Gil

    2016-11-01

    Full Text Available This work proposes an adaptive recommendation mechanism for smart parking that takes advantage of the popularity of smartphones and the rise of the Internet of Things. The proposal includes a centralized system to forecast available indoor parking spaces, and a low-cost mobile application to obtain data of actual and predicted parking occupancy. The described scheme uses data from both sources bidirectionally so that the centralized forecast system is fed with data obtained with the distributed system based on smartphones, and vice versa. The mobile application uses different wireless technologies to provide the forecast system with actual parking data and receive from the system useful recommendations about where to park. Thus, the proposal can be used by any driver to easily find available parking spaces in indoor facilities. The client software developed for smartphones is a lightweight Android application that supplies precise indoor positioning systems based on Quick Response codes or Near Field Communication tags, and semi-precise indoor positioning systems based on Bluetooth Low Energy beacons. The performance of the proposed approach has been evaluated by conducting computer simulations and real experimentation with a preliminary implementation. The results have shown the strengths of the proposal in the reduction of the time and energy costs to find available parking spaces.

  3. Cellular Immune Response to an Engineered Cell-Based Tumor Vaccine at the Vaccination Site

    OpenAIRE

    Zhou,Qiang; Johnson, Bryon D.; Rimas J Orentas

    2007-01-01

    The engineered expression of the immune co-stimulatory molecules CD80 and CD137L on the surface of a neuroblastoma cell line converts this tumor into a cell-based cancer vaccine. The mechanism by which this vaccine activates the immune system was investigated by capturing and analyzing immune cells responding to the vaccine cell line embedded in a collagen matrix and injected subcutaneously. The vaccine induced a significant increase in the number of activated CD62L− CCR7− CD49b+ CD8 effector...

  4. INTERFERENCE COORDINATION METHOD BASED ON GRAPH THEORY IN TWO-TIER CELLULAR NETWORKS

    Institute of Scientific and Technical Information of China (English)

    Shi Jurong; Zhu Qi

    2013-01-01

    This paper studies an interference coordination method by means of spectrum allocation in Long-Term Evolution (LTE) multi-cell scenario that comprises of macrocells and femtocells.The purpose is to maximize the total throughput of femtocells while ensuring the Signal-to-Interference plus Noise Ratio (SINR) of the edge macro mobile stations (mMSs) and the edge femtocell Mobile Stations (fMSs).A new spectrum allocation algorithm based on graph theory is proposed to reduce the interference.Firstly,the ratio of Resource Blocks (RBs) that mMSs occupy is obtained by genetic algorithm.Then,after considering the impact of the macro Base Stations (mBSs) and small scale fading to the fMS on different RBs,multi-interference graphs are established and the spectrum is allocated dynamically.The simulation results show that the proposed algorithm can meet the Quality of Service (QoS) requirements of the mMSs.It can strike a balance between the edge fMSs' throughput and the whole fMSs' throughput.

  5. A Relaying Incentive Scheme in Multihop Cellular Networks Based on Coalitional Game with Externalities

    CERN Document Server

    Li, Cuilian; Tian, Feng

    2008-01-01

    Cooperative multihop communication can greatly increase network throughput, yet packet forwarding for other nodes involves opportunity and energy cost for relays. Thus one of the pre-requisite problems in the successful implementation of multihop transmission is how to foster cooperation among selfish nodes. Existing researches mainly adopt monetary stimulating. In this manuscript, we propose instead a simple and self-enforcing forwarding incentive scheme free of indirect monetary remunerating for asymmetric (uplink multihop, downlink single-hop) cellar network based on coalitional game theory, which comprises double compensation, namely, Inter- BEA, global stimulating policy allotting resources among relaying coalitions according to group size, and Intra-BEA, local compensating and allocating rule within coalitions. Firstly, given the global allotting policy, we introduce a fair allocation estimating approach which includes remunerating for relaying cost using Myerson value for partition function game, to en...

  6. Creative elements: network-based predictions of active centres in proteins, cellular and social networks

    CERN Document Server

    Csermely, Peter

    2008-01-01

    Active centres and hot spots of proteins have a paramount importance in enzyme action, protein complex formation and drug design. Recently a number of publications successfully applied the analysis of residue networks to predict active centres in proteins. Most real-world networks show a number of properties, such as small-worldness or scale-free degree distribution, which are rather general features of networks from molecules to the society. Based on extensive analogies I propose that the existing findings and methodology enable us to detect active centres in cells, social networks and ecosystems. Members of these active centres are creative elements of the respective networks, which may help them to survive unprecedented, novel challenges, and play a key role in the development, survival and evolvability of complex systems.

  7. Knowledge-Based Intelligent Software Support of Cellular Adaptation to Microgravity Investigations

    Science.gov (United States)

    Groleau, Nick; Grymes, Rosalind A.; Alizadeh, Babak; Friedland, Peter (Technical Monitor)

    1994-01-01

    One of the most significant new opportunities that the Space Station affords cell biologists is the ability to do long-term cultivation of cells in the space environment. This facility is essential for investigations that are primarily focused on effects requiring a longer timeline of observation than that provided by the STS (Space Transportation System) platform. Such work requires both very strong laboratory skills to properly and quickly interact with the hardware hosting the culture and deep knowledge of the cell biology domain in order to optimally react to unanticipated scientific developments. Such work can be enabled by advanced automation techniques that have recently been used in the STS-based Spacelab, and that are being readied for the Space Station. In this paper, we describe the adaptation of PI-in-a-Box, the first interactive space science assistant system, to the study of the effects of space flight on cell cycle progression and proliferation.

  8. Structural basis for isoform selectivity in a class of benzothiazole inhibitors of phosphoinositide 3-kinase γ.

    Science.gov (United States)

    Collier, Philip N; Martinez-Botella, Gabriel; Cornebise, Mark; Cottrell, Kevin M; Doran, John D; Griffith, James P; Mahajan, Sudipta; Maltais, François; Moody, Cameron S; Huck, Emilie Porter; Wang, Tiansheng; Aronov, Alex M

    2015-01-08

    Phosphoinositide 3-kinase γ (PI3Kγ) is an attractive target to potentially treat a range of disease states. Herein, we describe the evolution of a reported phenylthiazole pan-PI3K inhibitor into a family of potent and selective benzothiazole inhibitors. Using X-ray crystallography, we discovered that compound 22 occupies a previously unreported hydrophobic binding cleft adjacent to the ATP binding site of PI3Kγ, and achieves its selectivity by exploiting natural sequence differences among PI3K isoforms in this region.

  9. Cellular Automata-based Chloride Ion Diffusion Simulation of Concrete Bridges under Multi-factor Coupling Actions

    Institute of Scientific and Technical Information of China (English)

    ZHU Jinsong; HE Likun

    2012-01-01

    Abstract In order to accurately simulate the diffusion of chloride ion in the existing concrete bridge and acquire the precise chloride ion concentration at given time,a cellular automata (CA)-based model is proposed.The process of chloride ion diffusion is analyzed by the CA-based method and a nonlinear solution of the Fick's second law is obtained.Considering the impact of various factors such as stress states,temporal and spatial variability of diffusion parameters and water-cement ratio on the process of chloride ion diffusion,the model of chloride ion diffusion under multi-factor coupling actions is presented.A chloride ion penetrating experiment reported in the literature is used to prove the effectiveness and reasonability of the present method,and a T-type beam is taken as an illustrative example to analyze the process of chloride ion diffusion in practical application.The results indicate that CA-based method can simulate the diffusion of chloride ion in the concrete structures with acceptable precision.

  10. GIS BASED SYSTEM FOR POST-EARTHQUAKE CRISIS MANAGMENT USING CELLULAR NETWORK

    Directory of Open Access Journals (Sweden)

    M. Raeesi

    2013-09-01

    Full Text Available Earthquakes are among the most destructive natural disasters. Earthquakes happen mainly near the edges of tectonic plates, but they may happen just about anywhere. Earthquakes cannot be predicted. Quick response after disasters, like earthquake, decreases loss of life and costs. Massive earthquakes often cause structures to collapse, trapping victims under dense rubble for long periods of time. After the earthquake and destroyed some areas, several teams are sent to find the location of the destroyed areas. The search and rescue phase usually is maintained for many days. Time reduction for surviving people is very important. A Geographical Information System (GIS can be used for decreasing response time and management in critical situations. Position estimation in short period of time time is important. This paper proposes a GIS based system for post–earthquake disaster management solution. This system relies on several mobile positioning methods such as cell-ID and TA method, signal strength method, angel of arrival method, time of arrival method and time difference of arrival method. For quick positioning, the system can be helped by any person who has a mobile device. After positioning and specifying the critical points, the points are sent to a central site for managing the procedure of quick response for helping. This solution establishes a quick way to manage the post–earthquake crisis.

  11. Dynamic Resource Management in MC-CDMA Based Cellular Wireless Networks

    Directory of Open Access Journals (Sweden)

    Bala Jeevitha Vani

    2009-10-01

    Full Text Available Most of the multimedia and Internet services today are asymmetric in nature, and require high data rate support. Allocating equal band width in both uplink and downlink is not prudent solution, as most of the time user requirement is more either in uplink or downlink. The Multi Carrier Code Division Multiple Access (MC-CDMA system with time division duplex mode can easily met this requirement by dynamically declaring traffic direction in TDD slot, and adaptively allocating the sub channels. In this paper, we propose a adaptive slot and sub carrier allocation algorithm, that can be independently implemented in each cell of mobile communication network. Our analytical model is generalization of two cell concept to represent a multi cell model. Based on two cell concept four cases of interference pattern has been considered and simulated separately in presence of Additive White Gaussian Noise (AWGN and Rayleigh Channel. The simulated result suggests the requirement of approximately 9dB of Signal to Noise Ratio (SNR to maintain Bit Error Rate below 10-3. We also analyze the average delay incurred by the proposed algorithm in allocating resources.

  12. The lack of histological changes of CDMA cellular phone-based radio frequency on rat testis.

    Science.gov (United States)

    Lee, Hae-June; Pack, Jeong-Ki; Kim, Tae-Hong; Kim, Nam; Choi, Soo-Yong; Lee, Jae-Seon; Kim, Sung-Ho; Lee, Yun-Sil

    2010-10-01

    We examined the histological changes by radiofrequency (RF) fields on rat testis, specifically with respect to sensitive processes such as spermatogenesis. Male rats were exposed to 848.5 MHz RF for 12 weeks. The RF exposure schedule consisted of two 45-min RF exposure periods, separated by a 15-min interval. The whole-body average specific absorption rate (SAR) of RF was 2.0 W/kg. We then investigated correlates of testicular function such as sperm counts in the cauda epididymis, malondialdehyde concentrations in the testes and epididymis, frequency of spermatogenesis stages, germ cell counts, and appearance of apoptotic cells in the testes. We also performed p53, bcl-2, caspase 3, p21, and PARP immunoblotting of the testes in sham- and RF-exposed animals. Based on these results, we concluded that subchronic exposure to 848.5 MHz with 2.0 W/kg SAR RF did not have any observable adverse effects on rat spermatogenesis.

  13. Biomimetic synthesis of cellular SiC based ceramics from plant precursor

    Indian Academy of Sciences (India)

    O P Chakrabarti; H S Maiti; R Majumdar

    2004-10-01

    A novel biomimetic approach in designing and fabricating engineering ceramic materials has gained much interest in recent times. Following this approach, synthesis has been made of dense Si–SiC duplex ceramic composites and highly porous SiC ceramics in the image of the morphological features inherent in the caudex stem of a local monocotyledonous plant. The process route involves making of a carbonaceous biopreform and its subsequent reaction with an infiltrating silicon melt to yield the biomorphic Si–SiC ceramic composites with flexural strength and Young’s modulus of 264 MPa and 247 Gpa, respectively and loss in weight of only ∼ 9% during oxidative heating up to 1200°C in flowing air. The Si–SiC composites were transformed into porous (49 vol.%) SiC ceramics with complete preservation of microcellular anatomy of the parent plant, by depleting residual silicon phase in channel pores through reaction with carbon. SiC based materials so derived can be used in structural applications and in designing high temperature filters and catalyst supports.

  14. A STUDY ON CELLULAR AUTOMATA BASED ON RELATIONAL DATABASES AND SPATIO-TEMPORAL SIMULATIONS OF CULTURE DIFFUSION

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper presents a development of the extended Cellular Automata (CA), based on relational databases(RDB), to model dynamic interactions among spatial objects. The integration of Geographical Information System (GIS)and CA has the great advantage of simulating geographical processes. But standard CA has some restrictions in cellularshape and neighbourhood and neighbour rules, which restrict the CA's ability to simulate complex, real world environ-ments. This paper discusses a cell's spatial relation based on the spatial object's geometrical and non-geometrical characteris-tics, and extends the cell' s neighbour definition, and considers that the cell' s neighbour lies in the forms of not only spa-tial adjacency but also attribute correlation. This paper then puts forward that spatial relations between two different cellscan be divided into three types, including spatial adjacency, neighbourhood and complicated separation. Based on tradition-al ideas, it is impossible to settle CA's restrictions completely. RDB-based CA is an academic experiment, in whichsome fields are designed to describe the essential information needed to define and select a cell's neighbour. The cultureinnovation diffusion system has multiple forms of space diffusion and inherited characteristics that the RDB-based CA iscapable of simulating more effectively. Finally this paper details a successful case study on the diffusion of fashion weartrends. Compared to the original CA, the RDB-based CA is a more natural and efficient representation of human knowl-edge over space, and is an effective tool in simulating complex systems that have multiple forms of spatial diffusion.

  15. Digital Morphing Wing: Active Wing Shaping Concept Using Composite Lattice-Based Cellular Structures

    Science.gov (United States)

    Jenett, Benjamin; Calisch, Sam; Cellucci, Daniel; Cramer, Nick; Gershenfeld, Neil; Swei, Sean

    2017-01-01

    Abstract We describe an approach for the discrete and reversible assembly of tunable and actively deformable structures using modular building block parts for robotic applications. The primary technical challenge addressed by this work is the use of this method to design and fabricate low density, highly compliant robotic structures with spatially tuned stiffness. This approach offers a number of potential advantages over more conventional methods for constructing compliant robots. The discrete assembly reduces manufacturing complexity, as relatively simple parts can be batch-produced and joined to make complex structures. Global mechanical properties can be tuned based on sub-part ordering and geometry, because local stiffness and density can be independently set to a wide range of values and varied spatially. The structure's intrinsic modularity can significantly simplify analysis and simulation. Simple analytical models for the behavior of each building block type can be calibrated with empirical testing and synthesized into a highly accurate and computationally efficient model of the full compliant system. As a case study, we describe a modular and reversibly assembled wing that performs continuous span-wise twist deformation. It exhibits high performance aerodynamic characteristics, is lightweight and simple to fabricate and repair. The wing is constructed from discrete lattice elements, wherein the geometric and mechanical attributes of the building blocks determine the global mechanical properties of the wing. We describe the mechanical design and structural performance of the digital morphing wing, including their relationship to wind tunnel tests that suggest the ability to increase roll efficiency compared to a conventional rigid aileron system. We focus here on describing the approach to design, modeling, and construction as a generalizable approach for robotics that require very lightweight, tunable, and actively deformable structures. PMID:28289574

  16. Frequency Resource Sharing and Allocation Scheme Based on Coalition Formation Game in Hybrid D2D-Cellular Network

    Directory of Open Access Journals (Sweden)

    Qing Ou

    2015-01-01

    Full Text Available A distributed cooperation scheme on frequency resource sharing is proposed to improve the quality of service (QoS in device-to-device (D2D communications underlaying cellular networks. Specifically, we formulate the resource allocation problem as a coalition formation game with transferable utility, in which all users have the incentive to cooperate with some others and form a competitive group to maximize the probability of obtaining their favorite spectrum resources. Taking the cost for coalition formation into account, such as the path loss for data sharing, we prove that the core of the proposed game is empty, which shows the impossibility of grand coalition. Hence, we propose a distributed merge-and-split based coalition formation algorithm based on a new defined Max-Coalition order to effectively solve the coalition game. Compared with the exhaustive search, our algorithm has much lower computer complexity. In addition, we prove that stability and convergence of the proposed algorithm using the concept of a defection function. Finally, the simulation results show that the proposed scheme achieves a suboptimal performance in terms of network sum rate compared with the centralized optimal resource allocation scheme obtained via exhaustive search.

  17. Discrimination of liver cancer in cellular level based on backscatter micro-spectrum with PCA algorithm and BP neural network

    Science.gov (United States)

    Yang, Jing; Wang, Cheng; Cai, Gan; Dong, Xiaona

    2016-10-01

    The incidence and mortality rate of the primary liver cancer are very high and its postoperative metastasis and recurrence have become important factors to the prognosis of patients. Circulating tumor cells (CTC), as a new tumor marker, play important roles in the early diagnosis and individualized treatment. This paper presents an effective method to distinguish liver cancer based on the cellular scattering spectrum, which is a non-fluorescence technique based on the fiber confocal microscopic spectrometer. Combining the principal component analysis (PCA) with back propagation (BP) neural network were utilized to establish an automatic recognition model for backscatter spectrum of the liver cancer cells from blood cell. PCA was applied to reduce the dimension of the scattering spectral data which obtained by the fiber confocal microscopic spectrometer. After dimensionality reduction by PCA, a neural network pattern recognition model with 2 input layer nodes, 11 hidden layer nodes, 3 output nodes was established. We trained the network with 66 samples and also tested it. Results showed that the recognition rate of the three types of cells is more than 90%, the relative standard deviation is only 2.36%. The experimental results showed that the fiber confocal microscopic spectrometer combining with the algorithm of PCA and BP neural network can automatically identify the liver cancer cell from the blood cells. This will provide a better tool for investigating the metastasis of liver cancers in vivo, the biology metabolic characteristics of liver cancers and drug transportation. Additionally, it is obviously referential in practical application.

  18. Design, synthesis, biochemical studies, cellular characterization, and structure-based computational studies of small molecules targeting the urokinase receptor.

    Science.gov (United States)

    Wang, Fang; Eric Knabe, W; Li, Liwei; Jo, Inha; Mani, Timmy; Roehm, Hartmut; Oh, Kyungsoo; Li, Jing; Khanna, May; Meroueh, Samy O

    2012-08-01

    The urokinase receptor (uPAR) serves as a docking site to the serine protease urokinase-type plasminogen activator (uPA) to promote extracellular matrix (ECM) degradation and tumor invasion and metastasis. Previously, we had reported a small molecule inhibitor of the uPAR·uPA interaction that emerged from structure-based virtual screening. Here, we measure the affinity of a large number of derivatives from commercial sources. Synthesis of additional compounds was carried out to probe the role of various groups on the parent compound. Extensive structure-based computational studies suggested a binding mode for these compounds that led to a structure-activity relationship study. Cellular studies in non-small cell lung cancer (NSCLC) cell lines that include A549, H460 and H1299 showed that compounds blocked invasion, migration and adhesion. The effects on invasion of active compounds were consistent with their inhibition of uPA and MMP proteolytic activity. These compounds showed weak cytotoxicity consistent with the confined role of uPAR to metastasis.

  19. Performance Evaluation of 5G Millimeter-Wave Cellular Access Networks Using a Capacity-Based Network Deployment Tool

    Directory of Open Access Journals (Sweden)

    Michel Matalatala

    2017-01-01

    Full Text Available The next fifth generation (5G of wireless communication networks comes with a set of new features to satisfy the demand of data-intensive applications: millimeter-wave frequencies, massive antenna arrays, beamforming, dense cells, and so forth. In this paper, we investigate the use of beamforming techniques through various architectures and evaluate the performance of 5G wireless access networks, using a capacity-based network deployment tool. This tool is proposed and applied to a realistic area in Ghent, Belgium, to simulate realistic 5G networks that respond to the instantaneous bit rate required by the active users. The results show that, with beamforming, 5G networks require almost 15% more base stations and 4 times less power to provide more capacity to the users and the same coverage performances, in comparison with the 4G reference network. Moreover, they are 3 times more energy efficient than the 4G network and the hybrid beamforming architecture appears to be a suitable architecture for beamforming to be considered when designing a 5G cellular network.

  20. Phyto-mediated nanostructured carriers based on dual vegetable actives involved in the prevention of cellular damage.

    Science.gov (United States)

    Istrati, D; Lacatusu, I; Bordei, N; Badea, G; Oprea, O; Stefan, L M; Stan, R; Badea, N; Meghea, A

    2016-07-01

    The growing scientific interest in exploitation of vegetable bioactives has raised a number of questions regarding their imminent presence in pharmaceutical formulations. This study intends to demonstrate that a dual combination between vegetable oil (e.g. thistle oil, safflower oil, sea buckthorn oil) and a carrot extract represents an optimal approach to formulate safe carrier systems that manifest cell regeneration effect and promising antioxidant and anti-inflammatory activity. Inclusion of both natural actives into lipid carriers imparted a strong negative charge on the nanocarrier surface (up to -45mV) and displayed average sizes of 70nm to 140nm. The entrapment efficiency of carrot extract into nanostructured carriers ranged between 78.3 and 88.3%. The in vitro release study has demonstrated that the entrapment of the extract represents a viable way for an equilibrated release of carotenoids. Besides the excellent antioxidant properties (e.g. scavenging up to 98% of the free oxygen radicals), the results of cellular integrity (e.g. cell viability of 133%) recommend these nanocarriers based on dual carrot extract-bioactive oil as a promising trend for the treatment of certain disorders in which oxidative stress plays a prominent role. In addition, the lipid nanocarriers based on safflower oil and sea buckthorn oil demonstrated an anti-inflammatory effect on LPS induced THP-1 macrophages, by inhibiting the secretion of two pro-inflammatory cytokines, IL-6 and TNF-α.

  1. Sac1--Vps74 structure reveals a mechanism to terminate phosphoinositide signaling in the Golgi apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Yiying; Deng, Yongqiang; Horenkamp, Florian; Reinisch, Karin M.; Burd, Christopher G. [Yale-MED

    2014-08-25

    Sac1 is a phosphoinositide phosphatase of the endoplasmic reticulum and Golgi apparatus that controls organelle membrane composition principally via regulation of phosphatidylinositol 4-phosphate signaling. We present a characterization of the structure of the N-terminal portion of yeast Sac1, containing the conserved Sac1 homology domain, in complex with Vps74, a phosphatidylinositol 4-kinase effector and the orthologue of human GOLPH3. The interface involves the N-terminal subdomain of the Sac1 homology domain, within which mutations in the related Sac3/Fig4 phosphatase have been linked to Charcot–Marie–Tooth disorder CMT4J and amyotrophic lateral sclerosis. Disruption of the Sac1–Vps74 interface results in a broader distribution of phosphatidylinositol 4-phosphate within the Golgi apparatus and failure to maintain residence of a medial Golgi mannosyltransferase. The analysis prompts a revision of the membrane-docking mechanism for GOLPH3 family proteins and reveals how an effector of phosphoinositide signaling serves a dual function in signal termination.

  2. Sac1-Vps74 structure reveals a mechanism to terminate phosphoinositide signaling in the Golgi apparatus.

    Science.gov (United States)

    Cai, Yiying; Deng, Yongqiang; Horenkamp, Florian; Reinisch, Karin M; Burd, Christopher G

    2014-08-18

    Sac1 is a phosphoinositide phosphatase of the endoplasmic reticulum and Golgi apparatus that controls organelle membrane composition principally via regulation of phosphatidylinositol 4-phosphate signaling. We present a characterization of the structure of the N-terminal portion of yeast Sac1, containing the conserved Sac1 homology domain, in complex with Vps74, a phosphatidylinositol 4-kinase effector and the orthologue of human GOLPH3. The interface involves the N-terminal subdomain of the Sac1 homology domain, within which mutations in the related Sac3/Fig4 phosphatase have been linked to Charcot-Marie-Tooth disorder CMT4J and amyotrophic lateral sclerosis. Disruption of the Sac1-Vps74 interface results in a broader distribution of phosphatidylinositol 4-phosphate within the Golgi apparatus and failure to maintain residence of a medial Golgi mannosyltransferase. The analysis prompts a revision of the membrane-docking mechanism for GOLPH3 family proteins and reveals how an effector of phosphoinositide signaling serves a dual function in signal termination.

  3. INPP5E regulates phosphoinositide-dependent cilia transition zone function.

    Science.gov (United States)

    Dyson, Jennifer M; Conduit, Sarah E; Feeney, Sandra J; Hakim, Sandra; DiTommaso, Tia; Fulcher, Alex J; Sriratana, Absorn; Ramm, Georg; Horan, Kristy A; Gurung, Rajendra; Wicking, Carol; Smyth, Ian; Mitchell, Christina A

    2017-01-02

    Human ciliopathies, including Joubert syndrome (JBTS), arise from cilia dysfunction. The inositol polyphosphate 5-phosphatase INPP5E localizes to cilia and is mutated in JBTS. Murine Inpp5e ablation is embryonically lethal and recapitulates JBTS, including neural tube defects and polydactyly; however, the underlying defects in cilia signaling and the function of INPP5E at cilia are still emerging. We report Inpp5e(-/-) embryos exhibit aberrant Hedgehog-dependent patterning with reduced Hedgehog signaling. Using mouse genetics, we show increasing Hedgehog signaling via Smoothened M2 expression rescues some Inpp5e(-/-) ciliopathy phenotypes and "normalizes" Hedgehog signaling. INPP5E's phosphoinositide substrates PI(4,5)P2 and PI(3,4,5)P3 accumulated at the transition zone (TZ) in Hedgehog-stimulated Inpp5e(-/-) cells, which was associated with reduced recruitment of TZ scaffolding proteins and reduced Smoothened levels at cilia. Expression of wild-type, but not 5-phosphatase-dead, INPP5E restored TZ molecular organization and Smoothened accumulation at cilia. Therefore, we identify INPP5E as an essential point of convergence between Hedgehog and phosphoinositide signaling at cilia that maintains TZ function and Hedgehog-dependent embryonic development.

  4. Novel small molecule inhibitors of 3-phosphoinositide-dependent kinase-1.

    Science.gov (United States)

    Feldman, Richard I; Wu, James M; Polokoff, Mark A; Kochanny, Monica J; Dinter, Harald; Zhu, Daguang; Biroc, Sandra L; Alicke, Bruno; Bryant, Judi; Yuan, Shendong; Buckman, Brad O; Lentz, Dao; Ferrer, Mike; Whitlow, Marc; Adler, Marc; Finster, Silke; Chang, Zheng; Arnaiz, Damian O

    2005-05-20

    The phosphoinositide 3-kinase/3-phosphoinositide-dependent kinase 1 (PDK1)/Akt signaling pathway plays a key role in cancer cell growth, survival, and tumor angiogenesis and represents a promising target for anticancer drugs. Here, we describe three potent PDK1 inhibitors, BX-795, BX-912, and BX-320 (IC(50) = 11-30 nm) and their initial biological characterization. The inhibitors blocked PDK1/Akt signaling in tumor cells and inhibited the anchorage-dependent growth of a variety of tumor cell lines in culture or induced apoptosis. A number of cancer cell lines with elevated Akt activity were >30-fold more sensitive to growth inhibition by PDK1 inhibitors in soft agar than on tissue culture plastic, consistent with the cell survival function of the PDK1/Akt signaling pathway, which is particularly important for unattached cells. BX-320 inhibited the growth of LOX melanoma tumors in the lungs of nude mice after injection of tumor cells into the tail vein. The effect of BX-320 on cancer cell growth in vitro and in vivo indicates that PDK1 inhibitors may have clinical utility as anticancer agents.

  5. Activation of TRPV1 channels inhibits mechanosensitive Piezo channel activity by depleting membrane phosphoinositides.

    Science.gov (United States)

    Borbiro, Istvan; Badheka, Doreen; Rohacs, Tibor

    2015-02-10

    Capsaicin is an activator of the heat-sensitive TRPV1 (transient receptor potential vanilloid 1) ion channels and has been used as a local analgesic. We found that activation of TRPV1 channels with capsaicin either in dorsal root ganglion neurons or in a heterologous expression system inhibited the mechanosensitive Piezo1 and Piezo2 channels by depleting phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] and its precursor phosphatidylinositol 4-phosphate [PI(4)P] from the plasma membrane through Ca(2+)-induced phospholipase Cδ (PLCδ) activation. Experiments with chemically inducible phosphoinositide phosphatases and receptor-induced activation of PLCβ indicated that inhibition of Piezo channels required depletion of both PI(4)P and PI(4,5)P2. The mechanically activated current amplitudes decreased substantially in the excised inside-out configuration, where the membrane patch containing Piezo1 channels is removed from the cell. PI(4,5)P2 and PI(4)P applied to these excised patches inhibited this decrease. Thus, we concluded that Piezo channel activity requires the presence of phosphoinositides, and the combined depletion of PI(4,5)P2 and PI(4)P reduces channel activity. In addition to revealing a role for distinct membrane lipids in mechanosensitive ion channel regulation, these data suggest that inhibition of Piezo2 channels may contribute to the analgesic effect of capsaicin.

  6. Phyto-mediated nanostructured carriers based on dual vegetable actives involved in the prevention of cellular damage

    Energy Technology Data Exchange (ETDEWEB)

    Istrati, D.; Lacatusu, I.; Bordei, N.; Badea, G.; Oprea, O. [University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, Polizu Street No. 1, 011061 Bucharest (Romania); Stefan, L.M. [National Institute of Research and Development for Biological Sciences, Splaiul Independentei Street No. 296, 060031 Bucharest (Romania); Stan, R. [University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, Polizu Street No. 1, 011061 Bucharest (Romania); Badea, N., E-mail: nicoleta.badea@gmail.com [University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, Polizu Street No. 1, 011061 Bucharest (Romania); Meghea, A. [University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, Polizu Street No. 1, 011061 Bucharest (Romania)

    2016-07-01

    The growing scientific interest in exploitation of vegetable bioactives has raised a number of questions regarding their imminent presence in pharmaceutical formulations. This study intends to demonstrate that a dual combination between vegetable oil (e.g. thistle oil, safflower oil, sea buckthorn oil) and a carrot extract represents an optimal approach to formulate safe carrier systems that manifest cell regeneration effect and promising antioxidant and anti-inflammatory activity. Inclusion of both natural actives into lipid carriers imparted a strong negative charge on the nanocarrier surface (up to − 45 mV) and displayed average sizes of 70 nm to 140 nm. The entrapment efficiency of carrot extract into nanostructured carriers ranged between 78.3 and 88.3%. The in vitro release study has demonstrated that the entrapment of the extract represents a viable way for an equilibrated release of carotenoids. Besides the excellent antioxidant properties (e.g. scavenging up to 98% of the free oxygen radicals), the results of cellular integrity (e.g. cell viability of 133%) recommend these nanocarriers based on dual carrot extract–bioactive oil as a promising trend for the treatment of certain disorders in which oxidative stress plays a prominent role. In addition, the lipid nanocarriers based on safflower oil and sea buckthorn oil demonstrated an anti-inflammatory effect on LPS induced THP-1 macrophages, by inhibiting the secretion of two pro-inflammatory cytokines, IL-6 and TNF-α. - Highlights: • Safety phyto-mediated nanostructured carriers (NLC) based on two kinds of bioactives • Carrot extract incorporation into nanostructured carriers ranged from 78 to 88.3%. • High antioxidant activity of NLC by scavenging up to 98% free oxygen radicals • Extract entrapment represents a viable way for an equilibrated release of carotenoids. • Remarkable regenerative effect of L929 cell, with a proliferation of 133.4%.

  7. Cellular attachment and differentiation on titania nanotubes exposed to air- or nitrogen-based non-thermal atmospheric pressure plasma.

    Directory of Open Access Journals (Sweden)

    Hye Yeon Seo

    Full Text Available The surface topography and chemistry of titanium implants are important factors for successful osseointegration. However, chemical modification of an implant surface using currently available methods often results in the disruption of topographical features and the loss of beneficial effects during the shelf life of the implant. Therefore, the aim of this study was to apply the recently highlighted portable non-thermal atmospheric pressure plasma jet (NTAPPJ, elicited from one of two different gas sources (nitrogen and air, to TiO2 nanotube surfaces to further improve their osteogenic properties while preserving the topographical morphology. The surface treatment was performed before implantation to avoid age-related decay. The surface chemistry and morphology of the TiO2 nanotube surfaces before and after the NTAPPJ treatment were determined using a field-emission scanning electron microscope, a surface profiler, a contact angle goniometer, and an X-ray photoelectron spectroscope. The MC3T3-E1 cell viability, attachment and morphology were confirmed using calcein AM and ethidium homodimer-1 staining, and analysis of gene expression using rat mesenchymal stem cells was performed using a real-time reverse-transcription polymerase chain reaction. The results indicated that both portable nitrogen- and air-based NTAPPJ could be used on TiO2 nanotube surfaces easily and without topographical disruption. NTAPPJ resulted in a significant increase in the hydrophilicity of the surfaces as well as changes in the surface chemistry, which consequently increased the cell viability, attachment and differentiation compared with the control samples. The nitrogen-based NTAPPJ treatment group exhibited a higher osteogenic gene expression level than the air-based NTAPPJ treatment group due to the lower atomic percentage of carbon on the surface that resulted from treatment. It was concluded that NTAPPJ treatment of TiO2 nanotube surfaces results in an increase in

  8. Green Networking in Cellular HetNets: A Unified Radio Resource Management Framework with Base Station ON/OFF Switching

    KAUST Repository

    Ghazzai, Hakim

    2016-12-07

    In this paper, the problem of energy efficiency in cellular heterogeneous networks (HetNets) is investigated using radio resource and power management combined with the base station (BS) ON/OFF switching. The objective is to minimize the total power consumption of the network while satisfying the quality of service (QoS) requirements of each connected user. We consider the case of co-existing macrocell BS, small cell BSs, and private femtocell access points (FAPs). Three different network scenarios are investigated, depending on the status of the FAPs, i.e., HetNets without FAPs, HetNets with closed FAPs, and HetNets with semi-closed FAPs. A unified framework is proposed to simultaneously allocate spectrum resources to users in an energy efficient manner and switch off redundant small cell BSs. The high complexity dual decomposition technique is employed to achieve optimal solutions for the problem. A low complexity iterative algorithm is also proposed and its performances are compared to those of the optimal technique. The particularly interesting case of semi-closed FAPs, in which the FAPs accept to serve external users, achieves the highest energy efficiency due to increased degrees of freedom. In this paper, a cooperation scheme between FAPs and mobile operator is also investigated. The incentives for FAPs, e.g., renewable energy sharing and roaming prices, enabling cooperation are discussed to be considered as a useful guideline for inter-operator agreements.

  9. Spatiotemporal Simulation of Tourist Town Growth Based on the Cellular Automata Model: The Case of Sanpo Town in Hebei Province

    Directory of Open Access Journals (Sweden)

    Jun Yang

    2013-01-01

    Full Text Available Spatiotemporal simulation of tourist town growth is important for research on land use/cover change under the influence of urbanization. Many scholars have shown great interest in the unique pattern of driving urban development with tourism development. Based on the cellular automata (CA model, we simulated and predicted the spatiotemporal growth of Sanpo town in Hebei Province, using the tourism urbanization growth model. Results showed that (1 average annual growth rate of the entire region was 1.5 Ha2 per year from 2005 to 2010, 4 Ha2 per year from 2010 to 2015, and 2.5 Ha2 per year from 2015 to 2020; (2 urban growth rate increased yearly, with regional differences, and had a high degree of correlation with the Euclidean distance of town center, traffic route, attractions, and other factors; (3 Gougezhuang, an important village center in the west of the town, demonstrated traffic advantages and increased growth rate since 2010; (4 Magezhuang village has the largest population in the region, so economic advantages have driven the development of rural urbanization. It showed that CA had high reliability in simulating the spatiotemporal evolution of tourist town, which assists the study of spatiotemporal growth under urbanization and rational protection of tourism resources.

  10. Quantum-dot cellular automata based reversible low power parity generator and parity checker design for nanocommunication

    Institute of Scientific and Technical Information of China (English)

    Jadav Chandra DAS; Debashis DE

    2016-01-01

    Quantum-dot cellular automata (QCA) is an emerging area of research in reversible computing. It can be used to design nanoscale circuits. In nanocommunication, the detection and correction of errors in a received message is a major factor. Besides, device density and power dissipation are the key issues in the nanocommunication architecture. For the first time, QCA-based designs of the reversible low-power odd parity generator and odd parity checker using the Feynman gate have been achieved in this study. Using the proposed parity generator and parity checker circuit, a nanocommunication architecture is pro-posed. The detection of errors in the received message during transmission is also explored. The proposed QCA Feynman gate outshines the existing ones in terms of area, cell count, and delay. The quantum costs of the proposed conventional reversible circuits and their QCA layouts are calculated and compared, which establishes that the proposed QCA circuits have very low quantum cost compared to conventional designs. The energy dissipation by the layouts is estimated, which ensures the possibility of QCA nano-device serving as an alternative platform for the implementation of reversible circuits. The stability of the proposed circuits under thermal randomness is analyzed, showing the operational efficiency of the circuits. The simulation results of the proposed design are tested with theoretical values, showing the accuracy of the circuits. The proposed circuits can be used to design more complex low-power nanoscale lossless nanocommunication architecture such as nano-transmitters and nano-receivers.

  11. Simulating the conversion of rural settlements to town land based on multi-agent systems and cellular automata.

    Science.gov (United States)

    Liu, Yaolin; Kong, Xuesong; Liu, Yanfang; Chen, Yiyun

    2013-01-01

    Rapid urbanization in China has triggered the conversion of land from rural to urban use, particularly the conversion of rural settlements to town land. This conversion is the result of the joint effects of the geographic environment and agents involving the government, investors, and farmers. To understand the dynamic interaction dominated by agents and to predict the future landscape of town expansion, a small town land-planning model is proposed based on the integration of multi-agent systems (MAS) and cellular automata (CA). The MAS-CA model links the decision-making behaviors of agents with the neighbor effect of CA. The interaction rules are projected by analyzing the preference conflicts among agents. To better illustrate the effects of the geographic environment, neighborhood, and agent behavior, a comparative analysis between the CA and MAS-CA models in three different towns is presented, revealing interesting patterns in terms of quantity, spatial characteristics, and the coordinating process. The simulation of rural settlements conversion to town land through modeling agent decision and human-environment interaction is very useful for understanding the mechanisms of rural-urban land-use change in developing countries. This process can assist town planners in formulating appropriate development plans.

  12. Dynamic cellular manufacturing system design considering alternative routing and part operation tradeoff using simulated annealing based genetic algorithm

    Indian Academy of Sciences (India)

    KAMAL DEEP; PARDEEP K SINGH

    2016-09-01

    In this paper, an integrated mathematical model of multi-period cell formation and part operation tradeoff in a dynamic cellular manufacturing system is proposed in consideration with multiple part process route. This paper puts emphasize on the production flexibility (production/subcontracting part operation) to satisfy the product demand requirement in different period segments of planning horizon considering production capacity shortage and/or sudden machine breakdown. The proposed model simultaneously generates machine cells and part families and selects the optimum process route instead of the user specifying predetermined routes. Conventional optimization method for the optimal cell formation problem requires substantial amount of time and memory space. Hence a simulated annealing based genetic algorithm is proposed to explore the solution regions efficiently and to expedite the solution search space. To evaluate the computability of the proposed algorithm, different problem scenarios are adopted from literature. The results approve the effectiveness of theproposed approach in designing the manufacturing cell and minimization of the overall cost, considering various manufacturing aspects such as production volume, multiple process route, production capacity, machine duplication, system reconfiguration, material handling and subcontracting part operation.

  13. Differential expression proteomics of human colorectal cancer based on a syngeneic cellular model for the progression of adenoma to carcinoma.

