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Sample records for tgfbeta1 signaling attenutates

  1. Inhibition of TGFbeta1 Signaling Attenutates ATM Activity inResponse to Genotoxic Stress

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    Kirshner, Julia; Jobling, Michael F.; Pajares, Maria Jose; Ravani, Shraddha A.; Glick, Adam B.; Lavin, Martin J.; Koslov, Sergei; Shiloh, Yosef; Barcellos-Hoff, Mary Helen

    2006-09-15

    Ionizing radiation causes DNA damage that elicits a cellular program of damage control coordinated by the kinase activity of ataxia telangiectasia mutated protein (ATM). Transforming growth factor {beta}1 (TGF{beta}), which is activated by radiation, is a potent and pleiotropic mediator of physiological and pathological processes. Here we show that TGF{beta} inhibition impedes the canonical cellular DNA damage stress response. Irradiated Tgf{beta}1 null murine epithelial cells or human epithelial cells treated with a small molecule inhibitor of TGF{beta} type I receptor kinase exhibit decreased phosphorylation of Chk2, Rad17 and p53, reduced {gamma}H2AX radiation-induced foci, and increased radiosensitivity compared to TGF{beta} competent cells. We determined that loss of TGF{beta} signaling in epithelial cells truncated ATM autophosphorylation and significantly reduced its kinase activity, without affecting protein abundance. Addition of TGF{beta} restored functional ATM and downstream DNA damage responses. These data reveal a heretofore undetected critical link between the microenvironment and ATM that directs epithelial cell stress responses, cell fate and tissue integrity. Thus, TGF{beta}1, in addition to its role in homoeostatic growth control, plays a complex role in regulating responses to genotoxic stress, the failure of which would contribute to the development of cancer; conversely, inhibiting TGF{beta} may be used to advantage in cancer therapy.

  2. beta-Catenin signaling is required for TGF-beta(1)-induced extracellular matrix production by airway smooth muscle cells

    NARCIS (Netherlands)

    Baarsma, Hoeke A.; Menzen, Mark H.; Halayko, Andrew J.; Meurs, Herman; Kerstjens, Huib A. M.; Gosens, Reinoud

    2011-01-01

    Baarsma HA, Menzen MH, Halayko AJ, Meurs H, Kerstjens HA, Gosens R. beta-Catenin signaling is required for TGF-beta(1)-induced extracellular matrix production by airway smooth muscle cells. Am J Physiol Lung Cell Mol Physiol 301: L956-L965, 2011. First published September 9, 2011; doi:

  3. Evidence for TGF-beta1 and bleomycin intracellular signaling through autocrine regulation of Smad 3 binding to the proximal promoter of the Smad 7 gene.

    Science.gov (United States)

    Cutroneo, Kenneth R

    2006-04-01

    Both Bleomycin and TGF-beta1 increase the transcription of the COL1A1 gene. Bleomycin acts through TGF-beta1. Bleomycin stimulates the COL1A1 promoter through the distal TGF-beta response element by intracellular and extracellular signaling. As demonstrated in this manuscript, Bleomycin's intracellular signaling can be explained by a decrease of Smad 3 transcription factor binding to the SBE located in the proximal promoter of the inhibitory Smad 7 gene. This would result in TGF-beta1-induced activated SMADS, which would result in more collagen. Bleomycin's extracellular signaling results from the secretion of more latent TGF-beta produced by lung fibroblasts and cleaved to active TGF-beta extracellularly. Since the TGF-beta genes are auto-induced in human embryonic IMR-90 lung fibroblasts, this study indicates an autocrine mechanism to maintain homeostasis in vivo for fibroblasts and other cell types, which produce TGF-beta1 to limit the fibrogenic response to TGF-beta1 and Bleomycin. (c) 2005 Wiley-Liss, Inc.

  4. Radioinduced intestinal fibrosis: from molecular mechanisms to therapy applications. Contribution of the TGF--{beta}1, of the CTGF and of the transduction pathway of the Rho/ROCK signal; La fibrose intestinale radio-induite: des mecanismes moleculaires aux applications therapeutiques. Roles du TGF-{beta}1, du CTGF et de la voie de transduction du signal Rho/ROCK

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    Haydont, V

    2006-12-15

    Delayed radiation enteritis is an intestinal fibrosis induced by accidental or therapeutic radiation for pelvic and abdominal cancer treatments. Studies of molecular mechanisms involved in the development and maintenance of fibrosis have showed the respective contribution of CTGF, low TGF-{beta}1 concentrations and Rho/ROCK pathway. Thus, based on the relationship between CTGF, TGF-{beta}1 and Rho pathway, 2 therapeutics strategies have been develop. First, a pravastatin curative gift leads to a fibro-lysis involving an inhibition of Rho and in cascade a reduction of CTGF expression and extracellular matrix deposition. The data suggest that reversal of established radiation fibrosis in the gut is possible. Second, a pravastatin prophylactic gift prevents the installation of a chronic fibrosis but does not protect the tumor. On the base of these results, the radiation therapy department of the Institut Gustave Roussy will soon initiate 2 clinical trials. (author)

  5. Transforming growth factor-beta1 (TGF-beta1) induces human osteoclast apoptosis by up-regulating Bim.

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    Houde, Nicolas; Chamoux, Estelle; Bisson, Martine; Roux, Sophie

    2009-08-28

    Transforming growth factor-beta1 (TGF-beta1) is the most abundant TGF-beta isoform detected in bone and is an important functional modulator of osteoclasts. TGF-beta1 can induce osteoclast apoptosis; however, the apoptotic pathways involved in this process are not known. We show here that human osteoclasts express both type-I and type-II TGF-beta receptors. In the absence of survival factors, TGF-beta1 (1 ng/ml) induced osteoclast apoptosis. The expression of activated caspase-9, but not that of caspase-8, was increased by TGF-beta1 stimulation, and the rate of TGF-beta1-induced apoptosis was significantly lower in the presence of a caspase-9 inhibitor. To study further the mechanisms involved in TGF-beta1-induced osteoclast apoptosis, we investigated TGF-beta1 signaling, which primarily involves the Smad pathway, but also other pathways that may interfere with intracellular modulators of apoptosis, such as mitogen-activated protein (MAP) kinases and Bcl2 family members. We show here that early events consisted of a trend toward increased expression of extracellular signal-regulated kinase (ERK), and then TGF-beta1 significantly induced the activation of p38 and Smad2 in a time-dependent manner. These signaling cascades may activate the intrinsic apoptosis pathway, which involves Bim, the expression of which was increased in the presence of TGF-beta1. Furthermore, the rate of TGF-beta1-induced osteoclast apoptosis was lower when Bim expression was suppressed, and inhibiting the Smad pathway abolished Bim up-regulation following TGF-beta stimulation. This could correspond to a regulatory mechanism involved in the inhibition of osteoclast activity by TGF-beta1.

  6. Calcium input potentiates the transforming growth factor (TGF)-beta1-dependent signaling to promote the export of inorganic pyrophosphate by articular chondrocyte.

    Science.gov (United States)

    Cailotto, Frederic; Reboul, Pascal; Sebillaud, Sylvie; Netter, Patrick; Jouzeau, Jean-Yves; Bianchi, Arnaud

    2011-06-03

    Transforming growth factor (TGF)-β1 stimulates extracellular PP(i) (ePP(i)) generation and promotes chondrocalcinosis, which also occurs secondary to hyperparathyroidism-induced hypercalcemia. We previously demonstrated that ANK was up-regulated by TGF-β1 activation of ERK1/2 and Ca(2+)-dependent protein kinase C (PKCα). Thus, we investigated mechanisms by which calcium could affect ePP(i) metabolism, especially its main regulating proteins ANK and PC-1 (plasma cell membrane glycoprotein-1). We stimulated articular chondrocytes with TGF-β1 under extracellular (eCa(2+)) or cytosolic Ca(2+) (cCa(2+)) modulations. We studied ANK, PC-1 expression (quantitative RT-PCR, Western blotting), ePP(i) levels (radiometric assay), and cCa(2+) input (fluorescent probe). Voltage-operated Ca(2+)-channels (VOC) and signaling pathways involved were investigated with selective inhibitors. Finally, Ank promoter activity was evaluated (gene reporter). TGF-β1 elevated cCa(2+) and ePP(i) levels (by up-regulating Ank and PC-1 mRNA/proteins) in an eCa(2+) dose-dependent manner. TGF-β1 effects were suppressed by cCa(2+) chelation or L- and T-VOC blockade while being mostly reproduced by ionomycin. In the same experimental conditions, the activation of Ras, the phosphorylation of ERK1/2 and PKCα, and the stimulation of Ank promoter activity were affected similarly. Activation of SP1 (specific protein 1) and ELK-1 (Ets-like protein-1) transcription factors supported the regulatory role of Ca(2+). SP1 or ELK-1 overexpression or blockade experiments demonstrated a major contribution of ELK-1, which acted synergistically with SP1 to activate Ank promoter in response to TGF-β1. TGF-β1 promotes input of eCa(2+) through opening of L- and T-VOCs, to potentiate ERK1/2 and PKCα signaling cascades, resulting in an enhanced activation of Ank promoter and ePP(i) production in chondrocyte.

  7. Proliferation of Estrogen Receptor alpha Positive Mammary Epithelial Cells is Restrained by TGFbeta1 in Adult Mice

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    Ewan, Kenneth B.R.; Oketch-Rabah, Hellen A.; Ravani, Shraddha A.; Shyamala, G.; Moses, Harold L.; Barcellos-Hoff, Mary Helen

    2005-03-03

    Transforming growth factor {beta}1 (TGF{beta}1) is a potent inhibitor of mammary epithelial proliferation. In human breast, estrogen receptor {alpha} (ER{alpha}) cells rarely co-localize with markers of proliferation, but their increased frequency correlates with breast cancer risk. To determine whether TGF{beta}1 is necessary for the quiescence of ER{alpha}-positive population, we examined mouse mammary epithelial gland at estrus. Approximately 35% of cells showed TGF{beta}1 activation, which co-localized with nuclear receptor-phosphorylated Smad 2/3, indicating that TGF{beta} signaling is autocrine. Furthermore, nuclear Smad co-localized with nuclear ER{alpha}. To test whether TGF{beta} was functional, we examined genetically engineered mice with different levels of TGF{beta}1. ER{alpha} co-localization with markers of proliferation (i.e. Ki-67 or BrdU) at estrus was significantly increased in the mammary glands of Tgf{beta}1 C57/bl/129SV heterozygote mice. This relationship was maintained following pregnancy, but was absent at puberty. Conversely, mammary epithelial expression of constitutively active TGF{beta}1 via the MMTV promoter suppressed proliferation of ER{alpha} positive cells. Thus, TGF{beta}1 activation functionally restrains ER{alpha} positive cells from proliferating in adult mammary gland. Accordingly, we propose that TGF{beta}1 dysregulation may promote proliferation of ER{alpha} positive cells associated with breast cancer risk in humans.

  8. TGF-{beta}1 increases invasiveness of SW1990 cells through Rac1/ROS/NF-{kappa}B/IL-6/MMP-2

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    Binker, Marcelo G. [Departments of Medicine and Physiology, University of Toronto, Toronto, Ontario, Canada M5S 1A8 (Canada); CBRHC Research Center, Buenos Aires (Argentina); Binker-Cosen, Andres A. [CBRHC Research Center, Buenos Aires (Argentina); Gaisano, Herbert Y. [Departments of Medicine and Physiology, University of Toronto, Toronto, Ontario, Canada M5S 1A8 (Canada); Cosen, Rodica H. de [CBRHC Research Center, Buenos Aires (Argentina); Cosen-Binker, Laura I., E-mail: laura.cosen.binker@utoronto.ca [Departments of Medicine and Physiology, University of Toronto, Toronto, Ontario, Canada M5S 1A8 (Canada); CBRHC Research Center, Buenos Aires (Argentina)

    2011-02-04

    Research highlights: {yields} Rac1 mediates TGF-{beta}1-induced SW1990 invasion through MMP-2 secretion and activation. {yields} NADPH-generated ROS act downstream of Rac1 in TGF-{beta}1-challenged SW1990 cells. {yields} TGF-{beta}1-stimulated ROS activate NF-{kappa}B in SW1990 cells. {yields} NF{kappa}B-induced IL-6 release is required for secretion and activation of MMP-2 in SW1990 cells. -- Abstract: Human pancreatic cancer invasion and metastasis have been found to correlate with increased levels of active matrix metalloproteinase 2 (MMP-2). The multifunctional cytokine transforming growth factor beta 1 (TGF-{beta}1) has been shown to increase both secretion of MMP-2 and invasion by several pancreatic cancer cell types. In the present study, we investigated the signaling pathway involved in TGF-{beta}1-promoted MMP-2 secretion and invasion by human pancreatic cancer cells SW1990. Using specific inhibitors, we found that stimulation of these tumor cells with TGF-{beta}1 induced secretion and activation of the collagenase MMP-2, which was required for TGF-{beta}1-stimulated invasion. Our results also indicate that signaling events involved in TGF-{beta}1-enhanced SW1990 invasiveness comprehend activation of Rac1 followed by generation of reactive oxygen species through nicotinamide adenine dinucleotide phosphate-oxidase, activation of nuclear factor-kappa beta, release of interleukin-6, and secretion and activation of MMP-2.

  9. Therapies for bleomycin induced lung fibrosis through regulation of TGF-beta1 induced collagen gene expression.

    Science.gov (United States)

    Cutroneo, Kenneth R; White, Sheryl L; Phan, Sem H; Ehrlich, H Paul

    2007-06-01

    This review describes normal and abnormal wound healing, the latter characterized by excessive fibrosis and scarring, which for lung can result in morbidity and sometimes mortality. The cells, the extracellular matrix (ECM) proteins, and the growth factors regulating the synthesis, degradation, and deposition of the ECM proteins will be discussed. Therapeutics with particular emphasis given to gene therapies and their effects on specific signaling pathways are described. Bleomycin (BM), a potent antineoplastic antibiotic increases TGF-beta1 transcription, TGF-beta1 gene expression, and TGF-beta protein. Like TGF-beta1, BM acts through the same distal promoter cis-element of the COL1A1 gene causing increased COL1 synthesis and lung fibrosis. Lung fibroblasts exist as subpopulations with one subset predominantly responding to fibrogenic stimuli which could be a specific cell therapeutic target for the onset and development of pulmonary fibrosis.

  10. TGF-beta1-induced Smad 3 binding to the Smad 7 gene: knockout of Smad 7 gene transcription by sense phosphorothioate oligos, autoregulation, and effect on TGF-beta1 secretion: bleomycin acts through TGF-beta1.

    Science.gov (United States)

    Cutroneo, Kenneth R; Phan, Sem H

    2003-06-01

    Bleomycin produces its fibrogenic effect, at least in part, by TGF-beta1 secretion. Treatment of IMR-90 human embryonic lung fibroblasts with bleomycin at 0.5 microg/ml results in a 1.6-fold increase of TGF-beta1 as determined by a specific ELISA assay for TGF-beta1 after acidification of the conditioned media. This elevation of TGF-beta1 secretion is furthermore enhanced in vivo by TGF-beta1 autoinduction of the TGF-beta1 gene. To demonstrate TGF-beta1 autoinduction, the fibroblasts were pretreated with 12.5 ng/ml TGF-beta1, washed extensively to remove any residual TGF-beta1, and then allowed to incubate for 24 h in AIM V synthetic serum-free media. The media when assayed using the ELISA assay contained a 1.6-fold increase of TGF-beta1. The distal promoter of the human TGF-beta1 gene contains a Smad 3 element (CAGGACA), which is homologous to the Smad 3 binding element motif (CAGA). The nuclear extracts of human embryonic lung fibroblasts treated for either 15 min or 24 h with TGF-beta1 did not demonstrate specificity of binding of a protein(s) to the homologous Smad 3 element as determined by cold wild-type oligodeoxynucleotide competition experiments. However, specific Smad 3 binding to the Smad 3 element (GTCTAGAC) found in proximal promoter of the Smad 7 gene was observed by cold oligo competition and supershift assays using a goat polyclonal Smad 3 antibody in the presence and absence of an N-terminal Smad 3 peptide. To determine the functionality of this Smad 3 binding to the Smad 3 element in the proximal promoter of the Smad 7 inhibitory gene to TGF-beta1 secretion, fibroblasts were transiently pretransfected with double-stranded phosphorothioate oligo "decoys" containing the Smad 7/Smad 3 element in the presence of plasmin to convert latent TGF-beta1 to active TGF-beta1. Under these conditions, which simulate the in vivo situation of 2.2-fold increase of total active TGF-beta1 was observed. Fibroblasts were also pretransfected with these double-stranded oligo "decoys," washed, then treated with TGF-beta1, washed and incubated in AIM V for an additional 24 h. In this latter experiment, a superinduction of TGF-beta1 secretion was observed. We propose that these oligo "decoys" bind Smad 3 preventing this initiation factor from binding to the Smad 7/Smad 3 element thereby decreasing the transcription of the Smad 7 gene. The decrease of the inhibitory Smad 7 would result in less binding of this Smad inhibitor to the Type I TGF-beta receptor and less antagonism of active TGF-beta1, more autoinduction of the TGF-beta1 gene, and more of the fibrogenic effects of TGF-beta1. Copyright 2003 Wiley-Liss, Inc.

  11. TGF-beta1 and WISP-1/CCN-4 can regulate each other's activity to cooperatively control osteoblast function.

    Science.gov (United States)

    Inkson, Colette A; Ono, Mitsuaki; Kuznetsov, Sergei A; Fisher, Larry W; Robey, Pamela Gehron; Young, Marian F

    2008-08-01

    Wnt-induced secreted protein-1 (WISP-1), like other members of the CCN family, is expressed in skeletal tissues. Its mechanism of action remains unknown. Expression of WISP-1 was analyzed in human bone marrow stroma cells (hBMSC) by RT-PCR. We identified two major transcripts corresponding to those of full-length WISP-1, and of the splice variant WISP-1va which lacks a putative BMP/TGF-beta binding site. To investigate the function of WISP-1 in bone, hBMSC cultures were treated with recombinant human (rh)WISP-1 and analyzed for proliferation and osteogenic differentiation. WISP-1 treatment increased both BrdU incorporation and alkaline phosphatase (AP) activity. Considering the known functional synergy found between the TGF-beta super-family and members of the CCN family, we next tested the effect of WISP-1 on TGF-beta1 activity. We found that rhWISP-1 could reduce rhTGF-beta1 induced BrdU incorporation. Similarly, rhTGF-beta1 inhibited rhWISP-1 induction of AP activity. To explore functional differences between the WISP-1 variants, WISP-1 or WISP-1va were transfected into hBMSC. Both variants could strongly induce BrdU incorporation. However, there were no effects of either variant on AP activity without an additional osteogenic stimulus such as TGF-beta1. Taken together our results suggest a functional relationship between WISP-1 and TGF-beta1. To further define this relationship we analyzed the effect of WISP-1 on TGF-beta signaling. rhWISP-1 significantly reduced TGF-beta1 induced phosphorylation of Smad-2. Our data indicates that full-length WISP-1 and its variant WISP-1va are modulators of proliferation and osteogenic differentiation, and may be novel regulators of TGF-beta1 signaling in osteoblast-like cells.

  12. Boswellia serrata and Salvia miltiorrhiza extracts reduce DMN-induced hepatic fibrosis in mice by TGF-beta1 downregulation.

    Science.gov (United States)

    Sferra, R; Vetuschi, A; Catitti, V; Ammanniti, S; Pompili, S; Melideo, D; Frieri, G; Gaudio, E; Latella, G

    2012-10-01

    Hepatic fibrosis is characterised by a progressive accumulation of fibrillar extracellular matrix (ECM) proteins, including collagen that occurs in chronic liver diseases. Transforming growth factor-beta1 (TGF-beta)/Smad3 signalling plays a major role in tissue fibrogenesis acting as a potent stimulus of ECM accumulation. To evaluate the effects of a combined therapy with anti-inflammatory Boswellia and anti-fibrotic Salvia extracts on the course of chronic hepatitis-associated fibrosis induced by dimethylnitrosamine (DMN) in mice, as well as on the hepatic expression of TGF-beta1 and Smad proteins. Chronic hepatitis-associated fibrosis was induced in mice by intraperitoneal DMN administration. Mice were assigned to 5 groups: controls; DMN without any treatment; DMN treated orally with Boswellia extracts (50 mg/kg/day); DMN treated orally with Salvia extracts (150 mg/ kg/day); DMN treated orally with both Boswellia (50 mg/kg/day) and Salvia extracts (150 mg/kg/ day). The liver was excised for macroscopic examination and histological, morphometric and immunohistochemical (IHC) analyses. For IHC, alpha-smooth muscle actin (alpha-SMA), collagen types I-III, TGF-beta1, connective tissue growth factor (CTGF), Smad3, Smad7, CD3, PCNA and TUNEL antibodies were used. The combined oral administration of Boswellia and Salvia extracts improved the course and macroscopic findings of DMN-induced chronic hepatitis-associated fibrosis. The histological severity of the hepatic fibrosis showed a marked improvement following treatment and was associated with a reduction in the hepatic expression of alpha-SMA, collagen I-III, CTGF, TGF-beta1, Smad3, and Smad7. These data demonstrate that co-treatment of Boswellia plus Salvia extracts is effective in preventing hepatic fibrosis in DMN-induced chronic hepatitis. The anti-fibrotic properties are mainly related to Salvia extracts and appear to be mediated by the inhibition of the TGF-beta1/Smad3 pathway.

  13. Loss of expression of TGF-beta1, TbetaRI, and TbetaRII correlates with differentiation in human oral squamous cell carcinomas.

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    Mincione, Gabriella; Di Marcantonio, Maria Carmela; Artese, Luciano; Vianale, Giovina; Piccirelli, Alessandro; Piccirilli, Marcello; Perrotti, Vittoria; Rubini, Corrado; Piattelli, Adriano; Muraro, Raffaella

    2008-02-01

    Despite advances in biological and molecular characteristics, the prognosis of oral squamous cell carcinomas is still very unfavourable and is based on the classical clinicopathological parameters. However, tumors with similar clinicopathological characteristics may differ dramatically in their clinical outcome. Thus, the identification of novel prognostic factors is necessary to improve prognostic and therapeutic approaches. Transforming growth factor-beta1 (TGF-beta1) is a potent growth inhibitor of epithelial cell proliferation, thus, inactivation of TGF-beta1 signalling may play a role in cancer. The expression levels of TGF-beta1 and its type I and type II receptors (TbetaRI and TbetaRII) were assessed by immunohistochemical and Western blot analyses in 22 oral squamous cell carcinoma lesions, in their normal adjacent mucosa and in the squamous carcinoma cell lines FaDu and CAL27. Immunohistochemistry on 22 oral carcinomas and case-matched normal oral mucosae demonstrated that TGF-beta1, TbetaRI, and TbetaRII were intensively and homogeneously expressed in all normal epithelia. In contrast, TGF-beta1 and its receptors were significantly reduced in poorly (G3) differentiated tumors as compared to moderately (G2) and well differentiated (G1) lesions (p=2.8 x 10(-3), p=1.3 x 10(-3), p=2.8 x 10(-3) and p=1.3 x 10(-3), respectively). The progressive reduction of the expression levels was confirmed by Western blotting. The oral squamous carcinoma cell lines Cal27 and FaDu demonstrated a reduced and a lack of TbetaRI expression, respectively. A significant decrease of TbetaRII expression, as compared to Cal27 cells, was shown in FaDu cells. Thus, the decreased expression of TbetaRII combined with the absence of TbetaRI could account for the resistance of FaDu cells to the growth-inhibiting effect of TGF-beta1. TGF-beta1 and TGF-beta1 receptor expression significantly decreased as tumors became less differentiated and thus more aggressive, suggesting a functional role

  14. In vivo evaluation of expression of TGF{beta}1 in the irradiated heart; Expressao da proteina TGF{beta}1 em coracao irradiado in vivo

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    Affonso Junior, Renato Jose [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Escola Paulista de Medicina. Dept. Diagnostico por Imagem; Oshima, Celina Tizuko Fujiyama; Silva, Maria Regina Regis [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Escola Paulista de Medicina. Setor de Anatomia Patologica; Kimura, Edna Teruko [Sao Paulo Univ., SP (Brazil). Inst. de Ciencias Biomedicas. Dept. de Histologia; Egami, Mizue Imoto [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Escola Paulista de Medicina. Dept. de Morfologia; Segreto, Roberto Araujo; Segreto, Helena Regina Comodo [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Escola Paulista de Medicina. Setor de Radioterapia]. E-mail: hrcs.dmed@unifesp.epm.br

    2004-04-01

    The objectives of this study were to assess the latent and active TGF{beta}1 localization in the heart, to evaluate whether or not radiation induces latent TGF{beta}1 activation, and to study the distribution of collagen fibers in the irradiated heart. Thirty-two C 57 BL mice were randomly assigned in two groups: GI (non irradiated animals) and GII (irradiated animals). The mice from G II received a single whole-body radiation dose of 7 Gy, using a {sup 60}Co source at a dose rate of 0.97 Gy/min. The animals were sacrificed by cervical dislocation at 1, 14, 30 and 90 days after irradiation. The irradiated hearts showed: nuclear changes and muscle cells with decreased striations; significant increase in the collagen deposition 90 days after irradiation; latent TGF{beta}1 activation in the cardio myocytes and connective tissue cells after irradiation. Our results show the importance of TGF{beta}1 protein in the process of radiation-induced heart fibrosis and suggest that cardio myocytes and connective cells may play a role in this mechanism acting as cellular sources of active TGF{beta}1. (author)

  15. TGF-beta1 expression in EL4 lymphoma cells overexpressing growth hormone.

    Science.gov (United States)

    Farmer, John T; Weigent, Douglas A

    2006-03-01

    Our previous studies show that growth hormone overexpression (GHo) upregulates the expression of the IGF-1R and IGF-2R resulting in the protection of the EL4 lymphoma cell line from apoptosis. In this study, we report that GHo also increases TGF-beta1 protein expression measured by luciferase promoter assay, Western analysis, and ELISA. Further, the data show that antibody to TGF-betaR2 decreases TGF-beta1 promoter activity to the level of vector alone control cells. GHo cells treated with (125)I-rh-latent TGF-beta1 showed increased activation of latent TGF-beta1 as measured by an increase in the active 24kDa, TGF-beta1 compared to vector alone control cells. The ability of endogenous GH to increase TGF-beta1 expression is blocked in EL4 cells by antisense but not sense oligodeoxynucleotides or in cells cultured with antibody to growth hormone (GH). The data suggest that endogenous GH may protect from apoptosis through the IGF-1R receptor while limiting cellular growth through increased expression and activation of TGF-beta1.

  16. The antifibrotic effects of TGF-{beta}1 siRNA on hepatic fibrosis in rats

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    Lang, Qing; Liu, Qi [Key Laboratory of Molecular Biology for Infectious Diseases, Ministry of Education, Instituted for Virus Hepatitis and Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing (China); Xu, Ning [The Second Hospital of YuLin, Shanxi Province (China); Qian, Ke-Li; Qi, Jing-Hu; Sun, Yin-Chun; Xiao, Lang [Key Laboratory of Molecular Biology for Infectious Diseases, Ministry of Education, Instituted for Virus Hepatitis and Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing (China); Shi, Xiao-Feng, E-mail: sxff2003@yahoo.com.cn [Key Laboratory of Molecular Biology for Infectious Diseases, Ministry of Education, Instituted for Virus Hepatitis and Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing (China)

    2011-06-10

    Highlights: {yields} We constructed CCL4 induced liver fibrosis model successfully. {yields} We proofed that the TGF-{beta}1 siRNA had a definite therapy effect to CCL4 induced liver fibrosis. {yields} The therapy effect of TGF-{beta}1 siRNA had dose-dependent. -- Abstract: Background/aims: Hepatic fibrosis results from the excessive secretion of matrix proteins by hepatic stellate cells (HSCs), which proliferate during fibrotic liver injury. Transforming growth factor (TGF)-{beta}1 is the dominant stimulus for extracellular matrix (ECM) production by stellate cells. Our study was designed to investigate the antifibrotic effects of using short interference RNA (siRNA) to target TGF-{beta}1 in hepatic fibrosis and its mechanism in rats exposed to a high-fat diet and carbon tetrachloride (CCL4). Methods: A total of 40 healthy, male SD (Sprague-Dawley) rats were randomly divided into five even groups containing of eight rats each: normal group, model group, TGF-{beta}1 siRNA 0.125 mg/kg treatment group, TGF-{beta}1 siRNA 0.25 mg/kg treatment group and TGF-{beta}1 siRNA negative control group (0.25 mg/kg). CCL4 and a high-fat diet were used for 8 weeks to induce hepatic fibrosis. All the rats were then sacrificed to collect liver tissue samples. A portion of the liver samples were soaked in formalin for Hematoxylin-Eosin staining, classifying the degree of liver fibrosis, and detecting the expression of type I and III collagen and TGF-{beta}1; the remaining liver samples were stored in liquid nitrogen to be used for detecting TGF-{beta}1 by Western blotting and for measuring the mRNA expression of type I and III collagen and TGF-{beta}1 by quantitative real-time polymerase chain reaction. Results: Comparing the TGF-{beta}1 siRNA 0.25 mg/kg treatment group to the model group, the TGF-{beta}1 siRNA negative control group and the TGF-{beta}1 siRNA 0.125 mg/kg treatment group showed significantly reduced levels of pathological changes, protein expression and the mRNA expression of TGF-{beta}1, type I collagen and type III collagen (P < 0.01). Conclusions: Using siRNA to target TGF-{beta}1 can inhibit the expression of TGF-{beta}1 and attenuate rat hepatic fibrosis induced by a high-fat diet and CCL4. A possible mechanism is through the down-regulation of TGF-{beta}1 expression, which could inhibit HSC activation, as well as the proliferation and collagen production of collagen reducing, so that collagen deposition in the liver is reduced.

  17. Effects of TGF-beta 1 on interleukin profile of human dental pulp and odontoblasts.

    Science.gov (United States)

    Pääkkönen, Virve; Vuoristo, Jussi; Salo, Tuula; Tjäderhane, Leo

    2007-10-01

    Transforming growth factor-beta 1 (TGF-beta1) is the most extensively studied growth factor in dentin-pulp complex, with pleiotropic effects on pulp response and healing. Our main objective was to analyze the expression profile of pulp tissue and odontoblasts, and the effects of TGF-beta1 on these profiles in cultured human pulp and odontoblasts with a specific interest in the anti- and pro-inflammatory cytokines. For that purpose, pulps and odontoblasts were cultured for different time periods, and microarray was performed to both cultured and native samples. Of cytokines, various interleukins (IL) were confirmed by RT-PCR, and in +/- TGF-beta1 treated pulps also by antibody array. Pro-inflammatory IL-7, -12alpha and -16 mRNAs were detected in native pulp. The expression levels of pro-inflammatory IL-1alpha, -1beta, -6 and -8 were clearly induced after TGF-beta1 treatment, while no anti-inflammatory cytokines were induced. Of all pulpal interleukins analyzed IL-6 and -8 were present at the highest levels in conditioned pulp tissue media. In native odontoblasts pro-inflammatory IL-6 and -7 mRNAs were detected, and in cultured odontoblasts pro-inflammatory IL-8 mRNA showed over 20-fold transient induction after TGF-beta1 treatment. Our results demonstrate that TGF-beta1 is a potent regulator of pro-inflammatory responses and defensive reactions in dentin-pulp complex.

  18. TGF-beta1 release from biodegradable polymer microparticles: its effects on marrow stromal osteoblast function

    Science.gov (United States)

    Lu, L.; Yaszemski, M. J.; Mikos, A. G.; McIntire, L. V. (Principal Investigator)

    2001-01-01

    BACKGROUND: Controlled release of transforming growth factor-beta1 (TGF-beta1) to a bone defect may be beneficial for the induction of a bone regeneration cascade. The objectives of this work were to assess the feasibility of using biodegradable polymer microparticles as carriers for controlled TGF-beta1 delivery and the effects of released TGF-beta1 on the proliferation and differentiation of marrow stromal cells in vitro. METHODS: Recombinant human TGF-beta1 was incorporated into microparticles of blends of poly(DL-lactic-co-glycolic acid) (PLGA) and poly(ethylene glycol) (PEG). Fluorescein isothiocynate-labeled bovine serum albumin (FITC-BSA) was co-encapsulated as a porogen. The effects of PEG content (0, 1, or 5% by weight [wt%]) and buffer pH (3, 5, or 7.4) on the protein release kinetics and the degradation of PLGA were determined in vitro for as long as 28 days. Rat marrow stromal cells were seeded on a biodegradable poly(propylene fumarate) (PPF) substrate. The dose response and biological activity of released TGF-beta1 was determined after 3 days in culture. The effects of TGF-beta1 released from PLGA/PEG microparticles on marrow stromal cell proliferation and osteoblastic differentiation were assessed during a 21-day period. RESULTS: TGF-beta1 was encapsulated along with FITC-BSA into PLGA/PEG blend microparticles and released in a multiphasic fashion including an initial burst for as long as 28 days in vitro. Increasing the initial PEG content resulted in a decreased cumulative mass of released proteins. Aggregation of FITC-BSA occurred at lower buffer pH, which led to decreased release rates of both proteins. The degradation of PLGA was increased at higher PEG content and significantly accelerated at acidic pH conditions. Rat marrow stromal cells cultured on PPF substrates showed a dose response to TGF-beta1 released from the microparticles similar to that of added TGF-beta1, indicating that the activity of TGF-beta1 was retained during microparticle fabrication and after growth factor release. At an optimal TGF-beta1 dosage of 1.0 ng/ml after 3 days, the released TGF-beta1 enhanced the proliferation and osteoblastic differentiation of marrow stromal cells over 21 days of culture, with increased total cell number, alkaline phosphatase activity, and osteocalcin production. CONCLUSIONS: PLGA/PEG blend microparticles can serve as delivery vehicles for controlled release of TGF-beta1, and the released growth factor enhances marrow stromal cell proliferation and osteoblastic differentiation in vitro. CLINICAL RELEVANCE: Controlled release of TGF-beta1 from PLGA/PEG microparticles is representative of emerging tissue engineering technologies that may modulate cellular responses to encourage bone regeneration at a skeletal defect site.

  19. Genetic variation in TGF-beta 1 gene promoter and risk of gestational trophoblastic disease.

    Science.gov (United States)

    Dehaghani, Alamtaj Samsami; Zamanpour, Tarlan; Naeimi, Sirous; Sameni, Safoura; Robati, Minoo; Ghaderi, Abbas

    2010-01-01

    To examine the relationship of transforming growth factor beta 1 (TGF-beta 1) gene polymorphisms at promoter positions -509 (C/T) and -800 (G/A) with the risk of gestational trophoblastic disease (GTD) as compared to normal controls Polymerase chain reaction-restriction fragment length polymorphism was performed on peripheral blood of 102 patients with GTD and 124 normal, healthy, pregnant women as the control group. In this study, TGF-beta 1 gene polymorphisms at positions -509 (C/T) and -800 (G/A) failed to correlate with GTD. Our findings suggest that promoter gene polymorphisms of TGF-beta 1 do not play major roles in GTD and may not be risk factors for this disease.

  20. Two Faces of TGF-Beta1 in Breast Cancer

    Directory of Open Access Journals (Sweden)

    Joanna Magdalena Zarzynska

    2014-01-01

    Full Text Available Breast cancer (BC is potentially life-threatening malignancy that still causes high mortality among women. Scientific research in this field is focused on deeper understanding of pathogenesis and progressing of BC, in order to develop relevant diagnosis and improve therapeutic treatment. Multifunctional cytokine TGF-β1 is one of many factors that have a direct influence on BC pathophysiology. Expression of TGF-β1, induction of canonical and noncanonical signaling pathways, and mutations in genes encoding TGF-β1 and its receptors are correlated with oncogenic activity of this cytokine. In early stages of BC this cytokine inhibits epithelial cell cycle progression and promotes apoptosis, showing tumor suppressive effects. However, in late stages, TGF-β1 is linked with increased tumor progression, higher cell motility, cancer invasiveness, and metastasis. It is also involved in cancer microenvironment modification and promotion of epithelial to mesenchymal transition (EMT. This review summarizes the current knowledge on the phenomenon called “TGF-β1 paradox”, showing that better understanding of TGF-β1 functions can be a step towards development of new therapeutic approaches. According to current knowledge several drugs against TGF-β1 have been developed and are either in nonclinical or in early stages of clinical investigation.

  1. Differential effects of BMP-2 and TGF-beta1 on chondrogenic differentiation of adipose derived stem cells

    DEFF Research Database (Denmark)

    Mehlhorn, A T; Niemeyer, P; Kaschte, K

    2007-01-01

    transcriptional regulation of Dlx-5, Msx-2 and Runx-2. MATERIALS AND METHODS: Encapsulated ASC were cultured for 14 days in medium containing TGF-beta1 and/or BMP-2. mRNA expression of the extracellular matrix molecules col2a1, cartilage oligomeric matrix protein, col10a1, alkaline phosphatase (AP...... and an additive effect on col2a1 mRNA expression. Synthesis of glycosaminoglycans was enhanced by combined growth factor treatment. Addition of TGF-beta1 inhibited BMP-2 induced AP expression and activity and both proteins promoted chondrogenic maturation. CONCLUSIONS: Prevention of BMP-2-induced osteogenic......OBJECTIVES: This article addresses the interaction of transforming growth factor beta1 (TGF-beta1) and bone morphogenic protein 2 (BMP-2) during osteo-chondrogenic differentiation of adipose-derived adult stem cells (ASC). TGF-beta1 was expected to modulate the BMP-2-induced effects through...

  2. Experimental study of plasmid TGF-beta 1 DNA gene transfer with lipofectamine into rabbit corneal epithelial cells in vitro.

    Science.gov (United States)

    Huang, Qiong; Hu, Yanhua; Jiang, Fagang; Chen, Hong

    2002-01-01

    To investigate whether the TGF-beta 1 plasmid DNA carried by lipofectamine could be introduced into cultured rabbit corneal epithelial cells, specific expression of the plasmid pMAM TGF-beta 1 in the cultured corneal epithelial cells was studied. Two days after 12 h of transfection of pMAMT-GF-beta 1 mediated by lipofectamine into the cultured corneal epithelial cells, the TGF-beta 1 protein expression specific for pMAMTGF-beta 1 in the cells was detected by means of immunohistochemical staining and the positive rate was 23.37%. The results suggested that foreign plasmid DNA could be effectively delivered into cultured rabbit corneal epithelial cells by means of lipofectamine, and this will provide a promising method of studying TGF-beta 1 on the mechanism of physiology and pathology concerned with corneal epithelial cells.

  3. Release of PMN elastase, TGF-beta1 and neopterin during blood storage; unfiltered versus filtered blood.

    Science.gov (United States)

    Tylman, Maria; Bengtson, Jan Peter; Hyllner, Monica; Bengtsson, Anders

    2006-10-01

    Release of inflammatory mediators from blood cells during prestorage leukocyte filtration may result in recipient immune suppression. To investigate the effects of prestorage leukocyte filtration on the quality of blood components, twenty-four blood units were collected from healthy donors and randomised into 3 groups. Eight units were stored as whole blood, eight units were separated into plasma, red blood cells (RBC) and buffy coat and eight units were collected and filtered through the ASAHI RZ 2000 leukocyte filter and separated into plasma and RBC. The units were stored for 35 days. Samples were collected weekly for analyses of polymorphonuclear elastase (PMN elastase), transforming growth factor-beta1 (TGF-beta1) and neopterin. PMN elastase and neopterin increased during storage of whole blood and RBC. From the beginning and throughout storage, PMN elastase was increased in filtered plasma as compared with unfiltered plasma. Filtration per se did not influence the neopterin concentration in plasma or RBC. TGF-beta1 increased in plasma and RBC during storage. In filtered plasma, an elevation of the TGF-beta1 concentration was observed from the start of storage. The TGF-beta1 levels were higher in filtered plasma compared with unfiltered plasma. Prestorage leukocyte filtration increased the release of PMN elastase and TGF-beta1 in plasma and RBC.

  4. Role of TGF-beta1 in relation to exercise-induced type I collagen synthesis in human tendinous tissue

    DEFF Research Database (Denmark)

    Heinemeier, Katja; Langberg, Henning; Olesen, Jens L

    2003-01-01

    Mechanical loading of tissue is known to influence local collagen synthesis, and microdialysis studies indicate that mechanical loading of human tendon during exercise elevates tendinous type I collagen production. Transforming growth factor-beta1 (TGF-beta1), a potent stimulator of type I collagen...

  5. Bone response and mechanical strength of rabbit femoral defects filled with injectable CaP cements containing TGF-beta 1 loaded gelatin microparticles.

    NARCIS (Netherlands)

    Link, D.P.; Dolder, J. van den; Beucken, J.J.J.P van den; Wolke, J.G.C.; Mikos, A.G.; Jansen, J.A.

    2008-01-01

    This study focused at the potential of transforming growth factor beta 1 (TGF-beta 1) loaded gelatin microparticles to enhance the bone response and mechanical strength of rabbit femoral defects filled with injectable calcium phosphate (CaP)/gelatin microparticle composites. Therefore, TGF-beta1

  6. Influence of different forms of fluid shear stress on vascular endothelial TGF-beta1 mRNA expression.

    Science.gov (United States)

    Lum, R M; Wiley, L M; Barakat, A I

    2000-06-01

    This study investigated the effects of long-term exposure of steady (19 dyne/cm2), 1-Hz non-reversing pulsatile (19+/-6 dyne/cm2) and 1-Hz purely oscillatory (0+/-19 dyne/cm2) shear stress on endothelial transforming growth factor-beta1 (TGF-beta1) mRNA expression. Cultured bovine aortic endothelial cells (BAECs) were systematically exposed to the three flow conditions for periods of 2, 6, 12 and 24 h, and relative differences in TGF-beta1 mRNA levels were measured by semi-quantitative RT-PCR. In response to steady shear stress, TGF-beta1 mRNA levels normalized to no-flow controls were 1.24, 1.42, 1.30 and 1.47 at the 2-, 6-, 12- and 24-h time points, respectively. In response to non-reversing pulsatile flow, these levels were 1.49, 1.64, 1.64 and 1.73, while the respective transcript levels for oscillatory flow were 1.33, 1.12, 1.12 and 1. 93. These results indicate that BAEC TGF-beta1 mRNA was up-regulated with the kinetics of the up-regulation faster for steady and non-reversing pulsatile flow than for oscillatory flow. Given the preferential localization of early atherosclerotic lesions in arterial regions exposed to low and/or oscillatory shear stress and the implication of TGF-beta1 as an athero-protective gene, these results are consistent with the notion that regions transiently exposed to oscillatory flow may be particularly prone to atherosclerosis.

  7. The effects of TGF-{beta}1 on the bone regeneration in guinea pig mandible

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Do; Hwang, Eui Hwan; Lee, Sang Rae [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Kyung Hee University, Seoul (Korea, Republic of); Hong, Jung Pyo [Dept. of Oral Diagnosis and Oral Mediaine, College of Dentistry, Kyung Hee University, Seoul (Korea, Republic of)

    1995-08-15

    The purpose of this study was to observe the effect of TGF-{beta}1, which promotes differentiation and proliferation of osteoblasts, on bone regeneration. Experimental bone defects that measured 3 mm in diameter were created on the mandibles of guinea pig by removal of bone with the use of trephine burs. In one side of mandibular body, the experimental groups, bone defects were grafted with Biogran (Orthovita Co., U.S.A) and TGF-{beta}1 (R and D System Co., U.S.A). In the remaining side of the mandibular body, the control groups, bone defects were grafted with only Biogran. Guinea pigs in the control and experimental groups were serially terminated by fours on the 3 days, the 1 weeks, the 2 weeks, the 3 weeks, and the 4 weeks after experiment, and both sides of the mandibular bodies were removed and fixed with 10% neutral formalin. They were decalcifiec and embedded in paraffin as using the usual method. The specimen sectioned and stained with hematoxylin and eosin. Also, they were radiographed with a soft X-ray apparatus. The following results were obtained: 1. Hemorrhagic condition, observed in the granulation tissues, disappeared on the 1 week after experiment in both groups, and more prominent in the experimental group. The granulation tissues of the experimental group had larger number of cells than those of the control group. 2. Osteoblastic differentiation in the margin of grafted material and adjacent bone was observed on the 1 week after experiment in both groups. Also, bone formation was observed in immature form on the 1 week after experiment, and more prominent in the experimental group. 3. In the polarizing microscopic examination, bone matrix was very loose on the 1 week after experiment, but increase in density with time, and more prominent in the experimental group. 4. In the microradiographic examination, newly formed bone was observed in the experimental group on the 2 weeks after experiment, and this was observed earlier than in the control group. Newly formed bone was increased with time and defected area was markedly decreased on the 4 weeks after experiment.

  8. TGF-beta 1 attenuates the acquisition and expression of effector function by tumor antigen-specific human memory CD8 T cells.

    Science.gov (United States)

    Ahmadzadeh, Mojgan; Rosenberg, Steven A

    2005-05-01

    TGF-beta1 is a potent immunoregulatory cytokine. However, its impact on the generation and effector function of Ag-specific human effector memory CD8 T cells had not been evaluated. Using Ag-specific CD8 T cells derived from melanoma patients immunized with the gp100 melanoma Ag, we demonstrate that the addition of TGF-beta1 to the initial Ag activation cultures attenuated the gain of effector function by Ag-specific memory CD8 T cells while the phenotypic changes associated with activation and differentiation into effector memory were comparable to control cultures. These activated memory CD8 T cells consistently expressed lower mRNA levels for T-bet, suggesting a mechanism for TGF-beta1-mediated suppression of gain of effector function in memory T cells. Moreover, TGF-beta1 induced a modest expression of CCR7 on Ag-activated memory CD8 T cells. TGF-beta1 also suppressed cytokine secretion by Ag-specific effector memory CD8 T cells, as well as melanoma-reactive tumor-infiltrating lymphocytes and CD8 T cell clones. These results demonstrate that TGF-beta1 suppresses not only the acquisition but also expression of effector function on human memory CD8 T cells and tumor-infiltrating lymphocytes reactive against melanoma, suggesting that TGF-beta1-mediated suppression can hinder the therapeutic benefits of vaccination, as well as immunotherapy in cancer patients.

  9. Model applied to wistar rats for analysis of atrial alteration radioinduced: role of the TGFBeta1 cytokine on the lesions development; Modelo em ratos Wistar para analise de alteracoes atriais radioinduzidas: papel da citocina TGFBeta1 no desenvolvimento das lesoes

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Viviane Fernandes da; Andrade, Cherley Borba V. de; Nascimento, Ana Lucia Rosa do; Silva, Claudia Marcello da; Ribeiro, Andreia Fortes; Mandarim-de-Lacerda, Carlos Alberto; Carvalho, Jorge Jose de; Almeida, Carlos Eduardo de, E-mail: vivifis@gmail.co [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Inst. de Biologia Roberto Alcantara Gomes

    2009-07-01

    This paper develops a radiobiological model on Wistar rats for evaluation of atrium radioinduced alterations. Male Wistar rats were anaesthetised, immobilized and irradiated with 500, 1000 and 1500 cGy irradiated doses in the cardiac volume, pre-define through tomography. The animals were sacrificed after 15 days irradiation. The atriums were collected, fixed in formaldehyde and soaked into paraffin. A part of samples were dyed with hematoxyline-eosin (HE) and another submitted to immunohistochemistry for visualization of the cytokine TGFbeta1 expression. The observation of samples with HE indicated lesions om blood vessels and discrete inflamed infiltrated on some samples. The immunohistochemistry shown an intense expression of the TGFbeta1 cytokine, mainly on the only intine of the blood vessels. The data indicate that the atria develop alterations compatible to inflammatory answer as reaction to the damage caused by the tissue irradiation, and this answer is responsible by the production of TGFbeta1 cytokine, considered a cytokine pro-fibrotic on various models of cardiac disease. The lesions at atrium level can reflect on the correct functioning of the system generator of cardiac impulse, and can induce arrythmias and to prejudice the production of natriuretic peptides, molecules involved on the cardiac homeostasis

  10. TGF-beta1, -beta2 and -beta3 cooperate to facilitate tubulogenesis in the explanted quail heart.

    Science.gov (United States)

    Holifield, Jennifer S; Arlen, Angela M; Runyan, Raymond B; Tomanek, Robert J

    2004-01-01

    Transforming growth factor-beta (TGF-beta) isoforms have been implicated as both pro- and anti-angiogenic modulators. In this study we addressed the roles of TGF-beta isoforms on coronary tubulogenesis. Embryonic (E6) quail ventricular specimens were explanted onto collagen gels allowing endothelial cells to migrate and form vascular tubes. Growth factors and/or neutralizing growth factor antibodies were added to the cultures. Endothelial cells were identified using a quail endothelial cell marker, QH1. Image analysis was used to quantify aggregate tube length. Addition of any isoform (TGF-beta(1), TGF-beta(2) or TGF-beta(3)) virtually prevented tubulogenesis (>95% inhibition), while stimulation of tubulogenesis occurred by adding neutralizing antibodies to TGF-beta(3), but not to TGF-beta(1) or -beta(2). When all three isoforms were added, tubulogenesis was enhanced, indicating the key role of TGF-beta(3). Documentation of the inhibitory effect of TGF-beta isoforms on tubulogenesis is further supported by our experiments in which the marked enhancement of tube formation by bFGF and VEGF was negated when exogenous TGF-beta(1), -beta(2), or -beta(3) were added to the cultures. (1) TGF-beta(1), -beta(2) and -beta(3) each inhibits angiogenesis; (2) cooperation between the three TGF-beta isoforms and other angiogenic factors is essential for the regulation of normal tubulogenesis and (3) the stimulatory effect of VEGF or bFGF on tubulogenesis is negated by exogenous TGB-betas. Copyright 2004 S. Karger AG, Basel.

  11. Transforming growth factor-beta1 (TGF-beta1) in plasma is associated with preeclampsia risk in Peruvian women with systemic inflammation.

    Science.gov (United States)

    Muy-Rivera, Martin; Sanchez, Sixto E; Vadachkoria, Surab; Qiu, Chunfang; Bazul, Victor; Williams, Michelle A

    2004-04-01

    In a case-control study of 100 preeclamptics and 100 controls, we assessed plasma transforming growth factor-beta1 (TGF-beta1) concentrations in relation to preeclampsia risk among Peruvian women with and without systemic inflammation. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). The OR of preeclampsia increased across quartiles of TGF-beta1 concentrations. Women with elevated TGF-beta1 and a proinflammatory profile experienced the highest risk of preeclampsia (OR = 15.4, 95% CI 4.7-50.4). Our results confirm an association between TGF-beta1 and risk of preeclampsia and extend the literature by indicating a strong association in women with systemic inflammation.

  12. Pretreatment of periosteum with TGF-beta1 in situ enhances the quality of osteochondral tissue regenerated from transplanted periosteal grafts in adult rabbits.

    Science.gov (United States)

    Olivos-Meza, A; Fitzsimmons, J S; Casper, M E; Chen, Q; An, K-N; Ruesink, T J; O'Driscoll, S W; Reinholz, G G

    2010-09-01

    To compare the efficacy of in situ transforming growth factor-beta1 (TGF-beta1)-pretreated periosteum to untreated periosteum for regeneration of osteochondral tissue in rabbits. In the pretreatment group, 12 month-old New Zealand white rabbits received subperiosteal injections of 200 ng of TGF-beta1 percutaneously in the medial side of the proximal tibia, 7 days prior to surgery. Control rabbits received no treatment prior surgery. Osteochondral transverse defects measuring 5mm proximal to distal and spanning the entire width of the patellar groove were created and repaired with untreated or TGF-beta1-pretreated periosteal grafts. Post-operatively the rabbits resumed normal cage activity for 6 weeks. Complete filling of the defects with regenerated tissue was observed in both the TGF-beta1-pretreated and control groups with reformation of the original contours of the patellar groove. The total histological score (modified O'Driscoll) in the TGF-beta1-pretreated group, 20 (95% Confidence Interval (CI), 19-21), was significantly higher (P=0.0001) than the control group, 18 (16-19). The most notable improvements were in structural integrity and subchondral bone regeneration. No significant differences in glycosaminoglycan or type II collagen content, or equilibrium modulus were found between the surgical groups. The cambium of the periosteum regenerated at the graft harvest site was significantly thicker (P=0.0065) in the TGF-beta1-pretreated rabbits, 121 microm (94-149), compared to controls, 74 microm (52-96), after 6 weeks. This study demonstrates that in situ pretreatment of periosteum with TGF-beta1 improves osteochondral tissue regeneration at 6-weeks post-op compared to untreated periosteum in 12 month-old rabbits. Copyright 2010 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  13. Role of TGF-beta1 and MAP kinases in the antiproliferative effect of aspirin in human vascular smooth muscle cells.

    Directory of Open Access Journals (Sweden)

    Santiago Redondo

    2010-03-01

    Full Text Available We aimed to test the antiproliferative effect of acetylsalicylic acid (ASA on vascular smooth muscle cells (VSMC from bypass surgery patients and the role of transforming growth factor beta 1 (TGF-beta1.VSMC were isolated from remaining internal mammary artery from patients who underwent bypass surgery. Cell proliferation and DNA fragmentation were assessed by ELISA. Protein expression was assessed by Western blot. ASA inhibited BrdU incorporation at 2 mM. Anti-TGF-beta1 was able to reverse this effect. ASA (2 mM induced TGF-beta1 secretion; however it was unable to induce Smad activation. ASA increased p38(MAPK phosphorylation in a TGF-beta1-independent manner. Anti-CD105 (endoglin was unable to reverse the antiproliferative effect of ASA. Pre-surgical serum levels of TGF-beta1 in patients who took at antiplatelet doses ASA were assessed by ELISA and remained unchanged.In vitro antiproliferative effects of aspirin (at antiinflammatory concentration on human VSMC obtained from bypass patients are mediated by TGF-beta1 and p38(MAPK. Pre-surgical serum levels of TGF- beta1 from bypass patients who took aspirin at antiplatelet doses did not change.

  14. [The effects of core proteoglycan on the expressions of I and III collagen in human renal tubular epithelial cell induced by TGFbeta1 in vitro].

    Science.gov (United States)

    Cheng, Xue-Qin; Bao, Hua-Ying; Pan, Xiao-Qin; Fei, Li; Huang, Song-Ming; Zhang, Wei-Zhen

    2008-12-01

    To explore the roles of core proteoglycan and TGFbeta1 on the expressions of I and III collagen in human renal tubular epithelial cell line(HK-2) in vitro. Confluent HK-2 cells were exposed to TGFbeta1 and core proteoglycan for up to 48 h. The cells were divided into four groups. Group (1), negative control group; group(2), single 10 microg/L TGFbeta1 treated group; group (3), 10 microg/L TGFbeta1+10 microg/L core proteoglycan group; group (4), 10 microg/L TGFbeta1+100 microg/L core proteoglycan group. Morphologic characterization of HK-2 cells was shown by invertmicroscope; Precise amounts of I and III collagen mRNA were measured by RT-PCR. After 48 h, morphology of (1) group cells had no changes, most cells were normal shape; (2) group cells took great changes, most cells converted into spindle shape, like fibroblast, (3) and (4) groups, spindle shape cells reduced significantly. In contrast to (1) group, the expressions of I collagen in (2) group from mRNA significant increased by 27.86-fold. The expressions of III collagen increased by 21.83-fold. Comparing (3) and (4) groups to(2) group, the expressions of I collagen from mRNA effectively decreased 36.39% and 53.36%. III collagen expressions increased 26.35% and 47.96%èP<0.05érespectively. But, neither (3) group nor (4) group alone could regulate I and III collagen mRNA to normal levels. Core proteoglycan can inhibit the expressions of I and III collagen in HK-2 cells induced by TGFbeta1 in vitro. Possibly, suggest core proteoglycan contribute to the regulation of renal fibrosis.

  15. Tissue stretch decreases soluble TGF-beta1 and type-1 procollagen in mouse subcutaneous connective tissue: evidence from ex vivo and in vivo models.

    Science.gov (United States)

    Bouffard, Nicole A; Cutroneo, Kenneth R; Badger, Gary J; White, Sheryl L; Buttolph, Thomas R; Ehrlich, H Paul; Stevens-Tuttle, Debbie; Langevin, Helene M

    2008-02-01

    Transforming growth factor beta 1 (TGF-beta1) plays a key role in connective tissue remodeling, scarring, and fibrosis. The effects of mechanical forces on TGF-beta1 and collagen deposition are not well understood. We tested the hypothesis that brief (10 min) static tissue stretch attenuates TGF-beta1-mediated new collagen deposition in response to injury. We used two different models: (1) an ex vivo model in which excised mouse subcutaneous tissue (N = 44 animals) was kept in organ culture for 4 days and either stretched (20% strain for 10 min 1 day after excision) or not stretched; culture media was assayed by ELISA for TGF-beta1; (2) an in vivo model in which mice (N = 22 animals) underwent unilateral subcutaneous microsurgical injury on the back, then were randomized to stretch (20-30% strain for 10 min twice a day for 7 days) or no stretch; subcutaneous tissues of the back were immunohistochemically stained for Type-1 procollagen. In the ex vivo model, TGF-beta1 protein was lower in stretched versus non-stretched tissue (repeated measures ANOVA, P < 0.01). In the in vivo model, microinjury resulted in a significant increase in Type-1 procollagen in the absence of stretch (P < 0.001), but not in the presence of stretch (P = 0.21). Thus, brief tissue stretch attenuated the increase in both soluble TGF-beta1 (ex vivo) and Type-1 procollagen (in vivo) following tissue injury. These results have potential relevance to the mechanisms of treatments applying brief mechanical stretch to tissues (e.g., physical therapy, respiratory therapy, mechanical ventilation, massage, yoga, acupuncture). (c) 2007 Wiley-Liss, Inc.

