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Sample records for cellular scf complex

  1. Simian Virus 40 Large T Antigen's Association with the CUL7 SCF Complex Contributes to Cellular Transformation

    OpenAIRE

    Kasper, Jocelyn S.; Kuwabara, Hiroshi; Arai, Takehiro; Ali, Syed Hamid; DeCaprio, James A.

    2005-01-01

    Simian virus 40 large T antigen (T Ag) is capable of immortalizing and transforming rodent cells. The transforming activity of T Ag is due in large part to perturbation of the tumor suppressor proteins p53 and the retinoblastoma (pRB) family members. Inactivation of these tumor suppressors may not be sufficient for T Ag-mediated cellular transformation. It has been shown that T Ag associates with an SCF-like complex that contains a member of the cullin family of E3 ubiquitin ligases, CUL7, as...

  2. Simian virus 40 large T antigen's association with the CUL7 SCF complex contributes to cellular transformation.

    Science.gov (United States)

    Kasper, Jocelyn S; Kuwabara, Hiroshi; Arai, Takehiro; Ali, Syed Hamid; DeCaprio, James A

    2005-09-01

    Simian virus 40 large T antigen (T Ag) is capable of immortalizing and transforming rodent cells. The transforming activity of T Ag is due in large part to perturbation of the tumor suppressor proteins p53 and the retinoblastoma (pRB) family members. Inactivation of these tumor suppressors may not be sufficient for T Ag-mediated cellular transformation. It has been shown that T Ag associates with an SCF-like complex that contains a member of the cullin family of E3 ubiquitin ligases, CUL7, as well as SKP1, RBX1, and an F-box protein, FBXW8. We identified T Ag residues 69 to 83 as required for T Ag binding to the CUL7 complex. We demonstrate that delta69-83 T Ag, while it lost its ability to associate with CUL7, retained binding to p53 and pRB family members. In the presence of CUL7, wild-type (WT) T Ag but not delta69-83 T Ag was able to induce proliferation of mouse embryo fibroblasts, an indication of cellular transformation. In contrast, WT and delta69-83 T Ag enabled mouse embryo fibroblasts to proliferate to similarly high densities in the absence of CUL7. Our data suggest that, in addition to p53 and the pRB family members, T Ag serves to bind to and inactivate the growth-suppressing properties of CUL7. In addition, these results imply that, at least in the presence of T Ag, CUL7 may function as a tumor suppressor. PMID:16140746

  3. MNF, an ankyrin repeat protein of myxoma virus, is part of a native cellular SCF complex during viral infection

    Directory of Open Access Journals (Sweden)

    Gelfi Jacqueline

    2010-03-01

    Full Text Available Abstract Myxoma virus (MYXV, a member of the Poxviridae family, is the agent responsible for myxomatosis, a fatal disease in the European rabbit (Oryctolagus cuniculus. Like all poxviruses, MYXV is known for encoding multiple proteins that regulate cellular signaling pathways. Among them, four proteins share the same ANK/PRANC structure: M148R, M149R, MNF (Myxoma Nuclear factor and M-T5, all of them described as virulence factors. This family of poxvirus proteins, recently identified, has drawn considerable attention for its potential role in modulating the host ubiquitin-proteasome system during viral infection. To date, many members of this novel protein family have been shown to interact with SCF components, in vitro. Here, we focus on MNF gene, which has been shown to express a nuclear protein presenting nine ANK repeats, one of which has been identified as a nuclear localization signal. In transfection, MNF has been shown to colocalise with the transcription factor NF-κB in the nucleus of TNFα-stimulated cells. Functionally, MNF is a critical virulence factor since its deletion generates an almost apathogenic virus. In this study, to pursue the investigation of proteins interacting with MNF and of its mechanism of action, we engineered a recombinant MYXV expressing a GFP-linked MNF under the control of MNF native promoter. Infection of rabbits with MYXV-GFPMNF recombinant virus provided the evidence that the GFP fusion does not disturb the main function of MNF. Hence, cells were infected with MYXV-GFPMNF and immunoprecipitation of the GFPMNF fusion protein was performed to identify MNF's partners. For the first time, endogenous components of SCF (Cullin-1 and Skp1 were co-precipitated with an ANK myxoma virus protein, expressed in an infectious context, and without over-expression of any protein.

  4. MNF, an ankyrin repeat protein of myxoma virus, is part of a native cellular SCF complex during viral infection.

    Science.gov (United States)

    Blanié, Sophie; Gelfi, Jacqueline; Bertagnoli, Stéphane; Camus-Bouclainville, Christelle

    2010-01-01

    Myxoma virus (MYXV), a member of the Poxviridae family, is the agent responsible for myxomatosis, a fatal disease in the European rabbit (Oryctolagus cuniculus). Like all poxviruses, MYXV is known for encoding multiple proteins that regulate cellular signaling pathways. Among them, four proteins share the same ANK/PRANC structure: M148R, M149R, MNF (Myxoma Nuclear factor) and M-T5, all of them described as virulence factors. This family of poxvirus proteins, recently identified, has drawn considerable attention for its potential role in modulating the host ubiquitin-proteasome system during viral infection. To date, many members of this novel protein family have been shown to interact with SCF components, in vitro. Here, we focus on MNF gene, which has been shown to express a nuclear protein presenting nine ANK repeats, one of which has been identified as a nuclear localization signal. In transfection, MNF has been shown to colocalise with the transcription factor NF-kappaB in the nucleus of TNFalpha-stimulated cells. Functionally, MNF is a critical virulence factor since its deletion generates an almost apathogenic virus. In this study, to pursue the investigation of proteins interacting with MNF and of its mechanism of action, we engineered a recombinant MYXV expressing a GFP-linked MNF under the control of MNF native promoter. Infection of rabbits with MYXV-GFPMNF recombinant virus provided the evidence that the GFP fusion does not disturb the main function of MNF. Hence, cells were infected with MYXV-GFPMNF and immunoprecipitation of the GFPMNF fusion protein was performed to identify MNF's partners. For the first time, endogenous components of SCF (Cullin-1 and Skp1) were co-precipitated with an ANK myxoma virus protein, expressed in an infectious context, and without over-expression of any protein. PMID:20211013

  5. MNF, an ankyrin repeat protein of myxoma virus, is part of a native cellular SCF complex during viral infection

    OpenAIRE

    Gelfi Jacqueline; Blanié Sophie; Bertagnoli Stéphane; Camus-Bouclainville Christelle

    2010-01-01

    Abstract Myxoma virus (MYXV), a member of the Poxviridae family, is the agent responsible for myxomatosis, a fatal disease in the European rabbit (Oryctolagus cuniculus). Like all poxviruses, MYXV is known for encoding multiple proteins that regulate cellular signaling pathways. Among them, four proteins share the same ANK/PRANC structure: M148R, M149R, MNF (Myxoma Nuclear factor) and M-T5, all of them described as virulence factors. This family of poxvirus proteins, recently identified, has ...

  6. Supercritical fluid extraction of actinide element complexes. II. SCF of actinide complexes with β-diketones

    International Nuclear Information System (INIS)

    Data on solubility of β-diketones complexes with uranium (VI), plutonium, neptunium, and americium in supercritical carbon dioxide (SC-CO2) are presented. It is established that content of actinide complexes with β-diketones in SC-CO2 can achieve 10-100 g/l. Complexes with dipivaloylmethane, trifluoroacetylacetone and hexafluoroacetylacetone and adducts with tributylphosphate and water in particular are the most highly soluble in it. Residues of complexes after dissolution in SC-CO2 are investigated spectroscopically

  7. Identification of SFBB-containing canonical and noncanonical SCF complexes in pollen of apple (Malus × domestica).

    Science.gov (United States)

    Minamikawa, Mai F; Koyano, Ruriko; Kikuchi, Shinji; Koba, Takato; Sassa, Hidenori

    2014-01-01

    Gametophytic self-incompatibility (GSI) of Rosaceae, Solanaceae and Plantaginaceae is controlled by a single polymorphic S locus. The S locus contains at least two genes, S-RNase and F-box protein encoding gene SLF/SFB/SFBB that control pistil and pollen specificity, respectively. Generally, the F-box protein forms an E3 ligase complex, SCF complex with Skp1, Cullin1 (CUL1) and Rbx1, however, in Petunia inflata, SBP1 (S-RNase binding protein1) was reported to play the role of Skp1 and Rbx1, and form an SCFSLF-like complex for ubiquitination of non-self S-RNases. On the other hand, in Petunia hybrida and Petunia inflata of Solanaceae, Prunus avium and Pyrus bretschneideri of Rosaceae, SSK1 (SLF-interacting Skp1-like protein1) is considered to form the SCFSLF/SFB complex. Here, we isolated pollen-expressed apple homologs of SSK1 and CUL1, and named MdSSK1, MdCUL1A and MdCUL1B. MdSSK1 was preferentially expressed in pollen, but weakly in other organs analyzed, while, MdCUL1A and MdCUL1B were almost equally expressed in all the organs analyzed. MdSSK1 transcript abundance was significantly (>100 times) higher than that of MdSBP1. In vitro binding assays showed that MdSSK1 and MdSBP1 interacted with MdSFBB1-S9 and MdCUL1, and MdSFBB1-S9 interacted more strongly with MdSSK1 than with MdSBP1. The results suggest that both MdSSK1-containing SCFSFBB1 and MdSBP1-containing SCFSFBB1-like complexes function in pollen of apple, and the former plays a major role. PMID:24847858

  8. Identification of SFBB-containing canonical and noncanonical SCF complexes in pollen of apple (Malus × domestica.

    Directory of Open Access Journals (Sweden)

    Mai F Minamikawa

    Full Text Available Gametophytic self-incompatibility (GSI of Rosaceae, Solanaceae and Plantaginaceae is controlled by a single polymorphic S locus. The S locus contains at least two genes, S-RNase and F-box protein encoding gene SLF/SFB/SFBB that control pistil and pollen specificity, respectively. Generally, the F-box protein forms an E3 ligase complex, SCF complex with Skp1, Cullin1 (CUL1 and Rbx1, however, in Petunia inflata, SBP1 (S-RNase binding protein1 was reported to play the role of Skp1 and Rbx1, and form an SCFSLF-like complex for ubiquitination of non-self S-RNases. On the other hand, in Petunia hybrida and Petunia inflata of Solanaceae, Prunus avium and Pyrus bretschneideri of Rosaceae, SSK1 (SLF-interacting Skp1-like protein1 is considered to form the SCFSLF/SFB complex. Here, we isolated pollen-expressed apple homologs of SSK1 and CUL1, and named MdSSK1, MdCUL1A and MdCUL1B. MdSSK1 was preferentially expressed in pollen, but weakly in other organs analyzed, while, MdCUL1A and MdCUL1B were almost equally expressed in all the organs analyzed. MdSSK1 transcript abundance was significantly (>100 times higher than that of MdSBP1. In vitro binding assays showed that MdSSK1 and MdSBP1 interacted with MdSFBB1-S9 and MdCUL1, and MdSFBB1-S9 interacted more strongly with MdSSK1 than with MdSBP1. The results suggest that both MdSSK1-containing SCFSFBB1 and MdSBP1-containing SCFSFBB1-like complexes function in pollen of apple, and the former plays a major role.

  9. Line Complexity Asymptotics of Polynomial Cellular Automata

    OpenAIRE

    Stone, Bertrand

    2016-01-01

    Cellular automata are discrete dynamical systems that consist of patterns of symbols on a grid, which change according to a locally determined transition rule. In this paper, we will consider cellular automata that arise from polynomial transition rules, where the symbols in the automaton are integers modulo some prime $p$. We are principally concerned with the asymptotic behavior of the line complexity sequence $a_T(k)$, which counts, for each $k$, the number of coefficient strings of length...

  10. RIN3 is a negative regulator of mast cell responses to SCF.

    Directory of Open Access Journals (Sweden)

    Christine Janson

    Full Text Available Stimulation of the receptor tyrosine kinase KIT by Stem Cell Factor (SCF triggers activation of RAS and its downstream effectors. Proper KIT activation is essential for the maturation, survival and proliferation of mast cells. In addition, SCF activation of KIT is critical for recruiting mast cells to sites of infection or injury, where they release a mix of pro-inflammatory substances. RIN3, a RAS effector and RAB5-directed guanine nucleotide exchange factor (GEF, is highly expressed and enriched in human mast cells. SCF treatment of mast cells increased the amount of GTP-bound RAB5, and the degree of RAB5 activation correlated with the expression level of RIN3. At the same time, SCF caused the dissociation of a pre-formed complex of RIN3 with BIN2, a membrane bending protein implicated in endocytosis. Silencing of RIN3 increased the rate of SCF-induced KIT internalization, while persistent RIN3 over-expression led to KIT down regulation. These observations strongly support a role for RIN3 in coordinating the early steps of KIT endocytosis. Importantly, RIN3 also functioned as an inhibitor of mast cell migration toward SCF. Finally, we demonstrate that elevated RIN3 levels sensitize mastocytosis cells to treatment with a KIT tyrosine kinase inhibitor, suggesting the value of a two-pronged inhibitor approach for this difficult to treat malignancy. These findings directly connect KIT activation with a mast cell-specific RAS effector that regulates the cellular response to SCF and provide new insight for the development of more effective mastocytosis treatments.

  11. JFK, a Kelch domain-containing F-box protein, links the SCF complex to p53 regulation

    OpenAIRE

    Sun, Luyang; Shi, Lei; Li, Wenqian; Yu, Wenhua; Liang, Jing; Zhang, Hua; Yang, Xiaohan; Wang, Yan; Li, Ruifang; Yao, Xingrong; Yi, Xia; Shang, Yongfeng

    2009-01-01

    The p53 tumor suppressor plays a central role in integrating cellular responses to various stresses. Tight regulation of p53 is thus essential for the maintenance of genome integrity and normal cell proliferation. Currently, several ubiquitin ligases, including the single-subunit RING-finger types—MDM2, Pirh2, and COP1—and the HECT-domain type—ARF-BP1—have been reported to target p53 for degradation. Here, we report the identification of a human Kelch domain-containing F-box protein, JFK. We ...

  12. Simulating Complex Systems by Cellular Automata

    CERN Document Server

    Kroc, Jiri; Hoekstra, Alfons G

    2010-01-01

    Deeply rooted in fundamental research in Mathematics and Computer Science, Cellular Automata (CA) are recognized as an intuitive modeling paradigm for Complex Systems. Already very basic CA, with extremely simple micro dynamics such as the Game of Life, show an almost endless display of complex emergent behavior. Conversely, CA can also be designed to produce a desired emergent behavior, using either theoretical methodologies or evolutionary techniques. Meanwhile, beyond the original realm of applications - Physics, Computer Science, and Mathematics – CA have also become work horses in very different disciplines such as epidemiology, immunology, sociology, and finance. In this context of fast and impressive progress, spurred further by the enormous attraction these topics have on students, this book emerges as a welcome overview of the field for its practitioners, as well as a good starting point for detailed study on the graduate and post-graduate level. The book contains three parts, two major parts on th...

  13. Mathematical analysis of complex cellular activity

    CERN Document Server

    Bertram, Richard; Teka, Wondimu; Vo, Theodore; Wechselberger, Martin; Kirk, Vivien; Sneyd, James

    2015-01-01

    This book contains two review articles on mathematical physiology that deal with closely related topics but were written and can be read independently. The first article reviews the basic theory of calcium oscillations (common to almost all cell types), including spatio-temporal behaviors such as waves. The second article uses, and expands on, much of this basic theory to show how the interaction of cytosolic calcium oscillators with membrane ion channels can result in highly complex patterns of electrical spiking. Through these examples one can see clearly how multiple oscillatory processes interact within a cell, and how mathematical methods can be used to understand such interactions better. The two reviews provide excellent examples of how mathematics and physiology can learn from each other, and work jointly towards a better understanding of complex cellular processes. Review 1: Richard Bertram, Joel Tabak, Wondimu Teka, Theodore Vo, Martin Wechselberger: Geometric Singular Perturbation Analysis of Burst...

  14. The brittleness model of complex system based on cellular automata

    Institute of Scientific and Technical Information of China (English)

    LIN De-ming; JIN Hong-zhang; LI Qi; WU Hong-mei

    2004-01-01

    Now the research on the complex system is a hot spot. Brittleness is one of the basic characteristics of a complex system. In a complex system, after one of subsystems is struck to be collapsed, the whole system will collapse. Meanwhile, cellular automata is a discrete dynamic system. When the rule is given, the cellular automata could be defined. Then it can imitate the complex action. Cellular automata is used to simulate the brittleness action in this study. Entropy was used to analyze the action and get the rule. Then,three normal brittleness models were given. The result shows that the brittleness of complex system is existent and in addition some important behavior mode of complex system brittleness has been achieved.

  15. EVOLUTION COMPLEXITY OF THEELEMENTARY CELLULAR AUTOMATON OF RULE 22

    Institute of Scientific and Technical Information of China (English)

    WangYi; JiangZhisong

    2002-01-01

    Cellular automata are the discrete dynamical systems of simple construction but with complex and varied behaviors. In this paper, the elementary cellular automaton of rule 22 is studied by the tools of formal language theory and symbolic dynamics. Its temporal evolution orbits are coarse-grained into evolution sequences and the evolution languages are defined. It is proved that for every n≥2 its width n evolution language is not regular.

  16. The GARP complex is required for cellular sphingolipid homeostasis

    DEFF Research Database (Denmark)

    Fröhlich, Florian; Petit, Constance; Kory, Nora;

    2015-01-01

    (GARP) complex, which functions in endosome-to-Golgi retrograde vesicular transport, as a critical player in sphingolipid homeostasis. GARP deficiency leads to accumulation of sphingolipid synthesis intermediates, changes in sterol distribution, and lysosomal dysfunction. A GARP complex mutation...... the phenotypes of GARP-deficient yeast or mammalian cells. Together, these data show that GARP is essential for cellular sphingolipid homeostasis and suggest a therapeutic strategy for the treatment of PCCA2....

  17. Caractérisation biochimique et moléculaire du complexe SCF (SKP1-CULLIN-FBOX) chez le blé tendre

    OpenAIRE

    El Beji, Imen

    2011-01-01

    The selective degradation of proteins is an important means of regulating gene expression and plays crucial roles in the control of various cellular processes. The Ubiquitin (Ub)-Proteasome System (UPS) is the principal non-lysosomal proteolytic pathway in eukaryotic cells and is required for the degradation of key regulatory proteins. Ubiquitin is a 76-residue protein that can be attached covalently to target proteins through an enzymatic conjugation cascade involving three enzymes denoted, ...

  18. Human more complex than mouse at cellular level.

    Directory of Open Access Journals (Sweden)

    Alexander E Vinogradov

    Full Text Available The family of transcription factors with the C2H2 zinc finger domain is expanding in the evolution of vertebrates, reaching its highest numbers in the mammals. The question arises: whether an increased amount of these transcription factors is related to embryogenesis, nervous system, pathology or more of them are expressed in individual cells? Among mammals, the primates have a more complex anatomical structure than the rodents (e.g., brain. In this work, I show that a greater number of C2H2-ZF genes are expressed in the human cells than in the mouse cells. The effect is especially pronounced for C2H2-ZF genes accompanied with the KRAB domain. The relative difference between the numbers of C2H2-ZF(-KRAB genes in the human and mouse cellular transcriptomes even exceeds their difference in the genomes (i.e. a greater subset of existing in the genome genes is expressed in the human cellular transcriptomes compared to the mouse transcriptomes. The evolutionary turnover of C2H2-ZF(-KRAB genes acts in the direction of the revealed phenomenon, i.e. gene duplication and loss enhances the difference in the relative number of C2H2-ZF(-KRAB genes between human and mouse cellular transcriptomes. A higher amount of these genes is expressed in the brain and embryonic cells (compared with other tissues, whereas a lower amount--in the cancer cells. It is specifically the C2H2-ZF transcription factors whose repertoire is poorer in the cancer and richer in the brain (other transcription factors taken together do not show this trend. These facts suggest that increase of anatomical complexity is accompanied by a more complex intracellular regulation involving these transcription factors. Malignization is associated with simplification of this regulation. These results agree with the known fact that human cells are more resistant to oncogenic transformation than mouse cells. The list of C2H2-ZF genes whose suppression might be involved in malignization is provided.

  19. On nonadiabatic SCF calculations of molecular properties

    OpenAIRE

    Fernández, Francisco M.

    2009-01-01

    We argue that the dynamic extended molecular orbital (DEMO) method may be less accurate than expected because the motion of the center of mass was not properly removed prior to the SCF calculation. Under such conditions the virial theorem is a misleading indication of the accuracy of the wavefunction.

  20. Cul7/p185/p193 Binding to Simian Virus 40 Large T Antigen Has a Role in Cellular Transformation

    OpenAIRE

    Ali, Syed Hamid; Kasper, Jocelyn S.; Arai, Takehiro; DeCaprio, James A.

    2004-01-01

    Simian virus 40 large T antigen (TAg) is a viral oncoprotein that can promote cellular transformation. TAg's transforming activity results in part by binding and inactivating key tumor suppressors, including p53 and the retinoblastoma protein (pRb). We have identified a TAg-associated 185-kDa protein that has significant homology to the cullin family of E3 ubiquitin ligases. TAg binds to an SCF-like complex that contains p185/Cul7, Rbx1, and the F box protein Fbw6. This SCF-like complex binds...

  1. Challenges in Characterizing and Controlling Complex Cellular Systems

    Science.gov (United States)

    Wikswo, John

    2011-03-01

    Multicellular dynamic biological processes such as developmental differentiation, wound repair, disease, aging, and even homeostasis can be represented by trajectories through a phase space whose extent reflects the genetic, post-translational, and metabolic complexity of the process - easily extending to tens of thousands of dimensions. Intra- and inter-cellular sensing and regulatory systems and their nested, redundant, and non-linear feed-forward and feed-back controls create high-dimensioned attractors in this phase space. Metabolism provides free energy to drive non-equilibrium processes and dynamically reconfigure attractors. Studies of single molecules and cells provide only minimalist projections onto a small number of axes. It may be difficult to infer larger-scale emergent behavior from linearized experiments that perform only small amplitude perturbations on a limited number of the dimensions. Complete characterization may succeed for bounded component problems, such as an individual cell cycle or signaling cascade, but larger systems problems will require a coarse-grained approach. Hence a new experimental and analytical framework is needed. Possibly one could utilize high-amplitude, multi-variable driving of the system to infer coarse-grained, effective models, which in turn can be tested by their ability to control systems behavior. Navigation at will between attractors in a high-dimensioned dynamical system will provide not only detailed knowledge of the shape of attractor basins, but also measures of underlying stochastic events such as noise in gene expression or receptor binding and how both affect system stability and robustness. Needed for this are wide-bandwidth methods to sense and actuate large numbers of intracellular and extracellular variables and automatically and rapidly infer dynamic control models. The success of this approach may be determined by how broadly the sensors and actuators can span the full dimensionality of the phase space

  2. Complex cellular responses to tooth wear in rodent molar.

    Science.gov (United States)

    Mahdee, A; Alhelal, A; Eastham, J; Whitworth, J; Gillespie, J I

    2016-01-01

    The arrangement and roles of the odontoblast and its process in sensing and responding to injuries such as tooth wear are incompletely understood. Evidence is presented that dentine exposure by tooth wear triggers structural and functional changes that aim to maintain tooth integrity. Mandibular first molars from freshly culled 8 week Wistar rats were prepared for light microscopy ground-sections (n=6), or fixed in 4% paraformaldehyde, decalcified in 17% EDTA, sectioned and stained with antibodies to cyto-skeletal proteins (vimentin (vim), α-tubulin (tub) and α-actin), cellular homeostatic elements (sodium potassium ATPase (NaK-ATPase) and sodium hydrogen exchanger (NHE-1)), and sensory nerve fibres (CGRP) (n=10) for fluorescence microscopy of worn and unworn regions of the mesial cusp. Immunoreactivity (IR) to vim, actin, NaK-ATPase and CGRP was confined to the pulpal third of odontoblast processes (OPs). IR to tub and nhe-1 was expressed by OPs in full dentine thickness. In areas associated with dentine exposure, the tubules contained no OPs. In regions with intact dentine, odontoblasts were arranged in a single cell layer and easily distinguished from the sub-odontoblast cells. In regions with open tubules, the odontoblasts were in stratified or pseudo-stratified in arrangement. Differences in structural antibody expression suggest a previously unreported heterogeneity of the odontoblast population and variations in different regions of the OP. This combined with differences in OPs extension and pulp cellular arrangement in worn and unworn regions suggests active and dynamic cellular responses to the opening of dentinal tubules by tooth wear. PMID:26547699

  3. The novel ubiquitin ligase complex, SCF(Fbxw4, interacts with the COP9 signalosome in an F-box dependent manner, is mutated, lost and under-expressed in human cancers.

    Directory of Open Access Journals (Sweden)

    William W Lockwood

    Full Text Available Identification of novel proteins that can potentially contribute to carcinogenesis is a requisite venture. Herein, we report the first biochemical characterization of the novel F-box and WD40 containing protein, FBXW4. We have identified interacting protein partners and demonstrated that FBXW4 is part of a ubiquitin ligase complex. Furthermore, the Fbxw4 locus is a common site of proviral insertion in a variety of retroviral insertional mutagenesis murine cancer models and Fbxw4 mRNA is highly expressed in the involuting murine mammary gland. To begin to characterize the biochemical function of Fbxw4, we used proteomic analysis to demonstrate that Fbxw4 interacts with Skp1 (SKP1, Cullin1 (CUL1, Ring-box1 (RBX1 and all components of the COP9 signalosome. All of these interactions are dependent on an intact F-box domain of Fbxw4. Furthermore, Fbxw4 is capable of interacting with ubiquitinated proteins within cells in an F-box dependent manner. Finally, we demonstrate that FBXW4 is mutated, lost and under-expressed in a variety of human cancer cell lines and clinical patient samples. Importantly, expression of FBXW4 correlates with survival of patients with non-small cell lung cancer. Taken together, we suggest that FBXW4 may be a novel tumor suppressor that regulates important cellular processes.

  4. Location Management Technique to Reduce Complexity in Cellular Networks

    Directory of Open Access Journals (Sweden)

    C. Selvan

    2010-07-01

    Full Text Available An important issue in the design of mobile computing is how to manage the location information of mobile nodes in wireless cellular networks. The existing system has two approaches. First approach is spatial quantization technique in which location update takes place only when the mobile terminal move from one location area to other and second approach is temporal quantization in which location update takes place only after a specific time threshold. In this paper, we introduce Intelligent Agent Quantization(IAQ which is based on prediction of movements and distance between node and Base Station Controller(BSC to locate the mobile nodes. The main idea of using IAQ is reduce the update cost considerably with slight increase in paging cost.

  5. Starting SCF Calculations by Superposition of Atomic Densities

    NARCIS (Netherlands)

    van Lenthe, J.H.; Zwaans, R.; van Dam, H.J.J.; Guest, M.F.

    2006-01-01

    We describe the procedure to start an SCF calculation of the general type from a sum of atomic electron densities, as implemented in GAMESS-UK. Although the procedure is well-known for closed-shell calculations and was already suggested when the Direct SCF procedure was proposed, the general procedu

  6. Inhibition of SCF ubiquitin ligases by engineered ubiquitin variants that target the Cul1 binding site on the Skp1–F-box interface

    Energy Technology Data Exchange (ETDEWEB)

    Gorelik, Maryna; Orlicky, Stephen; Sartori, Maria A.; Tang, Xiaojing; Marcon, Edyta; Kurinov, Igor; Greenblatt, Jack F.; Tyers, Mike; Moffat, Jason; Sicheri, Frank; Sidhu, Sachdev S.

    2016-03-14

    The ubiquitin proteasome components are often misregulated in numerous diseases, encouraging the search for drug targets and inhibitors. E3 ligases that specify ubiquitination targets are of particular interest. Multimeric Skp1–Cul1–F-box (SCF) E3 ligases constitute one of the largest E3 families connected to every cellular process and multiple diseases; however, their characterization as therapeutic targets is impeded by functional diversity and poor characterization of its members. Herein we describe a strategy to inhibit SCF E3 ligases using engineered ubiquitin-based binders. We identify a previously uncharacterized inhibitory site and design ubiquitin-based libraries targeting this site. Our strategy to target SCF E3 ligases with small-molecule–like agents will have broad applications for basic research and drug development relating to SCF E3 ligase function.

  7. SCF{sup TM}, Single Column Floater - a deepwater solution

    Energy Technology Data Exchange (ETDEWEB)

    Basak, Jayanto K.; Denman, Jeremy [ABB Lummus Global Inc., Duque de Caxias, RJ (Brazil). Deepwater Technology and Engineering

    2004-07-01

    As commercially attractive oil and gas discoveries are found in ever increasing water depths, the associated technical, operational and economic challenges become formidable. Appropriate selection of development architecture is essential for the overall success of a project. To properly address this wide range of development options, ABB has developed a portfolio of various hull forms. The SCF{sup TM} concept is one such hull form for a deep water solution. This paper presents the development of the SCF platform by addressing design issues, model test, product storage, fabrication, quay side integration, transportation, installation, schedule and cost estimate. The SCF concept brings tangible benefits to many of the deep water developments around the globe. The attributes of the SCF concept can commercially benefit deep water developments in Brazil as well as potentially generate in-country fabrication and service opportunities. (author)

  8. Radiation increases the cellular uptake of exosomes through CD29/CD81 complex formation

    International Nuclear Information System (INIS)

    Highlights: • Radiation increases cellular uptake of exosomes. • Radiation induces colocalization of CD29 and CD81. • Exosomes selectively bind the CD29/CD81 complex. • Radiation increases the cellular uptake of exosomes through CD29/CD81 complex formation. - Abstract: Exosomes mediate intercellular communication, and mesenchymal stem cells (MSC) or their secreted exosomes affect a number of pathophysiologic states. Clinical applications of MSC and exosomes are increasingly anticipated. Radiation therapy is the main therapeutic tool for a number of various conditions. The cellular uptake mechanisms of exosomes and the effects of radiation on exosome–cell interactions are crucial, but they are not well understood. Here we examined the basic mechanisms and effects of radiation on exosome uptake processes in MSC. Radiation increased the cellular uptake of exosomes. Radiation markedly enhanced the initial cellular attachment to exosomes and induced the colocalization of integrin CD29 and tetraspanin CD81 on the cell surface without affecting their expression levels. Exosomes dominantly bound to the CD29/CD81 complex. Knockdown of CD29 completely inhibited the radiation-induced uptake, and additional or single knockdown of CD81 inhibited basal uptake as well as the increase in radiation-induced uptake. We also examined possible exosome uptake processes affected by radiation. Radiation-induced changes did not involve dynamin2, reactive oxygen species, or their evoked p38 mitogen-activated protein kinase-dependent endocytic or pinocytic pathways. Radiation increased the cellular uptake of exosomes through CD29/CD81 complex formation. These findings provide essential basic insights for potential therapeutic applications of exosomes or MSC in combination with radiation

  9. Radiation increases the cellular uptake of exosomes through CD29/CD81 complex formation

    Energy Technology Data Exchange (ETDEWEB)

    Hazawa, Masaharu; Tomiyama, Kenichi; Saotome-Nakamura, Ai; Obara, Chizuka; Yasuda, Takeshi; Gotoh, Takaya; Tanaka, Izumi; Yakumaru, Haruko; Ishihara, Hiroshi; Tajima, Katsushi, E-mail: tajima@nirs.go.jp

    2014-04-18

    Highlights: • Radiation increases cellular uptake of exosomes. • Radiation induces colocalization of CD29 and CD81. • Exosomes selectively bind the CD29/CD81 complex. • Radiation increases the cellular uptake of exosomes through CD29/CD81 complex formation. - Abstract: Exosomes mediate intercellular communication, and mesenchymal stem cells (MSC) or their secreted exosomes affect a number of pathophysiologic states. Clinical applications of MSC and exosomes are increasingly anticipated. Radiation therapy is the main therapeutic tool for a number of various conditions. The cellular uptake mechanisms of exosomes and the effects of radiation on exosome–cell interactions are crucial, but they are not well understood. Here we examined the basic mechanisms and effects of radiation on exosome uptake processes in MSC. Radiation increased the cellular uptake of exosomes. Radiation markedly enhanced the initial cellular attachment to exosomes and induced the colocalization of integrin CD29 and tetraspanin CD81 on the cell surface without affecting their expression levels. Exosomes dominantly bound to the CD29/CD81 complex. Knockdown of CD29 completely inhibited the radiation-induced uptake, and additional or single knockdown of CD81 inhibited basal uptake as well as the increase in radiation-induced uptake. We also examined possible exosome uptake processes affected by radiation. Radiation-induced changes did not involve dynamin2, reactive oxygen species, or their evoked p38 mitogen-activated protein kinase-dependent endocytic or pinocytic pathways. Radiation increased the cellular uptake of exosomes through CD29/CD81 complex formation. These findings provide essential basic insights for potential therapeutic applications of exosomes or MSC in combination with radiation.

  10. Complex I Disorders: Causes, Mechanisms, and Development of Treatment Strategies at the Cellular Level

    Science.gov (United States)

    Valsecchi, Federica; Koopman, Werner J. H.; Manjeri, Ganesh R.; Rodenburg, Richard J.; Smeitink, Jan A. M.; Willems, Peter H. G. M.

    2010-01-01

    Mitochondrial oxidative phosphorylation (OXPHOS) represents the final step in the conversion of nutrients into cellular energy. Genetic defects in the OXPHOS system have an incidence between 1:5,000 and 1:10,000 live births. Inherited isolated deficiency of the first complex (CI) of this system, a multisubunit assembly of 45 different proteins,…

  11. Dinuclear ruthenium(II) polypyridyl complexes as single and two-photon luminescence cellular imaging probes.

    Science.gov (United States)

    Xu, Wenchao; Zuo, Jiarui; Wang, Lili; Ji, Liangnian; Chao, Hui

    2014-02-28

    A new series of dinuclear ruthenium(II) polypyridyl complexes, which possess larger π-conjugated systems, good water solubility and pH resistance, and high photostability, were developed to act as single and two-photon luminescence cellular imaging probes. PMID:24418839

  12. RHFPPP, SCF-LCAO-MO Calculation for Closed Shell and Open Shell Organic Molecules

    International Nuclear Information System (INIS)

    1 - Nature of physical problem solved: Complete program performs SCF-LCAO-MO calculations for both closed and open-shell organic pi-molecules. The Pariser-Parr-People approximations are used with- in the framework of the restricted Hartree-Fock method. The SCF calculation is followed, if desired, by a variational configuration interaction (CI) calculation including singly excited configurations. 2 - Method of solution: A standard procedure is used; at each step a real symmetric matrix has to be diagonalized. The self-consistency is checked by comparing the eigenvectors between two consecutive steps. 3 - Restrictions on the complexity of the problem: i) The calculations are restricted to planar molecules. ii) In order to avoid accumulation of round-off errors, in the iterative procedure, double precision arithmetic is used. iii) The program is restricted to systems up to about 16 atoms; however the size of the systems can easily be modified if required

  13. Genetically engineered mouse models for functional studies of SKP1-CUL1-F-box-protein (SCF) E3 ubiquitin ligases

    Institute of Scientific and Technical Information of China (English)

    Weihua Zhou; Wenyi Wei; Yi Sun

    2013-01-01

    The SCF (SKP1 (S-phase-kinase-associated protein 1),Cullin-1,F-box protein) E3 ubiquitin ligases,the founding member of Cullin-RING ligases (CRLs),are the largest family of E3 ubiquitin ligases in mammals.Each individual SCF E3 ligase consists of one adaptor protein SKP1,one scaffold protein cullin-1 (the first family member of the eight cullins),one F-box protein out of 69 family members,and one out of two RING (Really Interesting New Gene) family proteins RBX1/ROC1 or RBX2/ROC2/SAG/RNF7.Various combinations of these four components construct a large number of SCF E3s that promote the degradation of many key regulatory proteins in cell-context,temporally,and spatially dependent manners,thus controlling precisely numerous important cellular processes,including cell cycle progression,apoptosis,gene transcription,signal transduction,DNA replication,maintenance of genome integrity,and tumorigenesis.To understand how the SCF E3 ligases regulate these cellular processes and embryonic development under in vivo physiological conditions,a number of mouse models with transgenic (Tg) expression or targeted deletion of components of SCF have been established and characterized.In this review,we will provide a brief introduction to the ubiquitin-proteasome system (UPS) and the SCF E3 ubiquitin ligases,followed by a comprehensive overview on the existing Tg and knockout (KO) mouse models of the SCF E3s,and discuss the role of each component in mouse embryogenesis,cell proliferation,apoptosis,carcinogenesis,as well as other pathogenic processes associated with human diseases.We will end with a brief discussion on the future directions of this research area and the potential applications of the knowledge gained to more effective therapeutic interventions of human diseases.

  14. Effect of iron poly (sorbitolgluconic acid) complex on urinary cellular excretion.

    Science.gov (United States)

    Elliott, H L; Lawrence, J R; Campbell, B C; Goldberg, A; Smart, L E

    1981-01-01

    The intramuscular injection of 250 mg iron poly (sorbitol-gluconic acid) complex caused no increase in urinary cellular or bacterial excretion in 8 patients with chronic pyelonephritis, 4 patients with non-infective renal disease, and 4 controls. However, in 4 patients with chronic infective disease of the renal tract given 500 g there was a significant increase in cellular excretion. This response was not seen in 2 control patients, nor in 2 patients with non-infective renal disease. Using a differential staining technique, this increase in urinary cellular excretion was found to be due, not to leucocytes, but to renal tubular cells. The precise significance of this is unclear, but there would be concern that the high concentration of excreted iron was providing a 'toxic' insult to susceptible, infection-damaged cells. PMID:7226874

  15. The COP9 signalosome interacts with SCF UFO and participates in Arabidopsis flower development.

    Science.gov (United States)

    Wang, Xiping; Feng, Suhua; Nakayama, Naomi; Crosby, W L; Irish, Vivian; Deng, Xing Wang; Wei, Ning

    2003-05-01

    The COP9 signalosome (CSN) is involved in multiple developmental processes. It interacts with SCF ubiquitin ligases and deconjugates Nedd8/Rub1 from cullins (deneddylation). CSN is highly expressed in Arabidopsis floral tissues. To investigate the role of CSN in flower development, we examined the expression pattern of CSN in developing flowers. We report here that two csn1 partially deficient Arabidopsis strains exhibit aberrant development of floral organs, decline of APETALA3 (AP3) expression, and low fertility in addition to defects in shoot and inflorescence meristems. We show that UNUSUAL FLORAL ORGANS (UFO) forms a SCF(UFO) complex, which is associated with CSN in vivo. Genetic interaction analysis indicates that CSN is necessary for the gain-of-function activity of the F-box protein UFO in AP3 activation and in floral organ transformation. Compared with the previously reported csn5 antisense and csn1 null mutants, partial deficiency of CSN1 causes a reduction in the level of CUL1 in the mutant flowers without an obvious defect in CUL1 deneddylation. We conclude that CSN is an essential regulator of Arabidopsis flower development and suggest that CSN regulates Arabidopsis flower development in part by modulating SCF(UFO)-mediated AP3 activation. PMID:12724534

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

    Science.gov (United States)

    Hickmott, Curtis W.

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

  17. Both Complexity and Location of DNA Damage Contribute to Cellular Senescence Induced by Ionizing Radiation

    Science.gov (United States)

    Zhang, Xurui; Ye, Caiyong; Sun, Fang; Wei, Wenjun; Hu, Burong; Wang, Jufang

    2016-01-01

    Persistent DNA damage is considered as a main cause of cellular senescence induced by ionizing radiation. However, the molecular bases of the DNA damage and their contribution to cellular senescence are not completely clear. In this study, we found that both heavy ions and X-rays induced senescence in human uveal melanoma 92–1 cells. By measuring senescence associated-β-galactosidase and cell proliferation, we identified that heavy ions were more effective at inducing senescence than X-rays. We observed less efficient repair when DNA damage was induced by heavy ions compared with X-rays and most of the irreparable damage was complex of single strand breaks and double strand breaks, while DNA damage induced by X-rays was mostly repaired in 24 hours and the remained damage was preferentially associated with telomeric DNA. Our results suggest that DNA damage induced by heavy ion is often complex and difficult to repair, thus presents as persistent DNA damage and pushes the cell into senescence. In contrast, persistent DNA damage induced by X-rays is preferentially associated with telomeric DNA and the telomere-favored persistent DNA damage contributes to X-rays induced cellular senescence. These findings provide new insight into the understanding of high relative biological effectiveness of heavy ions relevant to cancer therapy and space radiation research. PMID:27187621

  18. Both Complexity and Location of DNA Damage Contribute to Cellular Senescence Induced by Ionizing Radiation.

    Science.gov (United States)

    Zhang, Xurui; Ye, Caiyong; Sun, Fang; Wei, Wenjun; Hu, Burong; Wang, Jufang

    2016-01-01

    Persistent DNA damage is considered as a main cause of cellular senescence induced by ionizing radiation. However, the molecular bases of the DNA damage and their contribution to cellular senescence are not completely clear. In this study, we found that both heavy ions and X-rays induced senescence in human uveal melanoma 92-1 cells. By measuring senescence associated-β-galactosidase and cell proliferation, we identified that heavy ions were more effective at inducing senescence than X-rays. We observed less efficient repair when DNA damage was induced by heavy ions compared with X-rays and most of the irreparable damage was complex of single strand breaks and double strand breaks, while DNA damage induced by X-rays was mostly repaired in 24 hours and the remained damage was preferentially associated with telomeric DNA. Our results suggest that DNA damage induced by heavy ion is often complex and difficult to repair, thus presents as persistent DNA damage and pushes the cell into senescence. In contrast, persistent DNA damage induced by X-rays is preferentially associated with telomeric DNA and the telomere-favored persistent DNA damage contributes to X-rays induced cellular senescence. These findings provide new insight into the understanding of high relative biological effectiveness of heavy ions relevant to cancer therapy and space radiation research. PMID:27187621

  19. Both Complexity and Location of DNA Damage Contribute to Cellular Senescence Induced by Ionizing Radiation.

    Directory of Open Access Journals (Sweden)

    Xurui Zhang

    Full Text Available Persistent DNA damage is considered as a main cause of cellular senescence induced by ionizing radiation. However, the molecular bases of the DNA damage and their contribution to cellular senescence are not completely clear. In this study, we found that both heavy ions and X-rays induced senescence in human uveal melanoma 92-1 cells. By measuring senescence associated-β-galactosidase and cell proliferation, we identified that heavy ions were more effective at inducing senescence than X-rays. We observed less efficient repair when DNA damage was induced by heavy ions compared with X-rays and most of the irreparable damage was complex of single strand breaks and double strand breaks, while DNA damage induced by X-rays was mostly repaired in 24 hours and the remained damage was preferentially associated with telomeric DNA. Our results suggest that DNA damage induced by heavy ion is often complex and difficult to repair, thus presents as persistent DNA damage and pushes the cell into senescence. In contrast, persistent DNA damage induced by X-rays is preferentially associated with telomeric DNA and the telomere-favored persistent DNA damage contributes to X-rays induced cellular senescence. These findings provide new insight into the understanding of high relative biological effectiveness of heavy ions relevant to cancer therapy and space radiation research.

  20. Structural requirements for the assembly of LINC complexes and their function in cellular mechanical stiffness

    International Nuclear Information System (INIS)

    The evolutionary-conserved interactions between KASH and SUN domain-containing proteins within the perinuclear space establish physical connections, called LINC complexes, between the nucleus and the cytoskeleton. Here, we show that the KASH domains of Nesprins 1, 2 and 3 interact promiscuously with luminal domains of Sun1 and Sun2. These constructs disrupt endogenous LINC complexes as indicated by the displacement of endogenous Nesprins from the nuclear envelope. We also provide evidence that KASH domains most probably fit a pocket provided by SUN domains and that post-translational modifications are dispensable for that interaction. We demonstrate that the disruption of endogenous LINC complexes affect cellular mechanical stiffness to an extent that compares to the loss of mechanical stiffness previously reported in embryonic fibroblasts derived from mouse lacking A-type lamins, a mouse model of muscular dystrophies and cardiomyopathies. These findings support a model whereby physical connections between the nucleus and the cytoskeleton are mediated by interactions between diverse combinations of Sun proteins and Nesprins through their respective evolutionary-conserved domains. Furthermore, they emphasize, for the first time, the relevance of LINC complexes in cellular mechanical stiffness suggesting a possible involvement of their disruption in various laminopathies, a group of human diseases linked to mutations of A-type lamins

  1. SCF, regulated by HIF-1α, promotes pancreatic ductal adenocarcinoma cell progression.

    Directory of Open Access Journals (Sweden)

    Chuntao Gao

    Full Text Available Stem cell factor (SCF and hypoxia-inducible factor-1α (HIF-1α both have important functions in pancreatic ductal adenocarcinoma (PDAC. This study aims to analyze the expression and clinicopathological significance of SCF and HIF-1α in PDAC specimens and explore the molecular mechanism at PDAC cells in vitro and in vivo. We showed that the expression of SCF was significantly correlated with HIF-1α expression via Western blot, PCR, chromatin immunoprecipitation (ChIP assay, and luciferase assay analysis. The SCF level was also correlated with lymph node metastasis and the pathological tumor node metastasis (pTNM stage in PDAC samples. The SCF higher-expression group had significantly lower survival rates than the SCF lower-expression group (p<0.05. Hypoxia up-regulated the expression of SCF through the hypoxia-inducible factor (HIF-1α in PDAC cells at the protein and RNA levels. When HIF-1α was knocked down by RNA interference, the SCF level decreased significantly. Additionally, ChIP and luciferase results demonstrated that HIF-1α can directly bind to the hypoxia response element (HRE region of the SCF promoter and activate the SCF transcription under hypoxia. The results of colony formation, cell scratch, and transwell migration assay showed that SCF promoted the proliferation and invasion of PANC-1 cells under hypoxia. Furthermore, the down-regulated ability of cell proliferation and invasion following HIF-1α knockdown was rescued by adding exogenous SCF under hypoxia in vitro. Finally, when the HIF-1α expression was inhibited by digoxin, the tumor volume and the SCF level decreased, thereby proving the relationship between HIF-1α and SCF in vivo. In conclusion, SCF is an important factor for the growth of PDAC. In our experiments, we proved that SCF, a downstream gene of HIF-1α, can promote the development of PDAC under hypoxia. Thus, SCF might be a potential therapeutic target for PDAC.

  2. SCF, Regulated by HIF-1α, Promotes Pancreatic Ductal Adenocarcinoma Cell Progression

    Science.gov (United States)

    Chen, Jing; Ren, He; Zhang, Huan; Wang, Xiuchao; Lang, Mingxiao; Liu, Jingcheng; Gao, Song; Zhao, Xiao; Sheng, Jun; Yuan, Zhanna; Hao, Jihui

    2015-01-01

    Stem cell factor (SCF) and hypoxia-inducible factor-1α (HIF-1α) both have important functions in pancreatic ductal adenocarcinoma (PDAC). This study aims to analyze the expression and clinicopathological significance of SCF and HIF-1α in PDAC specimens and explore the molecular mechanism at PDAC cells in vitro and in vivo. We showed that the expression of SCF was significantly correlated with HIF-1α expression via Western blot, PCR, chromatin immunoprecipitation (ChIP) assay, and luciferase assay analysis. The SCF level was also correlated with lymph node metastasis and the pathological tumor node metastasis (pTNM) stage in PDAC samples. The SCF higher-expression group had significantly lower survival rates than the SCF lower-expression group (p<0.05). Hypoxia up-regulated the expression of SCF through the hypoxia-inducible factor (HIF)-1α in PDAC cells at the protein and RNA levels. When HIF-1α was knocked down by RNA interference, the SCF level decreased significantly. Additionally, ChIP and luciferase results demonstrated that HIF-1α can directly bind to the hypoxia response element (HRE) region of the SCF promoter and activate the SCF transcription under hypoxia. The results of colony formation, cell scratch, and transwell migration assay showed that SCF promoted the proliferation and invasion of PANC-1 cells under hypoxia. Furthermore, the down-regulated ability of cell proliferation and invasion following HIF-1α knockdown was rescued by adding exogenous SCF under hypoxia in vitro. Finally, when the HIF-1α expression was inhibited by digoxin, the tumor volume and the SCF level decreased, thereby proving the relationship between HIF-1α and SCF in vivo. In conclusion, SCF is an important factor for the growth of PDAC. In our experiments, we proved that SCF, a downstream gene of HIF-1α, can promote the development of PDAC under hypoxia. Thus, SCF might be a potential therapeutic target for PDAC. PMID:25799412

  3. Lysine acetylation targets protein complexes and co-regulates major cellular functions

    DEFF Research Database (Denmark)

    Choudhary, Chuna Ram; Kumar, Chanchal; Gnad, Florian; Nielsen, Michael L; Rehman, Michael; Walther, Tobias C; Olsen, Jesper V; Mann, Matthias

    2009-01-01

    Lysine acetylation is a reversible posttranslational modification of proteins and plays a key role in regulating gene expression. Technological limitations have so far prevented a global analysis of lysine acetylation's cellular roles. We used high-resolution mass spectrometry to identify 3600...... lysine acetylation sites on 1750 proteins and quantified acetylation changes in response to the deacetylase inhibitors suberoylanilide hydroxamic acid and MS-275. Lysine acetylation preferentially targets large macromolecular complexes involved in diverse cellular processes, such as chromatin remodeling......, cell cycle, splicing, nuclear transport, and actin nucleation. Acetylation impaired phosphorylation-dependent interactions of 14-3-3 and regulated the yeast cyclin-dependent kinase Cdc28. Our data demonstrate that the regulatory scope of lysine acetylation is broad and comparable with that of other...

  4. Cyanogen Azide. Ionization Potentials and Ab Initio SCF MO Calculation

    DEFF Research Database (Denmark)

    Bak, Börge; Jansen, Peter; Stafast, Herbert

    1975-01-01

    The Ne(I) and He(I) photoelectron(PE) spectra of cyanogen azide, NCN3, have been recorded at high resolution. Their interpretation is achieved by comparison with the PE spectrum of HN3 and an ab initio LCGO SCF MO calculation. Deviations from Koopmans' theorem of quite different magnitudes are fo...

  5. Characterization of SCF-Complex during Bovine Preimplantation Development

    Czech Academy of Sciences Publication Activity Database

    Benešová, Veronika; Kinterová, Veronika; Kaňka, Jiří; Toralová, Tereza

    2016-01-01

    Roč. 11, č. 1 (2016), e0147096-e0147096. E-ISSN 1932-6203 R&D Projects: GA ČR GP13-24730P Institutional support: RVO:67985904 Keywords : F-box protein * early development Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.234, year: 2014

  6. Synchronization, TIGoRS, and Information Flow in Complex Systems: Dispositional Cellular Automata.

    Science.gov (United States)

    Sulis, William H

    2016-04-01

    Synchronization has a long history in physics where it refers to the phase matching of two identical oscillators. This notion has been extensively studied in physics as well as in biology, where it has been applied to such widely varying phenomena as the flashing of fireflies and firing of neurons in the brain. Human behavior, however, may be recurrent but it is not oscillatory even though many physiological systems do exhibit oscillatory tendencies. Moreover, much of human behaviour is collaborative and cooperative, where the individual behaviours may be distinct yet contemporaneous (if not simultaneous) and taken collectively express some functionality. In the context of behaviour, the important aspect is the repeated co-occurrence in time of behaviours that facilitate the propagation of information or of functionality, regardless of whether or not these behaviours are similar or identical. An example of this weaker notion of synchronization is transient induced global response synchronization (TIGoRS). Previous work has shown that TIGoRS is a ubiquitous phenomenon among complex systems, enabling them to stably parse environmental transients into salient units to which they stably respond. This leads to the notion of Sulis machines, which emergently generate a primitive linguistic structure through their dynamics. This article reviews the notion of TIGoRS and its expression in several complex systems models including tempered neural networks, driven cellular automata and cocktail party automata. The emergent linguistics of Sulis machines are discussed. A new class of complex systems model, the dispositional cellular automaton is introduced. A new metric for TIGoRS, the excess synchronization, is introduced and applied to the study of TIGoRS in dispositional cellular automata. It is shown that these automata exhibit a nonlinear synchronization response to certain perturbing transients. PMID:27033136

  7. Gradient and mc scf calculations of the conformers and the formation of primary ethylene ozonide

    Science.gov (United States)

    Ruoff, Peter; Sæbø, Svein; Almlöf, Jan

    1981-11-01

    The confonners of primary ethylene ozonide have been studied by ab initio gradient and MC SCF calculations. At the MC SCF level they are more spread in energy than in SCF calculations. The planar conformer, carbon-carbon half chair and the oxygen envelope are much higher m energy than the other conformers. The MC SCF activation energy for cyclo-addition of ozone and ethylene is 91-99 kJ/mole.

  8. SELF-ADAPTIVE CONTROLS OF A COMPLEX CELLULAR SIGNALING TRANSDUCTION SYSTEM

    Institute of Scientific and Technical Information of China (English)

    LI Hong; ZHOU Zhiyuan; DAI Rongyang; LUO Bo; ZHENG Xiaoli; YANG Wenli; HE Tao; WU Minglu

    2004-01-01

    In cells, the interactions of distinct signaling transduction pathways originating from cross-talkings between signaling molecules give rise to the formation of signaling transduction networks, which contributes to the changes (emergency) of kinetic behaviors of signaling system compared with single molecule or pathway. Depending on the known experimental data, we have constructed a model for complex cellular signaling transduction system, which is derived from signaling transduction of epidermal growth factor receptor in neuron. By the computational simulating methods, the self-adaptive controls of this system have been investigated. We find that this model exhibits a relatively stable selfadaptive system, especially to over-stimulation of agonist, and the amplitude and duration of signaling intermediates in it could be controlled by multiple self-adaptive effects, such as "signal scattering", "positive feedback", "negative feedback" and "B-Raf shunt". Our results provide an approach to understanding the dynamic behaviors of complex biological systems.

  9. Structural Basis of the Cks1-Dependent Recognition of P27Kip1 by the SCF skp2 Ubiquitin Ligase

    Energy Technology Data Exchange (ETDEWEB)

    Hao,B.; Zheng, N.; Schulman, B.; Wu, G.; Miller, J.; Pagano, M.; Pavletich, N.

    2005-01-01

    The ubiquitin-mediated proteolysis of the Cdk2 inhibitor p27(Kip1) plays a central role in cell cycle progression, and enhanced degradation of p27(Kip1) is associated with many common cancers. Proteolysis of p27(Kip1) is triggered by Thr187 phosphorylation, which leads to the binding of the SCF(Skp2) (Skp1-Cul1-Rbx1-Skp2) ubiquitin ligase complex. Unlike other known SCF substrates, p27(Kip1) ubiquitination also requires the accessory protein Cks1. The crystal structure of the Skp1-Skp2-Cks1 complex bound to a p27(Kip1) phosphopeptide shows that Cks1 binds to the leucine-rich repeat (LRR) domain and C-terminal tail of Skp2, whereas p27(Kip1) binds to both Cks1 and Skp2. The phosphorylated Thr187 side chain of p27(Kip1) is recognized by a Cks1 phosphate binding site, whereas the side chain of an invariant Glu185 inserts into the interface between Skp2 and Cks1, interacting with both. The structure and biochemical data support the proposed model that Cdk2-cyclin A contributes to the recruitment of p27(Kip1) to the SCF(Skp2)-Cks1 complex.

  10. Modeling of the competition life cycle using the software complex of cellular automata PyCAlab

    Science.gov (United States)

    Berg, D. B.; Beklemishev, K. A.; Medvedev, A. N.; Medvedeva, M. A.

    2015-11-01

    The aim of the work is to develop a numerical model of the life cycle of competition on the basis of software complex cellular automata PyCAlab. The model is based on the general patterns of growth of various systems in resource-limited settings. At examples it is shown that the period of transition from an unlimited growth of the market agents to the stage of competitive growth takes quite a long time and may be characterized as monotonic. During this period two main strategies of competitive selection coexist: 1) capture of maximum market space with any reasonable costs; 2) saving by reducing costs. The obtained results allow concluding that the competitive strategies of companies must combine two mentioned types of behavior, and this issue needs to be given adequate attention in the academic literature on management. The created numerical model may be used for market research when developing of the strategies for promotion of new goods and services.

  11. Monitoring cellular uptake and cytotoxicity of copper(II) complex using a fluorescent anthracene thiosemicarbazone ligand.

    Science.gov (United States)

    Kate, Anup N; Kumbhar, Anupa A; Khan, Ayesha A; Joshi, Pranaya V; Puranik, Vedavati G

    2014-01-15

    The thiosemicarbazone derivative of anthracene (ATSC, anthracene thiosemicarbazone 1) and its copper(II) complex (CuATSC, 2) were synthesized and characterized by spectroscopic, electrochemical, and crystallographic techniques. Interaction of 1 and 2 with calf thymus (CT) DNA was explored using absorption and emission spectral methods, and viscosity measurements reveal a partial-intercalation binding mode. Their protein binding ability was monitored by the quenching of tryptophan emission using bovine serum albumin (BSA) as a model protein. Furthermore, their cellular uptake, in vitro cytotoxicity testing on the HeLa cell line, and flow cytometric analysis were carried out to ascertain the mode of cell death. Cell cycle analysis indicated that 1 and 2 cause cell cycle arrest in sub-G1 phase. PMID:24328322

  12. Identification of She3 as an SCF(Grr1 substrate in budding yeast.

    Directory of Open Access Journals (Sweden)

    Ruiwen Wang

    Full Text Available The highly orchestrated progression of the cell cycle depends on the degradation of many regulatory proteins at different cell cycle stages. One of the key cell cycle ubiquitin ligases is the Skp1-cullin-F-box (SCF complex. Acting in concert with the substrate-binding F-box protein Grr1, SCF(Grr1 promotes the degradation of cell cycle regulators as well as various metabolic enzymes. Using a yeast two-hybrid assay with a Grr1 derivative as the bait, we identified She3, which is an adaptor protein in the asymmetric mRNA transport system, as a novel Grr1 substrate. We generated stabilized She3 mutants, which no longer bound to Grr1, and found that the degradation of She3 is not required for regulating asymmetric mRNA transport. However, She3 stabilization leads to slower growth compared to wild-type cells in a co-culture assay, demonstrating that the degradation of She3 by Grr1 is required for optimal cell growth.