    Science.gov (United States)

    Roth, Udo; Razawi, Hanieh; Hommer, Julia; Engelmann, Katja; Schwientek, Tilo; Müller, Stefan; Baldus, Stephan E; Patsos, Georgios; Corfield, Anthony P; Paraskeva, Christos; Hanisch, Franz-Georg

    2010-01-01

    This is the first differential expression proteomics study on a human syngeneic cellular in vitro progression model of the colorectal adenoma-to-carcinoma sequence, the anchorage-dependent non-tumorigenic adenoma derived cell line AA/C1 and the derived anchorage-independent and tumorigenic carcinoma cell line AA/C1/SB10C. The study is based on quantitative 2-DE and is complemented by Western blot validation. Excluding redundancies due to proteolysis and post-translational modified isoforms of over 2000 protein spots, 13 proteins were revealed as regulated with statistical variance being within the 95th confidence level and were identified by peptide mass fingerprinting in MALDI MS. Progression-associated proteins belong to the functional complexes of anaerobic glycolysis/gluconeogenesis, steroid biosynthesis, prostaglandin biosynthesis, the regulation and maintenance of the cytoskeleton, protein biosynthesis and degradation, the regulation of apoptosis or other functions. Partial but significant overlap was revealed with previous proteomics and transcriptomics studies in colorectal carcinoma. Among upregulated proteins we identified 3-HMG-CoA synthase, protein phosphatase 1, prostaglandin E synthase 2, villin 1, annexin A1, triosephosphate isomerase, phosphoserine aminotransferase 1, fumarylacetoacetate hydrolase and pyrroline-5-carboxylate reductase 1 (PYCR1), while glucose-regulated protein 78, cathepsin D, lamin A/C and quinolate phosphoribosyltransferase were downregulated.

  14. Avian CD154 enhances humoral and cellular immune responses induced by an adenovirus vector-based vaccine in chickens.

    Science.gov (United States)

    Sánchez Ramos, Oliberto; González Pose, Alain; Gómez-Puerta, Silvia; Noda Gomez, Julia; Vega Redondo, Armando; Águila Benites, Julio César; Suárez Amarán, Lester; Parra, Natalie C; Toledo Alonso, Jorge R

    2011-05-01

    Recombinant adenoviral vectors have emerged as an attractive system for veterinary vaccines development. However, for poultry vaccination a very important criterion for an ideal vaccine is its low cost. The objective of this study was to test the ability of chicken CD154 to enhance the immunogenicity of an adenoviral vector-based vaccine against avian influenza virus in order to reduce the amount of antigen required to induce an effective immune response in avian. Chickens were vaccinated with three different doses of adenoviral vectors encoding either HA (AdHA), or HA fused to extracellular domain chicken's CD154 (AdHACD). Hemagglutination inhibition (HI) assay and relative quantification of IFN-γ showed that the adenoviral vector encoding for the chimeric antigen is able to elicit an improved humoral and cellular immune response, which demonstrated that CD154 can be used as a molecular adjuvant allowing to reduce in about 50-fold the amount of adenoviral vector vaccine required to induce an effective immune response.

  15. Real-time and label-free monitoring of nanoparticle cellular uptake using capacitance-based assays

    Science.gov (United States)

    Lee, Rimi; Jo, Dong hyun; Chung, Sang J.; Na, Hee-Kyung; Kim, Jeong Hun; Lee, Tae Geol

    2016-01-01

    Nanoparticles have shown great potential as vehicles for the delivery of drugs, nucleic acids, and therapeutic proteins; an efficient, high-throughput screening method to analyze nanoparticle interaction with the cytomembrane would substantially improve the efficiency and accuracy of the delivery. Here, we developed a capacitance sensor array that monitored the capacitance values of nanoparticle-treated cells in a real-time manner, without the need for labeling. Upon cellular uptake of the nanoparticles, a capacitance peak was observed at a low frequency (e.g., 100 Hz) as a function of time based on zeta potential changes. In the high frequency region (e.g., 15–20 kHz), the rate of decreasing capacitance slowed as a function of time compared to the cell growth control group, due to increased cytoplasm resistance and decreased membrane capacitance and resistance. The information provided by our capacitance sensor array will be a powerful tool for scientists designing nanoparticles for specific purposes. PMID:27641838

  16. Inhibition of the phosphoinositide 3-kinase pathway induces a senescence-like arrest mediated by p27Kip1

    NARCIS (Netherlands)

    Collado, M.; Medema, R.H.; Garcia-Cao, I.; Dubuisson, M.L.N.; Barradas, M.; Glassford, J.; Rivas, C.; Burgering, B.M.T.; Serrano, M.; Lam, E.W.-F.

    2000-01-01

    A senescence-like growth arrest is induced in mouse primary embryo fibroblasts by inhibitors of phosphoinositide 3-kinase (PI3K). We observed that senescence-like growth arrest is correlated with an increase in p27Kip1 but that down-regulation of other cyclin-dependent kinase (CDK) inhibitors, inclu

  17. Cellular Phone Towers, parcel data base attribute, Published in 2006, 1:1200 (1in=100ft) scale, Washoe County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Cellular Phone Towers dataset, published at 1:1200 (1in=100ft) scale, was produced all or in part from Published Reports/Deeds information as of 2006. It is...

  18. On the spatial dynamics and oscillatory behavior of a predator-prey model based on cellular automata and local particle swarm optimization.

    Science.gov (United States)

    Molina, Mario Martínez; Moreno-Armendáriz, Marco A; Carlos Seck Tuoh Mora, Juan

    2013-11-07

    A two-dimensional lattice model based on Cellular Automata theory and swarm intelligence is used to study the spatial and population dynamics of a theoretical ecosystem. It is found that the social interactions among predators provoke the formation of clusters, and that by increasing the mobility of predators the model enters into an oscillatory behavior.

  19. CVP2- and CVL1-mediated phosphoinositide signaling as a regulator of the ARF GAP SFC/VAN3 in establishment of foliar vein patterns.

    Science.gov (United States)

    Carland, Francine; Nelson, Timothy

    2009-09-01

    In foliar organs of dicots, veins are arranged in a highly branched or reticulated pattern for efficient distribution of water, photosynthates and signaling molecules. Recent evidence suggests that the patterns rely in part on regulation of intracellular vesicle transport and cell polarity in selected cells during leaf development. The sorting of vesicle cargos to discrete cellular sites is regulated in yeast and animal cells by the binding of specific phosphoinositides (PIs). We report here that, in the plant Arabidopsis, specific PIs guide the vesicle traffic that is essential for polarized and continuous vein pattern formation. Mutations in SFC/VAN3, an ADP-ribosylation factor GTPase-activating protein (ARF GAP) with a PI-binding pleckstrin homology domain, result in discontinuous vein patterns. Plants with mutations in both CVP2 and CVL1, which encode inositol polyphosphate 5'-phosphatases that generate the specific PI ligand for the pleckstrin homology domain of SFC/VAN3, phosphatidylinositol-4-monophosphate (PI(4)P), have a discontinuous vein phenotype identical to that of sfc/van3 mutants. Single cvp2 or cvl1 mutants show weak and no discontinuous vein phenotypes, respectively, suggesting that they act redundantly. We propose that these two 5'-phosphatases regulate vein continuity and cell polarity by generating a specific PI ligand for SFC/VAN3.

  20. Bio-nanoplatforms based on carbon dots conjugating with F-substituted nano-hydroxyapatite for cellular imaging

    Science.gov (United States)

    Zhao, Yafei; Shi, Liyi; Fang, Jianhui; Feng, Xin

    2015-11-01

    Carbon dots (CDs) have shown great promise in a wide range of bioapplications due to their tunable optical properties and noncytotoxicity. For the first time, a rational strategy was designed to construct new bio-nanoplatforms based on carboxylic acid terminated CDs (CDs-COOH) conjugating with amino terminated F-substituted nano-hydroxyapatite (NFAp) via EDC/NHS coupling chemistry. The monodisperse NFAp nanorods were functionalized with o-phosphoethanolamine (PEA) to provide them with amino groups and render them hydrophilic with respect to the ligand exchange process. The CDs-COOH@PEA-NFAp conjugates exhibits bright blue fluorescence under UV illumination, excellent photostability and colloidal stability. Due to their low cytotoxicity and good biocompatibility as determined by methyl thiazolyl tetrazolium (MTT) assay, the CDs-COOH@PEA-NFAp conjugates were successfully applied as bio-nanoplatforms to MCF-7 breast cancer cells for cellular imaging in vitro. More importantly, the functional CDs conjugated to NFAp provide an extended and general approach to construct different water-soluble NFAp bio-nanoplatforms for other easily functionalised luminescent materials. Therefore, these green nanoplatforms may be a prospective candidate for applications in bioimaging or targeted biological therapy and drug delivery.Carbon dots (CDs) have shown great promise in a wide range of bioapplications due to their tunable optical properties and noncytotoxicity. For the first time, a rational strategy was designed to construct new bio-nanoplatforms based on carboxylic acid terminated CDs (CDs-COOH) conjugating with amino terminated F-substituted nano-hydroxyapatite (NFAp) via EDC/NHS coupling chemistry. The monodisperse NFAp nanorods were functionalized with o-phosphoethanolamine (PEA) to provide them with amino groups and render them hydrophilic with respect to the ligand exchange process. The CDs-COOH@PEA-NFAp conjugates exhibits bright blue fluorescence under UV illumination

  1. Allosteric Activation of the Phosphoinositide Phosphatase Sac1 by Anionic Phospholipids

    Science.gov (United States)

    2012-01-01

    Sac family phosphoinositide phosphatases comprise an evolutionarily conserved family of enzymes in eukaryotes. Our recently determined crystal structure of the Sac phosphatase domain of yeast Sac1, the founding member of the Sac family proteins, revealed a unique conformation of the catalytic P-loop and a large positively charged groove at the catalytic site. We now report a unique mechanism for the regulation of its phosphatase activity. Sac1 is an allosteric enzyme that can be activated by its product phosphatidylinositol or anionic phospholipid phosphatidylserine. The activation of Sac1 may involve conformational changes of the catalytic P-loop induced by direct binding with the regulatory anionic phospholipids in the large cationic catalytic groove. These findings highlight the fact that lipid composition of the substrate membrane plays an important role in the control of Sac1 function. PMID:22452743

  2. Role of Host Type IA Phosphoinositide 3-Kinase Pathway Components in Invasin-Mediated Internalization of Yersinia enterocolitica.

    Science.gov (United States)

    Dowd, Georgina C; Bhalla, Manmeet; Kean, Bernard; Thomas, Rowan; Ireton, Keith

    2016-06-01

    Many bacterial pathogens subvert mammalian type IA phosphoinositide 3-kinase (PI3K) in order to induce their internalization into host cells. How PI3K promotes internalization is not well understood. Also unclear is whether type IA PI3K affects different pathogens through similar or distinct mechanisms. Here, we performed an RNA interference (RNAi)-based screen to identify components of the type IA PI3K pathway involved in invasin-mediated entry of Yersinia enterocolitica, an enteropathogen that causes enteritis and lymphadenitis. The 69 genes targeted encode known upstream regulators or downstream effectors of PI3K. A similar RNAi screen was previously performed with the food-borne bacterium Listeria monocytogenes The results of the screen with Y. enterocolitica indicate that at least nine members of the PI3K pathway are needed for invasin-mediated entry. Several of these proteins, including centaurin-α1, Dock180, focal adhesion kinase (FAK), Grp1, LL5α, LL5β, and PLD2 (phospholipase D2), were recruited to sites of entry. In addition, centaurin-α1, FAK, PLD2, and mTOR were required for remodeling of the actin cytoskeleton during entry. Six of the human proteins affecting invasin-dependent internalization also promote InlB-mediated entry of L. monocytogenes Our results identify several host proteins that mediate invasin-induced effects on the actin cytoskeleton and indicate that a subset of PI3K pathway components promote internalization of both Y. enterocolitica and L. monocytogenes.

  3. From the cyclooxygenase-2 inhibitor celecoxib to a novel class of 3-phosphoinositide-dependent protein kinase-1 inhibitors.

    Science.gov (United States)

    Zhu, Jiuxiang; Huang, Jui-Wen; Tseng, Ping-Hui; Yang, Ya-Ting; Fowble, Joseph; Shiau, Chung-Wai; Shaw, Yeng-Jeng; Kulp, Samuel K; Chen, Ching-Shih

    2004-06-15

    The blockade of Akt activation through the inhibition of 3-phosphoinositide-dependent kinase-1 (PDK-1) represents a major signaling mechanism whereby celecoxib mediates apoptosis. Celecoxib, however, is a weak PDK-1 inhibitor (IC(50), 48 microM), requiring at least 30 microM to exhibit discernable effects on the growth of tumor cells in vitro. Here, we report the structure-based optimization of celecoxib to develop PDK-1 inhibitors with greater potency in enzyme inhibition and growth inhibition. Kinetics of PDK-1 inhibition by celecoxib with respect to ATP suggest that celecoxib derivatives inhibit PDK-1 by competing with ATP for binding, a mechanism reminiscent to that of many kinase inhibitors. Structure-activity analysis together with molecular modeling was used to generate compounds that were tested for their potency in inhibiting PDK-1 kinase activity and in inducing apoptosis in PC-3 prostate cancer cells. Docking of potent compounds into the ATP-binding site of PDK-1 was performed for lead optimization, leading to two compounds, OSU-03012 and OSU-03013, with IC(50) values in PDK-1 inhibition and apoptosis induction in the low microM range. Exposure of PC-3 cells to these agents led to Akt dephosphorylation and inhibition of p70 S6 kinase activity. Moreover, overexpression of constitutively active forms of PDK-1 and Akt partially protected OSU-03012-induced apoptosis. Screening in a panel of 60 cell lines and more extensive testing in PC-3 cells indicated that the mean concentration for total growth inhibition was approximately 3 microM for both agents. Considering the conserved role of PDK-1/Akt signaling in promoting tumorigenesis, these celecoxib analogs are of translational relevance for cancer prevention and therapy.

  4. Phosphoinositide binding differentially regulates NHE1 Na+/H+ exchanger-dependent proximal tubule cell survival.

    Science.gov (United States)

    Abu Jawdeh, Bassam G; Khan, Shenaz; Deschênes, Isabelle; Hoshi, Malcolm; Goel, Monu; Lock, Jeffrey T; Shinlapawittayatorn, Krekwit; Babcock, Gerald; Lakhe-Reddy, Sujata; DeCaro, Garren; Yadav, Satya P; Mohan, Maradumane L; Naga Prasad, Sathyamangla V; Schilling, William P; Ficker, Eckhard; Schelling, Jeffrey R

    2011-12-01

    Tubular atrophy predicts chronic kidney disease progression, and is caused by proximal tubular epithelial cellcaused by proximal tubular epithelial cell (PTC) apoptosis. The normally quiescent Na(+)/H(+) exchanger-1 (NHE1) defends against PTC apoptosis, and is regulated by PI(4,5)P(2) binding. Because of the vast array of plasma membrane lipids, we hypothesized that NHE1-mediated cell survival is dynamically regulated by multiple anionic inner leaflet phospholipids. In membrane overlay and surface plasmon resonance assays, the NHE1 C terminus bound phospholipids with low affinity and according to valence (PIP(3) > PIP(2) > PIP = PA > PS). NHE1-phosphoinositide binding was enhanced by acidic pH, and abolished by NHE1 Arg/Lys to Ala mutations within two juxtamembrane domains, consistent with electrostatic interactions. PI(4,5)P(2)-incorporated vesicles were distributed to apical and lateral PTC domains, increased NHE1-regulated Na(+)/H(+) exchange, and blunted apoptosis, whereas NHE1 activity was decreased in cells enriched with PI(3,4,5)P(3), which localized to basolateral membranes. Divergent PI(4,5)P(2) and PI(3,4,5)P(3) effects on NHE1-dependent Na(+)/H(+) exchange and apoptosis were confirmed by selective phosphoinositide sequestration with pleckstrin homology domain-containing phospholipase Cδ and Akt peptides, PI 3-kinase, and Akt inhibition in wild-type and NHE1-null PTCs. The results reveal an on-off switch model, whereby NHE1 toggles between weak interactions with PI(4,5)P(2) and PI(3,4,5)P(3). In response to apoptotic stress, NHE1 is stimulated by PI(4,5)P(2), which leads to PI 3-kinase activation, and PI(4,5)P(2) phosphorylation. The resulting PI(3,4,5)P(3) dually stimulates sustained, downstream Akt survival signaling, and dampens NHE1 activity through competitive inhibition and depletion of PI(4,5)P(2).

  5. Phosphoinositide-signaling is one component of a robust plant defense response.

    Directory of Open Access Journals (Sweden)

    Imara Yasmin Perera

    2014-06-01

    Full Text Available The phosphoinositide pathway and inositol-1,4,5-triphosphate (InsP3 have been implicated in plant responses to many abiotic stresses; however, their role in response to biotic stress is not well characterized. In the current study, we show that both basal defense and systemic acquired resistance responses are affected in transgenic plants constitutively expressing the human type I inositol polyphosphate 5-phosphatase (InsP 5-ptase which have greatly reduced InsP3 levels. Flagellin induced Ca2+-release as well as the expressions of some flg22 responsive genes were attenuated in the InsP 5-ptase plants. Furthermore, the InsP 5-ptase plants were more susceptible to virulent and avirulent strains of Pseudomonas syringae pv. tomato (PstDC3000. The InsP 5-ptase plants had lower basal salicylic acid (SA levels and the induction of SAR in systemic leaves was reduced and delayed. Reciprocal exudate experiments showed that although the InsP 5-ptase plants produced equally effective molecules that could trigger PR-1 gene expression in wild type plants, exudates collected from either wild type or InsP 5-ptase plants triggered less PR-1 gene expression in InsP 5-ptase plants. Additionally, expression profiles indicated that several defense genes including PR-1, PR-2, PR-5 and AIG1 were basally down regulated in the InsP 5-ptase plants compared with wild type. Upon pathogen attack, expression of these genes was either not induced or showed delayed induction in systemic leaves. Our study shows that phosphoinositide signaling is one component of the plant defense network and is involved in both basal and systemic responses. The dampening of InsP3-mediated signaling affects Ca2+ release, modulates defense gene expression and compromises plant defense responses.

  6. Route Planning of Unmanned Target Drone Based on Cellular-Ant Colony Algorithm%基于元胞蚂蚁算法的无人靶机航路规划设计

    Institute of Scientific and Technical Information of China (English)

    刘志强; 陈景彬

    2013-01-01

      靶机飞行航路设计是实现靶机有效控制,确保高效完成供靶任务的保障。本文通过元胞蚂蚁算法对某型无人靶机飞行航路优化设计进行了研究,分析了实现航路优化应突出解决的问题,并通过仿真实验验证该方法的可行性。%  Route planning of unmanned target drone is the basis of its efficient control and ensuring its high-performance of completing target mission. The route planning of an unmanned target drone is studied based on cellular-ant colony algorithm. The main problem of the optimum of the route planning is analyzed. The possibility of this method has been tested by simulation experiments.

  7. Assessment of cellular estrogenic activity based on estrogen receptor-mediated reduction of soluble-form catechol-O-methyltransferase (COMT) expression in an ELISA-based system.

    Science.gov (United States)

    Ho, Philip Wing-Lok; Tse, Zero Ho-Man; Liu, Hui-Fang; Lu, Song; Ho, Jessica Wing-Man; Kung, Michelle Hiu-Wai; Ramsden, David Boyer; Ho, Shu-Leong

    2013-01-01

    Xenoestrogens are either natural or synthetic compounds that mimic the effects of endogenous estrogen. These compounds, such as bisphenol-A (BPA), and phthalates, are commonly found in plastic wares. Exposure to these compounds poses major risk to human health because of the potential to cause endocrine disruption. There is huge demand for a wide range of chemicals to be assessed for such potential for the sake of public health. Classical in vivo assays for endocrine disruption are comprehensive but time-consuming and require sacrifice of experimental animals. Simple preliminary in vitro screening assays can reduce the time and expense involved. We previously demonstrated that catechol-O-methyltransferase (COMT) is transcriptionally regulated by estrogen via estrogen receptor (ER). Therefore, detecting corresponding changes of COMT expression in estrogen-responsive cells may be a useful method to estimate estrogenic effects of various compounds. We developed a novel cell-based ELISA to evaluate cellular response to estrogenicity by reduction of soluble-COMT expression in ER-positive MCF-7 cells exposed to estrogenic compounds. In contrast to various existing methods that only detect bioactivity, this method elucidates direct physiological effect in a living cell in response to a compound. We validated our assay using three well-characterized estrogenic plasticizers - BPA, benzyl butyl phthalate (BBP), and di-n-butyl phthalate (DBP). Cells were exposed to either these plasticizers or 17β-estradiol (E2) in estrogen-depleted medium with or without an ER-antagonist, ICI 182,780, and COMT expression assayed. Exposure to each of these plasticizers (10(-9)-10(-7)M) dose-dependently reduced COMT expression (pvitro assays of similar sensitivity. To satisfy the demand for in vitro assays targeting different cellular components, a cell-based COMT assay provides useful initial screening to supplement the current assessments of xenoestrogens for potential estrogenic activity.

  8. Low probability of intercept-based adaptive radar waveform optimization in signal-dependent clutter for joint radar and cellular communication systems

    Science.gov (United States)

    Shi, Chenguang; Salous, Sana; Wang, Fei; Zhou, Jianjiang

    2016-12-01

    In this paper, we investigate the problem of low probability of intercept (LPI)-based adaptive radar waveform optimization in signal-dependent clutter for joint radar and cellular communication systems, where the radar system optimizes the transmitted waveform such that the interference caused to the cellular communication systems is strictly controlled. Assuming that the precise knowledge of the target spectra, the power spectral densities (PSDs) of signal-dependent clutters, the propagation losses of corresponding channels and the communication signals is known by the radar, three different LPI based criteria for radar waveform optimization are proposed to minimize the total transmitted power of the radar system by optimizing the multicarrier radar waveform with a predefined signal-to-interference-plus-noise ratio (SINR) constraint and a minimum required capacity for the cellular communication systems. These criteria differ in the way the communication signals scattered off the target are considered in the radar waveform design: (1) as useful energy, (2) as interference or (3) ignored altogether. The resulting problems are solved analytically and their solutions represent the optimum power allocation for each subcarrier in the multicarrier radar waveform. We show with numerical results that the LPI performance of the radar system can be significantly improved by exploiting the scattered echoes off the target due to cellular communication signals received at the radar receiver.

  9. Mortality by neoplasia and cellular telephone base stations in the Belo Horizonte municipality, Minas Gerais state, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Dode, Adilza C., E-mail: adilzadode@terra.com.br [Minas Methodist University Center Izabela Hendrix, Belo Horizonte City, Minas Gerais State (Brazil); Municipal Government of Belo Horizonte, Municipal Health Department, Belo Horizonte City, Minas Gerais State (Brazil); MRE Engenharia (Electromagnetic Radiations Measurement-Engineering), Belo Horizonte City, Minas Gerais State (Brazil); Leao, Monica M.D., E-mail: monica@desa.ufmg.br [UFMG-Universidade Federal de Minas Gerais-Belo Horizonte, Environmental and Sanitary Engineering Department, Belo Horizonte City, Minas Gerais State (Brazil); Tejo, Francisco de A.F. [UFCG-Universidade Federal de Campina Grande, Center of Electrical Engineering and Informatics, Academic Unit of Electrical Engineering, Paraiba State (Brazil); Gomes, Antonio C.R. [MRE Engenharia (Electromagnetic Radiations Measurement-Engineering), Belo Horizonte City, Minas Gerais State (Brazil); Dode, Daiana C. [MRE Engenharia (Electromagnetic Radiations Measurement-Engineering), Belo Horizonte City, Minas Gerais State (Brazil); Faculty of Medical Sciences, Medicine-Belo Horizonte, Belo Horizonte City, Minas Gerais State (Brazil); Dode, Michael C. [MRE Engenharia (Electromagnetic Radiations Measurement-Engineering), Belo Horizonte City, Minas Gerais State (Brazil); Moreira, Cristina W.; Condessa, Vania A.; Albinatti, Claudia [Municipal Government of Belo Horizonte, Municipal Health Department, Belo Horizonte City, Minas Gerais State (Brazil); Caiaffa, Waleska T. [UFMG-Universidade Federal de Minas Gerais-Belo Horizonte, Urban Health Observatory, Belo Horizonte City, Minas Gerais State (Brazil)

    2011-09-01

    Pollution caused by the electromagnetic fields (EMFs) of radio frequencies (RF) generated by the telecommunication system is one of the greatest environmental problems of the twentieth century. The purpose of this research was to verify the existence of a spatial correlation between base station (BS) clusters and cases of deaths by neoplasia in the Belo Horizonte municipality, Minas Gerais state, Brazil, from 1996 to 2006 and to measure the human exposure levels to EMF where there is a major concentration of cellular telephone transmitter antennas. A descriptive spatial analysis of the BSs and the cases of death by neoplasia identified in the municipality was performed through an ecological-epidemiological approach, using georeferencing. The database employed in the survey was composed of three data banks: 1. death by neoplasia documented by the Health Municipal Department; 2. BSs documented in ANATEL ('Agencia Nacional de Telecomunicacoes': 'Telecommunications National Agency'); and 3. census and demographic city population data obtained from official archives provided by IBGE ('Instituto Brasileiro de Geografia e Estatistica': 'Brazilian Institute of Geography and Statistics'). The results show that approximately 856 BSs were installed through December 2006. Most (39.60%) of the BSs were located in the 'Centro-Sul' ('Central-Southern') region of the municipality. Between 1996 and 2006, 7191 deaths by neoplasia occurred and within an area of 500 m from the BS, the mortality rate was 34.76 per 10,000 inhabitants. Outside of this area, a decrease in the number of deaths by neoplasia occurred. The greatest accumulated incidence was 5.83 per 1000 in the Central-Southern region and the lowest incidence was 2.05 per 1000 in the Barreiro region. During the environmental monitoring, the largest accumulated electric field measured was 12.4 V/m and the smallest was 0.4 V/m. The largest density power was 40.78 {mu

  10. Reactive Programming of Cellular Automata

    OpenAIRE

    Boussinot, Frédéric

    2004-01-01

    Implementation of cellular automata using reactive programming gives a way to code cell behaviors in an abstract and modular way. Multiprocessing also becomes possible. The paper describes the implementation of cellular automata with the reactive programming language LOFT, a thread-based extension of C. Self replicating loops considered in artificial life are coded to show the interest of the approach.

  11. A Self-Position Recognition Method for Mobile Robots Based on Robot Calling by a User Using a Cellular Phone

    Science.gov (United States)

    Saito, Yasuo; Choi, Yongwoon; Iyota, Taketoshi; Watanabe, Kazuhiro; Kubota, Yuzuru

    A service robot system consisting of a cellular phone available to common users and mobile robots has been investigated and developed for the purpose of supporting such human activities as the delivering documents and goods, guiding visitors and patrolling an indoor environment. The system has the feature that is spontaneously able to recognize the robot location on it using the notion of Map-matching, by complying with the request called by a user with a cellular phone. This is possible because the robot's location can be corrected with a barcode of simple structure which is detected by a slit-ray sensor on the robot and a QR-code including location information to be read by a cellular phone. These codes also have the features that are simple to install them in the environment and easy to operate because users don't use an exclusive controller like keyboard on computers, but their own accustomed cellular phone for calling the robot. From the repeated experiments performed with the robot in an indoor corridor, the proposed system was successfully evaluated in the measurement accuracy for some self-positions of the robot called and the reliability for practical navigation. In addition, when the robot was called at a certain location, its behaviors to unexpected action of the user and the effect affected on it are discussed.

  12. Bioprinting-Based High-Throughput Fabrication of Three-Dimensional MCF-7 Human Breast Cancer Cellular Spheroids

    Directory of Open Access Journals (Sweden)

    Kai Ling

    2015-06-01

    Full Text Available Cellular spheroids serving as three-dimensional (3D in vitro tissue models have attracted increasing interest for pathological study and drug-screening applications. Various methods, including microwells in particular, have been developed for engineering cellular spheroids. However, these methods usually suffer from either destructive molding operations or cell loss and non-uniform cell distribution among the wells due to two-step molding and cell seeding. We have developed a facile method that utilizes cell-embedded hydrogel arrays as templates for concave well fabrication and in situ MCF-7 cellular spheroid formation on a chip. A custom-built bioprinting system was applied for the fabrication of sacrificial gelatin arrays and sequentially concave wells in a high-throughput, flexible, and controlled manner. The ability to achieve in situ cell seeding for cellular spheroid construction was demonstrated with the advantage of uniform cell seeding and the potential for programmed fabrication of tissue models on chips. The developed method holds great potential for applications in tissue engineering, regenerative medicine, and drug screening.

  13. Mortality by neoplasia and cellular telephone base stations in the Belo Horizonte municipality, Minas Gerais state, Brazil.

    Science.gov (United States)

    Dode, Adilza C; Leão, Mônica M D; Tejo, Francisco de A F; Gomes, Antônio C R; Dode, Daiana C; Dode, Michael C; Moreira, Cristina W; Condessa, Vânia A; Albinatti, Cláudia; Caiaffa, Waleska T

    2011-09-01

    Pollution caused by the electromagnetic fields (EMFs) of radio frequencies (RF) generated by the telecommunication system is one of the greatest environmental problems of the twentieth century. The purpose of this research was to verify the existence of a spatial correlation between base station (BS) clusters and cases of deaths by neoplasia in the Belo Horizonte municipality, Minas Gerais state, Brazil, from 1996 to 2006 and to measure the human exposure levels to EMF where there is a major concentration of cellular telephone transmitter antennas. A descriptive spatial analysis of the BSs and the cases of death by neoplasia identified in the municipality was performed through an ecological-epidemiological approach, using georeferencing. The database employed in the survey was composed of three data banks: 1. death by neoplasia documented by the Health Municipal Department; 2. BSs documented in ANATEL ("Agência Nacional de Telecomunicações": 'Telecommunications National Agency'); and 3. census and demographic city population data obtained from official archives provided by IBGE ("Instituto Brasileiro de Geografia e Estatística": 'Brazilian Institute of Geography and Statistics'). The results show that approximately 856 BSs were installed through December 2006. Most (39.60%) of the BSs were located in the "Centro-Sul" ('Central-Southern') region of the municipality. Between 1996 and 2006, 7191 deaths by neoplasia occurred and within an area of 500 m from the BS, the mortality rate was 34.76 per 10,000 inhabitants. Outside of this area, a decrease in the number of deaths by neoplasia occurred. The greatest accumulated incidence was 5.83 per 1000 in the Central-Southern region and the lowest incidence was 2.05 per 1000 in the Barreiro region. During the environmental monitoring, the largest accumulated electric field measured was 12.4 V/m and the smallest was 0.4 V/m. The largest density power was 40.78 μW/cm(2), and the smallest was 0.04 μW/cm(2).

  14. Cellular automata-based tunnel fire simulation%基于元胞自动机的井巷火灾仿真

    Institute of Scientific and Technical Information of China (English)

    李翠平; 胡磊; 侯定勇; 张佳

    2013-01-01

    提出了一种基于元胞自动机的井巷火灾可视化仿真方法。在矿井巷道可视化的基础上,通过对火灾元胞进行表征,综合考虑可燃物类型与投放密度、井巷通风、井巷坡度等因素对井巷火源引燃效果的影响及双扩散作用、井巷通风、浮力作用和节流作用等因素对火灾烟气蔓延效果的影响,采用概率函数进行元胞自动机建模,构建了表达元胞温度的井巷火源燃烧模型和表达元胞浓度的井巷火灾烟气蔓延模型。基于火源元胞燃烧演化规则和烟气元胞蔓延演化规则,通过可视化手段展示了井巷火灾火源燃烧和有害气体浓度的时空发展变化。同时以矿山实际数据进行检验,说明了基于元胞自动机的井巷火灾仿真的可行性与有效性。%This article introduces a mine fire visualization simulation method based on cellular automata. On the basis of mine tunnel visualization, a tunnel fire combustion model for expressing cellular temperature and a tunnel fire smoke spread model for expressing cellular concentration were built by fire cell characterization. In these models the influence of fuel type and input density, ventilation and roadway slope on mine fire ignition and the effect of double diffusion, ventilation, buoyancy and throttling on fire smoke spread were taken into account, and a probability function was used for cellular automata modelling. Then according to the fire cellular combustion evolution rules and smoke cellular spreading evolution rules, the spatial changes of tunnel fire burning and harmful gas concentration were demonstrated through visualization means. Actual data from a mine proves the feasibility and effectiveness of tunnel fire simulation based on cellular automata.

  15. Enhanced cellular uptake of albumin-based lyophilisomes when functionalized with cell-penetrating peptide TAT in HeLa cells.

    Directory of Open Access Journals (Sweden)

    Etienne van Bracht

    Full Text Available Lyophilisomes are a novel class of biodegradable proteinaceous nano/micrometer capsules with potential use as drug delivery carrier. Cell-penetrating peptides (CPPs including the TAT peptide have been successfully implemented for intracellular delivery of a broad variety of cargos including various nanoparticulate pharmaceutical carriers. In the present study, lyophilisomes were modified using CPPs in order to achieve enhanced cellular uptake. Lyophilisomes were prepared by a freezing, annealing, and lyophilization method and a cystein-elongated TAT peptide was conjugated to the lyophilisomes using a heterobifunctional linker. Fluorescent-activated cell sorting (FACS was utilized to acquire a lyophilisome population with a particle diameter smaller than 1000 nm. Cultured HeLa, OVCAR-3, Caco-2 and SKOV-3 cells were exposed to unmodified lyophilisomes and TAT-conjugated lyophilisomes and examined with FACS. HeLa cells were investigated in more detail using a trypan blue quenching assay, confocal microscopy, and transmission electron microscopy. TAT-conjugation strongly increased binding and cellular uptake of lyophilisomes in a time-dependent manner in vitro, as assessed by FACS. These results were confirmed by confocal microscopy. Transmission electron microscopy indicated rapid cellular uptake of TAT-conjugated lyophilisomes via phagocytosis and/or macropinocytosis. In conclusion, TAT-peptides conjugated to albumin-based lyophilisomes are able to enhance cellular uptake of lyophilisomes in HeLa cells.

  16. Differential regulation of phosphoinositide metabolism by alphaVbeta3 and alphaVbeta5 integrins upon smooth muscle cell migration.

    Science.gov (United States)

    Paulhe, F; Racaud-Sultan, C; Ragab, A; Albiges-Rizo, C; Chap, H; Iberg, N; Morand, O; Perret, B

    2001-11-09

    Smooth muscle cell migration is a key step of atherosclerosis and angiogenesis. We demonstrate that alpha(V)beta(3) and alpha(V)beta(5) integrins synergistically regulate smooth muscle cell migration onto vitronectin. Using an original haptotactic cell migration assay, we measured a strong stimulation of phosphoinositide metabolism in migrating vascular smooth muscle cells. Phosphatidic acid production and phosphoinositide 3-kinase IA activation were triggered only upon alpha(V)beta(3) engagement. Blockade of alpha(V)beta(3) engagement or phospholipase C activity resulted in a strong inhibition of smooth muscle cell spreading on vitronectin. By contrast, blockade of alpha(V)beta(5) reinforced elongation and polarization of cell shape. Moreover, Pyk2-associated tyrosine kinase and phosphoinositide 4-kinase activities measured in Pyk2 immunoprecipitates were stimulated upon cell migration. Blockade of either alpha(V)beta(3) or alpha(V)beta(5) function, as well as inhibition of phospholipase C activity, decreased both Pyk2-associated activities. We demonstrated that the Pyk2-associated phosphoinositide 4-kinase corresponded to the beta isoform. Our data point to the metabolism of phosphoinositides as a regulatory pathway for the differential roles played by alpha(V)beta(3) and alpha(V)beta(5) upon cell migration and identify the Pyk2-associated phosphoinositide 4-kinase beta as a common target for both integrins.

  17. [Simulation of urban ecological security pattern based on cellular automata: a case of Dongguan City, Guangdong Province of South China].

    Science.gov (United States)

    Yang, Qing-Sheng; Qiao, Ji-Gang; Ai, Bin

    2013-09-01

    Taking the Dongguan City with rapid urbanization as a case, and selecting landscape ecological security level as evaluation criterion, the urbanization cellular number of 1 km x 1 km ecological security cells was obtained, and imbedded into the transition rules of cellular automata (CA) as the restraint term to control urban development, establish ecological security urban CA, and simulate ecological security urban development pattern. The results showed the integrated landscape ecological security index of the City decreased from 0.497 in 1998 to 0.395 in 2005, indicating that the ecological security at landscape scale was decreased. The CA-simulated integrated ecological security index of the City in 2005 was increased from the measured 0.395 to 0.479, showing that the simulated urban landscape ecological pressure from human became lesser, ecological security became better, and integrated landscape ecological security became higher. CA could be used as an effective tool in researching urban ecological security.

  18. Cellular uptake and transcytosis of lipid-based nanoparticles across the intestinal barrier: Relevance for oral drug delivery.

    Science.gov (United States)

    Neves, Ana Rute; Queiroz, Joana Fontes; Costa Lima, Sofia A; Figueiredo, Francisco; Fernandes, Rui; Reis, Salette

    2016-02-01

    Oral administration is the preferred route for drug delivery and nanosystems represent a promising tool for protection and transport of hardly soluble, chemically unstable and poorly permeable drugs through the intestinal barrier. In the present work, we have studied lipid nanoparticles cellular uptake, internalization pathways and transcytosis routes through Caco-2 cell monolayers. Both lipid nanosystems presented similar size (∼180nm) and surface charge (-30mV). Nanostructured lipid carriers showed a higher cellular uptake and permeability across the barrier, but solid lipid nanoparticles could enter cells faster than the former. The internalization of lipid nanoparticles occurs mainly through a clathrin-mediated endocytosis mechanism, although caveolae-mediated endocytosis is also involved in the uptake. Both lipid nanoparticles were able to cross the intestinal barrier by a preferential transcellular route. This work contributed to a better knowledge of the developed nanosystems for the oral delivery of a wide spectrum of drugs.

  19. Systems Biology-Based Investigation of Cellular Antiviral Drug Targets Identified by Gene-Trap Insertional Mutagenesis

    Science.gov (United States)

    Zhao, Junfei; Sheng, Jinsong; Rubin, Donald H.

    2016-01-01

    Viruses require host cellular factors for successful replication. A comprehensive systems-level investigation of the virus-host interactome is critical for understanding the roles of host factors with the end goal of discovering new druggable antiviral targets. Gene-trap insertional mutagenesis is a high-throughput forward genetics approach to randomly disrupt (trap) host genes and discover host genes that are essential for viral replication, but not for host cell survival. In this study, we used libraries of randomly mutagenized cells to discover cellular genes that are essential for the replication of 10 distinct cytotoxic mammalian viruses, 1 gram-negative bacterium, and 5 toxins. We herein reported 712 candidate cellular genes, characterizing distinct topological network and evolutionary signatures, and occupying central hubs in the human interactome. Cell cycle phase-specific network analysis showed that host cell cycle programs played critical roles during viral replication (e.g. MYC and TAF4 regulating G0/1 phase). Moreover, the viral perturbation of host cellular networks reflected disease etiology in that host genes (e.g. CTCF, RHOA, and CDKN1B) identified were frequently essential and significantly associated with Mendelian and orphan diseases, or somatic mutations in cancer. Computational drug repositioning framework via incorporating drug-gene signatures from the Connectivity Map into the virus-host interactome identified 110 putative druggable antiviral targets and prioritized several existing drugs (e.g. ajmaline) that may be potential for antiviral indication (e.g. anti-Ebola). In summary, this work provides a powerful methodology with a tight integration of gene-trap insertional mutagenesis testing and systems biology to identify new antiviral targets and drugs for the development of broadly acting and targeted clinical antiviral therapeutics. PMID:27632082

  20. A trans-well-based cellular model for the rapid pre-evaluation of tympanic membrane repair materials.

    Science.gov (United States)

    Hung, Shih-Han; Su, Chin-Hui; Tseng, How

    2016-08-01

    It is important to have a standardized tympanic membrane (TM) perforation platform to evaluate the various myringoplasty materials that have been studied and developed extensively during recent years. However, currently there are no cellular models specifically designed for this purpose, and animal models remain unsatisfactory. The purpose of this study is to propose an inexpensive, readily available, well-controlled, and easy-to-create cellular model as a substitute for use in the evaluation of TM repairing materials. A trans-well model was created using a cell culture insert with a round hole created at the center of the polycarbonate membrane. HaCaT cells were cultured on the fenestrated culture insert, and the desired myringoplasty graft was placed at the center of the window for one week and observed by fluorescent microscopy under vital staining. Under this cellular model, there was notable migration of HaCaT cells onto the positive control graft (rabbit fascia), while only a few cell clusters were observed on the negative control graft (paper). Model validation showed that the cell migration ratio for the PLLA + 1% hyaluronic acid (HA) graft is significantly higher than using myringoplasty paper, poly L-lactide (PLLA), or PLLA + 0.5% HA (p model might be a useful pre-evaluation platform for the evaluation of TM repairing materials. The model is inexpensive, readily available, easy to create, and standardized for use.