  16. Role of TGF-beta1-independent changes in protein neosynthesis, p38alphaMAPK, and cdc42 in hydrogen peroxide-induced senescence-like morphogenesis

    DEFF Research Database (Denmark)

    Chrétien, Aline; Dierick, Jean-François; Delaive, Edouard

    2008-01-01

    -beta1 overexpression. Among the multiple TGF-beta1-independent changes in protein neosynthesis, followed or not by posttranslational modifications, identified by proteomic analysis herein, those of ezrin, L-caldesmon, and HSP27 were particularly studied. Rho-GTPase cdc42 was shown to be responsible...... for p38(MAPK) activation, in turn triggering phosphorylation of L-caldesmon and HSP27. Cdc42 was also shown to be mainly responsible for the increase in TGF-beta1 mRNA level observed at 24 h after treatment with H(2)O(2) and onward. This study further clarified the mechanisms of senescence...

  17. Engineering of rat articular cartilage on porous sponges: effects of tgf-beta 1 and microgravity bioreactor culture.

    Science.gov (United States)

    Emin, Nuray; Koç, Aysel; Durkut, Serap; Elçin, A Eser; Elçin, Y Murat

    2008-01-01

    The objective of this study was to develop an engineered rat hyaline cartilage by culturing articular chondrocytes on three-dimensional (3D) macroporous poly(DL-lactic-co-glycolic acid) (PLGA) sponges under chondrogenic induction and microgravity bioreactor conditions. Experimental groups consisted of 3D static and dynamic cultures, while a single cell monolayer (2D) served as the control. The effect of seeding conditions (static vs. dynamic) on cellularization of the scaffolds was investigated. MTT assay was used to evaluate the number of viable cells in each group at different time points. Formation of a hyaline-like cartilage was evaluated for up to 4 weeks in vitro. While 2D culture resulted in cell sheets with very poor matrix production, 3D culture was in the favor of tissue formation. A higher yield of cell attachment and spatially uniform cell distribution was achieved when dynamic seeding technique was used. Dynamic culture promoted cell growth and infiltration throughout the sponge structure and showed the formation of cartilage tissue, while chondrogenesis appeared attenuated more towards the outer region of the constructs in the static culture group. Medium supplemented with TGF-beta 1 (5 ng/ml) had a positive impact on proteoglycan production as confirmed by histochemical analyses with Alcian blue and Safranin-O stainings. Formation of hyaline-like tissue was demonstrated by immunohistochemistry performed with antibodies against type II collagen and aggrecan. SEM confirmed higher level of cellularization and cartilage tissue formation in bioreactor cultures induced by TGF-beta 1. The data suggest that PLGA sponge inside rotating bioreactor with chondrogenic medium provides an environment that mediates isolated rat chondrocytes to redifferentiate and form hyaline-like rat cartilage, in vitro.

  18. Overexpression of active TGF-beta-1 in the murine knee joint: evidence for synovial-layer-dependent chondro-osteophyte formation.

    NARCIS (Netherlands)

    Bakker, A.C.; Loo, F.A.J. van de; Beuningen, H.M. van; Sime, P.; Lent, P.L.E.M. van; Kraan, P.M. van der; Richards, C.D.; Berg, W.B. van den

    2001-01-01

    OBJECTIVE: To investigate the impact of a prolonged and constant active TGF-beta expression by the synovial lining cells on cartilage and ligamentous joint structures in vivo. DESIGN: An adenoviral vector (AdTGF-beta1(223,225)) was used for the overexpression of active TGF-beta1 in knee joints of

  19. Splenic CD8(+) T cells secrete TGF-beta 1 to exert suppression in mice with anterior chamber-associated immune deviation

    NARCIS (Netherlands)

    Jiang, L.Q.; He, H.; Yang, P.Z.; Lin, X.M.; Zhou, H.Y.; Huang, X.K.; Kijlstra, A.

    2009-01-01

    Background CD8(+) regulatory T cells (Treg) have been considered to be involved in a model of ocular-induced tolerance, known as anterior chamber-associated immune deviation (ACAID). The mechanisms of suppression by CD8(+) T cells in ACAID remain only poorly understood. TGF-beta 1 is considered as

  20. Involvement of the serine/threonine p70S6 kinase in TGF-beta1-induced ADAM12 expression in cultured human hepatic stellate cells

    DEFF Research Database (Denmark)

    Le Pabic, Hélène; L'Helgoualc'h, Annie; Coutant, Alexandre

    2005-01-01

    In chronic liver injury, quiescent hepatic stellate cells change into proliferative myofibroblast-like cells, which are a main source of fibrosis. We have recently reported that these cells synthesize ADAM12, a disintegrin and metalloprotease whose expression is up-regulated by TGF-beta1 in liver...

  1. Treatment with unsaponifiable extracts of avocado and soybean increases TGF-beta1 and TGF-beta2 levels in canine joint fluid.

    Science.gov (United States)

    Altinel, Levent; Saritas, Z Kadir; Kose, Kamil Cagri; Pamuk, Kamuran; Aksoy, Yusuf; Serteser, Mustafa

    2007-02-01

    Avocado and soya unsaponifiables (ASU) are plant extracts used as a slow-acting antiarthritic agent. ASU stimulate the synthesis of matrix components by chondrocytes, probably by increasing the production of transforming growth factor-beta (TGF-beta). TGF-beta is expressed by chondrocytes and osteoblasts and is present in cartilage matrix. This study investigates the effect of ASU treatment on the levels of two isoforms of TGFbeta, TGF-beta1 and TGF-beta2, in the knee joint fluid using a canine model. Twenty-four outbred dogs were divided into three groups. The control animals were given a normal diet, while the treated animals were given 300 mg ASU every three days or every day. Joint fluid samples were obtained prior to treatment, and at the end of every month (up to three months). TGF-beta1 and TGF-beta2 levels were measured using a quantitative sandwich enzyme immunoassay technique. ASU treatment caused an increase in TGF-beta1 and TGF-beta2 levels in the joint fluid when compared to controls. The different doses did not cause a significant difference in joint fluid TGF levels. TGF-beta1 levels in the treated animals reached maximum values at the end of the second month and then decreased after the third month, while TGF-beta2 levels showed a marginal increase during the first two months, followed by a marked increase at the end of the third month. In conclusion, ASU increased both TGF-beta1 and TGF-beta2 levels in knee joint fluid.

  2. Research of TGF-beta1 Inducing Lung Adencarcinoma PC9 Cells to Mesenchymal Cells Transition

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    Xiaofeng CHEN

    2010-01-01

    Full Text Available Background and objective It has been proven that epithelial-mesenchymal transition (EMT not only correlated with embryonic development but also could promote tumor invasion and metastasis. Transforming growth factor beta-1 (TGF-β1 has been identified as the main inducer of tumor EMT. The aim of this study was to investigate the effects of TGF-β1 on EMT and PI3K/AKT signaling pathway in lung adencarcinoma PC9 cells. Methods Cultured PC9 cells were treated with different concentrations of TGF-β1 for 48 h. The morphological changes were observed under phase-contrast microscopy; EMT relative marker protein changes were assessed by Western blot and immunoflurescence staining. In addition, the expression of AKT and P-AKT were also measured by Western blot. Results The data showed that TGF-β1 could induce PC9 morphological alteration from epithelial to mesenchymal and upregulate the expression of mesenchymal maker protein Fibronectin. Obviously, the expression of P-AKT was downregulated by TGF-β1 treatment for 48 h. Conclusion TGF-β1 might induce EMT of PC9 cells , accompanied by the changes of PI3K/AKT signaling pathway.

  3. Expression of the TGF-beta1 system in human testicular pathologies

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    Puigdomenech Elisa

    2010-12-01

    Full Text Available Abstract Background In non-obstructive azoospermia, histological patterns of Sertoli cell-only Syndrome (SCO and hypospermatogenesis (H are commonly found. In these pathologies, Leydig cell hyperplasia (LCH is detected in some patients. Since TGF-β1 is involved in cellular proliferation/development, the aim of this work was to analyze the expression of TGF-β1, its receptors TGFBRII, TGFBRI (ALK-1 and ALK-5, and the co-receptor endoglin in human biopsies from patients with idiopathic infertility. Methods Specific immunostaining of TGF-β1, its receptors TGFBRII, TGFBRI (ALK-1 and ALK-5, co-receptor endoglin and Smads proteins, were carried out in testicular biopsies from normal and infertile men with SCO or H. Gene expression of TGF-β1 system were made in biopsies from infertile patients with semi-quantitative and quantitative PCR. Results Immunohistochemical studies revealed that TGF-β1 and its specific receptors are present in Leydig cells in biopsies from normal tissue or patients with SCO or H with or without LCH. Smad proteins, which are involved in TGF-β1 signaling, are also detected in both their phosphorylated (activated and dephosphorylated form in all samples TGF-β1, ALK-1 and endoglin gene expression are stronger in human biopsies with LCH than in those with SCO or H. Neither TGFBRII nor ALK-5 gene expression showed significant differences between pathologies. A significant correlation between ALK-1 and endoglin expression was observed. Conclusions In conclusion, the high levels of mRNA and protein expression of the TGF-β1 system in patients with LCH, particularly ALK1 and its correlation with endoglin, suggest that these proteins acting in concert might be, at least in part, committed actors in the Leydig cell hyperplasia.

  4. TGF-beta1 regulates human brain pericyte inflammatory processes involved in neurovasculature function.

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    Rustenhoven, Justin; Aalderink, Miranda; Scotter, Emma L; Oldfield, Robyn L; Bergin, Peter S; Mee, Edward W; Graham, E Scott; Faull, Richard L M; Curtis, Maurice A; Park, Thomas I-H; Dragunow, Mike

    2016-02-11

    Transforming growth factor beta 1 (TGFβ1) is strongly induced following brain injury and polarises microglia to an anti-inflammatory phenotype. Augmentation of TGFβ1 responses may therefore be beneficial in preventing inflammation in neurological disorders including stroke and neurodegenerative diseases. However, several other cell types display immunogenic potential and identifying the effect of TGFβ1 on these cells is required to more fully understand its effects on brain inflammation. Pericytes are multifunctional cells which ensheath the brain vasculature and have garnered recent attention with respect to their immunomodulatory potential. Here, we sought to investigate the inflammatory phenotype adopted by TGFβ1-stimulated human brain pericytes. Microarray analysis was performed to examine transcriptome-wide changes in TGFβ1-stimulated pericytes, and results were validated by qRT-PCR and cytometric bead arrays. Flow cytometry, immunocytochemistry and LDH/Alamar Blue® viability assays were utilised to examine phagocytic capacity of human brain pericytes, transcription factor modulation and pericyte health. TGFβ1 treatment of primary human brain pericytes induced the expression of several inflammatory-related genes (NOX4, COX2, IL6 and MMP2) and attenuated others (IL8, CX3CL1, MCP1 and VCAM1). A synergistic induction of IL-6 was seen with IL-1β/TGFβ1 treatment whilst TGFβ1 attenuated the IL-1β-induced expression of CX3CL1, MCP-1 and sVCAM-1. TGFβ1 was found to signal through SMAD2/3 transcription factors but did not modify nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) translocation. Furthermore, TGFβ1 attenuated the phagocytic ability of pericytes, possibly through downregulation of the scavenger receptors CD36, CD47 and CD68. Whilst TGFβ did decrease pericyte number, this was due to a reduction in proliferation, not apoptotic death or compromised cell viability. TGFβ1 attenuated pericyte expression of key chemokines and

  5. TGF-beta1 causes epithelial-mesenchymal transition in HaCaT derivatives, but induces expression of COX-2 and migration only in benign, not in malignant keratinocytes.

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    Räsänen, Kati; Vaheri, Antti

    2010-05-01

    Transforming growth factor beta (TGF-beta) acts as a tumor promoter by inducing epithelial-mesenchymal transition (EMT), which leads to a motile phenotype, enabling invasion and metastasis of cancer cells. Cancer-related inflammation, mediated by prostaglandins, has been proposed as a critical mechanism in conversion of benign cells to malignant. Induction of cyclooxygenase 2 (COX-2), producer of prostaglandins, is thought to be a prerequisite for TGF-beta-induced EMT in benign cells. We used HaCaT derivatives, representative of skin cancer progression, to investigate TGF-beta1 mediated EMT response, and the role of COX-2 in it. Effect of TGF-beta1 was investigated by analyzing cell proliferation, morphology and protein expression. Chemotaxis and scratch-wound assays were used to study migration. TGF-beta1 caused proliferation arrest of benign and malignant HaCaT cells, and changed the epithelial morphology of benign and low-grade malignant cells, but not metastatic cells, to mesenchymal spindle-shape. Epithelial junction proteins ZO-1 and E-cadherin were downregulated in all cell lines in response to TGF-beta1, but mesenchymal markers were not induced, suggesting a partial EMT response. COX-2 and migration were induced only in benign HaCaT derivatives. Malignant derivatives did not induce COX-2 in response to TGF-beta 1 treatment, thus emphasizing the role of inflammation in EMT response of benign cells. TGF-beta1 operates via distinct mechanisms in inducing EMT and metastasis, and supporting this we show that TGF-beta1 induces COX-2 and promotes the migration of benign cells, but does not further augment the migration of malignant cells, indicating their resistance to TGF-beta1 in the context of motility. 2010 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

  6. Effects of adeno-associated virus (AAV) of transforming growth factors beta1 and beta3 (TGFbeta1,3) on promoting synthesis of glycosaminoglycan and collagen type II of dedifferentiated nucleus pulposus (NP) cells.

    Science.gov (United States)

    Sai, JiaMing; Hu, YouGu; Wang, DeChun

    2007-10-01

    The effects of AAV-TGFbeta(1) and AAV-TGFbeta(3) on promoting synthesis of glycosaminoglycan and collagen type II of dedifferentiated rabbit lumbar disc NP cells were studied in this work. The rabbit lumbar disc NP cells were isolated and cultured. The earlier and later dedifferentiated NP cells were established by subculture. The AAV transfection efficiency to dedifferentiated NP cells was analyzed with AAV-EGFP in vitro. After dedifferentiated NP cells were transfected by AAV-TGFbeta(1) or AAV-TGFbeta(3), their biological effects on promoting synthesis of glycosaminoglycan or collagen type II were detected and compared by the methods of (35)S incorporation or immunoblotting. The experimental results showed that AAV could transfect efficiently the earlier dedifferentiated NP cells, but its transfection rate was shown to be at a low level to the later dedifferentiated NP cells. Both AAV-TGFbeta(1) and AAV-TGFbeta(3) could promote the earlier dedifferentiated NP cells to synthesize glycosaminoglycan and collagen type II, and the effect of AAV-TGFbeta(1) was better than that of AAV-TGFbeta(3). For the later dedifferentiated NP cells, the AAV-TGFbeta(3) could promote their synthesis, but AAV-TGFbeta(1) could slightly inhibit their synthesis. Therefore, AAV-TGFbeta(1) and AAV-TGFbeta(3) could be used for the earlier dedifferentiated NP cells, and the TGFbeta(3) could be used as the objective gene for the later dedifferentiated NP cells.

  7. Transforming growth factor-beta 1 (TGF-beta1) promotes IL-2 mRNA expression through the up-regulation of NF-kappaB, AP-1 and NF-AT in EL4 cells.

    Science.gov (United States)

    Han, S H; Yea, S S; Jeon, Y J; Yang, K H; Kaminski, N E

    1998-12-01

    Transforming growth factor beta1 (TGF-beta1) has been previously shown to modulate interleukin 2 (IL-2) secretion by activated T-cells. In the present studies, we determined that TGF-beta1 induced IL-2 mRNA expression in the murine T-cell line EL4, in the absence of other stimuli. IL-2 mRNA expression was significantly induced by TGF-beta1 (0.1-1 ng/ml) over a relatively narrow concentration range, which led to the induction of IL-2 secretion. Under identical condition, we examined the effect of TGF-beta1 on the activity of nuclear factor AT (NF-AT), nuclear factor kappaB (NF-kappaB), activator protein-1 (AP-1) and octamer, all of which contribute to the regulation of IL-2 gene expression. Electrophoretic mobility shift assays showed that TGF-beta1 markedly increased NF-AT, NF-kappaB and AP-1 binding to their respective cognate DNA binding sites, whereas octamer binding remained constant, as compared with untreated cells. Employing a reporter gene expression system with p(NF-kappaB)3-CAT, p(NF-AT)3-CAT and p(AP-1)3-CAT, TGF-beta1 treatment of transfected EL4 cells induced a dose-related increase in chloramphenicol acetyltransferase activity that correlated well with the DNA binding profile found in the electrophoretic mobility shift assay studies. These results show that TGF-beta1, in the absence of any additional stimuli, up-regulates the activity of key transcription factors involved in IL-2 gene expression, including NF-AT, NF-kappaB and AP-1, to help promote IL-2 mRNA expression by EL4 cells.

  8. Associação dos polimorfismos dos genes TGF-beta1, CD14, IL-4, IL-4R e ADAM33 com a gravidade da asma em crianças e adolescentes Association of TGF-beta1, CD14, IL-4, IL-4R and ADAM33 gene polymorphisms with asthma severity in children and adolescents

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    Isabel C. J. de Faria

    2008-06-01

    Full Text Available OBJETIVO: Verificar, em uma amostra de pacientes com asma atópica persistente leve, moderada e grave, a associação entre os polimorfismos dos genes fator de crescimento transformante-beta1 (TGF-beta1 (C-509T e T869C, CD14 (C-159T, IL-4 (C-590T, IL-4R (ILe50Val e ADAM33 (S_2 com a gravidade da asma. MÉTODOS: Realizou-se um estudo clínico laboratorial prospectivo em pacientes com asma atópica persistente, comparados a um grupo controle no Hospital Universitário da Universidade Estadual de Campinas nos anos de 2006 e 2007. A análise do polimorfismo T869C do gene TGF-beta1 foi realizada pela técnica de reação em cadeia da polimerase (PCR + sistema de amplificação refratária de mutação (ARMS. Os outros polimorfismos, C-509T do gene TGF-beta1, C-159T do gene CD14, C-590T da IL-4, ILe50Val da IL-4Ra e S2 do gene ADAM33, foram detectados por PCR e enzima de restrição. RESULTADOS: Foram incluídos 88 pacientes com asma atópica persistente (27 leves, 23 moderados e 38 graves e 202 indivíduos saudáveis, doadores de sangue. Em relação ao polimorfismo T869C (TGF-beta1, observou-se uma associação entre o genótipo CC e os pacientes com asma grave. Nenhuma associação foi encontrada com os polimorfismos C-509T (TGF-beta1, C-590T (IL4 e S_2 (ADAM33. Quando se comparou a distribuição da freqüência genotípica do polimorfismo C-159T (CD14 na asma grave com o grupo controle, foi observado um resultado significativo com o genótipo TT. Houve associação significativa do genótipo Val/Val (IL-4R com a asma leve. CONCLUSÃO: Nossos resultados indicam que os polimorfismos T869C (TGF-beta1, C-159T (CD14 e Val/Val (IL-4R podem estar envolvidos na modulação da gravidade da asma.OBJECTIVE: To verify the association of transforming growth factor-beta1 (TGF-beta1 (C-509T and T869C, CD14 (C-159T, IL-4 (C-590T, IL-4R (ILe50Val and ADAM33 (S_2 gene polymorphisms with asthma severity in a sample of patients with mild, moderate and severe persistent atopic asthma. METHODS: A clinical, laboratory, prospective study was performed in patients with persistent atopic asthma, compared to a control group at Hospital Universitário da Universidade Estadual de Campinas between 2006 and 2007. Analysis of the TGF-beta1 T869C gene polymorphism was performed using the technique polymerase chain reaction (PCR + amplification refractory mutation system (ARMS. TGF-beta1 C-509T, CD14 C-159T, IL-4 C-590T, IL-4Ra ILe50Val, and ADAM33 S2 gene polymorphisms were detected by PCR and restriction enzyme. RESULTS: This study included 88 patients with persistent atopic asthma (27 mild, 23 moderate and 38 severe and 202 healthy blood donors. As to T869C polymorphism (TGF-beta1, there was an association between the CC genotype and patients with severe asthma. There was no association in polymorphisms C-509T (TGF-beta1, C-590T (IL-4 and S_2 (ADAM33. When distribution of C-159T polymorphism genotype frequency (CD14 in severe asthma was compared with the control group, there was a significant result with the TT genotype. There was significant association of the Val/Val genotype (IL-4R with mild asthma. CONCLUSION: Our results indicate that T869C (TGF-beta1, C-159T (CD14 and Val/Val (IL-4R polymorphisms might be involved in modulation of asthma severity.

  9. The effects of erythromycin on the viability and the secretion of TNF-alpha and TGF-beta1 and expression of connexin43 by human pleural mesothelial cells.

    Science.gov (United States)

    Xie, Canmao; Huang, Jian Qiang; Light, Richard W

    2005-11-01

    The mechanism by which erythromycin produces pleurodesis remains unknown. The purpose of this study was to investigate the effects of erythromycin on human pleural mesothelial cell (HPMC) viability, the secretion of tumour necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta(1) (TGF-beta(1)) and the level of expression of connexin43. HPMC were incubated with different concentrations of erythromycin. The inhibitory effects of erythromycin on HPMC growth were measured using a tetrazolium-based colorimetric assay. The levels of TNF-alpha and TGF-beta(1) in supernatants were measured by ELISA and levels of connexin43 were assessed by Western blot. Erythromycin injured HPMC in a dose and time-dependent manner. The secretion of both TNF-alpha and TGF-beta(1) by HMPC increased significantly when they were incubated with 100 mg/L erythromycin for 3 or 5 days. The levels of connexin43 in HPMC decreased after incubation with 100 mg/L erythromycin and no relationship was observed between the levels and incubation time. Erythromycin injures HPMC in a dose- and time-dependent manner and results in the secretion of TNF-alpha and TGF-beta(1). This is one possible mechanism of pleurodesis with erythromycin. Furthermore, erythromycin decreased the levels of connexin43 in HPMC, which could possibly affect the response of HPMC to pleurodesis with erythromycin.

  10. [Transforming growth factor beta1/Smad3 signal transduction pathway and post-traumatic scar formation].

    Science.gov (United States)

    Yu, Rong; Cen, Ying

    2012-03-01

    To summarize the recent progress in related research on transforming growth factor beta1 (TGF-beta1)/Smad3 signal transduction pathway and post-traumatic scar formation. Recent related literature at home and abroad on TGF-beta1/Smad3 signal transduction pathway and post-traumatic scar formation was reviewed and summarized. TGF-beta1 is an important influence factor of fibrotic diseases, and it plays biological effects by TGF-beta1/ Smad3 signal transduction pathway. The pathway is regulated by many factors and has crosstalk with other signal pathways at cellular and molecular levels. The pathway is involved in the early post-traumatic inflammatory response, wound healing, and late pathological scar formation. Intervening the transduction pathway at the molecular level can influence the process of fibrosis and extracellular matrix deposition. TGF-beta1/Smad3 signal transduction pathway is an important way to affect post-traumatic scar formation and extracellular matrix deposition. The further study on the pathway will provide a theoretical basis for promotion of wound healing, as well as prevention and treatment of pathological scar formation.

  11. Expression of IL-10, TGF-beta(1) and TNF-alpha in Cultured Keratinocytes (HaCaT Cells) after IPL Treatment or ALA-IPL Photodynamic Treatment.

    Science.gov (United States)

    Byun, Ji Yeon; Choi, Hae Young; Myung, Ki Bum; Choi, You Won

    2009-02-01

    Depending on the light dose and concentration of photosensitizer for photodynamic treatment (PDT), a multitude of dose-related events are demonstrable in PDT-treated cells. Sublethal doses may result in the alteration of cytokine release and consequently modify immune actions, rather than cause cell death. The purpose of this study was to investigate cytokine expression in cultured HaCaT cells after intense pulse light (IPL) treatment or PDT utilizing 5-aminolevulinic acid (ALA) and IPL at sublethal doses. Cultured HaCaT cells were treated with either IPL only (4, 8 and 12 J/cm(2)) or ALA-IPL PDT (100micromol/L of ALA; 0, 4, 8, and 12 J/cm(2) of IPL). The expression of IL-10, TGF-beta(1) and TNF-alpha was investigated by reverse transcription-polymerase chain reaction and enzyme linked immunosorbent assay. IL-10 protein increased up to 5.95-fold after IPL treatment and up to 2.85-fold after PDT. TGF-beta(1) mRNA and protein showed slight increases after both IPL treatment and PDT, of which the latter induced slightly larger increases. TNF-alpha mRNA and protein showed no induction or reduction after PDT. Increased expressions of IL-10 and TGF-beta(1) was observed after PDT. The induction of IL-10 may contribute to the anti-inflammatory effect, which explains the therapeutic benefit of PDT for inflammatory dermatoses, and that of TGF-beta(1) may be related to the therapeutic effect for psoriasis. The finding that IL-10 induction was more marked after IPL treatment than after PDT suggests that other mechanisms than IL-10 induction in keratinocytes after PDT may participate in the anti-inflammatory effect of PDT.

  12. Activation of WNT/beta-Catenin Signaling in Pulmonary Fibroblasts by TGF-beta(1) Is Increased in Chronic Obstructive Pulmonary Disease

    NARCIS (Netherlands)

    Baarsma, Hoeke A.; Spanjer, Anita I. R.; Haitsma, Gertruud; Engelbertink, Lilian H. J. M.; Meurs, Herman; Jonker, Marnix R.; Timens, Wim; Postma, Dirkje S.; Kerstjens, Huib A. M.; Gosens, Reinoud

    2011-01-01

    Background: Chronic obstructive pulmonary disease (COPD) is characterized by abnormal extracellular matrix (ECM) turnover. Recently, activation of the WNT/beta-catenin pathway has been associated with abnormal ECM turnover in various chronic diseases. We determined WNT-pathway gene expression in

  13. Ativação da proteína TGFbetaI latente em pulmão irradiado in vivo Latent TGFbeta1 activation in the lung irradiated in vivo

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    MARCOS DUARTE MATTOS

    2002-12-01

    Full Text Available OBJETIVO: Investigar no pulmão, por imunohistoquímica, a localização das proteínas TGFbeta1 latente e TGFbeta1 ativa, se ocorre ativação radioinduzida da proteína TGFbeta1 latente e a distribuição das fibras colágenas em diversos períodos de tempo após irradiação. MÉTODOS: 32 camundongos isogênicos (C57BL foram divididos em dois grupos: GI (não irradiado com 12 animais e GII (irradiado com 20 animais. Os animais do GII receberam radiação gama (telecobaltoterapia, 60Co, com rendimento de 0,97Gy/min, dose única de 7Gy em corpo inteiro. Os camundongos dos grupos I e II foram sacrificados por estiramento cervical nos períodos de 1, 14, 30 e 90 dias após irradiação. RESULTADOS: Os pulmões irradiados apresentaram: 1 congestão vascular e espessamento dos septos alveolares aos 30 dias e mais intensamente aos 90 dias depois da irradiação; 2 aumento significante da deposição de colágeno em todos os períodos de tempo após irradiação; 3 fraca ativação da proteína TGFbeta1 latente em um dia e intensa aos 14 dias depois da irradiação em brônquios e alvéolos. Nossos resultados sugerem que células dos brônquios e alvéolos podem participar do complexo mecanismo de fibrose pulmonar radioinduzida atuando como fontes da proteína TGFbeta1 ativa.PURPOSE: assess the latent and active TGFb1 localization in the lung, whether or not radiation induces latent TGFbeta1 activation, and the distribution of collagen fibers in the irradiated lung. METHODS: Thirty two C57BL mice were randomly assigned in two groups: GI (non irradiated animals and GII (irradiated animals. The mice from GII received a single whole ¾ body radiation dose of 7Gy, using a 60Co source at a dose rate of 0.97 Gy/min. They were sacrificed by cervical dislocation at 1, 14, 30 and 90 days after radiation. RESULTS: The irradiated lungs showed: 1 vascular congestion and thickness of the alveolar septa 30 days and more intense 90 days after irradiation; 2

  14. Ethanol induces apoptotic death of developing beta-endorphin neurons via suppression of cyclic adenosine monophosphate production and activation of transforming growth factor-beta1-linked apoptotic signaling.

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    Chen, Cui Ping; Kuhn, Peter; Chaturvedi, Kirti; Boyadjieva, Nadka; Sarkar, Dipak K

    2006-03-01

    The mechanism by which ethanol induces beta-endorphin (beta-EP) neuronal death during the developmental period was determined using fetal rat hypothalamic cells in primary cultures. The addition of ethanol to hypothalamic cell cultures stimulated apoptotic cell death of beta-EP neurons by increasing caspase-3 activity. Ethanol lowered the levels of adenylyl cyclase (AC)7 mRNA, AC8 mRNA, and/or cAMP in hypothalamic cells, whereas a cAMP analog blocked the apoptotic action of ethanol on beta-EP neurons. The AC inhibitor dideoxyadenosine (DDA) increased cell apoptosis and reduced the number of beta-EP neurons, and it potentiated the apoptotic action of ethanol on these neurons. beta-EP neurons in hypothalamic cultures showed immunoreactivity to transforming growth factor-beta1 (TGF-beta1) protein. Ethanol and DDA increased TGF-beta1 production and/or release from hypothalamic cells. A cAMP analog blocked the activation by ethanol of TGF-beta1 in these cells. TGF-beta1 increased apoptosis of beta-EP neurons, but it did not potentiate the action of ethanol or DDA actions on these neurons. TGF-beta1 neutralizing antibody blocked the apoptotic action of ethanol on beta-EP neurons. Determination of TGF-beta1-controlled cell apoptosis regulatory gene levels in hypothalamic cell cultures and in isolated beta-EP neurons indicated that ethanol, TGF-beta1, and DDA similarly alter the expression of these genes in these cells. These data suggest that ethanol increases beta-EP neuronal death during the developmental period by cellular mechanisms involving, at least partly, the suppression of cAMP production and activation of TGF-beta1-linked apoptotic signaling.

  15. Influence of the selective oestrogen receptor modulator (raloxifene hydrochloride) on IL-6, TNF-alpha, TGF-beta1 and bone turnover markers in the treatment of postmenopausal osteoporosis.

    Science.gov (United States)

    Ozmen, Bilgin; Kirmaz, Cengiz; Aydin, Kadir; Kafesciler, Sabriye O; Guclu, Feyzullah; Hekimsoy, Zeliha

    2007-09-01

    Osteoporosis that is encountered frequently in postmenopausal women, may cause an increased incidence of vertebral and iliac fractures that are associated with excess morbidity. Raloxifene hydrochloride, a selective oestrogen receptor modulator, has been shown to increase bone mineral density and decrease biochemical markers of bone turnover in postmenopausal women, without stimulatory effects on breast or uterus. Levels of proinflammatory cytokines, including IL-6, and TNF-alpha and TGF-beta1 which are important cytokines involved in remodeling, have been evaluated previously in in vitro studies of osteoporosis. However, there seems to be a paucity of in vivo research concerned with changes in these cytokines in osteoporosis. In this study, we evaluated the effects of raloxifene (Evista); Lilly Pharmaceutical Co. USA, 60 mg/day) on biochemical bone turnover markers, serum parathyroid hormone, and 25-OH vitamin D, as well as the serum levels of IL-6, TNF-alpha and TGF-beta1, in 22 postmenopausal, osteoporotic women before and after 12 weeks of raloxifene treatment. Well-matched, postmenopausal, non-osteoporotic control subjects were also enrolled in the study. Serum levels of all the parameters were measured in postmenopausal, osteoporotic women at baseline and end of the study. It was found that serum osteocalcin and parathyroid hormone, and urine deoxypyridinoline levels decreased to normal levels with treatment. Serum 25-OH vitamin D levels after treatment in the patient group were higher than those in the control group. Serum IL-6, TNF-alpha and TGF-beta1 levels did not change significantly with treatment. However, serum levels of IL-6 and TGF-beta1 in the patient group after treatment, decreased to levels lower than those found in the control group. Serum TNF-alpha levels in the patient group before and after treatment, were lower than those in the control group. Raloxifene treatment reduces bone turnover biochemical markers, parathyroid hormone and induces 25-OH vitamin D in postmenopausal women. Moreover, it also affects some serum cytokine levels in the postmenopausal period.

  16. Suppression of TAK1 pathway by shear stress counteracts the inflammatory endothelial cell phenotype induced by oxidative stress and TGF-beta 1

    NARCIS (Netherlands)

    Lee, Ee Soo; Boldo, Llorenc Sole; Fernandez, Bernadette O; Feelisch, Martin; Harmsen, Martin C.

    2017-01-01

    Endothelial dysfunction is characterised by aberrant redox signalling and an inflammatory phenotype. Shear stress antagonises endothelial dysfunction by increasing nitric oxide formation, activating antiinflammatory pathways and suppressing inflammatory pathways. The TAK1 (MAP3K7) is a key mediator

  17. [Effects of fluvastatin on the expression of Janus kinase 2/signal transducers and activators of transcription (JAK/STAT) in glomerular mesangial cells under high concentration of glucose].

    Science.gov (United States)

    Shi, Yong-hong; Zhao, Song; Ren, Yun-zhuo; Liu, Qing-juan; Duan, Hui-jun

    2008-07-01

    To investigate the effects of fluvastatin on activation of Janus kinase 2 (JAK2) and signal transducers and activators of transcription 1, 3 (STAT1, 3) in glomerular mesangial cells(GMCs) under high concentration of glucose. Rat GMCs were cultured in vitro, and they were treated with glucose and fluvastatin respectively. Tyrosine phosphorylation of JAK2 (p-JAK2) expression was detected by immunoprecipitation and Western blotting analysis. The protein expressions of JAK2, STAT1, p-STAT1, STAT3 and p-STAT3 were assessed by Western blotting. The protein synthesis of transforming growth factor-beta1 (TGF-beta1) and fibronectin (FN) in the supernatants of the GMCs were determined by enzyme-linked immunoadsorbent assay (ELISA). TGF-beta1 mRNA was assessed by reverse transcription and polymerase chain reaction (RT-PCR). Compared with low glucose control group, the expressions of p-JAK2 (802+/-124 vs.204+/-31), p-STAT1 (2,856.6+/-337.8 vs. 617.7+/-76.2), p-STAT3 (3,049.8+/-421.3 vs. 946.7+/-141.2) and TGF-beta1 mRNA were significantly up-regulated in GMCs under high glucose medium, and the concentration of TGF-beta1 in the supernatants [(2.87+/-0.34) microg/L vs. (1.20+/-0.11) microg/L] and FN [(6.34+/-0.61) mg/L vs. (3.24+/-0.26) mg/L, both P<0.01] were higher in the supernatants. The expression levels of p-JAK2 (412+/-67), p-STAT1 (1,178.4+/-137.1), p-STAT3 (1,572.6+/-181.2) and TGF-beta1 mRNA were significantly lower in fluvastatin group than those in high glucose group. The concentration of TGF-beta1 [(1.94+/-0.27) microg/L] and FN [(4.27+/-0.33)mg/L] in the supernatants in fluvastatin group were lower than those in high glucose control group (all P<0.05). Fluvastatin can inhibit overproduction of TGF-beta1 and FN in GMCs under high concentration of glucose, the underlying mechanism may partly be attributable to its influence on phosphorylation of JAK/STAT.

  18. Asiatic acid inhibits liver fibrosis by blocking TGF-beta/Smad signaling in vivo and in vitro.

    Directory of Open Access Journals (Sweden)

    Li-xia Tang

    Full Text Available Liver fibrosis is a major cause of liver failure, but treatment remains ineffective. In the present study, we investigated the mechanisms and anti-hepatofibrotic activities of asiatic acid (AA in a rat model of liver fibrosis induced by carbon tetrachloride (CCl(4 and in vitro in TGF-beta1-stimulated rat hepatic stellate cell line (HSC-T6. Treatment with AA significantly attenuated CCl(4-induced liver fibrosis and functional impairment in a dosage-dependent manner, including blockade of the activation of HSC as determined by inhibiting de novo alpha smooth muscle actin (a-SMA and collagen matrix expression, and an increase in ALT and AST (all p<0.01. The hepatoprotective effects of AA on fibrosis were associated with upregulation of hepatic Smad7, an inhibitor of TGF-beta signaling, thereby blocking upregulation of TGF-beta1 and CTGF and the activation of TGF-beta/Smad signaling. The anti-fibrosis activity and mechanisms of AA were further detected in vitro in HSC-T6. Addition of AA significantly induced Smad7 expression by HSC-T6 cells, thereby inhibiting TGF-beta1-induced Smad2/3 activation, myofibroblast transformation, and collagen matrix expression in a dosage-dependent manner. In contrast, knockdown of Smad7 in HSC-T6 cells prevented AA-induced inhibition of HSC-T6 cell activation and fibrosis in response to TGF-beta1, revealing an essential role for Smad7 in AA-induced anti-fibrotic activities during liver fibrosis in vivo and in vitro. In conclusion, AA may be a novel therapeutic agent for liver fibrosis. Induction of Smad7-dependent inhibition of TGF-beta/Smad-mediated fibrogenesis may be a central mechanism by which AA protects liver from injury.

  19. TGFbeta1-induced SMAD2/3 and SMAD1/5 phosphorylation are both ALK5-kinase-dependent in primary chondrocytes and mediated by TAK1 kinase activity.

    NARCIS (Netherlands)

    Caam, A.P.M. van; Madej, W.M.; Garcia de Vinuesa, A.; Goumans, M.J.; Dijke, P. Ten; Blaney Davidson, E.N.; Kraan, P.M. van der

    2017-01-01

    BACKGROUND: Dysregulated transforming growth factor beta (TGFbeta) signaling is implicated in osteoarthritis development, making normalizing TGFbeta signaling a possible therapy. Theoretically, this can be achieved with small molecule inhibitors specifically targeting the various TGFbeta receptors

  20. Pregnancy Specific Glycoprotein 17 Binds to the Extracellular Loop 2 of its Receptor, CD9, and Induces the Secretion of IL-lO, IL-6, PGE2 and TGFbeta1 in Murine Macrophages

    Science.gov (United States)

    2004-07-09

    preeclampsia . J Immunol, 1999. 163(6): p. 3491-5. 149. Chaouat, G., et al., IL-10 prevents naturally occurring fetal loss in the CBA x DBA/2 mating...specific stimulation can trigger or prevent specific signaling pathways [73, 78]. In immune cells the incorporated proteins often found in multi...dendritic cells, a potent APC. For instance, IL-10 treatment of immature dendritic cells has been shown to prevent DC maturation, which in turn inhibits

  1. Role of increased penile expression of transforming growth factor-beta1 and activation of the Smad signaling pathway in erectile dysfunction in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Zhang, Lu Wei; Piao, Shuguang; Choi, Min Ji; Shin, Hwa-Yean; Jin, Hai-Rong; Kim, Woo Jean; Song, Sun U; Han, Jee-Young; Park, Seok Hee; Mamura, Mizuko; Kim, Seong-Jin; Ryu, Ji-Kan; Suh, Jun-Kyu

    2008-10-01

    It has been suggested that transforming growth factor-beta1 (TGF-beta1) plays an important role in the pathogenesis of diabetes-induced erectile dysfunction. To investigate the expression and activity of Smad transcriptional factors, the key molecules for the initiation of TGF-beta-mediated fibrosis, in the penis of streptozotocin (STZ)-induced diabetic rats. Fifty-two 8-week-old Sprague-Dawley rats were used and divided into control and diabetic groups. Diabetes was induced by an intravenous injection of STZ. Eight weeks later, erectile function was measured by electrical stimulation of the cavernous nerve (N = 12 per group). The penis was harvested and stained with Masson trichrome or antibody to TGF-beta1, phospho-Smad2 (P-Smad2), smooth muscle alpha-actin, and factor VIII (N = 12 per group). Penis specimens from a separate group of animals were used for TGF-beta1 enzyme-linked immunosorbent assay (ELISA), P-Smad2/Smad2, phospho-Smad3 (P-Smad3)/Smad3, fibronectin, collagen I, and collagen IV western blot, or hydroxyproline determination. Erectile function was significantly reduced in diabetic rats compared with that in controls. The expression of TGF-beta1, P-Smad2, and P-Smad3 protein evaluated by ELISA or western blot was higher in diabetic rats than in controls. Compared with that in control rats, P-Smad2 expression was higher mainly in smooth muscle cells and fibroblasts of diabetic rats, whereas no significant differences were noted in endothelial cells or in the dorsal nerve bundle. Cavernous smooth muscle and endothelial cell contents were lower in diabetic rats than in controls. Cavernous fibronectin, collagen IV, and hydroxyproline content was significantly higher in diabetic rats than in controls. Upregulation of TGF-beta1 and activation of the Smad signaling pathway in the penis of diabetic rats might play important roles in diabetes-induced structural changes and deterioration of erectile function.

  2. CUX1/Wnt signaling regulates Epithelial Mesenchymal Transition in EBV infected epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Malizia, Andrea P.; Lacey, Noreen [Clinical Research Centre, School of Medicine and Medical Science, University College Dublin. 21, Nelson Street. Dublin, 7. Ireland (Ireland); Walls, Dermot [School of Biotechnology, Dublin City University. Dublin, 9. Ireland (Ireland); Egan, Jim J. [Advanced Lung Disease and Lung Transplant Program, Mater Misericordiae University Hospital. 44, Eccles Street. Dublin, 7. Ireland (Ireland); Doran, Peter P., E-mail: peter.doran@ucd.ie [Clinical Research Centre, School of Medicine and Medical Science, University College Dublin. 21, Nelson Street. Dublin, 7. Ireland (Ireland)

    2009-07-01

    Idiopathic pulmonary fibrosis (IPF) is a refractory and lethal interstitial lung disease characterized by alveolar epithelial cells apoptosis, fibroblast proliferation and extra-cellular matrix protein deposition. EBV, localised to alveolar epithelial cells of pulmonary fibrosis patients is associated with a poor prognosis. A strategy based on microarray-differential gene expression analysis to identify molecular drivers of EBV-associated lung fibrosis was utilized. Alveolar epithelial cells were infected with EBV to identify genes whose expression was altered following TGF{beta}1-mediated lytic phase. EBV lytic reactivation by TGF{beta}1 drives a selective alteration in CUX1 variant (a) (NCBI accession number NM{sub 1}81552) expression, inducing activation of non-canonical Wnt pathway mediators, implicating it in Epithelial Mesenchymal Transition (EMT), the molecular event underpinning scar production in tissue fibrosis. The role of EBV in EMT can be attenuated by antiviral strategies and inhibition of Wnt signaling by using All-Trans Retinoic Acids (ATRA). Activation of non-canonical Wnt signaling pathway by EBV in epithelial cells suggests a novel mechanism of EMT via CUX1 signaling. These data present a framework for further description of the link between infectious agents and fibrosis, a significant disease burden.

  3. Bmi-1 extends the life span of normal human oral keratinocytes by inhibiting the TGF-{beta} signaling

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Reuben H., E-mail: rkim@dentistry.ucla.edu [UCLA School of Dentistry, Los Angeles, CA 90095 (United States); UCLA Dental Research Institute, Los Angeles, CA 90095 (United States); UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA 90095 (United States); Lieberman, Mark B.; Lee, Rachel [UCLA School of Dentistry, Los Angeles, CA 90095 (United States); Shin, Ki-Hyuk [UCLA School of Dentistry, Los Angeles, CA 90095 (United States); UCLA Dental Research Institute, Los Angeles, CA 90095 (United States); UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA 90095 (United States); Mehrazarin, Shebli; Oh, Ju-Eun [UCLA School of Dentistry, Los Angeles, CA 90095 (United States); Park, No-Hee [UCLA School of Dentistry, Los Angeles, CA 90095 (United States); UCLA Dental Research Institute, Los Angeles, CA 90095 (United States); UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA 90095 (United States); David Geffen School of Medicine at UCLA, Los Angeles, CA 90095 (United States); Kang, Mo K., E-mail: mkang@dentistry.ucla.edu [UCLA School of Dentistry, Los Angeles, CA 90095 (United States); UCLA Dental Research Institute, Los Angeles, CA 90095 (United States); UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA 90095 (United States)

    2010-10-01

    We previously demonstrated that Bmi-1 extended the in vitro life span of normal human oral keratinocytes (NHOK). We now report that the prolonged life span of NHOK by Bmi-1 is, in part, due to inhibition of the TGF-{beta} signaling pathway. Serial subculture of NHOK resulted in replicative senescence and terminal differentiation and activation of TGF-{beta} signaling pathway. This was accompanied with enhanced intracellular and secreted TGF-{beta}1 levels, phosphorylation of Smad2/3, and increased expression of p15{sup INK4B} and p57{sup KIP2}. An ectopic expression of Bmi-1 in NHOK (HOK/Bmi-1) decreased the level of intracellular and secreted TGF-{beta}1 induced dephosphorylation of Smad2/3, and diminished the level of p15{sup INK4B} and p57{sup KIP2}. Moreover, Bmi-1 expression led to the inhibition of TGF-{beta}-responsive promoter activity in a dose-specific manner. Knockdown of Bmi-1 in rapidly proliferating HOK/Bmi-1 and cancer cells increased the level of phosphorylated Smad2/3, p15{sup INK4B}, and p57{sup KIP2}. In addition, an exposure of senescent NHOK to TGF-{beta} receptor I kinase inhibitor or anti-TGF-{beta} antibody resulted in enhanced replicative potential of cells. Taken together, these data suggest that Bmi-1 suppresses senescence of cells by inhibiting the TGF-{beta} signaling pathway in NHOK.

  4. Age-Dependent Decrease in Serum Transforming Growth Factor (TGF-Beta 1 in Healthy Japanese Individuals; Population Study of Serum TGF-Beta 1 Level in Japanese

    Directory of Open Access Journals (Sweden)

    Yoshihiro Okamoto

    2005-01-01

    Full Text Available Transforming growth factor-beta1 (TGF-β1, a multi-functional cytokine, is involved in regulating a variety of cellular activities and the serum/plasma TGF-β1 level is altered with various diseases. However, most published reports have described adult patients, and so we investigated the clinical significance of serum TGF-β1 level in pediatric patients. The diagnostic application of the measurement of serum TGF-β1 level depends critically on the control value, however, there is no information on the control value of serum TGF-β1 for children.

  5. Role of the TGFBeta1 in the Prevention of Prostate Cancer

    Science.gov (United States)

    2002-04-01

    animals each received charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate...quantitated using the Adobe Photoshop 5.0 Acquisition 10" and ImageQuant Analysis (Molecular Dynamics) systems. 0 . 0 5 10 15 20 25 30 35 40 RESULTS Weeks

  6. Signal Words

    Science.gov (United States)

    SIGNAL WORDS TOPIC FACT SHEET NPIC fact sheets are designed to answer questions that are commonly asked by the ... making decisions about pesticide use. What are Signal Words? Signal words are found on pesticide product labels, ...

  7. Signaling aggression.

    Science.gov (United States)

    van Staaden, Moira J; Searcy, William A; Hanlon, Roger T

    2011-01-01

    From psychological and sociological standpoints, aggression is regarded as intentional behavior aimed at inflicting pain and manifested by hostility and attacking behaviors. In contrast, biologists define aggression as behavior associated with attack or escalation toward attack, omitting any stipulation about intentions and goals. Certain animal signals are strongly associated with escalation toward attack and have the same function as physical attack in intimidating opponents and winning contests, and ethologists therefore consider them an integral part of aggressive behavior. Aggressive signals have been molded by evolution to make them ever more effective in mediating interactions between the contestants. Early theoretical analyses of aggressive signaling suggested that signals could never be honest about fighting ability or aggressive intentions because weak individuals would exaggerate such signals whenever they were effective in influencing the behavior of opponents. More recent game theory models, however, demonstrate that given the right costs and constraints, aggressive signals are both reliable about strength and intentions and effective in influencing contest outcomes. Here, we review the role of signaling in lieu of physical violence, considering threat displays from an ethological perspective as an adaptive outcome of evolutionary selection pressures. Fighting prowess is conveyed by performance signals whose production is constrained by physical ability and thus limited to just some individuals, whereas aggressive intent is encoded in strategic signals that all signalers are able to produce. We illustrate recent advances in the study of aggressive signaling with case studies of charismatic taxa that employ a range of sensory modalities, viz. visual and chemical signaling in cephalopod behavior, and indicators of aggressive intent in the territorial calls of songbirds. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. Suramin inhibits growth and transforming growth factor-beta 1 (TGF-beta 1) binding in osteosarcoma cell lines

    NARCIS (Netherlands)

    Kloen, P.; Jennings, C. L.; Gebhardt, M. C.; Springfield, D. S.; Mankin, H. J.

    1994-01-01

    Autocrine production of growth factors has been shown to be involved in the multistep process of tumorigenesis. The ability of suramin, a polyanionic anti-parasitic drug, to block growth factor-induced cell proliferation makes it a potential antineoplastic drug. We studied the effects of suramin on

  9. Phenotypic plasticity of the ovarian surface epithelium: TGF-beta 1 induction of epithelial to mesenchymal transition (EMT) in vitro.

    Science.gov (United States)

    Zhu, Yihong; Nilsson, Mikael; Sundfeldt, Karin

    2010-11-01

    Ovarian surface epithelium (OSE) is the most conceivable cell origin of epithelial ovarian carcinomas. Unlike many other epithelial tumors, the precancerous lesion acquires expression of epithelial markers, e.g. E-cadherin and claudins, suggesting that OSE cells undergo mesenchymal to epithelial transition (MET) during transformation. Recent findings indicate that TGF-β1, a prototypic stimulus of epithelial to mesenchymal transition (EMT), i.e. reverse to MET, is produced at significant amounts in the intact ovary. In the present study, we therefore investigated whether TGF-β1 changes the OSE phenotype accordingly, focusing on epithelial junction proteins and transcriptional EMT regulators quantified by real-time RT-PCR and Western blotting in cultured normal human OSE. Early OSE passages were found to paradoxically express de novo E-cadherin and also establish tight junctions exhibiting claudin-1 (but not claudin-3 and -4) and occludin. Stimulation with TGF-β1 (100 ng/ml) for 3-5 d down-regulated all these epithelial markers including Crumbs3 and also prevented the formation of an epithelial barrier This was accompanied by sustained expression of Snail and N-cadherin and transient expression of Slug, whereas Zeb1 (zinc finger E-box binding homeobox 1) and Twist mRNA levels were not significantly changed. In conclusion, TGF-β1 enforces the mesenchymal phenotype of OSE cells in vitro by an EMT-like process, leading to an altered molecular composition of the epithelial junction complex that partly coincides with the expression pattern of the native OSE. This suggests a potential role of TGF-β1-induced EMT in OSE under physiological conditions and possibly also in epithelial ovarian tumorigenesis.

  10. Upregulation of TGF-beta 1 in neonates of mothers receiving Influenza A (H1N1) vaccination during pregnancy

    DEFF Research Database (Denmark)

    Bischoff, Anne Louise; Folsgaard, N.; Bisgaard, H.

    2012-01-01

    Background: Influenza vaccination of pregnant women is generally considered safe,but the effects on the immune system of the unborn child are unknown.Objectives: Our primary objective was to explore differences in cytokine and chemokine levels in nasal mucosal lining fluid in neonates of mothers....... aureus; older siblings; furred animals in home; smoking during 3rd trimester; and mothers’ atopic disease. Conclusion: These findings suggest that Influenza A (H1N1) vaccination during pregnancy affects the mucosal immune competence of the unborn child. The up-regulation of TGF-b1 and down...... vaccinated during or after pregnancy. Method: IFN-c, IL-1b, IL-2, -4, -5, -10, - 12p70, -13, -17, TNF-a, IL-8, eotaxin-1,eotaxin-3, IP-10, MCP-1, MCP-4, MDC, MIP-1b, TGF-b1 and TARC were quantified in nasal mucosal lining fluid in neonates of mothers receiving Influenza A (H1N1v) vaccine during (n = 52...

  11. Regional differences in effect of TGF-beta1 and PDGF on the early onset of intestinal fibrosis

    NARCIS (Netherlands)

    Pham, B.T.; Van Haaften, W.T.; Iswandana, R.; Oosterhuis, D.; Olinga, P.

    2014-01-01

    Background: Intestinal fibrosis (IF) is one of the major complications in inflammatory bowel disease patients. IF can cause narrowing of the intestinal lumen, which may lead to stricture formation. The mechanism of IF is still unknown and adequate models are lacking. By using precision-cut

  12. TGF-beta1 em fibroblastos dérmicos humanos cultivados em esponja de colágeno

    OpenAIRE

    Aloise, Antonio Carlos [UNIFESP

    2009-01-01

    Introduction: The research of new sources of cells for Tissue Engineering of the human bone, it is necessary because the use of the primary choice for this therapy (bone marrow cell), can result in a morbidity of the donor area and poor expansion in vitro. Therefore, it is important to seek other cellular sources to contribute to this therapy. Objective: To evaluate the influence of transforming growth factor-beta 1 (TGF-â1) in the osteogenic differentiation of human dermal fibroblasts cultur...

  13. Gibberellin signaling.

    Science.gov (United States)

    Hartweck, Lynn M

    2008-12-01

    This review covers recent advances in gibberellin (GA) signaling. GA signaling is now understood to hinge on DELLA proteins. DELLAs negatively regulate GA response by activating the promoters of several genes including Xerico, which upregulates the abscisic acid pathway which is antagonistic to GA. DELLAs also promote transcription of the GA receptor, GIBBERELLIN INSENSITIVE DWARF 1 (GID1) and indirectly regulate GA biosynthesis genes enhancing GA responsiveness and feedback control. A structural analysis of GID1 provides a model for understanding GA signaling. GA binds within a pocket of GID1, changes GID1 conformation and increases the affinity of GID1 for DELLA proteins. GA/GID1/DELLA has increased affinity for an F-Box protein and DELLAs are subsequently degraded via the proteasome. Therefore, GA induces growth through degradation of the DELLAs. The binding of DELLA proteins to three of the PHYTOCHROME INTERACTING FACTOR (PIF) proteins integrates light and GA signaling pathways. This binding prevents PIFs 3, 4, and 5 from functioning as positive transcriptional regulators of growth in the dark. Since PIFs are degraded in light, these PIFs can only function in the combined absence of light and presence of GA. New analyses suggest that GA signaling evolved at the same time or just after the plant vascular system and before plants acquired the capacity for seed reproduction. An analysis of sequences cloned from Physcomitrella suggests that GID1 and DELLAs were the first to evolve but did not initially interact. The more recently diverging spike moss Selaginella has all the genes required for GA biosynthesis and signaling, but the role of GA response in Selaginella physiology remains a mystery.

  14. Transforming growth factor-beta1 induces tumor stroma and reduces tumor infiltrate in cervical cancer.

    Science.gov (United States)

    Hazelbag, Suzanne; Gorter, Arko; Kenter, Gemma G; van den Broek, Lambert; Fleuren, Gertjan

    2002-12-01

    Cervical carcinomas consist of tumor cell nests surrounded by varying amounts of intratumoral stroma containing different quantities and types of immune cells. Besides controlling (epithelial) cell growth, the multifunctional cytokine transforming growth factor-beta(1) (TGF-beta(1)) is involved in the formation of stroma and extracellular matrix (ECM) and in immunosuppression. Several malignancies are known to be associated with enhanced production of TGF-beta(1), repression or mutation of TGF-beta transmembrane receptors, or mutations at the postreceptor intracellular signaling pathway. The aim of our study was to investigate the role of tumor cell-derived TGF-beta(1) on the amount of intratumoral stroma; the deposition of collagen IV, fibronectin, and laminin; and the tumor infiltrate in cervical carcinoma. The expression of TGF-beta(1) mRNA in 108 paraffin-embedded cervical carcinomas was detected by mRNA in situ hybridization. Immunohistochemistry was used to investigate the amount of tumor stroma and ECM proteins and the extent of the tumor infiltrate. Plasminogen activator inhibitor-1 (PAI-1) protein expression in tumor cells was determined to verify the biological activity of TGF-beta(1.) Cytoplasmatic TGF-beta(1) mRNA expression in tumor cells was significantly correlated with the amount of intratumoral stroma and the deposition of collagen IV. TGF-beta(1) mRNA expression in every tumor was accompanied by PAI-1 expression, indicating biological activity of TGF-beta(1). An inverse relationship between TGF-beta(1) mRNA expression in tumor cells and the extent of the tumor infiltrate was demonstrated. Our results indicate that cervical cancer cells affect the amount and the composition of the intratumoral stroma and the tumor infiltrate by the production and secretion of TGF-beta(1). Copyright 2002, Elsevier Science (USA). All rights reserved.

  15. Effect of transforming growth factor-beta1 on embryonic and posthatch muscle growth and development in normal and low score normal chicken.