  13. New water-soluble ruthenium(II) cytotoxic complex: biological activity and cellular distribution.

    Science.gov (United States)

    Morais, Tânia S; Santos, Filipa C; Jorge, Tiago F; Côrte-Real, Leonor; Madeira, Paulo J Amorim; Marques, Fernanda; Robalo, M Paula; Matos, António; Santos, Isabel; Garcia, M Helena

    2014-01-01

    A novel water soluble organometallic compound, [RuCp(mTPPMSNa)(2,2'-bipy)][CF3SO3] (TM85, where Cp=η(5)-cyclopentadienyl, mTPPMS=diphenylphosphane-benzene-3-sulfonate and 2,2'-bipy=2,2'-bipyridine) is presented herein. Studies of interactions with relevant proteins were performed to understand the behavior and mode of action of this complex in the biological environment. Electrochemical and fluorescence studies showed that TM85 strongly binds to albumin. Studies carried out to study the formation of TM85 which adducts with ubiquitin and cytochrome c were performed by electrospray ionization mass spectrometry (ESI-MS). Antitumor activity was evaluated against a variety of human cancer cell lines, namely A2780, A2780cisR, MCF7, MDAMB231, HT29, PC3 and V79 non-tumorigenic cells and compared with the reference drug cisplatin. TM85 cytotoxic effect was reduced in the presence of endocytosis modulators at low temperatures, suggesting an energy-dependent mechanism consistent with endocytosis. Ultrastructural analysis by transmission electron microscopy (TEM) revealed that TM85 targets the endomembranar system disrupting the Golgi and also affects the mitochondria. Disruption of plasma membrane observed by flow cytometry could lead to cellular damage and cell death. On the whole, the biological activity evaluated herein combined with the water solubility property suggests that complex TM85 could be a promising anticancer agent. PMID:24145065

  14. Conformational analysis of primary ethylene ozonide by gradient and multiconfigurational scf calculations

    Science.gov (United States)

    Ruoff, Peter; Almlöf, Jan; Sæbø, Svem

    1980-06-01

    Four conformers of ethylene primary ozonide have been studied by ab initio gradient and MC SCF calculations, using gaussian-type basis functions. The MC SCF results indicate that the conformers are not as close in energy as suggested from single-determinant SCF calculations. The oxygen-oxygen and carbon-oxygen half-chair structures are much lower in energy than the carbon-carbon half-chair.

  15. SCF, Regulated by HIF-1α, Promotes Pancreatic Ductal Adenocarcinoma Cell Progression

    OpenAIRE

    Gao, Chuntao; Li, Shasha; Zhao, Tiansuo; Chen, Jing; Ren, He; Zhang, Huan; Wang, Xiuchao; Lang, Mingxiao; Liu, Jingcheng; Gao, Song; Zhao, Xiao; Sheng, Jun; Yuan, Zhanna; Hao, Jihui

    2015-01-01

    Stem cell factor (SCF) and hypoxia-inducible factor-1α (HIF-1α) both have important functions in pancreatic ductal adenocarcinoma (PDAC). This study aims to analyze the expression and clinicopathological significance of SCF and HIF-1α in PDAC specimens and explore the molecular mechanism at PDAC cells in vitro and in vivo. We showed that the expression of SCF was significantly correlated with HIF-1α expression via Western blot, PCR, chromatin immunoprecipitation (ChIP) assay, and luciferase a...

  16. Stem cell factor (SCF) protects osteoblasts from oxidative stress through activating c-Kit-Akt signaling

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Lei [Department of Orthopedics, Changzhou Wujin People’s Hospital-South Division, Affiliated Hospital of Jiangsu University, Changzhou (China); Wu, Zhong [Department of Orthopedics, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai (China); Yin, Gang; Liu, Haifeng; Guan, Xiaojun; Zhao, Xiaoqiang [Department of Orthopedics, Changzhou Wujin People’s Hospital-South Division, Affiliated Hospital of Jiangsu University, Changzhou (China); Wang, Jianguang, E-mail: jianguangwang@163.com [Department of Orthopedics, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai (China); Zhu, Jianguo, E-mail: gehujianguo68@163.com [Department of Orthopedics, Changzhou Wujin People’s Hospital-South Division, Affiliated Hospital of Jiangsu University, Changzhou (China)

    2014-12-12

    Highlights: • SCF receptor c-Kit is functionally expressed in primary and transformed osteoblasts. • SCF protects primary and transformed osteoblasts from H{sub 2}O{sub 2}. • SCF activation of c-Kit in osteoblasts, required for its cyto-protective effects. • c-Kit mediates SCF-induced Akt activation in cultured osteoblasts. • Akt activation is required for SCF-regulated cyto-protective effects in osteoblasts. - Abstract: Osteoblasts regulate bone formation and remodeling, and are main target cells of oxidative stress in the progression of osteonecrosis. The stem cell factor (SCF)-c-Kit pathway plays important roles in the proliferation, differentiation and survival in a range of cell types, but little is known about its functions in osteoblasts. In this study, we found that c-Kit is functionally expressed in both osteoblastic-like MC3T3-E1 cells and primary murine osteoblasts. Its ligand SCF exerted significant cyto-protective effects against hydrogen peroxide (H{sub 2}O{sub 2}). SCF activated its receptor c-Kit in osteoblasts, which was required for its cyto-protective effects against H{sub 2}O{sub 2}. Pharmacological inhibition (by Imatinib and Dasatinib) or shRNA-mediated knockdown of c-Kit thus inhibited SCF-mediated osteoblast protection. Further investigations showed that protection by SCF against H{sub 2}O{sub 2} was mediated via activation of c-Kit-dependent Akt pathway. Inhibition of Akt activation, through pharmacological or genetic means, suppressed SCF-mediated anti-H{sub 2}O{sub 2} activity in osteoblasts. In summary, we have identified a new SCF-c-Kit-Akt physiologic pathway that protects osteoblasts from H{sub 2}O{sub 2}-induced damages, and might minimize the risk of osteonecrosis caused by oxidative stress.

  17. Low-complexity co-tier interference reduction scheme in open-access overlaid cellular networks

    KAUST Repository

    Radaydeh, Redha Mahmoud Mesleh

    2011-12-01

    This paper addresses the effect of co-tier interference on the performance of multiuser overlaid cellular networks that share the same available resources. It assumed that each macrocell contains a number of self-configurable and randomly located femtocells that employ the open-access control strategy to reduce the effect of cross-tier interference. It is also assumed that the desired user equipment (UE) can access only one of the available channels, maintains simple decoding circuitry with single receive antenna, and has limited knowledge of the instantaneous channel state information (CSI) due to resource limitation. To mitigate the effect of co-tier interference in the absence of the CSI of the desired UE, a low-complexity switched-based scheme for single channel selection based on the predicted interference levels associated with available channels is proposed for the case of over-loaded channels. Through the analysis, new general formulation for the statistics of the resulting instantaneous interference power and some performance measures are presented. The effect of the switching threshold on the efficiency and performance of the proposed scheme is studied. Numerical and simulation results to clarify the usefulness of the proposed scheme in reducing the impact of co-tier interference are also provided. © 2011 IEEE.

  18. Computer Experiment on the Complex Behavior of a Two-Dimensional Cellular Automaton as a Phenomenological Model for an Ecosystem

    Science.gov (United States)

    Satoh, Kazuhiro

    1989-10-01

    Numerical studies are made on the complex behavior of a cellular automaton which serves as a phenomenological model for an ecosystem. The ecosystem is assumed to contain only three populations, i.e., a population of plants, of herbivores, and of carnivores. A two-dimensional region where organisms live is divided into square cells and the population density in each cell is regarded as a discrete variable. The influence of the physical environment and the interactions between organisms are reduced to a simple rule of cellular automaton evolution. It is found that the time dependent spatial distribution of organisms is, in general, very random and complex. However, under certain conditions, the self-organization of ordered patterns such as rotating spirals or concentric circles takes place. The relevance of the cellular automaton as a model for the ecosystem is discussed.

  19. The transforming proteins of PRCII virus and Rous sarcoma virus form a complex with the same two cellular phosphoproteins.

    OpenAIRE

    Adkins, B.; Hunter, T; Sefton, B M

    1982-01-01

    P105 and P110, the presumptive transforming proteins of PRCII avian sarcoma virus, have been found to be present in transformed chicken cells in two forms: as monomers and as part of a complex which contains both a 50,000-dalton and a 90,000-dalton cellular phosphoprotein. The 90,000-dalton cellular protein was found to be identical to one of the proteins in chicken cells whose synthesis is induced by stress. The 50,000-dalton protein was found to contain phosphotyrosine when isolated from th...

  20. Depletion of Cellular Pre-Replication Complex Factors Results in Increased Human Cytomegalovirus DNA Replication

    OpenAIRE

    Tamara Evans Braun; Emma Poole; John Sinclair

    2012-01-01

    Although HCMV encodes many genes required for the replication of its DNA genome, no HCMV-encoded orthologue of the origin binding protein, which has been identified in other herpesviruses, has been identified. This has led to speculation that HCMV may use other viral proteins or possibly cellular factors for the initiation of DNA synthesis. It is also unclear whether cellular replication factors are required for efficient replication of viral DNA during or after viral replication origin recog...

  1. Both Complexity and Location of DNA Damage Contribute to Cellular Senescence Induced by Ionizing Radiation

    OpenAIRE

    Xurui Zhang; Caiyong Ye; Fang Sun; Wenjun Wei; Burong Hu; Jufang Wang

    2016-01-01

    Persistent DNA damage is considered as a main cause of cellular senescence induced by ionizing radiation. However, the molecular bases of the DNA damage and their contribution to cellular senescence are not completely clear. In this study, we found that both heavy ions and X-rays induced senescence in human uveal melanoma 92-1 cells. By measuring senescence associated-β-galactosidase and cell proliferation, we identified that heavy ions were more effective at inducing senescence than X-rays. ...

  2. The Effect of Β-casein Nanoparticles on Bioavailability and Cellular Uptake of Platinum Complex as a Cancer Drug

    OpenAIRE

    M Razmi; A Divsalar

    2013-01-01

    Abstract Background & aim: Due to the low solubility and high toxicity of drugs, treatment of cancers is problematic therefore, the encapsulation and targeted delivery of therapeutic effect is required. The aim of this study was to investigate the effect of nanoparticles on cellular uptake and bioavailability of beta-casein on platinum complexes as cancer drugs. Methods: In the present experimental study, the physicochemical properties of nanoparticles as drug carriers of beta-ca...

  3. DNA-binding, cytotoxicity, cellular uptake, apoptosis and photocleavage studies of Ru(II) complexes.

    Science.gov (United States)

    N Deepika; C Shobha Devi; Y Praveen Kumar; K Laxma Reddy; P Venkat Reddy; D Anil Kumar; Surya S Singh; S Satyanarayana

    2016-07-01

    Two Ru(II) complexes [Ru(phen)2bppp](ClO4)2 (1) and [Ru(phen)27-Br-dppz](ClO4)2 (2) [phen=1,10 phenanthroline, 7-Br-dppz=7-fluorodipyrido[3,2-a:2',3'-c]phenazine, bppp=11-bromo-pyrido[2',3':5,6]pyrazino[2,3-f] [1,10]phenanthroline] have been synthesized and characterized by elemental analysis, ES-MS, (1)H-NMR, (13)C-NMR and IR. The in vitro cytotoxicity of the complexes examined against a panel of cancer cell lines (HeLa, Du145 and A549) by MTT method, both complexes show prominent anticancer activity against various cancer cells. Live cell imaging study and flow cytometric analysis demonstrate that both the complexes 1 and 2 could cross the cell membrane accumulating in the nucleus. Further, flow cytometry experiments showed that the cytotoxic Ru(II) complexes 1 and 2 induced apoptosis of HeLa tumor cell lines. Photo induced DNA cleavage studies have been performed and results indicate that both the complexes efficiently photo cleave pBR322 DNA. The binding properties of two complexes toward CT-DNA were investigated by various optical methods and viscosity measurements. The experimental results suggested that both Ru(II) complexes can intercalate into DNA base pairs. The complexes were docked into DNA-base pairs using the GOLD docking program. PMID:27107334

  4. Structural basis of the Cks1-dependent recognition of p27(Kip1) by the SCF(Skp2) ubiquitin ligase

    Energy Technology Data Exchange (ETDEWEB)

    Hao, B.; Zheng, N.; Schulman, B.A.; Wu, G.; Miller, J.J.; Pagano, M.; Pavletich, N.P. (MSKCC); (HHMI)

    2010-07-19

    The ubiquitin-mediated proteolysis of the Cdk2 inhibitor p27{sup Kip1} plays a central role in cell cycle progression, and enhanced degradation of p27{sup Kip1} is associated with many common cancers. Proteolysis of p27{sup Kip1} is triggered by Thr187 phosphorylation, which leads to the binding of the SCF{sup Skp2} (Skp1-Cul1-Rbx1-Skp2) ubiquitin ligase complex. Unlike other known SCF substrates, p27{sup Kip1} ubiquitination also requires the accessory protein Cks1. The crystal structure of the Skp1-Skp2-Cks1 complex bound to a p27{sup Kip1} phosphopeptide shows that Cks1 binds to the leucine-rich repeat (LRR) domain and C-terminal tail of Skp2, whereas p27{sup Kip1} binds to both Cks1 and Skp2. The phosphorylated Thr187 side chain of p27{sup Kip1} is recognized by a Cks1 phosphate binding site, whereas the side chain of an invariant Glu185 inserts into the interface between Skp2 and Cks1, interacting with both. The structure and biochemical data support the proposed model that Cdk2-cyclin A contributes to the recruitment of p27{sup Kip1} to the SCF{sup Skp2}-Cks1 complex.

  5. Refining the thermodynamic functions of scandium triflouride ScF3 in the condensed state

    Science.gov (United States)

    Aristova, N. M.; Belov, G. V.

    2016-03-01

    Refined thermodynamic functions (entropy, enthalpy increments, and reduced Gibbs energy) of scandium trifluoride ScF3 in the crystalline and liquid states in the temperature range 5-2500 K are presented.

  6. Electronic structure of cubic ScF$_3$ from first-principles calculations

    OpenAIRE

    Zhgun, P.; Bocharov, D.; Piskunov, S.; Kuzmin, A; Purans, J.

    2012-01-01

    The first-principles calculations have been performed to investigate the ground state properties of cubic scandium trifluoride (ScF$_3$) perovskite. Using modified hybrid exchange-correlation functionals within the density functional theory (DFT) we have comprehensively compared the electronic properties of ScF$_3$ obtained by means of the linear combination of atomic orbitals (LCAO) and projector augmented-waves (PAW) methods. Both methods allowed us to reproduce the lattice constant experim...

  7. The Effect of Β-casein Nanoparticles on Bioavailability and Cellular Uptake of Platinum Complex as a Cancer Drug

    Directory of Open Access Journals (Sweden)

    M Razmi

    2013-12-01

    Full Text Available Abstract Background & aim: Due to the low solubility and high toxicity of drugs, treatment of cancers is problematic therefore, the encapsulation and targeted delivery of therapeutic effect is required. The aim of this study was to investigate the effect of nanoparticles on cellular uptake and bioavailability of beta-casein on platinum complexes as cancer drugs. Methods: In the present experimental study, the physicochemical properties of nanoparticles as drug carriers of beta-casein devices using dynamic light scattering (DLS and scanning electron microscopy (SEM were investigated. In order to evaluate the toxicity effects of platinum complexes, the colon cancer cells in the absence or presence of free platinum complex concentration and nanoparticle loaded with platinum complexes were incubated for 24 and 48 hours. LD50 Values (concentration of compound causing 50% mortality in the cells was determined using the MTT assay. Data were analyzed by ANOVA and post-hoc test. Results: At a concentration of 1 mg ml, beta-casein nanoparticle drug carriers were synthesized in the range of 100 to 300 µM. In addition, the mortality rate in cancer cells by the release of platinum complexes (without and with the capsule, were 70 and 26 in 24 hours, and 60 µM and 21 µM in 48 hours respectively, Conclusion: The study showed that the bioavailability of the encapsulated platinum complexes increases and new drug delivery system may be a good candidate for the treatment of cancer. Key words: Beta-casein, Pt (II Complex, Bioavalibility, Nanocarrier, Micelle

  8. Complex dynamics of selection and cellular memory in adaptation to a changing environment

    Science.gov (United States)

    Kussell, Edo; Lin, Wei-Hsiang

    We study a synthetic evolutionary system in bacteria in which an antibiotic resistance gene is controlled by a stochastic on/off switching promoter. At the population level, this system displays all the basic ingredients for evolutionary selection, including diversity, fitness differences, and heritability. At the single cell level, physiological processes can modulate the ability of selection to act. We expose the stochastic switching strains to pulses of antibiotics of different durations in periodically changing environments using microfluidics. Small populations are tracked over a large number of periods at single cell resolution, allowing the visualization and quantification of selective sweeps and counter-sweeps at the population level, as well as detailed single cell analysis. A simple model is introduced to predict long-term population growth rates from single cell measurements, and reveals unexpected aspects of population dynamics, including cellular memory that acts on a fast timescale to modulate growth rates. This work is supported by NIH Grant No. R01-GM097356.

  9. Cellular Nutrition in Complex Three-Dimensional Scaffolds: A Comparison between Experiments and Computer Simulations

    Science.gov (United States)

    Bergemann, Claudia; Elter, Patrick; Lange, Regina; Weißmann, Volker; Hansmann, Harald; Klinkenberg, Ernst-Dieter; Nebe, Barbara

    2015-01-01

    Studies on bone cell ingrowth into synthetic, porous three-dimensional (3D) implants showed difficulties arising from impaired cellular proliferation and differentiation in the core region of these scaffolds with increasing scaffold volume in vitro. Therefore, we developed an in vitro perfusion cell culture module, which allows the analysis of cells in the interior of scaffolds under different medium flow rates. For each flow rate the cell viability was measured and compared with results from computer simulations that predict the local oxygen supply and shear stress inside the scaffold based on the finite element method. We found that the local cell viability correlates with the local oxygen concentration and the local shear stress. On the one hand the oxygen supply of the cells in the core becomes optimal with a higher perfusion flow. On the other hand shear stress caused by high flow rates impedes cell vitality, especially at the surface of the scaffold. Our results demonstrate that both parameters must be considered to derive an optimal nutrient flow rate. PMID:26539216

  10. Cellular Nutrition in Complex Three-Dimensional Scaffolds: A Comparison between Experiments and Computer Simulations

    Directory of Open Access Journals (Sweden)

    Claudia Bergemann

    2015-01-01

    Full Text Available Studies on bone cell ingrowth into synthetic, porous three-dimensional (3D implants showed difficulties arising from impaired cellular proliferation and differentiation in the core region of these scaffolds with increasing scaffold volume in vitro. Therefore, we developed an in vitro perfusion cell culture module, which allows the analysis of cells in the interior of scaffolds under different medium flow rates. For each flow rate the cell viability was measured and compared with results from computer simulations that predict the local oxygen supply and shear stress inside the scaffold based on the finite element method. We found that the local cell viability correlates with the local oxygen concentration and the local shear stress. On the one hand the oxygen supply of the cells in the core becomes optimal with a higher perfusion flow. On the other hand shear stress caused by high flow rates impedes cell vitality, especially at the surface of the scaffold. Our results demonstrate that both parameters must be considered to derive an optimal nutrient flow rate.

  11. Sevoflurane-Sulfobutylether-β-Cyclodextrin Complex: Preparation, Characterization, Cellular Toxicity, Molecular Modeling and Blood-Brain Barrier Transport Studies

    Directory of Open Access Journals (Sweden)

    Sergey Shityakov

    2015-06-01

    Full Text Available The objective of the present investigation was to study the ability of sulfobutylether-β-cyclodextrin (SBEβCD to form an inclusion complex with sevoflurane (SEV, a volatile anesthetic with poor water solubility. The inclusion complex was prepared, characterized and its cellular toxicity and blood-brain barrier (BBB permeation potential of the formulated SEV have also been examined for the purpose of controlled drug delivery. The SEV-SBEβCD complex was nontoxic to the primary brain microvascular endothelial (pEND cells at a clinically relevant concentration of sevoflurane. The inclusion complex exhibited significantly higher BBB permeation profiles as compared with the reference substance (propranolol concerning calculated apparent permeability values (Papp. In addition, SEV binding affinity to SBEβCD was confirmed by a minimal Gibbs free energy of binding (ΔGbind value of −1.727 ± 0.042 kcal·mol−1 and an average binding constant (Kb of 53.66 ± 9.24 mM indicating rapid drug liberation from the cyclodextrin amphiphilic cavity.

  12. Sevoflurane-Sulfobutylether-β-Cyclodextrin Complex: Preparation, Characterization, Cellular Toxicity, Molecular Modeling and Blood-Brain Barrier Transport Studies.

    Science.gov (United States)

    Shityakov, Sergey; Puskás, István; Pápai, Katalin; Salvador, Ellaine; Roewer, Norbert; Förster, Carola; Broscheit, Jens-Albert

    2015-01-01

    The objective of the present investigation was to study the ability of sulfobutylether-β-cyclodextrin (SBEβCD) to form an inclusion complex with sevoflurane (SEV), a volatile anesthetic with poor water solubility. The inclusion complex was prepared, characterized and its cellular toxicity and blood-brain barrier (BBB) permeation potential of the formulated SEV have also been examined for the purpose of controlled drug delivery. The SEV-SBEβCD complex was nontoxic to the primary brain microvascular endothelial (pEND) cells at a clinically relevant concentration of sevoflurane. The inclusion complex exhibited significantly higher BBB permeation profiles as compared with the reference substance (propranolol) concerning calculated apparent permeability values (Papp). In addition, SEV binding affinity to SBEβCD was confirmed by a minimal Gibbs free energy of binding (ΔGbind) value of -1.727 ± 0.042 kcal·mol-1 and an average binding constant (Kb) of 53.66 ± 9.24 mM indicating rapid drug liberation from the cyclodextrin amphiphilic cavity. PMID:26046323

  13. Predominant Expression of Hybrid N-Glycans Has Distinct Cellular Roles Relative to Complex and Oligomannose N-Glycans

    Directory of Open Access Journals (Sweden)

    M. Kristen Hall

    2016-06-01

    Full Text Available Glycosylation modulates growth, maintenance, and stress signaling processes. Consequently, altered N-glycosylation is associated with reduced fitness and disease. Therefore, expanding our understanding of N-glycans in altering biological processes is of utmost interest. Herein, clustered regularly interspaced short palindromic repeats/caspase9 (CRISPR/Cas9 technology was employed to engineer a glycosylation mutant Chinese Hamster Ovary (CHO cell line, K16, which expresses predominantly hybrid type N-glycans. This newly engineered cell line enabled us to compare N-glycan effects on cellular properties of hybrid type N-glycans, to the well-established Pro−5 and Lec1 cell lines, which express complex and oligomannose types of N-glycans, respectively. Lectin binding studies revealed the predominant N-glycan expressed in K16 is hybrid type. Cell dissociation and migration assays demonstrated the greatest strength of cell–cell adhesion and fastest migratory rates for oligomannose N-glycans, and these properties decreased as oligomannose type were converted to hybrid type, and further decreased upon conversion to complex type. Next, we examined the roles of three general types of N-glycans on ectopic expression of E-cadherin, a cell–cell adhesion protein. Microscopy revealed more functional E-cadherin at the cell–cell border when N-glycans were oligomannose and these levels decreased as the oligomannose N-glycans were processed to hybrid and then to complex. Thus, we provide evidence that all three general types of N-glycans impact plasma membrane architecture and cellular properties.

  14. Cellular responses induced by Cu(II quinolinonato complexes in human tumor and hepatic cells

    Directory of Open Access Journals (Sweden)

    Trávníček Zdeněk

    2012-12-01

    Full Text Available Abstract Background Inspired by the unprecedented historical success of cisplatin, one of the most important research directions in bioinorganic and medicinal chemistry is dedicated to the development of new anticancer compounds with the potential to surpass it in antitumor activity, while having lower unwanted side-effects. Therefore, a series of copper(II mixed-ligand complexes of the type [Cu(qui(L]Y · xH2O (1–6, where Hqui = 2-phenyl-3-hydroxy-4(1H-quinolinone, Y = NO3 (1, 3, 5 or BF4 (2, 4, 6, and L = 1,10-phenanthroline (phen (1, 2, 5-methyl-1,10-phenanthroline (mphen (3, 4 and bathophenanthroline (bphen (5, 6, was studied for their in vitro cytotoxicity against several human cancer cell lines (A549 lung carcinoma, HeLa cervix epitheloid carcinoma, G361 melanoma cells, A2780 ovarian carcinoma, A2780cis cisplatin-resistant ovarian carcinoma, LNCaP androgen-sensitive prostate adenocarcinoma and THP-1 monocytic leukemia. Results The tested complexes displayed a stronger cytotoxic effect against all the cancer cells as compared to cisplatin. The highest cytotoxicity was found for the complexes 4 (IC50 = 0.36 ± 0.05 μM and 0.56 ± 0.15 μM, 5 (IC50 = 0.66 ± 0.07 μM and 0.73 ± 0.08 μM and 6 (IC50 = 0.57 ± 0.11 μM and 0.70 ± 0.20 μM against A2780, and A2780cis respectively, as compared with the values of 12.0 ± 0.8 μM and 27.0 ± 4.6 μM determined for cisplatin. Moreover, the tested complexes were much less cytotoxic to primary human hepatocytes than to the cancer cells. The complexes 5 and 6 exhibited significantly high ability to modulate secretion of the pro-inflammatory cytokines TNF-α (2873 ± 238 pg/mL and 3284 ± 139 pg/mL for 5, and 6 respectively and IL-1β (1177 ± 128 pg/mL and 1087 ± 101 pg/mL for 5, and 6 respectively tested on the lipopolysaccharide (LPS-stimulated THP-1 cells as compared with the values of 1173

  15. Fluorescent cDNA microarray hybridization reveals complexity and heterogeneity of cellular genotoxic stress responses.

    Science.gov (United States)

    Amundson, S A; Bittner, M; Chen, Y; Trent, J; Meltzer, P; Fornace, A J

    1999-06-17

    The fate of cells exposed to ionizing radiation (IR) may depend greatly on changes in gene expression, so that an improved view of gene induction profiles is important for understanding mechanisms of checkpoint control, repair and cell death following such exposures. We have used a quantitative fluorescent cDNA microarray hybridization approach to identify genes regulated in response to 7-irradiation in the p53 wild-type ML-1 human myeloid cell line. Hybridization of the array to fluorescently-labeled RNA from treated and untreated cells was followed by computer analysis to derive relative changes in expression levels of the genes present in the array, which agreed well with actual quantitative changes in expression. Forty-eight sequences, 30 not previously identified as IR-responsive, were significantly regulated by IR. Induction by IR and other stresses of a subset of these genes, including the previously characterized CIP1/ WAF1, MDM2 and BAX genes, as well as nine genes not previously reported to be IR-responsive, was examined in a panel of 12 human cell lines. Responses varied widely in cell lines with different tissues of origin and different genetic backgrounds, highlighting the importance of cellular context to genotoxic stress responses. Two of the newly identified IR-responsive genes, FRA-1 and ATF3, showed a p53-associated component to their IR-induction, and this was confirmed both in isogenic human cell lines and in mouse thymus. The majority of the IR-responsive genes, however, showed no indication of p53-dependent regulation, representing a potentially important class of stress-responsive genes in leukemic cells. PMID:10380890

  16. Complex Systems in APL: Fractals, Evolving Cellular Automata and Artificial Life

    OpenAIRE

    Alfonseca, Manuel; Ortega, Alfonso; Cruz Echeandía, Marina de la

    2002-01-01

    This is the author's version of the work. It is posted here for your personal use. Not for redistribution. The definitive Version of Record was published in APL Quote Quad 32.4 (2002): 17 – 26, http://dx.doi.org/10.1145/604444.602233 We have been working for several years on the representation, study and simulation of complex systems by means of formal methods. APL2 and other programming languages have been used to develop our tools and experiments. This paper summarizes our APL2 works on ...

  17. Surface Complexation-Based Biocompatible Magnetofluorescent Nanoprobe for Targeted Cellular Imaging.

    Science.gov (United States)

    Bhandari, Satyapriya; Khandelia, Rumi; Pan, Uday Narayan; Chattopadhyay, Arun

    2015-08-19

    We report the synthesis of a magnetofluorescent biocompatible nanoprobe-following room temperature complexation reaction between Fe3O4-ZnS nanocomposite and 8-hydroxyquinoline (HQ). The composite nanoprobe exhibited high luminescence quantum yield, low rate of photobleaching, reasonable excited-state lifetime, luminescence stability especially in human blood serum, superparamagnetism and no apparent cytotoxicity. Moreover, the nanoprobe could be used for spatio-controlled cell labeling in the presence of an external magnetic field. The ease of synthesis and cell labeling in vitro make it a suitable candidate for targeted bioimaging applications. PMID:26226317

  18. A differential genome-wide transcriptome analysis: impact of cellular copper on complex biological processes like aging and development.

    Directory of Open Access Journals (Sweden)

    Jörg Servos

    Full Text Available The regulation of cellular copper homeostasis is crucial in biology. Impairments lead to severe dysfunctions and are known to affect aging and development. Previously, a loss-of-function mutation in the gene encoding the copper-sensing and copper-regulated transcription factor GRISEA of the filamentous fungus Podospora anserina was reported to lead to cellular copper depletion and a pleiotropic phenotype with hypopigmentation of the mycelium and the ascospores, affected fertility and increased lifespan by approximately 60% when compared to the wild type. This phenotype is linked to a switch from a copper-dependent standard to an alternative respiration leading to both a reduced generation of reactive oxygen species (ROS and of adenosine triphosphate (ATP. We performed a genome-wide comparative transcriptome analysis of a wild-type strain and the copper-depleted grisea mutant. We unambiguously assigned 9,700 sequences of the transcriptome in both strains to the more than 10,600 predicted and annotated open reading frames of the P. anserina genome indicating 90% coverage of the transcriptome. 4,752 of the transcripts differed significantly in abundance with 1,156 transcripts differing at least 3-fold. Selected genes were investigated by qRT-PCR analyses. Apart from this general characterization we analyzed the data with special emphasis on molecular pathways related to the grisea mutation taking advantage of the available complete genomic sequence of P. anserina. This analysis verified but also corrected conclusions from earlier data obtained by single gene analysis, identified new candidates of factors as part of the cellular copper homeostasis system including target genes of transcription factor GRISEA, and provides a rich reference source of quantitative data for further in detail investigations. Overall, the present study demonstrates the importance of systems biology approaches also in cases were mutations in single genes are analyzed to

  19. The Complex Economic System of Supply Chain Financing

    Science.gov (United States)

    Zhang, Lili; Yan, Guangle

    Supply Chain Financing (SCF) refers to a series of innovative and complicated financial services based on supply chain. The SCF set-up is a complex system, where the supply chain management and Small and Medium Enterprises (SMEs) financing services interpenetrate systematically. This paper establishes the organization structure of SCF System, and presents two financing models respectively, with or without the participation of the third-party logistic provider (3PL). Using Information Economics and Game Theory, the interrelationship among diverse economic sectors is analyzed, and the economic mechanism of development and existent for SCF system is demonstrated. New thoughts and approaches to solve SMEs financing problem are given.

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

    Science.gov (United States)

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

    2015-10-30

    Systems biologists aim to decipher the structure and dynamics of signaling and regulatory networks underpinning cellular responses; synthetic biologists can use this insight to alter existing networks or engineer de novo ones. Both tasks will benefit from an understanding of which structural and dynamic features of networks can emerge from evolutionary processes, through which intermediary steps these arise, and whether they embody general design principles. As natural evolution at the level of network dynamics is difficult to study, in silico evolution of network models can provide important insights. However, current tools used for in silico evolution of network dynamics are limited to ad hoc computer simulations and models. Here we introduce BioJazz, an extendable, user-friendly tool for simulating the evolution of dynamic biochemical networks. Unlike previous tools for in silico evolution, BioJazz allows for the evolution of cellular networks with unbounded complexity by combining rule-based modeling with an encoding of networks that is akin to a genome. We show that BioJazz can be used to implement biologically realistic selective pressures and allows exploration of the space of network architectures and dynamics that implement prescribed physiological functions. BioJazz is provided as an open-source tool to facilitate its further development and use. Source code and user manuals are available at: http://oss-lab.github.io/biojazz and http://osslab.lifesci.warwick.ac.uk/BioJazz.aspx. PMID:26101250

  1. Ionization States, Cellular Toxicity and Molecular Modeling Studies of Midazolam Complexed with Trimethyl-β-Cyclodextrin

    Directory of Open Access Journals (Sweden)

    Sergey Shityakov

    2014-10-01

    Full Text Available We investigated the ionization profiles for open-ring (OR and closed-ring (CR forms of midazolam and drug-binding modes with heptakis-(2,3,6-tri-O-methyl-β-cyclodextrin (trimethyl-β-cyclodextrin; TRIMEB using molecular modeling techniques and quantum mechanics methods. The results indicated that the total net charges for different molecular forms of midazolam tend to be cationic for OR and neutral for CR at physiological pH levels. The thermodynamic calculations demonstrated that CR is less water-soluble than OR, mainly due to the maximal solvation energy (\\(\\Delta G_{solv}^{CR}\\ = −9.98 kcal·mol\\(^{−1}\\, which has a minimal \\(\\Delta G_{solv}^{OR}\\ of −67.01 kcal·mol\\(^{−1}\\. A cell viability assay did not detect any signs of TRIMEB and OR/CR-TRIMEB complex toxicity on the cEND cells after 24 h of incubation in either Dulbecco's Modified Eagles Medium or in heat-inactivated human serum. The molecular docking studies identified the more flexible OR form of midazolam as being a better binder to TRIMEB with the fluorophenyl ring introduced inside the amphiphilic cavity of the host molecule. The OR binding affinity was confirmed by a minimal Gibbs free energy of binding (\\(\\Delta G_{bind}\\ value of −5.57 ± 0.02 kcal·mol\\(^{−1}\\, an equilibrium binding constant (\\(K_{b}\\ of 79.89 ± 2.706 μM, and a ligand efficiency index (\\(LE_{lig}\\ of −0.21 ± 0.001. Our current data suggest that in order to improve the clinical applications of midazolam via its complexation with trimethyl-β-cyclodextrin to increase drug's overall aqueous solubility, it is important to concern the different forms and ionization states of this anesthetic. All mean values are indicated with their standard deviations.

  2. Ionization states, cellular toxicity and molecular modeling studies of midazolam complexed with trimethyl-β-cyclodextrin.

    Science.gov (United States)

    Shityakov, Sergey; Sohajda, Tamás; Puskás, István; Roewer, Norbert; Förster, Carola; Broscheit, Jens-Albert

    2014-01-01

    We investigated the ionization profiles for open-ring (OR) and closed-ring (CR) forms of midazolam and drug-binding modes with heptakis-(2,3,6-tri-O-methyl)-β-cyclodextrin (trimethyl-β-cyclodextrin; TRIMEB) using molecular modeling techniques and quantum mechanics methods. The results indicated that the total net charges for different molecular forms of midazolam tend to be cationic for OR and neutral for CR at physiological pH levels. The thermodynamic calculations demonstrated that CR is less water-soluble than OR, mainly due to the maximal solvation energy (ΔG(CR)(solv = -9.98 kcal·mol ⁻¹), which has a minimal ΔG(OR)(solv) of -67.01 kcal·mol⁻¹. A cell viability assay did not detect any signs of TRIMEB and OR/CR-TRIMEB complex toxicity on the cEND cells after 24 h of incubation in either Dulbecco's Modified Eagles Medium or in heat-inactivated human serum. The molecular docking studies identified the more flexible OR form of midazolam as being a better binder to TRIMEB with the fluorophenyl ring introduced inside the amphiphilic cavity of the host molecule. The OR binding affinity was confirmed by a minimal Gibbs free energy of binding (ΔG(bind)) value of -5.57 ± 0.02 kcal·mol⁻¹, an equilibrium binding constant (K(b)) of 79.89 ± 2.706 μM, and a ligand efficiency index (LE(lig)) of -0.21 ± 0.001. Our current data suggest that in order to improve the clinical applications of midazolam via its complexation with trimethyl-β-cyclodextrin to increase drug's overall aqueous solubility, it is important to concern the different forms and ionization states of this anesthetic. All mean values are indicated with their standard deviations. PMID:25338177

  3. 22号初等元胞自动机的演化复杂性%EVOLUTION COMPLEXITY OF THE ELEMENTARY CELLULAR AUTOMATON OF RULE 22

    Institute of Scientific and Technical Information of China (English)

    王益; 江志松

    2002-01-01

    Cellular automata are the discrete dynamical systems of simple construction but with complex and varied behaviors.In this paper,the elementary cellular automaton of rule 22 is studied by the tools of formal language theory and symbolic dynamics.Its temporal evolution orbits are coarse-grained into evolution sequences and the evolution languages are defined.It is proved that for every n≥2 its width n-evolution language is not regular.

  4. Stem Cell Factor (SCF) is a putative biomarker of antidepressant response.

    Science.gov (United States)

    Benedetti, Francesco; Poletti, Sara; Hoogenboezem, Thomas A; Locatelli, Clara; Ambrée, Oliver; de Wit, Harm; Wijkhuijs, Annemarie J M; Mazza, Elena; Bulgarelli, Chiara; Vai, Benedetta; Colombo, Cristina; Smeraldi, Enrico; Arolt, Volker; Drexhage, Hemmo A

    2016-06-01

    Growth factors involved in neurogenesis and neuroplasticity could play a role in biological processes that drive depression recovery. Combined total sleep deprivation and morning light therapy (TSD + LT) can acutely reverse depressive symptoms, thus allowing to investigate the neurobiological correlates of antidepressant response. We tested if changes on plasma levels of Brain Derived Neurotrophic Factor (BDNF), S100 calcium binding protein B (S100-B), Stem Cell Factor (SCF), Insulin-like Growth Factor-Binding Protein 2 (IGFBP-2), Epidermal Growth Factor (EGF), Platelet-Derived Growth Factor-BB (PDGF-BB), and Vascular Endothelial Growth Factor (VEGF) are associated with response to TSD + LT in 26 inpatients affected by a major depressive episode in the course of bipolar disorder. Regional grey matter (GM) volumes were assessed at baseline, and BOLD fMRI neural responses to a moral valence decision task were recorded before and after treatment. 61.5 % of patients responded to treatment. SCF plasma levels increased significantly more in responders, and correlated with GM volumes in frontal and parietal cortical areas. The pattern of change of SCF also associated with both GM volumes and changes of BOLD fMRI neural responses in the anterior cingulate and medial prefrontal cortex. SCF is both a hematopoietic growth factor and a neurotrophic factor, involved in neuron-neuron and neuron-(micro) glia interactions, fostering neuronal growth and an anti-inflammatory milieu. We correlated SCF levels with antidepressant response and with functional and structural MRI measures in cortical areas that are involved in the cognitive generation and control of affect. SCF may be a candidate growth factor that contributes to neurotrophic and immune effects that are involved in the process of remission/recovery from depression. PMID:27108110

  5. Unique Role for the UbL-UbA Protein Ddi1 in Turnover of SCFUfo1 Complexes

    OpenAIRE

    Ivantsiv, Yelena; Kaplun, Ludmila; Tzirkin-Goldin, Regina; Shabek, Nitzan; Raveh, Dina

    2006-01-01

    SCF complexes are E3 ubiquitin-protein ligases that mediate degradation of regulatory and signaling proteins and control G1/S cell cycle progression by degradation of G1 cyclins and the cyclin-dependent kinase inhibitor, Sic1. Interchangeable F-box proteins bind the core SCF components; each recruits a specific subset of substrates for ubiquitylation. The F-box proteins themselves are rapidly turned over by autoubiquitylation, allowing rapid recycling of SCF complexes. Here we report a role f...

  6. Cloning, characterization and sub-cellular localization of gamma subunit of T-complex protein-1 (chaperonin) from Leishmania donovani

    International Nuclear Information System (INIS)

    Highlights: ► The study presents cloning and characterization of TCP1γ gene from L. donovani. ► TCP1γ is a subunit of T-complex protein-1 (TCP1), a chaperonin class of protein. ► LdTCPγ exhibited differential expression in different stages of promastigotes. ► LdTCPγ co-localized with actin, a cytoskeleton protein. ► The data suggests that this gene may have a role in differentiation/biogenesis. ► First report on this chapronin in Leishmania. -- Abstract: T-complex protein-1 (TCP1) complex, a chaperonin class of protein, ubiquitous in all genera of life, is involved in intracellular assembly and folding of various proteins. The gamma subunit of TCP1 complex (TCP1γ), plays a pivotal role in the folding and assembly of cytoskeleton protein(s) as an individual or complexed with other subunits. Here, we report for the first time cloning, characterization and expression of the TCP1γ of Leishmania donovani (LdTCP1γ), the causative agent of Indian Kala-azar. Primary sequence analysis of LdTCP1γ revealed the presence of all the characteristic features of TCP1γ. However, leishmanial TCP1γ represents a distinct kinetoplastid group, clustered in a separate branch of the phylogenic tree. LdTCP1γ exhibited differential expression in different stages of promastigotes. The non-dividing stationary phase promastigotes exhibited 2.5-fold less expression of LdTCP1γ as compared to rapidly dividing log phase parasites. The sub-cellular distribution of LdTCP1γ was studied in log phase promastigotes by employing indirect immunofluorescence microscopy. The protein was present not only in cytoplasm but it was also localized in nucleus, peri-nuclear region, flagella, flagellar pocket and apical region. Co-localization of LdTCP1γ with actin suggests that, this gene may have a role in maintaining the structural dynamics of cytoskeleton of parasite.

  7. Cellular delivery of pyrenyl-arene ruthenium complexes by a water-soluble arene ruthenium metalla-cage.

    Science.gov (United States)

    Furrer, Mona Anca; Schmitt, Frédéric; Wiederkehr, Michaël; Juillerat-Jeanneret, Lucienne; Therrien, Bruno

    2012-06-28

    Three pyrenyl-arene ruthenium complexes (M(1)-M(3)) of the general formula [Ru(η(6)-arene-pyrenyl)Cl(2)(pta)] (pta = 1,3,5-triaza-7-phosphaadamantane) have been synthesised and characterised. Prior to the coordination to ruthenium, pyrene was connected to the arene ligand via an alkane chain containing different functional groups: ester (L(1)), ether (L(2)) and amide (L(3)), respectively. Furthermore, the pyrenyl moieties of the M(n) complexes were encapsulated within the hydrophobic cavity of the water soluble metalla-cage, [Ru(6)(η(6)-p-cymene)(6)(tpt)(2)(donq)(3)](6+) (tpt = 2,4,6-tri-(pyridin-4-yl)-1,3,5-triazine; donq = 5,8-dioxydo-1,4-naphthoquinonato), while the arene ruthenium end was pointing out of the cage, thus giving rise to the corresponding host-guest systems [M(n)⊂Ru(6)(η(6)-p-cymene)(6)(tpt)(2)(donq)(3)](6+) ([M(n)⊂cage](6+)). The antitumor activity of the pyrenyl-arene ruthenium complexes (M(n)) and the corresponding host-guest systems [M(n)⊂cage][CF(3)SO(3)](6) were evaluated in vitro in different types of human cancer cell lines (A549, A2780, A2780cisR, Me300 and HeLa). Complex M(2), which contains an ether group within the alkane chain, demonstrated at least a 10 times higher cytotoxicity than the reference compound [Ru(η(6)-p-cymene)Cl(2)(pta)] (RAPTA-C). All host-guest systems [M(n)⊂cage](6+) showed good anticancer activity with IC(50) values ranging from 2 to 8 μM after 72 h exposure. The fluorescence of the pyrenyl moiety allowed the monitoring of the cellular uptake and revealed an increase of uptake by a factor two of the M(2) complex when encapsulated in the metalla-cage [Ru(6)(η(6)-p-cymene)(6)(tpt)(2)(donq)(3)](6+). PMID:22506276

  8. Cloning, characterization and sub-cellular localization of gamma subunit of T-complex protein-1 (chaperonin) from Leishmania donovani

    Energy Technology Data Exchange (ETDEWEB)

    Bhaskar,; Kumari, Neeti [Division of Biochemistry, CSIR-Central Drug Research Institute, Chattar Manzil Palace, PO Box 173, Lucknow (India); Goyal, Neena, E-mail: neenacdri@yahoo.com [Division of Biochemistry, CSIR-Central Drug Research Institute, Chattar Manzil Palace, PO Box 173, Lucknow (India)

    2012-12-07

    Highlights: Black-Right-Pointing-Pointer The study presents cloning and characterization of TCP1{gamma} gene from L. donovani. Black-Right-Pointing-Pointer TCP1{gamma} is a subunit of T-complex protein-1 (TCP1), a chaperonin class of protein. Black-Right-Pointing-Pointer LdTCP{gamma} exhibited differential expression in different stages of promastigotes. Black-Right-Pointing-Pointer LdTCP{gamma} co-localized with actin, a cytoskeleton protein. Black-Right-Pointing-Pointer The data suggests that this gene may have a role in differentiation/biogenesis. Black-Right-Pointing-Pointer First report on this chapronin in Leishmania. -- Abstract: T-complex protein-1 (TCP1) complex, a chaperonin class of protein, ubiquitous in all genera of life, is involved in intracellular assembly and folding of various proteins. The gamma subunit of TCP1 complex (TCP1{gamma}), plays a pivotal role in the folding and assembly of cytoskeleton protein(s) as an individual or complexed with other subunits. Here, we report for the first time cloning, characterization and expression of the TCP1{gamma} of Leishmania donovani (LdTCP1{gamma}), the causative agent of Indian Kala-azar. Primary sequence analysis of LdTCP1{gamma} revealed the presence of all the characteristic features of TCP1{gamma}. However, leishmanial TCP1{gamma} represents a distinct kinetoplastid group, clustered in a separate branch of the phylogenic tree. LdTCP1{gamma} exhibited differential expression in different stages of promastigotes. The non-dividing stationary phase promastigotes exhibited 2.5-fold less expression of LdTCP1{gamma} as compared to rapidly dividing log phase parasites. The sub-cellular distribution of LdTCP1{gamma} was studied in log phase promastigotes by employing indirect immunofluorescence microscopy. The protein was present not only in cytoplasm but it was also localized in nucleus, peri-nuclear region, flagella, flagellar pocket and apical region. Co-localization of LdTCP1{gamma} with actin suggests

  9. Cul7/p185/p193 binding to simian virus 40 large T antigen has a role in cellular transformation.

    Science.gov (United States)

    Ali, Syed Hamid; Kasper, Jocelyn S; Arai, Takehiro; DeCaprio, James A

    2004-03-01

    Simian virus 40 large T antigen (TAg) is a viral oncoprotein that can promote cellular transformation. TAg's transforming activity results in part by binding and inactivating key tumor suppressors, including p53 and the retinoblastoma protein (pRb). We have identified a TAg-associated 185-kDa protein that has significant homology to the cullin family of E3 ubiquitin ligases. TAg binds to an SCF-like complex that contains p185/Cul7, Rbx1, and the F box protein Fbw6. This SCF-like complex binds to an N-terminal region of TAg. Several p185/Cul7-binding-deficient mutants of TAg were generated that retained binding to pRb and p53 and were capable of overcoming Rb-mediated repression of E2F transcription. Despite binding to pRb and p53, these p185/Cul7-binding-defective mutants of TAg were unable to transform primary mouse embryo fibroblasts. Cells expressing p185/Cul7-binding-defective mutants of TAg were unable to grow to high density or grow in an anchorage-independent manner as determined by growth in soft agar. Considering the significance of other TAg-interacting proteins in regulation of the cell cycle, p185/Cul7 may also regulate an important growth control pathway. PMID:14990695

  10. Priming with r-metHuSCF and filgrastim or chemotherapy and filgrastim in patients with malignant lymphomas: a randomized phase II pilot study of mobilization and engraftment

    DEFF Research Database (Denmark)

    Johnsen, H E; Geisler, C; Juvonen, E;

    2011-01-01

    SCF has been shown to synergize with G-CSF to mobilize CD34(+) PBPCs. In this study we report results from this combination after a phase II trial of 32 patients with malignant lymphoma randomized to receive recombinant methionyl human SCF (ancestim, r-metHuSCF) in combination with recombinant me...

  11. Effects of Banxiaxiexin Decoction on the SCF Gene Expression in the Stomach Wall of Rat Model of Electrogastric Dysrhythmias

    Institute of Scientific and Technical Information of China (English)

    Li Yuhang; Wang Qingguo; Chen meng; Wang Dan; Li Lina; Zhang Dongmei

    2003-01-01

    Objective:To observe the effects of Banxiaxiexin Decoction (BD) on rats with electrogastric dysrhythmias by divided design and discuss the mechanism of BD. Methods:To establish the rat model of electrogastric dysrhythmias and examine effects of BD on the SCF mRNA by reverse transcriptive polymerase chain reaction (RT-PCR).Results:BD and all the divided groups can reduce the mRNA expression of SCF, and show significant difference with model group (P0.05).Conclusion:The BD treatment of epigastric fullness (to regulate the movement of stomach and intestine) is in connection with adjustment of the mRNA expression of SCF.

  12. Evidence supporting dissimilatory and assimilatory lignin degradation in Enterobacter lignolyticus SCF1

    OpenAIRE

    DeAngelis, Kristen M.; Sharma, Deepak; Varney, Rebecca; Simmons, Blake; Isern, Nancy. G.; Markilllie, Lye Meng; Nicora, Carrie; Norbeck, Angela D.; Taylor, Ronald C.; Aldrich, Joshua T.; Robinson, Errol W.

    2013-01-01

    Lignocellulosic biofuels are promising as sustainable alternative fuels, but lignin inhibits access of enzymes to cellulose, and by-products of lignin degradation can be toxic to cells. The fast growth, high efficiency and specificity of enzymes employed in the anaerobic litter deconstruction carried out by tropical soil bacteria make these organisms useful templates for improving biofuel production. The facultative anaerobe Enterobacter lignolyticus SCF1 was initially cultivated from Cloud F...

  13. $\\sigma$-SCF: A Direct Energy-targeting Method To Mean-field Excited States

    CERN Document Server

    Ye, Hong-Zhou; Ricke, Nathan D; Van Voorhis, Troy

    2016-01-01

    The mean-field solutions of electronic excited states are much less accessible than ground state (e.g.\\ Hartree-Fock) solutions. Energy-based optimization methods for excited states, like $\\Delta$-scf, tend to fall into the lowest solution consistent with a given symmetry -- a problem known as "variational collapse". In this work, we combine the ideas of direct energy-targeting and variance-based optimization in order to describe excited states at the mean-field level. The resulting method, $\\sigma$-scf, has several advantages. First, it allows one to target any desired excited state by specifying a single parameter: a guess of the energy of that state. It can therefore, in principle, find \\emph{all} excited states. Second, it avoids variational collapse by using a variance-based, unconstrained local minimization. As a consequence, all states -- ground or excited -- are treated on an equal footing. Third, it provides an alternate approach to locate $\\Delta$-scf solutions that are otherwise inaccessible by the...

  14. Pseudosubstrate regulation of the SCF(beta-TrCP) ubiquitin ligase by hnRNP-U

    DEFF Research Database (Denmark)

    Davis, Matti; Hatzubai, Ada; Andersen, Jens S; Ben-Shushan, Etti; Fisher, Gregory Zvi; Yaron, Avraham; Bauskin, Asne; Mercurio, Frank; Mann, Matthias; Ben-Neriah, Yinon

    2002-01-01

    beta-TrCP/E3RS (E3RS) is the F-box protein that functions as the receptor subunit of the SCF(beta-TrCP) ubiquitin ligase (E3). Surprisingly, although its two recognized substrates, IkappaB(alpha) and beta-catenin, are present in the cytoplasm, we have found that E3RS is located predominantly in the...... competition with a pIkappaB(alpha) peptide, or by a specific point mutation in the E3RS WD region, indicating an E3-substrate-type interaction. However, unlike pI(kappa)Balpha, which is targeted by SCF(beta-TrCP) for degradation, the E3-bound hnRNP-U is stable and is, therefore, a pseudosubstrate....... Consequently, hnRNP-U engages a highly neddylated active SCF(beta-TrCP), which dissociates in the presence of a high-affinity substrate, resulting in ubiquitination of the latter. Our study points to a novel regulatory mechanism, which secures the localization, stability, substrate binding threshold, and...

  15. Combinatorial diversity of fission yeast SCF ubiquitin ligases by homo- and heterooligomeric assemblies of the F-box proteins Pop1p and Pop2p

    Directory of Open Access Journals (Sweden)

    Abderazzaq Kareem

    2002-08-01

    Full Text Available Abstract Background SCF ubiquitin ligases share the core subunits cullin 1, SKP1, and HRT1/RBX1/ROC1, which associate with different F-box proteins. F-box proteins bind substrates following their phosphorylation upon stimulation of various signaling pathways. Ubiquitin-mediated destruction of the fission yeast cyclin-dependent kinase inhibitor Rum1p depends on two heterooligomerizing F-box proteins, Pop1p and Pop2p. Both proteins interact with the cullin Pcu1p when overexpressed, but it is unknown whether this reflects their co-assembly into bona fide SCF complexes. Results We have identified Psh1p and Pip1p, the fission yeast homologues of human SKP1 and HRT1/RBX1/ROC1, and show that both associate with Pop1p, Pop2p, and Pcu1p into a ~500 kDa SCFPop1p-Pop2p complex, which supports polyubiquitylation of Rum1p. Only the F-box of Pop1p is required for SCFPop1p-Pop2p function, while Pop2p seems to be attracted into the complex through binding to Pop1p. Since all SCFPop1p-Pop2p subunits, except for Pop1p, which is exclusively nuclear, localize to both the nucleus and the cytoplasm, the F-box of Pop2p may be critical for the assembly of cytoplasmic SCFPop2p complexes. In support of this notion, we demonstrate individual SCFPop1p and SCFPop2p complexes bearing ubiquitin ligase activity. Conclusion Our data suggest that distinct homo- and heterooligomeric assemblies of Pop1p and Pop2p generate combinatorial diversity of SCFPop function in fission yeast. Whereas a heterooligomeric SCFPop1p-Pop2p complex mediates polyubiquitylation of Rum1p, homooligomeric SCFPop1p and SCFPop2p complexes may target unknown nuclear and cytoplasmic substrates.

  16. Stimulating recovery of hemopoietic and immunological functions by co-transferring IL-6 and SCF genes in irradiated mice

    International Nuclear Information System (INIS)

    Objective: To explore the hemopoietic and immunological functions of retroviral-mediated IL-6 and SCF genes co-transferred into bone marrow stromal cells in irradiated mice. Methods: IL-6 and SCF cDNA were recombined with retroviral vector pLXSN by gene recombination technology. Number of peripheral blood and bone marrow cells, CFU-GM of bone marrow cells, LTT and CD4/CD8 ratio of spleen were also assayed in vivo. Results: The bone marrow stromal cells transferred with IL-6 and SCF genes could stimulate the recovery of hemopoietic and immunological functions in irradiated mice in vivo. Conclusion: IL-6 and SCF genes are simultaneously expressed in bone marrow stromal cells, which provide a basis for studies on hematopoietic regulation by gene-transfected bone marrow stromal cells

  17. SCF(JFK) is a bona fide E3 ligase for ING4 and a potent promoter of the angiogenesis and metastasis of breast cancer.

    Science.gov (United States)

    Yan, Ruorong; He, Lin; Li, Zhongwu; Han, Xiao; Liang, Jing; Si, Wenzhe; Chen, Zhe; Li, Lei; Xie, Guojia; Li, Wanjin; Wang, Peiyan; Lei, Liandi; Zhang, Hongquan; Pei, Fei; Cao, Dengfeng; Sun, Luyang; Shang, Yongfeng

    2015-03-15

    Loss of function/dysregulation of inhibitor of growth 4 (ING4) and hyperactivation of NF-κB are frequent events in many types of human malignancies. However, the molecular mechanisms underlying these remarkable aberrations are not understood. Here, we report that ING4 is physically associated with JFK. We demonstrated that JFK targets ING4 for ubiquitination and degradation through assembly of an Skp1-Cul1-F-box (SCF) complex. We showed that JFK-mediated ING4 destabilization leads to the hyperactivation of the canonical NF-κB pathway and promotes angiogenesis and metastasis of breast cancer. Significantly, the expression of JFK is markedly up-regulated in breast cancer, and the level of JFK is negatively correlated with that of ING4 and positively correlated with an aggressive clinical behavior of breast carcinomas. Our study identified SCF(JFK) as a bona fide E3 ligase for ING4 and unraveled the JFK-ING4-NF-κB axis as an important player in the development and progression of breast cancer, supporting the pursuit of JFK as a potential target for breast cancer intervention. PMID:25792601

  18. Functionalization of osmium arene anticancer complexes with (poly)arginine: Effect on cellular uptake, internalization, and cytotoxicity

    Czech Academy of Sciences Publication Activity Database

    van Rijt, S.H.; Kostrhunová, Hana; Brabec, Viktor; Sadler, P.J.

    2011-01-01

    Roč. 22, č. 2 (2011), s. 218-226. ISSN 1043-1802 R&D Projects: GA ČR(CZ) GAP301/10/0598 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : osmium * arginine * cellular accumulation Subject RIV: BO - Biophysics Impact factor: 4.930, year: 2011

  19. Metal Dependence of Signal Transmission through MolecularQuantum-Dot Cellular Automata (QCA: A Theoretical Studyon Fe, Ru, and Os Mixed-Valence Complexes

    Directory of Open Access Journals (Sweden)

    Ken Tokunaga

    2010-08-01

    Full Text Available Dynamic behavior of signal transmission through metal complexes [L5M-BL-ML5]5+ (M=Fe, Ru, Os, BL=pyrazine (py, 4,4’-bipyridine (bpy, L=NH3, which are simplified models of the molecular quantum-dot cellular automata (molecular QCA, is discussed from the viewpoint of one-electron theory, density functional theory. It is found that for py complexes, the signal transmission time (tst is Fe(0.6 fs < Os(0.7 fs < Ru(1.1 fs and the signal amplitude (A is Fe(0.05 e < Os(0.06 e < Ru(0.10 e. For bpy complexes, tst and A are Fe(1.4 fs < Os(1.7 fs < Ru(2.5 fs and Os(0.11 e < Ru(0.12 e complexes generally have stronger signal amplitude, but waste longer time for signal transmission than py complexes. Among all complexes, Fe complex with bpy BL shows the best result. These results are discussed from overlap integral and energy gap of molecular orbitals.