  1. Assessment of cellular estrogenic activity based on estrogen receptor-mediated reduction of soluble-form catechol-O-methyltransferase (COMT expression in an ELISA-based system.

    Directory of Open Access Journals (Sweden)

    Philip Wing-Lok Ho

    Full Text Available Xenoestrogens are either natural or synthetic compounds that mimic the effects of endogenous estrogen. These compounds, such as bisphenol-A (BPA, and phthalates, are commonly found in plastic wares. Exposure to these compounds poses major risk to human health because of the potential to cause endocrine disruption. There is huge demand for a wide range of chemicals to be assessed for such potential for the sake of public health. Classical in vivo assays for endocrine disruption are comprehensive but time-consuming and require sacrifice of experimental animals. Simple preliminary in vitro screening assays can reduce the time and expense involved. We previously demonstrated that catechol-O-methyltransferase (COMT is transcriptionally regulated by estrogen via estrogen receptor (ER. Therefore, detecting corresponding changes of COMT expression in estrogen-responsive cells may be a useful method to estimate estrogenic effects of various compounds. We developed a novel cell-based ELISA to evaluate cellular response to estrogenicity by reduction of soluble-COMT expression in ER-positive MCF-7 cells exposed to estrogenic compounds. In contrast to various existing methods that only detect bioactivity, this method elucidates direct physiological effect in a living cell in response to a compound. We validated our assay using three well-characterized estrogenic plasticizers - BPA, benzyl butyl phthalate (BBP, and di-n-butyl phthalate (DBP. Cells were exposed to either these plasticizers or 17β-estradiol (E2 in estrogen-depleted medium with or without an ER-antagonist, ICI 182,780, and COMT expression assayed. Exposure to each of these plasticizers (10(-9-10(-7M dose-dependently reduced COMT expression (p<0.05, which was blocked by ICI 182,780. Reduction of COMT expression was readily detectable in cells exposed to picomolar level of E2, comparable to other in vitro assays of similar sensitivity. To satisfy the demand for in vitro assays targeting different

  2. Constitutive Macropinocytosis in Oncogene-transformed Fibroblasts Depends on Sequential Permanent Activation of Phosphoinositide 3-Kinase and Phospholipase C

    OpenAIRE

    Amyere, Mustapha; Payrastre, Bernard; Krause, Ulrike; Van Der Smissen, Patrick; Veithen, Alex; Courtoy, Pierre J

    2000-01-01

    Macropinocytosis results from the closure of lamellipodia generated by membrane ruffling, thereby reflecting cortical actin dynamics. Both transformation of Rat-1 fibroblasts by v-Src or K-Ras and stable transfection for expression of dominant-positive, wild-type phosphoinositide 3-kinase (PI3K) regulatory subunit p85α constitutively led to stress fiber disruption, cortical actin recruitment, extensive ruffling, and macropinosome formation, as measured by a selecti...

  3. Constitutive macropinocytosis in oncogene-transformed fibroblasts depends on sequential permanent activation of phosphoinositide 3-kinase and phospholipase C.

    OpenAIRE

    Amyere, Mustapha; Payrastre, B.; Krause, U.; Van Der Smissen, Patrick; Veithen, A.; Courtoy, Pierre J

    2000-01-01

    Macropinocytosis results from the closure of lamellipodia generated by membrane ruffling, thereby reflecting cortical actin dynamics. Both transformation of Rat-1 fibroblasts by v-Src or K-Ras and stable transfection for expression of dominant-positive, wild-type phosphoinositide 3-kinase (PI3K) regulatory subunit p85 alpha constitutively led to stress fiber disruption, cortical actin recruitment, extensive ruffling, and macropinosome formation, as measured by a selective acceleration of flui...

  4. An Option Pricing Model Based on Cellular Automaton%基于元胞自动机的期权定价模型

    Institute of Scientific and Technical Information of China (English)

    李捷

    2011-01-01

    Option pricing is one of the most difficult problems in financial research. The key to the problem is how to simulate the randomness of the underlying asset price. This paper designs and implements an option pricing model based on the cellular automaton, which treats market participants as the cells in the cellular automaton. The model uses cellular automaton rules to simulate the interactions between traders and the changes of underlying asset prices. The paper compares the output data of the model with the calculation results of the Black-Scholes model, tests the normality of the model's output data, and finds that the option pricing model based on the cellular automaton is not only feasible, but also more effective than the Black-Scholes model.%针对期权定价难于模拟基础资产价格波动随机性的问题,设计了基于元胞自动机的期权定价模型.该模型将市场参与者看作一个个的元胞,使用元胞规则来模拟金融市场中交易者之间的交互行为。从而在总体上模拟出基础资产价格的变化.比较了模型产出的数据和Black-Scholes模型的计算结果,检验了模型产出数据的正态性,发现基于元胞自动机的期权定价模型不仅具有可行性,而且比Black-Scholes模型更有效.

  5. Phosphoinositide 3-kinase δ gene mutation predisposes to respiratory infection and airway damage

    Science.gov (United States)

    Angulo, Ivan; Vadas, Oscar; Garçon, Fabien; Banham-Hall, Edward; Plagnol, Vincent; Leahy, Timothy R.; Baxendale, Helen; Coulter, Tanya; Curtis, James; Wu, Changxin; Blake-Palmer, Katherine; Perisic, Olga; Smyth, Deborah; Maes, Mailis; Fiddler, Christine; Juss, Jatinder; Cilliers, Deirdre; Markelj, Gašper; Chandra, Anita; Farmer, George; Kielkowska, Anna; Clark, Jonathan; Kracker, Sven; Debré, Marianne; Picard, Capucine; Pellier, Isabelle; Jabado, Nada; Morris, James A.; Barcenas-Morales, Gabriela; Fischer, Alain; Stephens, Len; Hawkins, Phillip; Barrett, Jeffrey C.; Abinun, Mario; Clatworthy, Menna; Durandy, Anne; Doffinger, Rainer; Chilvers, Edwin; Cant, Andrew J.; Kumararatne, Dinakantha; Okkenhaug, Klaus; Williams, Roger L.; Condliffe, Alison; Nejentsev, Sergey

    2014-01-01

    Genetic mutations cause primary immunodeficiencies (PIDs), which predispose to infections. Here we describe Activated PI3K-δ Syndrome (APDS), a PID associated with a dominant gain-of-function mutation E1021K in the p110δ protein, the catalytic subunit of phosphoinositide 3-kinase δ (PI3Kδ), encoded by the PIK3CD gene. We found E1021K in 17 patients from seven unrelated families, but not among 3,346 healthy subjects. APDS was characterized by recurrent respiratory infections, progressive airway damage, lymphopenia, increased circulating transitional B cells, increased IgM and reduced IgG2 levels in serum and impaired vaccine responses. The E1021K mutation enhanced membrane association and kinase activity of p110δ. Patient-derived lymphocytes had increased levels of phosphatidylinositol 3,4,5-trisphosphate and phosphorylated AKT protein and were prone to activation-induced cell death. Selective p110δ inhibitors IC87114 and GS-1101 reduced the activity of the mutant enzyme in vitro, suggesting a therapeutic approach for patients with APDS. PMID:24136356

  6. Ablation of phosphoinositide-3-kinase class II alpha suppresses hepatoma cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Stanley K.L. [Singapore Immunology Network A-STAR (Singapore); Neo, Soek-Ying, E-mail: neo_soek_ying@sics.a-star.edu.sg [Singapore Immunology Network A-STAR (Singapore); Yap, Yann-Wan [Singapore Immunology Network A-STAR (Singapore); Karuturi, R. Krishna Murthy; Loh, Evelyn S.L. [Genome Institute of Singapore A-STAR (Singapore); Liau, Kui-Hin [Department of General Surgery, Tan Tock Seng Hospital (Singapore); Ren, Ee-Chee, E-mail: ren_ee_chee@immunol.a-star.edu.sg [Singapore Immunology Network A-STAR (Singapore); Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore (Singapore)

    2009-09-18

    Cancer such as hepatocellular carcinoma (HCC) is characterized by complex perturbations in multiple signaling pathways, including the phosphoinositide-3-kinase (PI3K/AKT) pathways. Herein we investigated the role of PI3K catalytic isoforms, particularly class II isoforms in HCC proliferation. Among the siRNAs tested against the eight known catalytic PI3K isoforms, specific ablation of class II PI3K alpha (PIK3C2{alpha}) was the most effective in impairing cell growth and this was accompanied by concomitant decrease in PIK3C2{alpha} mRNA and protein levels. Colony formation ability of cells deficient for PIK3C2{alpha} was markedly reduced and growth arrest was associated with increased caspase 3 levels. A small but significant difference in gene dosage and expression levels was detected between tumor and non-tumor tissues in a cohort of 19 HCC patients. Taken together, these data suggest for the first time that in addition to class I PI3Ks in cancer, class II PIK3C2{alpha} can modulate HCC cell growth.

  7. Alpha-1 adrenergic receptor: Binding and phosphoinositide breakdown in human myometrium

    Energy Technology Data Exchange (ETDEWEB)

    Breuiller-Fouche, M.; Doualla-Bell Kotto Maka, F.; Geny, B.; Ferre, F. (INSERM U.166 Groupe de recherches sur l' Endocrinologie de la Reproduction, Maternite Baudelocque, Paris (France))

    1991-07-01

    Alpha-1 adrenergic receptors were examined in both inner and outer layers of human pregnant myometrium using radioligand binding of (3H)prazosin. (3H)prazosin bound rapidly and reversibly to a single class of high affinity binding sites in myometrial membrane preparations. Scatchard analysis gave similar values of equilibrium dissociation constants in both myometrial layers. In contrast, more alpha-1 adrenergic receptors were detected in the outer layer than in the inner layer. Antagonist inhibited (3H)prazosin binding with an order of potency of prazosin greater than phentolamine greater than idazoxan. Competition experiments have also revealed that a stable guanine nucleotide decreases the apparent affinity of norepinephrine for myometrial (3H)prazosin binding sites. The functional status of these alpha-1 adrenergic receptors was also assessed by measuring the norepinephrine-induced accumulation of inositol phosphates in myometrial tissue. Norepinephrine produced a concentration-dependent accumulation of inositol phosphates in both myometrial layers. However, norepinephrine-induced increases in inositol 1,4,5-triphosphate were only observed in the outer layer. These results indicate that alpha-1 adrenergic receptors in human myometrium at the end of pregnancy are linked to phosphoinositide hydrolysis and that this response occurs mainly in the outer layer.

  8. Involvement of phosphoinositide 3-kinases in neutrophil activation and the development of acute lung injury.

    Science.gov (United States)

    Yum, H K; Arcaroli, J; Kupfner, J; Shenkar, R; Penninger, J M; Sasaki, T; Yang, K Y; Park, J S; Abraham, E

    2001-12-01

    Activated neutrophils contribute to the development and severity of acute lung injury (ALI). Phosphoinositide 3-kinases (PI3-K) and the downstream serine/threonine kinase Akt/protein kinase B have a central role in modulating neutrophil function, including respiratory burst, chemotaxis, and apoptosis. In the present study, we found that exposure of neutrophils to endotoxin resulted in phosphorylation of Akt, activation of NF-kappaB, and expression of the proinflammatory cytokines IL-1beta and TNF-alpha through PI3-K-dependent pathways. In vivo, endotoxin administration to mice resulted in activation of PI3-K and Akt in neutrophils that accumulated in the lungs. The severity of endotoxemia-induced ALI was significantly diminished in mice lacking the p110gamma catalytic subunit of PI3-K. In PI3-Kgamma(-/-) mice, lung edema, neutrophil recruitment, nuclear translocation of NF-kappaB, and pulmonary levels of IL-1beta and TNF-alpha were significantly lower after endotoxemia as compared with PI3-Kgamma(+/+) controls. Among neutrophils that did accumulate in the lungs of the PI3-Kgamma(-/-) mice after endotoxin administration, activation of NF-kappaB and expression of proinflammatory cytokines was diminished compared with levels present in lung neutrophils from PI3-Kgamma(+/+) mice. These results show that PI3-K, and particularly PI3-Kgamma, occupies a central position in regulating endotoxin-induced neutrophil activation, including that involved in ALI.

  9. Targeting phosphoinositide 3-kinase δ for the treatment of respiratory diseases.

    Science.gov (United States)

    Sriskantharajah, Srividya; Hamblin, Nicole; Worsley, Sally; Calver, Andrew R; Hessel, Edith M; Amour, Augustin

    2013-03-01

    Asthma and chronic obstructive pulmonary disease (COPD) are characterized in their pathogenesis by chronic inflammation in the airways. Phosphoinositide 3-kinase δ (PI3Kδ), a lipid kinase expressed predominantly in leukocytes, is thought to hold much promise as a therapeutic target for such inflammatory conditions. Of particular interest for the treatment of severe respiratory disease is the observation that inhibition of PI3Kδ may restore steroid effectiveness under conditions of oxidative stress. PI3Kδ inhibition may also prevent recruitment of inflammatory cells, including T lymphocytes and neutrophils, as well as the release of proinflammatory mediators, such as cytokines, chemokines, reactive oxygen species, and proteolytic enzymes. In addition, targeting the PI3Kδ pathway could reduce the incidence of pathogen-induced exacerbations by improving macrophage-mediated bacterial clearance. In this review, we discuss the potential and highlight the unknowns of targeting PI3Kδ for the treatment of respiratory disease, focusing on recent developments in the role of the PI3Kδ pathway in inflammatory cell types believed to be critical to the pathogenesis of COPD.

  10. Activation of phosphoinositide 3-kinase by D2 receptor prevents apoptosis in dopaminergic cell lines.

    Science.gov (United States)

    Nair, Venugopalan D; Olanow, C Warren; Sealfon, Stuart C

    2003-07-01

    Whereas dopamine agonists are known to provide symptomatic benefits for Parkinson's disease, recent clinical trials suggest that they might also be neuroprotective. Laboratory studies demonstrate that dopamine agonists can provide neuroprotective effects in a number of model systems, but the role of receptor-mediated signalling in these effects is controversial. We find that dopamine agonists have robust, concentration-dependent anti-apoptotic activity in PC12 cells that stably express human D(2L) receptors from cell death due to H(2)O(2) or trophic withdrawal and that the protective effects are abolished in the presence of D(2)-receptor antagonists. D(2) agonists are also neuroprotective in the nigral dopamine cell line SN4741, which express endogenous D(2) receptors, whereas no anti-apoptotic activity is observed in native PC12 cells, which do not express detectable D(2) receptors. Notably, the agonists studied differ in their relative efficacy to mediate anti-apoptotic effects and in their capacity to stimulate [(35)S]guanosine 5'-[gamma-thio]triphosphate ([(35)S]GTP[S]) binding, an indicator of G-protein activation. Studies with inhibitors of phosphoinositide 3-kinase (PI 3-kinase), extracellular-signal-regulated kinase or p38 mitogen-activated protein kinase indicate that the PI 3-kinase pathway is required for D(2) receptor-mediated cell survival. These studies indicate that certain dopamine agonists can complex with D(2) receptors to preferentially transactivate neuroprotective signalling pathways and to mediate increased cell survival.

  11. New experimental trends for phosphoinositides research on ion transporter/channel regulation.

    Science.gov (United States)

    Mori, Masayuki X; Inoue, Ryuji

    2014-01-01

    Phosphoinositides(4,5)-bisphosphates [PI(4,5)P2] critically controls membrane excitability, the disruption of which leads to pathophysiological states. PI(4,5)P2 plays a primary role in regulating the conduction and gating properties of ion channels/transporters, through electrostatic and hydrophobic interactions that allow direct associations. In recent years, the development of many molecular tools have brought deep insights into the mechanisms underlying PI(4,5)P2-mediated regulation. This review summarizes the methods currently available to manipulate the cell membrane PI(4,5)P2 level including pharmacological interventions as well as newly designed molecular tools. We concisely introduce materials and experimental designs suitable for the study of PI(4,5)P2-mediated regulation of ion-conducting molecules, in order to assist researchers who are interested in this area. It is our further hope that the knowledge introduced in this review will help to promote our understanding about the pathology of diseases such as cardiac arrhythmias, bipolar disorders, and Alzheimer's disease which are somehow associated with a disruption of PI(4,5)P2 metabolism.

  12. Tyrosol Suppresses Allergic Inflammation by Inhibiting the Activation of Phosphoinositide 3-Kinase in Mast Cells.

    Science.gov (United States)

    Je, In-Gyu; Kim, Duk-Sil; Kim, Sung-Wan; Lee, Soyoung; Lee, Hyun-Shik; Park, Eui Kyun; Khang, Dongwoo; Kim, Sang-Hyun

    2015-01-01

    Allergic diseases such as atopic dermatitis, rhinitis, asthma, and anaphylaxis are attractive research areas. Tyrosol (2-(4-hydroxyphenyl)ethanol) is a polyphenolic compound with diverse biological activities. In this study, we investigated whether tyrosol has anti-allergic inflammatory effects. Ovalbumin-induced active systemic anaphylaxis and immunoglobulin E-mediated passive cutaneous anaphylaxis models were used for the immediate-type allergic responses. Oral administration of tyrosol reduced the allergic symptoms of hypothermia and pigmentation in both animal models. Mast cells that secrete allergic mediators are key regulators on allergic inflammation. Tyrosol dose-dependently decreased mast cell degranulation and expression of inflammatory cytokines. Intracellular calcium levels and activation of inhibitor of κB kinase (IKK) regulate cytokine expression and degranulation. Tyrosol blocked calcium influx and phosphorylation of the IKK complex. To define the molecular target for tyrosol, various signaling proteins involved in mast cell activation such as Lyn, Syk, phosphoinositide 3-kinase (PI3K), and Akt were examined. Our results showed that PI3K could be a molecular target for tyrosol in mast cells. Taken together, these findings indicated that tyrosol has anti-allergic inflammatory effects by inhibiting the degranulation of mast cells and expression of inflammatory cytokines; these effects are mediated via PI3K. Therefore, we expect tyrosol become a potential therapeutic candidate for allergic inflammatory disorders.

  13. Tyrosol Suppresses Allergic Inflammation by Inhibiting the Activation of Phosphoinositide 3-Kinase in Mast Cells.

    Directory of Open Access Journals (Sweden)

    In-Gyu Je

    Full Text Available Allergic diseases such as atopic dermatitis, rhinitis, asthma, and anaphylaxis are attractive research areas. Tyrosol (2-(4-hydroxyphenylethanol is a polyphenolic compound with diverse biological activities. In this study, we investigated whether tyrosol has anti-allergic inflammatory effects. Ovalbumin-induced active systemic anaphylaxis and immunoglobulin E-mediated passive cutaneous anaphylaxis models were used for the immediate-type allergic responses. Oral administration of tyrosol reduced the allergic symptoms of hypothermia and pigmentation in both animal models. Mast cells that secrete allergic mediators are key regulators on allergic inflammation. Tyrosol dose-dependently decreased mast cell degranulation and expression of inflammatory cytokines. Intracellular calcium levels and activation of inhibitor of κB kinase (IKK regulate cytokine expression and degranulation. Tyrosol blocked calcium influx and phosphorylation of the IKK complex. To define the molecular target for tyrosol, various signaling proteins involved in mast cell activation such as Lyn, Syk, phosphoinositide 3-kinase (PI3K, and Akt were examined. Our results showed that PI3K could be a molecular target for tyrosol in mast cells. Taken together, these findings indicated that tyrosol has anti-allergic inflammatory effects by inhibiting the degranulation of mast cells and expression of inflammatory cytokines; these effects are mediated via PI3K. Therefore, we expect tyrosol become a potential therapeutic candidate for allergic inflammatory disorders.

  14. Semi-automated curation of protein subcellular localization: a text mining-based approach to Gene Ontology (GO Cellular Component curation

    Directory of Open Access Journals (Sweden)

    Chan Juancarlos

    2009-07-01

    Full Text Available Abstract Background Manual curation of experimental data from the biomedical literature is an expensive and time-consuming endeavor. Nevertheless, most biological knowledge bases still rely heavily on manual curation for data extraction and entry. Text mining software that can semi- or fully automate information retrieval from the literature would thus provide a significant boost to manual curation efforts. Results We employ the Textpresso category-based information retrieval and extraction system http://www.textpresso.org, developed by WormBase to explore how Textpresso might improve the efficiency with which we manually curate C. elegans proteins to the Gene Ontology's Cellular Component Ontology. Using a training set of sentences that describe results of localization experiments in the published literature, we generated three new curation task-specific categories (Cellular Components, Assay Terms, and Verbs containing words and phrases associated with reports of experimentally determined subcellular localization. We compared the results of manual curation to that of Textpresso queries that searched the full text of articles for sentences containing terms from each of the three new categories plus the name of a previously uncurated C. elegans protein, and found that Textpresso searches identified curatable papers with recall and precision rates of 79.1% and 61.8%, respectively (F-score of 69.5%, when compared to manual curation. Within those documents, Textpresso identified relevant sentences with recall and precision rates of 30.3% and 80.1% (F-score of 44.0%. From returned sentences, curators were able to make 66.2% of all possible experimentally supported GO Cellular Component annotations with 97.3% precision (F-score of 78.8%. Measuring the relative efficiencies of Textpresso-based versus manual curation we find that Textpresso has the potential to increase curation efficiency by at least 8-fold, and perhaps as much as 15-fold, given

  15. Look-Ahead Strategies Based on Store-Carry and Forward Relaying for Energy Efficient Cellular Communications

    Directory of Open Access Journals (Sweden)

    Panayiotis Kolios

    2010-11-01

    Full Text Available With the increasing availability of Internet type services on mobile devices and the attractive flat rate all-you-can-eat billing system, cellular telecommunication networks are experiencing a tremendous growth in data usage demand. However, there are increasing concerns that current network deployment trends (including more efficient radio access techniques and increased spectrum allocation strategies, will be unable to support the increased Internet traffic in a sustainable way. The delay tolerant nature of mobile Internet traffic allows for a large degree of flexibility in optimizing network performance to meet different design objectives and it’s a feature that has mostly gone unexplored by the research community. In this paper, we introduce a novel message forwarding mechanism in cellular networks that benefits from the inherent delay tolerance of Internet type services to provide flexible and adjustable forwarding strategies for efficient network operation while guaranteeing timely deliveries. By capitalizing on the elasticity of message delivery deadlines and the actual mobility of nodes inside the cell, considerable performance gains can be achieved by physically propagating information messages within the network.

  16. Environment Aware Cellular Networks

    KAUST Repository

    Ghazzai, Hakim

    2015-02-01

    The unprecedented rise of mobile user demand over the years have led to an enormous growth of the energy consumption of wireless networks as well as the greenhouse gas emissions which are estimated currently to be around 70 million tons per year. This significant growth of energy consumption impels network companies to pay huge bills which represent around half of their operating expenditures. Therefore, many service providers, including mobile operators, are looking for new and modern green solutions to help reduce their expenses as well as the level of their CO2 emissions. Base stations are the most power greedy element in cellular networks: they drain around 80% of the total network energy consumption even during low traffic periods. Thus, there is a growing need to develop more energy-efficient techniques to enhance the green performance of future 4G/5G cellular networks. Due to the problem of traffic load fluctuations in cellular networks during different periods of the day and between different areas (shopping or business districts and residential areas), the base station sleeping strategy has been one of the main popular research topics in green communications. In this presentation, we present several practical green techniques that provide significant gains for mobile operators. Indeed, combined with the base station sleeping strategy, these techniques achieve not only a minimization of the fossil fuel consumption but also an enhancement of mobile operator profits. We start with an optimized cell planning method that considers varying spatial and temporal user densities. We then use the optimal transport theory in order to define the cell boundaries such that the network total transmit power is reduced. Afterwards, we exploit the features of the modern electrical grid, the smart grid, as a new tool of power management for cellular networks and we optimize the energy procurement from multiple energy retailers characterized by different prices and pollutant

  17. Cellular systems biology profiling applied to cellular models of disease.

    Science.gov (United States)

    Giuliano, Kenneth A; Premkumar, Daniel R; Strock, Christopher J; Johnston, Patricia; Taylor, Lansing

    2009-11-01

    Building cellular models of disease based on the approach of Cellular Systems Biology (CSB) has the potential to improve the process of creating drugs as part of the continuum from early drug discovery through drug development and clinical trials and diagnostics. This paper focuses on the application of CSB to early drug discovery. We discuss the integration of protein-protein interaction biosensors with other multiplexed, functional biomarkers as an example in using CSB to optimize the identification of quality lead series compounds.

  18. 基于GPU的元胞自动机熔岩流动模拟%Lava flow simulation in cellular automata based on GPU

    Institute of Scientific and Technical Information of China (English)

    高超; 孟宪海; 李吉刚; 杨钦

    2015-01-01

    为解决基于元胞自动机进行熔岩流动模拟的计算效率问题,提出一种应用在元胞自动机上的GPU并行计算方法。将元胞自动机中每一个方形网格映射到GPU的一个逻辑计算单元上,通过并行计算,提高模拟的效率,解决传统串行计算方法的不足,使模拟达到实时性。模拟结果表明,在元胞自动机的物理模型理论基础上,用GPU并行计算进行加速,在模拟效果和时间效率上均取得了良好的效果。%To solve the computing efficiency problem of lava flow simulation based on cellular automata ,a GPU parallel compu‐ting method applied to cellular automata was proposed .Each square mesh in cellular automata was mapped to each core in the GPU .Through GPU parallel computing ,the efficiency of real‐time simulation was improved ,which solved the deficiency of tra‐ditional serial computing .The result demonstrates that lava flow simulation in cellular automata ,with the combination of the GPU parallel computing ,can achieve a high computing efficiency and a better simulation performance .

  19. 5G Ultra-Dense Cellular Networks

    OpenAIRE

    Ge, Xiaohu; Tu, Song; Mao, Guoqiang; Wang, Cheng-xiang; Han, Tao

    2015-01-01

    Traditional ultra-dense wireless networks are recommended as a complement for cellular networks and are deployed in partial areas, such as hotspot and indoor scenarios. Based on the massive multiple-input multi-output (MIMO) antennas and the millimeter wavecommunication technologies, the 5G ultra-dense cellular network is proposed to deploy in overall cellular scenarios. Moreover, a distribution network architecture is presented for 5G ultra-dense cellular networks. Furthermore, the backhaul ...

  20. Expression of phosphoinositide-specific phospholipase C isoforms in native endothelial cells.

    Directory of Open Access Journals (Sweden)

    Delphine M Béziau

    Full Text Available Phospholipase C (PLC comprises a superfamily of enzymes that play a key role in a wide array of intracellular signalling pathways, including protein kinase C and intracellular calcium. Thirteen different mammalian PLC isoforms have been identified and classified into 6 families (PLC-β, γ, δ, ε, ζ and η based on their biochemical properties. Although the expression of PLC isoforms is tissue-specific, concomitant expression of different PLC has been reported, suggesting that PLC family is involved in multiple cellular functions. Despite their critical role, the PLC isoforms expressed in native endothelial cells (ECs remains undetermined. A conventional PCR approach was initially used to elucidate the mRNA expression pattern of PLC isoforms in 3 distinct murine vascular beds: mesenteric (MA, pulmonary (PA and middle cerebral arteries (MCA. mRNA encoding for most PLC isoforms was detected in MA, MCA and PA with the exception of η2 and β2 (only expressed in PA, δ4 (only expressed in MCA, η1 (expressed in all but MA and ζ (not detected in any vascular beds tested. The endothelial-specific PLC expression was then sought in freshly isolated ECs. Interestingly, the PLC expression profile appears to differ across the investigated arterial beds. While mRNA for 8 of the 13 PLC isoforms was detected in ECs from MA, two additional PLC isoforms were detected in ECs from PA and MCA. Co-expression of multiple PLC isoforms in ECs suggests an elaborate network of signalling pathways: PLC isoforms may contribute to the complexity or diversity of signalling by their selective localization in cellular microdomains. However in situ immunofluorescence revealed a homogeneous distribution for all PLC isoforms probed (β3, γ2 and δ1 in intact endothelium. Although PLC isoforms play a crucial role in endothelial signal transduction, subcellular localization alone does not appear to be sufficient to determine the role of PLC in the signalling microdomains found

  1. Failover in cellular automata

    CERN Document Server

    Kumar, Shailesh

    2010-01-01

    A cellular automata (CA) configuration is constructed that exhibits emergent failover. The configuration is based on standard Game of Life rules. Gliders and glider-guns form the core messaging structure in the configuration. The blinker is represented as the basic computational unit, and it is shown how it can be recreated in case of a failure. Stateless failover using primary-backup mechanism is demonstrated. The details of the CA components used in the configuration and its working are described, and a simulation of the complete configuration is also presented.

  2. 基于复合元胞自动机的分布式计算模型%A distributed computing model based on compound cellular automata

    Institute of Scientific and Technical Information of China (English)

    朱晓敏; 耿建东; 陈东华; 张润彤

    2012-01-01

    针对目前的分布式计算网络仍然缺乏较高的自治管理和自主认知能力,只能提供独立状态的服务,经常出现多点故障而造成分布式网络运作成本增加、延时加剧甚至网络崩溃等问题,将元胞自动机的相关概念及模型引入到分布式网络计算中,通过修正元胞自动机的原有机制,提出了复合元胞自动机模型,并建立了基于复合元胞自动机的分布式计算模型来提高分布式网络中认知自主管理能力,从而降低分布式计算成本和提高工作效率.通过模拟程序和GridSim软件包验证和展示了复合元胞自动机应用于分布式计算领域的可行性及优越性.%The concept of cellular automation and its model were introduced into distributed computation to solve current distributed computing networks' problems of high operating cost, serious time delay, and even debacle due to the multi-point failure caused by lack of high self-management and self-awareness and only providing independent services. By amending the original cellular automaton mechanism, a compound cellular automata model was proposed, and the distributed computing model based on compound cellular automata was established to enhance distributed networks' efficiency and reduce the operating cost. The comprehensive simulations and comparisons via GridSim verified the feasibility and efficiency of the proposed compound cellular automata model in the field of distributed computing.

  3. Dual Functional Nanocarrier for Cellular Imaging and Drug Delivery in Cancer Cells Based on π-Conjugated Core and Biodegradable Polymer Arms.

    Science.gov (United States)

    Kulkarni, Bhagyashree; Surnar, Bapurao; Jayakannan, Manickam

    2016-03-14

    Multipurpose polymer nanoscaffolds for cellular imaging and delivery of anticancer drug are urgently required for the cancer therapy. The present investigation reports a new polymer drug delivery concept based on biodegradable polycaprolactone (PCL) and highly luminescent π-conjugated fluorophore as dual functional nanocarrier for cellular imaging and delivery vehicles for anticancer drug to cancer cells. To accomplish this goal, a new substituted caprolactone monomer was designed, and it was subjected to ring opening polymerization using a blue luminescent bishydroxyloligo-phenylenevinylene (OPV) fluorophore as an initiator. A series of A-B-A triblock copolymer building blocks with a fixed OPV π-core and variable chain biodegradable PCL arm length were tailor-made. These triblocks self-assembled in organic solvents to produce well-defined helical nanofibers, whereas in water they produced spherical nanoparticles (size ∼150 nm) with blue luminescence. The hydrophobic pocket of the polymer nanoparticle was found to be an efficient host for loading water insoluble anticancer drug such as doxorubicin (DOX). The photophysical studies revealed that there was no cross-talking between the OPV and DOX chromophores, and their optical purity was retained in the nanoparticle assembly for cellular imaging. In vitro studies revealed that the biodegradable PCL arm was susceptible to enzymatic cleavage at the intracellular lysosomal esterase under physiological conditions to release the loaded drugs. The nascent nanoparticles were found to be nontoxic to cancer cells, whereas the DOX-loaded nanoparticles accomplished more than 80% killing in HeLa cells. Confocal microscopic analysis confirmed the cell penetrating ability of the blue luminescent polymer nanoparticles and their accumulation preferably in the cytoplasm. The DOX loaded red luminescent polymer nanoparticles were also taken up by the cells, and the drug was found to be accumulated at the perinuclear environment

  4. Cellular Phone Towers, Serve as base information for use in GIS systems for general planning, analytical, and research purposes., Published in 2007, 1:24000 (1in=2000ft) scale, Louisiana State University.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Cellular Phone Towers dataset, published at 1:24000 (1in=2000ft) scale as of 2007. It is described as 'Serve as base information for use in GIS systems for...

  5. Dual roles of hemidesmosomal proteins in the pancreatic epithelium: the phosphoinositide 3-kinase decides.

    Science.gov (United States)

    Laval, S; Laklai, H; Fanjul, M; Pucelle, M; Laurell, H; Billon-Galés, A; Le Guellec, S; Delisle, M-B; Sonnenberg, A; Susini, C; Pyronnet, S; Bousquet, C

    2014-04-10

    Given the failure of chemo- and biotherapies to fight advanced pancreatic cancer, one major challenge is to identify critical events that initiate invasion. One priming step in epithelia carcinogenesis is the disruption of epithelial cell anchorage to the basement membrane which can be provided by hemidesmosomes (HDs). However, the existence of HDs in pancreatic ductal epithelium and their role in carcinogenesis remain unexplored. HDs have been explored in normal and cancer pancreatic cells, and patient samples. Unique cancer cell models where HD assembly can be pharmacologically manipulated by somatostatin/sst2 signaling have been then used to investigate the role and molecular mechanisms of dynamic HD during pancreatic carcinogenesis. We surprisingly report the presence of mature type-1 HDs comprising the integrin α6β4 and bullous pemphigoid antigen BP180 in the human pancreatic ductal epithelium. Importantly, HDs are shown to disassemble during pancreatic carcinogenesis. HD breakdown requires phosphoinositide 3-kinase (PI3K)-dependent induction of the matrix-metalloprotease MMP-9, which cleaves BP180. Consequently, integrin α6β4 delocalizes to the cell-leading edges where it paradoxically promotes cell migration and invasion through S100A4 activation. As S100A4 in turn stimulates MMP-9 expression, a vicious cycle maintains BP180 cleavage. Inactivation of this PI3K-MMP-9-S100A4 signaling loop conversely blocks BP180 cleavage, induces HD reassembly and inhibits cell invasion. We conclude that mature type-1 HDs are critical anchoring structures for the pancreatic ductal epithelium whose disruption, upon PI3K activation during carcinogenesis, provokes pancreatic cancer cell migration and invasion.

  6. PPARδ activation acts cooperatively with 3-phosphoinositide-dependent protein kinase-1 to enhance mammary tumorigenesis.

    Directory of Open Access Journals (Sweden)

    Claire B Pollock

    Full Text Available Peroxisome proliferator-activated receptorδ (PPARδ is a transcription factor that is associated with metabolic gene regulation and inflammation. It has been implicated in tumor promotion and in the regulation of 3-phosphoinositide-dependent kinase-1 (PDK1. PDK1 is a key regulator of the AGC protein kinase family, which includes the proto-oncogene AKT/PKB implicated in several malignancies, including breast cancer. To assess the role of PDK1 in mammary tumorigenesis and its interaction with PPARδ, transgenic mice were generated in which PDK1 was expressed in mammary epithelium under the control of the MMTV enhancer/promoter region. Transgene expression increased pT308AKT and pS9GSK3β, but did not alter phosphorylation of mTOR, 4EBP1, ribosomal protein S6 and PKCα. The transgenic mammary gland also expressed higher levels of PPARδ and a gene expression profile resembling wild-type mice maintained on a diet containing the PPARδ agonist, GW501516. Both wild-type and transgenic mice treated with GW501516 exhibited accelerated rates of tumor formation that were more pronounced in transgenic animals. GW501516 treatment was accompanied by a distinct metabolic gene expression and metabolomic signature that was not present in untreated animals. GW501516-treated transgenic mice expressed higher levels of fatty acid and phospholipid metabolites than treated wild-type mice, suggesting the involvement of PDK1 in enhancing PPARδ-driven energy metabolism. These results reveal that PPARδ activation elicits a distinct metabolic and metabolomic profile in tumors that is in part related to PDK1 and AKT signaling.

  7. Endosomal maturation, Rab7 GTPase and phosphoinositides in African swine fever virus entry.

    Directory of Open Access Journals (Sweden)

    Miguel A Cuesta-Geijo

    Full Text Available Here we analyzed the dependence of African swine fever virus (ASFV infection on the integrity of the endosomal pathway. Using confocal immunofluorescence with antibodies against viral capsid proteins, we found colocalization of incoming viral particles with early endosomes (EE during the first minutes of infection. Conversely, viral capsid protein was not detected in acidic late endosomal compartments, multivesicular bodies (MVBs, late endosomes (LEs or lysosomes (LY. Using an antibody against a viral inner core protein, we found colocalization of viral cores with late compartments from 30 to 60 minutes postinfection. The absence of capsid protein staining in LEs and LYs suggested that virus desencapsidation would take place at the acid pH of these organelles. In fact, inhibitors of intraluminal acidification of endosomes caused retention of viral capsid staining virions in Rab7 expressing endosomes and more importantly, severely impaired subsequent viral protein production. Endosomal acidification in the first hour after virus entry was essential for successful infection but not thereafter. In addition, altering the balance of phosphoinositides (PIs which are responsible of the maintenance of the endocytic pathway impaired ASFV infection. Early infection steps were dependent on the production of phosphatidylinositol 3-phosphate (PtdIns3P which is involved in EE maturation and multivesicular body (MVB biogenesis and on the interconversion of PtdIns3P to phosphatidylinositol 3, 5-biphosphate (PtdIns(3,5P(2. Likewise, GTPase Rab7 activity should remain intact, as well as processes related to LE compartment physiology, which are crucial during early infection. Our data demonstrate that the EE and LE compartments and the integrity of the endosomal maturation pathway orchestrated by Rab proteins and PIs play a central role during early stages of ASFV infection.