    Science.gov (United States)

    Li, X; Velleman, S G

    2009-02-01

    During skeletal muscle development, transforming growth factor-beta1 (TGF-beta1) is a potent inhibitor of muscle cell proliferation and differentiation. The TGF-beta1 signal is carried by Smad proteins into the cell nucleus, inhibiting the expression of key myogenic regulatory factors including MyoD and myogenin. However, the molecular mechanism by which TGF-beta1 inhibits muscle cell proliferation and differentiation has not been well documented in vivo. The present study investigated the effect of TGF-beta1 on in vivo skeletal muscle growth and development. A chicken line, Low Score Normal (LSN) with reduced muscling and upregulated TGF-beta1 expression, was used and compared to a normal chicken line. The injection of TGF-beta1 at embryonic day (ED) 3 significantly reduced the pectoralis major (p. major) muscle weight in the normal birds at 1 wk posthatch, whereas no significant difference was observed in the LSN birds. The difference between normal and LSN birds in response to TGF-beta1 is likely due to different levels of endogenous TGF-beta1 where the LSN birds have increased TGF-beta1 expression in their p. major muscle at both 17 ED and 6 wk posthatch. Smad3 expression was reduced by TGF-beta1 from 10 ED to 1 wk posthatch in normal p. major muscle. Unlike Smad3, Smad7 expression was not significantly affected by TGF-beta1 until posthatch in both normal and LSN p. major muscle. Expression of MyoD was reduced 35% by TGF-beta1 during embryonic development in normal p. major muscle, whereas LSN p. major muscle showed a delayed decrease at 1 d posthatch in MyoD expression in response to the TGF-beta1 treatment. Myogenin expression was reduced 29% by TGF-beta1 after hatch in normal p. major muscle. In LSN p. major muscle, TGF-beta1 treatment significantly decreased myogenin expression by 43% at 1 d posthatch and 32% at 1 wk posthatch. These data suggested that TGF-beta1 reduced p. major muscle growth by inhibiting MyoD and myogenin expression during both embryonic

  16. Prosocial Signalling

    DEFF Research Database (Denmark)

    Kahsay, Goytom Abraha

    In contrast to the standard economic theory predictions, it seems clear that people do spend their time and resource to benefit others. Many lab and field experiment studies show that people display prosocial preferences such as altruism, reciprocity and conditional cooperation, fairness, etc...... signalling can cause reverse price reactions resembling the crowding-out of pre-existing motives for prosocial behavior seen in situations of volunteering and charitable giving. Using a unique combination of questionnaire and purchase panel data, it presents evidence of such reputation-driven reverse price...

  17. Transforming growth factor beta-1 induces snail transcription factor in epithelial cell lines: mechanisms for epithelial mesenchymal transitions

    National Research Council Canada - National Science Library

    Peinado, Hector; Quintanilla, Miguel; Cano, Amparo

    2003-01-01

    .... We show here that transforming growth factor beta-1 (TGFbeta1) induces Snail expression in Madin-Darby canine kidney cells and triggers epithelial-mesenchymal transitions by a mechanism dependent on the MAPK signaling pathway...

  18. Continuous-time signals

    CERN Document Server

    Shmaliy, Yuriy

    2006-01-01

    Gives a modern description of continuous-time deterministic signals Signal formation techniquesTime vs. frequency and frequency vs. time analysisCorrelation and energy analysisNarrowband signals and sampling.

  19. Basic digital signal processing

    CERN Document Server

    Lockhart, Gordon B

    1985-01-01

    Basic Digital Signal Processing describes the principles of digital signal processing and experiments with BASIC programs involving the fast Fourier theorem (FFT). The book reviews the fundamentals of the BASIC program, continuous and discrete time signals including analog signals, Fourier analysis, discrete Fourier transform, signal energy, power. The text also explains digital signal processing involving digital filters, linear time-variant systems, discrete time unit impulse, discrete-time convolution, and the alternative structure for second order infinite impulse response (IIR) sections.

  20. The role of transforming growth factor-β1 in airway inflammation of childhood asthma.

    Science.gov (United States)

    Gagliardo, R; Chanez, P; Gjomarkaj, M; La Grutta, S; Bonanno, A; Montalbano, A M; Di Sano, C; Albano, G D; Gras, D; Anzalone, G; Riccobono, L; Profita, M

    2013-01-01

    TGF-beta-targeting structural and inflammatory cells has been implicated in the mechanisms leading to the inflammatory and restructuring processes in asthma, suggesting an impact of TGF-beta1 signaling on the development and persistency of this disease. We investigated the potential early involvement of TGF-beta1 activity in the immunological and molecular mechanisms underlying progression of inflammation in childhood asthma. We evaluated the levels of TGF-beta1 in induced sputum supernatants (ISSs) and the expression of small mother cell against decapentaplegic (Smad) 2 and Smad7 proteins in induced sputum cells (ISCs) from children with intermittent asthma (IA), moderate asthma (MA) and control subjects (C). Furthermore, we investigated the regulatory role of TGF-beta1 activity on eosinophil and neutrophil adhesion to epithelial cells using adhesion assay, and on the granulocyte expression of adhesion molecule CD11b/CD18 Macrophage-1 antigen (MAC-1), by flow cytometry. We found that the levels of TGF-beta1 are increased in ISSs of IA and MA in comparison to C, concomitantly to the activation of intracellular signaling TGFbeta/Smads pathway in ISCs. In MA, TGF-beta1 levels correlated with the number of sputum eosinophils and neutrophils. Furthermore, we showed the ability of sputum TGF-beta1 to promote eosinophil and neutrophil adhesion to epithelial cells, and to increase the expression of MAC-1 on the granulocyte surface. This study shows the activation of TGFbeta/Smad signaling pathway in the airways of children with IA and, despite the regular ICS treatment, in children with MA, and provides evidence for the contribution of TGF-beta1 in the regulation of granulocyte activation and trafficking.

  1. Digital signal processing laboratory

    CERN Document Server

    Kumar, B Preetham

    2011-01-01

    INTRODUCTION TO DIGITAL SIGNAL PROCESSING Brief Theory of DSP ConceptsProblem SolvingComputer Laboratory: Introduction to MATLAB®/SIMULINK®Hardware Laboratory: Working with Oscilloscopes, Spectrum Analyzers, Signal SourcesDigital Signal Processors (DSPs)ReferencesDISCRETE-TIME LTI SIGNALS AND SYSTEMS Brief Theory of Discrete-Time Signals and SystemsProblem SolvingComputer Laboratory: Simulation of Continuous Time and Discrete-Time Signals and Systems ReferencesTIME AND FREQUENCY ANALYSIS OF COMMUNICATION SIGNALS Brief Theory of Discrete-Time Fourier Transform (DTFT), Discrete Fourier Transform

  2. Signal sciences workshop proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Candy, J.V.

    1997-05-01

    This meeting is aimed primarily at signal processing and controls. The technical program for the 1997 Workshop includes a variety of efforts in the Signal Sciences with applications in the Microtechnology Area a new program at LLNL and a future area of application for both Signal/Image Sciences. Special sessions organized by various individuals in Seismic and Optical Signal Processing as well as Micro-Impulse Radar Processing highlight the program, while the speakers at the Signal Processing Applications session discuss various applications of signal processing/control to real world problems. For the more theoretical, a session on Signal Processing Algorithms was organized as well as for the more pragmatic, featuring a session on Real-Time Signal Processing.

  3. Retinoid signalling during embryogenesis

    NARCIS (Netherlands)

    Pijnappel, W.W.M.; Hendriks, H.F.J.; Durston, A.J.

    1996-01-01

    Conclusion: Retinoids are suspected to have multiple functions during embryogenesis, which are carried out via various different signal transduction pathways involving active retinoids and nuclear retinoid receptors. Research focuses on the identification of the retinoid signal transduction

  4. Biomedical signal processing

    CERN Document Server

    Akay, Metin

    1994-01-01

    Sophisticated techniques for signal processing are now available to the biomedical specialist! Written in an easy-to-read, straightforward style, Biomedical Signal Processing presents techniques to eliminate background noise, enhance signal detection, and analyze computer data, making results easy to comprehend and apply. In addition to examining techniques for electrical signal analysis, filtering, and transforms, the author supplies an extensive appendix with several computer programs that demonstrate techniques presented in the text.

  5. Tetrapyrrole Signaling in Plants

    Directory of Open Access Journals (Sweden)

    Robert M. Larkin

    2016-10-01

    Full Text Available Tetrapyrroles make critical contributions to a number of important processes in diverse organisms. In plants, tetrapyrroles are essential for light signaling, the detoxification of reactive oxygen species, the assimilation of nitrate and sulfate, respiration, photosynthesis, and programed cell death. Thus, it is not surprising that tetrapyrrole metabolism is strictly regulated and that tetrapyrrole metabolism affects signaling mechanisms that regulate gene expression. In plants and algae, tetrapyrroles are synthesized in plastids and were some of the first plastid signals demonstrated to regulate nuclear gene expression. In plants, the mechanism of tetrapyrrole-dependent plastid-to-nucleus signaling remains poorly understood. Additionally, some of experiments that tested ideas for possible signaling mechanisms appeared to produce conflicting data. In some instances, these conflicts are potentially explained by different experimental conditions. Although the biological function of tetrapyrrole signaling is poorly understood, there is compelling evidence that this signaling is significant. Specifically, this signaling appears to affect the accumulation of starch and may promote abiotic stress tolerance. Tetrapyrrole-dependent plastid-to-nucleus signaling interacts with a distinct plastid-to-nucleus signaling mechanism that depends on GENOMES UNCUOPLED1 (GUN1. GUN1 contributes to a variety of processes, such as chloroplast biogenesis, the circadian rhythm, abiotic stress tolerance, and development. Thus, the contribution of tetrapyrrole signaling to plant function is potentially broader than we currently appreciate. In this review, I discuss these aspects of tetrapyrrole signaling.

  6. Growth factor signalling

    NARCIS (Netherlands)

    De Laat, SW; Boonstra, J; Defize, LHK; Kruijer, W; Van der Saag, PT; Tertoolen, LGJ; Van Zoelen, JJ; Den Hertog, J

    1999-01-01

    Signalling between cells in the developing vertebrate embryo is essential for nomal embryonic development. In the mid 1970's, signal transduction research started at the Hubrecht Laboratory with special emphasis on analysis of the signalling mechanisms that direct cell proliferation and

  7. Proteomic Profiling of Mesenchymal Stem Cell Responses to Mechanical Strain and TGF-B1

    Energy Technology Data Exchange (ETDEWEB)

    Kurpinski, Kyle; Chu, Julia; Wang, Daojing; Li, Song

    2009-10-12

    Mesenchymal stem cells (MSCs) are a potential source of smooth muscle cells (SMCs) for constructing tissue-engineered vascular grafts. However, the details of how specific combinations of vascular microenvironmental factors regulate MSCs are not well understood. Previous studies have suggested that both mechanical stimulation with uniaxial cyclic strain and chemical stimulation with transforming growth factor {beta}1 (TGF-{beta}1) can induce smooth muscle markers in MSCs. In this study, we investigated the combined effects of uniaxial cyclic strain and TGF-{beta}1 stimulation on MSCs. By using a proteomic analysis, we found differential regulation of several proteins and genes, such as the up-regulation of TGF-{beta}1-induced protein ig-h3 (BGH3) protein levels by TGF-{beta}1 and up-regulation of calponin 3 protein level by cyclic strain. At the gene expression level, BGH3 was induced by TGF-{beta}1, but calponin 3 was not significantly regulated by mechanical strain or TGF-{beta}1, which was in contrast to the synergistic up-regulation of calponin 1 gene expression by cyclic strain and TGF-{beta}1. Further experiments with cycloheximide treatment suggested that the up-regulation of calponin 3 by cyclic strain was at post-transcriptional level. The results in this study suggest that both mechanical stimulation and TGF-{beta}1 signaling play unique and important roles in the regulation of MSCs at both transcriptional and post-transcriptional levels, and that a precise combination of microenvironmental cues may promote MSC differentiation.

  8. Transforming growth factor-beta1 effects on endothelial monolayer permeability involve focal adhesion kinase/Src.

    Science.gov (United States)

    Lee, Young H; Kayyali, Usamah S; Sousa, Anne Marie; Rajan, Thomas; Lechleider, Robert J; Day, Regina M

    2007-10-01

    Transforming growth factor (TGF)-beta1 activity has been shown to increase vascular endothelial barrier permeability, which is believed to precede several pathologic conditions, including pulmonary edema and vessel inflammation. In endothelial monolayers, TGF-beta1 increases permeability, and a number of studies have demonstrated the alteration of cell-cell contacts by TGF-beta1. We hypothesized that focal adhesion complexes also likely contribute to alterations in endothelial permeability. We examined early signal transduction events associated with rapid changes in monolayer permeability and the focal adhesion complex of bovine pulmonary artery endothelial cells. Western blotting revealed rapid tyrosine phosphorylation of focal adhesion kinase (FAK) and Src kinase in response to TGF-beta1; inhibition of both of these kinases using pp2 (4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine), ameliorates TGF-beta1-induced monolayer permeability. Activation of FAK/Src requires activation of the epidermal growth factor receptor downstream of the TGF-beta receptors, and is blocked by the epidermal growth factor receptor inhibitor AG1478. Immunohistochemistry showed that actin and the focal adhesion proteins paxillin, vinculin, and hydrogen peroxide-inducible clone-5 (Hic-5) are rearranged in response to TGF-beta1; these proteins are released from focal adhesion complexes. Rearrangement of paxillin and vinculin by TGF-beta1 is not blocked by the FAK/Src inhibitor, pp2, or by SB431542 inhibition of the TGF-beta type I receptor, anaplastic lymphoma kinase 5; however, pp1 (4-Amino-5-(4-methylphenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine), which inhibits both type I and type II TGF-beta receptors, does block paxillin and vinculin rearrangement. Hic-5 protein rearrangement requires FAK/Src activity. Together, these results suggest that TGF-beta1-induced monolayer permeability involves focal adhesion and cytoskeletal rearrangement through both FAK/Src-dependent and

  9. Endoglin negatively regulates transforming growth factor beta1-induced profibrotic responses in intestinal fibroblasts.

    LENUS (Irish Health Repository)

    Burke, J P

    2012-02-01

    BACKGROUND: Fibroblasts isolated from strictures in Crohn\\'s disease (CD) exhibit reduced responsiveness to stimulation with transforming growth factor (TGF) beta1. TGF-beta1, acting through the smad pathway, is critical to fibroblast-mediated intestinal fibrosis. The membrane glycoprotein, endoglin, is a negative regulator of TGF-beta1. METHODS: Intestinal fibroblasts were cultured from seromuscular biopsies of patients undergoing intestinal resection for CD strictures or from control patients. Endoglin expression was assessed using confocal microscopy, flow cytometry and western blot. The effect of small interfering (si) RNA-mediated knockdown and plasmid-mediated overexpression of endoglin on fibroblast responsiveness to TGF-beta1 was assessed by examining smad phosphorylation, smad binding element (SBE) promoter activity, connective tissue growth factor (CTGF) expression and ability to contract collagen. RESULTS: Crohn\\'s stricture fibroblasts expressed increased constitutive cell-surface and whole-cell endoglin relative to control cells. Endoglin co-localized with filamentous actin. Fibroblasts treated with siRNA directed against endoglin exhibited enhanced TGF-beta1-mediated smad-3 phosphorylation, and collagen contraction. Cells transfected with an endoglin plasmid did not respond to TGF-beta1 by exhibiting SBE promoter activity or producing CTGF. CONCLUSION: Fibroblasts from strictures in CD express increased constitutive endoglin. Endoglin is a negative regulator of TGF-beta1 signalling in the intestinal fibroblast, modulating smad-3 phosphorylation, SBE promoter activity, CTGF production and collagen contraction.

  10. The Signal Distribution System

    CERN Document Server

    Belohrad, D; CERN. Geneva. AB Department

    2005-01-01

    For the purpose of LHC signal observation and high frequency signal distribution, the Signal Distribution System (SDS) was built. The SDS can contain up to 5 switching elements, where each element allows the user to switch between one of the maximum 8 bi-directional signals. The coaxial relays are used to switch the signals. Depending of the coaxial relay type used, the transfer bandwidth can go up to 18GHz. The SDS is controllable via TCP/IP, parallel port, or locally by rotary switch.

  11. Converging signals synergistically activate the LAMC2 promoter and lead to accumulation of the laminin gamma 2 chain in human colon carcinoma cells

    DEFF Research Database (Denmark)

    Olsen, Jørgen; Kirkeby, Lene T; Brorsson, Marianne M

    2003-01-01

    The trimeric extracellular matrix molecule laminin-5 and its constituent chains (alpha 3, beta 3, gamma 2) are normally not detectable intracellularly in intestinal epithelial cells but the laminin gamma 2 chain can be detected in cancer cells at the invasive front of a subset of colon carcinomas....... These cells are subjected to cytokines such as transforming growth factor beta 1 (TGF-beta 1) and hepatocyte growth factor (HGF), produced by the tumour cells or by the surrounding stromal cells. The purpose of the present work was to investigate whether TGF-beta 1 and HGF, known to stimulate the LAMC2 gene...... encoding the laminin gamma 2 chain, might synergize to activate the LAMC2 promoter, and to identify the promoter elements involved. We find evidence for synergy between TGF-beta and HGF with respect to laminin gamma 2 chain expression and promoter activation and demonstrate that this requires the 5...

  12. The formation of tertiary dentin after pulp capping with a calcium phosphate cement, loaded with PLGA microparticles containing TGF-beta1.

    NARCIS (Netherlands)

    Zhang, W.; Walboomers, X.F.; Jansen, J.A.

    2008-01-01

    The aim of the current study was to evaluate the effect of a calcium phosphate material equipped with poly (lactic-co-glycolic acid) microspheres for pulp capping, and to measure the dentin bridge formation, when using various concentrations of transforming growth factor (TGF) beta1. Preset samples

  13. Carbon nanotubes functionalized by click chemistry as scaffolds for the preparation of electrochemical immunosensors. Application to the determination of TGF-beta 1 cytokine

    OpenAIRE

    Sánchez Tirado, Esther; González Cortés, Araceli; Yáñez Sedeño, Paloma; Pingarrón Carrazon, José Manuel

    2016-01-01

    An electrochemical immunosensor for the determination of the multifunctional Transforming Growth Factor β1 (TGF-β1) cytokine has been prepared using multi-walled carbon nanotube (MWCNT)-modified screen-printed carbon electrodes. MWCNTs were functionalized by means of copper(i) catalyzed azide-alkyne cycloaddition ("click" chemistry) as an efficient strategy for the covalent immobilization of immunoreagents without altering their configurations and preserving their biological activity. Alkyne-...

  14. GATA3-driven Th2 responses inhibit TGF-beta1-induced FOXP3 expression and the formation of regulatory T cells.

    Directory of Open Access Journals (Sweden)

    Pierre-Yves Mantel

    2007-12-01

    Full Text Available Transcription factors act in concert to induce lineage commitment towards Th1, Th2, or T regulatory (Treg cells, and their counter-regulatory mechanisms were shown to be critical for polarization between Th1 and Th2 phenotypes. FOXP3 is an essential transcription factor for natural, thymus-derived (nTreg and inducible Treg (iTreg commitment; however, the mechanisms regulating its expression are as yet unknown. We describe a mechanism controlling iTreg polarization, which is overruled by the Th2 differentiation pathway. We demonstrated that interleukin 4 (IL-4 present at the time of T cell priming inhibits FOXP3. This inhibitory mechanism was also confirmed in Th2 cells and in T cells of transgenic mice overexpressing GATA-3 in T cells, which are shown to be deficient in transforming growth factor (TGF-beta-mediated FOXP3 induction. This inhibition is mediated by direct binding of GATA3 to the FOXP3 promoter, which represses its transactivation process. Therefore, this study provides a new understanding of tolerance development, controlled by a type 2 immune response. IL-4 treatment in mice reduces iTreg cell frequency, highlighting that therapeutic approaches that target IL-4 or GATA3 might provide new preventive strategies facilitating tolerance induction particularly in Th2-mediated diseases, such as allergy.

  15. Expression of transforming growth factor-beta (TGF-beta) receptors, TGF-beta 1 and TGF-beta 2 production and autocrine growth control in osteosarcoma cells

    NARCIS (Netherlands)

    Kloen, P.; Jennings, C. L.; Gebhardt, M. C.; Springfield, D. S.; Mankin, H. J.

    1994-01-01

    Transforming growth factor-beta (TGF-beta) is a polypeptide with multiple physiological functions. Isoforms of this growth factor have important roles in control of the cell cycle, in regulation of cell-cell interactions and in growth and development. Malignant transformation has been shown to be

  16. Adipose Tissue-Derived Stromal Cells Inhibit TGF-beta 1-Induced Differentiation of Human Dermal Fibroblasts and Keloid Scar-Derived Fibroblasts in a Paracrine Fashion

    NARCIS (Netherlands)

    Spiekman, Maroesjka; Przybyt, Ewa; Plantinga, Josee A.; Gibbs, Susan; van der Lei, Berend; Harmsen, Martin C.

    2014-01-01

    Background: Adipose tissue-derived stromal cells augment wound healing and skin regeneration. It is unknown whether and how they can also influence dermal scarring. The authors hypothesized that adipose tissue-derived stromal cells inhibit adverse differentiation of dermal fibroblasts induced by the

  17. Effects of excimer laser irradiation on the expression of Th17, Treg, TGF-beta1, and IL-6 in patients with psoriasis vulgaris

    Science.gov (United States)

    Xiong, Guo-Xin; Li, Xin-Zhong

    2017-11-01

    The effects of laser irradiation on the expression of T helper 17 (Th17) and regulatory T (Treg) cells and their related cytokines, transforming growth factor beta 1 (TGF-β1) and interleukin-6 (IL-6), respectively, in the peripheral blood of patients with psoriasis vulgaris were investigated. 38 patients with psoriasis vulgaris in the stable state were selected as the treatment group that was treated twice a week for eight weeks. Another 38 healthy persons were chosen as the control group. Before and after treatment, the percentages of Th17 cells and Treg cells in the patients’ peripheral blood were detected using flow cytometry, the content of TGF-β1 and IL-6 in the patients’ sera were detected using enzyme-linked immunosorbent assay, and the extent and severity of lesions were determined by weighing the psoriasis area and severity index (PASI). After laser treatment, the percentage of Th17 cells, the Th17/Treg cell ratio and the level of IL-6 in the peripheral blood of patients with psoriasis in the treatment group were significantly lower than those of the same patients before the treatment (P  psoriasis vulgaris was 84.21%, and the PASI score was significantly lower (P  psoriasis vulgaris.

  18. Pregnancy Specific Glycoprotein 23 binds to CD151 and Induces the Secretion of IL-10 and TGF-beta1 in Murine Macrophages

    Science.gov (United States)

    2007-07-11

    IL-10 in preeclampsia . J Immunol, 1999. 163(6): p. 3491-5. 5. Hunt, J.S., et al., HLA-G and immune tolerance in pregnancy. Faseb J, 2005. 19(7): p...Schwangerschaftsprotein 1 (SP1) and pregnancy-associated plasma protein-A (PAPP-A) in the clinical management of threatened abortion. Br J Obstet Gynaecol, 1983...Examination of distinct fetal and maternal molecualr pathways suggests a mechanism for the development of preeclampsia . J Reprod Immunol, 2007. 78 87

  19. Superluminal Signal Velocity

    OpenAIRE

    Nimtz, Guenter

    1998-01-01

    It recently has been demonstrated that signals conveyed by evanescent modes can travel faster than light. In this report some special features of signals are introduced and investigated, for instance the fundamental property that signals are frequency band limited. Evanescent modes are characterized by extraordinary properties: Their energy is {\\it negative}, they are not directly measurable, and the evanescent region is not causal since the modes traverse this region instantaneously. The stu...

  20. Noncausal Superluminal Nonlocal Signalling

    OpenAIRE

    Srikanth, R.

    1999-01-01

    We propose a thought experiment for classical superluminal signal transmission based on the quantum nonlocal influence of photons on their momentum entangled EPR twins. The signal sender measures either position or momentum of particles in a pure ensemble of the entangled pairs, leaving their twins as localized particles or plane waves. The signal receiver distinguishes these outcomes interferometrically using a double slit interferometer modified by a system of optical filters. Since the col...

  1. Digital signal processing

    CERN Document Server

    O'Shea, Peter; Hussain, Zahir M

    2011-01-01

    In three parts, this book contributes to the advancement of engineering education and that serves as a general reference on digital signal processing. Part I presents the basics of analog and digital signals and systems in the time and frequency domain. It covers the core topics: convolution, transforms, filters, and random signal analysis. It also treats important applications including signal detection in noise, radar range estimation for airborne targets, binary communication systems, channel estimation, banking and financial applications, and audio effects production. Part II considers sel

  2. Biomedical signals and systems

    CERN Document Server

    Tranquillo, Joseph V

    2013-01-01

    Biomedical Signals and Systems is meant to accompany a one-semester undergraduate signals and systems course. It may also serve as a quick-start for graduate students or faculty interested in how signals and systems techniques can be applied to living systems. The biological nature of the examples allows for systems thinking to be applied to electrical, mechanical, fluid, chemical, thermal and even optical systems. Each chapter focuses on a topic from classic signals and systems theory: System block diagrams, mathematical models, transforms, stability, feedback, system response, control, time

  3. Signal sampling circuit

    NARCIS (Netherlands)

    Louwsma, S.M.; Vertregt, Maarten

    2011-01-01

    A sampling circuit for sampling a signal is disclosed. The sampling circuit comprises a plurality of sampling channels adapted to sample the signal in time-multiplexed fashion, each sampling channel comprising a respective track-and-hold circuit connected to a respective analogue to digital

  4. Signal sampling circuit

    NARCIS (Netherlands)

    Louwsma, S.M.; Vertregt, Maarten

    2010-01-01

    A sampling circuit for sampling a signal is disclosed. The sampling circuit comprises a plurality of sampling channels adapted to sample the signal in time-multiplexed fashion, each sampling channel comprising a respective track-and-hold circuit connected to a respective analogue to digital

  5. Ubiquitination in apoptosis signaling

    NARCIS (Netherlands)

    van de Kooij, L.W.

    2014-01-01

    The work described in this thesis focuses on ubiquitination and protein degradation, with an emphasis on how these processes regulate apoptosis signaling. More specifically, our aims were: 1. To increase the understanding of ubiquitin-mediated regulation of apoptosis signaling. 2. To identify the E3

  6. SignalR blueprints

    CERN Document Server

    Ingebrigtsen, Einar

    2015-01-01

    This book is designed for software developers, primarily those with knowledge of C#, .NET, and JavaScript. Good knowledge and understanding of SignalR is assumed to allow efficient programming of core elements and applications in SignalR.

  7. Optimal fault signal estimation

    NARCIS (Netherlands)

    Stoorvogel, Antonie Arij; Niemann, H.H.; Saberi, A.; Sannuti, P.

    2002-01-01

    We consider here both fault identification and fault signal estimation. Regarding fault identification, we seek either exact or almost fault identification. On the other hand, regarding fault signal estimation, we seek either $H_2$ optimal, $H_2$ suboptimal or Hinfinity suboptimal estimation. By

  8. Multiresolution signal decomposition schemes

    NARCIS (Netherlands)

    J. Goutsias (John); H.J.A.M. Heijmans (Henk)

    1998-01-01

    textabstract[PNA-R9810] Interest in multiresolution techniques for signal processing and analysis is increasing steadily. An important instance of such a technique is the so-called pyramid decomposition scheme. This report proposes a general axiomatic pyramid decomposition scheme for signal analysis

  9. Neutron signal transfer analysis

    CERN Document Server

    Pleinert, H; Lehmann, E

    1999-01-01

    A new method called neutron signal transfer analysis has been developed for quantitative determination of hydrogenous distributions from neutron radiographic measurements. The technique is based on a model which describes the detector signal obtained in the measurement as a result of the action of three different mechanisms expressed by signal transfer functions. The explicit forms of the signal transfer functions are determined by Monte Carlo computer simulations and contain only the distribution as a variable. Therefore an unknown distribution can be determined from the detector signal by recursive iteration. This technique provides a simple and efficient tool for analysis of this type while also taking into account complex effects due to the energy dependency of neutron interaction and single and multiple scattering. Therefore this method provides an efficient tool for precise quantitative analysis using neutron radiography, as for example quantitative determination of moisture distributions in porous buil...

  10. Acoustic Signals and Systems

    DEFF Research Database (Denmark)

    2008-01-01

    The Handbook of Signal Processing in Acoustics will compile the techniques and applications of signal processing as they are used in the many varied areas of Acoustics. The Handbook will emphasize the interdisciplinary nature of signal processing in acoustics. Each Section of the Handbook...... will present topics on signal processing which are important in a specific area of acoustics. These will be of interest to specialists in these areas because they will be presented from their technical perspective, rather than a generic engineering approach to signal processing. Non-specialists, or specialists...... from different areas, will find the self-contained chapters accessible and will be interested in the similarities and differences between the approaches and techniques used in different areas of acoustics....

  11. 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 ...

  12. Plant cytokinin signalling.

    Science.gov (United States)

    Keshishian, Erika A; Rashotte, Aaron M

    2015-01-01

    Cytokinin is an essential plant hormone that is involved in a wide range of plant growth and developmental processes which are controlled through its signalling pathway. Cytokinins are a class of molecules that are N(6)-substituted adenine derivatives, such as isopentenyl adenine, and trans- and cis-zeatin, which are common in most plants. The ability to perceive and respond to cytokinin occurs through a modified bacterial two-component pathway that functions via a multi-step phosphorelay. This cytokinin signalling process is a crucial part of almost all stages of plant life, from embryo patterning to apical meristem regulation, organ development and eventually senescence. The cytokinin signalling pathway involves the co-ordination of three types of proteins: histidine kinase receptors to perceive the signal, histidine phosphotransfer proteins to relay the signal, and response regulators to provide signal output. This pathway contains both positive and negative elements that function in a complex co-ordinated manner to control cytokinin-regulated plant responses. Although much is known about how this cytokinin signal is perceived and initially regulated, there are still many avenues that need to be explored before the role of cytokinin in the control of plant processes is fully understood. © 2015 Authors; published by Portland Press Limited.

  13. Signal flow analysis

    CERN Document Server

    Abrahams, J R; Hiller, N

    1965-01-01

    Signal Flow Analysis provides information pertinent to the fundamental aspects of signal flow analysis. This book discusses the basic theory of signal flow graphs and shows their relation to the usual algebraic equations.Organized into seven chapters, this book begins with an overview of properties of a flow graph. This text then demonstrates how flow graphs can be applied to a wide range of electrical circuits that do not involve amplification. Other chapters deal with the parameters as well as circuit applications of transistors. This book discusses as well the variety of circuits using ther

  14. Signal Station Inspection Reports

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Handwritten reports resulting from detailed inspections of US Army Signal Service Stations, 1871-1889. Features reported included instrument exposure and condition,...

  15. Transmembrane Signalling: Membrane messengers

    Science.gov (United States)

    Cockroft, Scott L.

    2017-05-01

    Life has evolved elaborate means of communicating essential chemical information across cell membranes. Inspired by biology, two new artificial mechanisms have now been developed that use synthetic messenger molecules to relay chemical signals into or across lipid membranes.

  16. Topological signal processing

    CERN Document Server

    Robinson, Michael

    2014-01-01

    Signal processing is the discipline of extracting information from collections of measurements. To be effective, the measurements must be organized and then filtered, detected, or transformed to expose the desired information.  Distortions caused by uncertainty, noise, and clutter degrade the performance of practical signal processing systems. In aggressively uncertain situations, the full truth about an underlying signal cannot be known.  This book develops the theory and practice of signal processing systems for these situations that extract useful, qualitative information using the mathematics of topology -- the study of spaces under continuous transformations.  Since the collection of continuous transformations is large and varied, tools which are topologically-motivated are automatically insensitive to substantial distortion. The target audience comprises practitioners as well as researchers, but the book may also be beneficial for graduate students.

  17. Foundations of signal processing

    CERN Document Server

    Vetterli, Martin; Goyal, Vivek K

    2014-01-01

    This comprehensive and engaging textbook introduces the basic principles and techniques of signal processing, from the fundamental ideas of signals and systems theory to real-world applications. Students are introduced to the powerful foundations of modern signal processing, including the basic geometry of Hilbert space, the mathematics of Fourier transforms, and essentials of sampling, interpolation, approximation and compression. The authors discuss real-world issues and hurdles to using these tools, and ways of adapting them to overcome problems of finiteness and localisation, the limitations of uncertainty and computational costs. Standard engineering notation is used throughout, making mathematical examples easy for students to follow, understand and apply. It includes over 150 homework problems and over 180 worked examples, specifically designed to test and expand students' understanding of the fundamentals of signal processing, and is accompanied by extensive online materials designed to aid learning, ...

  18. Acoustic MIMO signal processing

    CERN Document Server

    Huang, Yiteng; Chen, Jingdong

    2006-01-01

    A timely and important book addressing a variety of acoustic signal processing problems under multiple-input multiple-output (MIMO) scenarios. It uniquely investigates these problems within a unified framework offering a novel and penetrating analysis.

  19. Traffic Signal Cycle Lengths

    Data.gov (United States)

    Town of Chapel Hill, North Carolina — Traffic signal location list for the town of Chapel Hill. This data set includes light cycle information as well as as intersection information.The Town of Chapel...

  20. Ultrahigh bandwidth signal processing

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo

    2016-01-01

    Optical time lenses have proven to be very versatile for advanced optical signal processing. Based on a controlled interplay between dispersion and phase-modulation by e.g. four-wave mixing, the processing is phase-preserving, an hence useful for all types of data signals including coherent multi......-level modulation founats. This has enabled processing of phase-modulated spectrally efficient data signals, such as orthogonal frequency division multiplexed (OFDM) signa In that case, a spectral telescope system was used, using two time lenses with different focal lengths (chirp rates), yielding a spectral...... regeneratio These operations require a broad bandwidth nonlinear platform, and novel photonic integrated nonlinear platform like aluminum gallium arsenide nano-waveguides used for 1.28 Tbaud optical signal processing will be described....

  1. Modest Advertising Signals Strength.

    OpenAIRE

    Ram Orzach; Per Baltzer Overgaard; Yair Tauman

    2001-01-01

    This paper presents a signaling model where both price and advertising expenditures are used as signals of the initially unobservable quality of a newly introduced experience good. Consumers can be either "fastidious" or "indifferent". Fastidious individuals place a greater value on a high-quality product and a lesser value on the low-quality product than do indifferent individuals. It is shown that a sensible separating equilibrium exists where both firms set their full information prices. H...

  2. Lipid Signaling in Tumorigenesis

    OpenAIRE

    Liu, Renyan; Huang, Ying

    2014-01-01

    Lipids are important cellular building blocks and components of signaling cascades. Deregulation of lipid metabolism or signaling is frequently linked to a variety of human diseases such as diabetes, cardiovascular diseases, and cancer. It is widely believed that lipid molecules or their metabolic products are involved in tumorigenic inflammation and thus, lipids are implicated as significant contributors or even primary triggers of tumorigenesis. Lipids are believed to directly or indirectly...

  3. Optical Signal Processing.

    Science.gov (United States)

    1983-11-30

    that the readaptation phenomena is minimized as signal components leave the tap weight plane (the accumulator). In principle, the performance could be...accumulators so that the readaptation phenomena caused by large values pleaving the accumulator are minimized. Several examples of the performance...the jammer signal. The system then goes into a " readaptation " phase where the new contributions to the tap weights must offset the older cont

  4. Digital Signal Processing applied to Physical Signals

    CERN Document Server

    Alberto, Diego; Musa, L

    2011-01-01

    It is well known that many of the scientific and technological discoveries of the XXI century will depend on the capability of processing and understanding a huge quantity of data. With the advent of the digital era, a fully digital and automated treatment can be designed and performed. From data mining to data compression, from signal elaboration to noise reduction, a processing is essential to manage and enhance features of interest after every data acquisition (DAQ) session. In the near future, science will go towards interdisciplinary research. In this work there will be given an example of the application of signal processing to different fields of Physics from nuclear particle detectors to biomedical examinations. In Chapter 1 a brief description of the collaborations that allowed this thesis is given, together with a list of the publications co-produced by the author in these three years. The most important notations, definitions and acronyms used in the work are also provided. In Chapter 2, the last r...

  5. Respiration signals from photoplethysmography.

    Science.gov (United States)

    Nilsson, Lena M

    2013-10-01

    Pulse oximetry is based on the technique of photoplethysmography (PPG) wherein light transmitted through tissues is modulated by the pulse. In addition to variations in light modulation by the cardiac cycle, the PPG signal contains a respiratory modulation and variations associated with changing tissue blood volume of other origins. Cardiovascular, respiratory, and neural fluctuations in the PPG signal are of different frequencies and can all be characterized according to their sinusoidal components. PPG was described in 1937 to measure blood volume changes. The technique is today increasingly used, in part because of developments in semiconductor technology during recent decades that have resulted in considerable advances in PPG probe design. Artificial neural networks help to detect complex nonlinear relationships and are extensively used in electronic signal analysis, including PPG. Patient and/or probe-tissue movement artifacts are sources of signal interference. Physiologic variations such as vasoconstriction, a deep gasp, or yawn also affect the signal. Monitoring respiratory rates from PPG are often based on respiratory-induced intensity variations (RIIVs) contained in the baseline of the PPG signal. Qualitative RIIV signals may be used for monitoring purposes regardless of age, gender, anesthesia, and mode of ventilation. Detection of breaths in adult volunteers had a maximal error of 8%, and in infants the rates of overdetected and missed breaths using PPG were 1.5% and 2.7%, respectively. During central apnea, the rhythmic RIIV signals caused by variations in intrathoracic pressure disappear. PPG has been evaluated for detecting airway obstruction with a sensitivity of 75% and a specificity of 85%. The RIIV and the pulse synchronous PPG waveform are sensitive for detecting hypovolemia. The respiratory synchronous variation of the PPG pulse amplitude is an accurate predictor of fluid responsiveness. Pleth variability index is a continuous measure of the

  6. VLSI signal processing technology

    CERN Document Server

    Swartzlander, Earl

    1994-01-01

    This book is the first in a set of forthcoming books focussed on state-of-the-art development in the VLSI Signal Processing area. It is a response to the tremendous research activities taking place in that field. These activities have been driven by two factors: the dramatic increase in demand for high speed signal processing, especially in consumer elec­ tronics, and the evolving microelectronic technologies. The available technology has always been one of the main factors in determining al­ gorithms, architectures, and design strategies to be followed. With every new technology, signal processing systems go through many changes in concepts, design methods, and implementation. The goal of this book is to introduce the reader to the main features of VLSI Signal Processing and the ongoing developments in this area. The focus of this book is on: • Current developments in Digital Signal Processing (DSP) pro­ cessors and architectures - several examples and case studies of existing DSP chips are discussed in...

  7. Signal integrity characterization techniques

    CERN Document Server

    Bogatin, Eric

    2009-01-01

    "Signal Integrity Characterization Techniques" addresses the gap between traditional digital and microwave curricula all while focusing on a practical and intuitive understanding of signal integrity effects within the data transmission channel. High-speed interconnects such as connectors, PCBs, cables, IC packages, and backplanes are critical elements of differential channels that must be designed using today's most powerful analysis and characterization tools.Both measurements and simulation must be done on the device under test, and both activities must yield data that correlates with each other. Most of this book focuses on real-world applications of signal integrity measurements - from backplane for design challenges to error correction techniques to jitter measurement technologies. The authors' approach wisely addresses some of these new high-speed technologies, and it also provides valuable insight into its future direction and will teach the reader valuable lessons on the industry.

  8. Integrin signaling in atherosclerosis.

    Science.gov (United States)

    Finney, Alexandra C; Stokes, Karen Y; Pattillo, Christopher B; Orr, A Wayne

    2017-06-01

    Atherosclerosis, a chronic lipid-driven inflammatory disease affecting large arteries, represents the primary cause of cardiovascular disease in the world. The local remodeling of the vessel intima during atherosclerosis involves the modulation of vascular cell phenotype, alteration of cell migration and proliferation, and propagation of local extracellular matrix remodeling. All of these responses represent targets of the integrin family of cell adhesion receptors. As such, alterations in integrin signaling affect multiple aspects of atherosclerosis, from the earliest induction of inflammation to the development of advanced fibrotic plaques. Integrin signaling has been shown to regulate endothelial phenotype, facilitate leukocyte homing, affect leukocyte function, and drive smooth muscle fibroproliferative remodeling. In addition, integrin signaling in platelets contributes to the thrombotic complications that typically drive the clinical manifestation of cardiovascular disease. In this review, we examine the current literature on integrin regulation of atherosclerotic plaque development and the suitability of integrins as potential therapeutic targets to limit cardiovascular disease and its complications.

  9. Separation of Climate Signals

    Energy Technology Data Exchange (ETDEWEB)

    Kamath, C; Fodor, I

    2002-11-13

    Understanding changes in global climate is a challenging scientific problem. Simulated and observed data include signals from many sources, and untangling their respective effects is difficult. In order to make meaningful comparisons between different models, and to understand human effects on global climate, we need to isolate the effects of different sources. Recent eruptions of the El Chichon and Mt. Pinatubo volcanoes coincided with large El Nino and Southern Oscillation (ENSO) events, which complicates the separation of their contributions on global temperatures. Current approaches for separating volcano and ENSO signals in global mean data involve parametric models and iterative techniques [3]. We investigate alternative methods based on principal component analysis (PCA) [2] and independent component analysis (ICA) [1]. Our goal is to determine if such techniques can automatically identify the signals corresponding to the different sources, without relying on parametric models.

  10. Purinergic signalling and diabetes

    DEFF Research Database (Denmark)

    Burnstock, Geoffrey; Novak, Ivana

    2013-01-01

    signalling, we will focus on the role of purinergic signalling and its changes associated with diabetes in the pancreas and selected tissues/organ systems affected by hyperglycaemia and other stress molecules of diabetes. Since this is the first review of this kind, a comprehensive historical angle is taken......The pancreas is an organ with a central role in nutrient breakdown, nutrient sensing and release of hormones regulating whole body nutrient homeostasis. In diabetes mellitus, the balance is broken-cells can be starving in the midst of plenty. There are indications that the incidence of diabetes...... type 1 and 2, and possibly pancreatogenic diabetes, is rising globally. Events leading to insulin secretion and action are complex, but there is emerging evidence that intracellular nucleotides and nucleotides are not only important as intracellular energy molecules but also as extracellular signalling...

  11. PKD signaling and pancreatitis.

    Science.gov (United States)

    Yuan, Jingzhen; Pandol, Stephen J

    2016-07-01

    Acute pancreatitis is a serious medical disorder with no current therapies directed to the molecular pathogenesis of the disorder. Inflammation, inappropriate intracellular activation of digestive enzymes, and parenchymal acinar cell death by necrosis are the critical pathophysiologic processes of acute pancreatitis. Thus, it is necessary to elucidate the key molecular signals that mediate these pathobiologic processes and develop new therapeutic strategies to attenuate the appropriate signaling pathways in order to improve outcomes for this disease. A novel serine/threonine protein kinase D (PKD) family has emerged as key participants in signal transduction, and this family is increasingly being implicated in the regulation of multiple cellular functions and diseases. This review summarizes recent findings of our group and others regarding the signaling pathway and the biological roles of the PKD family in pancreatic acinar cells. In particular, we highlight our studies of the functions of PKD in several key pathobiologic processes associated with acute pancreatitis in experimental models. Our findings reveal that PKD signaling is required for NF-κB activation/inflammation, intracellular zymogen activation, and acinar cell necrosis in rodent experimental pancreatitis. Novel small-molecule PKD inhibitors attenuate the severity of pancreatitis in both in vitro and in vivo experimental models. Further, this review emphasizes our latest advances in the therapeutic application of PKD inhibitors to experimental pancreatitis after the initiation of pancreatitis. These novel findings suggest that PKD signaling is a necessary modulator in key initiating pathobiologic processes of pancreatitis, and that it constitutes a novel therapeutic target for treatments of this disorder.

  12. Notch signaling and ageing.

    Science.gov (United States)

    Polychronidou, Eleftheria; Vlachakis, Dimitrios; Vlamos, Panayiotis; Baumann, Marc; Kossida, Sophia

    2015-01-01

    Notch signaling is a master controller of the neural stem cell and neural development maintaining a significant role in the normal brain function. Notch genes are involved in embryogenesis, nervous system, and cardiovascular and endocrine function. On the other side, there are studies representing the involvement of Notch mutations in sporadic Alzheimer disease, other neurodegenerative diseases such as Down syndrome, Pick's and Prion's disease, and CADASIL. This manuscript attempts to present a holistic view of the positive or negative contribution of Notch signaling in the adult brain, and at the same time to present and promote the promising research fields of study.

  13. Understanding signal integrity

    CERN Document Server

    Thierauf, Stephen C

    2010-01-01

    This unique book provides you with practical guidance on understanding and interpreting signal integrity (SI) performance to help you with your challenging circuit board design projects. You find high-level discussions of important SI concepts presented in a clear and easily accessible format, including question and answer sections and bulleted lists.This valuable resource features rules of thumb and simple equations to help you make estimates of critical signal integrity parameters without using circuit simulators of CAD (computer-aided design). The book is supported with over 120 illustratio

  14. Electronic signal conditioning

    CERN Document Server

    NEWBY, BRUCE

    1994-01-01

    At technician level, brief references to signal conditioning crop up in a fragmented way in various textbooks, but there has been no single textbook, until now!More advanced texts do exist but they are more mathematical and presuppose a higher level of understanding of electronics and statistics. Electronic Signal Conditioning is designed for HNC/D students and City & Guilds Electronics Servicing 2240 Parts 2 & 3. It will also be useful for BTEC National, Advanced GNVQ, A-level electronics and introductory courses at degree level.

  15. Genomic signal processing

    CERN Document Server

    Shmulevich, Ilya

    2007-01-01

    Genomic signal processing (GSP) can be defined as the analysis, processing, and use of genomic signals to gain biological knowledge, and the translation of that knowledge into systems-based applications that can be used to diagnose and treat genetic diseases. Situated at the crossroads of engineering, biology, mathematics, statistics, and computer science, GSP requires the development of both nonlinear dynamical models that adequately represent genomic regulation, and diagnostic and therapeutic tools based on these models. This book facilitates these developments by providing rigorous mathema

  16. Analog signal isolation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Beadle, E.R.

    1992-12-31

    This paper discusses several techniques for isolating analog signals in an accelerator environment. The techniques presented here encompass isolation amplifiers, voltage-to-frequency converters (VIFCs), transformers, optocouplers, discrete fiber optics, and commercial fiber optic links. Included within the presentation of each method are the design issues that must be considered when selecting the isolation method for a specific application.

  17. Analog signal isolation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Beadle, E.R.

    1992-01-01

    This paper discusses several techniques for isolating analog signals in an accelerator environment. The techniques presented here encompass isolation amplifiers, voltage-to-frequency converters (VIFCs), transformers, optocouplers, discrete fiber optics, and commercial fiber optic links. Included within the presentation of each method are the design issues that must be considered when selecting the isolation method for a specific application.

  18. Drought Signaling in Plants

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 6. Drought Signaling in Plants. G Sivakumar Swamy. General Article Volume 4 Issue 6 June 1999 pp 34-44. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/004/06/0034-0044. Author Affiliations.

  19. Symposium: Unveiling Affective Signals

    NARCIS (Netherlands)

    van den Broek, Egon; Nijholt, Antinus; Westerink, J.H.D.M.; Spink, A.J.; Grieco, F; Krips, O.E.; Loijens, L.W.S.; Noldus, L.P.J.J.; Zimmerman, P.H.

    2010-01-01

    The ability to process and, subsequently, understand affective signals is the core of emotional intelligence and empathy. However, more than a decade of research in affective computing has shown that it is hard to develop computational models of this process. We pose that the solution for this

  20. Unveiling Affective Signals

    NARCIS (Netherlands)

    van den Broek, Egon; Nijholt, Antinus; Westerink, J.H.D.M.; Barakova, E.; de Ruyter, B.; Spink, A

    2010-01-01

    The ability to process and, subsequently, understand affective signals is the core of emotional intelligence and empathy. However, more than a decade of research in affective computing has shown that it is hard to develop computational models of this process. We pose that the solution for this

  1. Selenium and redox signaling.

    Science.gov (United States)

    Brigelius-Flohé, Regina; Flohé, Leopold

    2017-03-01

    Selenium compounds that contain selenol functions or can be metabolized to selenols are toxic via superoxide and H2O2 generation, when ingested at dosages beyond requirement. At supra-nutritional dosages various forms of programmed cell death are observed. At physiological intakes, selenium exerts its function as constituent of selenoproteins, which overwhelmingly are oxidoreductases. Out of those, the glutathione peroxidases counteract hydroperoxide-stimulated signaling cascades comprising inflammation triggered by cytokines or lipid mediators, insulin signaling and different forms of programmed cell death. Similar events are exerted by peroxiredoxins, which functionally depend on the selenoproteins of the thioredoxin reductase family. The thiol peroxidases of both families can, however, also act as sensors for hydroperoxides, thereby initiating signaling cascades. Although the interaction of selenoproteins with signaling events has been established by genetic techniques, the in vivo relevance of these findings is still hard to delineate for several reasons: The biosynthesis of individual selenoproteins responds differently to variations of selenium intakes; selenium is preferentially delivered to privileged tissues via inter-organ trafficking and receptor-mediated uptake, and only half of the selenoproteins known by sequence have been functionally characterized. The fragmentary insights do not allow any uncritical use of selenium for optimizing human health. Copyright © 2016. Published by Elsevier Inc.

  2. Satiety signals and obesity.

    Science.gov (United States)

    Hellström, Per M

    2013-03-01

    The obesity epidemic over the world has called to attention different ways to manage this development. As bariatric surgery today is the only manner by which rapid and sustained weight control can be achieved, new ways of treating obesity are under investigation. This review focuses on today's knowledge on satiety signaling as a means to combat obesity. The combined knowledge achieved from obesity surgery with gastric bypass and duodenal switch together with the pharmacological treatment of type 2 diabetes have given us some clues of how to manage obesity. The basis for our understanding is the present research focusing on the gut peptide hormones that are released in response to food intake, and the paucity of satiety signaling seems to prevail in obesity. This means that obese patients experience less activation of higher brain centers in association with a meal and therefore compensate with increased meal size or frequent food intake. Altered satiety signaling primarily emanating from the gastrointestinal tract seems to lead to the development of obesity and type 2 diabetes. Pharmacological tools that enhance the gut hormone signaling are in focus for the upcoming venues of treatment.

  3. Signalling Nouns in Discourse.

    Science.gov (United States)

    Flowerdew, John

    2003-01-01

    Presents a description of a major class of vocabulary, signalling nouns, that have important discourse functions in establishing links across and within clauses. The description provides a framework useful to materials writers, teachers, and learners of English for academic purposes. (Author/VWL)

  4. Small Turing universal signal machines

    Directory of Open Access Journals (Sweden)

    Jérôme Durand-Lose

    2009-06-01

    Full Text Available This article aims at providing signal machines as small as possible able to perform any computation (in the classical understanding. After presenting signal machines, it is shown how to get universal ones from Turing machines, cellular-automata and cyclic tag systems. Finally a halting universal signal machine with 13 meta-signals and 21 collision rules is presented.

  5. Critical nodes in signalling pathways

    DEFF Research Database (Denmark)

    Taniguchi, Cullen M; Emanuelli, Brice; Kahn, C Ronald

    2006-01-01

    Physiologically important cell-signalling networks are complex, and contain several points of regulation, signal divergence and crosstalk with other signalling cascades. Here, we use the concept of 'critical nodes' to define the important junctions in these pathways and illustrate their unique role...... using insulin signalling as a model system....

  6. Multiresolution Analysis of EEG Signals

    OpenAIRE

    Borowska Marta; Białobłocka Natalia

    2016-01-01

    This paper reports on a multiresolution analysis of EEG signals. The dominant frequency components of signals with and without observed epileptic discharges were compared. The study showed that there were significant differences in dominant frequency between the signals with epileptic discharges and the signals without discharges. This gives the ability to identify epilepsy during EEG examination. The frequency of the signals coming from the frontal, central, parietal and occipital channels a...

  7. Signals and Responses

    Science.gov (United States)

    Lee, Angie

    2006-01-01

    The nitrogen-fixing symbiosis between bacteria in the family Rhizobiaceae and members of the legume family (Fabaceae) has been well studied, particularly from the perspective of the early signaling and recognition events. Recent studies of non-nodulating legume mutants have resulted in the identification of a number of genes that are responsive to signal molecules from the bacteria. However, a second group of nodule-forming bacteria, completely unrelated to the Rhizobiaceae, which are α-Proteobacteria, has been discovered. These bacteria belong to the β-Proteobacteria and have been designated β-rhizobia to distinguish them from the better-known α-rhizobia. Here, we review what is known in this economically important symbiosis about the interaction between legumes and α-rhizobia, and we incorporate information, where known, about the β-rhizobia. PMID:19521481

  8. Biomedical signal analysis

    CERN Document Server

    Rangayyan, Rangaraj M

    2015-01-01

    The book will help assist a reader in the development of techniques for analysis of biomedical signals and computer aided diagnoses with a pedagogical examination of basic and advanced topics accompanied by over 350 figures and illustrations. Wide range of filtering techniques presented to address various applications. 800 mathematical expressions and equations. Practical questions, problems and laboratory exercises. Includes fractals and chaos theory with biomedical applications.

  9. [The effect of different fluoride concentrations on the expression of transforming growth factor-beta1 in ameloblast of rat incisor].

    Science.gov (United States)

    Zhang, Xueli; Zhang, Ying; Xi, Shuhua; Cheng, Guangyan; Guo, Xiaoying

    2012-08-01

    To investigate the effect of different concentrations of fluoride on the expression of transforming growth factor-beta1 (TGF-beta1), and explore the mechanism of dental fluorosis. 40 Wistar rats were randomly divided into three groups, and supplied with low dose F(-)(60 mgxL(-1), 13 rats), high dose F(-)(120 mgxL(-1), 13 rats) and distilled water(control group, 14 rats) respectively. After 10 weeks, hematoxylin-eosin (HE) and immunohistochemistry staining were used to observe the changes of the ameloblasts and the expression of TGF-beta1 in rat incisors. The fluoride groups showed typical symptoms of dental fluorosis. The surfaces of the rat teeth fed with fluoride appeared chalky color and cross striation on the enamel surface. The HE staining showed that the morphous of ameloblast were disarranged and cellular derangement, even appeared vacuolar change. TGF-beta1 were expressed both in ameloblast of the secretory and maturation stage, and also in stellate reticulum and stratum intermedium. The expression of TGF-beta1 in rat's ameloblasts in experiment group was significantly lower than that in the control group (P0.05). By inhibiting the expression of TGF-beta1 in ameloblast, fluoride interferes the normal signal transduction between epithelial and mesenchymal, and affect the differentiation and development of enamel, so leading to the occurrence of dental fluorosis.

  10. Multimodal signalling in estrildid finches

    DEFF Research Database (Denmark)

    Gomes, A. C. R.; Funghi, C.; Soma, M.

    2017-01-01

    Sexual traits (e.g. visual ornaments, acoustic signals, courtship behaviour) are often displayed together as multimodal signals. Some hypotheses predict joint evolution of different sexual signals (e.g. to increase the efficiency of communication) or that different signals trade off with each other...... in reproduction, dance with commonness and habitat type, whereas colour ornamentation was shown previously to correlate mostly with gregariousness. We conclude that multimodal signals evolve in response to various socio-ecological traits, suggesting the accumulation of distinct signalling functions....

  11. Biomedical signal and image processing

    CERN Document Server

    Najarian, Kayvan

    2012-01-01

    INTRODUCTION TO DIGITAL SIGNAL AND IMAGE PROCESSINGSignals and Biomedical Signal ProcessingIntroduction and OverviewWhat is a ""Signal""?Analog, Discrete, and Digital SignalsProcessing and Transformation of SignalsSignal Processing for Feature ExtractionSome Characteristics of Digital ImagesSummaryProblemsFourier TransformIntroduction and OverviewOne-Dimensional Continuous Fourier TransformSampling and NYQUIST RateOne-Dimensional Discrete Fourier TransformTwo-Dimensional Discrete Fourier TransformFilter DesignSummaryProblemsImage Filtering, Enhancement, and RestorationIntroduction and Overview

  12. Signal analyser, the software support for education of signal processing

    Directory of Open Access Journals (Sweden)

    Tùma Jiøí

    2003-12-01

    Full Text Available The paper deals with the software that is supporting signal-processing lectures given for students of mechanical engineering. An application, named Signal Analyser is written in Visual Basic 6.0 language so it is working under Windows operating systems. The main idea is to demonstrate spectral analysis of signals that are taken from measurements in industry or synthesised by an incorporate signal generator.