  20. Covalent modifier NEDD8 is essential for SCF ubiquitin-ligase in fission yeast

    OpenAIRE

    Osaka, Fumio; Saeki, Mihoro; Katayama, Satoshi; Aida, Noriko; Toh-e, Akio; Kominami, Kin-ichiro; Toda, Takashi; Suzuki, Toshiaki; Chiba, Tomoki; Tanaka, Keiji; Kato, Seishi

    2000-01-01

    A ubiquitin-like modifier, NEDD8, is covalently attached to cullin-family proteins, but its physiological role is poorly understood. Here we report that the NEDD8-modifying pathway is essential for cell viability and function of Pcu1 (cullin-1 orthologue) in fission yeast. Pcu1 assembled on SCF ubiquitin-ligase was completely modified by NEDD8. Pcu1K713R defective for NEDD8 conjugation lost the ability to complement lethality due to pcu1 deletion. Forced expression of Pcu1K713R or depletion o...

  1. A new entropy based method for computing software structural complexity

    CERN Document Server

    Roca, J L

    2002-01-01

    In this paper a new methodology for the evaluation of software structural complexity is described. It is based on the entropy evaluation of the random uniform response function associated with the so called software characteristic function SCF. The behavior of the SCF with the different software structures and their relationship with the number of inherent errors is investigated. It is also investigated how the entropy concept can be used to evaluate the complexity of a software structure considering the SCF as a canonical representation of the graph associated with the control flow diagram. The functions, parameters and algorithms that allow to carry out this evaluation are also introduced. After this analytic phase follows the experimental phase, verifying the consistency of the proposed metric and their boundary conditions. The conclusion is that the degree of software structural complexity can be measured as the entropy of the random uniform response function of the SCF. That entropy is in direct relation...

  2. Interpretation of unexpected behavior of infrared absorption spectra of ScF3 beyond the quasiharmonic approximation

    Science.gov (United States)

    Piskunov, Sergei; Žguns, Pjotrs A.; Bocharov, Dmitry; Kuzmin, Alexei; Purans, Juris; Kalinko, Aleksandr; Evarestov, Robert A.; Ali, Shehab E.; Rocca, Francesco

    2016-06-01

    Scandium fluoride (ScF3), having cubic ReO3-type structure, has attracted much scientific attention due to its rather strong negative thermal expansion (NTE) in the broad temperature range from 10 to 1100 K. Here we use the results of diffraction and extended x-ray absorption fine-structure (EXAFS) spectroscopy to interpret the influence of NTE on the temperature dependence of infrared absorption spectra of ScF3. Original infrared absorption and EXAFS experiments in a large temperature range are presented and interpreted using ab initio lattice dynamics simulations within and beyond quasiharmonic approximations. We demonstrate that ab initio electronic structure calculations, based on the linear combination of atomic orbitals method with hybrid functionals, are able to reproduce well the experimental values of lattice parameter a0, band gap Eg, and lattice dynamics in ScF3. However, the simulations performed within quasiharmonic approximation fail to reproduce the temperature dependence of two infrared active bands due to the F-Sc-F bending (at 220 cm-1) and Sc-F stretching (at 520 cm-1) modes present in the infrared absorption spectra. To overcome this problem, an approach beyond the quasiharmonic approximation is proposed: It accounts for the negative thermal expansion of the lattice and for fluorine atom displacements due to strong F vibrational motion perpendicular to the cubic axes and allows us to explain qualitatively the temperature behavior of infrared spectra of ScF3.

  3. Role of SKP1-CUL1-F-Box-Protein (SCF) E3 Ubiquitin Ligases in Skin Cancer

    Institute of Scientific and Technical Information of China (English)

    Chuan-Ming Xie; Wenyi Wei; Yi Sun

    2013-01-01

    Many biological processes such as cell proliferation,differentiation,and cell death depend precisely on the timely synthesis and degradation of key regulatory proteins.While protein synthesis can be regulated at multiple levels,protein degradation is mainly controlled by the ubiquitin-proteasome system (UPS),which consists of two distinct steps:(1) ubiquitylation of targeted protein by E1 ubiquitin-activating enzyme,E2 ubiquitin-conjugating enzyme and E3 ubiquitin ligase,and (2) subsequent degradation by the 26S proteasome.Among all E3 ubiquitin ligases,the SCF (SKP1-CUL1-F-box protein) E3 ligases are the largest family and are responsible for the turnover of many key regulatory proteins.Aberrant regulation of SCF E3 ligases is associated with various human diseases,such as cancers,including skin cancer.In this review,we provide a comprehensive overview of all currently published data to define a promoting role of SCF E3 ligases in the development of skin cancer.The future directions in this area of research are also discussed with an ultimate goal to develop small molecule inhibitors of SCF E3 ligases as a novel approach for the treatment of human skin cancer.Furthermore,altered components or substrates of SCF E3 ligases may also be developed as the biomarkers for early diagnosis or predicting prognosis.

  4. Col2a1 lineage tracing reveals that the meniscus of the knee joint has a complex cellular origin

    OpenAIRE

    Hyde, Gareth; Boot-Handford, Raymond P.; Wallis, Gillian A

    2008-01-01

    The knee joint consists of multiple interacting tissues that are prone to injury- and disease-related degeneration. Although much is known about the structure and function of the knee’s constituent tissues, relatively little is known about their cellular origin and the mechanisms governing their segregation. To investigate the origin and segregation of knee tissues in vivo we performed lineage tracing using a Col2a1-Cre/R26R mouse model system and compared the data obtained with actual Col2a1...

  5. DNA Binding and Photocleavage Properties, Cellular Uptake and Localization, and in-Vitro Cytotoxicity of Dinuclear Ruthenium(II) Complexes with Varying Lengths in Bridging Alkyl Linkers.

    Science.gov (United States)

    Liu, Ping; Wu, Bao-Yan; Liu, Jin; Dai, Yong-Cheng; Wang, You-Jun; Wang, Ke-Zhi

    2016-02-15

    Two new dinuclear Ru(II) polypyridyl complexes containing three and ten methylene chains in their bridging linkers are synthesized and characterized. Their calf thymus DNA-binding and plasmid DNA photocleavage behaviors are comparatively studied with a previously reported, six-methylene-containing analog by absorption and luminescence spectroscopy, steady-state emission quenching by [Fe(CN)6](4-), DNA competitive binding with ethidium bromide, DNA viscosity measurements, DNA thermal denaturation, and agarose gel electrophoresis analyses. Theoretical calculations applying the density functional theory (DFT) method for the three complexes are also performed to understand experimentally observed DNA binding properties. The results show that the two complexes partially intercalate between the base pairs of DNA. Cellular uptake and colocalization studies have demonstrated that the complexes could enter HeLa cells efficiently and localize within lysosomes. The in-vitro antitumor activity against HeLa and MCF-7 tumor cells of the complexes are studied by MTT cytotoxic analysis. A new method, high-content analysis (HCA), is also used to assess cytotoxicity, apoptosis and cell cycle arrest of the three complexes. The results show that the lengths of the alkyl linkers could effectively tune their biological properties and that HCA is suitable for rapidly identifying cytotoxicity and can be substituted for MTT assays to evaluate the cell cytotoxicity of chemotherapeutic agents. PMID:26811966

  6. Proteomic analysis of HIV-1 Nef cellular binding partners reveals a role for exocyst complex proteins in mediating enhancement of intercellular nanotube formation

    Directory of Open Access Journals (Sweden)

    Mukerji Joya

    2012-06-01

    Full Text Available Abstract Background HIV-1 Nef protein contributes to pathogenesis via multiple functions that include enhancement of viral replication and infectivity, alteration of intracellular trafficking, and modulation of cellular signaling pathways. Nef stimulates formation of tunneling nanotubes and virological synapses, and is transferred to bystander cells via these intercellular contacts and secreted microvesicles. Nef associates with and activates Pak2, a kinase that regulates T-cell signaling and actin cytoskeleton dynamics, but how Nef promotes nanotube formation is unknown. Results To identify Nef binding partners involved in Pak2-association dependent Nef functions, we employed tandem mass spectrometry analysis of Nef immunocomplexes from Jurkat cells expressing wild-type Nef or Nef mutants defective for the ability to associate with Pak2 (F85L, F89H, H191F and A72P, A75P in NL4-3. We report that wild-type, but not mutant Nef, was associated with 5 components of the exocyst complex (EXOC1, EXOC2, EXOC3, EXOC4, and EXOC6, an octameric complex that tethers vesicles at the plasma membrane, regulates polarized exocytosis, and recruits membranes and proteins required for nanotube formation. Additionally, Pak2 kinase was associated exclusively with wild-type Nef. Association of EXOC1, EXOC2, EXOC3, and EXOC4 with wild-type, but not mutant Nef, was verified by co-immunoprecipitation assays in Jurkat cells. Furthermore, shRNA-mediated depletion of EXOC2 in Jurkat cells abrogated Nef-mediated enhancement of nanotube formation. Using bioinformatic tools, we visualized protein interaction networks that reveal functional linkages between Nef, the exocyst complex, and the cellular endocytic and exocytic trafficking machinery. Conclusions Exocyst complex proteins are likely a key effector of Nef-mediated enhancement of nanotube formation, and possibly microvesicle secretion. Linkages revealed between Nef and the exocyst complex suggest a new paradigm of

  7. Translating partitioned cellular automata into classical type cellular automata

    OpenAIRE

    Poupet, Victor

    2008-01-01

    Partitioned cellular automata are a variant of cellular automata that was defined in order to make it very simple to create complex automata having strong properties such as number conservation and reversibility (which are often difficult to obtain on cellular automata). In this article we show how a partitioned cellular automaton can be translated into a regular cellular automaton in such a way that these properties are conserved.

  8. Evidence supporting dissimilatory and assimilatory lignin degradation in Enterobacter lignolyticus SCF1

    Energy Technology Data Exchange (ETDEWEB)

    DeAngelis, Kristen M.; Sharma, Deepak; Varney, Rebecca; Simmons, Blake A.; Isern, Nancy G.; Markillie, Lye Meng; Nicora, Carrie D.; Norbeck, Angela D.; Taylor, Ronald C.; Aldrich, Joshua T.; Robinson, Errol W.

    2013-08-29

    The anaerobic isolate Enterobacter lignolyticus SCF1 was initially cultivated based on anaerobic growth on lignin as sole carbon source. The source of the isolated bacteria was from tropical forest soils that decompose litter rapidly with low and fluctuating redox potentials, making it likely that bacteria using oxygen-independent enzymes play an important role in decomposition. We have examined differential expression of the anaerobic isolate Enterobacter lignolyticus SCF1 during growth on lignin. After 48 hours of growth, we used transcriptomics and proteomics to define the enzymes and other regulatory machinery that these organisms use to degrade lignin, as well as metabolomics to measure lignin degradation and monitor the use of lignin and iron as terminal electron acceptors that facilitate more efficient use of carbon. Proteomics revealed accelerated xylose uptake and metabolism under lignin-amended growth, and lignin degradation via the 4-hydroxyphenylacetate degradation pathway, catalase/peroxidase enzymes, and the glutathione biosynthesis and glutathione S-transferase proteins. We also observed increased production of NADH-quinone oxidoreductase, other electron transport chain proteins, and ATP synthase and ATP-binding cassette (ABC) transporters. Our data shows the advantages of a multi-omics approach, where incomplete pathways identified by genomics were completed, and new observations made on coping with poor carbon availability. The fast growth, high efficiency and specificity of enzymes employed in bacterial anaerobic litter deconstruction makes these soils useful templates for improving biofuel production.

  9. Cellular and proteomic studies of the mitochondrial ABAD/Aβ complex : investigating its role in Alzheimer's disease

    OpenAIRE

    Taylor, Margaret Alexandra

    2012-01-01

    The focus of this thesis is to investigate the intracellular protein-peptide complex 3-hydroxyacyl-CoA dehydrogenase (HADH), also known as ABAD (amyloid- binding alcohol dehydrogenase) and amyloid-beta peptide (Aβ). This complex has been identified in the development of Alzheimer's disease (AD), and this study tries to identify if ABAD is a useful biomarker for genetic risk profiling strategies for the early diagnosis of Alzheimer’s disease, or a suitable target for disease-...

  10. An advanced approach for the generation of complex cellular material representative volume elements using distance fields and level sets

    Science.gov (United States)

    Sonon, B.; François, B.; Massart, T. J.

    2015-08-01

    A general and widely tunable method for the generation of representative volume elements for cellular materials based on distance and level set functions is presented. The approach is based on random tessellations constructed from random inclusion packings. A general methodology to obtain arbitrary-shaped tessellations to produce disordered foams is presented and illustrated. These tessellations can degenerate either in classical Voronoï tessellations potentially additively weighted depending on properties of the initial inclusion packing used, or in Laguerre tessellations through a simple modification of the formulation. A versatile approach to control the particular morphology of the obtained foam is introduced. Specific local features such as concave triangular Plateau borders and non-constant thickness heterogeneous coatings can be built from the tessellation in a straightforward way and are tuned by a small set of parameters with a clear morphological interpretation.

  11. Microwave gallium-68 radiochemistry for kinetically stable bis(thiosemicarbazone) complexes: structural investigations and cellular uptake under hypoxia.

    Science.gov (United States)

    Alam, Israt S; Arrowsmith, Rory L; Cortezon-Tamarit, Fernando; Twyman, Frazer; Kociok-Köhn, Gabriele; Botchway, Stanley W; Dilworth, Jonathan R; Carroll, Laurence; Aboagye, Eric O; Pascu, Sofia I

    2016-01-01

    We report the microwave synthesis of several bis(thiosemicarbazones) and the rapid gallium-68 incorporation to give the corresponding metal complexes. These proved kinetically stable under 'cold' and 'hot' biological assays and were investigated using laser scanning confocal microscopy, flow cytometry and radioactive cell retention studies under normoxia and hypoxia. (68)Ga complex retention was found to be 34% higher in hypoxic cells than in normoxic cells over 30 min, further increasing to 53% at 120 min. Our data suggests that this class of gallium complexes show hypoxia selectivity suitable for imaging in living cells and in vivo tests by microPET in nude athymic mice showed that they are excreted within 1 h of their administration. PMID:26583314

  12. Detailed Study of the Interaction between Human Herpesvirus 6B Glycoprotein Complex and Its Cellular Receptor, Human CD134

    OpenAIRE

    Tang, Huamin; Wang, Junjie; Mahmoud, Nora F.; Mori, Yasuko

    2014-01-01

    Recently, we identified a novel receptor, CD134, which interacts with the human herpesvirus 6B (HHV-6B) glycoprotein (g)H/gL/gQ1/gQ2 complex and plays a key role in the entry of HHV-6B into target cells. However, details of the interaction between the HHV-6B gH/gL/gQ1/gQ2 complex and CD134 were unknown. In this study, we identified a cysteine-rich domain (CRD), CDR2, of CD134 that is critical for binding to the HHV-6B glycoprotein complex and HHV-6B infection. Furthermore, we found that the e...

  13. Nuclear pore complex contains a family of glycoproteins that includes p62: glycosylation through a previously unidentified cellular pathway

    International Nuclear Information System (INIS)

    Using a monoclonal antibody (mAb 414), the authors previously identified a protein of 62 kDa (p62) that was localized to the nuclear pore complex by immunoelectron microscopy. They also showed that p62 binds specifically to wheat germ agglutinin. Therefore, they proposed that this nuclear pore complex protein might be a member of a recently characterized family of glycoproteins that are labeled by in vitro galactosylation of rat liver nuclei and contain O-linked monosaccharidic GlcNAc residues. In support of this, they now show that incubation with N-acetylglucosaminidase reduces the molecular mass of p62 by ≅ 3 kDa because of the removal of terminal GlcNAc residues. Moreover, p62 can be galactosylated in vitro by using UDP-[3H]galactose and galactosyltransferase. They also show that most of the GlcNAc residues are added within 5 min of synthesis, when p62 is soluble and cytosolic. Thus, the addition of GlcNAc is carried out in the cytoplasm and is clearly distinct from the N- and O-linked glycosylation pathways of the endoplasmic reticulum and Golgi complex. Using another mAb with a broad specificity for nuclear GlcNAc-containing proteins, they show by immunofluorescence and protein blotting of subnuclear fractions that some of these proteins are in the interior of the nucleus, and others are most likely located in the pore complex

  14. Unraveling the cellular uptake of bioreducible poly(amido amine) — Gene complexes in cells of the retinal pigment epithelium

    NARCIS (Netherlands)

    Vercauteren, D.; Piest, M.; Soraj, M. Al; Jones, A.T.; Engbersen, J.F.J.; Smedt, de S.C.; Braeckmans, K.

    2010-01-01

    In vitro endocytosis of gene complexes composed of a bioreducible polyamidoamine CBA ABOL and plasmid DNA, in cells of the retinal pigment epithelium (RPE) was studied, the latter being an interesting target for ocular gene therapy. We found that cationic CBA ABOL DNA polyplexes attach to cell surfa

  15. Mitochondrial DNA background modulates the assembly kinetics of OXPHOS complexes in a cellular model of mitochondrial disease.

    NARCIS (Netherlands)

    Pello, R.; Martin, M.A.; Carelli, V.; Nijtmans, L.G.J.; Achilli, A.; Pala, M.; Torroni, A.; Gomez-Duran, A.; Ruiz-Pesini, E.; Martinuzzi, A.; Smeitink, J.A.M.; Arenas, J.; Ugalde, C.

    2008-01-01

    Leber's hereditary optic neuropathy (LHON), the most frequent mitochondrial disorder, is mostly due to three mitochondrial DNA (mtDNA) mutations in respiratory chain complex I subunit genes: 3460/ND1, 11778/ND4 and 14484/ND6. Despite considerable clinical evidences, a genetic modifying role of the m

  16. Mapping enteroendocrine cell populations in transgenic mice reveals an unexpected degree of complexity in cellular differentiation within the gastrointestinal tract

    OpenAIRE

    1990-01-01

    The gastrointestinal tract is lined with a monolayer of cells that undergo perpetual and rapid renewal. Four principal, terminally differentiated cell types populate the monolayer, enterocytes, goblet cells, Paneth cells, and enteroendocrine cells. This epithelium exhibits complex patterns of regional differentiation, both from crypt- to-villus and from duodenum-to-colon. The "liver" fatty acid binding protein (L-FABP) gene represents a useful model for analyzing the molecular basis for intes...

  17. Differential effects of salen and manganese-salen complex (EUK-8) on the regulation of cellular cadmium uptake and toxicity.

    Science.gov (United States)

    Yang, Pei-Ming; Chiu, Shu-Jun; Lin, Lih-Yuan

    2005-05-01

    Cadmium (Cd) stimulates the production of reactive oxygen species (ROS) and causes cell damage. We investigated here the feasibility of using a cell permeable superoxide dismutase/catalase mimetic, EUK-8, to reduce the Cd-induced ROS and cytotoxicity in Chinese hamster ovary cells. EUK-8 reduces the ROS level caused by Cd treatment. EUK-8 also curtails propidium iodide (PI) influx and increases the viability of Cd-treated cells. The efficacy of EUK-8 as a Cd antidote diminishes gradually when added at a later stage of Cd treatment. EUK-8 blocks Cd transport into cells. It is ineffective in accelerating the efflux of metals from the cells. EUK-8 is a Mn-salen complex. Mn decreases the uptake and cytotoxicity of Cd, while salen perturbs the membrane integrity and increases the uptake and cytotoxicity of Cd. Salen is able to bind Cd, and the Cd-salen complex formed does not perturb the integrity of cell membranes and thus the influx of metal is not enhanced. Our results reveal a differential effect of salen and Mn-salen complex on the transport of Cd with subsequent different levels of cell damage. PMID:15689422

  18. Static distribution of tasks in the transputer network for the direct SCF method

    International Nuclear Information System (INIS)

    A simple 4-processor transputer network was applied to test a static task distribution in the framework of the direct SCF method. Various basis sets were used to examine the speedup and load balancing of the parallel system under study. The speedup was calculated: a) using total times including the times for diagonalization and communication between processors; b) using the net times for two-electron integrals evaluation; and c) using the net times as in case b) but with the speedup calculated according to the two-processor system. The load balancing of the parallel system is illustrated and total elapsed times consumed in the step of two-electron integrals evaluation are given. 2 tabs., 3 figs., 6 refs

  19. Evidence supporting dissimilatory and assimilatory lignin degradation in Enterobacter lignolyticus SCF1.

    Science.gov (United States)

    Deangelis, Kristen M; Sharma, Deepak; Varney, Rebecca; Simmons, Blake; Isern, Nancy G; Markilllie, Lye Meng; Nicora, Carrie; Norbeck, Angela D; Taylor, Ronald C; Aldrich, Joshua T; Robinson, Errol W

    2013-01-01

    Lignocellulosic biofuels are promising as sustainable alternative fuels, but lignin inhibits access of enzymes to cellulose, and by-products of lignin degradation can be toxic to cells. The fast growth, high efficiency and specificity of enzymes employed in the anaerobic litter deconstruction carried out by tropical soil bacteria make these organisms useful templates for improving biofuel production. The facultative anaerobe Enterobacter lignolyticus SCF1 was initially cultivated from Cloud Forest soils in the Luquillo Experimental Forest in Puerto Rico, based on anaerobic growth on lignin as sole carbon source. The source of the isolate was tropical forest soils that decompose litter rapidly with low and fluctuating redox potentials, where bacteria using oxygen-independent enzymes likely play an important role in decomposition. We have used transcriptomics and proteomics to examine the observed increased growth of SCF1 grown on media amended with lignin compared to unamended growth. Proteomics suggested accelerated xylose uptake and metabolism under lignin-amended growth, with up-regulation of proteins involved in lignin degradation via the 4-hydroxyphenylacetate degradation pathway, catalase/peroxidase enzymes, and the glutathione biosynthesis and glutathione S-transferase (GST) proteins. We also observed increased production of NADH-quinone oxidoreductase, other electron transport chain proteins, and ATP synthase and ATP-binding cassette (ABC) transporters. This suggested the use of lignin as terminal electron acceptor. We detected significant lignin degradation over time by absorbance, and also used metabolomics to demonstrate moderately significant decreased xylose concentrations as well as increased metabolic products acetate and formate in stationary phase in lignin-amended compared to unamended growth conditions. Our data show the advantages of a multi-omics approach toward providing insights as to how lignin may be used in nature by microorganisms coping

  20. Methyl 6-Amino-6-deoxy-d-pyranoside-Conjugated Platinum(II) Complexes for Glucose Transporter (GLUT)-Mediated Tumor Targeting: Synthesis, Cytotoxicity, and Cellular Uptake Mechanism.

    Science.gov (United States)

    Li, Taoli; Gao, Xiangqian; Yang, Liu; Shi, Yunli; Gao, Qingzhi

    2016-05-19

    Methyl 6-aminodeoxy-d-pyranoside-derived platinum(II) glycoconjugates were designed and synthesized based on the clinical drug oxaliplatin for glucose transporter (GLUT)-mediated tumor targeting. In addition to a substantial improvement in water solubility, the conjugates exhibited cytotoxicity similar to or higher than that of oxaliplatin in six different human cancer cell lines. GLUT-mediated transport of the complexes was investigated with a cell-based fluorescence competition assay and GLUT-inhibitor-mediated cytotoxicity analysis in a GLUT-overexpressing human colorectal adenocarcinoma (HT29) cell line. The antitumor effect of the aminodeoxypyranoside-conjugated platinum(II) complexes was found to depend significantly on the GLUT inhibitor, and the cellular uptake of the molecules was regulated by GLUT-mediated transport. The results from this study demonstrate the potential advantages of aminodeoxypyranosides as sugar motifs for glycoconjugation for Warburg-effect-targeted drug design. These fundamental results also support the potential of aminodeoxypyranoside-conjugated platinum(II) complexes as lead compounds for further preclinical evaluation. PMID:27135196

  1. Expression and cellular distribution of transient receptor potential vanilloid 4 in cortical tubers of the tuberous sclerosis complex.

    Science.gov (United States)

    Chen, Xin; Yang, Meihua; Sun, Feiji; Liang, Chao; Wei, Yujia; Wang, Lukang; Yue, Jiong; Chen, Bing; Li, Song; Liu, Shiyong; Yang, Hui

    2016-04-01

    Cortical tubers in patients with tuberous sclerosis complex (TSC) are highly associated with intractable epilepsy. Recent evidence has shown that transient receptor potential vanilloid 4 (TRPV4) has direct effects on both neurons and glial cells. To understand the role of TRPV4 in pathogenesis of cortical tubers, we investigated the expression patterns of TRPV4 in cortical tubers of TSC compared with normal control cortex (CTX). We found that TRPV4 was clearly up-regulated in cortical tubers at the protein levels. Immunostaining indicated that TRPV4 was specially distributed in abnormal cells, including dysplastic neurons (DNs) and giant cells (GCs). In addition, double immunofluorescent staining revealed that TRPV4 was localized on neurofilament proteins (NF200) positive neurons and glial fibrillary acidic portein (GFAP) positive reactive astrocytes. Moreover, TRPV4 co-localized with both glutamatergic and GABAergic neurons. Furthermore, protein levels of protein kinase C (PKC), but not protein kinase A (PKA), the important upstream factors of the TRPV4, were significantly increased in cortical tubers. Taken together, the overexpression and distribution patterns of TRPV4 may be linked with the intractable epilepsy caused by TSC. PMID:26874068

  2. 146号初等元胞自动机的演化语言的复杂性%COMPLEXITY OF EVOLUTION LANGUAGES OF THE ELEMENTARY CELLULAR AUTOMATON OF RULE 146

    Institute of Scientific and Technical Information of China (English)

    王益; Morita Kenichi

    2006-01-01

    Symbolic dynamics of cellular automata is introduced by coarse-graining the temporal evolution orbits. Evolution languages are defined. By using the theory of formal languages and automata, the complexity of evolution languages of the elementary cellular automaton of rule 146 is studied and it is proved that its width 1-evolution language is regular, but for every n ≥ 2 its width n-evolution language is not context-free but context-sensitive. Also, the same results hold for the equivalent (under conjugation) elementary cellular automaton of rule 182.

  3. Cellular automata

    CERN Document Server

    Codd, E F

    1968-01-01

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

  4. Dancing on damaged chromatin. Functions of ATM and the RAD50/MRE11/NBS1 complex in cellular responses to DNA damage

    International Nuclear Information System (INIS)

    In order to preserve and protect genetic information, eukaryotic cells have developed a signaling or communications network to help the cell respond to DNA damage, and ATM and NBS1 are key players in this network. ATM is a protein kinase which is activated immediately after a DNA double strand break (DSB) is formed, and the resulting signal cascade generated in response to cellular DSBs is regulated by post-translational protein modifications such as phosphorylation and acetylation. In addition, to ensure the efficient functioning of DNA repair and cell cycle checkpoints, the highly ordered structure of eukaryotic chromatin must be appropriately altered to permit access of repair-related factors to DNA. These alterations are termed chromatin remodeling, and are executed by a specific remodeling complex in conjunction with histone modifications. Current advances in the molecular analysis of DNA damage responses have shown that the auto-phosphorylation of ATM and the interaction between ATM and NBS1 are key steps for ATM activation, and that the association of ATM and NBS1 is involved in chromatin remodeling. Identification of novel factors which function in ubiquitination (RNF8, Ubc13, Rap80, etc.) has also enabled us to understand more details of the early stages in DNA repair pathways which respond to DSBs. In this review, the focus is on the role of ATM and the RAD50/MRE11/NBS1 complex in DSB response pathways, and their role in DSB repair and in the regulation of chromatin remodeling. (author)

  5. Efficient Cellular Entry of (r-x-r)-Type Carbamate-Plasmid DNA Complexes and Its Implication for Noninvasive Topical DNA Delivery to Skin.

    Science.gov (United States)

    Vij, Manika; Natarajan, Poornemaa; Yadav, Amit K; Patil, Kiran M; Pandey, Tanuja; Gupta, Nidhi; Santhiya, Deenan; Kumar, Vaijayanti A; Fernandes, Moneesha; Ganguli, Munia

    2016-06-01

    Arginine-rich cell penetrating peptides are powerful tools for in vitro as well as in vivo delivery of a wide plethora of biomolecules. However, presence of consecutive arginine residues leads to enhanced amenability for proteolytic degradation as well as steric hindrances for membrane interactions which compromise its bioavailability. In order to overcome these limitations we previously reported a safe and stable octaarginine based oligomer, i.e., (r-x-r)4-carbamate, where the backbone amide linkages were replaced by carbamate linkages and 6-aminohexanoic acid based spacer moieties were incorporated for better flexibility, hydrophobicity, optimal spacing of guanidinium groups, and protection against proteolytic cleavage; resulting in improved transfection efficiency over its amide counterpart. In the present work we have investigated the mechanism behind this enhanced transfection efficiency and, based on our observations, demonstrate how the synergistic effect of rationalized oligomer designing, complex characteristics, and cell type contributes to overall effective intracellular delivery. Our results indicate that the (r-x-r)4-carbamate-plasmid DNA complexes primarily utilize lipid raft dependent pathway of cellular entry more than other pathways, and this possibly facilitates their increased entry in the lipid raft rich milieu of skin cells. We also emphasize the utility of oligomer (r-x-r)4-carbamate as an efficient carrier for topical delivery of nucleic acids in skin tissue. This carrier can be utilized for safe, efficient, and noninvasive delivery of therapeutically relevant macromolecular hydrophilic cargo like nucleic acids to skin. PMID:27175623

  6. SCF (Fbxl17) ubiquitylation of Sufu regulates Hedgehog signaling and medulloblastoma development.

    Science.gov (United States)

    Raducu, Madalina; Fung, Ella; Serres, Sébastien; Infante, Paola; Barberis, Alessandro; Fischer, Roman; Bristow, Claire; Thézénas, Marie-Laëtitia; Finta, Csaba; Christianson, John C; Buffa, Francesca M; Kessler, Benedikt M; Sibson, Nicola R; Di Marcotullio, Lucia; Toftgård, Rune; D'Angiolella, Vincenzo

    2016-07-01

    Skp1-Cul1-F-box protein (SCF) ubiquitin ligases direct cell survival decisions by controlling protein ubiquitylation and degradation. Sufu (Suppressor of fused) is a central regulator of Hh (Hedgehog) signaling and acts as a tumor suppressor by maintaining the Gli (Glioma-associated oncogene homolog) transcription factors inactive. Although Sufu has a pivotal role in Hh signaling, the players involved in controlling Sufu levels and their role in tumor growth are unknown. Here, we show that Fbxl17 (F-box and leucine-rich repeat protein 17) targets Sufu for proteolysis in the nucleus. The ubiquitylation of Sufu, mediated by Fbxl17, allows the release of Gli1 from Sufu for proper Hh signal transduction. Depletion of Fbxl17 leads to defective Hh signaling associated with an impaired cancer cell proliferation and medulloblastoma tumor growth. Furthermore, we identify a mutation in Sufu, occurring in medulloblastoma of patients with Gorlin syndrome, which increases Sufu turnover through Fbxl17-mediated polyubiquitylation and leads to a sustained Hh signaling activation. In summary, our findings reveal Fbxl17 as a novel regulator of Hh pathway and highlight the perturbation of the Fbxl17-Sufu axis in the pathogenesis of medulloblastoma. PMID:27234298

  7. The ubiquitin ligase SCF (Grr1) is required for Gal2p degradation in the yeast Saccharomyces cerevisiae

    Czech Academy of Sciences Publication Activity Database

    Horák, Jaroslav; Wolf, D.H.

    2005-01-01

    Roč. 335, č. 4 (2005), s. 1185-1190. ISSN 0006-291X R&D Projects: GA ČR(CZ) GA204/05/2578; GA AV ČR(CZ) IAA5011407 Grant ostatní: Deutsche Forschungsgemeinschaft(DE) SFB 495 Institutional research plan: CEZ:AV0Z50110509 Keywords : SCF(Grr1) ubiquitin ligase * Gal2 transport er * catabolite degradation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.000, year: 2005

  8. Decreased SCF/c-kit signaling pathway contributes to loss of interstitial cells of Cajal in gallstone disease

    OpenAIRE

    Tan, Yu-Yan; Ji, Zhen-Ling; ZHAO, GANG; Jiang, Jia-Rui; Wang, Dong; Wang, Jing-Min

    2014-01-01

    Cholecystolithiasis is a common disease, and gallbladder dysmotility is considered as a pivotal pathogenesis. Interstitial cells of Cajal (ICCs) serve as pacemakers and mediators of neuromuscular transmission for gastrointestinal motility. Reduction of ICCs has been reported in gallstone diseases. However, there are no reasonable mechanisms for the cholecystolithiasis-associated loss of ICCs in humans. Stem cell factor (SCF) and its ligand c-kit are essential for normal development and surviv...

  9. Hsk1- and SCF(Pof3)-dependent proteolysis of S. pombe Ams2 ensures histone homeostasis and centromere function.

    Science.gov (United States)

    Takayama, Yuko; Mamnun, Yasmine M; Trickey, Michelle; Dhut, Susheela; Masuda, Fumie; Yamano, Hiroyuki; Toda, Takashi; Saitoh, Shigeaki

    2010-03-16

    Schizosaccharomyces pombe GATA factor Ams2 is responsible for cell cycle-dependent transcriptional activation of all the core histone genes peaking at G1/S phase. Intriguingly, its own protein level also fluctuates concurrently. Here, we show that Ams2 is ubiquitylated and degraded through the SCF (Skp1-Cdc53/Cullin-1-F-box) ubiquitin ligase, in which F box protein Pof3 binds this protein. Ams2 is phosphorylated at multiple sites, which is required for SCF(Pof3)-dependent proteolysis. Hsk1/Cdc7 kinase physically associates with and phosphorylates Ams2. Even mild overexpression of Ams2 induces constitutive histone expression and chromosome instability, and its toxicity is exaggerated when Hsk1 function is compromised. This is partly attributable to abnormal incorporation of canonical H3 into the central CENP-A/Cnp1-rich centromere, thereby reversing specific chromatin structures to apparently normal nucleosomes. We propose that Hsk1 plays a vital role during post S phase in genome stability via SCF(Pof3)-mediated degradation of Ams2, thereby maintaining centromere integrity. PMID:20230746

  10. Cellular delivery of quantum dot-bound hybridization probe for detection of intracellular pre-microRNA using chitosan/poly(γ-glutamic acid complex as a carrier.

    Directory of Open Access Journals (Sweden)

    Yao Geng

    Full Text Available A quantum dot (QD-bound hybridization probe was designed for detection of intracellular pre-miRNA using chitosan (CS/poly(γ-glutamic acid (γ-PGA complex as a gene vector. The probe was prepared by assembling thiolated RNA to gold nanoparticle (Au NP via Au-S bond and then binding 3'-end amine of the RNA to the carboxy group capped on quantum dot surface. The QD-RNA-Au NP probe was assembled on the vector by mixing with aqueous γ-PGA solution and then CS solution to construct a gene delivery system for highly effective cellular uptake and delivery. After the probe was released from CS/γ-PGA complex to the cytoplasm by electrostatic repulsion at intracellular pH, it hybridized with pre-miRNA precursor as target. The formed product was then cleaved by RNase III Dicer, leading to the separation of QDs from Au NPs and fluorescence emission of QDs, which could be detected by confocal microscopic imaging to monitor the amount of the intracellular pre-miRNA precursor. The in vitro assays revealed that the QD-RNA-Au NP was a robust, sensitive and selective probe for quantitative detection of target pre-miRNA. Using MDA-MB231 and MCF-7 breast cancer cells as models, the relative amount of pre-miRNA let-7a could be successfully compared. Since the amount of miRNA is related to the progress and prognosis of cancer, this strategy could be expected to hold promising application potential in medical research and clinical diagnostics.

  11. Cellular delivery of quantum dot-bound hybridization probe for detection of intracellular pre-microRNA using chitosan/poly(γ-glutamic acid) complex as a carrier.

    Science.gov (United States)

    Geng, Yao; Lin, Dajie; Shao, Lijia; Yan, Feng; Ju, Huangxian

    2013-01-01

    A quantum dot (QD)-bound hybridization probe was designed for detection of intracellular pre-miRNA using chitosan (CS)/poly(γ-glutamic acid) (γ-PGA) complex as a gene vector. The probe was prepared by assembling thiolated RNA to gold nanoparticle (Au NP) via Au-S bond and then binding 3'-end amine of the RNA to the carboxy group capped on quantum dot surface. The QD-RNA-Au NP probe was assembled on the vector by mixing with aqueous γ-PGA solution and then CS solution to construct a gene delivery system for highly effective cellular uptake and delivery. After the probe was released from CS/γ-PGA complex to the cytoplasm by electrostatic repulsion at intracellular pH, it hybridized with pre-miRNA precursor as target. The formed product was then cleaved by RNase III Dicer, leading to the separation of QDs from Au NPs and fluorescence emission of QDs, which could be detected by confocal microscopic imaging to monitor the amount of the intracellular pre-miRNA precursor. The in vitro assays revealed that the QD-RNA-Au NP was a robust, sensitive and selective probe for quantitative detection of target pre-miRNA. Using MDA-MB231 and MCF-7 breast cancer cells as models, the relative amount of pre-miRNA let-7a could be successfully compared. Since the amount of miRNA is related to the progress and prognosis of cancer, this strategy could be expected to hold promising application potential in medical research and clinical diagnostics. PMID:23762388

  12. Members of the NODE (Nanog and Oct4-associated deacetylase) complex and SOX-2 promote the initiation of a natural cellular reprogramming event in vivo.

    Science.gov (United States)

    Kagias, Konstantinos; Ahier, Arnaud; Fischer, Nadine; Jarriault, Sophie

    2012-04-24

    Differentiated cells can be forced to change identity, either to directly adopt another differentiated identity or to revert to a pluripotent state. Direct reprogramming events can also occur naturally. We recently characterized such an event in Caenorhabditis elegans, in which a rectal cell switches to a neuronal cell. Here we have used this single-cell paradigm to investigate the molecular requirements of direct cell-type conversion, with a focus on the early steps. Our genetic analyses revealed the requirement of sem-4/Sall, egl-27/Mta, and ceh-6/Oct, members of the NODE complex recently identified in embryonic stem (ES) cells, and of the OCT4 partner sox-2, for the initiation of this natural direct reprogramming event. These four factors have been shown to individually impact on ES cell pluripotency; however, whether they act together to control cellular potential during development remained an open question. We further found that, in addition to acting at the same time, these factors physically associate, suggesting that they could act together as a NODE-like complex during this in vivo process. Finally, we have elucidated the functional domains in EGL-27/MTA that mediate its reprogramming activity in this system and have found that modulation of the posterior HOX protein EGL-5 is a downstream event to allow the initiation of Y identity change. Our data reveal unique in vivo functions in a natural direct reprogramming event for these genes that impact on ES cells pluripotency and suggest that conserved nuclear events could be shared between different cell plasticity phenomena across phyla. PMID:22493276

  13. Evidence for faster etching at the mask-substrate interface: atomistic simulation of complex cavities at the micron-/submicron-scale by the continuous cellular automaton

    Science.gov (United States)

    Gosálvez, M. A.; Ferrando, N.; Fedoryshyn, Y.; Leuthold, J.; McPeak, K. M.

    2016-04-01

    We combine experiments and simulations to study the acceleration of anisotropic etching of crystalline silicon at the mask-substrate interface, as a function of the coordination number of the substrate atoms located at the junction between obtuse-angled {1 1 1} facets and the mask layer. Atomistic simulations based on the use of the continuous cellular automaton (CCA) conclude that the interface atoms react faster with the etchant, thus initiating a step flow process that results in increased etch rates for the obtuse facets. By generating a wide range of complex cavities on high-index silicon wafers with a single-side, single-step etching, the comparison of the experimental and simulated results strongly indicates that the CCA method is suitable for accurately describing not only the development of micron-scaled structures but also, for the first time, the formation of submicron shapes. The study also describes the acceleration of obtuse facets formed through double-side etching, obtaining results in good agreement with previous experiments.

  14. New Insights into the Negative Thermal Expansion: Direct Experimental Evidence for the "Guitar-String" Effect in Cubic ScF3.

    Science.gov (United States)

    Hu, Lei; Chen, Jun; Sanson, Andrea; Wu, Hui; Guglieri Rodriguez, Clara; Olivi, Luca; Ren, Yang; Fan, Longlong; Deng, Jinxia; Xing, Xianran

    2016-07-13

    The understanding of the negative thermal expansion (NTE) mechanism remains challenging but critical for the development of NTE materials. This study sheds light on NTE of ScF3, one of the most outstanding materials with NTE. The local dynamics of ScF3 has been investigated by a combined analysis of synchrotron-based X-ray total scattering, extended X-ray absorption fine structure, and neutron powder diffraction. Very interestingly, we observe that (i) the Sc-F nearest-neighbor distance strongly expands with increasing temperature, while the Sc-Sc next-nearest-neighbor distance contracts, (ii) the thermal ellipsoids of relative vibrations between Sc-F nearest-neighbors are highly elongated in the direction perpendicular to the Sc-F bond, indicating that the Sc-F bond is much softer to bend than to stretch, and (iii) there is mainly dynamically transverse motion of fluorine atoms, rather than static shifts. These results are direct experimental evidence for the NTE mechanism, in which the rigid unit is not necessary for the occurrence of NTE, and the key role is played by the transverse thermal vibrations of fluorine atoms through the "guitar-string" effect. PMID:27336200

  15. Never-ageing cellular senescence

    OpenAIRE

    Ogrunc, Müge; d’Adda di Fagagna, Fabrizio

    2011-01-01

    Cellular senescence was historically discovered as a form of cellular ageing of in vitro cultured cells. It has been under the spotlight following the evidence of oncogene-induced senescence in vivo and its role as a potent tumour suppressor mechanism. Presently, a PubMed search using keywords ‘cellular senescence and cancer’ reveals 8398 number of references (by April 2011) showing that while our knowledge of senescence keeps expanding, the complexity of the phenomenon keeps us – researchers...

  16. Cellular Automata

    OpenAIRE

    Bagnoli, Franco

    1998-01-01

    An introduction to cellular automata (both deterministic and probabilistic) with examples. Definition of deterministic automata, dynamical properties, damage spreading and Lyapunov exponents; probabilistic automata and Markov processes, nonequilibrium phase transitions, directed percolation, diffusion; simulation techniques, mean field. Investigation themes: life, epidemics, forest fires, percolation, modeling of ecosystems and speciation. They represent my notes for the school "Dynamical Mod...

  17. Cellular resilience.

    Science.gov (United States)

    Smirnova, Lena; Harris, Georgina; Leist, Marcel; Hartung, Thomas

    2015-01-01

    Cellular resilience describes the ability of a cell to cope with environmental changes such as toxicant exposure. If cellular metabolism does not collapse directly after the hit or end in programmed cell death, the ensuing stress responses promote a new homeostasis under stress. The processes of reverting "back to normal" and reversal of apoptosis ("anastasis") have been studied little at the cellular level. Cell types show astonishingly similar vulnerability to most toxicants, except for those that require a very specific target, metabolism or mechanism present only in specific cell types. The majority of chemicals triggers "general cytotoxicity" in any cell at similar concentrations. We hypothesize that cells differ less in their vulnerability to a given toxicant than in their resilience (coping with the "hit"). In many cases, cells do not return to the naive state after a toxic insult. The phenomena of "pre-conditioning", "tolerance" and "hormesis" describe this for low-dose exposures to toxicants that render the cell more resistant to subsequent hits. The defense and resilience programs include epigenetic changes that leave a "memory/scar" - an alteration as a consequence of the stress the cell has experienced. These memories might have long-term consequences, both positive (resistance) and negative, that contribute to chronic and delayed manifestations of hazard and, ultimately, disease. This article calls for more systematic analyses of how cells cope with toxic perturbations in the long-term after stressor withdrawal. A technical prerequisite for these are stable (organotypic) cultures and a characterization of stress response molecular networks. PMID:26536287

  18. Parallel SCF adaptor capture proteomics reveals a role for SCFFBXL17 in NRF2 activation via BACH1 repressor turnover.

    Science.gov (United States)

    Tan, Meng-Kwang Marcus; Lim, Hui-Jun; Bennett, Eric J; Shi, Yang; Harper, J Wade

    2013-10-10

    Modular cullin-RING E3 ubiquitin ligases (CRLs) use substrate binding adaptor proteins to specify target ubiquitylation. Many of the ~200 human CRL adaptor proteins remain poorly studied due to a shortage of efficient methods to identify biologically relevant substrates. Here, we report the development of parallel adaptor capture (PAC) proteomics and its use to systematically identify candidate targets for the leucine-rich repeat family of F-box proteins (FBXLs) that function with SKP1-CUL1-F-box protein (SCF) E3s. In validation experiments, we identify the unstudied F-box protein FBXL17 as a regulator of the NFR2 oxidative stress pathway. We demonstrate that FBXL17 controls the transcription of the NRF2 target HMOX1 via turnover of the transcriptional repressor BACH1 in the absence or presence of extrinsic oxidative stress. This work identifies a role for SCF(FBXL17) in controlling the threshold for NRF2-dependent gene activation and provides a framework for elucidating the functions of CRL adaptor proteins. PMID:24035498

  19. Phase transition from cubic to monoclinic phase in cryolite (NH4)3ScF6 - investigation by Raman spectroscopy

    International Nuclear Information System (INIS)

    The studies on the transition from the cubic to monoclinic phase in the (NH4)3ScF6 cryolite crystal are accomplished through the Raman spectroscopy method. The sharp anomalies of frequencies and half-widths of the RS lines, corresponding to the internal oscillations of the ScF63+ ions, and also the lattice oscillations were observed; the condensation of the soft lattice node was not identified. The conclusion is made that the studied phase transition is connected mainly with the orientation ordering of these ions

  20. Phase transition from cubic to monoclinic phase in cryolite (NH sub 4) sub 3 ScF sub 6 - investigation by Raman spectroscopy

    CERN Document Server

    Vtyurin, A N; Afanasev, M L; Belyu, A; Shebanin, A P

    2001-01-01

    The studies on the transition from the cubic to monoclinic phase in the (NH sub 4) sub 3 ScF sub 6 cryolite crystal are accomplished through the Raman spectroscopy method. The sharp anomalies of frequencies and half-widths of the RS lines, corresponding to the internal oscillations of the ScF sub 6 sup 3 sup + ions, and also the lattice oscillations were observed; the condensation of the soft lattice node was not identified. The conclusion is made that the studied phase transition is connected mainly with the orientation ordering of these ions

  1. Complexity

    CERN Document Server

    Gershenson, Carlos

    2011-01-01

    The term complexity derives etymologically from the Latin plexus, which means interwoven. Intuitively, this implies that something complex is composed by elements that are difficult to separate. This difficulty arises from the relevant interactions that take place between components. This lack of separability is at odds with the classical scientific method - which has been used since the times of Galileo, Newton, Descartes, and Laplace - and has also influenced philosophy and engineering. In recent decades, the scientific study of complexity and complex systems has proposed a paradigm shift in science and philosophy, proposing novel methods that take into account relevant interactions.

  2. From a Global View to Focused Examination:Understanding Cellular Function of Lipid Kinase VPS34-Beclin 1 Complex in Autophagy

    Institute of Scientific and Technical Information of China (English)

    Zhenyu Yue; Yun Zhong

    2010-01-01

    @@ Autophagy is a cell'self-digestion'process via lysosomal degradation.The bestknown type of autophagy is macroauto phagy(hereafter referred to as auto phagy).Which involves the formation,delivery and degradation of autophago somes.The physiological function of autophagy is the controI of cellular nutrient and organelle homeostasis and can be regulated by various extracellular and intracellular cues(Klionsky and Emr,2000;Levine and Klionsky.2004).

  3. Thermodynamics of polymer nematics described with a worm-like chain model: particle-based simulations and SCF theory calculations

    Science.gov (United States)

    Greco, Cristina; Yiang, Ying; Kremer, Kurt; Chen, Jeff; Daoulas, Kostas

    Polymer liquid crystals, apart from traditional applications as high strength materials, are important for new technologies, e.g. Organic Electronics. Their studies often invoke mesoscale models, parameterized to reproduce thermodynamic properties of the real material. Such top-down strategies require advanced simulation techniques, predicting accurately the thermodynamics of mesoscale models as a function of characteristic features and parameters. Here a recently developed model describing nematic polymers as worm-like chains interacting with soft directional potentials is considered. We present a special thermodynamic integration scheme delivering free energies in particle-based Monte Carlo simulations of this model, avoiding thermodynamic singularities. Conformational and structural properties, as well as Helmholtz free energies are reported as a function of interaction strength. They are compared with state-of-art SCF calculations invoking a continuum analog of the same model, demonstrating the role of liquid-packing and fluctuations.

  4. Theoretical investigation of force field and vibrational spectrum of BF3 molecule by MO LCAO SCF method

    International Nuclear Information System (INIS)

    Non-empirical calculations of equilibrium internuclear distances, force constants, frequencies of normal vibrations, isotope shifts and vibration intensities in IR spectrum of BF3 molecule have been made by MO LCAO SCF method using three bases of grouped gauss functions: DZ (9s5p/4s2p), TZ(10s6p/5s3p) and TZ+P (10s6p1d/5s3p1d). All the three bases lead to the results which are in good agreement with the experimental data. For instance, theoretical values of vibration frequencies differ from the experimental ones by average 3.2; 2.4 and 7.0% in the bases DZ, TZ and TZ+P respectively

  5. Cellular uptake of PLA nanoparticles studied by light and electron microscopy: synthesis, characterization and biocompatibility studies using an iridium(iii) complex as correlative label.

    Science.gov (United States)

    Reifarth, Martin; Pretzel, David; Schubert, Stephanie; Weber, Christine; Heintzmann, Rainer; Hoeppener, Stephanie; Schubert, Ulrich S

    2016-03-10

    We present the synthesis of polylactide by ring-opening polymerization using a luminescent iridium(iii) complex acting as initiator. The polymer was formulated into nanoparticles, which were taken up by HEK-293 cells. We could show that the particles provided an appropriate contrast in both superresolution fluorescence and electron microscopy, and, moreover, are non-toxic, in contrast to the free iridium complex. PMID:26923139

  6. Exploration of cellular DNA lesion, DNA-binding and biocidal ordeal of novel curcumin based Knoevenagel Schiff base complexes incorporating tryptophan: Synthesis and structural validation

    Science.gov (United States)

    Chandrasekar, Thiravidamani; Raman, Natarajan

    2016-07-01

    A few novel Schiff base transition metal complexes of general formula [MLCl] (where, L = Schiff base, obtained by the condensation reaction of Knoevenagel condensate of curcumin, L-tryptophan and M = Cu(II), Ni(II), Co(II), and Zn(II)), were prepared by stencil synthesis. They were typified using UV-vis, IR, EPR spectral techniques, micro analytical techniques, magnetic susceptibility and molar conductivity. Geometry of the metal complexes was examined and recognized as square planar. DNA binding and viscosity studies revealed that the metal(II) complexes powerfully bound via an intercalation mechanism with the calf thymus DNA. Gel-electrophoresis technique was used to investigate the DNA cleavage competence of the complexes and they establish to approve the cleavage of pBR322 DNA in presence of oxidant H2O2. This outcome inferred that the synthesized complexes showed better nuclease activity. Moreover, the complexes were monitored for antimicrobial activities. The results exposed that the synthesized compounds were forceful against all the microbes under exploration.

  7. Cellular responses of BRCA1-defective and triple-negative breast cancer cells and in vitro BRCA1 interactions induced by metallo-intercalator ruthenium(II) complexes containing chloro-substituted phenylazopyridine

    International Nuclear Information System (INIS)

    Triple-negative breast cancer (TNBC) is defined by the absence of expression of estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2. Breast cancers with a BRCA1 mutation are also frequently triple-negative. Currently, there is a lack of effective therapies and known specific molecular targets for this aggressive breast cancer subtype. To address this concern, we have explored the cellular responses of BRCA1-defective and triple-negative breast cancer cells, and in vitro BRCA1 interactions induced by the ruthenium(II) complexes containing the bidentate ligand, 5-chloro-2-(phenylazo)pyridine. Triple-negative MDA-MB-231, BRCA1-defective HCC1937 and BRCA1-competent MCF-7 breast cancer cell lines were treated with ruthenium(II) complexes. The cytoxoxicity of ruthenium-induced breast cancer cells was evaluated by a real time cellular analyzer (RTCA). Cellular uptake of ruthenium complexes was determined by ICP-MS. Cell cycle progression and apoptosis were assessed using propidium iodide and Annexin V flow cytometry. The N-terminal BRCA1 RING protein was used for conformational and functional studies using circular dichroism and in vitro ubiquitination. HCC1937 cells were significantly more sensitive to the ruthenium complexes than the MDA-MB-231 and MCF-7 cells. Treatment demonstrated a higher degree of cytotoxicity than cisplatin against all three cell lines. Most ruthenium atoms were retained in the nuclear compartment, particularly in HCC1937 cells, after 24 h of incubation, and produced a significant block at the G2/M phase. An increased induction of apoptotic cells as well as an upregulation of p53 mRNA was observed in all tested breast cancer cells. It was of interest that BRCA1 mRNA and replication of BRCA1-defective cells were downregulated. Changes in the conformation and binding constants of ruthenium-BRCA1 adducts were observed, causing inactivation of the RING heterodimer BRCA1/BARD1-mediated E3 ubiquitin ligase activity

  8. A new entropy based method for computing software structural complexity

    International Nuclear Information System (INIS)

    In this paper a new methodology for the evaluation of software structural complexity is described. It is based on the entropy evaluation of the random uniform response function associated with the so called software characteristic function SCF. The behavior of the SCF with the different software structures and their relationship with the number of inherent errors is investigated. It is also investigated how the entropy concept can be used to evaluate the complexity of a software structure considering the SCF as a canonical representation of the graph associated with the control flow diagram. The functions, parameters and algorithms that allow to carry out this evaluation are also introduced. After this analytic phase follows the experimental phase, verifying the consistency of the proposed metric and their boundary conditions. The conclusion is that the degree of software structural complexity can be measured as the entropy of the random uniform response function of the SCF. That entropy is in direct relationship with the number of inherent software errors and it implies a basic hazard failure rate for it, so that a minimum structure assures a certain stability and maturity of the program. This metric can be used, either to evaluate the product or the process of software development, as development tool or for monitoring the stability and the quality of the final product. (author)

  9. Extra-cellular release of microRNA and nucleoprotein complexes by malignant cells infected by EBV : role of exosomes and other carriers

    OpenAIRE

    Gourzones, Claire

    2011-01-01

    The study of tumoral microenvironment should take into account different modes of intercellular communications: direct contacts between extracellular membranes, secretion and uptake of cytokines and finally emission and uptake of complex biological objects like exosomes and microvesicles.Epstein-Barr virus (EBV) is associated with several human malignancies of epithelial origin (Nasopharyngeal carcinoma or NPC) or of lymphoïd origin (post-transplant lymphoproliferative disorder or PTLD). In t...

  10. Tracing the Origin of the HSC Hierarchy Reveals an SCF-Dependent, IL-3-Independent CD43− Embryonic Precursor

    Directory of Open Access Journals (Sweden)

    Stanislav Rybtsov

    2014-09-01

    Full Text Available Definitive hematopoietic stem cells (HSCs develop in the aorta gonad mesonephros (AGM region in a stepwise manner. Type I pre-HSCs express CD41 but lack CD45 expression, which is subsequently upregulated in type II pre-HSCs prior to their maturation into definitive HSCs. Here, using ex vivo modeling of HSC development, we identify precursors of definitive HSCs in the trunk of the embryonic day 9.5 (E9.5 mouse embryo. These precursors, termed here pro-HSCs, are less mature than type I and II pre-HSCs. Although pro-HSCs are CD41+, they lack the CD43 marker, which is gradually upregulated in the developing HSC lineage. We show that stem cell factor (SCF, but not interleukin-3 (IL-3, is a major effector of HSC maturation during E9–E10. This study extends further the previously established hierarchical organization of the developing HSC lineage and presents it as a differentially regulated four-step process and identifies additional targets that could facilitate the generation of transplantable HSCs from pluripotent cells for clinical needs.

  11. Improved electronic properties from third-order SCC-DFTB with cost efficient post-SCF extensions.

    Science.gov (United States)

    Kaminski, Steve; Gaus, Michael; Elstner, Marcus

    2012-12-01

    The present work outlines the implementation and performance of two cost efficient post-SCF extensions into the third-order SCC-DFTB code. The first one, the charge model 3 (CM3), corrects for errors in bond dipoles for an improved description of molecular charge distribution as compared to the standard Mulliken partitioning scheme. The second one focuses on the response of the charge density, that is, the electronic molecular polarizability, described inaccurately from SCC-DFTB due to the usage of a minimal atomic orbital basis. Here, a variational approach, based on scaled dipole integrals, was implemented, which clearly outperforms standard finite electric field approaches for polarizability calculations by approximately 1 order of magnitude. Both extensions in the present work rely on a set of empirical parameters, which were fitted against 112 organic molecules to match a reference data set from full density functional calculations with a large basis. As an achievement, notably improved electronic properties, that is, molecular dipole moments and polarizabilities, result from SCC-DFTB calculations at negligible additional computational cost. Furthermore, the accuracy of infrared and Raman intensities was tested as first-order derivatives of the new dipoles and polarizabilities as a function of normal mode vibrations. As a result, the current implementations cannot contribute to an improved prediction of relative intensity pattern from SCC-DFTB as compared to ab initio reference data. PMID:23167841

  12. MEK1-independent activation of MAPK and MEK1-dependent activation of p70 S6 kinase by stem cell factor (SCF) in ovarian cancer cells

    International Nuclear Information System (INIS)

    We discovered a stem cell factor (SCF)-triggered, MEK1-independent, and PI3K-dependent MAPK activation pathway in the Kit-expressing ovarian cancer cell line HEY. When we knocked down MEK1 with RNA interference (RNAi) to study the function of MEK1 on the proliferation and survival of ovarian cancer cells, we found that impaired cell growth still occurred after MEK1 expression had been suppressed, although MAPK activation remained intact. This suggests that there is MEK1-independent activation of MAPK in the SCF-induced ovarian cancer cell growth process, and that MEK1 still plays a crucial role in maintaining the malignant properties of ovarian cancer cells even when it fails to activate MAPK as expected.