  8. Phosphoinositides play differential roles in regulating phototropin1- and phototropin2-mediated chloroplast movements in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Chhavi Aggarwal

    Full Text Available Phototropins are UVA/blue-light receptors involved in controlling the light-dependent physiological responses which serve to optimize the photosynthetic activity of plants and promote growth. The phototropin-induced phosphoinositide (PI metabolism has been shown to be essential for stomatal opening and phototropism. However, the role of PIs in phototropin-induced chloroplast movements remains poorly understood. The aim of this work is to determine which PI species are involved in the control of chloroplast movements in Arabidopsis and the nature of their involvement. We present the effects of the inactivation of phospholipase C (PLC, PI3-kinase (PI3K and PI4-kinase (PI4K on chloroplast relocations in Arabidopsis. The inhibition of the phosphatidylinositol 4,5-bisphospahte [PI(4,5P2]-PLC pathway, using neomycin and U73122, suppressed the phot2-mediated chloroplast accumulation and avoidance responses, without affecting movement responses controlled by phot1. On the other hand, PI3K and PI4K activities are more restricted to phot1- and phot2-induced weak-light responses. The inactivation of PI3K and PI4K by wortmannin and LY294002 severely affected the weak blue-light-activated accumulation response but had little effect on the strong blue-light-activated avoidance response. The inhibitory effect observed with PI metabolism inhibitors is, at least partly, due to a disturbance in Ca(2+ ((c signaling. Using the transgenic aequorin system, we show that the application of these inhibitors suppresses the blue-light-induced transient Ca(2+ ((c rise. These results demonstrate the importance of PIs in chloroplast movements, with the PI(4,5P2-PLC pathway involved in phot2 signaling while PI3K and PI4K are required for the phot1- and phot2-induced accumulation response. Our results suggest that these PIs modulate cytosolic Ca(2+ signaling during movements.

  9. Phosphoinositides play differential roles in regulating phototropin1- and phototropin2-mediated chloroplast movements in Arabidopsis.

    Science.gov (United States)

    Aggarwal, Chhavi; Labuz, Justyna; Gabryś, Halina

    2013-01-01

    Phototropins are UVA/blue-light receptors involved in controlling the light-dependent physiological responses which serve to optimize the photosynthetic activity of plants and promote growth. The phototropin-induced phosphoinositide (PI) metabolism has been shown to be essential for stomatal opening and phototropism. However, the role of PIs in phototropin-induced chloroplast movements remains poorly understood. The aim of this work is to determine which PI species are involved in the control of chloroplast movements in Arabidopsis and the nature of their involvement. We present the effects of the inactivation of phospholipase C (PLC), PI3-kinase (PI3K) and PI4-kinase (PI4K) on chloroplast relocations in Arabidopsis. The inhibition of the phosphatidylinositol 4,5-bisphospahte [PI(4,5)P2]-PLC pathway, using neomycin and U73122, suppressed the phot2-mediated chloroplast accumulation and avoidance responses, without affecting movement responses controlled by phot1. On the other hand, PI3K and PI4K activities are more restricted to phot1- and phot2-induced weak-light responses. The inactivation of PI3K and PI4K by wortmannin and LY294002 severely affected the weak blue-light-activated accumulation response but had little effect on the strong blue-light-activated avoidance response. The inhibitory effect observed with PI metabolism inhibitors is, at least partly, due to a disturbance in Ca(2+) ((c)) signaling. Using the transgenic aequorin system, we show that the application of these inhibitors suppresses the blue-light-induced transient Ca(2+) ((c)) rise. These results demonstrate the importance of PIs in chloroplast movements, with the PI(4,5)P2-PLC pathway involved in phot2 signaling while PI3K and PI4K are required for the phot1- and phot2-induced accumulation response. Our results suggest that these PIs modulate cytosolic Ca(2+) signaling during movements.

  10. The Phosphoinositide-Gated Lysosomal Ca(2+) Channel, TRPML1, Is Required for Phagosome Maturation.

    Science.gov (United States)

    Dayam, Roya M; Saric, Amra; Shilliday, Ryan E; Botelho, Roberto J

    2015-09-01

    Macrophages internalize and sequester pathogens into a phagosome. Phagosomes then sequentially fuse with endosomes and lysosomes, converting into degradative phagolysosomes. Phagosome maturation is a complex process that requires regulators of the endosomal pathway including the phosphoinositide lipids. Phosphatidylinositol-3-phosphate and phosphatidylinositol-3,5-bisphosphate (PtdIns(3,5)P2 ), which respectively control early endosomes and late endolysosomes, are both required for phagosome maturation. Inhibition of PIKfyve, which synthesizes PtdIns(3,5)P2 , blocked phagosome-lysosome fusion and abated the degradative capacity of phagosomes. However, it is not known how PIKfyve and PtdIns(3,5)P2 participate in phagosome maturation. TRPML1 is a PtdIns(3,5)P2 -gated lysosomal Ca(2+) channel. Because Ca(2+) triggers membrane fusion, we postulated that TRPML1 helps mediate phagosome-lysosome fusion. Using Fcγ receptor-mediated phagocytosis as a model, we describe our research showing that silencing of TRPML1 hindered phagosome acquisition of lysosomal markers and reduced the bactericidal properties of phagosomes. Specifically, phagosomes isolated from TRPML1-silenced cells were decorated with lysosomes that docked but did not fuse. We could rescue phagosome maturation in TRPML1-silenced and PIKfyve-inhibited cells by forcible Ca(2+) release with ionomycin. We also provide evidence that cytosolic Ca(2+) concentration increases upon phagocytosis in a manner dependent on TRPML1 and PIKfyve. Overall, we propose a model where PIKfyve and PtdIns(3,5)P2 activate TRPML1 to induce phagosome-lysosome fusion.

  11. Rapamycin regulates connective tissue growth factor expression of lung epithelial cells via phosphoinositide 3-kinase.

    Science.gov (United States)

    Xu, Xuefeng; Wan, Xuan; Geng, Jing; Li, Fei; Yang, Ting; Dai, Huaping

    2013-09-01

    The pathogenesis of idiopathic pulmonary fibrosis (IPF) remains largely unknown. It is believed that IPF is mainly driven by activated alveolar epithelial cells that have a compromised migration capacity, and that also produce substances (such as connective tissue growth factor, CTGF) that contribute to fibroblast activation and matrix protein accumulation. Because the mechanisms regulating these processes are unclear, the aim of this study was to determine the role of rapamycin in regulating epithelial cell migration and CTGF expression. Transformed epithelial cell line A549 and normal human pulmonary alveolar or bronchial epithelial cells were cultured in regular medium or medium containing rapamycin. Real time reverse transcriptase polymerase chain reaction was employed to determine CTGF mRNA expression. Western blotting and an enzyme-linked immunosorbent assay were used for detecting CTGF protein. Wound healing and migration assays were used to determine the cell migration potential. Transforming growth factor (TGF)-β type I receptor (TβRI) inhibitor, SB431542 and phosphoinositide 3-kinase (PI3K) inhibitor, LY294002 were used to determine rapamycin's mechanism of action. It was found that treatment of A549 and normal human alveolar or bronchial epithelial cells with rapamycin significantly promoted basal or TGF-β1 induced CTGF expression. LY294002, not SB431542 attenuated the promotional effect of rapamycin on CTGF expression. Cell mobility was not affected by rapamycin in wound healing and migration assays. These data suggest rapamycin has a profibrotic effect in vitro and underscore the potential of combined therapeutic approach with PI3K and mammalian target of rapamycin inhibitors for the treatment of animal or human lung fibrosis.

  12. 基于元胞蚂蚁算法的防空靶机航路规划研究%Route Planning of Anti-Air Target Drone Based on Cellular-Ant Colony Algorithm

    Institute of Scientific and Technical Information of China (English)

    刘志强; 雷宇曜; 阳再清

    2014-01-01

    防空靶机飞行航路设计是实现靶机有效控制,确保高效完成供靶任务的保障。通过对靶机三维航路规划模型进行分析,给出了元胞蚂蚁算法的航路规划模型的求解方法及算法实现的具体流程,并分别应用蚁群算法和元胞蚂蚁算法进行仿真实验。结果表明:元胞蚂蚁算法克服了蚁群算法收敛速度慢、陷于局部最小值的缺陷,可得到较优的航路。%The design of the flight airway of anti-air target is essential to the effective target control and the high effective completion of target supply task. Through the analysis of the three-dimensional airway design model, the solution method and corresponding algorithm flow of the cellular-ant colony algorithm is provided in this paper. The simulation experiment of the ant colony and cellular-ant colony algorithms is carried out, which shows that the cellular ant algorithm over comes the ant colony algorithm disadvantages of the slow convergence and local optima, and it is able to obtain optimal airway.

  13. Handover initiation performance of a new multi-cell cellular configuration with a developed base-station multi-beam antenna

    Institute of Scientific and Technical Information of China (English)

    Zhang Zufan; Du Huiping; Zhu Weile; Yang Jing

    2005-01-01

    A new multi-cell cellular configuration networks is provided for analysis of handover initiation probability,which is based on multi-beam base-station antenna splitting in the elevation-radiating plane. The sum of the received signal power in the mobile station, including both desired and interference signal power, has been introduced into the handover initiation algorithm. Along with the idea, we present three models of handover initiation algorithm with the shadowing process of Gaussian distribution. The formulation of handover initiation probability of those algorithms is also analyzed. The validity of the presented models has been checked through the comparison with simulation results.The results present the performance characteristics of handover initiation vary with cluster number and base-station antenna elevation angle.

  14. A cellular automaton based model simulating HVAC fluid and heat transport in a building. Modeling approach and comparison with experimental results

    Energy Technology Data Exchange (ETDEWEB)

    Saiz, A. [Department of Applied Mathematics, Polytechnic University of Valencia, ETSGE School, Camino de Vera s/n, 46022 Valencia (Spain); Urchueguia, J.F. [Department of Applied Physics, Polytechnic University of Valencia, ETSII School, Camino de Vera s/n, 46022 Valencia (Spain); Martos, J. [Superior Technical School of Engineering, Department of Electronic Engineering, University of Valencia, Vicente Andres Estelles s/n, Burjassot 46100, Valencia (Spain)

    2010-09-15

    A discrete model characterizing heat and fluid flow in connection with thermal fluxes in a building is described and tested against experiment in this contribution. The model, based on a cellular automaton approach, relies on a set of a few quite simple rules and parameters in order to simulate the dynamic evolution of temperatures and energy flows in any water or brine based thermal energy distribution network in a building or system. Using an easy-to-record input, such as the instantaneous electrical power demand of the heating or cooling system, our model predicts time varying temperatures in characteristic spots and the related enthalpy flows whose simulation usually requires heavy computational tools and detailed knowledge of the network elements. As a particular example, we have applied our model to simulate an existing fan coil based hydronic heating system driven by a geothermal heat pump. When compared to the experimental temperature and thermal energy records, the outcome of the model coincides. (author)

  15. Analysis and simulation of land use spatial pattern in Harbin prefecture based on trajectories and cellular automata-Markov modelling

    Science.gov (United States)

    Gong, Wenfeng; Yuan, Li; Fan, Wenyi; Stott, Philip

    2015-02-01

    There have been rapid population and accelerating urban growth with associated changes in land use and soil degradation in northeast China, an important grain-producing region. The development of integrated use of remote sensing, geographic information systems, and combined cellular automata- Markov models has provided new means of assessing changes in land use and land cover, and has enabled projection of trajectories into the future. We applied such techniques to the prefecture-level city of Harbin, the tenth largest city in China. We found that there had been significant losses of the land uses termed "cropland", "grassland", "wetland", and "floodplain" in favour of "built-up land" and lesser transformations from "floodplain" to "forestland" and "water body" over the 18-year period. However, the transition was not a simple process but a complex network of changes, interchanges, and multiple transitions. In the absence of effective land use policies, projection of past trajectories into a balance state in the future would result in the decline of cropland from 65.6% to 46.9% and the increase of built-up area from 7.7% to 23.0% relative to the total area of the prefecture in 1989. It also led to the virtual elimination of land use types such as unused wetland and floodplain.

  16. Micro-simulation of vehicle conflicts involving right-turn vehicles at signalized intersections based on cellular automata.

    Science.gov (United States)

    Chai, C; Wong, Y D

    2014-02-01

    At intersection, vehicles coming from different directions conflict with each other. Improper geometric design and signal settings at signalized intersection will increase occurrence of conflicts between road users and results in a reduction of the safety level. This study established a cellular automata (CA) model to simulate vehicular interactions involving right-turn vehicles (as similar to left-turn vehicles in US). Through various simulation scenarios for four case cross-intersections, the relationships between conflict occurrences involving right-turn vehicles with traffic volume and right-turn movement control strategies are analyzed. Impacts of traffic volume, permissive right-turn compared to red-amber-green (RAG) arrow, shared straight-through and right-turn lane as well as signal setting are estimated from simulation results. The simulation model is found to be able to provide reasonable assessment of conflicts through comparison of existed simulation approach and observed accidents. Through the proposed approach, prediction models for occurrences and severity of vehicle conflicts can be developed for various geometric layouts and traffic control strategies.

  17. Simulation of Regionally Ecological Land Based on a Cellular Automation Model: A Case Study of Beijing, China

    Directory of Open Access Journals (Sweden)

    Xiubin Li

    2012-08-01

    Full Text Available Ecological land is like the “liver” of a city and is very useful to public health. Ecological land change is a spatially dynamic non-linear process under the interaction between natural and anthropogenic factors at different scales. In this study, by setting up natural development scenario, object orientation scenario and ecosystem priority scenario, a Cellular Automation (CA model has been established to simulate the evolution pattern of ecological land in Beijing in the year 2020. Under the natural development scenario, most of ecological land will be replaced by construction land and crop land. But under the scenarios of object orientation and ecosystem priority, the ecological land area will increase, especially under the scenario of ecosystem priority. When considering the factors such as total area of ecological land, loss of key ecological land and spatial patterns of land use, the scenarios from priority to inferiority are ecosystem priority, object orientation and natural development, so future land management policies in Beijing should be focused on conversion of cropland to forest, wetland protection and prohibition of exploitation of natural protection zones, water source areas and forest parks to maintain the safety of the regional ecosystem.

  18. Cellular communication through light.

    Directory of Open Access Journals (Sweden)

    Daniel Fels

    Full Text Available Information transfer is a fundamental of life. A few studies have reported that cells use photons (from an endogenous source as information carriers. This study finds that cells can have an influence on other cells even when separated with a glass barrier, thereby disabling molecule diffusion through the cell-containing medium. As there is still very little known about the potential of photons for intercellular communication this study is designed to test for non-molecule-based triggering of two fundamental properties of life: cell division and energy uptake. The study was performed with a cellular organism, the ciliate Paramecium caudatum. Mutual exposure of cell populations occurred under conditions of darkness and separation with cuvettes (vials allowing photon but not molecule transfer. The cell populations were separated either with glass allowing photon transmission from 340 nm to longer waves, or quartz being transmittable from 150 nm, i.e. from UV-light to longer waves. Even through glass, the cells affected cell division and energy uptake in neighboring cell populations. Depending on the cuvette material and the number of cells involved, these effects were positive or negative. Also, while paired populations with lower growth rates grew uncorrelated, growth of the better growing populations was correlated. As there were significant differences when separating the populations with glass or quartz, it is suggested that the cell populations use two (or more frequencies for cellular information transfer, which influences at least energy uptake, cell division rate and growth correlation. Altogether the study strongly supports a cellular communication system, which is different from a molecule-receptor-based system and hints that photon-triggering is a fine tuning principle in cell chemistry.

  19. Identification of microbes from the surfaces of food-processing lines based on the flow cytometric evaluation of cellular metabolic activity combined with cell sorting.

    Science.gov (United States)

    Juzwa, W; Duber, A; Myszka, K; Białas, W; Czaczyk, K

    2016-09-01

    In this study the design of a flow cytometry-based procedure to facilitate the detection of adherent bacteria from food-processing surfaces was evaluated. The measurement of the cellular redox potential (CRP) of microbial cells was combined with cell sorting for the identification of microorganisms. The procedure enhanced live/dead cell discrimination owing to the measurement of the cell physiology. The microbial contamination of the surface of a stainless steel conveyor used to process button mushrooms was evaluated in three independent experiments. The flow cytometry procedure provided a step towards monitoring of contamination and enabled the assessment of microbial food safety hazards by the discrimination of active, mid-active and non-active bacterial sub-populations based on determination of their cellular vitality and subsequently single cell sorting to isolate microbial strains from discriminated sub-populations. There was a significant correlation (r = 0.97; p flow cytometry, despite there being differences in the absolute number of cells detected. The combined approach of flow cytometric CRP measurement and cell sorting allowed an in situ analysis of microbial cell vitality and the identification of species from defined sub-populations, although the identified microbes were limited to culturable cells.

  20. Decoding Cellular Dynamics in Epidermal Growth Factor Signaling Using a New Pathway-Based Integration Approach for Proteomics and Transcriptomics Data

    Science.gov (United States)

    Wachter, Astrid; Beißbarth, Tim

    2016-01-01

    Identification of dynamic signaling mechanisms on different cellular layers is now facilitated as the increased usage of various high-throughput techniques goes along with decreasing costs for individual experiments. A lot of these signaling mechanisms are known to be coordinated by their dynamics, turning time-course data sets into valuable information sources for inference of regulatory mechanisms. However, the combined analysis of parallel time-course measurements from different high-throughput platforms still constitutes a major challenge requiring sophisticated bioinformatic tools in order to ease biological interpretation. We developed a new pathway-based integration approach for the analysis of coupled omics time-series data, which we implemented in the R package pwOmics. Unlike many other approaches, our approach acknowledges the role of the different cellular layers of measurement and infers consensus profiles and time profile clusters for further biological interpretation. We investigated a time-course data set on epidermal growth factor stimulation of human mammary epithelial cells generated on the two layers of RNA and proteins. The data was analyzed using our new approach with a focus on feedback signaling and pathway crosstalk. We could confirm known regulatory patterns relevant in the physiological cellular response to epidermal growth factor stimulation as well as identify interesting new interactions in this signaling context, such as the regulatory influence of the connective tissue growth factor on transferrin receptor or the influence of growth arrest and DNA-damage-inducible alpha on the connective tissue growth factor. Thus, we show that integrated cross-platform analysis provides a deeper understanding of regulatory signaling mechanisms. Combined with time-course information it enables the characterization of dynamic signaling processes and leads to the identification of important regulatory interactions which might be dysregulated in disease

  1. 0.8 /spl mu/m CMOS implementation of weighted-order statistic image filter based on cellular neural network architecture.

    Science.gov (United States)

    Kowalski, J

    2003-01-01

    In this paper, a very large scale integration chip of an analog image weighted-order statistic (WOS) filter based on cellular neural network (CNN) architecture for real-time applications is described. The chip has been implemented in CMOS AMS 0.8 /spl mu/m technology. CNN-based filter consists of feedforward nonlinear template B operating within the window of 3 /spl times/ 3 pixels around the central pixel being filtered. The feedforward nonlinear CNN coefficients have been realized using programmable nonlinear coupler circuits. The WOS filter chip allows for processing of images with 300 pixels horizontal resolution. The resolution can be increased by cascading of the chips. Experimental results of basic circuit building blocks measurements are presented. Functional tests of the chip have been performed using a special test setup for PAL composite video signal processing. Using the setup real images have been filtered by WOS filter chip under test.

  2. Base station MAC with APRMA protocol for broadband multimedia ATM in micro/pico-cellular mobile networks

    DEFF Research Database (Denmark)

    Le, Khanh Hoang; Nielsen, Søren Nørskov; Dittmann, Lars

    1998-01-01

    The concept for a wireless ATM access system that enables seamless mobile connectivity to the B-ISDN is presented. It is based on small, low cost and intelligent base stations running a medium access control (MAC) protocol using adaptive packet reservation multiple access (APRMA). Both the princi...

  3. Cell-based assay for the detection of chemically induced cellular stress by immortalized untransformed transgenic hepatocytes

    Directory of Open Access Journals (Sweden)

    Vezzoni Paolo

    2004-03-01

    Full Text Available Abstract Background Primary hepatocytes, one of the most widely used cell types for toxicological studies, have a very limited life span and must be freshly derived from mice or even humans. Attempts to use stable cell lines maintaining the enzymatic pattern of liver cells have been so far unsatisfactory. Stress proteins (heat shock proteins, HSPs have been proposed as general markers of cellular injury and their use for environmental monitoring has been suggested. The aim of this work is to develop a bi-transgenic hepatocyte cell line in order to evaluate the ability of various organic and inorganic chemicals to induce the expression of the HSP70 driven reporter gene. We previously described transgenic mice (Hsp70/hGH secreting high levels of human Growth Hormone (hGH following exposure to toxic compounds in vivo and in vitro in primary cultures derived from different organs. In addition, we also reported another transgenic model (AT/cytoMet allowing the reproducible immortalization of untransformed hepatocytes retaining in vitro complex liver functions. Results The transgenic mouse line Hsp70/hGH was crossed with the AT/cytoMet transgenic strain permitting the reproducible immortalization of untransformed hepatocytes. From double transgenic animals we derived several stable hepatic cell lines (MMH-GH which showed a highly-differentiated phenotype as judged from the retention of epithelial cell polarity and the profile of gene expression, including hepatocyte-enriched transcription factors and detoxifying enzymes. In these cell lines, stresses induced by exposure to inorganic [Sodium Arsenite (NaAsO2 and Cadmium Chloride (CdCl2], and organic [Benzo(aPyrene (BaP, PentaChloroPhenol (PCP, TetraChloroHydroQuinone (TCHQ, 1-Chloro-2,4-DiNitro-Benzene (CDNB] compounds, specifically induced hGH release in the culture medium. Conclusions MMH-GH, an innovative model to evaluate the toxic potential of chemical and physical xenobiotics, provides a simple

  4. Flat Cellular (UMTS) Networks

    NARCIS (Netherlands)

    Bosch, H.G.P.; Samuel, L.G.; Mullender, S.J.; Polakos, P.; Rittenhouse, G.

    2007-01-01

    Traditionally, cellular systems have been built in a hierarchical manner: many specialized cellular access network elements that collectively form a hierarchical cellular system. When 2G and later 3G systems were designed there was a good reason to make system hierarchical: from a cost-perspective i

  5. Mathematical Modeling of Cellular Metabolism.

    Science.gov (United States)

    Berndt, Nikolaus; Holzhütter, Hermann-Georg

    2016-01-01

    Cellular metabolism basically consists of the conversion of chemical compounds taken up from the extracellular environment into energy (conserved in energy-rich bonds of organic phosphates) and a wide array of organic molecules serving as catalysts (enzymes), information carriers (nucleic acids), and building blocks for cellular structures such as membranes or ribosomes. Metabolic modeling aims at the construction of mathematical representations of the cellular metabolism that can be used to calculate the concentration of cellular molecules and the rates of their mutual chemical interconversion in response to varying external conditions as, for example, hormonal stimuli or supply of essential nutrients. Based on such calculations, it is possible to quantify complex cellular functions as cellular growth, detoxification of drugs and xenobiotic compounds or synthesis of exported molecules. Depending on the specific questions to metabolism addressed, the methodological expertise of the researcher, and available experimental information, different conceptual frameworks have been established, allowing the usage of computational methods to condense experimental information from various layers of organization into (self-) consistent models. Here, we briefly outline the main conceptual frameworks that are currently exploited in metabolism research.

  6. Research on active queue management algorithm based on cellular ant%基于元胞蚁群的主动队列管理算法研究

    Institute of Scientific and Technical Information of China (English)

    张春琴; 谢立春

    2012-01-01

    order to mitigate the network congestion phenomenon, a novel active queue management algorithm (Drop Front algorithm based on Cellular Ant, DFCA) is proposed by Drop Front. In this algorithm, the maximum of actual network queue length is build by cellular ant. And the dropping N-pack-ets method from queue head is presented by comparing the relationship between network queue length and threshold. Then, with the long-rang dependence data, a simulation was conducted to study DFCA and RED, as well as DROP-TAIL algorithm. The results show that DFCA has better adaptability.%针对网络拥塞现象,基于弃头方式提出了一种新的主动队列管理算法.该算法首先利用元胞蚁群建立了实际网络队长最大值的计算方法,同时通过判断网络队长与阈值的关系,采取从队列头部丢弃N个数据包的方法.最后,以长相关数据进行仿真实验,对比分析了DFCA与RED、DROP-TAIL之间的优劣,结果表明该算法具有较好的适应性.

  7. Interaction of Frequency Allocation Schemes and Beam Forming on the Performance of Cellular Communication Systems Based on OFDM

    Directory of Open Access Journals (Sweden)

    R. Gholami

    2013-03-01

    Full Text Available In this study, the interaction of Beam Forming and frequency allocation schemes on an OFDM-based system such as LTE or WiMAX is investigated in order to support the maximum capacity and minimum outage probability. The results of simulation show that rank1 precode scheme based on MISO channel, according to what considered in LTE standard, along with the cell region division in order to allocate OFDM frequency carriers lead to a Considerable interest in the total capacity of the network in different traffics.

  8. Cell-Based Screening: Cellular Assays with a Molecular Endpoint Measured by SAMDI Mass Spectrometry (Small 28/2016).

    Science.gov (United States)

    Berns, Eric J; Cabezas, Maria D; Mrksich, Milan

    2016-07-01

    On page 3811, M. Mrksich and co-workers culture cells using self-assembled monolayers presenting cell adhesion ligands and enzyme substrates. A lysis buffer disrupts the cell membranes, releasing enzymes that modify the immobilized substrates. These modifications can be measured with SAMDI mass spectrometry, giving a high-throughput, cell-based assay.

  9. Stochastic asymptotical synchronization of chaotic Markovian jumping fuzzy cellular neural networks with mixed delays and the Wiener process based on sampled-data control

    Institute of Scientific and Technical Information of China (English)

    M.Kalpana; P.Balasubramaniam

    2013-01-01

    We investigate the stochastic asymptotical synchronization of chaotic Markovian jumping fuzzy cellular neural networks (MJFCNNs) with discrete,unbounded distributed delays,and the Wiener process based on sampled-data control using the linear matrix inequality (LMI) approach.The Lyapunov-Krasovskii functional combined with the input delay approach as well as the free-weighting matrix approach is employed to derive several sufficient criteria in terms of LMIs to ensure that the delayed MJFCNNs with the Wiener process is stochastic asymptotical synchronous.Restrictions (e.g.,time derivative is smaller than one) are removed to obtain a proposed sampled-data controller.Finally,a numerical example is provided to demonstrate the reliability of the derived results.

  10. ReaDDy--a software for particle-based reaction-diffusion dynamics in crowded cellular environments.

    Directory of Open Access Journals (Sweden)

    Johannes Schöneberg

    Full Text Available We introduce the software package ReaDDy for simulation of detailed spatiotemporal mechanisms of dynamical processes in the cell, based on reaction-diffusion dynamics with particle resolution. In contrast to other particle-based reaction kinetics programs, ReaDDy supports particle interaction potentials. This permits effects such as space exclusion, molecular crowding and aggregation to be modeled. The biomolecules simulated can be represented as a sphere, or as a more complex geometry such as a domain structure or polymer chain. ReaDDy bridges the gap between small-scale but highly detailed molecular dynamics or Brownian dynamics simulations and large-scale but little-detailed reaction kinetics simulations. ReaDDy has a modular design that enables the exchange of the computing core by efficient platform-specific implementations or dynamical models that are different from Brownian dynamics.

  11. Quantitative prediction of cellular metabolism with constraint-based models: the COBRA Toolbox v2.0

    OpenAIRE

    2011-01-01

    Over the past decade, a growing community of researchers has emerged around the use of COnstraint-Based Reconstruction and Analysis (COBRA) methods to simulate, analyze and predict a variety of metabolic phenotypes using genome-scale models. The COBRA Toolbox, a MATLAB package for implementing COBRA methods, was presented earlier. Here we present a significant update of this in silico ToolBox. Version 2.0 of the COBRA Toolbox expands the scope of computations by including in silico analysis m...

  12. Caveolin-1/PTRF upregulation constitutes a mechanism for mediating p53-induced cellular senescence: implications for evidence-based therapy of delayed wound healing in diabetes.

    Science.gov (United States)

    Bitar, Milad S; Abdel-Halim, Samy M; Al-Mulla, Fahd

    2013-10-15

    A heightened state of oxidative stress and senescence of fibroblasts constitute potential therapeutic targets in nonhealing diabetic wounds. Here, we studied the underlying mechanism mediating diabetes-induced cellular senescence using in vitro cultured dermal fibroblasts and in vivo circular wounds. Our results demonstrated that the total antioxidant capacity and mRNA levels of thioredoxinreductase and glucose-6-phosphate dehydrogenase as well as the ratio of NADPH/NADP were decreased markedly in fibroblasts from patients with type 2 diabetes (DFs). Consistent with this shift in favor of excessive reactive oxygen species, DFs also displayed a significant increase in senescence-associated β-galactosidase activity and phospho-γ-histone H2AX (pH2AX) level. Moreover, the ability of PDGF to promote cell proliferation/migration and regulate the phosphorylation-dependent activation of Akt and ERK1/2 appears to be attenuated as a function of diabetes. Mechanistically, we found that diabetes-induced oxidative stress upregulated caveolin-1 (Cav-1) and PTRF expression, which in turn sequestered Mdm2 away from p53. This process resulted in the activation of a p53/p21-dependent pathway and the induction of premature senescence in DFs. Most of the aforementioned oxidative stress and senescence-based features observed in DFs were recapitulated in a 10-day-old diabetic wound. Intriguingly, we confirmed that the targeted depletion of Cav-1 or PTRF using siRNA- or Vivo-Morpholino antisense-based gene therapy markedly inhibited diabetes/oxidative stress-induced premature senescence and also accelerated tissue repair in this disease state. Overall, our data illuminate Cav-1/PTRF-1 as a key player of a novel signaling pathway that may link a heightened state of oxidative stress to cellular senescence and impaired wound healing in diabetes.

  13. DS-CDMA Cellular Systems Performance with Base Station Assignment, Power Control Error and Beamforming over Multipath Fading

    Directory of Open Access Journals (Sweden)

    Mohamad Dosaranian Moghadam

    2011-01-01

    Full Text Available The interference reduction capability of antenna arrays, base station assignment and the power controlalgorithms have been considered separately as means to increase the capacity in wireless communicationnetworks. In this paper, we propose base station assignment method based on minimizing the transmitterpower (BSA-MTP technique in a direct sequence-code division multiple access (DS-CDMA receiver inthe presence of frequency-selective Rayleigh fading and power control error (PCE. This receiverconsists of constrained least mean squared (CLMS algorithm, matched filter (MF, and maximal ratiocombining (MRC in three stages. Also, we present switched-beam (SB technique in the first stage of theRAKE receiver for enhancing signal to interference plus noise ratio (SINR in DS-CDMA cellularsystems. The simulation results indicate that BSA-MTP technique can significantly improve the networkbit error rate (BER in comparison with the conventional case. Finally, we discuss on three parameters ofthe PCE, number of resolvable paths, and channel propagation conditions (path-loss exponent andshadowing and their effects on capacity of the system via some computer simulations.

  14. The Deleterious Effects of Oxidative and Nitrosative Stress on Palmitoylation, Membrane Lipid Rafts and Lipid-Based Cellular Signalling: New Drug Targets in Neuroimmune Disorders.

    Science.gov (United States)

    Morris, Gerwyn; Walder, Ken; Puri, Basant K; Berk, Michael; Maes, Michael

    2016-09-01

    Oxidative and nitrosative stress (O&NS) is causatively implicated in the pathogenesis of Alzheimer's and Parkinson's disease, multiple sclerosis, chronic fatigue syndrome, schizophrenia and depression. Many of the consequences stemming from O&NS, including damage to proteins, lipids and DNA, are well known, whereas the effects of O&NS on lipoprotein-based cellular signalling involving palmitoylation and plasma membrane lipid rafts are less well documented. The aim of this narrative review is to discuss the mechanisms involved in lipid-based signalling, including palmitoylation, membrane/lipid raft (MLR) and n-3 polyunsaturated fatty acid (PUFA) functions, the effects of O&NS processes on these processes and their role in the abovementioned diseases. S-palmitoylation is a post-translational modification, which regulates protein trafficking and association with the plasma membrane, protein subcellular location and functions. Palmitoylation and MRLs play a key role in neuronal functions, including glutamatergic neurotransmission, and immune-inflammatory responses. Palmitoylation, MLRs and n-3 PUFAs are vulnerable to the corruptive effects of O&NS. Chronic O&NS inhibits palmitoylation and causes profound changes in lipid membrane composition, e.g. n-3 PUFA depletion, increased membrane permeability and reduced fluidity, which together lead to disorders in intracellular signal transduction, receptor dysfunction and increased neurotoxicity. Disruption of lipid-based signalling is a source of the neuroimmune disorders involved in the pathophysiology of the abovementioned diseases. n-3 PUFA supplementation is a rational therapeutic approach targeting disruptions in lipid-based signalling.

  15. A hydrogel based nanosensor with an unprecedented broad sensitivity range for pH measurements in cellular compartments

    DEFF Research Database (Denmark)

    Zhang, M.; Søndergaard, Rikke Vicki; Ek, Pramod Kumar;

    2015-01-01

    of acidic intracellular pH (pH paper we successfully developed a multiple sensor, a fluorophore based nanosensor, with an unprecedented broad measurement range from pH 1.4 to 7.0. In this nanosensor, three p......H-sensitive fluorophores (difluoro-Oregon Green, Oregon Green 488, and fluorescein) and one pH-insensitive fluorophore (Alexa 568) were covalently incorporated into a nanoparticle hydrogel matrix. With this broad range quadruple-labelled nanosensor all physiological relevant pH levels in living cells can be measured...

  16. Gypsum-based biomaterials: Evaluation of physical and mechanical properties, cellular effects and its potential as a pulp liner.

    Science.gov (United States)

    Low, Amy; Mohd Yusof, Hamidah; Reza, Fazal; Abdullah Nurul, Asma; Sritharan, Shaminea; Haania Zain Ali, Niswathul; Subhi Azeez, Hasan; Husein, Adam

    2015-01-01

    This in vitro study aimed to evaluate setting time and compressive strength of gypsum-based chitosan biomaterials and its effect on proliferation of stem cells from human exfoliated deciduous teeth (SHED) and alkaline phosphatase (ALP) activity. Pure-GYP was mixed with water (2.5 g: 1.9 mL); Gyp-CHT was prepared with gypsum, chitosan, and water (2.5 g: 0.285 g: 1.9 mL). Cell viability and ALP activity were assessed at different periods. Data were analyzed using SPSS (pbiomaterials for its pulp protective potentialities.

  17. Regulation of the interaction between protein kinase C-related protein kinase 2 (PRK2) and its upstream kinase, 3-phosphoinositide-dependent protein kinase 1 (PDK1)

    DEFF Research Database (Denmark)

    Dettori, Rosalia; Sonzogni, Silvina; Meyer, Lucas;

    2009-01-01

    The members of the AGC kinase family frequently exhibit three conserved phosphorylation sites: the activation loop, the hydrophobic motif (HM), and the zipper (Z)/turn-motif (TM) phosphorylation site. 3-Phosphoinositide-dependent protein kinase 1 (PDK1) phosphorylates the activation loop of numer...

  18. The development and assessment of high-throughput mass spectrometry-based methods for the quantification of a nanoparticle drug delivery agent in cellular lysate.

    Science.gov (United States)

    Buse, Joshua; Purves, Randy W; Verrall, Ronald E; Badea, Ildiko; Zhang, Haixia; Mulligan, Christopher C; Peru, Kerry M; Bailey, Jonathan; Headley, John V; El-Aneed, Anas

    2014-11-01

    The safe use of lipid-based drug delivery agents requires fast and sensitive qualitative and quantitative assessment of their cellular interactions. Many mass spectrometry (MS) based analytical platforms can achieve such task with varying capabilities. Therefore, four novel high-throughput MS-based quantitative methods were evaluated for the analysis of a small organic gene delivery agent: N,N-bis(dimethylhexadecyl)-1,3-propane-diammonium dibromide (G16-3). Analysis utilized MS instruments that detect analytes using low-resolution tandem MS (MS/MS) analysis (i.e. QTRAP or linear ion trap in this work) or high-resolution MS analysis (i.e. time of flight (ToF) or Orbitrap). Our results indicate that the validated fast chromatography (FC)-QTRAP-MS/MS, FC- LTQ-Orbitrap-MS, desorption electrospray ionization-collision-induced dissociation (CID)-MS/MS and matrix assisted laser desorption ionization-ToF/ToF-MS MS methods were superior in the area of method development and sample analysis time to a previously developed liquid chromatography (LC)-CID-MS/MS. To our knowledge, this is the first evaluation of the abilities of five MS-based quantitative methods that target a single pharmaceutical analyte. Our findings indicate that, in comparison to conventional LC-CID-MS/MS, the new MS-based methods resulted in a (1) substantial reduction in the analysis time, (2) reduction in the time required for method development and (3) production of either superior or comparable quantitative data. The four new high-throughput MS methods, therefore, were faster, more efficient and less expensive than a conventional LC-CID-MS/MS for the quantification of the G16-3 analyte within tissue culture. When applied to cellular lysate, no significant change in the concentration of G16-3 gemini surfactant within PAM212 cells was observed between 5 and 53 h, suggesting the absence of any metabolism/excretion from PAM212 cells.

  19. Recursive definition of global cellular-automata mappings

    DEFF Research Database (Denmark)

    Feldberg, Rasmus; Knudsen, Carsten; Rasmussen, Steen

    1994-01-01

    A method for a recursive definition of global cellular-automata mappings is presented. The method is based on a graphical representation of global cellular-automata mappings. For a given cellular-automaton rule the recursive algorithm defines the change of the global cellular-automaton mapping as...

  20. Exposure of farm workers to electromagnetic radiation from cellular network radio base stations situated on rural agricultural land.

    Science.gov (United States)

    Pascuzzi, Simone; Santoro, Francesco

    2015-01-01

    The electromagnetic field (EMF) levels generated by mobile telephone radio base stations (RBS) situated on rural-agricultural lands were assessed in order to evaluate the exposure of farm workers in the surrounding area. The expected EMF at various distances from a mobile telephone RBS was calculated using an ad hoc numerical forecast model. Subsequently, the electric fields around some RBS on agricultural lands were measured, in order to obtain a good approximation of the effective conditions at the investigated sites. The viability of this study was tested according to the Italian Regulations concerning general and occupational public exposure to time-varying EMFs. The calculated E-field values were obtained with the RBS working constantly at full power, but during the in situ measurements the actual power emitted by RBS antennas was lower than the maximum level, and the E-field values actually registered were much lower than the calculated values.

  1. Nano-CeO2 decorated graphene based chitosan nanocomposites as enzymatic biosensing platform: fabrication and cellular biocompatibility assessment.

    Science.gov (United States)

    De, Sriparna; Mohanty, Smita; Nayak, Sanjay Kumar

    2015-09-01

    The present study summarizes the designing of a green transducer phase based on nano-cerium oxide (CeO2) decorated reduced graphene oxide (RGO) reinforced chitosan nanocomposites as an effective enzyme immobilizer and bio-sensing matrix for glucose analyte. Also, it scrutinizes the biocompatibility and cell viability of the synthesized nanohybrid with human fibroblastic macrophage cell line. CeO2 nanoparticles (NPs) were successfully grown on graphene nanosheet in the presence of cationic surfactant followed by facile hydrothermal treatment. The eventual growth of synthesized CeO2 nanocrystals on the graphene layer was confirmed from X-ray diffraction (XRD), transmission electron microscopy (TEM) and Raman analysis. The biocompatibility of the synthesized nanohybrid was also evident from the MTT assay. Glucose oxidase (GOx) was employed on the green polymer nanocomposites modified FTO electrode to fabricate an enzymatic bioelectrode. The electroanalytical response of the GOx/nano-CeO2/RGO/CS/FTO bioelectrode towards electrooxidation of glucose analyte was investigated by electrochemical impedance (EIS) and cyclic voltammetry (CV) study. The resulting biosensor exhibited a good electrochemical response to glucose within the linear detection range of 0.05-6.5 mM with a low detection limit of 2 μM and a sensitivity of 7.198 μA mM(-1) cm(-2). The bioelectrode also showed good shelf life (~10 weeks) and negligible interfering ability under controlled environment. The obtained results indicate that nano-CeO2/RGO nanohybrid based chitosan nanocomposites achieve a biocompatible biosensing platform for effective enzyme immobilization due to the excellent synergistic effects between the CeO2 nanoparticles and graphene sheet.