  13. Purinergic Signalling: Therapeutic Developments

    Directory of Open Access Journals (Sweden)

    Geoffrey Burnstock

    2017-09-01

    Full Text Available Purinergic signalling, i.e., the role of nucleotides as extracellular signalling molecules, was proposed in 1972. However, this concept was not well accepted until the early 1990’s when receptor subtypes for purines and pyrimidines were cloned and characterised, which includes four subtypes of the P1 (adenosine receptor, seven subtypes of P2X ion channel receptors and 8 subtypes of the P2Y G protein-coupled receptor. Early studies were largely concerned with the physiology, pharmacology and biochemistry of purinergic signalling. More recently, the focus has been on the pathophysiology and therapeutic potential. There was early recognition of the use of P1 receptor agonists for the treatment of supraventricular tachycardia and A2A receptor antagonists are promising for the treatment of Parkinson’s disease. Clopidogrel, a P2Y12 antagonist, is widely used for the treatment of thrombosis and stroke, blocking P2Y12 receptor-mediated platelet aggregation. Diquafosol, a long acting P2Y2 receptor agonist, is being used for the treatment of dry eye. P2X3 receptor antagonists have been developed that are orally bioavailable and stable in vivo and are currently in clinical trials for the treatment of chronic cough, bladder incontinence, visceral pain and hypertension. Antagonists to P2X7 receptors are being investigated for the treatment of inflammatory disorders, including neurodegenerative diseases. Other investigations are in progress for the use of purinergic agents for the treatment of osteoporosis, myocardial infarction, irritable bowel syndrome, epilepsy, atherosclerosis, depression, autism, diabetes, and cancer.

  14. Automatic Seismic Signal Processing

    Science.gov (United States)

    1982-02-04

    81-04 4 February 1982 AUTOMATIC SEISMIC SIGNAL PROCESSING FINAL TECHNICAL REPORT i j Contract F08606-80.C-0021" PREPARED BY ILKKA NOPONEN, ROBERT SAX...PERFORMING ORG. REPORT NUMBER SAS-FR-81-04 7. AUTHOR(e) a. CONTRACT OR GRANT NUMBER(e) F08606- 80-C-0021 ILKKA NOPONEN, ROBERT SAX AND F 6 C0 STEVEN...observed, as also Swindell and Snell (1977), that the distribu- tion of x was slightly skewed, we used the median of x instead of aver- age of x for U(x

  15. Phonocardiography Signal Processing

    CERN Document Server

    Abbas, Abbas K

    2009-01-01

    The auscultation method is an important diagnostic indicator for hemodynamic anomalies. Heart sound classification and analysis play an important role in the auscultative diagnosis. The term phonocardiography refers to the tracing technique of heart sounds and the recording of cardiac acoustics vibration by means of a microphone-transducer. Therefore, understanding the nature and source of this signal is important to give us a tendency for developing a competent tool for further analysis and processing, in order to enhance and optimize cardiac clinical diagnostic approach. This book gives the

  16. Micromechanical Signal Processors

    Science.gov (United States)

    Nguyen, Clark Tu-Cuong

    Completely monolithic high-Q micromechanical signal processors constructed of polycrystalline silicon and integrated with CMOS electronics are described. The signal processors implemented include an oscillator, a bandpass filter, and a mixer + filter--all of which are components commonly required for up- and down-conversion in communication transmitters and receivers, and all of which take full advantage of the high Q of micromechanical resonators. Each signal processor is designed, fabricated, then studied with particular attention to the performance consequences associated with miniaturization of the high-Q element. The fabrication technology which realizes these components merges planar integrated circuit CMOS technologies with those of polysilicon surface micromachining. The technologies are merged in a modular fashion, where the CMOS is processed in the first module, the microstructures in a following separate module, and at no point in the process sequence are steps from each module intermixed. Although the advantages of such modularity include flexibility in accommodating new module technologies, the developed process constrained the CMOS metallization to a high temperature refractory metal (tungsten metallization with TiSi _2 contact barriers) and constrained the micromachining process to long-term temperatures below 835^circC. Rapid-thermal annealing (RTA) was used to relieve residual stress in the mechanical structures. To reduce the complexity involved with developing this merged process, capacitively transduced resonators are utilized. High-Q single resonator and spring-coupled micromechanical resonator filters are also investigated, with particular attention to noise performance, bandwidth control, and termination design. The noise in micromechanical filters is found to be fairly high due to poor electromechanical coupling on the micro-scale with present-day technologies. Solutions to this high series resistance problem are suggested, including smaller

  17. Neural Membrane Signaling Platforms

    Directory of Open Access Journals (Sweden)

    Ron Wallace

    2010-06-01

    Full Text Available Throughout much of the history of biology, the cell membrane was functionally defined as a semi-permeable barrier separating aqueous compartments, and an anchoring site for proteins. Little attention was devoted to its possible regulatory role in intracellular molecular processes and neuron electrical signaling. This article reviews the history of membrane studies and the current state of the art. Emphasis is placed on natural and artificial membrane studies of electric field effects on molecular organization, especially as these may relate to impulse propagation in neurons. Implications of these studies for new designs in artificial intelligence are briefly examined.

  18. Neural membrane signaling platforms.

    Science.gov (United States)

    Wallace, Ron

    2010-06-10

    Throughout much of the history of biology, the cell membrane was functionally defined as a semi-permeable barrier separating aqueous compartments, and an anchoring site for proteins. Little attention was devoted to its possible regulatory role in intracellular molecular processes and neuron electrical signaling. This article reviews the history of membrane studies and the current state of the art. Emphasis is placed on natural and artificial membrane studies of electric field effects on molecular organization, especially as these may relate to impulse propagation in neurons. Implications of these studies for new designs in artificial intelligence are briefly examined.

  19. Strigolactone Signaling and Evolution.

    Science.gov (United States)

    Waters, Mark T; Gutjahr, Caroline; Bennett, Tom; Nelson, David C

    2017-04-28

    Strigolactones are a structurally diverse class of plant hormones that control many aspects of shoot and root growth. Strigolactones are also exuded by plants into the rhizosphere, where they promote symbiotic interactions with arbuscular mycorrhizal fungi and germination of root parasitic plants in the Orobanchaceae family. Therefore, understanding how strigolactones are made, transported, and perceived may lead to agricultural innovations as well as a deeper knowledge of how plants function. Substantial progress has been made in these areas over the past decade. In this review, we focus on the molecular mechanisms, core developmental roles, and evolutionary history of strigolactone signaling. We also propose potential translational applications of strigolactone research to agriculture.

  20. A photonic integrated signal processor

    Science.gov (United States)

    Yao, Jianping

    2017-02-01

    A photonic integrated signal processor based on the InP-InGaAsP material system consisting of a bypass waveguide and three mutually-coupled micro rings with each ring having two semiconductor optical amplifiers (SOAs) and a current-injection phase modulator (PM) for ultra-wideband signal processing and microwave signal generation is discussed. The signal processor can be reconfigured to perform signal processing functions including temporal differentiation, and temporal integration. The reconfigurability is achieved by controlling the coupling between the rings and the bypass waveguide by a multi-mode interference (MMI) Mach-Zehnder interferometer (MZI) coupler and the injection currents to the SOAs. The current injection PM in a ring is used for wavelength tuning. In addition to signal processing, the signal processor can also be reconfigured to operate as a microwave signal generator. The generation a linearly chirped microwave waveform is discussed.

  1. Biological signals classification and analysis

    CERN Document Server

    Kiasaleh, Kamran

    2015-01-01

    This authored monograph presents key aspects of signal processing analysis in the biomedical arena. Unlike wireless communication systems, biological entities produce signals with underlying nonlinear, chaotic nature that elude classification using the standard signal processing techniques, which have been developed over the past several decades for dealing primarily with standard communication systems. This book separates what is random from that which appears to be random, and yet is truly deterministic with random appearance. At its core, this work gives the reader a perspective on biomedical signals and the means to classify and process such signals. In particular, a review of random processes along with means to assess the behavior of random signals is also provided. The book also includes a general discussion of biological signals in order to demonstrate the inefficacy of the well-known techniques to correctly extract meaningful information from such signals. Finally, a thorough discussion of recently ...

  2. Operational semantics for signal handling

    Directory of Open Access Journals (Sweden)

    Maxim Strygin

    2012-08-01

    Full Text Available Signals are a lightweight form of interprocess communication in Unix. When a process receives a signal, the control flow is interrupted and a previously installed signal handler is run. Signal handling is reminiscent both of exception handling and concurrent interleaving of processes. In this paper, we investigate different approaches to formalizing signal handling in operational semantics, and compare them in a series of examples. We find the big-step style of operational semantics to be well suited to modelling signal handling. We integrate exception handling with our big-step semantics of signal handling, by adopting the exception convention as defined in the Definition of Standard ML. The semantics needs to capture the complex interactions between signal handling and exception handling.

  3. Recurrent Infections May Signal Immunodeficiencies

    Science.gov (United States)

    ... Recurrent Infections May Signal Immunodeficiencies Share | Recurrent Infections May Signal Immunodeficiencies This article has been reviewed by ... common bacterial infections? If so, these recurrent infections may be a sign of an immunodeficiency disorder. The ...

  4. Insulin receptor signaling in cones

    National Research Council Canada - National Science Library

    Rajala, Ammaji; Dighe, Radhika; Agbaga, Martin-Paul; Anderson, Robert E; Rajala, Raju V S

    2013-01-01

    .... To date there are no studies on the insulin receptor signaling in cones; however, mRNA levels of IR signaling proteins are significantly higher in cone-dominant neural retina leucine zipper (Nrl...

  5. Multiscale Signal Analysis and Modeling

    CERN Document Server

    Zayed, Ahmed

    2013-01-01

    Multiscale Signal Analysis and Modeling presents recent advances in multiscale analysis and modeling using wavelets and other systems. This book also presents applications in digital signal processing using sampling theory and techniques from various function spaces, filter design, feature extraction and classification, signal and image representation/transmission, coding, nonparametric statistical signal processing, and statistical learning theory. This book also: Discusses recently developed signal modeling techniques, such as the multiscale method for complex time series modeling, multiscale positive density estimations, Bayesian Shrinkage Strategies, and algorithms for data adaptive statistics Introduces new sampling algorithms for multidimensional signal processing Provides comprehensive coverage of wavelets with presentations on waveform design and modeling, wavelet analysis of ECG signals and wavelet filters Reviews features extraction and classification algorithms for multiscale signal and image proce...

  6. Digital Signal Processing (Second Edition)

    OpenAIRE

    Blackledge, Jonathan

    2006-01-01

    This book provides an account of the mathematical background, computational methods and software engineering associated with digital signal processing. The aim has been to provide the reader with the mathematical methods required for signal analysis which are then used to develop models and algorithms for processing digital signals and finally to encourage the reader to design software solutions for Digital Signal Processing (DSP). In this way, the reader is invited to develop a small DSP lib...

  7. Wireless data signal transmission system

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to a method for providing a radio frequency signal for transmission, a system for providing a radio frequency signal for transmission and a method for wireless data transmission between a transmitter and a receiver.......The present invention relates to a method for providing a radio frequency signal for transmission, a system for providing a radio frequency signal for transmission and a method for wireless data transmission between a transmitter and a receiver....

  8. Thermal Resonance in Signal Transmission

    OpenAIRE

    Reigada Sanz, Ramon; Sarmiento, Antonio; Lindenberg, Katja

    2001-01-01

    We use temperature tuning to control signal propagation in simple one-dimensional arrays of masses connected by hard anharmonic springs and with no local potentials. In our numerical model a sustained signal is applied at one site of a chain immersed in a thermal environment and the signal-to-noise ratio is measured at each oscillator. We show that raising the temperature can lead to enhanced signal propagation along the chain, resulting in thermal resonance effects akin to the resonance obse...

  9. Two-dimensional signal analysis

    CERN Document Server

    Garello, René

    2010-01-01

    This title sets out to show that 2-D signal analysis has its own role to play alongside signal processing and image processing.Concentrating its coverage on those 2-D signals coming from physical sensors (such as radars and sonars), the discussion explores a 2-D spectral approach but develops the modeling of 2-D signals and proposes several data-oriented analysis techniques for dealing with them. Coverage is also given to potential future developments in this area.

  10. Asymmetry In Biphase Data Signals

    Science.gov (United States)

    Nguyen, Tien M.

    1992-01-01

    Report presents analysis of some effects of asymmetry in Manchester (biphase) binary data signal transmitted by phase modulation of sinusoidal carrier signal. Report extends analysis described in article, "Effects of Asymmetry of NRZ Data Signals on Performance" (NPO-18261), to include case where data biphase-modulated directly on residual carrier.

  11. Cellular signalling properties in microcircuits

    DEFF Research Database (Denmark)

    Toledo-Rodriguez, Maria; El Manira, Abdeljabbar; Wallén, Peter

    2005-01-01

    Molecules and cells are the signalling elements in microcircuits. Recent studies have uncovered bewildering diversity in postsynaptic signalling properties in all areas of the vertebrate nervous system. Major effort is now being invested in establishing the specialized signalling properties at th...

  12. Advances in abscission signaling.

    Science.gov (United States)

    Patharkar, O Rahul; Walker, John C

    2018-02-12

    Abscission is a process in plants for shedding unwanted organs such as leaves, flowers, fruits, or floral organs. Shedding of leaves in the fall is the most visually obvious display of abscission in nature. The very shape plants take is forged by the processes of growth and abscission. Mankind manipulates abscission in modern agriculture to do things such as prevent pre-harvest fruit drop prior to mechanical harvesting in orchards. Abscission occurs specifically at abscission zones that are laid down as the organ that will one day abscise is developed. A sophisticated signaling network initiates abscission when it is time to shed the unwanted organ. In this article, we review recent advances in understanding the signaling mechanisms that activate abscission. Physiological advances and roles for hormones in abscission are also addressed. Finally, we discuss current avenues for basic abscission research and potentially lucrative future directions for its application to modern agriculture. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  13. Advances in TRH signaling.

    Science.gov (United States)

    Joseph-Bravo, Patricia; Jaimes-Hoy, Lorraine; Charli, Jean-Louis

    2016-12-01

    The activity of the hypothalamus-pituitary-thyroid axis (HPT) is coordinated by hypophysiotropic thyrotropin releasing hormone (TRH) neurons present in the paraventricular nucleus of the hypothalamus. Hypophysiotropic TRH neurons act as energy sensors. TRH controls the synthesis and release of thyrotropin, which activates the synthesis and secretion of thyroid hormones; in target tissues, transporters and deiodinases control their local availability. Thyroid hormones regulate many functions, including energy homeostasis. This review discusses recent evidence that covers several aspects of TRH role in HPT axis regulation. Knowledge about the mechanisms of TRH signaling has steadily increased. New transcription factors engaged in TRH gene expression have been identified, and advances made on how they interact with signaling pathways and define the dynamics of TRH neurons response to acute and/or long-term influences. Albeit yet incomplete, the relationship of TRH neurons activity with positive energy balance has emerged. The importance of tanycytes as a central relay for the feedback control of the axis, as well as for HPT responses to alterations in energy balance, and other stimuli has been reinforced. Finally, some studies have started to shed light on the interference of prenatal and postnatal stress and nutrition on HPT axis programing, which have confirmed the axis susceptibility to early insults.

  14. Signals and systems for dummies

    CERN Document Server

    Wickert, Mark

    2013-01-01

    Getting mixed signals in your signals and systems course? The concepts covered in a typical signals and systems course are often considered by engineering students to be some of the most difficult to master. Thankfully, Signals & Systems For Dummies is your intuitive guide to this tricky course, walking you step-by-step through some of the more complex theories and mathematical formulas in a way that is easy to understand. From Laplace Transforms to Fourier Analyses, Signals & Systems For Dummies explains in plain English the difficult concepts that can trip you up

  15. Multiresolution Analysis of EEG Signals

    Directory of Open Access Journals (Sweden)

    Borowska Marta

    2016-12-01

    Full Text Available This paper reports on a multiresolution analysis of EEG signals. The dominant frequency components of signals with and without observed epileptic discharges were compared. The study showed that there were significant differences in dominant frequency between the signals with epileptic discharges and the signals without discharges. This gives the ability to identify epilepsy during EEG examination. The frequency of the signals coming from the frontal, central, parietal and occipital channels are similar. Multiresolution analysis can be used to describe the activity of brain waves and to try to predict epileptic seizures, thereby contributing to precise medical diagnoses.

  16. Detection of signals in noise

    CERN Document Server

    Whalen, Anthony D; Declaris, Nicholas

    1971-01-01

    Detection of Signals in Noise serves as an introduction to the principles and applications of the statistical theory of signal detection. The book discusses probability and random processes; narrowband signals, their complex representation, and their properties described with the aid of the Hilbert transform; and Gaussian-derived processes. The text also describes the application of hypothesis testing for the detection of signals and the fundamentals required for statistical detection of signals in noise. Problem exercises, references, and a supplementary bibliography are included after each c

  17. Machine intelligence and signal processing

    CERN Document Server

    Vatsa, Mayank; Majumdar, Angshul; Kumar, Ajay

    2016-01-01

    This book comprises chapters on key problems in machine learning and signal processing arenas. The contents of the book are a result of a 2014 Workshop on Machine Intelligence and Signal Processing held at the Indraprastha Institute of Information Technology. Traditionally, signal processing and machine learning were considered to be separate areas of research. However in recent times the two communities are getting closer. In a very abstract fashion, signal processing is the study of operator design. The contributions of signal processing had been to device operators for restoration, compression, etc. Applied Mathematicians were more interested in operator analysis. Nowadays signal processing research is gravitating towards operator learning – instead of designing operators based on heuristics (for example wavelets), the trend is to learn these operators (for example dictionary learning). And thus, the gap between signal processing and machine learning is fast converging. The 2014 Workshop on Machine Intel...

  18. Systemic signaling during plant defense.

    Science.gov (United States)

    Kachroo, Aardra; Robin, Guillaume P

    2013-08-01

    Systemic acquired resistance (SAR) is a type of pathogen-induced broad-spectrum resistance in plants. During SAR, primary infection-induced rapid generation and transportation of mobile signal(s) 'prepare' the rest of the plant for subsequent infections. Several, seemingly unrelated, mobile chemical inducers of SAR have been identified, at least two of which function in a feed-back regulatory loop with a lipid transfer-like protein. Signal(s) perception in the systemic tissues relies on the presence of an intact cuticle, the waxy layer covering all aerial parts of the plant. SAR results in chromatin modifications, which prime systemic tissues for enhanced and rapid signaling derived from salicylic acid, which along with its signaling components is key for SAR induction. This review summarizes recent findings related to SAR signal generation, movement, and perception. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Measuring signal generators theory & design

    CERN Document Server

    Rybin, Yuriy K

    2014-01-01

    The book brings together the following issues: Theory of deterministic, random and discrete signals reproducible in oscillatory systems of generators; Generation of periodic signals with a specified spectrum, harmonic distortion factor and random signals with specified probability density function and spectral density; Synthesis of oscillatory system structures; Analysis of oscillatory systems with non-linear elements and oscillation amplitude stabilization systems; It considers the conditions and criteria of steady-state modes in signal generators on active four-pole elements with unidirectional and bidirectional transmission of signals and on two-pole elements; analogues of Barkhausen criteria; Optimization of oscillatory system structures by harmonic distortion level, minimization of a frequency error and set-up time of the steady state mode; Theory of construction of random signal generators; Construction of discrete and digital signal generators; Practical design of main units of generators; Practical bl...

  20. [Signal Processing Suite Design

    Science.gov (United States)

    Sahr, John D.; Mir, Hasan; Morabito, Andrew; Grossman, Matthew

    2003-01-01

    Our role in this project was to participate in the design of the signal processing suite to analyze plasma density measurements on board a small constellation (3 or 4) satellites in Low Earth Orbit. As we are new to space craft experiments, one of the challenges was to simply gain understanding of the quantity of data which would flow from the satellites, and possibly to interact with the design teams in generating optimal sampling patterns. For example, as the fleet of satellites were intended to fly through the same volume of space (displaced slightly in time and space), the bulk plasma structure should be common among the spacecraft. Therefore, an optimal, limited bandwidth data downlink would take advantage of this commonality. Also, motivated by techniques in ionospheric radar, we hoped to investigate the possibility of employing aperiodic sampling in order to gain access to a wider spatial spectrum without suffering aliasing in k-space.

  1. Signaling dynamics and peroxisomes.

    Science.gov (United States)

    Mast, Fred D; Rachubinski, Richard A; Aitchison, John D

    2015-08-01

    Peroxisomes are remarkably responsive organelles. Their composition, abundance and even their mechanism of biogenesis are influenced strongly by cell type and the environment. This plasticity underlies peroxisomal functions in metabolism and the detoxification of dangerous reactive oxygen species. However, peroxisomes are integrated into the cellular system as a whole such that they communicate intimately with other organelles, control signaling dynamics as in the case of innate immune responses to infectious disease, and contribute to processes as fundamental as longevity. The increasing evidence for peroxisomes having roles in various cellular and organismal functions, combined with their malleability, suggests complex mechanisms operate to control cellular dynamics and the specificity of cellular responses and functions extending well beyond the peroxisome itself. A deeper understanding of the functions of peroxisomes and the mechanisms that control their plasticity could offer opportunities for exploiting changes in peroxisome abundance to control cellular function. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. HVEM signalling promotes colitis.

    Directory of Open Access Journals (Sweden)

    Corinne Schaer

    Full Text Available BACKGROUND: Tumor necrosis factor super family (TNFSF members regulate important processes involved in cell proliferation, survival and differentiation and are therefore crucial for the balance between homeostasis and inflammatory responses. Several members of the TNFSF are closely associated with inflammatory bowel disease (IBD. Thus, they represent interesting new targets for therapeutic treatment of IBD. METHODOLOGY/PRINCIPAL FINDINGS: We have used mice deficient in TNFSF member HVEM in experimental models of IBD to investigate its role in the disease process. Two models of IBD were employed: i chemical-induced colitis primarily mediated by innate immune cells; and ii colitis initiated by CD4(+CD45RB(high T cells following their transfer into immuno-deficient RAG1(-/- hosts. In both models of disease the absence of HVEM resulted in a significant reduction in colitis and inflammatory cytokine production. CONCLUSIONS: These data show that HVEM stimulatory signals promote experimental colitis driven by innate or adaptive immune cells.

  3. PKC signaling in glioblastoma

    Science.gov (United States)

    do Carmo, Anália; Balça-Silva, Joana; Matias, Diana; Lopes, Maria Celeste

    2013-01-01

    Glioblastoma Multiforme (GBM) is the most aggressive brain tumor characterized by intratumoral heterogeneity at cytopathological, genomic and transcriptional levels. Despite the efforts to develop new therapeutic strategies the median survival of GBM patients is 12−14 months. Results from large-scale gene expression profile studies confirmed that the genetic alterations in GBM affect pathways controlling cell cycle progression, cellular proliferation and survival and invasion ability, which may explain the difficulty to treat GBM patients. One of the signaling pathways that contribute to the aggressive behavior of glioma cells is the protein kinase C (PKC) pathway. PKC is a family of serine/threonine-specific protein kinases organized into three groups according the activating domains. Due to the variability of actions controlled by PKC isoforms, its contribution to the development of GBM is poorly understood. This review intends to highlight the contribution of PKC isoforms to proliferation, survival and invasive ability of glioma cells. PMID:23358475

  4. Regulation of Hippo signalling by p38 signalling.

    Science.gov (United States)

    Huang, Dashun; Li, Xiaojiao; Sun, Li; Huang, Ping; Ying, Hao; Wang, Hui; Wu, Jiarui; Song, Haiyun

    2016-08-01

    The Hippo signalling pathway has a crucial role in growth control during development, and its dysregulation contributes to tumorigenesis. Recent studies uncover multiple upstream regulatory inputs into Hippo signalling, which affects phosphorylation of the transcriptional coactivator Yki/YAP/TAZ by Wts/Lats. Here we identify the p38 mitogen-activated protein kinase (MAPK) pathway as a new upstream branch of the Hippo pathway. In Drosophila, overexpression of MAPKK gene licorne (lic), or MAPKKK gene Mekk1, promotes Yki activity and induces Hippo target gene expression. Loss-of-function studies show that lic regulates Hippo signalling in ovary follicle cells and in the wing disc. Epistasis analysis indicates that Mekk1 and lic affect Hippo signalling via p38b and wts We further demonstrate that the Mekk1-Lic-p38b cascade inhibits Hippo signalling by promoting F-actin accumulation and Jub phosphorylation. In addition, p38 signalling modulates actin filaments and Hippo signalling in parallel to small GTPases Ras, Rac1, and Rho1. Lastly, we show that p38 signalling regulates Hippo signalling in mammalian cell lines. The Lic homologue MKK3 promotes nuclear localization of YAP via the actin cytoskeleton. Upregulation or downregulation of the p38 pathway regulates YAP-mediated transcription. Our work thus reveals a conserved crosstalk between the p38 MAPK pathway and the Hippo pathway in growth regulation. © The Author (2016). Published by Oxford University Press on behalf of Journal of Molecular Cell Biology, IBCB, SIBS, CAS.

  5. Ultrasound imaging using coded signals

    DEFF Research Database (Denmark)

    Misaridis, Athanasios

    Modulated (or coded) excitation signals can potentially improve the quality and increase the frame rate in medical ultrasound scanners. The aim of this dissertation is to investigate systematically the applicability of modulated signals in medical ultrasound imaging and to suggest appropriate...... of the excitation signal. Although a gain in signal-to-noise ratio of about 20 dB is theoretically possible for the time-bandwidth product available in ultrasound, it is shown that the effects of transducer weighting and tissue attenuation reduce the maximum gain at 10 dB for robust compression with low sidelobes...... is described. Application of coded excitation in array imaging is evaluated through simulations in Field II. The low degree of the orthogonality among coded signals for ultrasound systems is first discussed, and the effect of mismatched filtering in the cross-correlation properties of the signals is evaluated...

  6. Volcanic signals in oceans

    KAUST Repository

    Stenchikov, Georgiy L.

    2009-08-22

    Sulfate aerosols resulting from strong volcanic explosions last for 2–3 years in the lower stratosphere. Therefore it was traditionally believed that volcanic impacts produce mainly short-term, transient climate perturbations. However, the ocean integrates volcanic radiative cooling and responds over a wide range of time scales. The associated processes, especially ocean heat uptake, play a key role in ongoing climate change. However, they are not well constrained by observations, and attempts to simulate them in current climate models used for climate predictions yield a range of uncertainty. Volcanic impacts on the ocean provide an independent means of assessing these processes. This study focuses on quantification of the seasonal to multidecadal time scale response of the ocean to explosive volcanism. It employs the coupled climate model CM2.1, developed recently at the National Oceanic and Atmospheric Administration\\'s Geophysical Fluid Dynamics Laboratory, to simulate the response to the 1991 Pinatubo and the 1815 Tambora eruptions, which were the largest in the 20th and 19th centuries, respectively. The simulated climate perturbations compare well with available observations for the Pinatubo period. The stronger Tambora forcing produces responses with higher signal-to-noise ratio. Volcanic cooling tends to strengthen the Atlantic meridional overturning circulation. Sea ice extent appears to be sensitive to volcanic forcing, especially during the warm season. Because of the extremely long relaxation time of ocean subsurface temperature and sea level, the perturbations caused by the Tambora eruption could have lasted well into the 20th century.

  7. High resolution signal processing

    Science.gov (United States)

    Tufts, Donald W.

    1993-08-01

    Motivated by the goal of efficient, effective, high-speed integrated-circuit realization, we have discovered an algorithm for high speed Fourier analysis called the Arithmetic Fourier Transform (AFT). It is based on the number-theoretic method of Mobius inversion, a method that is well suited for integrated-circuit realization. The computation of the AFT can be carried out in parallel, pipelined channels, and the individual operations are very simple to execute and control. Except for a single scaling in each channel, all the operations are additions or subtractions. Thus, it can reduce the required power, volume, and cost. Also, analog switched-capacitor realizations of the AFT have been studied. We have also analyzed the performance of a broad and useful class of data adaptive signal estimation algorithms. This in turn has led to our proposed improvements in the methods. We have used perturbation analysis of the rank-reduced data matrix to calculate its statistical properties. The improvements made have been demonstrated by computer simulation as well as by comparison with the Cramer-Rao Bound.

  8. Unmixing binocular signals

    Directory of Open Access Journals (Sweden)

    Sidney R Lehky

    2011-08-01

    Full Text Available Incompatible images presented to the two eyes lead to perceptual oscillations in which one image at a time is visible. Early models portrayed this binocular rivalry as involving reciprocal inhibition between monocular representations of images, occurring at an early visual stage prior to binocular mixing. However, psychophysical experiments found conditions where rivalry could also occur at a higher, more abstract level of representation. In those cases, the rivalry was between image representations dissociated from eye-of-origin information, rather than between monocular representations from the two eyes. Moreover, neurophysiological recordings found the strongest rivalry correlate in inferotemporal cortex, a high-level, predominantly binocular visual area involved in object recognition, rather than early visual structures. An unresolved issue is how can the separate identities of the two images be maintained after binocular mixing in order for rivalry to be possible at higher levels? Here we demonstrate that after the two images are mixed, they can be unmixed at any subsequent stage using a physiologically plausible nonlinear signal-processing algorithm, non-negative matrix factorization, previously proposed for parsing object parts during object recognition. The possibility that unmixed left and right images can be regenerated at late stages within the visual system provides a mechanism for creating various binocular representations and interactions de novo in different cortical areas for different purposes, rather than inheriting then from early areas. This is a clear example how nonlinear algorithms can lead to highly non-intuitive behavior in neural information processing.

  9. An algebra for signal processing

    OpenAIRE

    Thielemann, Henning

    2011-01-01

    Our paper presents an attempt to axiomatise signal processing. Our long-term goal is to formulate signal processing algorithms for an ideal world of exact computation and prove properties about them, then interpret these ideal formulations and apply them without change to real world discrete data. We give models of the axioms that are based on Gaussian functions, that allow for exact computations and automated tests of signal algorithm properties.

  10. Traffic Signals in School Zones

    OpenAIRE

    Kevin S Lee; Bullock, Darcy M.

    2003-01-01

    Traffic signals are used to control the right of way at intersections. Strict engineering guidelines are published in the Manual on Uniform Traffic Control Devices (MUTCD) that engineers use to determine if a traffic signal is “warranted”. The warrants provide consistent national balance between mobility, safety, efficiency, and costs. However, signalized intersections are often viewed by the general public as safer then unsignalized intersections. This belief is often heightened when there a...

  11. Semi-classical signal analysis

    KAUST Repository

    Laleg-Kirati, Taous-Meriem

    2012-09-30

    This study introduces a new signal analysis method, based on a semi-classical approach. The main idea in this method is to interpret a pulse-shaped signal as a potential of a Schrödinger operator and then to use the discrete spectrum of this operator for the analysis of the signal. We present some numerical examples and the first results obtained with this method on the analysis of arterial blood pressure waveforms. © 2012 Springer-Verlag London Limited.

  12. Synchronous Photodiode-Signal Sampler

    Science.gov (United States)

    Primus, Howard K.

    1988-01-01

    Synchronous sampling circuit increases signal-to-noise ratio of measurements of chopped signal of known phase and frequency in presence of low-frequency or dc background noise. Used with linear array of photoelectric sensors for locating edge of metal plate. Multiplexing circuit cycles through 16 light-emitting-diode/photodiode pairs, under computer control. Synchronized with multiplexer so edge detector makes one background-subtracted signal measurement per emitter/detector pair in turn.

  13. Postsynaptic Signaling and Plasticity Mechanisms

    Science.gov (United States)

    Sheng, Morgan; Jong Kim, Myung

    2002-10-01

    In excitatory synapses of the brain, specific receptors in the postsynaptic membrane lie ready to respond to the release of the neurotransmitter glutamate from the presynaptic terminal. Upon stimulation, these glutamate receptors activate multiple biochemical pathways that transduce signals into the postsynaptic neuron. Different kinds of synaptic activity elicit different patterns of postsynaptic signals that lead to short- or long-lasting strengthening or weakening of synaptic transmission. The complex molecular mechanisms that underlie postsynaptic signaling and plasticity are beginning to emerge.

  14. Virtual Vertical Aircraft Signal Training

    National Research Council Canada - National Science Library

    Norling, William

    1998-01-01

    .... Advances in virtual environments may provide a cost effective solution to the current live helicopter operations method of training, provided technical issues associated with hand and wand signal...

  15. Pragmatic circuits signals and filters

    CERN Document Server

    Eccles, William

    2006-01-01

    Pragmatic Circuits: Signals and Filters is built around the processing of signals. Topics include spectra, a short introduction to the Fourier series, design of filters, and the properties of the Fourier transform. The focus is on signals rather than power. But the treatment is still pragmatic. For example, the author accepts the work of Butterworth and uses his results to design filters in a fairly methodical fashion. This third of three volumes finishes with a look at spectra by showing how to get a spectrum even if a signal is not periodic. The Fourier transform provides a way of dealing wi

  16. Signal transduction by growth factor receptors: signaling in an instant

    DEFF Research Database (Denmark)

    Dengjel, Joern; Akimov, Vyacheslav; Blagoev, Blagoy

    2007-01-01

    -out by mass spectrometry-based proteomics has allowed exciting views on the very early events in signal transduction. Activation profiles of regulated phosphorylation sites on epidermal growth factor receptor and downstream signal transducers showed different kinetics within the first ten seconds...

  17. Introduction to Random Signals and Noise

    NARCIS (Netherlands)

    van Etten, Wim

    Random signals and noise are present in many engineering systems and networks. Signal processing techniques allow engineers to distinguish between useful signals in audio, video or communication equipment, and interference, which disturbs the desired signal. With a strong mathematical grounding,

  18. Bacterial lipopolysaccharide promotes profibrotic activation of intestinal fibroblasts.

    LENUS (Irish Health Repository)

    Burke, J P

    2012-02-01

    BACKGROUND: Fibroblasts play a critical role in intestinal wound healing. Lipopolysaccharide (LPS) is a cell wall component of commensal gut bacteria. The effects of LPS on intestinal fibroblast activation were characterized. METHODS: Expression of the LPS receptor, toll-like receptor (TLR) 4, was assessed in cultured primary human intestinal fibroblasts using flow cytometry and confocal microscopy. Fibroblasts were treated with LPS and\\/or transforming growth factor (TGF) beta1. Nuclear factor kappaB (NFkappaB) pathway activation was assessed by inhibitory kappaBalpha (IkappaBalpha) degradation and NFkappaB promoter activity. Fibroblast contractility was measured using a fibroblast-populated collagen lattice. Smad-7, a negative regulator of TGF-beta1 signalling, and connective tissue growth factor (CTGF) expression were assessed using reverse transcriptase-polymerase chain reaction and western blot. The NFkappaB pathway was inhibited by IkappaBalpha transfection. RESULTS: TLR-4 was present on the surface of intestinal fibroblasts. LPS treatment of fibroblasts induced IkappaBalpha degradation, enhanced NFkappaB promoter activity and increased collagen contraction. Pretreatment with LPS (before TGF-beta1) significantly increased CTGF production relative to treatment with TGF-beta1 alone. LPS reduced whereas TGF-beta1 increased smad-7 expression. Transfection with an IkappaBalpha plasmid enhanced basal smad-7 expression. CONCLUSION: Intestinal fibroblasts express TLR-4 and respond to LPS by activating NFkappaB and inducing collagen contraction. LPS acts in concert with TGF-beta1 to induce CTGF. LPS reduces the expression of the TGF-beta1 inhibitor, smad-7.

  19. Signal propagation in cortical networks: a digital signal processing approach.

    Science.gov (United States)

    Rodrigues, Francisco Aparecido; da Fontoura Costa, Luciano

    2009-01-01

    This work reports a digital signal processing approach to representing and modeling transmission and combination of signals in cortical networks. The signal dynamics is modeled in terms of diffusion, which allows the information processing undergone between any pair of nodes to be fully characterized in terms of a finite impulse response (FIR) filter. Diffusion without and with time decay are investigated. All filters underlying the cat and macaque cortical organization are found to be of low-pass nature, allowing the cortical signal processing to be summarized in terms of the respective cutoff frequencies (a high cutoff frequency meaning little alteration of signals through their intermixing). Several findings are reported and discussed, including the fact that the incorporation of temporal activity decay tends to provide more diversified cutoff frequencies. Different filtering intensity is observed for each community in those networks. In addition, the brain regions involved in object recognition tend to present the highest cutoff frequencies for both the cat and macaque networks.

  20. Signaling a Change of Heart

    DEFF Research Database (Denmark)

    Schumacher, Gijs

    2011-01-01

    introduced welfare state retrenchment measures. Social Democrats can win votes and join coalitions by shifting rightwards. In contrast, they can pursue policy objectives by shifting leftwards. To communicate these shifts, in other words, ‘changes of heart’, parties send signals to voters and other parties...... after having signalled ‘a change of heart’....

  1. Intracellular signal modulation by nanomaterials.

    Science.gov (United States)

    Hussain, Salik; Garantziotis, Stavros; Rodrigues-Lima, Fernando; Dupret, Jean-Marie; Baeza-Squiban, Armelle; Boland, Sonja

    2014-01-01

    A thorough understanding of the interactions of nanomaterials with biological systems and the resulting activation of signal transduction pathways is essential for the development of safe and consumer friendly nanotechnology. Here we present an overview of signaling pathways induced by nanomaterial exposures and describe the possible correlation of their physicochemical characteristics with biological outcomes. In addition to the hierarchical oxidative stress model and a review of the intrinsic and cell-mediated mechanisms of reactive oxygen species (ROS) generating capacities of nanomaterials, we also discuss other oxidative stress dependent and independent cellular signaling pathways. Induction of the inflammasome, calcium signaling, and endoplasmic reticulum stress are reviewed. Furthermore, the uptake mechanisms can be of crucial importance for the cytotoxicity of nanomaterials and membrane-dependent signaling pathways have also been shown to be responsible for cellular effects of nanomaterials. Epigenetic regulation by nanomaterials, effects of nanoparticle-protein interactions on cell signaling pathways, and the induction of various cell death modalities by nanomaterials are described. We describe the common trigger mechanisms shared by various nanomaterials to induce cell death pathways and describe the interplay of different modalities in orchestrating the final outcome after nanomaterial exposures. A better understanding of signal modulations induced by nanomaterials is not only essential for the synthesis and design of safer nanomaterials but will also help to discover potential nanomedical applications of these materials. Several biomedical applications based on the different signaling pathways induced by nanomaterials are already proposed and will certainly gain a great deal of attraction in the near future.

  2. Signals and systems with MATLAB

    CERN Document Server

    Yang, Won Young; Song, Ik H; Cho, Yong S

    2009-01-01

    Covers some of the theoretical foundations and mathematical derivations that can be used in higher-level related subjects such as signal processing, communication, and control, minimizing the mathematical difficulty and computational burden. This book illustrates the usage of MATLAB and Simulink for signal and system analysis and design.

  3. Smoke Signal or Smoke Screen?

    DEFF Research Database (Denmark)

    Vergne, Jean-Philippe; Wernicke, Georg; Brenner, Steffen

    disapproval, whereas ambiguous signals represent a form of category straddling that attenuates disapproval. We find empirical support for this proposition in the context of CEO overcompensation in the U.S. (1995-2007) after examining two organizational signals that affect perceptions of economic fairness (i...

  4. Spatial regulation of Rap signaling

    NARCIS (Netherlands)

    Gloerich, M.

    2011-01-01

    By cycling between an inactive GDP-bound and active GTP-bound state, small G-proteins of the Rap family act as molecular switches that relay upstream signals to diverse cellular processes. This GDP/GTP-cycle and consequently downstream signaling by Rap is under tight regulation by its GEFs and GAPs.

  5. Signals in Communication Engineering History

    Science.gov (United States)

    Consonni, Denise; Silva, Magno T. M.

    2010-01-01

    This paper is a study of various electric signals, which have been employed throughout the history of communication engineering in its two main landmarks: the telegraph and the telephone. The signals are presented in their time and frequency domain representations. The historical order has been followed in the presentation: wired systems, spark…

  6. Innate immune signaling in CLL.

    Science.gov (United States)

    Maus, Marcela V

    2016-01-28

    In this issue of Blood, Wagner et al describe a complex signaling model that explains the mechanism of action of a long-known prognostic marker in chronic lymphocytic leukemia (CLL) and integrates its function with the innate immune system and B-cell receptor signaling.

  7. Hippo signalling directs intestinal fate

    DEFF Research Database (Denmark)

    le Bouteiller, Marie Catherine M; Jensen, Kim Bak

    2015-01-01

    Hippo signalling has been associated with many important tissue functions including the regulation of organ size. In the intestinal epithelium differing functions have been proposed for the effectors of Hippo signalling, YAP and TAZ1. These are now shown to have a dual role in the intestinal epit...

  8. Aberrant Signaling Pathways in Glioma

    Energy Technology Data Exchange (ETDEWEB)

    Nakada, Mitsutoshi, E-mail: nakada@ns.m.kanazawa-u.ac.jp; Kita, Daisuke; Watanabe, Takuya; Hayashi, Yutaka [Department of Neurosurgery, Graduate School of Medical Science, Kanazawa University, Kanazawa, Ishikawa 920-8641 (Japan); Teng, Lei [Department of Neurosurgery, Graduate School of Medical Science, Kanazawa University, Kanazawa, Ishikawa 920-8641 (Japan); Department of Neurosurgery, The First Clinical College of Harbin Medical University, Nangang, Harbin 150001 (China); Pyko, Ilya V.; Hamada, Jun-Ichiro [Department of Neurosurgery, Graduate School of Medical Science, Kanazawa University, Kanazawa, Ishikawa 920-8641 (Japan)

    2011-08-10

    Glioblastoma multiforme (GBM), a WHO grade IV malignant glioma, is the most common and lethal primary brain tumor in adults; few treatments are available. Median survival rates range from 12–15 months. The biological characteristics of this tumor are exemplified by prominent proliferation, active invasiveness, and rich angiogenesis. This is mainly due to highly deregulated signaling pathways in the tumor. Studies of these signaling pathways have greatly increased our understanding of the biology and clinical behavior of GBM. An integrated view of signal transduction will provide a more useful approach in designing novel therapies for this devastating disease. In this review, we summarize the current understanding of GBM signaling pathways with a focus on potential molecular targets for anti-signaling molecular therapies.

  9. Signal focusing through active transport

    Science.gov (United States)

    Godec, Aljaž; Metzler, Ralf

    2015-07-01

    The accuracy of molecular signaling in biological cells and novel diagnostic devices is ultimately limited by the counting noise floor imposed by the thermal diffusion. Motivated by the fact that messenger RNA and vesicle-engulfed signaling molecules transiently bind to molecular motors and are actively transported in biological cells, we show here that the random active delivery of signaling particles to within a typical diffusion distance to the receptor generically reduces the correlation time of the counting noise. Considering a variety of signaling particle sizes from mRNA to vesicles and cell sizes from prokaryotic to eukaryotic cells, we show that the conditions for active focusing—faster and more precise signaling—are indeed compatible with observations in living cells. Our results improve the understanding of molecular cellular signaling and novel diagnostic devices.

  10. Signal processing devices and networks

    Science.gov (United States)

    Graveline, S. W.

    1985-02-01

    According to an axiom employed with respect to electronic warfare (EW) behavior, system effectiveness increases directly with the amount of information recovered from an intercepted signal. The evolution in EW signal processing capability has proceeded accordingly. After an initiation of EW systems as broadband receivers, the most significant advance was related to the development of digital instantaneous frequency measurement (DIFM) devices. The use of such devices provides significant improvements regarding signal identification and RF measurement to within a few MHz. An even more accurate processing device, the digital RF memory (DRFM), allows frequency characterization to within a few Hz. This invention was made in response to the need to process coherent pulse signals. Attention is given to the generic EW system, the modern EW system, and the generic receiver function for a modern EW system showing typical output signals.

  11. Signal processing for radiation detectors

    CERN Document Server

    Nakhostin, Mohammad

    2018-01-01

    This book provides a clear understanding of the principles of signal processing of radiation detectors. It puts great emphasis on the characteristics of pulses from various types of detectors and offers a full overview on the basic concepts required to understand detector signal processing systems and pulse processing techniques. Signal Processing for Radiation Detectors covers all of the important aspects of signal processing, including energy spectroscopy, timing measurements, position-sensing, pulse-shape discrimination, and radiation intensity measurement. The book encompasses a wide range of applications so that readers from different disciplines can benefit from all of the information. In addition, this resource: * Describes both analog and digital techniques of signal processing * Presents a complete compilation of digital pulse processing algorithms * Extrapolates content from more than 700 references covering classic papers as well as those of today * Demonstrates concepts with more than 340 origin...

  12. TGF-beta-induced fibrosis and SMAD signaling: oligo decoys as natural therapeutics for inhibition of tissue fibrosis and scarring.

    Science.gov (United States)

    Cutroneo, Kenneth R

    2007-01-01

    Transforming-growth factor-beta (TGF-beta) is a pleiotrophic growth factor that is synthesized by many cells in the body. This growth factor is chemotactic for fibroblasts, stimulates fibroblast proliferation, and increases the synthesis of a number of extracellular matrix proteins including collagens. The TGF-beta activator protein is a transacting factor, which binds to the TGF-beta element in the distal promoter of the COL1A1 collagen gene and induces transcription of this gene. Although transient TGF-beta 1 activity participates in repair and regeneration of tissues, persistent TGF-beta 1 function affects excessive fibrosis and ultimately scarring of both skin and internal organs. Scarring of internal organ (e.g., liver and lung) results in a loss of function and ultimately death may occur. The central issue of this review is that phosphorothioate double-stranded decoys or other decoys decrease procollagen gene expression, procollagen synthesis, and collagen during fibrogenesis. The rationale is that the decoys containing the TGF-beta element or other gene transcription regulatory CIS-elements bind the transacting proteins preventing the latter from binding to the CIS-element in the 5'-flanking region of the natural gene resulting in transcription inhibition. We will, in part, focus on aspects involved in TGF-beta 1-induced fibrosis that occur during fibrogenesis and the use of the dsTGF-beta element containing oligodeoxynucleotide decoys to control excessive collagen synthesis, and deposition resulting from persistent TGF-beta. In our model of regulation of collagen synthesis, these double-stranded oligo decoys act as promoter competitors, binding to the activator protein either in the cytoplasm or in the nucleus. The significance of the proposed studies is that these novel natural antifibrotics will mimic the effect of glucocorticoids on collagen synthesis during fibrogenesis without the unwanted side effects of these steroids. Based on our previous studies on the molecular mechanisms by which glucocorticoids selectively decrease collagen synthesis, designed phosphorothioate oligodeoxynucleotides resistant to nuclease action will mimic the effects of glucocorticoids at the molecular, cellular, and in vivo levels of collagen synthesis. However, the glucocorticoids significantly inhibit noncollagen protein synthesis. Both the single-stranded and double-stranded oligodeoxynucleotide specifically decrease collagen synthesis without an inhibitory effect on noncollagen protein synthesis. In this review, we will specifically ask if TGF-beta-induced collagen synthesis is inhibited in cell culture and in vivo by using the double-stranded oligodeoxynucleotide decoys, will this inhibit fibrogenesis and ultimately scarring?

  13. Some dynamics of signaling games.

    Science.gov (United States)

    Huttegger, Simon; Skyrms, Brian; Tarrès, Pierre; Wagner, Elliott

    2014-07-22

    Information transfer is a basic feature of life that includes signaling within and between organisms. Owing to its interactive nature, signaling can be investigated by using game theory. Game theoretic models of signaling have a long tradition in biology, economics, and philosophy. For a long time the analyses of these games has mostly relied on using static equilibrium concepts such as Pareto optimal Nash equilibria or evolutionarily stable strategies. More recently signaling games of various types have been investigated with the help of game dynamics, which includes dynamical models of evolution and individual learning. A dynamical analysis leads to more nuanced conclusions as to the outcomes of signaling interactions. Here we explore different kinds of signaling games that range from interactions without conflicts of interest between the players to interactions where their interests are seriously misaligned. We consider these games within the context of evolutionary dynamics (both infinite and finite population models) and learning dynamics (reinforcement learning). Some results are specific features of a particular dynamical model, whereas others turn out to be quite robust across different models. This suggests that there are certain qualitative aspects that are common to many real-world signaling interactions.

  14. Quorum Quenching Revisited—From Signal Decays to Signalling Confusion

    Directory of Open Access Journals (Sweden)

    Kok-Gan Chan

    2012-04-01

    Full Text Available In a polymicrobial community, while some bacteria are communicating with neighboring cells (quorum sensing, others are interrupting the communication (quorum quenching, thus creating a constant arms race between intercellular communication. In the past decade, numerous quorum quenching enzymes have been found and initially thought to inactivate the signalling molecules. Though this is widely accepted, the actual roles of these quorum quenching enzymes are now being uncovered. Recent evidence extends the role of quorum quenching to detoxification or metabolism of signalling molecules as food and energy source; this includes “signalling confusion”, a term coined in this paper to refer to the phenomenon of non-destructive modification of signalling molecules. While quorum quenching has been explored as a novel anti-infective therapy targeting, quorum sensing evidence begins to show the development of resistance against quorum quenching.

  15. Microsystem for signal processing applications

    Science.gov (United States)

    Frankenstein, B.; Froehlich, K.-J.; Hentschel, D.; Reppe, G.

    2005-05-01

    Acoustic monitoring of technological processes requires methods that eliminate noise as much as possible. Sensor-near signal evaluation can contribute substantially. Frequently, a further necessity exists to integrate the measuring technique in the monitored structure. The solution described contains components for analog preprocessing of acoustic signals, their digitization, algorithms for data reduction, and digital communication. The core component is a digital signal processor (DSP). Digital signal processors perform the algorithms necessary for filtering, down sampling, FFT computation and correlation of spectral components particularly effective. A compact, sensor-near signal processing structure was realized. It meets the Match-X standard, which as specified by the German Association for Mechanical and Plant Engineering (VDMA) for development of micro-technical modules, which can be combined to applicaiton specific systems. The solution is based on AL2O3 ceramic components including different signal processing modules as ADC, as well as memory and power supply. An arbitrary waveform generator has been developed and combined with a power amplifier for piezoelectric transducers in a special module. A further module interfaces to these transducers. It contains a multi-channel preamplifier, some high-pass filters for analog signal processing and an ADC-driver. A Bluetooth communication chip for wireless data transmission and a DiscOnChip module are under construction. As a first application, the combustion behavior of safety-relevant contacts is monitored. A special waveform up to 5MHz is produced and sent to the monitored object. The resulting signal form is evaluated with special algorithms, which extract significant parameters of the signal, and transmitted via CAN-bus.

  16. Advanced optical signal processing of broadband parallel data signals

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Hu, Hao; Kjøller, Niels-Kristian

    2016-01-01

    Optical signal processing may aid in reducing the number of active components in communication systems with many parallel channels, by e.g. using telescopic time lens arrangements to perform format conversion and allow for WDM regeneration.......Optical signal processing may aid in reducing the number of active components in communication systems with many parallel channels, by e.g. using telescopic time lens arrangements to perform format conversion and allow for WDM regeneration....

  17. Regulation of matrix contraction in chronic venous disease.

    Science.gov (United States)

    Pappas, P J; Lal, B K; Ohara, N; Saito, S; Zapiach, L; Durán, W N

    2009-10-01

    The role of TGF-beta(1) in venous ulcer healing and the signalling cascades regulating dermal fibroblast function are poorly understood. To elucidate these processes, we hypothesized that TGF-beta(1) facilitates wound healing by increasing chronic venous insufficiency (CVI) induced matrix contraction via intracellular cross-talk between TGF-beta(1) and the ERK-1/2 MAP kinase signalling cascades. Fibroblasts isolated from calf biopsies (LC) of patients with different severity of CVI (CEAP, Clinical Etiological Anatomical Pathological classes) were seeded into 200 microl collagen gels under isometric conditions. Fibroblasts from neonatal foreskins (HS68), non-CVI patients (NC), and the ipsilateral normal thigh of each CVI patient (LT) served as controls. Thirteen patients with CVI (class 2, n=5; class 4, n=5; class 6, n=3) and 2 non-CVI controls (NC, n=2) were included in the study. All experimental conditions were determined by dose-response and time-course experiments. Gels were cultured with/without 0.1 ng/ml TGF-beta(1) and with/without 50 microM PD98059 (MEK and downstream-MAPK inhibitor). Additional patient fibroblasts were transfected with constitutively active Ras (pCMV-Ras) or an empty vector (pCMV-beta) with/without 0.1 ng/ml TGF-beta(1) and with/without 50 microm PD98059. The collagen gels were released after 4 days and the percent contraction was determined by area measurements using image analysis. Differences in alpha-smooth muscle actin (alpha-SMA) and ERK-1/2 MAPK (phosphorylated and total) protein levels were analyzed with western blotting. Gels seeded with CVI fibroblasts contracted more than HS68, NC and LT fibroblasts. Inhibition of MAPK and/or stimulation with TGF-beta(1) increased the contraction of LC gels compared to unstimulated controls. Agonist induced gel contraction correlated with CVI disease severity. alpha-SMA protein expression in LC fibroblasts increased with MAPK inhibition with/without TGF-beta(1) stimulation, and correlated with

  18. Statistical theory of signal detection

    CERN Document Server

    Helstrom, Carl Wilhelm; Costrell, L; Kandiah, K

    1968-01-01

    Statistical Theory of Signal Detection, Second Edition provides an elementary introduction to the theory of statistical testing of hypotheses that is related to the detection of signals in radar and communications technology. This book presents a comprehensive survey of digital communication systems. Organized into 11 chapters, this edition begins with an overview of the theory of signal detection and the typical detection problem. This text then examines the goals of the detection system, which are defined through an analogy with the testing of statistical hypotheses. Other chapters consider

  19. On Generalized Fractional Differentiator Signals

    Directory of Open Access Journals (Sweden)

    Hamid A. Jalab

    2013-01-01

    Full Text Available By employing the generalized fractional differential operator, we introduce a system of fractional order derivative for a uniformly sampled polynomial signal. The calculation of the bring in signal depends on the additive combination of the weighted bring-in of N cascaded digital differentiators. The weights are imposed in a closed formula containing the Stirling numbers of the first kind. The approach taken in this work is to consider that signal function in terms of Newton series. The convergence of the system to a fractional time differentiator is discussed.

  20. GA signalling and cross-talk with other signalling pathways.

    Science.gov (United States)

    Lor, Vai S; Olszewski, Neil E

    2015-01-01

    Gibberellins (GAs) are phytohormones that regulate growth and development. DELLA proteins repress GA responses. GA binding to its receptor triggers a series of events that culminate in the destruction of DELLA proteins by the 26S proteasome, which removes the repression of GA signalling. DELLA proteins are transcription co-activators that induce the expression of genes which encode products that inhibit GA responses. In addition to repressing GA responses, DELLA proteins influence the activity of other signalling pathways and serve as a central hub from which other pathways influence GA signalling. In this role, DELLA proteins bind to and inhibit proteins, including transcription factors that act in the signalling pathways of other hormones and light. The binding of these proteins to DELLA proteins also inhibits DELLA activity. GA signalling is subject to homoeostatic regulation through GA-induced repression of GA biosynthesis gene expression, and increased production of the GA receptor and enzymes that catabolize bioactive GAs. This review also discusses the nature of mutant DELLA alleles that are used to produce high-yielding 'Green Revolution' cereal varieties, and highlights important gaps in our knowledge of GA signalling. © 2015 Authors; published by Portland Press Limited.

  1. Signal processing with free software practical experiments

    CERN Document Server

    Auger, François

    2014-01-01

    An ideal resource for students, industrial engineers, and researchers, Signal Processing with Free Software Practical Experiments presents practical experiments in signal processing using free software. The text introduces elementary signals through elementary waveform, signal storage files and elementary operations on signals and then presents the first tools to signal analysis such as temporal and frequency characteristics leading to Time-frequency analysis. Non-parametric spectral analysis is also discussed as well as signal processing through sampling, resampling, quantification, an

  2. Angiotensin II increases CTGF expression via MAPKs/TGF-{beta}1/TRAF6 pathway in atrial fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Jun [Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University School of medicine, Shanghai (China); Liu, Xu, E-mail: xkliuxu@yahoo.cn [Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University School of medicine, Shanghai (China); Wang, Quan-xing, E-mail: shmywqx@126.com [National Key Laboratory of Medical Immunology, Second Military Medical University, Shanghai (China); Tan, Hong-wei [Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University School of medicine, Shanghai (China); Guo, Meng [National Key Laboratory of Medical Immunology, Second Military Medical University, Shanghai (China); Jiang, Wei-feng; Zhou, Li [Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University School of medicine, Shanghai (China)

    2012-10-01

    The activation of transforming growth factor-{beta}1(TGF-{beta}1)/Smad signaling pathway and increased expression of connective tissue growth factor (CTGF) induced by angiotensin II (AngII) have been proposed as a mechanism for atrial fibrosis. However, whether TGF{beta}1/non-Smad signaling pathways involved in AngII-induced fibrogenetic factor expression remained unknown. Recently tumor necrosis factor receptor associated factor 6 (TRAF6)/TGF{beta}-associated kinase 1 (TAK1) has been shown to be crucial for the activation of TGF-{beta}1/non-Smad signaling pathways. In the present study, we explored the role of TGF-{beta}1/TRAF6 pathway in AngII-induced CTGF expression in cultured adult atrial fibroblasts. AngII (1 {mu}M) provoked the activation of P38 mitogen activated protein kinase (P38 MAPK), extracellular signal-regulated kinase 1/2(ERK1/2) and c-Jun NH(2)-terminal kinase (JNK). AngII (1 {mu}M) also promoted TGF{beta}1, TRAF6, CTGF expression and TAK1 phosphorylation, which were suppressed by angiotensin type I receptor antagonist (Losartan) as well as p38 MAPK inhibitor (SB202190), ERK1/2 inhibitor (PD98059) and JNK inhibitor (SP600125). Meanwhile, both TGF{beta}1 antibody and TRAF6 siRNA decreased the stimulatory effect of AngII on TRAF6, CTGF expression and TAK1 phosphorylation, which also attenuated AngII-induced atrial fibroblasts proliferation. In summary, the MAPKs/TGF{beta}1/TRAF6 pathway is an important signaling pathway in AngII-induced CTGF expression, and inhibition of TRAF6 may therefore represent a new target for reversing Ang II-induced atrial fibrosis. -- Highlights: Black-Right-Pointing-Pointer MAPKs/TGF{beta}1/TRAF6 participates in AngII-induced CTGF expression in atrial fibroblasts. Black-Right-Pointing-Pointer TGF{beta}1/TRAF6 participates in AngII-induced atrial fibroblasts proliferation. Black-Right-Pointing-Pointer TRAF6 may represent a new target for reversing Ang II-induced atrial fibrosis.