  13. Cellular Delivery of Quantum Dot-Bound Hybridization Probe for Detection of Intracellular Pre-MicroRNA Using Chitosan/Poly(γ-Glutamic Acid) Complex as a Carrier

    OpenAIRE

    Yao Geng; Dajie Lin; Lijia Shao; Feng Yan; Huangxian Ju

    2013-01-01

    A quantum dot (QD)-bound hybridization probe was designed for detection of intracellular pre-miRNA using chitosan (CS)/poly(γ-glutamic acid) (γ-PGA) complex as a gene vector. The probe was prepared by assembling thiolated RNA to gold nanoparticle (Au NP) via Au-S bond and then binding 3'-end amine of the RNA to the carboxy group capped on quantum dot surface. The QD-RNA-Au NP probe was assembled on the vector by mixing with aqueous γ-PGA solution and then CS solution to construct a gene deliv...

  14. CDK-mediated activation of the SCF(FBXO) (28) ubiquitin ligase promotes MYC-driven transcription and tumourigenesis and predicts poor survival in breast cancer

    DEFF Research Database (Denmark)

    Cepeda, Diana; Ng, Hwee-Fang; Sharifi, Hamid Reza;

    2013-01-01

    results in an impairment of MYC-driven transcription, transformation and tumourigenesis. Finally, in human breast cancer, high FBXO28 expression and phosphorylation are strong and independent predictors of poor outcome. In conclusion, our data suggest that SCF(FBXO28) plays an important role in...... transmitting CDK activity to MYC function during the cell cycle, emphasizing the CDK-FBXO28-MYC axis as a potential molecular drug target in MYC-driven cancers, including breast cancer....

  15. The mammary cellular hierarchy and breast cancer

    OpenAIRE

    Oakes, Samantha R.; Gallego-Ortega, David; Ormandy, Christopher J.

    2014-01-01

    Advances in the study of hematopoietic cell maturation have paved the way to a deeper understanding the stem and progenitor cellular hierarchy in the mammary gland. The mammary epithelium, unlike the hematopoietic cellular hierarchy, sits in a complex niche where communication between epithelial cells and signals from the systemic hormonal milieu, as well as from extra-cellular matrix, influence cell fate decisions and contribute to tissue homeostasis. We review the discovery, definition and ...

  16. Cellular Uptake and Photo-Cytotoxicity of a Gadolinium(III-DOTA-Naphthalimide Complex “Clicked” to a Lipidated Tat Peptide

    Directory of Open Access Journals (Sweden)

    William I. O’Malley

    2016-02-01

    Full Text Available A new bifunctional macrocyclic chelator featuring a conjugatable alkynyl-naphthalimide fluorophore pendant group has been prepared and its Gd(III complex coupled to a cell-penetrating lipidated azido-Tat peptide derivative using Cu(I-catalysed “click” chemistry. The resulting fluorescent conjugate is able to enter CAL-33 tongue squamous carcinoma cells, as revealed by confocal microscopy, producing a very modest anti-proliferative effect (IC50 = 93 µM. Due to the photo-reactivity of the naphthalimide moiety, however, the conjugate’s cytotoxicity is significantly enhanced (IC50 = 16 µM upon brief low-power UV-A irradiation.

  17. Cellular immune responses to ESAT-6 discriminate between patients with pulmonary disease due to Mycobacterium avium complex and those with pulmonary disease due to Mycobacterium tuberculosis

    DEFF Research Database (Denmark)

    Lein, A D; von Reyn, C F; Ravn, P;

    1999-01-01

    disease due to either Mycobacterium avium complex (MAC) or Mycobacterium tuberculosis with those in healthy, skin test-negative, control subjects. Significant IFN-gamma responses to ESAT-6 were detected in 16 (59%) of 27 M. tuberculosis pulmonary disease patients, 0 (0%) of 8 MAC disease patients, and 0...... (0%) of 8 controls. Significant IFN-gamma responses to M. tuberculosis purified protein derivative were detected in 23 (85%) of 27 M. tuberculosis disease patients, 2 (25%) of 8 MAC disease patients, and 5 (63%) of 8 healthy controls. M. avium sensitin was recognized in 24 (89%) of 27 M. tuberculosis...... disease patients, 4 (50%) of 8 MAC disease patients, and 1 (13%) of 8 controls. IFN-gamma responses to ESAT-6 are specificfor disease due to M. tuberculosis and are not observed in patients with MAC disease or in healthy controls....

  18. Cellular immune responses to ESAT-6 discriminate between patients with pulmonary disease due to Mycobacterium avium complex and those with pulmonary disease due to Mycobacterium tuberculosis

    DEFF Research Database (Denmark)

    Lein, A D; von Reyn, C F; Ravn, P;

    1999-01-01

    disease due to either Mycobacterium avium complex (MAC) or Mycobacterium tuberculosis with those in healthy, skin test-negative, control subjects. Significant IFN-gamma responses to ESAT-6 were detected in 16 (59%) of 27 M. tuberculosis pulmonary disease patients, 0 (0%) of 8 MAC disease patients, and 0...... (0%) of 8 controls. Significant IFN-gamma responses to M. tuberculosis purified protein derivative were detected in 23 (85%) of 27 M. tuberculosis disease patients, 2 (25%) of 8 MAC disease patients, and 5 (63%) of 8 healthy controls. M. avium sensitin was recognized in 24 (89%) of 27 M. tuberculosis...... disease patients, 4 (50%) of 8 MAC disease patients, and 1 (13%) of 8 controls. IFN-gamma responses to ESAT-6 are specific for disease due to M. tuberculosis and are not observed in patients with MAC disease or in healthy controls....

  19. New Markov-Shannon Entropy models to assess connectivity quality in complex networks: from molecular to cellular pathway, Parasite-Host, Neural, Industry, and Legal-Social networks.

    Science.gov (United States)

    Riera-Fernández, Pablo; Munteanu, Cristian R; Escobar, Manuel; Prado-Prado, Francisco; Martín-Romalde, Raquel; Pereira, David; Villalba, Karen; Duardo-Sánchez, Aliuska; González-Díaz, Humberto

    2012-01-21

    Graph and Complex Network theory is expanding its application to different levels of matter organization such as molecular, biological, technological, and social networks. A network is a set of items, usually called nodes, with connections between them, which are called links or edges. There are many different experimental and/or theoretical methods to assign node-node links depending on the type of network we want to construct. Unfortunately, the use of a method for experimental reevaluation of the entire network is very expensive in terms of time and resources; thus the development of cheaper theoretical methods is of major importance. In addition, different methods to link nodes in the same type of network are not totally accurate in such a way that they do not always coincide. In this sense, the development of computational methods useful to evaluate connectivity quality in complex networks (a posteriori of network assemble) is a goal of major interest. In this work, we report for the first time a new method to calculate numerical quality scores S(L(ij)) for network links L(ij) (connectivity) based on the Markov-Shannon Entropy indices of order k-th (θ(k)) for network nodes. The algorithm may be summarized as follows: (i) first, the θ(k)(j) values are calculated for all j-th nodes in a complex network already constructed; (ii) A Linear Discriminant Analysis (LDA) is used to seek a linear equation that discriminates connected or linked (L(ij)=1) pairs of nodes experimentally confirmed from non-linked ones (L(ij)=0); (iii) the new model is validated with external series of pairs of nodes; (iv) the equation obtained is used to re-evaluate the connectivity quality of the network, connecting/disconnecting nodes based on the quality scores calculated with the new connectivity function. This method was used to study different types of large networks. The linear models obtained produced the following results in terms of overall accuracy for network reconstruction

  20. 抗苗勒氏管激素(AMH)对离体人卵巢黄素化颗粒细胞干细胞因子(SCF)表达负调控的研究%Impact of Anti Miillerian Hormone(AMH) on the Expression of Stem Cell Factor (SCF) in Human Granulosa Cells Cultured in Vitro

    Institute of Scientific and Technical Information of China (English)

    胡蓉; 王飞苗; 罗艳; 马会明; 吴昕

    2011-01-01

    Objective: To explore the influence of anti Mullerian hormone (AMH) on the expression of SCF in human granulosa cells cultured in vitro. Methods: Fifteen patients were recruited who received in vitro fertilization and embryo transfer (IVF-ET) at age 0.05). Conclusion: AMH can effectively down-regulate the expressions of SCF mRNA and protein in human granulosa cells.%目的:研究人卵巢黄素化颗粒细胞中抗苗勒氏管激素(AMH)对干细胞因子(SCF)表达的影响.方法:收集15例年龄<35岁因男方因素行体外受精-胚胎移植(IVF-ET)患者的卵巢颗粒细胞,经原代培养,加入不同浓度基因重组人抗苗勒氏管激素(rhAMH),分别于培养的第4日与第6日采用实时定量PCR(RT-PCR)和免疫组织化学检测空白对照组与各实验组SCF mRNA及蛋白的表达.结果:RT-PCR和免疫组织化学均证实人卵巢黄素化颗粒细胞在不同浓度rhAMH干预后,SCFmRNA及蛋白的表达显著减少(P<0.05),其中15 ng/ml rhAMH抑制作用最明显;实验组第4日与第6日颗粒细胞表达SCFmRNA及蛋白无明显差异(P>0.05).结论:AMH可有效抑制人卵巢黄素化颗粒细胞SCF mRNA及蛋白的表达.

  1. Transfer of Ho Endonuclease and Ufo1 to the Proteasome by the UbL-UbA Shuttle Protein, Ddi1, Analysed by Complex Formation In Vitro

    OpenAIRE

    Olga Voloshin; Anya Bakhrat; Sharon Herrmann; Dina Raveh

    2012-01-01

    The F-box protein, Ufo1, recruits Ho endonuclease to the SCF(Ufo1) complex for ubiquitylation. Both ubiquitylated Ho and Ufo1 are transferred by the UbL-UbA protein, Ddi1, to the 19S Regulatory Particle (RP) of the proteasome for degradation. The Ddi1-UbL domain binds Rpn1 of the 19S RP, the Ddi1-UbA domain binds ubiquitin chains on the degradation substrate. Here we used complex reconstitution in vitro to identify stages in the transfer of Ho and Ufo1 from the SCF(Ufo1) complex to the protea...

  2. Continuum representations of cellular solids

    Energy Technology Data Exchange (ETDEWEB)

    Neilsen, M.K.

    1993-09-01

    Cellular materials consist of interconnected struts or plates which form cells. The struts or plates are constructed from a variety of metals, polymers, ceramics and wood products. Cellular materials are often used in impact limiters for shipping containers to protect the contents from accidental impact events. These materials exhibit a variety of complex behavior when subjected to crushing loads. This research focuses on the development of continuum representations of cellular solids that can be used in the finite element analysis of shipping container accidents. A significant portion of this work is the development of a new methodology to relate localized deformations to appropriate constitutive descriptions. This methodology provides the insight needed to select constitutive descriptions for cellular solids that capture the localized deformations that are observed experimentally. Constitutive relations are developed for two different cellular materials, aluminum honeycomb and polyurethane foam. These constitutive relations are based on plasticity and continuum damage theories. Plasticity is used to describe the permanent deformation exhibited by both aluminum honeycomb and polyurethane foam. Continuum damage is needed to capture the change in elastic parameters due to cracking of the polyurethane cell wall materials. The new constitutive description of polyurethane foam is implemented in both static and dynamic finite element codes, and analytical and numerical predictions are compared with available experimental data.

  3. Association and dissociation of the GlnK-AmtB complex in response to cellular nitrogen status can occur in the absence of GlnK post-translational modification

    Directory of Open Access Journals (Sweden)

    Mike eMerrick

    2014-12-01

    Full Text Available PII proteins are pivotal players in the control of nitrogen metabolism in bacteria and archaea, and are also found in the plastids of plants. PII proteins control the activities of a diverse range of enzymes, transcription factors and membrane transport proteins, and their regulatory effect is achieved by direct interaction with their target. Many, but by no means all, PII proteins are subject to post-translational modification of a residue within the T-loop of the protein. The protein’s modification state is influenced by the cellular nitrogen status and in the past this has been considered to regulate PII activity by controlling interaction with target proteins. However the fundamental ability of PII proteins to respond to the cellular nitrogen status has been shown to be dependent on binding of key effector molecules, ATP, ADP and 2-oxoglutarate which brings into question the precise role of post-translational modification. In this study we have used the Escherichia coli PII protein GlnK to examine the influence of post-translational modification (uridylylation on the interaction between GlnK and its cognate target the ammonia channel protein AmtB. We have compared the interaction with AmtB of wild-type GlnK and a variant protein, GlnKTyr51Ala, that cannot be uridylylated. This analysis was carried out both in vivo and in vitro and showed that association and dissociation of the GlnK-AmtB complex is not dependent on the uridylylation state of GlnK. However our in vivo studies show that post-translational modification of GlnK does influence the dynamics of its interaction with AmtB.

  4. Integrating mitochondrial translation into the cellular context.

    Science.gov (United States)

    Richter-Dennerlein, Ricarda; Dennerlein, Sven; Rehling, Peter

    2015-10-01

    Mitochondrial-encoded subunits of the oxidative phosphorylation system assemble with nuclear-encoded subunits into enzymatic complexes. Recent findings showed that mitochondrial translation is linked to other mitochondrial functions, as well as to cellular processes. The supply of mitochondrial-encoded proteins is coordinated by the coupling of mitochondrial protein synthesis with assembly of respiratory chain complexes. MicroRNAs imported from the cytoplasm into mitochondria were, surprisingly, found to act as regulators of mitochondrial translation. In turn, translation in mitochondria controls cellular proliferation, and mitochondrial ribosomal subunits contribute to the cytoplasmic stress response. Thus, translation in mitochondria is apparently integrated into cellular processes. PMID:26535422

  5. Investigation of energy stability, geometric structure, force fields, and vibrational spectra of LiNaF2, LiMgF3, and LiAlF4 molecules by means of MO LCAO SCF method

    International Nuclear Information System (INIS)

    By the MO LCAO SCF method with Huzinaga-Dumming and McLean-Chandler two-exponent basis sets, supplemented by d-functions on the Period III atoms, ab initio calculations have been performed for the equilibrium geometric parameters, coefficients of the quadratic force field, vibrational frequencies and intensities in the IR spectra, dipole moments, ionization potentials (according to the Koopmans theorem), Mulliken populations, and enthalpy and entropy of complexation of the molecules LiNaF2, LiMgF3, and LiAlF4. A study has been made of the effects on the calculated results when the basis is extended by inclusion of polarization and diffuse functions on the fluorine atoms. The calculated characteristics are compared with the available experimental data. A reassignment has been performed for certain frequencies in the IR spectrum of LiNaF2, as assigned previously by S.J. Syvin, B.N. Syvin, and A Snelson, J. Phys. Chem., 74, No. 25, 4338 (1970). Certain frequencies of low-intensity vibrations have been predicted in the IR spectra, frequencies not yet found experimentally

  6. The Origins of Cellular Life

    OpenAIRE

    Schrum, Jason P.; Zhu, Ting F.; SZOSTAK, JACK W.

    2010-01-01

    Understanding the origin of cellular life on Earth requires the discovery of plausible pathways for the transition from complex prebiotic chemistry to simple biology, defined as the emergence of chemical assemblies capable of Darwinian evolution. We have proposed that a simple primitive cell, or protocell, would consist of two key components: a protocell membrane that defines a spatially localized compartment, and an informational polymer that allows for the replication and inheritance of fun...

  7. Cellular and molecular mechanism study of declined intestinal transit function in the cholesterol gallstone formation process of the guinea pig

    OpenAIRE

    Fan, Ying; Wu, Shuodong; YIN, ZHENHUA; Fu, Bei-Bei

    2014-01-01

    The aim of this study was to investigate the cellular and molecular mechanisms of declined intestinal transit (IT) function in the cholesterol gallstone (CG) formation process. Forty guinea pigs were divided into an experimental group (EG) and a control group (CoG), and the reverse transcription-polymerase chain reaction (RT-PCR) was performed for the analysis of c-kit and stem cell factor (scf) mRNA expression in the small bowel. In addition, immunofluorescence staining and confocal laser mi...

  8. Modelling of Octahedral Manganese II Complexes with Inorganic Ligands: A Problem with Spin-States

    Directory of Open Access Journals (Sweden)

    Ludwik Adamowicz

    2003-08-01

    Full Text Available Abstract: Quantum mechanical ab initio UHF, MP2, MC-SCF and DFT calculations with moderate Gaussian basis sets were performed for MnX6, X = H2O, F-, CN-, manganese octahedral complexes. The correct spin-state of the complexes was obtained only when the counter ions neutralizing the entire complexes were used in the modelling at the B3LYP level of theory.

  9. On the Behavior Characteristics of Cellular Automata

    Institute of Scientific and Technical Information of China (English)

    CHEN Jin-cai; ZHANG Jiang-ling; FENG Dan

    2005-01-01

    In this paper, the inherent relationships between the running regulations and behavior characteristics of cellular automata are presented; an imprecise taxonomy of such systems is put forward; the three extreme cases of stable systems are discussed; and the illogicalness of evolutional strategies of cellular automata is analyzed. The result is suitable for the emulation and prediction of behavior of discrete dynamics systems; especially it can be taken as an important analysis means of dynamic performance of complex networks.

  10. Modelling cellular behaviour

    Science.gov (United States)

    Endy, Drew; Brent, Roger

    2001-01-01

    Representations of cellular processes that can be used to compute their future behaviour would be of general scientific and practical value. But past attempts to construct such representations have been disappointing. This is now changing. Increases in biological understanding combined with advances in computational methods and in computer power make it possible to foresee construction of useful and predictive simulations of cellular processes.

  11. Silver(I) and copper(I) bis(pyridine-2-carbaldehyde-imine) triflate complexes studied in solution by 1H, 1H-{109Ag}, INEPT 15N and INEPT 109Ag NMR

    OpenAIRE

    Koten, G. van; Stein, G.C. van; Bok, B. de; Taylor, L C; Vrieze, K.; Brevard, C.

    1984-01-01

    The reactions of the neutral pyridine-imine, 6-R-py-2-CH=N-R' (NN'), donor ligands with [M(O{3}SCF{3})] [M = Ag(I) or Cu(I)] yield ionic complexes, consisting of a [M(NN'){2}]}+{ cation and a O{3}SCF{3}}-{ anion. }1{H NMR studies of the complexes which contain the prochiral substituent (R') i-Pr or the chiral (S)-CHMePh show that in the slow exchange limit the metal IB centres have tetrahedral geometries as a result of chelate bonding of the pyridine-imine ligands. The metal IB centres have e...

  12. Cellular automata a parallel model

    CERN Document Server

    Mazoyer, J

    1999-01-01

    Cellular automata can be viewed both as computational models and modelling systems of real processes. This volume emphasises the first aspect. In articles written by leading researchers, sophisticated massive parallel algorithms (firing squad, life, Fischer's primes recognition) are treated. Their computational power and the specific complexity classes they determine are surveyed, while some recent results in relation to chaos from a new dynamic systems point of view are also presented. Audience: This book will be of interest to specialists of theoretical computer science and the parallelism challenge.

  13. Mathematical Physics of Cellular Automata

    CERN Document Server

    Garcia-Morales, Vladimir

    2012-01-01

    A universal map is derived for all deterministic 1D cellular automata (CA) containing no freely adjustable parameters. The map can be extended to an arbitrary number of dimensions and topologies and its invariances allow to classify all CA rules into equivalence classes. Complexity in 1D systems is then shown to emerge from the weak symmetry breaking of the addition modulo an integer number p. The latter symmetry is possessed by certain rules that produce Pascal simplices in their time evolution. These results elucidate Wolfram's classification of CA dynamics.

  14. Heterogeneous cellular networks

    CERN Document Server

    Hu, Rose Qingyang

    2013-01-01

    A timely publication providing coverage of radio resource management, mobility management and standardization in heterogeneous cellular networks The topic of heterogeneous cellular networks has gained momentum in industry and the research community, attracting the attention of standardization bodies such as 3GPP LTE and IEEE 802.16j, whose objectives are looking into increasing the capacity and coverage of the cellular networks. This book focuses on recent progresses,  covering the related topics including scenarios of heterogeneous network deployment, interference management i

  15. Cellular Reflectarray Antenna

    Science.gov (United States)

    Romanofsky, Robert R.

    2010-01-01

    The cellular reflectarray antenna is intended to replace conventional parabolic reflectors that must be physically aligned with a particular satellite in geostationary orbit. These arrays are designed for specified geographical locations, defined by latitude and longitude, each called a "cell." A particular cell occupies nominally 1,500 square miles (3,885 sq. km), but this varies according to latitude and longitude. The cellular reflectarray antenna designed for a particular cell is simply positioned to align with magnetic North, and the antenna surface is level (parallel to the ground). A given cellular reflectarray antenna will not operate in any other cell.

  16. Les déterminants des choix de méthodes comptables dans les entreprises algériennes lors de l’adoption du SCF

    OpenAIRE

    BENSABEUR-SLIMANE, Asma

    2016-01-01

    Dans ce travail notre but est d’expliquer le choix des méthodes comptables adoptées par les entreprises algériennes, dans le cadre de la théorie positive de la comptabilité (Watts et Zimmerman, 1978) et la théorie institutionnelle (DiMaggio et Powell, 1983), lors de leur transition comptable vers le SCF. L'analyse empirique de 68 entreprises (publiques et privées), sur les données de l'année 2010, a été réalisée à travers un modèle logistique multinomial. Les résultats statistiques permettent...

  17. A non-empirical LCAO MO SCF and experimental investigation on the core-ionized states of acetylacetone and some of its enol tautomers

    International Nuclear Information System (INIS)

    Non-empirical LCAO MO SCF calculations have been performed on the ground and core-hole states of acetylacetone for a range of geometries. The theoretical studies have been complemented by gas-phase ESCA studies of both the O 1s and C 1s core levels. A comparison of the theoretical and experimental data shows excellent agreement for an unsymmetrical Csub(s) enol structure and a discussion is given of the low-energy shake-up satellites accompanying both C 1s and O 1s core ionization. Consideration is also given to the relative energies of the various tautomeric model systems as a function of the hole states. (orig.)

  18. Effect of basis on calculation results of force field and vibrational spectrum of BeF2 molecule by LCAO MO SCF method

    International Nuclear Information System (INIS)

    The method of LCAO MO SCF in the seven different bases of the groupped Gaussian functions-two-exponent, valent-three-exponent, with account and without account of polarization d-functions on the fluorine atoms has been used to found the force constants, the frequencies and intensities of the normal vibrations in IR spectrum of the BeF2 molecule. The effect of the basis on the calculation results of the considered characteristics is analyzed. According to the calculations an anharmonicity of the deformation vibration of the BeF2 molecule is insignificant. The frequency of the full-symmetrical valent vibration of BeF2(#betta#1=712+-20 cm-1) is predicted

  19. Cellular oncogenes in neoplasia.

    OpenAIRE

    Chan, V T; McGee, J O

    1987-01-01

    In recent years cellular homologues of many viral oncogenes have been identified. As these genes are partially homologous to viral oncogenes and are activated in some tumour cell lines they are termed "proto-oncogenes". In tumour cell lines proto-oncogenes are activated by either quantitative or qualitative changes in gene structure: activation of these genes was originally thought to be a necessary primary event in carcinogenesis, but activated cellular oncogenes, unlike viral oncogenes, do ...

  20. Cellular Cardiomyoplasty: Clinical Application

    OpenAIRE

    Chachques, J. (J.); Acar, C; J. Herreros; Trainini, J. (Jorge); Prosper, F.; D’Attellis, N. (N.); Fabiani, J. N.; Carpentier, A

    2004-01-01

    Myocardial regeneration can be induced with the implantation of a variety of myogenic and angiogenic cell types. More than 150 patients have been treated with cellular cardiomyoplasty worldwide, 18 patients have been treated by our group. Cellular cardiomyoplasty seems to reduce the size and fibrosis of infarct scars, limit postischemic remodelling, and restore regional myocardial contractility. Techniques for skeletal myoblasts culture and ex vivo expansion using auto...

  1. Structure of a glomulin-RBX1-CUL1 complex: inhibition of a RING E3 ligase through masking of its E2-binding surface.

    Science.gov (United States)

    Duda, David M; Olszewski, Jennifer L; Tron, Adriana E; Hammel, Michal; Lambert, Lester J; Waddell, M Brett; Mittag, Tanja; DeCaprio, James A; Schulman, Brenda A

    2012-08-10

    The approximately 300 human cullin-RING ligases (CRLs) are multisubunit E3s in which a RING protein, either RBX1 or RBX2, recruits an E2 to catalyze ubiquitination. RBX1-containing CRLs also can bind Glomulin (GLMN), which binds RBX1's RING domain, regulates the RBX1-CUL1-containing SCF(FBW7) complex, and is disrupted in the disease Glomuvenous Malformation. Here we report the crystal structure of a complex between GLMN, RBX1, and a fragment of CUL1. Structural and biochemical analyses reveal that GLMN adopts a HEAT-like repeat fold that tightly binds the E2-interacting surface of RBX1, inhibiting CRL-mediated chain formation by the E2 CDC34. The structure explains the basis for GLMN's selectivity toward RBX1 over RBX2, and how disease-associated mutations disrupt GLMN-RBX1 interactions. Our study reveals a mechanism for RING E3 ligase regulation, whereby an inhibitor blocks E2 access, and raises the possibility that other E3s are likewise controlled by cellular proteins that mask E2-binding surfaces to mediate inhibition. PMID:22748924

  2. Structure of a Glomulin-RBX1-CUL1 Complex: Inhibition of a RING E3 Ligase through Masking of Its E2-Binding Surface

    Energy Technology Data Exchange (ETDEWEB)

    Duda, David M.; Olszewski, Jennifer L.; Tron, Adriana E.; Hammel, Michal; Lambert, Lester J.; Waddell, M. Brett; Mittag, Tanja; DeCaprio, James A.; Schulman, Brenda A. (BWH); (LBNL); (SJCH); (DFCI)

    2012-11-01

    The approximately 300 human cullin-RING ligases (CRLs) are multisubunit E3s in which a RING protein, either RBX1 or RBX2, recruits an E2 to catalyze ubiquitination. RBX1-containing CRLs also can bind Glomulin (GLMN), which binds RBX1's RING domain, regulates the RBX1-CUL1-containing SCF{sup FBW7} complex, and is disrupted in the disease Glomuvenous Malformation. Here we report the crystal structure of a complex between GLMN, RBX1, and a fragment of CUL1. Structural and biochemical analyses reveal that GLMN adopts a HEAT-like repeat fold that tightly binds the E2-interacting surface of RBX1, inhibiting CRL-mediated chain formation by the E2 CDC34. The structure explains the basis for GLMN's selectivity toward RBX1 over RBX2, and how disease-associated mutations disrupt GLMN-RBX1 interactions. Our study reveals a mechanism for RING E3 ligase regulation, whereby an inhibitor blocks E2 access, and raises the possibility that other E3s are likewise controlled by cellular proteins that mask E2-binding surfaces to mediate inhibition.

  3. Non-empirical calculations of force field and vibrational spectrum of LiBH3+ complex ion using the MO lcao sct method

    International Nuclear Information System (INIS)

    Non-empiric calculations of the force field, frequencies of normal oscillations and intensities of oscillations in JR spectrum of LiBH3+ complex ions are performed using the MO lcao SCF method. The alteration of the force field and vibrational spectrum of BH3 molecule is analyzed in the case of its coordination with Li+ cation

  4. Caractérisation biochimique et moléculaire du complexe SCF (SKP1-CULLIN-FBOX) chez le blé tendre

    OpenAIRE

    El Beji, Imen

    2011-01-01

    Les modifications post-traductionnelles des protéines constituent un niveau crucial de régulation de l'expression des gènes. Parmi elles, la conjugaison peptidique impliquant l'ubiquitine intervient entre autre dans la régulation de la stabilité protéique. La fixation de ce peptide de 76 acides aminés, extrêmement conservé, sous forme de chaîne de polyubiquitine, nécessite l'intervention de trois enzymes (E1, E2 et E3) et constitue un signal de dégradation de la protéine ainsi modifiée. Cette...

  5. Atrogin-1/muscle atrophy F-box inhibits calcineurin-dependent cardiac hypertrophy by participating in an SCF ubiquitin ligase complex

    OpenAIRE

    Li, Hui-Hua; Kedar, Vishram; Zhang, Chunlian; McDonough, Holly; Arya, Ranjana; Wang, Da-Zhi; Patterson, Cam

    2004-01-01

    Calcineurin, which binds to the Z-disc in cardiomyocytes via α-actinin, promotes cardiac hypertrophy in response to numerous pathologic stimuli. However, the endogenous mechanisms regulating calcineurin activity in cardiac muscle are not well understood. We demonstrate that a muscle-specific F-box protein called atrogin-1, or muscle atrophy F-box, directly interacts with calcineurin A and α-actinin-2 at the Z-disc of cardiomyocytes. Atrogin-1 associates with Skp1, Cul1, and Roc1 to assemble a...

  6. Integrating mitochondrial translation into the cellular context.

    OpenAIRE

    Richter-Dennerlein, R.; Dennerlein Sven, S.; Rehling, P

    2015-01-01

    Mitochondrial-encoded subunits of the oxidative phosphorylation system assemble with nuclear-encoded subunits into enzymatic complexes. Recent findings showed that mitochondrial translation is linked to other mitochondrial functions, as well as to cellular processes. The supply of mitochondrial- encoded proteins is coordinated by the coupling of mitochondrial protein synthesis with assembly of respiratory chain complexes. MicroRNAs imported from the cytoplasm into mitochondria were, surprisin...

  7. Cellular and synaptic network defects in autism

    OpenAIRE

    Peça, João; Feng, Guoping

    2012-01-01

    Many candidate genes are now thought to confer susceptibility to autism spectrum disorders (ASDs). Here we review four interrelated complexes, each composed of multiple families of genes that functionally coalesce on common cellular pathways. We illustrate a common thread in the organization of glutamatergic synapses and suggest a link between genes involved in Tuberous Sclerosis Complex, Fragile X syndrome, Angelman syndrome and several synaptic ASD candidate genes. When viewed in this conte...

  8. Cellular automata and self-organized criticality

    OpenAIRE

    Creutz, Michael

    1996-01-01

    Cellular automata provide a fascinating class of dynamical systems capable of diverse complex behavior. These include simplified models for many phenomena seen in nature. Among other things, they provide insight into self-organized criticality, wherein dissipative systems naturally drive themselves to a critical state with important phenomena occurring over a wide range of length and time scales.

  9. Pathologic changes and expressions of SCF and c-kit in contralateral testes in rat model of unilateral cryptorchidism%单侧隐睾大鼠对侧睾丸组织中SCF/c-kit基因表达变化及意义

    Institute of Scientific and Technical Information of China (English)

    徐明; 郑新民; 李世文; 丁协刚; 周克文; 汪聪

    2010-01-01

    目的 研究单侧隐睾大鼠对侧睾丸病理变化及SCF/c-kit基因表达,探讨单侧隐睾致对侧睾丸损害的机制.方法 30只SD大鼠随机分为对照组和实验组,实验组复制单侧(左侧)腹腔隐睾模型.3个月后分别取两组右侧睾丸组织进行real-time RT-PCR、Western blot及免疫组化检测干细胞生长因子(SCF)和其受体c-kit基因及其蛋白表达变化,TUNEL法检测细胞凋亡.结果 所有动物均存活,与对照组相比实验组对侧睾丸明显缩小,光镜下观察其曲细精管发生退化,生精上皮变薄,管腔较空,生殖细胞明显减少,细胞凋亡增加.两组凋亡指数分别为14.4±0.63和4.45±0.37,差异有统计学意义(P<0.05).荧光实时定量PT-PCR检测SCF、c-kit基因mRNA含量,实验组对侧睾丸明显降低,两组相比差异有统计学意义(P<0.05).Western blot检测SCF及c-kit蛋白表达含量,实验组对侧睾丸同样明显降低,两组相比差异有统计学意义(P<0.05).免疫组化染色显示各级生精细胞膜均有c-kit表达,SCF主要表达于支持细胞膜表面,但实验组两者的表达均较对照组减弱.相关性检验SCF与AI相关系数r=-0.941,P<0.01;c-kit与AI相关系数r=-0.908,P<0.01;SCF与c-kit相关系数r=0.956,P<0.01,均有统计学意义.结论 单侧隐睾可致对侧睾丸SCF/c-kit基因表达减弱,生精细胞凋亡增加引起不育.%Objective To investigate the pathologic changes and expressions of SCF and c-kit in the contralateral testes in rat model of unilateral cryptorchidism. Methods Thirty male SD rats were maintained under controlled temperature and constant photoperiodic conditions with access to food and water. The rats were randomly assaigned to the control group and the experimental unilateral cryptorchidism group. The left testis of the rats in the unilateral cryptorchidism group was placed into the abdominal cavity. The control group rats were subjected to sham surgery. Three months later, the rats were

  10. Irregular Cellular Learning Automata.

    Science.gov (United States)

    Esnaashari, Mehdi; Meybodi, Mohammad Reza

    2015-08-01

    Cellular learning automaton (CLA) is a recently introduced model that combines cellular automaton (CA) and learning automaton (LA). The basic idea of CLA is to use LA to adjust the state transition probability of stochastic CA. This model has been used to solve problems in areas such as channel assignment in cellular networks, call admission control, image processing, and very large scale integration placement. In this paper, an extension of CLA called irregular CLA (ICLA) is introduced. This extension is obtained by removing the structure regularity assumption in CLA. Irregularity in the structure of ICLA is needed in some applications, such as computer networks, web mining, and grid computing. The concept of expediency has been introduced for ICLA and then, conditions under which an ICLA becomes expedient are analytically found. PMID:25291810

  11. Architected Cellular Materials

    Science.gov (United States)

    Schaedler, Tobias A.; Carter, William B.

    2016-07-01

    Additive manufacturing enables fabrication of materials with intricate cellular architecture, whereby progress in 3D printing techniques is increasing the possible configurations of voids and solids ad infinitum. Examples are microlattices with graded porosity and truss structures optimized for specific loading conditions. The cellular architecture determines the mechanical properties and density of these materials and can influence a wide range of other properties, e.g., acoustic, thermal, and biological properties. By combining optimized cellular architectures with high-performance metals and ceramics, several lightweight materials that exhibit strength and stiffness previously unachievable at low densities were recently demonstrated. This review introduces the field of architected materials; summarizes the most common fabrication methods, with an emphasis on additive manufacturing; and discusses recent progress in the development of architected materials. The review also discusses important applications, including lightweight structures, energy absorption, metamaterials, thermal management, and bioscaffolds.

  12. Cellular Homeostasis and Aging.

    Science.gov (United States)

    Hartl, F Ulrich

    2016-06-01

    Aging and longevity are controlled by a multiplicity of molecular and cellular signaling events that interface with environmental factors to maintain cellular homeostasis. Modulation of these pathways to extend life span, including insulin-like signaling and the response to dietary restriction, identified the cellular machineries and networks of protein homeostasis (proteostasis) and stress resistance pathways as critical players in the aging process. A decline of proteostasis capacity during aging leads to dysfunction of specific cell types and tissues, rendering the organism susceptible to a range of chronic diseases. This volume of the Annual Review of Biochemistry contains a set of two reviews addressing our current understanding of the molecular mechanisms underlying aging in model organisms and humans. PMID:27050288

  13. PARC and CUL7 form atypical cullin RING ligase complexes.

    Science.gov (United States)

    Skaar, Jeffrey R; Florens, Laurence; Tsutsumi, Takeya; Arai, Takehiro; Tron, Adriana; Swanson, Selene K; Washburn, Michael P; DeCaprio, James A

    2007-03-01

    CUL7 and the p53-associated, PARkin-like cytoplasmic protein (PARC) were previously reported to form homodimers and heterodimers, the first demonstration of cullin dimerization. Although a CUL7-based SKP1/CUL1/F-box (SCF)-like complex has been observed, little is known about the existence of a PARC-based SCF-like complex and how PARC interacts with CUL7-based complexes. To further characterize PARC-containing complexes, we examined the ability of PARC to form an SCF-like complex. PARC binds RBX1 and is covalently modified by NEDD8, defining PARC as a true cullin. However, PARC fails to bind SKP1 or F-box proteins, including the CUL7-associated FBXW8. To examine the assembly of PARC- and CUL7-containing complexes, tandem affinity purification followed by multidimensional protein identification technology were used. Multidimensional protein identification technology analysis revealed that the CUL7 interaction with FBXW8 was mutually exclusive of CUL7 binding to PARC or p53. Notably, although heterodimers of CUL7 and PARC bind p53, p53 is not required for the dimerization of CUL7 and PARC. The observed physical separation of FBXW8 and PARC is supported functionally by the generation of Parc-/-, Fbxw8-/- mice, which do not show exacerbation of the Fbxw8-/- phenotype. Finally, all of the PARC and CUL7 subcomplexes examined exhibit E3 ubiquitin ligase activity in vitro. Together, these findings indicate that the intricate assembly of PARC- and CUL7-containing complexes is highly regulated, and multiple subcomplexes may exhibit ubiquitin ligase activity. PMID:17332328

  14. Wireless Cellular Mobile Communications

    Directory of Open Access Journals (Sweden)

    V. Zalud

    2002-12-01

    Full Text Available In this article is briefly reviewed the history of wireless cellularmobile communications, examined the progress in current secondgeneration (2G cellular standards and discussed their migration to thethird generation (3G. The European 2G cellular standard GSM and itsevolution phases GPRS and EDGE are described somewhat in detail. Thethird generation standard UMTS taking up on GSM/GPRS core network andequipped with a new advanced access network on the basis of codedivision multiple access (CDMA is investigated too. A sketch of theperspective of mobile communication beyond 3G concludes this article.

  15. Cellular host responses to gliomas.

    Directory of Open Access Journals (Sweden)

    Joseph Najbauer

    together with pericytes give rise to tumor vasculature. Mapping the cellular composition of glioma microenvironment and deciphering the complex 'crosstalk' between tumor and host may ultimately aid the development of novel anti-glioma therapies.

  16. Genetic Dominance & Cellular Processes

    Science.gov (United States)

    Seager, Robert D.

    2014-01-01

    In learning genetics, many students misunderstand and misinterpret what "dominance" means. Understanding is easier if students realize that dominance is not a mechanism, but rather a consequence of underlying cellular processes. For example, metabolic pathways are often little affected by changes in enzyme concentration. This means that…

  17. Radioactivity of cellular concrete

    International Nuclear Information System (INIS)

    The natural radioactivity of cellular concrete is discussed. Some data on the concentrations of 40K, 226Ra and 232Th in building materials in Poland are given. The results of dose rates measurements in living quarters as well as outside are presented. (A.S.)

  18. The New Cellular Immunology

    Science.gov (United States)

    Claman, Henry N.

    1973-01-01

    Discusses the nature of the immune response and traces many of the discoveries that have led to the present state of knowledge in immunology. The new cellular immunology is directing its efforts toward improving health by proper manipulation of the immune mechanisms of the body. (JR)

  19. Cellular Therapy for Heart Failure.

    Science.gov (United States)

    Psaltis, Peter J; Schwarz, Nisha; Toledo-Flores, Deborah; Nicholls, Stephen J

    2016-01-01

    The pathogenesis of cardiomyopathy and heart failure (HF) is underpinned by complex changes at subcellular, cellular and extracellular levels in the ventricular myocardium. For all of the gains that conventional treatments for HF have brought to mortality and morbidity, they do not adequately address the loss of cardiomyocyte numbers in the remodeling ventricle. Originally conceived to address this problem, cellular transplantation for HF has already gone through several stages of evolution over the past two decades. Various cell types and delivery routes have been implemented to positive effect in preclinical models of ischemic and nonischemic cardiomyopathy, with pleiotropic benefits observed in terms of myocardial remodeling, systolic and diastolic performance, perfusion, fibrosis, inflammation, metabolism and electrophysiology. To a large extent, these salubrious effects are now attributed to the indirect, paracrine capacity of transplanted stem cells to facilitate endogenous cardiac repair processes. Promising results have also followed in early phase human studies, although these have been relatively modest and somewhat inconsistent. This review details the preclinical and clinical evidence currently available regarding the use of pluripotent stem cells and adult-derived progenitor cells for cardiomyopathy and HF. It outlines the important lessons that have been learned to this point in time, and balances the promise of this exciting field against the key challenges and questions that still need to be addressed at all levels of research, to ensure that cell therapy realizes its full potential by adding to the armamentarium of HF management. PMID:27280304

  20. An ab initio study of complexes between ethylene and ozone

    Energy Technology Data Exchange (ETDEWEB)

    McKee, M.L. (Auburn Univ., AL (USA)); Rohlfing, C.M. (Sandia National Labs., Livermore, CA (USA))

    1989-03-29

    A series of complexes between ethylene and ozone have been examined at the SCF, MP2, and MP4(SDTQ) levels of theory within a split-valence-plus-polarization basis. The conformational nature of the primary ozonide (PO) is determined to be an O-envelope, and the theoretically predicted geometry is in excellent agreement with a recently reported microwave structure. The binding energy of PO at correlated levels is computed to be slightly less than 50 kcal/mol, which is also in very good agreement with thermochemical estimates. Five other weakly bound complexes and the transition state to PO have also been investigated.

  1. 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 ...

  2. Electromagnetic cellular interactions

    Czech Academy of Sciences Publication Activity Database

    Cifra, Michal; Fields, J. S.; Farhadi, A.

    2011-01-01

    Roč. 105, č. 3 (2011), 223-246. ISSN 0079-6107. [36th International Congress of Physiological Sciences (IUPS2009). Kyoto, 27.07.2009-01.08.2009] R&D Projects: GA ČR(CZ) GPP102/10/P454 Institutional research plan: CEZ:AV0Z20670512 Keywords : bioelectric phenomena * cellular biophysics Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 3.203, year: 2011

  3. Magnetic Cellular Switches

    OpenAIRE

    Overby, Darryl R.; Alenghat, Francis J.; Montoya-Zavala, Martín; Bei, HuCheng; Oh, Philmo; Karavitis, John; Ingber, Donald E.

    2004-01-01

    This paper focuses on the development of magnetic cellular switches to enable magnetic control of intracellular functions in living mammalian cells, including receptor signal transduction and gene transcription. Our approach takes advantage of the mechanosensitivity of adenosine 3′,5′-monophosphate (cAMP) induction and downstream transcription controlled by the cAMP regulatory element (CRE) to engineer gene constructs that optically report gene expression in living cells. We activate transcri...

  4. Cellular Signaling in Health and Disease

    CERN Document Server

    Beckerman, Martin

    2009-01-01

    In today’s world, three great classes of non-infectious diseases – the metabolic syndromes (such as type 2 diabetes and atherosclerosis), the cancers, and the neurodegenerative disorders – have risen to the fore. These diseases, all associated with increasing age of an individual, have proven to be remarkably complex and difficult to treat. This is because, in large measure, when the cellular signaling pathways responsible for maintaining homeostasis and health of the body become dysregulated, they generate equally stable disease states. As a result the body may respond positively to a drug, but only for a while and then revert back to the disease state. Cellular Signaling in Health and Disease summarizes our current understanding of these regulatory networks in the healthy and diseased states, showing which molecular components might be prime targets for drug interventions. This is accomplished by presenting models that explain in mechanistic, molecular detail how a particular part of the cellular sign...

  5. Cellular therapy in Tuberculosis

    Directory of Open Access Journals (Sweden)

    Shreemanta K. Parida

    2015-03-01

    Full Text Available Cellular therapy now offer promise of potential adjunct therapeutic options for treatment of drug-resistant tuberculosis (TB. We review here the role of Mesenchymal stromal cells, (MSCs, as well as other immune effector cells in the therapy of infectious diseases with a focus on TB. MSCs represent a population of tissue-resident non-hematopoietic adult progenitor cells which home into injured tissues increase the proliferative potential of broncho-alveolar stem cells and restore lung epithelium. MSCs have been shown to be immune-modulatory and anti-inflammatory mediated via cell-cell contacts as well as soluble factors. We discuss the functional profile of MSCs and their potential use for adjunct cellular therapy of multi-drug resistant TB, with the aim of limiting tissue damage, and to convert unproductive inflammatory responses into effective anti-pathogen directed immune responses. Adjunct cellular therapy could potentially offer salvage therapy options for patients with drug-resistant TB, increase clinically relevant anti-M.tuberculosis directed immune responses and possibly shorten the duration of anti-TB therapy.

  6. Cellular therapy in tuberculosis.

    Science.gov (United States)

    Parida, Shreemanta K; Madansein, Rajhmun; Singh, Nalini; Padayatchi, Nesri; Master, Iqbal; Naidu, Kantharuben; Zumla, Alimuddin; Maeurer, Markus

    2015-03-01

    Cellular therapy now offer promise of potential adjunct therapeutic options for treatment of drug-resistant tuberculosis (TB). We review here the role of Mesenchymal stromal cells, (MSCs), as well as other immune effector cells in the therapy of infectious diseases with a focus on TB. MSCs represent a population of tissue-resident non-hematopoietic adult progenitor cells which home into injured tissues increase the proliferative potential of broncho-alveolar stem cells and restore lung epithelium. MSCs have been shown to be immune-modulatory and anti-inflammatory mediated via cell-cell contacts as well as soluble factors. We discuss the functional profile of MSCs and their potential use for adjunct cellular therapy of multi-drug resistant TB, with the aim of limiting tissue damage, and to convert unproductive inflammatory responses into effective anti-pathogen directed immune responses. Adjunct cellular therapy could potentially offer salvage therapy options for patients with drug-resistant TB, increase clinically relevant anti-M.tuberculosis directed immune responses and possibly shorten the duration of anti-TB therapy. PMID:25809753

  7. Quantum cellular automata

    Science.gov (United States)

    Porod, Wolfgang; Lent, Craig S.; Bernstein, Gary H.

    1994-06-01

    The Notre Dame group has developed a new paradigm for ultra-dense and ultra-fast information processing in nanoelectronic systems. These Quantum Cellular Automata (QCA's) are the first concrete proposal for a technology based on arrays of coupled quantum dots. The basic building block of these cellular arrays is the Notre Dame Logic Cell, as it has been called in the literature. The phenomenon of Coulomb exclusion, which is a synergistic interplay of quantum confinement and Coulomb interaction, leads to a bistable behavior of each cell which makes possible their use in large-scale cellular arrays. The physical interaction between neighboring cells has been exploited to implement logic functions. New functionality may be achieved in this fashion, and the Notre Dame group invented a versatile majority logic gate. In a series of papers, the feasibility of QCA wires, wire crossing, inverters, and Boolean logic gates was demonstrated. A major finding is that all logic functions may be integrated in a hierarchial fashion which allows the design of complicated QCA structures. The most complicated system which was simulated to date is a one-bit full adder consisting of some 200 cells. In addition to exploring these new concepts, efforts are under way to physically realize such structures both in semiconductor and metal systems. Extensive modeling work of semiconductor quantum dot structures has helped identify optimum design parameters for QCA experimental implementations.

  8. Optimal ex vivo expansion of neutrophils from PBSC CD34+ cells by a combination of SCF, Flt3-L and G-CSF and its inhibition by further addition of TPO

    Directory of Open Access Journals (Sweden)

    Turner Marc L

    2007-10-01

    Full Text Available Abstract Background Autologous mobilised peripheral blood stem cell (PBSC transplantation is now a standard approach in the treatment of haematological diseases to reconstitute haematopoiesis following myeloablative chemotherapy. However, there remains a period of severe neutropenia and thrombocytopenia before haematopoietic reconstitution is achieved. Ex vivo expanded PBSC have been employed as an adjunct to unmanipulated HSC transplantation, but have tended to be produced using complex cytokine mixtures aimed at multilineage (neutrophil and megakaryocyte progenitor expansion. These have been reported to reduce or abrogate neutropenia but have little major effect on thrombocytopenia. Selective megakaryocyte expansion has been to date ineffective in reducing thrombocytopenia. This study was implemented to evaluate neutrophil specific rather than multilineage ex vivo expansion of PBSC for specifically focusing on reduction or abrogation of neutropenia. Methods CD34+ cells (PBSC were enriched from peripheral blood mononuclear cells following G-CSF-mobilisation and cultured with different permutations of cytokines to determine optimal cytokine combinations and doses for expansion and functional differentiation and maturation of neutrophils and their progenitors. Results were assessed by cell number, morphology, phenotype and function. Results A simple cytokine combination, SCF + Flt3-L + G-CSF, synergised to optimally expand and mature neutrophil progenitors assessed by cell number, phenotype, morphology and function (superoxide respiratory burst measured by chemiluminescence. G-CSF appears mandatory for functional maturation. Addition of other commonly employed cytokines, IL-3 and IL-6, had no demonstrable additive effect on numbers or function compared to this optimal combination. Addition of TPO, commonly included in multilineage progenitor expansion for development of megakaryocytes, reduced the maturation of neutrophil progenitors as assessed

  9. Environment Aware Cellular Networks

    KAUST Repository

    Ghazzai, Hakim

    2015-02-01

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

  10. Designing beauty the art of cellular automata

    CERN Document Server

    Martínez, Genaro

    2016-01-01

    This fascinating, colourful book offers in-depth insights and first-hand working experiences in the production of art works, using simple computational models with rich morphological behaviour, at the edge of mathematics, computer science, physics and biology. It organically combines ground breaking scientific discoveries in the theory of computation and complex systems with artistic representations of the research results. In this appealing book mathematicians, computer scientists, physicists, and engineers brought together marvelous and esoteric patterns generated by cellular automata, which are arrays of simple machines with complex behavior. Configurations produced by cellular automata uncover mechanics of dynamic patterns formation, their propagation and interaction in natural systems: heart pacemaker, bacterial membrane proteins, chemical rectors, water permeation in soil, compressed gas, cell division, population dynamics, reaction-diffusion media and self-organisation. The book inspires artists to tak...

  11. Failover in cellular automata

    CERN Document Server

    Kumar, Shailesh

    2010-01-01

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

  12. Cellular-scale hydrodynamics

    DEFF Research Database (Denmark)

    Abkarian, Manouk; Faivre, Magalie; Horton, Renita; Smistrup, Kristian; Best-Popescu, Catherine A; Stone, Howard A.

    2008-01-01

    Microfluidic tools are providing many new insights into the chemical, physical and physicochemical responses of cells. Both suspension-level and single-cell measurements have been studied. We review our studies of these kinds of problems for red blood cells with particular focus on the shapes of ...... mechanical effects on suspended cells can be studied systematically in small devices, and how these features can be exploited to develop methods for characterizing physicochemical responses and possibly for the diagnosis of cellular-scale changes to environmental factors....

  13. Cellular mechanics and motility

    Science.gov (United States)

    Hénon, Sylvie; Sykes, Cécile

    2015-10-01

    The term motility defines the movement of a living organism. One widely known example is the motility of sperm cells, or the one of flagellar bacteria. The propulsive element of such organisms is a cilium(or flagellum) that beats. Although cells in our tissues do not have a flagellum in general, they are still able to move, as we will discover in this chapter. In fact, in both cases of movement, with or without a flagellum, cell motility is due to a dynamic re-arrangement of polymers inside the cell. Let us first have a closer look at the propulsion mechanism in the case of a flagellum or a cilium, which is the best known, but also the simplest, and which will help us to define the hydrodynamic general conditions of cell movement. A flagellum is sustained by cellular polymers arranged in semi-flexible bundles and flagellar beating generates cell displacement. These polymers or filaments are part of the cellular skeleton, or "cytoskeleton", which is, in this case, external to the cellular main body of the organism. In fact, bacteria move in a hydrodynamic regime in which viscosity dominates over inertia. The system is thus in a hydrodynamic regime of low Reynolds number (Box 5.1), which is nearly exclusively the case in all cell movements. Bacteria and their propulsion mode by flagella beating are our unicellular ancestors 3.5 billion years ago. Since then, we have evolved to form pluricellular organisms. However, to keep the ability of displacement, to heal our wounds for example, our cells lost their flagellum, since it was not optimal in a dense cell environment: cells are too close to each other to leave enough space for the flagella to accomplish propulsion. The cytoskeleton thus developed inside the cell body to ensure cell shape changes and movement, and also mechanical strength within a tissue. The cytoskeleton of our cells, like the polymers or filaments that sustain the flagellum, is also composed of semi-flexible filaments arranged in bundles, and also in

  14. Radiolabelled Cellular Blood Elements

    International Nuclear Information System (INIS)

    This volume contains the abstracts of the 5th International Symposion on Radiolabelling of Cellular Blood Elements to be held in Vienna, Austria, September 10-14, 1989. The Meeting is the fifth in a series of meetings designed to discuss the basics and clinical application of radiolabelling techniques. In these days, beside the search for new labelling agents and extending the knowledge in clinical use, the use of monoclonal antibodies is a big new challenge. All reviewed contributions that have been accepted for presentation are contained in this volume. (authors) 58 of them are of INIS scope

  15. Involvement of an SCFSlmb complex in timely elimination of E2F upon initiation of DNA replication in Drosophila

    Directory of Open Access Journals (Sweden)

    O'Farrell Patrick H

    2003-06-01

    Full Text Available Abstract Background Cul1 is a core component of the evolutionarily conserved SCF-type ubiquitin ligases that target specific proteins for destruction. SCF action contributes to cell cycle progression but few of the key targets of its action have been identified. Results We found that expression of the mouse Cul1 (mCul1 in the larval wing disc has a dominant negative effect. It reduces, but does not eliminate, the function of SCF complexes, promotes accumulation of Cubitus interruptus (a target of SCF action, triggers apoptosis, and causes a small wing phenotype. A screen for mutations that dominantly modify this phenotype showed effective suppression upon reduction of E2F function, suggesting that compromised downregulation of E2F contributes to the phenotype. Partial inactivation of Cul1 delayed the abrupt loss of E2F immunofluorescence beyond its normal point of downregulation at the onset of S phase. Additional screens showed that mild reduction in function of the F-box encoding gene slimb enhanced the mCul1 overexpression phenotype. Cell cycle modulation of E2F levels is virtually absent in slimb mutant cells in which slimb function is severely reduced. This implicates Slimb, a known targeting subunit of SCF, in E2F downregulation. In addition, Slimb and E2F interacted in vitro in a phosphorylation-dependent manner. Conclusion We have used genetic and physical interactions to identify the G1/S transcription factor E2F as an SCFSlmb target in Drosophila. These results argue that the SCFSlmb ubiquitin ligase directs E2F destruction in S phase.

  16. Mapping functional connectivity in cellular networks

    OpenAIRE

    Buibas, Marius

    2011-01-01

    My thesis is a collection of theoretical and practical techniques for mapping functional or effective connectivity in cellular neuronal networks, at the cell scale. This is a challenging scale to work with, primarily because of the difficulty in labeling and measuring the activities of networks of cells. It is also important as it underlies behavior, function, and complex diseases. I present methods to measure and quantify the dynamic activities of cells using the optical flow technique, whic...

  17. Aging cellular networks: chaperones as major participants

    OpenAIRE

    Soti, Csaba; Csermely, Peter

    2006-01-01

    We increasingly rely on the network approach to understand the complexity of cellular functions. Chaperones (heat shock proteins) are key "networkers", which have among their functions to sequester and repair damaged protein. In order to link the network approach and chaperones with the aging process, we first summarize the properties of aging networks suggesting a "weak link theory of aging". This theory suggests that age-related random damage primarily affects the overwhelming majority of t...

  18. Cellular Signaling in the Bovine Antral Follicles

    OpenAIRE

    Juan F. Vásquez - Cano; Martha Olivera - A.

    2010-01-01

    Antral follicle development in the ovary of female cattle is the product of a complex of endocrine, paracrine and autocrine relationships. The interactions of the pituitary gonadotropins over granulosa and theca cells prepare the follicle to produce estradiol and for the final stages of maturation of the oocyte and its potencial ovulation or atresia inside subordinate follicles. It is a dynamic event where cellular signaling patterns changes sequentiallyand quickly at different stages of foll...

  19. Cellular Dynamic Simulator: An Event Driven Molecular Simulation Environment for Cellular Physiology

    Science.gov (United States)

    Byrne, Michael J.; Waxham, M. Neal; Kubota, Yoshihisa

    2010-01-01

    In this paper, we present the Cellular Dynamic Simulator (CDS) for simulating diffusion and chemical reactions within crowded molecular environments. CDS is based on a novel event driven algorithm specifically designed for precise calculation of the timing of collisions, reactions and other events for each individual molecule in the environment. Generic mesh based compartments allow the creation / importation of very simple or detailed cellular structures that exist in a 3D environment. Multiple levels of compartments and static obstacles can be used to create a dense environment to mimic cellular boundaries and the intracellular space. The CDS algorithm takes into account volume exclusion and molecular crowding that may impact signaling cascades in small sub-cellular compartments such as dendritic spines. With the CDS, we can simulate simple enzyme reactions; aggregation, channel transport, as well as highly complicated chemical reaction networks of both freely diffusing and membrane bound multi-protein complexes. Components of the CDS are generally defined such that the simulator can be applied to a wide range of environments in terms of scale and level of detail. Through an initialization GUI, a simple simulation environment can be created and populated within minutes yet is powerful enough to design complex 3D cellular architecture. The initialization tool allows visual confirmation of the environment construction prior to execution by the simulator. This paper describes the CDS algorithm, design implementation, and provides an overview of the types of features available and the utility of those features are highlighted in demonstrations. PMID:20361275

  20. Integrated cellular systems

    Science.gov (United States)

    Harper, Jason C.