  2. Crowd evacuation model for large sports venues based on multi-Agent and Cellular Automata technology%Agent-CA的体育场馆人群疏散模型

    Institute of Scientific and Technical Information of China (English)

    曹爱春; 杨晓艇; 侯旭东

    2013-01-01

    A crowd evacuation model for large sports venues based on multi-agent and cellular automata technology according to the behavior characteristics and rules of evacuation is proposed. The cell in the cellular space occupied by virtual individuals is taken as an independent agent, and cellular and state are encapsulated and extended to the autonomy agent, and then individual differences are realized through the design of evacuation behavior strategy as the evolution rules to reflect the individual character, physical strength, mental effect on evacuation behavior. The evacuation simulation are carried out in sports venues. The results show that the proposed model fully considers the factors. Case evacuation is closer to the reality of large sports venues shortening the time of evacuation.%根据体育场馆人群疏散的特点与规律,提出一种基于多智能体和元胞自动机相融合的大型体育场馆人群疏散模型(Agent-CA)。将元胞空间中被虚拟人个体占据的元胞视为一个独立的智能体,将元胞及其状态进行封装,扩展为具有自主性的智能体,通过设计各种人群疏散行为策略做为演化规则,实现个体的差异性以体现个人个性、体力、心理等对疏散行为的影响,对体育场馆的人群疏散进行仿真实验。结果表明,Agent-CA综合了多智能体和元胞自动机的优点,充分考虑了个体内在因素,更接近现实大型体育场馆的人群疏散情形,缩短了疏散时间。

  3. Cellular Genetic Algorithm Based on Chaotic Map%基于混沌映射的元胞遗传算法

    Institute of Scientific and Technical Information of China (English)

    李雪岩; 李雪梅; 李学伟; 吴今培

    2015-01-01

    针对元胞遗传算法( CGA)的功能及结构特点,将元胞遗传算法与混沌算法进行有机结合,分别设计基于Cat映射、Logistic映射及Tent映射的混沌映射元胞遗传算法( CCGA),并解释三种映射的遍历性。文中利用混沌映射的遍历特点及初值敏感性优化种群的初始分布,扩大搜索范围,设计遗传算子中的局部混沌交叉操作及混沌变异扰动机制,并比较不同混沌映射算子作用下种群多样性的变化。理论分析及计算机仿真实验表明,引入三种混沌映射的元胞遗传算法在提升寻优精度,提高算法收敛速度,避免局部极值方面均取得良好的效果。%According to the function and structure characteristics of cellular genetic algorithm ( CGA) , chaos cellular genetic algorithm ( CCGA ) based on Cat map, Logistic map and Tent map are designed respectively with the organic combination of cellular genetic algorithm and chaos algorithm. Besides, the ergodicity of three chaotic mappings are explained. Taking advantage of chaotic ergodicity and sensitivity to initial condition, the initial distribution of population is optimized, the searching scope of the algorithm is enlarged, the mechanism of local chaotic crossover operator and chaotic mutation disturbance are designed, and the changes of population diversity are compared under different mapping operators. Theoretical analysis and simulation results show that the proposed algorithm has obtained good performance in improving optimizing accuracy, accelerating convergence and avoiding the local optimum by introducing three chaotic maps.

  4. Lipid-based liquid crystalline nanoparticles as oral drug delivery vehicles for poorly water-soluble drugs: cellular interaction and in vivo absorption

    Directory of Open Access Journals (Sweden)

    Zeng N

    2012-07-01

    Full Text Available Ni Zeng,1,3,* Xiaoling Gao,2,* Quanyin Hu,1 Qingxiang Song,2 Huimin Xia,1 Zhongyang Liu,1 Guangzhi Gu,1 Mengyin Jiang,1,4 Zhiqing Pang,1 Hongzhuan Chen,2 Jun Chen,1 Liang Fang3 1Key Laboratory of Smart Drug Delivery, Ministry of Education and PLA, School of Pharmacy, Fudan University, Shanghai, 2Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiaotong University School of Medicine, Shanghai, 3Department of Pharmaceutical Science, School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, Liaoning, 4School of Pharmacy, Shandong University of Traditional Chinese Medicine, Jinan, Shandong People's Republic of China, *These authors contributed equally to this workBackground: Lipid-based liquid crystalline nanoparticles (LCNPs have attracted growing interest as novel drug-delivery systems for improving the bioavailability of both hydrophilic and hydrophobic drugs. However, their cellular interaction and in vivo behavior have not been fully developed and characterized.Methods: In this study, self-assembled LCNPs prepared from soy phosphatidylcholine and glycerol dioleate were developed as a platform for oral delivery of paclitaxel. The particle size of empty LCNPs and paclitaxel-loaded LCNPs was around 80 nm. The phase behavior of the liquid crystalline matrix was characterized using crossed polarized light microscopy and small-angle X-ray scattering, and showed both reversed cubic and hexagonal phase in the liquid crystalline matrix. Transmission electron microscopy and cryofield emission scanning electron microscopy analysis revealed an inner winding water channel in LCNPs and a "ball-like"/"hexagonal" morphology.Results: Cellular uptake of LCNPs in Caco-2 cells was found to be concentration-dependent and time-dependent, with involvement of both clathrin and caveolae/lipid raft-mediated endocytosis. Under confocal laser scanning microscopy, soy phosphatidylcholine was observed to segregate from the internalized LCNPs and

  5. Classifying cellular automata using grossone

    Science.gov (United States)

    D'Alotto, Louis

    2016-10-01

    This paper proposes an application of the Infinite Unit Axiom and grossone, introduced by Yaroslav Sergeyev (see [7] - [12]), to the development and classification of one and two-dimensional cellular automata. By the application of grossone, new and more precise nonarchimedean metrics on the space of definition for one and two-dimensional cellular automata are established. These new metrics allow us to do computations with infinitesimals. Hence configurations in the domain space of cellular automata can be infinitesimally close (but not equal). That is, they can agree at infinitely many places. Using the new metrics, open disks are defined and the number of points in each disk computed. The forward dynamics of a cellular automaton map are also studied by defined sets. It is also shown that using the Infinite Unit Axiom, the number of configurations that follow a given configuration, under the forward iterations of cellular automaton maps, can now be computed and hence a classification scheme developed based on this computation.

  6. Characterization of the microchemical structure of seed endosperm within a cellular dimension among six barley varieties with distinct degradation kinetics, using ultraspatially resolved synchrotron-based infrared microspectroscopy.

    Science.gov (United States)

    Liu, Na; Yu, Peiqiang

    2010-07-14

    Barley varieties have similar chemical composition but exhibit different rumen degradation kinetics and nutrient availability. These biological differences may be related to molecular, structural, and chemical makeup among the seed endosperm tissue. No detailed study was carried out. The objectives of this study were: (1) to use a molecular spectroscopy technique, synchrotron-based Fourier transform infrared microspectroscopy (SFTIRM), to determine the microchemical-structural features in seed endosperm tissue of six developed barley varieties; (2) to study the relationship among molecular-structural characteristics, degradation kinetics, and nutrient availability in six genotypes of barley. The results showed that inherent microchemical-structural differences in the endosperm among the six barley varieties were detected by the synchrotron-based analytical technique, SFTIRM, with the univariate molecular spectral analysis. The SFTIRM spectral profiles differed (P degradation). Weak correlations may indicate that limited variations of these six barley varieties might not be sufficient to interpret the relationship between spectroscopic information and the nutrient value of barley grain, although significant differences in biodegradation kinetics were observed. In conclusion, the studies demonstrated the potential of ultraspatially resolved synchrotron based technology (SFTIRM) to reveal the structural and chemical makeup within cellular and subcellular dimensions without destruction of the inherent structure of cereal grain tissue.

  7. On the safety assessment of human exposure in the proximity of cellular communications base-station antennas at 900, 1800 and 2170 MHz

    Science.gov (United States)

    Martínez-Búrdalo, M.; Martín, A.; Anguiano, M.; Villar, R.

    2005-09-01

    In this work, the procedures for safety assessment in the close proximity of cellular communications base-station antennas at three different frequencies (900, 1800 and 2170 MHz) are analysed. For each operating frequency, we have obtained and compared the distances to the antenna from the exposure places where electromagnetic fields are below reference levels and the distances where the specific absorption rate (SAR) values in an exposed person are below the basic restrictions, according to the European safety guidelines. A high-resolution human body model has been located, in front of each base-station antenna as a worst case, at different distances, to compute whole body averaged SAR and maximum 10 g averaged SAR inside the exposed body. The finite-difference time-domain method has been used for both electromagnetic fields and SAR calculations. This paper shows that, for antenna-body distances in the near zone of the antenna, the fact that averaged field values be below the reference levels could, at certain frequencies, not guarantee guidelines compliance based on basic restrictions.

  8. Enhanced cellular activities of polycaprolactone/alginate-based cell-laden hierarchical scaffolds for hard tissue engineering applications.

    Science.gov (United States)

    Lee, HyeongJin; Kim, GeunHyung

    2014-09-15

    Biomedical scaffolds have been widely investigated because they are essential for support and promotion of cell adhesion, proliferation and differentiation in three-dimensional (3D) structures. An ideal scaffold should be highly porous to enable efficient nutrient and oxygen transfer and have a 3D structure that provides optimal micro-environmental conditions for the seeded cells to obtain homogeneous growth after a long culture period. In this study, new hierarchical osteoblast-like cell (MG-63)-laden scaffolds consisting of micro-sized struts/inter-layered micro-nanofibres and cell-laden hydrogel struts with mechanically stable and biologically superior properties were introduced. Poly(ethylene oxide) (PEO) was used as a sacrificial component to generate pores within the cell-laden hydrogel struts to attain a homogeneous cell distribution and rapid cell growth in the scaffold interior. The alginate-based cell-laden struts with PEO induced fast/homogeneous cell release, in contrast to nonporous cell-laden struts. Various weight fractions (0.5, 1, 2, 3 and 3.5 wt%) of PEO were used, of which 2 wt% PEO in the cell-laden strut resulted in the most appropriate cell release and enhanced biological activities (cell proliferation and calcium deposition), compared to nonporous cell-laden struts.

  9. Hybrid microscaffold-based 3D bioprinting of multi-cellular constructs with high compressive strength: A new biofabrication strategy

    Science.gov (United States)

    Tan, Yu Jun; Tan, Xipeng; Yeong, Wai Yee; Tor, Shu Beng

    2016-01-01

    A hybrid 3D bioprinting approach using porous microscaffolds and extrusion-based printing method is presented. Bioink constitutes of cell-laden poly(D,L-lactic-co-glycolic acid) (PLGA) porous microspheres with thin encapsulation of agarose-collagen composite hydrogel (AC hydrogel). Highly porous microspheres enable cells to adhere and proliferate before printing. Meanwhile, AC hydrogel allows a smooth delivery of cell-laden microspheres (CLMs), with immediate gelation of construct upon printing on cold build platform. Collagen fibrils were formed in the AC hydrogel during culture at body temperature, improving the cell affinity and spreading compared to pure agarose hydrogel. Cells were proven to proliferate in the bioink and the bioprinted construct. High cell viability up to 14 days was observed. The compressive strength of the bioink is more than 100 times superior to those of pure AC hydrogel. A potential alternative in tissue engineering of tissue replacements and biological models is made possible by combining the advantages of the conventional solid scaffolds with the new 3D bioprinting technology. PMID:27966623

  10. GPU-based rapid reconstruction of cellular 3D refractive index maps from tomographic phase microscopy (Conference Presentation)

    Science.gov (United States)

    Dardikman, Gili; Shaked, Natan T.

    2016-03-01

    We present highly parallel and efficient algorithms for real-time reconstruction of the quantitative three-dimensional (3-D) refractive-index maps of biological cells without labeling, as obtained from the interferometric projections acquired by tomographic phase microscopy (TPM). The new algorithms are implemented on the graphic processing unit (GPU) of the computer using CUDA programming environment. The reconstruction process includes two main parts. First, we used parallel complex wave-front reconstruction of the TPM-based interferometric projections acquired at various angles. The complex wave front reconstructions are done on the GPU in parallel, while minimizing the calculation time of the Fourier transforms and phase unwrapping needed. Next, we implemented on the GPU in parallel the 3-D refractive index map retrieval using the TPM filtered-back projection algorithm. The incorporation of algorithms that are inherently parallel with a programming environment such as Nvidia's CUDA makes it possible to obtain real-time processing rate, and enables high-throughput platform for label-free, 3-D cell visualization and diagnosis.

  11. Alleviating liver failure conditions using an integrated hybrid cryogel based cellular bioreactor as a bioartificial liver support

    Science.gov (United States)

    Damania, Apeksha; Hassan, Mohsin; Shirakigawa, Nana; Mizumoto, Hiroshi; Kumar, Anupam; Sarin, Shiv K.; Ijima, Hiroyuki; Kamihira, Masamichi; Kumar, Ashok

    2017-01-01

    Conventionally, some bioartificial liver devices are used with separate plasmapheresis unit to separate out plasma from whole blood and adsorbent column to detoxify plasma before it passes through a hepatocytes-laden bioreactor. We aim to develop a hybrid bioreactor that integrates the separate modules in one compact design improving the efficacy of the cryogel based bioreactor as a bioartificial liver support. A plasma separation membrane and an activated carbon cloth are placed over a HepG2-loaded cryogel scaffold in a three-chambered bioreactor design. This bioreactor is consequently connected extracorporeally to a rat model of acute liver failure for 3 h and major biochemical parameters studied. Bilirubin and aspartate transaminase showed a percentage decrease of 20–60% in the integrated bioreactor as opposed to 5–15% in the conventional setup. Urea and ammonia levels which showed negligible change in the conventional setup increase (40%) and decrease (18%), respectively in the integrated system. Also, an overall increase of 5% in human albumin in rat plasma indicated bioreactor functionality in terms of synthetic functions. These results were corroborated by offline evaluation of patient plasma. Hence, integrating the plasmapheresis and adsorbent units with the bioreactor module in one compact design improves the efficacy of the bioartificial liver device. PMID:28079174

  12. GC-TOF/MS-based metabolomics approach to study the cellular immunotoxicity of deoxynivalenol on murine macrophage ANA-1 cells.

    Science.gov (United States)

    Ji, Jian; Sun, Jiadi; Pi, Fuwei; Zhang, Shuang; Sun, Chao; Wang, Xiumei; Zhang, Yinzhi; Sun, Xiulan

    2016-08-25

    Gas chromatography-time of fly/mass spectrum (GC-TOF/MS) based complete murine macrophage ANA-1 cell metabolome strategy, including the endo-metabolome and the exo-metabolome, ANA-1 cell viability assays and apoptosis induced by diverse concentrations of DON were evaluated for selection of an optimized dose for in-depth metabolomic research. Using the optimized chromatography and mass spectrometry parameters, the metabolites detected by GC-TOF/MS were identified and processed with multivariate statistical analysis, including principal componentanalysis (PCA) and orthogonal projection to latent structures-discriminant analysis (OPLS-DA) analysis. The data sets were screened with a t-test (P) value  1, similarity value > 500, leaving 16 exo-metabolite variables and 11 endo-metabolite variables for further pathway analysis. Implementing the integration of key metabolic pathways, the metabolism pathways were categorized into two dominating types, metabolism of amino acid and glycometabolism. Glycine, serine and threonine metabolism, phenylalanine, tyrosine and tryptophan biosynthesis and phenylalanine metabolism were the significant amino acids affected by the metabolic pathways, indicating statistically significant fold changes including pyruvate, serine, glycine, lactate and threonine. Glycolysis or gluconeogenesis, starch and sucrose metabolism, and galactose metabolism, belonging to glycometabolism, were the pathways that were found to be primarily affected, resulting in abnormal metabolites such as glucose-1P, Glucose, gluconic acid, myo-inositol, sorbitol and glycerol.

  13. Quantitative prediction of cellular metabolism with constraint-based models: the COBRA Toolbox v2.0.

    Science.gov (United States)

    Schellenberger, Jan; Que, Richard; Fleming, Ronan M T; Thiele, Ines; Orth, Jeffrey D; Feist, Adam M; Zielinski, Daniel C; Bordbar, Aarash; Lewis, Nathan E; Rahmanian, Sorena; Kang, Joseph; Hyduke, Daniel R; Palsson, Bernhard Ø

    2011-08-04

    Over the past decade, a growing community of researchers has emerged around the use of constraint-based reconstruction and analysis (COBRA) methods to simulate, analyze and predict a variety of metabolic phenotypes using genome-scale models. The COBRA Toolbox, a MATLAB package for implementing COBRA methods, was presented earlier. Here we present a substantial update of this in silico toolbox. Version 2.0 of the COBRA Toolbox expands the scope of computations by including in silico analysis methods developed since its original release. New functions include (i) network gap filling, (ii) (13)C analysis, (iii) metabolic engineering, (iv) omics-guided analysis and (v) visualization. As with the first version, the COBRA Toolbox reads and writes systems biology markup language-formatted models. In version 2.0, we improved performance, usability and the level of documentation. A suite of test scripts can now be used to learn the core functionality of the toolbox and validate results. This toolbox lowers the barrier of entry to use powerful COBRA methods.

  14. Static magnetic field enhances the viability and proliferation rate of adipose tissue-derived mesenchymal stem cells potentially through activation of the phosphoinositide 3-kinase/Akt (PI3K/Akt) pathway.

    Science.gov (United States)

    Marędziak, Monika; Tomaszewski, Krzysztof; Polinceusz, Paulina; Lewandowski, Daniel; Marycz, Krzysztof

    2017-01-01

    The aim of this work was to investigate the effects of 0.5T static magnetic field (sMF) on the viability and proliferation rate of human adipose-derived mesenchymal stromal stem cells (hASCs) via activation of the phosphoinositide 3-kinase/Akt (PI3K/Akt) signaling pathway. In a 7-d culture we examined cell growth kinetic and population doubling time (PDT). We also examined cell morphology and the cellular senescence markers level. Exposure to sMF enhanced the viability of these cells. However, the effect was blocked by treating the cells with LY294002, a P13K inhibitor. We compared this effect by Western Blot analysis of Akt protein expression. We also examined whether the cell response on sMF stimulation is dependent on integrin engagement and we measured integrin gene expression. Our results suggest that stimulation using sMF is a viable method to improve hASC viability. sMF is involved in mechanisms associated with controlling cell proliferative potential signaling events.

  15. Multicolor probe-based confocal laser endomicroscopy: a new world for in vivo and real-time cellular imaging

    Science.gov (United States)

    Vercauteren, Tom; Doussoux, François; Cazaux, Matthieu; Schmid, Guillaume; Linard, Nicolas; Durin, Marie-Amélie; Gharbi, Hédi; Lacombe, François

    2013-03-01

    Since its inception in the field of in vivo imaging, endomicroscopy through optical fiber bundles, or probe-based Confocal Laser Endomicroscopy (pCLE), has extensively proven the benefit of in situ and real-time examination of living tissues at the microscopic scale. By continuously increasing image quality, reducing invasiveness and improving system ergonomics, Mauna Kea Technologies has turned pCLE not only into an irreplaceable research instrument for small animal imaging, but also into an accurate clinical decision making tool with applications as diverse as gastrointestinal endoscopy, pulmonology and urology. The current implementation of pCLE relies on a single fluorescence spectral band making different sources of in vivo information challenging to distinguish. Extending the pCLE approach to multi-color endomicroscopy therefore appears as a natural plan. Coupling simultaneous multi-laser excitation with minimally invasive, microscopic resolution, thin and flexible optics, allows the fusion of complementary and valuable biological information, thus paving the way to a combination of morphological and functional imaging. This paper will detail the architecture of a new system, Cellvizio Dual Band, capable of video rate in vivo and in situ multi-spectral fluorescence imaging with a microscopic resolution. In its standard configuration, the system simultaneously operates at 488 and 660 nm, where it automatically performs the necessary spectral, photometric and geometric calibrations to provide unambiguously co-registered images in real-time. The main hardware and software features, including calibration procedures and sub-micron registration algorithms, will be presented as well as a panorama of its current applications, illustrated with recent results in the field of pre-clinical imaging.

  16. Response to platelet-activating factor in human platelets stored and aged in plasma. Decrease in aggregation, phosphoinositide turnover, and receptor affinity

    Energy Technology Data Exchange (ETDEWEB)

    Shukla, S.D.; Morrison, W.J.; Klachko, D.M.

    1989-07-01

    Human platelet concentrates were stored in polyolefin bags at 22 to 24 degrees C on a horizontal shaker for up to 8 days. At different intervals, aliquots of platelet-rich plasma (PRP) were removed aseptically and five variables, i.e., platelet counts, morphology, platelet-activating factor (PAF)-stimulated aggregation, phosphoinositide turnover, and (3H)PAF binding to platelet receptors, were studied. The number of platelets did not change during the 8 days of storage. Scanning electron microscopy of the platelets revealed a gradual morphologic change from biconcave flat discs to irregular, crenated forms. The PAF-induced aggregation of platelets declined with time of storage. A decrease to 50 percent of the Day 1 aggregatory response to PAF was evident on Day 2, and there was a further decline to about 20 percent by Day 6. Similarly, PAF receptor-coupled phosphoinositide turnover, as monitored by 32P incorporation into individual phosphoinositides, decreased dramatically with storage. After 2 to 3 days of storage, the phosphoinositide turnover was reduced to 50 percent of the original response, and it continued to decline to about 25 percent of original response by Day 5 or 6. The binding of (3H)PAF to washed human platelets indicated subtle changes between Days 2 and 4, which became more noticeable by Day 6. These results have raised the possibility of changes in the number of the receptors and/or their affinity for the ligand during storage. We conclude that although the number of platelets was maintained during storage for 8 days, a general deterioration of their responses to PAF occurred at the levels of cell surface receptor, transmembrane signaling (phosphoinositide turnover), and response (aggregation).

  17. A new adenovirus based vaccine vector expressing an Eimeria tenella derived TLR agonist improves cellular immune responses to an antigenic target.

    Directory of Open Access Journals (Sweden)

    Daniel M Appledorn

    Full Text Available BACKGROUND: Adenoviral based vectors remain promising vaccine platforms for use against numerous pathogens, including HIV. Recent vaccine trials utilizing Adenovirus based vaccines expressing HIV antigens confirmed induction of cellular immune responses, but these responses failed to prevent HIV infections in vaccinees. This illustrates the need to develop vaccine formulations capable of generating more potent T-cell responses to HIV antigens, such as HIV-Gag, since robust immune responses to this antigen correlate with improved outcomes in long-term non-progressor HIV infected individuals. METHODOLOGY/PRINCIPAL FINDINGS: In this study we designed a novel vaccine strategy utilizing an Ad-based vector expressing a potent TLR agonist derived from Eimeria tenella as an adjuvant to improve immune responses from a [E1-]Ad-based HIV-Gag vaccine. Our results confirm that expression of rEA elicits significantly increased TLR mediated innate immune responses as measured by the influx of plasma cytokines and chemokines, and activation of innate immune responding cells. Furthermore, our data show that the quantity and quality of HIV-Gag specific CD8(+ and CD8(- T-cell responses were significantly improved when coupled with rEA expression. These responses also correlated with a significantly increased number of HIV-Gag derived epitopes being recognized by host T cells. Finally, functional assays confirmed that rEA expression significantly improved antigen specific CTL responses, in vivo. Moreover, we show that these improved responses were dependent upon improved TLR pathway interactions. CONCLUSION/SIGNIFICANCE: The data presented in this study illustrate the potential utility of Ad-based vectors expressing TLR agonists to improve clinical outcomes dependent upon induction of robust, antigen specific immune responses.

  18. Markers of cellular senescence. Telomere shortening as a marker of cellular senescence.

    Science.gov (United States)

    Bernadotte, Alexandra; Mikhelson, Victor M; Spivak, Irina M

    2016-01-01

    The cellular senescence definition comes to the fact of cells irreversible proliferation disability. Besides the cell cycle arrest, senescent cells go through some morphological, biochemical, and functional changes which are the signs of cellular senescence. The senescent cells (including replicative senescence and stress-induced premature senescence) of all the tissues look alike. They are metabolically active and possess the set of characteristics in vitro and in vivo, which are known as biomarkers of aging and cellular senescence. Among biomarkers of cellular senescence telomere shortening is a rather elegant frequently used biomarker. Validity of telomere shortening as a marker for cellular senescence is based on theoretical and experimental data.

  19. Regioselective synthesis of 5- and 6-methoxybenzimidazole-1,3,5-triazines as inhibitors of phosphoinositide 3-kinase.

    Science.gov (United States)

    Miller, Michelle S; Pinson, Jo-Anne; Zheng, Zhaohua; Jennings, Ian G; Thompson, Philip E

    2013-02-01

    Phosphoinositide 3-kinases (PI3K) hold significant therapeutic potential as novel targets for the treatment of cancer. ZSTK474 (4a) is a potent, pan-PI3K inhibitor currently under clinical evaluation for the treatment of cancer. Structural studies have shown that derivatisation at the 5- or 6-position of the benzimidazole ring may influence potency and isoform selectivity. However, synthesis of these derivatives by the traditional route results in a mixture of the two regioisomers. We have developed a straightforward regioselective synthesis that gave convenient access to 5- and 6-methoxysubstituted benzimidazole derivatives of ZSTK474. While 5-methoxy substitution abolished activity at all isoforms, the 6-methoxy substitution is consistently 10-fold more potent. This synthesis will allow convenient access to further 6-position derivatives, thus allowing the full scope of the structure-activity relationships of ZSTK474 to be probed.

  20. Integration of mobile satellite and cellular systems

    Science.gov (United States)

    Drucker, Elliott H.; Estabrook, Polly; Pinck, Deborah; Ekroot, Laura

    1993-01-01

    By integrating the ground based infrastructure component of a mobile satellite system with the infrastructure systems of terrestrial 800 MHz cellular service providers, a seamless network of universal coverage can be established. Users equipped for both cellular and satellite service can take advantage of a number of features made possible by such integration, including seamless handoff and universal roaming. To provide maximum benefit at lowest posible cost, the means by which these systems are integrated must be carefully considered. Mobile satellite hub stations must be configured to efficiently interface with cellular Mobile Telephone Switching Offices (MTSO's), and cost effective mobile units that provide both cellular and satellite capability must be developed.

  1. Dual phosphoinositide 3-kinase/mammalian target of rapamycin inhibitor NVP-BEZ235 has a therapeutic potential and sensitizes cisplatin in nasopharyngeal carcinoma.

    Directory of Open Access Journals (Sweden)

    Fen Yang

    Full Text Available Phosphoinositide 3-kinase (PI3K/AKT/mammalian target of rapamycin inhibitor (mTOR pathway is often constitutively activated in human tumor cells and thus has been considered as a promising drug target. To ascertain a therapeutical approach of nasopharyngeal carcinoma (NPC, we hypothesized NVP-BEZ235, a novel and potent imidazo[4,5-c] quinolone derivative, that dually inhibits both PI3K and mTOR kinases activities, had antitumor activity in NPC. Expectedly, we found that NVP-BEZ235 selectively inhibited proliferation of NPC cells rather than normal nasopharyngeal cells using MTT assay. In NPC cell lines, with the extended exposure, NVP-BEZ235 selectively inhibited proliferation of NPC cells harboring PIK3CA mutation, compared to cells with wild-type PIK3CA. Furthermore, exposure of NPC cells to NVP-BEZ235 resulted in G1 growth arrest by Propidium iodide uptake assay, reduction of cyclin D1and CDK4, and increased levels of P27 and P21 by Western blotting, but negligible apoptosis. Moreover, we found that cisplatin (CDDP activated PI3K/AKT and mTORC1 pathways and NVP-BEZ235 alleviated the activation by CDDP through dually targeting PI3K and mTOR kinases. Also, NVP-BEZ235 combining with CDDP synergistically inhibited proliferation and induced apoptosis in NPC cells. In CNE2 and HONE1 nude mice xenograft models, orally NVP-BEZ235 efficiently attenuated tumor growth with no obvious toxicity. In combination with NVP-BEZ235 and CDDP, there was dramatic synergy in shrinking tumor volumes and inducing apoptosis through increasing Noxa, Bax and decreasing Mcl-1, Bcl-2. Based on the above results, NVP-BEZ235, which has entered phase I/II clinical trials in patients with advanced solid tumors, has a potential as a monotherapy or in combination with CDDP for NPC treatment.

  2. PAQR3 modulates insulin signaling by shunting phosphoinositide 3-kinase p110α to the Golgi apparatus.

    Science.gov (United States)

    Wang, Xiao; Wang, Lingdi; Zhu, Lu; Pan, Yi; Xiao, Fei; Liu, Weizhong; Wang, Zhenzhen; Guo, Feifan; Liu, Yong; Thomas, Walter G; Chen, Yan

    2013-02-01

    Phosphoinositide 3-kinase (PI3K) mediates insulin actions by relaying signals from insulin receptors (IRs) to downstream targets. The p110α catalytic subunit of class IA PI3K is the primary insulin-responsive PI3K implicated in insulin signaling. We demonstrate here a new mode of spatial regulation for the p110α subunit of PI3K by PAQR3 that is exclusively localized in the Golgi apparatus. PAQR3 interacts with p110α, and the intracellular targeting of p110α to the Golgi apparatus is reduced by PAQR3 downregulation and increased by PAQR3 overexpression. Insulin-stimulated PI3K activity and phosphoinositide (3,4,5)-triphosphate production are enhanced by Paqr3 deletion and reduced by PAQR3 overexpression in hepatocytes. Deletion of Paqr3 enhances insulin-stimulated phosphorylation of AKT and glycogen synthase kinase 3β, but not phosphorylation of IR and IR substrate-1 (IRS-1), in hepatocytes, mouse liver, and skeletal muscle. Insulin-stimulated GLUT4 translocation to the plasma membrane and glucose uptake are enhanced by Paqr3 ablation. Furthermore, PAQR3 interacts with the domain of p110α involved in its binding with p85, the regulatory subunit of PI3K. Overexpression of PAQR3 dose-dependently reduces the interaction of p85α with p110α. Thus, PAQR3 negatively regulates insulin signaling by shunting cytosolic p110α to the Golgi apparatus while competing with p85 subunit in forming a PI3K complex with p110α.

  3. Maternal Disononyl Phthalate Exposure Activates Allergic Airway Inflammation via Stimulatingthe Phosphoinositide 3-kinase/Akt Pathway in Rat Pups

    Institute of Scientific and Technical Information of China (English)

    CHEN Li; CHEN Jiao; XIE ChangMing; ZHAO Yan; WANG Xiu; andZHANG YunHui

    2015-01-01

    ObjectiveTo evaluate the effectof diisononyl phthalate (DINP) exposure during gestation and lacta-tion on allergic response in pups and to explore the role of phosphoinositide 3-kinase/Akt pathway on it. MethodsFemale Wistar rats were treated with DINP at different dosages (0, 5, 50,and 500 mg/kg of body weight per day). The pups were sensitized and challenged by ovalbumin (OVA). The airway response was assessed; the airway histological studies were performed by hematoxylin and eosin (HE) staining; and the relative cytokines in phosphoinositide 3-kinase (PI3K)/Akt pathway were measured by enzyme-linked immunosorbent assay (ELISA) and western blot analysis. ResultsThere was no significant difference in DINP’s effect on airway hyperresponsiveness (AHR) between male pups and female pups. In the 50 mg/(kg·d) DINP-treated group, airway response to OVA significantly increased and pups showed dramatically enhanced pulmonary resistance (RI) compared with those from controls (P<0.05). Enhanced Akt phosphorylation and NF-κB translocation, and Th2 cytokines expression were observed in pups of 50 mg/(kg·d) DINP-treated group. However, in the 5 and 500 mg/(kg·d) DINP-treated pups, no significant effects were observed. ConclusionTherewas an adjuvant effect of DINP on allergic airway inflammation in pups. Maternal DINP exposure could promote OVA-induced allergic airway response in pups in part by upregulation of PI3K/Akt pathway.

  4. Predicting the impact of lava flows at Mount Etna by an innovative method based on Cellular Automata: Applications regarding land-use and civil defence planning

    Science.gov (United States)

    Crisci, G. M.; Avolio, M. V.; D'Ambrosio, D.; di Gregorio, S.; Lupiano, G. V.; Rongo, R.; Spataro, W.; Benhcke, B.; Neri, M.

    2009-04-01

    Forecasting the time, character and impact of future eruptions is difficult at volcanoes with complex eruptive behaviour, such as Mount Etna, where eruptions occur from the summit and on the flanks, affecting areas distant from each other. Modern efforts for hazard evaluation and contingency planning in volcanic areas draw heavily on hazard maps and numerical simulations. The computational model here applied belongs to the SCIARA family of lava flow simulation models. In the specific case this is the SCIARA-fv release, which is considered to give the most accurate and efficient performance, given the extent (567 km2) of the study area and the great number of simulations to be carried out. The model is based on the Cellular Automata computational paradigm and, specifically, on the Macroscopic Cellular Automata approach for the modelling of spatially extended dynamic systems2. This work addresses the problem of compiling high-detailed susceptibility maps with an elaborate approach in the numerical simulation of Etnean lava flows, based on the results of 39,300 simulations of flows erupted from a grid of 393 hypothetical vents in the eastern sector of Etna. This sector was chosen because it is densely populated and frequently affected by flank eruptions. Besides the definition of general susceptibility maps, the availability of a large number of lava flows of different eruption types, magnitudes and locations simulated for this study allows the instantaneous extraction of various scenarios on demand. For instance, in a Civil Defence oriented application, it is possible to identify all source areas of lava flows capable of affecting a given area of interest, such as a town or a major infrastructure. Indeed, this application is rapidly accomplished by querying the simulation database, by selecting the lava flows that affect the area of interest and by circumscribing their sources. Eventually, a specific category of simulation is dedicated to the assessment of protective

  5. Simulation of changes in heavy metal contamination in farmland soils of a typical manufacturing center through logistic-based cellular automata modeling.

    Science.gov (United States)

    Qiu, Menglong; Wang, Qi; Li, Fangbai; Chen, Junjian; Yang, Guoyi; Liu, Liming

    2016-01-01

    A customized logistic-based cellular automata (CA) model was developed to simulate changes in heavy metal contamination (HMC) in farmland soils of Dongguan, a manufacturing center in Southern China, and to discover the relationship between HMC and related explanatory variables (continuous and categorical). The model was calibrated through the simulation and validation of HMC in 2012. Thereafter, the model was implemented for the scenario simulation of development alternatives for HMC in 2022. The HMC in 2002 and 2012 was determined through soil tests and cokriging. Continuous variables were divided into two groups by odds ratios. Positive variables (odds ratios >1) included the Nemerow synthetic pollution index in 2002, linear drainage density, distance from the city center, distance from the railway, slope, and secondary industrial output per unit of land. Negative variables (odds ratios soil pH, and distance from bodies of water. Categorical variables, including soil type, parent material type, organic content grade, and land use type, also significantly influenced HMC according to Wald statistics. The relative operating characteristic and kappa coefficients were 0.91 and 0.64, respectively, which proved the validity and accuracy of the model. The scenario simulation shows that the government should not only implement stricter environmental regulation but also strengthen the remediation of the current polluted area to effectively mitigate HMC.

  6. Heterogeneous cellular networks

    CERN Document Server

    Hu, Rose Qingyang

    2013-01-01

    A timely publication providing coverage of radio resource management, mobility management and standardization in heterogeneous cellular networks The topic of heterogeneous cellular networks has gained momentum in industry and the research community, attracting the attention of standardization bodies such as 3GPP LTE and IEEE 802.16j, whose objectives are looking into increasing the capacity and coverage of the cellular networks. This book focuses on recent progresses,  covering the related topics including scenarios of heterogeneous network deployment, interference management i

  7. On Cellular MIMO Channel Capacity

    Science.gov (United States)

    Adachi, Koichi; Adachi, Fumiyuki; Nakagawa, Masao

    To increase the transmission rate without bandwidth expansion, the multiple-input multiple-output (MIMO) technique has recently been attracting much attention. The MIMO channel capacity in a cellular system is affected by the interference from neighboring co-channel cells. In this paper, we introduce the cellular channel capacity and evaluate its outage capacity, taking into account the frequency-reuse factor, path loss exponent, standard deviation of shadowing loss, and transmission power of a base station (BS). Furthermore, we compare the cellular MIMO downlink channel capacity with those of other multi-antenna transmission techniques such as single-input multiple-output (SIMO) and space-time block coded multiple-input single-output (STBC-MISO). We show that the optimum frequency-reuse factor F that maximizes 10%-outage capacity is 3 and both 50%- and 90%-outage capacities is 1 irrespective of the type of multi-antenna transmission technique, where q%-outage capacity is defined as the channel capacity that gives an outage probability of q%. We also show that the cellular MIMO channel capacity is always higher than those of SIMO and STBC-MISO.

  8. Encryption Based on the Permutation of Cellular Automata%细胞自动机置换群加密技术研究

    Institute of Scientific and Technical Information of China (English)

    张传武; 彭启琮; 朱甫臣

    2003-01-01

    With the development of the information technology ,information security ,as well as the implementation ofthe encryption system becomes more and more complexity,and therefore new methods are explored to simplify com-plexity of the implementation. Cellular automata has the characters of simplicity of basic components ,locality of cellu-lar automata interactions ,massive parallelism of information processing ,and exhibits complex global properties, whichmakes it suitable for the application in cryptography. This paper presents a new method of encryption,the key of thenew method consists of the permutation cellular automata, the vectors inputted, and the number of the itera-tion. Evidently,it has larger kev space than other methods with only the cellular automata itself as the key.

  9. Epitope-based vaccines with the Anaplasma marginale MSP1a functional motif induce a balanced humoral and cellular immune response in mice.

    Directory of Open Access Journals (Sweden)

    Paula S Santos

    Full Text Available Bovine anaplasmosis is a hemoparasitic disease that causes considerable economic loss to the dairy and beef industries. Cattle immunized with the Anaplasma marginale MSP1 outer membrane protein complex presents a protective humoral immune response; however, its efficacy is variable. Immunodominant epitopes seem to be a key-limiting factor for the adaptive immunity. We have successfully demonstrated that critical motifs of the MSP1a functional epitope are essential for antibody recognition of infected animal sera, but its protective immunity is yet to be tested. We have evaluated two synthetic vaccine formulations against A. marginale, using epitope-based approach in mice. Mice infection with bovine anaplasmosis was demonstrated by qPCR analysis of erythrocytes after 15-day exposure. A proof-of-concept was obtained in this murine model, in which peptides conjugated to bovine serum albumin were used for immunization in three 15-day intervals by intraperitoneal injections before challenging with live bacteria. Blood samples were analyzed for the presence of specific IgG2a and IgG1 antibodies, as well as for the rickettsemia analysis. A panel containing the cytokines' transcriptional profile for innate and adaptive immune responses was carried out through qPCR. Immunized BALB/c mice challenged with A. marginale presented stable body weight, reduced number of infected erythrocytes, and no mortality; and among control groups mortality rates ranged from 15% to 29%. Additionally, vaccines have significantly induced higher IgG2a than IgG1 response, followed by increased expression of pro-inflammatory cytokines. This is a successful demonstration of epitope-based vaccines, and protection against anaplasmosis may be associated with elicitation of effector functions of humoral and cellular immune responses in murine model.

  10. Architectural insight into inovirus-associated vectors (IAVs) and development of IAV-based vaccines inducing humoral and cellular responses: implications in HIV-1 vaccines.