  3. Invariants of DNA genomic signals

    Science.gov (United States)

    Cristea, Paul Dan A.

    2005-02-01

    For large scale analysis purposes, the conversion of genomic sequences into digital signals opens the possibility to use powerful signal processing methods for handling genomic information. The study of complex genomic signals reveals large scale features, maintained over the scale of whole chromosomes, that would be difficult to find by using only the symbolic representation. Based on genomic signal methods and on statistical techniques, the paper defines parameters of DNA sequences which are invariant to transformations induced by SNPs, splicing or crossover. Re-orienting concatenated coding regions in the same direction, regularities shared by the genomic material in all exons are revealed, pointing towards the hypothesis of a regular ancestral structure from which the current chromosome structures have evolved. This property is not found in non-nuclear genomic material, e.g., plasmids.

  4. Signal transforms in dynamic measurements

    CERN Document Server

    Layer, Edward

    2015-01-01

    This book is devoted to the analysis of measurement signals which requires specific mathematical operations like Convolution, Deconvolution, Laplace, Fourier, Hilbert, Wavelet or Z transform which are all presented in the present book. The different problems refer to the modulation of signals, filtration of disturbance as well as to the orthogonal signals and their use in digital form for the measurement of current, voltage, power and frequency are also widely discussed. All the topics covered in this book are presented in detail and illustrated by means of examples in MathCad and LabVIEW. This book provides a useful source for researchers, scientists and engineers who in their daily work are required to deal with problems of measurement and signal processing and can also be helpful to undergraduate students of electrical engineering.    

  5. Apoptotic signaling in mouse odontogenesis.

    Science.gov (United States)

    Matalova, Eva; Svandova, Eva; Tucker, Abigail S

    2012-01-01

    Apoptosis is an important morphogenetic event in embryogenesis as well as during postnatal life. In the last 2 decades, apoptosis in tooth development (odontogenesis) has been investigated with gradually increasing focus on the mechanisms and signaling pathways involved. The molecular machinery responsible for apoptosis exhibits a high degree of conservation but also organ and tissue specific patterns. This review aims to discuss recent knowledge about apoptotic signaling networks during odontogenesis, concentrating on the mouse, which is often used as a model organism for human dentistry. Apoptosis accompanies the entire development of the tooth and corresponding remodeling of the surrounding bony tissue. It is most evident in its role in the elimination of signaling centers within developing teeth, removal of vestigal tooth germs, and in odontoblast and ameloblast organization during tooth mineralization. Dental apoptosis is caspase dependent and proceeds via mitochondrial mediated cell death with possible amplification by Fas-FasL signaling modulated by Bcl-2 family members.

  6. Subcellular Organization of GPCR Signaling.

    Science.gov (United States)

    Eichel, Kelsie; von Zastrow, Mark

    2018-02-01

    G protein-coupled receptors (GPCRs) comprise a large and diverse class of signal-transducing receptors that undergo dynamic and isoform-specific membrane trafficking. GPCRs thus have an inherent potential to initiate or regulate signaling reactions from multiple membrane locations. This review discusses emerging insights into the subcellular organization of GPCR function in mammalian cells, focusing on signaling transduced by heterotrimeric G proteins and β-arrestins. We summarize recent evidence indicating that GPCR-mediated activation of G proteins occurs not only from the plasma membrane (PM) but also from endosomes and Golgi membranes and that β-arrestin-dependent signaling can be transduced from the PM by β-arrestin trafficking to clathrin-coated pits (CCPs) after dissociation from a ligand-activated GPCR. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. SIGNAL DETECTION WITH UNKNOWN PARAMETERS

    Directory of Open Access Journals (Sweden)

    Y. A. Sidorkina

    2015-01-01

    Full Text Available The likelihood ratio of the pulse signal with unknown time position while detecting and detecting the signal with unknown frequency, are considered. Is shown that an FFT algorithm should be performed while detecting the signal with unknown frequency, the maximum value of all spectral samples should be found and compared to the detection threshold. Upon detection of a pulse signal with unknown time position a fast convolution algorithm should be performed, the maximum value of all the spectral inverse FFT samples should be found and compared to the detection threshold. The effectiveness of this algorithm is determined by the sampling distribution of the maximum values of random variables distributed according to Rayleigh.

  8. Nuclear Receptor Signaling Atlas (NURSA)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Nuclear Receptor Signaling Atlas (NURSA) is designed to foster the development of a comprehensive understanding of the structure, function, and role in disease...

  9. Galileo Signal Generation. Simulation Analysis

    OpenAIRE

    Canalda Pedrós, Roger

    2009-01-01

    Projecte realitzat eb col.laboració amb el Department of Computer and Electronic Engineering. University of Limerick This work presents the navigation signals and their allocation in the radio frequency band used in the new European Global Navigation Satellite System (GNSS): Galileo. All signals are described mathematically and then simulated using Matlab language (in transmission). Results are shown thus proving the theory provided by the European Space Agency document: “Open Service Sign...

  10. Simulation Of Cell Signaling Communications

    OpenAIRE

    Huertas González, Daniel

    2014-01-01

    Simulation of cell signaling communications using the Omnet ++ Simulation Framework and molecular dynamics algorithms. [ANGLÈS] Cells, whether they be unicellular organisms or belong to a multicellular organism, are able to encode and transmit information to each other by means of signaling molecules and the diffusion processes in the extracellular fluid. The aim of this project is to develop an Event Driven Molecular Dynamics (EDMD) simulator using the Omnet++ Simulation Framework in orde...

  11. Neurotransmitter signaling in white matter.

    Science.gov (United States)

    Butt, Arthur M; Fern, Robert F; Matute, Carlos

    2014-11-01

    White matter (WM) tracts are bundles of myelinated axons that provide for rapid communication throughout the CNS and integration in grey matter (GM). The main cells in myelinated tracts are oligodendrocytes and astrocytes, with small populations of microglia and oligodendrocyte precursor cells. The prominence of neurotransmitter signaling in WM, which largely exclude neuronal cell bodies, indicates it must have physiological functions other than neuron-to-neuron communication. A surprising aspect is the diversity of neurotransmitter signaling in WM, with evidence for glutamatergic, purinergic (ATP and adenosine), GABAergic, glycinergic, adrenergic, cholinergic, dopaminergic and serotonergic signaling, acting via a wide range of ionotropic and metabotropic receptors. Both axons and glia are potential sources of neurotransmitters and may express the respective receptors. The physiological functions of neurotransmitter signaling in WM are subject to debate, but glutamate and ATP-mediated signaling have been shown to evoke Ca(2+) signals in glia and modulate axonal conduction. Experimental findings support a model of neurotransmitters being released from axons during action potential propagation acting on glial receptors to regulate the homeostatic functions of astrocytes and myelination by oligodendrocytes. Astrocytes also release neurotransmitters, which act on axonal receptors to strengthen action potential propagation, maintaining signaling along potentially long axon tracts. The co-existence of multiple neurotransmitters in WM tracts suggests they may have diverse functions that are important for information processing. Furthermore, the neurotransmitter signaling phenomena described in WM most likely apply to myelinated axons of the cerebral cortex and GM areas, where they are doubtless important for higher cognitive function. © 2014 Wiley Periodicals, Inc.

  12. Sentiment analysis for PTSD signals

    CERN Document Server

    Kagan, Vadim; Sapounas, Demetrios

    2013-01-01

    This book describes a computational framework for real-time detection of psychological signals related to Post-Traumatic Stress Disorder (PTSD) in online text-based posts, including blogs and web forums. Further, it explores how emerging computational techniques such as sentiment mining can be used in real-time to identify posts that contain PTSD-related signals, flag those posts, and bring them to the attention of psychologists, thus providing an automated flag and referral capability.

  13. Signal Synthesizer and Method Therefor

    OpenAIRE

    Pace, Phillip E.; Surratt, Robert E.; Yeo, Siew-Yam

    2006-01-01

    Patent A method and system for signal processing, especially useful as a signal repeater, i.e. for simulating the characteristic echo signature of a preselected target. The system has a digital radio frequency memory (DRFM) and associated circuitry, including digital tapped delay lines, and a modulator in each delay line to impose both amplitude and frequency modulation in each line. Use of digital semiconductor technology increases the bandwidth and sensitivity of ...

  14. Handbook of signal processing systems

    CERN Document Server

    Deprettere, Ed; Leupers, Rainer; Takala, Jarmo

    2013-01-01

    Handbook of Signal Processing Systems is organized in three parts. The first part motivates representative applications that drive and apply state-of-the art methods for design and implementation of signal processing systems; the second part discusses architectures for implementing these applications; the third part focuses on compilers and simulation tools, describes models of computation and their associated design tools and methodologies. This handbook is an essential tool for professionals in many fields and researchers of all levels.

  15. Universal vocal signals of emotion

    OpenAIRE

    Sauter, D.; Eisner, F; Ekman, P.; Scott, S

    2009-01-01

    Emotional signals allow for the sharing of important information with conspecifics, for example to warn them of danger. Humans use a range of different cues to communicate to others how they feel, including facial, vocal, and gestural signals. Although much is known about facial expressions of emotion, less research has focused on affect in the voice. We compare British listeners to individuals from remote Namibian villages who have had no exposure to Western culture, and examine recognition ...

  16. Hedgehog Signaling in Endochondral Ossification

    Directory of Open Access Journals (Sweden)

    Shinsuke Ohba

    2016-06-01

    Full Text Available Hedgehog (Hh signaling plays crucial roles in the patterning and morphogenesis of various organs within the bodies of vertebrates and insects. Endochondral ossification is one of the notable developmental events in which Hh signaling acts as a master regulator. Among three Hh proteins in mammals, Indian hedgehog (Ihh is known to work as a major Hh input that induces biological impact of Hh signaling on the endochondral ossification. Ihh is expressed in prehypertrophic and hypertrophic chondrocytes of developing endochondral bones. Genetic studies so far have demonstrated that the Ihh-mediated activation of Hh signaling synchronizes chondrogenesis and osteogenesis during endochondral ossification by regulating the following processes: (1 chondrocyte differentiation; (2 chondrocyte proliferation; and (3 specification of bone-forming osteoblasts. Ihh not only forms a negative feedback loop with parathyroid hormone-related protein (PTHrP to maintain the growth plate length, but also directly promotes chondrocyte propagation. Ihh input is required for the specification of progenitors into osteoblast precursors. The combinatorial approaches of genome-wide analyses and mouse genetics will facilitate understanding of the regulatory mechanisms underlying the roles of Hh signaling in endochondral ossification, providing genome-level evidence of the potential of Hh signaling for the treatment of skeletal disorders.

  17. Insulin Signaling and Heart Failure

    Science.gov (United States)

    Riehle, Christian; Abel, E. Dale

    2016-01-01

    Heart failure is associated with generalized insulin resistance. Moreover, insulin resistant states such as type 2 diabetes and obesity increases the risk of heart failure even after adjusting for traditional risk factors. Insulin resistance or type 2 diabetes alters the systemic and neurohumoral milieu leading to changes in metabolism and signaling pathways in the heart that may contribute to myocardial dysfunction. In addition, changes in insulin signaling within cardiomyocytes develop in the failing heart. The changes range from activation of proximal insulin signaling pathways that may contribute to adverse left ventricular remodeling and mitochondrial dysfunction to repression of distal elements of insulin signaling pathways such as forkhead (FOXO) transcriptional signaling or glucose transport which may also impair cardiac metabolism, structure and function. This article will review the complexities of insulin signaling within the myocardium and ways in which these pathways are altered in heart failure or in conditions associated with generalized insulin resistance. The implications of these changes for therapeutic approaches to treating or preventing heart failure will be discussed. PMID:27034277

  18. Wnt signaling during cochlear development.

    Science.gov (United States)

    Munnamalai, Vidhya; Fekete, Donna M

    2013-05-01

    Wnt signaling is a hallmark of all embryonic development with multiple roles at multiple developmental time points. Wnt signaling is also important in the development of several organs, one of which is the inner ear, where it participates in otic specification, the formation of vestibular structures, and the development of the cochlea. In particular, we focus on Wnt signaling in the auditory organ, the cochlea. Attempting to dissect the multiple Wnt signaling pathways in the mammalian cochlea is a challenging task due to limited expression data, particularly at proliferating stages. To offer predictions about Wnt activity, we compare cochlear development with that of other biological systems such as Xenopus retina, brain, cancer cells and osteoblasts. Wnts are likely to regulate development through crosstalk with other signaling pathways, particularly Notch and FGF, leading to changes in the expression of Sox2 and proneural (pro-hair cell) genes. In this review we have consolidated the known signaling pathways in the cochlea with known developmental roles of Wnts from other systems to generate a potential timeline of cochlear development. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Metabolites in vertebrate Hedgehog signaling.

    Science.gov (United States)

    Roberg-Larsen, Hanne; Strand, Martin Frank; Krauss, Stefan; Wilson, Steven Ray

    2014-04-11

    The Hedgehog (HH) signaling pathway is critical in embryonic development, stem cell biology, tissue homeostasis, chemoattraction and synapse formation. Irregular HH signaling is associated with a number of disease conditions including congenital disorders and cancer. In particular, deregulation of HH signaling has been linked to skin, brain, lung, colon and pancreatic cancers. Key mediators of the HH signaling pathway are the 12-pass membrane protein Patched (PTC), the 7-pass membrane protein Smoothened (SMO) and the GLI transcription factors. PTC shares homology with the RND family of small-molecule transporters and it has been proposed that it interferes with SMO through metabolites. Although a conclusive picture is lacking, substantial efforts are made to identify and understand natural metabolites/sterols, including cholesterol, vitamin D3, oxysterols and glucocorticoides, that may be affected by, or influence the HH signaling cascade at the level of PTC and SMO. In this review we will elaborate the role of metabolites in HH signaling with a focus on oxysterols, and discuss advancements in modern analytical approaches in the field. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Bystander signaling via oxidative metabolism.

    Science.gov (United States)

    Sawal, Humaira Aziz; Asghar, Kashif; Bureik, Matthias; Jalal, Nasir

    2017-01-01

    The radiation-induced bystander effect (RIBE) is the initiation of biological end points in cells (bystander cells) that are not directly traversed by an incident-radiation track, but are in close proximity to cells that are receiving the radiation. RIBE has been indicted of causing DNA damage via oxidative stress, besides causing direct damage, inducing tumorigenesis, producing micronuclei, and causing apoptosis. RIBE is regulated by signaling proteins that are either endogenous or secreted by cells as a means of communication between cells, and can activate intracellular or intercellular oxidative metabolism that can further trigger signaling pathways of inflammation. Bystander signals can pass through gap junctions in attached cell lines, while the suspended cell lines transmit these signals via hormones and soluble proteins. This review provides the background information on how reactive oxygen species (ROS) act as bystander signals. Although ROS have a very short half-life and have a nanometer-scale sphere of influence, the wide variety of ROS produced via various sources can exert a cumulative effect, not only in forming DNA adducts but also setting up signaling pathways of inflammation, apoptosis, cell-cycle arrest, aging, and even tumorigenesis. This review outlines the sources of the bystander effect linked to ROS in a cell, and provides methods of investigation for researchers who would like to pursue this field of science.

  1. 33 CFR 117.15 - Signals.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Signals. 117.15 Section 117.15... REGULATIONS General Requirements § 117.15 Signals. (a) General. (1) The operator of each vessel requesting a drawbridge to open shall signal the drawtender and the drawtender shall acknowledge that signal. The signal...

  2. SignalPlant: an open signal processing software platform.

    Science.gov (United States)

    Plesinger, F; Jurco, J; Halamek, J; Jurak, P

    2016-07-01

    The growing technical standard of acquisition systems allows the acquisition of large records, often reaching gigabytes or more in size as is the case with whole-day electroencephalograph (EEG) recordings, for example. Although current 64-bit software for signal processing is able to process (e.g. filter, analyze, etc) such data, visual inspection and labeling will probably suffer from rather long latency during the rendering of large portions of recorded signals. For this reason, we have developed SignalPlant-a stand-alone application for signal inspection, labeling and processing. The main motivation was to supply investigators with a tool allowing fast and interactive work with large multichannel records produced by EEG, electrocardiograph and similar devices. The rendering latency was compared with EEGLAB and proves significantly faster when displaying an image from a large number of samples (e.g. 163-times faster for 75  ×  10(6) samples). The presented SignalPlant software is available free and does not depend on any other computation software. Furthermore, it can be extended with plugins by third parties ensuring its adaptability to future research tasks and new data formats.

  3. Bystander signaling via oxidative metabolism

    Directory of Open Access Journals (Sweden)

    Sawal HA

    2017-08-01

    Full Text Available Humaira Aziz Sawal,1 Kashif Asghar,2 Matthias Bureik,3 Nasir Jalal4 1Healthcare Biotechnology Department, Atta-ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, 2Basic Sciences Research, Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, Pakistan; 3Health Science Platform, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, China; 4Health Science Platform, Department of Molecular and Cellular Pharmacology, Tianjin University, Tianjin, China Abstract: The radiation-induced bystander effect (RIBE is the initiation of biological end points in cells (bystander cells that are not directly traversed by an incident-radiation track, but are in close proximity to cells that are receiving the radiation. RIBE has been indicted of causing DNA damage via oxidative stress, besides causing direct damage, inducing tumorigenesis, producing micronuclei, and causing apoptosis. RIBE is regulated by signaling proteins that are either endogenous or secreted by cells as a means of communication between cells, and can activate intracellular or intercellular oxidative metabolism that can further trigger signaling pathways of inflammation. Bystander signals can pass through gap junctions in attached cell lines, while the suspended cell lines transmit these signals via hormones and soluble proteins. This review provides the background information on how reactive oxygen species (ROS act as bystander signals. Although ROS have a very short half-life and have a nanometer-scale sphere of influence, the wide variety of ROS produced via various sources can exert a cumulative effect, not only in forming DNA adducts but also setting up signaling pathways of inflammation, apoptosis, cell-cycle arrest, aging, and even tumorigenesis. This review outlines the sources of the bystander effect linked to ROS in a cell, and provides methods of investigation for researchers who would like to

  4. Liquid Argon TPC Signal Formation, Signal Processing and Hit Reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Baller, Bruce [Fermilab

    2017-03-11

    This document describes the early stage of the reconstruction chain that was developed for the ArgoNeuT and MicroBooNE experiments at Fermilab. These experiments study accelerator neutrino interactions that occur in a Liquid Argon Time Projection Chamber. Reconstructing the properties of particles produced in these interactions requires knowledge of the micro-physics processes that affect the creation and transport of ionization electrons to the readout system. A wire signal deconvolution technique was developed to convert wire signals to a standard form for hit reconstruction, to remove artifacts in the electronics chain and to remove coherent noise.

  5. Mathematical model for classification of EEG signals

    Science.gov (United States)

    Ortiz, Victor H.; Tapia, Juan J.

    2015-09-01

    A mathematical model to filter and classify brain signals from a brain machine interface is developed. The mathematical model classifies the signals from the different lobes of the brain to differentiate the signals: alpha, beta, gamma and theta, besides the signals from vision, speech, and orientation. The model to develop further eliminates noise signals that occur in the process of signal acquisition. This mathematical model can be used on different platforms interfaces for rehabilitation of physically handicapped persons.

  6. Applied signal processing concepts, circuits, and systems

    CERN Document Server

    Hamdy, Nadder

    2008-01-01

    Introduction What are Signals? Signal parameters Why Signal processing? Analog vs. Digital Signal processing Practical Signal processing Systems Analog Signal Processing Amplitude Shaping Frequency Spectrum Shaping Phase Errors Correction Waveform Generation Analog Filter Design Describing Equations Design Procedures Filter Specifications Approximations to the Ideal Response Realization Practical RC-Filters Design Switched Capacitor Filter Realization Design examples Data Converters Introduction A typical DSP System Specifications of Data Converters Sampling Samp

  7. Optical time-lens signal processing

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Galili, Michael; Mulvad, Hans Christian Hansen

    2014-01-01

    This paper describes the use of optical time lenses for optical signal processing of advanced optical data signals. Examples given include 1.28 Tbaud Nyquist channel serial-to-parallel conversion and spectral magnification of OFDM signals.......This paper describes the use of optical time lenses for optical signal processing of advanced optical data signals. Examples given include 1.28 Tbaud Nyquist channel serial-to-parallel conversion and spectral magnification of OFDM signals....

  8. Biomedical signal and image processing.

    Science.gov (United States)

    Cerutti, Sergio; Baselli, Giuseppe; Bianchi, Anna; Caiani, Enrico; Contini, Davide; Cubeddu, Rinaldo; Dercole, Fabio; Rienzo, Luca; Liberati, Diego; Mainardi, Luca; Ravazzani, Paolo; Rinaldi, Sergio; Signorini, Maria; Torricelli, Alessandro

    2011-01-01

    Generally, physiological modeling and biomedical signal processing constitute two important paradigms of biomedical engineering (BME): their fundamental concepts are taught starting from undergraduate studies and are more completely dealt with in the last years of graduate curricula, as well as in Ph.D. courses. Traditionally, these two cultural aspects were separated, with the first one more oriented to physiological issues and how to model them and the second one more dedicated to the development of processing tools or algorithms to enhance useful information from clinical data. A practical consequence was that those who did models did not do signal processing and vice versa. However, in recent years,the need for closer integration between signal processing and modeling of the relevant biological systems emerged very clearly [1], [2]. This is not only true for training purposes(i.e., to properly prepare the new professional members of BME) but also for the development of newly conceived research projects in which the integration between biomedical signal and image processing (BSIP) and modeling plays a crucial role. Just to give simple examples, topics such as brain–computer machine or interfaces,neuroengineering, nonlinear dynamical analysis of the cardiovascular (CV) system,integration of sensory-motor characteristics aimed at the building of advanced prostheses and rehabilitation tools, and wearable devices for vital sign monitoring and others do require an intelligent fusion of modeling and signal processing competences that are certainly peculiar of our discipline of BME.

  9. Piezoelectric extraction of ECG signal

    Science.gov (United States)

    Ahmad, Mahmoud Al

    2016-01-01

    The monitoring and early detection of abnormalities or variations in the cardiac cycle functionality are very critical practices and have significant impact on the prevention of heart diseases and their associated complications. Currently, in the field of biomedical engineering, there is a growing need for devices capable of measuring and monitoring a wide range of cardiac cycle parameters continuously, effectively and on a real-time basis using easily accessible and reusable probes. In this paper, the revolutionary generation and extraction of the corresponding ECG signal using a piezoelectric transducer as alternative for the ECG will be discussed. The piezoelectric transducer pick up the vibrations from the heart beats and convert them into electrical output signals. To this end, piezoelectric and signal processing techniques were employed to extract the ECG corresponding signal from the piezoelectric output voltage signal. The measured electrode based and the extracted piezoelectric based ECG traces are well corroborated. Their peaks amplitudes and locations are well aligned with each other. PMID:27853180

  10. Calcium signaling in taste cells.

    Science.gov (United States)

    Medler, Kathryn F

    2015-09-01

    The sense of taste is a common ability shared by all organisms and is used to detect nutrients as well as potentially harmful compounds. Thus taste is critical to survival. Despite its importance, surprisingly little is known about the mechanisms generating and regulating responses to taste stimuli. All taste responses depend on calcium signals to generate appropriate responses which are relayed to the brain. Some taste cells have conventional synapses and rely on calcium influx through voltage-gated calcium channels. Other taste cells lack these synapses and depend on calcium release to formulate an output signal through a hemichannel. Beyond establishing these characteristics, few studies have focused on understanding how these calcium signals are formed. We identified multiple calcium clearance mechanisms that regulate calcium levels in taste cells as well as a calcium influx that contributes to maintaining appropriate calcium homeostasis in these cells. Multiple factors regulate the evoked taste signals with varying roles in different cell populations. Clearly, calcium signaling is a dynamic process in taste cells and is more complex than has previously been appreciated. This article is part of a Special Issue entitled: 13th European Symposium on Calcium. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Epigenetic Mechanisms of Serotonin Signaling.

    Science.gov (United States)

    Holloway, Terrell; González-Maeso, Javier

    2015-07-15

    Histone modifications and DNA methylation represent central dynamic and reversible processes that regulate gene expression and contribute to cellular phenotypes. These epigenetic marks have been shown to play fundamental roles in a diverse set of signaling and behavioral outcomes. Serotonin is a monoamine that regulates numerous physiological responses including those in the central nervous system. The cardinal signal transduction mechanisms via serotonin and its receptors are well established, but fundamental questions regarding complex interactions between the serotonin system and heritable epigenetic modifications that exert control on gene function remain a topic of intense research and debate. This review focuses on recent advances and contributions to our understanding of epigenetic mechanisms of serotonin receptor-dependent signaling, with focus on psychiatric disorders such as schizophrenia and depression.

  12. The Welfare Cost of Signaling

    Directory of Open Access Journals (Sweden)

    Fan Yang

    2017-02-01

    Full Text Available Might the resource costliness of making signals credible be low or negligible? Using a job market as an example, we build a signaling model to determine the extent to which a transfer from an applicant might replace a resource cost as an equilibrium method of achieving signal credibility. Should a firm’s announcement of hiring for an open position be believed, the firm has an incentive to use a properly-calibrated fee to implement a separating equilibrium. The result is robust to institutional changes, outside options, many firms or many applicants and applicant risk aversion, though a sufficiently risk-averse applicant who is sufficiently likely to be a high type may lead to a preference for a pooling equilibrium.

  13. Notch Signaling and Brain Tumors

    DEFF Research Database (Denmark)

    Stockhausen, Marie; Kristoffersen, Karina; Poulsen, Hans Skovgaard

    2011-01-01

    Human brain tumors are a heterogenous group of neoplasms occurring inside the cranium and the central spinal cord. In adults and children, astrocytic glioma and medulloblastoma are the most common subtypes of primary brain tumors. These tumor types are thought to arise from cells in which Notch...... signaling plays a fundamental role during development. Recent findings have shown that Notch signaling is dysregulated, and contributes to the malignant potential of these tumors. Growing evidence point towards an important role for cancer stem cells in the initiation and maintenance of glioma...... and medulloblastoma. In this chapter we will cover the present findings of Notch signaling in human glioma and medulloblastoma and try to create an overall picture of its relevance in the pathogenesis of these tumors....

  14. Hedgehog signaling in the stomach.

    Science.gov (United States)

    Konstantinou, Daniel; Bertaux-Skeirik, Nina; Zavros, Yana

    2016-12-01

    The Hedgehog (Hh) signaling pathway not only plays a key part in controlling embryonic development, but in the adult stomach governs important cellular events such as epithelial cell differentiation, proliferation, gastric disease, and regeneration. In particular, Sonic Hedgehog (Shh) signaling has been well studied for its role in gastric physiology and pathophysiology. Shh is secreted from the gastric parietal cells and contributes to the regeneration of the epithelium in response to injury, or the development of gastritis during Helicobacter pylori infection. Dysregulation of the Shh signaling pathway leads to the disruption of gastric differentiation, loss of gastric acid secretion and the development of cancer. In this chapter, we will review the most recent findings that reveal the role of Shh as a regulator of gastric physiology, regeneration, and disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. The Dynamics of Costly Signaling

    Directory of Open Access Journals (Sweden)

    Elliott O. Wagner

    2013-04-01

    Full Text Available Costly signaling is a mechanism through which the honesty of signals can be secured in equilibrium, even in interactions where communicators have conflicting interests. This paper explores the dynamics of one such signaling game: Spence’s model of education. It is found that separating equilibria are unlikely to emerge under either the replicator or best response dynamics, but that partially communicative mixed equilibria are quite important dynamically. These mixtures are Lyapunov stable in the replicator dynamic and asymptotically stable in the best response dynamic. Moreover, they have large basins of attraction, in fact larger than those of either pooling or separating equilibria. This suggests that these mixtures may play significant, and underappreciated, roles in the explanation of the emergence and stability of information transfer.

  16. Development of Signal Processing Blocks

    Science.gov (United States)

    James, Xavier; Voinov, Alexey

    2017-09-01

    Experiments executed on the Dubna Gas Filled Recoil Separator (DGFRS) at the Flerov Laboratory of Nuclear Reactions, Joint Institute of Nuclear Research, has proved the hypothesis of the existence of an `island of stability' of super heavy nuclei. It is a highly sensitive detection system that uses the method of ``active correlations'' which allows rare events of the decay of super heavy nuclei to be detected in almost background-free conditions. The role of the signal processing block is to distribute an event signal to the rest of the data acquisition components within the trigger system. In doing so, it will synchronize the rest of the data acquisition signal blocks when an alpha particle recoil appears in the Dubna Gas-Filled Recoil Separator detector. This helps to limit the amount of background interference as the DGFRS undergoes an experiment with a targeted heavy nucleus to receive coherent and succinct results. Joint Institute of Nuclear Research and NSF Grant Number PHY 1713816.

  17. Ocean circulation generated magnetic signals

    DEFF Research Database (Denmark)

    Manoj, C.; Kuvshinov, A.; Maus, S.

    2006-01-01

    Conducting ocean water, as it flows through the Earth's magnetic field, generates secondary electric and magnetic fields. An assessment of the ocean-generated magnetic fields and their detectability may be of importance for geomagnetism and oceanography. Motivated by the clear identification...... of ocean tidal signatures in the CHAMP magnetic field data we estimate the ocean magnetic signals of steady flow using a global 3-D EM numerical solution. The required velocity data are from the ECCO ocean circulation experiment and alternatively from the OCCAM model for higher resolution. We assume...... of the magnetic field, as compared to the ECCO simulation. Besides the expected signatures of the global circulation patterns, we find significant seasonal variability of ocean magnetic signals in the Indian and Western Pacific Oceans. Compared to seasonal variation, interannual variations produce weaker signals....

  18. Flagellar activation of epithelial signaling.

    Science.gov (United States)

    Prince, Alice

    2006-05-01

    Mucosal epithelial cells are an important component of the innate immune system forming a physical and immunologic barrier to inhaled bacteria. As polarized cells with tight junctions, the immunologic signaling functions of airway epithelial cells differ from those of professional immune cells. While many bacterial gene products activate airway mucosal cells, flagella are especially immunostimulatory. The motility function provided by flagella is essential for the initial stages of respiratory infection associated with opportunists such as Pseudomonas aeruginosa. Apically presented toll-like receptor 5 responds specifically to bacterial flagellin transducing a number of epithelial proinflammatory signaling cascades, including the induction of Ca2+ fluxes; activation of NF-kappaB, IL-8, and matrilysin; and mucin expression. The complexities of flagella and flagellin structures, how these bacterial components initiate host signaling and their potential as a vaccine target are reviewed.

  19. Endocannabinoid signaling in female reproduction.

    Science.gov (United States)

    Sun, Xiaofei; Dey, Sudhansu K

    2012-05-16

    Marijuana is a preparation of the flower, as well as the leaves and seeds, of the plant Cannabis sativa. Marijuana has been used for medicinal and recreational purposes for thousands of years due to its psychoactive effects including euphoria, sedation, and analgesia. Although it has been suspected for decades that marijuana has adverse effects on female fertility, the underlying molecular mechanism was not clear. The discovery of cannabinoid receptors and endocannabinoids has advanced studies if cannabinoid signaling. Since then, numerous studies have been published on cannabinoid signaling in female reproductive events, including preimplantation embryo development, oviductal embryo transport, embryo implantation, placentation, and parturition. This review focuses on various aspects of endocannabinoid signaling in female fertility.

  20. Signals, systems, transforms, and digital signal processing with Matlab

    CERN Document Server

    Corinthios, Michael

    2009-01-01

    Continuous-Time and Discrete-Time Signals and SystemsIntroductionContinuous-Time SignalsPeriodic FunctionsUnit Step FunctionGraphical Representation of FunctionsEven and Odd Parts of a FunctionDirac-Delta ImpulseBasic Properties of the Dirac-Delta ImpulseOther Important Properties of the ImpulseContinuous-Time SystemsCausality, StabilityExamples of Electrical Continuous-Time SystemsMechanical SystemsTransfer Function and Frequency ResponseConvolution and CorrelationA Right-Sided and a Left-Sided FunctionConvolution with an Impulse and Its DerivativesAdditional Convolution PropertiesCorrelation FunctionProperties of the Correlation FunctionGraphical InterpretationCorrelation of Periodic FunctionsAverage, Energy and Power of Continuous-Time SignalsDiscrete-Time SignalsPeriodicityDifference EquationsEven/Odd DecompositionAverage Value, Energy and Power SequencesCausality, StabilityProblemsAnswers to Selected ProblemsFourier Series ExpansionTrigonometric Fourier SeriesExponential Fourier SeriesExponential versus ...

  1. Genomic Signals of Reoriented ORFs

    Directory of Open Access Journals (Sweden)

    Paul Dan Cristea

    2004-01-01

    Full Text Available Complex representation of nucleotides is used to convert DNA sequences into complex digital genomic signals. The analysis of the cumulated phase and unwrapped phase of DNA genomic signals reveals large-scale features of eukaryote and prokaryote chromosomes that result from statistical regularities of base and base-pair distributions along DNA strands. By reorienting the chromosome coding regions, a “hidden” linear variation of the cumulated phase has been revealed, along with the conspicuous almost linear variation of the unwrapped phase. A model of chromosome longitudinal structure is inferred on these bases.

  2. Superluminal Signaling and Time Machine

    CERN Document Server

    Shan Gao

    2003-01-01

    Recently, time machine becomes a hot topic in the physics community[1-7]. But it is still unclear whether or not time machine does exist. In this short paper, we will analyze the possible relation between superluminal signaling and time machine. It will be shown that the realization of superluminal signaling will exclude the existence of time machine, or vice versa. Furthermore, we denote that the usual proof for the possible existence of time machine may fail due to ignoring the limitation of relativity.

  3. Subgraph detection using graph signals

    KAUST Repository

    Chepuri, Sundeep Prabhakar

    2017-03-06

    In this paper we develop statistical detection theory for graph signals. In particular, given two graphs, namely, a background graph that represents an usual activity and an alternative graph that represents some unusual activity, we are interested in answering the following question: To which of the two graphs does the observed graph signal fit the best? To begin with, we assume both the graphs are known, and derive an optimal Neyman-Pearson detector. Next, we derive a suboptimal detector for the case when the alternative graph is not known. The developed theory is illustrated with numerical experiments.

  4. Chaotic signals in digital communications

    CERN Document Server

    Eisencraft, Marcio; Suyama, Ricardo

    2013-01-01

    Chaotic Signals in Digital Communications combines fundamental background knowledge with state-of-the-art methods for using chaotic signals and systems in digital communications. The book builds a bridge between theoretical works and practical implementation to help researchers attain consistent performance in realistic environments. It shows the possible shortcomings of the chaos-based communication systems proposed in the literature, particularly when they are subjected to non-ideal conditions. It also presents a toolbox of techniques for researchers working to actually implement such system

  5. Signal processing for remote sensing

    CERN Document Server

    Chen, CH

    2007-01-01

    Written by leaders in the field, Signal Processing for Remote Sensing explores the data acquisitions segment of remote sensing. Each chapter presents a major research result or the most up to date development of a topic. The book includes a chapter by Dr. Norden Huang, inventor of the Huang-Hilbert transform who, along with and Dr. Steven Long discusses the application of the transform to remote sensing problems. It also contains a chapter by Dr. Enders A. Robinson, who has made major contributions to seismic signal processing for over half a century, on the basic problem of constructing seism

  6. PSpice for digital signal processing

    CERN Document Server

    Tobin, Paul

    2007-01-01

    PSpice for Digital Signal Processing is the last in a series of five books using Cadence Orcad PSpice version 10.5 and introduces a very novel approach to learning digital signal processing (DSP). DSP is traditionally taught using Matlab/Simulink software but has some inherent weaknesses for students particularly at the introductory level. The 'plug in variables and play' nature of these software packages can lure the student into thinking they possess an understanding they don't actually have because these systems produce results quicklywithout revealing what is going on. However, it must be

  7. Signal processing for cognitive radios

    CERN Document Server

    Jayaweera, Sudharman K

    2014-01-01

    This book covers power electronics, in depth, by presenting the basic principles and application details, and it can be used both as a textbook and reference book.  Introduces the specific type of CR that has gained the most research attention in recent years: the CR for Dynamic Spectrum Access (DSA). Provides signal processing solutions to each task by relating the tasks to materials covered in Part II. Specialized chapters then discuss specific signal processing algorithms required for DSA and DSS cognitive radios  

  8. Phosphoinositide signaling in somatosensory neurons

    Science.gov (United States)

    Rohacs, Tibor

    2015-01-01

    Somatosensory neurons of the dorsal root ganglia (DRG) and trigeminal ganglia (TG) are responsible for detecting thermal and tactile stimuli. They are also the primary neurons mediating pain and itch. A large number of cell surface receptors in these neurons couple to phospholipase C (PLC) enzymes leading to the hydrolysis of phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] and the generation of downstream signaling molecules. These neurons also express many different ion channels, several of which are regulated by phosphoinositides. This review will summarize the knowledge on phosphoinositide signaling in these neurons, with special focus on effects on sensory and other ion channels. PMID:26724974

  9. Basis for recording seismoacoustic signals

    Energy Technology Data Exchange (ETDEWEB)

    Kornowski, J.; Sokolowski, H.; Wasko, A.

    1986-06-01

    Accuracy is evaluated of the PRS-4a seismic detection system developed and manufactured by the EMAG Center for forecasting rock burst hazards in underground coal mines. The system consists of seismic detectors, preamplifiers, amplifiers, cables and receivers. The PRS-4a accurately records seismic signals within a range of 400-1000 Hz. The measuring range of the system is 200 to 1700 Hz but intensive attenuation occurs at both ends of frequency range; excessive amplification is a cause of signal distortion within the range 1200 to 1400 Hz. Test results are shown in 6 diagrams.

  10. VLSI mixed signal processing system

    Science.gov (United States)

    Alvarez, A.; Premkumar, A. B.

    1993-01-01

    An economical and efficient VLSI implementation of a mixed signal processing system (MSP) is presented in this paper. The MSP concept is investigated and the functional blocks of the proposed MSP are described. The requirements of each of the blocks are discussed in detail. A sample application using active acoustic cancellation technique is described to demonstrate the power of the MSP approach.

  11. Noisy signaling: theory and experiment

    NARCIS (Netherlands)

    de Haan, T.; Offerman, T.; Sloof, R.

    2009-01-01

    We investigate a noisy signaling game, in which nature adds random noise to the message chosen. Theoretically, with an unfavorable prior the separating equilibrium vanishes for low noise. It reappears for intermediate and high noise, where messages increase with noise. A pooling equilibrium always

  12. Purinergic signaling in schistosomal infection

    Directory of Open Access Journals (Sweden)

    Claudia Lucia Martins Silva

    2016-10-01

    Full Text Available Human schistosomiasis is a chronic inflammatory disease caused by blood fluke worms belonging to the genus Schistosoma. Health metrics indicate that the disease is related to an elevated number of years lost-to-disability and years lost-to-life. Schistosomiasis is an intravascular disease that is related to a Th1 and Th2 immune response polarization, and the degree of polarization affects the outcome of the disease. The purinergic system is composed of adenosine and nucleotides acting as key messenger molecules. Moreover, nucleotide-transforming enzymes and cell-surface purinergic receptors are obligatory partners of this purinergic signaling. In mammalian cells, purinergic signaling modulates innate immune responses and inflammation among other functions; conversely purinergic signaling may also be modulated by inflammatory mediators. Moreover, schistosomes also express some enzymes of the purinergic system, and it is possible that worms modulate host purinergic signaling. Current data obtained in murine models of schistosomiasis support the notion that the host purinergic system is altered by the disease. The dysfunction of adenosine receptors, metabotropic P2Y and ionotropic P2X7 receptors, and NTPDases likely contributes to disease morbidity. Keywords: Purinergic receptor, NTPDases, Schistosomiasis, Macrophages, Endothelial cell, Inflammation

  13. Mathematical Modelling Plant Signalling Networks

    KAUST Repository

    Muraro, D.

    2013-01-01

    During the last two decades, molecular genetic studies and the completion of the sequencing of the Arabidopsis thaliana genome have increased knowledge of hormonal regulation in plants. These signal transduction pathways act in concert through gene regulatory and signalling networks whose main components have begun to be elucidated. Our understanding of the resulting cellular processes is hindered by the complex, and sometimes counter-intuitive, dynamics of the networks, which may be interconnected through feedback controls and cross-regulation. Mathematical modelling provides a valuable tool to investigate such dynamics and to perform in silico experiments that may not be easily carried out in a laboratory. In this article, we firstly review general methods for modelling gene and signalling networks and their application in plants. We then describe specific models of hormonal perception and cross-talk in plants. This mathematical analysis of sub-cellular molecular mechanisms paves the way for more comprehensive modelling studies of hormonal transport and signalling in a multi-scale setting. © EDP Sciences, 2013.

  14. The Pseudomonas Quinolone Signal (PQS)

    DEFF Research Database (Denmark)

    Sams, Thomas; Baker, Ysobel; Hodgkinson, James

    2015-01-01

    , we pres-ent the discovery and elucidation of PQS signaling froma historical perspective, and also outline some of the out-standing research questions that still need to be addressed.Finally, we show how a better understanding of the bio-chemistry underpinning this pathway is leading to the devel...

  15. Velocimetry signal synthesis with fringen.

    Energy Technology Data Exchange (ETDEWEB)

    Dolan, Daniel H., III

    2011-02-01

    An important part of velocimetry analysis is the recovery of a known velocity history from simulated data signals. The fringen program synthesizes VISAR and PDV signals, given a specified velocity history, using exact formulations for the optical signal. Time-dependent light conditions, non-ideal measurement conditions, and various diagnostic limitations (noise, etc.) may be incorporated into the simulated signals. This report describes the fringen program, which performs forward VISAR (Velocity Interferometer System for Any Reflector) and PDV (Photonic Doppler Velocimetry, also known as heterodyne velocimetry) analysis. Nearly all effects that might occur in VISAR/PDV measurement of a single velocity can be modeled by fringen. The program operates in MATLAB, either within a graphical interface or as a user-callable function. The current stable version of fringen is 0.3, which was released in October 2010. The following sections describe the operation and use of fringen. Section 2 gives a brief overview of VISAR and PDV synthesis. Section 3 illustrates the graphical and console interface of fringen. Section 4 presents several example uses of the program. Section 5 summarizes program capabilities and discusses potential future work.

  16. Handbook of signal processing systems

    CERN Document Server

    Bhattacharyya, Shuvra S; Leupers, Rainer; Takala, Jarmo

    2010-01-01

    The Handbook is organized in four parts. The first part motivates representative applications that drive and apply state-of-the art methods for design and implementation of signal processing systems; the second part discusses architectures for implementing these applications; the third part focuses on compilers and simulation tools; and the fourth part describes models of computation and their associated design tools and methodologies.

  17. Biophysical Aspects of Transmembrane Signaling

    CERN Document Server

    Damjanovich, Sandor

    2005-01-01

    Transmembrane signaling is one of the most significant cell biological events in the life and death of cells in general and lymphocytes in particular. Until recently biochemists and biophysicists were not accustomed to thinking of these processes from the side of a high number of complex biochemical events and an equally high number of physical changes at molecular and cellular levels at the same time. Both types of researchers were convinced that their findings are the most decisive, having higher importance than the findings of the other scientist population. Both casts were wrong. Life, even at cellular level, has a number of interacting physical and biochemical mechanisms, which finally build up the creation of an "excited" cell that will respond to particular signals from the outer or inner world. This book handles both aspects of the signalling events, and in some cases tries to unify our concepts and help understand the signals that govern the life and death of our cells. Not only the understanding, bu...

  18. computer based speech signal processing

    African Journals Online (AJOL)

    An alternative tool for research in phonetics: computer based speech signal processing. EE Williams, RC Okoro, Z Lipcsey. Abstract. No abstract available. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/gjpas.v10i3.16424 · AJOL African ...

  19. Loco signaling pathway in longevity.

    Science.gov (United States)

    Lin, Yuh-Ru; Parikh, Hardik; Park, Yongkyu

    2011-05-01

    Despite the various roles of regulator of G protein signaling (RGS) protein in the G protein signaling pathway that have been defined, the function of RGS has not been characterized in longevity signaling pathways. We found that reduced expression of Loco, a Drosophila RGS protein, resulted in a longer lifespan of flies with stronger resistance to stress, higher MnSOD activity and increased fat content. In contrast, overexpression of the loco gene shortened the fly lifespan significantly, lowered stress resistance and reduced fat content, also indicating that the RGS domain containing GTPase-activating protein (GAP) activity is related to the regulation of longevity. Interestingly, expressional changes of yeast RGS2 and rat RGS14, homologs to the fly Loco, also affected oxidative stress resistance and longevity in the respective species. It is known that Loco inactivates inhibitory Gαi•GTP protein to reduce activity of adenylate cyclase (AC) and RGS14 interacts with activated H-Ras and Raf-1 kinases, which subsequently inhibits ERK phosphorylation. We propose that Loco/RGS14 protein may regulate stress resistance and longevity as an activator in AC-cAMP-PKA pathway and/or as a molecular scaffold that sequesters active Ras and Raf from Ras•GTP-Raf-MEK-ERK signaling pathway. Consistently, our data showed that downregulation of Loco significantly diminishes cAMP amounts and increases p-ERK levels with higher resistance to the oxidative stress.

  20. Error signals driving locomotor adaptation

    DEFF Research Database (Denmark)

    Choi, Julia T; Jensen, Peter; Nielsen, Jens Bo

    2016-01-01

    anaesthesia (n = 5) instead of repetitive nerve stimulation. Foot anaesthesia reduced ankle adaptation to external force perturbations during walking. Our results suggest that cutaneous input plays a role in force perception, and may contribute to the 'error' signal involved in driving walking adaptation when...

  1. Cell signaling in root development

    NARCIS (Netherlands)

    Scheres, B.J.G.

    1997-01-01

    Cell signaling has recently been shown to be of major importance in cell specification during Arabidopsis root development. In the ground tissue, cues of unknown molecular nature convey positional information and two genes provide an interesting link between asymmetric cell division and the

  2. Queen signaling in social wasps

    DEFF Research Database (Denmark)

    van Zweden, Jelle Stijn; Bonckaert, Wim; Wenseleers, Tom

    2014-01-01

    saxonica, queens emit reliable chemical cues of their true fertility and that these putative queen signals decrease as the colony develops and worker reproduction increases. Moreover, these putative pheromones of D. saxonica show significant conservation with those of Vespula vulgaris and other Vespinae...

  3. Neural synchronization via potassium signaling

    DEFF Research Database (Denmark)

    Postnov, Dmitry E; Ryazanova, Ludmila S; Mosekilde, Erik

    2006-01-01

    Using a relatively simple model we examine how variations of the extracellular potassium concentration can give rise to synchronization of two nearby pacemaker cells. With the volume of the extracellular space and the rate of potassium diffusion as control parameters, the dual nature...... junctional coupling, potassium signaling gives rise to considerable changes of the cellular response to external stimuli....

  4. BPSK Demodulation Using Digital Signal Processing

    Science.gov (United States)

    Garcia, Thomas R.

    1996-01-01

    A digital communications signal is a sinusoidal waveform that is modified by a binary (digital) information signal. The sinusoidal waveform is called the carrier. The carrier may be modified in amplitude, frequency, phase, or a combination of these. In this project a binary phase shift keyed (BPSK) signal is the communication signal. In a BPSK signal the phase of the carrier is set to one of two states, 180 degrees apart, by a binary (i.e., 1 or 0) information signal. A digital signal is a sampled version of a "real world" time continuous signal. The digital signal is generated by sampling the continuous signal at discrete points in time. The rate at which the signal is sampled is called the sampling rate (f(s)). The device that performs this operation is called an analog-to-digital (A/D) converter or a digitizer. The digital signal is composed of the sequence of individual values of the sampled BPSK signal. Digital signal processing (DSP) is the modification of the digital signal by mathematical operations. A device that performs this processing is called a digital signal processor. After processing, the digital signal may then be converted back to an analog signal using a digital-to-analog (D/A) converter. The goal of this project is to develop a system that will recover the digital information from a BPSK signal using DSP techniques. The project is broken down into the following steps: (1) Development of the algorithms required to demodulate the BPSK signal; (2) Simulation of the system; and (3) Implementation a BPSK receiver using digital signal processing hardware.

  5. Estimates of Small Signal/Noise Ratios

    Science.gov (United States)

    Howard, L. D.

    1985-01-01

    Signal/Noise Ratio Meter measures ratio of signal power to noise power in input that contains both signal and noise. Signal and noise first filtered and normalized in analog circuitry, then digitized and sampled. Performance of SNR meter determined by statistical algorithm chosen for analysis of samples.

  6. Predicting Secretory Proteins with SignalP

    DEFF Research Database (Denmark)

    Nielsen, Henrik

    2017-01-01

    SignalP is the currently most widely used program for prediction of signal peptides from amino acid sequences. Proteins with signal peptides are targeted to the secretory pathway, but are not necessarily secreted. After a brief introduction to the biology of signal peptides and the history...

  7. Consistent Signal Reconstruction and Convex Coding

    OpenAIRE

    Moonen, Marc; De Moor, Bart; Thao, Nguyen Truong; Vetterli, Martin

    1995-01-01

    The field of signal processing has known tremendous progress with the development of digital signal processing. The first foundation of digital signal processing is due to Shannon's sampling theorem which shows that any bandlimited analog signal can...

  8. Cloning and superluminal signaling£

    Indian Academy of Sciences (India)

    is possible, we can then have (usable) superluminal signaling [8]. The basic principle behind no exact cloning is the principle of no-signaling (i.e., no superluminal signaling). Allowing no-signaling, Gisin [7] has reproduced the 1. 2 optimal universal symmetric cloning machine of Buzek and Hillery [2] for qubits. We shall ...

  9. Purinergic signaling in kidney disease.

    Science.gov (United States)

    Menzies, Robert I; Tam, Frederick W; Unwin, Robert J; Bailey, Matthew A

    2017-02-01

    Nucleotides are key subunits for nucleic acids and provide energy for intracellular metabolism. They can also be released from cells to act physiologically as extracellular messengers or pathologically as danger signals. Extracellular nucleotides stimulate membrane receptors in the P2 and P1 family. P2X are ATP-activated cation channels; P2Y and P1 are G-protein coupled receptors activated by ATP, ADP, UTP, and UDP in the case of P2 or adenosine for P1. Renal P2 receptors influence both vascular contractility and tubular function. Renal cells also express ectonucleotidases that rapidly hydrolyze extracellular nucleotides. These enzymes integrate this multireceptor purinergic-signaling complex by determining the nucleotide milieu to titrate receptor activation. Purinergic signaling also regulates immune cell function by modulating the synthesis and release of various cytokines such as IL1-β and IL-18 as part of inflammasome activation. Abnormal or excessive stimulation of this intricate paracrine system can be pro- or anti-inflammatory, and is also linked to necrosis and apoptosis. Kidney tissue injury causes a localized increase in ATP concentration, and sustained activation of P2 receptors can lead to renal glomerular, tubular, and vascular cell damage. Purinergic receptors also regulate the activity and proliferation of fibroblasts, promoting both inflammation and fibrosis in chronic disease. In this short review we summarize some of the recent findings related to purinergic signaling in the kidney. We focus predominantly on the P2X7 receptor, discussing why antagonists have so far disappointed in clinical trials and how advances in our understanding of purinergic signaling might help to reposition these compounds as potential treatments for renal disease. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  10. Effect of doxycycline on transforming growth factor-beta-1-induced matrix metalloproteinase 2 expression, migration, and collagen contraction in nasal polyp-derived fibroblasts.

    Science.gov (United States)

    Shin, Jae-Min; Park, Joo-Hoo; Kang, Byungjin; Lee, Seoung-Ae; Park, Il-Ho; Lee, Heung-Man

    2016-11-01

    It is well known that doxycycline has antibacterial and anti-inflammatory effects. In this study, we aimed to investigate the effects of doxycycline on the transforming growth factor (TGF) beta 1-induced matrix metalloproteinase (MMP) 2 expression, migration, and collagen contraction, and to determine its molecular mechanism on nasal polyp-derived fibroblasts (NPDF). NPDFs were isolated from the nasal polyps of six patients. Doxycycline was used to pretreat TGF-beta-1-induced NPDFs and ex vivo organ cultures of nasal polyps. Cytotoxicity was evaluated by using a 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl-tetrazolium bromide assay. Smad2/3 is one of the major transcription factors of TGF-beta signaling. The expression levels of MMP2 and Smad2/3 were measured by using Western blotting, reverse transcription-polymerase chain reaction, and immunofluorescence staining. The enzymic activity of MMP2 was analyzed by using gelatin zymography. Fibroblast migration was evaluated by using transwell migration assays. Contractile activity was measured by a collagen gel contraction assay. The expression level of MMP2 in nasal polyp tissues increased in comparison with inferior turbinate tissues. TGF-beta-1-induced NPDFs were not affected by doxycycline (0-40 μg/mL). The expression levels of MMP2 and activation of Smad2/3 in TGF-beta-1-induced NPDFs and in organ cultures of nasal polyps were significantly downregulated with doxycycline pretreatment. Doxycycline also reduced TGF-beta-1-induced fibroblast migration and collagen contraction in NPDFs. Doxycycline inhibited TGF-beta-1-induced MMP2 expression, migration, and collagen contraction via the Smad2/3 signal pathways in NPDFs.

  11. Digital Signal Treatment in Beam Instrumentation

    CERN Document Server

    Schilcher, T

    2001-01-01

    Digital Signal Processing has grown dramatically over the last five years. The evolution of digital logic and processors has opened up the use of digital signal processing in domains, which were reserved to analog signal processing. In this discussion session we would like to review digital signal treatment for beam diagnostics application. Emphasis shall be put on the following subjects: Digital Signal Processing for: image processing BPMs current monitors beam loss monitors feedback systems others

  12. New method for analysis of nonstationary signals

    OpenAIRE

    Stepien, Robert A

    2011-01-01

    Background Analysis of signals by means of symbolic methods consists in calculating a measure of signal complexity, for example informational entropy or Lempel-Ziv algorithmic complexity. For construction of these entropic measures one uses distributions of symbols representing the analyzed signal. Results We introduce a new signal characteristic named sequential spectrum that is suitable for analysis of the wide group of signals, including biosignals. The paper contains a brief review of ana...

  13. Signal-to-Signal Ratio Independent Speaker Identification for Co-channel Speech Signals

    DEFF Research Database (Denmark)

    Saeidi, Rahim; Mowlaee, Pejman; Kinnunen, Tomi

    2010-01-01

    In this paper, we consider speaker identification for the co-channel scenario in which speech mixture from speakers is recorded by one microphone only. The goal is to identify both of the speakers from their mixed signal. High recognition accuracies have already been reported when an accurately...

  14. Signal processing for smart cards

    Science.gov (United States)

    Quisquater, Jean-Jacques; Samyde, David

    2003-06-01

    In 1998, Paul Kocher showed that when a smart card computes cryptographic algorithms, for signatures or encryption, its consumption or its radiations leak information. The keys or the secrets hidden in the card can then be recovered using a differential measurement based on the intercorrelation function. A lot of silicon manufacturers use desynchronization countermeasures to defeat power analysis. In this article we detail a new resynchronization technic. This method can be used to facilitate the use of a neural network to do the code recognition. It becomes possible to reverse engineer a software code automatically. Using data and clock separation methods, we show how to optimize the synchronization using signal processing. Then we compare these methods with watermarking methods for 1D and 2D signal. The very last watermarking detection improvements can be applied to signal processing for smart cards with very few modifications. Bayesian processing is one of the best ways to do Differential Power Analysis, and it is possible to extract a PIN code from a smart card in very few samples. So this article shows the need to continue to set up effective countermeasures for cryptographic processors. Although the idea to use advanced signal processing operators has been commonly known for a long time, no publication explains that results can be obtained. The main idea of differential measurement is to use the cross-correlation of two random variables and to repeat consumption measurements on the processor to be analyzed. We use two processors clocked at the same external frequency and computing the same data. The applications of our design are numerous. Two measurements provide the inputs of a central operator. With the most accurate operator we can improve the signal noise ratio, re-synchronize the acquisition clock with the internal one, or remove jitter. The analysis based on consumption or electromagnetic measurements can be improved using our structure. At first sight

  15. Cellular semiotics and signal transduction

    DEFF Research Database (Denmark)

    Bruni, Luis Emilio

    2007-01-01

    Semiosis, the processes of production, communication and interpretation of signs - coding and de-coding - takes place within and between organisms. The term "endosemiosis" refers to the processes of interpretation and sign transmission inside an organism (as opposed to "exosemiosis", which refers...... to the processes of sign interpretation and transmission between organisms of the same or different species). In Biosemiotics it is customary to recognise the cell as the most elementary integration unit for semiosis. Therefore intra and intercellular communication constitute the departure point for the study...... considering semiotic logic in order to construct our understanding of living phenomena. Given the central integrating role of signal transduction in physiological and ecological studies, this chapter outlines its semiotic implications. The multi-modality and modularity of signal molecules and relative...