    The generation of new three-dimensional (3D) matrices that enable integration of biomolecular components and whole cells into device architectures, without adversely altering their morphology or activity, continues to be an expanding and challenging field of research. This research is driven by the promise that encapsulated biomolecules and cells can significantly impact areas as diverse as biocatalysis, controlled delivery of therapeutics, environmental and industrial process monitoring, early warning of warfare agents, bioelectronics, photonics, smart prosthetics, advanced physiological sensors, portable medical diagnostic devices, and tissue/organ replacement. This work focuses on the development of a fundamental understanding of the biochemical and nanomaterial mechanisms that govern the cell directed assembly and integration process. It was shown that this integration process relies on the ability of cells to actively develop a pH gradient in response to evaporation induced osmotic stress, which catalyzes silica condensation within a thin 3D volume surrounding the cells, creating a functional bio/nano interface. The mechanism responsible for introducing functional foreign membrane-bound proteins via proteoliposome addition to the silica-lipid-cell matrix was also determined. Utilizing this new understanding, 3D cellular immobilization capabilities were extended using sol-gel matrices endowed with glycerol, trehalose, and media components. The effects of these additives, and the metabolic phase of encapsulated S. cerivisiase cells, on long-term viability and the rate of inducible gene expression was studied. This enabled the entrapment of cells within a novel microfluidic platform capable of simultaneous colorimetric, fluorescent, and electrochemical detection of a single analyte, significantly improving confidence in the biosensor output. As a complementary approach, multiphoton protein lithography was utilized to engineer 3D protein matrices in which to

  1. Multiuser Cellular Network

    CERN Document Server

    Bao, Yi; Chen, Ming

    2011-01-01

    Modern radio communication is faced with a problem about how to distribute restricted frequency to users in a certain space. Since our task is to minimize the number of repeaters, a natural idea is enlarging coverage area. However, coverage has restrictions. First, service area has to be divided economically as repeater's coverage is limited. In this paper, our fundamental method is to adopt seamless cellular network division. Second, underlying physics content in frequency distribution problem is interference between two close frequencies. Consequently, we choose a proper frequency width of 0.1MHz and a relevantly reliable setting to apply one frequency several times. We make a few general assumptions to simplify real situation. For instance, immobile users yield to homogenous distribution; repeaters can receive and transmit information in any given frequency in duplex operation; coverage is mainly decided by antenna height. Two models are built up to solve 1000 users and 10000 users situations respectively....

  2. Modeling and cellular studies

    International Nuclear Information System (INIS)

    Testing the applicability of mathematical models with carefully designed experiments is a powerful tool in the investigations of the effects of ionizing radiation on cells. The modeling and cellular studies complement each other, for modeling provides guidance for designing critical experiments which must provide definitive results, while the experiments themselves provide new input to the model. Based on previous experimental results the model for the accumulation of damage in Chlamydomonas reinhardi has been extended to include various multiple two-event combinations. Split dose survival experiments have shown that models tested to date predict most but not all the observed behavior. Stationary-phase mammalian cells, required for tests of other aspects of the model, have been shown to be at different points in the cell cycle depending on how they were forced to stop proliferating. These cultures also demonstrate different capacities for repair of sublethal radiation damage

  3. Engineering Cellular Metabolism

    DEFF Research Database (Denmark)

    Nielsen, Jens; Keasling, Jay

    2016-01-01

    Metabolic engineering is the science of rewiring the metabolism of cells to enhance production of native metabolites or to endow cells with the ability to produce new products. The potential applications of such efforts are wide ranging, including the generation of fuels, chemicals, foods, feeds......, and pharmaceuticals. However, making cells into efficient factories is challenging because cells have evolved robust metabolic networks with hard-wired, tightly regulated lines of communication between molecular pathways that resist efforts to divert resources. Here, we will review the current status and challenges...... of metabolic engineering and will discuss how new technologies can enable metabolic engineering to be scaled up to the industrial level, either by cutting off the lines of control for endogenous metabolism or by infiltrating the system with disruptive, heterologous pathways that overcome cellular regulation....

  4. Nuclear desalination for the petrochemical complex of the Natuna project

    International Nuclear Information System (INIS)

    On the basis of environmental considerations, a high temperature gas cooled reactor (HTGR) was proposed as the heat source for the Natuna project for CO2 conversion. To convert CO2 to useful products, a large amount of high quality water is required for the chemical processes, boilers and other purposes. One LNG production train (maximum of six trains) would produce 0.4 x 109 SCF/d of saleable gas and 1.4 x 109 SCF/d of CO2 (in the case of the Exxon process). This CO2 gas would then be converted to automobile fuel (methane, methanol), which requires a large amount of water. Natural gas from an off- shore gas field is piped to the petrochemical complex on Natuna Island (about 228 km). Natuna is a small island that, apart from sea water, does not have much available water. The desalination process is considered to be the only solution to the water demand problems of the petrochemical complex. A nuclear desalination system was designed to provide high quality water for this complex. Of the commercial scale desalination processes, multi-stage flash, multi-effect distillation and reverse osmosis and hybrids are considered to be good candidates for the coupling scheme for producing high quality water. The availability of waste heat from the HTGR and an exothermic chemical reaction was also evaluated. It seems that an additional small to medium sized nuclear power plant may be required to produce water for the petrochemical complex of the Natuna project

  5. Efficiency of cellular information processing

    CERN Document Server

    Barato, Andre C; Seifert, Udo

    2014-01-01

    We show that a rate of conditional Shannon entropy reduction, characterizing the learning of an internal process about an external process, is bounded by the thermodynamic entropy production. This approach allows for the definition of an informational efficiency that can be used to study cellular information processing. We analyze three models of increasing complexity inspired by the E. coli sensory network, where the external process is an external ligand concentration jumping between two values. We start with a simple model for which ATP must be consumed so that a protein inside the cell can learn about the external concentration. With a second model for a single receptor we show that the rate at which the receptor learns about the external environment can be nonzero even without any dissipation inside the cell since chemical work done by the external process compensates for this learning rate. The third model is more complete, also containing adaptation. For this model we show inter alia that a bacterium i...

  6. The State of Cellular Probes

    OpenAIRE

    Yim, Youngbin

    2003-01-01

    Cellular probe technology is one of several potentially promising technologies for obtaining accurate travel time information. In 1996, the Federal Communications Commission (FCC) mandated E911 requirements that cellular location be provided when 911 emergency calls come in to emergency management authorities. The E911 requirements allow 50 -300 meters from the emergency call location, depending on the type of cellular phone technology used and whether handset-based or network-based solutions...

  7. Active Cellular Nematics

    Science.gov (United States)

    Duclos, Guillaume; Erlenkaemper, Christoph; Garcia, Simon; Yevick, Hannah; Joanny, Jean-François; Silberzan, Pascal; Biology inspired physics at mesoscales Team; Physical approach of biological problems Team

    We study the emergence of a nematic order in a two-dimensional tissue of apolar elongated fibroblast cells. Initially, these cells are very motile and the monolayer is characterized by giant density fluctuations, a signature of far-from-equilibrium systems. As the cell density increases because of proliferation, the cells align with each other forming large perfectly oriented domains while the cellular movements slow down and eventually freeze. Therefore topological defects characteristic of nematic phases remain trapped at long times, preventing the development of infinite domains. By analogy with classical non-active nematics, we have investigated the role of boundaries and we have shown that cells confined in stripes of width smaller than typically 500 µm are perfectly aligned in the stripe direction. Experiments performed in cross-shaped patterns show that both the number of cells and the degree of alignment impact the final orientation. Reference: Duclos G., Garcia S., Yevick H.G. and Silberzan P., ''Perfect nematic order in confined monolayers of spindle-shaped cells'', Soft Matter, 10, 14, 2014

  8. 47 CFR 22.909 - Cellular markets.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Cellular markets. 22.909 Section 22.909... Cellular Radiotelephone Service § 22.909 Cellular markets. Cellular markets are standard geographic areas used by the FCC for administrative convenience in the licensing of cellular systems. Cellular...

  9. SELF-ORGANIZED CRITICALITY AND CELLULAR AUTOMATA

    Energy Technology Data Exchange (ETDEWEB)

    CREUTZ,M.

    2007-01-01

    Cellular automata provide a fascinating class of dynamical systems based on very simple rules of evolution yet capable of displaying highly complex behavior. These include simplified models for many phenomena seen in nature. Among other things, they provide insight into self-organized criticality, wherein dissipative systems naturally drive themselves to a critical state with important phenomena occurring over a wide range of length and the scales. This article begins with an overview of self-organized criticality. This is followed by a discussion of a few examples of simple cellular automaton systems, some of which may exhibit critical behavior. Finally, some of the fascinating exact mathematical properties of the Bak-Tang-Wiesenfeld sand-pile model [1] are discussed.

  10. Cellular bridges: Routes for intercellular communication and cell migration

    OpenAIRE

    Zani, Brett G.; Edelman, Elazer R.

    2010-01-01

    Cell-to-cell communication is the basis of all biology in multicellular organisms, allowing evolution of complex forms and viability in dynamic environments. Though biochemical interactions occur over distances, physical continuity remains the most direct means of cellular interactions. Cellular bridging through thin cytoplasmic channels—plasmodesmata in plants and tunneling nanotubes in animals—creates direct routes for transfer of signals and components, even pathogens, between cells. Recen...

  11. Transductions Computed by One-Dimensional Cellular Automata

    OpenAIRE

    Martin Kutrib; Andreas Malcher

    2012-01-01

    Cellular automata are investigated towards their ability to compute transductions, that is, to transform inputs into outputs. The families of transductions computed are classified with regard to the time allowed to process the input and to compute the output. Since there is a particular interest in fast transductions, we mainly focus on the time complexities real time and linear time. We first investigate the computational capabilities of cellular automaton transducers by comparing them to it...

  12. Autocatalytic closure and the evolution of cellular information processing networks

    OpenAIRE

    Decraene, James

    2009-01-01

    Cellular Information Processing Networks (CIPNs) are chemical networks of interacting molecules occurring in living cells. Through complex molecular interactions, CIPNs are able to coordinate critical cellular activities in response to internal and external stimuli. We hypothesise that CIPNs may be abstractly regarded as subsets of collectively autocatalytic (i.e., organisationally closed) reaction networks. These closure properties would subsequently interact with the evolution and adaptatio...

  13. SoftCell: Taking Control of Cellular Core Networks

    OpenAIRE

    Jin, Xin; Li, Li Erran; Vanbever, Laurent; Rexford, Jennifer

    2013-01-01

    Existing cellular networks suffer from inflexible and expensive equipment, and complex control-plane protocols. To address these challenges, we present SoftCell, a scalable architecture for supporting fine-grained policies for mobile devices in cellular core networks. The SoftCell controller realizes high-level service polices by directing traffic over paths that traverse a sequence of middleboxes, optimized to the network conditions and user locations. To ensure scalability, the core switche...

  14. Metodología de diseño para la recogida de residuos sólidos urbanos mediante factores punta de generación: sistemas de caja fija (scf)

    OpenAIRE

    Zafra Mejía, Carlos Alfonso

    2010-01-01

    El desarrollo económico y de la sociedad de consumo implica una gran producción de residuos sólidos en una localidad, hecho que se constituye en un serio problema ambiental si no se cuenta con la infraestructura adecuada para su gestión integral. En este artículo se presenta un desarrollo metodológico para el diseño de la recogida de residuos sólidos urbanos con sistemas de caja fija (SCF), considerando la variación temporal en las cantidades generadas y recolectadas. La variación temporal s...

  15. Structure and vibrational spectra of M2SO4 (M=L, Na, K) molecules: ab initio SCF MO LCAO calculations with the effective core potentials and with taking account of all electrons

    International Nuclear Information System (INIS)

    Geometrical parameters, strength fields, vibration frequencies and IR spectra intensities of M2SO4 molecules (M=Li, Na, K) and SO42- free ion have been calculated by the SCF MO LCAO nonempirical method. The calculations involved both direct account of all electrons and frame electrons of the Durand semilocal effective potentials, etc. The errors brought about by the use of effective frame potentials have been analyzed. Regularities in the change of molecular parameters in the series of compounds considered have been revealed. The calculated results, are compared with experimental data available. Refs. 33, figs. 1, tabs. 7

  16. Exploring the Possibilities of a Cellular Automata in Minecraft

    OpenAIRE

    Saunders, Stephen

    2014-01-01

    Complex systems are not always generated by complex individuals. Simple, cell-like individuals can produce sophisticated outcomes. Structures implementing this nature area called cellular automation. In this paper, we discuss the difficulties associated with the creation of one such automation in a pre-existing environment, in this case the game MineCraft. A subsequent study of the behavior of this automation is presented, using an objective information measure called set complexity.

  17. MIMO Communication for Cellular Networks

    CERN Document Server

    Huang, Howard; Venkatesan, Sivarama

    2012-01-01

    As the theoretical foundations of multiple-antenna techniques evolve and as these multiple-input multiple-output (MIMO) techniques become essential for providing high data rates in wireless systems, there is a growing need to understand the performance limits of MIMO in practical networks. To address this need, MIMO Communication for Cellular Networks presents a systematic description of MIMO technology classes and a framework for MIMO system design that takes into account the essential physical-layer features of practical cellular networks. In contrast to works that focus on the theoretical performance of abstract MIMO channels, MIMO Communication for Cellular Networks emphasizes the practical performance of realistic MIMO systems. A unified set of system simulation results highlights relative performance gains of different MIMO techniques and provides insights into how best to use multiple antennas in cellular networks under various conditions. MIMO Communication for Cellular Networks describes single-user,...

  18. Cytokines as cellular communicators

    Directory of Open Access Journals (Sweden)

    R. Debets

    1996-01-01

    Full Text Available Cytokines and their receptors are involved in the pathophysiology of many diseases. Here we present a detailed review on cytokines, receptors and signalling routes, and show that one important lesson from cytokine biology is the complex and diverse regulation of cytokine activity. The activity of cytokines is controlled at the level of transcription, translation, storage, processing, posttranslational modification, trapping, binding by soluble proteins, and receptor number and/or function. Translation of this diverse regulation in strategies aimed at the control of cytokine activity will result in the development of more specific and selective drugs to treat diseases.

  19. Imaging protein interactions in vivo with sub-cellular resolution

    CERN Document Server

    Raicu, Valerica; Fung, Russell; Melnichuk, Mike; Jansma, David B; Pisterzi, Luca; Fox, Michael; Wells, James W; Saldin, Dilano K

    2008-01-01

    Resonant Energy Transfer (RET) from an optically excited donor molecule (D) to a non-excited acceptor molecule (A) residing nearby is widely used to detect molecular interactions in living cells. Stoichiometric information, such as the number of proteins forming a complex, has been obtained so far for a handful of proteins, but only after exposing the sample sequentially to at least two different excitation wavelengths. During this lengthy process of measurement, the molecular makeup of a cellular region may change, and this has so far limited the applicability of RET to determination of cellular averages. Here we demonstrate a method for imaging protein complex distribution in living cells with sub-cellular spatial resolution, which relies on a spectrally-resolved two-photon microscope, a simple but competent theory, and a keen selection of fluorescent tags. This technology may eventually lead to tracking dynamics of macromolecular complex formation and dissociation with spatial resolution inside living cell...

  20. Actual problems of cellular cardiomyoplasty

    Directory of Open Access Journals (Sweden)

    Bulat Kaupov

    2010-04-01

    Full Text Available The paper provides review of cellular technologies used incardiology, describes types of cellular preparations depending onsources of cells and types of compounding cells. The generalmechanisms of therapies with stem cells applications are described.Use of cellular preparations for treatment of cardiovascular diseasesand is improvement of the forecast at patients with heartinsufficiency of various genesis is considered as alternative topractice with organ transplantations. Efforts of biotechnologicallaboratories are directed on search of optimum population of cellsfor application in cardiology and studying of mechanisms andfactors regulating function of cardiac stem cells.

  1. Origami interleaved tube cellular materials

    International Nuclear Information System (INIS)

    A novel origami cellular material based on a deployable cellular origami structure is described. The structure is bi-directionally flat-foldable in two orthogonal (x and y) directions and is relatively stiff in the third orthogonal (z) direction. While such mechanical orthotropicity is well known in cellular materials with extruded two dimensional geometry, the interleaved tube geometry presented here consists of two orthogonal axes of interleaved tubes with high interfacial surface area and relative volume that changes with fold-state. In addition, the foldability still allows for fabrication by a flat lamination process, similar to methods used for conventional expanded two dimensional cellular materials. This article presents the geometric characteristics of the structure together with corresponding kinematic and mechanical modeling, explaining the orthotropic elastic behavior of the structure with classical dimensional scaling analysis. (paper)

  2. Relação da expressão de fatores de crescimento celular (IGF-1 e (SCF com fatores prognósticos e o alvo da rapamicina em mamíferos (m-TOR em mastocitomas cutâneos caninos IGF-1 and SCF protein expression in cutaneous mast cell tumors in dogs and relation to prognostic factors and mammalian target of rapamycin (m-TOR

    Directory of Open Access Journals (Sweden)

    Raquel B. Ferioli

    2013-04-01

    Full Text Available O mastocitoma cutâneo (MTC é a neoplasia maligna mais comum na pele dos cães e seu comportamento biológico é muito variável. Dentre os fatores prognósticos estudados nos MTCs, a classificação histopatológica, o índice proliferativo e o padrão de expressão doc-KIT são os que apresentam uma associação mais relevante com o provável prognóstico deste tumor. O objetivo deste trabalho foi avaliar a expressão proteica de fator de crescimento semelhante à insulina tipo 1 (IGF-1, fator de célula tronco (SCF e sua relação com o receptor tirosina quinase (c-KIT, alvo da rapamicina em mamíferos (m-TOR, grau histológico, índice proliferativo pelo KI-67e o número de figuras de mitose (IM com dados clínicos de cães com MTCs . Foram utilizadas 133 amostras de MTCs, provenientes de 133 cães, dispostas em lâminas de microarranjo de tecidos (TMA. A técnica de imuno-histoquímica foi utilizada para a avaliação destas proteínas. Observou-se associação entre SCF e, a graduação histopatológica proposta em 2011, índice mitótico, proliferação celular (KI-67, escore de IGF-1, local da lesão, idade dos animais e padrão imuno-histoquímico do receptor c-KIT. A relação de dependência também foi observada entre IGF-1 e o porte dos animais, IM, m-TOR e c-KIT. A expressão de SCF teve relacção com a agressividade dos MTCs caninos, uma vez que foi mais freqüente em MTCs com c-KIT citoplasmático. A relação entre a expressão de IGF-1, SCF, c-KIT e m-TOR pode estar associada à integralização de suas vias de ação. A expressão de IGF-1 está associada à MTCs em cães de porte grande.Cutaneous mast cell tumor (MCT is one of the most common neoplasms in the skin of dogs and express variable biological behavior. Among the MTC aspects studied, histological classification, proliferative index and protein expression of c-KIT show the most defined connection with the tumor prognostic. The aim of this study was to evaluate the

  3. Cellular mechanisms during vascular development

    OpenAIRE

    Blum, Yannick

    2012-01-01

    The vascular system is an essential organ in vertebrate animals and provides the organism with enough oxygen and nutrients. It is composed of an interconnected network of blood vessels, which form using a number of different morphogenetic mechanisms. Angiogenesis describes the formation of new blood vessels from preexisting vessels. A number of molecular pathways have been shown to be essential during angiogenesis. However, cellular architecture of blood vessels as well as cellular mechanisms...

  4. Predictive Modelling of Cellular Load

    OpenAIRE

    Carolan, Emmett; McLoone, Seamus; Farrell, Ronan

    2015-01-01

    This work examines the temporal dynamics of cellular load in four Irish regions. Large scale underutilisation of network resources is identified both at the regional level and at the level of individual cells. Cellular load is modeled and prediction intervals are generated. These prediction intervals are used to put an upper bound on usage in a particular cell at a particular time. Opportunities for improvements in network utilization by incorporating these upper bounds on usage are identifie...

  5. Cellular automaton for chimera states

    OpenAIRE

    García-Morales, Vladimir

    2016-01-01

    A minimalistic model for chimera states is presented. The model is a cellular automaton (CA) which depends on only one adjustable parameter, the range of the nonlocal coupling, and is built from elementary cellular automata and the majority (voting) rule. This suggests the universality of chimera-like behavior from a new point of view: Already simple CA rules based on the majority rule exhibit this behavior. After a short transient, we find chimera states for arbitrary initial conditions, the...

  6. Knowledge discovery for geographical cellular automata

    Institute of Scientific and Technical Information of China (English)

    LI; Xia; Anthony; Gar-On; Yeh

    2005-01-01

    This paper proposes a new method for geographical simulation by applying data mining techniques to cellular automata. CA has strong capabilities in simulating complex systems. The core of CA is how to define transition rules. There are no good methods for defining these transition rules. They are usually defined by using heuristic methods and thus subject to uncertainties. Mathematical equations are used to represent transition rules implicitly and have limitations in capturing complex relationships. This paper demonstrates that the explicit transition rules of CA can be automatically reconstructed through the rule induction procedure of data mining. The proposed method can reduce the influences of individual knowledge and preferences in defining transition rules and generate more reliable simulation results. It can efficiently discover knowledge from a vast volume of spatial data.

  7. Hierarchical Cellular Structures in High-Capacity Cellular Communication Systems

    CERN Document Server

    Jain, R K; Agrawal, N K

    2011-01-01

    In the prevailing cellular environment, it is important to provide the resources for the fluctuating traffic demand exactly in the place and at the time where and when they are needed. In this paper, we explored the ability of hierarchical cellular structures with inter layer reuse to increase the capacity of mobile communication network by applying total frequency hopping (T-FH) and adaptive frequency allocation (AFA) as a strategy to reuse the macro and micro cell resources without frequency planning in indoor pico cells [11]. The practical aspects for designing macro- micro cellular overlays in the existing big urban areas are also explained [4]. Femto cells are inducted in macro / micro / pico cells hierarchical structure to achieve the required QoS cost effectively.

  8. Prognosis of Different Cellular Generations

    Directory of Open Access Journals (Sweden)

    Preetish Ranjan

    2013-04-01

    Full Text Available Technological advancement in mobile telephony from 1G to 3G, 4G and 5G has a very axiomatic fact that made an entire world a global village. The cellular system employs a different design approach and technology that most commercial radio and television system use. In the cellular system, the service area is divided into cells and a transmitter is designed to serve an individual cell. The system seeks to make efficient use of available channels by using low-power transmitters to allow frequency reuse at a smaller distance. Maximizing the number of times each channel can be reused in a given geographical area is the key to an efficient cellular system design. During the past three decades, the world has seen significant changes in telecommunications industry. There have been some remarkable aspects to the rapid growth in wireless communications, as seen by the large expansion in mobile systems. This paper focuses on “Past, Present & Future of Cellular Telephony” and some light has been thrown upon the technologies of the cellular systems, namely 1G, 2G, 2.5G, 3G and future generations like 4G and 5G systems as well.

  9. Cellular Resolutions of Ideals Defined by Simplicial Homomorphisms

    CERN Document Server

    Braun, Benjamin; Klee, Steven

    2011-01-01

    In this paper we introduce the class of ordered homomorphism ideals and prove that these ideals admit minimal cellular resolutions constructed as homomorphism complexes. As a key ingredient of our work, we introduce the class of cointerval simplicial complexes and investigate their combinatorial and topological properties. As a concrete illustration of these structural results, we introduce and study nonnesting monomial ideals, an interesting family of combinatorially defined ideals.

  10. Aging, cellular senescence, and cancer.

    Science.gov (United States)

    Campisi, Judith

    2013-01-01

    For most species, aging promotes a host of degenerative pathologies that are characterized by debilitating losses of tissue or cellular function. However, especially among vertebrates, aging also promotes hyperplastic pathologies, the most deadly of which is cancer. In contrast to the loss of function that characterizes degenerating cells and tissues, malignant (cancerous) cells must acquire new (albeit aberrant) functions that allow them to develop into a lethal tumor. This review discusses the idea that, despite seemingly opposite characteristics, the degenerative and hyperplastic pathologies of aging are at least partly linked by a common biological phenomenon: a cellular stress response known as cellular senescence. The senescence response is widely recognized as a potent tumor suppressive mechanism. However, recent evidence strengthens the idea that it also drives both degenerative and hyperplastic pathologies, most likely by promoting chronic inflammation. Thus, the senescence response may be the result of antagonistically pleiotropic gene action. PMID:23140366

  11. Novel Materials for Cellular Nanosensors

    DEFF Research Database (Denmark)

    Sasso, Luigi

    The monitoring of cellular behavior is useful for the advancement of biomedical diagnostics, drug development and the understanding of a cell as the main unit of the human body. Micro- and nanotechnology allow for the creation of functional devices that enhance the study of cellular dynamics by...... modifications for electrochemical nanosensors for the detection of analytes released from cells. Two type of materials were investigated, each pertaining to the two different aspects of such devices: peptide nanostructures were studied for the creation of cellular sensing substrates that mimic in vivo surfaces...... and that offer advantages of functionalization, and conducting polymers were used as electrochemical sensor surface modifications for increasing the sensitivity towards relevant analytes, with focus on the detection of dopamine released from cells via exocytosis. Vertical peptide nanowires were...

  12. Cellular-based preemption system

    Science.gov (United States)

    Bachelder, Aaron D. (Inventor)

    2011-01-01

    A cellular-based preemption system that uses existing cellular infrastructure to transmit preemption related data to allow safe passage of emergency vehicles through one or more intersections. A cellular unit in an emergency vehicle is used to generate position reports that are transmitted to the one or more intersections during an emergency response. Based on this position data, the one or more intersections calculate an estimated time of arrival (ETA) of the emergency vehicle, and transmit preemption commands to traffic signals at the intersections based on the calculated ETA. Additional techniques may be used for refining the position reports, ETA calculations, and the like. Such techniques include, without limitation, statistical preemption, map-matching, dead-reckoning, augmented navigation, and/or preemption optimization techniques, all of which are described in further detail in the above-referenced patent applications.

  13. Adaptive stochastic cellular automata: Applications

    Science.gov (United States)

    Qian, S.; Lee, Y. C.; Jones, R. D.; Barnes, C. W.; Flake, G. W.; O'Rourke, M. K.; Lee, K.; Chen, H. H.; Sun, G. Z.; Zhang, Y. Q.; Chen, D.; Giles, C. L.

    1990-09-01

    The stochastic learning cellular automata model has been applied to the problem of controlling unstable systems. Two example unstable systems studied are controlled by an adaptive stochastic cellular automata algorithm with an adaptive critic. The reinforcement learning algorithm and the architecture of the stochastic CA controller are presented. Learning to balance a single pole is discussed in detail. Balancing an inverted double pendulum highlights the power of the stochastic CA approach. The stochastic CA model is compared to conventional adaptive control and artificial neural network approaches.

  14. Cellular senescence in aging primates.

    Science.gov (United States)

    Herbig, Utz; Ferreira, Mark; Condel, Laura; Carey, Dee; Sedivy, John M

    2006-03-01

    The aging of organisms is characterized by a gradual functional decline of all organ systems. Mammalian somatic cells in culture display a limited proliferative life span, at the end of which they undergo an irreversible cell cycle arrest known as replicative senescence. Whether cellular senescence contributes to organismal aging has been controversial. We investigated telomere dysfunction, a recently discovered biomarker of cellular senescence, and found that the number of senescent fibroblasts increases exponentially in the skin of aging baboons, reaching >15% of all cells in very old individuals. In addition, the same cells contain activated ataxia-telangiectasia mutated kinase and heterochromatinized nuclei, confirming their senescent status. PMID:16456035

  15. Cellular automaton for chimera states

    Science.gov (United States)

    García-Morales, Vladimir

    2016-04-01

    A minimalistic model for chimera states is presented. The model is a cellular automaton (CA) which depends on only one adjustable parameter, the range of the nonlocal coupling, and is built from elementary cellular automata and the majority (voting) rule. This suggests the universality of chimera-like behavior from a new point of view: Already simple CA rules based on the majority rule exhibit this behavior. After a short transient, we find chimera states for arbitrary initial conditions, the system spontaneously splitting into stable domains separated by static boundaries, some synchronously oscillating and the others incoherent. When the coupling range is local, nontrivial coherent structures with different periodicities are formed.

  16. Prognosis of Different Cellular Generations

    OpenAIRE

    Preetish Ranjan; Prabhat Kumar

    2013-01-01

    Technological advancement in mobile telephony from 1G to 3G, 4G and 5G has a very axiomatic fact that made an entire world a global village. The cellular system employs a different design approach and technology that most commercial radio and television system use. In the cellular system, the service area is divided into cells and a transmitter is designed to serve an individual cell. The system seeks to make efficient use of available channels by using low-power transmitters to allow frequen...

  17. Method for analyzing signaling networks in complex cellular systems.

    Science.gov (United States)

    Plavec, Ivan; Sirenko, Oksana; Privat, Sylvie; Wang, Yuker; Dajee, Maya; Melrose, Jennifer; Nakao, Brian; Hytopoulos, Evangelos; Berg, Ellen L; Butcher, Eugene C

    2004-02-01

    Now that the human genome has been sequenced, the challenge of assigning function to human genes has become acute. Existing approaches using microarrays or proteomics frequently generate very large volumes of data not directly related to biological function, making interpretation difficult. Here, we describe a technique for integrative systems biology in which: (i) primary cells are cultured under biologically meaningful conditions; (ii) a limited number of biologically meaningful readouts are measured; and (iii) the results obtained under several different conditions are combined for analysis. Studies of human endothelial cells overexpressing different signaling molecules under multiple inflammatory conditions show that this system can capture a remarkable range of functions by a relatively small number of simple measurements. In particular, measurement of seven different protein levels by ELISA under four different conditions is capable of reconstructing pathway associations of 25 different proteins representing four known signaling pathways, implicating additional participants in the NF-kappaBorRAS/mitogen-activated protein kinase pathways and defining additional interactions between these pathways. PMID:14745015

  18. Force control for mechanoinduction of impedance variation in cellular organisms

    International Nuclear Information System (INIS)

    Constantly exposed to various forms of mechanical forces inherent in their physical environment (such as gravity, stress induced by fluid flow or cell–cell interactions, etc), cellular organisms sense such forces and convert them into biochemical signals through the processes of mechanosensing and mechanotransduction that eventually lead to biological changes. The effect of external forces on the internal structures and activities in a cellular organism may manifest in changes its physical properties, such as impedance. Studying variation in the impedance of a cellular organism induced by the application of an external mechanical force represents a meaningful endeavor (from a biosystems perspective) in exploring the complex mechanosensing and mechanotransduction mechanisms that govern the behavior of a cellular organism under the influence of external mechanical stimuli. In this paper we describe the development of an explicit force-feedback control system for exerting an indentation force on a cellular organism while simultaneously measuring its impedance. To demonstrate the effectiveness of this force-control system, we have conducted experiments using zebrafish embryos as a test model of a cellular organism. We report experimental results demonstrating that the application of a properly controlled external force leads to a significant change in the impedance of a zebrafish embryo. These results offer support for a plausible explanation that activities of pore canals in the chorion are responsible for the observed change in impedance.

  19. Repaglinide at a cellular level

    DEFF Research Database (Denmark)

    Krogsgaard Thomsen, M; Bokvist, K; Høy, M;

    2002-01-01

    To investigate the hormonal and cellular selectivity of the prandial glucose regulators, we have undertaken a series of experiments, in which we characterised the effects of repaglinide and nateglinide on ATP-sensitive potassium ion (KATP) channel activity, membrane potential and exocytosis in ra...

  20. Cellular signalling properties in microcircuits

    DEFF Research Database (Denmark)

    Toledo-Rodriguez, Maria; El Manira, Abdeljabbar; Wallén, Peter; Svirskis, Gytis; Hounsgaard, Jørn

    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...... cellular and molecular levels in microcircuits in specific brain regions. This review is part of the TINS Microcircuits Special Feature....

  1. Quantum Cloning by Cellular Automata

    OpenAIRE

    D'Ariano, G. M.; Macchiavello, C.; M. Rossi

    2012-01-01

    We introduce a quantum cellular automaton that achieves approximate phase-covariant cloning of qubits. The automaton is optimized for 1-to-2N economical cloning. The use of the automaton for cloning allows us to exploit different foliations for improving the performance with given resources.

  2. Analysis of cellular manufacturing systems

    NARCIS (Netherlands)

    Heragu, Sunderesh; Meng, Gang; Zijm, Henk; Ommeren, van Jan-Kees

    2001-01-01

    In this paper, we present an open queuing network modeling approach to estimate performance measures of a cellular manufacturing layout. It is assumed a layout and production data for a planning period of specified length are available. The production data takes into account, processing and handli

  3. Single-Molecule Imaging of Cellular Signaling

    Science.gov (United States)

    De Keijzer, Sandra; Snaar-Jagalska, B. Ewa; Spaink, Herman P.; Schmidt, Thomas

    Single-molecule microscopy is an emerging technique to understand the function of a protein in the context of its natural environment. In our laboratory this technique has been used to study the dynamics of signal transduction in vivo. A multitude of signal transduction cascades are initiated by interactions between proteins in the plasma membrane. These cascades start by binding a ligand to its receptor, thereby activating downstream signaling pathways which finally result in complex cellular responses. To fully understand these processes it is important to study the initial steps of the signaling cascades. Standard biological assays mostly call for overexpression of the proteins and high concentrations of ligand. This sets severe limits to the interpretation of, for instance, the time-course of the observations, given the large temporal spread caused by the diffusion-limited binding processes. Methods and limitations of single-molecule microscopy for the study of cell signaling are discussed on the example of the chemotactic signaling of the slime-mold Dictyostelium discoideum. Single-molecule studies, as reviewed in this chapter, appear to be one of the essential methodologies for the full spatiotemporal clarification of cellular signaling, one of the ultimate goals in cell biology.

  4. Cellular Auxin Homeostasis:Gatekeeping Is Housekeeping

    Institute of Scientific and Technical Information of China (English)

    Michel Ruiz Rosquete; Elke Barbez; Jürgen Kleine-Vehn

    2012-01-01

    The phytohormone auxin is essential for plant development and contributes to nearly every aspect of the plant life cycle.The spatio-temporal distribution of auxin depends on a complex interplay between auxin metabolism and cell-to-cell auxin transport.Auxin metabolism and transport are both crucial for plant development;however,it largely remains to be seen how these processes are integrated to ensure defined cellular auxin levels or even gradients within tissues or organs.In this review,we provide a glance at very diverse topics of auxin biology,such as biosynthesis,conjugation,oxidation,and transport of auxin.This broad,but certainly superficial,overview highlights the mutual importance of auxin metabolism and transport.Moreover,it allows pinpointing how auxin metabolism and transport get integrated to jointly regulate cellular auxin homeostasis.Even though these processes have been so far only separately studied,we assume that the phytohormonal crosstalk integrates and coordinates auxin metabolism and transport.Besides the integrative power of the global hormone signaling,we additionally introduce the hypothetical concept considering auxin transport components as gatekeepers for auxin responses.

  5. Tension and robustness in multitasking cellular networks.

    Directory of Open Access Journals (Sweden)

    Jeffrey V Wong

    Full Text Available Cellular networks multitask by exhibiting distinct, context-dependent dynamics. However, network states (parameters that generate a particular dynamic are often sub-optimal for others, defining a source of "tension" between them. Though multitasking is pervasive, it is not clear where tension arises, what consequences it has, and how it is resolved. We developed a generic computational framework to examine the source and consequences of tension between pairs of dynamics exhibited by the well-studied RB-E2F switch regulating cell cycle entry. We found that tension arose from task-dependent shifts in parameters associated with network modules. Although parameter sets common to distinct dynamics did exist, tension reduced both their accessibility and resilience to perturbation, indicating a trade-off between "one-size-fits-all" solutions and robustness. With high tension, robustness can be preserved by dynamic shifting of modules, enabling the network to toggle between tasks, and by increasing network complexity, in this case by gene duplication. We propose that tension is a general constraint on the architecture and operation of multitasking biological networks. To this end, our work provides a framework to quantify the extent of tension between any network dynamics and how it affects network robustness. Such analysis would suggest new ways to interfere with network elements to elucidate the design principles of cellular networks.

  6. ESR studies of some oxotetrahalo complexes of vanadium(IV) and molybdenum(V)

    International Nuclear Information System (INIS)

    ESR spectra of [VOF4]2- and [MoOF4]- have been studied in single crystals of (NH4)2SbF5 and spectra of [MoOCl4]- in single crystals of (NH4)2SbCl5. The spin-Hamiltonian parameters of these pentacoordinated complexes have been obtained and compared with those for the corresponding hexacoordinated species. Molecular orbital parameters for the penta- and hexacoordinated species obtained from experimental g- and A-tensor components have been compared with values calculated by the MS-SCF-Xα method

  7. CELLULAR INTERACTIONS MEDIATED BY GLYCONECTIDS

    Directory of Open Access Journals (Sweden)

    O.Popescu

    1999-01-01

    Full Text Available Cellular interactions involve many types of cell surface molecules and operate via homophilic and/or heterophilic protein-protein and protein-carbohydrate binding. Our investigations in different model-systems (marine invertebrates and mammals have provided direct evidence that a novel class of primordial proteoglycans, named by us gliconectins, can mediate cell adhesion via a new alternative molecular mechanism of polyvalent carbohydrate-carbohydrate binding. Biochemical characterization of isolated and purified glyconectins revealed the presence of specific carbohydrate structures, acidic glycans, different from classical glycosaminoglycans. Such acidic glycans of high molecular weight containing fucose, glucuronic or galacturonic acids, and sulfate groups, originally found in sponges and sea urchin embryos, may represent a new class of carbohydrate carcino-embryonal antigens in mice and humans. Such interactions between biological macromolecules are usually investigated by kinetic binding studies, calorimetric methods, X-ray diffraction, nuclear magnetic resonance, and other spectroscopic analyses. However, these methods do not supply a direct estimation of the intermolecular binding forces that are fundamental for the function of the ligand-receptor association. Recently, we have introduced atomic force microscopy to quantify the binding strength between cell adhesion proteoglycans. Measurement of binding forces intrinsic to cell adhesion proteoglycans is necessary to assess their contribution to the maintenance of the anatomical integrity of multicellular organisms. As a model, we selected the glyconectin 1, a cell adhesion proteoglycan isolated from the marine sponge Microciona prolifera. This glyconectin mediates in vivo cell recognition and aggregation via homophilic, species-specific, polyvalent, and calcium ion-dependent carbohydrate-carbohydrate interactions. Under physiological conditions, an adhesive force of up to 400 piconewtons

  8. A systematic approach to identify cellular auxetic materials

    International Nuclear Information System (INIS)

    Auxetics are materials showing a negative Poisson’s ratio. This characteristic leads to unusual mechanical properties that make this an interesting class of materials. So far no systematic approach for generating auxetic cellular materials has been reported. In this contribution, we present a systematic approach to identifying auxetic cellular materials based on eigenmode analysis. The fundamental mechanism generating auxetic behavior is identified as rotation. With this knowledge, a variety of complex two-dimensional (2D) and three-dimensional (3D) auxetic structures based on simple unit cells can be identified. (paper)

  9. Hyper bio assembler for 3D cellular systems

    CERN Document Server

    Arai, Fumihito; Yamato, Masayuki

    2015-01-01

    Hyper Bio Assembler for Cellular Systems is the first book to present a new methodology for measuring and separating target cells at high speed and constructing 3D cellular systems in vitro. This book represents a valuable resource for biologists, biophysicists and robotic engineers, as well as researchers interested in this new frontier area, offering a better understanding of the measurement, separation, assembly, analysis and synthesis of complex biological tissue, and of the medical applications of these technologies. This book is the outcome of the new academic fields of the Ministry of Education, Culture, Sports, Science and Technology’s Grant-in-Aid for Scientific Research in Japan.

  10. Modeling chemical systems using cellular automata a textbook and laboratory manual

    CERN Document Server

    Kier, Lemont B; Cheng, Chao-Kun

    2006-01-01

    Provides a practical introduction to an exciting modeling paradigm for complex systems. This book discusses the nature of scientific inquiry using models and simulations, and describes the nature of cellular automata models. It gives descriptions of how cellular automata models can be used in the study of a variety of phenomena.

  11. Commercialization of cellular immunotherapies for cancer.

    Science.gov (United States)

    Walker, Anthony; Johnson, Robert

    2016-04-15

    Successful commercialization of a cell therapy requires more than proving safety and efficacy to the regulators. The inherent complexity of cellular products delivers particular manufacturing, logistical and reimbursement hurdles that threaten commercial viability for any therapy with a less than spectacular clinical profile that truly changes the standard of care. This is particularly acute for autologous cell therapies where patients receive bespoke treatments manufactured from a sample of their own cells and where economies of scale, which play an important role in containing the production costs for small molecule and antibody therapeutics, are highly limited. Nevertheless, the promise of 'game-changing' efficacy, as exemplified by very high levels of complete responses in refractory haematological malignancies, has attracted capital investments on a vast scale, and the attendant pace of technology development provides promising indicators for future clinical and commercial success. PMID:27068936

  12. Cellular solidification of transparent monotectics

    Science.gov (United States)

    Kaulker, W. F.

    1986-01-01

    Understanding how liquid phase particles are engulfed or pushed during freezing of a monotectic is addressed. The additional complication is that the solid-liquid interface is nonplanar due to constitutional undercooling. Some evidence of particle pushing where the particles are the liquid phase of the montectic was already observed. Cellular freezing of the succinonitrile-glycerol system also occurred. Only a few compositions were tested at that time. The starting materials were not especially pure so that cellular interface observed was likely due to the presence of unkown impurities, the major portion of which was water. Topics addressed include: the effort of modeling the particle pushing process using the computer, establishing an apparatus for the determination of phase diagrams, and the measurement of the temperature gradients with a specimen which will solidify on the temperature gradient microscope stage.

  13. Cellular ceramics in combustion environments

    Energy Technology Data Exchange (ETDEWEB)

    Fuessel, Alexander; Boettge, Daniela; Adler, Joerg; Marschallek, Felix; Michaelis, Alexander [Fraunhofer Institute for Ceramic Technologies and Systems IKTS, Dresden (Germany)

    2011-11-15

    Cellular materials have become increasingly interesting for applications in combustion environments. Improvements like high power efficiency and low emissions are the main targets of technological development in combustion processes. However, despite scientific and technical success in developing new or improved burner concepts over recent years, a lot of problems remain to be solved in the field of materials science: due to the high power density of the burners the materials are subjected to high loads in terms of thermal shock, temperature and corrosion, especially in so-called porous burner technology. This article shows some examples of research and development strategies and results in developing improved cellular ceramics. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Designing Underwater Cellular Networks Parameters

    Directory of Open Access Journals (Sweden)

    Pejman Khadivi

    2008-09-01

    Full Text Available Oceanographic data collection, pollution monitoring, offshore exploration, disaster prevention, assisted navigation and tactical surveillance are some of the applications of underwater networks. Underwater networks should send the gathered information to other users or an offshore station via a base station in the sea. Since the available bandwidth in underwater is severely limited, frequency reuse and cellular networks concepts are very important. In this paper, after driving the ratio of signal to interference for underwater acoustic channels, the constraints for the cell radius are determined. One of the important results of this work is that, for special parameters like bandwidth, it may be impossible to provide the required signal to interference ratio and bandwidth for the network users. Furthermore, in this paper, number of supportable users, per-user bandwidth, and the user capacity for a cellular underwater network are determined.

  15. Stochastic Nature in Cellular Processes

    Institute of Scientific and Technical Information of China (English)

    刘波; 刘圣君; 王祺; 晏世伟; 耿轶钊; SAKATA Fumihiko; GAO Xing-Fa

    2011-01-01

    The importance of stochasticity in cellular processes is increasingly recognized in both theoretical and experimental studies. General features of stochasticity in gene regulation and expression are briefly reviewed in this article, which include the main experimental phenomena, classification, quantization and regulation of noises. The correlation and transmission of noise in cascade networks are analyzed further and the stochastic simulation methods that can capture effects of intrinsic and extrinsic noise are described.

  16. Xtoys cellular automata on xwindows

    CERN Document Server

    Creutz, M

    1995-01-01

    Xtoys is a collection of xwindow programs for demonstrating simulations of various statistical models. Included are xising, for the two dimensional Ising model, xpotts, for the q-state Potts model, xautomalab, for a fairly general class of totalistic cellular automata, xsand, for the Bak-Tang-Wiesenfield model of self organized criticality, and xfires, a simple forest fire simulation. The programs should compile on any machine supporting xwindows.

  17. Cellular reactions to patterned biointerfaces

    OpenAIRE

    Schulte, Vera Antonie

    2012-01-01

    The subject of this thesis is to study cellular reactions to topographically, mechanically and biochemically tunable polymeric biomaterials. Different aspects of in vitro cell-biomaterial interactions were systematically studied with the murine fibroblast cell line NIH L929 and primary human dermal fibroblasts (HDFs). Besides a general cytocompatibility assessment of the applied materials and the quantification of cell adhesion per se, cell morphological changes (e.g. cell spreading) and intr...

  18. Signal processing in cellular clocks

    OpenAIRE

    Forger, Daniel B.

    2011-01-01

    Many biochemical events within a cell need to be timed properly to occur at specific times of day, after other events have happened within the cell or in response to environmental signals. The cellular biochemical feedback loops that time these events have already received much recent attention in the experimental and modeling communities. Here, we show how ideas from signal processing can be applied to understand the function of these clocks. Consider two signals from the network s(t) and r(...

  19. Analysis of cellular manufacturing systems

    OpenAIRE

    Heragu, Sunderesh; Meng, Gang; Zijm, Henk; Ommeren, van, J.C.

    2001-01-01

    In this paper, we present an open queuing network modeling approach to estimate performance measures of a cellular manufacturing layout. It is assumed a layout and production data for a planning period of specified length are available. The production data takes into account, processing and handling set-up times as well as transfer and process batch size information of multiple products that flow through the system. It is assumed that two sets of discrete material handling devices are used fo...

  20. Cellular Dynamics of RNA Modification

    OpenAIRE

    Yi, Chengqi; Pan, Tao

    2011-01-01

    Decades of research have identified over 100 types of ribonucleosides that are post-transcriptionally modified. Many modified nucleosides are conserved in bacteria, archeae and eukaryotes, while some modified nucleosides are unique to each branch of life. However, the cellular and functional dynamics of RNA modifications remains largely unexplored, mostly due to the lack of functional hypotheses and experimental methods for quantification and large scale analysis. Just as many well characteri...

  1. Cellular Dynamics of RNA Modification

    Science.gov (United States)

    Yi, Chengqi; Pan, Tao

    2011-01-01

    Conspectus Decades of research have identified over 100 types of ribonucleosides that are post-transcriptionally modified. Many modified nucleosides are conserved in bacteria, archeae and eukaryotes, while some modified nucleosides are unique to each branch of life. However, the cellular and functional dynamics of RNA modifications remains largely unexplored, mostly due to the lack of functional hypotheses and experimental methods for quantification and large scale analysis. Just as many well characterized protein and DNA modifications, many RNA modifications are not essential for life. Instead, increasingly more evidence indicates that RNA modifications can play regulatory roles in cells, especially in response to stress conditions. In this Account, we review some known examples of RNA modifications that are dynamically controlled in cells and introduce some contemporary technologies and methods that enhance the studies of cellular dynamics of RNA modifications. Examples of RNA modifications discussed in this Account include (Figure 1): (1) 4-thio uridine (s4U) which can act as a cellular sensor of near UV-light; (2) queuosine (Q) which is a potential biomarker for malignancy; (3) N6-methyl adenine (m6A) which is the prevalent modification in eukaryotic mRNAs; and (4) pseudouridine (ψ) which are inducible by nutrient deprivation. Two recent technical advances that stimulated the studies of cellular dynamics of modified ribonucleosides are also described. First, a genome-wide method combines primer extension and microarray to study N1-methyl adenine (m1A) hypomodification in human tRNA. Second, a quantitative mass spectrometric method investigates dynamic changes of a wide range of tRNA modifications under stress conditions in yeast. In addition, we discuss potential mechanisms that control dynamic regulation of RNA modifications, and hypotheses for discovering potential RNA de-modification enzymes. We conclude the Account by highlighting the need to develop new

  2. CELLULAR FETAL MICROCHIMERISM IN PREECLAMPSIA

    OpenAIRE

    Gammill, Hilary S; Aydelotte, Tessa M.; Guthrie, Katherine A.; Nkwopara, Evangelyn C.; Nelson, J. Lee

    2013-01-01

    Previous studies have shown elevated concentrations of free fetal deoxyribonucleic acid and erythroblasts in maternal circulation in preeclampsia compared with normal pregnancy. Pluripotent and immunocompetent fetal cells also transfer to the maternal circulation during pregnancy, but whether concentrations of fetal mononuclear cells also differed in preeclampsia was unknown. We sought to quantify cellular fetal microchimerism in maternal circulation in women with preeclampsia and healthy con...

  3. Cellular pressure and volume regulation and implications for cell mechanics.

    Science.gov (United States)

    Jiang, Hongyuan; Sun, Sean X

    2013-08-01

    In eukaryotic cells, small changes in cell volume can serve as important signals for cell proliferation, death, and migration. Volume and shape regulation also directly impacts the mechanics of cells and tissues. Here, we develop a mathematical model of cellular volume and pressure regulation, incorporating essential elements such as water permeation, mechanosensitive channels, active ion pumps, and active stresses in the cortex. The model can fully explain recent experimental data, and it predicts cellular volume and pressure for several models of cell cortical mechanics. Moreover, we show that when cells are subjected to an externally applied load, such as in an atomic force microscopy indentation experiment, active regulation of volume and pressure leads to a complex cellular response. Instead of the passive mechanics of the cortex, the observed cell stiffness depends on several factors working together. This provides a mathematical explanation of rate-dependent response of cells under force. PMID:23931309

  4. Error performance analysis in downlink cellular networks with interference management

    KAUST Repository

    Afify, Laila H.

    2015-05-01

    Modeling aggregate network interference in cellular networks has recently gained immense attention both in academia and industry. While stochastic geometry based models have succeeded to account for the cellular network geometry, they mostly abstract many important wireless communication system aspects (e.g., modulation techniques, signal recovery techniques). Recently, a novel stochastic geometry model, based on the Equivalent-in-Distribution (EiD) approach, succeeded to capture the aforementioned communication system aspects and extend the analysis to averaged error performance, however, on the expense of increasing the modeling complexity. Inspired by the EiD approach, the analysis developed in [1] takes into consideration the key system parameters, while providing a simple tractable analysis. In this paper, we extend this framework to study the effect of different interference management techniques in downlink cellular network. The accuracy of the proposed analysis is verified via Monte Carlo simulations.

  5. Progress of cellular dedifferentiation research

    Institute of Scientific and Technical Information of China (English)

    LIU Hu-xian; HU Da-hai; JIA Chi-yu; FU Xiao-bing

    2006-01-01

    Differentiation, the stepwise specialization of cells, and transdifferentiation, the apparent switching of one cell type into another, capture much of the stem cell spotlight. But dedifferentiation, the developmental reversal of a cell before it reinvents itself, is an important process too. In multicellular organisms, cellular dedifferentiation is the major process underlying totipotency, regeneration and formation of new stem cell lineages. In humans,dedifferentiation is often associated with carcinogenesis.The study of cellular dedifferentiation in animals,particularly early events related to cell fate-switch and determination, is limited by the lack of a suitable,convenient experimental system. The classic example of dedifferentiation is limb and tail regeneration in urodele amphibians, such as salamanders. Recently, several investigators have shown that certain mammalian cell types can be induced to dedifferentiate to progenitor cells when stimulated with the appropriate signals or materials. These discoveries open the possibility that researchers might enhance the endogenous regenerative capacity of mammals by inducing cellular dedifferentiation in vivo.

  6. A Parallel Encryption Algorithm for Block Ciphers Based on Reversible Programmable Cellular Automata

    CERN Document Server

    Das, Debasis

    2010-01-01

    A Cellular Automata (CA) is a computing model of complex System using simple rule. In CA the problem space into number of cell and each cell can be one or several final state. Cells are affected by neighbours' to the simple rule. Cellular Automata are highly parallel and discrete dynamical systems, whose behaviour is completely specified in terms of a local relation. This paper deals with the Cellular Automata (CA) in cryptography for a class of Block Ciphers through a new block encryption algorithm based on Reversible Programmable Cellular Automata Theory. The proposed algorithm belongs to the class of symmetric key systems.

  7. The role of actin networks in cellular mechanosensing

    Science.gov (United States)

    Azatov, Mikheil

    behavior as in cancer metastasis. In addition to stiffness, the local geometry or topography of the surface has been shown to modulate the movement, morphology, and cytoskeletal organization of cells. However, the effect of topography on fluctuations of intracellular structures, which arise from motor driven activity on a viscoelastic actin network are not known. I have used nanofabricated substrates with parallel ridges to show that the cell shape, the actin cytoskeleton and focal adhesions all align along the direction of the ridges, exhibiting a biphasic dependence on the spacing between ridges. I further demonstrated that palladin bands along actin stress fibers undergo a complex diffusive motion with velocities aligned along the direction of ridges. These results provide insight into the mechanisms of cellular mechanosensing of the environment, suggesting a complex interplay between the actin cytoskeleton and cellular adhesions in coordinating cellular response to surface topography. Overall, this work has advanced our understanding of mechanisms that govern cellular responses to their physical environment.

  8. Dynamic properties of cellular neural networks

    Directory of Open Access Journals (Sweden)

    Angela Slavova

    1993-01-01

    Full Text Available Dynamic behavior of a new class of information-processing systems called Cellular Neural Networks is investigated. In this paper we introduce a small parameter in the state equation of a cellular neural network and we seek for periodic phenomena. New approach is used for proving stability of a cellular neural network by constructing Lyapunov's majorizing equations. This algorithm is helpful for finding a map from initial continuous state space of a cellular neural network into discrete output. A comparison between cellular neural networks and cellular automata is made.

  9. Cellular communications a comprehensive and practical guide

    CERN Document Server

    Tripathi, Nishith

    2014-01-01

    Even as newer cellular technologies and standards emerge, many of the fundamental principles and the components of the cellular network remain the same. Presenting a simple yet comprehensive view of cellular communications technologies, Cellular Communications provides an end-to-end perspective of cellular operations, ranging from physical layer details to call set-up and from the radio network to the core network. This self-contained source forpractitioners and students represents a comprehensive survey of the fundamentals of cellular communications and the landscape of commercially deployed

  10. Mast cells modulate transport of CD23/IgE/antigen complex across human intestinal epithelial barrier

    Directory of Open Access Journals (Sweden)

    Ping-Chang Yang

    2009-06-01

    Full Text Available Background: Food allergy and chronic intestinal inflammation are common in western countries. The complex of antigen/IgE is taken up into the body from the gut lumen with the aid of epithelial cell-derived CD23 (low affinity IgE receptor II that plays an important role in the pathogenesis of intestinal allergy. This study aimed to elucidate the role of mast cell on modulation of antigen/IgE complex transport across intestinal epithelial barrier. Methods: Human intestinal epithelial cell line HT29 cell monolayer was used as a study platform. Transepithelial electric resistance (TER and permeability to ovalbumin (OVA were used as the markers of intestinal epithelial barrier function that were recorded in response to the stimulation of mast cell-derived chemical mediators. Results: Conditioned media from naïve mast cell line HMC-1 cells or monocyte cell line THP-1 cells significantly upregulated the expression of CD23 and increased the antigen transport across the epithelium. Treatment with stem cell factor (SCF, nerve growth factor (NGF, retinoic acid (RA or dimethyl sulphoxide (DMSO enhanced CD23 expression in HT29 cells. Conditioned media from SCF, NGF or RA-treated HMC-1 cells, and SCF, NGF, DMSO or RA-treated THP-1 cells enhanced immune complex transport via enhancing the expression of the CD23 in HT29 cells and the release of inflammatory mediator TNF-α. Nuclear factor kappa B inhibitor, tryptase and TNF-α inhibited the increase in CD23 in HT29 cells and prevents the enhancement of epithelial barrier permeability. Conclusions: Mast cells play an important role in modulating the intestinal CD23 expression and the transport of antigen/IgE/CD23 complex across epithelial barrier.

  11. Transductions Computed by One-Dimensional Cellular Automata

    Directory of Open Access Journals (Sweden)

    Martin Kutrib

    2012-08-01

    Full Text Available Cellular automata are investigated towards their ability to compute transductions, that is, to transform inputs into outputs. The families of transductions computed are classified with regard to the time allowed to process the input and to compute the output. Since there is a particular interest in fast transductions, we mainly focus on the time complexities real time and linear time. We first investigate the computational capabilities of cellular automaton transducers by comparing them to iterative array transducers, that is, we compare parallel input/output mode to sequential input/output mode of massively parallel machines. By direct simulations, it turns out that the parallel mode is not weaker than the sequential one. Moreover, with regard to certain time complexities cellular automaton transducers are even more powerful than iterative arrays. In the second part of the paper, the model in question is compared with the sequential devices single-valued finite state transducers and deterministic pushdown transducers. It turns out that both models can be simulated by cellular automaton transducers faster than by iterative array transducers.

  12. Modeling evolution and immune system by cellular automata

    Energy Technology Data Exchange (ETDEWEB)

    Bezzi, M. [Scuola Internazionale Superiore di Studi Avanzati, Trieste (Italy); Istituto Nazionale di Fisica della Materia, Florence (Italy)

    2001-07-01

    In this review the behavior of two different biological systems is investigated using cellular automata. Starting from this spatially extended approach it is also tried, in some cases, to reduce the complexity of the system introducing mean-field approximation, and solving (or trying to solve) these simplified systems. It is discussed the biological meaning of the results, the comparison with experimental data (if available) and the different features between spatially extended and mean-field versions. The biological systems considered in this review are the following: Darwinian evolution in simple ecosystems and immune system response. In the first section the main features of molecular evolution are introduced, giving a short survey of genetics for physicists and discussing some models for prebiotic systems and simple ecosystems. It is also introduced a cellular automaton model for studying a set of evolving individuals in a general fitness landscape, considering also the effects of co-evolution. In particular the process of species formation (speciation) is described in sect. 5. The second part deals with immune system modeling. The biological features of immune response are discussed, as well as it is introduced the concept of shape space and of idiotypic network. More detailed reviews which deal with immune system models (mainly focused on idiotypic network models) can be found. Other themes here discussed: the applications of CA to immune system modeling, two complex cellular automata for humoral and cellular immune response. Finally, it is discussed the biological data and the general conclusions are drawn in the last section.