    Science.gov (United States)

    Hassapis, Kyriakos A; Stylianou, Dora C; Kostrikis, Leondios G

    2014-12-01

    Inovirus-associated vectors (IAVs) are engineered, non-lytic, filamentous bacteriophages that are assembled primarily from thousands of copies of the major coat protein gp8 and just five copies of each of the four minor coat proteins gp3, gp6, gp7 and gp9. Inovirus display studies have shown that the architecture of inoviruses makes all coat proteins of the inoviral particle accessible to the outside. This particular feature of IAVs allows foreign antigenic peptides to be displayed on the outer surface of the virion fused to its coat proteins and for more than two decades has been exploited in many applications including antibody or peptide display libraries, drug design, and vaccine development against infectious and non-infectious diseases. As vaccine carriers, IAVs have been shown to elicit both a cellular and humoral response against various pathogens through the display of antibody epitopes on their coat proteins. Despite their high immunogenicity, the goal of developing an effective vaccine against HIV-1 has not yet materialized. One possible limitation of previous efforts was the use of broadly neutralizing antibodies, which exhibited autoreactivity properties. In the past five years, however, new, more potent broadly neutralizing antibodies that do not exhibit autoreactivity properties have been isolated from HIV-1 infected individuals, suggesting that vaccination strategies aimed at producing such broadly neutralizing antibodies may confer protection against infection. The utilization of these new, broadly neutralizing antibodies in combination with the architectural traits of IAVs have driven the current developments in the design of an inovirus-based vaccine against HIV-1. This article reviews the applications of IAVs in vaccine development, with particular emphasis on the design of inoviral-based vaccines against HIV-1.

  11. Architectural Insight into Inovirus-Associated Vectors (IAVs and Development of IAV-Based Vaccines Inducing Humoral and Cellular Responses: Implications in HIV-1 Vaccines

    Directory of Open Access Journals (Sweden)

    Kyriakos A. Hassapis

    2014-12-01

    Full Text Available Inovirus-associated vectors (IAVs are engineered, non-lytic, filamentous bacteriophages that are assembled primarily from thousands of copies of the major coat protein gp8 and just five copies of each of the four minor coat proteins gp3, gp6, gp7 and gp9. Inovirus display studies have shown that the architecture of inoviruses makes all coat proteins of the inoviral particle accessible to the outside. This particular feature of IAVs allows foreign antigenic peptides to be displayed on the outer surface of the virion fused to its coat proteins and for more than two decades has been exploited in many applications including antibody or peptide display libraries, drug design, and vaccine development against infectious and non-infectious diseases. As vaccine carriers, IAVs have been shown to elicit both a cellular and humoral response against various pathogens through the display of antibody epitopes on their coat proteins. Despite their high immunogenicity, the goal of developing an effective vaccine against HIV-1 has not yet materialized. One possible limitation of previous efforts was the use of broadly neutralizing antibodies, which exhibited autoreactivity properties. In the past five years, however, new, more potent broadly neutralizing antibodies that do not exhibit autoreactivity properties have been isolated from HIV-1 infected individuals, suggesting that vaccination strategies aimed at producing such broadly neutralizing antibodies may confer protection against infection. The utilization of these new, broadly neutralizing antibodies in combination with the architectural traits of IAVs have driven the current developments in the design of an inovirus-based vaccine against HIV-1. This article reviews the applications of IAVs in vaccine development, with particular emphasis on the design of inoviral-based vaccines against HIV-1.

  12. The Mobile IP(IPv6) Based on Cellular Wireless Network Technology%基于蜂窝无线网络的移动IP(IPv6)研究

    Institute of Scientific and Technical Information of China (English)

    张全新; 宋瀚涛

    2003-01-01

    Introduce method and technology of combination of the TCP/IP protocol based on IPv6 and the cellular wireless communication network. Analyze the cut-in point and key technology of the combination from the view of frame, system structure and the realization of protocols. The 3G cellular wireless communication is a hotspot today and the mobile IP technology is one of the developing directions for the Internet's future. We put forward a new idea and method for the mobile communication technology from the practical view.

  13. Integration of Mobil Satellite and Cellular Systems

    Science.gov (United States)

    Drucker, E. H.; Estabrook, P.; Pinck, D.; Ekroot, L.

    1993-01-01

    By integrating the ground based infrastructure component of a mobile satellite system with the infrastructure systems of terrestrial 800 MHz cellular service providers, a seamless network of universal coverage can be established.

  14. Molecular cytogenetic interphase analysis of Phosphoinositide-specific Phospholipase C β1 gene in paraffin-embedded brain samples of major depression patients.

    Science.gov (United States)

    Lo Vasco, Vincenza Rita; Polonia, Patrizia

    2012-01-01

    Mood disorders represent a major medical need, as their chronic treatments are not effective in all patients. Literature data suggested that phosphoinositides (PI) signal transduction pathway and related molecules such as the Phosphoinositide-specific Phospholipase C (PI-PLC) enzymes, might be involved in the pathophysiology of mood disorders, including major depression. By using interphase fluorescent in situ hybridization methodology, we analyzed PLCB1 gene, which codifies for the PI-PLC β1 enzyme, in paraffin embedded samples of orbito-frontal cortex of 15 patients affected with major depression and in 15 normal controls. No deletions of PLCB1 were identified with the methodology used, which allows to exclude wide gene deletions. The results, the technical aspects of the FISH methodology, and its limitations are discussed.

  15. Nodule Detection in a Lung Region that's Segmented with Using Genetic Cellular Neural Networks and 3D Template Matching with Fuzzy Rule Based Thresholding

    Energy Technology Data Exchange (ETDEWEB)

    Ozekes, Serhat; Osman, Onur; Ucan, N. [Istanbul Commerce University, Ragip Gumuspala Cad. No: 84 34378 Eminonu, Istanbul (Turkmenistan)

    2008-02-15

    The purpose of this study was to develop a new method for automated lung nodule detection in serial section CT images with using the characteristics of the 3D appearance of the nodules that distinguish themselves from the vessels. Lung nodules were detected in four steps. First, to reduce the number of region of interests (ROIs) and the computation time, the lung regions of the CTs were segmented using Genetic Cellular Neural Networks (G-CNN). Then, for each lung region, ROIs were specified with using the 8 directional search; +1 or -1 values were assigned to each voxel. The 3D ROI image was obtained by combining all the 2-Dimensional (2D) ROI images. A 3D template was created to find the nodule-like structures on the 3D ROI image. Convolution of the 3D ROI image with the proposed template strengthens the shapes that are similar to those of the template and it weakens the other ones. Finally, fuzzy rule based thresholding was applied and the ROI's were found. To test the system's efficiency, we used 16 cases with a total of 425 slices, which were taken from the Lung Image Database Consortium (LIDC) dataset. The computer aided diagnosis (CAD) system achieved 100% sensitivity with 13.375 FPs per case when the nodule thickness was greater than or equal to 5.625 mm. Our results indicate that the detection performance of our algorithm is satisfactory, and this may well improve the performance of computer aided detection of lung nodules.

  16. Identification of Toxoplasma TgPH1, a pleckstrin homology domain-containing protein that binds to the phosphoinositide PI(3,5)P2.

    Science.gov (United States)

    Daher, Wassim; Morlon-Guyot, Juliette; Alayi, Tchilabalo Dilezitoko; Tomavo, Stan; Wengelnik, Kai; Lebrun, Maryse

    2016-05-01

    The phosphoinositide phosphatidylinositol-3,5-bisphosphate (PI(3,5)P2) plays crucial roles in the maintenance of lysosome/vacuole morphology, membrane trafficking and regulation of endolysosome-localized membrane channel activity. In Toxoplasma gondii, we previously reported that PI(3,5)P2 is essential for parasite survival by controlling homeostasis of the apicoplast, a particular organelle of algal origin. Here, by using a phosphoinositide pull-down assay, we identified TgPH1 in Toxoplasma a protein conserved in many apicomplexan parasites. TgPH1 binds specifically to PI(3,5)P2, shows punctate intracellular localization, but plays no vital role for tachyzoite growth in vitro. TgPH1 is a protein predominantly formed by a pleckstrin homology (PH) domain. So far, PH domains have been described to bind preferentially to bis- or trisphosphate phosphoinositides containing two adjacent phosphates (i.e. PI(3,4)P2, PI(4,5)P2, PI(3,4,5)P3). Therefore, our study reveals an unusual feature of TgPH1 which binds preferentially to PI(3,5)P2.

  17. Activated PTHLH Coupling Feedback Phosphoinositide to G-Protein Receptor Signal-Induced Cell Adhesion Network in Human Hepatocellular Carcinoma by Systems-Theoretic Analysis

    Directory of Open Access Journals (Sweden)

    Lin Wang

    2012-01-01

    Full Text Available Studies were done on analysis of biological processes in the same high expression (fold change ≥2 activated PTHLH feedback-mediated cell adhesion gene ontology (GO network of human hepatocellular carcinoma (HCC compared with the corresponding low expression activated GO network of no-tumor hepatitis/cirrhotic tissues (HBV or HCV infection. Activated PTHLH feedback-mediated cell adhesion network consisted of anaphase-promoting complex-dependent proteasomal ubiquitin-dependent protein catabolism, cell adhesion, cell differentiation, cell-cell signaling, G-protein-coupled receptor protein signaling pathway, intracellular transport, metabolism, phosphoinositide-mediated signaling, positive regulation of transcription, regulation of cyclin-dependent protein kinase activity, regulation of transcription, signal transduction, transcription, and transport in HCC. We proposed activated PTHLH coupling feedback phosphoinositide to G-protein receptor signal-induced cell adhesion network. Our hypothesis was verified by the different activated PTHLH feedback-mediated cell adhesion GO network of HCC compared with the corresponding inhibited GO network of no-tumor hepatitis/cirrhotic tissues, or the same compared with the corresponding inhibited GO network of HCC. Activated PTHLH coupling feedback phosphoinositide to G-protein receptor signal-induced cell adhesion network included BUB1B, GNG10, PTHR2, GNAZ, RFC4, UBE2C, NRXN3, BAP1, PVRL2, TROAP, and VCAN in HCC from GEO dataset using gene regulatory network inference method and our programming.

  18. Glycosylation regulates prestin cellular activity.

    Science.gov (United States)

    Rajagopalan, Lavanya; Organ-Darling, Louise E; Liu, Haiying; Davidson, Amy L; Raphael, Robert M; Brownell, William E; Pereira, Fred A

    2010-03-01

    Glycosylation is a common post-translational modification of proteins and is implicated in a variety of cellular functions including protein folding, degradation, sorting and trafficking, and membrane protein recycling. The membrane protein prestin is an essential component of the membrane-based motor driving electromotility changes (electromotility) in the outer hair cell (OHC), a central process in auditory transduction. Prestin was earlier identified to possess two N-glycosylation sites (N163, N166) that, when mutated, marginally affect prestin nonlinear capacitance (NLC) function in cultured cells. Here, we show that the double mutant prestin(NN163/166AA) is not glycosylated and shows the expected NLC properties in the untreated and cholesterol-depleted HEK 293 cell model. In addition, unlike WT prestin that readily forms oligomers, prestin(NN163/166AA) is enriched as monomers and more mobile in the plasma membrane, suggesting that oligomerization of prestin is dependent on glycosylation but is not essential for the generation of NLC in HEK 293 cells. However, in the presence of increased membrane cholesterol, unlike the hyperpolarizing shift in NLC seen with WT prestin, cells expressing prestin(NN163/166AA) exhibit a linear capacitance function. In an attempt to explain this finding, we discovered that both WT prestin and prestin(NN163/166AA) participate in cholesterol-dependent cellular trafficking. In contrast to WT prestin, prestin(NN163/166AA) shows a significant cholesterol-dependent decrease in cell-surface expression, which may explain the loss of NLC function. Based on our observations, we conclude that glycosylation regulates self-association and cellular trafficking of prestin(NN163/166AA). These observations are the first to implicate a regulatory role for cellular trafficking and sorting in prestin function. We speculate that the cholesterol regulation of prestin occurs through localization to and internalization from membrane microdomains by

  19. Epigenetics and Cellular Metabolism

    Science.gov (United States)

    Xu, Wenyi; Wang, Fengzhong; Yu, Zhongsheng; Xin, Fengjiao

    2016-01-01

    Living eukaryotic systems evolve delicate cellular mechanisms for responding to various environmental signals. Among them, epigenetic machinery (DNA methylation, histone modifications, microRNAs, etc.) is the hub in transducing external stimuli into transcriptional response. Emerging evidence reveals the concept that epigenetic signatures are essential for the proper maintenance of cellular metabolism. On the other hand, the metabolite, a main environmental input, can also influence the processing of epigenetic memory. Here, we summarize the recent research progress in the epigenetic regulation of cellular metabolism and discuss how the dysfunction of epigenetic machineries influences the development of metabolic disorders such as diabetes and obesity; then, we focus on discussing the notion that manipulating metabolites, the fuel of cell metabolism, can function as a strategy for interfering epigenetic machinery and its related disease progression as well. PMID:27695375

  20. Architected Cellular Materials

    Science.gov (United States)

    Schaedler, Tobias A.; Carter, William B.

    2016-07-01

    Additive manufacturing enables fabrication of materials with intricate cellular architecture, whereby progress in 3D printing techniques is increasing the possible configurations of voids and solids ad infinitum. Examples are microlattices with graded porosity and truss structures optimized for specific loading conditions. The cellular architecture determines the mechanical properties and density of these materials and can influence a wide range of other properties, e.g., acoustic, thermal, and biological properties. By combining optimized cellular architectures with high-performance metals and ceramics, several lightweight materials that exhibit strength and stiffness previously unachievable at low densities were recently demonstrated. This review introduces the field of architected materials; summarizes the most common fabrication methods, with an emphasis on additive manufacturing; and discusses recent progress in the development of architected materials. The review also discusses important applications, including lightweight structures, energy absorption, metamaterials, thermal management, and bioscaffolds.

  1. Identification and prioritization of candidate genes for symptom variability in breast cancer survivors based on disease characteristics at the cellular level

    Directory of Open Access Journals (Sweden)

    Koleck TA

    2016-03-01

    Full Text Available Theresa A Koleck,1 Yvette P Conley2 1School of Nursing, 2Department of Human Genetics, School of Nursing and Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA Abstract: Research is beginning to suggest that the presence and/or severity of symptoms reported by breast cancer survivors may be associated with disease-related factors of cancer. In this article, we present a novel approach to the identification and prioritization of biologically plausible candidate genes to investigate relationships between genomic variation and symptom variability in breast cancer survivors. Cognitive dysfunction is utilized as a representative breast cancer survivor symptom to elucidate the conceptualization of and justification for our cellular, disease-based approach to address symptom variability in cancer survivors. Initial candidate gene identification was based on genes evaluated as part of multigene expression profiles for breast cancer, which are commonly used in the clinical setting to characterize the biology of cancer cells for the purpose of describing overall tumor aggressiveness, prognostication, and individualization of therapy. A list of genes evaluated within five multigene expression profiles for breast cancer was compiled. In order to prioritize candidate genes for investigation, genes used in each profile were compared for duplication. Twenty-one genes (BAG1, BCL2, BIRC5, CCNB1, CENPA, CMC2, DIAPH3, ERBB2, ESR1, GRB7, MELK, MKI67, MMP11, MYBL2, NDC80, ORC6, PGR, RACGAP1, RFC4, RRM2, and SCUBE2 are utilized in two or more profiles, including five genes (CCNB1, CENPA, MELK, MYBL2, and ORC6 used in three profiles. To ensure that the parsimonious 21 gene set is representative of the more global biological hallmarks of cancer, an Ingenuity Pathway Analysis was conducted. Evaluation of genes known to impact pathways involved with cancer development and progression provide a means to evaluate the overlap between the

  2. The developments in the phosphoinositide 3-kinase/protein kinase B pathway in cerebral protection%磷脂酰肌醇-3-激酶/蛋白激酶B信号通路在脑保护中的作用

    Institute of Scientific and Technical Information of China (English)

    李翠; 王海云; 王国林

    2010-01-01

    Phosphoinositide 3 -kinase/protein kinase B (PI3K/Akt) signal pathway is an important intracellular transduction pathway. It plays an important role in inhibiting cellular apoptosis and promoting cell proliferation by affecting the activity of downstream targets. Studies show that pharmacological and other strategies can activate PI3K/Akt pathway and downstream targets accordingly to improve neuronal survival. Such findings indicate that PI3K and Akt may be potential targets for cerebral protective therapy. This review serves to introduce the construction and functionof PI3K/Akt pathway, its substrates, and the new developments of this pathway in cerebral protection.%磷脂酰肌醇-3-激酶/蛋白激酶B(phosphoinositide 3-kinase/protein kinase B,PI3K/Akt)通路是细胞内重要的信号转导通路,通过影响下游多个靶点而发挥抑制凋亡、促进增殖的作用.研究发现通过药物及非药物手段可以激活PI3K/Akt通路及其下游靶点,促进神经元存活.提示PI3K/Akt通路可能是脑保护的重要靶点.现就PI3K/Akt信号转导通路的组成、功能、下游靶点及其脑保护作用的研究进展作一综述.

  3. Exploration of cellular DNA lesion, DNA-binding and biocidal ordeal of novel curcumin based Knoevenagel Schiff base complexes incorporating tryptophan: Synthesis and structural validation

    Science.gov (United States)

    Chandrasekar, Thiravidamani; Raman, Natarajan

    2016-07-01

    A few novel Schiff base transition metal complexes of general formula [MLCl] (where, L = Schiff base, obtained by the condensation reaction of Knoevenagel condensate of curcumin, L-tryptophan and M = Cu(II), Ni(II), Co(II), and Zn(II)), were prepared by stencil synthesis. They were typified using UV-vis, IR, EPR spectral techniques, micro analytical techniques, magnetic susceptibility and molar conductivity. Geometry of the metal complexes was examined and recognized as square planar. DNA binding and viscosity studies revealed that the metal(II) complexes powerfully bound via an intercalation mechanism with the calf thymus DNA. Gel-electrophoresis technique was used to investigate the DNA cleavage competence of the complexes and they establish to approve the cleavage of pBR322 DNA in presence of oxidant H2O2. This outcome inferred that the synthesized complexes showed better nuclease activity. Moreover, the complexes were monitored for antimicrobial activities. The results exposed that the synthesized compounds were forceful against all the microbes under exploration.

  4. Cellular blue naevus

    Directory of Open Access Journals (Sweden)

    Mittal R

    2001-01-01

    Full Text Available A 31-year-old man had asymptomatic, stationary, 1.5X2 cm, shiny, smooth, dark blue nodule on dorsum of right hand since 12-14 years. In addition he had developed extensive eruption of yellow to orange papulonodular lesions on extensors of limbs and buttocks since one and half months. Investigations confirmed that yellow papules were xanthomatosis and he had associated diabetes mellitus and hyperlipidaemia. Biopsy of blue nodule confirmed the clinical diagnosis of cellular blue naevus. Cellular blue naevus is rare and its association with xanthomatosis and diabetes mellitus were interesting features of above patients which is being reported for its rarity.

  5. Phosphoinositides in Ca(2+) signaling and excitation-contraction coupling in skeletal muscle: an old player and newcomers.

    Science.gov (United States)

    Csernoch, Laszlo; Jacquemond, Vincent

    2015-12-01

    Since the postulate, 30 years ago, that phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P 2) as the precursor of inositol 1,4,5-trisphosphate (Ins(1,4,5)P 3) would be critical for skeletal muscle excitation-contraction (EC) coupling, the issue of whether phosphoinositides (PtdInsPs) may have something to do with Ca(2+) signaling in muscle raised limited interest, if any. In recent years however, the PtdInsP world has expanded considerably with new functions for PtdIns(4,5)P 2 but also with functions for the other members of the PtdInsP family. In this context, the discovery that genetic deficiency in a PtdInsP phosphatase has dramatic consequences on Ca(2+) homeostasis in skeletal muscle came unanticipated and opened up new perspectives in regards to how PtdInsPs modulate muscle Ca(2+) signaling under normal and disease conditions. This review intends to make an update of the established, the questioned, and the unknown regarding the role of PtdInsPs in skeletal muscle Ca(2+) homeostasis and EC coupling, with very specific emphasis given to Ca(2+) signals in differentiated skeletal muscle fibers.

  6. Myeloproliferative disorder FOP-FGFR1 fusion kinase recruits phosphoinositide-3 kinase and phospholipase Cγ at the centrosome

    Directory of Open Access Journals (Sweden)

    Tassin Anne-Marie

    2008-04-01

    Full Text Available Abstract Background The t(6;8 translocation found in rare and agressive myeloproliferative disorders results in a chimeric gene encoding the FOP-FGFR1 fusion protein. This protein comprises the N-terminal region of the centrosomal protein FOP and the tyrosine kinase of the FGFR1 receptor. FOP-FGFR1 is localized at the centrosome where it exerts a constitutive kinase activity. Results We show that FOP-FGFR1 interacts with the large centrosomal protein CAP350 and that CAP350 is necessary for FOP-FGFR1 localisation at centrosome. FOP-FGFR1 activates the phosphoinositide-3 kinase (PI3K pathway. We show that p85 interacts with tyrosine 475 of FOP-FGFR1, which is located in a YXXM consensus binding sequence for an SH2 domain of p85. This interaction is in part responsible for PI3K activation. Ba/F3 cells that express FOP-FGFR1 mutated at tyrosine 475 have reduced proliferative ability. Treatment with PI3K pathway inhibitors induces death of FOP-FGFR1 expressing cells. FOP-FGFR1 also recruits phospholipase Cγ1 (PLCγ1 at the centrosome. We show that this enzyme is recruited by FOP-FGFR1 at the centrosome during interphase. Conclusion These results delineate a particular type of oncogenic mechanism by which an ectopic kinase recruits its substrates at the centrosome whence unappropriate signaling induces continuous cell growth and MPD.

  7. Cbl participates in shikonin-induced apoptosis by negatively regulating phosphoinositide 3-kinase/protein kinase B signaling.

    Science.gov (United States)

    Qu, Dan; Xu, Xiao-Man; Zhang, Meng; Jiang, Ting-Shu; Zhang, Yi; Li, Sheng-Qi

    2015-07-01

    Shikonin, a naturally occurring naphthoquinone, exhibits anti-tumorigenic activity. However, its precise mechanisms of action have remained elusive. In the present study, the involvement in the action of shikonin of the ubiquitin ligases Cbl-b and c-Cbl, which are negative regulators of phosphoinositide 3-kinase (PI3K) activation, was investigated. Shikonin was observed to reduce cell viability and induce apoptosis and G2/M phase arrest in lung cancer cells. In addition, shikonin increased the protein levels of B-cell lymphoma 2 (Bcl-2)-associated X and p53 and reduced those of Bcl-2. Additionally, shikonin inhibited PI3k/Akt activity and upregulated Cbl protein expression. In addition, a specific inhibitor of PI3K, LY294002, was observed to have a synergistic effect on the proliferation inhibition and apoptotic induction of A549 cells with shikonin. In conclusion, the results of the present study suggested that Cbl proteins promote shikonin-induced apoptosis by negatively regulating PI3K/Akt signaling in lung cancer cells.

  8. Propofol pretreatment attenuates lipopolysaccharide-induced acute lung injury in rats by activating the phosphoinositide-3-kinase/Akt pathway

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, L.L. [Department of Anesthesiology, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu Province (China); Hu, G.C. [Department of Pharmacology, College of Medicine, University of Illinois at Chicago, Chicago, IL (United States); Zhu, S.S. [Department of Anesthesiology, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu Province (China); Li, J.F. [Department of Anesthesiology, Tengzhou Central People' s Hospital, Liaocheng, Shandong Province (China); Liu, G.J. [Department of Anesthesiology, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu Province (China)

    2014-10-14

    The aim of this study was to investigate the effect of propofol pretreatment on lipopolysaccharide (LPS)-induced acute lung injury (ALI) and the role of the phosphoinositide-3-kinase/protein kinase B (PI3K/Akt) pathway in this procedure. Survival was determined 48 h after LPS injection. At 1 h after LPS challenge, the lung wet- to dry-weight ratio was examined, and concentrations of protein, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) in bronchoalveolar lavage fluid (BALF) were determined using the bicinchoninic acid method or ELISA. Lung injury was assayed via lung histological examination. PI3K and p-Akt expression levels in the lung tissue were determined by Western blotting. Propofol pretreatment prolonged survival, decreased the concentrations of protein, TNF-α, and IL-6 in BALF, attenuated ALI, and increased PI3K and p-Akt expression in the lung tissue of LPS-challenged rats, whereas treatment with wortmannin, a PI3K/Akt pathway specific inhibitor, blunted this effect. Our study indicates that propofol pretreatment attenuated LPS-induced ALI, partly by activation of the PI3K/Akt pathway.

  9. Shiga toxin type-2 (Stx2 induces glutamate release via phosphoinositide 3-kinase (PI3K pathway in murine neurons.

    Directory of Open Access Journals (Sweden)

    Fumiko eObata

    2015-07-01

    Full Text Available Shiga toxin-producing Escherichia coli (STEC can cause central nervous system (CNS damage resulting in paralysis, seizures, and coma. The key STEC virulence factors associated with systemic illness resulting in CNS impairment are Shiga toxins (Stx. While neurons express the Stx receptor globotriaosylceramide (Gb3 in vivo, direct toxicity to neurons by Stx has not been studied. We used murine neonatal neuron cultures to study the interaction of Shiga toxin type 2 (Stx2 with cell surface expressed Gb3. Single molecule imaging three dimensional STochastic Optical Reconstruction Microscopy - Total Internal Reflection Fluorescence (3D STORM-TIRF allowed visualization and quantification of Stx2-Gb3 interactions. Furthermore, we demonstrate that Stx2 increases neuronal cytosolic Ca2+, and NMDA-receptor inhibition blocks Stx2-induced Ca2+ influx, suggesting that Stx2-mediates glutamate release. Phosphoinositide 3-kinase (PI3K-specific inhibition by Wortmannin reduces Stx2-induced intracellular Ca2+ indicating that the PI3K signaling pathway may be involved in Stx2-associated glutamate release, and that these pathways may contribute to CNS impairment associated with STEC infection.

  10. The effect of oxytocin on progesterone secretion, phosphoinositide hydrolysis and intracellular mobilisation of Ca2+ in porcine luteal cells.

    Science.gov (United States)

    Franczak, Anita; Kurowicka, Beata; Kowalik, Magdalena; Ciereszko, Renata Elzbieta; Kotwica, Genowefa

    2009-03-01

    Oxytocin (OT) is involved in the regulation of steroid secretion by the corpus luteum (CL) in pigs, but OT signal transduction in the porcine CL has not been identified. In this study, the effects of OT on in vitro progesterone (P4) secretion, phosphoinositide (PI) hydrolysis and intracellular mobilisation of Ca2+ ([Ca2+]i) were investigated in porcine luteal cells during the early (days 3-5), mid(days 8-10) and late luteal phases (days 12-14) of the oestrous cycle. Basal concentrations of P4 and accumulation of inositol phosphates (IPs) were higher (P < 0.05) on days 3-5 and 8-10 of the oestrous cycle than on days 12-14. Basal [Ca2+]i mobilisation did not differ among studied periods of the oestrous cycle. Oxytocin (10(-7) M) enhanced P4 secretion and PI hydrolysis (P < 0.05) by luteal cells harvested on days 8-10 of the oestrous cycle. Moreover, OT started to increase mobilisation of [Ca2+]i at the 15th (days 3-5 and 8-10) or 30th second (days 12-14) in porcine luteal cells. It was concluded that in pigs OT acts as a regulator of steroidogenesis, stimulating P4 secretion in mature CL. This OT action may be mediated by changes in PI hydrolysis and [Ca2+]i mobilisation.

  11. Phosphoinositide 3-kinase regulates crosstalk between Trk A tyrosine kinase and p75(NTR)-dependent sphingolipid signaling pathways.

    Science.gov (United States)

    Bilderback, T R; Gazula, V R; Dobrowsky, R T

    2001-03-01

    The mechanism of crosstalk between signaling pathways coupled to the Trk A and p75(NTR) neurotrophin receptors in PC12 cells was examined. In response to nerve growth factor (NGF), Trk A activation inhibited p75(NTR)-dependent sphingomyelin (SM) hydrolysis. The phosphoinositide 3-kinase (PI 3-kinase) inhibitor, LY294002, reversed this inhibition suggesting that Trk A activation of PI 3-kinase is necessary to inhibit sphingolipid signaling by p75(NTR). In contrast, SM hydrolysis induced by neurotrophin-3 (NT-3), which did not activate PI-3 kinase, was uneffected by LY294002. However, transient expression of a constituitively active PI 3-kinase inhibited p75(NTR)-dependent SM hydrolysis by both NGF and NT-3. Intriguingly, NGF induced an association of activated PI 3-kinase with acid sphingomyelinase (SMase). This interaction localized to caveolae-related domains and correlated with a 50% decrease in immunoprecipitated acid SMase activity. NGF-stimulated PI 3-kinase activity was necessary for inhibition of acid SMase but was not required for ligand-induced association of the p85 subunit of PI 3-kinase with the phospholipase. Finally, this interaction was specific for NGF since EGF did not induce an association of PI 3-kinase with acid SMase. In summary, our data suggest that PI 3-kinase regulates the inhibitory crosstalk between Trk A tyrosine kinase and p75(NTR)-dependent sphingolipid signaling pathways and that this interaction localizes to caveolae-related domains.

  12. Voltage-sensing phosphatase reveals temporal regulation of TRPC3/C6/C7 channels by membrane phosphoinositides.

    Science.gov (United States)

    Itsuki, Kyohei; Imai, Yuko; Okamura, Yasushi; Abe, Kihachiro; Inoue, Ryuji; Mori, Masayuki X

    2012-01-01

    TRPC3/C6/C7 channels, a subgroup of classical/canonical TRP channels, are activated by diacylglycerol produced via activation of phospholipase C (PLC)-coupled receptors. Recognition of the physiological importance of these channels has been steadily growing, but the mechanism by which they are regulated remains largely unknown. We recently used a membrane-resident danio rerio voltage-sensing phosphatase (DrVSP) to study TRPC3/C6/C7 regulation and found that the channel activity was controlled by PtdIns(4,5)P(2)-DAG signaling in a self-limiting manner (Imai Y et al., the Journal of Physiology, 2012). In this addendum, we present the advantages of using DrVSP as a molecular tool to study PtdIns(4,5)P(2) regulation. DrVSP should be readily applicable for studying phosphoinositide metabolism-linked channel regulation as well as lipid dynamics. Furthermore, in comparison to other modes of self-limiting ion channel regulation, the regulation of TRPC3/C6/C7 channels seems highly susceptible to activation signal strength, which could potentially affect both open duration and the time to peak activation and inactivation. Dysfunction of such self-limiting regulation may contribute to the pathology of the cardiovascular system, gastrointestinal tract and brain, as these channels are broadly distributed and affected by numerous neurohormonal agonists.

  13. A Computation in a Cellular Automaton Collider Rule 110

    CERN Document Server

    Martinez, Genaro J; McIntosh, Harold V

    2016-01-01

    A cellular automaton collider is a finite state machine build of rings of one-dimensional cellular automata. We show how a computation can be performed on the collider by exploiting interactions between gliders (particles, localisations). The constructions proposed are based on universality of elementary cellular automaton rule 110, cyclic tag systems, supercolliders, and computing on rings.

  14. On-Chip Detection of Cellular Activity

    Science.gov (United States)

    Almog, R.; Daniel, R.; Vernick, S.; Ron, A.; Ben-Yoav, H.; Shacham-Diamand, Y.

    The use of on-chip cellular activity monitoring for biological/chemical sensing is promising for environmental, medical and pharmaceutical applications. The miniaturization revolution in microelectronics is harnessed to provide on-chip detection of cellular activity, opening new horizons for miniature, fast, low cost and portable screening and monitoring devices. In this chapter we survey different on-chip cellular activity detection technologies based on electrochemical, bio-impedance and optical detection. Both prokaryotic and eukaryotic cell-on-chip technologies are mentioned and reviewed.

  15. Cellular rehabilitation of photobiomodulation

    Science.gov (United States)

    Liu, Timon Cheng-Yi; Yuan, Jian-Qin; Wang, Yan-Fang; Xu, Xiao-Yang; Liu, Song-Hao

    2007-05-01

    Homeostasis is a term that refers to constancy in a system. A cell in homeostasis normally functions. There are two kinds of processes in the internal environment and external environment of a cell, the pathogenic processes (PP) which disrupts the old homeostasis (OH), and the sanogenetic processes (SP) which restores OH or establishes a new homeostasis (NH). Photobiomodualtion (PBM), the cell-specific effects of low intensity monochromatic light or low intensity laser irradiation (LIL) on biological systems, is a kind of modulation on PP or SP so that there is no PBM on a cell in homeostasis. There are two kinds of pathways mediating PBM, the membrane endogenetic chromophores mediating pathways which often act through reactive oxygen species, and membrane proteins mediating pathways which often enhance cellular SP so that it might be called cellular rehabilitation. The cellular rehabilitation of PBM will be discussed in this paper. It is concluded that PBM might modulate the disruption of cellular homeostasis induced by pathogenic factors such as toxin until OH has been restored or NH has been established, but can not change homeostatic processes from one to another one.

  16. Cellular Response to Irradiation

    Institute of Scientific and Technical Information of China (English)

    LIU Bo; YAN Shi-Wei

    2011-01-01

    To explore the nonlinear activities of the cellular signaling system composed of one transcriptional arm and one protein-interaction arm, we use an irradiation-response module to study the dynamics of stochastic interactions.It is shown that the oscillatory behavior could be described in a unified way when the radiation-derived signal and noise are incorporated.

  17. Synthesis, DNA binding, cellular DNA lesion and cytotoxicity of a series of new benzimidazole-based Schiff base copper(II) complexes.

    Science.gov (United States)

    Paul, Anup; Anbu, Sellamuthu; Sharma, Gunjan; Kuznetsov, Maxim L; Koch, Biplob; Guedes da Silva, M Fátima C; Pombeiro, Armando J L

    2015-12-14

    A series of new benzimidazole containing compounds 2-((1-R-1-H-benzimidazol-2-yl)phenyl-imino)naphthol HL(1-3) (R = methyl, ethyl or propyl, respectively) have been synthesized by Schiff base condensation of 2-(1-R-1-H-benzo[d]imidazol-2-yl)aniline and 2-hydroxy-1-naphthaldehyde. The reactions of HL(1-3) with Cu(NO3)2·2.5H2O led to the corresponding copper(II) complexes [Cu(L)(NO3)] 1-3. All the compounds were characterized by conventional analytical techniques and, for 1 and 3, also by single-crystal X-ray analysis. The interactions of complexes 1-3 with calf thymus DNA were studied by absorption and fluorescence spectroscopic techniques and the calculated binding constants (K(b)) are in the range of 3.5 × 10(5) M(-1)-3.2 × 10(5) M(-1). Complexes 1-3 effectively bind DNA through an intercalative mode, as proved by molecular docking studies. The binding affinity of the complexes decreases with the size increase of the N-alkyl substituent, in the order of 1 > 2 > 3, which is also in accord with the calculated LUMO(complex) energies. They show substantial in vitro cytotoxic effect against human lung (A-549), breast (MDA-MB-231) and cervical (HeLa) cancer cell lines. Complex 1 exhibits a significant inhibitory effect on the proliferation of the A-549 cancer cells. The antiproliferative efficacy of 1 has also been analysed by a DNA fragmentation assay, fluorescence activated cell sorting (FACS) and nuclear morphology using a fluorescence microscope. The possible mode for the apoptosis pathway of 1 has also been evaluated by a reactive oxygen species (ROS) generation study.

  18. Flow cytometric readout based on Mitotracker Red CMXRos staining of live asexual blood stage malarial parasites reliably assesses antibody dependent cellular inhibition

    Directory of Open Access Journals (Sweden)

    Jogdand Prajakta S

    2012-07-01

    Full Text Available Abstract Background Functional in vitro assays could provide insights into the efficacy of malaria vaccine candidates. For estimating the anti-parasite effect induced by a vaccine candidate, an accurate determination of live parasite count is an essential component of most in vitro bioassays. Although traditionally parasites are counted microscopically, a faster, more accurate and less subjective method for counting parasites is desirable. In this study mitochondrial dye (Mitotracker Red CMXRos was used for obtaining reliable live parasite counts through flow cytometry. Methods Both asynchronous and tightly synchronized asexual blood stage cultures of Plasmodium falciparum were stained with CMXRos and subjected to detection by flow cytometry and fluorescence microscopy. The parasite counts obtained by flow cytometry were compared to standard microscopic counts obtained through examination of Giemsa-stained thin smears. A comparison of the ability of CMXRos to stain live and compromised parasites (induced by either medium starvation or by anti-malarial drug treatment was carried out. Finally, parasite counts obtained by CMXRos staining through flow cytometry were used to determine specific growth inhibition index (SGI in an antibody-dependent cellular inhibition (ADCI assay. Results Mitotracker Red CMXRos can reliably detect live intra-erythrocytic stages of P. falciparum. Comparison between staining of live with compromised parasites shows that CMXRos predominantly stains live parasites with functional mitochondria. Parasite counts obtained by CMXRos staining and flow cytometry were highly reproducible and can reliably determine the ability of IgG from hyper-immune individuals to inhibit parasite growth in presence of monocytes in ADCI assay. Further, a dose-dependent parasite growth inhibitory effect could be detected for both total IgG purified from hyper-immune sera and affinity purified IgGs against the N-terminal non-repeat region of GLURP

  19. 100 gigasamples per second 12 bits optoelectronic analog-to-digital converter design and implementation based on cellular polyphase-sampling architecture

    Science.gov (United States)

    Villa-Angulo, Carlos

    The next generation digital information systems such as high performance computers, multigigabit/sec communication networks, distributed sensors, three dimensional digital imaging systems etc, will require analog-to-digital converters (ADCs) with high sampling rates exceeding 10 Gigasamples per second (GSPS) and high bit resolution of at least 10 bits. Such performance criteria are difficult to achieve with silicon electronics technology because the switching speeds peak at about 10-20GHz. Also, timing jitters, amplitude fluctuations, phase noise, thermal noise, and harmonic distortion, all contribute to reductions in ADC bit resolution as sampling rate increases. Photonics ADCs are rapidly emerging as the enabling technologies for high-performance digital signal processing systems. For this technology, high optical pulses repetition rate (in the order of GHz) with low time jitter and pulse width in the femtoseconds regime are the major attractive characteristics of optical sources. In this dissertation work, a novel 102.4 GSPS 12-bit optoelectronic analog-to-digital converter architecture that is based on a Cellular Polyphase-Sampling architecture is introduced. First, a 102.4 GHz all-optical clock was designed and implemented using a femtosecond laser source and passive optical components. Second, a novel optoelectronic architecture for optical sampling and parallel demultiplexing of different phases (polyphase) of an input analog signal is presented. The optoelectronic sampling and demultiplexing architecture is composed by 20 optoelectronic subcircuit referred as "OE-Cell"; these have been designed and implemented using optical passive components and InGaAs PIN photodiodes. A unique feature of this approach is that the optically sampled RF signal always remains in the electrical domain and thus eliminates the need for electrical-to-optical and optical-to-electrical conversions. The electrical-in to electrical-out transfer functions of the sampling and

  20. A Snaking and Interweaving Bicycle Flow Model Based on Cellular Automata%基于元胞自动机的自行车流蛇行、穿插模型

    Institute of Scientific and Technical Information of China (English)

    邓建华

    2011-01-01

    通过重新定义元胞尺寸、状态值及元胞邻域,建立了自行车元胞自动机基本模型,并在基本模型中引入随机偏移概率来表达自行车不遵循车道行驶的特性.通过模型模拟运行,并对获得的自行车流参数进行分析,结果表明引入随机偏移概率能很好地描述自行车不遵循车道随机蛇行、穿插的特性.%Through the re-definition of cellular size, cellular state value and the neighborhood, The paper establishs a bicycle basic cellular automata model and introduc the stochastic offset probability in bicycle’s base cellular automata model innovatively to express the property of riding not following with one lane.Through models simulation, the paper analyzs the result of the bicycle flow-parameters of simulated models and shows that the stochastic offset probability is corresponding sufficiently to describe the bicycle’s snaking and interweaving property.