  16. Signal processing of anthropometric data

    Science.gov (United States)

    Zimmermann, W. J.

    1983-01-01

    The Anthropometric Measurements Laboratory has accumulated a large body of data from a number of previous experiments. The data is very noisy, therefore it requires the application of some signal processing schemes. Moreover, it was not regarded as time series measurements but as positional information; hence, the data is stored as coordinate points as defined by the motion of the human body. The accumulated data defines two groups or classes. Some of the data was collected from an experiment designed to measure the flexibility of the limbs, referred to as radial movement. The remaining data was collected from experiments designed to determine the surface of the reach envelope. An interactive signal processing package was designed and implemented. Since the data does not include time this package does not include a time series element. Presently the results is restricted to processing data obtained from those experiments designed to measure flexibility.

  17. Cancer, signal transduction and nanotechnology.

    Science.gov (United States)

    Sengupta, Poulomi; Basu, Sudipta; Sengupta, Shiladitya

    2011-05-01

    Understanding the mechanisms underlying different cellular signaling pathways implicated in the pathogenesis of cancer are leading to the identification of novel drug targets as well as novel drug candidates. Multiple targeted therapeutics that modulate aberrant molecular pathways have already reached the clinic. However, targeted therapeutics can exert mechanism-driven side effects as a result of the implication of the molecular target in normal physiological functions besides tumorigenesis. We hypothesize that targeted therapeutics can be optimized by merging them with nanotechnology, which offers the potential for preferential targeting to the tumor, resulting in increased intratumoral concentrations of the active agent with reduced distribution to other parts of the body. This review will address some of the emerging concepts that integrate these two disciplines to engineer novel nanovectors that target different signaling pathways.

  18. Tile Calorimeter Muon Trigger Signal

    CERN Document Server

    Cerqueira, A S; Usai, G L

    2002-01-01

    The Tile Calorimeter contributes to the first level trigger with the fast analog signal coming from the trigger summing boards, so-called analog adder. The adders provide two kinds of output: the total energy sum in a trigger tower and the signal from the respective cell of the last radial calorimeter layer, which can be used for identifying muons, thus making the muon first level trigger more robust. This note reviews the adder specifications and laboratory tests, whereas the main focus is put on the data analysis from the testbeam periods in~2001. Several improvements achieved by tuning the read-out are described. Using the testbeam results, the ability to identify muons in the last radial Tilecal layer is discussed. The experimental results obtained at the testbeams are completed with the Monte Carlo simulations.

  19. Leptin signaling and leptin resistance

    Science.gov (United States)

    Zhou, Yingjiang; Rui, Liangyou

    2014-01-01

    Leptin is secreted into the bloodstream by adipocytes and is required for the maintenance of energy homeostasis and body weight. Leptin deficiency or genetic defects in the components of the leptin signaling pathways causes obesity. Leptin controls energy balance and body weight primarily by targeting LEPRb-expressing neurons in the brain, particularly in the hypothalamus. These LEPRb-expressing neurons function as the first-order neurons that project to the second-order neurons located within and outside the hypothalamus, forming a neural network that controls the energy homeostasis and body weight. Multiple factors, including inflammation and ER stress, contribute to leptin resistance, and leptin resistance is the key risk factor for obesity. This review is focused on recent advance about leptin action, leptin signaling, and leptin resistance. PMID:23580174

  20. Zinc Signal in Brain Diseases

    Directory of Open Access Journals (Sweden)

    Stuart D. Portbury

    2017-11-01

    Full Text Available The divalent cation zinc is an integral requirement for optimal cellular processes, whereby it contributes to the function of over 300 enzymes, regulates intracellular signal transduction, and contributes to efficient synaptic transmission in the central nervous system. Given the critical role of zinc in a breadth of cellular processes, its cellular distribution and local tissue level concentrations remain tightly regulated via a series of proteins, primarily including zinc transporter and zinc import proteins. A loss of function of these regulatory pathways, or dietary alterations that result in a change in zinc homeostasis in the brain, can all lead to a myriad of pathological conditions with both acute and chronic effects on function. This review aims to highlight the role of zinc signaling in the central nervous system, where it may precipitate or potentiate diverse issues such as age-related cognitive decline, depression, Alzheimer’s disease or negative outcomes following brain injury.

  1. Multimedia signal coding and transmission

    CERN Document Server

    Ohm, Jens-Rainer

    2015-01-01

    This textbook covers the theoretical background of one- and multidimensional signal processing, statistical analysis and modelling, coding and information theory with regard to the principles and design of image, video and audio compression systems. The theoretical concepts are augmented by practical examples of algorithms for multimedia signal coding technology, and related transmission aspects. On this basis, principles behind multimedia coding standards, including most recent developments like High Efficiency Video Coding, can be well understood. Furthermore, potential advances in future development are pointed out. Numerous figures and examples help to illustrate the concepts covered. The book was developed on the basis of a graduate-level university course, and most chapters are supplemented by exercises. The book is also a self-contained introduction both for researchers and developers of multimedia compression systems in industry.

  2. Cell signalling and phospholipid metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Boss, W.F.

    1990-01-01

    These studies explored whether phosphoinositide (PI) has a role in plants analogous to its role in animal cells. Although no parallel activity of PI in signal transduction was found in plant cells, activity of inositol phospholipid kinase was found to be modulated by light and by cell wall degrading enzymes. These studies indicate a major role for inositol phospholipids in plant growth and development as membrane effectors but not as a source of second messengers.

  3. Notch Signaling and Brain Tumors

    DEFF Research Database (Denmark)

    Stockhausen, Marie; Kristoffersen, Karina; Poulsen, Hans Skovgaard

    2011-01-01

    Human brain tumors are a heterogenous group of neoplasms occurring inside the cranium and the central spinal cord. In adults and children, astrocytic glioma and medulloblastoma are the most common subtypes of primary brain tumors. These tumor types are thought to arise from cells in which Notch...... and medulloblastoma. In this chapter we will cover the present findings of Notch signaling in human glioma and medulloblastoma and try to create an overall picture of its relevance in the pathogenesis of these tumors....

  4. Signal and image multiresolution analysis

    CERN Document Server

    Ouahabi, Abdelialil

    2012-01-01

    Multiresolution analysis using the wavelet transform has received considerable attention in recent years by researchers in various fields. It is a powerful tool for efficiently representing signals and images at multiple levels of detail with many inherent advantages, including compression, level-of-detail display, progressive transmission, level-of-detail editing, filtering, modeling, fractals and multifractals, etc.This book aims to provide a simple formalization and new clarity on multiresolution analysis, rendering accessible obscure techniques, and merging, unifying or completing

  5. Detection of signals in noise

    CERN Document Server

    McDonough, Robert N

    1995-01-01

    The Second Edition is an updated revision to the authors highly successful and widely used introduction to the principles and application of the statistical theory of signal detection. This book emphasizes those theories that have been found to be particularly useful in practice including principles applied to detection problems encountered in digital communications, radar, and sonar.Detection processing based upon the fast Fourier transform

  6. Dynamics in atomic signaling games

    KAUST Repository

    Fox, Michael J.

    2015-04-08

    We study an atomic signaling game under stochastic evolutionary dynamics. There are a finite number of players who repeatedly update from a finite number of available languages/signaling strategies. Players imitate the most fit agents with high probability or mutate with low probability. We analyze the long-run distribution of states and show that, for sufficiently small mutation probability, its support is limited to efficient communication systems. We find that this behavior is insensitive to the particular choice of evolutionary dynamic, a property that is due to the game having a potential structure with a potential function corresponding to average fitness. Consequently, the model supports conclusions similar to those found in the literature on language competition. That is, we show that efficient languages eventually predominate the society while reproducing the empirical phenomenon of linguistic drift. The emergence of efficiency in the atomic case can be contrasted with results for non-atomic signaling games that establish the non-negligible possibility of convergence, under replicator dynamics, to states of unbounded efficiency loss.

  7. ROS signalling - specificity is required

    DEFF Research Database (Denmark)

    Møller, Ian M; Sweetlove, Lee J

    2010-01-01

    Reactive oxygen species (ROS) production increases in plants under stress. ROS can damage cellular components, but they can also act in signal transduction to help the cell counteract the oxidative damage in the stressed compartment. H2O2 might induce a general stress response, but it does not ha...... and regulate source-specific genes and in this way contribute to retrograde ROS signalling during oxidative stress. Likewise, unmodified peptides deriving from the breakdown of redundant proteins could help coordinate organellar and nuclear gene expression......Reactive oxygen species (ROS) production increases in plants under stress. ROS can damage cellular components, but they can also act in signal transduction to help the cell counteract the oxidative damage in the stressed compartment. H2O2 might induce a general stress response, but it does not have...... the required specificity to selectively regulate nuclear genes required for dealing with localized stress, e.g. in chloroplasts or mitochondria. Here we argue that peptides deriving from proteolytic breakdown of oxidatively damaged proteins have the requisite specificity to act as secondary ROS messengers...

  8. Dynamics in atomic signaling games.

    Science.gov (United States)

    Fox, Michael J; Touri, Behrouz; Shamma, Jeff S

    2015-07-07

    We study an atomic signaling game under stochastic evolutionary dynamics. There are a finite number of players who repeatedly update from a finite number of available languages/signaling strategies. Players imitate the most fit agents with high probability or mutate with low probability. We analyze the long-run distribution of states and show that, for sufficiently small mutation probability, its support is limited to efficient communication systems. We find that this behavior is insensitive to the particular choice of evolutionary dynamic, a property that is due to the game having a potential structure with a potential function corresponding to average fitness. Consequently, the model supports conclusions similar to those found in the literature on language competition. That is, we show that efficient languages eventually predominate the society while reproducing the empirical phenomenon of linguistic drift. The emergence of efficiency in the atomic case can be contrasted with results for non-atomic signaling games that establish the non-negligible possibility of convergence, under replicator dynamics, to states of unbounded efficiency loss. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Calcium Signals from the Vacuole

    Directory of Open Access Journals (Sweden)

    Gerald Schönknecht

    2013-10-01

    Full Text Available The vacuole is by far the largest intracellular Ca2+ store in most plant cells. Here, the current knowledge about the molecular mechanisms of vacuolar Ca2+ release and Ca2+ uptake is summarized, and how different vacuolar Ca2+ channels and Ca2+ pumps may contribute to Ca2+ signaling in plant cells is discussed. To provide a phylogenetic perspective, the distribution of potential vacuolar Ca2+ transporters is compared for different clades of photosynthetic eukaryotes. There are several candidates for vacuolar Ca2+ channels that could elicit cytosolic [Ca2+] transients. Typical second messengers, such as InsP3 and cADPR, seem to trigger vacuolar Ca2+ release, but the molecular mechanism of this Ca2+ release still awaits elucidation. Some vacuolar Ca2+ channels have been identified on a molecular level, the voltage-dependent SV/TPC1 channel, and recently two cyclic-nucleotide-gated cation channels. However, their function in Ca2+ signaling still has to be demonstrated. Ca2+ pumps in addition to establishing long-term Ca2+ homeostasis can shape cytosolic [Ca2+] transients by limiting their amplitude and duration, and may thus affect Ca2+ signaling.

  10. Platelet signaling-a primer.

    Science.gov (United States)

    Goggs, Robert; Poole, Alastair W

    2012-02-01

    To review the receptors and signal transduction pathways involved in platelet plug formation and to highlight links between platelets, leukocytes, endothelium, and the coagulation system. Original studies, review articles, and book chapters in the human and veterinary medical fields. Platelets express numerous surface receptors. Critical among these are glycoprotein VI, the glycoprotein Ib-IX-V complex, integrin α(IIb) β(3) , and the G-protein-coupled receptors for thrombin, ADP, and thromboxane. Activation of these receptors leads to various important functional events, in particular activation of the principal adhesion receptor α(IIb) β(3) . Integrin activation allows binding of ligands such as fibrinogen, mediating platelet-platelet interaction in the process of aggregation. Signals activated by these receptors also couple to 3 other important functional events, secretion of granule contents, change in cell shape through cytoskeletal rearrangement, and procoagulant membrane expression. These processes generate a stable thrombus to limit blood loss and promote restoration of endothelial integrity. Improvements in our understanding of how platelets operate through their signaling networks are critical for diagnosis of unusual primary hemostatic disorders and for rational antithrombotic drug design. © Veterinary Emergency and Critical Care Society 2012.

  11. Advanced digital signal processing and noise reduction

    CERN Document Server

    Vaseghi, Saeed V

    2008-01-01

    Digital signal processing plays a central role in the development of modern communication and information processing systems. The theory and application of signal processing is concerned with the identification, modelling and utilisation of patterns and structures in a signal process. The observation signals are often distorted, incomplete and noisy and therefore noise reduction, the removal of channel distortion, and replacement of lost samples are important parts of a signal processing system. The fourth edition of Advanced Digital Signal Processing and Noise Reduction updates an

  12. [Dynamic pulse signal acquisition and processing].

    Science.gov (United States)

    Zhang, Aihua; Chou, Yongxin

    2012-03-01

    In order to obtain and process pulse signal in real-time, the integer coefficients notch, low-pass filters and an envelope filtering method were designed in consideration of the characteristics of disturbances in pulse signal and then were verified by MATLAB. The pulse signal was processed on DSP in time domain and frequency domain after simplifying the programming. The pulse wave height and pulse rate were calculated in real-time, and the pulse signal's spectrum was illustrated by FFT. The results show that the filters can effectively suppress the interference in pulse signal, and the system can detect and analyze the dynamic pulse signal in real-time.

  13. Silicon Photonics for Signal Processing of Tbit/s Serial Data Signals

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Ji, Hua; Galili, Michael

    2012-01-01

    In this paper, we describe our recent work on signal processing of terabit per second optical serial data signals using pure silicon waveguides. We employ nonlinear optical signal processing in nanoengineered silicon waveguides to perform demultiplexing and optical waveform sampling of 1.28-Tbit....../s data signals as well as wavelength conversion of up to 320-Gbit/s data signals. We demonstrate that the silicon waveguides are equally useful for amplitude and phase-modulated data signals....

  14. Investigation of integrin expression on the surface of osteoblast-like cells by atomic force microscopy.

    Science.gov (United States)

    Soumetz, Federico Caneva; Saenz, Jose F; Pastorino, Laura; Ruggiero, Carmelina; Nosi, Daniele; Raiteri, Roberto

    2010-03-01

    The transforming growth factor beta1 (TGF-beta1) is a human cytokine which has been demonstrated to modulate cell surface integrin repertoire. In this work integrin expression in response to TGF-beta1 stimulation has been investigated on the surface of human osteoblast-like cells. We used atomic force microscopy (AFM) and confocal laser scanning microscopy to assess integrin expression and to evaluate their distribution over the dorsal side of the plasma membrane. AFM probes have been covalently functionalized with monoclonal antibodies specific to the beta1 integrin subunit. Force curves have been collected in order to obtain maps of the interaction between the immobilized antibody and the respective cell membrane receptors. Adhesion peaks have been automatically detected by means of an ad hoc developed data analysis software. The specificity of the detected interactions has been assessed by adding free antibody in the solution and monitoring the dramatic decrease in the recorded interactions. In addition, the effect of TGF-beta1 treatment on both the fluorescence signal and the adhesion events has been tested. The level of expression of the beta1 integrin subunit was enhanced by TGF-beta1. As a further analysis, the adhesion force of the single living cells to the substrate was measured by laterally pushing the cell with the AFM tip and measuring the force necessary to displace it. The treatment with TGF-beta1 resulted in a decrease of the cell/substrate adhesion force. Results obtained by AFM have been validated by confocal laser scanning microscopy thus demonstrating the high potential of the AFM technique for the investigation of cell surface receptors distribution and trafficking at the nanoscale. (c) 2010 Elsevier B.V. All rights reserved.

  15. Investigation of integrin expression on the surface of osteoblast-like cells by atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Caneva Soumetz, Federico [Department of Communication, Computer and System Sciences, University of Genova, Via Opera Pia, 13-16145 Genova (Italy); Saenz, Jose F. [Biophysical and Electronic Engineering Department, University of Genova, Via All' Opera Pia 11a, 16145 Genova (Italy); Pastorino, Laura; Ruggiero, Carmelina [Department of Communication, Computer and System Sciences, University of Genova, Via Opera Pia, 13-16145 Genova (Italy); Nosi, Daniele [Department of Anatomy, Histology and Forensic Medicine, Bio-photonic Laboratory, University of Florence, viale Morgagni, 85 Firenze, CAP 50134 Florence (Italy); Raiteri, Roberto, E-mail: rr@unige.it [Biophysical and Electronic Engineering Department, University of Genova, Via All' Opera Pia 11a, 16145 Genova (Italy)

    2010-03-15

    The transforming growth factor {beta}1 (TGF-{beta}1) is a human cytokine which has been demonstrated to modulate cell surface integrin repertoire. In this work integrin expression in response to TGF-{beta}1 stimulation has been investigated on the surface of human osteoblast-like cells. We used atomic force microscopy (AFM) and confocal laser scanning microscopy to assess integrin expression and to evaluate their distribution over the dorsal side of the plasma membrane. AFM probes have been covalently functionalised with monoclonal antibodies specific to the {beta}1 integrin subunit. Force curves have been collected in order to obtain maps of the interaction between the immobilized antibody and the respective cell membrane receptors. Adhesion peaks have been automatically detected by means of an ad hoc developed data analysis software. The specificity of the detected interactions has been assessed by adding free antibody in the solution and monitoring the dramatic decrease in the recorded interactions. In addition, the effect of TGF-{beta}1 treatment on both the fluorescence signal and the adhesion events has been tested. The level of expression of the {beta}1 integrin subunit was enhanced by TGF-{beta}1. As a further analysis, the adhesion force of the single living cells to the substrate was measured by laterally pushing the cell with the AFM tip and measuring the force necessary to displace it. The treatment with TGF-{beta}1 resulted in a decrease of the cell/substrate adhesion force. Results obtained by AFM have been validated by confocal laser scanning microscopy thus demonstrating the high potential of the AFM technique for the investigation of cell surface receptors distribution and trafficking at the nanoscale.

  16. Biomedical signals, imaging, and informatics

    CERN Document Server

    Bronzino, Joseph D

    2014-01-01

    Known as the bible of biomedical engineering, The Biomedical Engineering Handbook, Fourth Edition, sets the standard against which all other references of this nature are measured. As such, it has served as a major resource for both skilled professionals and novices to biomedical engineering.Biomedical Signals, Imaging, and Informatics, the third volume of the handbook, presents material from respected scientists with diverse backgrounds in biosignal processing, medical imaging, infrared imaging, and medical informatics.More than three dozen specific topics are examined, including biomedical s

  17. Purinergic signaling during intestinal inflammation.

    Science.gov (United States)

    Longhi, Maria Serena; Moss, Alan; Jiang, Zhenghui Gordon; Robson, Simon C

    2017-09-01

    Inflammatory bowel disease (IBD) is a devastating disease that is associated with excessive inflammation in the intestinal tract in genetically susceptible individuals and potentially triggered by microbial dysbiosis. This illness markedly predisposes patients to thrombophilia and chronic debility as well as bowel, lymphatic, and liver cancers. Development of new therapies is needed to re-establish long-term immune tolerance in IBD patients without increasing the risk of opportunistic infections and cancer. Aberrant purinergic signaling pathways have been implicated in disordered thromboregulation and immune dysregulation, as noted in the pathogenesis of IBD and other gastrointestinal/hepatic autoimmune diseases. Expression of CD39 on endothelial or immune cells allows for homeostatic integration of hemostasis and immunity, which are disrupted in IBD. Our focus in this review is on novel aspects of the functions of CD39 and related NTPDases in IBD. Regulated CD39 activity allows for scavenging of extracellular nucleotides, the maintenance of P2-receptor integrity and coordination of adenosinergic signaling responses. CD39 together with CD73, serves as an integral component of the immunosuppressive machinery of dendritic cells, myeloid cells, T and B cells. Genetic inheritance and environental factors closely regulate the levels of expression and phosphohydrolytic activity of CD39, both on immune cells and released microparticles. Purinergic mechanisms associated with T regulatory and supressor T helper type 17 cells modulate disease activity in IBD, as can be modeled in experimental colitis. As a recent example, upregulation of CD39 is dependent upon ligation of the aryl hydrocarbon receptor (AHR), as with natural ligands such as bilirubin and 2-(1' H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE). Decreased expression of CD39 and/or dysfunctional AHR signaling, however, abrogates the protective effects of immunosuppressive AHR ligands. These

  18. Wnt Signaling and Colorectal Cancer.

    Science.gov (United States)

    Schatoff, Emma M; Leach, Benjamin I; Dow, Lukas E

    2017-04-01

    The WNT signaling pathway is a critical mediator of tissue homeostasis and repair, and frequently co-opted during tumor development. Almost all colorectal cancers (CRC) demonstrate hyperactivation of the WNT pathway, which in many cases is believed to be the initiating and driving event. In this short review, we provide a focused overview of recent developments in our understanding of the WNT pathway in CRC, describe new research tools that are enabling a deeper understanding of WNT biology, and outline ongoing efforts to target this pathway therapeutically.

  19. EUROmediCAT signal detection

    DEFF Research Database (Denmark)

    Given, Joanne E; Loane, Maria; Luteijn, Johannes Michiel

    2016-01-01

    and levonorgestrel/ethinylestradiol (OR 4.10, 95% CI 1.70-8.53; congenital heart disease/pulmonary valve stenosis and nucleoside/tide reverse transcriptase inhibitors (OR 5.01, 95% CI 1.99-14.20/OR 28.20, 95% CI 4.63-122.24); complete absence of a limb and pregnen (4) derivatives (OR 6.60, 95% CI 1......AIMS: To evaluate congenital anomaly (CA)-medication exposure associations produced by the new EUROmediCAT signal detection system and determine which require further investigation. METHODS: Data from 15 EUROCAT registries (1995-2011) with medication exposures at the chemical substance (5th level...

  20. Fixed-point signal processing

    CERN Document Server

    Padgett, Wayne T

    2009-01-01

    This book is intended to fill the gap between the ""ideal precision"" digital signal processing (DSP) that is widely taught, and the limited precision implementation skills that are commonly required in fixed-point processors and field programmable gate arrays (FPGAs). These skills are often neglected at the university level, particularly for undergraduates. We have attempted to create a resource both for a DSP elective course and for the practicing engineer with a need to understand fixed-point implementation. Although we assume a background in DSP, Chapter 2 contains a review of basic theory

  1. Relativistic solitons and superluminal signals

    Energy Technology Data Exchange (ETDEWEB)

    Maccari, Attilio [Technical Institute ' G. Cardano' , Piazza della Resistenza 1, Monterotondo, Rome 00015 (Italy)]. E-mail: solitone@yahoo.it

    2005-02-01

    Envelope solitons in the weakly nonlinear Klein-Gordon equation in 1 + 1 dimensions are investigated by the asymptotic perturbation (AP) method. Two different types of solitons are possible according to the properties of the dispersion relation. In the first case, solitons propagate with the group velocity (less than the light speed) of the carrier wave, on the contrary in the second case solitons always move with the group velocity of the carrier wave, but now this velocity is greater than the light speed. Superluminal signals are then possible in classical relativistic nonlinear field equations.

  2. EUROmediCAT signal detection

    DEFF Research Database (Denmark)

    Given, Joanne E; Loane, Maria; Luteijn, Johannes Michiel

    2016-01-01

    AIMS: To evaluate congenital anomaly (CA)-medication exposure associations produced by the new EUROmediCAT signal detection system and determine which require further investigation. METHODS: Data from 15 EUROCAT registries (1995-2011) with medication exposures at the chemical substance (5th level...... and levonorgestrel/ethinylestradiol (OR 4.10, 95% CI 1.70-8.53; congenital heart disease/pulmonary valve stenosis and nucleoside/tide reverse transcriptase inhibitors (OR 5.01, 95% CI 1.99-14.20/OR 28.20, 95% CI 4.63-122.24); complete absence of a limb and pregnen (4) derivatives (OR 6.60, 95% CI 1...

  3. Low power digital signal processing

    DEFF Research Database (Denmark)

    Paker, Ozgun

    2003-01-01

    -cores as well as standard DSP/CPU-cores that communicate using message passing. The work has been based on a study of the algorithm suite covering the application domain. The observation of dominant tasks for certain algorithms (FIR, IIR, correlation, etc.) that require custom computational units and special...... data addressing capabilities lead to the design of low power mini-cores. The algorithm suite also consisted of less demanding and/or irregular algorithms (LMS, compression) that required subsample rate signal processing justifying the use of a DSP/CPU-core. The thesis also contributes to the recent...

  4. Small signal microwave amplifier design

    CERN Document Server

    Grosch, Theodore

    2000-01-01

    This book explains techniques and examples for designing stable amplifiers for high-frequency applications in which the signal is small and the amplifier circuit is linear. An in-depth discussion of linear network theory provides the foundation needed to develop actual designs. Examples throughout the book will show you how to apply the knowledge gained in each chapter leading to the complex design of low noise amplifiers. Many exercises at the end of each chapter will help students to practice their skills. The solutions to these design problems are available in an accompanying solutions book

  5. Detection of Transient Signals in Doppler Spectra

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Signal processing is used to detect transient signals in the presence of noise. Two embodiments are disclosed. In both embodiments, the time series from a remote...

  6. Molecular deregulation of signaling in lymphoid tumors.

    Science.gov (United States)

    Spina, Valeria; Martuscelli, Lavinia; Rossi, Davide

    2015-10-01

    Genomic studies have led to a significant impact both on the pace and the nature of understanding the molecular and biological bases of a variety of lymphoid tumors. An increasingly emerging aspect from genomic studies is that malignant lymphoid cells manipulate signaling pathways that are central to the homeostasis of their normal counterpart, including B- and T-cell receptor signaling, NF-κB signaling, Toll-like receptor signaling, cytokine signaling, MAP kinase signaling, and NOTCH signaling. This review aims at covering the signaling pathways that are affected by mutations in lymphoid tumors, and how genetic alteration of these pathways may contribute to disease pathogenesis and management. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Induced disease resistance signaling in plants

    NARCIS (Netherlands)

    Verhagen, B.W.M.; Loon, L.C. van; Pieterse, C.M.J.

    2006-01-01

    To protect themselves from disease, plants have evolved sophisticated inducible defense mechanisms in which the signal molecules salicylic acid, jasmonic acid and ethylene often play crucial roles. Elucidation of signaling pathways controlling induced disease resistance is a major objective in

  8. Signal-transducing proteins for nanoelectronics.

    Science.gov (United States)

    Pichierri, Fabio

    2006-12-01

    This aim of this article is to provide novel paradigms for 21st century nanoelectronics by taking inspiration from the biology of signal transduction events where Nature has solved many complex problems, particularly those concerned with signal integration and amplification.

  9. The recognition of extraterrestrial artificial signals

    Science.gov (United States)

    Seeger, C. L.

    1980-01-01

    Considerations in the design of receivers for the detection and recognition of artificial microwave signals of extraterrestrial origin are discussed. Following a review of the objectives of SETI and the probable reception and detection characteristics of extraterrestrial signals, means for the improvement of the sensitivity, signal-to-noise ratios and on-line data processing capabilities of SETI receivers are indicated. The characteristics of the signals likely to be present at the output of an ultra-low-noise microwave receiver are then examined, including the system background noise, terrestrial radiations, astrophysical radiations, accidental artificial radiations of terrestrial origin, and intentional radiations produced by humans and by extraterrestrial intelligence. The classes of extraterrestrial signals likely to be detected, beacons and leakage signals, are considered, and options in the specification of gating and thresholding for a high-spectral resolution, high-time-resolution signal discriminator are indicated. Possible tests for the nonhuman origin of a received signal are also pointed out.

  10. Digital Signal Processing Based Biotelemetry Receivers

    Science.gov (United States)

    Singh, Avtar; Hines, John; Somps, Chris

    1997-01-01

    This is an attempt to develop a biotelemetry receiver using digital signal processing technology and techniques. The receiver developed in this work is based on recovering signals that have been encoded using either Pulse Position Modulation (PPM) or Pulse Code Modulation (PCM) technique. A prototype has been developed using state-of-the-art digital signal processing technology. A Printed Circuit Board (PCB) is being developed based on the technique and technology described here. This board is intended to be used in the UCSF Fetal Monitoring system developed at NASA. The board is capable of handling a variety of PPM and PCM signals encoding signals such as ECG, temperature, and pressure. A signal processing program has also been developed to analyze the received ECG signal to determine heart rate. This system provides a base for using digital signal processing in biotelemetry receivers and other similar applications.

  11. Determining Aliasing in Isolated Signal Conditioning Modules

    Science.gov (United States)

    2009-01-01

    The basic concept of aliasing is this: Converting analog data into digital data requires sampling the signal at a specific rate, known as the sampling frequency. The result of this conversion process is a new function, which is a sequence of digital samples. This new function has a frequency spectrum, which contains all the frequency components of the original signal. The Fourier transform mathematics of this process show that the frequency spectrum of the sequence of digital samples consists of the original signal s frequency spectrum plus the spectrum shifted by all the harmonics of the sampling frequency. If the original analog signal is sampled in the conversion process at a minimum of twice the highest frequency component contained in the analog signal, and if the reconstruction process is limited to the highest frequency of the original signal, then the reconstructed signal accurately duplicates the original analog signal. It is this process that can give birth to aliasing.

  12. Generation of medium frequency electrotherapeutic signals

    Science.gov (United States)

    Płaza, Mirosław; Szcześniak, Zbigniew; Dudek, Jolanta

    2017-08-01

    In this paper, generation methods of sinusoidal medium frequency electrotherapeutic signals have been studied. Signals of this type are increasingly used in electrotherapy owing to the development of both physical medicine and engineering sciences. The article presents analysis and comparison of analogue and digital methods of generation therapeutic signals. Analysis presented in the paper attempts to answer the question which technique of medium frequency signal generation can be most broadly applied in electrotherapy methods.

  13. Laboratory Stands for Wideband Analysis Radiocommunication Signals

    OpenAIRE

    Studanski, Ryszard; Was, Radosław; Studanska, Agnieszka; Garus, Jarosław

    2012-01-01

    A laboratory stand for wideband analysis radiocommunication signals is presented in the paper. The stand is designed for signals acquisition in wide spectrum and research a field of digital signal processing. Procedures used for simultaneous acquiring many frequency channels in selected wide band are described. The method of detection of direct sequence spread spectrum signals (DS SS) which power spectral density is lower than noise is also discussed. Executed research were performed with sig...

  14. Nonstationary weak signal detection based on normalization ...

    Indian Academy of Sciences (India)

    Haibin Zhang

    model performs well in the detection of a time-varying signal with background noise for denoising and signal recovery. We take the fitness ..... The amplitude of signal and noise are amplified ffiffiffiffi b a3 q. -fold at the same time. ...... This work was supported in part by the National Natural. Science Foundation of China with ...

  15. Nonstationary weak signal detection based on normalization ...

    Indian Academy of Sciences (India)

    ... than the traditional stochastic resonance. The method develops the area of time-varying signal detection with stochastic resonance and presents new strategy for detection and denoising of a time-varying signal. It can be expected to be widely used in the areas of aperiodic signal processing, radar communication,etc ...

  16. Simulated evolution of signal transduction networks.

    Directory of Open Access Journals (Sweden)

    Mohammad Mobashir

    Full Text Available Signal transduction is the process of routing information inside cells when receiving stimuli from their environment that modulate the behavior and function. In such biological processes, the receptors, after receiving the corresponding signals, activate a number of biomolecules which eventually transduce the signal to the nucleus. The main objective of our work is to develop a theoretical approach which will help to better understand the behavior of signal transduction networks due to changes in kinetic parameters and network topology. By using an evolutionary algorithm, we designed a mathematical model which performs basic signaling tasks similar to the signaling process of living cells. We use a simple dynamical model of signaling networks of interacting proteins and their complexes. We study the evolution of signaling networks described by mass-action kinetics. The fitness of the networks is determined by the number of signals detected out of a series of signals with varying strength. The mutations include changes in the reaction rate and network topology. We found that stronger interactions and addition of new nodes lead to improved evolved responses. The strength of the signal does not play any role in determining the response type. This model will help to understand the dynamic behavior of the proteins involved in signaling pathways. It will also help to understand the robustness of the kinetics of the output response upon changes in the rate of reactions and the topology of the network.

  17. Light signal perception in Arabidopsis rosettes

    NARCIS (Netherlands)

    Evers, J.B.; Pierik, R.; Krol, van der A.R.

    2013-01-01

    Light signals are important signals for future and present competition. We used an architectural model of Arabidopsis development to show that vertical growth of neighboring vegetation is more important than proximity for early detection of competition. Self-signaling is greatly enhanced when own

  18. Syndecan signaling: when, where and why?

    DEFF Research Database (Denmark)

    Multhaupt, H A B; Yoneda, A; Whiteford, J R

    2009-01-01

    make important interactions and/or signalling contributions. It has been established that all syndecans can interact with proteins of the actin-associated cytoskeleton, but details of signalling have been harder to ascertain. However, it appears that Syndecans can signal, primarily to the cytoskeleton...

  19. Radar signal analysis and processing using Matlab

    CERN Document Server

    Mahafza, Bassem R

    2008-01-01

    Offering radar-related software for the analysis and design of radar waveform and signal processing, this book provides comprehensive coverage of radar signals and signal processing techniques and algorithms. It contains numerous graphical plots, common radar-related functions, table format outputs, and end-of-chapter problems. The complete set of MATLAB[registered] functions and routines are available for download online.

  20. Phasor representation for the nonlinear photoacoustic signal

    Science.gov (United States)

    Santosa, I. E.; Oetama, E. J.; Harren, F. J. M.

    2017-11-01

    In CO2 laser-based photoacoustic (PA) systems, N2 takes part in the generation of the PA signal. This process causes the nonlinear relation of the photoacoustic signal to the CO2 concentration. This phenomenon can be explained simply using a phasor diagram. The model leads to the determination of the lag in the PA signal due to CO2 relaxation.

  1. Cost Discrepancy, Signaling, and Risk Taking

    Science.gov (United States)

    Lemon, Jim

    2005-01-01

    If risk taking is in some measure a signal to others by the person taking risks, the model of "costly signaling" predicts that the more the apparent cost of the risk to others exceeds the perceived cost of the risk to the risk taker, the more attractive that risk will be as a signal. One hundred and twelve visitors to youth…

  2. An elementary introduction to applied signal analysis

    DEFF Research Database (Denmark)

    Jacobsen, Finn

    1997-01-01

    An introduction to some of the most fundamental concepts and methods of signal analysis and signal processing is presented with particular regard to acoustic measurements. The purpose is to give the reader so much basic knowledge of signal analysis that he can use modern digital equipment in some...

  3. An elementary introduction to applied signal analysis

    DEFF Research Database (Denmark)

    Jacobsen, Finn

    2000-01-01

    An introduction to some of the most fundamental concepts and methods of signal analysis and signal processing is presented with particular regard to acoustic measurements. The purpose is to give the reader so much basic knowledge of signal analysis that he can use modern digital equipment in some...

  4. 33 CFR 62.47 - Sound signals.

    Science.gov (United States)

    2010-07-01

    ....47 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.47 Sound signals. (a) Often sound signals are located on or adjacent to aids to navigation. When visual signals are obscured...

  5. Signal Frequency Spectra with Audacity®

    Science.gov (United States)

    Gailey, Alycia

    2015-01-01

    The primary objective of the activity presented here is to allow students to explore the frequency components of various simple signals, with the ultimate goal of teaching them how to remove unwanted noise from a voice signal. Analysis of the frequency components of a signal allows students to design filters that remove unwanted components of a…

  6. Cytoskeleton in Mast Cell Signaling

    Science.gov (United States)

    Dráber, Pavel; Sulimenko, Vadym; Dráberová, Eduarda

    2012-01-01

    Mast cell activation mediated by the high affinity receptor for IgE (FcεRI) is a key event in allergic response and inflammation. Other receptors on mast cells, as c-Kit for stem cell factor and G protein-coupled receptors (GPCRs) synergistically enhance the FcεRI-mediated release of inflammatory mediators. Activation of various signaling pathways in mast cells results in changes in cell morphology, adhesion to substrate, exocytosis, and migration. Reorganization of cytoskeleton is pivotal in all these processes. Cytoskeletal proteins also play an important role in initial stages of FcεRI and other surface receptors induced triggering. Highly dynamic microtubules formed by αβ-tubulin dimers as well as microfilaments build up from polymerized actin are affected in activated cells by kinases/phosphatases, Rho GTPases and changes in concentration of cytosolic Ca2+. Also important are nucleation proteins; the γ-tubulin complexes in case of microtubules or Arp 2/3 complex with its nucleation promoting factors and formins in case of microfilaments. The dynamic nature of microtubules and microfilaments in activated cells depends on many associated/regulatory proteins. Changes in rigidity of activated mast cells reflect changes in intermediate filaments build up from vimentin. This review offers a critical appraisal of current knowledge on the role of cytoskeleton in mast cells signaling. PMID:22654883

  7. Signaling circuitry in vascular morphogenesis.

    Science.gov (United States)

    Warren, Carmen M; Iruela-Arispe, M Luisa

    2010-05-01

    In this mini-review, we have highlighted the recent breakthroughs in growth factor signaling that have made conceptual changes in our understanding of how blood vessels are formed. Studies conducted over the past few years have focused on understanding the cell biology of vascular morphogenesis. The major themes include characterization of the different cell types that comprise a vascular sprout, as well as the regulatory influence of cell-cell and cell-matrix interactions on signaling outcomes. In addition, novel trends have emerged, including nonconventional ways in which vascular endothelial growth factor contributes to cell survival and metabolic balance. The growth of new capillary sprouts from a preexisting vascular network requires a highly coordinated cellular response to both growth factors and morphogens. This response is sensed and triggered by cell surface receptors responsible for the activation of an intracellular cascade that efficiently initiates migration and proliferation programs. While the molecular players that coordinate these effects have been identified, recent findings have expanded our understanding of how context, in particular cell-cell and cell-matrix interactions, affects endothelial cell responses to growth factors.

  8. Redox signaling in acute pancreatitis

    Science.gov (United States)

    Pérez, Salvador; Pereda, Javier; Sabater, Luis; Sastre, Juan

    2015-01-01

    Acute pancreatitis is an inflammatory process of the pancreatic gland that eventually may lead to a severe systemic inflammatory response. A key event in pancreatic damage is the intracellular activation of NF-κB and zymogens, involving also calcium, cathepsins, pH disorders, autophagy, and cell death, particularly necrosis. This review focuses on the new role of redox signaling in acute pancreatitis. Oxidative stress and redox status are involved in the onset of acute pancreatitis and also in the development of the systemic inflammatory response, being glutathione depletion, xanthine oxidase activation, and thiol oxidation in proteins critical features of the disease in the pancreas. On the other hand, the release of extracellular hemoglobin into the circulation from the ascitic fluid in severe necrotizing pancreatitis enhances lipid peroxidation in plasma and the inflammatory infiltrate into the lung and up-regulates the HIF–VEGF pathway, contributing to the systemic inflammatory response. Therefore, redox signaling and oxidative stress contribute to the local and systemic inflammatory response during acute pancreatitis. PMID:25778551

  9. CCN3 and calcium signaling

    Directory of Open Access Journals (Sweden)

    Li Chang Long

    2003-08-01

    Full Text Available Abstract The CCN family of genes consists presently of six members in human (CCN1-6 also known as Cyr61 (Cystein rich 61, CTGF (Connective Tissue Growth Factor, NOV (Nephroblastoma Overexpressed gene, WISP-1, 2 and 3 (Wnt-1 Induced Secreted Proteins. Results obtained over the past decade have indicated that CCN proteins are matricellular proteins, which are involved in the regulation of various cellular functions, such as proliferation, differentiation, survival, adhesion and migration. The CCN proteins have recently emerged as regulatory factors involved in both internal and external cell signaling. CCN3 was reported to physically interact with fibulin-1C, integrins, Notch and S100A4. Considering that, the conformation and biological activity of these proteins are dependent upon calcium binding, we hypothesized that CCN3 might be involved in signaling pathways mediated by calcium ions. In this article, we review the data showing that CCN3 regulates the levels of intracellular calcium and discuss potential models that may account for the biological effects of CCN3.

  10. Extracellular nucleotide signaling in plants

    Energy Technology Data Exchange (ETDEWEB)

    Stacey, Gary [Univ. of Missouri, Columbia, MO (United States)

    2016-09-08

    Over the life of this funded project, our research group identified and characterized two key receptor proteins in plants; one mediating the innate immunity response to chitin and the other elucidating the key receptor for extracellular ATP. In the case of chitin recognition, we recently described the quaternary structure of this receptor, shedding light on how the receptor functions. Perhaps more importantly, we demonstrated that all plants have the ability to recognize both chitin oligomers and lipochitooligosacchardes, fundamentally changing how the community views the evolution of these systems and strategies that might be used, for example, to extend symbiotic nitrogen fixation to non-legumes. Our discovery of DORN1 opens a new chapter in plant physiology documenting conclusively that eATP is an important extracellular signal in plants, as it is in animals. At this point, we cannot predict just how far reaching this discovery may prove to be but we are convinced that eATP signaling is fundamental to plant growth and development and, hence, we believe that the future will be very exciting for the study of DORN1 and its overall function in plants.

  11. Signals of lepton number violation

    CERN Document Server

    Panella, O; Srivastava, Y N

    1999-01-01

    The production of like-sign-dileptons (LSD), in the high energy lepton number violating ( Delta L=+2) reaction, pp to 2jets+l/sup +/l /sup +/, (l=e, mu , tau ), of interest for the experiments to be performed at the forthcoming Large Hadron Collider (LHC), is reported, taking up a composite model scenario in which the exchanged virtual composite neutrino is assumed to be a Majorana particle. Numerical estimates of the corresponding signal cross-section that implement kinematical cuts needed to suppress the standard model background, are presented which show that in some regions of the parameter space the total number of LSD events is well above the background. Assuming non-observation of the LSD signal it is found that LHC would exclude a composite Majorana neutrino up to 700 GeV (if one requires 10 events for discovery). The sensitivity of LHC experiments to the parameter space is then compared to that of the next generation of neutrinoless double beta decay ( beta beta /sub 0 nu /) experiment, GENIUS, and i...

  12. Simulation of Silicon Photomultiplier Signals

    Science.gov (United States)

    Seifert, Stefan; van Dam, Herman T.; Huizenga, Jan; Vinke, Ruud; Dendooven, Peter; Lohner, Herbert; Schaart, Dennis R.

    2009-12-01

    In a silicon photomultiplier (SiPM), also referred to as multi-pixel photon counter (MPPC), many Geiger-mode avalanche photodiodes (GM-APDs) are connected in parallel so as to combine the photon counting capabilities of each of these so-called microcells into a proportional light sensor. The discharge of a single microcell is relatively well understood and electronic models exist to simulate this process. In this paper we introduce an extended model that is able to simulate the simultaneous discharge of multiple cells. This model is used to predict the SiPM signal in response to fast light pulses as a function of the number of fired cells, taking into account the influence of the input impedance of the SiPM preamplifier. The model predicts that the electronic signal is not proportional to the number of fired cells if the preamplifier input impedance is not zero. This effect becomes more important for SiPMs with lower parasitic capacitance (which otherwise is a favorable property). The model is validated by comparing its predictions to experimental data obtained with two different SiPMs (Hamamatsu S10362-11-25u and Hamamatsu S10362-33-25c) illuminated with ps laser pulses. The experimental results are in good agreement with the model predictions.

  13. Spying on IgE receptor signaling

    Science.gov (United States)

    Toomre, Derek

    2005-01-01

    Plasma membrane organization and the potential role, or not, of lipid raft microdomains in signal transduction is a controversial topic. Cross-correlation fluorescent correlation spectroscopy (CC-FCS) shows promise as a new approach to rapidly probe protein–protein interactions in living cells during signal transduction. CC-FCS data from studies of IgE receptor signaling challenge models of large stable lipid raft signaling domains and reveal a new complexity in the dynamic (re)organization of signaling complexes. PMID:16275748

  14. Structure and dynamics of GPCR signaling complexes.

    Science.gov (United States)

    Hilger, Daniel; Masureel, Matthieu; Kobilka, Brian K

    2018-01-01

    G-protein-coupled receptors (GPCRs) relay numerous extracellular signals by triggering intracellular signaling through coupling with G proteins and arrestins. Recent breakthroughs in the structural determination of GPCRs and GPCR-transducer complexes represent important steps toward deciphering GPCR signal transduction at a molecular level. A full understanding of the molecular basis of GPCR-mediated signaling requires elucidation of the dynamics of receptors and their transducer complexes as well as their energy landscapes and conformational transition rates. Here, we summarize current insights into the structural plasticity of GPCR-G-protein and GPCR-arrestin complexes that underlies the regulation of the receptor's intracellular signaling profile.

  15. Probabilistic Recovery Guarantees for Sparsely Corrupted Signals

    CERN Document Server

    Pope, Graeme; Studer, Christoph

    2012-01-01

    We consider the recovery of sparse signals subject to sparse interference, as introduced in Studer et al., IEEE Trans. IT, 2012. We present novel probabilistic recovery guarantees for this framework, covering varying degrees of knowledge of the signal and interference support, which are relevant for a large number of practical applications. Our results assume that the sparsifying dictionaries are solely characterized by coherence parameters and we require randomness only in the signal and/or interference. The obtained recovery guarantees show that one can recover sparsely corrupted signals with overwhelming probability, even if the sparsity of both the signal and interference scale (near) linearly with the number of measurements.

  16. A signal theoretic introduction to random processes

    CERN Document Server

    Howard, Roy M

    2015-01-01

    A fresh introduction to random processes utilizing signal theory By incorporating a signal theory basis, A Signal Theoretic Introduction to Random Processes presents a unique introduction to random processes with an emphasis on the important random phenomena encountered in the electronic and communications engineering field. The strong mathematical and signal theory basis provides clarity and precision in the statement of results. The book also features:  A coherent account of the mathematical fundamentals and signal theory that underpin the presented material Unique, in-depth coverage of

  17. Signal prediction by anticipatory relaxation dynamics

    Science.gov (United States)

    Voss, Henning U.

    2016-03-01

    Real-time prediction of signals is a task often encountered in control problems as well as by living systems. Here, a parsimonious prediction approach based on the coupling of a linear relaxation-delay system to a smooth, stationary signal is described. The resulting anticipatory relaxation dynamics (ARD) is a frequency-dependent predictor of future signal values. ARD not only approximately predicts signals on average but can anticipate the occurrence of signal peaks, too. This can be explained by recognizing ARD as an input-output system with negative group delay. It is characterized, including its prediction horizon, by its analytically given frequency response function.

  18. Subaperture clutter filter with CFAR signal detection

    Energy Technology Data Exchange (ETDEWEB)

    Ormesher, Richard C.; Naething, Richard M.

    2016-08-30

    The various technologies presented herein relate to the determination of whether a received signal comprising radar clutter further comprises a communication signal. The communication signal can comprise of a preamble, a data symbol, communication data, etc. A first portion of the radar clutter is analyzed to determine a radar signature of the first portion of the radar clutter. A second portion of the radar clutter can be extracted based on the radar signature of the first portion. Following extraction, any residual signal can be analyzed to retrieve preamble data, etc. The received signal can be based upon a linear frequency modulation (e.g., a chirp modulation) whereby the chirp frequency can be determined and the frequency of transmission of the communication signal can be based accordingly thereon. The duration and/or bandwidth of the communication signal can be a portion of the duration and/or the bandwidth of the radar clutter.

  19. Biologically-based signal processing system applied to noise removal for signal extraction

    Science.gov (United States)

    Fu, Chi Yung; Petrich, Loren I.

    2004-07-13

    The method and system described herein use a biologically-based signal processing system for noise removal for signal extraction. A wavelet transform may be used in conjunction with a neural network to imitate a biological system. The neural network may be trained using ideal data derived from physical principles or noiseless signals to determine to remove noise from the signal.

  20. Phantom phone signals: An investigation into the prevalence and predictors of imagined cell phone signals

    NARCIS (Netherlands)

    Tanis, M.A.; Beukeboom, C.J.; Hartmann, T.; Vermeulen, I.E.

    2015-01-01

    This paper aims to elucidate the peculiar phenomenon of imagined cell phone signals, or Phantom Phone Signals (PPS), which is defined as an individual's perception of a phone signal, indicating an incoming call, message, or social media notification, when in fact no such signal was transmitted. A

  1. Opposed turns at signalized intersections

    Energy Technology Data Exchange (ETDEWEB)

    Akcelik, R.

    1989-06-01

    The 1985 Highway Capacity Manual (HCM) brought the U.S. and Australian methodologies for signalized intersections closer together. An important element in this methodology is the techniques used for the estimation of opposed (permissive) turn saturation flows. Although the basic modeling philosophies of the HCM and Australian methods are similar, there are significant differences in the procedures used and therefore in the results from the two methods. In particular, the latest methodology employed in the SIDRA software has eliminated the use of opposed turn adjustment factors for lane groups and adopted an explicit and direct method of modeling individual lanes. The purpose of this paper is to bring these new methods to the attention of the U.S. researchers since it is understood that efforts are being made to improve the 1985 HCM method.

  2. Digital signal processing using MATLAB

    CERN Document Server

    Schilling, Robert L

    2016-01-01

    Focus on the development, implementation, and application of modern DSP techniques with DIGITAL SIGNAL PROCESSING USING MATLAB(R), 3E. Written in an engaging, informal style, this edition immediately captures your attention and encourages you to explore each critical topic. Every chapter starts with a motivational section that highlights practical examples and challenges that you can solve using techniques covered in the chapter. Each chapter concludes with a detailed case study example, a chapter summary with learning outcomes, and practical homework problems cross-referenced to specific chapter sections for your convenience. DSP Companion software accompanies each book to enable further investigation. The DSP Companion software operates with MATLAB(R) and provides intriguing demonstrations as well as interactive explorations of analysis and design concepts.

  3. Hydrogen Sulfide and Polysulfide Signaling.

    Science.gov (United States)

    Kimura, Hideo

    2017-10-01

    Hydrogen sulfide (H2S) has been demonstrated to have physiological roles such as neuromodulation, vascular tone regulation, cytoprotection, oxygen sensing, inflammatory regulation, and cell growth. Recently, hydrogen polysulfides (H2Sn) have been found to be produced by 3-mercaptopyruvate sulfurtransferase and to regulate the activity of ion channels, tumor suppressers, and protein kinases. Furthermore, some of the effects previously reported to be mediated by H2S are now ascribed to H2Sn. Cysteine persulfide and cysteine polysulfide may also be involved in cellular redox regulation. The chemical interaction between H2S and nitric oxide (NO) can also produce H2Sn, nitroxyl, and nitrosopersulfide, suggesting their involvement in the reactions previously thought to be mediated by NO alone. This Forum focuses on and critically discusses the recent progress in the study of H2Sn, H2S, and NO as well as other per- or polysulfide species. Antioxid. Redox Signal. 00, 000-000.

  4. Signal velocity in oscillator arrays

    Science.gov (United States)

    Cantos, C. E.; Veerman, J. J. P.; Hammond, D. K.

    2016-09-01

    We investigate a system of coupled oscillators on the circle, which arises from a simple model for behavior of large numbers of autonomous vehicles where the acceleration of each vehicle depends on the relative positions and velocities between itself and a set of local neighbors. After describing necessary and sufficient conditions for asymptotic stability, we derive expressions for the phase velocity of propagation of disturbances in velocity through this system. We show that the high frequencies exhibit damping, which implies existence of well-defined signal velocitiesc+ > 0 and c- < 0 such that low frequency disturbances travel through the flock as f+(x - c+t) in the direction of increasing agent numbers and f-(x - c-t) in the other.

  5. Engagement Assessment Using EEG Signals

    Science.gov (United States)

    Li, Feng; Li, Jiang; McKenzie, Frederic; Zhang, Guangfan; Wang, Wei; Pepe, Aaron; Xu, Roger; Schnell, Thomas; Anderson, Nick; Heitkamp, Dean

    2012-01-01

    In this paper, we present methods to analyze and improve an EEG-based engagement assessment approach, consisting of data preprocessing, feature extraction and engagement state classification. During data preprocessing, spikes, baseline drift and saturation caused by recording devices in EEG signals are identified and eliminated, and a wavelet based method is utilized to remove ocular and muscular artifacts in the EEG recordings. In feature extraction, power spectrum densities with 1 Hz bin are calculated as features, and these features are analyzed using the Fisher score and the one way ANOVA method. In the classification step, a committee classifier is trained based on the extracted features to assess engagement status. Finally, experiment results showed that there exist significant differences in the extracted features among different subjects, and we have implemented a feature normalization procedure to mitigate the differences and significantly improved the engagement assessment performance.

  6. Molecular basis for mitochondrial signaling

    CERN Document Server

    2017-01-01

    This book covers recent advances in the study of structure, function, and regulation of metabolite, protein and ion translocating channels, and transporters in mitochondria. A wide array of cutting-edge methods are covered, ranging from electrophysiology and cell biology to bioinformatics, as well as structural, systems, and computational biology. At last, the molecular identity of two important channels in the mitochondrial inner membrane, the mitochondrial calcium uniporter and the mitochondrial permeability transition pore have been established. After years of work on the physiology and structure of VDAC channels in the mitochondrial outer membrane, there have been multiple discoveries on VDAC permeation and regulation by cytosolic proteins. Recent breakthroughs in structural studies of the mitochondrial cholesterol translocator reveal a set of novel unexpected features and provide essential clues for defining therapeutic strategies. Molecular Basis for Mitochondrial Signaling covers these and many more re...

  7. Signal propagation in nerve fiber

    Science.gov (United States)

    Zayko, Yuriy N.

    2007-05-01

    In this paper the problem of signal propagation in nerve fiber is considered. Ohm losses and heat processes were taken into account. These permit to combine the two stages (metabolic and non-metabolic) of propagation and Na + and K + ions transmission through cell membrane due propagation. Electrodynamics of nerve fiber with losses is described by telegraph equations. Heat processes in fiber are described by an equation of entropy transfer. Ion motion at metabolic stage against the electro-chemical potential is described by negative conductance, responsible for the escape flow. The running- wave-type solutions of these equations are studied. An integral and an explicit solution of the given system are obtained. The solution represented by a series of quasi-harmonic pulses is investigated numerically. This proves the applicability of telegraph equation to the problem considered. Different types of solitary waves corresponding to various types of conductivity are also investigated.

  8. Calcium signaling and cell proliferation.

    Science.gov (United States)

    Pinto, Mauro Cunha Xavier; Kihara, Alexandre Hiroaki; Goulart, Vânia A M; Tonelli, Fernanda M P; Gomes, Katia N; Ulrich, Henning; Resende, Rodrigo R

    2015-11-01

    Cell proliferation is orchestrated through diverse proteins related to calcium (Ca(2+)) signaling inside the cell. Cellular Ca(2+) influx that occurs first by various mechanisms at the plasma membrane, is then followed by absorption of Ca(2+) ions by mitochondria and endoplasmic reticulum, and, finally, there is a connection of calcium stores to the nucleus. Experimental evidence indicates that the fluctuation of Ca(2+) from the endoplasmic reticulum provides a pivotal and physiological role for cell proliferation. Ca(2+) depletion in the endoplasmatic reticulum triggers Ca(2+) influx across the plasma membrane in an phenomenon called store-operated calcium entries (SOCEs). SOCE is activated through a complex interplay between a Ca(2+) sensor, denominated STIM, localized in the endoplasmic reticulum and a Ca(2+) channel at the cell membrane, denominated Orai. The interplay between STIM and Orai proteins with cell membrane receptors and their role in cell proliferation is discussed in this review. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Fundamentals of adaptive signal processing

    CERN Document Server

    Uncini, Aurelio

    2015-01-01

    This book is an accessible guide to adaptive signal processing methods that equips the reader with advanced theoretical and practical tools for the study and development of circuit structures and provides robust algorithms relevant to a wide variety of application scenarios. Examples include multimodal and multimedia communications, the biological and biomedical fields, economic models, environmental sciences, acoustics, telecommunications, remote sensing, monitoring, and, in general, the modeling and prediction of complex physical phenomena. The reader will learn not only how to design and implement the algorithms but also how to evaluate their performance for specific applications utilizing the tools provided. While using a simple mathematical language, the employed approach is very rigorous. The text will be of value both for research purposes and for courses of study.