  13. Modeling evolution and immune system by cellular automata

    International Nuclear Information System (INIS)

    In this review the behavior of two different biological systems is investigated using cellular automata. Starting from this spatially extended approach it is also tried, in some cases, to reduce the complexity of the system introducing mean-field approximation, and solving (or trying to solve) these simplified systems. It is discussed the biological meaning of the results, the comparison with experimental data (if available) and the different features between spatially extended and mean-field versions. The biological systems considered in this review are the following: Darwinian evolution in simple ecosystems and immune system response. In the first section the main features of molecular evolution are introduced, giving a short survey of genetics for physicists and discussing some models for prebiotic systems and simple ecosystems. It is also introduced a cellular automaton model for studying a set of evolving individuals in a general fitness landscape, considering also the effects of co-evolution. In particular the process of species formation (speciation) is described in sect. 5. The second part deals with immune system modeling. The biological features of immune response are discussed, as well as it is introduced the concept of shape space and of idiotypic network. More detailed reviews which deal with immune system models (mainly focused on idiotypic network models) can be found. Other themes here discussed: the applications of CA to immune system modeling, two complex cellular automata for humoral and cellular immune response. Finally, it is discussed the biological data and the general conclusions are drawn in the last section

  14. Return of the Quantum Cellular Automata: Episode VI

    Science.gov (United States)

    Carr, Lincoln D.; Hillberry, Logan E.; Rall, Patrick; Halpern, Nicole Yunger; Bao, Ning; Montangero, Simone

    2016-05-01

    There are now over 150 quantum simulators or analog quantum computers worldwide. Although exploring quantum phase transitions, many-body localization, and the generalized Gibbs ensemble are exciting and worthwhile endeavors, there are totally untapped directions we have not yet pursued. One of these is quantum cellular automata. In the past a principal goal of quantum cellular automata was to reproduce continuum single particle quantum physics such as the Schrodinger or Dirac equation from simple rule sets. Now that we begin to really understand entanglement and many-body quantum physics at a deeper level, quantum cellular automata present new possibilities. We explore several time evolution schemes on simple spin chains leading to high degrees of quantum complexity and nontrivial quantum dynamics. We explain how the 256 known classical elementary cellular automata reduce to just a few exciting quantum cases. Our analysis tools include mutual information based complex networks as well as more familiar quantifiers like sound speed and diffusion rate. Funded by NSF and AFOSR.

  15. Game of Life Cellular Automata

    CERN Document Server

    Adamatzky, Andrew

    2010-01-01

    In the late 1960s, British mathematician John Conway invented a virtual mathematical machine that operates on a two-dimensional array of square cell. Each cell takes two states, live and dead. The cells' states are updated simultaneously and in discrete time. A dead cell comes to life if it has exactly three live neighbours. A live cell remains alive if two or three of its neighbours are alive, otherwise the cell dies. Conway's Game of Life became the most programmed solitary game and the most known cellular automaton. The book brings together results of forty years of study into computational

  16. Estimation in Cellular Radio Systems

    OpenAIRE

    Blom, Jonas; Gunnarsson, Fredrik; Gustafsson, Fredrik

    1999-01-01

    The problem to track time-varying parameters in cellular radio systems is studied, and the focus is on estimation based only on the signals that are readily available. Previous work have demonstrated very good performance, but were relying on analog measurement that are not available. Most of the information is lost due to quantization and sampling at a rate that might be as low as 2 Hz (GSM case). For that matter a maximum likelihood estimator have been designed and exemplified in the case o...

  17. 'Biomoleculas': cellular metabolism didactic software

    International Nuclear Information System (INIS)

    'Biomoleculas' is a software that deals with topics such as the digestion, cellular metabolism and excretion of nutrients. It is a pleasant, simple and didactic guide, made by and for students. In this program, each biomolecule (carbohydrates, lipids and proteins) is accompanied until its degradation and assimilation by crossing and interrelating the different metabolic channels to finally show the destination of the different metabolites formed and the way in which these are excreted. It is used at present as a teaching-learning process tool by the chair of Physiology and Biophysics at the Facultad de Ingenieria - Universidad Nacional de Entre Rios

  18. Two Phase Flow Simulation Using Cellular Automata

    International Nuclear Information System (INIS)

    channel. It was noticed that the CHF phenomena generally starts in cells located at the boundary.The fact that the phenomena can be well described by using simple rules shows that the related physics and even the physics with stochastic characteristics, has been captured with t his simple model. Some fractal properties of automata were also studied, arriving at the conclusion that the internal dynamics present fractal characteristics.Findings hint towards a new approach to solve open issues.Finally, a calculus related to the Australian reactor designed by INVAP was performed.The problem consists of a simulation of helium bubble production by the mechanism of mass diffusion in heavy water.It was verified that cellular automata systems are a powerful tool for describing problems with high complexity and short reach interactions between components.It was proved that two-phase flows could be described very well with this model.The approach is a powerful tool to describe non-equilibrium features, such as boiling flow development and interfacial topological transitions.A novel computer model of boiling crisis was encountered following this type of analysis.By means of this research, without invalidating the important advances obtained in other directions, a new tool is offered which can be useful regarding the modeling of boiling heat transfer systems

  19. Protein accounting in the cellular economy

    Science.gov (United States)

    Vázquez-Laslop, Nora; Mankin, Alexander S.

    2014-01-01

    Knowing the copy number of cellular proteins is critical for understanding cell physiology. By being able to measure the absolute synthesis rates of the majority of cellular proteins, Li et al. (2014) gain insights into key aspects of translation regulation and fundamental principles of cellular strategies to adjust protein synthesis according to the needs. PMID:24766801

  20. Cellular Functions of Transient Receptor Potential channels

    OpenAIRE

    Dadon, Daniela; Minke, Baruch

    2010-01-01

    Transient Receptor Potential channels are polymodal cellular sensors involved in a wide variety of cellular processes, mainly by increasing cellular Ca2+. In this review we focus on the roles of these channels in: i) cell death ii) proliferation and differentiation and iii) synaptic vesicle release.

  1. Synthesis, characterization, and reactivity of alkyldisulfanido zinc complexes.

    Science.gov (United States)

    Galardon, Erwan; Tomas, Alain; Selkti, Mohamed; Roussel, Pascal; Artaud, Isabelle

    2009-07-01

    The alkyldisulfanido zinc complexes Tp(iPr,iPr)Zn(SSR) and Tp(Ph,Me)Zn(SSR) where Tp(iPr,iPr) is hydridotris-((3,5-isopropyl)pyrazolyl)borate, Tp(Ph,Me) is hydridotris-((3-phenyl,5-methyl)pyrazolyl)borate, and (SSR) is tert-butyldisulfanido or triphenylmethanedisulfanido were synthesized by reaction between the corresponding hydroxo complexes TpZn(OH) and the synthetic persulfide RSSH. All the complexes were characterized by elemental analysis and (1)H NMR spectroscopy, and representative members of the class were also structurally characterized. The reactivity of the alkyldisulfanido TpZn(SSR) complexes with thiols was studied. In the absence of base, a simple exchange reaction between the alkyldisulfanido ligand and the thiol was observed in dichloromethane; when in the presence of base, the corresponding hydrogen(sulfido) complexes TpZn(SH) were obtained. The mechanism of the latter reaction has been studied and does not involve the coordinated alkyldisulfanido group. Reaction of the hydrogen(sulfido) complexes Tp(iPr,iPr)Zn(SH) with the thiosulfonate PhCH(2)S-SO(2)CF(3) did not yield the expected alkyldisulfanido complex but benzyltrisulfide and a new complex tentatively assigned as Tp(iPr,iPr)Zn(O(2)SCF(3)). PMID:19514736

  2. Ion beam analysis based on cellular nonlinear networks

    OpenAIRE

    Senger, V.; R. Tetzlaff; H. Reichau; Ratzinger, U.

    2011-01-01

    The development of a non- destructive measurement method for ion beam parameters has been treated in various projects. Although results are promising, the high complexity of beam dynamics has made it impossible to implement a real time process control up to now. In this paper we will propose analysing methods based on the dynamics of Cellular Nonlinear Networks (CNN) that can be implemented on pixel parallel CNN based architectures and yield satisfying results even at low re...

  3. Typing of murine cell-surface antigens by cellular radioimmunoassay

    International Nuclear Information System (INIS)

    A cellular radioimmunoassay utilizing 125I-labelled Protein A was used for detecting antigen-antibody complexes on gultaraldehyde fixed cells attached to microtiter plates. This method is rapid, sensitive and specific for revealing H-2 private and public specificities as well as Ia and Lyt antigens. As plates may be kept for months, several reactivities can be tested in one step on a large panel rendering a regular supply of animals unnecessary. (Auth.)

  4. Finite Field Arithmetic Architecture Based on Cellular Array

    Directory of Open Access Journals (Sweden)

    Kee-Won Kim

    2015-05-01

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

  5. A Tractable Approach to Coverage and Rate in Cellular Networks

    OpenAIRE

    Andrews, Jeffrey G.; Baccelli, Francois; Ganti, Radha Krishna

    2010-01-01

    Cellular networks are usually modeled by placing the base stations on a grid, with mobile users either randomly scattered or placed deterministically. These models have been used extensively but suffer from being both highly idealized and not very tractable, so complex system-level simulations are used to evaluate coverage/outage probability and rate. More tractable models have long been desirable. We develop new general models for the multi-cell signal-to-interference-plus-noise ratio (SINR)...

  6. Knowledge Discovery in Database: Induction Graph and Cellular Automaton

    OpenAIRE

    Baghdad Atmani; Bouziane Beldjilali

    2012-01-01

    In this article we present the general architecture of a cellular machine, which makes it possible to reduce the size of induction graphs, and to optimize automatically the generation of symbolic rules. Our objective is to propose a tool for detecting and eliminating non relevant variables from the database. The goal, after acquisition by machine learning from a set of data, is to reduce the complexity of storage, thus to decrease the computing time. The objective of this work is to experimen...

  7. Cellular Chaperonin CCTγ Contributes to Rabies Virus Replication during Infection

    OpenAIRE

    Zhang, Jinyang; Wu, Xiaopeng; Zan, Jie; Wu, Yongping; YE, CHENGJIN; Ruan, Xizhen; Zhou, Jiyong

    2013-01-01

    Rabies, as the oldest known infectious disease, remains a serious threat to public health worldwide. The eukaryotic cytosolic chaperonin TRiC/CCT complex facilitates the folding of proteins through ATP hydrolysis. Here, we investigated the expression, cellular localization, and function of neuronal CCTγ during neurotropic rabies virus (RABV) infection using mouse N2a cells as a model. Following RABV infection, 24 altered proteins were identified by using two-dimensional electrophoresis and ma...

  8. The late stage of autophagy: cellular events and molecular regulation

    OpenAIRE

    Tong, Jingjing; Yan, Xianghua; Yu, Li

    2010-01-01

    Autophagy is an intracellular degradation system that delivers cytoplasmic contents to the lysosome for degradation. It is a “self-eating” process and plays a “house-cleaner” role in cells. The complex process consists of several sequential steps—induction, autophagosome formation, fusion of lysosome and autophagosome, degradation, efflux transportation of degradation products, and autophagic lysosome reformation. In this review, the cellular and molecular regulations of late stage of autopha...

  9. Ion beam analysis based on cellular nonlinear networks

    Science.gov (United States)

    Senger, V.; Tetzlaff, R.; Reichau, H.; Ratzinger, U.

    2011-07-01

    The development of a non- destructive measurement method for ion beam parameters has been treated in various projects. Although results are promising, the high complexity of beam dynamics has made it impossible to implement a real time process control up to now. In this paper we will propose analysing methods based on the dynamics of Cellular Nonlinear Networks (CNN) that can be implemented on pixel parallel CNN based architectures and yield satisfying results even at low resolutions.

  10. Evolution of Cellular Automata using Lindenmayer Systems and Fourier Transforms

    OpenAIRE

    Berg, Sivert

    2013-01-01

    Cellular automata (CAs) are a class of highly parallel computing systems consisting of many simple computing elements called cells. The cells can only communicate with neighboring cells, meaning there is no global communication in the system. Programming such a system to solve complex problems can be a daunting task, and indirect methods are often applied to make it easier. In this thesis we use evolutionary algorithms (EAs) to evolve CAs. We also look at the possibility of employing L-system...

  11. Molecular and cellular constraints on proteins

    Science.gov (United States)

    Kortemme, Tanja

    Engineering proteins with new sequences, structures and functions has many exciting practical applications, and provides new ways to dissect design principles for function. Recent successes in computational protein design provide a cause for optimism. Yet many functions are currently too complex to engineer predictively, and successful design of new biological activities also requires an understanding of the functional pressures acting on proteins in the context of cells and organisms. I will present two vignettes describing our progress with dissecting both molecular and cellular constraints on protein function. In the first, we characterized the cost and benefit of protein production upon sequence perturbations in a classic system for gene regulation, the lac operon. Our results were unexpected in light of the common assumption that the dominant fitness costs are due to protein expression. Instead, we discovered a direct linear relationship between cost and lacpermease activity, not protein or mRNA production. The magnitude of the cost of permease activity, relative to protein production, has consequences for regulation. Our model predicts an advantage of direct regulation of protein activity (not just expression), providing a new explanation for the long-known mechanism of ``inducer exclusion'' that inhibits transport through the permease. Similar pressures and cost/benefit tradeoffs may be key to engineering synthetic systems with improved fitness. In the second vignette, I will describe our recent efforts to develop computational approaches that predict protein sequences consistent with multiple functional conformations. We expect such ``multi-constraint'' models to improve predictions of functional sequences determined by deep mutational scanning in bacteria, to provide insights into how the balance between functional conformations shapes sequence space, and to highlight molecular and cellular constraints that cannot be captured by the model.

  12. Universal map for cellular automata

    Energy Technology Data Exchange (ETDEWEB)

    García-Morales, V., E-mail: vmorales@ph.tum.de [Institute for Advanced Study – Technische Universität München, Lichtenbergstr. 2a, D-85748 Garching (Germany)

    2012-08-20

    A universal map is derived for all deterministic 1D cellular automata (CAs) containing no freely adjustable parameters and valid for any alphabet size and any neighborhood range (including non-symmetrical neighborhoods). The map can be extended to an arbitrary number of dimensions and topologies and to arbitrary order in time. Specific CA maps for the famous Conway's Game of Life and Wolfram's 256 elementary CAs are given. An induction method for CAs, based in the universal map, allows mathematical expressions for the orbits of a wide variety of elementary CAs to be systematically derived. -- Highlights: ► A universal map is derived for all deterministic 1D cellular automata (CA). ► The map is generalized to 2D for Von Neumann, Moore and hexagonal neighborhoods. ► A map for all Wolfram's 256 elementary CAs is derived. ► A map for Conway's “Game of Life” is obtained.

  13. Multiuser Scheduling on the Downlink of an LTE Cellular System

    Directory of Open Access Journals (Sweden)

    Raymond Kwan

    2008-01-01

    Full Text Available The challenge of scheduling user transmissions on the downlink of a long-term evolution (LTE cellular communication system is addressed. In particular, a novel optimalmultiuser scheduler is proposed. Numerical results show that the system performance improves with increasing correlation among OFDMA subcarriers. It is found that only a limited amount of feedback information is needed to achieve relatively good performance. A suboptimal reduced-complexity scheduler is also proposed and shown to provide good performance. The suboptimal scheme is especially attractive when the number of users is large, in which case the complexity of the optimal scheme is high.

  14. Time scale of diffusion in molecular and cellular biology

    Science.gov (United States)

    Holcman, D.; Schuss, Z.

    2014-05-01

    Diffusion is the driver of critical biological processes in cellular and molecular biology. The diverse temporal scales of cellular function are determined by vastly diverse spatial scales in most biophysical processes. The latter are due, among others, to small binding sites inside or on the cell membrane or to narrow passages between large cellular compartments. The great disparity in scales is at the root of the difficulty in quantifying cell function from molecular dynamics and from simulations. The coarse-grained time scale of cellular function is determined from molecular diffusion by the mean first passage time of molecular Brownian motion to a small targets or through narrow passages. The narrow escape theory (NET) concerns this issue. The NET is ubiquitous in molecular and cellular biology and is manifested, among others, in chemical reactions, in the calculation of the effective diffusion coefficient of receptors diffusing on a neuronal cell membrane strewn with obstacles, in the quantification of the early steps of viral trafficking, in the regulation of diffusion between the mother and daughter cells during cell division, and many other cases. Brownian trajectories can represent the motion of a molecule, a protein, an ion in solution, a receptor in a cell or on its membrane, and many other biochemical processes. The small target can represent a binding site or an ionic channel, a hidden active site embedded in a complex protein structure, a receptor for a neurotransmitter on the membrane of a neuron, and so on. The mean time to attach to a receptor or activator determines diffusion fluxes that are key regulators of cell function. This review describes physical models of various subcellular microdomains, in which the NET coarse-grains the molecular scale to a higher cellular-level, thus clarifying the role of cell geometry in determining subcellular function.

  15. Thermomechanical characterisation of cellular rubber

    Science.gov (United States)

    Seibert, H.; Scheffer, T.; Diebels, S.

    2016-01-01

    This contribution discusses an experimental possibility to characterise a cellular rubber in terms of the influence of multiaxiality, rate dependency under environmental temperature and its behaviour under hydrostatic pressure. In this context, a mixed open and closed cell rubber based on an ethylene propylene diene monomer is investigated exemplarily. The present article intends to give a general idea of the characterisation method and the considerable effects of this special type of material. The main focus lies on the experimental procedure and the used testing devices in combination with the analysis methods such as true three-dimensional digital image correlation. The structural compressibility is taken into account by an approach for a material model using the Theory of Porous Media with additional temperature dependence.

  16. Discrete geodesics and cellular automata

    CERN Document Server

    Arrighi, Pablo

    2015-01-01

    This paper proposes a dynamical notion of discrete geodesics, understood as straightest trajectories in discretized curved spacetime. The notion is generic, as it is formulated in terms of a general deviation function, but readily specializes to metric spaces such as discretized pseudo-riemannian manifolds. It is effective: an algorithm for computing these geodesics naturally follows, which allows numerical validation---as shown by computing the perihelion shift of a Mercury-like planet. It is consistent, in the continuum limit, with the standard notion of timelike geodesics in a pseudo-riemannian manifold. Whether the algorithm fits within the framework of cellular automata is discussed at length. KEYWORDS: Discrete connection, parallel transport, general relativity, Regge calculus.

  17. Cellular compartmentalization of secondary metabolism

    Directory of Open Access Journals (Sweden)

    H. Corby eKistler

    2015-02-01

    Full Text Available Fungal secondary metabolism is often considered apart from the essential housekeeping functions of the cell. However, there are clear links between fundamental cellular metabolism and the biochemical pathways leading to secondary metabolite synthesis. Besides utilizing key biochemical precursors shared with the most essential processes of the cell (e.g. amino acids, acetyl CoA, NADPH, enzymes for secondary metabolite synthesis are compartmentalized at conserved subcellular sites that position pathway enzymes to use these common biochemical precursors. Co-compartmentalization of secondary metabolism pathway enzymes also may function to channel precursors, promote pathway efficiency and sequester pathway intermediates and products from the rest of the cell. In this review we discuss the compartmentalization of three well-studied fungal secondary metabolite biosynthetic pathways for penicillin G, aflatoxin and deoxynivalenol, and summarize evidence used to infer subcellular localization. We also discuss how these metabolites potentially are trafficked within the cell and may be exported.

  18. Cellular tolerance to pulsed heating

    Science.gov (United States)

    Simanovski, Dimitrii; Sarkar, M.; Irani, A.; O'Connell-Rodwell, C.; Contag, C.; Schwettman, H. Alan; Palanker, D.

    2005-04-01

    Many laser therapies involve significant heating of tissue with pulses varying from picoseconds to minutes in duration. In some of the applications heating is a primary goal, while in others it is an undesirable side effect. In both cases, if a hyperthermia is involved, the knowledge about the threshold temperature leading to irreversible cellular damage is critically important. We study the dependence of the threshold temperature on duration of the heat exposure in the range of 0.3 ms to 5 seconds. Thin layer of cells cultured in a Petri dish was exposed to a pulsed CO2 laser radiation. Laser beam was focused onto sample providing Gaussian intensity distribution in the focal plane with a beam diameter (2w) 2-10 mm. Surface temperature in the central part of the focal spot (1mm in diameter) was measured by thermal infrared (IR) emission from the sample, recorded with a fast IR detector. For pulses shorter than 1 s the temperature profile across the focal spot was found to closely correspond to the radial distribution of the laser beam intensity, thus allowing for accurate determination of temperature at any given distance from the center of the spot. Immediate cellular damage was assessed using vital staining with the live/dead fluorescent assay. Threshold temperatures were found to vary from 65 °C at 5 s of heating to 160 °C at pulses of 0.3 ms in duration. The shorter end of this range was limited by vaporization, which occurs during the laser pulse and results in mechanical damage to cells. Dependence of the maximal temperature on pulse duration could be approximated by Arrhenius law with activation energy being about 1 eV.

  19. CNN a paradigm for complexity

    CERN Document Server

    Chua, Leon O

    1998-01-01

    Revolutionary and original, this treatise presents a new paradigm of EMERGENCE and COMPLEXITY, with applications drawn from numerous disciplines, including artificial life, biology, chemistry, computation, physics, image processing, information science, etc.CNN is an acronym for Cellular Neural Networks when used in the context of brain science, or Cellular Nonlinear Networks, when used in the context of emergence and complexity. A CNN is modeled by cells and interactions: cells are defined as dynamical systems and interactions are defined via coupling laws. The CNN paradigm is a universal Tur

  20. Roles of Rho GTPases in Intracellular Transport and Cellular Transformation

    Directory of Open Access Journals (Sweden)

    Ji-Long Chen

    2013-03-01

    Full Text Available Rho family GTPases belong to the Ras GTPase superfamily and transduce intracellular signals known to regulate a variety of cellular processes, including cell polarity, morphogenesis, migration, apoptosis, vesicle trafficking, viral transport and cellular transformation. The three best-characterized Rho family members are Cdc42, RhoA and Rac1. Cdc42 regulates endocytosis, the transport between the endoplasmic reticulum and Golgi apparatus, post-Golgi transport and exocytosis. Cdc42 influences trafficking through interaction with Wiskott-Aldrich syndrome protein (N-WASP and the Arp2/3 complex, leading to changes in actin dynamics. Rac1 mediates endocytic and exocytic vesicle trafficking by interaction with its effectors, PI3kinase, synaptojanin 2, IQGAP1 and phospholipase D1. RhoA participates in the regulation of endocytosis through controlling its downstream target, Rho kinase. Interestingly, these GTPases play important roles at different stages of viral protein and genome transport in infected host cells. Importantly, dysregulation of Cdc42, Rac1 and RhoA leads to numerous disorders, including malignant transformation. In some cases, hyperactivation of Rho GTPases is required for cellular transformation. In this article, we review a number of findings related to Rho GTPase function in intracellular transport and cellular transformation.

  1. Mechanisms involved in cellular ceramide homeostasis

    Directory of Open Access Journals (Sweden)

    Hussain M

    2012-07-01

    Full Text Available Abstract Sphingolipids are ubiquitous and critical components of biological membranes. Their biosynthesis starts with soluble precursors in the endoplasmic reticulum and culminates in the Golgi complex and plasma membrane. Ceramides are important intermediates in the biosynthesis of sphingolipids, such as sphingomyelin, and their overload in the membranes is injurious to cells. The major product of ceramide metabolism is sphingomyelin. We observed that sphingomyelin synthase (SMS 1 or SMS2 deficiencies significantly decreased plasma and liver sphingomyelin levels. However, SMS2 but not SMS1 deficiency increased plasma ceramides. Surprisingly, SMS1 deficiency significantly increased glucosylceramide and ganglioside GM3, but SMS2 deficiency did not. To explain these unexpected findings about modest to no significant changes in ceramides and increases in other sphingolipids after the ablation of SMS1, we hypothesize that cells have evolved several organelle specific mechanisms to maintain ceramide homeostasis. First, ceramides in the endoplasmic reticulum membranes are controlled by its export to Golgi by protein mediated transfer. Second, in the Golgi, ceramide levels are modulated by their enzymatic conversion to different sphingolipids such as sphingomyelin, and glucosylceramides. Additionally, these sphingolipids can become part of triglyceride-rich apolipoprotein B-containing lipoproteins and be secreted. Third, in the plasma membrane ceramide levels are maintained by ceramide/sphingomyelin cycle, delivery to lysosomes, and efflux to extracellular plasma acceptors. All these pathways might have evolved to ensure steady cellular ceramide levels.

  2. Cellular automata modelling of biomolecular networks dynamics.

    Science.gov (United States)

    Bonchev, D; Thomas, S; Apte, A; Kier, L B

    2010-01-01

    The modelling of biological systems dynamics is traditionally performed by ordinary differential equations (ODEs). When dealing with intracellular networks of genes, proteins and metabolites, however, this approach is hindered by network complexity and the lack of experimental kinetic parameters. This opened the field for other modelling techniques, such as cellular automata (CA) and agent-based modelling (ABM). This article reviews this emerging field of studies on network dynamics in molecular biology. The basics of the CA technique are discussed along with an extensive list of related software and websites. The application of CA to networks of biochemical reactions is exemplified in detail by the case studies of the mitogen-activated protein kinase (MAPK) signalling pathway, the FAS-ligand (FASL)-induced and Bcl-2-related apoptosis. The potential of the CA method to model basic pathways patterns, to identify ways to control pathway dynamics and to help in generating strategies to fight with cancer is demonstrated. The different line of CA applications presented includes the search for the best-performing network motifs, an analysis of importance for effective intracellular signalling and pathway cross-talk. PMID:20373215

  3. Multistructural biomimetic substrates for controlled cellular differentiation

    International Nuclear Information System (INIS)

    Multidimensional scaffolds are considered to be ideal candidates for regenerative medicine and tissue engineering based on their potential to provide an excellent microenvironment and direct the fate of the cultured cells. More recently, the use of stem cells in medicine has opened a new technological opportunity for controlled tissue formation. However, the mechanism through which the substrate directs the differentiation of stem cells is still rather unclear. Data concerning its specific surface chemistry, topology, and its signaling ability need to be further understood and analyzed. In our study, atomic force microscopy was used to study the stiffness, roughness, and topology of the collagen (Coll) and metallized collagen (MC) substrates, proposed as an excellent substrate for regenerative medicine. The importance of signaling molecules was studied by constructing a new hybrid signaling substrate that contains both collagen and laminin extracellular matrix (ECM) proteins. The cellular response—such as attachment capability, proliferation and cardiac and neuronal phenotype expression on the metallized and non-metallized hybrid substrates (collagen + laminin)—was studied using MTT viability assay and immunohistochemistry studies. Our findings indicate that such hybrid materials could play an important role in the regeneration of complex tissues. (paper)

  4. Cellular and molecular mechanisms in liver fibrogenesis.

    Science.gov (United States)

    Novo, Erica; Cannito, Stefania; Paternostro, Claudia; Bocca, Claudia; Miglietta, Antonella; Parola, Maurizio

    2014-04-15

    Liver fibrogenesis is a dynamic and highly integrated molecular, tissue and cellular process, potentially reversible, that drives the progression of chronic liver diseases (CLD) towards liver cirrhosis and hepatic failure. Hepatic myofibroblasts (MFs), the pro-fibrogenic effector cells, originate mainly from activation of hepatic stellate cells and portal fibroblasts being characterized by a proliferative and survival attitude. MFs also contract in response to vasoactive agents, sustain angiogenesis and recruit and modulate activity of cells of innate or adaptive immunity. Chronic activation of wound healing and oxidative stress as well as derangement of epithelial-mesenchymal interactions are "major" pro-fibrogenic mechanisms, whatever the etiology. However, literature has outlined a complex network of pro-fibrogenic factors and mediators proposed to modulate CLD progression, with some of them being at present highly debated in the field, including the role of epithelial to mesenchymal transition and Hedgehog signaling pathways. Hypoxia and angiogenesis as well as inflammasomes are recently emerged as ubiquitous pro-inflammatory and pro-fibrogenic determinants whereas adipokines are mostly involved in CLD related to metabolic disturbances (metabolic syndrome and/or obesity and type 2 diabetes). Finally, autophagy as well as natural killer and natural killer-T cells have been recently proposed to significantly affect fibrogenic CLD progression. PMID:24631571

  5. Cellular recurrent deep network for image registration

    Science.gov (United States)

    Alam, M.; Vidyaratne, L.; Iftekharuddin, Khan M.

    2015-09-01

    Image registration using Artificial Neural Network (ANN) remains a challenging learning task. Registration can be posed as a two-step problem: parameter estimation and actual alignment/transformation using the estimated parameters. To date ANN based image registration techniques only perform the parameter estimation, while affine equations are used to perform the actual transformation. In this paper, we propose a novel deep ANN based image rigid registration that combines parameter estimation and transformation as a simultaneous learning task. Our previous work shows that a complex universal approximator known as Cellular Simultaneous Recurrent Network (CSRN) can successfully approximate affine transformations with known transformation parameters. This study introduces a deep ANN that combines a feed forward network with a CSRN to perform full rigid registration. Layer wise training is used to pre-train feed forward network for parameter estimation and followed by a CSRN for image transformation respectively. The deep network is then fine-tuned to perform the final registration task. Our result shows that the proposed deep ANN architecture achieves comparable registration accuracy to that of image affine transformation using CSRN with known parameters. We also demonstrate the efficacy of our novel deep architecture by a performance comparison with a deep clustered MLP.

  6. Analytical Modeling of Uplink Cellular Networks

    CERN Document Server

    Novlan, Thomas D; Andrews, Jeffrey G

    2012-01-01

    Cellular uplink analysis has typically been undertaken by either a simple approach that lumps all interference into a single deterministic or random parameter in a Wyner-type model, or via complex system level simulations that often do not provide insight into why various trends are observed. This paper proposes a novel middle way that is both accurate and also results in easy-to-evaluate integral expressions based on the Laplace transform of the interference. We assume mobiles and base stations are randomly placed in the network with each mobile pairing up to its closest base station. The model requires two important changes compared to related recent work on the downlink. First, dependence is introduced between the user and base station point processes to make sure each base station serves a single mobile in the given resource block. Second, per-mobile power control is included, which further couples the locations of the mobiles and their receiving base stations. Nevertheless, we succeed in deriving the cov...

  7. Cellular phones: are they detrimental?

    Science.gov (United States)

    Salama, Osama E; Abou El Naga, Randa M

    2004-01-01

    The issue of possible health effects of cellular phones is very much alive in the public's mind where the rapid increase in the number of the users of cell phones in the last decade has increased the exposure of people to the electromagnetic fields (EMFs). Health consequences of long term use of mobile phones are not known in detail but available data indicates the development of non specific annoying symptoms on acute exposure to mobile phone radiations. In an attempt to determine the prevalence of such cell phones associated health manifestations and the factors affecting their occurrence, a cross sectional study was conducted in five randomly selected faculties of Alexandria University. Where, 300 individuals including teaching staff, students and literate employee were equally allocated and randomly selected among the five faculties. Data about mobile phone's users and their medical history, their pattern of mobile usage and the possible deleterious health manifestations associated with cellular phone use was collected. The results revealed 68% prevalence of mobile phone usage, nearly three quarters of them (72.5%) were complainers of the health manifestations. They suffered from headache (43%), earache (38.3%), sense of fatigue (31.6%), sleep disturbance (29.5%), concentration difficulty (28.5%) and face burning sensation (19.2%). Both univariate and multivariate analysis were consistent in their findings. Symptomatic users were found to have significantly higher frequency of calls/day, longer call duration and longer total duration of mobile phone usage/day than non symptomatic users. For headache both call duration and frequency of calls/day were the significant predicting factors for its occurrence (chi2 = 18.208, p = 0.0001). For earache, in addition to call duration, the longer period of owning the mobile phone were significant predictors (chi2 = 16.996, p = 0.0002). Sense of fatigue was significantly affected by both call duration and age of the user

  8. A radiation measurement study on cellular phone

    International Nuclear Information System (INIS)

    This paper will explain the radiation level produced by various selected cellular phone from various models and brands available in the market. The result obtained from this study will also recommend whether a cellular phone is safe for public usage or it might cause any effect on public health. Finally, a database of radiation measurement level produced by selected various cellular phone will also be developed and exhibited in this paper. (Author)

  9. Predicting Cellular Growth from Gene Expression Signatures

    OpenAIRE

    Dunham, Maitreya J.; Troyanskaya, Olga G.; Airoldi, Edoardo; Broach, James R.; Caudy, Amy A.; Gresham, David; Botstein, David; Huttenhower, Curtis; Lu, Charles

    2009-01-01

    Maintaining balanced growth in a changing environment is a fundamental systems-level challenge for cellular physiology, particularly in microorganisms. While the complete set of regulatory and functional pathways supporting growth and cellular proliferation are not yet known, portions of them are well understood. In particular, cellular proliferation is governed by mechanisms that are highly conserved from unicellular to multicellular organisms, and the disruption of these processes in metazo...

  10. Cellular structure in system of interacting particles

    OpenAIRE

    Lev, Bohdan

    2008-01-01

    The general description of formation the cellular structure in the system of interacting particles is proposed. Interactions between particles are presumably well-understood and the phase transition in which can be studied in the scale of particle resolution. We presented analytical results of possible cellular structures for suspension of colloidal particles, in system particles immersed in liquid crystal and gravitational system. We have shown that cellular structure formation can occur in ...

  11. Radiation, nitric oxide and cellular death

    International Nuclear Information System (INIS)

    The mechanisms of radiation induced cellular death constitute an objective of research ever since the first biological effects of radiation were first observed. The explosion of information produced in the last 20 years calls for a careful analysis due to the apparent contradictory data related to the cellular system studied and the range of doses used. This review focuses on the role of the active oxygen species, in particular the nitric oxides, in its relevance as potential mediator of radiation induced cellular death

  12. Autophagy and mitophagy in cellular damage control

    Directory of Open Access Journals (Sweden)

    Jianhua Zhang

    2013-01-01

    Full Text Available Autophagy and mitophagy are important cellular processes that are responsible for breaking down cellular contents, preserving energy and safeguarding against accumulation of damaged and aggregated biomolecules. This graphic review gives a broad summary of autophagy and discusses examples where autophagy is important in controlling protein degradation. In addition we highlight how autophagy and mitophagy are involved in the cellular responses to reactive species and mitochondrial dysfunction. The key signaling pathways for mitophagy are described in the context of bioenergetic dysfunction.

  13. Ephemeral cellular segmentation in the thalamus of the neonatal rat.

    Science.gov (United States)

    Ivy, G O; Killackey, H P

    1981-08-01

    The distribution of thalamocortical relay cells in the rat ventrobasal complex was studied during the early postnatal period using the retrograde transport of horseradish peroxidase from the parietal cortex. It was found that the relay cells undergo marked changes in their distribution during the first two postnatal weeks. On postnatal days (PNDs) 0 and 1, the cells are rather homogeneously distributed throughout the ventrobasal complex. However, by PND 2, and more clearly by PND 3, the cells form a distinctly segmented pattern. This pattern consists of discrete curvilinear arrays of cells extending throughout most of the rostrocaudal extent of the nucleus. This distinct cellular pattern is present from PND 2 to about PND 8. In animals sacrificed on PND 15 or as adults, the pattern is no longer obvious. The cellular pattern seen at PND 8 was examined in the 3 standard planes of section and compared to both the somatotopic organization of the nucleus and to the organization of its major ascending and descending inputs. The developmental time course of the cellular segmentation was related to that of the lemniscal and corticothalamic afferents, which also show ephemeral segmentation patterns during the first two postnatal weeks. PMID:7272763

  14. Cellular chaperonin CCTγ contributes to rabies virus replication during infection.

    Science.gov (United States)

    Zhang, Jinyang; Wu, Xiaopeng; Zan, Jie; Wu, Yongping; Ye, Chengjin; Ruan, Xizhen; Zhou, Jiyong

    2013-07-01

    Rabies, as the oldest known infectious disease, remains a serious threat to public health worldwide. The eukaryotic cytosolic chaperonin TRiC/CCT complex facilitates the folding of proteins through ATP hydrolysis. Here, we investigated the expression, cellular localization, and function of neuronal CCTγ during neurotropic rabies virus (RABV) infection using mouse N2a cells as a model. Following RABV infection, 24 altered proteins were identified by using two-dimensional electrophoresis and mass spectrometry, including 20 upregulated proteins and 4 downregulated proteins. In mouse N2a cells infected with RABV or cotransfected with RABV genes encoding nucleoprotein (N) and phosphoprotein (P), confocal microscopy demonstrated that upregulated cellular CCTγ was colocalized with viral proteins N and P, which formed a hollow cricoid inclusion within the region around the nucleus. These inclusions, which correspond to Negri bodies (NBs), did not form in mouse N2a cells only expressing the viral protein N or P. Knockdown of CCTγ by lentivirus-mediated RNA interference led to significant inhibition of RABV replication. These results demonstrate that the complex consisting of viral proteins N and P recruits CCTγ to NBs and identify the chaperonin CCTγ as a host factor that facilitates intracellular RABV replication. This work illustrates how viruses can utilize cellular chaperonins and compartmentalization for their own benefit. PMID:23637400

  15. Coordination of plant mitochondrial biogenesis: keeping pace with cellular requirements.

    Directory of Open Access Journals (Sweden)

    Elina eWelchen

    2014-01-01

    Full Text Available Plant mitochondria are complex organelles that carry out numerous metabolic processes related with the generation of energy for cellular functions and the synthesis and degradation of several compounds. Mitochondria are semiautonomous and dynamic organelles changing in shape, number and composition depending on tissue or developmental stage. The biogenesis of functional mitochondria requires the coordination of genes present both in the nucleus and the organelle. In addition, due to their central role, all processes held inside mitochondria must be finely coordinated with those in other organelles according to cellular demands. Coordination is achieved by transcriptional control of nuclear genes encoding mitochondrial proteins by specific transcription factors that recognize conserved elements in their promoter regions. In turn, the expression of most of these transcription factors is linked to developmental and environmental cues, according to the availability of nutrients, light-dark cycles and warning signals generated in response to stress conditions. Among the signals impacting in the expression of nuclear genes, retrograde signals that originate inside mitochondria help to adjust mitochondrial biogenesis to organelle demands. Adding more complexity, several nuclear encoded proteins are dual localized to mitochondria and either chloroplasts or the nucleus. Dual targeting might establish a crosstalk between the nucleus and cell organelles to ensure a fine coordination of cellular activities. In this article, we discuss how the different levels of coordination of mitochondrial biogenesis interconnect to optimize the function of the organelle according to both internal and external demands.

  16. The cellular particle swarm optimization algorithm

    International Nuclear Information System (INIS)

    This work presents a variant of the Particle Swarm Optimization (PSO) original algorithm, the Cellular-PSO. Inspired by the cellular Genetic Algorithm (GA), particles in Cellular-PSO are arranged into a matrix of cells interconnected according to a given topology. Such topology defines particle's neighborhood, inside which social adaptation may occur. As a consequence, population diversity is increased and the optimization process becomes more efficient and robust. The proposed Cellular-PSO has been applied to the nuclear reactor core design optimization problem and comparative experiments demonstrated that it is superior to the standard PSO. (author)

  17. Optimized Cellular Core for Rotorcraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Patz Materials and Technologies proposes to develop a unique structural cellular core material to improve mechanical performance, reduce platform weight and lower...

  18. Illuminating cellular physiology: recent developments.

    Science.gov (United States)

    Brovko, Lubov Y; Griffiths, Mansel W

    2007-01-01

    Bioluminescent methods are gaining more and more attention among scientists due to their sensitivity, selectivity and simplicity; coupled with the fact that the bioluminescence can be monitored both in vitro and in vivo. Since the discovery of bioluminescence in the 19th century, enzymes involved in the bioluminescent process have been isolated and cloned. The bioluminescent reactions in several different organisms have also been fully characterized and used as reporters in a wide variety of biochemical assays. From the 1990s it became clear that bioluminescence can be detected and quantified directly from inside a living cell. This gave rise to numerous possibilities for the in vivo monitoring of intracellular processes non-invasively using bioluminescent molecules as reporters. This review describes recent developments in the area of bioluminescent imaging for cell biology. Newly developed imaging methods allow transcriptional/translational regulation, signal transduction, protein-protein interaction, oncogenic transformation, cell and protein trafficking, and target drug action to be monitored in vivo in real-time with high temporal and spatial resolution; thus providing researchers with priceless information on cellular functions. Advantages and limitations of these novel bioluminescent methods are discussed and possible future developments identified. PMID:17725230

  19. Methods for the Analysis of Protein Phosphorylation–Mediated Cellular Signaling Networks

    Science.gov (United States)

    White, Forest M.; Wolf-Yadlin, Alejandro

    2016-06-01

    Protein phosphorylation–mediated cellular signaling networks regulate almost all aspects of cell biology, including the responses to cellular stimulation and environmental alterations. These networks are highly complex and comprise hundreds of proteins and potentially thousands of phosphorylation sites. Multiple analytical methods have been developed over the past several decades to identify proteins and protein phosphorylation sites regulating cellular signaling, and to quantify the dynamic response of these sites to different cellular stimulation. Here we provide an overview of these methods, including the fundamental principles governing each method, their relative strengths and weaknesses, and some examples of how each method has been applied to the analysis of complex signaling networks. When applied correctly, each of these techniques can provide insight into the topology, dynamics, and regulation of protein phosphorylation signaling networks.

  20. Methods for the Analysis of Protein Phosphorylation-Mediated Cellular Signaling Networks.

    Science.gov (United States)

    White, Forest M; Wolf-Yadlin, Alejandro

    2016-06-12

    Protein phosphorylation-mediated cellular signaling networks regulate almost all aspects of cell biology, including the responses to cellular stimulation and environmental alterations. These networks are highly complex and comprise hundreds of proteins and potentially thousands of phosphorylation sites. Multiple analytical methods have been developed over the past several decades to identify proteins and protein phosphorylation sites regulating cellular signaling, and to quantify the dynamic response of these sites to different cellular stimulation. Here we provide an overview of these methods, including the fundamental principles governing each method, their relative strengths and weaknesses, and some examples of how each method has been applied to the analysis of complex signaling networks. When applied correctly, each of these techniques can provide insight into the topology, dynamics, and regulation of protein phosphorylation signaling networks. PMID:27049636

  1. Nanomechanics of Hierarchical Cellular Solids

    OpenAIRE

    Chen, Qiang

    2012-01-01

    Materials Science and Engineering, a young and vibrant discipline with its inception in the 1950s, has expanded into three directions: metals, polymers, and ceramics (and their mixtures, composites). Beyond the traditional scope, biological materials have drawn much attention since 1990s due to their optimal structures, which rise from hundreds of million years of evolution. Generally, biological materials are complex composites and possess varieties of hierarchical structures, multifunctiona...

  2. Modeling integrated cellular machinery using hybrid Petri-Boolean networks.

    Directory of Open Access Journals (Sweden)

    Natalie Berestovsky

    Full Text Available The behavior and phenotypic changes of cells are governed by a cellular circuitry that represents a set of biochemical reactions. Based on biological functions, this circuitry is divided into three types of networks, each encoding for a major biological process: signal transduction, transcription regulation, and metabolism. This division has generally enabled taming computational complexity dealing with the entire system, allowed for using modeling techniques that are specific to each of the components, and achieved separation of the different time scales at which reactions in each of the three networks occur. Nonetheless, with this division comes loss of information and power needed to elucidate certain cellular phenomena. Within the cell, these three types of networks work in tandem, and each produces signals and/or substances that are used by the others to process information and operate normally. Therefore, computational techniques for modeling integrated cellular machinery are needed. In this work, we propose an integrated hybrid model (IHM that combines Petri nets and Boolean networks to model integrated cellular networks. Coupled with a stochastic simulation mechanism, the model simulates the dynamics of the integrated network, and can be perturbed to generate testable hypotheses. Our model is qualitative and is mostly built upon knowledge from the literature and requires fine-tuning of very few parameters. We validated our model on two systems: the transcriptional regulation of glucose metabolism in human cells, and cellular osmoregulation in S. cerevisiae. The model produced results that are in very good agreement with experimental data, and produces valid hypotheses. The abstract nature of our model and the ease of its construction makes it a very good candidate for modeling integrated networks from qualitative data. The results it produces can guide the practitioner to zoom into components and interconnections and investigate them

  3. A sub-cellular viscoelastic model for cell population mechanics.

    Directory of Open Access Journals (Sweden)

    Yousef Jamali

    Full Text Available Understanding the biomechanical properties and the effect of biomechanical force on epithelial cells is key to understanding how epithelial cells form uniquely shaped structures in two or three-dimensional space. Nevertheless, with the limitations and challenges posed by biological experiments at this scale, it becomes advantageous to use mathematical and 'in silico' (computational models as an alternate solution. This paper introduces a single-cell-based model representing the cross section of a typical tissue. Each cell in this model is an individual unit containing several sub-cellular elements, such as the elastic plasma membrane, enclosed viscoelastic elements that play the role of cytoskeleton, and the viscoelastic elements of the cell nucleus. The cell membrane is divided into segments where each segment (or point incorporates the cell's interaction and communication with other cells and its environment. The model is capable of simulating how cells cooperate and contribute to the overall structure and function of a particular tissue; it mimics many aspects of cellular behavior such as cell growth, division, apoptosis and polarization. The model allows for investigation of the biomechanical properties of cells, cell-cell interactions, effect of environment on cellular clusters, and how individual cells work together and contribute to the structure and function of a particular tissue. To evaluate the current approach in modeling different topologies of growing tissues in distinct biochemical conditions of the surrounding media, we model several key cellular phenomena, namely monolayer cell culture, effects of adhesion intensity, growth of epithelial cell through interaction with extra-cellular matrix (ECM, effects of a gap in the ECM, tensegrity and tissue morphogenesis and formation of hollow epithelial acini. The proposed computational model enables one to isolate the effects of biomechanical properties of individual cells and the

  4. A Parallel Encryption Algorithm for Block Ciphers Based on Reversible Programmable Cellular Automata

    OpenAIRE

    Das, Debasis; Ray, Abhishek

    2010-01-01

    A Cellular Automata (CA) is a computing model of complex System using simple rule. In CA the problem space into number of cell and each cell can be one or several final state. Cells are affected by neighbours' to the simple rule. Cellular Automata are highly parallel and discrete dynamical systems, whose behaviour is completely specified in terms of a local relation. This paper deals with the Cellular Automata (CA) in cryptography for a class of Block Ciphers through a new block encryption al...

  5. Pulsed feedback defers cellular differentiation.

    Directory of Open Access Journals (Sweden)

    Joe H Levine

    2012-01-01

    Full Text Available Environmental signals induce diverse cellular differentiation programs. In certain systems, cells defer differentiation for extended time periods after the signal appears, proliferating through multiple rounds of cell division before committing to a new fate. How can cells set a deferral time much longer than the cell cycle? Here we study Bacillus subtilis cells that respond to sudden nutrient limitation with multiple rounds of growth and division before differentiating into spores. A well-characterized genetic circuit controls the concentration and phosphorylation of the master regulator Spo0A, which rises to a critical concentration to initiate sporulation. However, it remains unclear how this circuit enables cells to defer sporulation for multiple cell cycles. Using quantitative time-lapse fluorescence microscopy of Spo0A dynamics in individual cells, we observed pulses of Spo0A phosphorylation at a characteristic cell cycle phase. Pulse amplitudes grew systematically and cell-autonomously over multiple cell cycles leading up to sporulation. This pulse growth required a key positive feedback loop involving the sporulation kinases, without which the deferral of sporulation became ultrasensitive to kinase expression. Thus, deferral is controlled by a pulsed positive feedback loop in which kinase expression is activated by pulses of Spo0A phosphorylation. This pulsed positive feedback architecture provides a more robust mechanism for setting deferral times than constitutive kinase expression. Finally, using mathematical modeling, we show how pulsing and time delays together enable "polyphasic" positive feedback, in which different parts of a feedback loop are active at different times. Polyphasic feedback can enable more accurate tuning of long deferral times. Together, these results suggest that Bacillus subtilis uses a pulsed positive feedback loop to implement a "timer" that operates over timescales much longer than a cell cycle.

  6. Immune cellular response to HPV: current concepts

    Directory of Open Access Journals (Sweden)

    Maria Alice Guimarães Gonçalves

    2004-02-01

    Full Text Available Although cellular immunity is essential for the elimination of human papillomavirus (HPV, the mechanisms involved are still poorly understood. We summarize the main mechanisms involved in cellular immune response to infections caused by HPV. Immunotherapies for HPV-related cancers require the disruption of T-cell response control mechanisms, associated with the stimulation of the Th1 cytokine response.

  7. Mechanisms of cellular transformation by carcinogenic agents

    International Nuclear Information System (INIS)

    This book contains 14 chapters. Some of the chapter titles are: DNA Modification by Chemical Carcinogens; Role of DNA Lesions and Repair in the Transformation of Human Cells; The Induction and Regulation of Radiogenic Transformation In Vitro: Cellular and Molecular Mechanisms; Cellular Transformation by Adenoviruses; and The fos Gene

  8. Recent development of cellular manufacturing systems

    Indian Academy of Sciences (India)

    P K Arora; A Haleem; M K Singh

    2013-06-01

    Cellular manufacturing system has been proved a vital approach for batch and job shop production systems. Group technology has been an essential tool for developing a cellular manufacturing system. The paper aims to discuss various cell formation techniques and highlights the significant research work done in past over the years and attempts to points out the gap in research.

  9. Mechanisms of cellular transformation by carcinogenic agents

    Energy Technology Data Exchange (ETDEWEB)

    Grunberger, D.; Goff, S.P.

    1987-01-01

    This book contains 14 chapters. Some of the chapter titles are: DNA Modification by Chemical Carcinogens; Role of DNA Lesions and Repair in the Transformation of Human Cells; The Induction and Regulation of Radiogenic Transformation In Vitro: Cellular and Molecular Mechanisms; Cellular Transformation by Adenoviruses; and The fos Gene.

  10. LMS filters for cellular CDMA overlay

    OpenAIRE

    Wang, J.

    1996-01-01

    This paper extends and complements previous research we have performed on the performance of nonadaptive narrowband suppression filters when used in cellular CDMA overlay situations. In this paper, an adaptive LMS filter is applied to cellular CDMA overlay situations in order to reject narrowband interference.

  11. From Cnn Dynamics to Cellular Wave Computers

    Science.gov (United States)

    Roska, Tamas

    2013-01-01

    Embedded in a historical overview, the development of the Cellular Wave Computing paradigm is presented, starting from the standard CNN dynamics. The theoretical aspects, the physical implementation, the innovation process, as well as the biological relevance are discussed in details. Finally, the latest developments, the physical versus virtual cellular machines, as well as some open questions are presented.

  12. The Universe as a Cellular System

    CERN Document Server

    Aragón-Calvo, Miguel A

    2014-01-01

    Cellular systems are observed everywhere in nature, from crystal domains in metals, soap froth and cucumber cells to the network of cosmological voids. Surprisingly, despite their disparate scale and origin all cellular systems follow certain scaling laws relating their geometry, topology and dynamics. Using a cosmological N-body simulation we found that the Cosmic Web, the largest known cellular system, follows the same scaling relations seen elsewhere in nature. Our results extend the validity of scaling relations in cellular systems by over 30 orders of magnitude in scale with respect to previous studies. The dynamics of cellular systems can be used to interpret local observations such as the local velocity anomaly as the result of a collapsing void in our cosmic backyard. Moreover, scaling relations depend on the curvature of space, providing an independent measure of geometry.

  13. Complex Beauty

    OpenAIRE

    Franceschet, Massimo

    2014-01-01

    Complex systems and their underlying convoluted networks are ubiquitous, all we need is an eye for them. They pose problems of organized complexity which cannot be approached with a reductionist method. Complexity science and its emergent sister network science both come to grips with the inherent complexity of complex systems with an holistic strategy. The relevance of complexity, however, transcends the sciences. Complex systems and networks are the focal point of a philosophical, cultural ...

  14. Cellular Cations Control Conformational Switching of Inositol Pyrophosphate Analogues.

    Science.gov (United States)

    Hager, Anastasia; Wu, Mingxuan; Wang, Huanchen; Brown, Nathaniel W; Shears, Stephen B; Veiga, Nicolás; Fiedler, Dorothea

    2016-08-22

    The inositol pyrophosphate messengers (PP-InsPs) are emerging as an important class of cellular regulators. These molecules have been linked to numerous biological processes, including insulin secretion and cancer cell migration, but how they trigger such a wide range of cellular responses has remained unanswered in many cases. Here, we show that the PP-InsPs exhibit complex speciation behaviour and propose that a unique conformational switching mechanism could contribute to their multifunctional effects. We synthesised non-hydrolysable bisphosphonate analogues and crystallised the analogues in complex with mammalian PPIP5K2 kinase. Subsequently, the bisphosphonate analogues were used to investigate the protonation sequence, metal-coordination properties, and conformation in solution. Remarkably, the presence of potassium and magnesium ions enabled the analogues to adopt two different conformations near physiological pH. Understanding how the intrinsic chemical properties of the PP-InsPs can contribute to their complex signalling outputs will be essential to elucidate their regulatory functions. PMID:27460418

  15. Nanoparticle-cell interactions: molecular structure of the protein corona and cellular outcomes.

    Science.gov (United States)

    Fleischer, Candace C; Payne, Christine K

    2014-08-19

    The use of nanoparticles (NPs) in biology and medicine requires a molecular-level understanding of how NPs interact with cells in a physiological environment. A critical difference between well-controlled in vitro experiments and in vivo applications is the presence of a complex mixture of extracellular proteins. It has been established that extracellular serum proteins present in blood will adsorb onto the surface of NPs, forming a "protein corona". Our goal was to understand how this protein layer affected cellular-level events, including NP binding, internalization, and transport. A combination of microscopy, which provides spatial resolution, and spectroscopy, which provides molecular information, is necessary to probe protein-NP-cell interactions. Initial experiments used a model system composed of polystyrene NPs functionalized with either amine or carboxylate groups to provide a cationic or anionic surface, respectively. Serum proteins adsorb onto the surface of both cationic and anionic NPs, forming a net anionic protein-NP complex. Although these protein-NP complexes have similar diameters and effective surface charges, they show the exact opposite behavior in terms of cellular binding. In the presence of bovine serum albumin (BSA), the cellular binding of BSA-NP complexes formed from cationic NPs is enhanced, whereas the cellular binding of BSA-NP complexes formed from anionic NPs is inhibited. These trends are independent of NP diameter or cell type. Similar results were obtained for anionic quantum dots and colloidal gold nanospheres. Using competition assays, we determined that BSA-NP complexes formed from anionic NPs bind to albumin receptors on the cell surface. BSA-NP complexes formed from cationic NPs are redirected to scavenger receptors. The observation that similar NPs with identical protein corona compositions bind to different cellular receptors suggested that a difference in the structure of the adsorbed protein may be responsible for the

  16. Markers of cellular senescence. Telomere shortening as a marker of cellular senescence.

    Science.gov (United States)

    Bernadotte, Alexandra; Mikhelson, Victor M; Spivak, Irina M

    2016-01-01

    The cellular senescence definition comes to the fact of cells irreversible proliferation disability. Besides the cell cycle arrest, senescent cells go through some morphological, biochemical, and functional changes which are the signs of cellular senescence. The senescent cells (including replicative senescence and stress-induced premature senescence) of all the tissues look alike. They are metabolically active and possess the set of characteristics in vitro and in vivo, which are known as biomarkers of aging and cellular senescence. Among biomarkers of cellular senescence telomere shortening is a rather elegant frequently used biomarker. Validity of telomere shortening as a marker for cellular senescence is based on theoretical and experimental data. PMID:26805432

  17. Cellular interactions in the pathogenesis of interstitial lung diseases.

    Science.gov (United States)

    Bagnato, Gianluca; Harari, Sergio

    2015-03-01

    Interstitial lung disease (ILD) encompasses a large and diverse group of pathological conditions that share similar clinical, radiological and pathological manifestations, despite potentially having quite different aetiologies and comorbidities. Idiopathic pulmonary fibrosis (IPF) represents probably the most aggressive form of ILD and systemic sclerosis is a multiorgan fibrotic disease frequently associated with ILD. Although the aetiology of these disorders remains unknown, in this review we analyse the pathogenic mechanisms by cell of interest (fibroblast, fibrocyte, myofibroblast, endothelial and alveolar epithelial cells and immune competent cells). New insights into the complex cellular contributions and interactions will be provided, comparing the role of cell subsets in the pathogenesis of IPF and systemic sclerosis. PMID:25726561

  18. Two Novel Quantum-Dot Cellular Automata Full Adders

    Directory of Open Access Journals (Sweden)

    Mahdie Qanbari

    2013-01-01

    Full Text Available Quantum-dot cellular automata (QCA is an efficient technology to create computing devices. QCA is a suitable candidate for the next generation of digital systems. Full adders are the main member of computational systems because other operations can be implemented by adders. In this paper, two QCA full adders are introduced. The first one is implemented in one layer, and the second one is implemented in three layers. Five-input majority gate is used in both of them. These full adders are better than pervious designs in terms of area, delay, and complexity.

  19. HIV-1 Replication and the Cellular Eukaryotic Translation Apparatus

    Directory of Open Access Journals (Sweden)

    Santiago Guerrero

    2015-01-01

    Full Text Available Eukaryotic translation is a complex process composed of three main steps: initiation, elongation, and termination. During infections by RNA- and DNA-viruses, the eukaryotic translation machinery is used to assure optimal viral protein synthesis. Human immunodeficiency virus type I (HIV-1 uses several non-canonical pathways to translate its own proteins, such as leaky scanning, frameshifting, shunt, and cap-independent mechanisms. Moreover, HIV-1 modulates the host translation machinery by targeting key translation factors and overcomes different cellular obstacles that affect protein translation. In this review, we describe how HIV-1 proteins target several components of the eukaryotic translation machinery, which consequently improves viral translation and replication.

  20. HIV-1 replication and the cellular eukaryotic translation apparatus.

    Science.gov (United States)

    Guerrero, Santiago; Batisse, Julien; Libre, Camille; Bernacchi, Serena; Marquet, Roland; Paillart, Jean-Christophe

    2015-01-01

    Eukaryotic translation is a complex process composed of three main steps: initiation, elongation, and termination. During infections by RNA- and DNA-viruses, the eukaryotic translation machinery is used to assure optimal viral protein synthesis. Human immunodeficiency virus type I (HIV-1) uses several non-canonical pathways to translate its own proteins, such as leaky scanning, frameshifting, shunt, and cap-independent mechanisms. Moreover, HIV-1 modulates the host translation machinery by targeting key translation factors and overcomes different cellular obstacles that affect protein translation. In this review, we describe how HIV-1 proteins target several components of the eukaryotic translation machinery, which consequently improves viral translation and replication. PMID:25606970

  1. Chaotic phenomena in Josephson circuits coupled quantum cellular neural networks

    Institute of Scientific and Technical Information of China (English)

    Wang Sen; Cai Li; Li Qin; Wu Gang

    2007-01-01

    In this paper the nonlinear dynamical behaviour of a quantum cellular neural network (QCNN) by coupling Josephson circuits was investigated and it was shown that the QCNN using only two of them can cause the onset of chaotic oscillation. The theoretical analysis and simulation for the two Josephson-circuits-coupled QCNN have been done by using the amplitude and phase as state variables. The complex chaotic behaviours can be observed and then proved by calculating Lyapunov exponents. The study provides valuable information about QCNNs for future application in high-parallel signal processing and novel chaotic generators.