  1. 基于无线通信网络的移动电话定位新技术%A New Cellular Telephone Location Technology Based on Wireless Communication Network

    Institute of Scientific and Technical Information of China (English)

    张贵明黄顺吉; 张元莉

    2001-01-01

    由于GPS定位受多种因素的制约,提出了一种基于无线通信网络的移动电话定位新技术。该技术基于TDOA方法,只要求对现有移动通信网络中基站和控制中心的软硬件作适当的修改,就能实现对移动电话的定位和监控。该技术具有广阔的应用前景。%This paper presents a new cellular telephone location technology based on wireless communication network, which uses TDOA, only requires appropriate modification for hardware and software of base-station and control center, the location and tracking of cellular telephone will be realized. The application of this technology is wide.

  2. Green Cellular - Optimizing the Cellular Network for Minimal Emission from Mobile Stations

    CERN Document Server

    Ezri, Doron

    2009-01-01

    Wireless systems, which include cellular phones, have become an essential part of the modern life. However the mounting evidence that cellular radiation might adversely affect the health of its users, leads to a growing concern among authorities and the general public. Radiating antennas in the proximity of the user, such as antennas of mobile phones are of special interest for this matter. In this paper we suggest a new architecture for wireless networks, aiming at minimal emission from mobile stations, without any additional radiation sources. The new architecture, dubbed Green Cellular, abandons the classical transceiver base station design and suggests the augmentation of transceiver base stations with receive only devices. These devices, dubbed Green Antennas, are not aiming at coverage extension but rather at minimizing the emission from mobile stations. We discuss the implications of the Green Cellular architecture on 3G and 4G cellular technologies. We conclude by showing that employing the Green Cell...

  3. Molecular and Cellular Signaling

    CERN Document Server

    Beckerman, Martin

    2005-01-01

    A small number of signaling pathways, no more than a dozen or so, form a control layer that is responsible for all signaling in and between cells of the human body. The signaling proteins belonging to the control layer determine what kinds of cells are made during development and how they function during adult life. Malfunctions in the proteins belonging to the control layer are responsible for a host of human diseases ranging from neurological disorders to cancers. Most drugs target components in the control layer, and difficulties in drug design are intimately related to the architecture of the control layer. Molecular and Cellular Signaling provides an introduction to molecular and cellular signaling in biological systems with an emphasis on the underlying physical principles. The text is aimed at upper-level undergraduates, graduate students and individuals in medicine and pharmacology interested in broadening their understanding of how cells regulate and coordinate their core activities and how diseases ...

  4. Pulmonary administration of phosphoinositide 3-kinase inhibitor is a curative treatment for chronic obstructive pulmonary disease by alveolar regeneration.

    Science.gov (United States)

    Horiguchi, Michiko; Oiso, Yuki; Sakai, Hitomi; Motomura, Tomoki; Yamashita, Chikamasa

    2015-09-10

    Chronic obstructive pulmonary disease (COPD) is an intractable pulmonary disease, causing widespread and irreversible alveoli collapse. The discovery of a low-molecular-weight compound that induces regeneration of pulmonary alveoli is of utmost urgency to cure intractable pulmonary diseases such as COPD. However, a practically useful compound for regenerating pulmonary alveoli is yet to be reported. Previously, we have elucidated that Akt phosphorylation is involved in a differentiation-inducing molecular mechanism of human alveolar epithelial stem cells, which play a role in regenerating pulmonary alveoli. In the present study, we directed our attention to phosphoinositide 3-kinase (PI3K)-Akt signaling and examined whether PI3K inhibitors display the pulmonary alveolus regeneration. Three PI3K inhibitors with different PI3K subtype specificities (Wortmannin, AS605240, PIK-75 hydrochloride) were tested for the differentiation-inducing effect on human alveolar epithelial stem cells, and Wortmannin demonstrated the most potent differentiation-inducing activity. We evaluated Akt phosphorylation in pulmonary tissues of an elastase-induced murine COPD model and found that Akt phosphorylation in the pulmonary tissue was enhanced in the murine COPD model compared with normal mice. Then, the alveolus-repairing effect of pulmonary administration of Wortmannin to murine COPD model was evaluated using X-ray CT analysis and hematoxylin-eosin staining. As a result, alveolar damages were repaired in the Wortmannin-administered group to a similar level of normal mice. Furthermore, pulmonary administration of Wortmannin induced a significant recovery of the respiratory function, compared to the control group. These results indicate that Wortmannin is capable of inducing differentiation of human alveolar epithelial stem cells and represents a promising drug candidate for curative treatment of pulmonary alveolar destruction in COPD.

  5. The anti-esophageal cancer cell activity by a novel tyrosine/phosphoinositide kinase inhibitor PP121

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Yi; Zhou, Yajuan [Department of Radiation and Medical Oncology, Hubei Key Laboratory of Tumor Biological Behaviors, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China); Department of Radiation Oncology, Hubei Cancer Hospital, Wuhan 430071 (China); Cheng, Long [Department of Interventional Radiology, the Second Affiliated Hospital of Soochow University, Soochow University, Suzhou 215001 (China); Hu, Desheng; Zhou, Xiaoyi; Wang, Zhaohua [Department of Radiation Oncology, Hubei Cancer Hospital, Wuhan 430071 (China); Xie, Conghua, E-mail: chxie_65@hotmail.com [Department of Radiation and Medical Oncology, Hubei Key Laboratory of Tumor Biological Behaviors, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China); Zhou, Fuxiang, E-mail: ZhouFuxiangwuhan@126.com [Department of Radiation and Medical Oncology, Hubei Key Laboratory of Tumor Biological Behaviors, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China)

    2015-09-11

    Here we explored the potential effect of PP121, a novel dual inhibitor of tyrosine and phosphoinositide kinases, against human esophageal cancer cells. We showed that PP121 exerted potent cytotoxic effect in primary (patient-derived) and established (Eca-109, TE-1 and TE-3 lines) esophageal cancer cells, possibly through activating caspase-3-dependnent apoptosis. PP121 was, however, non-cytotoxic to the normal human esophageal epithelial cells (EECs). At the molecular level, we showed that PP121 blocked Akt-mTOR (mammalian target of rapamycin) activation in esophageal cancer cells, which was restored by introducing a constitutively-active Akt (CA-Akt). Yet, CA-Akt only partly inhibited cytotoxicity by PP121 in Eca-109 cells. Importantly, we showed that PP121 inhibited nuclear factor kappa B (NFκB) signaling activation in esophageal cancer cells, which appeared independent of Akt-mTOR blockage. In vivo, oral administration of PP121 remarkably inhibited Eca-109 xenograft growth in nude mice, and significantly improved mice survival. Further, the immunohistochemistry (IHC) and Western blot assays analyzing xenografted tumors showed that PP121 inhibited Akt-mTOR and NFκB activations in vivo. Together, we demonstrate that PP121 potently inhibits esophageal cancer cells in vitro and in vivo, possibly through concurrently inhibiting Akt-mTOR and NFκB signalings. - Highlights: • PP121 is cytotoxic against primary and established esophageal cancer cells. • PP121 induces caspase-3-dependnent apoptosis in esophageal cancer cells. • PP121 blocks Akt-mTOR activation in esophageal cancer cells. • PP121 inhibits NFκB activation, independent of Akt-mTOR blockage. • PP121 inhibits Eca-109 xenograft growth and Akt-mTOR/NFκB activation in vivo.

  6. Epigallocatechin gallate (EGCG), a major component of green tea, is a dual phosphoinositide-3-kinase/mTOR inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Van Aller, Glenn S., E-mail: glenn.s.van.aller@gsk.com [Department of Cancer Research, GlaxoSmithKline, Collegeville, PA 19426 (United States); Carson, Jeff D. [Department of Cancer Research, GlaxoSmithKline, Collegeville, PA 19426 (United States); Tang, Wei; Peng, Hao; Zhao, Lin [Discovery Biology, BioDuro, No. 29 Life Science Park Road, Changping, Beijing (China); Copeland, Robert A.; Tummino, Peter J. [Department of Cancer Research, GlaxoSmithKline, Collegeville, PA 19426 (United States); Luo, Lusong [Discovery Biology, BioDuro, No. 29 Life Science Park Road, Changping, Beijing (China)

    2011-03-11

    Research highlights: {yields} Epigallocatechin-3-gallate (EGCG) is an ATP-competitive inhibitor of PI3K and mTOR with Ki values around 300 nM. {yields} EGCG inhibits cell proliferation and AKT phosphorylation at Ser473 in MDA-MB-231and A549 cells. {yields} Molecular docking studies show that EGCG binds well to the PI3K kinase domain active site. {yields} These results suggest another important molecular mechanism for the anticancer activities of EGCG. -- Abstract: The PI3K signaling pathway is activated in a broad spectrum of human cancers, either directly by genetic mutation or indirectly via activation of receptor tyrosine kinases or inactivation of the PTEN tumor suppressor. The key nodes of this pathway have emerged as important therapeutic targets for the treatment of cancer. In this study, we show that (-)-epigallocatechin-3-gallate (EGCG), a major component of green tea, is an ATP-competitive inhibitor of both phosphoinositide-3-kinase (PI3K) and mammalian target of rapamycin (mTOR) with K{sub i} values of 380 and 320 nM respectively. The potency of EGCG against PI3K and mTOR is within physiologically relevant concentrations. In addition, EGCG inhibits cell proliferation and AKT phosphorylation at Ser473 in MDA-MB-231 and A549 cells. Molecular docking studies show that EGCG binds well to the PI3K kinase domain active site, agreeing with the finding that EGCG competes for ATP binding. Our results suggest another important molecular mechanism for the anticancer activities of EGCG.

  7. Leptin Regulated Insulin Secretion via Stimulating IRS2-associated Phosphoinositide 3-kinase Activity in the isolated Rat Pancreatic Islets

    Institute of Scientific and Technical Information of China (English)

    袁莉; 安汉祥; 李卓娅; 邓秀玲

    2003-01-01

    To investigate the molecular mechanism of leptin regulating insulin secretion through determining the regulation of insulin secretion and the insulin receptor substrate (IRS)-2-associated phosphoinositide 3-kinase (PI3K) activity by leptin in the isolated rat pancreatic islets, pancreatic islets were isolated from male SD rats by the collagenase method. The purified islets were incubated with leptin 2 nmol/L for 1 h in the presence of 5.6 mmol/L or 11.1 mmol/L glucose. Insulin release was measured using radioimmunoassay. IRS-2-associated activity of PI3K was determined by immunoprecipitate assay and Western blot. The results showed that in the presence of 5.6 mmol/L glucose, leptin had no significant effect on both insulin secretion and IRS-2-associated PI3K activity, but in the presence of 11.1 mmol/L glucose, insulin release was significantly inhibited after the islets were exposed to leptin for 1 h (P<0. 01). PI3K inhibitor wortmannin blocked the inhibitory regulation of leptin on insulin release (P<0. 05). Western Blot assay revealed that 2 nmol/L leptin could significantly increase the IRS-2-associated activity of PI3K by 51.5 % (P<0. 05) in the presence of 11.1 mmol/L glucose. It was concluded that Leptin could significantly inhibit insulin secretion in the presence of 11.1 mmol/L glucose by stimulating IRS-2-associated activity of PI3K, which might be the molecular mechanism of leptin regulating insulin secretion.

  8. Stimulation of Toll-like receptor 2 in human platelets induces a thromboinflammatory response through activation of phosphoinositide 3-kinase.

    Science.gov (United States)

    Blair, Price; Rex, Sybille; Vitseva, Olga; Beaulieu, Lea; Tanriverdi, Kahraman; Chakrabarti, Subrata; Hayashi, Chie; Genco, Caroline A; Iafrati, Mark; Freedman, Jane E

    2009-02-13

    Cells of the innate immune system use Toll-like receptors (TLRs) to initiate the proinflammatory response to microbial infection. Recent studies have shown acute infections are associated with a transient increase in the risk of vascular thrombotic events. Although platelets play a central role in acute thrombosis and accumulating evidence demonstrates their role in inflammation and innate immunity, investigations into the expression and functionality of platelet TLRs have been limited. In the present study, we demonstrate that human platelets express TLR2, TLR1, and TLR6. Incubation of isolated platelets with Pam(3)CSK4, a synthetic TLR2/TLR1 agonist, directly induced platelet aggregation and adhesion to collagen. These functional responses were inhibited in TLR2-deficient mice and, in human platelets, by pretreatment with TLR2-blocking antibody. Stimulation of platelet TLR2 also increased P-selectin surface expression, activation of integrin alpha(IIb)beta(3), generation of reactive oxygen species, and, in human whole blood, formation of platelet-neutrophil heterotypic aggregates. TLR2 stimulation also activated the phosphoinositide 3-kinase (PI3-K)/Akt signaling pathway in platelets, and inhibition of PI3-K significantly reduced Pam(3)CSK4-induced platelet responses. In vivo challenge with live Porphyromonas gingivalis, a Gram-negative pathogenic bacterium that uses TLR2 for innate immune signaling, also induced significant formation of platelet-neutrophil aggregates in wild-type but not TLR2-deficient mice. Together, these data provide the first demonstration that human platelets express functional TLR2 capable of recognizing bacterial components and activating the platelet thrombotic and/or inflammatory pathways. This work substantiates the role of platelets in the immune and inflammatory response and suggests a mechanism by which bacteria could directly activate platelets.

  9. The role of phosphoinositide 3-kinase and phosphatidic acid in the regulation of mammalian target of rapamycin following eccentric contractions.

    Science.gov (United States)

    O'Neil, T K; Duffy, L R; Frey, J W; Hornberger, T A

    2009-07-15

    Resistance exercise induces a hypertrophic response in skeletal muscle and recent studies have begun to shed light on the molecular mechanisms involved in this process. For example, several studies indicate that signalling by the mammalian target of rapamycin (mTOR) is necessary for a hypertrophic response. Furthermore, resistance exercise has been proposed to activate mTOR signalling through an upstream pathway involving the phosphoinositide 3-kinase (PI3K) and protein kinase B (PKB); however, this hypothesis has not been thoroughly tested. To test this hypothesis, we first evaluated the temporal pattern of signalling through PI3K-PKB and mTOR following a bout of resistance exercise with eccentric contractions (EC). Our results indicated that the activation of signalling through PI3K-PKB is a transient event (12 h). Furthermore, inhibition of PI3K-PKB activity did not prevent the activation of mTOR signalling by ECs, indicating that PI3K-PKB is not part of the upstream regulatory pathway. These observations led us to investigate an alternative pathway for the activation of mTOR signalling involving the synthesis of phosphatidic acid (PA) by phospholipase D (PLD). Our results demonstrate that ECs induce a sustained elevation in [PA] and inhibiting the synthesis of PA by PLD prevented the activation of mTOR. Furthermore, we determined that similar to ECs, PA activates mTOR signalling through a PI3K-PKB-independent mechanism. Combined, the results of this study indicate that the activation of mTOR following eccentric contractions occurs through a PI3K-PKB-independent mechanism that requires PLD and PA.

  10. Anti-malarial drug artesunate attenuates experimental allergic asthma via inhibition of the phosphoinositide 3-kinase/Akt pathway.

    Directory of Open Access Journals (Sweden)

    Chang Cheng

    Full Text Available BACKGROUND: Phosphoinositide 3-kinase (PI3K/Akt pathway is linked to the development of asthma. Anti-malarial drug artesunate is a semi-synthetic derivative of artemisinin, the principal active component of a medicinal plant Artemisia annua, and has been shown to inhibit PI3K/Akt activity. We hypothesized that artesunate may attenuate allergic asthma via inhibition of the PI3K/Akt signaling pathway. METHODOLOGY/PRINCIPAL FINDINGS: Female BALB/c mice sensitized and challenged with ovalbumin (OVA developed airway inflammation. Bronchoalveolar lavage fluid was assessed for total and differential cell counts, and cytokine and chemokine levels. Lung tissues were examined for cell infiltration and mucus hypersecretion, and the expression of inflammatory biomarkers. Airway hyperresponsiveness was monitored by direct airway resistance analysis. Artesunate dose-dependently inhibited OVA-induced increases in total and eosinophil counts, IL-4, IL-5, IL-13 and eotaxin levels in bronchoalveolar lavage fluid. It attenuated OVA-induced lung tissue eosinophilia and airway mucus production, mRNA expression of E-selectin, IL-17, IL-33 and Muc5ac in lung tissues, and airway hyperresponsiveness to methacholine. In normal human bronchial epithelial cells, artesunate blocked epidermal growth factor-induced phosphorylation of Akt and its downstream substrates tuberin, p70S6 kinase and 4E-binding protein 1, and transactivation of NF-κB. Similarly, artesunate blocked the phosphorylation of Akt and its downstream substrates in lung tissues from OVA-challenged mice. Anti-inflammatory effect of artesunate was further confirmed in a house dust mite mouse asthma model. CONCLUSION/SIGNIFICANCE: Artesunate ameliorates experimental allergic airway inflammation probably via negative regulation of PI3K/Akt pathway and the downstream NF-κB activity. These findings provide a novel therapeutic value for artesunate in the treatment of allergic asthma.

  11. Disulfiram Treatment Facilitates Phosphoinositide 3-Kinase Inhibition in Human Breast Cancer Cells In vitro and In vivo

    Science.gov (United States)

    Zhang, Haijun; Chen, Di; Ringler, Jonathan; Chen, Wei; Cui, Qiuzhi Cindy; Ethier, Stephen P.; Dou, Q. Ping; Wu, Guojun

    2013-01-01

    Frequent genetic alterations of the components in the phosphoinositide 3-kinase (PI3K)/PTEN/AKT signaling pathway contribute greatly to breast cancer initiation and progression, which makes targeting this signaling pathway a promising therapeutic strategy for breast cancer treatment. In this study, we showed that in the presence of copper (Cu), disulfiram (DSF), a clinically used antialcoholism drug, could potently inhibit breast cancer cell growth regardless of the PIK3CA status. Surprisingly, the treatment with a mixture of DSF and copper (DSF-Cu) led to the decreased expression of PTEN protein and the activation of AKT in a dose- and time-dependent manner in different cell lines with or without PIK3CA mutations. Treatment of breast cancer cell lines with a combination of DSF-Cu and LY294002, a pan-PI3K inhibitor, resulted in the significant inhibition of cell growth when compared with either drug alone. In addition, the combined treatment of DSF and LY294002 significantly inhibited the growth of the breast tumor xenograft in nude mice induced by MDA-MB-231 cells expressing mutant PIK3CA-H1047R and PIK3CA-E545K, whereas neither DSF nor LY294002 alone could significantly retard tumor growth. Finally, the observed in vivo inhibitory effects are found associated with aberrant signaling alterations and apoptosis-inducing activities in tumor samples. Thus, our finding shows for the first time that treatment of breast cancer with DSF results in a novel feedback mechanism that activates AKT signaling. Our study also suggests that the combination of DSF and a PI3K inhibitor may offer a new combinational treatment model for breast cancer, particularly for those with PIK3CA mutations. PMID:20424113

  12. 基于改进遗传算法的制造单元设计研究%Study on Manufacturing Cellular Design Based on Advanced Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    范佳静; 冯定忠

    2011-01-01

    针对制造单元构建问题的特征,构建了以总搬运成本以及机器设备的折旧和维修成本最低为主要目标,综合考虑了产品设备单元划分、单元内机器布局以及单元问布局的综合性制造单元模型.同时针对模型求解的复杂性,提出了改进遗传算法,并将其用于制造单元模型的求解.通过双层遗传算法,既保证了算法中染色体个体的有效性,又满足了遗传算法适者生存的根本原理;采用精英策略保证算法的收敛性;同时通过在求解过程中不断调整交叉算予和变异算子防止了算法收敛到局部最优解.最后将所提出的模型和改进的遗传算法应用于复杂实例,证明模型和算法的有效性.%A comprehensive model for manufacturing cellular was put forward which aimed at abtaining the minmum of material handling cost and machine depreciable and repair cost as well as synchronously considering the cellular formaiton, machine layout and cellular layout according to the characteristics of the problem of manufacturing cellular.And an advanced genetic algorithm was brought forward to solve this model.The individual validity and the characteristic of genetic algorithm were ensured; the convergence of algorithm through the elite strategy was ensured and the local convergence was protected by adjusting the crossover operator and mutation operator constantly.At last,the validity of the model and algorithm was proved by a complicated example.

  13. Degradable gene delivery systems based on Pluronics-modified low-molecular-weight polyethylenimine: preparation, characterization, intracellular trafficking, and cellular distribution

    Directory of Open Access Journals (Sweden)

    Ding X

    2012-02-01

    Full Text Available Wei Fan1,2,*, Xin Wu1,*, Baoyue Ding3,*, Jing Gao4, Zhen Cai1, Wei Zhang1, Dongfeng Yin1, Xiang Wang1, Quangang Zhu1, Jiyong Liu1, Xueying Ding4, Shen Gao1 1Department of Pharmaceutics, Changhai Hospital, Second Military Medical University, Shanghai, 2Department of Pharmaceutics, The 425th Hospital of PLA, Sanya, 3Department of Pharmaceutics, Medical College of Jiaxing University, Jiaxing, 4Department of Pharmaceutics, School of Pharmacy, Second Military Medical University, Shanghai, People's Republic of China*These authors contributed equally to this workBackground: Cationic copolymers consisting of polycations linked to nonionic amphiphilic block polymers have been evaluated as nonviral gene delivery systems, and a large number of different polymers and copolymers of linear, branched, and dendrimeric architectures have been tested in terms of their suitability and efficacy for in vitro and in vivo transfection. However, the discovery of new potent materials still largely relies on empiric approaches rather than a rational design. The authors investigated the relationship between the polymers' structures and their biological performance, including DNA compaction, toxicity, transfection efficiency, and the effect of cellular uptake.Methods: This article reports the synthesis and characterization of a series of cationic copolymers obtained by grafting polyethyleneimine with nonionic amphiphilic surfactant polyether-Pluronic® consisting of hydrophilic ethylene oxide and hydrophobic propylene oxide blocks. Transgene expression, cytotoxicity, localization of plasmids, and cellular uptake of these copolymers were evaluated following in vitro transfection of HeLa cell lines with various individual components of the copolymers.Results: Pluronics can exhibit biological activity including effects on enhancing DNA cellular uptake, nuclear translocation, and gene expression. The Pluronics with a higher hydrophilic-lipophilic balance value lead to

  14. Nodule Detection in a Lung Region that's Segmented with Using Genetic Cellular Neural Networks and 3D Template Matching with Fuzzy Rule Based Thresholding

    OpenAIRE

    Ozekes, Serhat; Osman, Onur; UCAN, Osman N.

    2008-01-01

    Objective The purpose of this study was to develop a new method for automated lung nodule detection in serial section CT images with using the characteristics of the 3D appearance of the nodules that distinguish themselves from the vessels. Materials and Methods Lung nodules were detected in four steps. First, to reduce the number of region of interests (ROIs) and the computation time, the lung regions of the CTs were segmented using Genetic Cellular Neural Networks (G-CNN). Then, for each lu...

  15. Cellular automata: structures

    OpenAIRE

    Ollinger, Nicolas

    2002-01-01

    Jury : François Blanchard (Rapporteur), Marianne Delorme (Directeur), Jarkko Kari (Président), Jacques Mazoyer (Directeur), Dominique Perrin, Géraud Sénizergues (Rapporteur); Cellular automata provide a uniform framework to study an important problem of "complex systems" theory: how and why do system with a easily understandable -- local -- microscopic behavior can generate a more complicated -- global -- macroscopic behavior? Since its introduction in the 40s, a lot of work has been done to ...

  16. Engineering Cellular Metabolism

    DEFF Research Database (Denmark)

    Nielsen, Jens; Keasling, Jay

    2016-01-01

    Metabolic engineering is the science of rewiring the metabolism of cells to enhance production of native metabolites or to endow cells with the ability to produce new products. The potential applications of such efforts are wide ranging, including the generation of fuels, chemicals, foods, feeds...... of metabolic engineering and will discuss how new technologies can enable metabolic engineering to be scaled up to the industrial level, either by cutting off the lines of control for endogenous metabolism or by infiltrating the system with disruptive, heterologous pathways that overcome cellular regulation....

  17. Characterization of VPS34-IN1, a selective inhibitor of Vps34, reveals that the phosphatidylinositol 3-phosphate-binding SGK3 protein kinase is a downstream target of class III phosphoinositide 3-kinase.

    Science.gov (United States)

    Bago, Ruzica; Malik, Nazma; Munson, Michael J; Prescott, Alan R; Davies, Paul; Sommer, Eeva; Shpiro, Natalia; Ward, Richard; Cross, Darren; Ganley, Ian G; Alessi, Dario R

    2014-11-01

    The Vps34 (vacuolar protein sorting 34) class III PI3K (phosphoinositide 3-kinase) phosphorylates PtdIns (phosphatidylinositol) at endosomal membranes to generate PtdIns(3)P that regulates membrane trafficking processes via its ability to recruit a subset of proteins possessing PtdIns(3)P-binding PX (phox homology) and FYVE domains. In the present study, we describe a highly selective and potent inhibitor of Vps34, termed VPS34-IN1, that inhibits Vps34 with 25 nM IC50 in vitro, but does not significantly inhibit the activity of 340 protein kinases or 25 lipid kinases tested that include all isoforms of class I as well as class II PI3Ks. Administration of VPS34-IN1 to cells induces a rapid dose-dependent dispersal of a specific PtdIns(3)P-binding probe from endosome membranes, within 1 min, without affecting the ability of class I PI3K to regulate Akt. Moreover, we explored whether SGK3 (serum- and glucocorticoid-regulated kinase-3), the only protein kinase known to interact specifically with PtdIns(3)P via its N-terminal PX domain, might be controlled by Vps34. Mutations disrupting PtdIns(3)P binding ablated SGK3 kinase activity by suppressing phosphorylation of the T-loop [PDK1 (phosphoinositide-dependent kinase 1) site] and hydrophobic motif (mammalian target of rapamycin site) residues. VPS34-IN1 induced a rapid ~50-60% loss of SGK3 phosphorylation within 1 min. VPS34-IN1 did not inhibit activity of the SGK2 isoform that does not possess a PtdIns(3)P-binding PX domain. Furthermore, class I PI3K inhibitors (GDC-0941 and BKM120) that do not inhibit Vps34 suppressed SGK3 activity by ~40%. Combining VPS34-IN1 and GDC-0941 reduced SGK3 activity ~80-90%. These data suggest SGK3 phosphorylation and hence activity is controlled by two pools of PtdIns(3)P. The first is produced through phosphorylation of PtdIns by Vps34 at the endosome. The second is due to the conversion of class I PI3K product, PtdIns(3,4,5)P3 into PtdIns(3)P, via the sequential actions of the Ptd

  18. Study on PI active queue management based on cellular automaton%基于元胞自动机的PI主动队列管理方法研究

    Institute of Scientific and Technical Information of China (English)

    俞立峰

    2013-01-01

    针对传统的PI(Proportional Integral)算法收敛速度慢等问题,基于瞬时到达速率提出了一种新的PI主动队列管理算法PICA(Proportional Integral Based on Cellular Automaton).首先,该算法结合瞬时队长和瞬时到达速率建立了丢包策略,并利用元胞自动机刻画了数据包的动态特性.同时,通过仿真实验,将该算法与传统的PI算法以及RPI (Rate based Proportional and Integral)算法进行比较,结果发现PICA算法在有效传输数据包、时延和丢包率等方面的性能都较优.%In order to mitigate the slow of convergence rate in traditional Proportional Integral algorithm, a novel active queue management algorithm (Proportional Integral Based on Cellular Automaton, PICA) is proposed based on instantaneous arrival rate. At first, combined with instantaneous queue length and instantaneous arrival rate, the dropping strategy is presented in this algorithm, and the dynamic characteristic of packet is depicted by cellular automaton. Then, a simulation was conducted to study on the algorithm performance between PICA and PI, as well as RPKRate based Proportional and Integral). The result shows that it is better performance in efficient transmission packets, delay and dropping rate for PICA algorithm.

  19. Multifunctional organic–inorganic hybrid nanoparticles and nanosheets based on chitosan derivative and layered double hydroxide: cellular uptake mechanism and application for topical ocular drug delivery

    Science.gov (United States)

    Chi, Huibo; Gu, Yan; Xu, Tingting; Cao, Feng

    2017-01-01

    To study the cellular uptake mechanism of multifunctional organic–inorganic hybrid nanoparticles and nanosheets, new chitosan–glutathione–valine–valine-layered double hydroxide (CG-VV-LDH) nanosheets with active targeting to peptide transporter-1 (PepT-1) were prepared, characterized and further compared with CG-VV-LDH nanoparticles. Both organic–inorganic hybrid nanoparticles and nanosheets showed a sustained release in vitro and prolonged precorneal retention time in vivo, but CG-VV-LDH nanoparticles showed superior permeability in the isolated cornea of rabbits than CG-VV-LDH nanosheets. Furthermore, results of cellular uptake on human corneal epithelial primary cells (HCEpiC) and retinal pigment epithelial (ARPE-19) cells indicated that both clathrin-mediated endocytosis and active transport of PepT-1 are involved in the internalization of CG-VV-LDH nanoparticles and CG-VV-LDH nanosheets. In summary, the CG-VV-LDH nanoparticle may be a promising carrier as a topical ocular drug delivery system for the treatment of ocular diseases of mid-posterior segments, while the CG-VV-LDH nanosheet may be suitable for the treatment of ocular surface diseases. PMID:28280329

  20. Ancient Jing De Zhen Dong He River Basin Kiln and Farmland Land-use Change Based on Cellular Automata and Cultural Algorithm Model

    Directory of Open Access Journals (Sweden)

    Liu Tao

    2013-09-01

    Full Text Available The aim of this study is to understand how farmland has transformed kiln in ancient Jing De Zhen Dong He River Basin; we created ancient virtual maps of study area and conducted a series of spatial analyses of the land-use pattern from the Yuan Dynasty to the Ming Dynasty. The results of the spatial analysis show that kiln can evolve from farmland, shrub, idle land etc. To simulate land-use change we developed a novel cellular automata model. Model parameters and neighborhood rules were obtained with the cellular automata model melt modified cultural algorithm. Virtual land-use maps from the Yuan Dynasty to the Ming Dynasty were used to implement the model with a time step of one year. Model performance was evaluated using Moran’s I index estimation for selected landscape pattern indices. The optimized parameter set using Particle Swarm Optimization poorly simulated land-use change as compared to the optimized parameter set using Cultural Algorithm. In summary, our results proved that the model is also effective and feasible in simulating farmland and kiln land-use evolution in ancient times when Geographic Information and System information were lacking.

  1. Cellular automata modelling of SEIRS

    Institute of Scientific and Technical Information of China (English)

    Liu Quan-Xing; Jin Zhen

    2005-01-01

    In this paper the SEIRS epidemic spread is analysed, and a two-dimensional probability cellular automata model for SEIRS is presented. Each cellular automation cell represents a part of the population that may be found in one of five states of individuals: susceptible, exposed (or latency), infected, immunized (or recovered) and death. Here studied are the effects of two cases on the epidemic spread. i.e. the effects of non-segregation and segregation on the latency and the infected of population. The conclusion is reached that the epidemic will persist in the case of non-segregation but it will decrease in the case of segregation. The proposed model can serve as a basis for the development of algorithms to simulate real epidemics based on real data. Last we find the density series of the exposed and the infected will fluctuate near a positive equilibrium point, when the constant for the immunized is less than its corresponding constant τ0. Our theoretical results are verified by numerical simulations.

  2. Order of amino acids in C-terminal cysteine-containing peptide-based chelators influences cellular processing and biodistribution of 99mTc-labeled recombinant Affibody molecules.

    Science.gov (United States)

    Altai, Mohamed; Wållberg, Helena; Orlova, Anna; Rosestedt, Maria; Hosseinimehr, Seyed Jalal; Tolmachev, Vladimir; Ståhl, Stefan

    2012-05-01

    Affibody molecules constitute a novel class of molecular display selected affinity proteins based on non-immunoglobulin scaffold. Preclinical investigations and pilot clinical data have demonstrated that Affibody molecules provide high contrast imaging of tumor-associated molecular targets shortly after injection. The use of cysteine-containing peptide-based chelators at the C-terminus of recombinant Affibody molecules enabled site-specific labeling with the radionuclide 99mTc. Earlier studies have demonstrated that position, composition and the order of amino acids in peptide-based chelators influence labeling stability, cellular processing and biodistribution of Affibody molecules. To investigate the influence of the amino acid order, a series of anti-HER2 Affibody molecules, containing GSGC, GEGC and GKGC chelators have been prepared and characterized. The affinity to HER2, cellular processing of 99mTc-labeled Affibody molecules and their biodistribution were investigated. These properties were compared with that of the previously studied 99mTc-labeled Affibody molecules containing GGSC, GGEC and GGKC chelators. All variants displayed picomolar affinities to HER2. The substitution of a single amino acid in the chelator had an appreciable influence on the cellular processing of 99mTc. The biodistribution of all 99mTc-labeled Affibody molecules was in general comparable, with the main difference in uptake and retention of radioactivity in excretory organs. The hepatic accumulation of radioactivity was higher for the lysine-containing chelators and the renal retention of 99mTc was significantly affected by the amino acid composition of chelators. The order of amino acids influenced renal uptake of some conjugates at 1 h after injection, but the difference decreased at later time points. Such information can be helpful for the development of other scaffold protein-based imaging and therapeutic radiolabeled conjugates.

  3. Green Cellular Networks: A Survey, Some Research Issues and Challenges

    CERN Document Server

    Hasan, Ziaul; Bhargava, Vijay K

    2011-01-01

    Energy efficiency in cellular networks is a growing concern for cellular operators to not only maintain profitability, but also to reduce the overall environment effects. This emerging trend of achieving energy efficiency in cellular networks is motivating the standardization authorities and network operators to continuously explore future technologies in order to bring improvements in the entire network infrastructure. In this article, we present a brief survey of methods to improve the power efficiency of cellular networks, explore some research issues and challenges and suggest some techniques to enable an energy efficient or "green" cellular network. Since base stations consume a maximum portion of the total energy used in a cellular system, we will first provide a comprehensive survey on techniques to obtain energy savings in base stations. Next, we discuss how heterogenous network deployment based on micro, pico and femto-cells can be used to achieve this goal. Since cognitive radio and cooperative rela...

  4. Infrared image enhancement using Cellular Automata

    Science.gov (United States)

    Qi, Wei; Han, Jing; Zhang, Yi; Bai, Lian-fa

    2016-05-01

    Image enhancement is a crucial technique for infrared images. The clear image details are important for improving the quality of infrared images in computer vision. In this paper, we propose a new enhancement method based on two priors via Cellular Automata. First, we directly learn the gradient distribution prior from the images via Cellular Automata. Second, considering the importance of image details, we propose a new gradient distribution error to encode the structure information via Cellular Automata. Finally, an iterative method is applied to remap the original image based on two priors, further improving the quality of enhanced image. Our method is simple in implementation, easy to understand, extensible to accommodate other vision tasks, and produces more accurate results. Experiments show that the proposed method performs better than other methods using qualitative and quantitative measures.

  5. Specificity determinants in phosphoinositide dephosphorylation: crystal structure of an archetypal inositol polyphosphate 5-phosphatase.

    Science.gov (United States)

    Tsujishita, Y; Guo, S; Stolz, L E; York, J D; Hurley, J H

    2001-05-04

    Inositol polyphosphate 5-phosphatases are central to intracellular processes ranging from membrane trafficking to Ca(2+) signaling, and defects in this activity result in the human disease Lowe syndrome. The 1.8 resolution structure of the inositol polyphosphate 5-phosphatase domain of SPsynaptojanin bound to Ca(2+) and inositol (1,4)-bisphosphate reveals a fold and an active site His and Asp pair resembling those of several Mg(2+)-dependent nucleases. Additional loops mediate specific inositol polyphosphate contacts. The 4-phosphate of inositol (1,4)-bisphosphate is misoriented by 4.6 compared to the reactive geometry observed in the apurinic/apyrimidinic endonuclease 1, explaining the dephosphorylation site selectivity of the 5-phosphatases. Based on the structure, a series of mutants are described that exhibit altered substrate specificity providing general determinants for substrate recognition.

  6. A fluorescent chemodosimeter for Hg2+ based on a spirolactam ring-opening strategy and its application towards mercury determination in aqueous and cellular media.

    Science.gov (United States)

    Kumar, Kempahanumakkagaari Suresh; Ramakrishnappa, Thippeswamy; Balakrishna, R Geetha; Pandurangappa, Mallingappagari

    2014-01-01

    A novel fluorescent chemosensor rhodamine B phenyl hydrazide (RBPH) for Hg(2+) was designed and synthesized. This probe is highly sensitive, selective, and irreversible for Hg(2+) and exhibits fluorescent response at 580 nm. RBPH also displayed detectable color change from colorless to pink upon treatment with Hg(2+). This property has been utilized as naked eye detection for Hg(2+) in various industrial samples. Fluorescence microscopic experiments demonstrated that this chemosensor is cell permeable and can be used for fluorescence imaging of Hg(2+) in cellular media. This probe can detect Hg(2+) with good linear relationships from 1 to 100 nM with r = 0.99983 and the limit of detection were found to be 0.019 nM with ± 0.91 % RSD at 10 nM concentrations.

  7. Protective effects of a Modified Vaccinia Ankara-based vaccine candidate against Crimean-Congo Haemorrhagic Fever virus require both cellular and humoral responses.

    Directory of Open Access Journals (Sweden)

    Stuart D Dowall

    Full Text Available Crimean-Congo Haemorrhagic Fever (CCHF is a severe tick-borne disease, endemic in many countries in Africa, the Middle East, Eastern Europe and Asia. There is no approved vaccine currently available against CCHF. The most promising candidate, which has previously been shown to confer protection in the small animal model, is a modified Vaccinia Ankara virus vector expressing the CCHF viral glycoprotein (MVA-GP. It has been shown that MVA-GP induces both humoral and cellular immunogenicity. In the present study, sera and T-lymphocytes were passively and adoptively transferred into recipient mice prior to challenge with CCHF virus. Results demonstrated that mediators from both arms of the immune system were required to demonstrate protective effects against lethal challenge.

  8. Protective effects of a Modified Vaccinia Ankara-based vaccine candidate against Crimean-Congo Haemorrhagic Fever virus require both cellular and humoral responses.

    Science.gov (United States)

    Dowall, Stuart D; Graham, Victoria A; Rayner, Emma; Hunter, Laura; Watson, Robert; Taylor, Irene; Rule, Antony; Carroll, Miles W; Hewson, Roger

    2016-01-01

    Crimean-Congo Haemorrhagic Fever (CCHF) is a severe tick-borne disease, endemic in many countries in Africa, the Middle East, Eastern Europe and Asia. There is no approved vaccine currently available against CCHF. The most promising candidate, which has previously been shown to confer protection in the small animal model, is a modified Vaccinia Ankara virus vector expressing the CCHF viral glycoprotein (MVA-GP). It has been shown that MVA-GP induces both humoral and cellular immunogenicity. In the present study, sera and T-lymphocytes were passively and adoptively transferred into recipient mice prior to challenge with CCHF virus. Results demonstrated that mediators from both arms of the immune system were required to demonstrate protective effects against lethal challenge.