  10. Conflicting Signals for Cancer Treatment.

    Science.gov (United States)

    Sujobert, Pierre; Trautmann, Alain

    2016-12-01

    Next-generation sequencing technologies have provided us with a precise description of the mutational burden of cancers, making it possible to identify targetable oncogene addictions. However, the emergence of resistant clones is an inevitable limitation of therapies targeting these addictions. Alternative approaches to cancer treatment are therefore required. We propose here a novel approach, based on the notion of conflicting signals and on a phenotypic description of cancer cells. "Phenotype" is an inherently complex notion that we describe in the conceptual framework of the epigenetic landscape, with a view to bridging the gap between theory and practice at the patient's bedside. By passing from theory to the description of several examples, we will illustrate how this approach can facilitate data analysis and the design of new strategies for cancer treatment. Cancer Res; 76(23); 6768-73. ©2016 AACR. ©2016 American Association for Cancer Research.

  11. Hypothalamic signaling mechanisms in hypertension.

    Science.gov (United States)

    Carmichael, Casey Y; Wainford, Richard D

    2015-05-01

    The etiology of hypertension, a critical public health issue affecting one in three US adults, involves the integration of the actions of multiple organ systems, including the central nervous system. Increased activation of the central nervous system, driving enhanced sympathetic outflow and increased blood pressure, has emerged as a major contributor to the pathogenesis of hypertension. The hypothalamus is a key brain site acting to integrate central and peripheral inputs to ultimately impact blood pressure in multiple disease states that evoke hypertension. This review highlights recent advances that have identified novel signal transduction mechanisms within multiple hypothalamic nuclei (e.g., paraventricular nucleus, arcuate nucleus) acting to drive the pathophysiology of hypertension in neurogenic hypertension, angiotensin II hypertension, salt-sensitive hypertension, chronic intermittent hypoxia, and obesity-induced hypertension. Increased understanding of hypothalamic activity in hypertension has the potential to identify novel targets for future therapeutic interventions designed to treat hypertension.

  12. Normalization of vibration signals generated under highly varying speed and load with application to signal separation

    Science.gov (United States)

    Urbanek, Jacek; Barszcz, Tomasz; Strączkiewicz, Marcin; Jablonski, Adam

    2017-01-01

    The paper presents a normalization dedicated to transform non-stationary vibration signals into signals characterized by purely stationary properties. For this purpose, a novel class of generalized periodic signals is defined followed by a proposition of a normalization technique, which takes advantage of available, instantaneous values of operational parameters. Within the paper, a well-known discrete-random separation (DRS) technique is recalled as an exemplary technique, which has been restricted to stationary signals so far. The authors present a step-by-step adoption of the DRS to non-stationary signals. The method is applied to simulated signal, test rig signal, and a vibration signal from industrial object. Additionally, for the purpose of synthesis of simulated signal, a new model of multi-component vibrations generated under varying regime is proposed. The presented method aims to expand existing solutions dealing with varying frequency to a more general solution dealing with independent, simultaneous varying frequency and amplitude of signal components.

  13. Strigolactone versus gibberellin signaling: reemerging concepts?

    Science.gov (United States)

    Wallner, Eva-Sophie; López-Salmerón, Vadir; Greb, Thomas

    2016-06-01

    In this review, we compare knowledge about the recently discovered strigolactone signaling pathway and the well established gibberellin signaling pathway to identify gaps of knowledge and putative research directions in strigolactone biology. Communication between and inside cells is integral for the vitality of living organisms. Hormonal signaling cascades form a large part of this communication and an understanding of both their complexity and interactive nature is only beginning to emerge. In plants, the strigolactone (SL) signaling pathway is the most recent addition to the classically acting group of hormones and, although fundamental insights have been made, knowledge about the nature and impact of SL signaling is still cursory. This narrow understanding is in spite of the fact that SLs influence a specific spectrum of processes, which includes shoot branching and root system architecture in response, partly, to environmental stimuli. This makes these hormones ideal tools for understanding the coordination of plant growth processes, mechanisms of long-distance communication and developmental plasticity. Here, we summarize current knowledge about SL signaling and employ the well-characterized gibberellin (GA) signaling pathway as a scaffold to highlight emerging features as well as gaps in our knowledge in this context. GA signaling is particularly suitable for this comparison because both signaling cascades share key features of hormone perception and of immediate downstream events. Therefore, our comparative view demonstrates the possible level of complexity and regulatory interfaces of SL signaling.

  14. Interkingdom signaling in plant-microbe interactions.

    Science.gov (United States)

    Kan, Jinhong; Fang, Rongxiang; Jia, Yantao

    2017-08-01

    The widespread communications between prokaryotes and eukaryotes via signaling molecules are believed to affect gene expression in both partners. During the communication process, the contacted organisms produce and release small molecules that establish communication channels between two kingdoms-this procedure is known as interkingdom signaling. Interkingdom communications are widespread between pathogenic or beneficial bacteria and their host plants, with diversified outcomes depending on the specific chemical-triggered signaling pathways. Deciphering the signals or language of this interkingdom communication and uncovering the underlying mechanisms are major current challenges in this field. It is evident that diverse signaling molecules can be produced or derived from bacteria and plants, and researchers have sought to identify these signals and explore the mechanisms of the signaling pathways. The results of such studies will lead to the development of strategies to improve plant disease resistance through controlling interkingdom signals, rather than directly killing the pathogenic bacteria. Also, the identification of signals produced by beneficial bacteria will be useful for agricultural applications. In this review, we summarize the recent progress of cross-kingdom interactions between plant and bacteria, and how LuxR-family transcription factors in plant associated bacterial quorum sensing system are involved in the interkingdom signaling.

  15. Digital Signal Processing Methods for Ultrasonic Echoes.

    Science.gov (United States)

    Sinding, Kyle; Drapaca, Corina; Tittmann, Bernhard

    2016-04-28

    Digital signal processing has become an important component of data analysis needed in industrial applications. In particular, for ultrasonic thickness measurements the signal to noise ratio plays a major role in the accurate calculation of the arrival time. For this application a band pass filter is not sufficient since the noise level cannot be significantly decreased such that a reliable thickness measurement can be performed. This paper demonstrates the abilities of two regularization methods - total variation and Tikhonov - to filter acoustic and ultrasonic signals. Both of these methods are compared to a frequency based filtering for digitally produced signals as well as signals produced by ultrasonic transducers. This paper demonstrates the ability of the total variation and Tikhonov filters to accurately recover signals from noisy acoustic signals faster than a band pass filter. Furthermore, the total variation filter has been shown to reduce the noise of a signal significantly for signals with clear ultrasonic echoes. Signal to noise ratios have been increased over 400% by using a simple parameter optimization. While frequency based filtering is efficient for specific applications, this paper shows that the reduction of noise in ultrasonic systems can be much more efficient with regularization methods.

  16. Prediction of twin-arginine signal peptides

    Directory of Open Access Journals (Sweden)

    Widdick David

    2005-07-01

    Full Text Available Abstract Background Proteins carrying twin-arginine (Tat signal peptides are exported into the periplasmic compartment or extracellular environment independently of the classical Sec-dependent translocation pathway. To complement other methods for classical signal peptide prediction we here present a publicly available method, TatP, for prediction of bacterial Tat signal peptides. Results We have retrieved sequence data for Tat substrates in order to train a computational method for discrimination of Sec and Tat signal peptides. The TatP method is able to positively classify 91% of 35 known Tat signal peptides and 84% of the annotated cleavage sites of these Tat signal peptides were correctly predicted. This method generates far less false positive predictions on various datasets than using simple pattern matching. Moreover, on the same datasets TatP generates less false positive predictions than a complementary rule based prediction method. Conclusion The method developed here is able to discriminate Tat signal peptides from cytoplasmic proteins carrying a similar motif, as well as from Sec signal peptides, with high accuracy. The method allows filtering of input sequences based on Perl syntax regular expressions, whereas hydrophobicity discrimination of Tat- and Sec-signal peptides is carried out by an artificial neural network. A potential cleavage site of the predicted Tat signal peptide is also reported. The TatP prediction server is available as a public web server at http://www.cbs.dtu.dk/services/TatP/.

  17. Auxiliary and autonomous proteoglycan signaling networks.

    Science.gov (United States)

    Elfenbein, Arye; Simons, Michael

    2010-01-01

    Proteoglycans represent a structurally heterogeneous family of proteins that typically undergo extensive posttranslational modification with sulfated sugar chains. Although historically believed to affect signaling pathways exclusively as growth factor coreceptors, proteoglycans are now understood to initiate and modulate signal transduction cascades independently of other receptors. From within the extracellular matrix, proteoglycans are able to shield protein growth factors from circulating proteases and establish gradients that guide cell migration. Extracellular proteoglycans are also critical in the maintenance of growth factor stores and are thus instrumental in modulating paracrine signaling. At the cell membrane, proteoglycans stabilize ligand-receptor interactions, creating potentiated ternary signaling complexes that regulate cell proliferation, endocytosis, migration, growth factor sensitivity, and matrix adhesion. In some cases, proteoglycans are able to independently activate various signaling cascades, attenuate the signaling of growth factors, or orchestrate multimeric intracellular signaling complexes. Signaling between cells is also modulated by proteoglycan activity at the cell membrane, as exemplified by the proteoglycan requirement for effective synaptogenesis between neurons. Finally, proteoglycans are able to regulate signaling from intracellular compartments, particularly in the context of storage granule formation and maintenance. These proteoglycans are also major determinants of exocytic vesicle fate and other vesicular trafficking pathways. In contrast to the mechanisms underlying classical ligand-receptor signaling, proteoglycan signaling is frequently characterized by ligand promiscuity and low-affinity binding; likewise, these events commonly do not exhibit the same degree of reliance on intermolecular structure or charge configurations as other ligand-receptor interactions. Such unique features often defy conventional mechanisms of

  18. Reconfigurable Analog Signal Processing by Living Cells.

    Science.gov (United States)

    Lewis, Daniel D; Chavez, Michael; Chiu, Kwan Lun; Tan, Cheemeng

    2018-01-19

    Living cells are known for their capacity for versatile signal processing, particularly the ability to respond differently to the same stimuli using biochemical networks that integrate environmental signals and reconfigure their dynamic responses. However, the complexity of natural biological networks confounds the discovery of fundamental mechanisms behind versatile signaling. Here, we study one specific aspect of reconfigurable signal processing in which a minimal biological network integrates two signals, using one to reconfigure the network's transfer function with respect to the other, producing an emergent switch between induction and repression. In contrast to known mechanisms, the new mechanism reconfigures transfer functions through genetic networks without extensive protein-protein interactions. These results provide a novel explanation for the versatility of genetic programs, and suggest a new mechanism of signal integration that may govern flexibility and plasticity of gene expression.

  19. Seizure detection algorithms based on EMG signals

    DEFF Research Database (Denmark)

    Conradsen, Isa

    Background: the currently used non-invasive seizure detection methods are not reliable. Muscle fibers are directly connected to the nerves, whereby electric signals are generated during activity. Therefore, an alarm system on electromyography (EMG) signals is a theoretical possibility. Objective......: to show whether medical signal processing of EMG data is feasible for detection of epileptic seizures. Methods: EMG signals during generalised seizures were recorded from 3 patients (with 20 seizures in total). Two possible medical signal processing algorithms were tested. The first algorithm was based...... the frequency-based algorithm was efficient for detecting the seizures in the third patient. Conclusion: Our results suggest that EMG signals could be used to develop an automatic seizuredetection system. However, different patients might require different types of algorithms /approaches....

  20. Modified BTC Algorithm for Audio Signal Coding

    Directory of Open Access Journals (Sweden)

    TOMIC, S.

    2016-11-01

    Full Text Available This paper describes modification of a well-known image coding algorithm, named Block Truncation Coding (BTC and its application in audio signal coding. BTC algorithm was originally designed for black and white image coding. Since black and white images and audio signals have different statistical characteristics, the application of this image coding algorithm to audio signal presents a novelty and a challenge. Several implementation modifications are described in this paper, while the original idea of the algorithm is preserved. The main modifications are performed in the area of signal quantization, by designing more adequate quantizers for audio signal processing. The result is a novel audio coding algorithm, whose performance is presented and analyzed in this research. The performance analysis indicates that this novel algorithm can be successfully applied in audio signal coding.

  1. Automatic modulation recognition of communication signals

    CERN Document Server

    Azzouz, Elsayed Elsayed

    1996-01-01

    Automatic modulation recognition is a rapidly evolving area of signal analysis. In recent years, interest from the academic and military research institutes has focused around the research and development of modulation recognition algorithms. Any communication intelligence (COMINT) system comprises three main blocks: receiver front-end, modulation recogniser and output stage. Considerable work has been done in the area of receiver front-ends. The work at the output stage is concerned with information extraction, recording and exploitation and begins with signal demodulation, that requires accurate knowledge about the signal modulation type. There are, however, two main reasons for knowing the current modulation type of a signal; to preserve the signal information content and to decide upon the suitable counter action, such as jamming. Automatic Modulation Recognition of Communications Signals describes in depth this modulation recognition process. Drawing on several years of research, the authors provide a cr...

  2. Signal detection amid noise with known statistics

    Science.gov (United States)

    Zepka, A. F.; Cordes, J. M.; Wasserman, I.

    1994-01-01

    Conventional methods of signal detection are based on the comparison of a local signal-to-noise ratio S/N to some threshold value. We present a new method that compares instead the histogram of the data with the one expected for background noise alone. Signals are detected from discrepancies between the two. We expect it to be applicable in the detection of signals from any data whose background statistics is known. To illustrate the method, we apply it to the case of photon-limited imaging data where the underlying background is Poissonian. Numerical simulations are used to check the efficiency of our method, finding that for signals with low S/N (less than 5), it detects signals with a higher degree of reliability than the conventional method.

  3. Signal-to-noise ratio determination circuit

    Science.gov (United States)

    Deerkoski, L. F. (Inventor)

    1973-01-01

    A signal-to-noise ratio (SNR) determination of an input is described, having signal components within a given frequency range and noise components, without actual measurement of the noise components. Bandpass limiter having a constant signal plus noise output level is connected to the output of the first filter, the signal-to-noise ratio of the input to the bandpass limiter being linearly related to the dbm level of signal components at the output. Calibration is connected to the bandpass limiter and is responsive to the signal components at the output to derive the SNR of the input to the determination circuit. The SNR determination circuit is disclosed for use in a diversity receiver having a plurality of input channels.

  4. Long Lived NMR Signal in Bone

    CERN Document Server

    Zhang, Boyang; Khitrin, Anatoly; Jerschow, Alexej

    2012-01-01

    Solids and rigid tissues such as bone, ligaments, and tendons, typically appear dark in magnetic resonance imaging (MRI), which is due to the extremely short-lived proton nuclear magnetic resonance (NMR) signals. This short lifetime is due to strong dipolar interactions between immobilized proton spins, which render it challenging to detect these signals with sufficient resolution and sensitivity. Here we show the possibility of exciting long-lived signals in cortical bone tissue with a signature consistent with that of bound water signals. Contrary to long-standing belief, it is further shown that dipolar coupling networks are an integral requirement for the excitation of these long-lived signals. The use of these signals could enhance the ability to visualize rigid tissues and solid samples with high sensitivity, resolution, and specificity via MRI.

  5. Selection-Mutation Dynamics of Signaling Games

    Directory of Open Access Journals (Sweden)

    Josef Hofbauer

    2015-01-01

    Full Text Available We study the structure of the rest points of signaling games and their dynamic behavior under selection-mutation dynamics by taking the case of three signals as our canonical example. Many rest points of the replicator dynamics of signaling games are not isolated and, therefore, not robust under perturbations. However, some of them attract open sets of initial conditions. We prove the existence of certain rest points of the selection-mutation dynamics close to Nash equilibria of the signaling game and show that all but the perturbed rest points close to strict Nash equilibria are dynamically unstable. This is an important result for the evolution of signaling behavior, since it shows that the second-order forces that are governed by mutation can increase the chances of successful signaling.

  6. Evolution of Cooperation Via Covert Signaling

    CERN Document Server

    Smaldino, Paul E; McElreath, Richard

    2015-01-01

    Human sociality depends upon the benefits of mutual aid and extensive communication. However mutual aid is made difficult by the problems of coordinating diverse norms and preferences, and communication is harried by substantial ambiguity in meaning. Here we demonstrate that these two facts can work together to allow cooperation to develop, by the strategic use of deliberately ambiguous signals, covert signaling. Covert signaling is the transmission of information that is accurately received by its intended audience but obscured when perceived by others. Such signals may allow coordination and enhanced cooperation while also avoiding the alienation or hostile reactions of individuals with different preferences. Although the empirical literature has identified potential mechanisms of covert signaling, such as encryption in humor, there is to date no formal theory of its dynamics. We introduce a novel mathematical model to assess the conditions under which a covert signaling strategy will be favored. We show th...

  7. ECG signal denoising via empirical wavelet transform.

    Science.gov (United States)

    Singh, Omkar; Sunkaria, Ramesh Kumar

    2017-03-01

    This paper presents new methods for baseline wander correction and powerline interference reduction in electrocardiogram (ECG) signals using empirical wavelet transform (EWT). During data acquisition of ECG signal, various noise sources such as powerline interference, baseline wander and muscle artifacts contaminate the information bearing ECG signal. For better analysis and interpretation, the ECG signal must be free of noise. In the present work, a new approach is used to filter baseline wander and power line interference from the ECG signal. The technique utilized is the empirical wavelet transform, which is a new method used to compute the building modes of a given signal. Its performance as a filter is compared to the standard linear filters and empirical mode decomposition.The results show that EWT delivers a better performance.

  8. Prediction of twin-arginine signal peptides

    DEFF Research Database (Denmark)

    Bendtsen, Jannick Dyrløv; Nielsen, Henrik; Widdick, D.

    2005-01-01

    a publicly available method, TatP, for prediction of bacterial Tat signal peptides. Results: We have retrieved sequence data for Tat substrates in order to train a computational method for discrimination of Sec and Tat signal peptides. The TatP method is able to positively classify 91% of 35 known Tat signal...... peptides and 84% of the annotated cleavage sites of these Tat signal peptides were correctly predicted. This method generates far less false positive predictions on various datasets than using simple pattern matching. Moreover, on the same datasets TatP generates less false positive predictions than...... expressions, whereas hydrophobicity discrimination of Tat- and Sec- signal peptides is carried out by an artificial neural network. A potential cleavage site of the predicted Tat signal peptide is also reported. The TatP prediction server is available as a public web server at http://www.cbs.dtu.dk/services/TatP/....

  9. Huntington's Disease and Striatal Signaling

    Directory of Open Access Journals (Sweden)

    Emmanuel eRoze

    2011-08-01

    Full Text Available Huntington’s Disease (HD is the most frequent neurodegenerative disease caused by an expansion of polyglutamines (CAG. The main clinical manifestations of HD are chorea, cognitive impairment and psychiatric disorders. The transmission of HD is autosomal dominant with a complete penetrance. HD has a single genetic cause, a well-defined neuropathology, and informative pre-manifest genetic testing of the disease is available. Striatal atrophy begins as early as 15 years before disease onset and continues throughout the period of manifest illness. Therefore, patients could theoretically benefit from therapy at early stages of the disease. One important characteristic of HD is the striatal vulnerability to neurodegeneration, despite similar expression of the protein in other brain areas. Aggregation of the mutated Huntingtin (HTT, impaired axonal transport, excitotoxicity, transcriptional dysregulation as well as mitochondrial dysfunction and energy deficits, are all part of the cellular events that underlie neuronal dysfunction and striatal death. Among these non-exclusive mechanisms, an alteration of striatal signaling is thought to orchestrate the downstream events involved in the cascade of striatal dysfunction.

  10. Interception of LPI radar signals

    Science.gov (United States)

    Lee, Jim P.

    1991-11-01

    Most current radars are designed to transmit short duration pulses with relatively high peak power. These radars can be detected easily by the use of relatively modest EW intercept receivers. Three radar functions (search, anti-ship missile (ASM) seeker, and navigation) are examined to evaluate the effectiveness of potential low probability of intercept (LPI) techniques, such as waveform coding, antenna profile control, and power management that a radar may employ against current Electronic Warfare (EW) receivers. The general conclusion is that it is possible to design a LPI radar which is effective against current intercept EW receivers. LPI operation is most easily achieved at close ranges and against a target with a large radar cross section. The general system sensitivity requirement for the detection of current and projected LPI radars is found to be on the order of -100 dBmi which cannot be met by current EW receivers. Finally, three potential LPI receiver architectures, using channelized, superhet, and acousto-optic receivers with narrow RF and video bandwidths are discussed. They have shown some potential in terms of providing the sensitivity and capability in an environment where both conventional and LPI signals are present.

  11. A Method to Decompose the Streamed Acoustic Emission Signals for Detecting Embedded Fatigue Crack Signals

    Directory of Open Access Journals (Sweden)

    Lu Zhang

    2017-12-01

    Full Text Available The data collection of Acoustic Emission (AE method is typically based on threshold-dependent approach, where the AE system acquires data when the output of AE sensor is above the pre-defined threshold. However, this approach fails to detect flaws in noisy environment, as the signal level of noise may overcome the signal level of AE from flaws, and saturate the AE system. Time-dependent approach is based on streaming waveforms and extracting features at every pre-defined time interval. It is hypothesized that the relevant AE signals representing active flaws are embedded into the streamed signals. In this study, a decomposition method of the streamed AE signals to separate noise signal and crack signal is demonstrated. The AE signals representing fatigue crack growth in steel are obtained from the laboratory scale testing. The streamed AE signals in a noisy operational condition are obtained from the gearbox testing at the Naval Air Systems Command (NAVAIR facility. The signal addition and decomposition is achieved to determine the minimum detectable signal to noise ratio that is embedded into the streamed AE signals. The developed decomposition approach is demonstrated on detecting burst signals embedded into the streamed signals recorded in the spline testing of the helicopter gearbox test rig located at the NAVAIR facility.

  12. Pseudo random signal processing theory and application

    CERN Document Server

    Zepernick, Hans-Jurgen

    2013-01-01

    In recent years, pseudo random signal processing has proven to be a critical enabler of modern communication, information, security and measurement systems. The signal's pseudo random, noise-like properties make it vitally important as a tool for protecting against interference, alleviating multipath propagation and allowing the potential of sharing bandwidth with other users. Taking a practical approach to the topic, this text provides a comprehensive and systematic guide to understanding and using pseudo random signals. Covering theoretical principles, design methodologies and applications

  13. Microprocessor-based boxcar signal averager

    Science.gov (United States)

    Bano, S. S.; Reddy, P. N.; Reddy, B. P. N.; Eswara Reddy, N. C.

    1987-10-01

    A boxcar signal averager using Intel 8085AH, an 8-bit microprocessor developed for processing free-induction decay (FID) signals from a pulsed nuclear-magnetic-resonance (NMR) spectrometer, is described. The boxcar signal averager works either in single-point mode or in scan mode. In addition to the software developed, the constructional features, circuit details, and the operation of the boxcar are discussed in detail.

  14. Signal and image processing in medical applications

    CERN Document Server

    Kumar, Amit; Rahim, B Abdul; Kumar, D Sravan

    2016-01-01

    This book highlights recent findings on and analyses conducted on signals and images in the area of medicine. The experimental investigations involve a variety of signals and images and their methodologies range from very basic to sophisticated methods. The book explains how signal and image processing methods can be used to detect and forecast abnormalities in an easy-to-follow manner, offering a valuable resource for researchers, engineers, physicians and bioinformatics researchers alike.

  15. Integrated Microwave Photonics for Wideband Signal Processing

    Directory of Open Access Journals (Sweden)

    Xiaoke Yi

    2017-11-01

    Full Text Available We describe recent progress in integrated microwave photonics in wideband signal processing applications with a focus on the key signal processing building blocks, the realization of monolithic integration, and cascaded photonic signal processing for analog radio frequency (RF photonic links. New developments in integration-based microwave photonic techniques, that have high potentialities to be used in a variety of sensing applications for enhanced resolution and speed are also presented.

  16. 32 CFR 935.134 - Arm signals.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Arm signals. 935.134 Section 935.134 National... WAKE ISLAND CODE Motor Vehicle Code § 935.134 Arm signals. (a) Any person operating a motor vehicle and... signal for a turn or stop is made by fully extending the left arm as follows: (1) Left turn—extend left...

  17. Neuron-mediated generation of regulatory T cells from encephalitogenic T cells suppresses EAE

    DEFF Research Database (Denmark)

    Liu, Yawei; Teige, Ingrid; Birnir, Bryndis

    2006-01-01

    ) inflammation. Neurons induce the proliferation of activated CD4+ T cells through B7-CD28 and transforming growth factor (TGF)-beta1-TGF-beta receptor signaling pathways, resulting in amplification of T-cell receptor signaling through phosphorylated ZAP-70, interleukin (IL)-2 and IL-9. The interaction between......Neurons have been neglected as cells with a major immune-regulatory function because they do not express major histocompatibility complex class II. Our data show that neurons are highly immune regulatory, having a crucial role in governing T-cell response and central nervous system (CNS...... neurons and T cells results in the conversion of encephalitogenic T cells to CD25+ TGF-beta1+ CTLA-4+ FoxP3+ T regulatory (Treg) cells that suppress encephalitogenic T cells and inhibit experimental autoimmune encephalomyelitis. Suppression is dependent on cytotoxic T lymphocyte antigen (CTLA)-4...

  18. Random signals and noise a mathematical introduction

    CERN Document Server

    Engelberg, Shlomo

    2011-01-01

    Understanding the nature of random signals and noise is critically important for detecting signals and for reducing and minimizing the effects of noise in applications such as communications and control systems. Outlining a variety of techniques and explaining when and how to use them, Random Signals and Noise: A Mathematical Introduction focuses on applications and practical problem solving rather than probability theory.A Firm FoundationBefore launching into the particulars of random signals and noise, the author outlines the elements of probability that are used throughout the book and incl

  19. [Wnt signaling molecules related to osteoporosis].

    Science.gov (United States)

    Kubota, Takuo; Ozono, Keiichi

    2013-06-01

    Wnt signaling pathway components have been shown to be involved in bone biology since mutations in the LRP5 gene proved to cause osteoporosis-pseudoglioma syndrome and high bone mass trait. Genome wide association studies have indicated that single nucleotide polymorphisms of various components in Wnt signaling pathways are associated with bone mineral density and risk for low-trauma fracture. Mouse genetic studies have demonstrated that multiple components in Wnt signaling pathways play significant roles in skeletal development and bone mass maintenance. Here we review several components in Wnt signaling pathways with their association with bone mineral density in humans.

  20. Cognitive Control Signals for Neural Prosthetics

    National Research Council Canada - National Science Library

    S. Musallam; B. D. Corneil; B. Greger; H. Scherberger; R. A. Andersen

    2004-01-01

    Recent development of neural prosthetics for assisting paralyzed patients has focused on decoding intended hand trajectories from motor cortical neurons and using this signal to control external devices...

  1. Radar signal processing and its applications

    CERN Document Server

    Hummel, Robert; Stoica, Petre; Zelnio, Edmund

    2003-01-01

    Radar Signal Processing and Its Applications brings together in one place important contributions and up-to-date research results in this fast-moving area. In twelve selected chapters, it describes the latest advances in architectures, design methods, and applications of radar signal processing. The contributors to this work were selected from the leading researchers and practitioners in the field. This work, originally published as Volume 14, Numbers 1-3 of the journal, Multidimensional Systems and Signal Processing, will be valuable to anyone working or researching in the field of radar signal processing. It serves as an excellent reference, providing insight into some of the most challenging issues being examined today.

  2. Understanding and exploiting autophagy signaling in plants.

    Science.gov (United States)

    Batoko, Henri; Dagdas, Yasin; Baluska, Frantisek; Sirko, Agnieszka

    2017-12-12

    Autophagy is an essential catabolic pathway and is activated by various endogenous and exogenous stimuli. In particular, autophagy is required to allow sessile organisms such as plants to cope with biotic or abiotic stress conditions. It is thought that these various environmental signaling pathways are somehow integrated with autophagy signaling. However, the molecular mechanisms of plant autophagy signaling are not well understood, leaving a big gap of knowledge as a barrier to being able to manipulate this important pathway to improve plant growth and development. In this review, we discuss possible regulatory mechanisms at the core of plant autophagy signaling. © 2017 The Author(s).

  3. GPCR-Mediated Signaling of Metabolites

    DEFF Research Database (Denmark)

    Husted, Anna Sofie; Trauelsen, Mette; Rudenko, Olga

    2017-01-01

    In addition to their bioenergetic intracellular function, several classical metabolites act as extracellular signaling molecules activating cell-surface G-protein-coupled receptors (GPCRs), similar to hormones and neurotransmitters. "Signaling metabolites" generated from nutrients or by gut...... in adipose tissue, the liver, and the endocrine pancreas. Importantly, distinct metabolite GPCRs act as efficient pro- and anti-inflammatory regulators of key immune cells, and signaling metabolites may thus function as important drivers of the low-grade inflammation associated with insulin resistance...... and obesity. The concept of key metabolites as ligands for specific GPCRs has broadened our understanding of metabolic signaling significantly and provides a number of novel potential drug targets....

  4. Multivariate Analysis for the Processing of Signals

    Directory of Open Access Journals (Sweden)

    Beattie J.R.

    2014-01-01

    Full Text Available Real-world experiments are becoming increasingly more complex, needing techniques capable of tracking this complexity. Signal based measurements are often used to capture this complexity, where a signal is a record of a sample’s response to a parameter (e.g. time, displacement, voltage, wavelength that is varied over a range of values. In signals the responses at each value of the varied parameter are related to each other, depending on the composition or state sample being measured. Since signals contain multiple information points, they have rich information content but are generally complex to comprehend. Multivariate Analysis (MA has profoundly transformed their analysis by allowing gross simplification of the tangled web of variation. In addition MA has also provided the advantage of being much more robust to the influence of noise than univariate methods of analysis. In recent years, there has been a growing awareness that the nature of the multivariate methods allows exploitation of its benefits for purposes other than data analysis, such as pre-processing of signals with the aim of eliminating irrelevant variations prior to analysis of the signal of interest. It has been shown that exploiting multivariate data reduction in an appropriate way can allow high fidelity denoising (removal of irreproducible non-signals, consistent and reproducible noise-insensitive correction of baseline distortions (removal of reproducible non-signals, accurate elimination of interfering signals (removal of reproducible but unwanted signals and the standardisation of signal amplitude fluctuations. At present, the field is relatively small but the possibilities for much wider application are considerable. Where signal properties are suitable for MA (such as the signal being stationary along the x-axis, these signal based corrections have the potential to be highly reproducible, and highly adaptable and are applicable in situations where the data is noisy or

  5. How do cilia organize signalling cascades?

    Science.gov (United States)

    Nachury, Maxence V

    2014-09-05

    Cilia and flagella are closely related centriole-nucleated protrusions of the cell with roles in motility and signal transduction. Two of the best-studied signalling pathways organized by cilia are the transduction cascade for the morphogen Hedgehog in vertebrates and the mating pathway that initiates gamete fusion in the unicellular green alga Chlamydomonas reinhardtii. What is the role of cilia in these signalling transduction cascades? In both Hedgehog and mating pathways, all signalling intermediates have been found to localize to cilia, and, for some signalling factors, ciliary localization is regulated by pathway activation. Given a concentration factor of three orders of magnitude provided by translocating a protein into the cilium, the compartment model proposes that cilia act as miniaturized reaction tubes bringing signalling factors and processing enzymes in close proximity. On the other hand, the scaffolding model views the intraflagellar transport machinery, whose primary function is to build cilia and flagella, as a molecular scaffold for the mating transduction cascade at the flagellar membrane. While these models may coexist, it is hoped that a precise understanding of the mechanisms that govern signalling inside cilia will provide a satisfying answer to the question 'how do cilia organize signalling?'. This review covers the evidence supporting each model of signalling and outlines future directions that may address which model applies in given biological settings. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  6. Computing angle of arrival of radio signals

    Science.gov (United States)

    Borchardt, John J.; Steele, David K.

    2017-11-07

    Various technologies pertaining to computing angle of arrival of radio signals are described. A system that is configured for computing the angle of arrival of a radio signal includes a cylindrical sheath wrapped around a cylindrical object, where the cylindrical sheath acts as a ground plane. The system further includes a plurality of antennas that are positioned about an exterior surface of the cylindrical sheath, and receivers respectively coupled to the antennas. The receivers output measurements pertaining to the radio signal. A processing circuit receives the measurements and computes the angle of arrival of the radio signal based upon the measurements.

  7. Signals and systems primer with Matlab

    CERN Document Server

    Poularikas, Alexander D

    2006-01-01

    Signals and Systems Primer with MATLAB® equally emphasizes the fundamentals of both analog and digital signals and systems. To ensure insight into the basic concepts and methods, the text presents a variety of examples that illustrate a wide range of applications, from microelectromechanical to worldwide communication systems. It also provides MATLAB functions and procedures for practice and verification of these concepts.Taking a pedagogical approach, the author builds a solid foundation in signal processing as well as analog and digital systems. The book first introduces orthogonal signals,

  8. Digital signal processing an experimental approach

    CERN Document Server

    Engelberg, Shlomo

    2008-01-01

    Digital Signal Processing is a mathematically rigorous but accessible treatment of digital signal processing that intertwines basic theoretical techniques with hands-on laboratory instruction. Divided into three parts, the book covers various aspects of the digital signal processing (DSP) ""problem."" It begins with the analysis of discrete-time signals and explains sampling and the use of the discrete and fast Fourier transforms. The second part of the book???covering digital to analog and analog to digital conversion???provides a practical interlude in the mathematical content before Part II

  9. Advanced Methods of Biomedical Signal Processing

    CERN Document Server

    Cerutti, Sergio

    2011-01-01

    This book grew out of the IEEE-EMBS Summer Schools on Biomedical Signal Processing, which have been held annually since 2002 to provide the participants state-of-the-art knowledge on emerging areas in biomedical engineering. Prominent experts in the areas of biomedical signal processing, biomedical data treatment, medicine, signal processing, system biology, and applied physiology introduce novel techniques and algorithms as well as their clinical or physiological applications. The book provides an overview of a compelling group of advanced biomedical signal processing techniques, such as mult

  10. Filtering multifocal VEP signals using Prony's method.

    Science.gov (United States)

    Fernández, A; de Santiago, L; Blanco, R; Pérez-Rico, C; Rodríguez-Ascariz, J M; Barea, R; Miguel-Jiménez, J M; García-Luque, J R; Ortiz del Castillo, M; Sánchez-Morla, E M; Boquete, L

    2015-01-01

    This paper describes use of Prony's method as a filter applied to multifocal visual-evoked-potential (mfVEP) signals. Prony's method can be viewed as an extension of Fourier analysis that allows a signal to be decomposed into a linear combination of functions with different amplitudes, damping factors, frequencies and phase angles. By selecting Prony method parameters, a frequency filter has been developed which improves signal-to-noise ratio (SNR). Three different criteria were applied to data recorded from control subjects to produce three separate datasets: unfiltered raw data, data filtered using the traditional method (fast Fourier transform: FFT), and data filtered using Prony's method. Filtering using Prony's method improved the signals' original SNR by 44.52%, while the FFT filter improved the SNR by 33.56%. The extent to which signal can be separated from noise was analysed using receiver-operating-characteristic (ROC) curves. The area under the curve (AUC) was greater in the signals filtered using Prony's method than in the original signals or in those filtered using the FFT. filtering using Prony's method improves the quality of mfVEP signal pre-processing when compared with the original signals, or with those filtered using the FFT. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Mitochondrial signaling in health and disease

    National Research Council Canada - National Science Library

    Orrenius, Sten; Packer, Lester; Cadenas, Enrique

    2012-01-01

    .... The text covers themes essential for the maintenance of mitochondrial activity, including electron transport and energy production, mitochondrial biogenesis and dynamics, mitochondrial signaling...

  12. TGF-β signaling in C. elegans.

    Science.gov (United States)

    Gumienny, Tina L; Savage-Dunn, Cathy

    2013-07-10

    Transforming Growth Factor-β (TGF-β) superfamily ligands regulate many aspects of cell identity, function, and survival in multicellular animals. Genes encoding five TGF-β family members are present in the genome of C. elegans. Two of the ligands, DBL-1 and DAF-7, signal through a canonical receptor-Smad signaling pathway; while a third ligand, UNC-129, interacts with a noncanonical signaling pathway. No function has yet been associated with the remaining two ligands. Here we summarize these signaling pathways and their biological functions.

  13. Endocannabinoid Signaling Regulates Sleep Stability.

    Directory of Open Access Journals (Sweden)

    Matthew J Pava

    Full Text Available The hypnogenic properties of cannabis have been recognized for centuries, but endogenous cannabinoid (endocannabinoid regulation of vigilance states is poorly characterized. We report findings from a series of experiments in mice measuring sleep with polysomnography after various systemic pharmacological manipulations of the endocannabinoid system. Rapid, unbiased scoring of vigilance states was achieved using an automated algorithm that we devised and validated. Increasing endocannabinoid tone with a selective inhibitor of monoacyglycerol lipase (JZL184 or fatty acid amide hydrolase (AM3506 produced a transient increase in non-rapid eye movement (NREM sleep due to an augmentation of the length of NREM bouts (NREM stability. Similarly, direct activation of type 1 cannabinoid (CB1 receptors with CP47,497 increased NREM stability, but both CP47,497 and JZL184 had a secondary effect that reduced NREM sleep time and stability. This secondary response to these drugs was similar to the early effect of CB1 blockade with the antagonist/inverse agonist AM281, which fragmented NREM sleep. The magnitude of the effects produced by JZL184 and AM281 were dependent on the time of day this drug was administered. While activation of CB1 resulted in only a slight reduction in gamma power, CB1 blockade had dramatic effects on broadband power in the EEG, particularly at low frequencies. However, CB1 blockade did not significantly reduce the rebound in NREM sleep following total sleep deprivation. These results support the hypothesis that endocannabinoid signaling through CB1 is necessary for NREM stability but it is not necessary for sleep homeostasis.

  14. Nitric oxide signaling in hypoxia.

    Science.gov (United States)

    Ho, J J David; Man, H S Jeffrey; Marsden, Philip A

    2012-03-01

    Endothelial-derived nitric oxide (NO) is classically viewed as a regulator of vasomotor tone. NO plays an important role in regulating O(2) delivery through paracrine control of vasomotor tone locally and cardiovascular and respiratory responses centrally. Very soon after the cloning and functional characterization of the endothelial nitric oxide synthase (eNOS), studies on the interaction between O(2) and NO made the paradoxical finding that hypoxia led to decreases in eNOS expression and function. Why would decreases in O(2) content in tissues elicit a loss of a potent endothelial-derived vasodilator? We now know that restricting our view of NO as a regulator of vasomotor tone or blood pressure limited deeper levels of mechanistic insight. Exciting new studies indicate that functional interactions between NO and O(2) exhibit profound complexity and are relevant to diseases states, especially those associated with hypoxia in tissues. NOS isoforms catalytically require O(2). Hypoxia regulates steady-state expression of the mRNA and protein abundance of the NOS enzymes. Animals genetically deficient in NOS isoforms have perturbations in their ability to adapt to changes in O(2) supply or demand. Most interestingly, the intracellular pathways for O(2) sensing that evolved to ensure an appropriate balance of O(2) delivery and utilization intersect with NO signaling networks. Recent studies demonstrate that hypoxia-inducible factor (HIF) stabilization and transcriptional activity is achieved through two parallel pathways: (1) a decrease in O(2)-dependent prolyl hydroxylation of HIF and (2) S-nitrosylation of HIF pathway components. Recent findings support a role for S-nitrosothiols as hypoxia-mimetics in certain biological and/or disease settings, such as living at high altitude, exposure to small molecules that can bind NO, or anemia.

  15. [Glutamate signaling and neural plasticity].

    Science.gov (United States)

    Watanabe, Masahiko

    2013-07-01

    Proper functioning of the nervous system relies on the precise formation of neural circuits during development. At birth, neurons have redundant synaptic connections not only to their proper targets but also to other neighboring cells. Then, functional neural circuits are formed during early postnatal development by the selective strengthening of necessary synapses and weakening of surplus connections. Synaptic connections are also modified so that projection fields of active afferents expand at the expense of lesser ones. We have studied the molecular mechanisms underlying these activity-dependent prunings and the plasticity of synaptic circuitry using gene-engineered mice defective in the glutamatergic signaling system. NMDA-type glutamate receptors are critically involved in the establishment of the somatosensory pathway ascending from the brainstem trigeminal nucleus to the somatosensory cortex. Without NMDA receptors, whisker-related patterning fails to develop, whereas lesion-induced plasticity occurs normally during the critical period. In contrast, mice lacking the glutamate transporters GLAST or GLT1 are selectively impaired in the lesion-induced critical plasticity of cortical barrels, although whisker-related patterning itself develops normally. In the developing cerebellum, multiple climbing fibers initially innervating given Purkinje cells are eliminated one by one until mono-innervation is achieved. In this pruning process, P/Q-type Ca2+ channels expressed on Purkinje cells are critically involved by the selective strengthening of single main climbing fibers against other lesser afferents. Therefore, the activation of glutamate receptors that leads to an activity-dependent increase in the intracellular Ca2+ concentration plays a key role in the pruning of immature synaptic circuits into functional circuits. On the other hand, glutamate transporters appear to control activity-dependent plasticity among afferent fields, presumably through adjusting

  16. A comb filter based signal processing method to effectively reduce motion artifacts from photoplethysmographic signals.

    Science.gov (United States)

    Peng, Fulai; Liu, Hongyun; Wang, Weidong

    2015-10-01

    A photoplethysmographic (PPG) signal can provide very useful information about a subject's cardiovascular status. Motion artifacts (MAs), which usually deteriorate the waveform of a PPG signal, severely obstruct its applications in the clinical diagnosis and healthcare area. To reduce the MAs from a PPG signal, in the present study we present a comb filter based signal processing method. Firstly, wavelet de-noising was implemented to preliminarily suppress a part of the MAs. Then, the PPG signal in the time domain was transformed into the frequency domain by a fast Fourier transform (FFT). Thirdly, the PPG signal period was estimated from the frequency domain by tracking the fundamental frequency peak of the PPG signal. Lastly, the MAs were removed by the comb filter which was designed based on the obtained PPG signal period. Experiments with synthetic and real-world datasets were implemented to validate the performance of the method. Results show that the proposed method can effectively restore the PPG signals from the MA corrupted signals. Also, the accuracy of blood oxygen saturation (SpO2), calculated from red and infrared PPG signals, was significantly improved after the MA reduction by the proposed method. Our study demonstrates that the comb filter can effectively reduce the MAs from a PPG signal provided that the PPG signal period is obtained.

  17. Calcium signalling silencing in atrial fibrillation.

    Science.gov (United States)

    Greiser, Maura

    2017-06-15

    Subcellular calcium signalling silencing is a novel and distinct cellular and molecular adaptive response to rapid cardiac activation. Calcium signalling silencing develops during short-term sustained rapid atrial activation as seen clinically during paroxysmal atrial fibrillation (AF). It is the first 'anti-arrhythmic' adaptive response in the setting of AF and appears to counteract the maladaptive changes that lead to intracellular Ca(2+) signalling instability and Ca(2+) -based arrhythmogenicity. Calcium signalling silencing results in a failed propagation of the [Ca(2+) ]i signal to the myocyte centre both in patients with AF and in a rabbit model. This adaptive mechanism leads to a substantial reduction in the expression levels of calcium release channels (ryanodine receptors, RyR2) in the sarcoplasmic reticulum, and the frequency of Ca(2+) sparks and arrhythmogenic Ca(2+) waves remains low. Less Ca(2+) release per [Ca(2+) ]i transient, increased fast Ca(2+) buffering strength, shortened action potentials and reduced L-type Ca(2+) current contribute to a substantial reduction of intracellular [Na(+) ]. These features of Ca(2+) signalling silencing are distinct and in contrast to the changes attributed to Ca(2+) -based arrhythmogenicity. Some features of Ca(2+) signalling silencing prevail in human AF suggesting that the Ca(2+) signalling 'phenotype' in AF is a sum of Ca(2+) stabilizing (Ca(2+) signalling silencing) and Ca(2+) destabilizing (arrhythmogenic unstable Ca(2+) signalling) factors. Calcium signalling silencing is a part of the mechanisms that contribute to the natural progression of AF and may limit the role of Ca(2+) -based arrhythmogenicity after the onset of AF. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

  18. Growth regulation of simian and human AIDS-related non-Hodgkin's lymphoma cell lines by TGF-β1 and IL-6

    Directory of Open Access Journals (Sweden)

    Levy Laura S

    2007-02-01

    Full Text Available Abstract Background AIDS-related non-Hodgkin's lymphoma (AIDS-NHL is the second most frequent cancer associated with AIDS, and is a frequent cause of death in HIV-infected individuals. Experimental analysis of AIDS-NHL has been facilitated by the availability of an excellent animal model, i.e., simian Acquired Immunodeficiency Syndrome (SAIDS in the rhesus macaque consequent to infection with simian immunodeficiency virus. A recent study of SAIDS-NHL demonstrated a lymphoma-derived cell line to be sensitive to the growth inhibitory effects of the ubiquitous cytokine, transforming growth factor-beta (TGF-beta. The authors concluded that TGF-beta acts as a negative growth regulator of the lymphoma-derived cell line and, potentially, as an inhibitory factor in the regulatory network of AIDS-related lymphomagenesis. The present study was conducted to assess whether other SAIDS-NHL and AIDS-NHL cell lines are similarly sensitive to the growth inhibitory effects of TGF-beta, and to test the hypothesis that interleukin-6 (IL-6 may represent a counteracting positive influence in their growth regulation. Methods Growth stimulation or inhibition in response to cytokine treatment was quantified using trypan blue exclusion or colorimetric MTT assay. Intracellular flow cytometry was used to analyze the activation of signaling pathways and to examine the expression of anti-apoptotic proteins and distinguishing hallmarks of AIDS-NHL subclass. Apoptosis was quantified by flow cytometric analysis of cell populations with sub-G1 DNA content and by measuring activated caspase-3. Results Results confirmed the sensitivity of LCL8664, an immunoblastic SAIDS-NHL cell line, to TGF-beta1-mediated growth inhibition, and further demonstrated the partial rescue by simultaneous treatment with IL-6. IL-6 was shown to activate STAT3, even in the presence of TGF-beta1, and thereby to activate proliferative and anti-apoptotic pathways. By comparison, human AIDS-NHL cell lines

  19. Laser heterodyne interferometric signal processing method based on rising edge locking with high frequency clock signal.

    Science.gov (United States)

    Zhang, Enzheng; Chen, Benyong; Yan, Liping; Yang, Tao; Hao, Qun; Dong, Wenjun; Li, Chaorong

    2013-02-25

    A novel phase measurement method composed of the rising-edge locked signal processing and the digital frequency mixing is proposed for laser heterodyne interferometer. The rising-edge locked signal processing, which employs a high frequency clock signal to lock the rising-edges of the reference and measurement signals, not only can improve the steepness of the rising-edge, but also can eliminate the error counting caused by multi-rising-edge phenomenon in fringe counting. The digital frequency mixing is realized by mixing the digital interference signal with a digital base signal that is different from conventional frequency mixing with analogue signals. These signal processing can improve the measurement accuracy and enhance anti-interference and measurement stability. The principle and implementation of the method are described in detail. An experimental setup was constructed and a series of experiments verified the feasibility of the method in large displacement measurement with high speed and nanometer resolution.

  20. Multi-Modal Intelligent Traffic Signal Systems Signal Plans for Roadside Equipment

    Data.gov (United States)

    Department of Transportation — Data were collected during the Multi-Modal Intelligent Transportation Signal Systems (MMITSS) study. MMITSS is a next-generation traffic signal system that seeks to...

  1. Spectral Correlation of Multicarrier Modulated Signals and Its Application for Signal Detection

    Directory of Open Access Journals (Sweden)

    Zhang Haijian

    2010-01-01

    Full Text Available Spectral correlation theory for cyclostationary time-series signals has been studied for decades. Explicit formulas of spectral correlation function for various types of analog-modulated and digital-modulated signals are already derived. In this paper, we investigate and exploit the cyclostationarity characteristics for two kinds of multicarrier modulated (MCM signals: conventional OFDM and filter bank based multicarrier (FBMC signals. The spectral correlation characterization of MCM signal can be described by a special linear periodic time-variant (LPTV system. Using this LPTV description, we have derived the explicit theoretical formulas of nonconjugate and conjugate cyclic autocorrelation function (CAF and spectral correlation function (SCF for OFDM and FBMC signals. According to theoretical spectral analysis, Cyclostationary Signatures (CS are artificially embedded into MCM signal and a low-complexity signature detector is, therefore, presented for detecting MCM signal. Theoretical analysis and simulation results demonstrate the efficiency and robustness of this CS detector compared to traditionary energy detector.

  2. Digital signal processing for fiber nonlinearities [Invited

    DEFF Research Database (Denmark)

    Cartledge, John C.; Guiomar, Fernando P.; Kschischang, Frank R.

    2017-01-01

    This paper reviews digital signal processing techniques that compensate, mitigate, and exploit fiber nonlinearities in coherent optical fiber transmission systems......This paper reviews digital signal processing techniques that compensate, mitigate, and exploit fiber nonlinearities in coherent optical fiber transmission systems...

  3. Ultrafast Nonlinear Signal Processing in Silicon Waveguides

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Mulvad, Hans Christian Hansen; Hu, Hao

    2012-01-01

    We describe recent demonstrations of exploiting highly nonlinear silicon waveguides for ultrafast optical signal processing. We describe wavelength conversion and serial-to-parallel conversion of 640 Gbit/s data signals and 1.28 Tbit/s demultiplexing and all-optical sampling....

  4. Encrypted Signal Processing for Privacy Protection

    NARCIS (Netherlands)

    Cavallaro, A.; Lagendijk, R. (Inald) L.; Erkin, Zekeriya; Erkin, Zekeriya; Kwasinski, A.; Barni, Mauro

    In recent years, signal processing applications that deal with user-related data have aroused privacy concerns. For instance, face recognition and personalized recommendations rely on privacy-sensitive information that can be abused if the signal processing is executed on remote servers or in the

  5. Polypetide signaling molecules in plant development

    Science.gov (United States)

    Intercellular communication mediated by small signaling molecules is a key mechanism for coordinating plant growth and development. In the past few years, polypeptide signals have been shown to play prominent roles in processes as diverse as shoot and root meristem maintenance, vascular differentiat...

  6. SPdb – a signal peptide database

    Directory of Open Access Journals (Sweden)

    Tan Tin

    2005-10-01

    Full Text Available Abstract Background The signal peptide plays an important role in protein targeting and protein translocation in both prokaryotic and eukaryotic cells. This transient, short peptide sequence functions like a postal address on an envelope by targeting proteins for secretion or for transfer to specific organelles for further processing. Understanding how signal peptides function is crucial in predicting where proteins are translocated. To support this understanding, we present SPdb signal peptide database http://proline.bic.nus.edu.sg/spdb, a repository of experimentally determined and computationally predicted signal peptides. Results SPdb integrates information from two sources (a Swiss-Prot protein sequence database which is now part of UniProt and (b EMBL nucleotide sequence database. The database update is semi-automated with human checking and verification of the data to ensure the correctness of the data stored. The latest release SPdb release 3.2 contains 18,146 entries of which 2,584 entries are experimentally verified signal sequences; the remaining 15,562 entries are either signal sequences that fail to meet our filtering criteria or entries that contain unverified signal sequences. Conclusion SPdb is a manually curated database constructed to support the understanding and analysis of signal peptides. SPdb tracks the major updates of the two underlying primary databases thereby ensuring that its information remains up-to-date.

  7. Net analyte signal based statistical quality control

    NARCIS (Netherlands)

    Skibsted, E.T.S.; Boelens, H.F.M.; Westerhuis, J.A.; Smilde, A.K.; Broad, N.W.; Rees, D.R.; Witte, D.T.

    2005-01-01

    Net analyte signal statistical quality control (NAS-SQC) is a new methodology to perform multivariate product quality monitoring based on the net analyte signal approach. The main advantage of NAS-SQC is that the systematic variation in the product due to the analyte (or property) of interest is

  8. Thyroid hormone signaling in the hypothalamus

    NARCIS (Netherlands)

    Alkemade, Anneke; Visser, Theo J.; Fliers, Eric

    2008-01-01

    PURPOSE OF REVIEW: Proper thyroid hormone signaling is essential for brain development and adult brain function. Signaling can be disrupted at many levels due to altered thyroid hormone secretion, conversion or thyroid hormone receptor binding. RECENT FINDINGS: Mutated genes involved in thyroid

  9. Modeling Response Signal and Response Time Data

    Science.gov (United States)

    Ratcliff, Roger

    2006-01-01

    The diffusion model (Ratcliff, 1978) and the leaky competing accumulator model (LCA, Usher & McClelland, 2001) were tested against two-choice data collected from the same subjects with the standard response time procedure and the response signal procedure. In the response signal procedure, a stimulus is presented and then, at one of a number of…

  10. Managing Data From Signal-Propagation Experiments

    Science.gov (United States)

    Kantak, Anil V.

    1992-01-01

    Report dicusses system for management of data from Pilot Field Experiment (PiFEx) program, which consists of series of experiments on propagation of signals from transmitter at one fixed location to transponder on tower at another fixed location and from transponder to mobile receiver in van. Purpose of experiments to simulate signal-propagation conditions of land-mobile/satellite communication system.

  11. Extracting Periodic Signals From Irregularly Sampled Data

    Science.gov (United States)

    Wilcox, Jaroslava Z.

    1995-01-01

    Successive approximations formed in Fourier space. Algorithm extracts periodic signals from sparse, irregularly sampled sets of measurement data. Pertains to data processed via fast Fourier transforms (FFTs). Data represents signal components with initially unknown frequencies spanning large spectral range and includes frequencies not integer multiples of minimum FFT frequency.

  12. Electrical Signaling, Photosynthesis and Systemic Acquired Acclimation

    Directory of Open Access Journals (Sweden)

    Magdalena Szechyńska-Hebda

    2017-09-01

    Full Text Available Electrical signaling in higher plants is required for the appropriate intracellular and intercellular communication, stress responses, growth and development. In this review, we have focus on recent findings regarding the electrical signaling, as a major regulator of the systemic acquired acclimation (SAA and the systemic acquired resistance (SAR. The electric signaling on its own cannot confer the required specificity of information to trigger SAA and SAR, therefore, we have also discussed a number of other mechanisms and signaling systems that can operate in combination with electric signaling. We have emphasized the interrelation between ionic mechanism of electrical activity and regulation of photosynthesis, which is intrinsic to a proper induction of SAA and SAR. In a special way, we have summarized the role of non-photochemical quenching and its regulator PsbS. Further, redox status of the cell, calcium and hydraulic waves, hormonal circuits and stomatal aperture regulation have been considered as components of the signaling. Finally, a model of light-dependent mechanisms of electrical signaling propagation has been presented together with the systemic regulation of light-responsive genes encoding both, ion channels and proteins involved in regulation of their activity. Due to space limitations, we have not addressed many other important aspects of hormonal and ROS signaling, which were presented in a number of recent excellent reviews.

  13. Volume control device for digital signals

    NARCIS (Netherlands)

    Schinkel, Daniel; van Tuijl, Adrianus Johannes Maria; Nuijten, Petrus A.C.M.

    2004-01-01

    A digital volume control device comprises a logic unit for volume control of digital input signals. Successively supplied m-bits words with maximally k bits active, derived from the output signals of or supplied by a volume control (4) with a quantizer (5) element the filtered m-bits workds are

  14. Statistical issues in signal extraction from microarrays

    Science.gov (United States)

    Bergemann, Tracy; Quiaoit, Filemon; Delrow, Jeffrey J.; Zhao, Lue Ping

    2001-06-01

    Microarray technologies are increasingly used in biomedical research to study genome-wide expression profiles in the post genomic era. Their popularity is largely due to their high throughput and economical affordability. For example, microarrays have been applied to studies of cell cycle, regulatory circuitry, cancer cell lines, tumor tissues, and drug discoveries. One obstacle facing the continued success of applying microarray technologies, however, is the random variaton present on microarrays: within signal spots, between spots and among chips. In addition, signals extracted by available software packages seem to vary significantly. Despite a variety of software packages, it appears that there are two major approaches to signal extraction. One approach is to focus on the identification of signal regions and hence estimation of signal levels above background levels. The other approach is to use the distribution of intensity values as a way of identifying relevant signals. Building upon both approaches, the objective of our work is to develop a method that is statistically rigorous and also efficient and robust. Statistical issues to be considered here include: (1) how to refine grid alignment so that the overall variation is minimized, (2) how to estimate the signal levels relative to the local background levels as well as the variance of this estimate, and (3) how to integrate red and green channel signals so that the ratio of interest is stable, simultaneously relaxing distributional assumptions.

  15. White light signal simulator microcontroller design | Haghighi ...

    African Journals Online (AJOL)

    White light signal simulator microcontroller design. ... Journal of Fundamental and Applied Sciences ... signals associated with the light white from human retina cells were digitized, then the digital data were calculated and the resulted mathematical equation was programmed on a microcontroller, and by designing a circuit, ...