  2. The Flagellum Attachment Zone: 'The Cellular Ruler' of Trypanosome Morphology.

    Science.gov (United States)

    Sunter, Jack D; Gull, Keith

    2016-04-01

    A defining feature of Trypanosoma brucei cell shape is the lateral attachment of the flagellum to the cell body, mediated by the flagellum attachment zone (FAZ). The FAZ is a complex cytoskeletal structure that connects the flagellum skeleton through two membranes to the cytoskeleton. The FAZ acts as a 'cellular ruler' of morphology by regulating cell length and organelle position and is therefore critical for both cell division and life cycle differentiations. Here we provide an overview of the advances in our understanding of the composition, assembly, and function of the FAZ. PMID:26776656

  3. Estimating cellular network performance during hurricanes

    International Nuclear Information System (INIS)

    Cellular networks serve a critical role during and immediately after a hurricane, allowing citizens to contact emergency services when land-line communication is lost and serving as a backup communication channel for emergency responders. However, due to their ubiquitous deployment and limited design for extreme loading events, basic network elements, such as cellular towers and antennas are prone to failures during adverse weather conditions such as hurricanes. Accordingly, a systematic and computationally feasible approach is required for assessing and improving the reliability of cellular networks during hurricanes. In this paper we develop a new multi-disciplinary approach to efficiently and accurately assess cellular network reliability during hurricanes. We show how the performance of a cellular network during and immediately after future hurricanes can be estimated based on a combination of hurricane wind field models, structural reliability analysis, Monte Carlo simulation, and cellular network models and simulation tools. We then demonstrate the use of this approach for assessing the improvement in system reliability that can be achieved with discrete topological changes in the system. Our results suggest that adding redundancy, particularly through a mesh topology or through the addition of an optical fiber ring around the perimeter of the system can be an effective way to significantly increase the reliability of some cellular systems during hurricanes.

  4. Cellular Microbiology of Mycoplasma canis.

    Science.gov (United States)

    Michaels, Dina L; Leibowitz, Jeffrey A; Azaiza, Mohammed T; Shil, Pollob K; Shama, Suzanne M; Kutish, Gerald F; Distelhorst, Steven L; Balish, Mitchell F; May, Meghan A; Brown, Daniel R

    2016-06-01

    Mycoplasma canis can infect many mammalian hosts but is best known as a commensal or opportunistic pathogen of dogs. The unexpected presence of M. canis in brains of dogs with idiopathic meningoencephalitis prompted new in vitro studies to help fill the void of basic knowledge about the organism's candidate virulence factors, the host responses that it elicits, and its potential roles in pathogenesis. Secretion of reactive oxygen species and sialidase varied quantitatively (P < 0.01) among strains of M. canis isolated from canine brain tissue or mucosal surfaces. All strains colonized the surface of canine MDCK epithelial and DH82 histiocyte cells and murine C8-D1A astrocytes. Transit through MDCK and DH82 cells was demonstrated by gentamicin protection assays and three-dimensional immunofluorescence imaging. Strains further varied (P < 0.01) in the extents to which they influenced the secretion of tumor necrosis factor alpha (TNF-α) and the neuroendocrine regulatory peptide endothelin-1 by DH82 cells. Inoculation with M. canis also decreased major histocompatibility complex class II (MHC-II) antigen expression by DH82 cells (P < 0.01), while secretion of gamma interferon (IFN-γ), interleukin-6 (IL-6), interleukin-10 (IL-10), and complement factor H was unaffected. The basis for differences in the responses elicited by these strains was not obvious in their genome sequences. No acute cytopathic effects on any homogeneous cell line, or consistent patterns of M. canis polyvalent antigen distribution in canine meningoencephalitis case brain tissues, were apparent. Thus, while it is not likely a primary neuropathogen, M. canis has the capacity to influence meningoencephalitis through complex interactions within the multicellular and neurochemical in vivo milieu. PMID:27045036

  5. Macromolecular lesions and cellular radiation chemistry

    International Nuclear Information System (INIS)

    Our studies of the interaction of densely ionizing particles with macromolecules in the living cell may be divided into four parts: characterization of lesions to cellular DNA in the unmodified Bragg ionization curve; characterization of lesions to cellular DNA in the spread Bragg curve as used in radiation therapy; elucidation of the cellular radiation chemistry characteristic of high vs. low LET radiation qualities; and the introduction of novel techniques designed to give a better understanding of the fundamental properties of induction of lesions and their repair potentials in high LET radiation

  6. Cellular and molecular mechanisms in kidney fibrosis

    Science.gov (United States)

    Duffield, Jeremy S.

    2014-01-01

    Fibrosis is a characteristic feature of all forms of chronic kidney disease. Deposition of pathological matrix in the interstitial space and within the walls of glomerular capillaries as well as the cellular processes resulting in this deposition are increasingly recognized as important factors amplifying kidney injury and accelerating nephron demise. Recent insights into the cellular and molecular mechanisms of fibrogenesis herald the promise of new therapies to slow kidney disease progression. This review focuses on new findings that enhance understanding of cellular and molecular mechanisms of fibrosis, the characteristics of myofibroblasts, their progenitors, and molecular pathways regulating both fibrogenesis and its resolution. PMID:24892703

  7. Nanomechanics of magnetically driven cellular endocytosis

    Science.gov (United States)

    Zablotskii, V.; Lunov, O.; Dejneka, A.; Jastrabík, L.; Polyakova, T.; Syrovets, T.; Simmet, Th.

    2011-10-01

    Being essential for many pharmacodynamic and pharmacokinetic processes and playing a crucial role in regulating substrate detachment that enables cellular locomotion, endocytotic mechanisms in many aspects still remain a mystery and therefore can hardly be controlled. Here, we report on experimental and modeling studies of the magnetically assisted endocytosis of functionalized superparamagnetic iron oxide nanoparticles by prostate cancer cells (PC-3) and characterize the time and force scales of the cellular uptake machinery. The results indicate how the cellular uptake rate could be controlled by applied magnetic field, membrane elasticity, and nanoparticle magnetic moment.

  8. Cellular Signaling Pathways and Their Clinical Reflections

    Directory of Open Access Journals (Sweden)

    N. Ceren Sumer-Turanligil

    2010-06-01

    Full Text Available Cellular signaling pathways have important roles in cellular growth, differentiation, inflammatory response and apoptosis and in regulation of cellular responses under various chemical stimulators. Different proteins which belong to these pathways may be exposed to loss-of-function or gain-of-function mutations; this may lead to many clinical phenotypes including primarily cancer. In this review information about basic working principles of these pathways and diseases related to them are included. [Archives Medical Review Journal 2010; 19(3.000: 180-191

  9. Imaging in cellular and tissue engineering

    CERN Document Server

    Yu, Hanry

    2013-01-01

    Details on specific imaging modalities for different cellular and tissue engineering applications are scattered throughout articles and chapters in the literature. Gathering this information into a single reference, Imaging in Cellular and Tissue Engineering presents both the fundamentals and state of the art in imaging methods, approaches, and applications in regenerative medicine. The book underscores the broadening scope of imaging applications in cellular and tissue engineering. It covers a wide range of optical and biological applications, including the repair or replacement of whole tiss

  10. Cellular Cell Bifurcation of Cylindrical Detonations

    Institute of Scientific and Technical Information of China (English)

    HAN Gui-Lai; JIANG Zong-Lin; WANG Chun; ZHANG Fan

    2008-01-01

    Cellular cell pattern evolution of cylindrically-diverging detonations is numerically simulated successfully by solving two-dimensional Euler equations implemented with an improved two-step chemical kinetic model. From the simulation, three cell bifurcation modes are observed during the evolution and referred to as concave front focusing, kinked and wrinkled wave front instability, and self-merging of cellular cells. Numerical research demonstrates that the wave front expansion resulted from detonation front diverging plays a major role in the cellular cell bifurcation, which can disturb the nonlinearly self-sustained mechanism of detonations and finally lead to cell bifurcations.

  11. Cellular chain formation in Escherichia coli biofilms

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk; Klemm, Per

    2009-01-01

    In this study we report on a novel structural phenotype in Escherichia coli biofilms: cellular chain formation. Biofilm chaining in E. coli K-12 was found to occur primarily by clonal expansion, but was not due to filamentous growth. Rather, chain formation was the result of intercellular......; type I fimbriae expression significantly reduced cellular chain formation, presumably by steric hindrance. Cellular chain formation did not appear to be specific to E coli K-12. Although many urinary tract infection (UTI) isolates were found to form rather homogeneous, flat biofilms, three isolates...

  12. Interworking of Wireless LANs and Cellular Networks

    CERN Document Server

    Song, Wei

    2012-01-01

    The next-generation of wireless communications are envisioned to be supported by heterogeneous networks by using various wireless access technologies. The popular cellular networks and wireless local area networks (WLANs) present perfectly complementary characteristics in terms of service capacity, mobility support, and quality-of-service (QoS) provisioning. The cellular/WLAN interworking is an effective way to promote the evolution of wireless networks. "Interworking of Wireless LANs and Cellular Networks" focuses on three aspects, namely access selection, call admission control and

  13. Biological Augmentation of Flexor Tendon Repair: A Challenging Cellular Landscape.

    Science.gov (United States)

    Loiselle, Alayna E; Kelly, Meghan; Hammert, Warren C

    2016-01-01

    Advances in surgical technique and rehabilitation have transformed zone II flexor tendon injuries from an inoperable no-man's land to a standard surgical procedure. Despite these advances, many patients develop substantial range of motion-limiting adhesions after primary flexor tendon repair. These suboptimal outcomes may benefit from biologic augmentation or intervention during the flexor tendon healing process. However, there is no consensus biological approach to promote satisfactory flexor tendon healing; we propose that insufficient understanding of the complex cellular milieu in the healing tendon has hindered the development of successful therapies. This article reviews recent advances in our understanding of the cellular components of flexor tendon healing and adhesion formation, including resident tendon cells, synovial sheath, macrophages, and bone marrow-derived cells. In addition, it examines molecular approaches that have been used in translational animal models to improve flexor tendon healing and gliding function, with a specific focus on progress made using murine models of healing. This information highlights the importance of understanding and potentially exploiting the heterogeneity of the cellular environment during flexor tendon healing, to define rational therapeutic approaches to improve healing outcomes. PMID:26652792

  14. A cellular automata evacuation model considering friction and repulsion

    Institute of Scientific and Technical Information of China (English)

    SONG Weiguo; YU Yanfei; FAN Weicheng; Zhang Heping

    2005-01-01

    There exist interactions among pedestrians and between pedestrian and environment in evacuation. These interactions include attraction, repulsion and friction that play key roles in human evacuation behaviors, speed and efficiency. Most former evacuation models focus on the attraction force, while repulsion and friction are not well modeled. As a kind of multi-particle self-driven model, the social force model introduced in recent years can represent those three forces but with low simulation efficiency because it is a continuous model with complex rules. Discrete models such as the cellular automata model and the lattice gas model have simple rules and high simulation efficiency, but are not quite suitable for interactions' simulation. In this paper, a new cellular automata model based on traditional models is introduced in which repulsion and friction are modeled quantitatively. It is indicated that the model can simulate some basic behaviors, e.g.arching and the "faster-is-slower" phenomenon, in evacuation as multi-particle self-driven models, but with high efficiency as the normal cellular automata model and the lattice gas model.

  15. Using RNA as Molecular Code for Programming Cellular Function.

    Science.gov (United States)

    Kushwaha, Manish; Rostain, William; Prakash, Satya; Duncan, John N; Jaramillo, Alfonso

    2016-08-19

    RNA is involved in a wide-range of important molecular processes in the cell, serving diverse functions: regulatory, enzymatic, and structural. Together with its ease and predictability of design, these properties can lead RNA to become a useful handle for biological engineers with which to control the cellular machinery. By modifying the many RNA links in cellular processes, it is possible to reprogram cells toward specific design goals. We propose that RNA can be viewed as a molecular programming language that, together with protein-based execution platforms, can be used to rewrite wide ranging aspects of cellular function. In this review, we catalogue developments in the use of RNA parts, methods, and associated computational models that have contributed to the programmability of biology. We discuss how RNA part repertoires have been combined to build complex genetic circuits, and review recent applications of RNA-based parts and circuitry. We explore the future potential of RNA engineering and posit that RNA programmability is an important resource for firmly establishing an era of rationally designed synthetic biology. PMID:26999422

  16. Complex chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bong Gon; Kim, Jae Sang; Kim, Jin Eun; Lee, Boo Yeon

    2006-06-15

    This book introduces complex chemistry with ten chapters, which include development of complex chemistry on history coordination theory and Warner's coordination theory and new development of complex chemistry, nomenclature on complex with conception and define, chemical formula on coordination compound, symbol of stereochemistry, stereo structure and isomerism, electron structure and bond theory on complex, structure of complex like NMR and XAFS, balance and reaction on solution, an organo-metallic chemistry, biology inorganic chemistry, material chemistry of complex, design of complex and calculation chemistry.

  17. Complex chemistry

    International Nuclear Information System (INIS)

    This book introduces complex chemistry with ten chapters, which include development of complex chemistry on history coordination theory and Warner's coordination theory and new development of complex chemistry, nomenclature on complex with conception and define, chemical formula on coordination compound, symbol of stereochemistry, stereo structure and isomerism, electron structure and bond theory on complex, structure of complex like NMR and XAFS, balance and reaction on solution, an organo-metallic chemistry, biology inorganic chemistry, material chemistry of complex, design of complex and calculation chemistry.

  18. Study of complexation between two 1,3-alternate calix[4]crown derivatives and alkali metal ions by electrospray ionization mass spectrometry and density functional theory calculations

    Science.gov (United States)

    Shamsipur, Mojtaba; Allahyari, Leila; Fasihi, Javad; Taherpour, Avat (Arman); Asfari, Zuhair; Valinejad, Azizollah

    2016-03-01

    Complexation of two 1,3-alternate calix[4]crown ligands with alkali metals (K+, Rb+ and Cs+) has been investigated by electrospray ionization mass spectrometry (ESI-MS) and density functional theory calculations. The binding selectivities of the ligands and the binding constants of their complexes in solution have been determined using the obtained mass spectra. Also the percentage of each formed complex species in the mixture of each ligand and alkali metal has been experimentally evaluated. For both calix[4]crown-5 and calix[4]crown-6 ligands the experimental and theoretical selectivity of their alkali metal complexes found to follow the trend K+ > Rb+ > Cs+. The structures of ligands were optimized by DFT-B3LYP/6-31G method and the structures of complexes were obtained by QM-SCF-MO/PM6 method and discussed in the text.

  19. The role of sirtuins in cellular homeostasis.

    Science.gov (United States)

    Kupis, Wioleta; Pałyga, Jan; Tomal, Ewa; Niewiadomska, Ewa

    2016-09-01

    Sirtuins are evolutionarily conserved nicotinamide adenine dinucleotide (NAD(+))-dependent lysine deacylases or ADP-ribosyltransferases. These cellular enzymes are metabolic sensors sensitive to NAD(+) levels that maintain physiological homeostasis in the animal and plant cells. PMID:27154583

  20. Optimized Cellular Core for Rotorcraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Patz Materials and Technologies has developed, produced and tested, as part of the Phase-I SBIR, a new form of composite cellular core material, named Interply...

  1. MILLIMETER-WAVE EMISSIVITY OF CELLULAR SYSTEMS

    Science.gov (United States)

    A general analysis has been presented of the millimeter-wave and farinfrared spectroscopic properties of in vivo cellular systems, and of the boson radiative equilibrium with steady-state nonequilibrium molecular systems. The frequency threshhold of spectroscopic properties assoc...

  2. A Matrix Construction of Cellular Algebras

    Institute of Scientific and Technical Information of China (English)

    Dajing Xiang

    2005-01-01

    In this paper, we give a concrete method to construct cellular algebras from matrix algebras by specifying certain fixed matrices for the data of inflations. In particular,orthogonal matrices can be chosen for such data.

  3. Probing Cellular Dynamics with Mesoscopic Simulations

    DEFF Research Database (Denmark)

    Shillcock, Julian C.

    2010-01-01

    Cellular processes span a huge range of length and time scales from the molecular to the near-macroscopic. Understanding how effects on one scale influence, and are themselves influenced by, those on lower and higher scales is a critical issue for the construction of models in Systems Biology....... Advances in computing hardware and software now allow explicit simulation of some aspects of cellular dynamics close to the molecular scale. Vesicle fusion is one example of such a process. Experiments, however, typically probe cellular behavior from the molecular scale up to microns. Standard particle...... soon be coupled to Mass Action models allowing the parameters in such models to be continuously tuned according to the finer resolution simulation. This will help realize the goal of a computational cellular simulation that is able to capture the dynamics of membrane-associated processes such as...

  4. Vectorized multisite coding for hydrodynamic cellular automata

    International Nuclear Information System (INIS)

    Simulating eight lattices for Pomeau's cellular automata simultaneously through bit-per-bit operations, a vectorized Fortran program reached 30 million updates per second and per Cray YMP processor. They authors give the full innermost loops

  5. 47 CFR 22.911 - Cellular geographic service area.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Cellular geographic service area. 22.911... PUBLIC MOBILE SERVICES Cellular Radiotelephone Service § 22.911 Cellular geographic service area. The Cellular Geographic Service Area (CGSA) of a cellular system is the geographic area considered by the...

  6. Study and Simulation of Traffic Behavior in Cellular Network

    Science.gov (United States)

    Madhup, D. K.; Shrestha, C. L.; Sharma, R. K.

    2007-07-01

    Cellular radio systems accommodate a large number of users with a limited radio spectrum. The concept of trunking allows a large number of users to share the relatively small number of channels in a cell by providing access to each user, on demand, from a pool of available channels. Traffic engineering deals with provisioning of communication circuits in a given area for a number of subscribers with a required grade of service. Traffic in any cell depends upon the number of users, the average request rate and average call duration. Certain number of channels is required for the required GOS. To design an optimum capacity cellular system, traffic behavior on that system is important. The number of channel required can be estimated by using Erlang formula and Erlang table. Erlang table is not always useful to calculate the probability of blocking in various complex scenarios such as channel borrowing strategies. When the total number of channel available in a given cell are divided to serve partly for newly generated calls and partly for handover calls, and if they use dynamic channel assignment strategies like channel borrowing, then the probability of blocking can't be calculated from Erlang table. Simulation model of the behavior help us to determine the blocking and the channel utilization while using various channel assignment strategies. The title "Study and Simulation of Traffic Behavior in Cellular Network" entail the study of the blocking probability of traffic in cellular network for static channel assignment strategies and dynamic channel borrowing strategies through MATLAB programming language and graphic user interface (GUI). The result shows that the dynamic scheme can perform better than static maximizing the overall utilization of the circuits and minimizing the overall blocking.

  7. Cellular Restriction Factors of Feline Immunodeficiency Virus

    OpenAIRE

    Carsten Münk; Jörg Zielonka

    2011-01-01

    Lentiviruses are known for their narrow cell- and species-tropisms, which are determined by cellular proteins whose absence or presence either support viral replication (dependency factors, cofactors) or inhibit viral replication (restriction factors). Similar to Human immunodeficiency virus type 1 (HIV-1), the cat lentivirus Feline immunodeficiency virus (FIV) is sensitive to recently discovered cellular restriction factors from non-host species that are able to stop viruses from replicating...

  8. Cellular and molecular mechanisms in kidney fibrosis

    OpenAIRE

    Duffield, Jeremy S.

    2014-01-01

    Fibrosis is a characteristic feature of all forms of chronic kidney disease. Deposition of pathological matrix in the interstitial space and within the walls of glomerular capillaries as well as the cellular processes resulting in this deposition are increasingly recognized as important factors amplifying kidney injury and accelerating nephron demise. Recent insights into the cellular and molecular mechanisms of fibrogenesis herald the promise of new therapies to slow kidney disease progressi...

  9. Building mathematics cellular phone learning communities

    OpenAIRE

    Wajeeh M. Daher

    2011-01-01

    Researchers emphasize the importance of maintaining learning communities and environments. This article describes the building and nourishment of a learning community, one comprised of middle school students who learned mathematics out-of-class using the cellular phone. The building of the learning community was led by three third year pre-service teachers majoring in mathematics and computers. The pre-service teachers selected thirty 8th grade students to learn mathematics with the cellular ...

  10. Directed Percolation arising in Stochastic Cellular Automata

    OpenAIRE

    Regnault, Damien

    2008-01-01

    Cellular automata are both seen as a model of computation and as tools to model real life systems. Historically they were studied under synchronous dynamics where all the cells of the system are updated at each time step. Meanwhile the question of probabilistic dynamics emerges: on the one hand, to develop cellular automata which are capable of reliable computation even when some random errors occur; on the other hand, because synchronous dynamics is not a reasonable assumption to simulate re...

  11. Apoptotic regulation of epithelial cellular extrusion

    OpenAIRE

    De Andrade, Daniel,; Rosenblatt, Jody

    2011-01-01

    Cellular extrusion is a mechanism that removes dying cells from epithelial tissues to prevent compromising their barrier function. Extrusion occurs in all observed epithelia in vivo and can be modeled in vitro by inducing apoptosis in cultured epithelial monolayers. We established that actin and myosin form a ring that contracts in the surrounding cells that drives cellular extrusion. It is not clear, however, if all apoptotic pathways lead to extrusion and how apoptosis and extrusion are mol...

  12. Understanding cisplatin resistance using cellular models.

    OpenAIRE

    STORDAL, BRITTA KRISTINA

    2007-01-01

    PUBLISHED Many mechanisms of cisplatin resistance have been proposed from studies of cellular models of resistance including changes in cellular drug accumulation, detoxification of the drug, inhibition of apoptosis and repair of the DNA adducts. A series of resistant models were developed from CCRF-CEM leukaemia cells with increasing doses of cisplatin from 100 ng/ml. This produced increasing resistance up to 7-fold with a treatment dose of 1.6 ?g/ml. Cisplatin resistance i...

  13. Understanding cisplatin resistance using cellular models

    OpenAIRE

    Stordal, Britta; Davey, Mary

    2007-01-01

    Many mechanisms of cisplatin resistance have been proposed from studies of cellular models of resistance including changes in cellular drug accumulation, detoxification of the drug, inhibition of apoptosis and repair of the DNA adducts. A series of resistant models were developed from CCRF-CEM leukaemia cells with increasing doses of cisplatin from 100 ng/ml. This produced increasing resistance up to 7-fold with a treatment dose of 1.6 microg/ml. Cisplatin resistance in these cells correlated...

  14. Cellular Hyperproliferation and Cancer as Evolutionary Variables

    OpenAIRE

    Alvarado, Alejandro Sánchez

    2012-01-01

    Technological advances in biology have begun to dramatically change the way we think about evolution, development, health and disease. The ability to sequence the genomes of many individuals within a population, and across multiple species, has opened the door to the possibility of answering some long-standing and perplexing questions about our own genetic heritage. One such question revolves around the nature of cellular hyperproliferation. This cellular behavior is used to effect wound heal...

  15. Cellular Scaling Rules of Insectivore Brains

    OpenAIRE

    Sarko, Diana K.; Catania, Kenneth C.; Leitch, Duncan B.; Kaas, Jon H.; Herculano-Houzel, Suzana

    2009-01-01

    Insectivores represent extremes in mammalian body size and brain size, retaining various “primitive” morphological characteristics, and some species of Insectivora are thought to share similarities with small-bodied ancestral eutherians. This raises the possibility that insectivore brains differ from other taxa, including rodents and primates, in cellular scaling properties. Here we examine the cellular scaling rules for insectivore brains and demonstrate that insectivore scaling rules overla...

  16. Cellular scaling rules of insectivore brains

    OpenAIRE

    Sarko, Diana K.; Catania, Kenneth C.; Leitch, Duncan B.; Kaas, Jon H.; Suzana Herculano-Houzel

    2009-01-01

    Insectivores represent extremes in mammalian body size and brain size, retaining various “primitive” morphological characteristics, and some species of Insectivora are thought to share similarities with small-bodied ancestral eutherians. This raises the possibility that insectivore brains differ from other taxa, including rodents and primates, in cellular scaling properties. Here we examine the cellular scaling rules for insectivore brains and demonstrate that insectivore scaling ...

  17. Cellular scaling rules for primate brains

    OpenAIRE

    Herculano-Houzel, Suzana; Collins, Christine E.; Wong, Peiyan; Kaas, Jon H.

    2007-01-01

    Primates are usually found to have richer behavioral repertoires and better cognitive abilities than rodents of similar brain size. This finding raises the possibility that primate brains differ from rodent brains in their cellular composition. Here we examine the cellular scaling rules for primate brains and show that brain size increases approximately isometrically as a function of cell numbers, such that an 11× larger brain is built with 10× more neurons and ≈12× more nonneuronal cells of ...

  18. Stochastic Simulations on the Cellular Wave Computers

    OpenAIRE

    Ercsey-Ravasz, M.; Roska, T.; Néda, Z.

    2006-01-01

    The computational paradigm represented by Cellular Neural/nonlinear Networks (CNN) and the CNN Universal Machine (CNN-UM) as a Cellular Wave Computer, gives new perspectives for computational physics. Many numerical problems and simulations can be elegantly addressed on this fully parallelized and analogic architecture. Here we study the possibility of performing stochastic simulations on this chip. First a realistic random number generator is implemented on the CNN-UM, and then as an example...

  19. Weighted Centroid Correction Localization in Cellular Systems

    Directory of Open Access Journals (Sweden)

    Rong-Zheng Li

    2011-01-01

    Full Text Available Problem statement: There is a large demand for wireless Location-Based Service (LBS and it is provided by many wireless cellular systems. In process of positioning a Mobile Station (MS, the computing speed is as important as the positioning accuracy and the algorithm should also be resistant to environmental influences. Approach: A new positioning method based on Weighted Centroid Correction Localization (WCCL for wireless cellular systems is introduced in this article. Firstly, referring to the receiving-state of an MS in cellular systems, it computes a weighted centroid of surrounding Base Stations (BSs as a rough approximate position of the MS. Then, according to the distances between the MS and the BSs being less or bigger than the computed distances between the BSs and the weighted centroid, it corrects the coordinate of the weighted centroid towards the directions of the BSs by moving it closer or farther in turn. Results: According to our experiments, WCCL improves the positioning accuracy, as well as to provide a better resistance to environmental influences. Conclusion: As a modified centroid-based localization algorithm, WCCL obtains weighting factors from the receiving-state of MS in multi-cells structured cellular systems and obtains a better positioning result in cellular systems without updating the network equipment. Therefore, for the cellular positioning problem, WCCL algorithm can be an alternate solution.

  20. Role of XPD in cellular functions: To TFIIH and beyond.

    Science.gov (United States)

    Houten, Bennett Van; Kuper, Jochen; Kisker, Caroline

    2016-08-01

    XPD, as part of the TFIIH complex, has classically been linked to the damage verification step of nucleotide excision repair (NER). However, recent data indicate that XPD, due to its iron-sulfur center interacts with the iron sulfur cluster assembly proteins, and may interact with other proteins in the cell to mediate a diverse set of biological functions including cell cycle regulation, mitosis, and mitochondrial function. In this perspective, after first reviewing the function and some of the key disease causing variants that affect XPD's interaction with TFIIH and the CDK-activating kinase complex (CAK), we investigate these intriguing cellular roles of XPD and highlight important unanswered questions that provide a fertile ground for further scientific exploration. PMID:27262611

  1. Relação da expressão de fatores de crescimento celular (IGF-1 e (SCF com fatores prognósticos e o alvo da rapamicina em mamíferos (m-TOR em mastocitomas cutâneos caninos

    Directory of Open Access Journals (Sweden)

    Raquel B. Ferioli

    2013-04-01

    Full Text Available O mastocitoma cutâneo (MTC é a neoplasia maligna mais comum na pele dos cães e seu comportamento biológico é muito variável. Dentre os fatores prognósticos estudados nos MTCs, a classificação histopatológica, o índice proliferativo e o padrão de expressão doc-KIT são os que apresentam uma associação mais relevante com o provável prognóstico deste tumor. O objetivo deste trabalho foi avaliar a expressão proteica de fator de crescimento semelhante à insulina tipo 1 (IGF-1, fator de célula tronco (SCF e sua relação com o receptor tirosina quinase (c-KIT, alvo da rapamicina em mamíferos (m-TOR, grau histológico, índice proliferativo pelo KI-67e o número de figuras de mitose (IM com dados clínicos de cães com MTCs . Foram utilizadas 133 amostras de MTCs, provenientes de 133 cães, dispostas em lâminas de microarranjo de tecidos (TMA. A técnica de imuno-histoquímica foi utilizada para a avaliação destas proteínas. Observou-se associação entre SCF e, a graduação histopatológica proposta em 2011, índice mitótico, proliferação celular (KI-67, escore de IGF-1, local da lesão, idade dos animais e padrão imuno-histoquímico do receptor c-KIT. A relação de dependência também foi observada entre IGF-1 e o porte dos animais, IM, m-TOR e c-KIT. A expressão de SCF teve relacção com a agressividade dos MTCs caninos, uma vez que foi mais freqüente em MTCs com c-KIT citoplasmático. A relação entre a expressão de IGF-1, SCF, c-KIT e m-TOR pode estar associada à integralização de suas vias de ação. A expressão de IGF-1 está associada à MTCs em cães de porte grande.

  2. Structural Basis of Cargo Recognition by Unconventional Myosins in Cellular Trafficking.

    Science.gov (United States)

    Li, Jianchao; Lu, Qing; Zhang, Mingjie

    2016-08-01

    Unconventional myosins are a superfamily of actin-based molecular motors playing diverse roles including cellular trafficking, mechanical supports, force sensing and transmission, etc. The variable neck and tail domains of unconventional myosins function to bind to specific cargoes including proteins and lipid vesicles and thus are largely responsible for the diverse cellular functions of myosins in vivo. In addition, the tail regions, together with their cognate cargoes, can regulate activities of the motor heads. This review outlines the advances made in recent years on cargo recognition and cargo binding-induced regulation of the activity of several unconventional myosins including myosin-I, V, VI and X in cellular trafficking. We approach this topic by describing a series of high-resolution structures of the neck and tail domains of these unconventional myosins either alone or in complex with their specific cargoes, and by discussing potential implications of these structural studies on cellular trafficking of these myosin motors. PMID:26842936

  3. 47 CFR 22.970 - Unacceptable interference to part 90 non-cellular 800 MHz licensees from cellular radiotelephone...

    Science.gov (United States)

    2010-10-01

    .... Except as provided in 47 CFR 90.617(k), unacceptable interference to non-cellular part 90 licensees in...-cellular 800 MHz licensees from cellular radiotelephone or part 90-800 MHz cellular systems. 22.970 Section... MOBILE SERVICES Cellular Radiotelephone Service § 22.970 Unacceptable interference to part 90...

  4. Cellular Recycling of Proteins in Seed Dormancy Alleviation and Germination.

    Science.gov (United States)

    Oracz, Krystyna; Stawska, Marlena

    2016-01-01

    Each step of the seed-to-seed cycle of plant development including seed germination is characterized by a specific set of proteins. The continual renewal and/or replacement of these biomolecules are crucial for optimal plant adaptation. As proteins are the main effectors inside the cells, their levels need to be tightly regulated. This is partially achieved by specific proteolytic pathways via multicatalytic protease complexes defined as 20S and 26S proteasomes. In plants, the 20S proteasome is responsible for degradation of carbonylated proteins, while the 26S being a part of ubiquitin-proteasome pathway is known to be involved in proteolysis of phytohormone signaling regulators. On the other hand, the role of translational control of plant development is also well-documented, especially in the context of pollen tube growth and light signaling. Despite the current progress that has been made in seed biology, the sequence of cellular events that determine if the seed can germinate or not are still far from complete understanding. The role and mechanisms of regulation of proteome composition during processes occurring in the plant's photosynthetic tissues have been well-characterized since many years, but in non-photosynthetic seeds it has emerged as a tempting research task only since the last decade. This review discusses the recent discoveries providing insights into the role of protein turnover in seed dormancy alleviation, and germination, with a focus on the control of translation and proteasomal proteolysis. The presented novel data of translatome profiling in seeds highlighted that post-transcriptional regulation of germination results from a timely regulated initiation of translation. In addition, the importance of 26S proteasome in the degradation of regulatory elements of cellular signaling and that of the 20S complex in proteolysis of specific carbonylated proteins in hormonal- and light-dependent processes occurring in seeds is discussed. Based on the

  5. Bucolic Complexes

    CERN Document Server

    Brešar, Bostjan; Chepoi, Victor; Gologranc, Tanja; Osajda, Damian

    2012-01-01

    In this article, we introduce and investigate bucolic complexes, a common generalization of systolic complexes and of CAT(0) cubical complexes. This class of complexes is closed under Cartesian products and amalgamations over some convex subcomplexes. We study various approaches to bucolic complexes: from graph-theoretic and topological viewpoints, as well as from the point of view of geometric group theory. Bucolic complexes can be defined as locally-finite simply connected prism complexes satisfying some local combinatorial conditions. We show that bucolic complexes are contractible, and satisfy some nonpositive-curvature-like properties. In particular, we prove a version of the Cartan-Hadamard theorem, the fixed point theorem for finite group actions, and establish some results on groups acting geometrically on such complexes. We also characterize the 1-skeletons (which we call bucolic graphs) and the 2-skeletons of bucolic complexes. In particular, we prove that bucolic graphs are precisely retracts of Ca...

  6. Hypoxia targeting copper complexes

    International Nuclear Information System (INIS)

    The importance and incidence of tumour hypoxia, its measurement and current treatments available, including pharmacological and radiopharmacological methods of targeting hypoxia, are discussed. A variety of in vitro and in vivo methods for imposing hypoxia have been developed and are reviewed. Copper, its chemistry, biochemistry and radiochemistry, the potential for use of copper radionuclides and its use to date in this field is considered with particular reference to the thiosemicarbazones. Their biological activity, metal chelation, in vitro and in vivo studies of their radiocopper complexes and the potential for their use as hypoxia targeting radiopharmaceuticals is described. The reduction of the copper(II) complex to copper(l), its pivotal importance in their biological behaviour, and the potential for manipulation of this to effect hypoxia selectivity are described. An in vitro method for assessing the hypoxia selectivity of radiopharmaceuticals is reported. The rapid deoxygenation and high viability of a mammalian cell culture in this system is discussed and factors which may affect the cellular uptake of a radiopharmaceutical are described. The design, synthesis and complexation with copper and radiocopper of a range of bis(thiosemicarbazones) is reported. Synthesis of these compounds is simple giving high yields of pure products. The characteristics of the radiocopper complexes (64Cu) including lipophilicity and redox activity are reported (reduction potentials in the range -0.314 - -0.590 V). High cellular uptakes of the radiocopper complexes of the ligands, in hypoxic and normoxic EMT6 and CHO320 cells, were observed. Extremes of selectivity are shown ranging from the hypoxia selective 64Cu(II)ATSM to normoxic cell selective 64Cu(II)GTS. The selectivities observed are compared with the physico chemical characteristics of the complexes. A good correlation exists between selectivity of the complex and its Cu(II)/Cu(I) reduction potential, with hypoxia

  7. Hypoxia targeting copper complexes

    Energy Technology Data Exchange (ETDEWEB)

    Dearling, J.L

    1998-11-01

    The importance and incidence of tumour hypoxia, its measurement and current treatments available, including pharmacological and radiopharmacological methods of targeting hypoxia, are discussed. A variety of in vitro and in vivo methods for imposing hypoxia have been developed and are reviewed. Copper, its chemistry, biochemistry and radiochemistry, the potential for use of copper radionuclides and its use to date in this field is considered with particular reference to the thiosemicarbazones. Their biological activity, metal chelation, in vitro and in vivo studies of their radiocopper complexes and the potential for their use as hypoxia targeting radiopharmaceuticals is described. The reduction of the copper(II) complex to copper(l), its pivotal importance in their biological behaviour, and the potential for manipulation of this to effect hypoxia selectivity are described. An in vitro method for assessing the hypoxia selectivity of radiopharmaceuticals is reported. The rapid deoxygenation and high viability of a mammalian cell culture in this system is discussed and factors which may affect the cellular uptake of a radiopharmaceutical are described. The design, synthesis and complexation with copper and radiocopper of a range of bis(thiosemicarbazones) is reported. Synthesis of these compounds is simple giving high yields of pure products. The characteristics of the radiocopper complexes ({sup 64}Cu) including lipophilicity and redox activity are reported (reduction potentials in the range -0.314 - -0.590 V). High cellular uptakes of the radiocopper complexes of the ligands, in hypoxic and normoxic EMT6 and CHO320 cells, were observed. Extremes of selectivity are shown ranging from the hypoxia selective {sup 64}Cu(II)ATSM to normoxic cell selective {sup 64}Cu(II)GTS. The selectivities observed are compared with the physico chemical characteristics of the complexes. A good correlation exists between selectivity of the complex and its Cu(II)/Cu(I) reduction potential

  8. Bilayer Beams and Relay Sharing based OFDMA Cellular Architecture

    Directory of Open Access Journals (Sweden)

    Yanxiong Pan

    2011-08-01

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

  9. A hybrid parallel framework for the cellular Potts model simulations

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Yi [Los Alamos National Laboratory; He, Kejing [SOUTH CHINA UNIV; Dong, Shoubin [SOUTH CHINA UNIV

    2009-01-01

    The Cellular Potts Model (CPM) has been widely used for biological simulations. However, most current implementations are either sequential or approximated, which can't be used for large scale complex 3D simulation. In this paper we present a hybrid parallel framework for CPM simulations. The time-consuming POE solving, cell division, and cell reaction operation are distributed to clusters using the Message Passing Interface (MPI). The Monte Carlo lattice update is parallelized on shared-memory SMP system using OpenMP. Because the Monte Carlo lattice update is much faster than the POE solving and SMP systems are more and more common, this hybrid approach achieves good performance and high accuracy at the same time. Based on the parallel Cellular Potts Model, we studied the avascular tumor growth using a multiscale model. The application and performance analysis show that the hybrid parallel framework is quite efficient. The hybrid parallel CPM can be used for the large scale simulation ({approx}10{sup 8} sites) of complex collective behavior of numerous cells ({approx}10{sup 6}).

  10. Neural networks and cellular automata in experimental high energy physics

    International Nuclear Information System (INIS)

    Within the past few years, two novel computing techniques, cellular automata and neural networks, have shown considerable promise in the solution of problems of a very high degree of complexity, such as turbulent fluid flow, image processing, and pattern recognition. Many of the problems faced in experimental high energy physics are also of this nature. Track reconstruction in wire chambers and cluster finding in cellular calorimeters, for instance, involve pattern recognition and high combinatorial complexity since many combinations of hits or cells must be considered in order to arrive at the final tracks or clusters. Here we examine in what way connective network methods can be applied to some of the problems of experimental high physics. It is found that such problems as track and cluster finding adapt naturally to these approaches. When large scale hardwired connective networks become available, it will be possible to realize solutions to such problems in a fraction of the time required by traditional methods. For certain types of problems, faster solutions are already possible using model networks implemented on vector or other massively parallel machines. It should also be possible, using existing technology, to build simplified networks that will allow detailed reconstructed event information to be used in fast trigger decisions

  11. Optimization of Inter Cellular Movement of Parts in Cellular Manufacturing System Using Genetic Algorithm

    OpenAIRE

    Siva Prasad Darla; C.D. Naiju; Polu Vidya Sagar; B. Venkat Likhit

    2014-01-01

    In the modern manufacturing environment, Cellular Manufacturing Systems (CMS) have gained greater importance in job shop or batch-type production to gain economic advantage similar to those of mass production. Successful implementation of CMS highly depends on the determination of part families; machine cells and minimizing inter cellular movement. This study considers machine component grouping problems namely inter-cellular movement and cell load variation by developing a mathematical model...

  12. Optimization of Inter Cellular Movement of Parts in Cellular Manufacturing System Using Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Siva Prasad Darla

    2014-01-01

    Full Text Available In the modern manufacturing environment, Cellular Manufacturing Systems (CMS have gained greater importance in job shop or batch-type production to gain economic advantage similar to those of mass production. Successful implementation of CMS highly depends on the determination of part families; machine cells and minimizing inter cellular movement. This study considers machine component grouping problems namely inter-cellular movement and cell load variation by developing a mathematical model and optimizing the solution using Genetic Algorithm to arrive at a cell formation to minimize the inter-cellular movement and cell load variation. The results are presented with a numerical example.

  13. Shape Memory Alloy-Based Periodic Cellular Structures Project

    Data.gov (United States)

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

  14. The vault complex.

    Science.gov (United States)

    van Zon, A; Mossink, M H; Scheper, R J; Sonneveld, P; Wiemer, E A C

    2003-09-01

    Vaults are large ribonucleoprotein particles found in eukaryotic cells. They are composed of multiple copies of a Mr 100,000 major vault protein and two minor vault proteins of Mr 193,000 and 240,000, as well as small untranslated RNAs of 86-141 bases. The vault components are arranged into a highly characteristic hollow barrel-like structure of 35 x 65 nm in size. Vaults are predominantly localized in the cytoplasm where they may associate with cytoskeletal elements. A small fraction of vaults are found to be associated with the nucleus. As of yet, the precise cellular function of the vault complex is unknown. However, their distinct morphology and intracellular distribution suggest a role in intracellular transport processes. Here we review the current knowledge on the vault complex, its structure, components and possible functions. PMID:14523546

  15. Host-Parasite Interaction of Root-Knot Nematodes (Nematoda: Meloidogynidae): Cellular and Molecular Aspect

    OpenAIRE

    Gökhan Aydınlı; Sevilhan Mennan

    2014-01-01

    Root-knot nematodes (Meloidogyne spp.) have specialized and complex relationships with their host plants. A better understanding of interaction between nematode and their host will help to provide new point of view for root-knot nematode management. For this purpose, recently investigations on cellular and molecular basis of root-knot nematode parasitism and host response were reviewed.

  16. Modeling Complex Systems

    International Nuclear Information System (INIS)

    This book by Nino Boccara presents a compilation of model systems commonly termed as 'complex'. It starts with a definition of the systems under consideration and how to build up a model to describe the complex dynamics. The subsequent chapters are devoted to various categories of mean-field type models (differential and recurrence equations, chaos) and of agent-based models (cellular automata, networks and power-law distributions). Each chapter is supplemented by a number of exercises and their solutions. The table of contents looks a little arbitrary but the author took the most prominent model systems investigated over the years (and up until now there has been no unified theory covering the various aspects of complex dynamics). The model systems are explained by looking at a number of applications in various fields. The book is written as a textbook for interested students as well as serving as a comprehensive reference for experts. It is an ideal source for topics to be presented in a lecture on dynamics of complex systems. This is the first book on this 'wide' topic and I have long awaited such a book (in fact I planned to write it myself but this is much better than I could ever have written it!). Only section 6 on cellular automata is a little too limited to the author's point of view and one would have expected more about the famous Domany-Kinzel model (and more accurate citation!). In my opinion this is one of the best textbooks published during the last decade and even experts can learn a lot from it. Hopefully there will be an actualization after, say, five years since this field is growing so quickly. The price is too high for students but this, unfortunately, is the normal case today. Nevertheless I think it will be a great success! (book review)

  17. Decomposing PPI networks for complex discovery

    OpenAIRE

    Chua Hon Nian; Yong Chern Han; Liu Guimei; Wong Limsoon

    2011-01-01

    Abstract Background Protein complexes are important for understanding principles of cellular organization and functions. With the availability of large amounts of high-throughput protein-protein interactions (PPI), many algorithms have been proposed to discover protein complexes from PPI networks. However, existing algorithms generally do not take into consideration the fact that not all the interactions in a PPI network take place at the same time. As a result, predicted complexes often cont...

  18. Mitochondria and ionizing radiation: their inter relationship toward cellular dysfunction

    International Nuclear Information System (INIS)

    The contemporary theory of radiobiology posit that cellular damage during an event of radiation exposure is mediated through DNA damage/repair signaling processes along with secondary mechanisms induced by free radical generation. Nevertheless, up-coming experimental data suggests that this speculative framework is not enough for unfolding extranuclear radiation effects, particularly the response of mitochondria, key organelles for maintaining cellular function. Therefore, the present study aims at understanding ionizing radiation induced cellular damage and the associated mitochondrial structure/functional changes, using normal human fibroblast cells as an experimental model. Cells were exposed to X-rays (using Faxitron CP 160; dose rate 1 Gray (Gy)/min, fitted with 0.5 mm Al filter). Changes in the mitochondrial structure/mass were investigated by fluorescence microscopy and fluorimetry using MiTotracker red/nonyl-acridine orange dyes. Functional changes were measured by comparative measurement of cytosolic/mitochondrial ROS release using DCFH2DA/MiToSOX dye, mitochondrial membrane potential (MMP) using Rhodamine 123, activity of respiratory complexes, ATP synthesis and DNA damage using long amplicon (LA) PCR. Results obtained showed that exposure to X-rays led to mitochondrial fragmentation, concomitantly increasing the mitochondrial mass. Elevated cytosolic ROS levels were correlated with increased mitochondrial superoxide levels in case of X-ray treated cells indicating increased oxidative stress accompanied by depletion in MMP and activity of respiratory enzyme complexes followed by lowering of ATP levels. LA-PCR data showed time dependent decrease in the amplification of 8.9 kb region of mitochondrial DNA and 13.5 kb region of beta-globin nuclear gene segment indicating ROS precedes mtDNA damage exhibiting the deleterious nature of X-ray which may be considered as a key causative factor for mitochondrial dysfunction. Also, the role of DRP1 (dynamin

  19. Spin Echo Studies on Cellular Water

    CERN Document Server

    Chang, D C; Nichols, B L; Rorschach, H E

    2014-01-01

    Previous studies indicated that the physical state of cellular water could be significantly different from pure liquid water. To experimentally investigate this possibility, we conducted a series of spin-echo NMR measurements on water protons in rat skeletal muscle. Our result indicated that the spin-lattice relaxation time and the spin-spin relaxation time of cellular water protons are both significantly shorter than that of pure water (by 4.3-fold and 34-fold, respectively). Furthermore, the spin diffusion coefficient of water proton is almost 1/2 of that of pure water. These data suggest that cellular water is in a more ordered state in comparison to pure water.

  20. Software-Defined Cellular Mobile Network Solutions

    Institute of Scientific and Technical Information of China (English)

    Jiandong Li; Peng Liu; Hongyan Li

    2014-01-01

    The emergency relating to software-defined networking (SDN), especially in terms of the prototype associated with OpenFlow, pro-vides new possibilities for innovating on network design. Researchers have started to extend SDN to cellular networks. Such new programmable architecture is beneficial to the evolution of mobile networks and allows operators to provide better services. The typical cellular network comprises radio access network (RAN) and core network (CN); hence, the technique roadmap diverges in two ways. In this paper, we investigate SoftRAN, the latest SDN solution for RAN, and SoftCell and MobileFlow, the latest solu-tions for CN. We also define a series of control functions for CROWD. Unlike in the other literature, we emphasize only software-defined cellular network solutions and specifications in order to provide possible research directions.

  1. Cellular automatons applied to gas dynamic problems

    Science.gov (United States)

    Long, Lyle N.; Coopersmith, Robert M.; McLachlan, B. G.

    1987-06-01

    This paper compares the results of a relatively new computational fluid dynamics method, cellular automatons, with experimental data and analytical results. This technique has been shown to qualitatively predict fluidlike behavior; however, there have been few published comparisons with experiment or other theories. Comparisons are made for a one-dimensional supersonic piston problem, Stokes first problem, and the flow past a normal flat plate. These comparisons are used to assess the ability of the method to accurately model fluid dynamic behavior and to point out its limitations. Reasonable results were obtained for all three test cases, but the fundamental limitations of cellular automatons are numerous. It may be misleading, at this time, to say that cellular automatons are a computationally efficient technique. Other methods, based on continuum or kinetic theory, would also be very efficient if as little of the physics were included.

  2. Infrared image enhancement using Cellular Automata

    Science.gov (United States)

    Qi, Wei; Han, Jing; Zhang, Yi; Bai, Lian-fa

    2016-05-01

    Image enhancement is a crucial technique for infrared images. The clear image details are important for improving the quality of infrared images in computer vision. In this paper, we propose a new enhancement method based on two priors via Cellular Automata. First, we directly learn the gradient distribution prior from the images via Cellular Automata. Second, considering the importance of image details, we propose a new gradient distribution error to encode the structure information via Cellular Automata. Finally, an iterative method is applied to remap the original image based on two priors, further improving the quality of enhanced image. Our method is simple in implementation, easy to understand, extensible to accommodate other vision tasks, and produces more accurate results. Experiments show that the proposed method performs better than other methods using qualitative and quantitative measures.

  3. Cellular automatons applied to gas dynamic problems

    Science.gov (United States)

    Long, Lyle N.; Coopersmith, Robert M.; Mclachlan, B. G.

    1987-01-01

    This paper compares the results of a relatively new computational fluid dynamics method, cellular automatons, with experimental data and analytical results. This technique has been shown to qualitatively predict fluidlike behavior; however, there have been few published comparisons with experiment or other theories. Comparisons are made for a one-dimensional supersonic piston problem, Stokes first problem, and the flow past a normal flat plate. These comparisons are used to assess the ability of the method to accurately model fluid dynamic behavior and to point out its limitations. Reasonable results were obtained for all three test cases, but the fundamental limitations of cellular automatons are numerous. It may be misleading, at this time, to say that cellular automatons are a computationally efficient technique. Other methods, based on continuum or kinetic theory, would also be very efficient if as little of the physics were included.

  4. Parametric study of double cellular detonation structure

    Science.gov (United States)

    Khasainov, B.; Virot, F.; Presles, H.-N.; Desbordes, D.

    2013-05-01

    A parametric numerical study is performed of a detonation cellular structure in a model gaseous explosive mixture whose decomposition occurs in two successive exothermic reaction steps with markedly different characteristic times. Kinetic and energetic parameters of both reactions are varied in a wide range in the case of one-dimensional steady and two-dimensional (2D) quasi-steady self-supported detonations. The range of governing parameters of both exothermic steps is defined where a "marked" double cellular structure exists. It is shown that the two-level cellular structure is completely governed by the kinetic parameters and the local overdrive ratio of the detonation front propagating inside large cells. Furthermore, since it is quite cumbersome to use detailed chemical kinetics in unsteady 2D case, the proposed work should help to identify the mixtures and the domain of their equivalence ratio where double detonation structure could be observed.

  5. Online isolation of defects in cellular nanocomputers

    Institute of Scientific and Technical Information of China (English)

    Teijiro Isokawa; Shin'ya Kowada; Ferdinand Peper; Naotake Kamiura; Nobuyuki Matsui

    2007-01-01

    Unreliability will be a major issue for computers built from components at nanometer scales.Thus,it's to be expected that such computers will need a high degree of defect-tolerance to overcome components' defects which have arisen during the process of manufacturing.This paper presents a novel approach to defect-tolerance that is especially geared towards nanocomputers based on asynchronous cellular automata.According to this approach,defective cells are detected and isolated by small configurations that move around randomly in cellular space.These configurations,called random flies,will attach to configurations that are static,which is typical for configurations that contain defective cells.On the other hand,dynamic configurations,like those that conduct computations,will not be isolated from the rest of the cellular space by the random flies,and will be able to continue their operations unaffectedly.

  6. Phagocytosis, a cellular immune response in insects

    Directory of Open Access Journals (Sweden)

    C Rosales

    2011-06-01

    Full Text Available Insects like many other organisms are exposed to a wide range of infectious agents. Defense against these agents is provided by innate immune systems, which include physical barriers, humoral responses, and cellular responses. The humoral responses are characterized by the production of antimicrobial peptides, while the cellular defense responses include nodulation, encapsulation, melanization and phagocytosis. The phagocytic process, whereby cells ingest large particles, is of fundamental importance for insects’ development and survival. Phagocytic cells recognize foreign particles through a series of receptors on their cell membrane for pathogen-associated molecules. These receptors in turn initiate a series of signaling pathways that instruct the cell to ingest and eventually destroy the foreign particle. This review describes insect innate humoral and cellular immune functions with emphasis on phagocytosis. Recent advances in our understanding of the phagocytic cell types in various insect species; the receptors involved and the signaling pathways activated during phagocytosis are discussed.

  7. Alleviate Cellular Congestion Through Opportunistic Trough Filling

    Directory of Open Access Journals (Sweden)

    Yichuan Wang

    2014-04-01

    Full Text Available The demand for cellular data service has been skyrocketing since the debut of data-intensive smart phones and touchpads. However, not all data are created equal. Many popular applications on mobile devices, such as email synchronization and social network updates, are delay tolerant. In addition, cellular load varies significantly in both large and small time scales. To alleviate network congestion and improve network performance, we present a set of opportunistic trough filling schemes that leverage the time-variation of network congestion and delay-tolerance of certain traffic in this paper. We consider average delay, deadline, and clearance time as the performance metrics. Simulation results show promising performance improvement over the standard schemes. The work shed lights on addressing the pressing issue of cellular overload.

  8. Cellular Stress Response to Engineered Nanoparticles: Effect of Size, Surface Coating, and Cellular Uptake

    Science.gov (United States)

    CELLULAR STRESS RESPONSE TO ENGINEERED NANOPARTICLES: EFFECT OF SIZE, SURFACE COATING, AND CELLULAR UPTAKE RY Prasad 1, JK McGee2, MG Killius1 D Ackerman2, CF Blackman2 DM DeMarini2 , SO Simmons2 1 Student Services Contractor, US EPA, RTP, NC 2 US EPA, RTP, NC The num...

  9. About the embedding of one dimensional cellular automata into hyperbolic cellular automata

    OpenAIRE

    Margenstern, Maurice

    2010-01-01

    In this paper, we look at two ways to implement determinisitic one dimensional cellular automata into hyperbolic cellular automata in three contexts: the pentagrid, the heptagrid and the dodecagrid, these tilings being classically denoted by $\\{5,4\\}$, $\\{7,3\\}$ and $\\{5,3,4\\}$ respectively.

  10. Nonlinear optical methods for cellular imaging and localization.

    Science.gov (United States)

    McVey, A; Crain, J

    2014-07-01

    Of all the ways in which complex materials (including many biological systems) can be explored, imaging is perhaps the most powerful because delivering high information content directly. This is particular relevant in aspects of cellular localization where the physical proximity of molecules is crucial in biochemical processes. A great deal of effort in imaging has been spent on enabling chemically selective imaging so that only specific features are revealed. This is almost always achieved by adding fluorescent chemical labels to specific molecules. Under appropriate illumination conditions only the molecules (via their labels) will be visible. The technique is simple and elegant but does suffer from fundamental limitations: (1) the fluorescent labels may fade when illuminated (a phenomenon called photobleaching) thereby constantly decreasing signal contrast over the course of image acquisition. To combat photobleaching one must reduce observation times or apply unfavourably low excitation levels all of which reduce the information content of images; (2) the fluorescent species may be deactivated by various environmental factors (the general term is fluorescence quenching); (3) the presence of fluorescent labels may introduce unexpected complications or may interfere with processes of interest (4) Some molecules of interest cannot be labelled. In these circumstances we require a fundamentally different strategy. One of the most promising alternative is based on a technique called Coherent Anti-Stokes Raman scattering (CARS). CARS is a fundamentally more complex process than is fluorescence and the experimental procedures and optical systems required to deliver high quality CARS images are intricate. However, the rewards are correspondingly very high: CARS probes the chemically distinct vibrations of the constituent molecules in a complex system and is therefore also chemically selective as are fluorescence-based methods. Moreover,the potentially severe problems of

  11. Tropical complexes

    OpenAIRE

    Cartwright, Dustin

    2013-01-01

    We introduce tropical complexes, which are Delta-complexes together with additional numerical data. On a tropical complex, we define divisors and linear equivalence between divisors, analogous to the notions for algebraic varieties, and generalizing previous work for graphs. We prove a comparison theorem showing that divisor-curve intersection numbers agree under certain conditions.

  12. Medical Complex

    OpenAIRE

    Kumaraswamy, Mohan

    2002-01-01

    One element of the CIVCAL project Web-based resources containing images, tables, texts and associated data on the construction of the Medical Complex. This project covers the construction of a new Hong Kong University Medical Complex on Sassoon Road, Pokfulam. The complex will comprise two buildings, one will house laboratories and a car park, while the other will contain lecture halls

  13. Cellularity of certain quantum endomorphism algebras

    DEFF Research Database (Denmark)

    Andersen, Henning Haahr; Lehrer, Gus; Zhang, Ruibin

    2015-01-01

    For any ring A˜ such that Z[q±1∕2]⊆A˜⊆Q(q1∕2), let ΔA˜(d) be an A˜-form of the Weyl module of highest weight d∈N of the quantised enveloping algebra UA˜ of sl2. For suitable A˜, we exhibit for all positive integers r an explicit cellular structure for EndUA˜(ΔA˜(d)⊗r). This algebra and its cellul...... we independently recover the weight multiplicities of indecomposable tilting modules for Uζ(sl2) from the decomposition numbers of the endomorphism algebras, which are known through cellular theory....

  14. Rapid Cellular Turnover in Adipose Tissue

    OpenAIRE

    Alessandra Rigamonti; Kristen Brennand; Frank Lau; Cowan, Chad A.

    2011-01-01

    It was recently shown that cellular turnover occurs within the human adipocyte population. Through three independent experimental approaches — dilution of an inducible histone 2B-green fluorescent protein (H2BGFP), labeling with the cell cycle marker Ki67 and incorporation of BrdU — we characterized the degree of cellular turnover in murine adipose tissue. We observed rapid turnover of the adipocyte population, finding that 4.8% of preadipocytes are replicating at any time and that between 1–...

  15. Cellular effects of LRRK2 mutations

    OpenAIRE

    Cookson, Mark R.