  9. Multifunctional organic–inorganic hybrid nanoparticles and nanosheets based on chitosan derivative and layered double hydroxide: cellular uptake mechanism and application for topical ocular drug delivery

    Directory of Open Access Journals (Sweden)

    Chi H

    2017-02-01

    Full Text Available Huibo Chi,1,2,* Yan Gu,1,* Tingting Xu,1 Feng Cao1 1Department of Pharmaceutics, School of Pharmacy, China Pharmaceutical University, Nanjing, 2State Key Laboratory of Drug Delivery Technology and Pharmacokinetics, Tianjin Institute of Pharmaceutical Research Co., Ltd., Tianjin, People’s Republic of China *These authors contributed equally to this work Abstract: To study the cellular uptake mechanism of multifunctional organic–inorganic hybrid nanoparticles and nanosheets, new chitosan–glutathione–valine–valine-layered double hydroxide (CG-VV-LDH nanosheets with active targeting to peptide transporter-1 (PepT-1 were prepared, characterized and further compared with CG-VV-LDH nanoparticles. Both organic–inorganic hybrid nanoparticles and nanosheets showed a sustained release in vitro and prolonged precorneal retention time in vivo, but CG-VV-LDH nanoparticles showed superior permeability in the isolated cornea of rabbits than CG-VV-LDH nanosheets. Furthermore, results of cellular uptake on human corneal epithelial primary cells (HCEpiC and retinal pigment epithelial (ARPE-19 cells indicated that both clathrin-mediated endocytosis and active transport of PepT-1 are involved in the internalization of CG-VV-LDH nanoparticles and CG-VV-LDH nanosheets. In summary, the CG-VV-LDH nanoparticle may be a promising carrier as a topical ocular drug delivery system for the treatment of ocular diseases of mid-posterior segments, while the CG-VV-LDH nanosheet may be suitable for the treatment of ocular surface diseases. Keywords: LDH nanoparticles, LDH nanosheets, ocular drug delivery, human corneal epithelial primary cell, retinal pigment cell, ARPE-19, active targeting

  10. Characterizing heterogeneous cellular responses to perturbations.

    Science.gov (United States)

    Slack, Michael D; Martinez, Elisabeth D; Wu, Lani F; Altschuler, Steven J

    2008-12-01

    Cellular populations have been widely observed to respond heterogeneously to perturbation. However, interpreting the observed heterogeneity is an extremely challenging problem because of the complexity of possible cellular phenotypes, the large dimension of potential perturbations, and the lack of methods for separating meaningful biological information from noise. Here, we develop an image-based approach to characterize cellular phenotypes based on patterns of signaling marker colocalization. Heterogeneous cellular populations are characterized as mixtures of phenotypically distinct subpopulations, and responses to perturbations are summarized succinctly as probabilistic redistributions of these mixtures. We apply our method to characterize the heterogeneous responses of cancer cells to a panel of drugs. We find that cells treated with drugs of (dis-)similar mechanism exhibit (dis-)similar patterns of heterogeneity. Despite the observed phenotypic diversity of cells observed within our data, low-complexity models of heterogeneity were sufficient to distinguish most classes of drug mechanism. Our approach offers a computational framework for assessing the complexity of cellular heterogeneity, investigating the degree to which perturbations induce redistributions of a limited, but nontrivial, repertoire of underlying states and revealing functional significance contained within distinct patterns of heterogeneous responses.

  11. Cellular image classification

    CERN Document Server

    Xu, Xiang; Lin, Feng

    2017-01-01

    This book introduces new techniques for cellular image feature extraction, pattern recognition and classification. The authors use the antinuclear antibodies (ANAs) in patient serum as the subjects and the Indirect Immunofluorescence (IIF) technique as the imaging protocol to illustrate the applications of the described methods. Throughout the book, the authors provide evaluations for the proposed methods on two publicly available human epithelial (HEp-2) cell datasets: ICPR2012 dataset from the ICPR'12 HEp-2 cell classification contest and ICIP2013 training dataset from the ICIP'13 Competition on cells classification by fluorescent image analysis. First, the reading of imaging results is significantly influenced by one’s qualification and reading systems, causing high intra- and inter-laboratory variance. The authors present a low-order LP21 fiber mode for optical single cell manipulation and imaging staining patterns of HEp-2 cells. A focused four-lobed mode distribution is stable and effective in optical...

  12. Multiuser Cellular Network

    CERN Document Server

    Bao, Yi; Chen, Ming

    2011-01-01

    Modern radio communication is faced with a problem about how to distribute restricted frequency to users in a certain space. Since our task is to minimize the number of repeaters, a natural idea is enlarging coverage area. However, coverage has restrictions. First, service area has to be divided economically as repeater's coverage is limited. In this paper, our fundamental method is to adopt seamless cellular network division. Second, underlying physics content in frequency distribution problem is interference between two close frequencies. Consequently, we choose a proper frequency width of 0.1MHz and a relevantly reliable setting to apply one frequency several times. We make a few general assumptions to simplify real situation. For instance, immobile users yield to homogenous distribution; repeaters can receive and transmit information in any given frequency in duplex operation; coverage is mainly decided by antenna height. Two models are built up to solve 1000 users and 10000 users situations respectively....

  13. Engineering Cellular Metabolism.

    Science.gov (United States)

    Nielsen, Jens; Keasling, Jay D

    2016-03-10

    Metabolic engineering is the science of rewiring the metabolism of cells to enhance production of native metabolites or to endow cells with the ability to produce new products. The potential applications of such efforts are wide ranging, including the generation of fuels, chemicals, foods, feeds, and pharmaceuticals. However, making cells into efficient factories is challenging because cells have evolved robust metabolic networks with hard-wired, tightly regulated lines of communication between molecular pathways that resist efforts to divert resources. Here, we will review the current status and challenges of metabolic engineering and will discuss how new technologies can enable metabolic engineering to be scaled up to the industrial level, either by cutting off the lines of control for endogenous metabolism or by infiltrating the system with disruptive, heterologous pathways that overcome cellular regulation.

  14. 基于智能天线阵接收的蜂窝CDMA网络性能分析%Performance analysis of cellular CDMA network based on smart antenna receiver

    Institute of Scientific and Technical Information of China (English)

    郑洪明; 朱为君; 毕光国

    2001-01-01

    本文分析了在频率选择性信道中基于智能天线阵接收的蜂窝CDMA网络上行链路的性能。分析基于多个小区的异步蜂窝CDMA系统,系统采用BPSK调制,并采用智能天线阵接收的RAKE合并技术。通过分析最终得到了在该环境下的闭合的CDMA系统误码率公式,结果表明基于智能天线阵接收的蜂窝CDMA性能要比不采用的好得多,并给出了误码率与系统用户数,小区数和衰落模型之间的关系,结果对于分析蜂窝CDMA系统容量具有一定的指导意义%In this paper the performance of uplink in the cellular CDMA network, based on the reception of smart antenna, is analyzed in the frequency-selective fading channel. The analysis is under the asynchronous cellular CDMA system of multiple cells, in which BPSK modulation and Rake combination based on smart antenna reception are employed. The closed-forms of average error probability are derived in this paper finally. The numerical results show that the performance of cellular CDMA system based on smart antenna is improved greatly; in addition, the final formula describes the inter-relations among BER, the user number of system, the number of cellsand fading model.

  15. Interaction between phosphoinositide turnover system and cyclic AMP pathway for the secretion of pancreastatin and somatostatin from QGP-1N cells.

    Science.gov (United States)

    Tateishi, K; Funakoshi, A; Kitayama, N; Matsuoka, Y

    1992-06-30

    It is found that secretion of pancreastatin and somatostatin from QGP-1N cells is regulated through muscarinic receptor-mediated activation of phosphatidylinositide hydrolysis system. In this report, whether the cAMP pathway interacts with the phosphoinositide turnover system for the secretion of pancreastatin and somatostatin from QGP-1N cells through muscarinic receptors was studied. Stimulation of QGP-1N cells with carbachol increased intracellular cAMP levels. The carbachol-induced increase in cAMP levels was inhibited by atropine. Calcium ionophore (A23187) and phorbol 12-myristate 13-acetate increased cAMP synthesis. Dibutyryl cAMP, forskolin and theophylline stimulated secretion of pancreastatin and somatostatin. When either dibutyryl cAMP, forskolin or theophylline was added in culture medium with A23187, phorbol ester or carbachol, a synergistic effect was found on pancreastatin and somatostatin secretion. These results suggest that interaction between the phosphoinositide turnover system and the cAMP pathway occurs in QGP-1N cells through muscarinic receptor stimulation for the secretion of pancreastatin and somatostatin.

  16. Phosphoinositide-3-kinases p110alpha and p110beta mediate S phase entry in astroglial cells in the marginal zone of rat neocortex

    Directory of Open Access Journals (Sweden)

    Rabea eMüller

    2013-03-01

    Full Text Available In cells cultured from neocortex of newborn rats, phosphoinositide-3-kinases of class I regulate the DNA synthesis in a subgroup of astroglial cells. We have studied the location of these cells as well as the kinase isoforms which facilitate the S phase entry. Using dominant negative isoforms as well as selective pharmacological inhibitors we quantified S phase entry by nuclear labeling with bromodeoxyuridine. Only in astroglial cells harvested from the marginal zone of the neocortex inhibition of phosphoinositide-3-kinases reduced the nuclear labeling with bromodeoxyuridine, indicating that neocortical astroglial cells differ in the regulation of proliferation. The two kinase isoforms p110 and p110were essential for S phase entry. p110 diminished the level of the p27Kip1 which inactivates the complex of cyclin E and CDK2 necessary for entry into the S phase. p110phosphorylated and inhibited glycogen synthase kinase-3which can prevent S-phase entry. Taken together, both isoforms mediated S phase in a subgroup of neocortical astroglial cells and acted via distinct pathways.

  17. Phosphoinositide 5- and 3-phosphatase activities of a voltage-sensing phosphatase in living cells show identical voltage dependence.

    Science.gov (United States)

    Keum, Dongil; Kruse, Martin; Kim, Dong-Il; Hille, Bertil; Suh, Byung-Chang

    2016-06-28

    Voltage-sensing phosphatases (VSPs) are homologs of phosphatase and tensin homolog (PTEN), a phosphatidylinositol 3,4-bisphosphate [PI(3,4)P2] and phosphatidylinositol 3,4,5-trisphosphate [PI(3,4,5)P3] 3-phosphatase. However, VSPs have a wider range of substrates, cleaving 3-phosphate from PI(3,4)P2 and probably PI(3,4,5)P3 as well as 5-phosphate from phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] and PI(3,4,5)P3 in response to membrane depolarization. Recent proposals say these reactions have differing voltage dependence. Using Förster resonance energy transfer probes specific for different PIs in living cells with zebrafish VSP, we quantitate both voltage-dependent 5- and 3-phosphatase subreactions against endogenous substrates. These activities become apparent with different voltage thresholds, voltage sensitivities, and catalytic rates. As an analytical tool, we refine a kinetic model that includes the endogenous pools of phosphoinositides, endogenous phosphatase and kinase reactions connecting them, and four exogenous voltage-dependent 5- and 3-phosphatase subreactions of VSP. We show that apparent voltage threshold differences for seeing effects of the 5- and 3-phosphatase activities in cells are not due to different intrinsic voltage dependence of these reactions. Rather, the reactions have a common voltage dependence, and apparent differences arise only because each VSP subreaction has a different absolute catalytic rate that begins to surpass the respective endogenous enzyme activities at different voltages. For zebrafish VSP, our modeling revealed that 3-phosphatase activity against PI(3,4,5)P3 is 55-fold slower than 5-phosphatase activity against PI(4,5)P2; thus, PI(4,5)P2 generated more slowly from dephosphorylating PI(3,4,5)P3 might never accumulate. When 5-phosphatase activity was counteracted by coexpression of a phosphatidylinositol 4-phosphate 5-kinase, there was accumulation of PI(4,5)P2 in parallel to PI(3,4,5)P3 dephosphorylation

  18. Signaling via class IA Phosphoinositide 3-kinases (PI3K in human, breast-derived cell lines.

    Directory of Open Access Journals (Sweden)

    Veronique Juvin

    Full Text Available We have addressed the differential roles of class I Phosphoinositide 3-kinases (PI3K in human breast-derived MCF10a (and iso-genetic derivatives and MDA-MB 231 and 468 cells. Class I PI3Ks are heterodimers of p110 catalytic (α, β, δ and γ and p50-101 regulatory subunits and make the signaling lipid, phosphatidylinositol (3,4,5-trisphosphate (PtdIns(3,4,5P3 that can activate effectors, eg protein kinase B (PKB, and responses, eg migration. The PtdIns(3,4,5P3-3-phosphatase and tumour-suppressor, PTEN inhibits this pathway. p110α, but not other p110s, has a number of onco-mutant variants that are commonly found in cancers. mRNA-seq data shows that MCF10a cells express p110β>>α>δ with undetectable p110γ. Despite this, EGF-stimulated phosphorylation of PKB depended upon p110α-, but not β- or δ- activity. EGF-stimulated chemokinesis, but not chemotaxis, was also dependent upon p110α, but not β- or δ- activity. In the presence of single, endogenous alleles of onco-mutant p110α (H1047R or E545K, basal, but not EGF-stimulated, phosphorylation of PKB was increased and the effect of EGF was fully reversed by p110α inhibitors. Cells expressing either onco-mutant displayed higher basal motility and EGF-stimulated chemokinesis.This latter effect was, however, only partially-sensitive to PI3K inhibitors. In PTEN(-/- cells, basal and EGF-stimulated phosphorylation of PKB was substantially increased, but the p110-dependency was variable between cell types. In MDA-MB 468s phosphorylation of PKB was significantly dependent on p110β, but not α- or δ- activity; in PTEN(-/- MCF10a it remained, like the parental cells, p110α-dependent. Surprisingly, loss of PTEN suppressed basal motility and EGF-stimulated chemokinesis. These results indicate that; p110α is required for EGF signaling to PKB and chemokinesis, but not chemotaxis; onco-mutant alleles of p110α augment signaling in the absence of EGF and may increase motility, in part, via acutely

  19. Modulation of the cellular content of metabolites in adipocytes by insulin.

    Science.gov (United States)

    Qiao, Yuhang; Tomonaga, Shozo; Matsui, Tohru; Funaba, Masayuki

    2016-03-15

    Although the insulin-mediated cell signaling pathway has been extensively examined, changes in the cellular content of metabolites currently remain unclear. We herein examined metabolite contents in 3T3-L1 adipocytes treated with insulin using a metabolomic analysis. Fifty-four compounds were detected, and the contents of metabolites from the citric acid cycle increased in response to the insulin treatment for 4 h, which was sensitive to U0126 and LY294002, inhibitors for mitogen-activated protein kinase kinase-1 and phosphoinositide 3-kinase, respectively. The cellular contents of fumaric acid and malic acid were increased more by insulin than those of citric acid and succinic acid. Time-course changes in metabolites from the citric acid cycle exhibited oscillations with a 2-h cycle. A metabolic pathway analysis also indicated that insulin affected the metabolism of alanine, aspartate and glutamate, as well as that of arginine and proline. The contents of free amino acids were slightly decreased by the insulin treatment, while the co-treatment with U0126 and LY294002 abrogated these insulin-mediated decreases. The present study revealed the unexpected accumulation of citric acid cycle metabolites in adipocytes by insulin. Our results indicate the usefulness of metabolomic analyses for obtaining a more comprehensive understanding of the regulation of metabolic pathways in cell-culture systems.

  20. Indolinone based phosphoinositide-dependent kinase-1 (PDK1) inhibitors. Part 1: design, synthesis and biological activity.

    Science.gov (United States)

    Islam, Imadul; Bryant, Judi; Chou, Yuo-Ling; Kochanny, Monica J; Lee, Wheeseong; Phillips, Gary B; Yu, Hongyi; Adler, Marc; Whitlow, Marc; Ho, Elena; Lentz, Dao; Polokoff, Mark A; Subramanyam, Babu; Wu, James M; Zhu, Daguang; Feldman, Richard I; Arnaiz, Damian O

    2007-07-15

    HTS screening identified 1 with micromolar inhibitory activity against PDK1. Optimization of 1 afforded 4i (BX-517) which has single-digit nanomolar activity against PDK1 and excellent selectivity against PKA.

  1. Thermomechanical characterisation of cellular rubber

    Science.gov (United States)

    Seibert, H.; Scheffer, T.; Diebels, S.

    2016-09-01

    This contribution discusses an experimental possibility to characterise a cellular rubber in terms of the influence of multiaxiality, rate dependency under environmental temperature and its behaviour under hydrostatic pressure. In this context, a mixed open and closed cell rubber based on an ethylene propylene diene monomer is investigated exemplarily. The present article intends to give a general idea of the characterisation method and the considerable effects of this special type of material. The main focus lies on the experimental procedure and the used testing devices in combination with the analysis methods such as true three-dimensional digital image correlation. The structural compressibility is taken into account by an approach for a material model using the Theory of Porous Media with additional temperature dependence.

  2. Mobile node localization in cellular networks

    CERN Document Server

    Malik, Yasir; Abdulrazak, Bessam; Tariq, Usman; 10.5121/ijwmn.2011.3607

    2012-01-01

    Location information is the major component in location based applications. This information is used in different safety and service oriented applications to provide users with services according to their Geolocation. There are many approaches to locate mobile nodes in indoor and outdoor environments. In this paper, we are interested in outdoor localization particularly in cellular networks of mobile nodes and presented a localization method based on cell and user location information. Our localization method is based on hello message delay (sending and receiving time) and coordinate information of Base Transceiver Station (BTSs). To validate our method across cellular network, we implemented and simulated our method in two scenarios i.e. maintaining database of base stations in centralize and distributed system. Simulation results show the effectiveness of our approach and its implementation applicability in telecommunication systems.

  3. Mobile Node Localization in Cellular Networks

    Directory of Open Access Journals (Sweden)

    Yasir Malik

    2012-01-01

    Full Text Available Location information is the major component in location based applications. This information is used in different safety and service oriented applications to provide users with services according to their Geolocation. There are many approaches to locate mobile nodes in indoor and outdoor environments. In thispaper, we are interested in outdoor localization particularly in cellular networks of mobile nodes andpresented a localization method based on cell and user location information. Our localization method is based on hello message delay (sending and receiving time and coordinate information of Base Transceiver Station (BTSs. To validate our method across cellular network, we implemented and simulated our method in two scenarios i.e. maintaining database of base stations in centralize and distributed system. Simulation results show the effectiveness of our approach and its implementation applicability in telecommunication systems.

  4. External insulation with cellular plastic materials

    DEFF Research Database (Denmark)

    Sørensen, Lars Schiøtt; Nielsen, Anker

    2014-01-01

    External thermal insulation composite systems (ETICS) can be used as extra insulation of existing buildings. The system can be made of cellular plastic materials or mineral wool. There is a European Technical guideline, ETAG 004, that describe the tests that shall be conducted on such systems....... This paper gives a comparison of systems with mineral wool and cellular plastic, based on experience from practice and literature. It is important to look at the details in the system and at long time stability of the properties such as thermal insulation, moisture and fire. Investigation of fire properties...... insulation....

  5. Study of bridge crack diagnosis based on cellular neural network%基于细胞神经网络的桥梁裂痕诊断研究

    Institute of Scientific and Technical Information of China (English)

    张福新; 李国东

    2014-01-01

    In order to detecting the bridge crack, we come up with a fixed way of bridge rift image detection by using cellular neural networks. By image processing, building rift networks and details networks and adding the model of similarity rift networks. It can avoid the problem that can not accurately detect crack by only taking the crack feature value. The experiment proved that fixed crack detect computing is easy to do, more accurate to detect the cracks on the road and can reach the standard level of current detect technique.%为了更好的监测桥梁裂痕,文章提出了一种改进的细胞神经网络桥梁裂痕图像识别方法。该方法通过一定的图像处理,建立裂痕网络和细节网络,同时增加了裂痕相似网络模型,避免了仅对裂痕特征提取信息不能准确识别裂痕的问题。实验证明,改进的裂痕识别算法实现简单,识别桥梁裂痕准确率高,达到了实时识别技术的要求。

  6. Online isolation of defects in cellular nanocomputers

    Institute of Scientific and Technical Information of China (English)

    Teijiro Isokawa; Shin'ya Kowada; Ferdinand Peper; Naotake Kamiura; Nobuyuki Matsui

    2007-01-01

    Unreliability will be a major issue for computers built from components at nanometer scales.Thus,it's to be expected that such computers will need a high degree of defect-tolerance to overcome components' defects which have arisen during the process of manufacturing.This paper presents a novel approach to defect-tolerance that is especially geared towards nanocomputers based on asynchronous cellular automata.According to this approach,defective cells are detected and isolated by small configurations that move around randomly in cellular space.These configurations,called random flies,will attach to configurations that are static,which is typical for configurations that contain defective cells.On the other hand,dynamic configurations,like those that conduct computations,will not be isolated from the rest of the cellular space by the random flies,and will be able to continue their operations unaffectedly.

  7. Cellular bioluminescence imaging.

    Science.gov (United States)

    Welsh, David K; Noguchi, Takako

    2012-08-01

    Bioluminescence imaging of live cells has recently been recognized as an important alternative to fluorescence imaging. Fluorescent probes are much brighter than bioluminescent probes (luciferase enzymes) and, therefore, provide much better spatial and temporal resolution and much better contrast for delineating cell structure. However, with bioluminescence imaging there is virtually no background or toxicity. As a result, bioluminescence can be superior to fluorescence for detecting and quantifying molecules and their interactions in living cells, particularly in long-term studies. Structurally diverse luciferases from beetle and marine species have been used for a wide variety of applications, including tracking cells in vivo, detecting protein-protein interactions, measuring levels of calcium and other signaling molecules, detecting protease activity, and reporting circadian clock gene expression. Such applications can be optimized by the use of brighter and variously colored luciferases, brighter microscope optics, and ultrasensitive, low-noise cameras. This article presents a review of how bioluminescence differs from fluorescence, its applications to cellular imaging, and available probes, optics, and detectors. It also gives practical suggestions for optimal bioluminescence imaging of single cells.

  8. Cellular neurothekeoma with melanocytosis.

    Science.gov (United States)

    Wu, Ren-Chin; Hsieh, Yi-Yueh; Chang, Yi-Chin; Kuo, Tseng-Tong

    2008-02-01

    Cellular neurothekeoma (CNT) is a benign dermal tumor mainly affecting the head and neck and the upper extremities. It is characterized histologically by interconnecting fascicles of plump spindle or epithelioid cells with ample cytoplasm infiltrating in the reticular dermis. The histogenesis of CNT has been controversial, although it is generally regarded as an immature counterpart of classic/myxoid neurothekeoma, a tumor with nerve sheath differentiation. Two rare cases of CNT containing melanin-laden cells were described. Immunohistochemical study with NKI/C3, vimentin, epithelial membrane antigen, smooth muscle antigen, CD34, factor XIIIa, collagen type IV, S100 protein and HMB-45 was performed. Both cases showed typical growth pattern of CNT with interconnecting fascicles of epithelioid cells infiltrating in collagenous stroma. One of the nodules contained areas exhibiting atypical cytological features. Melanin-laden epithelioid or dendritic cells were diffusely scattered throughout one nodule, and focally present in the peripheral portion of the other nodule. Both nodules were strongly immunoreactive to NKI/C3 and vimentin, but negative to all the other markers employed. CNT harboring melanin-laden cells may pose diagnostic problems because of their close resemblance to nevomelanocytic lesions and other dermal mesenchymal tumors. These peculiar cases may also provide further clues to the histogenesis of CNT.

  9. 基于元胞自动机理论的协同设计任务调度模型%Collaboration Design Tasks Scheduling Model Based on Cellular Automaton

    Institute of Scientific and Technical Information of China (English)

    徐鸿翔; 吴晶华; 张向华

    2011-01-01

    分析了设计任务调度的特点,提出了基于元胞自动机理论的调度模型。对元胞自动机任务调度模型进行了数学描述,对设计任务调度的策略进行了分析,建立了元胞自动机目标调度模型,通过具体算例对所提出的模型进行了验证,表明元胞自动机模型可以有效地进行任务调度的优化。%The characteristic of design tasks scheduling was analyzed,and a collaborative tasks scheduling model based on Cellular Automaton(CA) was put forward.Firstly,mathematics description was done for design tasks scheduling model based on Cellular Automaton.Secondly,the strategy for design tasks scheduling was analyzed.And so,the scheduling target model was established.Finally,a simulation experiment was carried out by using the proposed algorithm.The convergent velocity would be fast and the ability to optimize would be better.

  10. Cellular Automata Model Based on Safety Distance%基于安全距离的元胞自动机交通流模型研究

    Institute of Scientific and Technical Information of China (English)

    邱小平; 于丹; 孙若晓; 杨达

    2015-01-01

    With the traffic congestion increasing significantly, traffic safety level declines and traffic accident rate increases gradually. To improve driving safety, the length of the cellular cells is fined, and the Gipps’safe distance rule is introduced to improve the NaSch model, further, a new cellular automata traffic flow model is proposed. The Gipps’safe distance rule is widely proved to have good performance in describing the vehicle driving behavior. In addition, we use the field data to calibrate and evaluate the proposed model. The numerical simulation analysis is carried out to analyze the model. Model evaluation results show that the performance of the new model is better than NaSch model. The simulation results show that the improved model can describe the traffic flow characteristics well and can reproduce free flow, synchronized flow, congestion and other traffic phenomenon in the real traffic flow. Furthermore, the study also found that the drivers’overestimation of the maximum deceleration of vehicle ahead will lead to decreased road capacity. However, the drivers’overestimation of their own vehicle maximum deceleration will increase the capacity of the road, but is likely to cause unsafe driving behaviors and increase accident rate.%随着交通拥堵状况日益显著,整体交通安全性下降,交通事故率逐渐增大。基于提高驾驶安全性考虑,细化元胞长度,引入被广泛证明在描述车辆驾驶行为方面具有很高精度的Gipps安全距离规则,对NaSch模型进行改进,提出一个新的基于安全距离的元胞自动机交通流模型。采用实测数据对模型进行标定和评估,进一步对模型进行数值模拟分析。模型评估结果显示,新建立的模型相对NaSch模型精度更高。数值模拟结果表明,改进模型能够很好地表现交通流特性,再现实际交通中的自由流、同步流及拥堵流等交通现象。此外,还发现驾驶员对前车最大

  11. Free fall and cellular automata

    Directory of Open Access Journals (Sweden)

    Pablo Arrighi

    2016-03-01

    Full Text Available Three reasonable hypotheses lead to the thesis that physical phenomena can be described and simulated with cellular automata. In this work, we attempt to describe the motion of a particle upon which a constant force is applied, with a cellular automaton, in Newtonian physics, in Special Relativity, and in General Relativity. The results are very different for these three theories.

  12. About Strongly Universal Cellular Automata

    Directory of Open Access Journals (Sweden)

    Maurice Margenstern

    2013-09-01

    Full Text Available In this paper, we construct a strongly universal cellular automaton on the line with 11 states and the standard neighbourhood. We embed this construction into several tilings of the hyperbolic plane and of the hyperbolic 3D space giving rise to strongly universal cellular automata with 10 states.

  13. 基于元胞自动机的海上溢油扩散模拟%Simulation of marine oil spill diffusion based on cellular automata

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    利用逻辑回归算法和决策树C5.0算法分别获取溢油扩散的转换规则,并构建了基于逻辑回归的CA模型和决策树CA模型。这两个模型仅需要设置起始影像、影响因子和权重等少数的变量,便可以方便地模拟出溢油的动态变化情况。把逻辑回归CA模型和决策树CA模型应用到DeepSpill项目的海上溢油模拟实验,结果表明逻辑回归CA模型的模拟总精度达到96.4%,Kappa系数达0.893,而决策树CA模型的模拟结果更为理想,其精度和kappa系数分别提高了0.2%和0.006。利用元胞自动机能够很好地模拟并预测出海上溢油的动态变化,可以满足对溢油快速响应的要求。%Cellular automata (CA) is an effective tool for simulating geographical process. In this paper, logistic regression and decision tree algorithm (C5.0) are introduced to obtain transition rules, which are used to build logistic regression CA model and decision-tree CA model. These two models are very convenient because they only need a few variables, such as starting image, impact factors and weights. And the simulation results of oil spill can be obtained. The logistic regression CA model and decision-tree CA model are applied to simulate the movement of oil spill in Deep Spill projects. Experiment re-sults showed that the overall accuracy and Kappa coefficient of simulation results in logistic regression CA were 96.4%and 0.893.Better results could be obtained using decision-tree CA model. Its overall accuracy and kappa coefficients increased by 0.2%and 0.006. Our experiment results showed that the CA models could simulate the dynamic changes of the oil spill and meet the requirements for rapid response of governments.

  14. MIMO Communication for Cellular Networks

    CERN Document Server

    Huang, Howard; Venkatesan, Sivarama

    2012-01-01

    As the theoretical foundations of multiple-antenna techniques evolve and as these multiple-input multiple-output (MIMO) techniques become essential for providing high data rates in wireless systems, there is a growing need to understand the performance limits of MIMO in practical networks. To address this need, MIMO Communication for Cellular Networks presents a systematic description of MIMO technology classes and a framework for MIMO system design that takes into account the essential physical-layer features of practical cellular networks. In contrast to works that focus on the theoretical performance of abstract MIMO channels, MIMO Communication for Cellular Networks emphasizes the practical performance of realistic MIMO systems. A unified set of system simulation results highlights relative performance gains of different MIMO techniques and provides insights into how best to use multiple antennas in cellular networks under various conditions. MIMO Communication for Cellular Networks describes single-user,...

  15. A retinoic acid receptor beta agonist (CD2019) overcomes inhibition of axonal outgrowth via phosphoinositide 3-kinase signalling in the injured adult spinal cord.

    Science.gov (United States)

    Agudo, Marta; Yip, Ping; Davies, Meirion; Bradbury, Elizabeth; Doherty, Patrick; McMahon, Stephen; Maden, Malcolm; Corcoran, Jonathan P T

    2010-01-01

    After spinal cord injury in the adult mammal, axons do not normally regrow and this commonly leads to paralysis. Retinoic acid (RA) can stimulate neurite outgrowth in vitro of both the embryonic central and peripheral nervous system, via activation of the retinoic acid receptor (RAR) beta2. We show here that regions of the adult CNS, including the cerebellum and cerebral cortex, express RARbeta2. We show that when cerebellar neurons are grown in the presence of myelin-associated glycoprotein (MAG) which inhibits neurite outgrowth, RARbeta can be activated in a dose dependent manner by a RARbeta agonist (CD2019) and neurite outgrowth can occur via phosphoinositide 3-kinase (PI3K) signalling. In a model of spinal cord injury CD2019 also acts through PI3K signalling to induce axonal outgrowth of descending corticospinal fibres and promote functional recovery. Our data suggest that RARbeta agonists may be of therapeutic potential for human spinal cord injuries.

  16. Progesterone increases brain-derived neuroptrophic factor expression and protects against glutamate toxicity in a mitogen-activated protein kinase- and phosphoinositide-3 kinase-dependent manner in cerebral cortical explants.

    Science.gov (United States)

    Kaur, Paramjit; Jodhka, Parmeet K; Underwood, Wendy A; Bowles, Courtney A; de Fiebre, Nancyellen C; de Fiebre, Christopher M; Singh, Meharvan

    2007-08-15

    The higher prevalence and risk for Alzheimer's disease in women relative to men has been partially attributed to the precipitous decline in gonadal hormone levels that occurs in women following the menopause. Although considerable attention has been focused on the consequence of estrogen loss, and thus estrogen's neuroprotective potential, it is important to recognize that the menopause results in a precipitous decline in progesterone levels as well. In fact, progesterone is neuroprotective, although the precise mechanisms involved remain unclear. Based on our previous observation that progesterone elicits the phosphorylation of ERK and Akt, key effectors of the neuroprotective mitogen-activated protein kinase (MAPK) and phosphoinositide-3 kinase (PI3-K) pathways, respectively, we determined whether activation of either of these pathways was necessary for progesterone-induced protection. With organotypic explants (slice culture) of the cerebral cortex, we found that progesterone protected against glutamate-induced toxicity. Furthermore, these protective effects were inhibited by either the MEK1/2 inhibitor UO126 or the PI3-K inhibitor LY294002, supporting the requirement for both the MAPK and PI3-K pathways in progesterone-induced protection. In addition, at a concentration and duration of treatment consistent with our neuroprotection data, progesterone also increased the expression of brain-derived neurotrophic factor (BDNF), at the level of both protein and mRNA. This induction of BDNF may be relevant to the protective effects of progesterone, in that inhibition of Trk signaling, with K252a, inhibited the protective effects of progesterone. Collectively, these data suggest that progesterone is protective via multiple and potentially related mechanisms. (c) 2007 Wiley-Liss, Inc.

  17. 3-phosphoinositide-dependent protein kinase-1/Akt signaling represents a major cyclooxygenase-2-independent target for celecoxib in prostate cancer cells.

    Science.gov (United States)

    Kulp, Samuel K; Yang, Ya-Ting; Hung, Chin-Chun; Chen, Kuen-Feng; Lai, Ju-Ping; Tseng, Ping-Hui; Fowble, Joseph W; Ward, Patrick J; Chen, Ching-Shih

    2004-02-15

    Regarding the involvement of cyclooxygenase-2 (COX-2)-independent pathways in celecoxib-mediated antineoplastic effects, the following two issues remain outstanding: identity of the non-COX-2 targets and relative contributions of COX-2-dependent versus -independent mechanisms. We use a close celecoxib analog deficient in COX-2-inhibitory activity, DMC (4-[5-(2,5-dimethylphenyl)-3(trifluoromethyl)-1H-pyrazol-1-yl]benzene-sulfonamide), to examine the premise that Akt signaling represents a major non-COX-2 target. Celecoxib and DMC block Akt activation in PC-3 cells through the inhibition of phosphoinositide-dependent kinase-1 (PDK-1) with IC(50) of 48 and 38 micro M, respectively. The consequent effect on Akt activation is more pronounced (IC(50) values of 28 and 20 micro M, respectively), which might be attributed to the concomitant dephosphorylation by protein phosphatase 2A. In serum-supplemented medium, celecoxib and DMC cause G(1) arrest, and at higher concentrations, they induce apoptosis with relative potency comparable with that in blocking Akt activation. Moreover, the effect of daily oral celecoxib and DMC at 100 and 200 mg/kg on established PC-3 xenograft tumors is assessed. Celecoxib at both doses and DMC at 100 mg/kg had marginal impacts. However, a correlation exists between the in vitro potency of DMC and its ability at 200 mg/kg to inhibit xenograft tumor growth through the inhibition of Akt activation. Analysis of the tumor samples indicates that a differential reduction in the phospho-Akt/Akt ratio was noted in celecoxib- and DMC-treated groups vis-à-vis the control group. Together, these data underscore the role of 3-phosphoinositide-dependent protein kinase-1/Akt signaling in celecoxib-mediated in vitro antiproliferative effects in prostate cancer cells.

  18. Phosphoinositide-dependent kinase-1 inhibits TRAF6 ubiquitination by interrupting the formation of TAK1-TAB2 complex in TLR4 signaling.

    Science.gov (United States)

    Moon, Gyuyoung; Kim, Juhong; Min, Yoon; Wi, Sae Mi; Shim, Jae-Hyuck; Chun, Eunyoung; Lee, Ki-Young

    2015-12-01

    Phosphoinositide-dependent protein kinase 1 (PDK1) plays a key role in the phosphoinositide 3-kinase (PI3K)-PDK1-Akt pathway that induces cell survival and cardiovascular protections through anti-apoptosis, vasodilation, anti-inflammation, and anti-oxidative stress activities. Although several reports have proposed the negative role of PDK1 in Toll-like receptor 4 (TLR4) signaling, the molecular mechanism is still unknown. Here we show that PDK1 inhibits tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6) ubiquitination by interrupting the complex between transforming growth factor beta-activated kinase 1 (TAK1) and TAK1 binding protein 2 (TAB2), which negatively regulates TAK1 activity. The overexpression of PDK1 in 293/TLR4 cells resulted in suppressions of nuclear factor kappa B (NF-κB) activation and production of proinflammatory cytokines including interleukin (IL)-6 and TNF-α in response to lipopolysaccharide stimulation. Conversely, THP-1 human monocytes transiently cultured in low glucose medium displayed down-regulated PDK1 expression, and significantly enhanced TLR4-mediated signaling for the activation of NF-κB, demonstrating a negative role of PDK1. Biochemical studies revealed that PDK1 significantly interacted with TAK1, resulting in the inhibition of the association of TAB2 with TAK1, which led to the attenuation of TRAF6 ubiquitination. Moreover, PDK1-knockdown THP-1 cells displayed enhancement of downstream signals, activation of NF-κB, and increased production of pro-inflammatory cytokines IL-6, IL-1β, and TNF-α, which potentially led to the up-regulation of NF-κB-dependent genes in response to TLR4 stimulation. Collectively, the results demonstrate that PDK1 inhibits the formation of the TAK1-TAB2-TRAF6 complex and leads to the inhibition of TRAF6 ubiquitination, which negatively regulates the TLR4-mediated signaling for NF-κB activation.

  19. Improved Case-Based Reasoning Based Cellular Automaton for Simulating Land Cover Change%改进的案例推理CA模型及土地覆盖变化模拟

    Institute of Scientific and Technical Information of China (English)

    张琴; 张友静; 张滔

    2012-01-01

    This paper presents an improved Case-Based Reasoning based Cellular Automata model (CBR-CA) in modeling multiple land covers changes. Currently, various research communities have tried to build and apply mathematic models with CBR or CA as systemic method to study concerning specific geo-scientific problems. However.original CBR-CA model has problems in modeling numerous class changes,especially in modeling land cover changes with large region and long time. In this paper,an improved CBR-CA is designed to calculate conversion probabilities for computing multiple land cover. Firstly, the macro transition probability of each class is added to the objective function, which can express the characteristic of multiple class changes. Then, considering the time weight, which can reflect the space-time changes of land cover, the final probability function is derived by both. In addition, due to variation of land cover types and their spatial relationships in complex geography changes, Monte Carlo is made use of deciding the final transition classes. This model has been applied to simulate the land cover changes of the source of the Yellow River in 1995,2000 and 2006,and has been applied to predict this region in 2012 and 2018 by building the historical case-based database with the land cover data in 1977 and 1985. The simulated and actual patterns are basic consistent in amounts,accounting for 0.002% ,0.012% and 0.005% of the total error,respectively, the space accuracies totally beyond 70%. The result indicates that this model can simulate and predict the land cover changes which are with multiple classes and with long time.%对基于案例推理的元胞自动机模型(CBR-CA)进行改进,将各类别的宏观转移概率添加到目标函数中,体现各类别的转变特征,并增加时间权重来确定转移概率,实现时间尺度上的模拟;由于土地覆盖变化的多样性和空间结构的复杂性,利用Monte Carlo(M-C)法确定土地覆盖的最终转换

  20. 蜂窝网络单基站定位技术的研究与实现%Research and implementation of cellular network single base station positioning technology

    Institute of Scientific and Technical Information of China (English)

    秦艳珊; 宁彬; 徐凯; 谷琼

    2015-01-01

    Base station positioning has become a hotspot of mobile software development, this paper studies the mobile cellular network communication principle, acquisition of base station information, single base station positioning technology, and the basic principle and realization method for map marking. By creating a Json string, activating mobile phone GPRS, accessing Google servers,the main information of single base station is obtained, then the latitude and longitude of the base station is obtained, and mobile phone positioning technology is realized.%基站定位已成为手机软件研发的热点。研究了手机蜂窝网络通信原理、基站信息的获取、单基站定位技术以及地图标示的基本原理与实现方法。通过创建Json串、激活手机GPRS、访问google服务器等获取单基站的主要信息,进而获得基站的经纬度,实现了手机定位技术。