  16. 78 FR 36738 - Signal System Reporting Requirements

    Science.gov (United States)

    2013-06-19

    ... Federal Railroad Administration 49 CFR Part 233 RIN 2130-AC44 Signal System Reporting Requirements AGENCY... regulatory requirement that each carrier must file with FRA a signal system status report every five years... Reporting Requirements by updating an outdated statutory citation. DATES: Written comments must be received...

  17. Digital signal processing in microwave radiometers

    Science.gov (United States)

    Lawrence, R. W.; Stanley, W. D.; Harrington, R. F.

    1980-01-01

    A microprocessor based digital signal processing unit has been proposed to replace analog sections of a microwave radiometer. A brief introduction to the radiometer system involved and a description of problems encountered in the use of digital techniques in radiometer design are discussed. An analysis of the digital signal processor as part of the radiometer is then presented.

  18. Signalling Signalhood and the Emergence of Communication

    Science.gov (United States)

    Scott-Phillips, Thomas C.; Kirby, Simon; Ritchie, Graham R. S.

    2009-01-01

    A unique hallmark of human language is that it uses signals that are both learnt and symbolic. The emergence of such signals was therefore a defining event in human cognitive evolution, yet very little is known about how such a process occurs. Previous work provides some insights on how meaning can become attached to form, but a more foundational…

  19. Bandlimited graph signal reconstruction by diffusion operator

    Science.gov (United States)

    Yang, Lishan; You, Kangyong; Guo, Wenbin

    2016-12-01

    Signal processing on graphs extends signal processing concepts and methodologies from the classical signal processing theory to data indexed by general graphs. For a bandlimited graph signal, the unknown data associated with unsampled vertices can be reconstructed from the sampled data by exploiting the spatial relationship of graph signal. In this paper, we propose a generalized analytical framework of unsampled graph signal and introduce a concept of diffusion operator which consists of local-mean and global-bias diffusion operator. Then, a diffusion operator-based iterative algorithm is proposed to reconstruct bandlimited graph signal from sampled data. In each iteration, the reconstructed residuals associated with the sampled vertices are diffused to all the unsampled vertices for accelerating the convergence. We then prove that the proposed reconstruction strategy converges to the original graph signal. The simulation results demonstrate the effectiveness of the proposed reconstruction strategy with various downsampling patterns, fluctuation of graph cut-off frequency, robustness on the classic graph structures, and noisy scenarios.

  20. Conversion of phase-modulated signals to amplitude-modulated signals in SOAs due to mirror reflections

    DEFF Research Database (Denmark)

    Blaaberg, Søren; Mørk, Jesper

    2009-01-01

    We present theoretical results that show conversion of phase modulated signals to amplitude modulated signals in an SOA. Large-signal and small-signal calculations show significant conversion responses caused by even minute reflections at the end mirrors.......We present theoretical results that show conversion of phase modulated signals to amplitude modulated signals in an SOA. Large-signal and small-signal calculations show significant conversion responses caused by even minute reflections at the end mirrors....

  1. Mathematical properties of a semi-classical signal analysis method: Noisy signal case

    KAUST Repository

    Liu, Dayan

    2012-08-01

    Recently, a new signal analysis method based on a semi-classical approach has been proposed [1]. The main idea in this method is to interpret a signal as a potential of a Schrodinger operator and then to use the discrete spectrum of this operator to analyze the signal. In this paper, we are interested in a mathematical analysis of this method in discrete case considering noisy signals. © 2012 IEEE.

  2. Mischer zum Mischen eines Signals und Verfahren zum Mischen eines Signals

    OpenAIRE

    Wagner, C.; Stadali, H.

    2006-01-01

    DE1004059980 A UPAB: 20060714 NOVELTY - Mixer has first mixer (102) which is used to convert signal from actual frequency to intermediate frequency in order to obtain intermediate frequency signal (ZFS1A), based on first sampling frequency, spectral distance between intermediate frequency and the actual frequency depending on the first sampling frequency. DETAILED DESCRIPTION - Converting device (104) for converting intermediate frequency signal into converted intermediate frequency signal (Z...

  3. ROS and ROS-Mediated Cellular Signaling

    Directory of Open Access Journals (Sweden)

    Jixiang Zhang

    2016-01-01

    Full Text Available It has long been recognized that an increase of reactive oxygen species (ROS can modify the cell-signaling proteins and have functional consequences, which successively mediate pathological processes such as atherosclerosis, diabetes, unchecked growth, neurodegeneration, inflammation, and aging. While numerous articles have demonstrated the impacts of ROS on various signaling pathways and clarify the mechanism of action of cell-signaling proteins, their influence on the level of intracellular ROS, and their complex interactions among multiple ROS associated signaling pathways, the systemic summary is necessary. In this review paper, we particularly focus on the pattern of the generation and homeostasis of intracellular ROS, the mechanisms and targets of ROS impacting on cell-signaling proteins (NF-κB, MAPKs, Keap1-Nrf2-ARE, and PI3K-Akt, ion channels and transporters (Ca2+ and mPTP, and modifying protein kinase and Ubiquitination/Proteasome System.

  4. Presynaptic calcium signalling in cerebellar mossy fibres

    DEFF Research Database (Denmark)

    Thomsen, Louiza Bohn; Jörntell, Henrik; Midtgaard, Jens

    2010-01-01

    Whole-cell recordings were obtained from mossy fibre terminals in adult turtles in order to characterize the basic membrane properties. Calcium imaging of presynaptic calcium signals was carried out in order to analyse calcium dynamics and presynaptic GABA B inhibition. A tetrodotoxin (TTX....... Calcium imaging using Calcium-Green dextran revealed a stimulus-evoked all-or-none TTX-sensitive calcium signal in simple and complex rosettes. All compartments of a complex rosette were activated during electrical activation of the mossy fibre, while individual simple and complex rosettes along an axon...... appeared to be isolated from one another in terms of calcium signalling. CGP55845 application showed that GABA B receptors mediated presynaptic inhibition of the calcium signal over the entire firing frequency range of mossy fibres. A paired-pulse depression of the calcium signal lasting more than 1 s...

  5. Surface Electromyography Signal Processing and Classification Techniques

    Science.gov (United States)

    Chowdhury, Rubana H.; Reaz, Mamun B. I.; Ali, Mohd Alauddin Bin Mohd; Bakar, Ashrif A. A.; Chellappan, Kalaivani; Chang, Tae. G.

    2013-01-01

    Electromyography (EMG) signals are becoming increasingly important in many applications, including clinical/biomedical, prosthesis or rehabilitation devices, human machine interactions, and more. However, noisy EMG signals are the major hurdles to be overcome in order to achieve improved performance in the above applications. Detection, processing and classification analysis in electromyography (EMG) is very desirable because it allows a more standardized and precise evaluation of the neurophysiological, rehabitational and assistive technological findings. This paper reviews two prominent areas; first: the pre-processing method for eliminating possible artifacts via appropriate preparation at the time of recording EMG signals, and second: a brief explanation of the different methods for processing and classifying EMG signals. This study then compares the numerous methods of analyzing EMG signals, in terms of their performance. The crux of this paper is to review the most recent developments and research studies related to the issues mentioned above. PMID:24048337

  6. Neural network signal understanding for instrumentation

    DEFF Research Database (Denmark)

    Pau, L. F.; Johansen, F. S.

    1990-01-01

    A report is presented on the use of neural signal interpretation theory and techniques for the purpose of classifying the shapes of a set of instrumentation signals, in order to calibrate devices, diagnose anomalies, generate tuning/settings, and interpret the measurement results. Neural signal...... understanding research is surveyed, and the selected implementation and its performance in terms of correct classification rates and robustness to noise are described. Formal results on neural net training time and sensitivity to weights are given. A theory for neural control using functional link nets is given......, and an explanation facility designed to help neural signal understanding is described. The results are compared to those obtained with a knowledge-based signal interpretation system using the same instrument and data...

  7. Optimal signal patterns for dynamical cellular communication

    CERN Document Server

    Hasegawa, Yoshihiko

    2015-01-01

    Cells transmit information via signaling pathways, using temporal dynamical patterns. As optimality with respect to environments is the universal principle in biological systems, organisms have acquired an optimal way of transmitting information. Here we obtain optimal dynamical signal patterns which can transmit information efficiently (low power) and reliably (high accuracy) using the optimal control theory. Adopting an activation-inactivation decoding network, we reproduced several dynamical patterns found in actual signals, such as steep, gradual and overshooting dynamics. Notably, when minimizing the power of the input signal, optimal signals exhibit the overshooting pattern, which is a biphasic pattern with transient and steady phases; this pattern is prevalent in actual dynamical patterns as it can be generated by an incoherent feed-forward loop (FFL), a common motif in biochemical networks. We also identified conditions when the three patterns, steep, gradual and overshooting, confer advantages.

  8. Handbook of Signal Processing in Acoustics

    CERN Document Server

    Havelock, David; Vorländer, Michael

    2009-01-01

    The Handbook of Signal Processing in Acoustics presents signal processing as it is practiced in the field of acoustics. The Handbook is organized by areas of acoustics, with recognized leaders coordinating the self-contained chapters of each section. It brings together a wide range of perspectives from over 100 authors to reveal the interdisciplinary nature of signal processing in acoustics. Success in acoustic applications often requires juggling both the acoustic and the signal processing parameters of the problem. This handbook brings the key issues from both into perspective and is complementary to other reference material on the two subjects. It is a unique resource for experts and practitioners alike to find new ideas and techniques within the diversity of signal processing in acoustics.

  9. Adaptive Interference Cancellation of ECG Signals.

    Science.gov (United States)

    Ren, Aifeng; Du, Zhenxing; Li, Juan; Hu, Fangming; Yang, Xiaodong; Abbas, Haider

    2017-04-25

    As an important biological signal, electrocardiogram (ECG) signals provide a valuable basis for the clinical diagnosis and treatment of several diseases. However, its reference significance is based on the effective acquisition and correct recognition of ECG signals. In fact, this mV-level weak signal can be easily affected by various interferences caused by the power of magnetic field, patient respiratory motion or contraction, and so on from the sampling terminal to the receiving and display end. The overlapping interference affects the quality of ECG waveform, leading to the false detection and recognition of wave groups, and thus causing misdiagnosis or faulty treatment. Therefore, the elimination of the interference of the ECG signal and the subsequent wave group identification technology has been a hot research topic, and their study has important significance. Based on the above, this paper introduces two improved adaptive algorithms based on the classical least mean square (LMS) algorithm by introducing symbolic functions and block-processing concepts.

  10. Altered calcium signaling in cancer cells.

    Science.gov (United States)

    Stewart, Teneale A; Yapa, Kunsala T D S; Monteith, Gregory R

    2015-10-01

    It is the nature of the calcium signal, as determined by the coordinated activity of a suite of calcium channels, pumps, exchangers and binding proteins that ultimately guides a cell's fate. Deregulation of the calcium signal is often deleterious and has been linked to each of the 'cancer hallmarks'. Despite this, we do not yet have a full understanding of the remodeling of the calcium signal associated with cancer. Such an understanding could aid in guiding the development of therapies specifically targeting altered calcium signaling in cancer cells during tumorigenic progression. Findings from some of the studies that have assessed the remodeling of the calcium signal associated with tumorigenesis and/or processes important in invasion and metastasis are presented in this review. The potential of new methodologies is also discussed. This article is part of a Special Issue entitled: Membrane channels and transporters in cancers. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. One laser pulse generates two photoacoustic signals

    CERN Document Server

    Gao, Fei; Zheng, Yuanjin

    2016-01-01

    Photoacoustic sensing and imaging techniques have been studied widely to explore optical absorption contrast based on nanosecond laser illumination. In this paper, we report a long laser pulse induced dual photoacoustic (LDPA) nonlinear effect, which originates from unsatisfied stress and thermal confinements. Being different from conventional short laser pulse illumination, the proposed method utilizes a long square-profile laser pulse to induce dual photoacoustic signals. Without satisfying the stress confinement, the dual photoacoustic signals are generated following the positive and negative edges of the long laser pulse. More interestingly, the first expansion-induced photoacoustic signal exhibits positive waveform due to the initial sharp rising of temperature. On the contrary, the second contraction-induced photoacoustic signal exhibits exactly negative waveform due to the falling of temperature, as well as pulse-width-dependent, signal amplitude which is caused by the concurrent heat accumulation and ...

  12. Electronic devices for analog signal processing

    CERN Document Server

    Rybin, Yu K

    2012-01-01

    Electronic Devices for Analog Signal Processing is intended for engineers and post graduates and considers electronic devices applied to process analog signals in instrument making, automation, measurements, and other branches of technology. They perform various transformations of electrical signals: scaling, integration, logarithming, etc. The need in their deeper study is caused, on the one hand, by the extension of the forms of the input signal and increasing accuracy and performance of such devices, and on the other hand, new devices constantly emerge and are already widely used in practice, but no information about them are written in books on electronics. The basic approach of presenting the material in Electronic Devices for Analog Signal Processing can be formulated as follows: the study with help from self-education. While divided into seven chapters, each chapter contains theoretical material, examples of practical problems, questions and tests. The most difficult questions are marked by a diamon...

  13. Social knowledge and signals in primates.

    Science.gov (United States)

    Bergman, Thore J; Sheehan, Michael J

    2013-07-01

    Primates are notable for having a rich and detailed understanding of their social environment and there has been great interest in the evolution and function of social knowledge in primates. Indeed, primates have been shown to have impressive understandings of not only other group members but also the complex relationships among them. To be useful, however, social knowledge requires memories from previous encounters and observations about individual traits that are stable. Here, we argue that social systems or traits that make social knowledge more costly or less accurate will favor signals that either supplement or replace social knowledge. Thus, the relationship between signals and social knowledge can be complementary or antagonistic depending on the type of signal. Our goal in this review is to elucidate the relationships between signals and social knowledge in primates. We categorize signals into three types, each with different relationships to social knowledge. (1) Identity signals directly facilitate social knowledge, (2) current-state signals supplement information gained through social knowledge, and (3) badges of status replace social knowledge. Primates rely extensively on identity information, but it remains to be determined to what extent this is based on receiver perception of individual variation or senders using identity signals. Primates frequently utilize current-state signals including signals of intent to augment their interactions with familiar individuals. Badges of status are rare in primates, and the cases where they are used point to a functional and evolutionary trade-off between badges of status and social knowledge. However, the nature of this relationship needs further exploration. © 2012 Wiley Periodicals, Inc.

  14. Signals in Science - On the Importance of Signaling in Gaining Attention in Science

    NARCIS (Netherlands)

    H.P. van Dalen (Hendrik); K. Henkens

    2004-01-01

    textabstractWhich signals are important in gaining attention in science? For a group of 1,371 scientific articles published in 17 demography journals in the years 1990-1992 we track their influence and discern which signals are important in receiving citations. Three types of signals are examined:

  15. Ultra-high-speed optical signal processing of serial data signals

    DEFF Research Database (Denmark)

    Clausen, Anders; Mulvad, Hans Christian Hansen; Palushani, Evarist

    2012-01-01

    To ensure that ultra high-speed serial data signals can be utilised in future optical communication networks, it is indispensable to have all-optical signal processing elements at our disposal. In this paper, the most recent advances in our use of non-linear materials incorporated in different...... function blocks for high-speed signal processing are reviewed....

  16. All-optical signal processing of OTDM and OFDM signals based on time-domain Optical Fourier Transformation

    DEFF Research Database (Denmark)

    Clausen, Anders; Guan, Pengyu; Mulvad, Hans Christian Hansen

    2014-01-01

    All-optical time-domain Optical Fourier Transformation utilised for signal processing of ultra-high-speed OTDM signals and OFDM signals will be presented.......All-optical time-domain Optical Fourier Transformation utilised for signal processing of ultra-high-speed OTDM signals and OFDM signals will be presented....

  17. The Hedgehog Signal Induced Modulation of Bone Morphogenetic Protein Signaling: An Essential Signaling Relay for Urinary Tract Morphogenesis

    Science.gov (United States)

    Nakagata, Naomi; Miyagawa, Shinichi; Suzuki, Kentaro; Kitazawa, Sohei; Yamada, Gen

    2012-01-01

    Background Congenital diseases of the urinary tract are frequently observed in infants. Such diseases present a number of developmental anomalies such as hydroureter and hydronephrosis. Although some genetically-modified mouse models of growth factor signaling genes reproduce urinary phenotypes, the pathogenic mechanisms remain obscure. Previous studies suggest that a portion of the cells in the external genitalia and bladder are derived from peri-cloacal mesenchymal cells that receive Hedgehog (Hh) signaling in the early developmental stages. We hypothesized that defects in such progenitor cells, which give rise to urinary tract tissues, may be a cause of such diseases. Methodology/Principal Findings To elucidate the pathogenic mechanisms of upper urinary tract malformations, we analyzed a series of Sonic hedgehog (Shh) deficient mice. Shh−/− displayed hydroureter and hydronephrosis phenotypes and reduced expression of several developmental markers. In addition, we suggested that Shh modulation at an early embryonic stage is responsible for such phenotypes by analyzing the Shh conditional mutants. Tissue contribution assays of Hh-responsive cells revealed that peri-cloacal mesenchymal cells, which received Hh signal secreted from cloacal epithelium, could contribute to the ureteral mesenchyme. Gain- and loss-of-functional mutants for Hh signaling revealed a correlation between Hh signaling and Bone morphogenetic protein (Bmp) signaling. Finally, a conditional ablation of Bmp receptor type IA (BmprIA) gene was examined in Hh-responsive cell lineages. This system thus made it possible to analyze the primary functions of the growth factor signaling relay. The defective Hh-to-Bmp signaling relay resulted in severe urinary tract phenotypes with a decrease in the number of Hh-responsive cells. Conclusions/Significance This study identified the essential embryonic stages for the pathogenesis of urinary tract phenotypes. These results suggested that Hh

  18. Signal transduction during cold stress in plants.

    Science.gov (United States)

    Solanke, Amolkumar U; Sharma, Arun K

    2008-04-01

    Cold stress signal transduction is a complex process. Many physiological changes like tissue break down and senescence occur due to cold stress. Low temperature is initially perceived by plasma membrane either due to change in membrane fluidity or with the help of sensors like Ca(2+) permeable channels, histidine kinases, receptor kinases and phospholipases. Subsequently, cytoskeleton reorganization and cytosolic Ca(2+) influx takes place. Increase in cytosolic Ca(2+) is sensed by CDPKs, phosphatase and MAPKs, which transduce the signals to switch on transcriptional cascades. Photosynthetic apparatus have also been thought to be responsible for low temperature perception and signal transduction. Many cold induced pathways are activated to protect plants from deleterious effects of cold stress, but till date, most studied pathway is ICE-CBF-COR signaling pathway. However, the importance of CBF independent pathways in cold acclimation is supported by few Arabidopsis mutants' studies. Cold stress signaling has certain pathways common with other abiotic and biotic stress signaling which suggest cross-talks among these. Most of the economically important crops are sensitive to low temperature, but very few studies are available on cold susceptible crop plants. Therefore, it is necessary to understand signal transducing components from model plants and utilize that knowledge to improve survival of cold sensitive crop plants at low temperature.

  19. Context modulates signal meaning in primate communication

    Science.gov (United States)

    Flack, Jessica C.; de Waal, Frans

    2007-01-01

    A central issue in the evolution of social complexity and the evolution of communication concerns the capacity to communicate about increasingly abstract objects and concepts. Many animals can communicate about immediate behavior, but to date, none have been reported to communicate about behavior during future interactions. In this study, we show that a special, unidirectional, cost-free dominance-related signal used by monkeys (pigtailed macaques: Macaca nemestrina) means submission (immediate behavior) or subordination (pattern of behavior) depending on the context of usage. We hypothesize that to decrease receiver uncertainty that the signal object is subordination, senders shift contextual usage from the conflict context, where the signal evolved, to a peaceful one, in which submission is unwarranted. We predict and find that deceasing receiver uncertainty through peaceful signal exchange facilitates the development of higher quality social relationships: Individuals exchanging the peaceful variant groom and reconcile more frequently and fight less frequently than individuals exchanging signals only in the conflict context or no signals. We rule out alternative hypotheses, including an underlying reciprocity rule, temperament, and proximity effects. Our results suggest that primates can communicate about behavioral patterns when these concern relationship rules. The invention of signals decreasing uncertainty about relationship state is likely to have been critical for the evolution of social complexity and to the emergence of robust power structures that feed down to influence rapidly changing individual behavior. PMID:17244712

  20. Calibration of Galileo signals for time metrology.

    Science.gov (United States)

    Defraigne, Pascale; Aerts, Wim; Cerretto, Giancarlo; Cantoni, Elena; Sleewaegen, Jean-Marie

    2014-12-01

    Using global navigation satellite system (GNSS) signals for accurate timing and time transfer requires the knowledge of all electric delays of the signals inside the receiving system. GNSS stations dedicated to timing or time transfer are classically calibrated only for Global Positioning System (GPS) signals. This paper proposes a procedure to determine the hardware delays of a GNSS receiving station for Galileo signals, once the delays of the GPS signals are known. This approach makes use of the broadcast satellite inter-signal biases, and is based on the ionospheric delay measured from dual-frequency combinations of GPS and Galileo signals. The uncertainty on the so-determined hardware delays is estimated to 3.7 ns for each isolated code in the L5 frequency band, and 4.2 ns for the ionosphere-free combination of E1 with a code of the L5 frequency band. For the calibration of a time transfer link between two stations, another approach can be used, based on the difference between the common-view time transfer results obtained with calibrated GPS data and with uncalibrated Galileo data. It is shown that the results obtained with this approach or with the ionospheric method are equivalent.

  1. cAMP signaling in subcellular compartments.

    Science.gov (United States)

    Lefkimmiatis, Konstantinos; Zaccolo, Manuela

    2014-09-01

    In the complex microcosm of a cell, information security and its faithful transmission are critical for maintaining internal stability. To achieve a coordinated response of all its parts to any stimulus the cell must protect the information received from potentially confounding signals. Physical segregation of the information transmission chain ensures that only the entities able to perform the encoded task have access to the relevant information. The cAMP intracellular signaling pathway is an important system for signal transmission responsible for the ancestral 'flight or fight' response and involved in the control of critical functions including frequency and strength of heart contraction, energy metabolism and gene transcription. It is becoming increasingly apparent that the cAMP signaling pathway uses compartmentalization as a strategy for coordinating the large number of key cellular functions under its control. Spatial confinement allows the formation of cAMP signaling "hot spots" at discrete subcellular domains in response to specific stimuli, bringing the information in proximity to the relevant effectors and their recipients, thus achieving specificity of action. In this report we discuss how the different constituents of the cAMP pathway are targeted and participate in the formation of cAMP compartmentalized signaling events. We illustrate a few examples of localized cAMP signaling, with a particular focus on the nucleus, the sarcoplasmic reticulum and the mitochondria. Finally, we discuss the therapeutic potential of interventions designed to perturb specific cAMP cascades locally. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Role of Cardiolipin in Mitochondrial Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Jan Dudek

    2017-09-01

    Full Text Available The phospholipid cardiolipin (CL is an essential constituent of mitochondrial membranes and plays a role in many mitochondrial processes, including respiration and energy conversion. Pathological changes in CL amount or species composition can have deleterious consequences for mitochondrial function and trigger the production of reactive oxygen species. Signaling networks monitor mitochondrial function and trigger an adequate cellular response. Here, we summarize the role of CL in cellular signaling pathways and focus on tissues with high-energy demand, like the heart. CL itself was recently identified as a precursor for the formation of lipid mediators. We highlight the concept of CL as a signaling platform. CL is exposed to the outer mitochondrial membrane upon mitochondrial stress and CL domains serve as a binding site in many cellular signaling events. During mitophagy, CL interacts with essential players of mitophagy like Beclin 1 and recruits the autophagic machinery by its interaction with LC3. Apoptotic signaling pathways require CL as a binding platform to recruit apoptotic factors such as tBid, Bax, caspase-8. CL required for the activation of the inflammasome and plays a role in inflammatory signaling. As changes in CL species composition has been observed in many diseases, the signaling pathways described here may play a general role in pathology.

  3. Macroevolution of perfume signalling in orchid bees.

    Science.gov (United States)

    Weber, Marjorie G; Mitko, Lukasz; Eltz, Thomas; Ramírez, Santiago R

    2016-11-01

    Theory predicts that both stabilising selection and diversifying selection jointly contribute to the evolution of sexual signalling traits by (1) maintaining the integrity of communication signals within species and (2) promoting the diversification of traits among lineages. However, for many important signalling traits, little is known about whether these dynamics translate into predictable macroevolutionary signatures. Here, we test for macroevolutionary patterns consistent with sexual signalling theory in the perfume signals of neotropical orchid bees, a group well studied for their chemical sexual communication. Our results revealed both high species-specificity and elevated rates of evolution in perfume signals compared to nonsignalling traits. Perfume complexity was correlated with the number of congeners in a species' range, suggesting that perfume evolution may be tied to the remarkably high number of orchid bee species coexisting together in some neotropical communities. Finally, sister-pair comparisons were consistent with both rapid divergence at speciation and character displacement upon secondary contact. Together, our results provide new insight into the macroevolution of sexual signalling in insects. © 2016 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

  4. Signals and systems laboratory with Matlab

    CERN Document Server

    Palamides, Alex

    2010-01-01

    Introduction to MATLAB®Working EnvironmentGetting StartedMemory ManagementVectorsMatricesPlotting with MATLABComplex NumbersM-FilesInput-Output CommandsFile ManagementLogical-Relational OperatorsControl FlowSymbolic VariablesPolynomials(Pseudo)Random NumbersSignalsCategorization by the Variable TypeBasic Continuous-Time SignalsDiscrete-Time SignalsProperties of SignalsTransformations of the Time Variable for Continuous-Time SignalsTransformations of the Time Variable for Discrete-Time SignalsSystemsSystems ClassificationProperties of SystemsTime Domain System AnalysisImpulse ResponseContinuous Time Convolution Convolution PropertiesInterconnections of SystemsStabilityDiscrete-Time ConvolutionSystems Described by Difference EquationsFiltersStability Criterion for Discrete-Time SystemsSystems Described by Differential EquationsStep Response of a SystemFourier SeriesOrthogonality of Complex Exponential SignalsComplex Exponential Fourier SeriesTrigonometric Fourier SeriesFourier Series in the Cosine with Phase F...

  5. Signaling in the arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

    Harrison, Maria J

    2005-01-01

    Many microorganisms form symbioses with plants that range, on a continuous scale, from parasitic to mutualistic. Among these, the most widespread mutualistic symbiosis is the arbuscular mycorrhiza, formed between arbuscular mycorrhizal (AM) fungi and vascular flowering plants. These associations occur in terrestrial ecosystems throughout the world and have a global impact on plant phosphorus nutrition. The arbuscular mycorrhiza is an endosymbiosis in which the fungus inhabits the root cortical cells and obtains carbon provided by the plant while it transfers mineral nutrients from the soil to the cortical cells. Development of the symbiosis involves the differentiation of both symbionts to create novel symbiotic interfaces within the root cells. The aim of this review is to explore the current understanding of the signals and signaling pathways used by the symbionts for the development of the AM symbiosis. Although the signal molecules used for initial communication are not yet known, recent studies point to their existence. Within the plant, there is evidence of arbuscular mycorrhiza-specific signals and of systemic signaling that influences phosphate-starvation responses and root development. The landmark cloning of three plant signaling proteins required for the development of the symbiosis has provided the first insights into a signaling pathway that is used by AM fungi and by rhizobia for their symbiotic associations with legumes.

  6. Beta-Amyloid Impairs Reelin Signaling

    Science.gov (United States)

    Cuchillo-Ibáñez, Inmaculada; Balmaceda, Valeria; Botella-López, Arancha; Rabano, Alberto; Avila, Jesus; Sáez-Valero, Javier

    2013-01-01

    Reelin is a signaling protein increasingly associated with the pathogenesis of Alzheimer’s disease that relevantly modulates tau phosphorylation. We have previously demonstrated that β-amyloid peptide (Aβ) alters reelin expression. We have now attempted to determine whether abnormal reelin triggered by Aβ will result in signaling malfunction, contributing to the pathogenic process. Here, we show that reelin forms induced by β-amyloid are less capable of down-regulating tau phosphorylation via disabled-1 and GSK3β kinase. We also demonstrate that the scaffold protein 14-3-3 that increases tau phosphorylation by modulating GSK3β activity, is up-regulated during defective reelin signaling. Binding of reelin to its receptor, mainly ApoER2 in the brain, relays the signal into the cell. We associate the impaired reelin signaling with inefficiency of reelin in forming active homodimers and decreased ability to bind efficiently to its receptor, ApoER2. More remarkably, reelin from Alzheimer cortex shows a tendency to form large complexes instead of homodimers, the active form for signaling. Our results suggest that reelin expression is altered by Aβ leading to impaired reelin signaling. PMID:23951306

  7. Glutamate signalling in healthy and diseased bone

    Directory of Open Access Journals (Sweden)

    Robert W. Cowan

    2012-07-01

    Full Text Available Bone relies on multiple extracellular signalling systems to maintain homeostasis of its normal structure and functions. The amino acid glutamate is a fundamental extracellular messenger molecule in many tissues, and is used in bone for both neural and non-neural signalling. This review focuses on the non-neural interactions, and examines the evolutionarily ancient glutamate signalling system in the context of its application to normal bone functioning and discusses recent findings on the role of glutamate signalling as they pertain to maintaining healthy bone structure. The underlying mechanisms of glutamate signalling and the many roles glutamate plays in modulating bone physiology are featured, including those involved in osteoclast and osteoblast differentiation and mature cell functions. Moreover, the relevance of glutamate signalling systems in diseases that affect bone, such as cancer and rheumatoid arthritis, is discussed, and will highlight how the glutamate system may be exploited as a viable therapeutic target. We will identify novel areas of research where knowledge of glutamate communication mechanisms may aid in our understanding of the complex nature of bone homeostasis. By uncovering the contributions of glutamate in maintaining healthy bone, the reader will discover how this complex molecular signalling system may advance our capacity to treat bone pathologies.

  8. Wnt signalling pathway parameters for mammalian cells.

    Directory of Open Access Journals (Sweden)

    Chin Wee Tan

    Full Text Available Wnt/β-catenin signalling regulates cell fate, survival, proliferation and differentiation at many stages of mammalian development and pathology. Mutations of two key proteins in the pathway, APC and β-catenin, have been implicated in a range of cancers, including colorectal cancer. Activation of Wnt signalling has been associated with the stabilization and nuclear accumulation of β-catenin and consequential up-regulation of β-catenin/TCF gene transcription. In 2003, Lee et al. constructed a computational model of Wnt signalling supported by experimental data from analysis of time-dependent concentration of Wnt signalling proteins in Xenopus egg extracts. Subsequent studies have used the Xenopus quantitative data to infer Wnt pathway dynamics in other systems. As a basis for understanding Wnt signalling in mammalian cells, a confocal live cell imaging measurement technique is developed to measure the cell and nuclear volumes of MDCK, HEK293T cells and 3 human colorectal cancer cell lines and the concentrations of Wnt signalling proteins β-catenin, Axin, APC, GSK3β and E-cadherin. These parameters provide the basis for formulating Wnt signalling models for kidney/intestinal epithelial mammalian cells. There are significant differences in concentrations of key proteins between Xenopus extracts and mammalian whole cell lysates. Higher concentrations of Axin and lower concentrations of APC are present in mammalian cells. Axin concentrations are greater than APC in kidney epithelial cells, whereas in intestinal epithelial cells the APC concentration is higher than Axin. Computational simulations based on Lee's model, with this new data, suggest a need for a recalibration of the model.A quantitative understanding of Wnt signalling in mammalian cells, in particular human colorectal cancers requires a detailed understanding of the concentrations of key protein complexes over time. Simulations of Wnt signalling in mammalian cells can be initiated

  9. Sparse Signal Representations of Bearing Fault Signals for Exhibiting Bearing Fault Features

    Directory of Open Access Journals (Sweden)

    Wei Peng

    2016-01-01

    Full Text Available Sparse signal representations attract much attention in the community of signal processing because only a few coefficients are required to represent a signal and these coefficients make the signal understandable. For bearing faults’ diagnosis, bearing faults signals collected from transducers are often overwhelmed by strong low-frequency periodic signals and heavy noises. In this paper, a joint signal processing method is proposed to extract sparse envelope coefficients, which are the sparse signal representations of bearing fault signals. Firstly, to enhance bearing fault signals, particle swarm optimization is introduced to tune the parameters of wavelet transform and the optimal wavelet transform is used for retaining one of the resonant frequency bands. Thus, sparse wavelet coefficients are obtained. Secondly, to reduce the in-band noises existing in the sparse wavelet coefficients, an adaptive morphological analysis with an iterative local maximum detection method is developed to extract sparse envelope coefficients. Simulated and real bearing fault signals are investigated to illustrate how the sparse envelope coefficients are extracted. The results show that the sparse envelope coefficients can be used to represent bearing fault features and identify different localized bearing faults.

  10. Quaternion-Based Signal Analysis for Motor Imagery Classification from Electroencephalographic Signals

    Science.gov (United States)

    Batres-Mendoza, Patricia; Montoro-Sanjose, Carlos R.; Guerra-Hernandez, Erick I.; Almanza-Ojeda, Dora L.; Rostro-Gonzalez, Horacio; Romero-Troncoso, Rene J.; Ibarra-Manzano, Mario A.

    2016-01-01

    Quaternions can be used as an alternative to model the fundamental patterns of electroencephalographic (EEG) signals in the time domain. Thus, this article presents a new quaternion-based technique known as quaternion-based signal analysis (QSA) to represent EEG signals obtained using a brain-computer interface (BCI) device to detect and interpret cognitive activity. This quaternion-based signal analysis technique can extract features to represent brain activity related to motor imagery accurately in various mental states. Experimental tests in which users where shown visual graphical cues related to left and right movements were used to collect BCI-recorded signals. These signals were then classified using decision trees (DT), support vector machine (SVM) and k-nearest neighbor (KNN) techniques. The quantitative analysis of the classifiers demonstrates that this technique can be used as an alternative in the EEG-signal modeling phase to identify mental states. PMID:26959029

  11. Quaternion-Based Signal Analysis for Motor Imagery Classification from Electroencephalographic Signals.

    Science.gov (United States)

    Batres-Mendoza, Patricia; Montoro-Sanjose, Carlos R; Guerra-Hernandez, Erick I; Almanza-Ojeda, Dora L; Rostro-Gonzalez, Horacio; Romero-Troncoso, Rene J; Ibarra-Manzano, Mario A

    2016-03-05

    Quaternions can be used as an alternative to model the fundamental patterns of electroencephalographic (EEG) signals in the time domain. Thus, this article presents a new quaternion-based technique known as quaternion-based signal analysis (QSA) to represent EEG signals obtained using a brain-computer interface (BCI) device to detect and interpret cognitive activity. This quaternion-based signal analysis technique can extract features to represent brain activity related to motor imagery accurately in various mental states. Experimental tests in which users where shown visual graphical cues related to left and right movements were used to collect BCI-recorded signals. These signals were then classified using decision trees (DT), support vector machine (SVM) and k-nearest neighbor (KNN) techniques. The quantitative analysis of the classifiers demonstrates that this technique can be used as an alternative in the EEG-signal modeling phase to identify mental states.

  12. Investigation of All-photonic Multiple Signals Format Converter to Carrier- suppressed Signals

    Directory of Open Access Journals (Sweden)

    Khairuddin N.Z.

    2016-01-01

    Full Text Available Advance modulation format such as carrier suppressed return to zero (CSRZ is used in several optical communication systems. The generation of CSRZ signal is reported in this paper by means of allphotonics format converter to its suppressed carrier signal. It examines five photonics signals of NRZ, RZ, CRZ, soliton and duobinary. All formats are successfully converted to the carrier suppressed return to zero, CSRZ. The converter utilizes the semiconductor optical amplifier in a loop mirror and the control signal which is typically at ten times higher than the input signals. The suppressed signal can reduce the peak power alteration in the transmission. It also minimizes the nonlinear effects due to unavailability of the peak carrier. The CSRZ in the WDM system with 4 and 8 channels shows soliton as the best suppressed signal within selected parameters.

  13. MAPK cascade signalling networks in plant defence.

    Science.gov (United States)

    Pitzschke, Andrea; Schikora, Adam; Hirt, Heribert

    2009-08-01

    The sensing of stress signals and their transduction into appropriate responses is crucial for the adaptation and survival of plants. Kinase cascades of the mitogen-activated protein kinase (MAPK) class play a remarkably important role in plant signalling of a variety of abiotic and biotic stresses. MAPK cascade-mediated signalling is an essential step in the establishment of resistance to pathogens. Here, we describe the most recent insights into MAPK-mediated pathogen defence response regulation with a particular focus on the cascades involving MPK3, MPK4 and MPK6. We also discuss the strategies developed by plant pathogens to circumvent, inactivate or even 'hijack' MAPK-mediated defence responses.

  14. Optical Profilometers Using Adaptive Signal Processing

    Science.gov (United States)

    Hall, Gregory A.; Youngquist, Robert; Mikhael, Wasfy

    2006-01-01

    A method of adaptive signal processing has been proposed as the basis of a new generation of interferometric optical profilometers for measuring surfaces. The proposed profilometers would be portable, hand-held units. Sizes could be thus reduced because the adaptive-signal-processing method would make it possible to substitute lower-power coherent light sources (e.g., laser diodes) for white light sources and would eliminate the need for most of the optical components of current white-light profilometers. The adaptive-signal-processing method would make it possible to attain scanning ranges of the order of decimeters in the proposed profilometers.

  15. Peptide signalling during angiosperm seed development.

    Science.gov (United States)

    Ingram, Gwyneth; Gutierrez-Marcos, Jose

    2015-08-01

    Cell-cell communication is pivotal for the coordination of various features of plant development. Recent studies in plants have revealed that, as in animals, secreted signal peptides play critical roles during reproduction. However, the precise signalling mechanisms in plants are not well understood. In this review, we discuss the known and putative roles of secreted peptides present in the seeds of angiosperms as key signalling factors involved in coordinating different aspects of seed development. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  16. Calcium Signaling Is Required for Erythroid Enucleation.

    Directory of Open Access Journals (Sweden)

    Christina B Wölwer

    Full Text Available Although erythroid enucleation, the property of erythroblasts to expel their nucleus, has been known for 7ore than a century, surprisingly little is known regarding the molecular mechanisms governing this unique developmental process. Here we show that similar to cytokinesis, nuclear extrusion requires intracellular calcium signaling and signal transduction through the calmodulin (CaM pathway. However, in contrast to cytokinesis we found that orthochromatic erythroblasts require uptake of extracellular calcium to enucleate. Together these functional studies highlight a critical role for calcium signaling in the regulation of erythroid enucleation.

  17. Advances in heuristic signal processing and applications

    CERN Document Server

    Chatterjee, Amitava; Siarry, Patrick

    2013-01-01

    There have been significant developments in the design and application of algorithms for both one-dimensional signal processing and multidimensional signal processing, namely image and video processing, with the recent focus changing from a step-by-step procedure of designing the algorithm first and following up with in-depth analysis and performance improvement to instead applying heuristic-based methods to solve signal-processing problems. In this book the contributing authors demonstrate both general-purpose algorithms and those aimed at solving specialized application problems, with a spec

  18. Knee joint vibroarthrographic signal processing and analysis

    CERN Document Server

    Wu, Yunfeng

    2015-01-01

    This book presents the cutting-edge technologies of knee joint vibroarthrographic signal analysis for the screening and detection of knee joint injuries. It describes a number of effective computer-aided methods for analysis of the nonlinear and nonstationary biomedical signals generated by complex physiological mechanics. This book also introduces several popular machine learning and pattern recognition algorithms for biomedical signal classifications. The book is well-suited for all researchers looking to better understand knee joint biomechanics and the advanced technology for vibration arthrometry. Dr. Yunfeng Wu is an Associate Professor at the School of Information Science and Technology, Xiamen University, Xiamen, Fujian, China.

  19. Signal processing in noise waveform radar

    CERN Document Server

    Kulpa, Krzysztof

    2013-01-01

    This book is devoted to the emerging technology of noise waveform radar and its signal processing aspects. It is a new kind of radar, which use noise-like waveform to illuminate the target. The book includes an introduction to basic radar theory, starting from classical pulse radar, signal compression, and wave radar. The book then discusses the properties, difficulties and potential of noise radar systems, primarily for low-power and short-range civil applications. The contribution of modern signal processing techniques to making noise radar practical are emphasized, and application examples

  20. Modelling ECG signals with hidden Markov models.

    Science.gov (United States)

    Koski, A

    1996-10-01

    In this paper, we have studied the use of continuous probability density function hidden Markov models for the ECG signal analysis problem. Our previous work has focused on syntactic pattern recognition methods in signal processing. Hidden Markov model is basically a non-deterministic probabilistic finite state machine, which can be constructed inductively. It has been widely used in speech recognition and DNA modelling. We have found that hidden Markov models are very suitable for ECG recognition and analysis problems and that they are able to model accurately segmented ECG signals.

  1. Reconstruction of periodic signals using neural networks

    Directory of Open Access Journals (Sweden)

    José Danilo Rairán Antolines

    2014-01-01

    Full Text Available In this paper, we reconstruct a periodic signal by using two neural networks. The first network is trained to approximate the period of a signal, and the second network estimates the corresponding coefficients of the signal's Fourier expansion. The reconstruction strategy consists in minimizing the mean-square error via backpro-pagation algorithms over a single neuron with a sine transfer function. Additionally, this paper presents mathematical proof about the quality of the approximation as well as a first modification of the algorithm, which requires less data to reach the same estimation; thus making the algorithm suitable for real-time implementations.

  2. Endocannabinoid signaling in reward and addiction

    Science.gov (United States)

    Parsons, Loren H.; Hurd, Yasmin L.

    2015-01-01

    Brain endocannabinoid signaling influences the motivation for natural rewards (such as palatable food, sexual activity and social interaction) and modulates the rewarding effects of addictive drugs. Pathological forms of natural and drug-induced reward are associated with dysregulated endocannabinoid signaling that may derive from pre-existing genetic factors or from prolonged drug exposure. Impaired endocannabinoid signaling contributes to dysregulated synaptic plasticity, increased stress responsivity, negative emotional states, and craving that propel addiction. Understanding the contributions of endocannabinoid disruptions to behavioral and physiological traits provides insight into the endocannabinoid influence on addiction vulnerability. PMID:26373473

  3. Analog and mixed-signal electronics

    CERN Document Server

    Stephan, Karl

    2015-01-01

    A practical guide to analog and mixed-signal electronics, with an emphasis on design problems and applications This book provides an in-depth coverage of essential analog and mixed-signal topics such as power amplifiers, active filters, noise and dynamic range, analog-to-digital and digital-to-analog conversion techniques, phase-locked loops, and switching power supplies. Readers will learn the basics of linear systems, types of nonlinearities and their effects, op-amp circuits, the high-gain analog filter-amplifier, and signal generation. The author uses system design examples to motivate

  4. Microwave signal processing with photorefractive dynamic holography

    Science.gov (United States)

    Fotheringham, Edeline B.

    Have you ever found yourself listening to the music playing from the closest stereo rather than to the bromidic (uninspiring) person speaking to you? Your ears receive information from two sources but your brain listens to only one. What if your cell phone could distinguish among signals sharing the same bandwidth too? There would be no "full" channels to stop you from placing or receiving a call. This thesis presents a nonlinear optical circuit capable of distinguishing uncorrelated signals that have overlapping temporal bandwidths. This so called autotuning filter is the size of a U.S. quarter dollar and requires less than 3 mW of optical power to operate. It is basically an oscillator in which the losses are compensated with dynamic holographic gain. The combination of two photorefractive crystals in the resonator governs the filter's winner-take-all dynamics through signal-competition for gain. This physical circuit extracts what is mathematically referred to as the largest principal component of its spatio-temporal input space. The circuit's practicality is demonstrated by its incorporation in an RF-photonic system. An unknown mixture of unknown microwave signals, received by an antenna array, constitutes the input to the system. The output electronically returns one of the original microwave signals. The front-end of the system down converts the 10 GHz microwave signals and amplifies them before the signals phase modulate optical beams. The optical carrier is suppressed from these beams so that it may not be considered as a signal itself to the autotuning filter. The suppression is achieved with two-beam coupling in a single photorefractive crystal. The filter extracts the more intense of the signals present on the carrier-suppressed input beams. The detection of the extracted signal restores the microwave signal to an electronic form. The system, without the receiving antenna array, is packaged in a 13 x 18 x 6″ briefcase. Its power consumption equals that

  5. Introduction to the concept of signal toxicity.

    Science.gov (United States)

    Kanno, Jun

    2016-01-01

    Silent Spring by Rachel Carson (1962) established a role for environmental chemicals in cancer and Our Stolen Future by Theo Colbone, Dianne Dumanoski and John Peterson Myers (1996) coined the concept of "Endocrine Disrupting Chemicals (EDCs)" with its mechanistic plausibility for all the living organisms. For basic biologists, seeing a non-monotonic dose-response curve was a matter of course. In contrast, for the toxicologists at that time, the dose-response curves should be monotonic. It took some time for toxicologists to accept the plausibility that animals and humans are subject to the effects of EDCs act in a way that is explained by the new paradigm of receptor-mediated toxicity or in other words "signal toxicity." In classical toxicology, a toxic substance reaches a cellular target and induces malfunction. The target molecules are proteins including enzymes, lipid membranes, DNA, and other components of the cell which are damaged by the toxic substances. On the other hand, in the case of signal toxicity, a chemical binds to a specific receptor - after that, the chemical itself is not important. The signal from the receptor initiates a cascade of molecular events that leads to various changes in the cells and organs. When the signal is abnormal for a cell or an organ in terms of quality, intensity and timing, then the signal will induce adverse effects to the target. An extreme example of signal toxicity is the 1981 Nobel Prize in Physiology or Medicine work by Drs. Hubel and Wiesel. They blocked the signal of sharp images from the retina to the brain and found that the visual cortex needed this signal at the correct time for its proper development. In humans, such signal disruption is well known to induce "form-deprivation amblyopia" in infants. The concept of signal toxicity widens the range of systems vulnerable to EDCs and facilitates the understanding of their biological characteristics. For example, compared with intrinsic ligands, xenobiotic chemicals

  6. The role of transforming growth factor-beta (TGF-beta during ovarian follicular development in sheep

    Directory of Open Access Journals (Sweden)

    Quirke Laurel D

    2004-11-01

    Full Text Available Abstract Background Recently, several members of the transforming growth factor-beta (TGF-beta superfamily have been shown to be essential for regulating the growth and differentiation of ovarian follicles and thus fertility. Methods Ovaries of neonatal and adult sheep were examined for expression of the TGF-betas 1–3 and their receptors (RI and RII by in situ hybridization using ovine cDNAs. The effects of TGF-beta 1 and 2 on proliferation and differentiation of ovine granulosa cells in vitro were also studied. Results The expression patterns of TGF-beta 1 and 2 were similar in that both mRNAs were first observed in thecal cells of type 3 (small pre-antral follicles. Expression of both mRNAs continued to be observed in the theca of larger follicles and was also present in cells within the stroma and associated with the vascular system of the ovary. There was no evidence for expression in granulosa cells or oocytes. Expression of TGF-beta 3 mRNA was limited to cells associated with the vascular system within the ovary. TGFbetaRI mRNA was observed in oocytes from the type 1 (primordial to type 5 (antral stages of follicular growth and granulosa and thecal cells expressed this mRNA at the type 3 (small pre-antral and subsequent stages of development. The TGFbetaRI signal was also observed in the ovarian stroma and vascular cells. In ovarian follicles, mRNA encoding TGFbetaRII was restricted to thecal cells of type 3 (small pre-antral and larger follicles. In addition, expression was also observed in some cells of the surface epithelium and in some stromal cells. In granulosa cells cultured for 6 days, both TGF-beta 1 and 2 decreased, in a dose dependent manner, both the amount of DNA and concentration of progesterone. Conclusion In summary, mRNA encoding both TGF-beta 1 and 2 were synthesized by ovarian theca, stroma and cells of the vascular system whereas TGF-beta 3 mRNA was synthesized by vascular cells. Luteinizing granulosa cells also

  7. Behavioral ecology, endocrinology and signal reliability of electric communication

    Science.gov (United States)

    Gavassa, Sat; Goldina, Anna; Silva, Ana C.; Stoddard, Philip K.

    2013-01-01

    Summary The balance between the costs and benefits of conspicuous animal communication signals ensures that signal expression relates to the quality of the bearer. Signal plasticity enables males to enhance conspicuous signals to impress mates and competitors and to reduce signal expression to lower energetic and predation-related signaling costs when competition is low. While signal plasticity may benefit the signaler, it can compromise the reliability of the information conveyed by the signals. In this paper we review the effect of signal plasticity on the reliability of the electrocommunication signal of the gymnotiform fish Brachyhypopomus gauderio. We (1) summarize the endocrine regulation of signal plasticity, (2) explore the regulation of signal plasticity in females, (3) examine the information conveyed by the signal, (4) show how that information changes when the signal changes, and (5) consider the energetic strategies used to sustain expensive signaling. The electric organ discharge (EOD) of B. gauderio changes in response to social environment on two time scales. Two hormone classes, melanocortins and androgens, underlie the short-term and long-term modulation of signal amplitude and duration observed during social interaction. Population density drives signal amplitude enhancement, unexpectedly improving the reliability with which the signal predicts the signaler's size. The signal's second phase elongation predicts androgen levels and male reproductive condition. Males sustain signal enhancement with dietary intake, but when food is limited, they ‘go for broke’ and put extra energy into electric signals. Cortisol diminishes EOD parameters, but energy-limited males offset cortisol effects by boosting androgen levels. While physiological constraints are sufficient to maintain signal amplitude reliability, phenotypic integration and signaling costs maintain reliability of signal duration, consistent with theory of honest signaling. PMID:23761465

  8. Primary Cilia, Signaling Networks and Cell Migration

    DEFF Research Database (Denmark)

    Veland, Iben Rønn

    on formation of the primary cilium and CDE at the pocket region. The ciliary protein Inversin functions as a molecular switch between canonical and non-canonical Wnt signaling. In paper II, we show that Inversin and the primary cilium control Wnt signaling and are required for polarization and cell migration....... A number of central Wnt components localize to the fibroblast primary cilium, including the Wnt5a-receptor, Fzd3, and Dvl proteins. Inversin-deficient MEFs have an elevated expression of canonical Wnt-associated genes and proteins, in addition to dysregulation of components in non-canonical Wnt signaling......, which leads to uncontrolled cell movements. Together, the results obtained from my PhD studies reflect the high level of complexity within signaling systems regulated by the primary cilium that control cellular processes during embryonic development and in tissue homeostasis. As such, this dissertation...

  9. Prerequisites for affective signal processing (ASP)

    NARCIS (Netherlands)

    van den Broek, Egon; Janssen, Joris H.; Westerink, Joyce H.D.M.; Healey, Jennifer A.; Encarnacao, P.; Veloso, A.

    2009-01-01

    Although emotions are embraced by science, their recognition has not reached a satisfying level. Through a concise overview of affect, its signals, features, and classification methods, we provide understanding for the problems encountered. Next, we identify the prerequisites for successful

  10. Adaptive Noise Suppression Using Digital Signal Processing

    Science.gov (United States)

    Kozel, David; Nelson, Richard

    1996-01-01

    A signal to noise ratio dependent adaptive spectral subtraction algorithm is developed to eliminate noise from noise corrupted speech signals. The algorithm determines the signal to noise ratio and adjusts the spectral subtraction proportion appropriately. After spectra subtraction low amplitude signals are squelched. A single microphone is used to obtain both eh noise corrupted speech and the average noise estimate. This is done by determining if the frame of data being sampled is a voiced or unvoiced frame. During unvoice frames an estimate of the noise is obtained. A running average of the noise is used to approximate the expected value of the noise. Applications include the emergency egress vehicle and the crawler transporter.

  11. Intelligent Multimodal Signal Adaptation System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Micro Analysis and Design (MA&D) is pleased to submit this proposal to design an Intelligent Multimodal Signal Adaptation System. This system will dynamically...

  12. Signal processing and display for electrochemical data

    Science.gov (United States)

    Young, R. N.; Wilkins, J. R.

    1977-01-01

    Two electrochemical electrodes provide signals; apparatus automatically determines reaction end point and displays lag period in time or cell concentration. Apparatus can be used with standard pH reference anode and platinum anode or with redox electrodes.

  13. Statistical Challenges in Modeling Big Brain Signals

    KAUST Repository

    Yu, Zhaoxia

    2017-11-01

    Brain signal data are inherently big: massive in amount, complex in structure, and high in dimensions. These characteristics impose great challenges for statistical inference and learning. Here we review several key challenges, discuss possible solutions, and highlight future research directions.

  14. Statistical Challenges in Modeling Big Brain Signals

    OpenAIRE

    Yu, Zhaoxia; Pluta, Dustin; Shen, Tong; Chen, Chuansheng; Xue, Gui; Ombao, Hernando

    2017-01-01

    Brain signal data are inherently big: massive in amount, complex in structure, and high in dimensions. These characteristics impose great challenges for statistical inference and learning. Here we review several key challenges, discuss possible solutions, and highlight future research directions.

  15. Hydrogen sulfide and polysulfides as signaling molecules

    National Research Council Canada - National Science Library

    KIMURA, Hideo

    2015-01-01

    .... Polysulfides, which have a higher number of inner sulfur atoms than that in H2S, were recently identified as potential signaling molecules that can activate ion channels, transcription factors...

  16. Oscillometric blood pressure measurements: A signal analysis

    Science.gov (United States)

    Barbé, K.; Van Moer, W.; Lauwers, L.

    2010-07-01

    In this paper, the oscillometric waveform measured by automatic non-invasive blood pressure meters (NIBP) is analyzed by transforming the data from the time domain to the frequency domain. The signal's spectrum of the oscillometric waveform is in current literature badly understood or explored. The only known link between the oscillometric waveform and the blood pressure is the maximum of the oscillometry's envelope equalling the mean arterial pressure (MAP). This link is established under the assumption that the oscillometry is an AM-signal. Unfortunately, computing the MAP is difficult in practice due to the non-sinusoidal nature of the actual measured signals. In this paper, we construct the best AM-signal approximation of the oscillometry and explore its use to compute the MAP.

  17. Primary Cilia, Signaling Networks and Cell Migration

    DEFF Research Database (Denmark)

    Veland, Iben Rønn

    composition of receptors and signal components in the cilium to regulate cellular processes such as transcriptional control or cytoskeletal reorganization. This dissertation focuses on selected signaling systems regulated by the primary cilium, including the PDGFRα, TGFβ and Wnt pathways, and how......, which leads to uncontrolled cell movements. Together, the results obtained from my PhD studies reflect the high level of complexity within signaling systems regulated by the primary cilium that control cellular processes during embryonic development and in tissue homeostasis. As such, this dissertation......-dependent regulation of signal transduction. Upon ligand-binding and activation in the cilium, TGFβ receptors accumulate and are internalized at the ciliary base together with Smad2/3 transcription factors that are phosphorylated here and translocated to the nucleus for target gene expression. These processes depend...

  18. Extracellular signaling and multicellularity in Bacillus subtilis.

    Science.gov (United States)

    Shank, Elizabeth Anne; Kolter, Roberto

    2011-12-01

    Bacillus subtilis regulates its ability to differentiate into distinct, co-existing cell types in response to extracellular signaling molecules produced either by itself, or present in its environment. The production of molecules by B. subtilis cells, as well as their response to these signals, is not uniform across the population. There is specificity and heterogeneity both within genetically identical populations as well as at the strain-level and species-level. This review will discuss how extracellular signaling compounds influence B. subtilis multicellularity with regard to matrix-producing cannibal differentiation, germination, and swarming behavior, as well as the specificity of the quorum-sensing peptides ComX and CSF. It will also highlight how imaging mass spectrometry can aid in identifying signaling compounds and contribute to our understanding of the functional relationship between such compounds and multicellular behavior. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Controlling Signal Transduction with Synthetic Ligands

    Science.gov (United States)

    Spencer, David M.; Wandless, Thomas J.; Schreiber, Stuart L.; Crabtree, Gerald R.

    1993-11-01

    Dimerization and oligomerization are general biological control mechanisms contributing to the activation of cell membrane receptors, transcription factors, vesicle fusion proteins, and other classes of intra- and extracellular proteins. Cell permeable, synthetic ligands were devised that can be used to control the intracellular oligomerization of specific proteins. To demonstrate their utility, these ligands were used to reduce intracellular oligomerization of cell surface receptors that lacked their transmembrane and extracellular regions but contained intracellular signaling domains. Addition of these ligands to cells in culture resulted in signal transmission and specific target gene activation. Monomeric forms of the ligands blocked the pathway. This method of ligandregulated activation and termination of signaling pathways has the potential to be applied wherever precise control of a signal transduction pathway is desired.

  20. Signal Analysis for Radiation Event Identification

    Energy Technology Data Exchange (ETDEWEB)

    Steven A. Wallace

    2004-12-30

    The method of digitizing the scintillation output signals from a lithiated sol-gel based glass is described. The design considerations for using the lithiated scintillator for the detection of Special Nuclear Material (SNM) is presented.