    2012-01-01

    Mutations in leucine-rich repeat kinase 2 (LRRK2) are a relatively common cause of inherited Parkinson's disease (PD) but the mechanism(s) by which mutations lead to disease are poorly understood. Here, I will discuss what is known about LRRK2 in cellular models, focusing on specifically on assays that have been used to tease apart the effects of LRRK2 mutations on cellular phenotypes. LRRK2 expression has been suggested to cause loss of neuronal viability, although because it also has a stro...

  16. Toxicology and cellular effect of manufactured nanomaterials

    Science.gov (United States)

    Chen, Fanqing

    2014-07-22

    The increasing use of nanotechnology in consumer products and medical applications underlies the importance of understanding its potential toxic effects to people and the environment. Herein are described methods and assays to predict and evaluate the cellular effects of nanomaterial exposure. Exposing cells to nanomaterials at cytotoxic doses induces cell cycle arrest and increases apoptosis/necrosis, activates genes involved in cellular transport, metabolism, cell cycle regulation, and stress response. Certain nanomaterials induce genes indicative of a strong immune and inflammatory response within skin fibroblasts. Furthermore, the described multiwall carbon nanoonions (MWCNOs) can be used as a therapeutic in the treatment of cancer due to its cytotoxicity.

  17. Cellular basis of radiation-induced fibrosis

    International Nuclear Information System (INIS)

    Fibrosis is a common sequela of both cancer treatment by radiotherapy and accidental irradiation and has been described in many tissues including skin, lung, heart and liver. The underlying mechanisms of the radiation-induced fibrosis still remain to be resolved. In the present review we tried to illustrate the basic cellular mechanisms of radiation-induced fibrosis based on the newest findings arising from molecular radiobiology and cell biology. Based on these findings the cellular mechanism of radiation-induced fibrosis can be seen as a multicellular process involving various interacting cell systems in the target organ resulting in the fibrotic phenotype of the fibroblast/fibrocyte cell system

  18. The cellular decision between apoptosis and autophagy

    Directory of Open Access Journals (Sweden)

    Yong-Jun Fan

    2013-03-01

    Full Text Available Apoptosis and autophagy are important molecular processes that maintain organismal and cellular homeostasis, respectively. While apoptosis fulfills its role through dismantling damaged or unwanted cells, autophagy maintains cellular homeostasis through recycling selective intracellular organelles and molecules. Yet in some conditions, autophagy can lead to cell death. Apoptosis and autophagy can be stimulated by the same stresses. Emerging evidence indicates an interplay between the core proteins in both pathways, which underlies the molecular mechanism of the crosstalk between apoptosis and autophagy. This review summarizes recent literature on molecules that regulate both the apoptotic and autophagic processes.

  19. Chaotic behavior in the disorder cellular automata

    International Nuclear Information System (INIS)

    Disordered cellular automata (DCA) represent an intermediate class between elementary cellular automata and the Kauffman network. Recently, Rule 126 of DCA has been explicated: the system can be accurately described by a discrete probability function. However, a means of extending to other rules has not been developed. In this investigation, a density map of the dynamical behavior of DCA is formulated based on Rule 22 and other totalistic rules. The numerical results reveal excellent agreement between the model and original automata. Furthermore, the inhomogeneous situation is also discussed

  20. External insulation with cellular plastic materials

    DEFF Research Database (Denmark)

    Sørensen, Lars Schiøtt; Nielsen, Anker

    2014-01-01

    External thermal insulation composite systems (ETICS) can be used as extra insulation of existing buildings. The system can be made of cellular plastic materials or mineral wool. There is a European Technical guideline, ETAG 004, that describe the tests that shall be conducted on such systems....... This paper gives a comparison of systems with mineral wool and cellular plastic, based on experience from practice and literature. It is important to look at the details in the system and at long time stability of the properties such as thermal insulation, moisture and fire. Investigation of fire properties...

  1. Dynamic Self-Consistent Field Theory of Inhomogeneous Complex Fluids Under Shear

    Science.gov (United States)

    Mihajlovic, Maja; Lo, Tak Shing; Shnidman, Yitzhak

    2003-03-01

    Understanding and predicting the interplay between morphology and rheology of sheared, inhomogeneous, complex fluids is of great importance. Yet modeling of such phenomena is in its infancy. We have developed a novel dynamic self-consistent field (DSCF) theory that makes possible detailed computational study of such phenomena. Our DSCF theory couples the time evolution of chain conformation statistics with probabilistic transport equations for volume fractions and momenta, based on local conservation laws formulated on a segmental scale. To generate chain conformation statistics, we are using a modification of the lattice random walk formalism of Scheutjens and Fleer. Their static SCF theory is limited to equilibrium systems, since probability distributions are obtained by free energy minimization, assuming isotropic Gaussian chain conformations. In contrast, our DSCF approach accounts for explicit time evolution of the segmental and (anisotropic) stepping probabilities used for generating chain conformations. We will present highlights of DSCF studies of a variety of inhomogenous fluids containing homopolymers, block copolymers and nanoparticles.

  2. Communication complexity and information complexity

    Science.gov (United States)

    Pankratov, Denis

    Information complexity enables the use of information-theoretic tools in communication complexity theory. Prior to the results presented in this thesis, information complexity was mainly used for proving lower bounds and direct-sum theorems in the setting of communication complexity. We present three results that demonstrate new connections between information complexity and communication complexity. In the first contribution we thoroughly study the information complexity of the smallest nontrivial two-party function: the AND function. While computing the communication complexity of AND is trivial, computing its exact information complexity presents a major technical challenge. In overcoming this challenge, we reveal that information complexity gives rise to rich geometrical structures. Our analysis of information complexity relies on new analytic techniques and new characterizations of communication protocols. We also uncover a connection of information complexity to the theory of elliptic partial differential equations. Once we compute the exact information complexity of AND, we can compute exact communication complexity of several related functions on n-bit inputs with some additional technical work. Previous combinatorial and algebraic techniques could only prove bounds of the form theta( n). Interestingly, this level of precision is typical in the area of information theory, so our result demonstrates that this meta-property of precise bounds carries over to information complexity and in certain cases even to communication complexity. Our result does not only strengthen the lower bound on communication complexity of disjointness by making it more exact, but it also shows that information complexity provides the exact upper bound on communication complexity. In fact, this result is more general and applies to a whole class of communication problems. In the second contribution, we use self-reduction methods to prove strong lower bounds on the information

  3. Microwave gallium-68 radiochemistry for kinetically stable bis(thiosemicarbazone) complexes: structural investigations and cellular uptake under hypoxia† †Electronic supplementary information (ESI) available. CCDC 1001632–1001634. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c5dt02537k Click here for additional data file. Click here for additional data file.

    Science.gov (United States)

    Alam, Israt S.; Arrowsmith, Rory L.; Cortezon-Tamarit, Fernando; Twyman, Frazer; Kociok-Köhn, Gabriele; Botchway, Stanley W.; Dilworth, Jonathan R.

    2016-01-01

    We report the microwave synthesis of several bis(thiosemicarbazones) and the rapid gallium-68 incorporation to give the corresponding metal complexes. These proved kinetically stable under ‘cold’ and ‘hot’ biological assays and were investigated using laser scanning confocal microscopy, flow cytometry and radioactive cell retention studies under normoxia and hypoxia. 68Ga complex retention was found to be 34% higher in hypoxic cells than in normoxic cells over 30 min, further increasing to 53% at 120 min. Our data suggests that this class of gallium complexes show hypoxia selectivity suitable for imaging in living cells and in vivo tests by microPET in nude athymic mice showed that they are excreted within 1 h of their administration. PMID:26583314

  4. On reversibility of cellular automata with periodic boundary conditions

    Energy Technology Data Exchange (ETDEWEB)

    Nobe, Atsushi [Graduate School of Engineering Science, Osaka University, Machikaneyama-cho 1-3, Toyonaka, Osaka 560-8531 (Japan); Yura, Fumitaka [Imai Quantum Computing and Information Project, ERATO, JST, Daini Hongo White Bldg 201, 5-28-3 Hongo, Bunkyo, Tokyo 113-0033 (Japan)

    2004-06-04

    Reversibility of one-dimensional cellular automata with periodic boundary conditions is discussed. It is shown that there exist exactly 16 reversible elementary cellular automaton rules for infinitely many cell sizes by means of a correspondence between elementary cellular automaton and the de Bruijn graph. In addition, a sufficient condition for reversibility of three-valued and two-neighbour cellular automaton is given.

  5. 47 CFR 22.905 - Channels for cellular service.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Channels for cellular service. 22.905 Section... MOBILE SERVICES Cellular Radiotelephone Service § 22.905 Channels for cellular service. The following frequency bands are allocated for assignment to service providers in the Cellular Radiotelephone Service....

  6. 47 CFR 22.923 - Cellular system configuration.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Cellular system configuration. 22.923 Section... MOBILE SERVICES Cellular Radiotelephone Service § 22.923 Cellular system configuration. Mobile stations... directly or through cellular repeaters. Auxiliary test stations may communicate with base or...

  7. Cellular Automata Rules and Linear Numbers

    OpenAIRE

    Nayak, Birendra Kumar; Sahoo, Sudhakar; Biswal, Sagarika

    2012-01-01

    In this paper, linear Cellular Automta (CA) rules are recursively generated using a binary tree rooted at "0". Some mathematical results on linear as well as non-linear CA rules are derived. Integers associated with linear CA rules are defined as linear numbers and the properties of these linear numbers are studied.

  8. Building mathematics cellular phone learning communities

    Directory of Open Access Journals (Sweden)

    Wajeeh M. Daher

    2011-04-01

    Full Text Available Researchers emphasize the importance of maintaining learning communities and environments. This article describes the building and nourishment of a learning community, one comprised of middle school students who learned mathematics out-of-class using the cellular phone. The building of the learning community was led by three third year pre-service teachers majoring in mathematics and computers. The pre-service teachers selected thirty 8th grade students to learn mathematics with the cellular phone and be part of a learning community experimenting with this learning. To analyze the building and development stages of the cellular phone learning community, two models of community building stages were used; first the team development model developed by Tuckman (1965, second the life cycle model of a virtual learning community developed by Garber (2004. The research findings indicate that a learning community which is centered on a new technology has five 'life' phases of development: Pre-birth, birth, formation, performing, and maturity. Further, the research finding indicate that the norms that were encouraged by the preservice teachers who initiated the cellular phone learning community resulted in a community which developed, nourished and matured to be similar to a community of experienced applied mathematicians who use mathematical formulae to study everyday phenomena.

  9. Phosphoproteomics: new insights into cellular signaling

    OpenAIRE

    Mumby, Marc; Brekken, Deirdre

    2005-01-01

    Developments in the field of phosphoproteomics have been fueled by the need simultaneously to monitor many different phosphoproteins within the signaling networks that coordinate responses to changes in the cellular environment. This article presents a brief review of phosphoproteomics with an emphasis on the biological insights that have been derived so far.

  10. Cellular grafts in management of leucoderma

    Directory of Open Access Journals (Sweden)

    Mysore Venkataram

    2009-01-01

    Full Text Available Cellular grafting methods constitute important advances in the surgical management of leucoderma. Different methods such as noncultured epidermal suspensions, melanocyte cultures, and melanocyte-keratinocyte cultures have all been shown to be effective. This article reviews these methods.

  11. Cellular basis of memory for addiction.

    Science.gov (United States)

    Nestler, Eric J

    2013-12-01

    DESPITE THE IMPORTANCE OF NUMEROUS PSYCHOSOCIAL FACTORS, AT ITS CORE, DRUG ADDICTION INVOLVES A BIOLOGICAL PROCESS: the ability of repeated exposure to a drug of abuse to induce changes in a vulnerable brain that drive the compulsive seeking and taking of drugs, and loss of control over drug use, that define a state of addiction. Here, we review the types of molecular and cellular adaptations that occur in specific brain regions to mediate addiction-associated behavioral abnormalities. These include alterations in gene expression achieved in part via epigenetic mechanisms, plasticity in the neurophysiological functioning of neurons and synapses, and associated plasticity in neuronal and synaptic morphology mediated in part by altered neurotrophic factor signaling. Each of these types of drug-induced modifications can be viewed as a form of "cellular or molecular memory." Moreover, it is striking that most addiction-related forms of plasticity are very similar to the types of plasticity that have been associated with more classic forms of "behavioral memory," perhaps reflecting the finite repertoire of adaptive mechanisms available to neurons when faced with environmental challenges. Finally, addiction-related molecular and cellular adaptations involve most of the same brain regions that mediate more classic forms of memory, consistent with the view that abnormal memories are important drivers of addiction syndromes. The goal of these studies which aim to explicate the molecular and cellular basis of drug addiction is to eventually develop biologically based diagnostic tests, as well as more effective treatments for addiction disorders. PMID:24459410

  12. Cellular dosimetry in nuclear medicine imaging: training

    International Nuclear Information System (INIS)

    The radionuclides used in nuclear medicine imaging emit not only diagnostically useful photons, but also energy electron emissions, responsible for dose heterogeneity at the cellular level. The mean dose delivered to the cell nucleus by electron emissions of 99mTc, 123I, 111In, 67Ga, and 201Tl, has been calculated, for the cell nucleus, a cytoplasmic and a cell membrane distribution of radioactivity. This model takes into account both the self-dose which results from the radionuclide located in the target cell, and the cross-dose, which comes from the surrounding cells. The results obtained by cellular dosimetry (Dcel) have been compared with those obtained with conventional dosimetry (Dconv), by assuming the same amount of radioactivity per cell. Cellular dosimetry shows, for a cytoplasmic and a cell membrane distributions of radioactivity, that the main contribution to the dose to the cell nucleus, comes from the surrounding cells. On the other hand, for a cell nucleus distribution of radioactivity, the self-dose is not negligible and may be the main contribution. The comparison between cellular and conventional dosimetry shows that Dcel/Dconv ratio ranges from 0.61 and O.89, in case of a cytoplasmic and a cell membrane distributions of radioactivity, depending on the radionuclide and cell dimensions. Thus, conventional dosimetry slightly overestimates the mean dose to the cell nucleus. On the other hand, Dcel/Dconv ranges from 1.1 to 75, in case of a cell nucleus distribution of radioactivity. Conventional dosimetry may strongly underestimates the absorbed dose to the nucleus, when radioactivity is located in the nucleus. The study indicates that in nuclear medicine imaging, cellular dosimetry may lead to a better understanding of biological effects of radiopharmaceuticals. (authors)

  13. Klotho-Dependent Cellular Transport Regulation.

    Science.gov (United States)

    Sopjani, M; Dërmaku-Sopjani, M

    2016-01-01

    Klotho is a transmembrane protein that in humans is encoded by the hKL gene. This protein is known to have aging suppressor effects and is predominantly expressed in the distal convoluted tubule of the kidney, parathyroid glands, and choroid plexus of the brain. The Klotho protein exists in both full-length membrane form and a soluble secreted form, which exerts numerous distinct functions. The extracellular domain of Klotho can be enzymatically cleaved off and released into the systemic circulation where it functions as β-glucuronidase and a hormone. Soluble Klotho is a multifunction protein present in the biological fluids including blood, urine, and cerebrospinal fluid of mammals. Klotho deficiency leads to multiple organ failure accompanied by early appearance of multiple age-related disorders and early death, whereas overexpression of Klotho results in the opposite effects. Klotho, an enzyme and hormone, has been reported to participate in the regulation of cellular transport processes across the plasma membrane either indirectly through inhibiting calcitriol (1,25(OH)2D3) formation or other mechanism, or by directly affecting transporter proteins, including ion channels, cellular carriers, and Na(+)/K(+)-ATPase. Accordingly, Klotho protein serves as a powerful regulator of cellular transport across the plasma membrane. Importantly, Klotho-dependent cellular transport regulation implies stimulatory or inhibitory effects. Klotho has been shown to play a key role in the regulation of multiple calcium and potassium ion channels, and various cellular carriers including the Na(+)-coupled cotransporters such as NaPi-IIa, NaPi-IIb, EAAT3, and EAAT4, CreaT1 as well as Na(+)/K(+)-ATPase. These regulations are parts of the antiaging function of Klotho, which will be discussing throughout this chapter. Clearly, further experimental efforts are required to investigate the effect of Klotho on other transport proteins and underlying molecular mechanisms by which Klotho

  14. Cellular glutathione prevents cytolethality of monomethylarsonic acid

    International Nuclear Information System (INIS)

    Inorganic arsenicals are clearly toxicants and carcinogens in humans. In mammals, including humans, inorganic arsenic often undergoes methylation, forming compounds such as monomethylarsonic acid (MMAsV) and dimethylarsinic acid (DMAsV). However, much less information is available on the in vitro toxic potential or mechanisms of these methylated arsenicals, especially MMAsV. We studied the molecular mechanisms of in vitro cytolethality of MMAsV using a rat liver epithelial cell line (TRL 1215). MMAsV was not cytotoxic in TRL 1215 cells even at concentrations exceeding 10 mM, but it became weakly cytotoxic and induced both necrotic and apoptotic cell death when cellular reduced glutathione (GSH) was depleted with the glutathione synthase inhibitor, L-buthionine-[S,R]-sulfoximine (BSO), or the glutathione reductase inhibitor, carmustine. Similar results were observed in the other mammalian cells, such as human skin TIG-112 cells, chimpanzee skin CRT-1609 cells, and mouse metallothionein (MT) positive and MT negative embryonic cells. Ethacrynic acid (EA), an inhibitor of glutathione S-transferase (GST) that catalyses GSH-substrate conjugation, also enhanced the cytolethality of MMAsV, but aminooxyacetic acid (AOAA), an inhibitor of β-lyase that catalyses the final breakdown of GSH-substrate conjugates, had no effect. Both the cellular GSH levels and the cellular GST activity were increased by the exposure to MMAsV in TRL 1215 cells. On the other hand, the addition of exogenous extracellular GSH enhanced the cytolethality of MMAsV, although cellular GSH levels actually prevented the cytolethality of combined MMAsV and exogenous GSH. These findings indicate that human arsenic metabolite MMAsV is not a highly toxic compound in mammalian cells, and the level of cellular GSH is critical to its eventual toxic effects

  15. Liposome-mediated cellular delivery of active gp91(phox.

    Directory of Open Access Journals (Sweden)

    Bruno Marques

    Full Text Available BACKGROUND: Gp91(phox is a transmembrane protein and the catalytic core of the NADPH oxidase complex of neutrophils. Lack of this protein causes chronic granulomatous disease (CGD, a rare genetic disorder characterized by severe and recurrent infections due to the incapacity of phagocytes to kill microorganisms. METHODOLOGY: Here we optimize a prokaryotic cell-free expression system to produce integral mammalian membrane proteins. CONCLUSIONS: Using this system, we over-express truncated forms of the gp91(phox protein under soluble form in the presence of detergents or lipids resulting in active proteins with a "native-like" conformation. All the proteins exhibit diaphorase activity in the presence of cytosolic factors (p67(phox, p47(phox, p40(phox and Rac and arachidonic acid. We also produce proteoliposomes containing gp91(phox protein and demonstrate that these proteins exhibit activities similar to their cellular counterpart. The proteoliposomes induce rapid cellular delivery and relocation of recombinant gp91(phox proteins to the plasma membrane. Our data support the concept of cell-free expression technology for producing recombinant proteoliposomes and their use for functional and structural studies or protein therapy by complementing deficient cells in gp91(phox protein.

  16. Cellular mechanisms of cadmium-induced toxicity: a review.

    Science.gov (United States)

    Rani, Anju; Kumar, Anuj; Lal, Ankita; Pant, Manu

    2014-08-01

    Cadmium is a widespread toxic pollutant of occupational and environmental concern because of its diverse toxic effects: extremely protracted biological half-life (approximately 20-30 years in humans), low rate of excretion from the body and storage predominantly in soft tissues (primarily, liver and kidneys). It is an extremely toxic element of continuing concern because environmental levels have risen steadily due to continued worldwide anthropogenic mobilization. Cadmium is absorbed in significant quantities from cigarette smoke, food, water and air contamination and is known to have numerous undesirable effects in both humans and animals. Cadmium has a diversity of toxic effects including nephrotoxicity, carcinogenicity, teratogenicity and endocrine and reproductive toxicities. At the cellular level, cadmium affects cell proliferation, differentiation, apoptosis and other cellular activities. Current evidence suggests that exposure to cadmium induces genomic instability through complex and multifactorial mechanisms. Most important seems to be cadmium interaction with DNA repair mechanism, generation of reactive oxygen species and induction of apoptosis. In this article, we have reviewed recent developments and findings on cadmium toxicology. PMID:24117228

  17. Cellular Transport Mechanisms of Cytotoxic Metallodrugs: An Overview beyond Cisplatin

    Directory of Open Access Journals (Sweden)

    Sarah Spreckelmeyer

    2014-09-01

    Full Text Available The field of medicinal inorganic chemistry has grown consistently during the past 50 years; however, metal-containing coordination compounds represent only a minor proportion of drugs currently on the market, indicating that research in this area has not yet been thoroughly realized. Although platinum-based drugs as cancer chemotherapeutic agents have been widely studied, exact knowledge of the mechanisms governing their accumulation in cells is still lacking. However, evidence suggests active uptake and efflux mechanisms are involved; this may be involved also in other experimental metal coordination and organometallic compounds with promising antitumor activities in vitro and in vivo, such as ruthenium and gold compounds. Such knowledge would be necessary to elucidate the balance between activity and toxicity profiles of metal compounds. In this review, we present an overview of the information available on the cellular accumulation of Pt compounds from in vitro, in vivo and clinical studies, as well as a summary of reports on the possible accumulation mechanisms for different families of experimental anticancer metal complexes (e.g., Ru Au and Ir. Finally, we discuss the need for rationalization of the investigational approaches available to study metallodrug cellular transport.

  18. Alkalizing reactions streamline cellular metabolism in acidogenic microorganisms.

    Directory of Open Access Journals (Sweden)

    Stefania Arioli

    Full Text Available An understanding of the integrated relationships among the principal cellular functions that govern the bioenergetic reactions of an organism is necessary to determine how cells remain viable and optimise their fitness in the environment. Urease is a complex enzyme that catalyzes the hydrolysis of urea to ammonia and carbonic acid. While the induction of urease activity by several microorganisms has been predominantly considered a stress-response that is initiated to generate a nitrogen source in response to a low environmental pH, here we demonstrate a new role of urease in the optimisation of cellular bioenergetics. We show that urea hydrolysis increases the catabolic efficiency of Streptococcus thermophilus, a lactic acid bacterium that is widely used in the industrial manufacture of dairy products. By modulating the intracellular pH and thereby increasing the activity of β-galactosidase, glycolytic enzymes and lactate dehydrogenase, urease increases the overall change in enthalpy generated by the bioenergetic reactions. A cooperative altruistic behaviour of urease-positive microorganisms on the urease-negative microorganisms within the same environment was also observed. The physiological role of a single enzymatic activity demonstrates a novel and unexpected view of the non-transcriptional regulatory mechanisms that govern the bioenergetics of a bacterial cell, highlighting a new role for cytosol-alkalizing biochemical pathways in acidogenic microorganisms.

  19. Alkalizing Reactions Streamline Cellular Metabolism in Acidogenic Microorganisms

    Science.gov (United States)

    Arioli, Stefania; Ragg, Enzio; Scaglioni, Leonardo; Fessas, Dimitrios; Signorelli, Marco; Karp, Matti; Daffonchio, Daniele; De Noni, Ivano; Mulas, Laura; Oggioni, Marco; Guglielmetti, Simone; Mora, Diego

    2010-01-01

    An understanding of the integrated relationships among the principal cellular functions that govern the bioenergetic reactions of an organism is necessary to determine how cells remain viable and optimise their fitness in the environment. Urease is a complex enzyme that catalyzes the hydrolysis of urea to ammonia and carbonic acid. While the induction of urease activity by several microorganisms has been predominantly considered a stress-response that is initiated to generate a nitrogen source in response to a low environmental pH, here we demonstrate a new role of urease in the optimisation of cellular bioenergetics. We show that urea hydrolysis increases the catabolic efficiency of Streptococcus thermophilus, a lactic acid bacterium that is widely used in the industrial manufacture of dairy products. By modulating the intracellular pH and thereby increasing the activity of β-galactosidase, glycolytic enzymes and lactate dehydrogenase, urease increases the overall change in enthalpy generated by the bioenergetic reactions. A cooperative altruistic behaviour of urease-positive microorganisms on the urease-negative microorganisms within the same environment was also observed. The physiological role of a single enzymatic activity demonstrates a novel and unexpected view of the non-transcriptional regulatory mechanisms that govern the bioenergetics of a bacterial cell, highlighting a new role for cytosol-alkalizing biochemical pathways in acidogenic microorganisms. PMID:21152088

  20. Parallel track reconstruction in CMS using the cellular automaton approach

    International Nuclear Information System (INIS)

    The Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) is a general-purpose particle detector and comprises the largest silicon-based tracking system built to date with 75 million individual readout channels. The precise reconstruction of particle tracks from this tremendous amount of input channels is a compute-intensive task. The foreseen LHC beam parameters for the next data taking period, starting in 2015, will result in an increase in the number of simultaneous proton-proton interactions and hence the number of particle tracks per event. Due to the stagnating clock frequencies of individual CPU cores, new approaches to particle track reconstruction need to be evaluated in order to cope with this computational challenge. Track finding methods that are based on cellular automata (CA) offer a fast and parallelizable alternative to the well-established Kalman filter-based algorithms. We present a new cellular automaton based track reconstruction, which copes with the complex detector geometry of CMS. We detail the specific design choices made to allow for a high-performance computation on GPU and CPU devices using the OpenCL framework. We conclude by evaluating the physics performance, as well as the computational properties of our implementation on various hardware platforms and show that a significant speedup can be attained by using GPU architectures while achieving a reasonable physics performance at the same time.

  1. Concepts of dose to soft tissue at the cellular level

    International Nuclear Information System (INIS)

    Radiation effects begin at the cellular level of biological organization. Radiation dosimetry at the cellular level is particularly important for internally deposited alpha and beta particle emitters. Microdosimetry is a mechanism for studying the dose imparted to microscopic sites, for determining hit probabilities, and for determining the probability that sites are missed. Internal microdosimetry calculations are complex, but can be easily executed using computer programs. The investigator must specify the target and its size, determine the radionuclide activity per unit mass for each region in which targets are located, describe the activity per radioactive particulate, understand the geometrical relationship between the activity and the targets, and account for the biological retention of the activity in the region as a function of time. Internal microdosimetry has many potential applications in radiological protection. Microdosimetry is a special research area designed to provide a better understanding of the importance of microscopic patterns of radiation interaction with cells within the broader framework of biochemistry and radiation biology. Its objective is to provide a methodology that is both consistent and precise for correlating biological response to varying levels and distributions of internal emitters. Microdosimetry may contribute to a more complete understanding of the mechanisms of cancer induction by radiation. The correlation between specific energy density and various biological effects might best be treated statistically, since the effects occur in response of stochastic processes. If applied correctly, these concepts should provide a reliable tool for learning more about the effects of radiation and for setting radiation protection standards

  2. Regulation and Cellular Roles of Ubiquitin-specific Deubiquitinating Enzymes

    Science.gov (United States)

    Turcu, Francisca E. Reyes; Ventii, Karen H.; Wilkinson, Keith D.

    2009-01-01

    Deubiquitinating enzymes (DUBs) are proteases that process ubiquitin or ubiquitin-like gene products, reverse the modification of proteins by a single ubiquitin (or ubiquitin-like protein), and remodel polyubiquitin (or ubiquitin-like) chains on target proteins. The human genome encodes nearly 100 DUBs with specificity for ubiquitin in five families: the UCH, USP, OTU, Josephin, and JAMM families. Four families are cysteine proteases, while the later is a family of metalloproteases. Most DUB activity is cryptic and active site rearrangements often occur during the binding of ubiquitin and/or scaffold proteins. DUBs with specificity for ubiquitin contain multiple domains with insertions and extensions modulating DUB substrate specificity, protein-protein interactions, and cellular localization. Binding partners and multi-protein complexes with which DUBs associate modulate DUB activity and substrate specificity. Quantitative studies of activity and protein-protein interactions, together with genetic studies and the advent of RNAi, have lead to new insights into the function of yeast and human DUBs. This review will discuss ubiquitin-specific DUBs, some of the generalizations emerging from recent studies of the regulation of DUB activity, and their roles in various cellular processes. Specific examples are drawn from studies of protein degradation, DNA repair, chromatin remodeling, cell cycle regulation, endocytosis, and modulation of signaling kinases. PMID:19489724

  3. Rapid detection of biothreat agents based on cellular machinery.

    Energy Technology Data Exchange (ETDEWEB)

    Lane, Todd W.; Gantt, Richard W.

    2004-12-01

    This research addresses rapid and sensitive identification of biological agents in a complex background. We attempted to devise a method by which the specificity of the cellular transcriptional machinery could be used to detect and identify bacterial bio-terror agents in a background of other organisms. Bacterial cells contain RNA polymerases and transcription factors that transcribe genes into mRNA for translation into proteins. RNA polymerases in conjunction with transcription factors recognize regulatory elements (promoters) upstream of the gene. These promoters are, in many cases, recognized by the polymerase and transcription factor combinations of one species only. We have engineered a plasmid, for Escherichia coli, containing the virA promoter from the target species Shigella flexneri. This promoter was fused to a reporter gene Green Fluorescent Protein (GFP). In theory the indicator strain (carrying the plasmid) is mixed with the target strain and the two are lysed. The cellular machinery from both cells mixes and the GFP is produced. This report details the results of testing this system.

  4. Open-cellular copper structures fabricated by additive manufacturing using electron beam melting

    International Nuclear Information System (INIS)

    Highlights: → Relative stiffness versus relative density measurements for reticulated mesh and stochastic open cellular copper were shown to follow the Gibson-Ashby foam model. → Microstructures for the mesh struts and foam ligaments illustrated a propensity of copper oxide precipitates which provided structural hardness and strength. → These components, fabricated by electron beam melting, exhibit interesting prospects for specialized, complex heat-transfer devices. - Abstract: Cu reticulated mesh and stochastic open cellular foams were fabricated by additive manufacturing using electron beam melting. Fabricated densities ranged from 0.73 g/cm3 to 6.67 g/cm3. The precursor Cu powder contained Cu2O precipitates and the fabricated components contained arrays of Cu2O precipitates and interconnected dislocation microstructures having average spacings of ∼2 μm, which provide hardness values ∼75% above commercial Cu products. Plots of stiffness (Young's modulus) versus density and relative stiffness versus relative density were in very close agreement with the Gibson-Ashby model for open cellular foams. These open cellular structure components exhibit considerable potential for novel, complex, multi-functional electrical and thermal management systems, especially complex, monolithic heat exchange devices.

  5. Alginate-Iron Speciation and Its Effect on In Vitro Cellular Iron Metabolism

    Science.gov (United States)

    Horniblow, Richard D.; Dowle, Miriam; Iqbal, Tariq H.; Latunde-Dada, Gladys O.; Palmer, Richard E.

    2015-01-01

    Alginates are a class of biopolymers with known iron binding properties which are routinely used in the fabrication of iron-oxide nanoparticles. In addition, alginates have been implicated in influencing human iron absorption. However, the synthesis of iron oxide nanoparticles employs non-physiological pH conditions and whether nanoparticle formation in vivo is responsible for influencing cellular iron metabolism is unclear. Thus the aims of this study were to determine how alginate and iron interact at gastric-comparable pH conditions and how this influences iron metabolism. Employing a range of spectroscopic techniques under physiological conditions alginate-iron complexation was confirmed and, in conjunction with aberration corrected scanning transmission electron microscopy, nanoparticles were observed. The results infer a nucleation-type model of iron binding whereby alginate is templating the condensation of iron-hydroxide complexes to form iron oxide centred nanoparticles. The interaction of alginate and iron at a cellular level was found to decrease cellular iron acquisition by 37% (p < 0.05) and in combination with confocal microscopy the alginate inhibits cellular iron transport through extracellular iron chelation with the resulting complexes not internalised. These results infer alginate as being useful in the chelation of excess iron, especially in the context of inflammatory bowel disease and colorectal cancer where excess unabsorbed luminal iron is thought to be a driver of disease. PMID:26378798

  6. The development of the orbital fasciae and cellular tissue spaces at an early stage of human ontogenesis

    OpenAIRE

    Shkrobanets A.A.

    2008-01-01

    The development of the orbital fasciae and cellular tissue spaces during the embryonic and prefetal periods of ontogenesis has been studied by means of the morphological research methods. It has been established that the said structures develop from the mesenchyme, surrounding the eyeballs germ and optic nerve. The forming of the cellular tissue spaces proceed simultaneously with the development of the orbital walls and the musculo-fascial complex of the oculomotor muscles and roughly takes s...

  7. Insulin receptors in isolated human adipocytes. Characterization by photoaffinity labeling and evidence for internalization and cellular processing.

    OpenAIRE

    Berhanu, P; Kolterman, O G; Baron, A; Tsai, P; Olefsky, J M; Brandenburg, D.

    1983-01-01

    We photolabeled and characterized insulin receptors in isolated adipocytes from normal human subjects and then studied the cellular fate of the labeled insulin-receptor complexes at physiologic temperatures. The biologically active photosensitive insulin derivative, B2(2-nitro-4-azidophenylacetyl)des-PheB1-insulin (NAPA-DP-insulin) was used to photoaffinity label the insulin receptors, and the specifically labeled cellular proteins were identified by sodium dodecyl sulfate-polyacrylamide gel ...

  8. Complexity Plots

    KAUST Repository

    Thiyagalingam, Jeyarajan

    2013-06-01

    In this paper, we present a novel visualization technique for assisting the observation and analysis of algorithmic complexity. In comparison with conventional line graphs, this new technique is not sensitive to the units of measurement, allowing multivariate data series of different physical qualities (e.g., time, space and energy) to be juxtaposed together conveniently and consistently. It supports multivariate visualization as well as uncertainty visualization. It enables users to focus on algorithm categorization by complexity classes, while reducing visual impact caused by constants and algorithmic components that are insignificant to complexity analysis. It provides an effective means for observing the algorithmic complexity of programs with a mixture of algorithms and black-box software through visualization. Through two case studies, we demonstrate the effectiveness of complexity plots in complexity analysis in research, education and application. © 2013 The Author(s) Computer Graphics Forum © 2013 The Eurographics Association and Blackwell Publishing Ltd.

  9. Papillomavirus E2 Proteins and the Host Brd4 Protein Associate with Transcriptionally Active Cellular Chromatin▿ †

    OpenAIRE

    Jang, Moon Kyoo; Kwon, Deukwoo; Alison A McBride

    2009-01-01

    The interaction of papillomavirus E2 proteins with cellular Brd4 protein is important for transcriptional regulation of viral genes and partitioning of viral genomes. Bovine papillomavirus type 1 (BPV-1) E2 binds cellular chromatin in complex with Brd4 in both mitotic and interphase cells. To identify specific sites of E2 interaction on cellular chromatin, a genome-wide chromatin immunoprecipitation-on-chip analysis was carried out using human promoter sequences. Both E2 and Brd4 were found b...

  10. Threshold-Range Scaling of Excitable Cellular Automata

    CERN Document Server

    Fisch, R; Griffeath, D; Fisch, Robert; Gravner, Janko; Griffeath, David

    1993-01-01

    Each cell of a two-dimensional lattice is painted one of k colors, arranged in a "color wheel." The colors advance (0 to k-1 mod k) either automatically or by contact with at least a threshold number of successor colors in a prescribed local neighborhood. Discrete-time parallel systems of this sort in which color 0 updates by contact and the rest update automatically are called Greenberg-Hastings (GH) rules. A system in which all colors update by contact is called a cyclic cellular automaton (CCA). Started from appropriate initial conditions these models generate periodic traveling waves. Started from random configurations the same rules exhibit complex self-organization, typically characterized by nucleation of locally periodic "ram's horns" or spirals. Corresponding random processes give rise to a variety of "forest fire" equilibria that display large-scale stochastic wave fronts. This article describes a framework, theoretically based, but relying on extensive interactive computer graphics experimentation,...

  11. Cellular interactions in the pathogenesis of interstitial lung diseases

    Directory of Open Access Journals (Sweden)

    Gianluca Bagnato

    2015-03-01

    Full Text Available Interstitial lung disease (ILD encompasses a large and diverse group of pathological conditions that share similar clinical, radiological and pathological manifestations, despite potentially having quite different aetiologies and comorbidities. Idiopathic pulmonary fibrosis (IPF represents probably the most aggressive form of ILD and systemic sclerosis is a multiorgan fibrotic disease frequently associated with ILD. Although the aetiology of these disorders remains unknown, in this review we analyse the pathogenic mechanisms by cell of interest (fibroblast, fibrocyte, myofibroblast, endothelial and alveolar epithelial cells and immune competent cells. New insights into the complex cellular contributions and interactions will be provided, comparing the role of cell subsets in the pathogenesis of IPF and systemic sclerosis.

  12. Mitochondria, cellular stress resistance, somatic cell depletion and lifespan.

    Science.gov (United States)

    Robb, Ellen L; Page, Melissa M; Stuart, Jeffrey A

    2009-03-01

    The causes of aging and determinants of maximum lifespan in animal species are multifaceted and complex. However, a wealth of experimental data suggests that mitochondria are involved both in the aging process and in regulating lifespan. Here we outline a somatic cell depletion (SCD) model to account for correlations between: (1) mitochondrial reactive oxygen species and lifespan; (2) mitochondrial antioxidant enzymes and lifespan; (3) mitochondrial DNA mutation and lifespan and (4) cellular stress resistance and lifespan. We examine the available data from within the framework of the SCD model, in which mitochondrial dysfunction leading to cell death and gradual loss of essential somatic cells eventually contributes to the decline in physiological performance that limits lifespan. This model is useful in explaining many of the mitochondrial manipulations that alter maximum lifespan in a variety of animal species; however, there are a number of caveats and critical experiments outstanding, and these are outlined in this review. PMID:20021396

  13. A cellular automaton model for neurogenesis in Drosophila

    Science.gov (United States)

    Luthi, Pascal O.; Chopard, Bastien; Preiss, Anette; Ramsden, Jeremy J.

    1998-07-01

    A cellular automaton (CA) is constructed for the formation of the central nervous system of the Drosophila embryo. This is an experimentally well-studied system in which complex interactions between neighbouring cells appear to drive their differentiation into different types. It appears that all the cells initially have the potential to become neuroblasts, and all strive to this end, but those which differentiate first block their as yet undifferentiated neighbours from doing so. The CA makes use of observational evidence for a lateral inhibition mechanism involving signalling products S of the ‘proneural’ or neuralizing genes. The key concept of the model is that cells are continuously producing S, but the production rate is lowered by inhibitory signals received from neighbouring cells which have advanced further along the developmental pathway. Comparison with experimental data shows that it well accounts for the observed proportion of neuroectodermal cells delaminating as neuroblasts.

  14. Quantification of asymmetric microtubule nucleation at sub-cellular structures

    Science.gov (United States)

    Zhu, Xiaodong; Kaverina, Irina

    2012-01-01

    Cell polarization is important for multiple physiological processes. In polarized cells, microtubules (MTs) are organized into a spatially polarized array. Generally, in non-differentiated cells, it is assumed that MTs are symmetrically nucleated exclusively from centrosome (microtubule organizing center, MTOC) and then reorganized into the asymmetric array. We have recently identified the Golgi complex as an additional MTOC that asymmetrically nucleates MTs toward one side of the cell. Methods used for alternative MTOC identification include microtubule re-growth after complete drug-induced depolymerization and tracking of growing microtubules using fluorescence labeled MT +TIP binding proteins in living cells. These approaches can be used for quantification of MT nucleation sites at diverse sub-cellular structures. PMID:21773933

  15. Periodic Cellular Structure Technology for Shape Memory Alloys

    Science.gov (United States)

    Chen, Edward Y.

    2015-01-01

    Shape memory alloys are being considered for a wide variety of adaptive components for engine and airframe applications because they can undergo large amounts of strain and then revert to their original shape upon heating or unloading. Transition45 Technologies, Inc., has developed an innovative periodic cellular structure (PCS) technology for shape memory alloys that enables fabrication of complex bulk configurations, such as lattice block structures. These innovative structures are manufactured using an advanced reactive metal casting technology that offers a relatively low cost and established approach for constructing near-net shape aerospace components. Transition45 is continuing to characterize these structures to determine how best to design a PCS to better exploit the use of shape memory alloys in aerospace applications.

  16. Cellular automata simulation of traffic including cars and bicycles

    Science.gov (United States)

    Vasic, Jelena; Ruskin, Heather J.

    2012-04-01

    As 'greening' of all aspects of human activity becomes mainstream, transportation science is also increasingly focused around sustainability. Modal co-existence between motorised and non-motorised traffic on urban networks is, in this context, of particular interest for traffic flow modelling. The main modelling problems here are posed by the heterogeneity of vehicles, including size and dynamics, and by the complex interactions at intersections. Herein we address these with a novel technique, based on one-dimensional cellular automata components, for modelling network infrastructure and its occupancy by vehicles. We use this modelling approach, together with a corresponding vehicle behaviour model, to simulate combined car and bicycle traffic for two elemental scenarios-examples of components that would be used in the building of an arbitrary network. Results of simulations performed on these scenarios, (i) a stretch of road and (ii) an intersection causing conflict between cars and bicycles sharing a lane, are presented and analysed.

  17. Engaging complexity

    Directory of Open Access Journals (Sweden)

    Gys M. Loubser

    2014-01-01

    Full Text Available In this article, I discuss studies in complexity and its epistemological implications for systematic and practical theology. I argue that engagement with complexity does not necessarily assurea non-reductionist approach. However, if complexity is engaged transversally, it becomes possible to transcend reductionist approaches. Moreover, systematic and practical the ologians can draw on complexity in developing new ways of understanding and, therefore, new ways of describing the focus, epistemic scope and heuristic structures of systematic and practical theology. Firstly, Edgar Morin draws a distinction between restricted and general complexity based on the epistemology drawn upon in studies in complexity. Moving away from foundationalist approaches to epistemology, Morin argues for a paradigm of systems. Secondly,I discuss Kees van Kooten Niekerk�s distinction between epistemology, methodology andontology in studies in complexity and offer an example of a theological argument that drawson complexity. Thirdly, I argue for the importance of transversality in engaging complexity by drawing on the work of Wentzel van Huyssteen and Paul Cilliers. In conclusion, I argue that theologians have to be conscious of the epistemic foundations of each study in complexity, and these studies illuminate the heart of Reformed theology.Intradisciplinary and/or interdisciplinary implications: Therefore, this article has both intradisciplinary and interdisciplinary implications. When theologians engage studies incomplexity, the epistemological roots of these studies need to be considered seeing thatresearchers in complexity draw on different epistemologies. Drawing on transversality wouldenhance such considerations. Furthermore, Edgar Morin�s and Paul Cilliers� approach tocomplexity will inform practical and theoretical considerations in church polity and unity.

  18. Cellular toxicity (High-Throughput Cellular Assays for Modeling Toxicity in the Fish Reproductive System)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The purpose of this project is to adapt cellular in vitro assay systems of the rainbow trout pituitary, liver and ovary for high-throughput screening (HTS) of...

  19. Cellular Dynamic Simulator: An Event Driven Molecular Simulation Environment for Cellular Physiology

    OpenAIRE

    Byrne, Michael J.; Waxham, M. Neal; Kubota, Yoshihisa

    2010-01-01

    In this paper, we present the Cellular Dynamic Simulator (CDS) for simulating diffusion and chemical reactions within crowded molecular environments. CDS is based on a novel event driven algorithm specifically designed for precise calculation of the timing of collisions, reactions and other events for each individual molecule in the environment. Generic mesh based compartments allow the creation / importation of very simple or detailed cellular structures that exist in a 3D environment. Multi...

  20. Synthesis of New Styrylquinoline Cellular Dyes, Fluorescent Properties, Cellular Localization and Cytotoxic Behavior

    OpenAIRE

    Rams-Baron, Marzena; Dulski, Mateusz; Mrozek-Wilczkiewicz, Anna; Korzec, Mateusz; Cieslik, Wioleta; Spaczyńska, Ewelina; Bartczak, Piotr; Ratuszna, Alicja; Polanski, Jaroslaw; Musiol, Robert

    2016-01-01

    New styrylquinoline derivatives with their photophysical constants are described. The synthesis was achieved via Sonogashira coupling using the newly developed heterogeneous nano-Pd/Cu catalyst system, which provides an efficient synthesis of high purity products. The compounds were tested in preliminary fluorescent microscopy studies to in order to identify their preferable cellular localization, which appeared to be in the lipid cellular organelles. The spectroscopic properties of the compo...

  1. Carney Complex

    Science.gov (United States)

    ... of Carney complex are Cushing’s syndrome and multiple thyroid nodules (tumors). Cushing’s syndrome features a combination of weight gain, ... with Carney complex include adrenocortical carcinoma , pituitary gland tumors , thyroid , colorectal , liver and pancreatic cancers . Ovarian cancer in ...

  2. Simplifying complexity

    NARCIS (Netherlands)

    Leemput, van de I.A.

    2016-01-01

    In this thesis I use mathematical models to explore the properties of complex systems ranging from microbial nitrogen pathways and coral reefs to the human state of mind. All are examples of complex systems, defined as systems composed of a number of interconnected parts, where the systemic behavior

  3. Hamiltonian complexity

    International Nuclear Information System (INIS)

    In recent years we have seen the birth of a new field known as Hamiltonian complexity lying at the crossroads between computer science and theoretical physics. Hamiltonian complexity is directly concerned with the question: how hard is it to simulate a physical system? Here I review the foundational results, guiding problems, and future directions of this emergent field.

  4. Cellular and molecular introduction to brain development.

    Science.gov (United States)

    Jiang, Xiangning; Nardelli, Jeannette

    2016-08-01

    Advances in the study of brain development over the last decades, especially recent findings regarding the evolutionary expansion of the human neocortex, and large-scale analyses of the proteome/transcriptome in the human brain, have offered novel insights into the molecular mechanisms guiding neural maturation, and the pathophysiology of multiple forms of neurological disorders. As a preamble to reviews of this issue, we provide an overview of the cellular, molecular and genetic bases of brain development with an emphasis on the major mechanisms associated with landmarks of normal neural development in the embryonic stage and early postnatal life, including neural stem/progenitor cell proliferation, cortical neuronal migration, evolution and folding of the cerebral cortex, synaptogenesis and neural circuit development, gliogenesis and myelination. We will only briefly depict developmental disorders that result from perturbations of these cellular or molecular mechanisms, and the most common perinatal brain injuries that could disturb normal brain development. PMID:26184894

  5. Cellular and molecular basis of cerebellar development

    Science.gov (United States)

    Martinez, Salvador; Andreu, Abraham; Mecklenburg, Nora; Echevarria, Diego

    2013-01-01

    Historically, the molecular and cellular mechanisms of cerebellar development were investigated through structural descriptions and studying spontaneous mutations in animal models and humans. Advances in experimental embryology, genetic engineering, and neuroimaging techniques render today the possibility to approach the analysis of molecular mechanisms underlying histogenesis and morphogenesis of the cerebellum by experimental designs. Several genes and molecules were identified to be involved in the cerebellar plate regionalization, specification, and differentiation of cerebellar neurons, as well as the establishment of cellular migratory routes and the subsequent neuronal connectivity. Indeed, pattern formation of the cerebellum requires the adequate orchestration of both key morphogenetic signals, arising from distinct brain regions, and local expression of specific transcription factors. Thus, the present review wants to revisit and discuss these morphogenetic and molecular mechanisms taking place during cerebellar development in order to understand causal processes regulating cerebellar cytoarchitecture, its highly topographically ordered circuitry and its role in brain function. PMID:23805080

  6. A Modified Sensitive Driving Cellular Automaton Model

    Institute of Scientific and Technical Information of China (English)

    GE Hong-Xia; DAI Shi-Qiang; DONG Li-Yun; LEI Li

    2005-01-01

    A modified cellular automaton model for traffic flow on highway is proposed with a novel concept about the variable security gap. The concept is first introduced into the original Nagel-Schreckenberg model, which is called the non-sensitive driving cellular automaton model. And then it is incorporated with a sensitive driving NaSch model,in which the randomization brake is arranged before the deterministic deceleration. A parameter related to the variable security gap is determined through simulation. Comparison of the simulation results indicates that the variable security gap has different influence on the two models. The fundamental diagram obtained by simulation with the modified sensitive driving NaSch model shows that the maximumflow are in good agreement with the observed data, indicating that the presented model is more reasonable and realistic.

  7. Quantum features of natural cellular automata

    Science.gov (United States)

    Elze, Hans-Thomas

    2016-03-01

    Cellular automata can show well known features of quantum mechanics, such as a linear rule according to which they evolve and which resembles a discretized version of the Schrödinger equation. This includes corresponding conservation laws. The class of “natural” Hamiltonian cellular automata is based exclusively on integer-valued variables and couplings and their dynamics derives from an Action Principle. They can be mapped reversibly to continuum models by applying Sampling Theory. Thus, “deformed” quantum mechanical models with a finite discreteness scale l are obtained, which for l → 0 reproduce familiar continuum results. We have recently demonstrated that such automata can form “multipartite” systems consistently with the tensor product structures of nonrelativistic many-body quantum mechanics, while interacting and maintaining the linear evolution. Consequently, the Superposition Principle fully applies for such primitive discrete deterministic automata and their composites and can produce the essential quantum effects of interference and entanglement.

  8. Mobile Node Localization in Cellular Networks

    Directory of Open Access Journals (Sweden)

    Yasir Malik

    2012-01-01

    Full Text Available Location information is the major component in location based applications. This information is used in different safety and service oriented applications to provide users with services according to their Geolocation. There are many approaches to locate mobile nodes in indoor and outdoor environments. In thispaper, we are interested in outdoor localization particularly in cellular networks of mobile nodes andpresented a localization method based on cell and user location information. Our localization method is based on hello message delay (sending and receiving time and coordinate information of Base Transceiver Station (BTSs. To validate our method across cellular network, we implemented and simulated our method in two scenarios i.e. maintaining database of base stations in centralize and distributed system. Simulation results show the effectiveness of our approach and its implementation applicability in telecommunication systems.

  9. Cellular automata in image processing and geometry

    CERN Document Server

    Adamatzky, Andrew; Sun, Xianfang

    2014-01-01

    The book presents findings, views and ideas on what exact problems of image processing, pattern recognition and generation can be efficiently solved by cellular automata architectures. This volume provides a convenient collection in this area, in which publications are otherwise widely scattered throughout the literature. The topics covered include image compression and resizing; skeletonization, erosion and dilation; convex hull computation, edge detection and segmentation; forgery detection and content based retrieval; and pattern generation. The book advances the theory of image processing, pattern recognition and generation as well as the design of efficient algorithms and hardware for parallel image processing and analysis. It is aimed at computer scientists, software programmers, electronic engineers, mathematicians and physicists, and at everyone who studies or develops cellular automaton algorithms and tools for image processing and analysis, or develops novel architectures and implementations of mass...

  10. Molecular features of cellular reprogramming and development.

    Science.gov (United States)

    Smith, Zachary D; Sindhu, Camille; Meissner, Alexander

    2016-03-01

    Differentiating somatic cells are progressively restricted to specialized functions during ontogeny, but they can be experimentally directed to form other cell types, including those with complete embryonic potential. Early nuclear reprogramming methods, such as somatic cell nuclear transfer (SCNT) and cell fusion, posed significant technical hurdles to precise dissection of the regulatory programmes governing cell identity. However, the discovery of reprogramming by ectopic expression of a defined set of transcription factors, known as direct reprogramming, provided a tractable platform to uncover molecular characteristics of cellular specification and differentiation, cell type stability and pluripotency. We discuss the control and maintenance of cellular identity during developmental transitions as they have been studied using direct reprogramming, with an emphasis on transcriptional and epigenetic regulation. PMID:26883001

  11. Stochastic Simulations on the Cellular Wave Computers

    CERN Document Server

    Ercsey-Ravasz, M; Neda, Z

    2006-01-01

    The computational paradigm represented by Cellular Neural/nonlinear Networks (CNN) and the CNN Universal Machine (CNN-UM) as a Cellular Wave Computer, gives new perspectives for computational physics. Many numerical problems and simulations can be elegantly addressed on this fully parallelized and analogic architecture. Here we study the possibility of performing stochastic simulations on this chip. First a realistic random number generator is implemented on the CNN-UM, and then as an example the two-dimensional Ising model is studied by Monte Carlo type simulations. The results obtained on an experimental version of the CNN-UM with 128 * 128 cells are in good agreement with the results obtained on digital computers. Computational time measurements suggests that the developing trend of the CNN-UM chips - increasing the lattice size and the number of local logic memories - will assure an important advantage for the CNN-UM in the near future.

  12. Cellular and Molecular Basis of Cerebellar Development

    Directory of Open Access Journals (Sweden)

    Salvador eMartinez

    2013-06-01

    Full Text Available Historically, the molecular and cellular mechanisms of cerebellar development were investigated through structural descriptions and studying spontaneous mutations in animal models and humans. Advances in experimental embryology, genetic engineering and neuroimaging techniques render today the possibility to approach the analysis of molecular mechanisms underlying histogenesis and morphogenesis of the cerebellum by experimental designs. Several genes and molecules were identified to be involved in the cerebellar plate regionalization, specification and differentiation of cerebellar neurons, as well as the establishment of cellular migratory routes and the subsequent neuronal connectivity. Indeed, pattern formation of the cerebellum requires the adequate orchestration of both key morphogenetic signals, arising from distinct brain regions, and local expression of specific transcription factors. Thus, the present review wants to revisit and discuss these morphogenetic and molecular mechanisms taking place during cerebellar development in order to understand causal processes regulating cerebellar cytoarchitecture, its highly topographically ordered circuitry and its role in brain function.

  13. Quantum features of natural cellular automata

    CERN Document Server

    Elze, Hans-Thomas

    2016-01-01

    Cellular automata can show well known features of quantum mechanics, such as a linear rule according to which they evolve and which resembles a discretized version of the Schroedinger equation. This includes corresponding conservation laws. The class of "natural" Hamiltonian cellular automata is based exclusively on integer-valued variables and couplings and their dynamics derives from an Action Principle. They can be mapped reversibly to continuum models by applying Sampling Theory. Thus, "deformed" quantum mechanical models with a finite discreteness scale $l$ are obtained, which for $l\\rightarrow 0$ reproduce familiar continuum results. We have recently demonstrated that such automata can form "multipartite" systems consistently with the tensor product structures of nonrelativistic many-body quantum mechanics, while interacting and maintaining the linear evolution. Consequently, the Superposition Principle fully applies for such primitive discrete deterministic automata and their composites and can produce...

  14. Exponential Stability for Delayed Cellular Neural Networks

    Institute of Scientific and Technical Information of China (English)

    YANG Jin-xiang; ZHONG Shou-ming; YAN Ke-yu

    2005-01-01

    The exponential stability of the delayed cellular neural networks (DCNN's) is investigated. By dividing the network state variables into some parts according to the characters of the neural networks, some new sufficient conditions of exponential stability are derived via constructing a Liapunov function. It is shown that the conditions differ from previous ones. The new conditions, which are associated with some initial value, are represented by some blocks of the interconnection matrix.

  15. A framework for understanding cellular manufacturing systems

    OpenAIRE

    Silva, Sílvio Carmo; Alves, Anabela Carvalho

    2002-01-01

    Many practical benefits, such as superior quality of products and short manufacturing lead times, are usually associated with Cellular Manufacturing. These and other benefits can lead to important competitive advantages of companies. However, to fully achieve these benefits there is a need for an evolution from the traditional concept of CM to the more comprehensive one, which we call Product Oriented Manufacturing. Here systems are dynamically reconfigured for total manufac...

  16. Spectrum sharing for future mobile cellular systems

    OpenAIRE

    Bennis, M

    2009-01-01

    Abstract Spectrum sharing has become a high priority research area over the past few years. The motivation behind this lies in the fact that the limited spectrum is currently inefficiently utilized. As recognized by the World radio communication conference (WRC)-07, the amount of identified spectrum is not large enough to support large bandwidths for a substantial number of operators. Therefore, it is paramount for future mobile cellular systems to share the frequency spectrum and coexist ...

  17. Clinical applications of cellular therapy products

    OpenAIRE

    Serpil Yanbakan

    2015-01-01

    Adult stem cells have the potential to differentiate into multiple cell types and have usage about lots of regenerative medicine research fields. Especially bone marrow-derived mesenchymal stem cells have a wide range of case presentation. New discoveries about stem cell biology will progress new options about cellular therapy products and isolation of different stem cell types will increase hope for treatment of important illness such as Parkinson’s disease, diabetes, malign brain tumors. It...

  18. Cellular Automata Studies of Vertical Silicon Devices

    OpenAIRE

    M. Saraniti; G. Zandler; G. Formicone; S. Goodnick

    1998-01-01

    We present systematic theoretical Cellular Automata (CA) studies of a novel nanometer scale Si device, namely vertically grown Metal Oxide Field Effect Transistors (MOSFET) with channel lengths between 65 and 120 nm. The CA simulations predict drain characteristics and output conductance as a function of gate length. The excellent agreement with available experimental data indicates a high quality oxide/semiconductor interface. Impact ionization is shown to be of minor importance. For inhomog...

  19. Stability of Stochastic Neutral Cellular Neural Networks

    Science.gov (United States)

    Chen, Ling; Zhao, Hongyong

    In this paper, we study a class of stochastic neutral cellular neural networks. By constructing a suitable Lyapunov functional and employing the nonnegative semi-martingale convergence theorem we give some sufficient conditions ensuring the almost sure exponential stability of the networks. The results obtained are helpful to design stability of networks when stochastic noise is taken into consideration. Finally, two examples are provided to show the correctness of our analysis.

  20. Cognitive resource management for heterogeneous cellular networks

    CERN Document Server

    Liu, Yongkang

    2014-01-01

    This Springer Brief focuses on cognitive resource management in heterogeneous cellular networks (Het Net) with small cell deployment for the LTE-Advanced system. It introduces the Het Net features, presents practical approaches using cognitive radio technology in accommodating small cell data relay and optimizing resource allocation and examines the effectiveness of resource management among small cells given limited coordination bandwidth and wireless channel uncertainty. The authors introduce different network characteristics of small cell, investigate the mesh of small cell access points in